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