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