fs/btrfs/ioctl.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (C) 2007 Oracle.  All rights reserved.
   4  */
   5
   6 #include <linux/kernel.h>
   7 #include <linux/bio.h>
   8 #include <linux/file.h>
   9 #include <linux/fs.h>
  10 #include <linux/fsnotify.h>
  11 #include <linux/pagemap.h>
  12 #include <linux/highmem.h>
  13 #include <linux/time.h>
  14 #include <linux/string.h>
  15 #include <linux/backing-dev.h>
  16 #include <linux/mount.h>
  17 #include <linux/namei.h>
  18 #include <linux/writeback.h>
  19 #include <linux/compat.h>
  20 #include <linux/security.h>
  21 #include <linux/xattr.h>
  22 #include <linux/mm.h>
  23 #include <linux/slab.h>
  24 #include <linux/blkdev.h>
  25 #include <linux/uuid.h>
  26 #include <linux/btrfs.h>
  27 #include <linux/uaccess.h>
  28 #include <linux/iversion.h>
  29 #include "ctree.h"
  30 #include "disk-io.h"
  31 #include "transaction.h"
  32 #include "btrfs_inode.h"
  33 #include "print-tree.h"
  34 #include "volumes.h"
  35 #include "locking.h"
  36 #include "inode-map.h"
  37 #include "backref.h"
  38 #include "rcu-string.h"
  39 #include "send.h"
  40 #include "dev-replace.h"
  41 #include "props.h"
  42 #include "sysfs.h"
  43 #include "qgroup.h"
  44 #include "tree-log.h"
  45 #include "compression.h"
  46
  47 #ifdef CONFIG_64BIT
  48 /* If we have a 32-bit userspace and 64-bit kernel, then the UAPI
  49  * structures are incorrect, as the timespec structure from userspace
  50  * is 4 bytes too small. We define these alternatives here to teach
  51  * the kernel about the 32-bit struct packing.
  52  */
  53 struct btrfs_ioctl_timespec_32 {
  54         __u64 sec;
  55         __u32 nsec;
  56 } __attribute__ ((__packed__));
  57
  58 struct btrfs_ioctl_received_subvol_args_32 {
  59         char    uuid[BTRFS_UUID_SIZE];  /* in */
  60         __u64   stransid;               /* in */
  61         __u64   rtransid;               /* out */
  62         struct btrfs_ioctl_timespec_32 stime; /* in */
  63         struct btrfs_ioctl_timespec_32 rtime; /* out */
  64         __u64   flags;                  /* in */
  65         __u64   reserved[16];           /* in */
  66 } __attribute__ ((__packed__));
  67
  68 #define BTRFS_IOC_SET_RECEIVED_SUBVOL_32 _IOWR(BTRFS_IOCTL_MAGIC, 37, \
  69                                 struct btrfs_ioctl_received_subvol_args_32)
  70 #endif
  71
  72 #if defined(CONFIG_64BIT) && defined(CONFIG_COMPAT)
  73 struct btrfs_ioctl_send_args_32 {
  74         __s64 send_fd;                  /* in */
  75         __u64 clone_sources_count;      /* in */
  76         compat_uptr_t clone_sources;    /* in */
  77         __u64 parent_root;              /* in */
  78         __u64 flags;                    /* in */
  79         __u64 reserved[4];              /* in */
  80 } __attribute__ ((__packed__));
  81
  82 #define BTRFS_IOC_SEND_32 _IOW(BTRFS_IOCTL_MAGIC, 38, \
  83                                struct btrfs_ioctl_send_args_32)
  84 #endif
  85
  86 static int btrfs_clone(struct inode *src, struct inode *inode,
  87                        u64 off, u64 olen, u64 olen_aligned, u64 destoff,
  88                        int no_time_update);
  89
  90 /* Mask out flags that are inappropriate for the given type of inode. */
  91 static unsigned int btrfs_mask_fsflags_for_type(struct inode *inode,
  92                 unsigned int flags)
  93 {
  94         if (S_ISDIR(inode->i_mode))
  95                 return flags;
  96         else if (S_ISREG(inode->i_mode))
  97                 return flags & ~FS_DIRSYNC_FL;
  98         else
  99                 return flags & (FS_NODUMP_FL | FS_NOATIME_FL);
 100 }
 101
 102 /*
 103  * Export internal inode flags to the format expected by the FS_IOC_GETFLAGS
 104  * ioctl.
 105  */
 106 static unsigned int btrfs_inode_flags_to_fsflags(unsigned int flags)
 107 {
 108         unsigned int iflags = 0;
 109
 110         if (flags & BTRFS_INODE_SYNC)
 111                 iflags |= FS_SYNC_FL;
 112         if (flags & BTRFS_INODE_IMMUTABLE)
 113                 iflags |= FS_IMMUTABLE_FL;
 114         if (flags & BTRFS_INODE_APPEND)
 115                 iflags |= FS_APPEND_FL;
 116         if (flags & BTRFS_INODE_NODUMP)
 117                 iflags |= FS_NODUMP_FL;
 118         if (flags & BTRFS_INODE_NOATIME)
 119                 iflags |= FS_NOATIME_FL;
 120         if (flags & BTRFS_INODE_DIRSYNC)
 121                 iflags |= FS_DIRSYNC_FL;
 122         if (flags & BTRFS_INODE_NODATACOW)
 123                 iflags |= FS_NOCOW_FL;
 124
 125         if (flags & BTRFS_INODE_NOCOMPRESS)
 126                 iflags |= FS_NOCOMP_FL;
 127         else if (flags & BTRFS_INODE_COMPRESS)
 128                 iflags |= FS_COMPR_FL;
 129
 130         return iflags;
 131 }
 132
 133 /*
 134  * Update inode->i_flags based on the btrfs internal flags.
 135  */
 136 void btrfs_sync_inode_flags_to_i_flags(struct inode *inode)
 137 {
 138         struct btrfs_inode *binode = BTRFS_I(inode);
 139         unsigned int new_fl = 0;
 140
 141         if (binode->flags & BTRFS_INODE_SYNC)
 142                 new_fl |= S_SYNC;
 143         if (binode->flags & BTRFS_INODE_IMMUTABLE)
 144                 new_fl |= S_IMMUTABLE;
 145         if (binode->flags & BTRFS_INODE_APPEND)
 146                 new_fl |= S_APPEND;
 147         if (binode->flags & BTRFS_INODE_NOATIME)
 148                 new_fl |= S_NOATIME;
 149         if (binode->flags & BTRFS_INODE_DIRSYNC)
 150                 new_fl |= S_DIRSYNC;
 151
 152         set_mask_bits(&inode->i_flags,
 153                       S_SYNC | S_APPEND | S_IMMUTABLE | S_NOATIME | S_DIRSYNC,
 154                       new_fl);
 155 }
 156
 157 static int btrfs_ioctl_getflags(struct file *file, void __user *arg)
 158 {
 159         struct btrfs_inode *binode = BTRFS_I(file_inode(file));
 160         unsigned int flags = btrfs_inode_flags_to_fsflags(binode->flags);
 161
 162         if (copy_to_user(arg, &flags, sizeof(flags)))
 163                 return -EFAULT;
 164         return 0;
 165 }
 166
 167 /* Check if @flags are a supported and valid set of FS_*_FL flags */
 168 static int check_fsflags(unsigned int flags)
 169 {
 170         if (flags & ~(FS_IMMUTABLE_FL | FS_APPEND_FL | \
 171                       FS_NOATIME_FL | FS_NODUMP_FL | \
 172                       FS_SYNC_FL | FS_DIRSYNC_FL | \
 173                       FS_NOCOMP_FL | FS_COMPR_FL |
 174                       FS_NOCOW_FL))
 175                 return -EOPNOTSUPP;
 176
 177         if ((flags & FS_NOCOMP_FL) && (flags & FS_COMPR_FL))
 178                 return -EINVAL;
 179
 180         return 0;
 181 }
 182
 183 static int btrfs_ioctl_setflags(struct file *file, void __user *arg)
 184 {
 185         struct inode *inode = file_inode(file);
 186         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
 187         struct btrfs_inode *binode = BTRFS_I(inode);
 188         struct btrfs_root *root = binode->root;
 189         struct btrfs_trans_handle *trans;
 190         unsigned int fsflags, old_fsflags;
 191         int ret;
 192         u64 old_flags;
 193         unsigned int old_i_flags;
 194         umode_t mode;
 195
 196         if (!inode_owner_or_capable(inode))
 197                 return -EPERM;
 198
 199         if (btrfs_root_readonly(root))
 200                 return -EROFS;
 201
 202         if (copy_from_user(&fsflags, arg, sizeof(fsflags)))
 203                 return -EFAULT;
 204
 205         ret = check_fsflags(fsflags);
 206         if (ret)
 207                 return ret;
 208
 209         ret = mnt_want_write_file(file);
 210         if (ret)
 211                 return ret;
 212
 213         inode_lock(inode);
 214
 215         old_flags = binode->flags;
 216         old_i_flags = inode->i_flags;
 217         mode = inode->i_mode;
 218
 219         fsflags = btrfs_mask_fsflags_for_type(inode, fsflags);
 220         old_fsflags = btrfs_inode_flags_to_fsflags(binode->flags);
 221         if ((fsflags ^ old_fsflags) & (FS_APPEND_FL | FS_IMMUTABLE_FL)) {
 222                 if (!capable(CAP_LINUX_IMMUTABLE)) {
 223                         ret = -EPERM;
 224                         goto out_unlock;
 225                 }
 226         }
 227
 228         if (fsflags & FS_SYNC_FL)
 229                 binode->flags |= BTRFS_INODE_SYNC;
 230         else
 231                 binode->flags &= ~BTRFS_INODE_SYNC;
 232         if (fsflags & FS_IMMUTABLE_FL)
 233                 binode->flags |= BTRFS_INODE_IMMUTABLE;
 234         else
 235                 binode->flags &= ~BTRFS_INODE_IMMUTABLE;
 236         if (fsflags & FS_APPEND_FL)
 237                 binode->flags |= BTRFS_INODE_APPEND;
 238         else
 239                 binode->flags &= ~BTRFS_INODE_APPEND;
 240         if (fsflags & FS_NODUMP_FL)
 241                 binode->flags |= BTRFS_INODE_NODUMP;
 242         else
 243                 binode->flags &= ~BTRFS_INODE_NODUMP;
 244         if (fsflags & FS_NOATIME_FL)
 245                 binode->flags |= BTRFS_INODE_NOATIME;
 246         else
 247                 binode->flags &= ~BTRFS_INODE_NOATIME;
 248         if (fsflags & FS_DIRSYNC_FL)
 249                 binode->flags |= BTRFS_INODE_DIRSYNC;
 250         else
 251                 binode->flags &= ~BTRFS_INODE_DIRSYNC;
 252         if (fsflags & FS_NOCOW_FL) {
 253                 if (S_ISREG(mode)) {
 254                         /*
 255                          * It's safe to turn csums off here, no extents exist.
 256                          * Otherwise we want the flag to reflect the real COW
 257                          * status of the file and will not set it.
 258                          */
 259                         if (inode->i_size == 0)
 260                                 binode->flags |= BTRFS_INODE_NODATACOW
 261                                               | BTRFS_INODE_NODATASUM;
 262                 } else {
 263                         binode->flags |= BTRFS_INODE_NODATACOW;
 264                 }
 265         } else {
 266                 /*
 267                  * Revert back under same assumptions as above
 268                  */
 269                 if (S_ISREG(mode)) {
 270                         if (inode->i_size == 0)
 271                                 binode->flags &= ~(BTRFS_INODE_NODATACOW
 272                                              | BTRFS_INODE_NODATASUM);
 273                 } else {
 274                         binode->flags &= ~BTRFS_INODE_NODATACOW;
 275                 }
 276         }
 277
 278         /*
 279          * The COMPRESS flag can only be changed by users, while the NOCOMPRESS
 280          * flag may be changed automatically if compression code won't make
 281          * things smaller.
 282          */
 283         if (fsflags & FS_NOCOMP_FL) {
 284                 binode->flags &= ~BTRFS_INODE_COMPRESS;
 285                 binode->flags |= BTRFS_INODE_NOCOMPRESS;
 286
 287                 ret = btrfs_set_prop(inode, "btrfs.compression", NULL, 0, 0);
 288                 if (ret && ret != -ENODATA)
 289                         goto out_drop;
 290         } else if (fsflags & FS_COMPR_FL) {
 291                 const char *comp;
 292
 293                 binode->flags |= BTRFS_INODE_COMPRESS;
 294                 binode->flags &= ~BTRFS_INODE_NOCOMPRESS;
 295
 296                 comp = btrfs_compress_type2str(fs_info->compress_type);
 297                 if (!comp || comp[0] == 0)
 298                         comp = btrfs_compress_type2str(BTRFS_COMPRESS_ZLIB);
 299
 300                 ret = btrfs_set_prop(inode, "btrfs.compression",
 301                                      comp, strlen(comp), 0);
 302                 if (ret)
 303                         goto out_drop;
 304
 305         } else {
 306                 ret = btrfs_set_prop(inode, "btrfs.compression", NULL, 0, 0);
 307                 if (ret && ret != -ENODATA)
 308                         goto out_drop;
 309                 binode->flags &= ~(BTRFS_INODE_COMPRESS | BTRFS_INODE_NOCOMPRESS);
 310         }
 311
 312         trans = btrfs_start_transaction(root, 1);
 313         if (IS_ERR(trans)) {
 314                 ret = PTR_ERR(trans);
 315                 goto out_drop;
 316         }
 317
 318         btrfs_sync_inode_flags_to_i_flags(inode);
 319         inode_inc_iversion(inode);
 320         inode->i_ctime = current_time(inode);
 321         ret = btrfs_update_inode(trans, root, inode);
 322
 323         btrfs_end_transaction(trans);
 324  out_drop:
 325         if (ret) {
 326                 binode->flags = old_flags;
 327                 inode->i_flags = old_i_flags;
 328         }
 329
 330  out_unlock:
 331         inode_unlock(inode);
 332         mnt_drop_write_file(file);
 333         return ret;
 334 }
 335
 336 /*
 337  * Translate btrfs internal inode flags to xflags as expected by the
 338  * FS_IOC_FSGETXATT ioctl. Filter only the supported ones, unknown flags are
 339  * silently dropped.
 340  */
 341 static unsigned int btrfs_inode_flags_to_xflags(unsigned int flags)
 342 {
 343         unsigned int xflags = 0;
 344
 345         if (flags & BTRFS_INODE_APPEND)
 346                 xflags |= FS_XFLAG_APPEND;
 347         if (flags & BTRFS_INODE_IMMUTABLE)
 348                 xflags |= FS_XFLAG_IMMUTABLE;
 349         if (flags & BTRFS_INODE_NOATIME)
 350                 xflags |= FS_XFLAG_NOATIME;
 351         if (flags & BTRFS_INODE_NODUMP)
 352                 xflags |= FS_XFLAG_NODUMP;
 353         if (flags & BTRFS_INODE_SYNC)
 354                 xflags |= FS_XFLAG_SYNC;
 355
 356         return xflags;
 357 }
 358
 359 /* Check if @flags are a supported and valid set of FS_XFLAGS_* flags */
 360 static int check_xflags(unsigned int flags)
 361 {
 362         if (flags & ~(FS_XFLAG_APPEND | FS_XFLAG_IMMUTABLE | FS_XFLAG_NOATIME |
 363                       FS_XFLAG_NODUMP | FS_XFLAG_SYNC))
 364                 return -EOPNOTSUPP;
 365         return 0;
 366 }
 367
 368 /*
 369  * Set the xflags from the internal inode flags. The remaining items of fsxattr
 370  * are zeroed.
 371  */
 372 static int btrfs_ioctl_fsgetxattr(struct file *file, void __user *arg)
 373 {
 374         struct btrfs_inode *binode = BTRFS_I(file_inode(file));
 375         struct fsxattr fa;
 376
 377         memset(&fa, 0, sizeof(fa));
 378         fa.fsx_xflags = btrfs_inode_flags_to_xflags(binode->flags);
 379
 380         if (copy_to_user(arg, &fa, sizeof(fa)))
 381                 return -EFAULT;
 382
 383         return 0;
 384 }
 385
 386 static int btrfs_ioctl_fssetxattr(struct file *file, void __user *arg)
 387 {
 388         struct inode *inode = file_inode(file);
 389         struct btrfs_inode *binode = BTRFS_I(inode);
 390         struct btrfs_root *root = binode->root;
 391         struct btrfs_trans_handle *trans;
 392         struct fsxattr fa;
 393         unsigned old_flags;
 394         unsigned old_i_flags;
 395         int ret = 0;
 396
 397         if (!inode_owner_or_capable(inode))
 398                 return -EPERM;
 399
 400         if (btrfs_root_readonly(root))
 401                 return -EROFS;
 402
 403         memset(&fa, 0, sizeof(fa));
 404         if (copy_from_user(&fa, arg, sizeof(fa)))
 405                 return -EFAULT;
 406
 407         ret = check_xflags(fa.fsx_xflags);
 408         if (ret)
 409                 return ret;
 410
 411         if (fa.fsx_extsize != 0 || fa.fsx_projid != 0 || fa.fsx_cowextsize != 0)
 412                 return -EOPNOTSUPP;
 413
 414         ret = mnt_want_write_file(file);
 415         if (ret)
 416                 return ret;
 417
 418         inode_lock(inode);
 419
 420         old_flags = binode->flags;
 421         old_i_flags = inode->i_flags;
 422
 423         /* We need the capabilities to change append-only or immutable inode */
 424         if (((old_flags & (BTRFS_INODE_APPEND | BTRFS_INODE_IMMUTABLE)) ||
 425              (fa.fsx_xflags & (FS_XFLAG_APPEND | FS_XFLAG_IMMUTABLE))) &&
 426             !capable(CAP_LINUX_IMMUTABLE)) {
 427                 ret = -EPERM;
 428                 goto out_unlock;
 429         }
 430
 431         if (fa.fsx_xflags & FS_XFLAG_SYNC)
 432                 binode->flags |= BTRFS_INODE_SYNC;
 433         else
 434                 binode->flags &= ~BTRFS_INODE_SYNC;
 435         if (fa.fsx_xflags & FS_XFLAG_IMMUTABLE)
 436                 binode->flags |= BTRFS_INODE_IMMUTABLE;
 437         else
 438                 binode->flags &= ~BTRFS_INODE_IMMUTABLE;
 439         if (fa.fsx_xflags & FS_XFLAG_APPEND)
 440                 binode->flags |= BTRFS_INODE_APPEND;
 441         else
 442                 binode->flags &= ~BTRFS_INODE_APPEND;
 443         if (fa.fsx_xflags & FS_XFLAG_NODUMP)
 444                 binode->flags |= BTRFS_INODE_NODUMP;
 445         else
 446                 binode->flags &= ~BTRFS_INODE_NODUMP;
 447         if (fa.fsx_xflags & FS_XFLAG_NOATIME)
 448                 binode->flags |= BTRFS_INODE_NOATIME;
 449         else
 450                 binode->flags &= ~BTRFS_INODE_NOATIME;
 451
 452         /* 1 item for the inode */
 453         trans = btrfs_start_transaction(root, 1);
 454         if (IS_ERR(trans)) {
 455                 ret = PTR_ERR(trans);
 456                 goto out_unlock;
 457         }
 458
 459         btrfs_sync_inode_flags_to_i_flags(inode);
 460         inode_inc_iversion(inode);
 461         inode->i_ctime = current_time(inode);
 462         ret = btrfs_update_inode(trans, root, inode);
 463
 464         btrfs_end_transaction(trans);
 465
 466 out_unlock:
 467         if (ret) {
 468                 binode->flags = old_flags;
 469                 inode->i_flags = old_i_flags;
 470         }
 471
 472         inode_unlock(inode);
 473         mnt_drop_write_file(file);
 474
 475         return ret;
 476 }
 477
 478 static int btrfs_ioctl_getversion(struct file *file, int __user *arg)
 479 {
 480         struct inode *inode = file_inode(file);
 481
 482         return put_user(inode->i_generation, arg);
 483 }
 484
 485 static noinline int btrfs_ioctl_fitrim(struct file *file, void __user *arg)
 486 {
 487         struct inode *inode = file_inode(file);
 488         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
 489         struct btrfs_device *device;
 490         struct request_queue *q;
 491         struct fstrim_range range;
 492         u64 minlen = ULLONG_MAX;
 493         u64 num_devices = 0;
 494         int ret;
 495
 496         if (!capable(CAP_SYS_ADMIN))
 497                 return -EPERM;
 498
 499         rcu_read_lock();
 500         list_for_each_entry_rcu(device, &fs_info->fs_devices->devices,
 501                                 dev_list) {
 502                 if (!device->bdev)
 503                         continue;
 504                 q = bdev_get_queue(device->bdev);
 505                 if (blk_queue_discard(q)) {
 506                         num_devices++;
 507                         minlen = min_t(u64, q->limits.discard_granularity,
 508                                      minlen);
 509                 }
 510         }
 511         rcu_read_unlock();
 512
 513         if (!num_devices)
 514                 return -EOPNOTSUPP;
 515         if (copy_from_user(&range, arg, sizeof(range)))
 516                 return -EFAULT;
 517
 518         /*
 519          * NOTE: Don't truncate the range using super->total_bytes.  Bytenr of
 520          * block group is in the logical address space, which can be any
 521          * sectorsize aligned bytenr in  the range [0, U64_MAX].
 522          */
 523         if (range.len < fs_info->sb->s_blocksize)
 524                 return -EINVAL;
 525
 526         range.minlen = max(range.minlen, minlen);
 527         ret = btrfs_trim_fs(fs_info, &range);
 528         if (ret < 0)
 529                 return ret;
 530
 531         if (copy_to_user(arg, &range, sizeof(range)))
 532                 return -EFAULT;
 533
 534         return 0;
 535 }
 536
 537 int btrfs_is_empty_uuid(u8 *uuid)
 538 {
 539         int i;
 540
 541         for (i = 0; i < BTRFS_UUID_SIZE; i++) {
 542                 if (uuid[i])
 543                         return 0;
 544         }
 545         return 1;
 546 }
 547
 548 static noinline int create_subvol(struct inode *dir,
 549                                   struct dentry *dentry,
 550                                   const char *name, int namelen,
 551                                   u64 *async_transid,
 552                                   struct btrfs_qgroup_inherit *inherit)
 553 {
 554         struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
 555         struct btrfs_trans_handle *trans;
 556         struct btrfs_key key;
 557         struct btrfs_root_item *root_item;
 558         struct btrfs_inode_item *inode_item;
 559         struct extent_buffer *leaf;
 560         struct btrfs_root *root = BTRFS_I(dir)->root;
 561         struct btrfs_root *new_root;
 562         struct btrfs_block_rsv block_rsv;
 563         struct timespec64 cur_time = current_time(dir);
 564         struct inode *inode;
 565         int ret;
 566         int err;
 567         u64 objectid;
 568         u64 new_dirid = BTRFS_FIRST_FREE_OBJECTID;
 569         u64 index = 0;
 570         uuid_le new_uuid;
 571
 572         root_item = kzalloc(sizeof(*root_item), GFP_KERNEL);
 573         if (!root_item)
 574                 return -ENOMEM;
 575
 576         ret = btrfs_find_free_objectid(fs_info->tree_root, &objectid);
 577         if (ret)
 578                 goto fail_free;
 579
 580         /*
 581          * Don't create subvolume whose level is not zero. Or qgroup will be
 582          * screwed up since it assumes subvolume qgroup's level to be 0.
 583          */
 584         if (btrfs_qgroup_level(objectid)) {
 585                 ret = -ENOSPC;
 586                 goto fail_free;
 587         }
 588
 589         btrfs_init_block_rsv(&block_rsv, BTRFS_BLOCK_RSV_TEMP);
 590         /*
 591          * The same as the snapshot creation, please see the comment
 592          * of create_snapshot().
 593          */
 594         ret = btrfs_subvolume_reserve_metadata(root, &block_rsv, 8, false);
 595         if (ret)
 596                 goto fail_free;
 597
 598         trans = btrfs_start_transaction(root, 0);
 599         if (IS_ERR(trans)) {
 600                 ret = PTR_ERR(trans);
 601                 btrfs_subvolume_release_metadata(fs_info, &block_rsv);
 602                 goto fail_free;
 603         }
 604         trans->block_rsv = &block_rsv;
 605         trans->bytes_reserved = block_rsv.size;
 606
 607         ret = btrfs_qgroup_inherit(trans, 0, objectid, inherit);
 608         if (ret)
 609                 goto fail;
 610
 611         leaf = btrfs_alloc_tree_block(trans, root, 0, objectid, NULL, 0, 0, 0);
 612         if (IS_ERR(leaf)) {
 613                 ret = PTR_ERR(leaf);
 614                 goto fail;
 615         }
 616
 617         btrfs_mark_buffer_dirty(leaf);
 618
 619         inode_item = &root_item->inode;
 620         btrfs_set_stack_inode_generation(inode_item, 1);
 621         btrfs_set_stack_inode_size(inode_item, 3);
 622         btrfs_set_stack_inode_nlink(inode_item, 1);
 623         btrfs_set_stack_inode_nbytes(inode_item,
 624                                      fs_info->nodesize);
 625         btrfs_set_stack_inode_mode(inode_item, S_IFDIR | 0755);
 626
 627         btrfs_set_root_flags(root_item, 0);
 628         btrfs_set_root_limit(root_item, 0);
 629         btrfs_set_stack_inode_flags(inode_item, BTRFS_INODE_ROOT_ITEM_INIT);
 630
 631         btrfs_set_root_bytenr(root_item, leaf->start);
 632         btrfs_set_root_generation(root_item, trans->transid);
 633         btrfs_set_root_level(root_item, 0);
 634         btrfs_set_root_refs(root_item, 1);
 635         btrfs_set_root_used(root_item, leaf->len);
 636         btrfs_set_root_last_snapshot(root_item, 0);
 637
 638         btrfs_set_root_generation_v2(root_item,
 639                         btrfs_root_generation(root_item));
 640         uuid_le_gen(&new_uuid);
 641         memcpy(root_item->uuid, new_uuid.b, BTRFS_UUID_SIZE);
 642         btrfs_set_stack_timespec_sec(&root_item->otime, cur_time.tv_sec);
 643         btrfs_set_stack_timespec_nsec(&root_item->otime, cur_time.tv_nsec);
 644         root_item->ctime = root_item->otime;
 645         btrfs_set_root_ctransid(root_item, trans->transid);
 646         btrfs_set_root_otransid(root_item, trans->transid);
 647
 648         btrfs_tree_unlock(leaf);
 649         free_extent_buffer(leaf);
 650         leaf = NULL;
 651
 652         btrfs_set_root_dirid(root_item, new_dirid);
 653
 654         key.objectid = objectid;
 655         key.offset = 0;
 656         key.type = BTRFS_ROOT_ITEM_KEY;
 657         ret = btrfs_insert_root(trans, fs_info->tree_root, &key,
 658                                 root_item);
 659         if (ret)
 660                 goto fail;
 661
 662         key.offset = (u64)-1;
 663         new_root = btrfs_read_fs_root_no_name(fs_info, &key);
 664         if (IS_ERR(new_root)) {
 665                 ret = PTR_ERR(new_root);
 666                 btrfs_abort_transaction(trans, ret);
 667                 goto fail;
 668         }
 669
 670         btrfs_record_root_in_trans(trans, new_root);
 671
 672         ret = btrfs_create_subvol_root(trans, new_root, root, new_dirid);
 673         if (ret) {
 674                 /* We potentially lose an unused inode item here */
 675                 btrfs_abort_transaction(trans, ret);
 676                 goto fail;
 677         }
 678
 679         mutex_lock(&new_root->objectid_mutex);
 680         new_root->highest_objectid = new_dirid;
 681         mutex_unlock(&new_root->objectid_mutex);
 682
 683         /*
 684          * insert the directory item
 685          */
 686         ret = btrfs_set_inode_index(BTRFS_I(dir), &index);
 687         if (ret) {
 688                 btrfs_abort_transaction(trans, ret);
 689                 goto fail;
 690         }
 691
 692         ret = btrfs_insert_dir_item(trans, name, namelen, BTRFS_I(dir), &key,
 693                                     BTRFS_FT_DIR, index);
 694         if (ret) {
 695                 btrfs_abort_transaction(trans, ret);
 696                 goto fail;
 697         }
 698
 699         btrfs_i_size_write(BTRFS_I(dir), dir->i_size + namelen * 2);
 700         ret = btrfs_update_inode(trans, root, dir);
 701         BUG_ON(ret);
 702
 703         ret = btrfs_add_root_ref(trans, objectid, root->root_key.objectid,
 704                                  btrfs_ino(BTRFS_I(dir)), index, name, namelen);
 705         BUG_ON(ret);
 706
 707         ret = btrfs_uuid_tree_add(trans, root_item->uuid,
 708                                   BTRFS_UUID_KEY_SUBVOL, objectid);
 709         if (ret)
 710                 btrfs_abort_transaction(trans, ret);
 711
 712 fail:
 713         kfree(root_item);
 714         trans->block_rsv = NULL;
 715         trans->bytes_reserved = 0;
 716         btrfs_subvolume_release_metadata(fs_info, &block_rsv);
 717
 718         if (async_transid) {
 719                 *async_transid = trans->transid;
 720                 err = btrfs_commit_transaction_async(trans, 1);
 721                 if (err)
 722                         err = btrfs_commit_transaction(trans);
 723         } else {
 724                 err = btrfs_commit_transaction(trans);
 725         }
 726         if (err && !ret)
 727                 ret = err;
 728
 729         if (!ret) {
 730                 inode = btrfs_lookup_dentry(dir, dentry);
 731                 if (IS_ERR(inode))
 732                         return PTR_ERR(inode);
 733                 d_instantiate(dentry, inode);
 734         }
 735         return ret;
 736
 737 fail_free:
 738         kfree(root_item);
 739         return ret;
 740 }
 741
 742 static int create_snapshot(struct btrfs_root *root, struct inode *dir,
 743                            struct dentry *dentry,
 744                            u64 *async_transid, bool readonly,
 745                            struct btrfs_qgroup_inherit *inherit)
 746 {
 747         struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
 748         struct inode *inode;
 749         struct btrfs_pending_snapshot *pending_snapshot;
 750         struct btrfs_trans_handle *trans;
 751         int ret;
 752         bool snapshot_force_cow = false;
 753
 754         if (!test_bit(BTRFS_ROOT_REF_COWS, &root->state))
 755                 return -EINVAL;
 756
 757         pending_snapshot = kzalloc(sizeof(*pending_snapshot), GFP_KERNEL);
 758         if (!pending_snapshot)
 759                 return -ENOMEM;
 760
 761         pending_snapshot->root_item = kzalloc(sizeof(struct btrfs_root_item),
 762                         GFP_KERNEL);
 763         pending_snapshot->path = btrfs_alloc_path();
 764         if (!pending_snapshot->root_item || !pending_snapshot->path) {
 765                 ret = -ENOMEM;
 766                 goto free_pending;
 767         }
 768
 769         /*
 770          * Force new buffered writes to reserve space even when NOCOW is
 771          * possible. This is to avoid later writeback (running dealloc) to
 772          * fallback to COW mode and unexpectedly fail with ENOSPC.
 773          */
 774         atomic_inc(&root->will_be_snapshotted);
 775         smp_mb__after_atomic();
 776         /* wait for no snapshot writes */
 777         wait_event(root->subv_writers->wait,
 778                    percpu_counter_sum(&root->subv_writers->counter) == 0);
 779
 780         ret = btrfs_start_delalloc_inodes(root);
 781         if (ret)
 782                 goto dec_and_free;
 783
 784         /*
 785          * All previous writes have started writeback in NOCOW mode, so now
 786          * we force future writes to fallback to COW mode during snapshot
 787          * creation.
 788          */
 789         atomic_inc(&root->snapshot_force_cow);
 790         snapshot_force_cow = true;
 791
 792         btrfs_wait_ordered_extents(root, U64_MAX, 0, (u64)-1);
 793
 794         btrfs_init_block_rsv(&pending_snapshot->block_rsv,
 795                              BTRFS_BLOCK_RSV_TEMP);
 796         /*
 797          * 1 - parent dir inode
 798          * 2 - dir entries
 799          * 1 - root item
 800          * 2 - root ref/backref
 801          * 1 - root of snapshot
 802          * 1 - UUID item
 803          */
 804         ret = btrfs_subvolume_reserve_metadata(BTRFS_I(dir)->root,
 805                                         &pending_snapshot->block_rsv, 8,
 806                                         false);
 807         if (ret)
 808                 goto dec_and_free;
 809
 810         pending_snapshot->dentry = dentry;
 811         pending_snapshot->root = root;
 812         pending_snapshot->readonly = readonly;
 813         pending_snapshot->dir = dir;
 814         pending_snapshot->inherit = inherit;
 815
 816         trans = btrfs_start_transaction(root, 0);
 817         if (IS_ERR(trans)) {
 818                 ret = PTR_ERR(trans);
 819                 goto fail;
 820         }
 821
 822         spin_lock(&fs_info->trans_lock);
 823         list_add(&pending_snapshot->list,
 824                  &trans->transaction->pending_snapshots);
 825         spin_unlock(&fs_info->trans_lock);
 826         if (async_transid) {
 827                 *async_transid = trans->transid;
 828                 ret = btrfs_commit_transaction_async(trans, 1);
 829                 if (ret)
 830                         ret = btrfs_commit_transaction(trans);
 831         } else {
 832                 ret = btrfs_commit_transaction(trans);
 833         }
 834         if (ret)
 835                 goto fail;
 836
 837         ret = pending_snapshot->error;
 838         if (ret)
 839                 goto fail;
 840
 841         ret = btrfs_orphan_cleanup(pending_snapshot->snap);
 842         if (ret)
 843                 goto fail;
 844
 845         inode = btrfs_lookup_dentry(d_inode(dentry->d_parent), dentry);
 846         if (IS_ERR(inode)) {
 847                 ret = PTR_ERR(inode);
 848                 goto fail;
 849         }
 850
 851         d_instantiate(dentry, inode);
 852         ret = 0;
 853 fail:
 854         btrfs_subvolume_release_metadata(fs_info, &pending_snapshot->block_rsv);
 855 dec_and_free:
 856         if (snapshot_force_cow)
 857                 atomic_dec(&root->snapshot_force_cow);
 858         if (atomic_dec_and_test(&root->will_be_snapshotted))
 859                 wake_up_var(&root->will_be_snapshotted);
 860 free_pending:
 861         kfree(pending_snapshot->root_item);
 862         btrfs_free_path(pending_snapshot->path);
 863         kfree(pending_snapshot);
 864
 865         return ret;
 866 }
 867
 868 /*  copy of may_delete in fs/namei.c()
 869  *      Check whether we can remove a link victim from directory dir, check
 870  *  whether the type of victim is right.
 871  *  1. We can't do it if dir is read-only (done in permission())
 872  *  2. We should have write and exec permissions on dir
 873  *  3. We can't remove anything from append-only dir
 874  *  4. We can't do anything with immutable dir (done in permission())
 875  *  5. If the sticky bit on dir is set we should either
 876  *      a. be owner of dir, or
 877  *      b. be owner of victim, or
 878  *      c. have CAP_FOWNER capability
 879  *  6. If the victim is append-only or immutable we can't do anything with
 880  *     links pointing to it.
 881  *  7. If we were asked to remove a directory and victim isn't one - ENOTDIR.
 882  *  8. If we were asked to remove a non-directory and victim isn't one - EISDIR.
 883  *  9. We can't remove a root or mountpoint.
 884  * 10. We don't allow removal of NFS sillyrenamed files; it's handled by
 885  *     nfs_async_unlink().
 886  */
 887
 888 static int btrfs_may_delete(struct inode *dir, struct dentry *victim, int isdir)
 889 {
 890         int error;
 891
 892         if (d_really_is_negative(victim))
 893                 return -ENOENT;
 894
 895         BUG_ON(d_inode(victim->d_parent) != dir);
 896         audit_inode_child(dir, victim, AUDIT_TYPE_CHILD_DELETE);
 897
 898         error = inode_permission(dir, MAY_WRITE | MAY_EXEC);
 899         if (error)
 900                 return error;
 901         if (IS_APPEND(dir))
 902                 return -EPERM;
 903         if (check_sticky(dir, d_inode(victim)) || IS_APPEND(d_inode(victim)) ||
 904             IS_IMMUTABLE(d_inode(victim)) || IS_SWAPFILE(d_inode(victim)))
 905                 return -EPERM;
 906         if (isdir) {
 907                 if (!d_is_dir(victim))
 908                         return -ENOTDIR;
 909                 if (IS_ROOT(victim))
 910                         return -EBUSY;
 911         } else if (d_is_dir(victim))
 912                 return -EISDIR;
 913         if (IS_DEADDIR(dir))
 914                 return -ENOENT;
 915         if (victim->d_flags & DCACHE_NFSFS_RENAMED)
 916                 return -EBUSY;
 917         return 0;
 918 }
 919
 920 /* copy of may_create in fs/namei.c() */
 921 static inline int btrfs_may_create(struct inode *dir, struct dentry *child)
 922 {
 923         if (d_really_is_positive(child))
 924                 return -EEXIST;
 925         if (IS_DEADDIR(dir))
 926                 return -ENOENT;
 927         return inode_permission(dir, MAY_WRITE | MAY_EXEC);
 928 }
 929
 930 /*
 931  * Create a new subvolume below @parent.  This is largely modeled after
 932  * sys_mkdirat and vfs_mkdir, but we only do a single component lookup
 933  * inside this filesystem so it's quite a bit simpler.
 934  */
 935 static noinline int btrfs_mksubvol(const struct path *parent,
 936                                    const char *name, int namelen,
 937                                    struct btrfs_root *snap_src,
 938                                    u64 *async_transid, bool readonly,
 939                                    struct btrfs_qgroup_inherit *inherit)
 940 {
 941         struct inode *dir = d_inode(parent->dentry);
 942         struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
 943         struct dentry *dentry;
 944         int error;
 945
 946         error = down_write_killable_nested(&dir->i_rwsem, I_MUTEX_PARENT);
 947         if (error == -EINTR)
 948                 return error;
 949
 950         dentry = lookup_one_len(name, parent->dentry, namelen);
 951         error = PTR_ERR(dentry);
 952         if (IS_ERR(dentry))
 953                 goto out_unlock;
 954
 955         error = btrfs_may_create(dir, dentry);
 956         if (error)
 957                 goto out_dput;
 958
 959         /*
 960          * even if this name doesn't exist, we may get hash collisions.
 961          * check for them now when we can safely fail
 962          */
 963         error = btrfs_check_dir_item_collision(BTRFS_I(dir)->root,
 964                                                dir->i_ino, name,
 965                                                namelen);
 966         if (error)
 967                 goto out_dput;
 968
 969         down_read(&fs_info->subvol_sem);
 970
 971         if (btrfs_root_refs(&BTRFS_I(dir)->root->root_item) == 0)
 972                 goto out_up_read;
 973
 974         if (snap_src) {
 975                 error = create_snapshot(snap_src, dir, dentry,
 976                                         async_transid, readonly, inherit);
 977         } else {
 978                 error = create_subvol(dir, dentry, name, namelen,
 979                                       async_transid, inherit);
 980         }
 981         if (!error)
 982                 fsnotify_mkdir(dir, dentry);
 983 out_up_read:
 984         up_read(&fs_info->subvol_sem);
 985 out_dput:
 986         dput(dentry);
 987 out_unlock:
 988         inode_unlock(dir);
 989         return error;
 990 }
 991
 992 /*
 993  * When we're defragging a range, we don't want to kick it off again
 994  * if it is really just waiting for delalloc to send it down.
 995  * If we find a nice big extent or delalloc range for the bytes in the
 996  * file you want to defrag, we return 0 to let you know to skip this
 997  * part of the file
 998  */
 999 static int check_defrag_in_cache(struct inode *inode, u64 offset, u32 thresh)
1000 {
1001         struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
1002         struct extent_map *em = NULL;
1003         struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
1004         u64 end;
1005
1006         read_lock(&em_tree->lock);
1007         em = lookup_extent_mapping(em_tree, offset, PAGE_SIZE);
1008         read_unlock(&em_tree->lock);
1009
1010         if (em) {
1011                 end = extent_map_end(em);
1012                 free_extent_map(em);
1013                 if (end - offset > thresh)
1014                         return 0;
1015         }
1016         /* if we already have a nice delalloc here, just stop */
1017         thresh /= 2;
1018         end = count_range_bits(io_tree, &offset, offset + thresh,
1019                                thresh, EXTENT_DELALLOC, 1);
1020         if (end >= thresh)
1021                 return 0;
1022         return 1;
1023 }
1024
1025 /*
1026  * helper function to walk through a file and find extents
1027  * newer than a specific transid, and smaller than thresh.
1028  *
1029  * This is used by the defragging code to find new and small
1030  * extents
1031  */
1032 static int find_new_extents(struct btrfs_root *root,
1033                             struct inode *inode, u64 newer_than,
1034                             u64 *off, u32 thresh)
1035 {
1036         struct btrfs_path *path;
1037         struct btrfs_key min_key;
1038         struct extent_buffer *leaf;
1039         struct btrfs_file_extent_item *extent;
1040         int type;
1041         int ret;
1042         u64 ino = btrfs_ino(BTRFS_I(inode));
1043
1044         path = btrfs_alloc_path();
1045         if (!path)
1046                 return -ENOMEM;
1047
1048         min_key.objectid = ino;
1049         min_key.type = BTRFS_EXTENT_DATA_KEY;
1050         min_key.offset = *off;
1051
1052         while (1) {
1053                 ret = btrfs_search_forward(root, &min_key, path, newer_than);
1054                 if (ret != 0)
1055                         goto none;
1056 process_slot:
1057                 if (min_key.objectid != ino)
1058                         goto none;
1059                 if (min_key.type != BTRFS_EXTENT_DATA_KEY)
1060                         goto none;
1061
1062                 leaf = path->nodes[0];
1063                 extent = btrfs_item_ptr(leaf, path->slots[0],
1064                                         struct btrfs_file_extent_item);
1065
1066                 type = btrfs_file_extent_type(leaf, extent);
1067                 if (type == BTRFS_FILE_EXTENT_REG &&
1068                     btrfs_file_extent_num_bytes(leaf, extent) < thresh &&
1069                     check_defrag_in_cache(inode, min_key.offset, thresh)) {
1070                         *off = min_key.offset;
1071                         btrfs_free_path(path);
1072                         return 0;
1073                 }
1074
1075                 path->slots[0]++;
1076                 if (path->slots[0] < btrfs_header_nritems(leaf)) {
1077                         btrfs_item_key_to_cpu(leaf, &min_key, path->slots[0]);
1078                         goto process_slot;
1079                 }
1080
1081                 if (min_key.offset == (u64)-1)
1082                         goto none;
1083
1084                 min_key.offset++;
1085                 btrfs_release_path(path);
1086         }
1087 none:
1088         btrfs_free_path(path);
1089         return -ENOENT;
1090 }
1091
1092 static struct extent_map *defrag_lookup_extent(struct inode *inode, u64 start)
1093 {
1094         struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
1095         struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
1096         struct extent_map *em;
1097         u64 len = PAGE_SIZE;
1098
1099         /*
1100          * hopefully we have this extent in the tree already, try without
1101          * the full extent lock
1102          */
1103         read_lock(&em_tree->lock);
1104         em = lookup_extent_mapping(em_tree, start, len);
1105         read_unlock(&em_tree->lock);
1106
1107         if (!em) {
1108                 struct extent_state *cached = NULL;
1109                 u64 end = start + len - 1;
1110
1111                 /* get the big lock and read metadata off disk */
1112                 lock_extent_bits(io_tree, start, end, &cached);
1113                 em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, start, len, 0);
1114                 unlock_extent_cached(io_tree, start, end, &cached);
1115
1116                 if (IS_ERR(em))
1117                         return NULL;
1118         }
1119
1120         return em;
1121 }
1122
1123 static bool defrag_check_next_extent(struct inode *inode, struct extent_map *em)
1124 {
1125         struct extent_map *next;
1126         bool ret = true;
1127
1128         /* this is the last extent */
1129         if (em->start + em->len >= i_size_read(inode))
1130                 return false;
1131
1132         next = defrag_lookup_extent(inode, em->start + em->len);
1133         if (!next || next->block_start >= EXTENT_MAP_LAST_BYTE)
1134                 ret = false;
1135         else if ((em->block_start + em->block_len == next->block_start) &&
1136                  (em->block_len > SZ_128K && next->block_len > SZ_128K))
1137                 ret = false;
1138
1139         free_extent_map(next);
1140         return ret;
1141 }
1142
1143 static int should_defrag_range(struct inode *inode, u64 start, u32 thresh,
1144                                u64 *last_len, u64 *skip, u64 *defrag_end,
1145                                int compress)
1146 {
1147         struct extent_map *em;
1148         int ret = 1;
1149         bool next_mergeable = true;
1150         bool prev_mergeable = true;
1151
1152         /*
1153          * make sure that once we start defragging an extent, we keep on
1154          * defragging it
1155          */
1156         if (start < *defrag_end)
1157                 return 1;
1158
1159         *skip = 0;
1160
1161         em = defrag_lookup_extent(inode, start);
1162         if (!em)
1163                 return 0;
1164
1165         /* this will cover holes, and inline extents */
1166         if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
1167                 ret = 0;
1168                 goto out;
1169         }
1170
1171         if (!*defrag_end)
1172                 prev_mergeable = false;
1173
1174         next_mergeable = defrag_check_next_extent(inode, em);
1175         /*
1176          * we hit a real extent, if it is big or the next extent is not a
1177          * real extent, don't bother defragging it
1178          */
1179         if (!compress && (*last_len == 0 || *last_len >= thresh) &&
1180             (em->len >= thresh || (!next_mergeable && !prev_mergeable)))
1181                 ret = 0;
1182 out:
1183         /*
1184          * last_len ends up being a counter of how many bytes we've defragged.
1185          * every time we choose not to defrag an extent, we reset *last_len
1186          * so that the next tiny extent will force a defrag.
1187          *
1188          * The end result of this is that tiny extents before a single big
1189          * extent will force at least part of that big extent to be defragged.
1190          */
1191         if (ret) {
1192                 *defrag_end = extent_map_end(em);
1193         } else {
1194                 *last_len = 0;
1195                 *skip = extent_map_end(em);
1196                 *defrag_end = 0;
1197         }
1198
1199         free_extent_map(em);
1200         return ret;
1201 }
1202
1203 /*
1204  * it doesn't do much good to defrag one or two pages
1205  * at a time.  This pulls in a nice chunk of pages
1206  * to COW and defrag.
1207  *
1208  * It also makes sure the delalloc code has enough
1209  * dirty data to avoid making new small extents as part
1210  * of the defrag
1211  *
1212  * It's a good idea to start RA on this range
1213  * before calling this.
1214  */
1215 static int cluster_pages_for_defrag(struct inode *inode,
1216                                     struct page **pages,
1217                                     unsigned long start_index,
1218                                     unsigned long num_pages)
1219 {
1220         unsigned long file_end;
1221         u64 isize = i_size_read(inode);
1222         u64 page_start;
1223         u64 page_end;
1224         u64 page_cnt;
1225         int ret;
1226         int i;
1227         int i_done;
1228         struct btrfs_ordered_extent *ordered;
1229         struct extent_state *cached_state = NULL;
1230         struct extent_io_tree *tree;
1231         struct extent_changeset *data_reserved = NULL;
1232         gfp_t mask = btrfs_alloc_write_mask(inode->i_mapping);
1233
1234         file_end = (isize - 1) >> PAGE_SHIFT;
1235         if (!isize || start_index > file_end)
1236                 return 0;
1237
1238         page_cnt = min_t(u64, (u64)num_pages, (u64)file_end - start_index + 1);
1239
1240         ret = btrfs_delalloc_reserve_space(inode, &data_reserved,
1241                         start_index << PAGE_SHIFT,
1242                         page_cnt << PAGE_SHIFT);
1243         if (ret)
1244                 return ret;
1245         i_done = 0;
1246         tree = &BTRFS_I(inode)->io_tree;
1247
1248         /* step one, lock all the pages */
1249         for (i = 0; i < page_cnt; i++) {
1250                 struct page *page;
1251 again:
1252                 page = find_or_create_page(inode->i_mapping,
1253                                            start_index + i, mask);
1254                 if (!page)
1255                         break;
1256
1257                 page_start = page_offset(page);
1258                 page_end = page_start + PAGE_SIZE - 1;
1259                 while (1) {
1260                         lock_extent_bits(tree, page_start, page_end,
1261                                          &cached_state);
1262                         ordered = btrfs_lookup_ordered_extent(inode,
1263                                                               page_start);
1264                         unlock_extent_cached(tree, page_start, page_end,
1265                                              &cached_state);
1266                         if (!ordered)
1267                                 break;
1268
1269                         unlock_page(page);
1270                         btrfs_start_ordered_extent(inode, ordered, 1);
1271                         btrfs_put_ordered_extent(ordered);
1272                         lock_page(page);
1273                         /*
1274                          * we unlocked the page above, so we need check if
1275                          * it was released or not.
1276                          */
1277                         if (page->mapping != inode->i_mapping) {
1278                                 unlock_page(page);
1279                                 put_page(page);
1280                                 goto again;
1281                         }
1282                 }
1283
1284                 if (!PageUptodate(page)) {
1285                         btrfs_readpage(NULL, page);
1286                         lock_page(page);
1287                         if (!PageUptodate(page)) {
1288                                 unlock_page(page);
1289                                 put_page(page);
1290                                 ret = -EIO;
1291                                 break;
1292                         }
1293                 }
1294
1295                 if (page->mapping != inode->i_mapping) {
1296                         unlock_page(page);
1297                         put_page(page);
1298                         goto again;
1299                 }
1300
1301                 pages[i] = page;
1302                 i_done++;
1303         }
1304         if (!i_done || ret)
1305                 goto out;
1306
1307         if (!(inode->i_sb->s_flags & SB_ACTIVE))
1308                 goto out;
1309
1310         /*
1311          * so now we have a nice long stream of locked
1312          * and up to date pages, lets wait on them
1313          */
1314         for (i = 0; i < i_done; i++)
1315                 wait_on_page_writeback(pages[i]);
1316
1317         page_start = page_offset(pages[0]);
1318         page_end = page_offset(pages[i_done - 1]) + PAGE_SIZE;
1319
1320         lock_extent_bits(&BTRFS_I(inode)->io_tree,
1321                          page_start, page_end - 1, &cached_state);
1322         clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start,
1323                           page_end - 1, EXTENT_DIRTY | EXTENT_DELALLOC |
1324                           EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG, 0, 0,
1325                           &cached_state);
1326
1327         if (i_done != page_cnt) {
1328                 spin_lock(&BTRFS_I(inode)->lock);
1329                 btrfs_mod_outstanding_extents(BTRFS_I(inode), 1);
1330                 spin_unlock(&BTRFS_I(inode)->lock);
1331                 btrfs_delalloc_release_space(inode, data_reserved,
1332                                 start_index << PAGE_SHIFT,
1333                                 (page_cnt - i_done) << PAGE_SHIFT, true);
1334         }
1335
1336
1337         set_extent_defrag(&BTRFS_I(inode)->io_tree, page_start, page_end - 1,
1338                           &cached_state);
1339
1340         unlock_extent_cached(&BTRFS_I(inode)->io_tree,
1341                              page_start, page_end - 1, &cached_state);
1342
1343         for (i = 0; i < i_done; i++) {
1344                 clear_page_dirty_for_io(pages[i]);
1345                 ClearPageChecked(pages[i]);
1346                 set_page_extent_mapped(pages[i]);
1347                 set_page_dirty(pages[i]);
1348                 unlock_page(pages[i]);
1349                 put_page(pages[i]);
1350         }
1351         btrfs_delalloc_release_extents(BTRFS_I(inode), page_cnt << PAGE_SHIFT,
1352                                        false);
1353         extent_changeset_free(data_reserved);
1354         return i_done;
1355 out:
1356         for (i = 0; i < i_done; i++) {
1357                 unlock_page(pages[i]);
1358                 put_page(pages[i]);
1359         }
1360         btrfs_delalloc_release_space(inode, data_reserved,
1361                         start_index << PAGE_SHIFT,
1362                         page_cnt << PAGE_SHIFT, true);
1363         btrfs_delalloc_release_extents(BTRFS_I(inode), page_cnt << PAGE_SHIFT,
1364                                        true);
1365         extent_changeset_free(data_reserved);
1366         return ret;
1367
1368 }
1369
1370 int btrfs_defrag_file(struct inode *inode, struct file *file,
1371                       struct btrfs_ioctl_defrag_range_args *range,
1372                       u64 newer_than, unsigned long max_to_defrag)
1373 {
1374         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1375         struct btrfs_root *root = BTRFS_I(inode)->root;
1376         struct file_ra_state *ra = NULL;
1377         unsigned long last_index;
1378         u64 isize = i_size_read(inode);
1379         u64 last_len = 0;
1380         u64 skip = 0;
1381         u64 defrag_end = 0;
1382         u64 newer_off = range->start;
1383         unsigned long i;
1384         unsigned long ra_index = 0;
1385         int ret;
1386         int defrag_count = 0;
1387         int compress_type = BTRFS_COMPRESS_ZLIB;
1388         u32 extent_thresh = range->extent_thresh;
1389         unsigned long max_cluster = SZ_256K >> PAGE_SHIFT;
1390         unsigned long cluster = max_cluster;
1391         u64 new_align = ~((u64)SZ_128K - 1);
1392         struct page **pages = NULL;
1393         bool do_compress = range->flags & BTRFS_DEFRAG_RANGE_COMPRESS;
1394
1395         if (isize == 0)
1396                 return 0;
1397
1398         if (range->start >= isize)
1399                 return -EINVAL;
1400
1401         if (do_compress) {
1402                 if (range->compress_type > BTRFS_COMPRESS_TYPES)
1403                         return -EINVAL;
1404                 if (range->compress_type)
1405                         compress_type = range->compress_type;
1406         }
1407
1408         if (extent_thresh == 0)
1409                 extent_thresh = SZ_256K;
1410
1411         /*
1412          * If we were not given a file, allocate a readahead context. As
1413          * readahead is just an optimization, defrag will work without it so
1414          * we don't error out.
1415          */
1416         if (!file) {
1417                 ra = kzalloc(sizeof(*ra), GFP_KERNEL);
1418                 if (ra)
1419                         file_ra_state_init(ra, inode->i_mapping);
1420         } else {
1421                 ra = &file->f_ra;
1422         }
1423
1424         pages = kmalloc_array(max_cluster, sizeof(struct page *), GFP_KERNEL);
1425         if (!pages) {
1426                 ret = -ENOMEM;
1427                 goto out_ra;
1428         }
1429
1430         /* find the last page to defrag */
1431         if (range->start + range->len > range->start) {
1432                 last_index = min_t(u64, isize - 1,
1433                          range->start + range->len - 1) >> PAGE_SHIFT;
1434         } else {
1435                 last_index = (isize - 1) >> PAGE_SHIFT;
1436         }
1437
1438         if (newer_than) {
1439                 ret = find_new_extents(root, inode, newer_than,
1440                                        &newer_off, SZ_64K);
1441                 if (!ret) {
1442                         range->start = newer_off;
1443                         /*
1444                          * we always align our defrag to help keep
1445                          * the extents in the file evenly spaced
1446                          */
1447                         i = (newer_off & new_align) >> PAGE_SHIFT;
1448                 } else
1449                         goto out_ra;
1450         } else {
1451                 i = range->start >> PAGE_SHIFT;
1452         }
1453         if (!max_to_defrag)
1454                 max_to_defrag = last_index - i + 1;
1455
1456         /*
1457          * make writeback starts from i, so the defrag range can be
1458          * written sequentially.
1459          */
1460         if (i < inode->i_mapping->writeback_index)
1461                 inode->i_mapping->writeback_index = i;
1462
1463         while (i <= last_index && defrag_count < max_to_defrag &&
1464                (i < DIV_ROUND_UP(i_size_read(inode), PAGE_SIZE))) {
1465                 /*
1466                  * make sure we stop running if someone unmounts
1467                  * the FS
1468                  */
1469                 if (!(inode->i_sb->s_flags & SB_ACTIVE))
1470                         break;
1471
1472                 if (btrfs_defrag_cancelled(fs_info)) {
1473                         btrfs_debug(fs_info, "defrag_file cancelled");
1474                         ret = -EAGAIN;
1475                         break;
1476                 }
1477
1478                 if (!should_defrag_range(inode, (u64)i << PAGE_SHIFT,
1479                                          extent_thresh, &last_len, &skip,
1480                                          &defrag_end, do_compress)){
1481                         unsigned long next;
1482                         /*
1483                          * the should_defrag function tells us how much to skip
1484                          * bump our counter by the suggested amount
1485                          */
1486                         next = DIV_ROUND_UP(skip, PAGE_SIZE);
1487                         i = max(i + 1, next);
1488                         continue;
1489                 }
1490
1491                 if (!newer_than) {
1492                         cluster = (PAGE_ALIGN(defrag_end) >>
1493                                    PAGE_SHIFT) - i;
1494                         cluster = min(cluster, max_cluster);
1495                 } else {
1496                         cluster = max_cluster;
1497                 }
1498
1499                 if (i + cluster > ra_index) {
1500                         ra_index = max(i, ra_index);
1501                         if (ra)
1502                                 page_cache_sync_readahead(inode->i_mapping, ra,
1503                                                 file, ra_index, cluster);
1504                         ra_index += cluster;
1505                 }
1506
1507                 inode_lock(inode);
1508                 if (do_compress)
1509                         BTRFS_I(inode)->defrag_compress = compress_type;
1510                 ret = cluster_pages_for_defrag(inode, pages, i, cluster);
1511                 if (ret < 0) {
1512                         inode_unlock(inode);
1513                         goto out_ra;
1514                 }
1515
1516                 defrag_count += ret;
1517                 balance_dirty_pages_ratelimited(inode->i_mapping);
1518                 inode_unlock(inode);
1519
1520                 if (newer_than) {
1521                         if (newer_off == (u64)-1)
1522                                 break;
1523
1524                         if (ret > 0)
1525                                 i += ret;
1526
1527                         newer_off = max(newer_off + 1,
1528                                         (u64)i << PAGE_SHIFT);
1529
1530                         ret = find_new_extents(root, inode, newer_than,
1531                                                &newer_off, SZ_64K);
1532                         if (!ret) {
1533                                 range->start = newer_off;
1534                                 i = (newer_off & new_align) >> PAGE_SHIFT;
1535                         } else {
1536                                 break;
1537                         }
1538                 } else {
1539                         if (ret > 0) {
1540                                 i += ret;
1541                                 last_len += ret << PAGE_SHIFT;
1542                         } else {
1543                                 i++;
1544                                 last_len = 0;
1545                         }
1546                 }
1547         }
1548
1549         if ((range->flags & BTRFS_DEFRAG_RANGE_START_IO)) {
1550                 filemap_flush(inode->i_mapping);
1551                 if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
1552                              &BTRFS_I(inode)->runtime_flags))
1553                         filemap_flush(inode->i_mapping);
1554         }
1555
1556         if (range->compress_type == BTRFS_COMPRESS_LZO) {
1557                 btrfs_set_fs_incompat(fs_info, COMPRESS_LZO);
1558         } else if (range->compress_type == BTRFS_COMPRESS_ZSTD) {
1559                 btrfs_set_fs_incompat(fs_info, COMPRESS_ZSTD);
1560         }
1561
1562         ret = defrag_count;
1563
1564 out_ra:
1565         if (do_compress) {
1566                 inode_lock(inode);
1567                 BTRFS_I(inode)->defrag_compress = BTRFS_COMPRESS_NONE;
1568                 inode_unlock(inode);
1569         }
1570         if (!file)
1571                 kfree(ra);
1572         kfree(pages);
1573         return ret;
1574 }
1575
1576 static noinline int btrfs_ioctl_resize(struct file *file,
1577                                         void __user *arg)
1578 {
1579         struct inode *inode = file_inode(file);
1580         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1581         u64 new_size;
1582         u64 old_size;
1583         u64 devid = 1;
1584         struct btrfs_root *root = BTRFS_I(inode)->root;
1585         struct btrfs_ioctl_vol_args *vol_args;
1586         struct btrfs_trans_handle *trans;
1587         struct btrfs_device *device = NULL;
1588         char *sizestr;
1589         char *retptr;
1590         char *devstr = NULL;
1591         int ret = 0;
1592         int mod = 0;
1593
1594         if (!capable(CAP_SYS_ADMIN))
1595                 return -EPERM;
1596
1597         ret = mnt_want_write_file(file);
1598         if (ret)
1599                 return ret;
1600
1601         if (test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags)) {
1602                 mnt_drop_write_file(file);
1603                 return BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
1604         }
1605
1606         vol_args = memdup_user(arg, sizeof(*vol_args));
1607         if (IS_ERR(vol_args)) {
1608                 ret = PTR_ERR(vol_args);
1609                 goto out;
1610         }
1611
1612         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1613
1614         sizestr = vol_args->name;
1615         devstr = strchr(sizestr, ':');
1616         if (devstr) {
1617                 sizestr = devstr + 1;
1618                 *devstr = '\0';
1619                 devstr = vol_args->name;
1620                 ret = kstrtoull(devstr, 10, &devid);
1621                 if (ret)
1622                         goto out_free;
1623                 if (!devid) {
1624                         ret = -EINVAL;
1625                         goto out_free;
1626                 }
1627                 btrfs_info(fs_info, "resizing devid %llu", devid);
1628         }
1629
1630         device = btrfs_find_device(fs_info, devid, NULL, NULL);
1631         if (!device) {
1632                 btrfs_info(fs_info, "resizer unable to find device %llu",
1633                            devid);
1634                 ret = -ENODEV;
1635                 goto out_free;
1636         }
1637
1638         if (!test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state)) {
1639                 btrfs_info(fs_info,
1640                            "resizer unable to apply on readonly device %llu",
1641                        devid);
1642                 ret = -EPERM;
1643                 goto out_free;
1644         }
1645
1646         if (!strcmp(sizestr, "max"))
1647                 new_size = device->bdev->bd_inode->i_size;
1648         else {
1649                 if (sizestr[0] == '-') {
1650                         mod = -1;
1651                         sizestr++;
1652                 } else if (sizestr[0] == '+') {
1653                         mod = 1;
1654                         sizestr++;
1655                 }
1656                 new_size = memparse(sizestr, &retptr);
1657                 if (*retptr != '\0' || new_size == 0) {
1658                         ret = -EINVAL;
1659                         goto out_free;
1660                 }
1661         }
1662
1663         if (test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state)) {
1664                 ret = -EPERM;
1665                 goto out_free;
1666         }
1667
1668         old_size = btrfs_device_get_total_bytes(device);
1669
1670         if (mod < 0) {
1671                 if (new_size > old_size) {
1672                         ret = -EINVAL;
1673                         goto out_free;
1674                 }
1675                 new_size = old_size - new_size;
1676         } else if (mod > 0) {
1677                 if (new_size > ULLONG_MAX - old_size) {
1678                         ret = -ERANGE;
1679                         goto out_free;
1680                 }
1681                 new_size = old_size + new_size;
1682         }
1683
1684         if (new_size < SZ_256M) {
1685                 ret = -EINVAL;
1686                 goto out_free;
1687         }
1688         if (new_size > device->bdev->bd_inode->i_size) {
1689                 ret = -EFBIG;
1690                 goto out_free;
1691         }
1692
1693         new_size = round_down(new_size, fs_info->sectorsize);
1694
1695         btrfs_info_in_rcu(fs_info, "new size for %s is %llu",
1696                           rcu_str_deref(device->name), new_size);
1697
1698         if (new_size > old_size) {
1699                 trans = btrfs_start_transaction(root, 0);
1700                 if (IS_ERR(trans)) {
1701                         ret = PTR_ERR(trans);
1702                         goto out_free;
1703                 }
1704                 ret = btrfs_grow_device(trans, device, new_size);
1705                 btrfs_commit_transaction(trans);
1706         } else if (new_size < old_size) {
1707                 ret = btrfs_shrink_device(device, new_size);
1708         } /* equal, nothing need to do */
1709
1710 out_free:
1711         kfree(vol_args);
1712 out:
1713         clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
1714         mnt_drop_write_file(file);
1715         return ret;
1716 }
1717
1718 static noinline int btrfs_ioctl_snap_create_transid(struct file *file,
1719                                 const char *name, unsigned long fd, int subvol,
1720                                 u64 *transid, bool readonly,
1721                                 struct btrfs_qgroup_inherit *inherit)
1722 {
1723         int namelen;
1724         int ret = 0;
1725
1726         if (!S_ISDIR(file_inode(file)->i_mode))
1727                 return -ENOTDIR;
1728
1729         ret = mnt_want_write_file(file);
1730         if (ret)
1731                 goto out;
1732
1733         namelen = strlen(name);
1734         if (strchr(name, '/')) {
1735                 ret = -EINVAL;
1736                 goto out_drop_write;
1737         }
1738
1739         if (name[0] == '.' &&
1740            (namelen == 1 || (name[1] == '.' && namelen == 2))) {
1741                 ret = -EEXIST;
1742                 goto out_drop_write;
1743         }
1744
1745         if (subvol) {
1746                 ret = btrfs_mksubvol(&file->f_path, name, namelen,
1747                                      NULL, transid, readonly, inherit);
1748         } else {
1749                 struct fd src = fdget(fd);
1750                 struct inode *src_inode;
1751                 if (!src.file) {
1752                         ret = -EINVAL;
1753                         goto out_drop_write;
1754                 }
1755
1756                 src_inode = file_inode(src.file);
1757                 if (src_inode->i_sb != file_inode(file)->i_sb) {
1758                         btrfs_info(BTRFS_I(file_inode(file))->root->fs_info,
1759                                    "Snapshot src from another FS");
1760                         ret = -EXDEV;
1761                 } else if (!inode_owner_or_capable(src_inode)) {
1762                         /*
1763                          * Subvolume creation is not restricted, but snapshots
1764                          * are limited to own subvolumes only
1765                          */
1766                         ret = -EPERM;
1767                 } else {
1768                         ret = btrfs_mksubvol(&file->f_path, name, namelen,
1769                                              BTRFS_I(src_inode)->root,
1770                                              transid, readonly, inherit);
1771                 }
1772                 fdput(src);
1773         }
1774 out_drop_write:
1775         mnt_drop_write_file(file);
1776 out:
1777         return ret;
1778 }
1779
1780 static noinline int btrfs_ioctl_snap_create(struct file *file,
1781                                             void __user *arg, int subvol)
1782 {
1783         struct btrfs_ioctl_vol_args *vol_args;
1784         int ret;
1785
1786         if (!S_ISDIR(file_inode(file)->i_mode))
1787                 return -ENOTDIR;
1788
1789         vol_args = memdup_user(arg, sizeof(*vol_args));
1790         if (IS_ERR(vol_args))
1791                 return PTR_ERR(vol_args);
1792         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1793
1794         ret = btrfs_ioctl_snap_create_transid(file, vol_args->name,
1795                                               vol_args->fd, subvol,
1796                                               NULL, false, NULL);
1797
1798         kfree(vol_args);
1799         return ret;
1800 }
1801
1802 static noinline int btrfs_ioctl_snap_create_v2(struct file *file,
1803                                                void __user *arg, int subvol)
1804 {
1805         struct btrfs_ioctl_vol_args_v2 *vol_args;
1806         int ret;
1807         u64 transid = 0;
1808         u64 *ptr = NULL;
1809         bool readonly = false;
1810         struct btrfs_qgroup_inherit *inherit = NULL;
1811
1812         if (!S_ISDIR(file_inode(file)->i_mode))
1813                 return -ENOTDIR;
1814
1815         vol_args = memdup_user(arg, sizeof(*vol_args));
1816         if (IS_ERR(vol_args))
1817                 return PTR_ERR(vol_args);
1818         vol_args->name[BTRFS_SUBVOL_NAME_MAX] = '\0';
1819
1820         if (vol_args->flags &
1821             ~(BTRFS_SUBVOL_CREATE_ASYNC | BTRFS_SUBVOL_RDONLY |
1822               BTRFS_SUBVOL_QGROUP_INHERIT)) {
1823                 ret = -EOPNOTSUPP;
1824                 goto free_args;
1825         }
1826
1827         if (vol_args->flags & BTRFS_SUBVOL_CREATE_ASYNC)
1828                 ptr = &transid;
1829         if (vol_args->flags & BTRFS_SUBVOL_RDONLY)
1830                 readonly = true;
1831         if (vol_args->flags & BTRFS_SUBVOL_QGROUP_INHERIT) {
1832                 if (vol_args->size > PAGE_SIZE) {
1833                         ret = -EINVAL;
1834                         goto free_args;
1835                 }
1836                 inherit = memdup_user(vol_args->qgroup_inherit, vol_args->size);
1837                 if (IS_ERR(inherit)) {
1838                         ret = PTR_ERR(inherit);
1839                         goto free_args;
1840                 }
1841         }
1842
1843         ret = btrfs_ioctl_snap_create_transid(file, vol_args->name,
1844                                               vol_args->fd, subvol, ptr,
1845                                               readonly, inherit);
1846         if (ret)
1847                 goto free_inherit;
1848
1849         if (ptr && copy_to_user(arg +
1850                                 offsetof(struct btrfs_ioctl_vol_args_v2,
1851                                         transid),
1852                                 ptr, sizeof(*ptr)))
1853                 ret = -EFAULT;
1854
1855 free_inherit:
1856         kfree(inherit);
1857 free_args:
1858         kfree(vol_args);
1859         return ret;
1860 }
1861
1862 static noinline int btrfs_ioctl_subvol_getflags(struct file *file,
1863                                                 void __user *arg)
1864 {
1865         struct inode *inode = file_inode(file);
1866         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1867         struct btrfs_root *root = BTRFS_I(inode)->root;
1868         int ret = 0;
1869         u64 flags = 0;
1870
1871         if (btrfs_ino(BTRFS_I(inode)) != BTRFS_FIRST_FREE_OBJECTID)
1872                 return -EINVAL;
1873
1874         down_read(&fs_info->subvol_sem);
1875         if (btrfs_root_readonly(root))
1876                 flags |= BTRFS_SUBVOL_RDONLY;
1877         up_read(&fs_info->subvol_sem);
1878
1879         if (copy_to_user(arg, &flags, sizeof(flags)))
1880                 ret = -EFAULT;
1881
1882         return ret;
1883 }
1884
1885 static noinline int btrfs_ioctl_subvol_setflags(struct file *file,
1886                                               void __user *arg)
1887 {
1888         struct inode *inode = file_inode(file);
1889         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1890         struct btrfs_root *root = BTRFS_I(inode)->root;
1891         struct btrfs_trans_handle *trans;
1892         u64 root_flags;
1893         u64 flags;
1894         int ret = 0;
1895
1896         if (!inode_owner_or_capable(inode))
1897                 return -EPERM;
1898
1899         ret = mnt_want_write_file(file);
1900         if (ret)
1901                 goto out;
1902
1903         if (btrfs_ino(BTRFS_I(inode)) != BTRFS_FIRST_FREE_OBJECTID) {
1904                 ret = -EINVAL;
1905                 goto out_drop_write;
1906         }
1907
1908         if (copy_from_user(&flags, arg, sizeof(flags))) {
1909                 ret = -EFAULT;
1910                 goto out_drop_write;
1911         }
1912
1913         if (flags & BTRFS_SUBVOL_CREATE_ASYNC) {
1914                 ret = -EINVAL;
1915                 goto out_drop_write;
1916         }
1917
1918         if (flags & ~BTRFS_SUBVOL_RDONLY) {
1919                 ret = -EOPNOTSUPP;
1920                 goto out_drop_write;
1921         }
1922
1923         down_write(&fs_info->subvol_sem);
1924
1925         /* nothing to do */
1926         if (!!(flags & BTRFS_SUBVOL_RDONLY) == btrfs_root_readonly(root))
1927                 goto out_drop_sem;
1928
1929         root_flags = btrfs_root_flags(&root->root_item);
1930         if (flags & BTRFS_SUBVOL_RDONLY) {
1931                 btrfs_set_root_flags(&root->root_item,
1932                                      root_flags | BTRFS_ROOT_SUBVOL_RDONLY);
1933         } else {
1934                 /*
1935                  * Block RO -> RW transition if this subvolume is involved in
1936                  * send
1937                  */
1938                 spin_lock(&root->root_item_lock);
1939                 if (root->send_in_progress == 0) {
1940                         btrfs_set_root_flags(&root->root_item,
1941                                      root_flags & ~BTRFS_ROOT_SUBVOL_RDONLY);
1942                         spin_unlock(&root->root_item_lock);
1943                 } else {
1944                         spin_unlock(&root->root_item_lock);
1945                         btrfs_warn(fs_info,
1946                                    "Attempt to set subvolume %llu read-write during send",
1947                                    root->root_key.objectid);
1948                         ret = -EPERM;
1949                         goto out_drop_sem;
1950                 }
1951         }
1952
1953         trans = btrfs_start_transaction(root, 1);
1954         if (IS_ERR(trans)) {
1955                 ret = PTR_ERR(trans);
1956                 goto out_reset;
1957         }
1958
1959         ret = btrfs_update_root(trans, fs_info->tree_root,
1960                                 &root->root_key, &root->root_item);
1961         if (ret < 0) {
1962                 btrfs_end_transaction(trans);
1963                 goto out_reset;
1964         }
1965
1966         ret = btrfs_commit_transaction(trans);
1967
1968 out_reset:
1969         if (ret)
1970                 btrfs_set_root_flags(&root->root_item, root_flags);
1971 out_drop_sem:
1972         up_write(&fs_info->subvol_sem);
1973 out_drop_write:
1974         mnt_drop_write_file(file);
1975 out:
1976         return ret;
1977 }
1978
1979 static noinline int key_in_sk(struct btrfs_key *key,
1980                               struct btrfs_ioctl_search_key *sk)
1981 {
1982         struct btrfs_key test;
1983         int ret;
1984
1985         test.objectid = sk->min_objectid;
1986         test.type = sk->min_type;
1987         test.offset = sk->min_offset;
1988
1989         ret = btrfs_comp_cpu_keys(key, &test);
1990         if (ret < 0)
1991                 return 0;
1992
1993         test.objectid = sk->max_objectid;
1994         test.type = sk->max_type;
1995         test.offset = sk->max_offset;
1996
1997         ret = btrfs_comp_cpu_keys(key, &test);
1998         if (ret > 0)
1999                 return 0;
2000         return 1;
2001 }
2002
2003 static noinline int copy_to_sk(struct btrfs_path *path,
2004                                struct btrfs_key *key,
2005                                struct btrfs_ioctl_search_key *sk,
2006                                size_t *buf_size,
2007                                char __user *ubuf,
2008                                unsigned long *sk_offset,
2009                                int *num_found)
2010 {
2011         u64 found_transid;
2012         struct extent_buffer *leaf;
2013         struct btrfs_ioctl_search_header sh;
2014         struct btrfs_key test;
2015         unsigned long item_off;
2016         unsigned long item_len;
2017         int nritems;
2018         int i;
2019         int slot;
2020         int ret = 0;
2021
2022         leaf = path->nodes[0];
2023         slot = path->slots[0];
2024         nritems = btrfs_header_nritems(leaf);
2025
2026         if (btrfs_header_generation(leaf) > sk->max_transid) {
2027                 i = nritems;
2028                 goto advance_key;
2029         }
2030         found_transid = btrfs_header_generation(leaf);
2031
2032         for (i = slot; i < nritems; i++) {
2033                 item_off = btrfs_item_ptr_offset(leaf, i);
2034                 item_len = btrfs_item_size_nr(leaf, i);
2035
2036                 btrfs_item_key_to_cpu(leaf, key, i);
2037                 if (!key_in_sk(key, sk))
2038                         continue;
2039
2040                 if (sizeof(sh) + item_len > *buf_size) {
2041                         if (*num_found) {
2042                                 ret = 1;
2043                                 goto out;
2044                         }
2045
2046                         /*
2047                          * return one empty item back for v1, which does not
2048                          * handle -EOVERFLOW
2049                          */
2050
2051                         *buf_size = sizeof(sh) + item_len;
2052                         item_len = 0;
2053                         ret = -EOVERFLOW;
2054                 }
2055
2056                 if (sizeof(sh) + item_len + *sk_offset > *buf_size) {
2057                         ret = 1;
2058                         goto out;
2059                 }
2060
2061                 sh.objectid = key->objectid;
2062                 sh.offset = key->offset;
2063                 sh.type = key->type;
2064                 sh.len = item_len;
2065                 sh.transid = found_transid;
2066
2067                 /* copy search result header */
2068                 if (copy_to_user(ubuf + *sk_offset, &sh, sizeof(sh))) {
2069                         ret = -EFAULT;
2070                         goto out;
2071                 }
2072
2073                 *sk_offset += sizeof(sh);
2074
2075                 if (item_len) {
2076                         char __user *up = ubuf + *sk_offset;
2077                         /* copy the item */
2078                         if (read_extent_buffer_to_user(leaf, up,
2079                                                        item_off, item_len)) {
2080                                 ret = -EFAULT;
2081                                 goto out;
2082                         }
2083
2084                         *sk_offset += item_len;
2085                 }
2086                 (*num_found)++;
2087
2088                 if (ret) /* -EOVERFLOW from above */
2089                         goto out;
2090
2091                 if (*num_found >= sk->nr_items) {
2092                         ret = 1;
2093                         goto out;
2094                 }
2095         }
2096 advance_key:
2097         ret = 0;
2098         test.objectid = sk->max_objectid;
2099         test.type = sk->max_type;
2100         test.offset = sk->max_offset;
2101         if (btrfs_comp_cpu_keys(key, &test) >= 0)
2102                 ret = 1;
2103         else if (key->offset < (u64)-1)
2104                 key->offset++;
2105         else if (key->type < (u8)-1) {
2106                 key->offset = 0;
2107                 key->type++;
2108         } else if (key->objectid < (u64)-1) {
2109                 key->offset = 0;
2110                 key->type = 0;
2111                 key->objectid++;
2112         } else
2113                 ret = 1;
2114 out:
2115         /*
2116          *  0: all items from this leaf copied, continue with next
2117          *  1: * more items can be copied, but unused buffer is too small
2118          *     * all items were found
2119          *     Either way, it will stops the loop which iterates to the next
2120          *     leaf
2121          *  -EOVERFLOW: item was to large for buffer
2122          *  -EFAULT: could not copy extent buffer back to userspace
2123          */
2124         return ret;
2125 }
2126
2127 static noinline int search_ioctl(struct inode *inode,
2128                                  struct btrfs_ioctl_search_key *sk,
2129                                  size_t *buf_size,
2130                                  char __user *ubuf)
2131 {
2132         struct btrfs_fs_info *info = btrfs_sb(inode->i_sb);
2133         struct btrfs_root *root;
2134         struct btrfs_key key;
2135         struct btrfs_path *path;
2136         int ret;
2137         int num_found = 0;
2138         unsigned long sk_offset = 0;
2139
2140         if (*buf_size < sizeof(struct btrfs_ioctl_search_header)) {
2141                 *buf_size = sizeof(struct btrfs_ioctl_search_header);
2142                 return -EOVERFLOW;
2143         }
2144
2145         path = btrfs_alloc_path();
2146         if (!path)
2147                 return -ENOMEM;
2148
2149         if (sk->tree_id == 0) {
2150                 /* search the root of the inode that was passed */
2151                 root = BTRFS_I(inode)->root;
2152         } else {
2153                 key.objectid = sk->tree_id;
2154                 key.type = BTRFS_ROOT_ITEM_KEY;
2155                 key.offset = (u64)-1;
2156                 root = btrfs_read_fs_root_no_name(info, &key);
2157                 if (IS_ERR(root)) {
2158                         btrfs_free_path(path);
2159                         return PTR_ERR(root);
2160                 }
2161         }
2162
2163         key.objectid = sk->min_objectid;
2164         key.type = sk->min_type;
2165         key.offset = sk->min_offset;
2166
2167         while (1) {
2168                 ret = btrfs_search_forward(root, &key, path, sk->min_transid);
2169                 if (ret != 0) {
2170                         if (ret > 0)
2171                                 ret = 0;
2172                         goto err;
2173                 }
2174                 ret = copy_to_sk(path, &key, sk, buf_size, ubuf,
2175                                  &sk_offset, &num_found);
2176                 btrfs_release_path(path);
2177                 if (ret)
2178                         break;
2179
2180         }
2181         if (ret > 0)
2182                 ret = 0;
2183 err:
2184         sk->nr_items = num_found;
2185         btrfs_free_path(path);
2186         return ret;
2187 }
2188
2189 static noinline int btrfs_ioctl_tree_search(struct file *file,
2190                                            void __user *argp)
2191 {
2192         struct btrfs_ioctl_search_args __user *uargs;
2193         struct btrfs_ioctl_search_key sk;
2194         struct inode *inode;
2195         int ret;
2196         size_t buf_size;
2197
2198         if (!capable(CAP_SYS_ADMIN))
2199                 return -EPERM;
2200
2201         uargs = (struct btrfs_ioctl_search_args __user *)argp;
2202
2203         if (copy_from_user(&sk, &uargs->key, sizeof(sk)))
2204                 return -EFAULT;
2205
2206         buf_size = sizeof(uargs->buf);
2207
2208         inode = file_inode(file);
2209         ret = search_ioctl(inode, &sk, &buf_size, uargs->buf);
2210
2211         /*
2212          * In the origin implementation an overflow is handled by returning a
2213          * search header with a len of zero, so reset ret.
2214          */
2215         if (ret == -EOVERFLOW)
2216                 ret = 0;
2217
2218         if (ret == 0 && copy_to_user(&uargs->key, &sk, sizeof(sk)))
2219                 ret = -EFAULT;
2220         return ret;
2221 }
2222
2223 static noinline int btrfs_ioctl_tree_search_v2(struct file *file,
2224                                                void __user *argp)
2225 {
2226         struct btrfs_ioctl_search_args_v2 __user *uarg;
2227         struct btrfs_ioctl_search_args_v2 args;
2228         struct inode *inode;
2229         int ret;
2230         size_t buf_size;
2231         const size_t buf_limit = SZ_16M;
2232
2233         if (!capable(CAP_SYS_ADMIN))
2234                 return -EPERM;
2235
2236         /* copy search header and buffer size */
2237         uarg = (struct btrfs_ioctl_search_args_v2 __user *)argp;
2238         if (copy_from_user(&args, uarg, sizeof(args)))
2239                 return -EFAULT;
2240
2241         buf_size = args.buf_size;
2242
2243         /* limit result size to 16MB */
2244         if (buf_size > buf_limit)
2245                 buf_size = buf_limit;
2246
2247         inode = file_inode(file);
2248         ret = search_ioctl(inode, &args.key, &buf_size,
2249                            (char __user *)(&uarg->buf[0]));
2250         if (ret == 0 && copy_to_user(&uarg->key, &args.key, sizeof(args.key)))
2251                 ret = -EFAULT;
2252         else if (ret == -EOVERFLOW &&
2253                 copy_to_user(&uarg->buf_size, &buf_size, sizeof(buf_size)))
2254                 ret = -EFAULT;
2255
2256         return ret;
2257 }
2258
2259 /*
2260  * Search INODE_REFs to identify path name of 'dirid' directory
2261  * in a 'tree_id' tree. and sets path name to 'name'.
2262  */
2263 static noinline int btrfs_search_path_in_tree(struct btrfs_fs_info *info,
2264                                 u64 tree_id, u64 dirid, char *name)
2265 {
2266         struct btrfs_root *root;
2267         struct btrfs_key key;
2268         char *ptr;
2269         int ret = -1;
2270         int slot;
2271         int len;
2272         int total_len = 0;
2273         struct btrfs_inode_ref *iref;
2274         struct extent_buffer *l;
2275         struct btrfs_path *path;
2276
2277         if (dirid == BTRFS_FIRST_FREE_OBJECTID) {
2278                 name[0]='\0';
2279                 return 0;
2280         }
2281
2282         path = btrfs_alloc_path();
2283         if (!path)
2284                 return -ENOMEM;
2285
2286         ptr = &name[BTRFS_INO_LOOKUP_PATH_MAX - 1];
2287
2288         key.objectid = tree_id;
2289         key.type = BTRFS_ROOT_ITEM_KEY;
2290         key.offset = (u64)-1;
2291         root = btrfs_read_fs_root_no_name(info, &key);
2292         if (IS_ERR(root)) {
2293                 ret = PTR_ERR(root);
2294                 goto out;
2295         }
2296
2297         key.objectid = dirid;
2298         key.type = BTRFS_INODE_REF_KEY;
2299         key.offset = (u64)-1;
2300
2301         while (1) {
2302                 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2303                 if (ret < 0)
2304                         goto out;
2305                 else if (ret > 0) {
2306                         ret = btrfs_previous_item(root, path, dirid,
2307                                                   BTRFS_INODE_REF_KEY);
2308                         if (ret < 0)
2309                                 goto out;
2310                         else if (ret > 0) {
2311                                 ret = -ENOENT;
2312                                 goto out;
2313                         }
2314                 }
2315
2316                 l = path->nodes[0];
2317                 slot = path->slots[0];
2318                 btrfs_item_key_to_cpu(l, &key, slot);
2319
2320                 iref = btrfs_item_ptr(l, slot, struct btrfs_inode_ref);
2321                 len = btrfs_inode_ref_name_len(l, iref);
2322                 ptr -= len + 1;
2323                 total_len += len + 1;
2324                 if (ptr < name) {
2325                         ret = -ENAMETOOLONG;
2326                         goto out;
2327                 }
2328
2329                 *(ptr + len) = '/';
2330                 read_extent_buffer(l, ptr, (unsigned long)(iref + 1), len);
2331
2332                 if (key.offset == BTRFS_FIRST_FREE_OBJECTID)
2333                         break;
2334
2335                 btrfs_release_path(path);
2336                 key.objectid = key.offset;
2337                 key.offset = (u64)-1;
2338                 dirid = key.objectid;
2339         }
2340         memmove(name, ptr, total_len);
2341         name[total_len] = '\0';
2342         ret = 0;
2343 out:
2344         btrfs_free_path(path);
2345         return ret;
2346 }
2347
2348 static int btrfs_search_path_in_tree_user(struct inode *inode,
2349                                 struct btrfs_ioctl_ino_lookup_user_args *args)
2350 {
2351         struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
2352         struct super_block *sb = inode->i_sb;
2353         struct btrfs_key upper_limit = BTRFS_I(inode)->location;
2354         u64 treeid = BTRFS_I(inode)->root->root_key.objectid;
2355         u64 dirid = args->dirid;
2356         unsigned long item_off;
2357         unsigned long item_len;
2358         struct btrfs_inode_ref *iref;
2359         struct btrfs_root_ref *rref;
2360         struct btrfs_root *root;
2361         struct btrfs_path *path;
2362         struct btrfs_key key, key2;
2363         struct extent_buffer *leaf;
2364         struct inode *temp_inode;
2365         char *ptr;
2366         int slot;
2367         int len;
2368         int total_len = 0;
2369         int ret;
2370
2371         path = btrfs_alloc_path();
2372         if (!path)
2373                 return -ENOMEM;
2374
2375         /*
2376          * If the bottom subvolume does not exist directly under upper_limit,
2377          * construct the path in from the bottom up.
2378          */
2379         if (dirid != upper_limit.objectid) {
2380                 ptr = &args->path[BTRFS_INO_LOOKUP_USER_PATH_MAX - 1];
2381
2382                 key.objectid = treeid;
2383                 key.type = BTRFS_ROOT_ITEM_KEY;
2384                 key.offset = (u64)-1;
2385                 root = btrfs_read_fs_root_no_name(fs_info, &key);
2386                 if (IS_ERR(root)) {
2387                         ret = PTR_ERR(root);
2388                         goto out;
2389                 }
2390
2391                 key.objectid = dirid;
2392                 key.type = BTRFS_INODE_REF_KEY;
2393                 key.offset = (u64)-1;
2394                 while (1) {
2395                         ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2396                         if (ret < 0) {
2397                                 goto out;
2398                         } else if (ret > 0) {
2399                                 ret = btrfs_previous_item(root, path, dirid,
2400                                                           BTRFS_INODE_REF_KEY);
2401                                 if (ret < 0) {
2402                                         goto out;
2403                                 } else if (ret > 0) {
2404                                         ret = -ENOENT;
2405                                         goto out;
2406                                 }
2407                         }
2408
2409                         leaf = path->nodes[0];
2410                         slot = path->slots[0];
2411                         btrfs_item_key_to_cpu(leaf, &key, slot);
2412
2413                         iref = btrfs_item_ptr(leaf, slot, struct btrfs_inode_ref);
2414                         len = btrfs_inode_ref_name_len(leaf, iref);
2415                         ptr -= len + 1;
2416                         total_len += len + 1;
2417                         if (ptr < args->path) {
2418                                 ret = -ENAMETOOLONG;
2419                                 goto out;
2420                         }
2421
2422                         *(ptr + len) = '/';
2423                         read_extent_buffer(leaf, ptr,
2424                                         (unsigned long)(iref + 1), len);
2425
2426                         /* Check the read+exec permission of this directory */
2427                         ret = btrfs_previous_item(root, path, dirid,
2428                                                   BTRFS_INODE_ITEM_KEY);
2429                         if (ret < 0) {
2430                                 goto out;
2431                         } else if (ret > 0) {
2432                                 ret = -ENOENT;
2433                                 goto out;
2434                         }
2435
2436                         leaf = path->nodes[0];
2437                         slot = path->slots[0];
2438                         btrfs_item_key_to_cpu(leaf, &key2, slot);
2439                         if (key2.objectid != dirid) {
2440                                 ret = -ENOENT;
2441                                 goto out;
2442                         }
2443
2444                         temp_inode = btrfs_iget(sb, &key2, root, NULL);
2445                         if (IS_ERR(temp_inode)) {
2446                                 ret = PTR_ERR(temp_inode);
2447                                 goto out;
2448                         }
2449                         ret = inode_permission(temp_inode, MAY_READ | MAY_EXEC);
2450                         iput(temp_inode);
2451                         if (ret) {
2452                                 ret = -EACCES;
2453                                 goto out;
2454                         }
2455
2456                         if (key.offset == upper_limit.objectid)
2457                                 break;
2458                         if (key.objectid == BTRFS_FIRST_FREE_OBJECTID) {
2459                                 ret = -EACCES;
2460                                 goto out;
2461                         }
2462
2463                         btrfs_release_path(path);
2464                         key.objectid = key.offset;
2465                         key.offset = (u64)-1;
2466                         dirid = key.objectid;
2467                 }
2468
2469                 memmove(args->path, ptr, total_len);
2470                 args->path[total_len] = '\0';
2471                 btrfs_release_path(path);
2472         }
2473
2474         /* Get the bottom subvolume's name from ROOT_REF */
2475         root = fs_info->tree_root;
2476         key.objectid = treeid;
2477         key.type = BTRFS_ROOT_REF_KEY;
2478         key.offset = args->treeid;
2479         ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2480         if (ret < 0) {
2481                 goto out;
2482         } else if (ret > 0) {
2483                 ret = -ENOENT;
2484                 goto out;
2485         }
2486
2487         leaf = path->nodes[0];
2488         slot = path->slots[0];
2489         btrfs_item_key_to_cpu(leaf, &key, slot);
2490
2491         item_off = btrfs_item_ptr_offset(leaf, slot);
2492         item_len = btrfs_item_size_nr(leaf, slot);
2493         /* Check if dirid in ROOT_REF corresponds to passed dirid */
2494         rref = btrfs_item_ptr(leaf, slot, struct btrfs_root_ref);
2495         if (args->dirid != btrfs_root_ref_dirid(leaf, rref)) {
2496                 ret = -EINVAL;
2497                 goto out;
2498         }
2499
2500         /* Copy subvolume's name */
2501         item_off += sizeof(struct btrfs_root_ref);
2502         item_len -= sizeof(struct btrfs_root_ref);
2503         read_extent_buffer(leaf, args->name, item_off, item_len);
2504         args->name[item_len] = 0;
2505
2506 out:
2507         btrfs_free_path(path);
2508         return ret;
2509 }
2510
2511 static noinline int btrfs_ioctl_ino_lookup(struct file *file,
2512                                            void __user *argp)
2513 {
2514         struct btrfs_ioctl_ino_lookup_args *args;
2515         struct inode *inode;
2516         int ret = 0;
2517
2518         args = memdup_user(argp, sizeof(*args));
2519         if (IS_ERR(args))
2520                 return PTR_ERR(args);
2521
2522         inode = file_inode(file);
2523
2524         /*
2525          * Unprivileged query to obtain the containing subvolume root id. The
2526          * path is reset so it's consistent with btrfs_search_path_in_tree.
2527          */
2528         if (args->treeid == 0)
2529                 args->treeid = BTRFS_I(inode)->root->root_key.objectid;
2530
2531         if (args->objectid == BTRFS_FIRST_FREE_OBJECTID) {
2532                 args->name[0] = 0;
2533                 goto out;
2534         }
2535
2536         if (!capable(CAP_SYS_ADMIN)) {
2537                 ret = -EPERM;
2538                 goto out;
2539         }
2540
2541         ret = btrfs_search_path_in_tree(BTRFS_I(inode)->root->fs_info,
2542                                         args->treeid, args->objectid,
2543                                         args->name);
2544
2545 out:
2546         if (ret == 0 && copy_to_user(argp, args, sizeof(*args)))
2547                 ret = -EFAULT;
2548
2549         kfree(args);
2550         return ret;
2551 }
2552
2553 /*
2554  * Version of ino_lookup ioctl (unprivileged)
2555  *
2556  * The main differences from ino_lookup ioctl are:
2557  *
2558  *   1. Read + Exec permission will be checked using inode_permission() during
2559  *      path construction. -EACCES will be returned in case of failure.
2560  *   2. Path construction will be stopped at the inode number which corresponds
2561  *      to the fd with which this ioctl is called. If constructed path does not
2562  *      exist under fd's inode, -EACCES will be returned.
2563  *   3. The name of bottom subvolume is also searched and filled.
2564  */
2565 static int btrfs_ioctl_ino_lookup_user(struct file *file, void __user *argp)
2566 {
2567         struct btrfs_ioctl_ino_lookup_user_args *args;
2568         struct inode *inode;
2569         int ret;
2570
2571         args = memdup_user(argp, sizeof(*args));
2572         if (IS_ERR(args))
2573                 return PTR_ERR(args);
2574
2575         inode = file_inode(file);
2576
2577         if (args->dirid == BTRFS_FIRST_FREE_OBJECTID &&
2578             BTRFS_I(inode)->location.objectid != BTRFS_FIRST_FREE_OBJECTID) {
2579                 /*
2580                  * The subvolume does not exist under fd with which this is
2581                  * called
2582                  */
2583                 kfree(args);
2584                 return -EACCES;
2585         }
2586
2587         ret = btrfs_search_path_in_tree_user(inode, args);
2588
2589         if (ret == 0 && copy_to_user(argp, args, sizeof(*args)))
2590                 ret = -EFAULT;
2591
2592         kfree(args);
2593         return ret;
2594 }
2595
2596 /* Get the subvolume information in BTRFS_ROOT_ITEM and BTRFS_ROOT_BACKREF */
2597 static int btrfs_ioctl_get_subvol_info(struct file *file, void __user *argp)
2598 {
2599         struct btrfs_ioctl_get_subvol_info_args *subvol_info;
2600         struct btrfs_fs_info *fs_info;
2601         struct btrfs_root *root;
2602         struct btrfs_path *path;
2603         struct btrfs_key key;
2604         struct btrfs_root_item *root_item;
2605         struct btrfs_root_ref *rref;
2606         struct extent_buffer *leaf;
2607         unsigned long item_off;
2608         unsigned long item_len;
2609         struct inode *inode;
2610         int slot;
2611         int ret = 0;
2612
2613         path = btrfs_alloc_path();
2614         if (!path)
2615                 return -ENOMEM;
2616
2617         subvol_info = kzalloc(sizeof(*subvol_info), GFP_KERNEL);
2618         if (!subvol_info) {
2619                 btrfs_free_path(path);
2620                 return -ENOMEM;
2621         }
2622
2623         inode = file_inode(file);
2624         fs_info = BTRFS_I(inode)->root->fs_info;
2625
2626         /* Get root_item of inode's subvolume */
2627         key.objectid = BTRFS_I(inode)->root->root_key.objectid;
2628         key.type = BTRFS_ROOT_ITEM_KEY;
2629         key.offset = (u64)-1;
2630         root = btrfs_read_fs_root_no_name(fs_info, &key);
2631         if (IS_ERR(root)) {
2632                 ret = PTR_ERR(root);
2633                 goto out;
2634         }
2635         root_item = &root->root_item;
2636
2637         subvol_info->treeid = key.objectid;
2638
2639         subvol_info->generation = btrfs_root_generation(root_item);
2640         subvol_info->flags = btrfs_root_flags(root_item);
2641
2642         memcpy(subvol_info->uuid, root_item->uuid, BTRFS_UUID_SIZE);
2643         memcpy(subvol_info->parent_uuid, root_item->parent_uuid,
2644                                                     BTRFS_UUID_SIZE);
2645         memcpy(subvol_info->received_uuid, root_item->received_uuid,
2646                                                     BTRFS_UUID_SIZE);
2647
2648         subvol_info->ctransid = btrfs_root_ctransid(root_item);
2649         subvol_info->ctime.sec = btrfs_stack_timespec_sec(&root_item->ctime);
2650         subvol_info->ctime.nsec = btrfs_stack_timespec_nsec(&root_item->ctime);
2651
2652         subvol_info->otransid = btrfs_root_otransid(root_item);
2653         subvol_info->otime.sec = btrfs_stack_timespec_sec(&root_item->otime);
2654         subvol_info->otime.nsec = btrfs_stack_timespec_nsec(&root_item->otime);
2655
2656         subvol_info->stransid = btrfs_root_stransid(root_item);
2657         subvol_info->stime.sec = btrfs_stack_timespec_sec(&root_item->stime);
2658         subvol_info->stime.nsec = btrfs_stack_timespec_nsec(&root_item->stime);
2659
2660         subvol_info->rtransid = btrfs_root_rtransid(root_item);
2661         subvol_info->rtime.sec = btrfs_stack_timespec_sec(&root_item->rtime);
2662         subvol_info->rtime.nsec = btrfs_stack_timespec_nsec(&root_item->rtime);
2663
2664         if (key.objectid != BTRFS_FS_TREE_OBJECTID) {
2665                 /* Search root tree for ROOT_BACKREF of this subvolume */
2666                 root = fs_info->tree_root;
2667
2668                 key.type = BTRFS_ROOT_BACKREF_KEY;
2669                 key.offset = 0;
2670                 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2671                 if (ret < 0) {
2672                         goto out;
2673                 } else if (path->slots[0] >=
2674                            btrfs_header_nritems(path->nodes[0])) {
2675                         ret = btrfs_next_leaf(root, path);
2676                         if (ret < 0) {
2677                                 goto out;
2678                         } else if (ret > 0) {
2679                                 ret = -EUCLEAN;
2680                                 goto out;
2681                         }
2682                 }
2683
2684                 leaf = path->nodes[0];
2685                 slot = path->slots[0];
2686                 btrfs_item_key_to_cpu(leaf, &key, slot);
2687                 if (key.objectid == subvol_info->treeid &&
2688                     key.type == BTRFS_ROOT_BACKREF_KEY) {
2689                         subvol_info->parent_id = key.offset;
2690
2691                         rref = btrfs_item_ptr(leaf, slot, struct btrfs_root_ref);
2692                         subvol_info->dirid = btrfs_root_ref_dirid(leaf, rref);
2693
2694                         item_off = btrfs_item_ptr_offset(leaf, slot)
2695                                         + sizeof(struct btrfs_root_ref);
2696                         item_len = btrfs_item_size_nr(leaf, slot)
2697                                         - sizeof(struct btrfs_root_ref);
2698                         read_extent_buffer(leaf, subvol_info->name,
2699                                            item_off, item_len);
2700                 } else {
2701                         ret = -ENOENT;
2702                         goto out;
2703                 }
2704         }
2705
2706         if (copy_to_user(argp, subvol_info, sizeof(*subvol_info)))
2707                 ret = -EFAULT;
2708
2709 out:
2710         btrfs_free_path(path);
2711         kzfree(subvol_info);
2712         return ret;
2713 }
2714
2715 /*
2716  * Return ROOT_REF information of the subvolume containing this inode
2717  * except the subvolume name.
2718  */
2719 static int btrfs_ioctl_get_subvol_rootref(struct file *file, void __user *argp)
2720 {
2721         struct btrfs_ioctl_get_subvol_rootref_args *rootrefs;
2722         struct btrfs_root_ref *rref;
2723         struct btrfs_root *root;
2724         struct btrfs_path *path;
2725         struct btrfs_key key;
2726         struct extent_buffer *leaf;
2727         struct inode *inode;
2728         u64 objectid;
2729         int slot;
2730         int ret;
2731         u8 found;
2732
2733         path = btrfs_alloc_path();
2734         if (!path)
2735                 return -ENOMEM;
2736
2737         rootrefs = memdup_user(argp, sizeof(*rootrefs));
2738         if (IS_ERR(rootrefs)) {
2739                 btrfs_free_path(path);
2740                 return PTR_ERR(rootrefs);
2741         }
2742
2743         inode = file_inode(file);
2744         root = BTRFS_I(inode)->root->fs_info->tree_root;
2745         objectid = BTRFS_I(inode)->root->root_key.objectid;
2746
2747         key.objectid = objectid;
2748         key.type = BTRFS_ROOT_REF_KEY;
2749         key.offset = rootrefs->min_treeid;
2750         found = 0;
2751
2752         ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2753         if (ret < 0) {
2754                 goto out;
2755         } else if (path->slots[0] >=
2756                    btrfs_header_nritems(path->nodes[0])) {
2757                 ret = btrfs_next_leaf(root, path);
2758                 if (ret < 0) {
2759                         goto out;
2760                 } else if (ret > 0) {
2761                         ret = -EUCLEAN;
2762                         goto out;
2763                 }
2764         }
2765         while (1) {
2766                 leaf = path->nodes[0];
2767                 slot = path->slots[0];
2768
2769                 btrfs_item_key_to_cpu(leaf, &key, slot);
2770                 if (key.objectid != objectid || key.type != BTRFS_ROOT_REF_KEY) {
2771                         ret = 0;
2772                         goto out;
2773                 }
2774
2775                 if (found == BTRFS_MAX_ROOTREF_BUFFER_NUM) {
2776                         ret = -EOVERFLOW;
2777                         goto out;
2778                 }
2779
2780                 rref = btrfs_item_ptr(leaf, slot, struct btrfs_root_ref);
2781                 rootrefs->rootref[found].treeid = key.offset;
2782                 rootrefs->rootref[found].dirid =
2783                                   btrfs_root_ref_dirid(leaf, rref);
2784                 found++;
2785
2786                 ret = btrfs_next_item(root, path);
2787                 if (ret < 0) {
2788                         goto out;
2789                 } else if (ret > 0) {
2790                         ret = -EUCLEAN;
2791                         goto out;
2792                 }
2793         }
2794
2795 out:
2796         if (!ret || ret == -EOVERFLOW) {
2797                 rootrefs->num_items = found;
2798                 /* update min_treeid for next search */
2799                 if (found)
2800                         rootrefs->min_treeid =
2801                                 rootrefs->rootref[found - 1].treeid + 1;
2802                 if (copy_to_user(argp, rootrefs, sizeof(*rootrefs)))
2803                         ret = -EFAULT;
2804         }
2805
2806         kfree(rootrefs);
2807         btrfs_free_path(path);
2808
2809         return ret;
2810 }
2811
2812 static noinline int btrfs_ioctl_snap_destroy(struct file *file,
2813                                              void __user *arg)
2814 {
2815         struct dentry *parent = file->f_path.dentry;
2816         struct btrfs_fs_info *fs_info = btrfs_sb(parent->d_sb);
2817         struct dentry *dentry;
2818         struct inode *dir = d_inode(parent);
2819         struct inode *inode;
2820         struct btrfs_root *root = BTRFS_I(dir)->root;
2821         struct btrfs_root *dest = NULL;
2822         struct btrfs_ioctl_vol_args *vol_args;
2823         int namelen;
2824         int err = 0;
2825
2826         if (!S_ISDIR(dir->i_mode))
2827                 return -ENOTDIR;
2828
2829         vol_args = memdup_user(arg, sizeof(*vol_args));
2830         if (IS_ERR(vol_args))
2831                 return PTR_ERR(vol_args);
2832
2833         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
2834         namelen = strlen(vol_args->name);
2835         if (strchr(vol_args->name, '/') ||
2836             strncmp(vol_args->name, "..", namelen) == 0) {
2837                 err = -EINVAL;
2838                 goto out;
2839         }
2840
2841         err = mnt_want_write_file(file);
2842         if (err)
2843                 goto out;
2844
2845
2846         err = down_write_killable_nested(&dir->i_rwsem, I_MUTEX_PARENT);
2847         if (err == -EINTR)
2848                 goto out_drop_write;
2849         dentry = lookup_one_len(vol_args->name, parent, namelen);
2850         if (IS_ERR(dentry)) {
2851                 err = PTR_ERR(dentry);
2852                 goto out_unlock_dir;
2853         }
2854
2855         if (d_really_is_negative(dentry)) {
2856                 err = -ENOENT;
2857                 goto out_dput;
2858         }
2859
2860         inode = d_inode(dentry);
2861         dest = BTRFS_I(inode)->root;
2862         if (!capable(CAP_SYS_ADMIN)) {
2863                 /*
2864                  * Regular user.  Only allow this with a special mount
2865                  * option, when the user has write+exec access to the
2866                  * subvol root, and when rmdir(2) would have been
2867                  * allowed.
2868                  *
2869                  * Note that this is _not_ check that the subvol is
2870                  * empty or doesn't contain data that we wouldn't
2871                  * otherwise be able to delete.
2872                  *
2873                  * Users who want to delete empty subvols should try
2874                  * rmdir(2).
2875                  */
2876                 err = -EPERM;
2877                 if (!btrfs_test_opt(fs_info, USER_SUBVOL_RM_ALLOWED))
2878                         goto out_dput;
2879
2880                 /*
2881                  * Do not allow deletion if the parent dir is the same
2882                  * as the dir to be deleted.  That means the ioctl
2883                  * must be called on the dentry referencing the root
2884                  * of the subvol, not a random directory contained
2885                  * within it.
2886                  */
2887                 err = -EINVAL;
2888                 if (root == dest)
2889                         goto out_dput;
2890
2891                 err = inode_permission(inode, MAY_WRITE | MAY_EXEC);
2892                 if (err)
2893                         goto out_dput;
2894         }
2895
2896         /* check if subvolume may be deleted by a user */
2897         err = btrfs_may_delete(dir, dentry, 1);
2898         if (err)
2899                 goto out_dput;
2900
2901         if (btrfs_ino(BTRFS_I(inode)) != BTRFS_FIRST_FREE_OBJECTID) {
2902                 err = -EINVAL;
2903                 goto out_dput;
2904         }
2905
2906         inode_lock(inode);
2907         err = btrfs_delete_subvolume(dir, dentry);
2908         inode_unlock(inode);
2909         if (!err)
2910                 d_delete(dentry);
2911
2912 out_dput:
2913         dput(dentry);
2914 out_unlock_dir:
2915         inode_unlock(dir);
2916 out_drop_write:
2917         mnt_drop_write_file(file);
2918 out:
2919         kfree(vol_args);
2920         return err;
2921 }
2922
2923 static int btrfs_ioctl_defrag(struct file *file, void __user *argp)
2924 {
2925         struct inode *inode = file_inode(file);
2926         struct btrfs_root *root = BTRFS_I(inode)->root;
2927         struct btrfs_ioctl_defrag_range_args *range;
2928         int ret;
2929
2930         ret = mnt_want_write_file(file);
2931         if (ret)
2932                 return ret;
2933
2934         if (btrfs_root_readonly(root)) {
2935                 ret = -EROFS;
2936                 goto out;
2937         }
2938
2939         switch (inode->i_mode & S_IFMT) {
2940         case S_IFDIR:
2941                 if (!capable(CAP_SYS_ADMIN)) {
2942                         ret = -EPERM;
2943                         goto out;
2944                 }
2945                 ret = btrfs_defrag_root(root);
2946                 break;
2947         case S_IFREG:
2948                 /*
2949                  * Note that this does not check the file descriptor for write
2950                  * access. This prevents defragmenting executables that are
2951                  * running and allows defrag on files open in read-only mode.
2952                  */
2953                 if (!capable(CAP_SYS_ADMIN) &&
2954                     inode_permission(inode, MAY_WRITE)) {
2955                         ret = -EPERM;
2956                         goto out;
2957                 }
2958
2959                 range = kzalloc(sizeof(*range), GFP_KERNEL);
2960                 if (!range) {
2961                         ret = -ENOMEM;
2962                         goto out;
2963                 }
2964
2965                 if (argp) {
2966                         if (copy_from_user(range, argp,
2967                                            sizeof(*range))) {
2968                                 ret = -EFAULT;
2969                                 kfree(range);
2970                                 goto out;
2971                         }
2972                         /* compression requires us to start the IO */
2973                         if ((range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)) {
2974                                 range->flags |= BTRFS_DEFRAG_RANGE_START_IO;
2975                                 range->extent_thresh = (u32)-1;
2976                         }
2977                 } else {
2978                         /* the rest are all set to zero by kzalloc */
2979                         range->len = (u64)-1;
2980                 }
2981                 ret = btrfs_defrag_file(file_inode(file), file,
2982                                         range, BTRFS_OLDEST_GENERATION, 0);
2983                 if (ret > 0)
2984                         ret = 0;
2985                 kfree(range);
2986                 break;
2987         default:
2988                 ret = -EINVAL;
2989         }
2990 out:
2991         mnt_drop_write_file(file);
2992         return ret;
2993 }
2994
2995 static long btrfs_ioctl_add_dev(struct btrfs_fs_info *fs_info, void __user *arg)
2996 {
2997         struct btrfs_ioctl_vol_args *vol_args;
2998         int ret;
2999
3000         if (!capable(CAP_SYS_ADMIN))
3001                 return -EPERM;
3002
3003         if (test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags))
3004                 return BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
3005
3006         vol_args = memdup_user(arg, sizeof(*vol_args));
3007         if (IS_ERR(vol_args)) {
3008                 ret = PTR_ERR(vol_args);
3009                 goto out;
3010         }
3011
3012         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
3013         ret = btrfs_init_new_device(fs_info, vol_args->name);
3014
3015         if (!ret)
3016                 btrfs_info(fs_info, "disk added %s", vol_args->name);
3017
3018         kfree(vol_args);
3019 out:
3020         clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
3021         return ret;
3022 }
3023
3024 static long btrfs_ioctl_rm_dev_v2(struct file *file, void __user *arg)
3025 {
3026         struct inode *inode = file_inode(file);
3027         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3028         struct btrfs_ioctl_vol_args_v2 *vol_args;
3029         int ret;
3030
3031         if (!capable(CAP_SYS_ADMIN))
3032                 return -EPERM;
3033
3034         ret = mnt_want_write_file(file);
3035         if (ret)
3036                 return ret;
3037
3038         vol_args = memdup_user(arg, sizeof(*vol_args));
3039         if (IS_ERR(vol_args)) {
3040                 ret = PTR_ERR(vol_args);
3041                 goto err_drop;
3042         }
3043
3044         /* Check for compatibility reject unknown flags */
3045         if (vol_args->flags & ~BTRFS_VOL_ARG_V2_FLAGS_SUPPORTED) {
3046                 ret = -EOPNOTSUPP;
3047                 goto out;
3048         }
3049
3050         if (test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags)) {
3051                 ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
3052                 goto out;
3053         }
3054
3055         if (vol_args->flags & BTRFS_DEVICE_SPEC_BY_ID) {
3056                 ret = btrfs_rm_device(fs_info, NULL, vol_args->devid);
3057         } else {
3058                 vol_args->name[BTRFS_SUBVOL_NAME_MAX] = '\0';
3059                 ret = btrfs_rm_device(fs_info, vol_args->name, 0);
3060         }
3061         clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
3062
3063         if (!ret) {
3064                 if (vol_args->flags & BTRFS_DEVICE_SPEC_BY_ID)
3065                         btrfs_info(fs_info, "device deleted: id %llu",
3066                                         vol_args->devid);
3067                 else
3068                         btrfs_info(fs_info, "device deleted: %s",
3069                                         vol_args->name);
3070         }
3071 out:
3072         kfree(vol_args);
3073 err_drop:
3074         mnt_drop_write_file(file);
3075         return ret;
3076 }
3077
3078 static long btrfs_ioctl_rm_dev(struct file *file, void __user *arg)
3079 {
3080         struct inode *inode = file_inode(file);
3081         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3082         struct btrfs_ioctl_vol_args *vol_args;
3083         int ret;
3084
3085         if (!capable(CAP_SYS_ADMIN))
3086                 return -EPERM;
3087
3088         ret = mnt_want_write_file(file);
3089         if (ret)
3090                 return ret;
3091
3092         if (test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags)) {
3093                 ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
3094                 goto out_drop_write;
3095         }
3096
3097         vol_args = memdup_user(arg, sizeof(*vol_args));
3098         if (IS_ERR(vol_args)) {
3099                 ret = PTR_ERR(vol_args);
3100                 goto out;
3101         }
3102
3103         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
3104         ret = btrfs_rm_device(fs_info, vol_args->name, 0);
3105
3106         if (!ret)
3107                 btrfs_info(fs_info, "disk deleted %s", vol_args->name);
3108         kfree(vol_args);
3109 out:
3110         clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
3111 out_drop_write:
3112         mnt_drop_write_file(file);
3113
3114         return ret;
3115 }
3116
3117 static long btrfs_ioctl_fs_info(struct btrfs_fs_info *fs_info,
3118                                 void __user *arg)
3119 {
3120         struct btrfs_ioctl_fs_info_args *fi_args;
3121         struct btrfs_device *device;
3122         struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
3123         int ret = 0;
3124
3125         fi_args = kzalloc(sizeof(*fi_args), GFP_KERNEL);
3126         if (!fi_args)
3127                 return -ENOMEM;
3128
3129         rcu_read_lock();
3130         fi_args->num_devices = fs_devices->num_devices;
3131
3132         list_for_each_entry_rcu(device, &fs_devices->devices, dev_list) {
3133                 if (device->devid > fi_args->max_id)
3134                         fi_args->max_id = device->devid;
3135         }
3136         rcu_read_unlock();
3137
3138         memcpy(&fi_args->fsid, fs_info->fsid, sizeof(fi_args->fsid));
3139         fi_args->nodesize = fs_info->nodesize;
3140         fi_args->sectorsize = fs_info->sectorsize;
3141         fi_args->clone_alignment = fs_info->sectorsize;
3142
3143         if (copy_to_user(arg, fi_args, sizeof(*fi_args)))
3144                 ret = -EFAULT;
3145
3146         kfree(fi_args);
3147         return ret;
3148 }
3149
3150 static long btrfs_ioctl_dev_info(struct btrfs_fs_info *fs_info,
3151                                  void __user *arg)
3152 {
3153         struct btrfs_ioctl_dev_info_args *di_args;
3154         struct btrfs_device *dev;
3155         int ret = 0;
3156         char *s_uuid = NULL;
3157
3158         di_args = memdup_user(arg, sizeof(*di_args));
3159         if (IS_ERR(di_args))
3160                 return PTR_ERR(di_args);
3161
3162         if (!btrfs_is_empty_uuid(di_args->uuid))
3163                 s_uuid = di_args->uuid;
3164
3165         rcu_read_lock();
3166         dev = btrfs_find_device(fs_info, di_args->devid, s_uuid, NULL);
3167
3168         if (!dev) {
3169                 ret = -ENODEV;
3170                 goto out;
3171         }
3172
3173         di_args->devid = dev->devid;
3174         di_args->bytes_used = btrfs_device_get_bytes_used(dev);
3175         di_args->total_bytes = btrfs_device_get_total_bytes(dev);
3176         memcpy(di_args->uuid, dev->uuid, sizeof(di_args->uuid));
3177         if (dev->name) {
3178                 strncpy(di_args->path, rcu_str_deref(dev->name),
3179                                 sizeof(di_args->path) - 1);
3180                 di_args->path[sizeof(di_args->path) - 1] = 0;
3181         } else {
3182                 di_args->path[0] = '\0';
3183         }
3184
3185 out:
3186         rcu_read_unlock();
3187         if (ret == 0 && copy_to_user(arg, di_args, sizeof(*di_args)))
3188                 ret = -EFAULT;
3189
3190         kfree(di_args);
3191         return ret;
3192 }
3193
3194 static struct page *extent_same_get_page(struct inode *inode, pgoff_t index)
3195 {
3196         struct page *page;
3197
3198         page = grab_cache_page(inode->i_mapping, index);
3199         if (!page)
3200                 return ERR_PTR(-ENOMEM);
3201
3202         if (!PageUptodate(page)) {
3203                 int ret;
3204
3205                 ret = btrfs_readpage(NULL, page);
3206                 if (ret)
3207                         return ERR_PTR(ret);
3208                 lock_page(page);
3209                 if (!PageUptodate(page)) {
3210                         unlock_page(page);
3211                         put_page(page);
3212                         return ERR_PTR(-EIO);
3213                 }
3214                 if (page->mapping != inode->i_mapping) {
3215                         unlock_page(page);
3216                         put_page(page);
3217                         return ERR_PTR(-EAGAIN);
3218                 }
3219         }
3220
3221         return page;
3222 }
3223
3224 static int gather_extent_pages(struct inode *inode, struct page **pages,
3225                                int num_pages, u64 off)
3226 {
3227         int i;
3228         pgoff_t index = off >> PAGE_SHIFT;
3229
3230         for (i = 0; i < num_pages; i++) {
3231 again:
3232                 pages[i] = extent_same_get_page(inode, index + i);
3233                 if (IS_ERR(pages[i])) {
3234                         int err = PTR_ERR(pages[i]);
3235
3236                         if (err == -EAGAIN)
3237                                 goto again;
3238                         pages[i] = NULL;
3239                         return err;
3240                 }
3241         }
3242         return 0;
3243 }
3244
3245 static int lock_extent_range(struct inode *inode, u64 off, u64 len,
3246                              bool retry_range_locking)
3247 {
3248         /*
3249          * Do any pending delalloc/csum calculations on inode, one way or
3250          * another, and lock file content.
3251          * The locking order is:
3252          *
3253          *   1) pages
3254          *   2) range in the inode's io tree
3255          */
3256         while (1) {
3257                 struct btrfs_ordered_extent *ordered;
3258                 lock_extent(&BTRFS_I(inode)->io_tree, off, off + len - 1);
3259                 ordered = btrfs_lookup_first_ordered_extent(inode,
3260                                                             off + len - 1);
3261                 if ((!ordered ||
3262                      ordered->file_offset + ordered->len <= off ||
3263                      ordered->file_offset >= off + len) &&
3264                     !test_range_bit(&BTRFS_I(inode)->io_tree, off,
3265                                     off + len - 1, EXTENT_DELALLOC, 0, NULL)) {
3266                         if (ordered)
3267                                 btrfs_put_ordered_extent(ordered);
3268                         break;
3269                 }
3270                 unlock_extent(&BTRFS_I(inode)->io_tree, off, off + len - 1);
3271                 if (ordered)
3272                         btrfs_put_ordered_extent(ordered);
3273                 if (!retry_range_locking)
3274                         return -EAGAIN;
3275                 btrfs_wait_ordered_range(inode, off, len);
3276         }
3277         return 0;
3278 }
3279
3280 static void btrfs_double_inode_unlock(struct inode *inode1, struct inode *inode2)
3281 {
3282         inode_unlock(inode1);
3283         inode_unlock(inode2);
3284 }
3285
3286 static void btrfs_double_inode_lock(struct inode *inode1, struct inode *inode2)
3287 {
3288         if (inode1 < inode2)
3289                 swap(inode1, inode2);
3290
3291         inode_lock_nested(inode1, I_MUTEX_PARENT);
3292         inode_lock_nested(inode2, I_MUTEX_CHILD);
3293 }
3294
3295 static void btrfs_double_extent_unlock(struct inode *inode1, u64 loff1,
3296                                       struct inode *inode2, u64 loff2, u64 len)
3297 {
3298         unlock_extent(&BTRFS_I(inode1)->io_tree, loff1, loff1 + len - 1);
3299         unlock_extent(&BTRFS_I(inode2)->io_tree, loff2, loff2 + len - 1);
3300 }
3301
3302 static int btrfs_double_extent_lock(struct inode *inode1, u64 loff1,
3303                                     struct inode *inode2, u64 loff2, u64 len,
3304                                     bool retry_range_locking)
3305 {
3306         int ret;
3307
3308         if (inode1 < inode2) {
3309                 swap(inode1, inode2);
3310                 swap(loff1, loff2);
3311         }
3312         ret = lock_extent_range(inode1, loff1, len, retry_range_locking);
3313         if (ret)
3314                 return ret;
3315         ret = lock_extent_range(inode2, loff2, len, retry_range_locking);
3316         if (ret)
3317                 unlock_extent(&BTRFS_I(inode1)->io_tree, loff1,
3318                               loff1 + len - 1);
3319         return ret;
3320 }
3321
3322 struct cmp_pages {
3323         int             num_pages;
3324         struct page     **src_pages;
3325         struct page     **dst_pages;
3326 };
3327
3328 static void btrfs_cmp_data_free(struct cmp_pages *cmp)
3329 {
3330         int i;
3331         struct page *pg;
3332
3333         for (i = 0; i < cmp->num_pages; i++) {
3334                 pg = cmp->src_pages[i];
3335                 if (pg) {
3336                         unlock_page(pg);
3337                         put_page(pg);
3338                         cmp->src_pages[i] = NULL;
3339                 }
3340                 pg = cmp->dst_pages[i];
3341                 if (pg) {
3342                         unlock_page(pg);
3343                         put_page(pg);
3344                         cmp->dst_pages[i] = NULL;
3345                 }
3346         }
3347 }
3348
3349 static int btrfs_cmp_data_prepare(struct inode *src, u64 loff,
3350                                   struct inode *dst, u64 dst_loff,
3351                                   u64 len, struct cmp_pages *cmp)
3352 {
3353         int ret;
3354         int num_pages = PAGE_ALIGN(len) >> PAGE_SHIFT;
3355
3356         cmp->num_pages = num_pages;
3357
3358         ret = gather_extent_pages(src, cmp->src_pages, num_pages, loff);
3359         if (ret)
3360                 goto out;
3361
3362         ret = gather_extent_pages(dst, cmp->dst_pages, num_pages, dst_loff);
3363
3364 out:
3365         if (ret)
3366                 btrfs_cmp_data_free(cmp);
3367         return ret;
3368 }
3369
3370 static int btrfs_cmp_data(u64 len, struct cmp_pages *cmp)
3371 {
3372         int ret = 0;
3373         int i;
3374         struct page *src_page, *dst_page;
3375         unsigned int cmp_len = PAGE_SIZE;
3376         void *addr, *dst_addr;
3377
3378         i = 0;
3379         while (len) {
3380                 if (len < PAGE_SIZE)
3381                         cmp_len = len;
3382
3383                 BUG_ON(i >= cmp->num_pages);
3384
3385                 src_page = cmp->src_pages[i];
3386                 dst_page = cmp->dst_pages[i];
3387                 ASSERT(PageLocked(src_page));
3388                 ASSERT(PageLocked(dst_page));
3389
3390                 addr = kmap_atomic(src_page);
3391                 dst_addr = kmap_atomic(dst_page);
3392
3393                 flush_dcache_page(src_page);
3394                 flush_dcache_page(dst_page);
3395
3396                 if (memcmp(addr, dst_addr, cmp_len))
3397                         ret = -EBADE;
3398
3399                 kunmap_atomic(addr);
3400                 kunmap_atomic(dst_addr);
3401
3402                 if (ret)
3403                         break;
3404
3405                 len -= cmp_len;
3406                 i++;
3407         }
3408
3409         return ret;
3410 }
3411
3412 static int extent_same_check_offsets(struct inode *inode, u64 off, u64 *plen,
3413                                      u64 olen)
3414 {
3415         u64 len = *plen;
3416         u64 bs = BTRFS_I(inode)->root->fs_info->sb->s_blocksize;
3417
3418         if (off + olen > inode->i_size || off + olen < off)
3419                 return -EINVAL;
3420
3421         /* if we extend to eof, continue to block boundary */
3422         if (off + len == inode->i_size)
3423                 *plen = len = ALIGN(inode->i_size, bs) - off;
3424
3425         /* Check that we are block aligned - btrfs_clone() requires this */
3426         if (!IS_ALIGNED(off, bs) || !IS_ALIGNED(off + len, bs))
3427                 return -EINVAL;
3428
3429         return 0;
3430 }
3431
3432 static int btrfs_extent_same_range(struct inode *src, u64 loff, u64 olen,
3433                                    struct inode *dst, u64 dst_loff,
3434                                    struct cmp_pages *cmp)
3435 {
3436         int ret;
3437         u64 len = olen;
3438         bool same_inode = (src == dst);
3439         u64 same_lock_start = 0;
3440         u64 same_lock_len = 0;
3441
3442         ret = extent_same_check_offsets(src, loff, &len, olen);
3443         if (ret)
3444                 return ret;
3445
3446         ret = extent_same_check_offsets(dst, dst_loff, &len, olen);
3447         if (ret)
3448                 return ret;
3449
3450         if (same_inode) {
3451                 /*
3452                  * Single inode case wants the same checks, except we
3453                  * don't want our length pushed out past i_size as
3454                  * comparing that data range makes no sense.
3455                  *
3456                  * extent_same_check_offsets() will do this for an
3457                  * unaligned length at i_size, so catch it here and
3458                  * reject the request.
3459                  *
3460                  * This effectively means we require aligned extents
3461                  * for the single-inode case, whereas the other cases
3462                  * allow an unaligned length so long as it ends at
3463                  * i_size.
3464                  */
3465                 if (len != olen)
3466                         return -EINVAL;
3467
3468                 /* Check for overlapping ranges */
3469                 if (dst_loff + len > loff && dst_loff < loff + len)
3470                         return -EINVAL;
3471
3472                 same_lock_start = min_t(u64, loff, dst_loff);
3473                 same_lock_len = max_t(u64, loff, dst_loff) + len - same_lock_start;
3474         } else {
3475                 /*
3476                  * If the source and destination inodes are different, the
3477                  * source's range end offset matches the source's i_size, that
3478                  * i_size is not a multiple of the sector size, and the
3479                  * destination range does not go past the destination's i_size,
3480                  * we must round down the length to the nearest sector size
3481                  * multiple. If we don't do this adjustment we end replacing
3482                  * with zeroes the bytes in the range that starts at the
3483                  * deduplication range's end offset and ends at the next sector
3484                  * size multiple.
3485                  */
3486                 if (loff + olen == i_size_read(src) &&
3487                     dst_loff + len < i_size_read(dst)) {
3488                         const u64 sz = BTRFS_I(src)->root->fs_info->sectorsize;
3489
3490                         len = round_down(i_size_read(src), sz) - loff;
3491                         olen = len;
3492                 }
3493         }
3494
3495 again:
3496         ret = btrfs_cmp_data_prepare(src, loff, dst, dst_loff, olen, cmp);
3497         if (ret)
3498                 return ret;
3499
3500         if (same_inode)
3501                 ret = lock_extent_range(src, same_lock_start, same_lock_len,
3502                                         false);
3503         else
3504                 ret = btrfs_double_extent_lock(src, loff, dst, dst_loff, len,
3505                                                false);
3506         /*
3507          * If one of the inodes has dirty pages in the respective range or
3508          * ordered extents, we need to flush dellaloc and wait for all ordered
3509          * extents in the range. We must unlock the pages and the ranges in the
3510          * io trees to avoid deadlocks when flushing delalloc (requires locking
3511          * pages) and when waiting for ordered extents to complete (they require
3512          * range locking).
3513          */
3514         if (ret == -EAGAIN) {
3515                 /*
3516                  * Ranges in the io trees already unlocked. Now unlock all
3517                  * pages before waiting for all IO to complete.
3518                  */
3519                 btrfs_cmp_data_free(cmp);
3520                 if (same_inode) {
3521                         btrfs_wait_ordered_range(src, same_lock_start,
3522                                                  same_lock_len);
3523                 } else {
3524                         btrfs_wait_ordered_range(src, loff, len);
3525                         btrfs_wait_ordered_range(dst, dst_loff, len);
3526                 }
3527                 goto again;
3528         }
3529         ASSERT(ret == 0);
3530         if (WARN_ON(ret)) {
3531                 /* ranges in the io trees already unlocked */
3532                 btrfs_cmp_data_free(cmp);
3533                 return ret;
3534         }
3535
3536         /* pass original length for comparison so we stay within i_size */
3537         ret = btrfs_cmp_data(olen, cmp);
3538         if (ret == 0)
3539                 ret = btrfs_clone(src, dst, loff, olen, len, dst_loff, 1);
3540
3541         if (same_inode)
3542                 unlock_extent(&BTRFS_I(src)->io_tree, same_lock_start,
3543                               same_lock_start + same_lock_len - 1);
3544         else
3545                 btrfs_double_extent_unlock(src, loff, dst, dst_loff, len);
3546
3547         btrfs_cmp_data_free(cmp);
3548
3549         return ret;
3550 }
3551
3552 #define BTRFS_MAX_DEDUPE_LEN    SZ_16M
3553
3554 static int btrfs_extent_same(struct inode *src, u64 loff, u64 olen,
3555                              struct inode *dst, u64 dst_loff)
3556 {
3557         int ret;
3558         struct cmp_pages cmp;
3559         int num_pages = PAGE_ALIGN(BTRFS_MAX_DEDUPE_LEN) >> PAGE_SHIFT;
3560         bool same_inode = (src == dst);
3561         u64 i, tail_len, chunk_count;
3562
3563         if (olen == 0)
3564                 return 0;
3565
3566         if (same_inode)
3567                 inode_lock(src);
3568         else
3569                 btrfs_double_inode_lock(src, dst);
3570
3571         /* don't make the dst file partly checksummed */
3572         if ((BTRFS_I(src)->flags & BTRFS_INODE_NODATASUM) !=
3573             (BTRFS_I(dst)->flags & BTRFS_INODE_NODATASUM)) {
3574                 ret = -EINVAL;
3575                 goto out_unlock;
3576         }
3577
3578         tail_len = olen % BTRFS_MAX_DEDUPE_LEN;
3579         chunk_count = div_u64(olen, BTRFS_MAX_DEDUPE_LEN);
3580         if (chunk_count == 0)
3581                 num_pages = PAGE_ALIGN(tail_len) >> PAGE_SHIFT;
3582
3583         /*
3584          * If deduping ranges in the same inode, locking rules make it
3585          * mandatory to always lock pages in ascending order to avoid deadlocks
3586          * with concurrent tasks (such as starting writeback/delalloc).
3587          */
3588         if (same_inode && dst_loff < loff)
3589                 swap(loff, dst_loff);
3590
3591         /*
3592          * We must gather up all the pages before we initiate our extent
3593          * locking. We use an array for the page pointers. Size of the array is
3594          * bounded by len, which is in turn bounded by BTRFS_MAX_DEDUPE_LEN.
3595          */
3596         cmp.src_pages = kvmalloc_array(num_pages, sizeof(struct page *),
3597                                        GFP_KERNEL | __GFP_ZERO);
3598         cmp.dst_pages = kvmalloc_array(num_pages, sizeof(struct page *),
3599                                        GFP_KERNEL | __GFP_ZERO);
3600         if (!cmp.src_pages || !cmp.dst_pages) {
3601                 ret = -ENOMEM;
3602                 goto out_free;
3603         }
3604
3605         for (i = 0; i < chunk_count; i++) {
3606                 ret = btrfs_extent_same_range(src, loff, BTRFS_MAX_DEDUPE_LEN,
3607                                               dst, dst_loff, &cmp);
3608                 if (ret)
3609                         goto out_free;
3610
3611                 loff += BTRFS_MAX_DEDUPE_LEN;
3612                 dst_loff += BTRFS_MAX_DEDUPE_LEN;
3613         }
3614
3615         if (tail_len > 0)
3616                 ret = btrfs_extent_same_range(src, loff, tail_len, dst,
3617                                               dst_loff, &cmp);
3618
3619 out_free:
3620         kvfree(cmp.src_pages);
3621         kvfree(cmp.dst_pages);
3622
3623 out_unlock:
3624         if (same_inode)
3625                 inode_unlock(src);
3626         else
3627                 btrfs_double_inode_unlock(src, dst);
3628
3629         return ret;
3630 }
3631
3632 static int clone_finish_inode_update(struct btrfs_trans_handle *trans,
3633                                      struct inode *inode,
3634                                      u64 endoff,
3635                                      const u64 destoff,
3636                                      const u64 olen,
3637                                      int no_time_update)
3638 {
3639         struct btrfs_root *root = BTRFS_I(inode)->root;
3640         int ret;
3641
3642         inode_inc_iversion(inode);
3643         if (!no_time_update)
3644                 inode->i_mtime = inode->i_ctime = current_time(inode);
3645         /*
3646          * We round up to the block size at eof when determining which
3647          * extents to clone above, but shouldn't round up the file size.
3648          */
3649         if (endoff > destoff + olen)
3650                 endoff = destoff + olen;
3651         if (endoff > inode->i_size)
3652                 btrfs_i_size_write(BTRFS_I(inode), endoff);
3653
3654         ret = btrfs_update_inode(trans, root, inode);
3655         if (ret) {
3656                 btrfs_abort_transaction(trans, ret);
3657                 btrfs_end_transaction(trans);
3658                 goto out;
3659         }
3660         ret = btrfs_end_transaction(trans);
3661 out:
3662         return ret;
3663 }
3664
3665 static void clone_update_extent_map(struct btrfs_inode *inode,
3666                                     const struct btrfs_trans_handle *trans,
3667                                     const struct btrfs_path *path,
3668                                     const u64 hole_offset,
3669                                     const u64 hole_len)
3670 {
3671         struct extent_map_tree *em_tree = &inode->extent_tree;
3672         struct extent_map *em;
3673         int ret;
3674
3675         em = alloc_extent_map();
3676         if (!em) {
3677                 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &inode->runtime_flags);
3678                 return;
3679         }
3680
3681         if (path) {
3682                 struct btrfs_file_extent_item *fi;
3683
3684                 fi = btrfs_item_ptr(path->nodes[0], path->slots[0],
3685                                     struct btrfs_file_extent_item);
3686                 btrfs_extent_item_to_extent_map(inode, path, fi, false, em);
3687                 em->generation = -1;
3688                 if (btrfs_file_extent_type(path->nodes[0], fi) ==
3689                     BTRFS_FILE_EXTENT_INLINE)
3690                         set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
3691                                         &inode->runtime_flags);
3692         } else {
3693                 em->start = hole_offset;
3694                 em->len = hole_len;
3695                 em->ram_bytes = em->len;
3696                 em->orig_start = hole_offset;
3697                 em->block_start = EXTENT_MAP_HOLE;
3698                 em->block_len = 0;
3699                 em->orig_block_len = 0;
3700                 em->compress_type = BTRFS_COMPRESS_NONE;
3701                 em->generation = trans->transid;
3702         }
3703
3704         while (1) {
3705                 write_lock(&em_tree->lock);
3706                 ret = add_extent_mapping(em_tree, em, 1);
3707                 write_unlock(&em_tree->lock);
3708                 if (ret != -EEXIST) {
3709                         free_extent_map(em);
3710                         break;
3711                 }
3712                 btrfs_drop_extent_cache(inode, em->start,
3713                                         em->start + em->len - 1, 0);
3714         }
3715
3716         if (ret)
3717                 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &inode->runtime_flags);
3718 }
3719
3720 /*
3721  * Make sure we do not end up inserting an inline extent into a file that has
3722  * already other (non-inline) extents. If a file has an inline extent it can
3723  * not have any other extents and the (single) inline extent must start at the
3724  * file offset 0. Failing to respect these rules will lead to file corruption,
3725  * resulting in EIO errors on read/write operations, hitting BUG_ON's in mm, etc
3726  *
3727  * We can have extents that have been already written to disk or we can have
3728  * dirty ranges still in delalloc, in which case the extent maps and items are
3729  * created only when we run delalloc, and the delalloc ranges might fall outside
3730  * the range we are currently locking in the inode's io tree. So we check the
3731  * inode's i_size because of that (i_size updates are done while holding the
3732  * i_mutex, which we are holding here).
3733  * We also check to see if the inode has a size not greater than "datal" but has
3734  * extents beyond it, due to an fallocate with FALLOC_FL_KEEP_SIZE (and we are
3735  * protected against such concurrent fallocate calls by the i_mutex).
3736  *
3737  * If the file has no extents but a size greater than datal, do not allow the
3738  * copy because we would need turn the inline extent into a non-inline one (even
3739  * with NO_HOLES enabled). If we find our destination inode only has one inline
3740  * extent, just overwrite it with the source inline extent if its size is less
3741  * than the source extent's size, or we could copy the source inline extent's
3742  * data into the destination inode's inline extent if the later is greater then
3743  * the former.
3744  */
3745 static int clone_copy_inline_extent(struct inode *dst,
3746                                     struct btrfs_trans_handle *trans,
3747                                     struct btrfs_path *path,
3748                                     struct btrfs_key *new_key,
3749                                     const u64 drop_start,
3750                                     const u64 datal,
3751                                     const u64 skip,
3752                                     const u64 size,
3753                                     char *inline_data)
3754 {
3755         struct btrfs_fs_info *fs_info = btrfs_sb(dst->i_sb);
3756         struct btrfs_root *root = BTRFS_I(dst)->root;
3757         const u64 aligned_end = ALIGN(new_key->offset + datal,
3758                                       fs_info->sectorsize);
3759         int ret;
3760         struct btrfs_key key;
3761
3762         if (new_key->offset > 0)
3763                 return -EOPNOTSUPP;
3764
3765         key.objectid = btrfs_ino(BTRFS_I(dst));
3766         key.type = BTRFS_EXTENT_DATA_KEY;
3767         key.offset = 0;
3768         ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3769         if (ret < 0) {
3770                 return ret;
3771         } else if (ret > 0) {
3772                 if (path->slots[0] >= btrfs_header_nritems(path->nodes[0])) {
3773                         ret = btrfs_next_leaf(root, path);
3774                         if (ret < 0)
3775                                 return ret;
3776                         else if (ret > 0)
3777                                 goto copy_inline_extent;
3778                 }
3779                 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
3780                 if (key.objectid == btrfs_ino(BTRFS_I(dst)) &&
3781                     key.type == BTRFS_EXTENT_DATA_KEY) {
3782                         ASSERT(key.offset > 0);
3783                         return -EOPNOTSUPP;
3784                 }
3785         } else if (i_size_read(dst) <= datal) {
3786                 struct btrfs_file_extent_item *ei;
3787                 u64 ext_len;
3788
3789                 /*
3790                  * If the file size is <= datal, make sure there are no other
3791                  * extents following (can happen do to an fallocate call with
3792                  * the flag FALLOC_FL_KEEP_SIZE).
3793                  */
3794                 ei = btrfs_item_ptr(path->nodes[0], path->slots[0],
3795                                     struct btrfs_file_extent_item);
3796                 /*
3797                  * If it's an inline extent, it can not have other extents
3798                  * following it.
3799                  */
3800                 if (btrfs_file_extent_type(path->nodes[0], ei) ==
3801                     BTRFS_FILE_EXTENT_INLINE)
3802                         goto copy_inline_extent;
3803
3804                 ext_len = btrfs_file_extent_num_bytes(path->nodes[0], ei);
3805                 if (ext_len > aligned_end)
3806                         return -EOPNOTSUPP;
3807
3808                 ret = btrfs_next_item(root, path);
3809                 if (ret < 0) {
3810                         return ret;
3811                 } else if (ret == 0) {
3812                         btrfs_item_key_to_cpu(path->nodes[0], &key,
3813                                               path->slots[0]);
3814                         if (key.objectid == btrfs_ino(BTRFS_I(dst)) &&
3815                             key.type == BTRFS_EXTENT_DATA_KEY)
3816                                 return -EOPNOTSUPP;
3817                 }
3818         }
3819
3820 copy_inline_extent:
3821         /*
3822          * We have no extent items, or we have an extent at offset 0 which may
3823          * or may not be inlined. All these cases are dealt the same way.
3824          */
3825         if (i_size_read(dst) > datal) {
3826                 /*
3827                  * If the destination inode has an inline extent...
3828                  * This would require copying the data from the source inline
3829                  * extent into the beginning of the destination's inline extent.
3830                  * But this is really complex, both extents can be compressed
3831                  * or just one of them, which would require decompressing and
3832                  * re-compressing data (which could increase the new compressed
3833                  * size, not allowing the compressed data to fit anymore in an
3834                  * inline extent).
3835                  * So just don't support this case for now (it should be rare,
3836                  * we are not really saving space when cloning inline extents).
3837                  */
3838                 return -EOPNOTSUPP;
3839         }
3840
3841         btrfs_release_path(path);
3842         ret = btrfs_drop_extents(trans, root, dst, drop_start, aligned_end, 1);
3843         if (ret)
3844                 return ret;
3845         ret = btrfs_insert_empty_item(trans, root, path, new_key, size);
3846         if (ret)
3847                 return ret;
3848
3849         if (skip) {
3850                 const u32 start = btrfs_file_extent_calc_inline_size(0);
3851
3852                 memmove(inline_data + start, inline_data + start + skip, datal);
3853         }
3854
3855         write_extent_buffer(path->nodes[0], inline_data,
3856                             btrfs_item_ptr_offset(path->nodes[0],
3857                                                   path->slots[0]),
3858                             size);
3859         inode_add_bytes(dst, datal);
3860
3861         return 0;
3862 }
3863
3864 /**
3865  * btrfs_clone() - clone a range from inode file to another
3866  *
3867  * @src: Inode to clone from
3868  * @inode: Inode to clone to
3869  * @off: Offset within source to start clone from
3870  * @olen: Original length, passed by user, of range to clone
3871  * @olen_aligned: Block-aligned value of olen
3872  * @destoff: Offset within @inode to start clone
3873  * @no_time_update: Whether to update mtime/ctime on the target inode
3874  */
3875 static int btrfs_clone(struct inode *src, struct inode *inode,
3876                        const u64 off, const u64 olen, const u64 olen_aligned,
3877                        const u64 destoff, int no_time_update)
3878 {
3879         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3880         struct btrfs_root *root = BTRFS_I(inode)->root;
3881         struct btrfs_path *path = NULL;
3882         struct extent_buffer *leaf;
3883         struct btrfs_trans_handle *trans;
3884         char *buf = NULL;
3885         struct btrfs_key key;
3886         u32 nritems;
3887         int slot;
3888         int ret;
3889         const u64 len = olen_aligned;
3890         u64 last_dest_end = destoff;
3891
3892         ret = -ENOMEM;
3893         buf = kvmalloc(fs_info->nodesize, GFP_KERNEL);
3894         if (!buf)
3895                 return ret;
3896
3897         path = btrfs_alloc_path();
3898         if (!path) {
3899                 kvfree(buf);
3900                 return ret;
3901         }
3902
3903         path->reada = READA_FORWARD;
3904         /* clone data */
3905         key.objectid = btrfs_ino(BTRFS_I(src));
3906         key.type = BTRFS_EXTENT_DATA_KEY;
3907         key.offset = off;
3908
3909         while (1) {
3910                 u64 next_key_min_offset = key.offset + 1;
3911
3912                 /*
3913                  * note the key will change type as we walk through the
3914                  * tree.
3915                  */
3916                 path->leave_spinning = 1;
3917                 ret = btrfs_search_slot(NULL, BTRFS_I(src)->root, &key, path,
3918                                 0, 0);
3919                 if (ret < 0)
3920                         goto out;
3921                 /*
3922                  * First search, if no extent item that starts at offset off was
3923                  * found but the previous item is an extent item, it's possible
3924                  * it might overlap our target range, therefore process it.
3925                  */
3926                 if (key.offset == off && ret > 0 && path->slots[0] > 0) {
3927                         btrfs_item_key_to_cpu(path->nodes[0], &key,
3928                                               path->slots[0] - 1);
3929                         if (key.type == BTRFS_EXTENT_DATA_KEY)
3930                                 path->slots[0]--;
3931                 }
3932
3933                 nritems = btrfs_header_nritems(path->nodes[0]);
3934 process_slot:
3935                 if (path->slots[0] >= nritems) {
3936                         ret = btrfs_next_leaf(BTRFS_I(src)->root, path);
3937                         if (ret < 0)
3938                                 goto out;
3939                         if (ret > 0)
3940                                 break;
3941                         nritems = btrfs_header_nritems(path->nodes[0]);
3942                 }
3943                 leaf = path->nodes[0];
3944                 slot = path->slots[0];
3945
3946                 btrfs_item_key_to_cpu(leaf, &key, slot);
3947                 if (key.type > BTRFS_EXTENT_DATA_KEY ||
3948                     key.objectid != btrfs_ino(BTRFS_I(src)))
3949                         break;
3950
3951                 if (key.type == BTRFS_EXTENT_DATA_KEY) {
3952                         struct btrfs_file_extent_item *extent;
3953                         int type;
3954                         u32 size;
3955                         struct btrfs_key new_key;
3956                         u64 disko = 0, diskl = 0;
3957                         u64 datao = 0, datal = 0;
3958                         u8 comp;
3959                         u64 drop_start;
3960
3961                         extent = btrfs_item_ptr(leaf, slot,
3962                                                 struct btrfs_file_extent_item);
3963                         comp = btrfs_file_extent_compression(leaf, extent);
3964                         type = btrfs_file_extent_type(leaf, extent);
3965                         if (type == BTRFS_FILE_EXTENT_REG ||
3966                             type == BTRFS_FILE_EXTENT_PREALLOC) {
3967                                 disko = btrfs_file_extent_disk_bytenr(leaf,
3968                                                                       extent);
3969                                 diskl = btrfs_file_extent_disk_num_bytes(leaf,
3970                                                                  extent);
3971                                 datao = btrfs_file_extent_offset(leaf, extent);
3972                                 datal = btrfs_file_extent_num_bytes(leaf,
3973                                                                     extent);
3974                         } else if (type == BTRFS_FILE_EXTENT_INLINE) {
3975                                 /* take upper bound, may be compressed */
3976                                 datal = btrfs_file_extent_ram_bytes(leaf,
3977                                                                     extent);
3978                         }
3979
3980                         /*
3981                          * The first search might have left us at an extent
3982                          * item that ends before our target range's start, can
3983                          * happen if we have holes and NO_HOLES feature enabled.
3984                          */
3985                         if (key.offset + datal <= off) {
3986                                 path->slots[0]++;
3987                                 goto process_slot;
3988                         } else if (key.offset >= off + len) {
3989                                 break;
3990                         }
3991                         next_key_min_offset = key.offset + datal;
3992                         size = btrfs_item_size_nr(leaf, slot);
3993                         read_extent_buffer(leaf, buf,
3994                                            btrfs_item_ptr_offset(leaf, slot),
3995                                            size);
3996
3997                         btrfs_release_path(path);
3998                         path->leave_spinning = 0;
3999
4000                         memcpy(&new_key, &key, sizeof(new_key));
4001                         new_key.objectid = btrfs_ino(BTRFS_I(inode));
4002                         if (off <= key.offset)
4003                                 new_key.offset = key.offset + destoff - off;
4004                         else
4005                                 new_key.offset = destoff;
4006
4007                         /*
4008                          * Deal with a hole that doesn't have an extent item
4009                          * that represents it (NO_HOLES feature enabled).
4010                          * This hole is either in the middle of the cloning
4011                          * range or at the beginning (fully overlaps it or
4012                          * partially overlaps it).
4013                          */
4014                         if (new_key.offset != last_dest_end)
4015                                 drop_start = last_dest_end;
4016                         else
4017                                 drop_start = new_key.offset;
4018
4019                         /*
4020                          * 1 - adjusting old extent (we may have to split it)
4021                          * 1 - add new extent
4022                          * 1 - inode update
4023                          */
4024                         trans = btrfs_start_transaction(root, 3);
4025                         if (IS_ERR(trans)) {
4026                                 ret = PTR_ERR(trans);
4027                                 goto out;
4028                         }
4029
4030                         if (type == BTRFS_FILE_EXTENT_REG ||
4031                             type == BTRFS_FILE_EXTENT_PREALLOC) {
4032                                 /*
4033                                  *    a  | --- range to clone ---|  b
4034                                  * | ------------- extent ------------- |
4035                                  */
4036
4037                                 /* subtract range b */
4038                                 if (key.offset + datal > off + len)
4039                                         datal = off + len - key.offset;
4040
4041                                 /* subtract range a */
4042                                 if (off > key.offset) {
4043                                         datao += off - key.offset;
4044                                         datal -= off - key.offset;
4045                                 }
4046
4047                                 ret = btrfs_drop_extents(trans, root, inode,
4048                                                          drop_start,
4049                                                          new_key.offset + datal,
4050                                                          1);
4051                                 if (ret) {
4052                                         if (ret != -EOPNOTSUPP)
4053                                                 btrfs_abort_transaction(trans,
4054                                                                         ret);
4055                                         btrfs_end_transaction(trans);
4056                                         goto out;
4057                                 }
4058
4059                                 ret = btrfs_insert_empty_item(trans, root, path,
4060                                                               &new_key, size);
4061                                 if (ret) {
4062                                         btrfs_abort_transaction(trans, ret);
4063                                         btrfs_end_transaction(trans);
4064                                         goto out;
4065                                 }
4066
4067                                 leaf = path->nodes[0];
4068                                 slot = path->slots[0];
4069                                 write_extent_buffer(leaf, buf,
4070                                             btrfs_item_ptr_offset(leaf, slot),
4071                                             size);
4072
4073                                 extent = btrfs_item_ptr(leaf, slot,
4074                                                 struct btrfs_file_extent_item);
4075
4076                                 /* disko == 0 means it's a hole */
4077                                 if (!disko)
4078                                         datao = 0;
4079
4080                                 btrfs_set_file_extent_offset(leaf, extent,
4081                                                              datao);
4082                                 btrfs_set_file_extent_num_bytes(leaf, extent,
4083                                                                 datal);
4084
4085                                 if (disko) {
4086                                         inode_add_bytes(inode, datal);
4087                                         ret = btrfs_inc_extent_ref(trans,
4088                                                         root,
4089                                                         disko, diskl, 0,
4090                                                         root->root_key.objectid,
4091                                                         btrfs_ino(BTRFS_I(inode)),
4092                                                         new_key.offset - datao);
4093                                         if (ret) {
4094                                                 btrfs_abort_transaction(trans,
4095                                                                         ret);
4096                                                 btrfs_end_transaction(trans);
4097                                                 goto out;
4098
4099                                         }
4100                                 }
4101                         } else if (type == BTRFS_FILE_EXTENT_INLINE) {
4102                                 u64 skip = 0;
4103                                 u64 trim = 0;
4104
4105                                 if (off > key.offset) {
4106                                         skip = off - key.offset;
4107                                         new_key.offset += skip;
4108                                 }
4109
4110                                 if (key.offset + datal > off + len)
4111                                         trim = key.offset + datal - (off + len);
4112
4113                                 if (comp && (skip || trim)) {
4114                                         ret = -EINVAL;
4115                                         btrfs_end_transaction(trans);
4116                                         goto out;
4117                                 }
4118                                 size -= skip + trim;
4119                                 datal -= skip + trim;
4120
4121                                 ret = clone_copy_inline_extent(inode,
4122                                                                trans, path,
4123                                                                &new_key,
4124                                                                drop_start,
4125                                                                datal,
4126                                                                skip, size, buf);
4127                                 if (ret) {
4128                                         if (ret != -EOPNOTSUPP)
4129                                                 btrfs_abort_transaction(trans,
4130                                                                         ret);
4131                                         btrfs_end_transaction(trans);
4132                                         goto out;
4133                                 }
4134                                 leaf = path->nodes[0];
4135                                 slot = path->slots[0];
4136                         }
4137
4138                         /* If we have an implicit hole (NO_HOLES feature). */
4139                         if (drop_start < new_key.offset)
4140                                 clone_update_extent_map(BTRFS_I(inode), trans,
4141                                                 NULL, drop_start,
4142                                                 new_key.offset - drop_start);
4143
4144                         clone_update_extent_map(BTRFS_I(inode), trans,
4145                                         path, 0, 0);
4146
4147                         btrfs_mark_buffer_dirty(leaf);
4148                         btrfs_release_path(path);
4149
4150                         last_dest_end = ALIGN(new_key.offset + datal,
4151                                               fs_info->sectorsize);
4152                         ret = clone_finish_inode_update(trans, inode,
4153                                                         last_dest_end,
4154                                                         destoff, olen,
4155                                                         no_time_update);
4156                         if (ret)
4157                                 goto out;
4158                         if (new_key.offset + datal >= destoff + len)
4159                                 break;
4160                 }
4161                 btrfs_release_path(path);
4162                 key.offset = next_key_min_offset;
4163
4164                 if (fatal_signal_pending(current)) {
4165                         ret = -EINTR;
4166                         goto out;
4167                 }
4168         }
4169         ret = 0;
4170
4171         if (last_dest_end < destoff + len) {
4172                 /*
4173                  * We have an implicit hole (NO_HOLES feature is enabled) that
4174                  * fully or partially overlaps our cloning range at its end.
4175                  */
4176                 btrfs_release_path(path);
4177
4178                 /*
4179                  * 1 - remove extent(s)
4180                  * 1 - inode update
4181                  */
4182                 trans = btrfs_start_transaction(root, 2);
4183                 if (IS_ERR(trans)) {
4184                         ret = PTR_ERR(trans);
4185                         goto out;
4186                 }
4187                 ret = btrfs_drop_extents(trans, root, inode,
4188                                          last_dest_end, destoff + len, 1);
4189                 if (ret) {
4190                         if (ret != -EOPNOTSUPP)
4191                                 btrfs_abort_transaction(trans, ret);
4192                         btrfs_end_transaction(trans);
4193                         goto out;
4194                 }
4195                 clone_update_extent_map(BTRFS_I(inode), trans, NULL,
4196                                 last_dest_end,
4197                                 destoff + len - last_dest_end);
4198                 ret = clone_finish_inode_update(trans, inode, destoff + len,
4199                                                 destoff, olen, no_time_update);
4200         }
4201
4202 out:
4203         btrfs_free_path(path);
4204         kvfree(buf);
4205         return ret;
4206 }
4207
4208 static noinline int btrfs_clone_files(struct file *file, struct file *file_src,
4209                                         u64 off, u64 olen, u64 destoff)
4210 {
4211         struct inode *inode = file_inode(file);
4212         struct inode *src = file_inode(file_src);
4213         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4214         struct btrfs_root *root = BTRFS_I(inode)->root;
4215         int ret;
4216         u64 len = olen;
4217         u64 bs = fs_info->sb->s_blocksize;
4218         int same_inode = src == inode;
4219
4220         /*
4221          * TODO:
4222          * - split compressed inline extents.  annoying: we need to
4223          *   decompress into destination's address_space (the file offset
4224          *   may change, so source mapping won't do), then recompress (or
4225          *   otherwise reinsert) a subrange.
4226          *
4227          * - split destination inode's inline extents.  The inline extents can
4228          *   be either compressed or non-compressed.
4229          */
4230
4231         if (btrfs_root_readonly(root))
4232                 return -EROFS;
4233
4234         if (file_src->f_path.mnt != file->f_path.mnt ||
4235             src->i_sb != inode->i_sb)
4236                 return -EXDEV;
4237
4238         if (S_ISDIR(src->i_mode) || S_ISDIR(inode->i_mode))
4239                 return -EISDIR;
4240
4241         if (!same_inode) {
4242                 btrfs_double_inode_lock(src, inode);
4243         } else {
4244                 inode_lock(src);
4245         }
4246
4247         /* don't make the dst file partly checksummed */
4248         if ((BTRFS_I(src)->flags & BTRFS_INODE_NODATASUM) !=
4249             (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)) {
4250                 ret = -EINVAL;
4251                 goto out_unlock;
4252         }
4253
4254         /* determine range to clone */
4255         ret = -EINVAL;
4256         if (off + len > src->i_size || off + len < off)
4257                 goto out_unlock;
4258         if (len == 0)
4259                 olen = len = src->i_size - off;
4260         /* if we extend to eof, continue to block boundary */
4261         if (off + len == src->i_size)
4262                 len = ALIGN(src->i_size, bs) - off;
4263
4264         if (len == 0) {
4265                 ret = 0;
4266                 goto out_unlock;
4267         }
4268
4269         /* verify the end result is block aligned */
4270         if (!IS_ALIGNED(off, bs) || !IS_ALIGNED(off + len, bs) ||
4271             !IS_ALIGNED(destoff, bs))
4272                 goto out_unlock;
4273
4274         /* verify if ranges are overlapped within the same file */
4275         if (same_inode) {
4276                 if (destoff + len > off && destoff < off + len)
4277                         goto out_unlock;
4278         }
4279
4280         if (destoff > inode->i_size) {
4281                 ret = btrfs_cont_expand(inode, inode->i_size, destoff);
4282                 if (ret)
4283                         goto out_unlock;
4284         }
4285
4286         /*
4287          * Lock the target range too. Right after we replace the file extent
4288          * items in the fs tree (which now point to the cloned data), we might
4289          * have a worker replace them with extent items relative to a write
4290          * operation that was issued before this clone operation (i.e. confront
4291          * with inode.c:btrfs_finish_ordered_io).
4292          */
4293         if (same_inode) {
4294                 u64 lock_start = min_t(u64, off, destoff);
4295                 u64 lock_len = max_t(u64, off, destoff) + len - lock_start;
4296
4297                 ret = lock_extent_range(src, lock_start, lock_len, true);
4298         } else {
4299                 ret = btrfs_double_extent_lock(src, off, inode, destoff, len,
4300                                                true);
4301         }
4302         ASSERT(ret == 0);
4303         if (WARN_ON(ret)) {
4304                 /* ranges in the io trees already unlocked */
4305                 goto out_unlock;
4306         }
4307
4308         ret = btrfs_clone(src, inode, off, olen, len, destoff, 0);
4309
4310         if (same_inode) {
4311                 u64 lock_start = min_t(u64, off, destoff);
4312                 u64 lock_end = max_t(u64, off, destoff) + len - 1;
4313
4314                 unlock_extent(&BTRFS_I(src)->io_tree, lock_start, lock_end);
4315         } else {
4316                 btrfs_double_extent_unlock(src, off, inode, destoff, len);
4317         }
4318         /*
4319          * Truncate page cache pages so that future reads will see the cloned
4320          * data immediately and not the previous data.
4321          */
4322         truncate_inode_pages_range(&inode->i_data,
4323                                 round_down(destoff, PAGE_SIZE),
4324                                 round_up(destoff + len, PAGE_SIZE) - 1);
4325 out_unlock:
4326         if (!same_inode)
4327                 btrfs_double_inode_unlock(src, inode);
4328         else
4329                 inode_unlock(src);
4330         return ret;
4331 }
4332
4333 loff_t btrfs_remap_file_range(struct file *src_file, loff_t off,
4334                 struct file *dst_file, loff_t destoff, loff_t len,
4335                 unsigned int remap_flags)
4336 {
4337         int ret;
4338
4339         if (remap_flags & ~(REMAP_FILE_DEDUP | REMAP_FILE_ADVISORY))
4340                 return -EINVAL;
4341
4342         if (remap_flags & REMAP_FILE_DEDUP) {
4343                 struct inode *src = file_inode(src_file);
4344                 struct inode *dst = file_inode(dst_file);
4345                 u64 bs = BTRFS_I(src)->root->fs_info->sb->s_blocksize;
4346
4347                 if (WARN_ON_ONCE(bs < PAGE_SIZE)) {
4348                         /*
4349                          * Btrfs does not support blocksize < page_size. As a
4350                          * result, btrfs_cmp_data() won't correctly handle
4351                          * this situation without an update.
4352                          */
4353                         return -EINVAL;
4354                 }
4355
4356                 ret = btrfs_extent_same(src, off, len, dst, destoff);
4357         } else {
4358                 ret = btrfs_clone_files(dst_file, src_file, off, len, destoff);
4359         }
4360         return ret < 0 ? ret : len;
4361 }
4362
4363 static long btrfs_ioctl_default_subvol(struct file *file, void __user *argp)
4364 {
4365         struct inode *inode = file_inode(file);
4366         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4367         struct btrfs_root *root = BTRFS_I(inode)->root;
4368         struct btrfs_root *new_root;
4369         struct btrfs_dir_item *di;
4370         struct btrfs_trans_handle *trans;
4371         struct btrfs_path *path;
4372         struct btrfs_key location;
4373         struct btrfs_disk_key disk_key;
4374         u64 objectid = 0;
4375         u64 dir_id;
4376         int ret;
4377
4378         if (!capable(CAP_SYS_ADMIN))
4379                 return -EPERM;
4380
4381         ret = mnt_want_write_file(file);
4382         if (ret)
4383                 return ret;
4384
4385         if (copy_from_user(&objectid, argp, sizeof(objectid))) {
4386                 ret = -EFAULT;
4387                 goto out;
4388         }
4389
4390         if (!objectid)
4391                 objectid = BTRFS_FS_TREE_OBJECTID;
4392
4393         location.objectid = objectid;
4394         location.type = BTRFS_ROOT_ITEM_KEY;
4395         location.offset = (u64)-1;
4396
4397         new_root = btrfs_read_fs_root_no_name(fs_info, &location);
4398         if (IS_ERR(new_root)) {
4399                 ret = PTR_ERR(new_root);
4400                 goto out;
4401         }
4402         if (!is_fstree(new_root->root_key.objectid)) {
4403                 ret = -ENOENT;
4404                 goto out;
4405         }
4406
4407         path = btrfs_alloc_path();
4408         if (!path) {
4409                 ret = -ENOMEM;
4410                 goto out;
4411         }
4412         path->leave_spinning = 1;
4413
4414         trans = btrfs_start_transaction(root, 1);
4415         if (IS_ERR(trans)) {
4416                 btrfs_free_path(path);
4417                 ret = PTR_ERR(trans);
4418                 goto out;
4419         }
4420
4421         dir_id = btrfs_super_root_dir(fs_info->super_copy);
4422         di = btrfs_lookup_dir_item(trans, fs_info->tree_root, path,
4423                                    dir_id, "default", 7, 1);
4424         if (IS_ERR_OR_NULL(di)) {
4425                 btrfs_free_path(path);
4426                 btrfs_end_transaction(trans);
4427                 btrfs_err(fs_info,
4428                           "Umm, you don't have the default diritem, this isn't going to work");
4429                 ret = -ENOENT;
4430                 goto out;
4431         }
4432
4433         btrfs_cpu_key_to_disk(&disk_key, &new_root->root_key);
4434         btrfs_set_dir_item_key(path->nodes[0], di, &disk_key);
4435         btrfs_mark_buffer_dirty(path->nodes[0]);
4436         btrfs_free_path(path);
4437
4438         btrfs_set_fs_incompat(fs_info, DEFAULT_SUBVOL);
4439         btrfs_end_transaction(trans);
4440 out:
4441         mnt_drop_write_file(file);
4442         return ret;
4443 }
4444
4445 static void get_block_group_info(struct list_head *groups_list,
4446                                  struct btrfs_ioctl_space_info *space)
4447 {
4448         struct btrfs_block_group_cache *block_group;
4449
4450         space->total_bytes = 0;
4451         space->used_bytes = 0;
4452         space->flags = 0;
4453         list_for_each_entry(block_group, groups_list, list) {
4454                 space->flags = block_group->flags;
4455                 space->total_bytes += block_group->key.offset;
4456                 space->used_bytes +=
4457                         btrfs_block_group_used(&block_group->item);
4458         }
4459 }
4460
4461 static long btrfs_ioctl_space_info(struct btrfs_fs_info *fs_info,
4462                                    void __user *arg)
4463 {
4464         struct btrfs_ioctl_space_args space_args;
4465         struct btrfs_ioctl_space_info space;
4466         struct btrfs_ioctl_space_info *dest;
4467         struct btrfs_ioctl_space_info *dest_orig;
4468         struct btrfs_ioctl_space_info __user *user_dest;
4469         struct btrfs_space_info *info;
4470         static const u64 types[] = {
4471                 BTRFS_BLOCK_GROUP_DATA,
4472                 BTRFS_BLOCK_GROUP_SYSTEM,
4473                 BTRFS_BLOCK_GROUP_METADATA,
4474                 BTRFS_BLOCK_GROUP_DATA | BTRFS_BLOCK_GROUP_METADATA
4475         };
4476         int num_types = 4;
4477         int alloc_size;
4478         int ret = 0;
4479         u64 slot_count = 0;
4480         int i, c;
4481
4482         if (copy_from_user(&space_args,
4483                            (struct btrfs_ioctl_space_args __user *)arg,
4484                            sizeof(space_args)))
4485                 return -EFAULT;
4486
4487         for (i = 0; i < num_types; i++) {
4488                 struct btrfs_space_info *tmp;
4489
4490                 info = NULL;
4491                 rcu_read_lock();
4492                 list_for_each_entry_rcu(tmp, &fs_info->space_info,
4493                                         list) {
4494                         if (tmp->flags == types[i]) {
4495                                 info = tmp;
4496                                 break;
4497                         }
4498                 }
4499                 rcu_read_unlock();
4500
4501                 if (!info)
4502                         continue;
4503
4504                 down_read(&info->groups_sem);
4505                 for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) {
4506                         if (!list_empty(&info->block_groups[c]))
4507                                 slot_count++;
4508                 }
4509                 up_read(&info->groups_sem);
4510         }
4511
4512         /*
4513          * Global block reserve, exported as a space_info
4514          */
4515         slot_count++;
4516
4517         /* space_slots == 0 means they are asking for a count */
4518         if (space_args.space_slots == 0) {
4519                 space_args.total_spaces = slot_count;
4520                 goto out;
4521         }
4522
4523         slot_count = min_t(u64, space_args.space_slots, slot_count);
4524
4525         alloc_size = sizeof(*dest) * slot_count;
4526
4527         /* we generally have at most 6 or so space infos, one for each raid
4528          * level.  So, a whole page should be more than enough for everyone
4529          */
4530         if (alloc_size > PAGE_SIZE)
4531                 return -ENOMEM;
4532
4533         space_args.total_spaces = 0;
4534         dest = kmalloc(alloc_size, GFP_KERNEL);
4535         if (!dest)
4536                 return -ENOMEM;
4537         dest_orig = dest;
4538
4539         /* now we have a buffer to copy into */
4540         for (i = 0; i < num_types; i++) {
4541                 struct btrfs_space_info *tmp;
4542
4543                 if (!slot_count)
4544                         break;
4545
4546                 info = NULL;
4547                 rcu_read_lock();
4548                 list_for_each_entry_rcu(tmp, &fs_info->space_info,
4549                                         list) {
4550                         if (tmp->flags == types[i]) {
4551                                 info = tmp;
4552                                 break;
4553                         }
4554                 }
4555                 rcu_read_unlock();
4556
4557                 if (!info)
4558                         continue;
4559                 down_read(&info->groups_sem);
4560                 for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) {
4561                         if (!list_empty(&info->block_groups[c])) {
4562                                 get_block_group_info(&info->block_groups[c],
4563                                                      &space);
4564                                 memcpy(dest, &space, sizeof(space));
4565                                 dest++;
4566                                 space_args.total_spaces++;
4567                                 slot_count--;
4568                         }
4569                         if (!slot_count)
4570                                 break;
4571                 }
4572                 up_read(&info->groups_sem);
4573         }
4574
4575         /*
4576          * Add global block reserve
4577          */
4578         if (slot_count) {
4579                 struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
4580
4581                 spin_lock(&block_rsv->lock);
4582                 space.total_bytes = block_rsv->size;
4583                 space.used_bytes = block_rsv->size - block_rsv->reserved;
4584                 spin_unlock(&block_rsv->lock);
4585                 space.flags = BTRFS_SPACE_INFO_GLOBAL_RSV;
4586                 memcpy(dest, &space, sizeof(space));
4587                 space_args.total_spaces++;
4588         }
4589
4590         user_dest = (struct btrfs_ioctl_space_info __user *)
4591                 (arg + sizeof(struct btrfs_ioctl_space_args));
4592
4593         if (copy_to_user(user_dest, dest_orig, alloc_size))
4594                 ret = -EFAULT;
4595
4596         kfree(dest_orig);
4597 out:
4598         if (ret == 0 && copy_to_user(arg, &space_args, sizeof(space_args)))
4599                 ret = -EFAULT;
4600
4601         return ret;
4602 }
4603
4604 static noinline long btrfs_ioctl_start_sync(struct btrfs_root *root,
4605                                             void __user *argp)
4606 {
4607         struct btrfs_trans_handle *trans;
4608         u64 transid;
4609         int ret;
4610
4611         trans = btrfs_attach_transaction_barrier(root);
4612         if (IS_ERR(trans)) {
4613                 if (PTR_ERR(trans) != -ENOENT)
4614                         return PTR_ERR(trans);
4615
4616                 /* No running transaction, don't bother */
4617                 transid = root->fs_info->last_trans_committed;
4618                 goto out;
4619         }
4620         transid = trans->transid;
4621         ret = btrfs_commit_transaction_async(trans, 0);
4622         if (ret) {
4623                 btrfs_end_transaction(trans);
4624                 return ret;
4625         }
4626 out:
4627         if (argp)
4628                 if (copy_to_user(argp, &transid, sizeof(transid)))
4629                         return -EFAULT;
4630         return 0;
4631 }
4632
4633 static noinline long btrfs_ioctl_wait_sync(struct btrfs_fs_info *fs_info,
4634                                            void __user *argp)
4635 {
4636         u64 transid;
4637
4638         if (argp) {
4639                 if (copy_from_user(&transid, argp, sizeof(transid)))
4640                         return -EFAULT;
4641         } else {
4642                 transid = 0;  /* current trans */
4643         }
4644         return btrfs_wait_for_commit(fs_info, transid);
4645 }
4646
4647 static long btrfs_ioctl_scrub(struct file *file, void __user *arg)
4648 {
4649         struct btrfs_fs_info *fs_info = btrfs_sb(file_inode(file)->i_sb);
4650         struct btrfs_ioctl_scrub_args *sa;
4651         int ret;
4652
4653         if (!capable(CAP_SYS_ADMIN))
4654                 return -EPERM;
4655
4656         sa = memdup_user(arg, sizeof(*sa));
4657         if (IS_ERR(sa))
4658                 return PTR_ERR(sa);
4659
4660         if (!(sa->flags & BTRFS_SCRUB_READONLY)) {
4661                 ret = mnt_want_write_file(file);
4662                 if (ret)
4663                         goto out;
4664         }
4665
4666         ret = btrfs_scrub_dev(fs_info, sa->devid, sa->start, sa->end,
4667                               &sa->progress, sa->flags & BTRFS_SCRUB_READONLY,
4668                               0);
4669
4670         if (copy_to_user(arg, sa, sizeof(*sa)))
4671                 ret = -EFAULT;
4672
4673         if (!(sa->flags & BTRFS_SCRUB_READONLY))
4674                 mnt_drop_write_file(file);
4675 out:
4676         kfree(sa);
4677         return ret;
4678 }
4679
4680 static long btrfs_ioctl_scrub_cancel(struct btrfs_fs_info *fs_info)
4681 {
4682         if (!capable(CAP_SYS_ADMIN))
4683                 return -EPERM;
4684
4685         return btrfs_scrub_cancel(fs_info);
4686 }
4687
4688 static long btrfs_ioctl_scrub_progress(struct btrfs_fs_info *fs_info,
4689                                        void __user *arg)
4690 {
4691         struct btrfs_ioctl_scrub_args *sa;
4692         int ret;
4693
4694         if (!capable(CAP_SYS_ADMIN))
4695                 return -EPERM;
4696
4697         sa = memdup_user(arg, sizeof(*sa));
4698         if (IS_ERR(sa))
4699                 return PTR_ERR(sa);
4700
4701         ret = btrfs_scrub_progress(fs_info, sa->devid, &sa->progress);
4702
4703         if (copy_to_user(arg, sa, sizeof(*sa)))
4704                 ret = -EFAULT;
4705
4706         kfree(sa);
4707         return ret;
4708 }
4709
4710 static long btrfs_ioctl_get_dev_stats(struct btrfs_fs_info *fs_info,
4711                                       void __user *arg)
4712 {
4713         struct btrfs_ioctl_get_dev_stats *sa;
4714         int ret;
4715
4716         sa = memdup_user(arg, sizeof(*sa));
4717         if (IS_ERR(sa))
4718                 return PTR_ERR(sa);
4719
4720         if ((sa->flags & BTRFS_DEV_STATS_RESET) && !capable(CAP_SYS_ADMIN)) {
4721                 kfree(sa);
4722                 return -EPERM;
4723         }
4724
4725         ret = btrfs_get_dev_stats(fs_info, sa);
4726
4727         if (copy_to_user(arg, sa, sizeof(*sa)))
4728                 ret = -EFAULT;
4729
4730         kfree(sa);
4731         return ret;
4732 }
4733
4734 static long btrfs_ioctl_dev_replace(struct btrfs_fs_info *fs_info,
4735                                     void __user *arg)
4736 {
4737         struct btrfs_ioctl_dev_replace_args *p;
4738         int ret;
4739
4740         if (!capable(CAP_SYS_ADMIN))
4741                 return -EPERM;
4742
4743         p = memdup_user(arg, sizeof(*p));
4744         if (IS_ERR(p))
4745                 return PTR_ERR(p);
4746
4747         switch (p->cmd) {
4748         case BTRFS_IOCTL_DEV_REPLACE_CMD_START:
4749                 if (sb_rdonly(fs_info->sb)) {
4750                         ret = -EROFS;
4751                         goto out;
4752                 }
4753                 if (test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags)) {
4754                         ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
4755                 } else {
4756                         ret = btrfs_dev_replace_by_ioctl(fs_info, p);
4757                         clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
4758                 }
4759                 break;
4760         case BTRFS_IOCTL_DEV_REPLACE_CMD_STATUS:
4761                 btrfs_dev_replace_status(fs_info, p);
4762                 ret = 0;
4763                 break;
4764         case BTRFS_IOCTL_DEV_REPLACE_CMD_CANCEL:
4765                 p->result = btrfs_dev_replace_cancel(fs_info);
4766                 ret = 0;
4767                 break;
4768         default:
4769                 ret = -EINVAL;
4770                 break;
4771         }
4772
4773         if (copy_to_user(arg, p, sizeof(*p)))
4774                 ret = -EFAULT;
4775 out:
4776         kfree(p);
4777         return ret;
4778 }
4779
4780 static long btrfs_ioctl_ino_to_path(struct btrfs_root *root, void __user *arg)
4781 {
4782         int ret = 0;
4783         int i;
4784         u64 rel_ptr;
4785         int size;
4786         struct btrfs_ioctl_ino_path_args *ipa = NULL;
4787         struct inode_fs_paths *ipath = NULL;
4788         struct btrfs_path *path;
4789
4790         if (!capable(CAP_DAC_READ_SEARCH))
4791                 return -EPERM;
4792
4793         path = btrfs_alloc_path();
4794         if (!path) {
4795                 ret = -ENOMEM;
4796                 goto out;
4797         }
4798
4799         ipa = memdup_user(arg, sizeof(*ipa));
4800         if (IS_ERR(ipa)) {
4801                 ret = PTR_ERR(ipa);
4802                 ipa = NULL;
4803                 goto out;
4804         }
4805
4806         size = min_t(u32, ipa->size, 4096);
4807         ipath = init_ipath(size, root, path);
4808         if (IS_ERR(ipath)) {
4809                 ret = PTR_ERR(ipath);
4810                 ipath = NULL;
4811                 goto out;
4812         }
4813
4814         ret = paths_from_inode(ipa->inum, ipath);
4815         if (ret < 0)
4816                 goto out;
4817
4818         for (i = 0; i < ipath->fspath->elem_cnt; ++i) {
4819                 rel_ptr = ipath->fspath->val[i] -
4820                           (u64)(unsigned long)ipath->fspath->val;
4821                 ipath->fspath->val[i] = rel_ptr;
4822         }
4823
4824         ret = copy_to_user((void __user *)(unsigned long)ipa->fspath,
4825                            ipath->fspath, size);
4826         if (ret) {
4827                 ret = -EFAULT;
4828                 goto out;
4829         }
4830
4831 out:
4832         btrfs_free_path(path);
4833         free_ipath(ipath);
4834         kfree(ipa);
4835
4836         return ret;
4837 }
4838
4839 static int build_ino_list(u64 inum, u64 offset, u64 root, void *ctx)
4840 {
4841         struct btrfs_data_container *inodes = ctx;
4842         const size_t c = 3 * sizeof(u64);
4843
4844         if (inodes->bytes_left >= c) {
4845                 inodes->bytes_left -= c;
4846                 inodes->val[inodes->elem_cnt] = inum;
4847                 inodes->val[inodes->elem_cnt + 1] = offset;
4848                 inodes->val[inodes->elem_cnt + 2] = root;
4849                 inodes->elem_cnt += 3;
4850         } else {
4851                 inodes->bytes_missing += c - inodes->bytes_left;
4852                 inodes->bytes_left = 0;
4853                 inodes->elem_missed += 3;
4854         }
4855
4856         return 0;
4857 }
4858
4859 static long btrfs_ioctl_logical_to_ino(struct btrfs_fs_info *fs_info,
4860                                         void __user *arg, int version)
4861 {
4862         int ret = 0;
4863         int size;
4864         struct btrfs_ioctl_logical_ino_args *loi;
4865         struct btrfs_data_container *inodes = NULL;
4866         struct btrfs_path *path = NULL;
4867         bool ignore_offset;
4868
4869         if (!capable(CAP_SYS_ADMIN))
4870                 return -EPERM;
4871
4872         loi = memdup_user(arg, sizeof(*loi));
4873         if (IS_ERR(loi))
4874                 return PTR_ERR(loi);
4875
4876         if (version == 1) {
4877                 ignore_offset = false;
4878                 size = min_t(u32, loi->size, SZ_64K);
4879         } else {
4880                 /* All reserved bits must be 0 for now */
4881                 if (memchr_inv(loi->reserved, 0, sizeof(loi->reserved))) {
4882                         ret = -EINVAL;
4883                         goto out_loi;
4884                 }
4885                 /* Only accept flags we have defined so far */
4886                 if (loi->flags & ~(BTRFS_LOGICAL_INO_ARGS_IGNORE_OFFSET)) {
4887                         ret = -EINVAL;
4888                         goto out_loi;
4889                 }
4890                 ignore_offset = loi->flags & BTRFS_LOGICAL_INO_ARGS_IGNORE_OFFSET;
4891                 size = min_t(u32, loi->size, SZ_16M);
4892         }
4893
4894         path = btrfs_alloc_path();
4895         if (!path) {
4896                 ret = -ENOMEM;
4897                 goto out;
4898         }
4899
4900         inodes = init_data_container(size);
4901         if (IS_ERR(inodes)) {
4902                 ret = PTR_ERR(inodes);
4903                 inodes = NULL;
4904                 goto out;
4905         }
4906
4907         ret = iterate_inodes_from_logical(loi->logical, fs_info, path,
4908                                           build_ino_list, inodes, ignore_offset);
4909         if (ret == -EINVAL)
4910                 ret = -ENOENT;
4911         if (ret < 0)
4912                 goto out;
4913
4914         ret = copy_to_user((void __user *)(unsigned long)loi->inodes, inodes,
4915                            size);
4916         if (ret)
4917                 ret = -EFAULT;
4918
4919 out:
4920         btrfs_free_path(path);
4921         kvfree(inodes);
4922 out_loi:
4923         kfree(loi);
4924
4925         return ret;
4926 }
4927
4928 void btrfs_update_ioctl_balance_args(struct btrfs_fs_info *fs_info,
4929                                struct btrfs_ioctl_balance_args *bargs)
4930 {
4931         struct btrfs_balance_control *bctl = fs_info->balance_ctl;
4932
4933         bargs->flags = bctl->flags;
4934
4935         if (test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags))
4936                 bargs->state |= BTRFS_BALANCE_STATE_RUNNING;
4937         if (atomic_read(&fs_info->balance_pause_req))
4938                 bargs->state |= BTRFS_BALANCE_STATE_PAUSE_REQ;
4939         if (atomic_read(&fs_info->balance_cancel_req))
4940                 bargs->state |= BTRFS_BALANCE_STATE_CANCEL_REQ;
4941
4942         memcpy(&bargs->data, &bctl->data, sizeof(bargs->data));
4943         memcpy(&bargs->meta, &bctl->meta, sizeof(bargs->meta));
4944         memcpy(&bargs->sys, &bctl->sys, sizeof(bargs->sys));
4945
4946         spin_lock(&fs_info->balance_lock);
4947         memcpy(&bargs->stat, &bctl->stat, sizeof(bargs->stat));
4948         spin_unlock(&fs_info->balance_lock);
4949 }
4950
4951 static long btrfs_ioctl_balance(struct file *file, void __user *arg)
4952 {
4953         struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
4954         struct btrfs_fs_info *fs_info = root->fs_info;
4955         struct btrfs_ioctl_balance_args *bargs;
4956         struct btrfs_balance_control *bctl;
4957         bool need_unlock; /* for mut. excl. ops lock */
4958         int ret;
4959
4960         if (!capable(CAP_SYS_ADMIN))
4961                 return -EPERM;
4962
4963         ret = mnt_want_write_file(file);
4964         if (ret)
4965                 return ret;
4966
4967 again:
4968         if (!test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags)) {
4969                 mutex_lock(&fs_info->balance_mutex);
4970                 need_unlock = true;
4971                 goto locked;
4972         }
4973
4974         /*
4975          * mut. excl. ops lock is locked.  Three possibilities:
4976          *   (1) some other op is running
4977          *   (2) balance is running
4978          *   (3) balance is paused -- special case (think resume)
4979          */
4980         mutex_lock(&fs_info->balance_mutex);
4981         if (fs_info->balance_ctl) {
4982                 /* this is either (2) or (3) */
4983                 if (!test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags)) {
4984                         mutex_unlock(&fs_info->balance_mutex);
4985                         /*
4986                          * Lock released to allow other waiters to continue,
4987                          * we'll reexamine the status again.
4988                          */
4989                         mutex_lock(&fs_info->balance_mutex);
4990
4991                         if (fs_info->balance_ctl &&
4992                             !test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags)) {
4993                                 /* this is (3) */
4994                                 need_unlock = false;
4995                                 goto locked;
4996                         }
4997
4998                         mutex_unlock(&fs_info->balance_mutex);
4999                         goto again;
5000                 } else {
5001                         /* this is (2) */
5002                         mutex_unlock(&fs_info->balance_mutex);
5003                         ret = -EINPROGRESS;
5004                         goto out;
5005                 }
5006         } else {
5007                 /* this is (1) */
5008                 mutex_unlock(&fs_info->balance_mutex);
5009                 ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
5010                 goto out;
5011         }
5012
5013 locked:
5014         BUG_ON(!test_bit(BTRFS_FS_EXCL_OP, &fs_info->flags));
5015
5016         if (arg) {
5017                 bargs = memdup_user(arg, sizeof(*bargs));
5018                 if (IS_ERR(bargs)) {
5019                         ret = PTR_ERR(bargs);
5020                         goto out_unlock;
5021                 }
5022
5023                 if (bargs->flags & BTRFS_BALANCE_RESUME) {
5024                         if (!fs_info->balance_ctl) {
5025                                 ret = -ENOTCONN;
5026                                 goto out_bargs;
5027                         }
5028
5029                         bctl = fs_info->balance_ctl;
5030                         spin_lock(&fs_info->balance_lock);
5031                         bctl->flags |= BTRFS_BALANCE_RESUME;
5032                         spin_unlock(&fs_info->balance_lock);
5033
5034                         goto do_balance;
5035                 }
5036         } else {
5037                 bargs = NULL;
5038         }
5039
5040         if (fs_info->balance_ctl) {
5041                 ret = -EINPROGRESS;
5042                 goto out_bargs;
5043         }
5044
5045         bctl = kzalloc(sizeof(*bctl), GFP_KERNEL);
5046         if (!bctl) {
5047                 ret = -ENOMEM;
5048                 goto out_bargs;
5049         }
5050
5051         if (arg) {
5052                 memcpy(&bctl->data, &bargs->data, sizeof(bctl->data));
5053                 memcpy(&bctl->meta, &bargs->meta, sizeof(bctl->meta));
5054                 memcpy(&bctl->sys, &bargs->sys, sizeof(bctl->sys));
5055
5056                 bctl->flags = bargs->flags;
5057         } else {
5058                 /* balance everything - no filters */
5059                 bctl->flags |= BTRFS_BALANCE_TYPE_MASK;
5060         }
5061
5062         if (bctl->flags & ~(BTRFS_BALANCE_ARGS_MASK | BTRFS_BALANCE_TYPE_MASK)) {
5063                 ret = -EINVAL;
5064                 goto out_bctl;
5065         }
5066
5067 do_balance:
5068         /*
5069          * Ownership of bctl and filesystem flag BTRFS_FS_EXCL_OP goes to
5070          * btrfs_balance.  bctl is freed in reset_balance_state, or, if
5071          * restriper was paused all the way until unmount, in free_fs_info.
5072          * The flag should be cleared after reset_balance_state.
5073          */
5074         need_unlock = false;
5075
5076         ret = btrfs_balance(fs_info, bctl, bargs);
5077         bctl = NULL;
5078
5079         if (arg) {
5080                 if (copy_to_user(arg, bargs, sizeof(*bargs)))
5081                         ret = -EFAULT;
5082         }
5083
5084 out_bctl:
5085         kfree(bctl);
5086 out_bargs:
5087         kfree(bargs);
5088 out_unlock:
5089         mutex_unlock(&fs_info->balance_mutex);
5090         if (need_unlock)
5091                 clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
5092 out:
5093         mnt_drop_write_file(file);
5094         return ret;
5095 }
5096
5097 static long btrfs_ioctl_balance_ctl(struct btrfs_fs_info *fs_info, int cmd)
5098 {
5099         if (!capable(CAP_SYS_ADMIN))
5100                 return -EPERM;
5101
5102         switch (cmd) {
5103         case BTRFS_BALANCE_CTL_PAUSE:
5104                 return btrfs_pause_balance(fs_info);
5105         case BTRFS_BALANCE_CTL_CANCEL:
5106                 return btrfs_cancel_balance(fs_info);
5107         }
5108
5109         return -EINVAL;
5110 }
5111
5112 static long btrfs_ioctl_balance_progress(struct btrfs_fs_info *fs_info,
5113                                          void __user *arg)
5114 {
5115         struct btrfs_ioctl_balance_args *bargs;
5116         int ret = 0;
5117
5118         if (!capable(CAP_SYS_ADMIN))
5119                 return -EPERM;
5120
5121         mutex_lock(&fs_info->balance_mutex);
5122         if (!fs_info->balance_ctl) {
5123                 ret = -ENOTCONN;
5124                 goto out;
5125         }
5126
5127         bargs = kzalloc(sizeof(*bargs), GFP_KERNEL);
5128         if (!bargs) {
5129                 ret = -ENOMEM;
5130                 goto out;
5131         }
5132
5133         btrfs_update_ioctl_balance_args(fs_info, bargs);
5134
5135         if (copy_to_user(arg, bargs, sizeof(*bargs)))
5136                 ret = -EFAULT;
5137
5138         kfree(bargs);
5139 out:
5140         mutex_unlock(&fs_info->balance_mutex);
5141         return ret;
5142 }
5143
5144 static long btrfs_ioctl_quota_ctl(struct file *file, void __user *arg)
5145 {
5146         struct inode *inode = file_inode(file);
5147         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5148         struct btrfs_ioctl_quota_ctl_args *sa;
5149         int ret;
5150
5151         if (!capable(CAP_SYS_ADMIN))
5152                 return -EPERM;
5153
5154         ret = mnt_want_write_file(file);
5155         if (ret)
5156                 return ret;
5157
5158         sa = memdup_user(arg, sizeof(*sa));
5159         if (IS_ERR(sa)) {
5160                 ret = PTR_ERR(sa);
5161                 goto drop_write;
5162         }
5163
5164         down_write(&fs_info->subvol_sem);
5165
5166         switch (sa->cmd) {
5167         case BTRFS_QUOTA_CTL_ENABLE:
5168                 ret = btrfs_quota_enable(fs_info);
5169                 break;
5170         case BTRFS_QUOTA_CTL_DISABLE:
5171                 ret = btrfs_quota_disable(fs_info);
5172                 break;
5173         default:
5174                 ret = -EINVAL;
5175                 break;
5176         }
5177
5178         kfree(sa);
5179         up_write(&fs_info->subvol_sem);
5180 drop_write:
5181         mnt_drop_write_file(file);
5182         return ret;
5183 }
5184
5185 static long btrfs_ioctl_qgroup_assign(struct file *file, void __user *arg)
5186 {
5187         struct inode *inode = file_inode(file);
5188         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5189         struct btrfs_root *root = BTRFS_I(inode)->root;
5190         struct btrfs_ioctl_qgroup_assign_args *sa;
5191         struct btrfs_trans_handle *trans;
5192         int ret;
5193         int err;
5194
5195         if (!capable(CAP_SYS_ADMIN))
5196                 return -EPERM;
5197
5198         ret = mnt_want_write_file(file);
5199         if (ret)
5200                 return ret;
5201
5202         sa = memdup_user(arg, sizeof(*sa));
5203         if (IS_ERR(sa)) {
5204                 ret = PTR_ERR(sa);
5205                 goto drop_write;
5206         }
5207
5208         trans = btrfs_join_transaction(root);
5209         if (IS_ERR(trans)) {
5210                 ret = PTR_ERR(trans);
5211                 goto out;
5212         }
5213
5214         if (sa->assign) {
5215                 ret = btrfs_add_qgroup_relation(trans, sa->src, sa->dst);
5216         } else {
5217                 ret = btrfs_del_qgroup_relation(trans, sa->src, sa->dst);
5218         }
5219
5220         /* update qgroup status and info */
5221         err = btrfs_run_qgroups(trans);
5222         if (err < 0)
5223                 btrfs_handle_fs_error(fs_info, err,
5224                                       "failed to update qgroup status and info");
5225         err = btrfs_end_transaction(trans);
5226         if (err && !ret)
5227                 ret = err;
5228
5229 out:
5230         kfree(sa);
5231 drop_write:
5232         mnt_drop_write_file(file);
5233         return ret;
5234 }
5235
5236 static long btrfs_ioctl_qgroup_create(struct file *file, void __user *arg)
5237 {
5238         struct inode *inode = file_inode(file);
5239         struct btrfs_root *root = BTRFS_I(inode)->root;
5240         struct btrfs_ioctl_qgroup_create_args *sa;
5241         struct btrfs_trans_handle *trans;
5242         int ret;
5243         int err;
5244
5245         if (!capable(CAP_SYS_ADMIN))
5246                 return -EPERM;
5247
5248         ret = mnt_want_write_file(file);
5249         if (ret)
5250                 return ret;
5251
5252         sa = memdup_user(arg, sizeof(*sa));
5253         if (IS_ERR(sa)) {
5254                 ret = PTR_ERR(sa);
5255                 goto drop_write;
5256         }
5257
5258         if (!sa->qgroupid) {
5259                 ret = -EINVAL;
5260                 goto out;
5261         }
5262
5263         trans = btrfs_join_transaction(root);
5264         if (IS_ERR(trans)) {
5265                 ret = PTR_ERR(trans);
5266                 goto out;
5267         }
5268
5269         if (sa->create) {
5270                 ret = btrfs_create_qgroup(trans, sa->qgroupid);
5271         } else {
5272                 ret = btrfs_remove_qgroup(trans, sa->qgroupid);
5273         }
5274
5275         err = btrfs_end_transaction(trans);
5276         if (err && !ret)
5277                 ret = err;
5278
5279 out:
5280         kfree(sa);
5281 drop_write:
5282         mnt_drop_write_file(file);
5283         return ret;
5284 }
5285
5286 static long btrfs_ioctl_qgroup_limit(struct file *file, void __user *arg)
5287 {
5288         struct inode *inode = file_inode(file);
5289         struct btrfs_root *root = BTRFS_I(inode)->root;
5290         struct btrfs_ioctl_qgroup_limit_args *sa;
5291         struct btrfs_trans_handle *trans;
5292         int ret;
5293         int err;
5294         u64 qgroupid;
5295
5296         if (!capable(CAP_SYS_ADMIN))
5297                 return -EPERM;
5298
5299         ret = mnt_want_write_file(file);
5300         if (ret)
5301                 return ret;
5302
5303         sa = memdup_user(arg, sizeof(*sa));
5304         if (IS_ERR(sa)) {
5305                 ret = PTR_ERR(sa);
5306                 goto drop_write;
5307         }
5308
5309         trans = btrfs_join_transaction(root);
5310         if (IS_ERR(trans)) {
5311                 ret = PTR_ERR(trans);
5312                 goto out;
5313         }
5314
5315         qgroupid = sa->qgroupid;
5316         if (!qgroupid) {
5317                 /* take the current subvol as qgroup */
5318                 qgroupid = root->root_key.objectid;
5319         }
5320
5321         ret = btrfs_limit_qgroup(trans, qgroupid, &sa->lim);
5322
5323         err = btrfs_end_transaction(trans);
5324         if (err && !ret)
5325                 ret = err;
5326
5327 out:
5328         kfree(sa);
5329 drop_write:
5330         mnt_drop_write_file(file);
5331         return ret;
5332 }
5333
5334 static long btrfs_ioctl_quota_rescan(struct file *file, void __user *arg)
5335 {
5336         struct inode *inode = file_inode(file);
5337         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5338         struct btrfs_ioctl_quota_rescan_args *qsa;
5339         int ret;
5340
5341         if (!capable(CAP_SYS_ADMIN))
5342                 return -EPERM;
5343
5344         ret = mnt_want_write_file(file);
5345         if (ret)
5346                 return ret;
5347
5348         qsa = memdup_user(arg, sizeof(*qsa));
5349         if (IS_ERR(qsa)) {
5350                 ret = PTR_ERR(qsa);
5351                 goto drop_write;
5352         }
5353
5354         if (qsa->flags) {
5355                 ret = -EINVAL;
5356                 goto out;
5357         }
5358
5359         ret = btrfs_qgroup_rescan(fs_info);
5360
5361 out:
5362         kfree(qsa);
5363 drop_write:
5364         mnt_drop_write_file(file);
5365         return ret;
5366 }
5367
5368 static long btrfs_ioctl_quota_rescan_status(struct file *file, void __user *arg)
5369 {
5370         struct inode *inode = file_inode(file);
5371         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5372         struct btrfs_ioctl_quota_rescan_args *qsa;
5373         int ret = 0;
5374
5375         if (!capable(CAP_SYS_ADMIN))
5376                 return -EPERM;
5377
5378         qsa = kzalloc(sizeof(*qsa), GFP_KERNEL);
5379         if (!qsa)
5380                 return -ENOMEM;
5381
5382         if (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN) {
5383                 qsa->flags = 1;
5384                 qsa->progress = fs_info->qgroup_rescan_progress.objectid;
5385         }
5386
5387         if (copy_to_user(arg, qsa, sizeof(*qsa)))
5388                 ret = -EFAULT;
5389
5390         kfree(qsa);
5391         return ret;
5392 }
5393
5394 static long btrfs_ioctl_quota_rescan_wait(struct file *file, void __user *arg)
5395 {
5396         struct inode *inode = file_inode(file);
5397         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5398
5399         if (!capable(CAP_SYS_ADMIN))
5400                 return -EPERM;
5401
5402         return btrfs_qgroup_wait_for_completion(fs_info, true);
5403 }
5404
5405 static long _btrfs_ioctl_set_received_subvol(struct file *file,
5406                                             struct btrfs_ioctl_received_subvol_args *sa)
5407 {
5408         struct inode *inode = file_inode(file);
5409         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5410         struct btrfs_root *root = BTRFS_I(inode)->root;
5411         struct btrfs_root_item *root_item = &root->root_item;
5412         struct btrfs_trans_handle *trans;
5413         struct timespec64 ct = current_time(inode);
5414         int ret = 0;
5415         int received_uuid_changed;
5416
5417         if (!inode_owner_or_capable(inode))
5418                 return -EPERM;
5419
5420         ret = mnt_want_write_file(file);
5421         if (ret < 0)
5422                 return ret;
5423
5424         down_write(&fs_info->subvol_sem);
5425
5426         if (btrfs_ino(BTRFS_I(inode)) != BTRFS_FIRST_FREE_OBJECTID) {
5427                 ret = -EINVAL;
5428                 goto out;
5429         }
5430
5431         if (btrfs_root_readonly(root)) {
5432                 ret = -EROFS;
5433                 goto out;
5434         }
5435
5436         /*
5437          * 1 - root item
5438          * 2 - uuid items (received uuid + subvol uuid)
5439          */
5440         trans = btrfs_start_transaction(root, 3);
5441         if (IS_ERR(trans)) {
5442                 ret = PTR_ERR(trans);
5443                 trans = NULL;
5444                 goto out;
5445         }
5446
5447         sa->rtransid = trans->transid;
5448         sa->rtime.sec = ct.tv_sec;
5449         sa->rtime.nsec = ct.tv_nsec;
5450
5451         received_uuid_changed = memcmp(root_item->received_uuid, sa->uuid,
5452                                        BTRFS_UUID_SIZE);
5453         if (received_uuid_changed &&
5454             !btrfs_is_empty_uuid(root_item->received_uuid)) {
5455                 ret = btrfs_uuid_tree_remove(trans, root_item->received_uuid,
5456                                           BTRFS_UUID_KEY_RECEIVED_SUBVOL,
5457                                           root->root_key.objectid);
5458                 if (ret && ret != -ENOENT) {
5459                         btrfs_abort_transaction(trans, ret);
5460                         btrfs_end_transaction(trans);
5461                         goto out;
5462                 }
5463         }
5464         memcpy(root_item->received_uuid, sa->uuid, BTRFS_UUID_SIZE);
5465         btrfs_set_root_stransid(root_item, sa->stransid);
5466         btrfs_set_root_rtransid(root_item, sa->rtransid);
5467         btrfs_set_stack_timespec_sec(&root_item->stime, sa->stime.sec);
5468         btrfs_set_stack_timespec_nsec(&root_item->stime, sa->stime.nsec);
5469         btrfs_set_stack_timespec_sec(&root_item->rtime, sa->rtime.sec);
5470         btrfs_set_stack_timespec_nsec(&root_item->rtime, sa->rtime.nsec);
5471
5472         ret = btrfs_update_root(trans, fs_info->tree_root,
5473                                 &root->root_key, &root->root_item);
5474         if (ret < 0) {
5475                 btrfs_end_transaction(trans);
5476                 goto out;
5477         }
5478         if (received_uuid_changed && !btrfs_is_empty_uuid(sa->uuid)) {
5479                 ret = btrfs_uuid_tree_add(trans, sa->uuid,
5480                                           BTRFS_UUID_KEY_RECEIVED_SUBVOL,
5481                                           root->root_key.objectid);
5482                 if (ret < 0 && ret != -EEXIST) {
5483                         btrfs_abort_transaction(trans, ret);
5484                         btrfs_end_transaction(trans);
5485                         goto out;
5486                 }
5487         }
5488         ret = btrfs_commit_transaction(trans);
5489 out:
5490         up_write(&fs_info->subvol_sem);
5491         mnt_drop_write_file(file);
5492         return ret;
5493 }
5494
5495 #ifdef CONFIG_64BIT
5496 static long btrfs_ioctl_set_received_subvol_32(struct file *file,
5497                                                 void __user *arg)
5498 {
5499         struct btrfs_ioctl_received_subvol_args_32 *args32 = NULL;
5500         struct btrfs_ioctl_received_subvol_args *args64 = NULL;
5501         int ret = 0;
5502
5503         args32 = memdup_user(arg, sizeof(*args32));
5504         if (IS_ERR(args32))
5505                 return PTR_ERR(args32);
5506
5507         args64 = kmalloc(sizeof(*args64), GFP_KERNEL);
5508         if (!args64) {
5509                 ret = -ENOMEM;
5510                 goto out;
5511         }
5512
5513         memcpy(args64->uuid, args32->uuid, BTRFS_UUID_SIZE);
5514         args64->stransid = args32->stransid;
5515         args64->rtransid = args32->rtransid;
5516         args64->stime.sec = args32->stime.sec;
5517         args64->stime.nsec = args32->stime.nsec;
5518         args64->rtime.sec = args32->rtime.sec;
5519         args64->rtime.nsec = args32->rtime.nsec;
5520         args64->flags = args32->flags;
5521
5522         ret = _btrfs_ioctl_set_received_subvol(file, args64);
5523         if (ret)
5524                 goto out;
5525
5526         memcpy(args32->uuid, args64->uuid, BTRFS_UUID_SIZE);
5527         args32->stransid = args64->stransid;
5528         args32->rtransid = args64->rtransid;
5529         args32->stime.sec = args64->stime.sec;
5530         args32->stime.nsec = args64->stime.nsec;
5531         args32->rtime.sec = args64->rtime.sec;
5532         args32->rtime.nsec = args64->rtime.nsec;
5533         args32->flags = args64->flags;
5534
5535         ret = copy_to_user(arg, args32, sizeof(*args32));
5536         if (ret)
5537                 ret = -EFAULT;
5538
5539 out:
5540         kfree(args32);
5541         kfree(args64);
5542         return ret;
5543 }
5544 #endif
5545
5546 static long btrfs_ioctl_set_received_subvol(struct file *file,
5547                                             void __user *arg)
5548 {
5549         struct btrfs_ioctl_received_subvol_args *sa = NULL;
5550         int ret = 0;
5551
5552         sa = memdup_user(arg, sizeof(*sa));
5553         if (IS_ERR(sa))
5554                 return PTR_ERR(sa);
5555
5556         ret = _btrfs_ioctl_set_received_subvol(file, sa);
5557
5558         if (ret)
5559                 goto out;
5560
5561         ret = copy_to_user(arg, sa, sizeof(*sa));
5562         if (ret)
5563                 ret = -EFAULT;
5564
5565 out:
5566         kfree(sa);
5567         return ret;
5568 }
5569
5570 static int btrfs_ioctl_get_fslabel(struct file *file, void __user *arg)
5571 {
5572         struct inode *inode = file_inode(file);
5573         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5574         size_t len;
5575         int ret;
5576         char label[BTRFS_LABEL_SIZE];
5577
5578         spin_lock(&fs_info->super_lock);
5579         memcpy(label, fs_info->super_copy->label, BTRFS_LABEL_SIZE);
5580         spin_unlock(&fs_info->super_lock);
5581
5582         len = strnlen(label, BTRFS_LABEL_SIZE);
5583
5584         if (len == BTRFS_LABEL_SIZE) {
5585                 btrfs_warn(fs_info,
5586                            "label is too long, return the first %zu bytes",
5587                            --len);
5588         }
5589
5590         ret = copy_to_user(arg, label, len);
5591
5592         return ret ? -EFAULT : 0;
5593 }
5594
5595 static int btrfs_ioctl_set_fslabel(struct file *file, void __user *arg)
5596 {
5597         struct inode *inode = file_inode(file);
5598         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5599         struct btrfs_root *root = BTRFS_I(inode)->root;
5600         struct btrfs_super_block *super_block = fs_info->super_copy;
5601         struct btrfs_trans_handle *trans;
5602         char label[BTRFS_LABEL_SIZE];
5603         int ret;
5604
5605         if (!capable(CAP_SYS_ADMIN))
5606                 return -EPERM;
5607
5608         if (copy_from_user(label, arg, sizeof(label)))
5609                 return -EFAULT;
5610
5611         if (strnlen(label, BTRFS_LABEL_SIZE) == BTRFS_LABEL_SIZE) {
5612                 btrfs_err(fs_info,
5613                           "unable to set label with more than %d bytes",
5614                           BTRFS_LABEL_SIZE - 1);
5615                 return -EINVAL;
5616         }
5617
5618         ret = mnt_want_write_file(file);
5619         if (ret)
5620                 return ret;
5621
5622         trans = btrfs_start_transaction(root, 0);
5623         if (IS_ERR(trans)) {
5624                 ret = PTR_ERR(trans);
5625                 goto out_unlock;
5626         }
5627
5628         spin_lock(&fs_info->super_lock);
5629         strcpy(super_block->label, label);
5630         spin_unlock(&fs_info->super_lock);
5631         ret = btrfs_commit_transaction(trans);
5632
5633 out_unlock:
5634         mnt_drop_write_file(file);
5635         return ret;
5636 }
5637
5638 #define INIT_FEATURE_FLAGS(suffix) \
5639         { .compat_flags = BTRFS_FEATURE_COMPAT_##suffix, \
5640           .compat_ro_flags = BTRFS_FEATURE_COMPAT_RO_##suffix, \
5641           .incompat_flags = BTRFS_FEATURE_INCOMPAT_##suffix }
5642
5643 int btrfs_ioctl_get_supported_features(void __user *arg)
5644 {
5645         static const struct btrfs_ioctl_feature_flags features[3] = {
5646                 INIT_FEATURE_FLAGS(SUPP),
5647                 INIT_FEATURE_FLAGS(SAFE_SET),
5648                 INIT_FEATURE_FLAGS(SAFE_CLEAR)
5649         };
5650
5651         if (copy_to_user(arg, &features, sizeof(features)))
5652                 return -EFAULT;
5653
5654         return 0;
5655 }
5656
5657 static int btrfs_ioctl_get_features(struct file *file, void __user *arg)
5658 {
5659         struct inode *inode = file_inode(file);
5660         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5661         struct btrfs_super_block *super_block = fs_info->super_copy;
5662         struct btrfs_ioctl_feature_flags features;
5663
5664         features.compat_flags = btrfs_super_compat_flags(super_block);
5665         features.compat_ro_flags = btrfs_super_compat_ro_flags(super_block);
5666         features.incompat_flags = btrfs_super_incompat_flags(super_block);
5667
5668         if (copy_to_user(arg, &features, sizeof(features)))
5669                 return -EFAULT;
5670
5671         return 0;
5672 }
5673
5674 static int check_feature_bits(struct btrfs_fs_info *fs_info,
5675                               enum btrfs_feature_set set,
5676                               u64 change_mask, u64 flags, u64 supported_flags,
5677                               u64 safe_set, u64 safe_clear)
5678 {
5679         const char *type = btrfs_feature_set_names[set];
5680         char *names;
5681         u64 disallowed, unsupported;
5682         u64 set_mask = flags & change_mask;
5683         u64 clear_mask = ~flags & change_mask;
5684
5685         unsupported = set_mask & ~supported_flags;
5686         if (unsupported) {
5687                 names = btrfs_printable_features(set, unsupported);
5688                 if (names) {
5689                         btrfs_warn(fs_info,
5690                                    "this kernel does not support the %s feature bit%s",
5691                                    names, strchr(names, ',') ? "s" : "");
5692                         kfree(names);
5693                 } else
5694                         btrfs_warn(fs_info,
5695                                    "this kernel does not support %s bits 0x%llx",
5696                                    type, unsupported);
5697                 return -EOPNOTSUPP;
5698         }
5699
5700         disallowed = set_mask & ~safe_set;
5701         if (disallowed) {
5702                 names = btrfs_printable_features(set, disallowed);
5703                 if (names) {
5704                         btrfs_warn(fs_info,
5705                                    "can't set the %s feature bit%s while mounted",
5706                                    names, strchr(names, ',') ? "s" : "");
5707                         kfree(names);
5708                 } else
5709                         btrfs_warn(fs_info,
5710                                    "can't set %s bits 0x%llx while mounted",
5711                                    type, disallowed);
5712                 return -EPERM;
5713         }
5714
5715         disallowed = clear_mask & ~safe_clear;
5716         if (disallowed) {
5717                 names = btrfs_printable_features(set, disallowed);
5718                 if (names) {
5719                         btrfs_warn(fs_info,
5720                                    "can't clear the %s feature bit%s while mounted",
5721                                    names, strchr(names, ',') ? "s" : "");
5722                         kfree(names);
5723                 } else
5724                         btrfs_warn(fs_info,
5725                                    "can't clear %s bits 0x%llx while mounted",
5726                                    type, disallowed);
5727                 return -EPERM;
5728         }
5729
5730         return 0;
5731 }
5732
5733 #define check_feature(fs_info, change_mask, flags, mask_base)   \
5734 check_feature_bits(fs_info, FEAT_##mask_base, change_mask, flags,       \
5735                    BTRFS_FEATURE_ ## mask_base ## _SUPP,        \
5736                    BTRFS_FEATURE_ ## mask_base ## _SAFE_SET,    \
5737                    BTRFS_FEATURE_ ## mask_base ## _SAFE_CLEAR)
5738
5739 static int btrfs_ioctl_set_features(struct file *file, void __user *arg)
5740 {
5741         struct inode *inode = file_inode(file);
5742         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5743         struct btrfs_root *root = BTRFS_I(inode)->root;
5744         struct btrfs_super_block *super_block = fs_info->super_copy;
5745         struct btrfs_ioctl_feature_flags flags[2];
5746         struct btrfs_trans_handle *trans;
5747         u64 newflags;
5748         int ret;
5749
5750         if (!capable(CAP_SYS_ADMIN))
5751                 return -EPERM;
5752
5753         if (copy_from_user(flags, arg, sizeof(flags)))
5754                 return -EFAULT;
5755
5756         /* Nothing to do */
5757         if (!flags[0].compat_flags && !flags[0].compat_ro_flags &&
5758             !flags[0].incompat_flags)
5759                 return 0;
5760
5761         ret = check_feature(fs_info, flags[0].compat_flags,
5762                             flags[1].compat_flags, COMPAT);
5763         if (ret)
5764                 return ret;
5765
5766         ret = check_feature(fs_info, flags[0].compat_ro_flags,
5767                             flags[1].compat_ro_flags, COMPAT_RO);
5768         if (ret)
5769                 return ret;
5770
5771         ret = check_feature(fs_info, flags[0].incompat_flags,
5772                             flags[1].incompat_flags, INCOMPAT);
5773         if (ret)
5774                 return ret;
5775
5776         ret = mnt_want_write_file(file);
5777         if (ret)
5778                 return ret;
5779
5780         trans = btrfs_start_transaction(root, 0);
5781         if (IS_ERR(trans)) {
5782                 ret = PTR_ERR(trans);
5783                 goto out_drop_write;
5784         }
5785
5786         spin_lock(&fs_info->super_lock);
5787         newflags = btrfs_super_compat_flags(super_block);
5788         newflags |= flags[0].compat_flags & flags[1].compat_flags;
5789         newflags &= ~(flags[0].compat_flags & ~flags[1].compat_flags);
5790         btrfs_set_super_compat_flags(super_block, newflags);
5791
5792         newflags = btrfs_super_compat_ro_flags(super_block);
5793         newflags |= flags[0].compat_ro_flags & flags[1].compat_ro_flags;
5794         newflags &= ~(flags[0].compat_ro_flags & ~flags[1].compat_ro_flags);
5795         btrfs_set_super_compat_ro_flags(super_block, newflags);
5796
5797         newflags = btrfs_super_incompat_flags(super_block);
5798         newflags |= flags[0].incompat_flags & flags[1].incompat_flags;
5799         newflags &= ~(flags[0].incompat_flags & ~flags[1].incompat_flags);
5800         btrfs_set_super_incompat_flags(super_block, newflags);
5801         spin_unlock(&fs_info->super_lock);
5802
5803         ret = btrfs_commit_transaction(trans);
5804 out_drop_write:
5805         mnt_drop_write_file(file);
5806
5807         return ret;
5808 }
5809
5810 static int _btrfs_ioctl_send(struct file *file, void __user *argp, bool compat)
5811 {
5812         struct btrfs_ioctl_send_args *arg;
5813         int ret;
5814
5815         if (compat) {
5816 #if defined(CONFIG_64BIT) && defined(CONFIG_COMPAT)
5817                 struct btrfs_ioctl_send_args_32 args32;
5818
5819                 ret = copy_from_user(&args32, argp, sizeof(args32));
5820                 if (ret)
5821                         return -EFAULT;
5822                 arg = kzalloc(sizeof(*arg), GFP_KERNEL);
5823                 if (!arg)
5824                         return -ENOMEM;
5825                 arg->send_fd = args32.send_fd;
5826                 arg->clone_sources_count = args32.clone_sources_count;
5827                 arg->clone_sources = compat_ptr(args32.clone_sources);
5828                 arg->parent_root = args32.parent_root;
5829                 arg->flags = args32.flags;
5830                 memcpy(arg->reserved, args32.reserved,
5831                        sizeof(args32.reserved));
5832 #else
5833                 return -ENOTTY;
5834 #endif
5835         } else {
5836                 arg = memdup_user(argp, sizeof(*arg));
5837                 if (IS_ERR(arg))
5838                         return PTR_ERR(arg);
5839         }
5840         ret = btrfs_ioctl_send(file, arg);
5841         kfree(arg);
5842         return ret;
5843 }
5844
5845 long btrfs_ioctl(struct file *file, unsigned int
5846                 cmd, unsigned long arg)
5847 {
5848         struct inode *inode = file_inode(file);
5849         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5850         struct btrfs_root *root = BTRFS_I(inode)->root;
5851         void __user *argp = (void __user *)arg;
5852
5853         switch (cmd) {
5854         case FS_IOC_GETFLAGS:
5855                 return btrfs_ioctl_getflags(file, argp);
5856         case FS_IOC_SETFLAGS:
5857                 return btrfs_ioctl_setflags(file, argp);
5858         case FS_IOC_GETVERSION:
5859                 return btrfs_ioctl_getversion(file, argp);
5860         case FITRIM:
5861                 return btrfs_ioctl_fitrim(file, argp);
5862         case BTRFS_IOC_SNAP_CREATE:
5863                 return btrfs_ioctl_snap_create(file, argp, 0);
5864         case BTRFS_IOC_SNAP_CREATE_V2:
5865                 return btrfs_ioctl_snap_create_v2(file, argp, 0);
5866         case BTRFS_IOC_SUBVOL_CREATE:
5867                 return btrfs_ioctl_snap_create(file, argp, 1);
5868         case BTRFS_IOC_SUBVOL_CREATE_V2:
5869                 return btrfs_ioctl_snap_create_v2(file, argp, 1);
5870         case BTRFS_IOC_SNAP_DESTROY:
5871                 return btrfs_ioctl_snap_destroy(file, argp);
5872         case BTRFS_IOC_SUBVOL_GETFLAGS:
5873                 return btrfs_ioctl_subvol_getflags(file, argp);
5874         case BTRFS_IOC_SUBVOL_SETFLAGS:
5875                 return btrfs_ioctl_subvol_setflags(file, argp);
5876         case BTRFS_IOC_DEFAULT_SUBVOL:
5877                 return btrfs_ioctl_default_subvol(file, argp);
5878         case BTRFS_IOC_DEFRAG:
5879                 return btrfs_ioctl_defrag(file, NULL);
5880         case BTRFS_IOC_DEFRAG_RANGE:
5881                 return btrfs_ioctl_defrag(file, argp);
5882         case BTRFS_IOC_RESIZE:
5883                 return btrfs_ioctl_resize(file, argp);
5884         case BTRFS_IOC_ADD_DEV:
5885                 return btrfs_ioctl_add_dev(fs_info, argp);
5886         case BTRFS_IOC_RM_DEV:
5887                 return btrfs_ioctl_rm_dev(file, argp);
5888         case BTRFS_IOC_RM_DEV_V2:
5889                 return btrfs_ioctl_rm_dev_v2(file, argp);
5890         case BTRFS_IOC_FS_INFO:
5891                 return btrfs_ioctl_fs_info(fs_info, argp);
5892         case BTRFS_IOC_DEV_INFO:
5893                 return btrfs_ioctl_dev_info(fs_info, argp);
5894         case BTRFS_IOC_BALANCE:
5895                 return btrfs_ioctl_balance(file, NULL);
5896         case BTRFS_IOC_TREE_SEARCH:
5897                 return btrfs_ioctl_tree_search(file, argp);
5898         case BTRFS_IOC_TREE_SEARCH_V2:
5899                 return btrfs_ioctl_tree_search_v2(file, argp);
5900         case BTRFS_IOC_INO_LOOKUP:
5901                 return btrfs_ioctl_ino_lookup(file, argp);
5902         case BTRFS_IOC_INO_PATHS:
5903                 return btrfs_ioctl_ino_to_path(root, argp);
5904         case BTRFS_IOC_LOGICAL_INO:
5905                 return btrfs_ioctl_logical_to_ino(fs_info, argp, 1);
5906         case BTRFS_IOC_LOGICAL_INO_V2:
5907                 return btrfs_ioctl_logical_to_ino(fs_info, argp, 2);
5908         case BTRFS_IOC_SPACE_INFO:
5909                 return btrfs_ioctl_space_info(fs_info, argp);
5910         case BTRFS_IOC_SYNC: {
5911                 int ret;
5912
5913                 ret = btrfs_start_delalloc_roots(fs_info, -1);
5914                 if (ret)
5915                         return ret;
5916                 ret = btrfs_sync_fs(inode->i_sb, 1);
5917                 /*
5918                  * The transaction thread may want to do more work,
5919                  * namely it pokes the cleaner kthread that will start
5920                  * processing uncleaned subvols.
5921                  */
5922                 wake_up_process(fs_info->transaction_kthread);
5923                 return ret;
5924         }
5925         case BTRFS_IOC_START_SYNC:
5926                 return btrfs_ioctl_start_sync(root, argp);
5927         case BTRFS_IOC_WAIT_SYNC:
5928                 return btrfs_ioctl_wait_sync(fs_info, argp);
5929         case BTRFS_IOC_SCRUB:
5930                 return btrfs_ioctl_scrub(file, argp);
5931         case BTRFS_IOC_SCRUB_CANCEL:
5932                 return btrfs_ioctl_scrub_cancel(fs_info);
5933         case BTRFS_IOC_SCRUB_PROGRESS:
5934                 return btrfs_ioctl_scrub_progress(fs_info, argp);
5935         case BTRFS_IOC_BALANCE_V2:
5936                 return btrfs_ioctl_balance(file, argp);
5937         case BTRFS_IOC_BALANCE_CTL:
5938                 return btrfs_ioctl_balance_ctl(fs_info, arg);
5939         case BTRFS_IOC_BALANCE_PROGRESS:
5940                 return btrfs_ioctl_balance_progress(fs_info, argp);
5941         case BTRFS_IOC_SET_RECEIVED_SUBVOL:
5942                 return btrfs_ioctl_set_received_subvol(file, argp);
5943 #ifdef CONFIG_64BIT
5944         case BTRFS_IOC_SET_RECEIVED_SUBVOL_32:
5945                 return btrfs_ioctl_set_received_subvol_32(file, argp);
5946 #endif
5947         case BTRFS_IOC_SEND:
5948                 return _btrfs_ioctl_send(file, argp, false);
5949 #if defined(CONFIG_64BIT) && defined(CONFIG_COMPAT)
5950         case BTRFS_IOC_SEND_32:
5951                 return _btrfs_ioctl_send(file, argp, true);
5952 #endif
5953         case BTRFS_IOC_GET_DEV_STATS:
5954                 return btrfs_ioctl_get_dev_stats(fs_info, argp);
5955         case BTRFS_IOC_QUOTA_CTL:
5956                 return btrfs_ioctl_quota_ctl(file, argp);
5957         case BTRFS_IOC_QGROUP_ASSIGN:
5958                 return btrfs_ioctl_qgroup_assign(file, argp);
5959         case BTRFS_IOC_QGROUP_CREATE:
5960                 return btrfs_ioctl_qgroup_create(file, argp);
5961         case BTRFS_IOC_QGROUP_LIMIT:
5962                 return btrfs_ioctl_qgroup_limit(file, argp);
5963         case BTRFS_IOC_QUOTA_RESCAN:
5964                 return btrfs_ioctl_quota_rescan(file, argp);
5965         case BTRFS_IOC_QUOTA_RESCAN_STATUS:
5966                 return btrfs_ioctl_quota_rescan_status(file, argp);
5967         case BTRFS_IOC_QUOTA_RESCAN_WAIT:
5968                 return btrfs_ioctl_quota_rescan_wait(file, argp);
5969         case BTRFS_IOC_DEV_REPLACE:
5970                 return btrfs_ioctl_dev_replace(fs_info, argp);
5971         case BTRFS_IOC_GET_FSLABEL:
5972                 return btrfs_ioctl_get_fslabel(file, argp);
5973         case BTRFS_IOC_SET_FSLABEL:
5974                 return btrfs_ioctl_set_fslabel(file, argp);
5975         case BTRFS_IOC_GET_SUPPORTED_FEATURES:
5976                 return btrfs_ioctl_get_supported_features(argp);
5977         case BTRFS_IOC_GET_FEATURES:
5978                 return btrfs_ioctl_get_features(file, argp);
5979         case BTRFS_IOC_SET_FEATURES:
5980                 return btrfs_ioctl_set_features(file, argp);
5981         case FS_IOC_FSGETXATTR:
5982                 return btrfs_ioctl_fsgetxattr(file, argp);
5983         case FS_IOC_FSSETXATTR:
5984                 return btrfs_ioctl_fssetxattr(file, argp);
5985         case BTRFS_IOC_GET_SUBVOL_INFO:
5986                 return btrfs_ioctl_get_subvol_info(file, argp);
5987         case BTRFS_IOC_GET_SUBVOL_ROOTREF:
5988                 return btrfs_ioctl_get_subvol_rootref(file, argp);
5989         case BTRFS_IOC_INO_LOOKUP_USER:
5990                 return btrfs_ioctl_ino_lookup_user(file, argp);
5991         }
5992
5993         return -ENOTTY;
5994 }
5995
5996 #ifdef CONFIG_COMPAT
5997 long btrfs_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
5998 {
5999         /*
6000          * These all access 32-bit values anyway so no further
6001          * handling is necessary.
6002          */
6003         switch (cmd) {
6004         case FS_IOC32_GETFLAGS:
6005                 cmd = FS_IOC_GETFLAGS;
6006                 break;
6007         case FS_IOC32_SETFLAGS:
6008                 cmd = FS_IOC_SETFLAGS;
6009                 break;
6010         case FS_IOC32_GETVERSION:
6011                 cmd = FS_IOC_GETVERSION;
6012                 break;
6013         }
6014
6015         return btrfs_ioctl(file, cmd, (unsigned long) compat_ptr(arg));
6016 }
6017 #endif