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 <linux/fileattr.h>
  30 #include <linux/fsverity.h>
  31 #include <linux/sched/xacct.h>
  32 #include <linux/io_uring/cmd.h>
  33 #include "ctree.h"
  34 #include "disk-io.h"
  35 #include "export.h"
  36 #include "transaction.h"
  37 #include "btrfs_inode.h"
  38 #include "volumes.h"
  39 #include "locking.h"
  40 #include "backref.h"
  41 #include "send.h"
  42 #include "dev-replace.h"
  43 #include "props.h"
  44 #include "sysfs.h"
  45 #include "qgroup.h"
  46 #include "tree-log.h"
  47 #include "compression.h"
  48 #include "space-info.h"
  49 #include "block-group.h"
  50 #include "fs.h"
  51 #include "accessors.h"
  52 #include "extent-tree.h"
  53 #include "root-tree.h"
  54 #include "defrag.h"
  55 #include "dir-item.h"
  56 #include "uuid-tree.h"
  57 #include "ioctl.h"
  58 #include "file.h"
  59 #include "scrub.h"
  60 #include "super.h"
  61
  62 #ifdef CONFIG_64BIT
  63 /* If we have a 32-bit userspace and 64-bit kernel, then the UAPI
  64  * structures are incorrect, as the timespec structure from userspace
  65  * is 4 bytes too small. We define these alternatives here to teach
  66  * the kernel about the 32-bit struct packing.
  67  */
  68 struct btrfs_ioctl_timespec_32 {
  69         __u64 sec;
  70         __u32 nsec;
  71 } __attribute__ ((__packed__));
  72
  73 struct btrfs_ioctl_received_subvol_args_32 {
  74         char    uuid[BTRFS_UUID_SIZE];  /* in */
  75         __u64   stransid;               /* in */
  76         __u64   rtransid;               /* out */
  77         struct btrfs_ioctl_timespec_32 stime; /* in */
  78         struct btrfs_ioctl_timespec_32 rtime; /* out */
  79         __u64   flags;                  /* in */
  80         __u64   reserved[16];           /* in */
  81 } __attribute__ ((__packed__));
  82
  83 #define BTRFS_IOC_SET_RECEIVED_SUBVOL_32 _IOWR(BTRFS_IOCTL_MAGIC, 37, \
  84                                 struct btrfs_ioctl_received_subvol_args_32)
  85 #endif
  86
  87 #if defined(CONFIG_64BIT) && defined(CONFIG_COMPAT)
  88 struct btrfs_ioctl_send_args_32 {
  89         __s64 send_fd;                  /* in */
  90         __u64 clone_sources_count;      /* in */
  91         compat_uptr_t clone_sources;    /* in */
  92         __u64 parent_root;              /* in */
  93         __u64 flags;                    /* in */
  94         __u32 version;                  /* in */
  95         __u8  reserved[28];             /* in */
  96 } __attribute__ ((__packed__));
  97
  98 #define BTRFS_IOC_SEND_32 _IOW(BTRFS_IOCTL_MAGIC, 38, \
  99                                struct btrfs_ioctl_send_args_32)
 100
 101 struct btrfs_ioctl_encoded_io_args_32 {
 102         compat_uptr_t iov;
 103         compat_ulong_t iovcnt;
 104         __s64 offset;
 105         __u64 flags;
 106         __u64 len;
 107         __u64 unencoded_len;
 108         __u64 unencoded_offset;
 109         __u32 compression;
 110         __u32 encryption;
 111         __u8 reserved[64];
 112 };
 113
 114 #define BTRFS_IOC_ENCODED_READ_32 _IOR(BTRFS_IOCTL_MAGIC, 64, \
 115                                        struct btrfs_ioctl_encoded_io_args_32)
 116 #define BTRFS_IOC_ENCODED_WRITE_32 _IOW(BTRFS_IOCTL_MAGIC, 64, \
 117                                         struct btrfs_ioctl_encoded_io_args_32)
 118 #endif
 119
 120 /* Mask out flags that are inappropriate for the given type of inode. */
 121 static unsigned int btrfs_mask_fsflags_for_type(struct inode *inode,
 122                 unsigned int flags)
 123 {
 124         if (S_ISDIR(inode->i_mode))
 125                 return flags;
 126         else if (S_ISREG(inode->i_mode))
 127                 return flags & ~FS_DIRSYNC_FL;
 128         else
 129                 return flags & (FS_NODUMP_FL | FS_NOATIME_FL);
 130 }
 131
 132 /*
 133  * Export internal inode flags to the format expected by the FS_IOC_GETFLAGS
 134  * ioctl.
 135  */
 136 static unsigned int btrfs_inode_flags_to_fsflags(struct btrfs_inode *binode)
 137 {
 138         unsigned int iflags = 0;
 139         u32 flags = binode->flags;
 140         u32 ro_flags = binode->ro_flags;
 141
 142         if (flags & BTRFS_INODE_SYNC)
 143                 iflags |= FS_SYNC_FL;
 144         if (flags & BTRFS_INODE_IMMUTABLE)
 145                 iflags |= FS_IMMUTABLE_FL;
 146         if (flags & BTRFS_INODE_APPEND)
 147                 iflags |= FS_APPEND_FL;
 148         if (flags & BTRFS_INODE_NODUMP)
 149                 iflags |= FS_NODUMP_FL;
 150         if (flags & BTRFS_INODE_NOATIME)
 151                 iflags |= FS_NOATIME_FL;
 152         if (flags & BTRFS_INODE_DIRSYNC)
 153                 iflags |= FS_DIRSYNC_FL;
 154         if (flags & BTRFS_INODE_NODATACOW)
 155                 iflags |= FS_NOCOW_FL;
 156         if (ro_flags & BTRFS_INODE_RO_VERITY)
 157                 iflags |= FS_VERITY_FL;
 158
 159         if (flags & BTRFS_INODE_NOCOMPRESS)
 160                 iflags |= FS_NOCOMP_FL;
 161         else if (flags & BTRFS_INODE_COMPRESS)
 162                 iflags |= FS_COMPR_FL;
 163
 164         return iflags;
 165 }
 166
 167 /*
 168  * Update inode->i_flags based on the btrfs internal flags.
 169  */
 170 void btrfs_sync_inode_flags_to_i_flags(struct inode *inode)
 171 {
 172         struct btrfs_inode *binode = BTRFS_I(inode);
 173         unsigned int new_fl = 0;
 174
 175         if (binode->flags & BTRFS_INODE_SYNC)
 176                 new_fl |= S_SYNC;
 177         if (binode->flags & BTRFS_INODE_IMMUTABLE)
 178                 new_fl |= S_IMMUTABLE;
 179         if (binode->flags & BTRFS_INODE_APPEND)
 180                 new_fl |= S_APPEND;
 181         if (binode->flags & BTRFS_INODE_NOATIME)
 182                 new_fl |= S_NOATIME;
 183         if (binode->flags & BTRFS_INODE_DIRSYNC)
 184                 new_fl |= S_DIRSYNC;
 185         if (binode->ro_flags & BTRFS_INODE_RO_VERITY)
 186                 new_fl |= S_VERITY;
 187
 188         set_mask_bits(&inode->i_flags,
 189                       S_SYNC | S_APPEND | S_IMMUTABLE | S_NOATIME | S_DIRSYNC |
 190                       S_VERITY, new_fl);
 191 }
 192
 193 /*
 194  * Check if @flags are a supported and valid set of FS_*_FL flags and that
 195  * the old and new flags are not conflicting
 196  */
 197 static int check_fsflags(unsigned int old_flags, unsigned int flags)
 198 {
 199         if (flags & ~(FS_IMMUTABLE_FL | FS_APPEND_FL | \
 200                       FS_NOATIME_FL | FS_NODUMP_FL | \
 201                       FS_SYNC_FL | FS_DIRSYNC_FL | \
 202                       FS_NOCOMP_FL | FS_COMPR_FL |
 203                       FS_NOCOW_FL))
 204                 return -EOPNOTSUPP;
 205
 206         /* COMPR and NOCOMP on new/old are valid */
 207         if ((flags & FS_NOCOMP_FL) && (flags & FS_COMPR_FL))
 208                 return -EINVAL;
 209
 210         if ((flags & FS_COMPR_FL) && (flags & FS_NOCOW_FL))
 211                 return -EINVAL;
 212
 213         /* NOCOW and compression options are mutually exclusive */
 214         if ((old_flags & FS_NOCOW_FL) && (flags & (FS_COMPR_FL | FS_NOCOMP_FL)))
 215                 return -EINVAL;
 216         if ((flags & FS_NOCOW_FL) && (old_flags & (FS_COMPR_FL | FS_NOCOMP_FL)))
 217                 return -EINVAL;
 218
 219         return 0;
 220 }
 221
 222 static int check_fsflags_compatible(struct btrfs_fs_info *fs_info,
 223                                     unsigned int flags)
 224 {
 225         if (btrfs_is_zoned(fs_info) && (flags & FS_NOCOW_FL))
 226                 return -EPERM;
 227
 228         return 0;
 229 }
 230
 231 int btrfs_check_ioctl_vol_args_path(const struct btrfs_ioctl_vol_args *vol_args)
 232 {
 233         if (memchr(vol_args->name, 0, sizeof(vol_args->name)) == NULL)
 234                 return -ENAMETOOLONG;
 235         return 0;
 236 }
 237
 238 static int btrfs_check_ioctl_vol_args2_subvol_name(const struct btrfs_ioctl_vol_args_v2 *vol_args2)
 239 {
 240         if (memchr(vol_args2->name, 0, sizeof(vol_args2->name)) == NULL)
 241                 return -ENAMETOOLONG;
 242         return 0;
 243 }
 244
 245 /*
 246  * Set flags/xflags from the internal inode flags. The remaining items of
 247  * fsxattr are zeroed.
 248  */
 249 int btrfs_fileattr_get(struct dentry *dentry, struct fileattr *fa)
 250 {
 251         struct btrfs_inode *binode = BTRFS_I(d_inode(dentry));
 252
 253         fileattr_fill_flags(fa, btrfs_inode_flags_to_fsflags(binode));
 254         return 0;
 255 }
 256
 257 int btrfs_fileattr_set(struct mnt_idmap *idmap,
 258                        struct dentry *dentry, struct fileattr *fa)
 259 {
 260         struct inode *inode = d_inode(dentry);
 261         struct btrfs_fs_info *fs_info = inode_to_fs_info(inode);
 262         struct btrfs_inode *binode = BTRFS_I(inode);
 263         struct btrfs_root *root = binode->root;
 264         struct btrfs_trans_handle *trans;
 265         unsigned int fsflags, old_fsflags;
 266         int ret;
 267         const char *comp = NULL;
 268         u32 binode_flags;
 269
 270         if (btrfs_root_readonly(root))
 271                 return -EROFS;
 272
 273         if (fileattr_has_fsx(fa))
 274                 return -EOPNOTSUPP;
 275
 276         fsflags = btrfs_mask_fsflags_for_type(inode, fa->flags);
 277         old_fsflags = btrfs_inode_flags_to_fsflags(binode);
 278         ret = check_fsflags(old_fsflags, fsflags);
 279         if (ret)
 280                 return ret;
 281
 282         ret = check_fsflags_compatible(fs_info, fsflags);
 283         if (ret)
 284                 return ret;
 285
 286         binode_flags = binode->flags;
 287         if (fsflags & FS_SYNC_FL)
 288                 binode_flags |= BTRFS_INODE_SYNC;
 289         else
 290                 binode_flags &= ~BTRFS_INODE_SYNC;
 291         if (fsflags & FS_IMMUTABLE_FL)
 292                 binode_flags |= BTRFS_INODE_IMMUTABLE;
 293         else
 294                 binode_flags &= ~BTRFS_INODE_IMMUTABLE;
 295         if (fsflags & FS_APPEND_FL)
 296                 binode_flags |= BTRFS_INODE_APPEND;
 297         else
 298                 binode_flags &= ~BTRFS_INODE_APPEND;
 299         if (fsflags & FS_NODUMP_FL)
 300                 binode_flags |= BTRFS_INODE_NODUMP;
 301         else
 302                 binode_flags &= ~BTRFS_INODE_NODUMP;
 303         if (fsflags & FS_NOATIME_FL)
 304                 binode_flags |= BTRFS_INODE_NOATIME;
 305         else
 306                 binode_flags &= ~BTRFS_INODE_NOATIME;
 307
 308         /* If coming from FS_IOC_FSSETXATTR then skip unconverted flags */
 309         if (!fa->flags_valid) {
 310                 /* 1 item for the inode */
 311                 trans = btrfs_start_transaction(root, 1);
 312                 if (IS_ERR(trans))
 313                         return PTR_ERR(trans);
 314                 goto update_flags;
 315         }
 316
 317         if (fsflags & FS_DIRSYNC_FL)
 318                 binode_flags |= BTRFS_INODE_DIRSYNC;
 319         else
 320                 binode_flags &= ~BTRFS_INODE_DIRSYNC;
 321         if (fsflags & FS_NOCOW_FL) {
 322                 if (S_ISREG(inode->i_mode)) {
 323                         /*
 324                          * It's safe to turn csums off here, no extents exist.
 325                          * Otherwise we want the flag to reflect the real COW
 326                          * status of the file and will not set it.
 327                          */
 328                         if (inode->i_size == 0)
 329                                 binode_flags |= BTRFS_INODE_NODATACOW |
 330                                                 BTRFS_INODE_NODATASUM;
 331                 } else {
 332                         binode_flags |= BTRFS_INODE_NODATACOW;
 333                 }
 334         } else {
 335                 /*
 336                  * Revert back under same assumptions as above
 337                  */
 338                 if (S_ISREG(inode->i_mode)) {
 339                         if (inode->i_size == 0)
 340                                 binode_flags &= ~(BTRFS_INODE_NODATACOW |
 341                                                   BTRFS_INODE_NODATASUM);
 342                 } else {
 343                         binode_flags &= ~BTRFS_INODE_NODATACOW;
 344                 }
 345         }
 346
 347         /*
 348          * The COMPRESS flag can only be changed by users, while the NOCOMPRESS
 349          * flag may be changed automatically if compression code won't make
 350          * things smaller.
 351          */
 352         if (fsflags & FS_NOCOMP_FL) {
 353                 binode_flags &= ~BTRFS_INODE_COMPRESS;
 354                 binode_flags |= BTRFS_INODE_NOCOMPRESS;
 355         } else if (fsflags & FS_COMPR_FL) {
 356
 357                 if (IS_SWAPFILE(inode))
 358                         return -ETXTBSY;
 359
 360                 binode_flags |= BTRFS_INODE_COMPRESS;
 361                 binode_flags &= ~BTRFS_INODE_NOCOMPRESS;
 362
 363                 comp = btrfs_compress_type2str(fs_info->compress_type);
 364                 if (!comp || comp[0] == 0)
 365                         comp = btrfs_compress_type2str(BTRFS_COMPRESS_ZLIB);
 366         } else {
 367                 binode_flags &= ~(BTRFS_INODE_COMPRESS | BTRFS_INODE_NOCOMPRESS);
 368         }
 369
 370         /*
 371          * 1 for inode item
 372          * 2 for properties
 373          */
 374         trans = btrfs_start_transaction(root, 3);
 375         if (IS_ERR(trans))
 376                 return PTR_ERR(trans);
 377
 378         if (comp) {
 379                 ret = btrfs_set_prop(trans, BTRFS_I(inode), "btrfs.compression",
 380                                      comp, strlen(comp), 0);
 381                 if (ret) {
 382                         btrfs_abort_transaction(trans, ret);
 383                         goto out_end_trans;
 384                 }
 385         } else {
 386                 ret = btrfs_set_prop(trans, BTRFS_I(inode), "btrfs.compression",
 387                                      NULL, 0, 0);
 388                 if (ret && ret != -ENODATA) {
 389                         btrfs_abort_transaction(trans, ret);
 390                         goto out_end_trans;
 391                 }
 392         }
 393
 394 update_flags:
 395         binode->flags = binode_flags;
 396         btrfs_sync_inode_flags_to_i_flags(inode);
 397         inode_inc_iversion(inode);
 398         inode_set_ctime_current(inode);
 399         ret = btrfs_update_inode(trans, BTRFS_I(inode));
 400
 401  out_end_trans:
 402         btrfs_end_transaction(trans);
 403         return ret;
 404 }
 405
 406 /*
 407  * Start exclusive operation @type, return true on success
 408  */
 409 bool btrfs_exclop_start(struct btrfs_fs_info *fs_info,
 410                         enum btrfs_exclusive_operation type)
 411 {
 412         bool ret = false;
 413
 414         spin_lock(&fs_info->super_lock);
 415         if (fs_info->exclusive_operation == BTRFS_EXCLOP_NONE) {
 416                 fs_info->exclusive_operation = type;
 417                 ret = true;
 418         }
 419         spin_unlock(&fs_info->super_lock);
 420
 421         return ret;
 422 }
 423
 424 /*
 425  * Conditionally allow to enter the exclusive operation in case it's compatible
 426  * with the running one.  This must be paired with btrfs_exclop_start_unlock and
 427  * btrfs_exclop_finish.
 428  *
 429  * Compatibility:
 430  * - the same type is already running
 431  * - when trying to add a device and balance has been paused
 432  * - not BTRFS_EXCLOP_NONE - this is intentionally incompatible and the caller
 433  *   must check the condition first that would allow none -> @type
 434  */
 435 bool btrfs_exclop_start_try_lock(struct btrfs_fs_info *fs_info,
 436                                  enum btrfs_exclusive_operation type)
 437 {
 438         spin_lock(&fs_info->super_lock);
 439         if (fs_info->exclusive_operation == type ||
 440             (fs_info->exclusive_operation == BTRFS_EXCLOP_BALANCE_PAUSED &&
 441              type == BTRFS_EXCLOP_DEV_ADD))
 442                 return true;
 443
 444         spin_unlock(&fs_info->super_lock);
 445         return false;
 446 }
 447
 448 void btrfs_exclop_start_unlock(struct btrfs_fs_info *fs_info)
 449 {
 450         spin_unlock(&fs_info->super_lock);
 451 }
 452
 453 void btrfs_exclop_finish(struct btrfs_fs_info *fs_info)
 454 {
 455         spin_lock(&fs_info->super_lock);
 456         WRITE_ONCE(fs_info->exclusive_operation, BTRFS_EXCLOP_NONE);
 457         spin_unlock(&fs_info->super_lock);
 458         sysfs_notify(&fs_info->fs_devices->fsid_kobj, NULL, "exclusive_operation");
 459 }
 460
 461 void btrfs_exclop_balance(struct btrfs_fs_info *fs_info,
 462                           enum btrfs_exclusive_operation op)
 463 {
 464         switch (op) {
 465         case BTRFS_EXCLOP_BALANCE_PAUSED:
 466                 spin_lock(&fs_info->super_lock);
 467                 ASSERT(fs_info->exclusive_operation == BTRFS_EXCLOP_BALANCE ||
 468                        fs_info->exclusive_operation == BTRFS_EXCLOP_DEV_ADD ||
 469                        fs_info->exclusive_operation == BTRFS_EXCLOP_NONE ||
 470                        fs_info->exclusive_operation == BTRFS_EXCLOP_BALANCE_PAUSED);
 471                 fs_info->exclusive_operation = BTRFS_EXCLOP_BALANCE_PAUSED;
 472                 spin_unlock(&fs_info->super_lock);
 473                 break;
 474         case BTRFS_EXCLOP_BALANCE:
 475                 spin_lock(&fs_info->super_lock);
 476                 ASSERT(fs_info->exclusive_operation == BTRFS_EXCLOP_BALANCE_PAUSED);
 477                 fs_info->exclusive_operation = BTRFS_EXCLOP_BALANCE;
 478                 spin_unlock(&fs_info->super_lock);
 479                 break;
 480         default:
 481                 btrfs_warn(fs_info,
 482                         "invalid exclop balance operation %d requested", op);
 483         }
 484 }
 485
 486 static int btrfs_ioctl_getversion(struct inode *inode, int __user *arg)
 487 {
 488         return put_user(inode->i_generation, arg);
 489 }
 490
 491 static noinline int btrfs_ioctl_fitrim(struct btrfs_fs_info *fs_info,
 492                                         void __user *arg)
 493 {
 494         struct btrfs_device *device;
 495         struct fstrim_range range;
 496         u64 minlen = ULLONG_MAX;
 497         u64 num_devices = 0;
 498         int ret;
 499
 500         if (!capable(CAP_SYS_ADMIN))
 501                 return -EPERM;
 502
 503         /*
 504          * btrfs_trim_block_group() depends on space cache, which is not
 505          * available in zoned filesystem. So, disallow fitrim on a zoned
 506          * filesystem for now.
 507          */
 508         if (btrfs_is_zoned(fs_info))
 509                 return -EOPNOTSUPP;
 510
 511         /*
 512          * If the fs is mounted with nologreplay, which requires it to be
 513          * mounted in RO mode as well, we can not allow discard on free space
 514          * inside block groups, because log trees refer to extents that are not
 515          * pinned in a block group's free space cache (pinning the extents is
 516          * precisely the first phase of replaying a log tree).
 517          */
 518         if (btrfs_test_opt(fs_info, NOLOGREPLAY))
 519                 return -EROFS;
 520
 521         rcu_read_lock();
 522         list_for_each_entry_rcu(device, &fs_info->fs_devices->devices,
 523                                 dev_list) {
 524                 if (!device->bdev || !bdev_max_discard_sectors(device->bdev))
 525                         continue;
 526                 num_devices++;
 527                 minlen = min_t(u64, bdev_discard_granularity(device->bdev),
 528                                     minlen);
 529         }
 530         rcu_read_unlock();
 531
 532         if (!num_devices)
 533                 return -EOPNOTSUPP;
 534         if (copy_from_user(&range, arg, sizeof(range)))
 535                 return -EFAULT;
 536
 537         /*
 538          * NOTE: Don't truncate the range using super->total_bytes.  Bytenr of
 539          * block group is in the logical address space, which can be any
 540          * sectorsize aligned bytenr in  the range [0, U64_MAX].
 541          */
 542         if (range.len < fs_info->sectorsize)
 543                 return -EINVAL;
 544
 545         range.minlen = max(range.minlen, minlen);
 546         ret = btrfs_trim_fs(fs_info, &range);
 547
 548         if (copy_to_user(arg, &range, sizeof(range)))
 549                 return -EFAULT;
 550
 551         return ret;
 552 }
 553
 554 int __pure btrfs_is_empty_uuid(const u8 *uuid)
 555 {
 556         int i;
 557
 558         for (i = 0; i < BTRFS_UUID_SIZE; i++) {
 559                 if (uuid[i])
 560                         return 0;
 561         }
 562         return 1;
 563 }
 564
 565 /*
 566  * Calculate the number of transaction items to reserve for creating a subvolume
 567  * or snapshot, not including the inode, directory entries, or parent directory.
 568  */
 569 static unsigned int create_subvol_num_items(struct btrfs_qgroup_inherit *inherit)
 570 {
 571         /*
 572          * 1 to add root block
 573          * 1 to add root item
 574          * 1 to add root ref
 575          * 1 to add root backref
 576          * 1 to add UUID item
 577          * 1 to add qgroup info
 578          * 1 to add qgroup limit
 579          *
 580          * Ideally the last two would only be accounted if qgroups are enabled,
 581          * but that can change between now and the time we would insert them.
 582          */
 583         unsigned int num_items = 7;
 584
 585         if (inherit) {
 586                 /* 2 to add qgroup relations for each inherited qgroup */
 587                 num_items += 2 * inherit->num_qgroups;
 588         }
 589         return num_items;
 590 }
 591
 592 static noinline int create_subvol(struct mnt_idmap *idmap,
 593                                   struct inode *dir, struct dentry *dentry,
 594                                   struct btrfs_qgroup_inherit *inherit)
 595 {
 596         struct btrfs_fs_info *fs_info = inode_to_fs_info(dir);
 597         struct btrfs_trans_handle *trans;
 598         struct btrfs_key key;
 599         struct btrfs_root_item *root_item;
 600         struct btrfs_inode_item *inode_item;
 601         struct extent_buffer *leaf;
 602         struct btrfs_root *root = BTRFS_I(dir)->root;
 603         struct btrfs_root *new_root;
 604         struct btrfs_block_rsv block_rsv;
 605         struct timespec64 cur_time = current_time(dir);
 606         struct btrfs_new_inode_args new_inode_args = {
 607                 .dir = dir,
 608                 .dentry = dentry,
 609                 .subvol = true,
 610         };
 611         unsigned int trans_num_items;
 612         int ret;
 613         dev_t anon_dev;
 614         u64 objectid;
 615         u64 qgroup_reserved = 0;
 616
 617         root_item = kzalloc(sizeof(*root_item), GFP_KERNEL);
 618         if (!root_item)
 619                 return -ENOMEM;
 620
 621         ret = btrfs_get_free_objectid(fs_info->tree_root, &objectid);
 622         if (ret)
 623                 goto out_root_item;
 624
 625         /*
 626          * Don't create subvolume whose level is not zero. Or qgroup will be
 627          * screwed up since it assumes subvolume qgroup's level to be 0.
 628          */
 629         if (btrfs_qgroup_level(objectid)) {
 630                 ret = -ENOSPC;
 631                 goto out_root_item;
 632         }
 633
 634         ret = get_anon_bdev(&anon_dev);
 635         if (ret < 0)
 636                 goto out_root_item;
 637
 638         new_inode_args.inode = btrfs_new_subvol_inode(idmap, dir);
 639         if (!new_inode_args.inode) {
 640                 ret = -ENOMEM;
 641                 goto out_anon_dev;
 642         }
 643         ret = btrfs_new_inode_prepare(&new_inode_args, &trans_num_items);
 644         if (ret)
 645                 goto out_inode;
 646         trans_num_items += create_subvol_num_items(inherit);
 647
 648         btrfs_init_block_rsv(&block_rsv, BTRFS_BLOCK_RSV_TEMP);
 649         ret = btrfs_subvolume_reserve_metadata(root, &block_rsv,
 650                                                trans_num_items, false);
 651         if (ret)
 652                 goto out_new_inode_args;
 653         qgroup_reserved = block_rsv.qgroup_rsv_reserved;
 654
 655         trans = btrfs_start_transaction(root, 0);
 656         if (IS_ERR(trans)) {
 657                 ret = PTR_ERR(trans);
 658                 goto out_release_rsv;
 659         }
 660         btrfs_qgroup_convert_reserved_meta(root, qgroup_reserved);
 661         qgroup_reserved = 0;
 662         trans->block_rsv = &block_rsv;
 663         trans->bytes_reserved = block_rsv.size;
 664
 665         ret = btrfs_qgroup_inherit(trans, 0, objectid, btrfs_root_id(root), inherit);
 666         if (ret)
 667                 goto out;
 668
 669         leaf = btrfs_alloc_tree_block(trans, root, 0, objectid, NULL, 0, 0, 0,
 670                                       0, BTRFS_NESTING_NORMAL);
 671         if (IS_ERR(leaf)) {
 672                 ret = PTR_ERR(leaf);
 673                 goto out;
 674         }
 675
 676         btrfs_mark_buffer_dirty(trans, leaf);
 677
 678         inode_item = &root_item->inode;
 679         btrfs_set_stack_inode_generation(inode_item, 1);
 680         btrfs_set_stack_inode_size(inode_item, 3);
 681         btrfs_set_stack_inode_nlink(inode_item, 1);
 682         btrfs_set_stack_inode_nbytes(inode_item,
 683                                      fs_info->nodesize);
 684         btrfs_set_stack_inode_mode(inode_item, S_IFDIR | 0755);
 685
 686         btrfs_set_root_flags(root_item, 0);
 687         btrfs_set_root_limit(root_item, 0);
 688         btrfs_set_stack_inode_flags(inode_item, BTRFS_INODE_ROOT_ITEM_INIT);
 689
 690         btrfs_set_root_bytenr(root_item, leaf->start);
 691         btrfs_set_root_generation(root_item, trans->transid);
 692         btrfs_set_root_level(root_item, 0);
 693         btrfs_set_root_refs(root_item, 1);
 694         btrfs_set_root_used(root_item, leaf->len);
 695         btrfs_set_root_last_snapshot(root_item, 0);
 696
 697         btrfs_set_root_generation_v2(root_item,
 698                         btrfs_root_generation(root_item));
 699         generate_random_guid(root_item->uuid);
 700         btrfs_set_stack_timespec_sec(&root_item->otime, cur_time.tv_sec);
 701         btrfs_set_stack_timespec_nsec(&root_item->otime, cur_time.tv_nsec);
 702         root_item->ctime = root_item->otime;
 703         btrfs_set_root_ctransid(root_item, trans->transid);
 704         btrfs_set_root_otransid(root_item, trans->transid);
 705
 706         btrfs_tree_unlock(leaf);
 707
 708         btrfs_set_root_dirid(root_item, BTRFS_FIRST_FREE_OBJECTID);
 709
 710         key.objectid = objectid;
 711         key.offset = 0;
 712         key.type = BTRFS_ROOT_ITEM_KEY;
 713         ret = btrfs_insert_root(trans, fs_info->tree_root, &key,
 714                                 root_item);
 715         if (ret) {
 716                 int ret2;
 717
 718                 /*
 719                  * Since we don't abort the transaction in this case, free the
 720                  * tree block so that we don't leak space and leave the
 721                  * filesystem in an inconsistent state (an extent item in the
 722                  * extent tree with a backreference for a root that does not
 723                  * exists).
 724                  */
 725                 btrfs_tree_lock(leaf);
 726                 btrfs_clear_buffer_dirty(trans, leaf);
 727                 btrfs_tree_unlock(leaf);
 728                 ret2 = btrfs_free_tree_block(trans, objectid, leaf, 0, 1);
 729                 if (ret2 < 0)
 730                         btrfs_abort_transaction(trans, ret2);
 731                 free_extent_buffer(leaf);
 732                 goto out;
 733         }
 734
 735         free_extent_buffer(leaf);
 736         leaf = NULL;
 737
 738         new_root = btrfs_get_new_fs_root(fs_info, objectid, &anon_dev);
 739         if (IS_ERR(new_root)) {
 740                 ret = PTR_ERR(new_root);
 741                 btrfs_abort_transaction(trans, ret);
 742                 goto out;
 743         }
 744         /* anon_dev is owned by new_root now. */
 745         anon_dev = 0;
 746         BTRFS_I(new_inode_args.inode)->root = new_root;
 747         /* ... and new_root is owned by new_inode_args.inode now. */
 748
 749         ret = btrfs_record_root_in_trans(trans, new_root);
 750         if (ret) {
 751                 btrfs_abort_transaction(trans, ret);
 752                 goto out;
 753         }
 754
 755         ret = btrfs_uuid_tree_add(trans, root_item->uuid,
 756                                   BTRFS_UUID_KEY_SUBVOL, objectid);
 757         if (ret) {
 758                 btrfs_abort_transaction(trans, ret);
 759                 goto out;
 760         }
 761
 762         ret = btrfs_create_new_inode(trans, &new_inode_args);
 763         if (ret) {
 764                 btrfs_abort_transaction(trans, ret);
 765                 goto out;
 766         }
 767
 768         btrfs_record_new_subvolume(trans, BTRFS_I(dir));
 769
 770         d_instantiate_new(dentry, new_inode_args.inode);
 771         new_inode_args.inode = NULL;
 772
 773 out:
 774         trans->block_rsv = NULL;
 775         trans->bytes_reserved = 0;
 776         btrfs_end_transaction(trans);
 777 out_release_rsv:
 778         btrfs_block_rsv_release(fs_info, &block_rsv, (u64)-1, NULL);
 779         if (qgroup_reserved)
 780                 btrfs_qgroup_free_meta_prealloc(root, qgroup_reserved);
 781 out_new_inode_args:
 782         btrfs_new_inode_args_destroy(&new_inode_args);
 783 out_inode:
 784         iput(new_inode_args.inode);
 785 out_anon_dev:
 786         if (anon_dev)
 787                 free_anon_bdev(anon_dev);
 788 out_root_item:
 789         kfree(root_item);
 790         return ret;
 791 }
 792
 793 static int create_snapshot(struct btrfs_root *root, struct inode *dir,
 794                            struct dentry *dentry, bool readonly,
 795                            struct btrfs_qgroup_inherit *inherit)
 796 {
 797         struct btrfs_fs_info *fs_info = inode_to_fs_info(dir);
 798         struct inode *inode;
 799         struct btrfs_pending_snapshot *pending_snapshot;
 800         unsigned int trans_num_items;
 801         struct btrfs_trans_handle *trans;
 802         struct btrfs_block_rsv *block_rsv;
 803         u64 qgroup_reserved = 0;
 804         int ret;
 805
 806         /* We do not support snapshotting right now. */
 807         if (btrfs_fs_incompat(fs_info, EXTENT_TREE_V2)) {
 808                 btrfs_warn(fs_info,
 809                            "extent tree v2 doesn't support snapshotting yet");
 810                 return -EOPNOTSUPP;
 811         }
 812
 813         if (btrfs_root_refs(&root->root_item) == 0)
 814                 return -ENOENT;
 815
 816         if (!test_bit(BTRFS_ROOT_SHAREABLE, &root->state))
 817                 return -EINVAL;
 818
 819         if (atomic_read(&root->nr_swapfiles)) {
 820                 btrfs_warn(fs_info,
 821                            "cannot snapshot subvolume with active swapfile");
 822                 return -ETXTBSY;
 823         }
 824
 825         pending_snapshot = kzalloc(sizeof(*pending_snapshot), GFP_KERNEL);
 826         if (!pending_snapshot)
 827                 return -ENOMEM;
 828
 829         ret = get_anon_bdev(&pending_snapshot->anon_dev);
 830         if (ret < 0)
 831                 goto free_pending;
 832         pending_snapshot->root_item = kzalloc(sizeof(struct btrfs_root_item),
 833                         GFP_KERNEL);
 834         pending_snapshot->path = btrfs_alloc_path();
 835         if (!pending_snapshot->root_item || !pending_snapshot->path) {
 836                 ret = -ENOMEM;
 837                 goto free_pending;
 838         }
 839
 840         block_rsv = &pending_snapshot->block_rsv;
 841         btrfs_init_block_rsv(block_rsv, BTRFS_BLOCK_RSV_TEMP);
 842         /*
 843          * 1 to add dir item
 844          * 1 to add dir index
 845          * 1 to update parent inode item
 846          */
 847         trans_num_items = create_subvol_num_items(inherit) + 3;
 848         ret = btrfs_subvolume_reserve_metadata(BTRFS_I(dir)->root, block_rsv,
 849                                                trans_num_items, false);
 850         if (ret)
 851                 goto free_pending;
 852         qgroup_reserved = block_rsv->qgroup_rsv_reserved;
 853
 854         pending_snapshot->dentry = dentry;
 855         pending_snapshot->root = root;
 856         pending_snapshot->readonly = readonly;
 857         pending_snapshot->dir = BTRFS_I(dir);
 858         pending_snapshot->inherit = inherit;
 859
 860         trans = btrfs_start_transaction(root, 0);
 861         if (IS_ERR(trans)) {
 862                 ret = PTR_ERR(trans);
 863                 goto fail;
 864         }
 865         ret = btrfs_record_root_in_trans(trans, BTRFS_I(dir)->root);
 866         if (ret) {
 867                 btrfs_end_transaction(trans);
 868                 goto fail;
 869         }
 870         btrfs_qgroup_convert_reserved_meta(root, qgroup_reserved);
 871         qgroup_reserved = 0;
 872
 873         trans->pending_snapshot = pending_snapshot;
 874
 875         ret = btrfs_commit_transaction(trans);
 876         if (ret)
 877                 goto fail;
 878
 879         ret = pending_snapshot->error;
 880         if (ret)
 881                 goto fail;
 882
 883         ret = btrfs_orphan_cleanup(pending_snapshot->snap);
 884         if (ret)
 885                 goto fail;
 886
 887         inode = btrfs_lookup_dentry(d_inode(dentry->d_parent), dentry);
 888         if (IS_ERR(inode)) {
 889                 ret = PTR_ERR(inode);
 890                 goto fail;
 891         }
 892
 893         d_instantiate(dentry, inode);
 894         ret = 0;
 895         pending_snapshot->anon_dev = 0;
 896 fail:
 897         /* Prevent double freeing of anon_dev */
 898         if (ret && pending_snapshot->snap)
 899                 pending_snapshot->snap->anon_dev = 0;
 900         btrfs_put_root(pending_snapshot->snap);
 901         btrfs_block_rsv_release(fs_info, block_rsv, (u64)-1, NULL);
 902         if (qgroup_reserved)
 903                 btrfs_qgroup_free_meta_prealloc(root, qgroup_reserved);
 904 free_pending:
 905         if (pending_snapshot->anon_dev)
 906                 free_anon_bdev(pending_snapshot->anon_dev);
 907         kfree(pending_snapshot->root_item);
 908         btrfs_free_path(pending_snapshot->path);
 909         kfree(pending_snapshot);
 910
 911         return ret;
 912 }
 913
 914 /*  copy of may_delete in fs/namei.c()
 915  *      Check whether we can remove a link victim from directory dir, check
 916  *  whether the type of victim is right.
 917  *  1. We can't do it if dir is read-only (done in permission())
 918  *  2. We should have write and exec permissions on dir
 919  *  3. We can't remove anything from append-only dir
 920  *  4. We can't do anything with immutable dir (done in permission())
 921  *  5. If the sticky bit on dir is set we should either
 922  *      a. be owner of dir, or
 923  *      b. be owner of victim, or
 924  *      c. have CAP_FOWNER capability
 925  *  6. If the victim is append-only or immutable we can't do anything with
 926  *     links pointing to it.
 927  *  7. If we were asked to remove a directory and victim isn't one - ENOTDIR.
 928  *  8. If we were asked to remove a non-directory and victim isn't one - EISDIR.
 929  *  9. We can't remove a root or mountpoint.
 930  * 10. We don't allow removal of NFS sillyrenamed files; it's handled by
 931  *     nfs_async_unlink().
 932  */
 933
 934 static int btrfs_may_delete(struct mnt_idmap *idmap,
 935                             struct inode *dir, struct dentry *victim, int isdir)
 936 {
 937         int error;
 938
 939         if (d_really_is_negative(victim))
 940                 return -ENOENT;
 941
 942         /* The @victim is not inside @dir. */
 943         if (d_inode(victim->d_parent) != dir)
 944                 return -EINVAL;
 945         audit_inode_child(dir, victim, AUDIT_TYPE_CHILD_DELETE);
 946
 947         error = inode_permission(idmap, dir, MAY_WRITE | MAY_EXEC);
 948         if (error)
 949                 return error;
 950         if (IS_APPEND(dir))
 951                 return -EPERM;
 952         if (check_sticky(idmap, dir, d_inode(victim)) ||
 953             IS_APPEND(d_inode(victim)) || IS_IMMUTABLE(d_inode(victim)) ||
 954             IS_SWAPFILE(d_inode(victim)))
 955                 return -EPERM;
 956         if (isdir) {
 957                 if (!d_is_dir(victim))
 958                         return -ENOTDIR;
 959                 if (IS_ROOT(victim))
 960                         return -EBUSY;
 961         } else if (d_is_dir(victim))
 962                 return -EISDIR;
 963         if (IS_DEADDIR(dir))
 964                 return -ENOENT;
 965         if (victim->d_flags & DCACHE_NFSFS_RENAMED)
 966                 return -EBUSY;
 967         return 0;
 968 }
 969
 970 /* copy of may_create in fs/namei.c() */
 971 static inline int btrfs_may_create(struct mnt_idmap *idmap,
 972                                    struct inode *dir, struct dentry *child)
 973 {
 974         if (d_really_is_positive(child))
 975                 return -EEXIST;
 976         if (IS_DEADDIR(dir))
 977                 return -ENOENT;
 978         if (!fsuidgid_has_mapping(dir->i_sb, idmap))
 979                 return -EOVERFLOW;
 980         return inode_permission(idmap, dir, MAY_WRITE | MAY_EXEC);
 981 }
 982
 983 /*
 984  * Create a new subvolume below @parent.  This is largely modeled after
 985  * sys_mkdirat and vfs_mkdir, but we only do a single component lookup
 986  * inside this filesystem so it's quite a bit simpler.
 987  */
 988 static noinline int btrfs_mksubvol(const struct path *parent,
 989                                    struct mnt_idmap *idmap,
 990                                    const char *name, int namelen,
 991                                    struct btrfs_root *snap_src,
 992                                    bool readonly,
 993                                    struct btrfs_qgroup_inherit *inherit)
 994 {
 995         struct inode *dir = d_inode(parent->dentry);
 996         struct btrfs_fs_info *fs_info = inode_to_fs_info(dir);
 997         struct dentry *dentry;
 998         struct fscrypt_str name_str = FSTR_INIT((char *)name, namelen);
 999         int error;
1000
1001         error = down_write_killable_nested(&dir->i_rwsem, I_MUTEX_PARENT);
1002         if (error == -EINTR)
1003                 return error;
1004
1005         dentry = lookup_one(idmap, name, parent->dentry, namelen);
1006         error = PTR_ERR(dentry);
1007         if (IS_ERR(dentry))
1008                 goto out_unlock;
1009
1010         error = btrfs_may_create(idmap, dir, dentry);
1011         if (error)
1012                 goto out_dput;
1013
1014         /*
1015          * even if this name doesn't exist, we may get hash collisions.
1016          * check for them now when we can safely fail
1017          */
1018         error = btrfs_check_dir_item_collision(BTRFS_I(dir)->root,
1019                                                dir->i_ino, &name_str);
1020         if (error)
1021                 goto out_dput;
1022
1023         down_read(&fs_info->subvol_sem);
1024
1025         if (btrfs_root_refs(&BTRFS_I(dir)->root->root_item) == 0)
1026                 goto out_up_read;
1027
1028         if (snap_src)
1029                 error = create_snapshot(snap_src, dir, dentry, readonly, inherit);
1030         else
1031                 error = create_subvol(idmap, dir, dentry, inherit);
1032
1033         if (!error)
1034                 fsnotify_mkdir(dir, dentry);
1035 out_up_read:
1036         up_read(&fs_info->subvol_sem);
1037 out_dput:
1038         dput(dentry);
1039 out_unlock:
1040         btrfs_inode_unlock(BTRFS_I(dir), 0);
1041         return error;
1042 }
1043
1044 static noinline int btrfs_mksnapshot(const struct path *parent,
1045                                    struct mnt_idmap *idmap,
1046                                    const char *name, int namelen,
1047                                    struct btrfs_root *root,
1048                                    bool readonly,
1049                                    struct btrfs_qgroup_inherit *inherit)
1050 {
1051         int ret;
1052
1053         /*
1054          * Force new buffered writes to reserve space even when NOCOW is
1055          * possible. This is to avoid later writeback (running dealloc) to
1056          * fallback to COW mode and unexpectedly fail with ENOSPC.
1057          */
1058         btrfs_drew_read_lock(&root->snapshot_lock);
1059
1060         ret = btrfs_start_delalloc_snapshot(root, false);
1061         if (ret)
1062                 goto out;
1063
1064         /*
1065          * All previous writes have started writeback in NOCOW mode, so now
1066          * we force future writes to fallback to COW mode during snapshot
1067          * creation.
1068          */
1069         atomic_inc(&root->snapshot_force_cow);
1070
1071         btrfs_wait_ordered_extents(root, U64_MAX, NULL);
1072
1073         ret = btrfs_mksubvol(parent, idmap, name, namelen,
1074                              root, readonly, inherit);
1075         atomic_dec(&root->snapshot_force_cow);
1076 out:
1077         btrfs_drew_read_unlock(&root->snapshot_lock);
1078         return ret;
1079 }
1080
1081 /*
1082  * Try to start exclusive operation @type or cancel it if it's running.
1083  *
1084  * Return:
1085  *   0        - normal mode, newly claimed op started
1086  *  >0        - normal mode, something else is running,
1087  *              return BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS to user space
1088  * ECANCELED  - cancel mode, successful cancel
1089  * ENOTCONN   - cancel mode, operation not running anymore
1090  */
1091 static int exclop_start_or_cancel_reloc(struct btrfs_fs_info *fs_info,
1092                         enum btrfs_exclusive_operation type, bool cancel)
1093 {
1094         if (!cancel) {
1095                 /* Start normal op */
1096                 if (!btrfs_exclop_start(fs_info, type))
1097                         return BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
1098                 /* Exclusive operation is now claimed */
1099                 return 0;
1100         }
1101
1102         /* Cancel running op */
1103         if (btrfs_exclop_start_try_lock(fs_info, type)) {
1104                 /*
1105                  * This blocks any exclop finish from setting it to NONE, so we
1106                  * request cancellation. Either it runs and we will wait for it,
1107                  * or it has finished and no waiting will happen.
1108                  */
1109                 atomic_inc(&fs_info->reloc_cancel_req);
1110                 btrfs_exclop_start_unlock(fs_info);
1111
1112                 if (test_bit(BTRFS_FS_RELOC_RUNNING, &fs_info->flags))
1113                         wait_on_bit(&fs_info->flags, BTRFS_FS_RELOC_RUNNING,
1114                                     TASK_INTERRUPTIBLE);
1115
1116                 return -ECANCELED;
1117         }
1118
1119         /* Something else is running or none */
1120         return -ENOTCONN;
1121 }
1122
1123 static noinline int btrfs_ioctl_resize(struct file *file,
1124                                         void __user *arg)
1125 {
1126         BTRFS_DEV_LOOKUP_ARGS(args);
1127         struct inode *inode = file_inode(file);
1128         struct btrfs_fs_info *fs_info = inode_to_fs_info(inode);
1129         u64 new_size;
1130         u64 old_size;
1131         u64 devid = 1;
1132         struct btrfs_root *root = BTRFS_I(inode)->root;
1133         struct btrfs_ioctl_vol_args *vol_args;
1134         struct btrfs_trans_handle *trans;
1135         struct btrfs_device *device = NULL;
1136         char *sizestr;
1137         char *retptr;
1138         char *devstr = NULL;
1139         int ret = 0;
1140         int mod = 0;
1141         bool cancel;
1142
1143         if (!capable(CAP_SYS_ADMIN))
1144                 return -EPERM;
1145
1146         ret = mnt_want_write_file(file);
1147         if (ret)
1148                 return ret;
1149
1150         /*
1151          * Read the arguments before checking exclusivity to be able to
1152          * distinguish regular resize and cancel
1153          */
1154         vol_args = memdup_user(arg, sizeof(*vol_args));
1155         if (IS_ERR(vol_args)) {
1156                 ret = PTR_ERR(vol_args);
1157                 goto out_drop;
1158         }
1159         ret = btrfs_check_ioctl_vol_args_path(vol_args);
1160         if (ret < 0)
1161                 goto out_free;
1162
1163         sizestr = vol_args->name;
1164         cancel = (strcmp("cancel", sizestr) == 0);
1165         ret = exclop_start_or_cancel_reloc(fs_info, BTRFS_EXCLOP_RESIZE, cancel);
1166         if (ret)
1167                 goto out_free;
1168         /* Exclusive operation is now claimed */
1169
1170         devstr = strchr(sizestr, ':');
1171         if (devstr) {
1172                 sizestr = devstr + 1;
1173                 *devstr = '\0';
1174                 devstr = vol_args->name;
1175                 ret = kstrtoull(devstr, 10, &devid);
1176                 if (ret)
1177                         goto out_finish;
1178                 if (!devid) {
1179                         ret = -EINVAL;
1180                         goto out_finish;
1181                 }
1182                 btrfs_info(fs_info, "resizing devid %llu", devid);
1183         }
1184
1185         args.devid = devid;
1186         device = btrfs_find_device(fs_info->fs_devices, &args);
1187         if (!device) {
1188                 btrfs_info(fs_info, "resizer unable to find device %llu",
1189                            devid);
1190                 ret = -ENODEV;
1191                 goto out_finish;
1192         }
1193
1194         if (!test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state)) {
1195                 btrfs_info(fs_info,
1196                            "resizer unable to apply on readonly device %llu",
1197                        devid);
1198                 ret = -EPERM;
1199                 goto out_finish;
1200         }
1201
1202         if (!strcmp(sizestr, "max"))
1203                 new_size = bdev_nr_bytes(device->bdev);
1204         else {
1205                 if (sizestr[0] == '-') {
1206                         mod = -1;
1207                         sizestr++;
1208                 } else if (sizestr[0] == '+') {
1209                         mod = 1;
1210                         sizestr++;
1211                 }
1212                 new_size = memparse(sizestr, &retptr);
1213                 if (*retptr != '\0' || new_size == 0) {
1214                         ret = -EINVAL;
1215                         goto out_finish;
1216                 }
1217         }
1218
1219         if (test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state)) {
1220                 ret = -EPERM;
1221                 goto out_finish;
1222         }
1223
1224         old_size = btrfs_device_get_total_bytes(device);
1225
1226         if (mod < 0) {
1227                 if (new_size > old_size) {
1228                         ret = -EINVAL;
1229                         goto out_finish;
1230                 }
1231                 new_size = old_size - new_size;
1232         } else if (mod > 0) {
1233                 if (new_size > ULLONG_MAX - old_size) {
1234                         ret = -ERANGE;
1235                         goto out_finish;
1236                 }
1237                 new_size = old_size + new_size;
1238         }
1239
1240         if (new_size < SZ_256M) {
1241                 ret = -EINVAL;
1242                 goto out_finish;
1243         }
1244         if (new_size > bdev_nr_bytes(device->bdev)) {
1245                 ret = -EFBIG;
1246                 goto out_finish;
1247         }
1248
1249         new_size = round_down(new_size, fs_info->sectorsize);
1250
1251         if (new_size > old_size) {
1252                 trans = btrfs_start_transaction(root, 0);
1253                 if (IS_ERR(trans)) {
1254                         ret = PTR_ERR(trans);
1255                         goto out_finish;
1256                 }
1257                 ret = btrfs_grow_device(trans, device, new_size);
1258                 btrfs_commit_transaction(trans);
1259         } else if (new_size < old_size) {
1260                 ret = btrfs_shrink_device(device, new_size);
1261         } /* equal, nothing need to do */
1262
1263         if (ret == 0 && new_size != old_size)
1264                 btrfs_info_in_rcu(fs_info,
1265                         "resize device %s (devid %llu) from %llu to %llu",
1266                         btrfs_dev_name(device), device->devid,
1267                         old_size, new_size);
1268 out_finish:
1269         btrfs_exclop_finish(fs_info);
1270 out_free:
1271         kfree(vol_args);
1272 out_drop:
1273         mnt_drop_write_file(file);
1274         return ret;
1275 }
1276
1277 static noinline int __btrfs_ioctl_snap_create(struct file *file,
1278                                 struct mnt_idmap *idmap,
1279                                 const char *name, unsigned long fd, int subvol,
1280                                 bool readonly,
1281                                 struct btrfs_qgroup_inherit *inherit)
1282 {
1283         int namelen;
1284         int ret = 0;
1285
1286         if (!S_ISDIR(file_inode(file)->i_mode))
1287                 return -ENOTDIR;
1288
1289         ret = mnt_want_write_file(file);
1290         if (ret)
1291                 goto out;
1292
1293         namelen = strlen(name);
1294         if (strchr(name, '/')) {
1295                 ret = -EINVAL;
1296                 goto out_drop_write;
1297         }
1298
1299         if (name[0] == '.' &&
1300            (namelen == 1 || (name[1] == '.' && namelen == 2))) {
1301                 ret = -EEXIST;
1302                 goto out_drop_write;
1303         }
1304
1305         if (subvol) {
1306                 ret = btrfs_mksubvol(&file->f_path, idmap, name,
1307                                      namelen, NULL, readonly, inherit);
1308         } else {
1309                 CLASS(fd, src)(fd);
1310                 struct inode *src_inode;
1311                 if (fd_empty(src)) {
1312                         ret = -EINVAL;
1313                         goto out_drop_write;
1314                 }
1315
1316                 src_inode = file_inode(fd_file(src));
1317                 if (src_inode->i_sb != file_inode(file)->i_sb) {
1318                         btrfs_info(BTRFS_I(file_inode(file))->root->fs_info,
1319                                    "Snapshot src from another FS");
1320                         ret = -EXDEV;
1321                 } else if (!inode_owner_or_capable(idmap, src_inode)) {
1322                         /*
1323                          * Subvolume creation is not restricted, but snapshots
1324                          * are limited to own subvolumes only
1325                          */
1326                         ret = -EPERM;
1327                 } else if (btrfs_ino(BTRFS_I(src_inode)) != BTRFS_FIRST_FREE_OBJECTID) {
1328                         /*
1329                          * Snapshots must be made with the src_inode referring
1330                          * to the subvolume inode, otherwise the permission
1331                          * checking above is useless because we may have
1332                          * permission on a lower directory but not the subvol
1333                          * itself.
1334                          */
1335                         ret = -EINVAL;
1336                 } else {
1337                         ret = btrfs_mksnapshot(&file->f_path, idmap,
1338                                                name, namelen,
1339                                                BTRFS_I(src_inode)->root,
1340                                                readonly, inherit);
1341                 }
1342         }
1343 out_drop_write:
1344         mnt_drop_write_file(file);
1345 out:
1346         return ret;
1347 }
1348
1349 static noinline int btrfs_ioctl_snap_create(struct file *file,
1350                                             void __user *arg, int subvol)
1351 {
1352         struct btrfs_ioctl_vol_args *vol_args;
1353         int ret;
1354
1355         if (!S_ISDIR(file_inode(file)->i_mode))
1356                 return -ENOTDIR;
1357
1358         vol_args = memdup_user(arg, sizeof(*vol_args));
1359         if (IS_ERR(vol_args))
1360                 return PTR_ERR(vol_args);
1361         ret = btrfs_check_ioctl_vol_args_path(vol_args);
1362         if (ret < 0)
1363                 goto out;
1364
1365         ret = __btrfs_ioctl_snap_create(file, file_mnt_idmap(file),
1366                                         vol_args->name, vol_args->fd, subvol,
1367                                         false, NULL);
1368
1369 out:
1370         kfree(vol_args);
1371         return ret;
1372 }
1373
1374 static noinline int btrfs_ioctl_snap_create_v2(struct file *file,
1375                                                void __user *arg, int subvol)
1376 {
1377         struct btrfs_ioctl_vol_args_v2 *vol_args;
1378         int ret;
1379         bool readonly = false;
1380         struct btrfs_qgroup_inherit *inherit = NULL;
1381
1382         if (!S_ISDIR(file_inode(file)->i_mode))
1383                 return -ENOTDIR;
1384
1385         vol_args = memdup_user(arg, sizeof(*vol_args));
1386         if (IS_ERR(vol_args))
1387                 return PTR_ERR(vol_args);
1388         ret = btrfs_check_ioctl_vol_args2_subvol_name(vol_args);
1389         if (ret < 0)
1390                 goto free_args;
1391
1392         if (vol_args->flags & ~BTRFS_SUBVOL_CREATE_ARGS_MASK) {
1393                 ret = -EOPNOTSUPP;
1394                 goto free_args;
1395         }
1396
1397         if (vol_args->flags & BTRFS_SUBVOL_RDONLY)
1398                 readonly = true;
1399         if (vol_args->flags & BTRFS_SUBVOL_QGROUP_INHERIT) {
1400                 struct btrfs_fs_info *fs_info = inode_to_fs_info(file_inode(file));
1401
1402                 if (vol_args->size < sizeof(*inherit) ||
1403                     vol_args->size > PAGE_SIZE) {
1404                         ret = -EINVAL;
1405                         goto free_args;
1406                 }
1407                 inherit = memdup_user(vol_args->qgroup_inherit, vol_args->size);
1408                 if (IS_ERR(inherit)) {
1409                         ret = PTR_ERR(inherit);
1410                         goto free_args;
1411                 }
1412
1413                 ret = btrfs_qgroup_check_inherit(fs_info, inherit, vol_args->size);
1414                 if (ret < 0)
1415                         goto free_inherit;
1416         }
1417
1418         ret = __btrfs_ioctl_snap_create(file, file_mnt_idmap(file),
1419                                         vol_args->name, vol_args->fd, subvol,
1420                                         readonly, inherit);
1421         if (ret)
1422                 goto free_inherit;
1423 free_inherit:
1424         kfree(inherit);
1425 free_args:
1426         kfree(vol_args);
1427         return ret;
1428 }
1429
1430 static noinline int btrfs_ioctl_subvol_getflags(struct inode *inode,
1431                                                 void __user *arg)
1432 {
1433         struct btrfs_fs_info *fs_info = inode_to_fs_info(inode);
1434         struct btrfs_root *root = BTRFS_I(inode)->root;
1435         int ret = 0;
1436         u64 flags = 0;
1437
1438         if (btrfs_ino(BTRFS_I(inode)) != BTRFS_FIRST_FREE_OBJECTID)
1439                 return -EINVAL;
1440
1441         down_read(&fs_info->subvol_sem);
1442         if (btrfs_root_readonly(root))
1443                 flags |= BTRFS_SUBVOL_RDONLY;
1444         up_read(&fs_info->subvol_sem);
1445
1446         if (copy_to_user(arg, &flags, sizeof(flags)))
1447                 ret = -EFAULT;
1448
1449         return ret;
1450 }
1451
1452 static noinline int btrfs_ioctl_subvol_setflags(struct file *file,
1453                                               void __user *arg)
1454 {
1455         struct inode *inode = file_inode(file);
1456         struct btrfs_fs_info *fs_info = inode_to_fs_info(inode);
1457         struct btrfs_root *root = BTRFS_I(inode)->root;
1458         struct btrfs_trans_handle *trans;
1459         u64 root_flags;
1460         u64 flags;
1461         int ret = 0;
1462
1463         if (!inode_owner_or_capable(file_mnt_idmap(file), inode))
1464                 return -EPERM;
1465
1466         ret = mnt_want_write_file(file);
1467         if (ret)
1468                 goto out;
1469
1470         if (btrfs_ino(BTRFS_I(inode)) != BTRFS_FIRST_FREE_OBJECTID) {
1471                 ret = -EINVAL;
1472                 goto out_drop_write;
1473         }
1474
1475         if (copy_from_user(&flags, arg, sizeof(flags))) {
1476                 ret = -EFAULT;
1477                 goto out_drop_write;
1478         }
1479
1480         if (flags & ~BTRFS_SUBVOL_RDONLY) {
1481                 ret = -EOPNOTSUPP;
1482                 goto out_drop_write;
1483         }
1484
1485         down_write(&fs_info->subvol_sem);
1486
1487         /* nothing to do */
1488         if (!!(flags & BTRFS_SUBVOL_RDONLY) == btrfs_root_readonly(root))
1489                 goto out_drop_sem;
1490
1491         root_flags = btrfs_root_flags(&root->root_item);
1492         if (flags & BTRFS_SUBVOL_RDONLY) {
1493                 btrfs_set_root_flags(&root->root_item,
1494                                      root_flags | BTRFS_ROOT_SUBVOL_RDONLY);
1495         } else {
1496                 /*
1497                  * Block RO -> RW transition if this subvolume is involved in
1498                  * send
1499                  */
1500                 spin_lock(&root->root_item_lock);
1501                 if (root->send_in_progress == 0) {
1502                         btrfs_set_root_flags(&root->root_item,
1503                                      root_flags & ~BTRFS_ROOT_SUBVOL_RDONLY);
1504                         spin_unlock(&root->root_item_lock);
1505                 } else {
1506                         spin_unlock(&root->root_item_lock);
1507                         btrfs_warn(fs_info,
1508                                    "Attempt to set subvolume %llu read-write during send",
1509                                    btrfs_root_id(root));
1510                         ret = -EPERM;
1511                         goto out_drop_sem;
1512                 }
1513         }
1514
1515         trans = btrfs_start_transaction(root, 1);
1516         if (IS_ERR(trans)) {
1517                 ret = PTR_ERR(trans);
1518                 goto out_reset;
1519         }
1520
1521         ret = btrfs_update_root(trans, fs_info->tree_root,
1522                                 &root->root_key, &root->root_item);
1523         if (ret < 0) {
1524                 btrfs_end_transaction(trans);
1525                 goto out_reset;
1526         }
1527
1528         ret = btrfs_commit_transaction(trans);
1529
1530 out_reset:
1531         if (ret)
1532                 btrfs_set_root_flags(&root->root_item, root_flags);
1533 out_drop_sem:
1534         up_write(&fs_info->subvol_sem);
1535 out_drop_write:
1536         mnt_drop_write_file(file);
1537 out:
1538         return ret;
1539 }
1540
1541 static noinline int key_in_sk(struct btrfs_key *key,
1542                               struct btrfs_ioctl_search_key *sk)
1543 {
1544         struct btrfs_key test;
1545         int ret;
1546
1547         test.objectid = sk->min_objectid;
1548         test.type = sk->min_type;
1549         test.offset = sk->min_offset;
1550
1551         ret = btrfs_comp_cpu_keys(key, &test);
1552         if (ret < 0)
1553                 return 0;
1554
1555         test.objectid = sk->max_objectid;
1556         test.type = sk->max_type;
1557         test.offset = sk->max_offset;
1558
1559         ret = btrfs_comp_cpu_keys(key, &test);
1560         if (ret > 0)
1561                 return 0;
1562         return 1;
1563 }
1564
1565 static noinline int copy_to_sk(struct btrfs_path *path,
1566                                struct btrfs_key *key,
1567                                struct btrfs_ioctl_search_key *sk,
1568                                u64 *buf_size,
1569                                char __user *ubuf,
1570                                unsigned long *sk_offset,
1571                                int *num_found)
1572 {
1573         u64 found_transid;
1574         struct extent_buffer *leaf;
1575         struct btrfs_ioctl_search_header sh;
1576         struct btrfs_key test;
1577         unsigned long item_off;
1578         unsigned long item_len;
1579         int nritems;
1580         int i;
1581         int slot;
1582         int ret = 0;
1583
1584         leaf = path->nodes[0];
1585         slot = path->slots[0];
1586         nritems = btrfs_header_nritems(leaf);
1587
1588         if (btrfs_header_generation(leaf) > sk->max_transid) {
1589                 i = nritems;
1590                 goto advance_key;
1591         }
1592         found_transid = btrfs_header_generation(leaf);
1593
1594         for (i = slot; i < nritems; i++) {
1595                 item_off = btrfs_item_ptr_offset(leaf, i);
1596                 item_len = btrfs_item_size(leaf, i);
1597
1598                 btrfs_item_key_to_cpu(leaf, key, i);
1599                 if (!key_in_sk(key, sk))
1600                         continue;
1601
1602                 if (sizeof(sh) + item_len > *buf_size) {
1603                         if (*num_found) {
1604                                 ret = 1;
1605                                 goto out;
1606                         }
1607
1608                         /*
1609                          * return one empty item back for v1, which does not
1610                          * handle -EOVERFLOW
1611                          */
1612
1613                         *buf_size = sizeof(sh) + item_len;
1614                         item_len = 0;
1615                         ret = -EOVERFLOW;
1616                 }
1617
1618                 if (sizeof(sh) + item_len + *sk_offset > *buf_size) {
1619                         ret = 1;
1620                         goto out;
1621                 }
1622
1623                 sh.objectid = key->objectid;
1624                 sh.offset = key->offset;
1625                 sh.type = key->type;
1626                 sh.len = item_len;
1627                 sh.transid = found_transid;
1628
1629                 /*
1630                  * Copy search result header. If we fault then loop again so we
1631                  * can fault in the pages and -EFAULT there if there's a
1632                  * problem. Otherwise we'll fault and then copy the buffer in
1633                  * properly this next time through
1634                  */
1635                 if (copy_to_user_nofault(ubuf + *sk_offset, &sh, sizeof(sh))) {
1636                         ret = 0;
1637                         goto out;
1638                 }
1639
1640                 *sk_offset += sizeof(sh);
1641
1642                 if (item_len) {
1643                         char __user *up = ubuf + *sk_offset;
1644                         /*
1645                          * Copy the item, same behavior as above, but reset the
1646                          * * sk_offset so we copy the full thing again.
1647                          */
1648                         if (read_extent_buffer_to_user_nofault(leaf, up,
1649                                                 item_off, item_len)) {
1650                                 ret = 0;
1651                                 *sk_offset -= sizeof(sh);
1652                                 goto out;
1653                         }
1654
1655                         *sk_offset += item_len;
1656                 }
1657                 (*num_found)++;
1658
1659                 if (ret) /* -EOVERFLOW from above */
1660                         goto out;
1661
1662                 if (*num_found >= sk->nr_items) {
1663                         ret = 1;
1664                         goto out;
1665                 }
1666         }
1667 advance_key:
1668         ret = 0;
1669         test.objectid = sk->max_objectid;
1670         test.type = sk->max_type;
1671         test.offset = sk->max_offset;
1672         if (btrfs_comp_cpu_keys(key, &test) >= 0)
1673                 ret = 1;
1674         else if (key->offset < (u64)-1)
1675                 key->offset++;
1676         else if (key->type < (u8)-1) {
1677                 key->offset = 0;
1678                 key->type++;
1679         } else if (key->objectid < (u64)-1) {
1680                 key->offset = 0;
1681                 key->type = 0;
1682                 key->objectid++;
1683         } else
1684                 ret = 1;
1685 out:
1686         /*
1687          *  0: all items from this leaf copied, continue with next
1688          *  1: * more items can be copied, but unused buffer is too small
1689          *     * all items were found
1690          *     Either way, it will stops the loop which iterates to the next
1691          *     leaf
1692          *  -EOVERFLOW: item was to large for buffer
1693          *  -EFAULT: could not copy extent buffer back to userspace
1694          */
1695         return ret;
1696 }
1697
1698 static noinline int search_ioctl(struct inode *inode,
1699                                  struct btrfs_ioctl_search_key *sk,
1700                                  u64 *buf_size,
1701                                  char __user *ubuf)
1702 {
1703         struct btrfs_fs_info *info = inode_to_fs_info(inode);
1704         struct btrfs_root *root;
1705         struct btrfs_key key;
1706         struct btrfs_path *path;
1707         int ret;
1708         int num_found = 0;
1709         unsigned long sk_offset = 0;
1710
1711         if (*buf_size < sizeof(struct btrfs_ioctl_search_header)) {
1712                 *buf_size = sizeof(struct btrfs_ioctl_search_header);
1713                 return -EOVERFLOW;
1714         }
1715
1716         path = btrfs_alloc_path();
1717         if (!path)
1718                 return -ENOMEM;
1719
1720         if (sk->tree_id == 0) {
1721                 /* search the root of the inode that was passed */
1722                 root = btrfs_grab_root(BTRFS_I(inode)->root);
1723         } else {
1724                 root = btrfs_get_fs_root(info, sk->tree_id, true);
1725                 if (IS_ERR(root)) {
1726                         btrfs_free_path(path);
1727                         return PTR_ERR(root);
1728                 }
1729         }
1730
1731         key.objectid = sk->min_objectid;
1732         key.type = sk->min_type;
1733         key.offset = sk->min_offset;
1734
1735         while (1) {
1736                 ret = -EFAULT;
1737                 /*
1738                  * Ensure that the whole user buffer is faulted in at sub-page
1739                  * granularity, otherwise the loop may live-lock.
1740                  */
1741                 if (fault_in_subpage_writeable(ubuf + sk_offset,
1742                                                *buf_size - sk_offset))
1743                         break;
1744
1745                 ret = btrfs_search_forward(root, &key, path, sk->min_transid);
1746                 if (ret != 0) {
1747                         if (ret > 0)
1748                                 ret = 0;
1749                         goto err;
1750                 }
1751                 ret = copy_to_sk(path, &key, sk, buf_size, ubuf,
1752                                  &sk_offset, &num_found);
1753                 btrfs_release_path(path);
1754                 if (ret)
1755                         break;
1756
1757         }
1758         if (ret > 0)
1759                 ret = 0;
1760 err:
1761         sk->nr_items = num_found;
1762         btrfs_put_root(root);
1763         btrfs_free_path(path);
1764         return ret;
1765 }
1766
1767 static noinline int btrfs_ioctl_tree_search(struct inode *inode,
1768                                             void __user *argp)
1769 {
1770         struct btrfs_ioctl_search_args __user *uargs = argp;
1771         struct btrfs_ioctl_search_key sk;
1772         int ret;
1773         u64 buf_size;
1774
1775         if (!capable(CAP_SYS_ADMIN))
1776                 return -EPERM;
1777
1778         if (copy_from_user(&sk, &uargs->key, sizeof(sk)))
1779                 return -EFAULT;
1780
1781         buf_size = sizeof(uargs->buf);
1782
1783         ret = search_ioctl(inode, &sk, &buf_size, uargs->buf);
1784
1785         /*
1786          * In the origin implementation an overflow is handled by returning a
1787          * search header with a len of zero, so reset ret.
1788          */
1789         if (ret == -EOVERFLOW)
1790                 ret = 0;
1791
1792         if (ret == 0 && copy_to_user(&uargs->key, &sk, sizeof(sk)))
1793                 ret = -EFAULT;
1794         return ret;
1795 }
1796
1797 static noinline int btrfs_ioctl_tree_search_v2(struct inode *inode,
1798                                                void __user *argp)
1799 {
1800         struct btrfs_ioctl_search_args_v2 __user *uarg = argp;
1801         struct btrfs_ioctl_search_args_v2 args;
1802         int ret;
1803         u64 buf_size;
1804         const u64 buf_limit = SZ_16M;
1805
1806         if (!capable(CAP_SYS_ADMIN))
1807                 return -EPERM;
1808
1809         /* copy search header and buffer size */
1810         if (copy_from_user(&args, uarg, sizeof(args)))
1811                 return -EFAULT;
1812
1813         buf_size = args.buf_size;
1814
1815         /* limit result size to 16MB */
1816         if (buf_size > buf_limit)
1817                 buf_size = buf_limit;
1818
1819         ret = search_ioctl(inode, &args.key, &buf_size,
1820                            (char __user *)(&uarg->buf[0]));
1821         if (ret == 0 && copy_to_user(&uarg->key, &args.key, sizeof(args.key)))
1822                 ret = -EFAULT;
1823         else if (ret == -EOVERFLOW &&
1824                 copy_to_user(&uarg->buf_size, &buf_size, sizeof(buf_size)))
1825                 ret = -EFAULT;
1826
1827         return ret;
1828 }
1829
1830 /*
1831  * Search INODE_REFs to identify path name of 'dirid' directory
1832  * in a 'tree_id' tree. and sets path name to 'name'.
1833  */
1834 static noinline int btrfs_search_path_in_tree(struct btrfs_fs_info *info,
1835                                 u64 tree_id, u64 dirid, char *name)
1836 {
1837         struct btrfs_root *root;
1838         struct btrfs_key key;
1839         char *ptr;
1840         int ret = -1;
1841         int slot;
1842         int len;
1843         int total_len = 0;
1844         struct btrfs_inode_ref *iref;
1845         struct extent_buffer *l;
1846         struct btrfs_path *path;
1847
1848         if (dirid == BTRFS_FIRST_FREE_OBJECTID) {
1849                 name[0]='\0';
1850                 return 0;
1851         }
1852
1853         path = btrfs_alloc_path();
1854         if (!path)
1855                 return -ENOMEM;
1856
1857         ptr = &name[BTRFS_INO_LOOKUP_PATH_MAX - 1];
1858
1859         root = btrfs_get_fs_root(info, tree_id, true);
1860         if (IS_ERR(root)) {
1861                 ret = PTR_ERR(root);
1862                 root = NULL;
1863                 goto out;
1864         }
1865
1866         key.objectid = dirid;
1867         key.type = BTRFS_INODE_REF_KEY;
1868         key.offset = (u64)-1;
1869
1870         while (1) {
1871                 ret = btrfs_search_backwards(root, &key, path);
1872                 if (ret < 0)
1873                         goto out;
1874                 else if (ret > 0) {
1875                         ret = -ENOENT;
1876                         goto out;
1877                 }
1878
1879                 l = path->nodes[0];
1880                 slot = path->slots[0];
1881
1882                 iref = btrfs_item_ptr(l, slot, struct btrfs_inode_ref);
1883                 len = btrfs_inode_ref_name_len(l, iref);
1884                 ptr -= len + 1;
1885                 total_len += len + 1;
1886                 if (ptr < name) {
1887                         ret = -ENAMETOOLONG;
1888                         goto out;
1889                 }
1890
1891                 *(ptr + len) = '/';
1892                 read_extent_buffer(l, ptr, (unsigned long)(iref + 1), len);
1893
1894                 if (key.offset == BTRFS_FIRST_FREE_OBJECTID)
1895                         break;
1896
1897                 btrfs_release_path(path);
1898                 key.objectid = key.offset;
1899                 key.offset = (u64)-1;
1900                 dirid = key.objectid;
1901         }
1902         memmove(name, ptr, total_len);
1903         name[total_len] = '\0';
1904         ret = 0;
1905 out:
1906         btrfs_put_root(root);
1907         btrfs_free_path(path);
1908         return ret;
1909 }
1910
1911 static int btrfs_search_path_in_tree_user(struct mnt_idmap *idmap,
1912                                 struct inode *inode,
1913                                 struct btrfs_ioctl_ino_lookup_user_args *args)
1914 {
1915         struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
1916         u64 upper_limit = btrfs_ino(BTRFS_I(inode));
1917         u64 treeid = btrfs_root_id(BTRFS_I(inode)->root);
1918         u64 dirid = args->dirid;
1919         unsigned long item_off;
1920         unsigned long item_len;
1921         struct btrfs_inode_ref *iref;
1922         struct btrfs_root_ref *rref;
1923         struct btrfs_root *root = NULL;
1924         struct btrfs_path *path;
1925         struct btrfs_key key, key2;
1926         struct extent_buffer *leaf;
1927         struct inode *temp_inode;
1928         char *ptr;
1929         int slot;
1930         int len;
1931         int total_len = 0;
1932         int ret;
1933
1934         path = btrfs_alloc_path();
1935         if (!path)
1936                 return -ENOMEM;
1937
1938         /*
1939          * If the bottom subvolume does not exist directly under upper_limit,
1940          * construct the path in from the bottom up.
1941          */
1942         if (dirid != upper_limit) {
1943                 ptr = &args->path[BTRFS_INO_LOOKUP_USER_PATH_MAX - 1];
1944
1945                 root = btrfs_get_fs_root(fs_info, treeid, true);
1946                 if (IS_ERR(root)) {
1947                         ret = PTR_ERR(root);
1948                         goto out;
1949                 }
1950
1951                 key.objectid = dirid;
1952                 key.type = BTRFS_INODE_REF_KEY;
1953                 key.offset = (u64)-1;
1954                 while (1) {
1955                         ret = btrfs_search_backwards(root, &key, path);
1956                         if (ret < 0)
1957                                 goto out_put;
1958                         else if (ret > 0) {
1959                                 ret = -ENOENT;
1960                                 goto out_put;
1961                         }
1962
1963                         leaf = path->nodes[0];
1964                         slot = path->slots[0];
1965
1966                         iref = btrfs_item_ptr(leaf, slot, struct btrfs_inode_ref);
1967                         len = btrfs_inode_ref_name_len(leaf, iref);
1968                         ptr -= len + 1;
1969                         total_len += len + 1;
1970                         if (ptr < args->path) {
1971                                 ret = -ENAMETOOLONG;
1972                                 goto out_put;
1973                         }
1974
1975                         *(ptr + len) = '/';
1976                         read_extent_buffer(leaf, ptr,
1977                                         (unsigned long)(iref + 1), len);
1978
1979                         /* Check the read+exec permission of this directory */
1980                         ret = btrfs_previous_item(root, path, dirid,
1981                                                   BTRFS_INODE_ITEM_KEY);
1982                         if (ret < 0) {
1983                                 goto out_put;
1984                         } else if (ret > 0) {
1985                                 ret = -ENOENT;
1986                                 goto out_put;
1987                         }
1988
1989                         leaf = path->nodes[0];
1990                         slot = path->slots[0];
1991                         btrfs_item_key_to_cpu(leaf, &key2, slot);
1992                         if (key2.objectid != dirid) {
1993                                 ret = -ENOENT;
1994                                 goto out_put;
1995                         }
1996
1997                         /*
1998                          * We don't need the path anymore, so release it and
1999                          * avoid deadlocks and lockdep warnings in case
2000                          * btrfs_iget() needs to lookup the inode from its root
2001                          * btree and lock the same leaf.
2002                          */
2003                         btrfs_release_path(path);
2004                         temp_inode = btrfs_iget(key2.objectid, root);
2005                         if (IS_ERR(temp_inode)) {
2006                                 ret = PTR_ERR(temp_inode);
2007                                 goto out_put;
2008                         }
2009                         ret = inode_permission(idmap, temp_inode,
2010                                                MAY_READ | MAY_EXEC);
2011                         iput(temp_inode);
2012                         if (ret) {
2013                                 ret = -EACCES;
2014                                 goto out_put;
2015                         }
2016
2017                         if (key.offset == upper_limit)
2018                                 break;
2019                         if (key.objectid == BTRFS_FIRST_FREE_OBJECTID) {
2020                                 ret = -EACCES;
2021                                 goto out_put;
2022                         }
2023
2024                         key.objectid = key.offset;
2025                         key.offset = (u64)-1;
2026                         dirid = key.objectid;
2027                 }
2028
2029                 memmove(args->path, ptr, total_len);
2030                 args->path[total_len] = '\0';
2031                 btrfs_put_root(root);
2032                 root = NULL;
2033                 btrfs_release_path(path);
2034         }
2035
2036         /* Get the bottom subvolume's name from ROOT_REF */
2037         key.objectid = treeid;
2038         key.type = BTRFS_ROOT_REF_KEY;
2039         key.offset = args->treeid;
2040         ret = btrfs_search_slot(NULL, fs_info->tree_root, &key, path, 0, 0);
2041         if (ret < 0) {
2042                 goto out;
2043         } else if (ret > 0) {
2044                 ret = -ENOENT;
2045                 goto out;
2046         }
2047
2048         leaf = path->nodes[0];
2049         slot = path->slots[0];
2050         btrfs_item_key_to_cpu(leaf, &key, slot);
2051
2052         item_off = btrfs_item_ptr_offset(leaf, slot);
2053         item_len = btrfs_item_size(leaf, slot);
2054         /* Check if dirid in ROOT_REF corresponds to passed dirid */
2055         rref = btrfs_item_ptr(leaf, slot, struct btrfs_root_ref);
2056         if (args->dirid != btrfs_root_ref_dirid(leaf, rref)) {
2057                 ret = -EINVAL;
2058                 goto out;
2059         }
2060
2061         /* Copy subvolume's name */
2062         item_off += sizeof(struct btrfs_root_ref);
2063         item_len -= sizeof(struct btrfs_root_ref);
2064         read_extent_buffer(leaf, args->name, item_off, item_len);
2065         args->name[item_len] = 0;
2066
2067 out_put:
2068         btrfs_put_root(root);
2069 out:
2070         btrfs_free_path(path);
2071         return ret;
2072 }
2073
2074 static noinline int btrfs_ioctl_ino_lookup(struct btrfs_root *root,
2075                                            void __user *argp)
2076 {
2077         struct btrfs_ioctl_ino_lookup_args *args;
2078         int ret = 0;
2079
2080         args = memdup_user(argp, sizeof(*args));
2081         if (IS_ERR(args))
2082                 return PTR_ERR(args);
2083
2084         /*
2085          * Unprivileged query to obtain the containing subvolume root id. The
2086          * path is reset so it's consistent with btrfs_search_path_in_tree.
2087          */
2088         if (args->treeid == 0)
2089                 args->treeid = btrfs_root_id(root);
2090
2091         if (args->objectid == BTRFS_FIRST_FREE_OBJECTID) {
2092                 args->name[0] = 0;
2093                 goto out;
2094         }
2095
2096         if (!capable(CAP_SYS_ADMIN)) {
2097                 ret = -EPERM;
2098                 goto out;
2099         }
2100
2101         ret = btrfs_search_path_in_tree(root->fs_info,
2102                                         args->treeid, args->objectid,
2103                                         args->name);
2104
2105 out:
2106         if (ret == 0 && copy_to_user(argp, args, sizeof(*args)))
2107                 ret = -EFAULT;
2108
2109         kfree(args);
2110         return ret;
2111 }
2112
2113 /*
2114  * Version of ino_lookup ioctl (unprivileged)
2115  *
2116  * The main differences from ino_lookup ioctl are:
2117  *
2118  *   1. Read + Exec permission will be checked using inode_permission() during
2119  *      path construction. -EACCES will be returned in case of failure.
2120  *   2. Path construction will be stopped at the inode number which corresponds
2121  *      to the fd with which this ioctl is called. If constructed path does not
2122  *      exist under fd's inode, -EACCES will be returned.
2123  *   3. The name of bottom subvolume is also searched and filled.
2124  */
2125 static int btrfs_ioctl_ino_lookup_user(struct file *file, void __user *argp)
2126 {
2127         struct btrfs_ioctl_ino_lookup_user_args *args;
2128         struct inode *inode;
2129         int ret;
2130
2131         args = memdup_user(argp, sizeof(*args));
2132         if (IS_ERR(args))
2133                 return PTR_ERR(args);
2134
2135         inode = file_inode(file);
2136
2137         if (args->dirid == BTRFS_FIRST_FREE_OBJECTID &&
2138             btrfs_ino(BTRFS_I(inode)) != BTRFS_FIRST_FREE_OBJECTID) {
2139                 /*
2140                  * The subvolume does not exist under fd with which this is
2141                  * called
2142                  */
2143                 kfree(args);
2144                 return -EACCES;
2145         }
2146
2147         ret = btrfs_search_path_in_tree_user(file_mnt_idmap(file), inode, args);
2148
2149         if (ret == 0 && copy_to_user(argp, args, sizeof(*args)))
2150                 ret = -EFAULT;
2151
2152         kfree(args);
2153         return ret;
2154 }
2155
2156 /* Get the subvolume information in BTRFS_ROOT_ITEM and BTRFS_ROOT_BACKREF */
2157 static int btrfs_ioctl_get_subvol_info(struct inode *inode, void __user *argp)
2158 {
2159         struct btrfs_ioctl_get_subvol_info_args *subvol_info;
2160         struct btrfs_fs_info *fs_info;
2161         struct btrfs_root *root;
2162         struct btrfs_path *path;
2163         struct btrfs_key key;
2164         struct btrfs_root_item *root_item;
2165         struct btrfs_root_ref *rref;
2166         struct extent_buffer *leaf;
2167         unsigned long item_off;
2168         unsigned long item_len;
2169         int slot;
2170         int ret = 0;
2171
2172         path = btrfs_alloc_path();
2173         if (!path)
2174                 return -ENOMEM;
2175
2176         subvol_info = kzalloc(sizeof(*subvol_info), GFP_KERNEL);
2177         if (!subvol_info) {
2178                 btrfs_free_path(path);
2179                 return -ENOMEM;
2180         }
2181
2182         fs_info = BTRFS_I(inode)->root->fs_info;
2183
2184         /* Get root_item of inode's subvolume */
2185         key.objectid = btrfs_root_id(BTRFS_I(inode)->root);
2186         root = btrfs_get_fs_root(fs_info, key.objectid, true);
2187         if (IS_ERR(root)) {
2188                 ret = PTR_ERR(root);
2189                 goto out_free;
2190         }
2191         root_item = &root->root_item;
2192
2193         subvol_info->treeid = key.objectid;
2194
2195         subvol_info->generation = btrfs_root_generation(root_item);
2196         subvol_info->flags = btrfs_root_flags(root_item);
2197
2198         memcpy(subvol_info->uuid, root_item->uuid, BTRFS_UUID_SIZE);
2199         memcpy(subvol_info->parent_uuid, root_item->parent_uuid,
2200                                                     BTRFS_UUID_SIZE);
2201         memcpy(subvol_info->received_uuid, root_item->received_uuid,
2202                                                     BTRFS_UUID_SIZE);
2203
2204         subvol_info->ctransid = btrfs_root_ctransid(root_item);
2205         subvol_info->ctime.sec = btrfs_stack_timespec_sec(&root_item->ctime);
2206         subvol_info->ctime.nsec = btrfs_stack_timespec_nsec(&root_item->ctime);
2207
2208         subvol_info->otransid = btrfs_root_otransid(root_item);
2209         subvol_info->otime.sec = btrfs_stack_timespec_sec(&root_item->otime);
2210         subvol_info->otime.nsec = btrfs_stack_timespec_nsec(&root_item->otime);
2211
2212         subvol_info->stransid = btrfs_root_stransid(root_item);
2213         subvol_info->stime.sec = btrfs_stack_timespec_sec(&root_item->stime);
2214         subvol_info->stime.nsec = btrfs_stack_timespec_nsec(&root_item->stime);
2215
2216         subvol_info->rtransid = btrfs_root_rtransid(root_item);
2217         subvol_info->rtime.sec = btrfs_stack_timespec_sec(&root_item->rtime);
2218         subvol_info->rtime.nsec = btrfs_stack_timespec_nsec(&root_item->rtime);
2219
2220         if (key.objectid != BTRFS_FS_TREE_OBJECTID) {
2221                 /* Search root tree for ROOT_BACKREF of this subvolume */
2222                 key.type = BTRFS_ROOT_BACKREF_KEY;
2223                 key.offset = 0;
2224                 ret = btrfs_search_slot(NULL, fs_info->tree_root, &key, path, 0, 0);
2225                 if (ret < 0) {
2226                         goto out;
2227                 } else if (path->slots[0] >=
2228                            btrfs_header_nritems(path->nodes[0])) {
2229                         ret = btrfs_next_leaf(fs_info->tree_root, path);
2230                         if (ret < 0) {
2231                                 goto out;
2232                         } else if (ret > 0) {
2233                                 ret = -EUCLEAN;
2234                                 goto out;
2235                         }
2236                 }
2237
2238                 leaf = path->nodes[0];
2239                 slot = path->slots[0];
2240                 btrfs_item_key_to_cpu(leaf, &key, slot);
2241                 if (key.objectid == subvol_info->treeid &&
2242                     key.type == BTRFS_ROOT_BACKREF_KEY) {
2243                         subvol_info->parent_id = key.offset;
2244
2245                         rref = btrfs_item_ptr(leaf, slot, struct btrfs_root_ref);
2246                         subvol_info->dirid = btrfs_root_ref_dirid(leaf, rref);
2247
2248                         item_off = btrfs_item_ptr_offset(leaf, slot)
2249                                         + sizeof(struct btrfs_root_ref);
2250                         item_len = btrfs_item_size(leaf, slot)
2251                                         - sizeof(struct btrfs_root_ref);
2252                         read_extent_buffer(leaf, subvol_info->name,
2253                                            item_off, item_len);
2254                 } else {
2255                         ret = -ENOENT;
2256                         goto out;
2257                 }
2258         }
2259
2260         btrfs_free_path(path);
2261         path = NULL;
2262         if (copy_to_user(argp, subvol_info, sizeof(*subvol_info)))
2263                 ret = -EFAULT;
2264
2265 out:
2266         btrfs_put_root(root);
2267 out_free:
2268         btrfs_free_path(path);
2269         kfree(subvol_info);
2270         return ret;
2271 }
2272
2273 /*
2274  * Return ROOT_REF information of the subvolume containing this inode
2275  * except the subvolume name.
2276  */
2277 static int btrfs_ioctl_get_subvol_rootref(struct btrfs_root *root,
2278                                           void __user *argp)
2279 {
2280         struct btrfs_ioctl_get_subvol_rootref_args *rootrefs;
2281         struct btrfs_root_ref *rref;
2282         struct btrfs_path *path;
2283         struct btrfs_key key;
2284         struct extent_buffer *leaf;
2285         u64 objectid;
2286         int slot;
2287         int ret;
2288         u8 found;
2289
2290         path = btrfs_alloc_path();
2291         if (!path)
2292                 return -ENOMEM;
2293
2294         rootrefs = memdup_user(argp, sizeof(*rootrefs));
2295         if (IS_ERR(rootrefs)) {
2296                 btrfs_free_path(path);
2297                 return PTR_ERR(rootrefs);
2298         }
2299
2300         objectid = btrfs_root_id(root);
2301         key.objectid = objectid;
2302         key.type = BTRFS_ROOT_REF_KEY;
2303         key.offset = rootrefs->min_treeid;
2304         found = 0;
2305
2306         root = root->fs_info->tree_root;
2307         ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2308         if (ret < 0) {
2309                 goto out;
2310         } else if (path->slots[0] >=
2311                    btrfs_header_nritems(path->nodes[0])) {
2312                 ret = btrfs_next_leaf(root, path);
2313                 if (ret < 0) {
2314                         goto out;
2315                 } else if (ret > 0) {
2316                         ret = -EUCLEAN;
2317                         goto out;
2318                 }
2319         }
2320         while (1) {
2321                 leaf = path->nodes[0];
2322                 slot = path->slots[0];
2323
2324                 btrfs_item_key_to_cpu(leaf, &key, slot);
2325                 if (key.objectid != objectid || key.type != BTRFS_ROOT_REF_KEY) {
2326                         ret = 0;
2327                         goto out;
2328                 }
2329
2330                 if (found == BTRFS_MAX_ROOTREF_BUFFER_NUM) {
2331                         ret = -EOVERFLOW;
2332                         goto out;
2333                 }
2334
2335                 rref = btrfs_item_ptr(leaf, slot, struct btrfs_root_ref);
2336                 rootrefs->rootref[found].treeid = key.offset;
2337                 rootrefs->rootref[found].dirid =
2338                                   btrfs_root_ref_dirid(leaf, rref);
2339                 found++;
2340
2341                 ret = btrfs_next_item(root, path);
2342                 if (ret < 0) {
2343                         goto out;
2344                 } else if (ret > 0) {
2345                         ret = -EUCLEAN;
2346                         goto out;
2347                 }
2348         }
2349
2350 out:
2351         btrfs_free_path(path);
2352
2353         if (!ret || ret == -EOVERFLOW) {
2354                 rootrefs->num_items = found;
2355                 /* update min_treeid for next search */
2356                 if (found)
2357                         rootrefs->min_treeid =
2358                                 rootrefs->rootref[found - 1].treeid + 1;
2359                 if (copy_to_user(argp, rootrefs, sizeof(*rootrefs)))
2360                         ret = -EFAULT;
2361         }
2362
2363         kfree(rootrefs);
2364
2365         return ret;
2366 }
2367
2368 static noinline int btrfs_ioctl_snap_destroy(struct file *file,
2369                                              void __user *arg,
2370                                              bool destroy_v2)
2371 {
2372         struct dentry *parent = file->f_path.dentry;
2373         struct dentry *dentry;
2374         struct inode *dir = d_inode(parent);
2375         struct btrfs_fs_info *fs_info = inode_to_fs_info(dir);
2376         struct inode *inode;
2377         struct btrfs_root *root = BTRFS_I(dir)->root;
2378         struct btrfs_root *dest = NULL;
2379         struct btrfs_ioctl_vol_args *vol_args = NULL;
2380         struct btrfs_ioctl_vol_args_v2 *vol_args2 = NULL;
2381         struct mnt_idmap *idmap = file_mnt_idmap(file);
2382         char *subvol_name, *subvol_name_ptr = NULL;
2383         int subvol_namelen;
2384         int ret = 0;
2385         bool destroy_parent = false;
2386
2387         /* We don't support snapshots with extent tree v2 yet. */
2388         if (btrfs_fs_incompat(fs_info, EXTENT_TREE_V2)) {
2389                 btrfs_err(fs_info,
2390                           "extent tree v2 doesn't support snapshot deletion yet");
2391                 return -EOPNOTSUPP;
2392         }
2393
2394         if (destroy_v2) {
2395                 vol_args2 = memdup_user(arg, sizeof(*vol_args2));
2396                 if (IS_ERR(vol_args2))
2397                         return PTR_ERR(vol_args2);
2398
2399                 if (vol_args2->flags & ~BTRFS_SUBVOL_DELETE_ARGS_MASK) {
2400                         ret = -EOPNOTSUPP;
2401                         goto out;
2402                 }
2403
2404                 /*
2405                  * If SPEC_BY_ID is not set, we are looking for the subvolume by
2406                  * name, same as v1 currently does.
2407                  */
2408                 if (!(vol_args2->flags & BTRFS_SUBVOL_SPEC_BY_ID)) {
2409                         ret = btrfs_check_ioctl_vol_args2_subvol_name(vol_args2);
2410                         if (ret < 0)
2411                                 goto out;
2412                         subvol_name = vol_args2->name;
2413
2414                         ret = mnt_want_write_file(file);
2415                         if (ret)
2416                                 goto out;
2417                 } else {
2418                         struct inode *old_dir;
2419
2420                         if (vol_args2->subvolid < BTRFS_FIRST_FREE_OBJECTID) {
2421                                 ret = -EINVAL;
2422                                 goto out;
2423                         }
2424
2425                         ret = mnt_want_write_file(file);
2426                         if (ret)
2427                                 goto out;
2428
2429                         dentry = btrfs_get_dentry(fs_info->sb,
2430                                         BTRFS_FIRST_FREE_OBJECTID,
2431                                         vol_args2->subvolid, 0);
2432                         if (IS_ERR(dentry)) {
2433                                 ret = PTR_ERR(dentry);
2434                                 goto out_drop_write;
2435                         }
2436
2437                         /*
2438                          * Change the default parent since the subvolume being
2439                          * deleted can be outside of the current mount point.
2440                          */
2441                         parent = btrfs_get_parent(dentry);
2442
2443                         /*
2444                          * At this point dentry->d_name can point to '/' if the
2445                          * subvolume we want to destroy is outsite of the
2446                          * current mount point, so we need to release the
2447                          * current dentry and execute the lookup to return a new
2448                          * one with ->d_name pointing to the
2449                          * <mount point>/subvol_name.
2450                          */
2451                         dput(dentry);
2452                         if (IS_ERR(parent)) {
2453                                 ret = PTR_ERR(parent);
2454                                 goto out_drop_write;
2455                         }
2456                         old_dir = dir;
2457                         dir = d_inode(parent);
2458
2459                         /*
2460                          * If v2 was used with SPEC_BY_ID, a new parent was
2461                          * allocated since the subvolume can be outside of the
2462                          * current mount point. Later on we need to release this
2463                          * new parent dentry.
2464                          */
2465                         destroy_parent = true;
2466
2467                         /*
2468                          * On idmapped mounts, deletion via subvolid is
2469                          * restricted to subvolumes that are immediate
2470                          * ancestors of the inode referenced by the file
2471                          * descriptor in the ioctl. Otherwise the idmapping
2472                          * could potentially be abused to delete subvolumes
2473                          * anywhere in the filesystem the user wouldn't be able
2474                          * to delete without an idmapped mount.
2475                          */
2476                         if (old_dir != dir && idmap != &nop_mnt_idmap) {
2477                                 ret = -EOPNOTSUPP;
2478                                 goto free_parent;
2479                         }
2480
2481                         subvol_name_ptr = btrfs_get_subvol_name_from_objectid(
2482                                                 fs_info, vol_args2->subvolid);
2483                         if (IS_ERR(subvol_name_ptr)) {
2484                                 ret = PTR_ERR(subvol_name_ptr);
2485                                 goto free_parent;
2486                         }
2487                         /* subvol_name_ptr is already nul terminated */
2488                         subvol_name = (char *)kbasename(subvol_name_ptr);
2489                 }
2490         } else {
2491                 vol_args = memdup_user(arg, sizeof(*vol_args));
2492                 if (IS_ERR(vol_args))
2493                         return PTR_ERR(vol_args);
2494
2495                 ret = btrfs_check_ioctl_vol_args_path(vol_args);
2496                 if (ret < 0)
2497                         goto out;
2498
2499                 subvol_name = vol_args->name;
2500
2501                 ret = mnt_want_write_file(file);
2502                 if (ret)
2503                         goto out;
2504         }
2505
2506         subvol_namelen = strlen(subvol_name);
2507
2508         if (strchr(subvol_name, '/') ||
2509             strncmp(subvol_name, "..", subvol_namelen) == 0) {
2510                 ret = -EINVAL;
2511                 goto free_subvol_name;
2512         }
2513
2514         if (!S_ISDIR(dir->i_mode)) {
2515                 ret = -ENOTDIR;
2516                 goto free_subvol_name;
2517         }
2518
2519         ret = down_write_killable_nested(&dir->i_rwsem, I_MUTEX_PARENT);
2520         if (ret == -EINTR)
2521                 goto free_subvol_name;
2522         dentry = lookup_one(idmap, subvol_name, parent, subvol_namelen);
2523         if (IS_ERR(dentry)) {
2524                 ret = PTR_ERR(dentry);
2525                 goto out_unlock_dir;
2526         }
2527
2528         if (d_really_is_negative(dentry)) {
2529                 ret = -ENOENT;
2530                 goto out_dput;
2531         }
2532
2533         inode = d_inode(dentry);
2534         dest = BTRFS_I(inode)->root;
2535         if (!capable(CAP_SYS_ADMIN)) {
2536                 /*
2537                  * Regular user.  Only allow this with a special mount
2538                  * option, when the user has write+exec access to the
2539                  * subvol root, and when rmdir(2) would have been
2540                  * allowed.
2541                  *
2542                  * Note that this is _not_ check that the subvol is
2543                  * empty or doesn't contain data that we wouldn't
2544                  * otherwise be able to delete.
2545                  *
2546                  * Users who want to delete empty subvols should try
2547                  * rmdir(2).
2548                  */
2549                 ret = -EPERM;
2550                 if (!btrfs_test_opt(fs_info, USER_SUBVOL_RM_ALLOWED))
2551                         goto out_dput;
2552
2553                 /*
2554                  * Do not allow deletion if the parent dir is the same
2555                  * as the dir to be deleted.  That means the ioctl
2556                  * must be called on the dentry referencing the root
2557                  * of the subvol, not a random directory contained
2558                  * within it.
2559                  */
2560                 ret = -EINVAL;
2561                 if (root == dest)
2562                         goto out_dput;
2563
2564                 ret = inode_permission(idmap, inode, MAY_WRITE | MAY_EXEC);
2565                 if (ret)
2566                         goto out_dput;
2567         }
2568
2569         /* check if subvolume may be deleted by a user */
2570         ret = btrfs_may_delete(idmap, dir, dentry, 1);
2571         if (ret)
2572                 goto out_dput;
2573
2574         if (btrfs_ino(BTRFS_I(inode)) != BTRFS_FIRST_FREE_OBJECTID) {
2575                 ret = -EINVAL;
2576                 goto out_dput;
2577         }
2578
2579         btrfs_inode_lock(BTRFS_I(inode), 0);
2580         ret = btrfs_delete_subvolume(BTRFS_I(dir), dentry);
2581         btrfs_inode_unlock(BTRFS_I(inode), 0);
2582         if (!ret)
2583                 d_delete_notify(dir, dentry);
2584
2585 out_dput:
2586         dput(dentry);
2587 out_unlock_dir:
2588         btrfs_inode_unlock(BTRFS_I(dir), 0);
2589 free_subvol_name:
2590         kfree(subvol_name_ptr);
2591 free_parent:
2592         if (destroy_parent)
2593                 dput(parent);
2594 out_drop_write:
2595         mnt_drop_write_file(file);
2596 out:
2597         kfree(vol_args2);
2598         kfree(vol_args);
2599         return ret;
2600 }
2601
2602 static int btrfs_ioctl_defrag(struct file *file, void __user *argp)
2603 {
2604         struct inode *inode = file_inode(file);
2605         struct btrfs_root *root = BTRFS_I(inode)->root;
2606         struct btrfs_ioctl_defrag_range_args range = {0};
2607         int ret;
2608
2609         ret = mnt_want_write_file(file);
2610         if (ret)
2611                 return ret;
2612
2613         if (btrfs_root_readonly(root)) {
2614                 ret = -EROFS;
2615                 goto out;
2616         }
2617
2618         switch (inode->i_mode & S_IFMT) {
2619         case S_IFDIR:
2620                 if (!capable(CAP_SYS_ADMIN)) {
2621                         ret = -EPERM;
2622                         goto out;
2623                 }
2624                 ret = btrfs_defrag_root(root);
2625                 break;
2626         case S_IFREG:
2627                 /*
2628                  * Note that this does not check the file descriptor for write
2629                  * access. This prevents defragmenting executables that are
2630                  * running and allows defrag on files open in read-only mode.
2631                  */
2632                 if (!capable(CAP_SYS_ADMIN) &&
2633                     inode_permission(&nop_mnt_idmap, inode, MAY_WRITE)) {
2634                         ret = -EPERM;
2635                         goto out;
2636                 }
2637
2638                 if (argp) {
2639                         if (copy_from_user(&range, argp, sizeof(range))) {
2640                                 ret = -EFAULT;
2641                                 goto out;
2642                         }
2643                         if (range.flags & ~BTRFS_DEFRAG_RANGE_FLAGS_SUPP) {
2644                                 ret = -EOPNOTSUPP;
2645                                 goto out;
2646                         }
2647                         /* compression requires us to start the IO */
2648                         if ((range.flags & BTRFS_DEFRAG_RANGE_COMPRESS)) {
2649                                 range.flags |= BTRFS_DEFRAG_RANGE_START_IO;
2650                                 range.extent_thresh = (u32)-1;
2651                         }
2652                 } else {
2653                         /* the rest are all set to zero by kzalloc */
2654                         range.len = (u64)-1;
2655                 }
2656                 ret = btrfs_defrag_file(file_inode(file), &file->f_ra,
2657                                         &range, BTRFS_OLDEST_GENERATION, 0);
2658                 if (ret > 0)
2659                         ret = 0;
2660                 break;
2661         default:
2662                 ret = -EINVAL;
2663         }
2664 out:
2665         mnt_drop_write_file(file);
2666         return ret;
2667 }
2668
2669 static long btrfs_ioctl_add_dev(struct btrfs_fs_info *fs_info, void __user *arg)
2670 {
2671         struct btrfs_ioctl_vol_args *vol_args;
2672         bool restore_op = false;
2673         int ret;
2674
2675         if (!capable(CAP_SYS_ADMIN))
2676                 return -EPERM;
2677
2678         if (btrfs_fs_incompat(fs_info, EXTENT_TREE_V2)) {
2679                 btrfs_err(fs_info, "device add not supported on extent tree v2 yet");
2680                 return -EINVAL;
2681         }
2682
2683         if (fs_info->fs_devices->temp_fsid) {
2684                 btrfs_err(fs_info,
2685                           "device add not supported on cloned temp-fsid mount");
2686                 return -EINVAL;
2687         }
2688
2689         if (!btrfs_exclop_start(fs_info, BTRFS_EXCLOP_DEV_ADD)) {
2690                 if (!btrfs_exclop_start_try_lock(fs_info, BTRFS_EXCLOP_DEV_ADD))
2691                         return BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
2692
2693                 /*
2694                  * We can do the device add because we have a paused balanced,
2695                  * change the exclusive op type and remember we should bring
2696                  * back the paused balance
2697                  */
2698                 fs_info->exclusive_operation = BTRFS_EXCLOP_DEV_ADD;
2699                 btrfs_exclop_start_unlock(fs_info);
2700                 restore_op = true;
2701         }
2702
2703         vol_args = memdup_user(arg, sizeof(*vol_args));
2704         if (IS_ERR(vol_args)) {
2705                 ret = PTR_ERR(vol_args);
2706                 goto out;
2707         }
2708
2709         ret = btrfs_check_ioctl_vol_args_path(vol_args);
2710         if (ret < 0)
2711                 goto out_free;
2712
2713         ret = btrfs_init_new_device(fs_info, vol_args->name);
2714
2715         if (!ret)
2716                 btrfs_info(fs_info, "disk added %s", vol_args->name);
2717
2718 out_free:
2719         kfree(vol_args);
2720 out:
2721         if (restore_op)
2722                 btrfs_exclop_balance(fs_info, BTRFS_EXCLOP_BALANCE_PAUSED);
2723         else
2724                 btrfs_exclop_finish(fs_info);
2725         return ret;
2726 }
2727
2728 static long btrfs_ioctl_rm_dev_v2(struct file *file, void __user *arg)
2729 {
2730         BTRFS_DEV_LOOKUP_ARGS(args);
2731         struct inode *inode = file_inode(file);
2732         struct btrfs_fs_info *fs_info = inode_to_fs_info(inode);
2733         struct btrfs_ioctl_vol_args_v2 *vol_args;
2734         struct file *bdev_file = NULL;
2735         int ret;
2736         bool cancel = false;
2737
2738         if (!capable(CAP_SYS_ADMIN))
2739                 return -EPERM;
2740
2741         vol_args = memdup_user(arg, sizeof(*vol_args));
2742         if (IS_ERR(vol_args))
2743                 return PTR_ERR(vol_args);
2744
2745         if (vol_args->flags & ~BTRFS_DEVICE_REMOVE_ARGS_MASK) {
2746                 ret = -EOPNOTSUPP;
2747                 goto out;
2748         }
2749
2750         ret = btrfs_check_ioctl_vol_args2_subvol_name(vol_args);
2751         if (ret < 0)
2752                 goto out;
2753
2754         if (vol_args->flags & BTRFS_DEVICE_SPEC_BY_ID) {
2755                 args.devid = vol_args->devid;
2756         } else if (!strcmp("cancel", vol_args->name)) {
2757                 cancel = true;
2758         } else {
2759                 ret = btrfs_get_dev_args_from_path(fs_info, &args, vol_args->name);
2760                 if (ret)
2761                         goto out;
2762         }
2763
2764         ret = mnt_want_write_file(file);
2765         if (ret)
2766                 goto out;
2767
2768         ret = exclop_start_or_cancel_reloc(fs_info, BTRFS_EXCLOP_DEV_REMOVE,
2769                                            cancel);
2770         if (ret)
2771                 goto err_drop;
2772
2773         /* Exclusive operation is now claimed */
2774         ret = btrfs_rm_device(fs_info, &args, &bdev_file);
2775
2776         btrfs_exclop_finish(fs_info);
2777
2778         if (!ret) {
2779                 if (vol_args->flags & BTRFS_DEVICE_SPEC_BY_ID)
2780                         btrfs_info(fs_info, "device deleted: id %llu",
2781                                         vol_args->devid);
2782                 else
2783                         btrfs_info(fs_info, "device deleted: %s",
2784                                         vol_args->name);
2785         }
2786 err_drop:
2787         mnt_drop_write_file(file);
2788         if (bdev_file)
2789                 fput(bdev_file);
2790 out:
2791         btrfs_put_dev_args_from_path(&args);
2792         kfree(vol_args);
2793         return ret;
2794 }
2795
2796 static long btrfs_ioctl_rm_dev(struct file *file, void __user *arg)
2797 {
2798         BTRFS_DEV_LOOKUP_ARGS(args);
2799         struct inode *inode = file_inode(file);
2800         struct btrfs_fs_info *fs_info = inode_to_fs_info(inode);
2801         struct btrfs_ioctl_vol_args *vol_args;
2802         struct file *bdev_file = NULL;
2803         int ret;
2804         bool cancel = false;
2805
2806         if (!capable(CAP_SYS_ADMIN))
2807                 return -EPERM;
2808
2809         vol_args = memdup_user(arg, sizeof(*vol_args));
2810         if (IS_ERR(vol_args))
2811                 return PTR_ERR(vol_args);
2812
2813         ret = btrfs_check_ioctl_vol_args_path(vol_args);
2814         if (ret < 0)
2815                 goto out_free;
2816
2817         if (!strcmp("cancel", vol_args->name)) {
2818                 cancel = true;
2819         } else {
2820                 ret = btrfs_get_dev_args_from_path(fs_info, &args, vol_args->name);
2821                 if (ret)
2822                         goto out;
2823         }
2824
2825         ret = mnt_want_write_file(file);
2826         if (ret)
2827                 goto out;
2828
2829         ret = exclop_start_or_cancel_reloc(fs_info, BTRFS_EXCLOP_DEV_REMOVE,
2830                                            cancel);
2831         if (ret == 0) {
2832                 ret = btrfs_rm_device(fs_info, &args, &bdev_file);
2833                 if (!ret)
2834                         btrfs_info(fs_info, "disk deleted %s", vol_args->name);
2835                 btrfs_exclop_finish(fs_info);
2836         }
2837
2838         mnt_drop_write_file(file);
2839         if (bdev_file)
2840                 fput(bdev_file);
2841 out:
2842         btrfs_put_dev_args_from_path(&args);
2843 out_free:
2844         kfree(vol_args);
2845         return ret;
2846 }
2847
2848 static long btrfs_ioctl_fs_info(struct btrfs_fs_info *fs_info,
2849                                 void __user *arg)
2850 {
2851         struct btrfs_ioctl_fs_info_args *fi_args;
2852         struct btrfs_device *device;
2853         struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
2854         u64 flags_in;
2855         int ret = 0;
2856
2857         fi_args = memdup_user(arg, sizeof(*fi_args));
2858         if (IS_ERR(fi_args))
2859                 return PTR_ERR(fi_args);
2860
2861         flags_in = fi_args->flags;
2862         memset(fi_args, 0, sizeof(*fi_args));
2863
2864         rcu_read_lock();
2865         fi_args->num_devices = fs_devices->num_devices;
2866
2867         list_for_each_entry_rcu(device, &fs_devices->devices, dev_list) {
2868                 if (device->devid > fi_args->max_id)
2869                         fi_args->max_id = device->devid;
2870         }
2871         rcu_read_unlock();
2872
2873         memcpy(&fi_args->fsid, fs_devices->fsid, sizeof(fi_args->fsid));
2874         fi_args->nodesize = fs_info->nodesize;
2875         fi_args->sectorsize = fs_info->sectorsize;
2876         fi_args->clone_alignment = fs_info->sectorsize;
2877
2878         if (flags_in & BTRFS_FS_INFO_FLAG_CSUM_INFO) {
2879                 fi_args->csum_type = btrfs_super_csum_type(fs_info->super_copy);
2880                 fi_args->csum_size = btrfs_super_csum_size(fs_info->super_copy);
2881                 fi_args->flags |= BTRFS_FS_INFO_FLAG_CSUM_INFO;
2882         }
2883
2884         if (flags_in & BTRFS_FS_INFO_FLAG_GENERATION) {
2885                 fi_args->generation = btrfs_get_fs_generation(fs_info);
2886                 fi_args->flags |= BTRFS_FS_INFO_FLAG_GENERATION;
2887         }
2888
2889         if (flags_in & BTRFS_FS_INFO_FLAG_METADATA_UUID) {
2890                 memcpy(&fi_args->metadata_uuid, fs_devices->metadata_uuid,
2891                        sizeof(fi_args->metadata_uuid));
2892                 fi_args->flags |= BTRFS_FS_INFO_FLAG_METADATA_UUID;
2893         }
2894
2895         if (copy_to_user(arg, fi_args, sizeof(*fi_args)))
2896                 ret = -EFAULT;
2897
2898         kfree(fi_args);
2899         return ret;
2900 }
2901
2902 static long btrfs_ioctl_dev_info(struct btrfs_fs_info *fs_info,
2903                                  void __user *arg)
2904 {
2905         BTRFS_DEV_LOOKUP_ARGS(args);
2906         struct btrfs_ioctl_dev_info_args *di_args;
2907         struct btrfs_device *dev;
2908         int ret = 0;
2909
2910         di_args = memdup_user(arg, sizeof(*di_args));
2911         if (IS_ERR(di_args))
2912                 return PTR_ERR(di_args);
2913
2914         args.devid = di_args->devid;
2915         if (!btrfs_is_empty_uuid(di_args->uuid))
2916                 args.uuid = di_args->uuid;
2917
2918         rcu_read_lock();
2919         dev = btrfs_find_device(fs_info->fs_devices, &args);
2920         if (!dev) {
2921                 ret = -ENODEV;
2922                 goto out;
2923         }
2924
2925         di_args->devid = dev->devid;
2926         di_args->bytes_used = btrfs_device_get_bytes_used(dev);
2927         di_args->total_bytes = btrfs_device_get_total_bytes(dev);
2928         memcpy(di_args->uuid, dev->uuid, sizeof(di_args->uuid));
2929         memcpy(di_args->fsid, dev->fs_devices->fsid, BTRFS_UUID_SIZE);
2930         if (dev->name)
2931                 strscpy(di_args->path, btrfs_dev_name(dev), sizeof(di_args->path));
2932         else
2933                 di_args->path[0] = '\0';
2934
2935 out:
2936         rcu_read_unlock();
2937         if (ret == 0 && copy_to_user(arg, di_args, sizeof(*di_args)))
2938                 ret = -EFAULT;
2939
2940         kfree(di_args);
2941         return ret;
2942 }
2943
2944 static long btrfs_ioctl_default_subvol(struct file *file, void __user *argp)
2945 {
2946         struct inode *inode = file_inode(file);
2947         struct btrfs_fs_info *fs_info = inode_to_fs_info(inode);
2948         struct btrfs_root *root = BTRFS_I(inode)->root;
2949         struct btrfs_root *new_root;
2950         struct btrfs_dir_item *di;
2951         struct btrfs_trans_handle *trans;
2952         struct btrfs_path *path = NULL;
2953         struct btrfs_disk_key disk_key;
2954         struct fscrypt_str name = FSTR_INIT("default", 7);
2955         u64 objectid = 0;
2956         u64 dir_id;
2957         int ret;
2958
2959         if (!capable(CAP_SYS_ADMIN))
2960                 return -EPERM;
2961
2962         ret = mnt_want_write_file(file);
2963         if (ret)
2964                 return ret;
2965
2966         if (copy_from_user(&objectid, argp, sizeof(objectid))) {
2967                 ret = -EFAULT;
2968                 goto out;
2969         }
2970
2971         if (!objectid)
2972                 objectid = BTRFS_FS_TREE_OBJECTID;
2973
2974         new_root = btrfs_get_fs_root(fs_info, objectid, true);
2975         if (IS_ERR(new_root)) {
2976                 ret = PTR_ERR(new_root);
2977                 goto out;
2978         }
2979         if (!is_fstree(btrfs_root_id(new_root))) {
2980                 ret = -ENOENT;
2981                 goto out_free;
2982         }
2983
2984         path = btrfs_alloc_path();
2985         if (!path) {
2986                 ret = -ENOMEM;
2987                 goto out_free;
2988         }
2989
2990         trans = btrfs_start_transaction(root, 1);
2991         if (IS_ERR(trans)) {
2992                 ret = PTR_ERR(trans);
2993                 goto out_free;
2994         }
2995
2996         dir_id = btrfs_super_root_dir(fs_info->super_copy);
2997         di = btrfs_lookup_dir_item(trans, fs_info->tree_root, path,
2998                                    dir_id, &name, 1);
2999         if (IS_ERR_OR_NULL(di)) {
3000                 btrfs_release_path(path);
3001                 btrfs_end_transaction(trans);
3002                 btrfs_err(fs_info,
3003                           "Umm, you don't have the default diritem, this isn't going to work");
3004                 ret = -ENOENT;
3005                 goto out_free;
3006         }
3007
3008         btrfs_cpu_key_to_disk(&disk_key, &new_root->root_key);
3009         btrfs_set_dir_item_key(path->nodes[0], di, &disk_key);
3010         btrfs_mark_buffer_dirty(trans, path->nodes[0]);
3011         btrfs_release_path(path);
3012
3013         btrfs_set_fs_incompat(fs_info, DEFAULT_SUBVOL);
3014         btrfs_end_transaction(trans);
3015 out_free:
3016         btrfs_put_root(new_root);
3017         btrfs_free_path(path);
3018 out:
3019         mnt_drop_write_file(file);
3020         return ret;
3021 }
3022
3023 static void get_block_group_info(struct list_head *groups_list,
3024                                  struct btrfs_ioctl_space_info *space)
3025 {
3026         struct btrfs_block_group *block_group;
3027
3028         space->total_bytes = 0;
3029         space->used_bytes = 0;
3030         space->flags = 0;
3031         list_for_each_entry(block_group, groups_list, list) {
3032                 space->flags = block_group->flags;
3033                 space->total_bytes += block_group->length;
3034                 space->used_bytes += block_group->used;
3035         }
3036 }
3037
3038 static long btrfs_ioctl_space_info(struct btrfs_fs_info *fs_info,
3039                                    void __user *arg)
3040 {
3041         struct btrfs_ioctl_space_args space_args = { 0 };
3042         struct btrfs_ioctl_space_info space;
3043         struct btrfs_ioctl_space_info *dest;
3044         struct btrfs_ioctl_space_info *dest_orig;
3045         struct btrfs_ioctl_space_info __user *user_dest;
3046         struct btrfs_space_info *info;
3047         static const u64 types[] = {
3048                 BTRFS_BLOCK_GROUP_DATA,
3049                 BTRFS_BLOCK_GROUP_SYSTEM,
3050                 BTRFS_BLOCK_GROUP_METADATA,
3051                 BTRFS_BLOCK_GROUP_DATA | BTRFS_BLOCK_GROUP_METADATA
3052         };
3053         int num_types = 4;
3054         int alloc_size;
3055         int ret = 0;
3056         u64 slot_count = 0;
3057         int i, c;
3058
3059         if (copy_from_user(&space_args,
3060                            (struct btrfs_ioctl_space_args __user *)arg,
3061                            sizeof(space_args)))
3062                 return -EFAULT;
3063
3064         for (i = 0; i < num_types; i++) {
3065                 struct btrfs_space_info *tmp;
3066
3067                 info = NULL;
3068                 list_for_each_entry(tmp, &fs_info->space_info, list) {
3069                         if (tmp->flags == types[i]) {
3070                                 info = tmp;
3071                                 break;
3072                         }
3073                 }
3074
3075                 if (!info)
3076                         continue;
3077
3078                 down_read(&info->groups_sem);
3079                 for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) {
3080                         if (!list_empty(&info->block_groups[c]))
3081                                 slot_count++;
3082                 }
3083                 up_read(&info->groups_sem);
3084         }
3085
3086         /*
3087          * Global block reserve, exported as a space_info
3088          */
3089         slot_count++;
3090
3091         /* space_slots == 0 means they are asking for a count */
3092         if (space_args.space_slots == 0) {
3093                 space_args.total_spaces = slot_count;
3094                 goto out;
3095         }
3096
3097         slot_count = min_t(u64, space_args.space_slots, slot_count);
3098
3099         alloc_size = sizeof(*dest) * slot_count;
3100
3101         /* we generally have at most 6 or so space infos, one for each raid
3102          * level.  So, a whole page should be more than enough for everyone
3103          */
3104         if (alloc_size > PAGE_SIZE)
3105                 return -ENOMEM;
3106
3107         space_args.total_spaces = 0;
3108         dest = kmalloc(alloc_size, GFP_KERNEL);
3109         if (!dest)
3110                 return -ENOMEM;
3111         dest_orig = dest;
3112
3113         /* now we have a buffer to copy into */
3114         for (i = 0; i < num_types; i++) {
3115                 struct btrfs_space_info *tmp;
3116
3117                 if (!slot_count)
3118                         break;
3119
3120                 info = NULL;
3121                 list_for_each_entry(tmp, &fs_info->space_info, list) {
3122                         if (tmp->flags == types[i]) {
3123                                 info = tmp;
3124                                 break;
3125                         }
3126                 }
3127
3128                 if (!info)
3129                         continue;
3130                 down_read(&info->groups_sem);
3131                 for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) {
3132                         if (!list_empty(&info->block_groups[c])) {
3133                                 get_block_group_info(&info->block_groups[c],
3134                                                      &space);
3135                                 memcpy(dest, &space, sizeof(space));
3136                                 dest++;
3137                                 space_args.total_spaces++;
3138                                 slot_count--;
3139                         }
3140                         if (!slot_count)
3141                                 break;
3142                 }
3143                 up_read(&info->groups_sem);
3144         }
3145
3146         /*
3147          * Add global block reserve
3148          */
3149         if (slot_count) {
3150                 struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
3151
3152                 spin_lock(&block_rsv->lock);
3153                 space.total_bytes = block_rsv->size;
3154                 space.used_bytes = block_rsv->size - block_rsv->reserved;
3155                 spin_unlock(&block_rsv->lock);
3156                 space.flags = BTRFS_SPACE_INFO_GLOBAL_RSV;
3157                 memcpy(dest, &space, sizeof(space));
3158                 space_args.total_spaces++;
3159         }
3160
3161         user_dest = (struct btrfs_ioctl_space_info __user *)
3162                 (arg + sizeof(struct btrfs_ioctl_space_args));
3163
3164         if (copy_to_user(user_dest, dest_orig, alloc_size))
3165                 ret = -EFAULT;
3166
3167         kfree(dest_orig);
3168 out:
3169         if (ret == 0 && copy_to_user(arg, &space_args, sizeof(space_args)))
3170                 ret = -EFAULT;
3171
3172         return ret;
3173 }
3174
3175 static noinline long btrfs_ioctl_start_sync(struct btrfs_root *root,
3176                                             void __user *argp)
3177 {
3178         struct btrfs_trans_handle *trans;
3179         u64 transid;
3180
3181         /*
3182          * Start orphan cleanup here for the given root in case it hasn't been
3183          * started already by other means. Errors are handled in the other
3184          * functions during transaction commit.
3185          */
3186         btrfs_orphan_cleanup(root);
3187
3188         trans = btrfs_attach_transaction_barrier(root);
3189         if (IS_ERR(trans)) {
3190                 if (PTR_ERR(trans) != -ENOENT)
3191                         return PTR_ERR(trans);
3192
3193                 /* No running transaction, don't bother */
3194                 transid = btrfs_get_last_trans_committed(root->fs_info);
3195                 goto out;
3196         }
3197         transid = trans->transid;
3198         btrfs_commit_transaction_async(trans);
3199 out:
3200         if (argp)
3201                 if (copy_to_user(argp, &transid, sizeof(transid)))
3202                         return -EFAULT;
3203         return 0;
3204 }
3205
3206 static noinline long btrfs_ioctl_wait_sync(struct btrfs_fs_info *fs_info,
3207                                            void __user *argp)
3208 {
3209         /* By default wait for the current transaction. */
3210         u64 transid = 0;
3211
3212         if (argp)
3213                 if (copy_from_user(&transid, argp, sizeof(transid)))
3214                         return -EFAULT;
3215
3216         return btrfs_wait_for_commit(fs_info, transid);
3217 }
3218
3219 static long btrfs_ioctl_scrub(struct file *file, void __user *arg)
3220 {
3221         struct btrfs_fs_info *fs_info = inode_to_fs_info(file_inode(file));
3222         struct btrfs_ioctl_scrub_args *sa;
3223         int ret;
3224
3225         if (!capable(CAP_SYS_ADMIN))
3226                 return -EPERM;
3227
3228         if (btrfs_fs_incompat(fs_info, EXTENT_TREE_V2)) {
3229                 btrfs_err(fs_info, "scrub is not supported on extent tree v2 yet");
3230                 return -EINVAL;
3231         }
3232
3233         sa = memdup_user(arg, sizeof(*sa));
3234         if (IS_ERR(sa))
3235                 return PTR_ERR(sa);
3236
3237         if (sa->flags & ~BTRFS_SCRUB_SUPPORTED_FLAGS) {
3238                 ret = -EOPNOTSUPP;
3239                 goto out;
3240         }
3241
3242         if (!(sa->flags & BTRFS_SCRUB_READONLY)) {
3243                 ret = mnt_want_write_file(file);
3244                 if (ret)
3245                         goto out;
3246         }
3247
3248         ret = btrfs_scrub_dev(fs_info, sa->devid, sa->start, sa->end,
3249                               &sa->progress, sa->flags & BTRFS_SCRUB_READONLY,
3250                               0);
3251
3252         /*
3253          * Copy scrub args to user space even if btrfs_scrub_dev() returned an
3254          * error. This is important as it allows user space to know how much
3255          * progress scrub has done. For example, if scrub is canceled we get
3256          * -ECANCELED from btrfs_scrub_dev() and return that error back to user
3257          * space. Later user space can inspect the progress from the structure
3258          * btrfs_ioctl_scrub_args and resume scrub from where it left off
3259          * previously (btrfs-progs does this).
3260          * If we fail to copy the btrfs_ioctl_scrub_args structure to user space
3261          * then return -EFAULT to signal the structure was not copied or it may
3262          * be corrupt and unreliable due to a partial copy.
3263          */
3264         if (copy_to_user(arg, sa, sizeof(*sa)))
3265                 ret = -EFAULT;
3266
3267         if (!(sa->flags & BTRFS_SCRUB_READONLY))
3268                 mnt_drop_write_file(file);
3269 out:
3270         kfree(sa);
3271         return ret;
3272 }
3273
3274 static long btrfs_ioctl_scrub_cancel(struct btrfs_fs_info *fs_info)
3275 {
3276         if (!capable(CAP_SYS_ADMIN))
3277                 return -EPERM;
3278
3279         return btrfs_scrub_cancel(fs_info);
3280 }
3281
3282 static long btrfs_ioctl_scrub_progress(struct btrfs_fs_info *fs_info,
3283                                        void __user *arg)
3284 {
3285         struct btrfs_ioctl_scrub_args *sa;
3286         int ret;
3287
3288         if (!capable(CAP_SYS_ADMIN))
3289                 return -EPERM;
3290
3291         sa = memdup_user(arg, sizeof(*sa));
3292         if (IS_ERR(sa))
3293                 return PTR_ERR(sa);
3294
3295         ret = btrfs_scrub_progress(fs_info, sa->devid, &sa->progress);
3296
3297         if (ret == 0 && copy_to_user(arg, sa, sizeof(*sa)))
3298                 ret = -EFAULT;
3299
3300         kfree(sa);
3301         return ret;
3302 }
3303
3304 static long btrfs_ioctl_get_dev_stats(struct btrfs_fs_info *fs_info,
3305                                       void __user *arg)
3306 {
3307         struct btrfs_ioctl_get_dev_stats *sa;
3308         int ret;
3309
3310         sa = memdup_user(arg, sizeof(*sa));
3311         if (IS_ERR(sa))
3312                 return PTR_ERR(sa);
3313
3314         if ((sa->flags & BTRFS_DEV_STATS_RESET) && !capable(CAP_SYS_ADMIN)) {
3315                 kfree(sa);
3316                 return -EPERM;
3317         }
3318
3319         ret = btrfs_get_dev_stats(fs_info, sa);
3320
3321         if (ret == 0 && copy_to_user(arg, sa, sizeof(*sa)))
3322                 ret = -EFAULT;
3323
3324         kfree(sa);
3325         return ret;
3326 }
3327
3328 static long btrfs_ioctl_dev_replace(struct btrfs_fs_info *fs_info,
3329                                     void __user *arg)
3330 {
3331         struct btrfs_ioctl_dev_replace_args *p;
3332         int ret;
3333
3334         if (!capable(CAP_SYS_ADMIN))
3335                 return -EPERM;
3336
3337         if (btrfs_fs_incompat(fs_info, EXTENT_TREE_V2)) {
3338                 btrfs_err(fs_info, "device replace not supported on extent tree v2 yet");
3339                 return -EINVAL;
3340         }
3341
3342         p = memdup_user(arg, sizeof(*p));
3343         if (IS_ERR(p))
3344                 return PTR_ERR(p);
3345
3346         switch (p->cmd) {
3347         case BTRFS_IOCTL_DEV_REPLACE_CMD_START:
3348                 if (sb_rdonly(fs_info->sb)) {
3349                         ret = -EROFS;
3350                         goto out;
3351                 }
3352                 if (!btrfs_exclop_start(fs_info, BTRFS_EXCLOP_DEV_REPLACE)) {
3353                         ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
3354                 } else {
3355                         ret = btrfs_dev_replace_by_ioctl(fs_info, p);
3356                         btrfs_exclop_finish(fs_info);
3357                 }
3358                 break;
3359         case BTRFS_IOCTL_DEV_REPLACE_CMD_STATUS:
3360                 btrfs_dev_replace_status(fs_info, p);
3361                 ret = 0;
3362                 break;
3363         case BTRFS_IOCTL_DEV_REPLACE_CMD_CANCEL:
3364                 p->result = btrfs_dev_replace_cancel(fs_info);
3365                 ret = 0;
3366                 break;
3367         default:
3368                 ret = -EINVAL;
3369                 break;
3370         }
3371
3372         if ((ret == 0 || ret == -ECANCELED) && copy_to_user(arg, p, sizeof(*p)))
3373                 ret = -EFAULT;
3374 out:
3375         kfree(p);
3376         return ret;
3377 }
3378
3379 static long btrfs_ioctl_ino_to_path(struct btrfs_root *root, void __user *arg)
3380 {
3381         int ret = 0;
3382         int i;
3383         u64 rel_ptr;
3384         int size;
3385         struct btrfs_ioctl_ino_path_args *ipa = NULL;
3386         struct inode_fs_paths *ipath = NULL;
3387         struct btrfs_path *path;
3388
3389         if (!capable(CAP_DAC_READ_SEARCH))
3390                 return -EPERM;
3391
3392         path = btrfs_alloc_path();
3393         if (!path) {
3394                 ret = -ENOMEM;
3395                 goto out;
3396         }
3397
3398         ipa = memdup_user(arg, sizeof(*ipa));
3399         if (IS_ERR(ipa)) {
3400                 ret = PTR_ERR(ipa);
3401                 ipa = NULL;
3402                 goto out;
3403         }
3404
3405         size = min_t(u32, ipa->size, 4096);
3406         ipath = init_ipath(size, root, path);
3407         if (IS_ERR(ipath)) {
3408                 ret = PTR_ERR(ipath);
3409                 ipath = NULL;
3410                 goto out;
3411         }
3412
3413         ret = paths_from_inode(ipa->inum, ipath);
3414         if (ret < 0)
3415                 goto out;
3416
3417         for (i = 0; i < ipath->fspath->elem_cnt; ++i) {
3418                 rel_ptr = ipath->fspath->val[i] -
3419                           (u64)(unsigned long)ipath->fspath->val;
3420                 ipath->fspath->val[i] = rel_ptr;
3421         }
3422
3423         btrfs_free_path(path);
3424         path = NULL;
3425         ret = copy_to_user((void __user *)(unsigned long)ipa->fspath,
3426                            ipath->fspath, size);
3427         if (ret) {
3428                 ret = -EFAULT;
3429                 goto out;
3430         }
3431
3432 out:
3433         btrfs_free_path(path);
3434         free_ipath(ipath);
3435         kfree(ipa);
3436
3437         return ret;
3438 }
3439
3440 static long btrfs_ioctl_logical_to_ino(struct btrfs_fs_info *fs_info,
3441                                         void __user *arg, int version)
3442 {
3443         int ret = 0;
3444         int size;
3445         struct btrfs_ioctl_logical_ino_args *loi;
3446         struct btrfs_data_container *inodes = NULL;
3447         struct btrfs_path *path = NULL;
3448         bool ignore_offset;
3449
3450         if (!capable(CAP_SYS_ADMIN))
3451                 return -EPERM;
3452
3453         loi = memdup_user(arg, sizeof(*loi));
3454         if (IS_ERR(loi))
3455                 return PTR_ERR(loi);
3456
3457         if (version == 1) {
3458                 ignore_offset = false;
3459                 size = min_t(u32, loi->size, SZ_64K);
3460         } else {
3461                 /* All reserved bits must be 0 for now */
3462                 if (memchr_inv(loi->reserved, 0, sizeof(loi->reserved))) {
3463                         ret = -EINVAL;
3464                         goto out_loi;
3465                 }
3466                 /* Only accept flags we have defined so far */
3467                 if (loi->flags & ~(BTRFS_LOGICAL_INO_ARGS_IGNORE_OFFSET)) {
3468                         ret = -EINVAL;
3469                         goto out_loi;
3470                 }
3471                 ignore_offset = loi->flags & BTRFS_LOGICAL_INO_ARGS_IGNORE_OFFSET;
3472                 size = min_t(u32, loi->size, SZ_16M);
3473         }
3474
3475         inodes = init_data_container(size);
3476         if (IS_ERR(inodes)) {
3477                 ret = PTR_ERR(inodes);
3478                 goto out_loi;
3479         }
3480
3481         path = btrfs_alloc_path();
3482         if (!path) {
3483                 ret = -ENOMEM;
3484                 goto out;
3485         }
3486         ret = iterate_inodes_from_logical(loi->logical, fs_info, path,
3487                                           inodes, ignore_offset);
3488         btrfs_free_path(path);
3489         if (ret == -EINVAL)
3490                 ret = -ENOENT;
3491         if (ret < 0)
3492                 goto out;
3493
3494         ret = copy_to_user((void __user *)(unsigned long)loi->inodes, inodes,
3495                            size);
3496         if (ret)
3497                 ret = -EFAULT;
3498
3499 out:
3500         kvfree(inodes);
3501 out_loi:
3502         kfree(loi);
3503
3504         return ret;
3505 }
3506
3507 void btrfs_update_ioctl_balance_args(struct btrfs_fs_info *fs_info,
3508                                struct btrfs_ioctl_balance_args *bargs)
3509 {
3510         struct btrfs_balance_control *bctl = fs_info->balance_ctl;
3511
3512         bargs->flags = bctl->flags;
3513
3514         if (test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags))
3515                 bargs->state |= BTRFS_BALANCE_STATE_RUNNING;
3516         if (atomic_read(&fs_info->balance_pause_req))
3517                 bargs->state |= BTRFS_BALANCE_STATE_PAUSE_REQ;
3518         if (atomic_read(&fs_info->balance_cancel_req))
3519                 bargs->state |= BTRFS_BALANCE_STATE_CANCEL_REQ;
3520
3521         memcpy(&bargs->data, &bctl->data, sizeof(bargs->data));
3522         memcpy(&bargs->meta, &bctl->meta, sizeof(bargs->meta));
3523         memcpy(&bargs->sys, &bctl->sys, sizeof(bargs->sys));
3524
3525         spin_lock(&fs_info->balance_lock);
3526         memcpy(&bargs->stat, &bctl->stat, sizeof(bargs->stat));
3527         spin_unlock(&fs_info->balance_lock);
3528 }
3529
3530 /*
3531  * Try to acquire fs_info::balance_mutex as well as set BTRFS_EXLCOP_BALANCE as
3532  * required.
3533  *
3534  * @fs_info:       the filesystem
3535  * @excl_acquired: ptr to boolean value which is set to false in case balance
3536  *                 is being resumed
3537  *
3538  * Return 0 on success in which case both fs_info::balance is acquired as well
3539  * as exclusive ops are blocked. In case of failure return an error code.
3540  */
3541 static int btrfs_try_lock_balance(struct btrfs_fs_info *fs_info, bool *excl_acquired)
3542 {
3543         int ret;
3544
3545         /*
3546          * Exclusive operation is locked. Three possibilities:
3547          *   (1) some other op is running
3548          *   (2) balance is running
3549          *   (3) balance is paused -- special case (think resume)
3550          */
3551         while (1) {
3552                 if (btrfs_exclop_start(fs_info, BTRFS_EXCLOP_BALANCE)) {
3553                         *excl_acquired = true;
3554                         mutex_lock(&fs_info->balance_mutex);
3555                         return 0;
3556                 }
3557
3558                 mutex_lock(&fs_info->balance_mutex);
3559                 if (fs_info->balance_ctl) {
3560                         /* This is either (2) or (3) */
3561                         if (test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags)) {
3562                                 /* This is (2) */
3563                                 ret = -EINPROGRESS;
3564                                 goto out_failure;
3565
3566                         } else {
3567                                 mutex_unlock(&fs_info->balance_mutex);
3568                                 /*
3569                                  * Lock released to allow other waiters to
3570                                  * continue, we'll reexamine the status again.
3571                                  */
3572                                 mutex_lock(&fs_info->balance_mutex);
3573
3574                                 if (fs_info->balance_ctl &&
3575                                     !test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags)) {
3576                                         /* This is (3) */
3577                                         *excl_acquired = false;
3578                                         return 0;
3579                                 }
3580                         }
3581                 } else {
3582                         /* This is (1) */
3583                         ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
3584                         goto out_failure;
3585                 }
3586
3587                 mutex_unlock(&fs_info->balance_mutex);
3588         }
3589
3590 out_failure:
3591         mutex_unlock(&fs_info->balance_mutex);
3592         *excl_acquired = false;
3593         return ret;
3594 }
3595
3596 static long btrfs_ioctl_balance(struct file *file, void __user *arg)
3597 {
3598         struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
3599         struct btrfs_fs_info *fs_info = root->fs_info;
3600         struct btrfs_ioctl_balance_args *bargs;
3601         struct btrfs_balance_control *bctl;
3602         bool need_unlock = true;
3603         int ret;
3604
3605         if (!capable(CAP_SYS_ADMIN))
3606                 return -EPERM;
3607
3608         ret = mnt_want_write_file(file);
3609         if (ret)
3610                 return ret;
3611
3612         bargs = memdup_user(arg, sizeof(*bargs));
3613         if (IS_ERR(bargs)) {
3614                 ret = PTR_ERR(bargs);
3615                 bargs = NULL;
3616                 goto out;
3617         }
3618
3619         ret = btrfs_try_lock_balance(fs_info, &need_unlock);
3620         if (ret)
3621                 goto out;
3622
3623         lockdep_assert_held(&fs_info->balance_mutex);
3624
3625         if (bargs->flags & BTRFS_BALANCE_RESUME) {
3626                 if (!fs_info->balance_ctl) {
3627                         ret = -ENOTCONN;
3628                         goto out_unlock;
3629                 }
3630
3631                 bctl = fs_info->balance_ctl;
3632                 spin_lock(&fs_info->balance_lock);
3633                 bctl->flags |= BTRFS_BALANCE_RESUME;
3634                 spin_unlock(&fs_info->balance_lock);
3635                 btrfs_exclop_balance(fs_info, BTRFS_EXCLOP_BALANCE);
3636
3637                 goto do_balance;
3638         }
3639
3640         if (bargs->flags & ~(BTRFS_BALANCE_ARGS_MASK | BTRFS_BALANCE_TYPE_MASK)) {
3641                 ret = -EINVAL;
3642                 goto out_unlock;
3643         }
3644
3645         if (fs_info->balance_ctl) {
3646                 ret = -EINPROGRESS;
3647                 goto out_unlock;
3648         }
3649
3650         bctl = kzalloc(sizeof(*bctl), GFP_KERNEL);
3651         if (!bctl) {
3652                 ret = -ENOMEM;
3653                 goto out_unlock;
3654         }
3655
3656         memcpy(&bctl->data, &bargs->data, sizeof(bctl->data));
3657         memcpy(&bctl->meta, &bargs->meta, sizeof(bctl->meta));
3658         memcpy(&bctl->sys, &bargs->sys, sizeof(bctl->sys));
3659
3660         bctl->flags = bargs->flags;
3661 do_balance:
3662         /*
3663          * Ownership of bctl and exclusive operation goes to btrfs_balance.
3664          * bctl is freed in reset_balance_state, or, if restriper was paused
3665          * all the way until unmount, in free_fs_info.  The flag should be
3666          * cleared after reset_balance_state.
3667          */
3668         need_unlock = false;
3669
3670         ret = btrfs_balance(fs_info, bctl, bargs);
3671         bctl = NULL;
3672
3673         if (ret == 0 || ret == -ECANCELED) {
3674                 if (copy_to_user(arg, bargs, sizeof(*bargs)))
3675                         ret = -EFAULT;
3676         }
3677
3678         kfree(bctl);
3679 out_unlock:
3680         mutex_unlock(&fs_info->balance_mutex);
3681         if (need_unlock)
3682                 btrfs_exclop_finish(fs_info);
3683 out:
3684         mnt_drop_write_file(file);
3685         kfree(bargs);
3686         return ret;
3687 }
3688
3689 static long btrfs_ioctl_balance_ctl(struct btrfs_fs_info *fs_info, int cmd)
3690 {
3691         if (!capable(CAP_SYS_ADMIN))
3692                 return -EPERM;
3693
3694         switch (cmd) {
3695         case BTRFS_BALANCE_CTL_PAUSE:
3696                 return btrfs_pause_balance(fs_info);
3697         case BTRFS_BALANCE_CTL_CANCEL:
3698                 return btrfs_cancel_balance(fs_info);
3699         }
3700
3701         return -EINVAL;
3702 }
3703
3704 static long btrfs_ioctl_balance_progress(struct btrfs_fs_info *fs_info,
3705                                          void __user *arg)
3706 {
3707         struct btrfs_ioctl_balance_args *bargs;
3708         int ret = 0;
3709
3710         if (!capable(CAP_SYS_ADMIN))
3711                 return -EPERM;
3712
3713         mutex_lock(&fs_info->balance_mutex);
3714         if (!fs_info->balance_ctl) {
3715                 ret = -ENOTCONN;
3716                 goto out;
3717         }
3718
3719         bargs = kzalloc(sizeof(*bargs), GFP_KERNEL);
3720         if (!bargs) {
3721                 ret = -ENOMEM;
3722                 goto out;
3723         }
3724
3725         btrfs_update_ioctl_balance_args(fs_info, bargs);
3726
3727         if (copy_to_user(arg, bargs, sizeof(*bargs)))
3728                 ret = -EFAULT;
3729
3730         kfree(bargs);
3731 out:
3732         mutex_unlock(&fs_info->balance_mutex);
3733         return ret;
3734 }
3735
3736 static long btrfs_ioctl_quota_ctl(struct file *file, void __user *arg)
3737 {
3738         struct inode *inode = file_inode(file);
3739         struct btrfs_fs_info *fs_info = inode_to_fs_info(inode);
3740         struct btrfs_ioctl_quota_ctl_args *sa;
3741         int ret;
3742
3743         if (!capable(CAP_SYS_ADMIN))
3744                 return -EPERM;
3745
3746         ret = mnt_want_write_file(file);
3747         if (ret)
3748                 return ret;
3749
3750         sa = memdup_user(arg, sizeof(*sa));
3751         if (IS_ERR(sa)) {
3752                 ret = PTR_ERR(sa);
3753                 goto drop_write;
3754         }
3755
3756         switch (sa->cmd) {
3757         case BTRFS_QUOTA_CTL_ENABLE:
3758         case BTRFS_QUOTA_CTL_ENABLE_SIMPLE_QUOTA:
3759                 down_write(&fs_info->subvol_sem);
3760                 ret = btrfs_quota_enable(fs_info, sa);
3761                 up_write(&fs_info->subvol_sem);
3762                 break;
3763         case BTRFS_QUOTA_CTL_DISABLE:
3764                 /*
3765                  * Lock the cleaner mutex to prevent races with concurrent
3766                  * relocation, because relocation may be building backrefs for
3767                  * blocks of the quota root while we are deleting the root. This
3768                  * is like dropping fs roots of deleted snapshots/subvolumes, we
3769                  * need the same protection.
3770                  *
3771                  * This also prevents races between concurrent tasks trying to
3772                  * disable quotas, because we will unlock and relock
3773                  * qgroup_ioctl_lock across BTRFS_FS_QUOTA_ENABLED changes.
3774                  *
3775                  * We take this here because we have the dependency of
3776                  *
3777                  * inode_lock -> subvol_sem
3778                  *
3779                  * because of rename.  With relocation we can prealloc extents,
3780                  * so that makes the dependency chain
3781                  *
3782                  * cleaner_mutex -> inode_lock -> subvol_sem
3783                  *
3784                  * so we must take the cleaner_mutex here before we take the
3785                  * subvol_sem.  The deadlock can't actually happen, but this
3786                  * quiets lockdep.
3787                  */
3788                 mutex_lock(&fs_info->cleaner_mutex);
3789                 down_write(&fs_info->subvol_sem);
3790                 ret = btrfs_quota_disable(fs_info);
3791                 up_write(&fs_info->subvol_sem);
3792                 mutex_unlock(&fs_info->cleaner_mutex);
3793                 break;
3794         default:
3795                 ret = -EINVAL;
3796                 break;
3797         }
3798
3799         kfree(sa);
3800 drop_write:
3801         mnt_drop_write_file(file);
3802         return ret;
3803 }
3804
3805 /*
3806  * Quick check for ioctl handlers if quotas are enabled. Proper locking must be
3807  * done before any operations.
3808  */
3809 static bool qgroup_enabled(struct btrfs_fs_info *fs_info)
3810 {
3811         bool ret = true;
3812
3813         mutex_lock(&fs_info->qgroup_ioctl_lock);
3814         if (!fs_info->quota_root)
3815                 ret = false;
3816         mutex_unlock(&fs_info->qgroup_ioctl_lock);
3817
3818         return ret;
3819 }
3820
3821 static long btrfs_ioctl_qgroup_assign(struct file *file, void __user *arg)
3822 {
3823         struct inode *inode = file_inode(file);
3824         struct btrfs_fs_info *fs_info = inode_to_fs_info(inode);
3825         struct btrfs_root *root = BTRFS_I(inode)->root;
3826         struct btrfs_ioctl_qgroup_assign_args *sa;
3827         struct btrfs_qgroup_list *prealloc = NULL;
3828         struct btrfs_trans_handle *trans;
3829         int ret;
3830         int err;
3831
3832         if (!capable(CAP_SYS_ADMIN))
3833                 return -EPERM;
3834
3835         if (!qgroup_enabled(root->fs_info))
3836                 return -ENOTCONN;
3837
3838         ret = mnt_want_write_file(file);
3839         if (ret)
3840                 return ret;
3841
3842         sa = memdup_user(arg, sizeof(*sa));
3843         if (IS_ERR(sa)) {
3844                 ret = PTR_ERR(sa);
3845                 goto drop_write;
3846         }
3847
3848         if (sa->assign) {
3849                 prealloc = kzalloc(sizeof(*prealloc), GFP_KERNEL);
3850                 if (!prealloc) {
3851                         ret = -ENOMEM;
3852                         goto drop_write;
3853                 }
3854         }
3855
3856         trans = btrfs_join_transaction(root);
3857         if (IS_ERR(trans)) {
3858                 ret = PTR_ERR(trans);
3859                 goto out;
3860         }
3861
3862         /*
3863          * Prealloc ownership is moved to the relation handler, there it's used
3864          * or freed on error.
3865          */
3866         if (sa->assign) {
3867                 ret = btrfs_add_qgroup_relation(trans, sa->src, sa->dst, prealloc);
3868                 prealloc = NULL;
3869         } else {
3870                 ret = btrfs_del_qgroup_relation(trans, sa->src, sa->dst);
3871         }
3872
3873         /* update qgroup status and info */
3874         mutex_lock(&fs_info->qgroup_ioctl_lock);
3875         err = btrfs_run_qgroups(trans);
3876         mutex_unlock(&fs_info->qgroup_ioctl_lock);
3877         if (err < 0)
3878                 btrfs_warn(fs_info,
3879                            "qgroup status update failed after %s relation, marked as inconsistent",
3880                            sa->assign ? "adding" : "deleting");
3881         err = btrfs_end_transaction(trans);
3882         if (err && !ret)
3883                 ret = err;
3884
3885 out:
3886         kfree(prealloc);
3887         kfree(sa);
3888 drop_write:
3889         mnt_drop_write_file(file);
3890         return ret;
3891 }
3892
3893 static long btrfs_ioctl_qgroup_create(struct file *file, void __user *arg)
3894 {
3895         struct inode *inode = file_inode(file);
3896         struct btrfs_root *root = BTRFS_I(inode)->root;
3897         struct btrfs_ioctl_qgroup_create_args *sa;
3898         struct btrfs_trans_handle *trans;
3899         int ret;
3900         int err;
3901
3902         if (!capable(CAP_SYS_ADMIN))
3903                 return -EPERM;
3904
3905         if (!qgroup_enabled(root->fs_info))
3906                 return -ENOTCONN;
3907
3908         ret = mnt_want_write_file(file);
3909         if (ret)
3910                 return ret;
3911
3912         sa = memdup_user(arg, sizeof(*sa));
3913         if (IS_ERR(sa)) {
3914                 ret = PTR_ERR(sa);
3915                 goto drop_write;
3916         }
3917
3918         if (!sa->qgroupid) {
3919                 ret = -EINVAL;
3920                 goto out;
3921         }
3922
3923         if (sa->create && is_fstree(sa->qgroupid)) {
3924                 ret = -EINVAL;
3925                 goto out;
3926         }
3927
3928         trans = btrfs_join_transaction(root);
3929         if (IS_ERR(trans)) {
3930                 ret = PTR_ERR(trans);
3931                 goto out;
3932         }
3933
3934         if (sa->create) {
3935                 ret = btrfs_create_qgroup(trans, sa->qgroupid);
3936         } else {
3937                 ret = btrfs_remove_qgroup(trans, sa->qgroupid);
3938         }
3939
3940         err = btrfs_end_transaction(trans);
3941         if (err && !ret)
3942                 ret = err;
3943
3944 out:
3945         kfree(sa);
3946 drop_write:
3947         mnt_drop_write_file(file);
3948         return ret;
3949 }
3950
3951 static long btrfs_ioctl_qgroup_limit(struct file *file, void __user *arg)
3952 {
3953         struct inode *inode = file_inode(file);
3954         struct btrfs_root *root = BTRFS_I(inode)->root;
3955         struct btrfs_ioctl_qgroup_limit_args *sa;
3956         struct btrfs_trans_handle *trans;
3957         int ret;
3958         int err;
3959         u64 qgroupid;
3960
3961         if (!capable(CAP_SYS_ADMIN))
3962                 return -EPERM;
3963
3964         if (!qgroup_enabled(root->fs_info))
3965                 return -ENOTCONN;
3966
3967         ret = mnt_want_write_file(file);
3968         if (ret)
3969                 return ret;
3970
3971         sa = memdup_user(arg, sizeof(*sa));
3972         if (IS_ERR(sa)) {
3973                 ret = PTR_ERR(sa);
3974                 goto drop_write;
3975         }
3976
3977         trans = btrfs_join_transaction(root);
3978         if (IS_ERR(trans)) {
3979                 ret = PTR_ERR(trans);
3980                 goto out;
3981         }
3982
3983         qgroupid = sa->qgroupid;
3984         if (!qgroupid) {
3985                 /* take the current subvol as qgroup */
3986                 qgroupid = btrfs_root_id(root);
3987         }
3988
3989         ret = btrfs_limit_qgroup(trans, qgroupid, &sa->lim);
3990
3991         err = btrfs_end_transaction(trans);
3992         if (err && !ret)
3993                 ret = err;
3994
3995 out:
3996         kfree(sa);
3997 drop_write:
3998         mnt_drop_write_file(file);
3999         return ret;
4000 }
4001
4002 static long btrfs_ioctl_quota_rescan(struct file *file, void __user *arg)
4003 {
4004         struct inode *inode = file_inode(file);
4005         struct btrfs_fs_info *fs_info = inode_to_fs_info(inode);
4006         struct btrfs_ioctl_quota_rescan_args *qsa;
4007         int ret;
4008
4009         if (!capable(CAP_SYS_ADMIN))
4010                 return -EPERM;
4011
4012         if (!qgroup_enabled(fs_info))
4013                 return -ENOTCONN;
4014
4015         ret = mnt_want_write_file(file);
4016         if (ret)
4017                 return ret;
4018
4019         qsa = memdup_user(arg, sizeof(*qsa));
4020         if (IS_ERR(qsa)) {
4021                 ret = PTR_ERR(qsa);
4022                 goto drop_write;
4023         }
4024
4025         if (qsa->flags) {
4026                 ret = -EINVAL;
4027                 goto out;
4028         }
4029
4030         ret = btrfs_qgroup_rescan(fs_info);
4031
4032 out:
4033         kfree(qsa);
4034 drop_write:
4035         mnt_drop_write_file(file);
4036         return ret;
4037 }
4038
4039 static long btrfs_ioctl_quota_rescan_status(struct btrfs_fs_info *fs_info,
4040                                                 void __user *arg)
4041 {
4042         struct btrfs_ioctl_quota_rescan_args qsa = {0};
4043
4044         if (!capable(CAP_SYS_ADMIN))
4045                 return -EPERM;
4046
4047         if (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN) {
4048                 qsa.flags = 1;
4049                 qsa.progress = fs_info->qgroup_rescan_progress.objectid;
4050         }
4051
4052         if (copy_to_user(arg, &qsa, sizeof(qsa)))
4053                 return -EFAULT;
4054
4055         return 0;
4056 }
4057
4058 static long btrfs_ioctl_quota_rescan_wait(struct btrfs_fs_info *fs_info)
4059 {
4060         if (!capable(CAP_SYS_ADMIN))
4061                 return -EPERM;
4062
4063         return btrfs_qgroup_wait_for_completion(fs_info, true);
4064 }
4065
4066 static long _btrfs_ioctl_set_received_subvol(struct file *file,
4067                                             struct mnt_idmap *idmap,
4068                                             struct btrfs_ioctl_received_subvol_args *sa)
4069 {
4070         struct inode *inode = file_inode(file);
4071         struct btrfs_fs_info *fs_info = inode_to_fs_info(inode);
4072         struct btrfs_root *root = BTRFS_I(inode)->root;
4073         struct btrfs_root_item *root_item = &root->root_item;
4074         struct btrfs_trans_handle *trans;
4075         struct timespec64 ct = current_time(inode);
4076         int ret = 0;
4077         int received_uuid_changed;
4078
4079         if (!inode_owner_or_capable(idmap, inode))
4080                 return -EPERM;
4081
4082         ret = mnt_want_write_file(file);
4083         if (ret < 0)
4084                 return ret;
4085
4086         down_write(&fs_info->subvol_sem);
4087
4088         if (btrfs_ino(BTRFS_I(inode)) != BTRFS_FIRST_FREE_OBJECTID) {
4089                 ret = -EINVAL;
4090                 goto out;
4091         }
4092
4093         if (btrfs_root_readonly(root)) {
4094                 ret = -EROFS;
4095                 goto out;
4096         }
4097
4098         /*
4099          * 1 - root item
4100          * 2 - uuid items (received uuid + subvol uuid)
4101          */
4102         trans = btrfs_start_transaction(root, 3);
4103         if (IS_ERR(trans)) {
4104                 ret = PTR_ERR(trans);
4105                 trans = NULL;
4106                 goto out;
4107         }
4108
4109         sa->rtransid = trans->transid;
4110         sa->rtime.sec = ct.tv_sec;
4111         sa->rtime.nsec = ct.tv_nsec;
4112
4113         received_uuid_changed = memcmp(root_item->received_uuid, sa->uuid,
4114                                        BTRFS_UUID_SIZE);
4115         if (received_uuid_changed &&
4116             !btrfs_is_empty_uuid(root_item->received_uuid)) {
4117                 ret = btrfs_uuid_tree_remove(trans, root_item->received_uuid,
4118                                           BTRFS_UUID_KEY_RECEIVED_SUBVOL,
4119                                           btrfs_root_id(root));
4120                 if (ret && ret != -ENOENT) {
4121                         btrfs_abort_transaction(trans, ret);
4122                         btrfs_end_transaction(trans);
4123                         goto out;
4124                 }
4125         }
4126         memcpy(root_item->received_uuid, sa->uuid, BTRFS_UUID_SIZE);
4127         btrfs_set_root_stransid(root_item, sa->stransid);
4128         btrfs_set_root_rtransid(root_item, sa->rtransid);
4129         btrfs_set_stack_timespec_sec(&root_item->stime, sa->stime.sec);
4130         btrfs_set_stack_timespec_nsec(&root_item->stime, sa->stime.nsec);
4131         btrfs_set_stack_timespec_sec(&root_item->rtime, sa->rtime.sec);
4132         btrfs_set_stack_timespec_nsec(&root_item->rtime, sa->rtime.nsec);
4133
4134         ret = btrfs_update_root(trans, fs_info->tree_root,
4135                                 &root->root_key, &root->root_item);
4136         if (ret < 0) {
4137                 btrfs_end_transaction(trans);
4138                 goto out;
4139         }
4140         if (received_uuid_changed && !btrfs_is_empty_uuid(sa->uuid)) {
4141                 ret = btrfs_uuid_tree_add(trans, sa->uuid,
4142                                           BTRFS_UUID_KEY_RECEIVED_SUBVOL,
4143                                           btrfs_root_id(root));
4144                 if (ret < 0 && ret != -EEXIST) {
4145                         btrfs_abort_transaction(trans, ret);
4146                         btrfs_end_transaction(trans);
4147                         goto out;
4148                 }
4149         }
4150         ret = btrfs_commit_transaction(trans);
4151 out:
4152         up_write(&fs_info->subvol_sem);
4153         mnt_drop_write_file(file);
4154         return ret;
4155 }
4156
4157 #ifdef CONFIG_64BIT
4158 static long btrfs_ioctl_set_received_subvol_32(struct file *file,
4159                                                 void __user *arg)
4160 {
4161         struct btrfs_ioctl_received_subvol_args_32 *args32 = NULL;
4162         struct btrfs_ioctl_received_subvol_args *args64 = NULL;
4163         int ret = 0;
4164
4165         args32 = memdup_user(arg, sizeof(*args32));
4166         if (IS_ERR(args32))
4167                 return PTR_ERR(args32);
4168
4169         args64 = kmalloc(sizeof(*args64), GFP_KERNEL);
4170         if (!args64) {
4171                 ret = -ENOMEM;
4172                 goto out;
4173         }
4174
4175         memcpy(args64->uuid, args32->uuid, BTRFS_UUID_SIZE);
4176         args64->stransid = args32->stransid;
4177         args64->rtransid = args32->rtransid;
4178         args64->stime.sec = args32->stime.sec;
4179         args64->stime.nsec = args32->stime.nsec;
4180         args64->rtime.sec = args32->rtime.sec;
4181         args64->rtime.nsec = args32->rtime.nsec;
4182         args64->flags = args32->flags;
4183
4184         ret = _btrfs_ioctl_set_received_subvol(file, file_mnt_idmap(file), args64);
4185         if (ret)
4186                 goto out;
4187
4188         memcpy(args32->uuid, args64->uuid, BTRFS_UUID_SIZE);
4189         args32->stransid = args64->stransid;
4190         args32->rtransid = args64->rtransid;
4191         args32->stime.sec = args64->stime.sec;
4192         args32->stime.nsec = args64->stime.nsec;
4193         args32->rtime.sec = args64->rtime.sec;
4194         args32->rtime.nsec = args64->rtime.nsec;
4195         args32->flags = args64->flags;
4196
4197         ret = copy_to_user(arg, args32, sizeof(*args32));
4198         if (ret)
4199                 ret = -EFAULT;
4200
4201 out:
4202         kfree(args32);
4203         kfree(args64);
4204         return ret;
4205 }
4206 #endif
4207
4208 static long btrfs_ioctl_set_received_subvol(struct file *file,
4209                                             void __user *arg)
4210 {
4211         struct btrfs_ioctl_received_subvol_args *sa = NULL;
4212         int ret = 0;
4213
4214         sa = memdup_user(arg, sizeof(*sa));
4215         if (IS_ERR(sa))
4216                 return PTR_ERR(sa);
4217
4218         ret = _btrfs_ioctl_set_received_subvol(file, file_mnt_idmap(file), sa);
4219
4220         if (ret)
4221                 goto out;
4222
4223         ret = copy_to_user(arg, sa, sizeof(*sa));
4224         if (ret)
4225                 ret = -EFAULT;
4226
4227 out:
4228         kfree(sa);
4229         return ret;
4230 }
4231
4232 static int btrfs_ioctl_get_fslabel(struct btrfs_fs_info *fs_info,
4233                                         void __user *arg)
4234 {
4235         size_t len;
4236         int ret;
4237         char label[BTRFS_LABEL_SIZE];
4238
4239         spin_lock(&fs_info->super_lock);
4240         memcpy(label, fs_info->super_copy->label, BTRFS_LABEL_SIZE);
4241         spin_unlock(&fs_info->super_lock);
4242
4243         len = strnlen(label, BTRFS_LABEL_SIZE);
4244
4245         if (len == BTRFS_LABEL_SIZE) {
4246                 btrfs_warn(fs_info,
4247                            "label is too long, return the first %zu bytes",
4248                            --len);
4249         }
4250
4251         ret = copy_to_user(arg, label, len);
4252
4253         return ret ? -EFAULT : 0;
4254 }
4255
4256 static int btrfs_ioctl_set_fslabel(struct file *file, void __user *arg)
4257 {
4258         struct inode *inode = file_inode(file);
4259         struct btrfs_fs_info *fs_info = inode_to_fs_info(inode);
4260         struct btrfs_root *root = BTRFS_I(inode)->root;
4261         struct btrfs_super_block *super_block = fs_info->super_copy;
4262         struct btrfs_trans_handle *trans;
4263         char label[BTRFS_LABEL_SIZE];
4264         int ret;
4265
4266         if (!capable(CAP_SYS_ADMIN))
4267                 return -EPERM;
4268
4269         if (copy_from_user(label, arg, sizeof(label)))
4270                 return -EFAULT;
4271
4272         if (strnlen(label, BTRFS_LABEL_SIZE) == BTRFS_LABEL_SIZE) {
4273                 btrfs_err(fs_info,
4274                           "unable to set label with more than %d bytes",
4275                           BTRFS_LABEL_SIZE - 1);
4276                 return -EINVAL;
4277         }
4278
4279         ret = mnt_want_write_file(file);
4280         if (ret)
4281                 return ret;
4282
4283         trans = btrfs_start_transaction(root, 0);
4284         if (IS_ERR(trans)) {
4285                 ret = PTR_ERR(trans);
4286                 goto out_unlock;
4287         }
4288
4289         spin_lock(&fs_info->super_lock);
4290         strcpy(super_block->label, label);
4291         spin_unlock(&fs_info->super_lock);
4292         ret = btrfs_commit_transaction(trans);
4293
4294 out_unlock:
4295         mnt_drop_write_file(file);
4296         return ret;
4297 }
4298
4299 #define INIT_FEATURE_FLAGS(suffix) \
4300         { .compat_flags = BTRFS_FEATURE_COMPAT_##suffix, \
4301           .compat_ro_flags = BTRFS_FEATURE_COMPAT_RO_##suffix, \
4302           .incompat_flags = BTRFS_FEATURE_INCOMPAT_##suffix }
4303
4304 int btrfs_ioctl_get_supported_features(void __user *arg)
4305 {
4306         static const struct btrfs_ioctl_feature_flags features[3] = {
4307                 INIT_FEATURE_FLAGS(SUPP),
4308                 INIT_FEATURE_FLAGS(SAFE_SET),
4309                 INIT_FEATURE_FLAGS(SAFE_CLEAR)
4310         };
4311
4312         if (copy_to_user(arg, &features, sizeof(features)))
4313                 return -EFAULT;
4314
4315         return 0;
4316 }
4317
4318 static int btrfs_ioctl_get_features(struct btrfs_fs_info *fs_info,
4319                                         void __user *arg)
4320 {
4321         struct btrfs_super_block *super_block = fs_info->super_copy;
4322         struct btrfs_ioctl_feature_flags features;
4323
4324         features.compat_flags = btrfs_super_compat_flags(super_block);
4325         features.compat_ro_flags = btrfs_super_compat_ro_flags(super_block);
4326         features.incompat_flags = btrfs_super_incompat_flags(super_block);
4327
4328         if (copy_to_user(arg, &features, sizeof(features)))
4329                 return -EFAULT;
4330
4331         return 0;
4332 }
4333
4334 static int check_feature_bits(struct btrfs_fs_info *fs_info,
4335                               enum btrfs_feature_set set,
4336                               u64 change_mask, u64 flags, u64 supported_flags,
4337                               u64 safe_set, u64 safe_clear)
4338 {
4339         const char *type = btrfs_feature_set_name(set);
4340         char *names;
4341         u64 disallowed, unsupported;
4342         u64 set_mask = flags & change_mask;
4343         u64 clear_mask = ~flags & change_mask;
4344
4345         unsupported = set_mask & ~supported_flags;
4346         if (unsupported) {
4347                 names = btrfs_printable_features(set, unsupported);
4348                 if (names) {
4349                         btrfs_warn(fs_info,
4350                                    "this kernel does not support the %s feature bit%s",
4351                                    names, strchr(names, ',') ? "s" : "");
4352                         kfree(names);
4353                 } else
4354                         btrfs_warn(fs_info,
4355                                    "this kernel does not support %s bits 0x%llx",
4356                                    type, unsupported);
4357                 return -EOPNOTSUPP;
4358         }
4359
4360         disallowed = set_mask & ~safe_set;
4361         if (disallowed) {
4362                 names = btrfs_printable_features(set, disallowed);
4363                 if (names) {
4364                         btrfs_warn(fs_info,
4365                                    "can't set the %s feature bit%s while mounted",
4366                                    names, strchr(names, ',') ? "s" : "");
4367                         kfree(names);
4368                 } else
4369                         btrfs_warn(fs_info,
4370                                    "can't set %s bits 0x%llx while mounted",
4371                                    type, disallowed);
4372                 return -EPERM;
4373         }
4374
4375         disallowed = clear_mask & ~safe_clear;
4376         if (disallowed) {
4377                 names = btrfs_printable_features(set, disallowed);
4378                 if (names) {
4379                         btrfs_warn(fs_info,
4380                                    "can't clear the %s feature bit%s while mounted",
4381                                    names, strchr(names, ',') ? "s" : "");
4382                         kfree(names);
4383                 } else
4384                         btrfs_warn(fs_info,
4385                                    "can't clear %s bits 0x%llx while mounted",
4386                                    type, disallowed);
4387                 return -EPERM;
4388         }
4389
4390         return 0;
4391 }
4392
4393 #define check_feature(fs_info, change_mask, flags, mask_base)   \
4394 check_feature_bits(fs_info, FEAT_##mask_base, change_mask, flags,       \
4395                    BTRFS_FEATURE_ ## mask_base ## _SUPP,        \
4396                    BTRFS_FEATURE_ ## mask_base ## _SAFE_SET,    \
4397                    BTRFS_FEATURE_ ## mask_base ## _SAFE_CLEAR)
4398
4399 static int btrfs_ioctl_set_features(struct file *file, void __user *arg)
4400 {
4401         struct inode *inode = file_inode(file);
4402         struct btrfs_fs_info *fs_info = inode_to_fs_info(inode);
4403         struct btrfs_root *root = BTRFS_I(inode)->root;
4404         struct btrfs_super_block *super_block = fs_info->super_copy;
4405         struct btrfs_ioctl_feature_flags flags[2];
4406         struct btrfs_trans_handle *trans;
4407         u64 newflags;
4408         int ret;
4409
4410         if (!capable(CAP_SYS_ADMIN))
4411                 return -EPERM;
4412
4413         if (copy_from_user(flags, arg, sizeof(flags)))
4414                 return -EFAULT;
4415
4416         /* Nothing to do */
4417         if (!flags[0].compat_flags && !flags[0].compat_ro_flags &&
4418             !flags[0].incompat_flags)
4419                 return 0;
4420
4421         ret = check_feature(fs_info, flags[0].compat_flags,
4422                             flags[1].compat_flags, COMPAT);
4423         if (ret)
4424                 return ret;
4425
4426         ret = check_feature(fs_info, flags[0].compat_ro_flags,
4427                             flags[1].compat_ro_flags, COMPAT_RO);
4428         if (ret)
4429                 return ret;
4430
4431         ret = check_feature(fs_info, flags[0].incompat_flags,
4432                             flags[1].incompat_flags, INCOMPAT);
4433         if (ret)
4434                 return ret;
4435
4436         ret = mnt_want_write_file(file);
4437         if (ret)
4438                 return ret;
4439
4440         trans = btrfs_start_transaction(root, 0);
4441         if (IS_ERR(trans)) {
4442                 ret = PTR_ERR(trans);
4443                 goto out_drop_write;
4444         }
4445
4446         spin_lock(&fs_info->super_lock);
4447         newflags = btrfs_super_compat_flags(super_block);
4448         newflags |= flags[0].compat_flags & flags[1].compat_flags;
4449         newflags &= ~(flags[0].compat_flags & ~flags[1].compat_flags);
4450         btrfs_set_super_compat_flags(super_block, newflags);
4451
4452         newflags = btrfs_super_compat_ro_flags(super_block);
4453         newflags |= flags[0].compat_ro_flags & flags[1].compat_ro_flags;
4454         newflags &= ~(flags[0].compat_ro_flags & ~flags[1].compat_ro_flags);
4455         btrfs_set_super_compat_ro_flags(super_block, newflags);
4456
4457         newflags = btrfs_super_incompat_flags(super_block);
4458         newflags |= flags[0].incompat_flags & flags[1].incompat_flags;
4459         newflags &= ~(flags[0].incompat_flags & ~flags[1].incompat_flags);
4460         btrfs_set_super_incompat_flags(super_block, newflags);
4461         spin_unlock(&fs_info->super_lock);
4462
4463         ret = btrfs_commit_transaction(trans);
4464 out_drop_write:
4465         mnt_drop_write_file(file);
4466
4467         return ret;
4468 }
4469
4470 static int _btrfs_ioctl_send(struct btrfs_inode *inode, void __user *argp, bool compat)
4471 {
4472         struct btrfs_ioctl_send_args *arg;
4473         int ret;
4474
4475         if (compat) {
4476 #if defined(CONFIG_64BIT) && defined(CONFIG_COMPAT)
4477                 struct btrfs_ioctl_send_args_32 args32 = { 0 };
4478
4479                 ret = copy_from_user(&args32, argp, sizeof(args32));
4480                 if (ret)
4481                         return -EFAULT;
4482                 arg = kzalloc(sizeof(*arg), GFP_KERNEL);
4483                 if (!arg)
4484                         return -ENOMEM;
4485                 arg->send_fd = args32.send_fd;
4486                 arg->clone_sources_count = args32.clone_sources_count;
4487                 arg->clone_sources = compat_ptr(args32.clone_sources);
4488                 arg->parent_root = args32.parent_root;
4489                 arg->flags = args32.flags;
4490                 arg->version = args32.version;
4491                 memcpy(arg->reserved, args32.reserved,
4492                        sizeof(args32.reserved));
4493 #else
4494                 return -ENOTTY;
4495 #endif
4496         } else {
4497                 arg = memdup_user(argp, sizeof(*arg));
4498                 if (IS_ERR(arg))
4499                         return PTR_ERR(arg);
4500         }
4501         ret = btrfs_ioctl_send(inode, arg);
4502         kfree(arg);
4503         return ret;
4504 }
4505
4506 static int btrfs_ioctl_encoded_read(struct file *file, void __user *argp,
4507                                     bool compat)
4508 {
4509         struct btrfs_ioctl_encoded_io_args args = { 0 };
4510         size_t copy_end_kernel = offsetofend(struct btrfs_ioctl_encoded_io_args,
4511                                              flags);
4512         size_t copy_end;
4513         struct btrfs_inode *inode = BTRFS_I(file_inode(file));
4514         struct btrfs_fs_info *fs_info = inode->root->fs_info;
4515         struct extent_io_tree *io_tree = &inode->io_tree;
4516         struct iovec iovstack[UIO_FASTIOV];
4517         struct iovec *iov = iovstack;
4518         struct iov_iter iter;
4519         loff_t pos;
4520         struct kiocb kiocb;
4521         ssize_t ret;
4522         u64 disk_bytenr, disk_io_size;
4523         struct extent_state *cached_state = NULL;
4524
4525         if (!capable(CAP_SYS_ADMIN)) {
4526                 ret = -EPERM;
4527                 goto out_acct;
4528         }
4529
4530         if (compat) {
4531 #if defined(CONFIG_64BIT) && defined(CONFIG_COMPAT)
4532                 struct btrfs_ioctl_encoded_io_args_32 args32;
4533
4534                 copy_end = offsetofend(struct btrfs_ioctl_encoded_io_args_32,
4535                                        flags);
4536                 if (copy_from_user(&args32, argp, copy_end)) {
4537                         ret = -EFAULT;
4538                         goto out_acct;
4539                 }
4540                 args.iov = compat_ptr(args32.iov);
4541                 args.iovcnt = args32.iovcnt;
4542                 args.offset = args32.offset;
4543                 args.flags = args32.flags;
4544 #else
4545                 return -ENOTTY;
4546 #endif
4547         } else {
4548                 copy_end = copy_end_kernel;
4549                 if (copy_from_user(&args, argp, copy_end)) {
4550                         ret = -EFAULT;
4551                         goto out_acct;
4552                 }
4553         }
4554         if (args.flags != 0) {
4555                 ret = -EINVAL;
4556                 goto out_acct;
4557         }
4558
4559         ret = import_iovec(ITER_DEST, args.iov, args.iovcnt, ARRAY_SIZE(iovstack),
4560                            &iov, &iter);
4561         if (ret < 0)
4562                 goto out_acct;
4563
4564         if (iov_iter_count(&iter) == 0) {
4565                 ret = 0;
4566                 goto out_iov;
4567         }
4568         pos = args.offset;
4569         ret = rw_verify_area(READ, file, &pos, args.len);
4570         if (ret < 0)
4571                 goto out_iov;
4572
4573         init_sync_kiocb(&kiocb, file);
4574         kiocb.ki_pos = pos;
4575
4576         ret = btrfs_encoded_read(&kiocb, &iter, &args, &cached_state,
4577                                  &disk_bytenr, &disk_io_size);
4578
4579         if (ret == -EIOCBQUEUED) {
4580                 bool unlocked = false;
4581                 u64 start, lockend, count;
4582
4583                 start = ALIGN_DOWN(kiocb.ki_pos, fs_info->sectorsize);
4584                 lockend = start + BTRFS_MAX_UNCOMPRESSED - 1;
4585
4586                 if (args.compression)
4587                         count = disk_io_size;
4588                 else
4589                         count = args.len;
4590
4591                 ret = btrfs_encoded_read_regular(&kiocb, &iter, start, lockend,
4592                                                  &cached_state, disk_bytenr,
4593                                                  disk_io_size, count,
4594                                                  args.compression, &unlocked);
4595
4596                 if (!unlocked) {
4597                         unlock_extent(io_tree, start, lockend, &cached_state);
4598                         btrfs_inode_unlock(inode, BTRFS_ILOCK_SHARED);
4599                 }
4600         }
4601
4602         if (ret >= 0) {
4603                 fsnotify_access(file);
4604                 if (copy_to_user(argp + copy_end,
4605                                  (char *)&args + copy_end_kernel,
4606                                  sizeof(args) - copy_end_kernel))
4607                         ret = -EFAULT;
4608         }
4609
4610 out_iov:
4611         kfree(iov);
4612 out_acct:
4613         if (ret > 0)
4614                 add_rchar(current, ret);
4615         inc_syscr(current);
4616         return ret;
4617 }
4618
4619 static int btrfs_ioctl_encoded_write(struct file *file, void __user *argp, bool compat)
4620 {
4621         struct btrfs_ioctl_encoded_io_args args;
4622         struct iovec iovstack[UIO_FASTIOV];
4623         struct iovec *iov = iovstack;
4624         struct iov_iter iter;
4625         loff_t pos;
4626         struct kiocb kiocb;
4627         ssize_t ret;
4628
4629         if (!capable(CAP_SYS_ADMIN)) {
4630                 ret = -EPERM;
4631                 goto out_acct;
4632         }
4633
4634         if (!(file->f_mode & FMODE_WRITE)) {
4635                 ret = -EBADF;
4636                 goto out_acct;
4637         }
4638
4639         if (compat) {
4640 #if defined(CONFIG_64BIT) && defined(CONFIG_COMPAT)
4641                 struct btrfs_ioctl_encoded_io_args_32 args32;
4642
4643                 if (copy_from_user(&args32, argp, sizeof(args32))) {
4644                         ret = -EFAULT;
4645                         goto out_acct;
4646                 }
4647                 args.iov = compat_ptr(args32.iov);
4648                 args.iovcnt = args32.iovcnt;
4649                 args.offset = args32.offset;
4650                 args.flags = args32.flags;
4651                 args.len = args32.len;
4652                 args.unencoded_len = args32.unencoded_len;
4653                 args.unencoded_offset = args32.unencoded_offset;
4654                 args.compression = args32.compression;
4655                 args.encryption = args32.encryption;
4656                 memcpy(args.reserved, args32.reserved, sizeof(args.reserved));
4657 #else
4658                 return -ENOTTY;
4659 #endif
4660         } else {
4661                 if (copy_from_user(&args, argp, sizeof(args))) {
4662                         ret = -EFAULT;
4663                         goto out_acct;
4664                 }
4665         }
4666
4667         ret = -EINVAL;
4668         if (args.flags != 0)
4669                 goto out_acct;
4670         if (memchr_inv(args.reserved, 0, sizeof(args.reserved)))
4671                 goto out_acct;
4672         if (args.compression == BTRFS_ENCODED_IO_COMPRESSION_NONE &&
4673             args.encryption == BTRFS_ENCODED_IO_ENCRYPTION_NONE)
4674                 goto out_acct;
4675         if (args.compression >= BTRFS_ENCODED_IO_COMPRESSION_TYPES ||
4676             args.encryption >= BTRFS_ENCODED_IO_ENCRYPTION_TYPES)
4677                 goto out_acct;
4678         if (args.unencoded_offset > args.unencoded_len)
4679                 goto out_acct;
4680         if (args.len > args.unencoded_len - args.unencoded_offset)
4681                 goto out_acct;
4682
4683         ret = import_iovec(ITER_SOURCE, args.iov, args.iovcnt, ARRAY_SIZE(iovstack),
4684                            &iov, &iter);
4685         if (ret < 0)
4686                 goto out_acct;
4687
4688         if (iov_iter_count(&iter) == 0) {
4689                 ret = 0;
4690                 goto out_iov;
4691         }
4692         pos = args.offset;
4693         ret = rw_verify_area(WRITE, file, &pos, args.len);
4694         if (ret < 0)
4695                 goto out_iov;
4696
4697         init_sync_kiocb(&kiocb, file);
4698         ret = kiocb_set_rw_flags(&kiocb, 0, WRITE);
4699         if (ret)
4700                 goto out_iov;
4701         kiocb.ki_pos = pos;
4702
4703         file_start_write(file);
4704
4705         ret = btrfs_do_write_iter(&kiocb, &iter, &args);
4706         if (ret > 0)
4707                 fsnotify_modify(file);
4708
4709         file_end_write(file);
4710 out_iov:
4711         kfree(iov);
4712 out_acct:
4713         if (ret > 0)
4714                 add_wchar(current, ret);
4715         inc_syscw(current);
4716         return ret;
4717 }
4718
4719 /*
4720  * Context that's attached to an encoded read io_uring command, in cmd->pdu. It
4721  * contains the fields in btrfs_uring_read_extent that are necessary to finish
4722  * off and cleanup the I/O in btrfs_uring_read_finished.
4723  */
4724 struct btrfs_uring_priv {
4725         struct io_uring_cmd *cmd;
4726         struct page **pages;
4727         unsigned long nr_pages;
4728         struct kiocb iocb;
4729         struct iovec *iov;
4730         struct iov_iter iter;
4731         struct extent_state *cached_state;
4732         u64 count;
4733         u64 start;
4734         u64 lockend;
4735         int err;
4736         bool compressed;
4737 };
4738
4739 struct io_btrfs_cmd {
4740         struct btrfs_uring_priv *priv;
4741 };
4742
4743 static void btrfs_uring_read_finished(struct io_uring_cmd *cmd, unsigned int issue_flags)
4744 {
4745         struct io_btrfs_cmd *bc = io_uring_cmd_to_pdu(cmd, struct io_btrfs_cmd);
4746         struct btrfs_uring_priv *priv = bc->priv;
4747         struct btrfs_inode *inode = BTRFS_I(file_inode(priv->iocb.ki_filp));
4748         struct extent_io_tree *io_tree = &inode->io_tree;
4749         unsigned long index;
4750         u64 cur;
4751         size_t page_offset;
4752         ssize_t ret;
4753
4754         /* The inode lock has already been acquired in btrfs_uring_read_extent.  */
4755         btrfs_lockdep_inode_acquire(inode, i_rwsem);
4756
4757         if (priv->err) {
4758                 ret = priv->err;
4759                 goto out;
4760         }
4761
4762         if (priv->compressed) {
4763                 index = 0;
4764                 page_offset = 0;
4765         } else {
4766                 index = (priv->iocb.ki_pos - priv->start) >> PAGE_SHIFT;
4767                 page_offset = offset_in_page(priv->iocb.ki_pos - priv->start);
4768         }
4769         cur = 0;
4770         while (cur < priv->count) {
4771                 size_t bytes = min_t(size_t, priv->count - cur, PAGE_SIZE - page_offset);
4772
4773                 if (copy_page_to_iter(priv->pages[index], page_offset, bytes,
4774                                       &priv->iter) != bytes) {
4775                         ret = -EFAULT;
4776                         goto out;
4777                 }
4778
4779                 index++;
4780                 cur += bytes;
4781                 page_offset = 0;
4782         }
4783         ret = priv->count;
4784
4785 out:
4786         unlock_extent(io_tree, priv->start, priv->lockend, &priv->cached_state);
4787         btrfs_inode_unlock(inode, BTRFS_ILOCK_SHARED);
4788
4789         io_uring_cmd_done(cmd, ret, 0, issue_flags);
4790         add_rchar(current, ret);
4791
4792         for (index = 0; index < priv->nr_pages; index++)
4793                 __free_page(priv->pages[index]);
4794
4795         kfree(priv->pages);
4796         kfree(priv->iov);
4797         kfree(priv);
4798 }
4799
4800 void btrfs_uring_read_extent_endio(void *ctx, int err)
4801 {
4802         struct btrfs_uring_priv *priv = ctx;
4803         struct io_btrfs_cmd *bc = io_uring_cmd_to_pdu(priv->cmd, struct io_btrfs_cmd);
4804
4805         priv->err = err;
4806         bc->priv = priv;
4807
4808         io_uring_cmd_complete_in_task(priv->cmd, btrfs_uring_read_finished);
4809 }
4810
4811 static int btrfs_uring_read_extent(struct kiocb *iocb, struct iov_iter *iter,
4812                                    u64 start, u64 lockend,
4813                                    struct extent_state *cached_state,
4814                                    u64 disk_bytenr, u64 disk_io_size,
4815                                    size_t count, bool compressed,
4816                                    struct iovec *iov, struct io_uring_cmd *cmd)
4817 {
4818         struct btrfs_inode *inode = BTRFS_I(file_inode(iocb->ki_filp));
4819         struct extent_io_tree *io_tree = &inode->io_tree;
4820         struct page **pages;
4821         struct btrfs_uring_priv *priv = NULL;
4822         unsigned long nr_pages;
4823         int ret;
4824
4825         nr_pages = DIV_ROUND_UP(disk_io_size, PAGE_SIZE);
4826         pages = kcalloc(nr_pages, sizeof(struct page *), GFP_NOFS);
4827         if (!pages)
4828                 return -ENOMEM;
4829         ret = btrfs_alloc_page_array(nr_pages, pages, 0);
4830         if (ret) {
4831                 ret = -ENOMEM;
4832                 goto out_fail;
4833         }
4834
4835         priv = kmalloc(sizeof(*priv), GFP_NOFS);
4836         if (!priv) {
4837                 ret = -ENOMEM;
4838                 goto out_fail;
4839         }
4840
4841         priv->iocb = *iocb;
4842         priv->iov = iov;
4843         priv->iter = *iter;
4844         priv->count = count;
4845         priv->cmd = cmd;
4846         priv->cached_state = cached_state;
4847         priv->compressed = compressed;
4848         priv->nr_pages = nr_pages;
4849         priv->pages = pages;
4850         priv->start = start;
4851         priv->lockend = lockend;
4852         priv->err = 0;
4853
4854         ret = btrfs_encoded_read_regular_fill_pages(inode, disk_bytenr,
4855                                                     disk_io_size, pages, priv);
4856         if (ret && ret != -EIOCBQUEUED)
4857                 goto out_fail;
4858
4859         /*
4860          * If we return -EIOCBQUEUED, we're deferring the cleanup to
4861          * btrfs_uring_read_finished(), which will handle unlocking the extent
4862          * and inode and freeing the allocations.
4863          */
4864
4865         /*
4866          * We're returning to userspace with the inode lock held, and that's
4867          * okay - it'll get unlocked in a worker thread.  Call
4868          * btrfs_lockdep_inode_release() to avoid confusing lockdep.
4869          */
4870         btrfs_lockdep_inode_release(inode, i_rwsem);
4871
4872         return -EIOCBQUEUED;
4873
4874 out_fail:
4875         unlock_extent(io_tree, start, lockend, &cached_state);
4876         btrfs_inode_unlock(inode, BTRFS_ILOCK_SHARED);
4877         kfree(priv);
4878         return ret;
4879 }
4880
4881 static int btrfs_uring_encoded_read(struct io_uring_cmd *cmd, unsigned int issue_flags)
4882 {
4883         size_t copy_end_kernel = offsetofend(struct btrfs_ioctl_encoded_io_args, flags);
4884         size_t copy_end;
4885         struct btrfs_ioctl_encoded_io_args args = { 0 };
4886         int ret;
4887         u64 disk_bytenr, disk_io_size;
4888         struct file *file;
4889         struct btrfs_inode *inode;
4890         struct btrfs_fs_info *fs_info;
4891         struct extent_io_tree *io_tree;
4892         struct iovec iovstack[UIO_FASTIOV];
4893         struct iovec *iov = iovstack;
4894         struct iov_iter iter;
4895         loff_t pos;
4896         struct kiocb kiocb;
4897         struct extent_state *cached_state = NULL;
4898         u64 start, lockend;
4899         void __user *sqe_addr;
4900
4901         if (!capable(CAP_SYS_ADMIN)) {
4902                 ret = -EPERM;
4903                 goto out_acct;
4904         }
4905         file = cmd->file;
4906         inode = BTRFS_I(file->f_inode);
4907         fs_info = inode->root->fs_info;
4908         io_tree = &inode->io_tree;
4909         sqe_addr = u64_to_user_ptr(READ_ONCE(cmd->sqe->addr));
4910
4911         if (issue_flags & IO_URING_F_COMPAT) {
4912 #if defined(CONFIG_64BIT) && defined(CONFIG_COMPAT)
4913                 struct btrfs_ioctl_encoded_io_args_32 args32;
4914
4915                 copy_end = offsetofend(struct btrfs_ioctl_encoded_io_args_32, flags);
4916                 if (copy_from_user(&args32, sqe_addr, copy_end)) {
4917                         ret = -EFAULT;
4918                         goto out_acct;
4919                 }
4920                 args.iov = compat_ptr(args32.iov);
4921                 args.iovcnt = args32.iovcnt;
4922                 args.offset = args32.offset;
4923                 args.flags = args32.flags;
4924 #else
4925                 return -ENOTTY;
4926 #endif
4927         } else {
4928                 copy_end = copy_end_kernel;
4929                 if (copy_from_user(&args, sqe_addr, copy_end)) {
4930                         ret = -EFAULT;
4931                         goto out_acct;
4932                 }
4933         }
4934
4935         if (args.flags != 0)
4936                 return -EINVAL;
4937
4938         ret = import_iovec(ITER_DEST, args.iov, args.iovcnt, ARRAY_SIZE(iovstack),
4939                            &iov, &iter);
4940         if (ret < 0)
4941                 goto out_acct;
4942
4943         if (iov_iter_count(&iter) == 0) {
4944                 ret = 0;
4945                 goto out_free;
4946         }
4947
4948         pos = args.offset;
4949         ret = rw_verify_area(READ, file, &pos, args.len);
4950         if (ret < 0)
4951                 goto out_free;
4952
4953         init_sync_kiocb(&kiocb, file);
4954         kiocb.ki_pos = pos;
4955
4956         if (issue_flags & IO_URING_F_NONBLOCK)
4957                 kiocb.ki_flags |= IOCB_NOWAIT;
4958
4959         start = ALIGN_DOWN(pos, fs_info->sectorsize);
4960         lockend = start + BTRFS_MAX_UNCOMPRESSED - 1;
4961
4962         ret = btrfs_encoded_read(&kiocb, &iter, &args, &cached_state,
4963                                  &disk_bytenr, &disk_io_size);
4964         if (ret < 0 && ret != -EIOCBQUEUED)
4965                 goto out_free;
4966
4967         file_accessed(file);
4968
4969         if (copy_to_user(sqe_addr + copy_end, (const char *)&args + copy_end_kernel,
4970                          sizeof(args) - copy_end_kernel)) {
4971                 if (ret == -EIOCBQUEUED) {
4972                         unlock_extent(io_tree, start, lockend, &cached_state);
4973                         btrfs_inode_unlock(inode, BTRFS_ILOCK_SHARED);
4974                 }
4975                 ret = -EFAULT;
4976                 goto out_free;
4977         }
4978
4979         if (ret == -EIOCBQUEUED) {
4980                 u64 count;
4981
4982                 /*
4983                  * If we've optimized things by storing the iovecs on the stack,
4984                  * undo this.
4985                  */
4986                 if (!iov) {
4987                         iov = kmalloc(sizeof(struct iovec) * args.iovcnt, GFP_NOFS);
4988                         if (!iov) {
4989                                 unlock_extent(io_tree, start, lockend, &cached_state);
4990                                 btrfs_inode_unlock(inode, BTRFS_ILOCK_SHARED);
4991                                 ret = -ENOMEM;
4992                                 goto out_acct;
4993                         }
4994
4995                         memcpy(iov, iovstack, sizeof(struct iovec) * args.iovcnt);
4996                 }
4997
4998                 count = min_t(u64, iov_iter_count(&iter), disk_io_size);
4999
5000                 /* Match ioctl by not returning past EOF if uncompressed. */
5001                 if (!args.compression)
5002                         count = min_t(u64, count, args.len);
5003
5004                 ret = btrfs_uring_read_extent(&kiocb, &iter, start, lockend,
5005                                               cached_state, disk_bytenr,
5006                                               disk_io_size, count,
5007                                               args.compression, iov, cmd);
5008
5009                 goto out_acct;
5010         }
5011
5012 out_free:
5013         kfree(iov);
5014
5015 out_acct:
5016         if (ret > 0)
5017                 add_rchar(current, ret);
5018         inc_syscr(current);
5019
5020         return ret;
5021 }
5022
5023 int btrfs_uring_cmd(struct io_uring_cmd *cmd, unsigned int issue_flags)
5024 {
5025         switch (cmd->cmd_op) {
5026         case BTRFS_IOC_ENCODED_READ:
5027 #if defined(CONFIG_64BIT) && defined(CONFIG_COMPAT)
5028         case BTRFS_IOC_ENCODED_READ_32:
5029 #endif
5030                 return btrfs_uring_encoded_read(cmd, issue_flags);
5031         }
5032
5033         return -EINVAL;
5034 }
5035
5036 static int btrfs_ioctl_subvol_sync(struct btrfs_fs_info *fs_info, void __user *argp)
5037 {
5038         struct btrfs_root *root;
5039         struct btrfs_ioctl_subvol_wait args = { 0 };
5040         signed long sched_ret;
5041         int refs;
5042         u64 root_flags;
5043         bool wait_for_deletion = false;
5044         bool found = false;
5045
5046         if (copy_from_user(&args, argp, sizeof(args)))
5047                 return -EFAULT;
5048
5049         switch (args.mode) {
5050         case BTRFS_SUBVOL_SYNC_WAIT_FOR_QUEUED:
5051                 /*
5052                  * Wait for the first one deleted that waits until all previous
5053                  * are cleaned.
5054                  */
5055                 spin_lock(&fs_info->trans_lock);
5056                 if (!list_empty(&fs_info->dead_roots)) {
5057                         root = list_last_entry(&fs_info->dead_roots,
5058                                                struct btrfs_root, root_list);
5059                         args.subvolid = btrfs_root_id(root);
5060                         found = true;
5061                 }
5062                 spin_unlock(&fs_info->trans_lock);
5063                 if (!found)
5064                         return -ENOENT;
5065
5066                 fallthrough;
5067         case BTRFS_SUBVOL_SYNC_WAIT_FOR_ONE:
5068                 if ((0 < args.subvolid && args.subvolid < BTRFS_FIRST_FREE_OBJECTID) ||
5069                     BTRFS_LAST_FREE_OBJECTID < args.subvolid)
5070                         return -EINVAL;
5071                 break;
5072         case BTRFS_SUBVOL_SYNC_COUNT:
5073                 spin_lock(&fs_info->trans_lock);
5074                 args.count = list_count_nodes(&fs_info->dead_roots);
5075                 spin_unlock(&fs_info->trans_lock);
5076                 if (copy_to_user(argp, &args, sizeof(args)))
5077                         return -EFAULT;
5078                 return 0;
5079         case BTRFS_SUBVOL_SYNC_PEEK_FIRST:
5080                 spin_lock(&fs_info->trans_lock);
5081                 /* Last in the list was deleted first. */
5082                 if (!list_empty(&fs_info->dead_roots)) {
5083                         root = list_last_entry(&fs_info->dead_roots,
5084                                                struct btrfs_root, root_list);
5085                         args.subvolid = btrfs_root_id(root);
5086                 } else {
5087                         args.subvolid = 0;
5088                 }
5089                 spin_unlock(&fs_info->trans_lock);
5090                 if (copy_to_user(argp, &args, sizeof(args)))
5091                         return -EFAULT;
5092                 return 0;
5093         case BTRFS_SUBVOL_SYNC_PEEK_LAST:
5094                 spin_lock(&fs_info->trans_lock);
5095                 /* First in the list was deleted last. */
5096                 if (!list_empty(&fs_info->dead_roots)) {
5097                         root = list_first_entry(&fs_info->dead_roots,
5098                                                 struct btrfs_root, root_list);
5099                         args.subvolid = btrfs_root_id(root);
5100                 } else {
5101                         args.subvolid = 0;
5102                 }
5103                 spin_unlock(&fs_info->trans_lock);
5104                 if (copy_to_user(argp, &args, sizeof(args)))
5105                         return -EFAULT;
5106                 return 0;
5107         default:
5108                 return -EINVAL;
5109         }
5110
5111         /* 32bit limitation: fs_roots_radix key is not wide enough. */
5112         if (sizeof(unsigned long) != sizeof(u64) && args.subvolid > U32_MAX)
5113                 return -EOVERFLOW;
5114
5115         while (1) {
5116                 /* Wait for the specific one. */
5117                 if (down_read_interruptible(&fs_info->subvol_sem) == -EINTR)
5118                         return -EINTR;
5119                 refs = -1;
5120                 spin_lock(&fs_info->fs_roots_radix_lock);
5121                 root = radix_tree_lookup(&fs_info->fs_roots_radix,
5122                                          (unsigned long)args.subvolid);
5123                 if (root) {
5124                         spin_lock(&root->root_item_lock);
5125                         refs = btrfs_root_refs(&root->root_item);
5126                         root_flags = btrfs_root_flags(&root->root_item);
5127                         spin_unlock(&root->root_item_lock);
5128                 }
5129                 spin_unlock(&fs_info->fs_roots_radix_lock);
5130                 up_read(&fs_info->subvol_sem);
5131
5132                 /* Subvolume does not exist. */
5133                 if (!root)
5134                         return -ENOENT;
5135
5136                 /* Subvolume not deleted at all. */
5137                 if (refs > 0)
5138                         return -EEXIST;
5139                 /* We've waited and now the subvolume is gone. */
5140                 if (wait_for_deletion && refs == -1) {
5141                         /* Return the one we waited for as the last one. */
5142                         if (copy_to_user(argp, &args, sizeof(args)))
5143                                 return -EFAULT;
5144                         return 0;
5145                 }
5146
5147                 /* Subvolume not found on the first try (deleted or never existed). */
5148                 if (refs == -1)
5149                         return -ENOENT;
5150
5151                 wait_for_deletion = true;
5152                 ASSERT(root_flags & BTRFS_ROOT_SUBVOL_DEAD);
5153                 sched_ret = schedule_timeout_interruptible(HZ);
5154                 /* Early wake up or error. */
5155                 if (sched_ret != 0)
5156                         return -EINTR;
5157         }
5158
5159         return 0;
5160 }
5161
5162 long btrfs_ioctl(struct file *file, unsigned int
5163                 cmd, unsigned long arg)
5164 {
5165         struct inode *inode = file_inode(file);
5166         struct btrfs_fs_info *fs_info = inode_to_fs_info(inode);
5167         struct btrfs_root *root = BTRFS_I(inode)->root;
5168         void __user *argp = (void __user *)arg;
5169
5170         switch (cmd) {
5171         case FS_IOC_GETVERSION:
5172                 return btrfs_ioctl_getversion(inode, argp);
5173         case FS_IOC_GETFSLABEL:
5174                 return btrfs_ioctl_get_fslabel(fs_info, argp);
5175         case FS_IOC_SETFSLABEL:
5176                 return btrfs_ioctl_set_fslabel(file, argp);
5177         case FITRIM:
5178                 return btrfs_ioctl_fitrim(fs_info, argp);
5179         case BTRFS_IOC_SNAP_CREATE:
5180                 return btrfs_ioctl_snap_create(file, argp, 0);
5181         case BTRFS_IOC_SNAP_CREATE_V2:
5182                 return btrfs_ioctl_snap_create_v2(file, argp, 0);
5183         case BTRFS_IOC_SUBVOL_CREATE:
5184                 return btrfs_ioctl_snap_create(file, argp, 1);
5185         case BTRFS_IOC_SUBVOL_CREATE_V2:
5186                 return btrfs_ioctl_snap_create_v2(file, argp, 1);
5187         case BTRFS_IOC_SNAP_DESTROY:
5188                 return btrfs_ioctl_snap_destroy(file, argp, false);
5189         case BTRFS_IOC_SNAP_DESTROY_V2:
5190                 return btrfs_ioctl_snap_destroy(file, argp, true);
5191         case BTRFS_IOC_SUBVOL_GETFLAGS:
5192                 return btrfs_ioctl_subvol_getflags(inode, argp);
5193         case BTRFS_IOC_SUBVOL_SETFLAGS:
5194                 return btrfs_ioctl_subvol_setflags(file, argp);
5195         case BTRFS_IOC_DEFAULT_SUBVOL:
5196                 return btrfs_ioctl_default_subvol(file, argp);
5197         case BTRFS_IOC_DEFRAG:
5198                 return btrfs_ioctl_defrag(file, NULL);
5199         case BTRFS_IOC_DEFRAG_RANGE:
5200                 return btrfs_ioctl_defrag(file, argp);
5201         case BTRFS_IOC_RESIZE:
5202                 return btrfs_ioctl_resize(file, argp);
5203         case BTRFS_IOC_ADD_DEV:
5204                 return btrfs_ioctl_add_dev(fs_info, argp);
5205         case BTRFS_IOC_RM_DEV:
5206                 return btrfs_ioctl_rm_dev(file, argp);
5207         case BTRFS_IOC_RM_DEV_V2:
5208                 return btrfs_ioctl_rm_dev_v2(file, argp);
5209         case BTRFS_IOC_FS_INFO:
5210                 return btrfs_ioctl_fs_info(fs_info, argp);
5211         case BTRFS_IOC_DEV_INFO:
5212                 return btrfs_ioctl_dev_info(fs_info, argp);
5213         case BTRFS_IOC_TREE_SEARCH:
5214                 return btrfs_ioctl_tree_search(inode, argp);
5215         case BTRFS_IOC_TREE_SEARCH_V2:
5216                 return btrfs_ioctl_tree_search_v2(inode, argp);
5217         case BTRFS_IOC_INO_LOOKUP:
5218                 return btrfs_ioctl_ino_lookup(root, argp);
5219         case BTRFS_IOC_INO_PATHS:
5220                 return btrfs_ioctl_ino_to_path(root, argp);
5221         case BTRFS_IOC_LOGICAL_INO:
5222                 return btrfs_ioctl_logical_to_ino(fs_info, argp, 1);
5223         case BTRFS_IOC_LOGICAL_INO_V2:
5224                 return btrfs_ioctl_logical_to_ino(fs_info, argp, 2);
5225         case BTRFS_IOC_SPACE_INFO:
5226                 return btrfs_ioctl_space_info(fs_info, argp);
5227         case BTRFS_IOC_SYNC: {
5228                 int ret;
5229
5230                 ret = btrfs_start_delalloc_roots(fs_info, LONG_MAX, false);
5231                 if (ret)
5232                         return ret;
5233                 ret = btrfs_sync_fs(inode->i_sb, 1);
5234                 /*
5235                  * There may be work for the cleaner kthread to do (subvolume
5236                  * deletion, delayed iputs, defrag inodes, etc), so wake it up.
5237                  */
5238                 wake_up_process(fs_info->cleaner_kthread);
5239                 return ret;
5240         }
5241         case BTRFS_IOC_START_SYNC:
5242                 return btrfs_ioctl_start_sync(root, argp);
5243         case BTRFS_IOC_WAIT_SYNC:
5244                 return btrfs_ioctl_wait_sync(fs_info, argp);
5245         case BTRFS_IOC_SCRUB:
5246                 return btrfs_ioctl_scrub(file, argp);
5247         case BTRFS_IOC_SCRUB_CANCEL:
5248                 return btrfs_ioctl_scrub_cancel(fs_info);
5249         case BTRFS_IOC_SCRUB_PROGRESS:
5250                 return btrfs_ioctl_scrub_progress(fs_info, argp);
5251         case BTRFS_IOC_BALANCE_V2:
5252                 return btrfs_ioctl_balance(file, argp);
5253         case BTRFS_IOC_BALANCE_CTL:
5254                 return btrfs_ioctl_balance_ctl(fs_info, arg);
5255         case BTRFS_IOC_BALANCE_PROGRESS:
5256                 return btrfs_ioctl_balance_progress(fs_info, argp);
5257         case BTRFS_IOC_SET_RECEIVED_SUBVOL:
5258                 return btrfs_ioctl_set_received_subvol(file, argp);
5259 #ifdef CONFIG_64BIT
5260         case BTRFS_IOC_SET_RECEIVED_SUBVOL_32:
5261                 return btrfs_ioctl_set_received_subvol_32(file, argp);
5262 #endif
5263         case BTRFS_IOC_SEND:
5264                 return _btrfs_ioctl_send(BTRFS_I(inode), argp, false);
5265 #if defined(CONFIG_64BIT) && defined(CONFIG_COMPAT)
5266         case BTRFS_IOC_SEND_32:
5267                 return _btrfs_ioctl_send(BTRFS_I(inode), argp, true);
5268 #endif
5269         case BTRFS_IOC_GET_DEV_STATS:
5270                 return btrfs_ioctl_get_dev_stats(fs_info, argp);
5271         case BTRFS_IOC_QUOTA_CTL:
5272                 return btrfs_ioctl_quota_ctl(file, argp);
5273         case BTRFS_IOC_QGROUP_ASSIGN:
5274                 return btrfs_ioctl_qgroup_assign(file, argp);
5275         case BTRFS_IOC_QGROUP_CREATE:
5276                 return btrfs_ioctl_qgroup_create(file, argp);
5277         case BTRFS_IOC_QGROUP_LIMIT:
5278                 return btrfs_ioctl_qgroup_limit(file, argp);
5279         case BTRFS_IOC_QUOTA_RESCAN:
5280                 return btrfs_ioctl_quota_rescan(file, argp);
5281         case BTRFS_IOC_QUOTA_RESCAN_STATUS:
5282                 return btrfs_ioctl_quota_rescan_status(fs_info, argp);
5283         case BTRFS_IOC_QUOTA_RESCAN_WAIT:
5284                 return btrfs_ioctl_quota_rescan_wait(fs_info);
5285         case BTRFS_IOC_DEV_REPLACE:
5286                 return btrfs_ioctl_dev_replace(fs_info, argp);
5287         case BTRFS_IOC_GET_SUPPORTED_FEATURES:
5288                 return btrfs_ioctl_get_supported_features(argp);
5289         case BTRFS_IOC_GET_FEATURES:
5290                 return btrfs_ioctl_get_features(fs_info, argp);
5291         case BTRFS_IOC_SET_FEATURES:
5292                 return btrfs_ioctl_set_features(file, argp);
5293         case BTRFS_IOC_GET_SUBVOL_INFO:
5294                 return btrfs_ioctl_get_subvol_info(inode, argp);
5295         case BTRFS_IOC_GET_SUBVOL_ROOTREF:
5296                 return btrfs_ioctl_get_subvol_rootref(root, argp);
5297         case BTRFS_IOC_INO_LOOKUP_USER:
5298                 return btrfs_ioctl_ino_lookup_user(file, argp);
5299         case FS_IOC_ENABLE_VERITY:
5300                 return fsverity_ioctl_enable(file, (const void __user *)argp);
5301         case FS_IOC_MEASURE_VERITY:
5302                 return fsverity_ioctl_measure(file, argp);
5303         case BTRFS_IOC_ENCODED_READ:
5304                 return btrfs_ioctl_encoded_read(file, argp, false);
5305         case BTRFS_IOC_ENCODED_WRITE:
5306                 return btrfs_ioctl_encoded_write(file, argp, false);
5307 #if defined(CONFIG_64BIT) && defined(CONFIG_COMPAT)
5308         case BTRFS_IOC_ENCODED_READ_32:
5309                 return btrfs_ioctl_encoded_read(file, argp, true);
5310         case BTRFS_IOC_ENCODED_WRITE_32:
5311                 return btrfs_ioctl_encoded_write(file, argp, true);
5312 #endif
5313         case BTRFS_IOC_SUBVOL_SYNC_WAIT:
5314                 return btrfs_ioctl_subvol_sync(fs_info, argp);
5315         }
5316
5317         return -ENOTTY;
5318 }
5319
5320 #ifdef CONFIG_COMPAT
5321 long btrfs_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
5322 {
5323         /*
5324          * These all access 32-bit values anyway so no further
5325          * handling is necessary.
5326          */
5327         switch (cmd) {
5328         case FS_IOC32_GETVERSION:
5329                 cmd = FS_IOC_GETVERSION;
5330                 break;
5331         }
5332
5333         return btrfs_ioctl(file, cmd, (unsigned long) compat_ptr(arg));
5334 }
5335 #endif