fs/btrfs/ioctl.c

   1 /*
   2  * Copyright (C) 2007 Oracle.  All rights reserved.
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public
   6  * License v2 as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  11  * General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public
  14  * License along with this program; if not, write to the
  15  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  16  * Boston, MA 021110-1307, USA.
  17  */
  18
  19 #include <linux/kernel.h>
  20 #include <linux/bio.h>
  21 #include <linux/buffer_head.h>
  22 #include <linux/file.h>
  23 #include <linux/fs.h>
  24 #include <linux/fsnotify.h>
  25 #include <linux/pagemap.h>
  26 #include <linux/highmem.h>
  27 #include <linux/time.h>
  28 #include <linux/init.h>
  29 #include <linux/string.h>
  30 #include <linux/backing-dev.h>
  31 #include <linux/mount.h>
  32 #include <linux/mpage.h>
  33 #include <linux/namei.h>
  34 #include <linux/swap.h>
  35 #include <linux/writeback.h>
  36 #include <linux/compat.h>
  37 #include <linux/bit_spinlock.h>
  38 #include <linux/security.h>
  39 #include <linux/xattr.h>
  40 #include <linux/mm.h>
  41 #include <linux/slab.h>
  42 #include <linux/blkdev.h>
  43 #include <linux/uuid.h>
  44 #include <linux/btrfs.h>
  45 #include <linux/uaccess.h>
  46 #include "ctree.h"
  47 #include "disk-io.h"
  48 #include "transaction.h"
  49 #include "btrfs_inode.h"
  50 #include "print-tree.h"
  51 #include "volumes.h"
  52 #include "locking.h"
  53 #include "inode-map.h"
  54 #include "backref.h"
  55 #include "rcu-string.h"
  56 #include "send.h"
  57 #include "dev-replace.h"
  58 #include "props.h"
  59 #include "sysfs.h"
  60 #include "qgroup.h"
  61 #include "tree-log.h"
  62 #include "compression.h"
  63
  64 #ifdef CONFIG_64BIT
  65 /* If we have a 32-bit userspace and 64-bit kernel, then the UAPI
  66  * structures are incorrect, as the timespec structure from userspace
  67  * is 4 bytes too small. We define these alternatives here to teach
  68  * the kernel about the 32-bit struct packing.
  69  */
  70 struct btrfs_ioctl_timespec_32 {
  71         __u64 sec;
  72         __u32 nsec;
  73 } __attribute__ ((__packed__));
  74
  75 struct btrfs_ioctl_received_subvol_args_32 {
  76         char    uuid[BTRFS_UUID_SIZE];  /* in */
  77         __u64   stransid;               /* in */
  78         __u64   rtransid;               /* out */
  79         struct btrfs_ioctl_timespec_32 stime; /* in */
  80         struct btrfs_ioctl_timespec_32 rtime; /* out */
  81         __u64   flags;                  /* in */
  82         __u64   reserved[16];           /* in */
  83 } __attribute__ ((__packed__));
  84
  85 #define BTRFS_IOC_SET_RECEIVED_SUBVOL_32 _IOWR(BTRFS_IOCTL_MAGIC, 37, \
  86                                 struct btrfs_ioctl_received_subvol_args_32)
  87 #endif
  88
  89
  90 static int btrfs_clone(struct inode *src, struct inode *inode,
  91                        u64 off, u64 olen, u64 olen_aligned, u64 destoff,
  92                        int no_time_update);
  93
  94 /* Mask out flags that are inappropriate for the given type of inode. */
  95 static inline __u32 btrfs_mask_flags(umode_t mode, __u32 flags)
  96 {
  97         if (S_ISDIR(mode))
  98                 return flags;
  99         else if (S_ISREG(mode))
 100                 return flags & ~FS_DIRSYNC_FL;
 101         else
 102                 return flags & (FS_NODUMP_FL | FS_NOATIME_FL);
 103 }
 104
 105 /*
 106  * Export inode flags to the format expected by the FS_IOC_GETFLAGS ioctl.
 107  */
 108 static unsigned int btrfs_flags_to_ioctl(unsigned int flags)
 109 {
 110         unsigned int iflags = 0;
 111
 112         if (flags & BTRFS_INODE_SYNC)
 113                 iflags |= FS_SYNC_FL;
 114         if (flags & BTRFS_INODE_IMMUTABLE)
 115                 iflags |= FS_IMMUTABLE_FL;
 116         if (flags & BTRFS_INODE_APPEND)
 117                 iflags |= FS_APPEND_FL;
 118         if (flags & BTRFS_INODE_NODUMP)
 119                 iflags |= FS_NODUMP_FL;
 120         if (flags & BTRFS_INODE_NOATIME)
 121                 iflags |= FS_NOATIME_FL;
 122         if (flags & BTRFS_INODE_DIRSYNC)
 123                 iflags |= FS_DIRSYNC_FL;
 124         if (flags & BTRFS_INODE_NODATACOW)
 125                 iflags |= FS_NOCOW_FL;
 126
 127         if (flags & BTRFS_INODE_NOCOMPRESS)
 128                 iflags |= FS_NOCOMP_FL;
 129         else if (flags & BTRFS_INODE_COMPRESS)
 130                 iflags |= FS_COMPR_FL;
 131
 132         return iflags;
 133 }
 134
 135 /*
 136  * Update inode->i_flags based on the btrfs internal flags.
 137  */
 138 void btrfs_update_iflags(struct inode *inode)
 139 {
 140         struct btrfs_inode *ip = BTRFS_I(inode);
 141         unsigned int new_fl = 0;
 142
 143         if (ip->flags & BTRFS_INODE_SYNC)
 144                 new_fl |= S_SYNC;
 145         if (ip->flags & BTRFS_INODE_IMMUTABLE)
 146                 new_fl |= S_IMMUTABLE;
 147         if (ip->flags & BTRFS_INODE_APPEND)
 148                 new_fl |= S_APPEND;
 149         if (ip->flags & BTRFS_INODE_NOATIME)
 150                 new_fl |= S_NOATIME;
 151         if (ip->flags & BTRFS_INODE_DIRSYNC)
 152                 new_fl |= S_DIRSYNC;
 153
 154         set_mask_bits(&inode->i_flags,
 155                       S_SYNC | S_APPEND | S_IMMUTABLE | S_NOATIME | S_DIRSYNC,
 156                       new_fl);
 157 }
 158
 159 static int btrfs_ioctl_getflags(struct file *file, void __user *arg)
 160 {
 161         struct btrfs_inode *ip = BTRFS_I(file_inode(file));
 162         unsigned int flags = btrfs_flags_to_ioctl(ip->flags);
 163
 164         if (copy_to_user(arg, &flags, sizeof(flags)))
 165                 return -EFAULT;
 166         return 0;
 167 }
 168
 169 static int check_flags(unsigned int flags)
 170 {
 171         if (flags & ~(FS_IMMUTABLE_FL | FS_APPEND_FL | \
 172                       FS_NOATIME_FL | FS_NODUMP_FL | \
 173                       FS_SYNC_FL | FS_DIRSYNC_FL | \
 174                       FS_NOCOMP_FL | FS_COMPR_FL |
 175                       FS_NOCOW_FL))
 176                 return -EOPNOTSUPP;
 177
 178         if ((flags & FS_NOCOMP_FL) && (flags & FS_COMPR_FL))
 179                 return -EINVAL;
 180
 181         return 0;
 182 }
 183
 184 static int btrfs_ioctl_setflags(struct file *file, void __user *arg)
 185 {
 186         struct inode *inode = file_inode(file);
 187         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
 188         struct btrfs_inode *ip = BTRFS_I(inode);
 189         struct btrfs_root *root = ip->root;
 190         struct btrfs_trans_handle *trans;
 191         unsigned int flags, oldflags;
 192         int ret;
 193         u64 ip_oldflags;
 194         unsigned int i_oldflags;
 195         umode_t mode;
 196
 197         if (!inode_owner_or_capable(inode))
 198                 return -EPERM;
 199
 200         if (btrfs_root_readonly(root))
 201                 return -EROFS;
 202
 203         if (copy_from_user(&flags, arg, sizeof(flags)))
 204                 return -EFAULT;
 205
 206         ret = check_flags(flags);
 207         if (ret)
 208                 return ret;
 209
 210         ret = mnt_want_write_file(file);
 211         if (ret)
 212                 return ret;
 213
 214         inode_lock(inode);
 215
 216         ip_oldflags = ip->flags;
 217         i_oldflags = inode->i_flags;
 218         mode = inode->i_mode;
 219
 220         flags = btrfs_mask_flags(inode->i_mode, flags);
 221         oldflags = btrfs_flags_to_ioctl(ip->flags);
 222         if ((flags ^ oldflags) & (FS_APPEND_FL | FS_IMMUTABLE_FL)) {
 223                 if (!capable(CAP_LINUX_IMMUTABLE)) {
 224                         ret = -EPERM;
 225                         goto out_unlock;
 226                 }
 227         }
 228
 229         if (flags & FS_SYNC_FL)
 230                 ip->flags |= BTRFS_INODE_SYNC;
 231         else
 232                 ip->flags &= ~BTRFS_INODE_SYNC;
 233         if (flags & FS_IMMUTABLE_FL)
 234                 ip->flags |= BTRFS_INODE_IMMUTABLE;
 235         else
 236                 ip->flags &= ~BTRFS_INODE_IMMUTABLE;
 237         if (flags & FS_APPEND_FL)
 238                 ip->flags |= BTRFS_INODE_APPEND;
 239         else
 240                 ip->flags &= ~BTRFS_INODE_APPEND;
 241         if (flags & FS_NODUMP_FL)
 242                 ip->flags |= BTRFS_INODE_NODUMP;
 243         else
 244                 ip->flags &= ~BTRFS_INODE_NODUMP;
 245         if (flags & FS_NOATIME_FL)
 246                 ip->flags |= BTRFS_INODE_NOATIME;
 247         else
 248                 ip->flags &= ~BTRFS_INODE_NOATIME;
 249         if (flags & FS_DIRSYNC_FL)
 250                 ip->flags |= BTRFS_INODE_DIRSYNC;
 251         else
 252                 ip->flags &= ~BTRFS_INODE_DIRSYNC;
 253         if (flags & FS_NOCOW_FL) {
 254                 if (S_ISREG(mode)) {
 255                         /*
 256                          * It's safe to turn csums off here, no extents exist.
 257                          * Otherwise we want the flag to reflect the real COW
 258                          * status of the file and will not set it.
 259                          */
 260                         if (inode->i_size == 0)
 261                                 ip->flags |= BTRFS_INODE_NODATACOW
 262                                            | BTRFS_INODE_NODATASUM;
 263                 } else {
 264                         ip->flags |= BTRFS_INODE_NODATACOW;
 265                 }
 266         } else {
 267                 /*
 268                  * Revert back under same assumptions as above
 269                  */
 270                 if (S_ISREG(mode)) {
 271                         if (inode->i_size == 0)
 272                                 ip->flags &= ~(BTRFS_INODE_NODATACOW
 273                                              | BTRFS_INODE_NODATASUM);
 274                 } else {
 275                         ip->flags &= ~BTRFS_INODE_NODATACOW;
 276                 }
 277         }
 278
 279         /*
 280          * The COMPRESS flag can only be changed by users, while the NOCOMPRESS
 281          * flag may be changed automatically if compression code won't make
 282          * things smaller.
 283          */
 284         if (flags & FS_NOCOMP_FL) {
 285                 ip->flags &= ~BTRFS_INODE_COMPRESS;
 286                 ip->flags |= BTRFS_INODE_NOCOMPRESS;
 287
 288                 ret = btrfs_set_prop(inode, "btrfs.compression", NULL, 0, 0);
 289                 if (ret && ret != -ENODATA)
 290                         goto out_drop;
 291         } else if (flags & FS_COMPR_FL) {
 292                 const char *comp;
 293
 294                 ip->flags |= BTRFS_INODE_COMPRESS;
 295                 ip->flags &= ~BTRFS_INODE_NOCOMPRESS;
 296
 297                 if (fs_info->compress_type == BTRFS_COMPRESS_LZO)
 298                         comp = "lzo";
 299                 else if (fs_info->compress_type == BTRFS_COMPRESS_ZLIB)
 300                         comp = "zlib";
 301                 else
 302                         comp = "zstd";
 303                 ret = btrfs_set_prop(inode, "btrfs.compression",
 304                                      comp, strlen(comp), 0);
 305                 if (ret)
 306                         goto out_drop;
 307
 308         } else {
 309                 ret = btrfs_set_prop(inode, "btrfs.compression", NULL, 0, 0);
 310                 if (ret && ret != -ENODATA)
 311                         goto out_drop;
 312                 ip->flags &= ~(BTRFS_INODE_COMPRESS | BTRFS_INODE_NOCOMPRESS);
 313         }
 314
 315         trans = btrfs_start_transaction(root, 1);
 316         if (IS_ERR(trans)) {
 317                 ret = PTR_ERR(trans);
 318                 goto out_drop;
 319         }
 320
 321         btrfs_update_iflags(inode);
 322         inode_inc_iversion(inode);
 323         inode->i_ctime = current_time(inode);
 324         ret = btrfs_update_inode(trans, root, inode);
 325
 326         btrfs_end_transaction(trans);
 327  out_drop:
 328         if (ret) {
 329                 ip->flags = ip_oldflags;
 330                 inode->i_flags = i_oldflags;
 331         }
 332
 333  out_unlock:
 334         inode_unlock(inode);
 335         mnt_drop_write_file(file);
 336         return ret;
 337 }
 338
 339 static int btrfs_ioctl_getversion(struct file *file, int __user *arg)
 340 {
 341         struct inode *inode = file_inode(file);
 342
 343         return put_user(inode->i_generation, arg);
 344 }
 345
 346 static noinline int btrfs_ioctl_fitrim(struct file *file, void __user *arg)
 347 {
 348         struct inode *inode = file_inode(file);
 349         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
 350         struct btrfs_device *device;
 351         struct request_queue *q;
 352         struct fstrim_range range;
 353         u64 minlen = ULLONG_MAX;
 354         u64 num_devices = 0;
 355         u64 total_bytes = btrfs_super_total_bytes(fs_info->super_copy);
 356         int ret;
 357
 358         if (!capable(CAP_SYS_ADMIN))
 359                 return -EPERM;
 360
 361         rcu_read_lock();
 362         list_for_each_entry_rcu(device, &fs_info->fs_devices->devices,
 363                                 dev_list) {
 364                 if (!device->bdev)
 365                         continue;
 366                 q = bdev_get_queue(device->bdev);
 367                 if (blk_queue_discard(q)) {
 368                         num_devices++;
 369                         minlen = min_t(u64, q->limits.discard_granularity,
 370                                      minlen);
 371                 }
 372         }
 373         rcu_read_unlock();
 374
 375         if (!num_devices)
 376                 return -EOPNOTSUPP;
 377         if (copy_from_user(&range, arg, sizeof(range)))
 378                 return -EFAULT;
 379         if (range.start > total_bytes ||
 380             range.len < fs_info->sb->s_blocksize)
 381                 return -EINVAL;
 382
 383         range.len = min(range.len, total_bytes - range.start);
 384         range.minlen = max(range.minlen, minlen);
 385         ret = btrfs_trim_fs(fs_info, &range);
 386         if (ret < 0)
 387                 return ret;
 388
 389         if (copy_to_user(arg, &range, sizeof(range)))
 390                 return -EFAULT;
 391
 392         return 0;
 393 }
 394
 395 int btrfs_is_empty_uuid(u8 *uuid)
 396 {
 397         int i;
 398
 399         for (i = 0; i < BTRFS_UUID_SIZE; i++) {
 400                 if (uuid[i])
 401                         return 0;
 402         }
 403         return 1;
 404 }
 405
 406 static noinline int create_subvol(struct inode *dir,
 407                                   struct dentry *dentry,
 408                                   const char *name, int namelen,
 409                                   u64 *async_transid,
 410                                   struct btrfs_qgroup_inherit *inherit)
 411 {
 412         struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
 413         struct btrfs_trans_handle *trans;
 414         struct btrfs_key key;
 415         struct btrfs_root_item *root_item;
 416         struct btrfs_inode_item *inode_item;
 417         struct extent_buffer *leaf;
 418         struct btrfs_root *root = BTRFS_I(dir)->root;
 419         struct btrfs_root *new_root;
 420         struct btrfs_block_rsv block_rsv;
 421         struct timespec cur_time = current_time(dir);
 422         struct inode *inode;
 423         int ret;
 424         int err;
 425         u64 objectid;
 426         u64 new_dirid = BTRFS_FIRST_FREE_OBJECTID;
 427         u64 index = 0;
 428         u64 qgroup_reserved;
 429         uuid_le new_uuid;
 430
 431         root_item = kzalloc(sizeof(*root_item), GFP_KERNEL);
 432         if (!root_item)
 433                 return -ENOMEM;
 434
 435         ret = btrfs_find_free_objectid(fs_info->tree_root, &objectid);
 436         if (ret)
 437                 goto fail_free;
 438
 439         /*
 440          * Don't create subvolume whose level is not zero. Or qgroup will be
 441          * screwed up since it assumes subvolume qgroup's level to be 0.
 442          */
 443         if (btrfs_qgroup_level(objectid)) {
 444                 ret = -ENOSPC;
 445                 goto fail_free;
 446         }
 447
 448         btrfs_init_block_rsv(&block_rsv, BTRFS_BLOCK_RSV_TEMP);
 449         /*
 450          * The same as the snapshot creation, please see the comment
 451          * of create_snapshot().
 452          */
 453         ret = btrfs_subvolume_reserve_metadata(root, &block_rsv,
 454                                                8, &qgroup_reserved, false);
 455         if (ret)
 456                 goto fail_free;
 457
 458         trans = btrfs_start_transaction(root, 0);
 459         if (IS_ERR(trans)) {
 460                 ret = PTR_ERR(trans);
 461                 btrfs_subvolume_release_metadata(fs_info, &block_rsv);
 462                 goto fail_free;
 463         }
 464         trans->block_rsv = &block_rsv;
 465         trans->bytes_reserved = block_rsv.size;
 466
 467         ret = btrfs_qgroup_inherit(trans, fs_info, 0, objectid, inherit);
 468         if (ret)
 469                 goto fail;
 470
 471         leaf = btrfs_alloc_tree_block(trans, root, 0, objectid, NULL, 0, 0, 0);
 472         if (IS_ERR(leaf)) {
 473                 ret = PTR_ERR(leaf);
 474                 goto fail;
 475         }
 476
 477         memzero_extent_buffer(leaf, 0, sizeof(struct btrfs_header));
 478         btrfs_set_header_bytenr(leaf, leaf->start);
 479         btrfs_set_header_generation(leaf, trans->transid);
 480         btrfs_set_header_backref_rev(leaf, BTRFS_MIXED_BACKREF_REV);
 481         btrfs_set_header_owner(leaf, objectid);
 482
 483         write_extent_buffer_fsid(leaf, fs_info->fsid);
 484         write_extent_buffer_chunk_tree_uuid(leaf, fs_info->chunk_tree_uuid);
 485         btrfs_mark_buffer_dirty(leaf);
 486
 487         inode_item = &root_item->inode;
 488         btrfs_set_stack_inode_generation(inode_item, 1);
 489         btrfs_set_stack_inode_size(inode_item, 3);
 490         btrfs_set_stack_inode_nlink(inode_item, 1);
 491         btrfs_set_stack_inode_nbytes(inode_item,
 492                                      fs_info->nodesize);
 493         btrfs_set_stack_inode_mode(inode_item, S_IFDIR | 0755);
 494
 495         btrfs_set_root_flags(root_item, 0);
 496         btrfs_set_root_limit(root_item, 0);
 497         btrfs_set_stack_inode_flags(inode_item, BTRFS_INODE_ROOT_ITEM_INIT);
 498
 499         btrfs_set_root_bytenr(root_item, leaf->start);
 500         btrfs_set_root_generation(root_item, trans->transid);
 501         btrfs_set_root_level(root_item, 0);
 502         btrfs_set_root_refs(root_item, 1);
 503         btrfs_set_root_used(root_item, leaf->len);
 504         btrfs_set_root_last_snapshot(root_item, 0);
 505
 506         btrfs_set_root_generation_v2(root_item,
 507                         btrfs_root_generation(root_item));
 508         uuid_le_gen(&new_uuid);
 509         memcpy(root_item->uuid, new_uuid.b, BTRFS_UUID_SIZE);
 510         btrfs_set_stack_timespec_sec(&root_item->otime, cur_time.tv_sec);
 511         btrfs_set_stack_timespec_nsec(&root_item->otime, cur_time.tv_nsec);
 512         root_item->ctime = root_item->otime;
 513         btrfs_set_root_ctransid(root_item, trans->transid);
 514         btrfs_set_root_otransid(root_item, trans->transid);
 515
 516         btrfs_tree_unlock(leaf);
 517         free_extent_buffer(leaf);
 518         leaf = NULL;
 519
 520         btrfs_set_root_dirid(root_item, new_dirid);
 521
 522         key.objectid = objectid;
 523         key.offset = 0;
 524         key.type = BTRFS_ROOT_ITEM_KEY;
 525         ret = btrfs_insert_root(trans, fs_info->tree_root, &key,
 526                                 root_item);
 527         if (ret)
 528                 goto fail;
 529
 530         key.offset = (u64)-1;
 531         new_root = btrfs_read_fs_root_no_name(fs_info, &key);
 532         if (IS_ERR(new_root)) {
 533                 ret = PTR_ERR(new_root);
 534                 btrfs_abort_transaction(trans, ret);
 535                 goto fail;
 536         }
 537
 538         btrfs_record_root_in_trans(trans, new_root);
 539
 540         ret = btrfs_create_subvol_root(trans, new_root, root, new_dirid);
 541         if (ret) {
 542                 /* We potentially lose an unused inode item here */
 543                 btrfs_abort_transaction(trans, ret);
 544                 goto fail;
 545         }
 546
 547         mutex_lock(&new_root->objectid_mutex);
 548         new_root->highest_objectid = new_dirid;
 549         mutex_unlock(&new_root->objectid_mutex);
 550
 551         /*
 552          * insert the directory item
 553          */
 554         ret = btrfs_set_inode_index(BTRFS_I(dir), &index);
 555         if (ret) {
 556                 btrfs_abort_transaction(trans, ret);
 557                 goto fail;
 558         }
 559
 560         ret = btrfs_insert_dir_item(trans, root,
 561                                     name, namelen, BTRFS_I(dir), &key,
 562                                     BTRFS_FT_DIR, index);
 563         if (ret) {
 564                 btrfs_abort_transaction(trans, ret);
 565                 goto fail;
 566         }
 567
 568         btrfs_i_size_write(BTRFS_I(dir), dir->i_size + namelen * 2);
 569         ret = btrfs_update_inode(trans, root, dir);
 570         BUG_ON(ret);
 571
 572         ret = btrfs_add_root_ref(trans, fs_info,
 573                                  objectid, root->root_key.objectid,
 574                                  btrfs_ino(BTRFS_I(dir)), index, name, namelen);
 575         BUG_ON(ret);
 576
 577         ret = btrfs_uuid_tree_add(trans, fs_info, root_item->uuid,
 578                                   BTRFS_UUID_KEY_SUBVOL, objectid);
 579         if (ret)
 580                 btrfs_abort_transaction(trans, ret);
 581
 582 fail:
 583         kfree(root_item);
 584         trans->block_rsv = NULL;
 585         trans->bytes_reserved = 0;
 586         btrfs_subvolume_release_metadata(fs_info, &block_rsv);
 587
 588         if (async_transid) {
 589                 *async_transid = trans->transid;
 590                 err = btrfs_commit_transaction_async(trans, 1);
 591                 if (err)
 592                         err = btrfs_commit_transaction(trans);
 593         } else {
 594                 err = btrfs_commit_transaction(trans);
 595         }
 596         if (err && !ret)
 597                 ret = err;
 598
 599         if (!ret) {
 600                 inode = btrfs_lookup_dentry(dir, dentry);
 601                 if (IS_ERR(inode))
 602                         return PTR_ERR(inode);
 603                 d_instantiate(dentry, inode);
 604         }
 605         return ret;
 606
 607 fail_free:
 608         kfree(root_item);
 609         return ret;
 610 }
 611
 612 static void btrfs_wait_for_no_snapshotting_writes(struct btrfs_root *root)
 613 {
 614         s64 writers;
 615         DEFINE_WAIT(wait);
 616
 617         do {
 618                 prepare_to_wait(&root->subv_writers->wait, &wait,
 619                                 TASK_UNINTERRUPTIBLE);
 620
 621                 writers = percpu_counter_sum(&root->subv_writers->counter);
 622                 if (writers)
 623                         schedule();
 624
 625                 finish_wait(&root->subv_writers->wait, &wait);
 626         } while (writers);
 627 }
 628
 629 static int create_snapshot(struct btrfs_root *root, struct inode *dir,
 630                            struct dentry *dentry,
 631                            u64 *async_transid, bool readonly,
 632                            struct btrfs_qgroup_inherit *inherit)
 633 {
 634         struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
 635         struct inode *inode;
 636         struct btrfs_pending_snapshot *pending_snapshot;
 637         struct btrfs_trans_handle *trans;
 638         int ret;
 639
 640         if (!test_bit(BTRFS_ROOT_REF_COWS, &root->state))
 641                 return -EINVAL;
 642
 643         pending_snapshot = kzalloc(sizeof(*pending_snapshot), GFP_KERNEL);
 644         if (!pending_snapshot)
 645                 return -ENOMEM;
 646
 647         pending_snapshot->root_item = kzalloc(sizeof(struct btrfs_root_item),
 648                         GFP_KERNEL);
 649         pending_snapshot->path = btrfs_alloc_path();
 650         if (!pending_snapshot->root_item || !pending_snapshot->path) {
 651                 ret = -ENOMEM;
 652                 goto free_pending;
 653         }
 654
 655         atomic_inc(&root->will_be_snapshotted);
 656         smp_mb__after_atomic();
 657         btrfs_wait_for_no_snapshotting_writes(root);
 658
 659         ret = btrfs_start_delalloc_inodes(root, 0);
 660         if (ret)
 661                 goto dec_and_free;
 662
 663         btrfs_wait_ordered_extents(root, U64_MAX, 0, (u64)-1);
 664
 665         btrfs_init_block_rsv(&pending_snapshot->block_rsv,
 666                              BTRFS_BLOCK_RSV_TEMP);
 667         /*
 668          * 1 - parent dir inode
 669          * 2 - dir entries
 670          * 1 - root item
 671          * 2 - root ref/backref
 672          * 1 - root of snapshot
 673          * 1 - UUID item
 674          */
 675         ret = btrfs_subvolume_reserve_metadata(BTRFS_I(dir)->root,
 676                                         &pending_snapshot->block_rsv, 8,
 677                                         &pending_snapshot->qgroup_reserved,
 678                                         false);
 679         if (ret)
 680                 goto dec_and_free;
 681
 682         pending_snapshot->dentry = dentry;
 683         pending_snapshot->root = root;
 684         pending_snapshot->readonly = readonly;
 685         pending_snapshot->dir = dir;
 686         pending_snapshot->inherit = inherit;
 687
 688         trans = btrfs_start_transaction(root, 0);
 689         if (IS_ERR(trans)) {
 690                 ret = PTR_ERR(trans);
 691                 goto fail;
 692         }
 693
 694         spin_lock(&fs_info->trans_lock);
 695         list_add(&pending_snapshot->list,
 696                  &trans->transaction->pending_snapshots);
 697         spin_unlock(&fs_info->trans_lock);
 698         if (async_transid) {
 699                 *async_transid = trans->transid;
 700                 ret = btrfs_commit_transaction_async(trans, 1);
 701                 if (ret)
 702                         ret = btrfs_commit_transaction(trans);
 703         } else {
 704                 ret = btrfs_commit_transaction(trans);
 705         }
 706         if (ret)
 707                 goto fail;
 708
 709         ret = pending_snapshot->error;
 710         if (ret)
 711                 goto fail;
 712
 713         ret = btrfs_orphan_cleanup(pending_snapshot->snap);
 714         if (ret)
 715                 goto fail;
 716
 717         inode = btrfs_lookup_dentry(d_inode(dentry->d_parent), dentry);
 718         if (IS_ERR(inode)) {
 719                 ret = PTR_ERR(inode);
 720                 goto fail;
 721         }
 722
 723         d_instantiate(dentry, inode);
 724         ret = 0;
 725 fail:
 726         btrfs_subvolume_release_metadata(fs_info, &pending_snapshot->block_rsv);
 727 dec_and_free:
 728         if (atomic_dec_and_test(&root->will_be_snapshotted))
 729                 wake_up_atomic_t(&root->will_be_snapshotted);
 730 free_pending:
 731         kfree(pending_snapshot->root_item);
 732         btrfs_free_path(pending_snapshot->path);
 733         kfree(pending_snapshot);
 734
 735         return ret;
 736 }
 737
 738 /*  copy of may_delete in fs/namei.c()
 739  *      Check whether we can remove a link victim from directory dir, check
 740  *  whether the type of victim is right.
 741  *  1. We can't do it if dir is read-only (done in permission())
 742  *  2. We should have write and exec permissions on dir
 743  *  3. We can't remove anything from append-only dir
 744  *  4. We can't do anything with immutable dir (done in permission())
 745  *  5. If the sticky bit on dir is set we should either
 746  *      a. be owner of dir, or
 747  *      b. be owner of victim, or
 748  *      c. have CAP_FOWNER capability
 749  *  6. If the victim is append-only or immutable we can't do anything with
 750  *     links pointing to it.
 751  *  7. If we were asked to remove a directory and victim isn't one - ENOTDIR.
 752  *  8. If we were asked to remove a non-directory and victim isn't one - EISDIR.
 753  *  9. We can't remove a root or mountpoint.
 754  * 10. We don't allow removal of NFS sillyrenamed files; it's handled by
 755  *     nfs_async_unlink().
 756  */
 757
 758 static int btrfs_may_delete(struct inode *dir, struct dentry *victim, int isdir)
 759 {
 760         int error;
 761
 762         if (d_really_is_negative(victim))
 763                 return -ENOENT;
 764
 765         BUG_ON(d_inode(victim->d_parent) != dir);
 766         audit_inode_child(dir, victim, AUDIT_TYPE_CHILD_DELETE);
 767
 768         error = inode_permission(dir, MAY_WRITE | MAY_EXEC);
 769         if (error)
 770                 return error;
 771         if (IS_APPEND(dir))
 772                 return -EPERM;
 773         if (check_sticky(dir, d_inode(victim)) || IS_APPEND(d_inode(victim)) ||
 774             IS_IMMUTABLE(d_inode(victim)) || IS_SWAPFILE(d_inode(victim)))
 775                 return -EPERM;
 776         if (isdir) {
 777                 if (!d_is_dir(victim))
 778                         return -ENOTDIR;
 779                 if (IS_ROOT(victim))
 780                         return -EBUSY;
 781         } else if (d_is_dir(victim))
 782                 return -EISDIR;
 783         if (IS_DEADDIR(dir))
 784                 return -ENOENT;
 785         if (victim->d_flags & DCACHE_NFSFS_RENAMED)
 786                 return -EBUSY;
 787         return 0;
 788 }
 789
 790 /* copy of may_create in fs/namei.c() */
 791 static inline int btrfs_may_create(struct inode *dir, struct dentry *child)
 792 {
 793         if (d_really_is_positive(child))
 794                 return -EEXIST;
 795         if (IS_DEADDIR(dir))
 796                 return -ENOENT;
 797         return inode_permission(dir, MAY_WRITE | MAY_EXEC);
 798 }
 799
 800 /*
 801  * Create a new subvolume below @parent.  This is largely modeled after
 802  * sys_mkdirat and vfs_mkdir, but we only do a single component lookup
 803  * inside this filesystem so it's quite a bit simpler.
 804  */
 805 static noinline int btrfs_mksubvol(const struct path *parent,
 806                                    const char *name, int namelen,
 807                                    struct btrfs_root *snap_src,
 808                                    u64 *async_transid, bool readonly,
 809                                    struct btrfs_qgroup_inherit *inherit)
 810 {
 811         struct inode *dir = d_inode(parent->dentry);
 812         struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
 813         struct dentry *dentry;
 814         int error;
 815
 816         error = down_write_killable_nested(&dir->i_rwsem, I_MUTEX_PARENT);
 817         if (error == -EINTR)
 818                 return error;
 819
 820         dentry = lookup_one_len(name, parent->dentry, namelen);
 821         error = PTR_ERR(dentry);
 822         if (IS_ERR(dentry))
 823                 goto out_unlock;
 824
 825         error = btrfs_may_create(dir, dentry);
 826         if (error)
 827                 goto out_dput;
 828
 829         /*
 830          * even if this name doesn't exist, we may get hash collisions.
 831          * check for them now when we can safely fail
 832          */
 833         error = btrfs_check_dir_item_collision(BTRFS_I(dir)->root,
 834                                                dir->i_ino, name,
 835                                                namelen);
 836         if (error)
 837                 goto out_dput;
 838
 839         down_read(&fs_info->subvol_sem);
 840
 841         if (btrfs_root_refs(&BTRFS_I(dir)->root->root_item) == 0)
 842                 goto out_up_read;
 843
 844         if (snap_src) {
 845                 error = create_snapshot(snap_src, dir, dentry,
 846                                         async_transid, readonly, inherit);
 847         } else {
 848                 error = create_subvol(dir, dentry, name, namelen,
 849                                       async_transid, inherit);
 850         }
 851         if (!error)
 852                 fsnotify_mkdir(dir, dentry);
 853 out_up_read:
 854         up_read(&fs_info->subvol_sem);
 855 out_dput:
 856         dput(dentry);
 857 out_unlock:
 858         inode_unlock(dir);
 859         return error;
 860 }
 861
 862 /*
 863  * When we're defragging a range, we don't want to kick it off again
 864  * if it is really just waiting for delalloc to send it down.
 865  * If we find a nice big extent or delalloc range for the bytes in the
 866  * file you want to defrag, we return 0 to let you know to skip this
 867  * part of the file
 868  */
 869 static int check_defrag_in_cache(struct inode *inode, u64 offset, u32 thresh)
 870 {
 871         struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
 872         struct extent_map *em = NULL;
 873         struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
 874         u64 end;
 875
 876         read_lock(&em_tree->lock);
 877         em = lookup_extent_mapping(em_tree, offset, PAGE_SIZE);
 878         read_unlock(&em_tree->lock);
 879
 880         if (em) {
 881                 end = extent_map_end(em);
 882                 free_extent_map(em);
 883                 if (end - offset > thresh)
 884                         return 0;
 885         }
 886         /* if we already have a nice delalloc here, just stop */
 887         thresh /= 2;
 888         end = count_range_bits(io_tree, &offset, offset + thresh,
 889                                thresh, EXTENT_DELALLOC, 1);
 890         if (end >= thresh)
 891                 return 0;
 892         return 1;
 893 }
 894
 895 /*
 896  * helper function to walk through a file and find extents
 897  * newer than a specific transid, and smaller than thresh.
 898  *
 899  * This is used by the defragging code to find new and small
 900  * extents
 901  */
 902 static int find_new_extents(struct btrfs_root *root,
 903                             struct inode *inode, u64 newer_than,
 904                             u64 *off, u32 thresh)
 905 {
 906         struct btrfs_path *path;
 907         struct btrfs_key min_key;
 908         struct extent_buffer *leaf;
 909         struct btrfs_file_extent_item *extent;
 910         int type;
 911         int ret;
 912         u64 ino = btrfs_ino(BTRFS_I(inode));
 913
 914         path = btrfs_alloc_path();
 915         if (!path)
 916                 return -ENOMEM;
 917
 918         min_key.objectid = ino;
 919         min_key.type = BTRFS_EXTENT_DATA_KEY;
 920         min_key.offset = *off;
 921
 922         while (1) {
 923                 ret = btrfs_search_forward(root, &min_key, path, newer_than);
 924                 if (ret != 0)
 925                         goto none;
 926 process_slot:
 927                 if (min_key.objectid != ino)
 928                         goto none;
 929                 if (min_key.type != BTRFS_EXTENT_DATA_KEY)
 930                         goto none;
 931
 932                 leaf = path->nodes[0];
 933                 extent = btrfs_item_ptr(leaf, path->slots[0],
 934                                         struct btrfs_file_extent_item);
 935
 936                 type = btrfs_file_extent_type(leaf, extent);
 937                 if (type == BTRFS_FILE_EXTENT_REG &&
 938                     btrfs_file_extent_num_bytes(leaf, extent) < thresh &&
 939                     check_defrag_in_cache(inode, min_key.offset, thresh)) {
 940                         *off = min_key.offset;
 941                         btrfs_free_path(path);
 942                         return 0;
 943                 }
 944
 945                 path->slots[0]++;
 946                 if (path->slots[0] < btrfs_header_nritems(leaf)) {
 947                         btrfs_item_key_to_cpu(leaf, &min_key, path->slots[0]);
 948                         goto process_slot;
 949                 }
 950
 951                 if (min_key.offset == (u64)-1)
 952                         goto none;
 953
 954                 min_key.offset++;
 955                 btrfs_release_path(path);
 956         }
 957 none:
 958         btrfs_free_path(path);
 959         return -ENOENT;
 960 }
 961
 962 static struct extent_map *defrag_lookup_extent(struct inode *inode, u64 start)
 963 {
 964         struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
 965         struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
 966         struct extent_map *em;
 967         u64 len = PAGE_SIZE;
 968
 969         /*
 970          * hopefully we have this extent in the tree already, try without
 971          * the full extent lock
 972          */
 973         read_lock(&em_tree->lock);
 974         em = lookup_extent_mapping(em_tree, start, len);
 975         read_unlock(&em_tree->lock);
 976
 977         if (!em) {
 978                 struct extent_state *cached = NULL;
 979                 u64 end = start + len - 1;
 980
 981                 /* get the big lock and read metadata off disk */
 982                 lock_extent_bits(io_tree, start, end, &cached);
 983                 em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, start, len, 0);
 984                 unlock_extent_cached(io_tree, start, end, &cached, GFP_NOFS);
 985
 986                 if (IS_ERR(em))
 987                         return NULL;
 988         }
 989
 990         return em;
 991 }
 992
 993 static bool defrag_check_next_extent(struct inode *inode, struct extent_map *em)
 994 {
 995         struct extent_map *next;
 996         bool ret = true;
 997
 998         /* this is the last extent */
 999         if (em->start + em->len >= i_size_read(inode))
1000                 return false;
1001
1002         next = defrag_lookup_extent(inode, em->start + em->len);
1003         if (!next || next->block_start >= EXTENT_MAP_LAST_BYTE)
1004                 ret = false;
1005         else if ((em->block_start + em->block_len == next->block_start) &&
1006                  (em->block_len > SZ_128K && next->block_len > SZ_128K))
1007                 ret = false;
1008
1009         free_extent_map(next);
1010         return ret;
1011 }
1012
1013 static int should_defrag_range(struct inode *inode, u64 start, u32 thresh,
1014                                u64 *last_len, u64 *skip, u64 *defrag_end,
1015                                int compress)
1016 {
1017         struct extent_map *em;
1018         int ret = 1;
1019         bool next_mergeable = true;
1020         bool prev_mergeable = true;
1021
1022         /*
1023          * make sure that once we start defragging an extent, we keep on
1024          * defragging it
1025          */
1026         if (start < *defrag_end)
1027                 return 1;
1028
1029         *skip = 0;
1030
1031         em = defrag_lookup_extent(inode, start);
1032         if (!em)
1033                 return 0;
1034
1035         /* this will cover holes, and inline extents */
1036         if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
1037                 ret = 0;
1038                 goto out;
1039         }
1040
1041         if (!*defrag_end)
1042                 prev_mergeable = false;
1043
1044         next_mergeable = defrag_check_next_extent(inode, em);
1045         /*
1046          * we hit a real extent, if it is big or the next extent is not a
1047          * real extent, don't bother defragging it
1048          */
1049         if (!compress && (*last_len == 0 || *last_len >= thresh) &&
1050             (em->len >= thresh || (!next_mergeable && !prev_mergeable)))
1051                 ret = 0;
1052 out:
1053         /*
1054          * last_len ends up being a counter of how many bytes we've defragged.
1055          * every time we choose not to defrag an extent, we reset *last_len
1056          * so that the next tiny extent will force a defrag.
1057          *
1058          * The end result of this is that tiny extents before a single big
1059          * extent will force at least part of that big extent to be defragged.
1060          */
1061         if (ret) {
1062                 *defrag_end = extent_map_end(em);
1063         } else {
1064                 *last_len = 0;
1065                 *skip = extent_map_end(em);
1066                 *defrag_end = 0;
1067         }
1068
1069         free_extent_map(em);
1070         return ret;
1071 }
1072
1073 /*
1074  * it doesn't do much good to defrag one or two pages
1075  * at a time.  This pulls in a nice chunk of pages
1076  * to COW and defrag.
1077  *
1078  * It also makes sure the delalloc code has enough
1079  * dirty data to avoid making new small extents as part
1080  * of the defrag
1081  *
1082  * It's a good idea to start RA on this range
1083  * before calling this.
1084  */
1085 static int cluster_pages_for_defrag(struct inode *inode,
1086                                     struct page **pages,
1087                                     unsigned long start_index,
1088                                     unsigned long num_pages)
1089 {
1090         unsigned long file_end;
1091         u64 isize = i_size_read(inode);
1092         u64 page_start;
1093         u64 page_end;
1094         u64 page_cnt;
1095         int ret;
1096         int i;
1097         int i_done;
1098         struct btrfs_ordered_extent *ordered;
1099         struct extent_state *cached_state = NULL;
1100         struct extent_io_tree *tree;
1101         struct extent_changeset *data_reserved = NULL;
1102         gfp_t mask = btrfs_alloc_write_mask(inode->i_mapping);
1103
1104         file_end = (isize - 1) >> PAGE_SHIFT;
1105         if (!isize || start_index > file_end)
1106                 return 0;
1107
1108         page_cnt = min_t(u64, (u64)num_pages, (u64)file_end - start_index + 1);
1109
1110         ret = btrfs_delalloc_reserve_space(inode, &data_reserved,
1111                         start_index << PAGE_SHIFT,
1112                         page_cnt << PAGE_SHIFT);
1113         if (ret)
1114                 return ret;
1115         i_done = 0;
1116         tree = &BTRFS_I(inode)->io_tree;
1117
1118         /* step one, lock all the pages */
1119         for (i = 0; i < page_cnt; i++) {
1120                 struct page *page;
1121 again:
1122                 page = find_or_create_page(inode->i_mapping,
1123                                            start_index + i, mask);
1124                 if (!page)
1125                         break;
1126
1127                 page_start = page_offset(page);
1128                 page_end = page_start + PAGE_SIZE - 1;
1129                 while (1) {
1130                         lock_extent_bits(tree, page_start, page_end,
1131                                          &cached_state);
1132                         ordered = btrfs_lookup_ordered_extent(inode,
1133                                                               page_start);
1134                         unlock_extent_cached(tree, page_start, page_end,
1135                                              &cached_state, GFP_NOFS);
1136                         if (!ordered)
1137                                 break;
1138
1139                         unlock_page(page);
1140                         btrfs_start_ordered_extent(inode, ordered, 1);
1141                         btrfs_put_ordered_extent(ordered);
1142                         lock_page(page);
1143                         /*
1144                          * we unlocked the page above, so we need check if
1145                          * it was released or not.
1146                          */
1147                         if (page->mapping != inode->i_mapping) {
1148                                 unlock_page(page);
1149                                 put_page(page);
1150                                 goto again;
1151                         }
1152                 }
1153
1154                 if (!PageUptodate(page)) {
1155                         btrfs_readpage(NULL, page);
1156                         lock_page(page);
1157                         if (!PageUptodate(page)) {
1158                                 unlock_page(page);
1159                                 put_page(page);
1160                                 ret = -EIO;
1161                                 break;
1162                         }
1163                 }
1164
1165                 if (page->mapping != inode->i_mapping) {
1166                         unlock_page(page);
1167                         put_page(page);
1168                         goto again;
1169                 }
1170
1171                 pages[i] = page;
1172                 i_done++;
1173         }
1174         if (!i_done || ret)
1175                 goto out;
1176
1177         if (!(inode->i_sb->s_flags & MS_ACTIVE))
1178                 goto out;
1179
1180         /*
1181          * so now we have a nice long stream of locked
1182          * and up to date pages, lets wait on them
1183          */
1184         for (i = 0; i < i_done; i++)
1185                 wait_on_page_writeback(pages[i]);
1186
1187         page_start = page_offset(pages[0]);
1188         page_end = page_offset(pages[i_done - 1]) + PAGE_SIZE;
1189
1190         lock_extent_bits(&BTRFS_I(inode)->io_tree,
1191                          page_start, page_end - 1, &cached_state);
1192         clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start,
1193                           page_end - 1, EXTENT_DIRTY | EXTENT_DELALLOC |
1194                           EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG, 0, 0,
1195                           &cached_state, GFP_NOFS);
1196
1197         if (i_done != page_cnt) {
1198                 spin_lock(&BTRFS_I(inode)->lock);
1199                 BTRFS_I(inode)->outstanding_extents++;
1200                 spin_unlock(&BTRFS_I(inode)->lock);
1201                 btrfs_delalloc_release_space(inode, data_reserved,
1202                                 start_index << PAGE_SHIFT,
1203                                 (page_cnt - i_done) << PAGE_SHIFT);
1204         }
1205
1206
1207         set_extent_defrag(&BTRFS_I(inode)->io_tree, page_start, page_end - 1,
1208                           &cached_state);
1209
1210         unlock_extent_cached(&BTRFS_I(inode)->io_tree,
1211                              page_start, page_end - 1, &cached_state,
1212                              GFP_NOFS);
1213
1214         for (i = 0; i < i_done; i++) {
1215                 clear_page_dirty_for_io(pages[i]);
1216                 ClearPageChecked(pages[i]);
1217                 set_page_extent_mapped(pages[i]);
1218                 set_page_dirty(pages[i]);
1219                 unlock_page(pages[i]);
1220                 put_page(pages[i]);
1221         }
1222         extent_changeset_free(data_reserved);
1223         return i_done;
1224 out:
1225         for (i = 0; i < i_done; i++) {
1226                 unlock_page(pages[i]);
1227                 put_page(pages[i]);
1228         }
1229         btrfs_delalloc_release_space(inode, data_reserved,
1230                         start_index << PAGE_SHIFT,
1231                         page_cnt << PAGE_SHIFT);
1232         extent_changeset_free(data_reserved);
1233         return ret;
1234
1235 }
1236
1237 int btrfs_defrag_file(struct inode *inode, struct file *file,
1238                       struct btrfs_ioctl_defrag_range_args *range,
1239                       u64 newer_than, unsigned long max_to_defrag)
1240 {
1241         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1242         struct btrfs_root *root = BTRFS_I(inode)->root;
1243         struct file_ra_state *ra = NULL;
1244         unsigned long last_index;
1245         u64 isize = i_size_read(inode);
1246         u64 last_len = 0;
1247         u64 skip = 0;
1248         u64 defrag_end = 0;
1249         u64 newer_off = range->start;
1250         unsigned long i;
1251         unsigned long ra_index = 0;
1252         int ret;
1253         int defrag_count = 0;
1254         int compress_type = BTRFS_COMPRESS_ZLIB;
1255         u32 extent_thresh = range->extent_thresh;
1256         unsigned long max_cluster = SZ_256K >> PAGE_SHIFT;
1257         unsigned long cluster = max_cluster;
1258         u64 new_align = ~((u64)SZ_128K - 1);
1259         struct page **pages = NULL;
1260         bool do_compress = range->flags & BTRFS_DEFRAG_RANGE_COMPRESS;
1261
1262         if (isize == 0)
1263                 return 0;
1264
1265         if (range->start >= isize)
1266                 return -EINVAL;
1267
1268         if (do_compress) {
1269                 if (range->compress_type > BTRFS_COMPRESS_TYPES)
1270                         return -EINVAL;
1271                 if (range->compress_type)
1272                         compress_type = range->compress_type;
1273         }
1274
1275         if (extent_thresh == 0)
1276                 extent_thresh = SZ_256K;
1277
1278         /*
1279          * If we were not given a file, allocate a readahead context. As
1280          * readahead is just an optimization, defrag will work without it so
1281          * we don't error out.
1282          */
1283         if (!file) {
1284                 ra = kzalloc(sizeof(*ra), GFP_KERNEL);
1285                 if (ra)
1286                         file_ra_state_init(ra, inode->i_mapping);
1287         } else {
1288                 ra = &file->f_ra;
1289         }
1290
1291         pages = kmalloc_array(max_cluster, sizeof(struct page *), GFP_KERNEL);
1292         if (!pages) {
1293                 ret = -ENOMEM;
1294                 goto out_ra;
1295         }
1296
1297         /* find the last page to defrag */
1298         if (range->start + range->len > range->start) {
1299                 last_index = min_t(u64, isize - 1,
1300                          range->start + range->len - 1) >> PAGE_SHIFT;
1301         } else {
1302                 last_index = (isize - 1) >> PAGE_SHIFT;
1303         }
1304
1305         if (newer_than) {
1306                 ret = find_new_extents(root, inode, newer_than,
1307                                        &newer_off, SZ_64K);
1308                 if (!ret) {
1309                         range->start = newer_off;
1310                         /*
1311                          * we always align our defrag to help keep
1312                          * the extents in the file evenly spaced
1313                          */
1314                         i = (newer_off & new_align) >> PAGE_SHIFT;
1315                 } else
1316                         goto out_ra;
1317         } else {
1318                 i = range->start >> PAGE_SHIFT;
1319         }
1320         if (!max_to_defrag)
1321                 max_to_defrag = last_index - i + 1;
1322
1323         /*
1324          * make writeback starts from i, so the defrag range can be
1325          * written sequentially.
1326          */
1327         if (i < inode->i_mapping->writeback_index)
1328                 inode->i_mapping->writeback_index = i;
1329
1330         while (i <= last_index && defrag_count < max_to_defrag &&
1331                (i < DIV_ROUND_UP(i_size_read(inode), PAGE_SIZE))) {
1332                 /*
1333                  * make sure we stop running if someone unmounts
1334                  * the FS
1335                  */
1336                 if (!(inode->i_sb->s_flags & MS_ACTIVE))
1337                         break;
1338
1339                 if (btrfs_defrag_cancelled(fs_info)) {
1340                         btrfs_debug(fs_info, "defrag_file cancelled");
1341                         ret = -EAGAIN;
1342                         break;
1343                 }
1344
1345                 if (!should_defrag_range(inode, (u64)i << PAGE_SHIFT,
1346                                          extent_thresh, &last_len, &skip,
1347                                          &defrag_end, do_compress)){
1348                         unsigned long next;
1349                         /*
1350                          * the should_defrag function tells us how much to skip
1351                          * bump our counter by the suggested amount
1352                          */
1353                         next = DIV_ROUND_UP(skip, PAGE_SIZE);
1354                         i = max(i + 1, next);
1355                         continue;
1356                 }
1357
1358                 if (!newer_than) {
1359                         cluster = (PAGE_ALIGN(defrag_end) >>
1360                                    PAGE_SHIFT) - i;
1361                         cluster = min(cluster, max_cluster);
1362                 } else {
1363                         cluster = max_cluster;
1364                 }
1365
1366                 if (i + cluster > ra_index) {
1367                         ra_index = max(i, ra_index);
1368                         if (ra)
1369                                 page_cache_sync_readahead(inode->i_mapping, ra,
1370                                                 file, ra_index, cluster);
1371                         ra_index += cluster;
1372                 }
1373
1374                 inode_lock(inode);
1375                 if (do_compress)
1376                         BTRFS_I(inode)->defrag_compress = compress_type;
1377                 ret = cluster_pages_for_defrag(inode, pages, i, cluster);
1378                 if (ret < 0) {
1379                         inode_unlock(inode);
1380                         goto out_ra;
1381                 }
1382
1383                 defrag_count += ret;
1384                 balance_dirty_pages_ratelimited(inode->i_mapping);
1385                 inode_unlock(inode);
1386
1387                 if (newer_than) {
1388                         if (newer_off == (u64)-1)
1389                                 break;
1390
1391                         if (ret > 0)
1392                                 i += ret;
1393
1394                         newer_off = max(newer_off + 1,
1395                                         (u64)i << PAGE_SHIFT);
1396
1397                         ret = find_new_extents(root, inode, newer_than,
1398                                                &newer_off, SZ_64K);
1399                         if (!ret) {
1400                                 range->start = newer_off;
1401                                 i = (newer_off & new_align) >> PAGE_SHIFT;
1402                         } else {
1403                                 break;
1404                         }
1405                 } else {
1406                         if (ret > 0) {
1407                                 i += ret;
1408                                 last_len += ret << PAGE_SHIFT;
1409                         } else {
1410                                 i++;
1411                                 last_len = 0;
1412                         }
1413                 }
1414         }
1415
1416         if ((range->flags & BTRFS_DEFRAG_RANGE_START_IO)) {
1417                 filemap_flush(inode->i_mapping);
1418                 if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
1419                              &BTRFS_I(inode)->runtime_flags))
1420                         filemap_flush(inode->i_mapping);
1421         }
1422
1423         if (do_compress) {
1424                 /* the filemap_flush will queue IO into the worker threads, but
1425                  * we have to make sure the IO is actually started and that
1426                  * ordered extents get created before we return
1427                  */
1428                 atomic_inc(&fs_info->async_submit_draining);
1429                 while (atomic_read(&fs_info->nr_async_submits) ||
1430                        atomic_read(&fs_info->async_delalloc_pages)) {
1431                         wait_event(fs_info->async_submit_wait,
1432                                    (atomic_read(&fs_info->nr_async_submits) == 0 &&
1433                                     atomic_read(&fs_info->async_delalloc_pages) == 0));
1434                 }
1435                 atomic_dec(&fs_info->async_submit_draining);
1436         }
1437
1438         if (range->compress_type == BTRFS_COMPRESS_LZO) {
1439                 btrfs_set_fs_incompat(fs_info, COMPRESS_LZO);
1440         } else if (range->compress_type == BTRFS_COMPRESS_ZSTD) {
1441                 btrfs_set_fs_incompat(fs_info, COMPRESS_ZSTD);
1442         }
1443
1444         ret = defrag_count;
1445
1446 out_ra:
1447         if (do_compress) {
1448                 inode_lock(inode);
1449                 BTRFS_I(inode)->defrag_compress = BTRFS_COMPRESS_NONE;
1450                 inode_unlock(inode);
1451         }
1452         if (!file)
1453                 kfree(ra);
1454         kfree(pages);
1455         return ret;
1456 }
1457
1458 static noinline int btrfs_ioctl_resize(struct file *file,
1459                                         void __user *arg)
1460 {
1461         struct inode *inode = file_inode(file);
1462         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1463         u64 new_size;
1464         u64 old_size;
1465         u64 devid = 1;
1466         struct btrfs_root *root = BTRFS_I(inode)->root;
1467         struct btrfs_ioctl_vol_args *vol_args;
1468         struct btrfs_trans_handle *trans;
1469         struct btrfs_device *device = NULL;
1470         char *sizestr;
1471         char *retptr;
1472         char *devstr = NULL;
1473         int ret = 0;
1474         int mod = 0;
1475
1476         if (!capable(CAP_SYS_ADMIN))
1477                 return -EPERM;
1478
1479         ret = mnt_want_write_file(file);
1480         if (ret)
1481                 return ret;
1482
1483         if (test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags)) {
1484                 mnt_drop_write_file(file);
1485                 return BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
1486         }
1487
1488         mutex_lock(&fs_info->volume_mutex);
1489         vol_args = memdup_user(arg, sizeof(*vol_args));
1490         if (IS_ERR(vol_args)) {
1491                 ret = PTR_ERR(vol_args);
1492                 goto out;
1493         }
1494
1495         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1496
1497         sizestr = vol_args->name;
1498         devstr = strchr(sizestr, ':');
1499         if (devstr) {
1500                 sizestr = devstr + 1;
1501                 *devstr = '\0';
1502                 devstr = vol_args->name;
1503                 ret = kstrtoull(devstr, 10, &devid);
1504                 if (ret)
1505                         goto out_free;
1506                 if (!devid) {
1507                         ret = -EINVAL;
1508                         goto out_free;
1509                 }
1510                 btrfs_info(fs_info, "resizing devid %llu", devid);
1511         }
1512
1513         device = btrfs_find_device(fs_info, devid, NULL, NULL);
1514         if (!device) {
1515                 btrfs_info(fs_info, "resizer unable to find device %llu",
1516                            devid);
1517                 ret = -ENODEV;
1518                 goto out_free;
1519         }
1520
1521         if (!device->writeable) {
1522                 btrfs_info(fs_info,
1523                            "resizer unable to apply on readonly device %llu",
1524                        devid);
1525                 ret = -EPERM;
1526                 goto out_free;
1527         }
1528
1529         if (!strcmp(sizestr, "max"))
1530                 new_size = device->bdev->bd_inode->i_size;
1531         else {
1532                 if (sizestr[0] == '-') {
1533                         mod = -1;
1534                         sizestr++;
1535                 } else if (sizestr[0] == '+') {
1536                         mod = 1;
1537                         sizestr++;
1538                 }
1539                 new_size = memparse(sizestr, &retptr);
1540                 if (*retptr != '\0' || new_size == 0) {
1541                         ret = -EINVAL;
1542                         goto out_free;
1543                 }
1544         }
1545
1546         if (device->is_tgtdev_for_dev_replace) {
1547                 ret = -EPERM;
1548                 goto out_free;
1549         }
1550
1551         old_size = btrfs_device_get_total_bytes(device);
1552
1553         if (mod < 0) {
1554                 if (new_size > old_size) {
1555                         ret = -EINVAL;
1556                         goto out_free;
1557                 }
1558                 new_size = old_size - new_size;
1559         } else if (mod > 0) {
1560                 if (new_size > ULLONG_MAX - old_size) {
1561                         ret = -ERANGE;
1562                         goto out_free;
1563                 }
1564                 new_size = old_size + new_size;
1565         }
1566
1567         if (new_size < SZ_256M) {
1568                 ret = -EINVAL;
1569                 goto out_free;
1570         }
1571         if (new_size > device->bdev->bd_inode->i_size) {
1572                 ret = -EFBIG;
1573                 goto out_free;
1574         }
1575
1576         new_size = round_down(new_size, fs_info->sectorsize);
1577
1578         btrfs_info_in_rcu(fs_info, "new size for %s is %llu",
1579                           rcu_str_deref(device->name), new_size);
1580
1581         if (new_size > old_size) {
1582                 trans = btrfs_start_transaction(root, 0);
1583                 if (IS_ERR(trans)) {
1584                         ret = PTR_ERR(trans);
1585                         goto out_free;
1586                 }
1587                 ret = btrfs_grow_device(trans, device, new_size);
1588                 btrfs_commit_transaction(trans);
1589         } else if (new_size < old_size) {
1590                 ret = btrfs_shrink_device(device, new_size);
1591         } /* equal, nothing need to do */
1592
1593 out_free:
1594         kfree(vol_args);
1595 out:
1596         mutex_unlock(&fs_info->volume_mutex);
1597         clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
1598         mnt_drop_write_file(file);
1599         return ret;
1600 }
1601
1602 static noinline int btrfs_ioctl_snap_create_transid(struct file *file,
1603                                 const char *name, unsigned long fd, int subvol,
1604                                 u64 *transid, bool readonly,
1605                                 struct btrfs_qgroup_inherit *inherit)
1606 {
1607         int namelen;
1608         int ret = 0;
1609
1610         if (!S_ISDIR(file_inode(file)->i_mode))
1611                 return -ENOTDIR;
1612
1613         ret = mnt_want_write_file(file);
1614         if (ret)
1615                 goto out;
1616
1617         namelen = strlen(name);
1618         if (strchr(name, '/')) {
1619                 ret = -EINVAL;
1620                 goto out_drop_write;
1621         }
1622
1623         if (name[0] == '.' &&
1624            (namelen == 1 || (name[1] == '.' && namelen == 2))) {
1625                 ret = -EEXIST;
1626                 goto out_drop_write;
1627         }
1628
1629         if (subvol) {
1630                 ret = btrfs_mksubvol(&file->f_path, name, namelen,
1631                                      NULL, transid, readonly, inherit);
1632         } else {
1633                 struct fd src = fdget(fd);
1634                 struct inode *src_inode;
1635                 if (!src.file) {
1636                         ret = -EINVAL;
1637                         goto out_drop_write;
1638                 }
1639
1640                 src_inode = file_inode(src.file);
1641                 if (src_inode->i_sb != file_inode(file)->i_sb) {
1642                         btrfs_info(BTRFS_I(file_inode(file))->root->fs_info,
1643                                    "Snapshot src from another FS");
1644                         ret = -EXDEV;
1645                 } else if (!inode_owner_or_capable(src_inode)) {
1646                         /*
1647                          * Subvolume creation is not restricted, but snapshots
1648                          * are limited to own subvolumes only
1649                          */
1650                         ret = -EPERM;
1651                 } else {
1652                         ret = btrfs_mksubvol(&file->f_path, name, namelen,
1653                                              BTRFS_I(src_inode)->root,
1654                                              transid, readonly, inherit);
1655                 }
1656                 fdput(src);
1657         }
1658 out_drop_write:
1659         mnt_drop_write_file(file);
1660 out:
1661         return ret;
1662 }
1663
1664 static noinline int btrfs_ioctl_snap_create(struct file *file,
1665                                             void __user *arg, int subvol)
1666 {
1667         struct btrfs_ioctl_vol_args *vol_args;
1668         int ret;
1669
1670         if (!S_ISDIR(file_inode(file)->i_mode))
1671                 return -ENOTDIR;
1672
1673         vol_args = memdup_user(arg, sizeof(*vol_args));
1674         if (IS_ERR(vol_args))
1675                 return PTR_ERR(vol_args);
1676         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1677
1678         ret = btrfs_ioctl_snap_create_transid(file, vol_args->name,
1679                                               vol_args->fd, subvol,
1680                                               NULL, false, NULL);
1681
1682         kfree(vol_args);
1683         return ret;
1684 }
1685
1686 static noinline int btrfs_ioctl_snap_create_v2(struct file *file,
1687                                                void __user *arg, int subvol)
1688 {
1689         struct btrfs_ioctl_vol_args_v2 *vol_args;
1690         int ret;
1691         u64 transid = 0;
1692         u64 *ptr = NULL;
1693         bool readonly = false;
1694         struct btrfs_qgroup_inherit *inherit = NULL;
1695
1696         if (!S_ISDIR(file_inode(file)->i_mode))
1697                 return -ENOTDIR;
1698
1699         vol_args = memdup_user(arg, sizeof(*vol_args));
1700         if (IS_ERR(vol_args))
1701                 return PTR_ERR(vol_args);
1702         vol_args->name[BTRFS_SUBVOL_NAME_MAX] = '\0';
1703
1704         if (vol_args->flags &
1705             ~(BTRFS_SUBVOL_CREATE_ASYNC | BTRFS_SUBVOL_RDONLY |
1706               BTRFS_SUBVOL_QGROUP_INHERIT)) {
1707                 ret = -EOPNOTSUPP;
1708                 goto free_args;
1709         }
1710
1711         if (vol_args->flags & BTRFS_SUBVOL_CREATE_ASYNC)
1712                 ptr = &transid;
1713         if (vol_args->flags & BTRFS_SUBVOL_RDONLY)
1714                 readonly = true;
1715         if (vol_args->flags & BTRFS_SUBVOL_QGROUP_INHERIT) {
1716                 if (vol_args->size > PAGE_SIZE) {
1717                         ret = -EINVAL;
1718                         goto free_args;
1719                 }
1720                 inherit = memdup_user(vol_args->qgroup_inherit, vol_args->size);
1721                 if (IS_ERR(inherit)) {
1722                         ret = PTR_ERR(inherit);
1723                         goto free_args;
1724                 }
1725         }
1726
1727         ret = btrfs_ioctl_snap_create_transid(file, vol_args->name,
1728                                               vol_args->fd, subvol, ptr,
1729                                               readonly, inherit);
1730         if (ret)
1731                 goto free_inherit;
1732
1733         if (ptr && copy_to_user(arg +
1734                                 offsetof(struct btrfs_ioctl_vol_args_v2,
1735                                         transid),
1736                                 ptr, sizeof(*ptr)))
1737                 ret = -EFAULT;
1738
1739 free_inherit:
1740         kfree(inherit);
1741 free_args:
1742         kfree(vol_args);
1743         return ret;
1744 }
1745
1746 static noinline int btrfs_ioctl_subvol_getflags(struct file *file,
1747                                                 void __user *arg)
1748 {
1749         struct inode *inode = file_inode(file);
1750         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1751         struct btrfs_root *root = BTRFS_I(inode)->root;
1752         int ret = 0;
1753         u64 flags = 0;
1754
1755         if (btrfs_ino(BTRFS_I(inode)) != BTRFS_FIRST_FREE_OBJECTID)
1756                 return -EINVAL;
1757
1758         down_read(&fs_info->subvol_sem);
1759         if (btrfs_root_readonly(root))
1760                 flags |= BTRFS_SUBVOL_RDONLY;
1761         up_read(&fs_info->subvol_sem);
1762
1763         if (copy_to_user(arg, &flags, sizeof(flags)))
1764                 ret = -EFAULT;
1765
1766         return ret;
1767 }
1768
1769 static noinline int btrfs_ioctl_subvol_setflags(struct file *file,
1770                                               void __user *arg)
1771 {
1772         struct inode *inode = file_inode(file);
1773         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1774         struct btrfs_root *root = BTRFS_I(inode)->root;
1775         struct btrfs_trans_handle *trans;
1776         u64 root_flags;
1777         u64 flags;
1778         int ret = 0;
1779
1780         if (!inode_owner_or_capable(inode))
1781                 return -EPERM;
1782
1783         ret = mnt_want_write_file(file);
1784         if (ret)
1785                 goto out;
1786
1787         if (btrfs_ino(BTRFS_I(inode)) != BTRFS_FIRST_FREE_OBJECTID) {
1788                 ret = -EINVAL;
1789                 goto out_drop_write;
1790         }
1791
1792         if (copy_from_user(&flags, arg, sizeof(flags))) {
1793                 ret = -EFAULT;
1794                 goto out_drop_write;
1795         }
1796
1797         if (flags & BTRFS_SUBVOL_CREATE_ASYNC) {
1798                 ret = -EINVAL;
1799                 goto out_drop_write;
1800         }
1801
1802         if (flags & ~BTRFS_SUBVOL_RDONLY) {
1803                 ret = -EOPNOTSUPP;
1804                 goto out_drop_write;
1805         }
1806
1807         down_write(&fs_info->subvol_sem);
1808
1809         /* nothing to do */
1810         if (!!(flags & BTRFS_SUBVOL_RDONLY) == btrfs_root_readonly(root))
1811                 goto out_drop_sem;
1812
1813         root_flags = btrfs_root_flags(&root->root_item);
1814         if (flags & BTRFS_SUBVOL_RDONLY) {
1815                 btrfs_set_root_flags(&root->root_item,
1816                                      root_flags | BTRFS_ROOT_SUBVOL_RDONLY);
1817         } else {
1818                 /*
1819                  * Block RO -> RW transition if this subvolume is involved in
1820                  * send
1821                  */
1822                 spin_lock(&root->root_item_lock);
1823                 if (root->send_in_progress == 0) {
1824                         btrfs_set_root_flags(&root->root_item,
1825                                      root_flags & ~BTRFS_ROOT_SUBVOL_RDONLY);
1826                         spin_unlock(&root->root_item_lock);
1827                 } else {
1828                         spin_unlock(&root->root_item_lock);
1829                         btrfs_warn(fs_info,
1830                                    "Attempt to set subvolume %llu read-write during send",
1831                                    root->root_key.objectid);
1832                         ret = -EPERM;
1833                         goto out_drop_sem;
1834                 }
1835         }
1836
1837         trans = btrfs_start_transaction(root, 1);
1838         if (IS_ERR(trans)) {
1839                 ret = PTR_ERR(trans);
1840                 goto out_reset;
1841         }
1842
1843         ret = btrfs_update_root(trans, fs_info->tree_root,
1844                                 &root->root_key, &root->root_item);
1845
1846         btrfs_commit_transaction(trans);
1847 out_reset:
1848         if (ret)
1849                 btrfs_set_root_flags(&root->root_item, root_flags);
1850 out_drop_sem:
1851         up_write(&fs_info->subvol_sem);
1852 out_drop_write:
1853         mnt_drop_write_file(file);
1854 out:
1855         return ret;
1856 }
1857
1858 /*
1859  * helper to check if the subvolume references other subvolumes
1860  */
1861 static noinline int may_destroy_subvol(struct btrfs_root *root)
1862 {
1863         struct btrfs_fs_info *fs_info = root->fs_info;
1864         struct btrfs_path *path;
1865         struct btrfs_dir_item *di;
1866         struct btrfs_key key;
1867         u64 dir_id;
1868         int ret;
1869
1870         path = btrfs_alloc_path();
1871         if (!path)
1872                 return -ENOMEM;
1873
1874         /* Make sure this root isn't set as the default subvol */
1875         dir_id = btrfs_super_root_dir(fs_info->super_copy);
1876         di = btrfs_lookup_dir_item(NULL, fs_info->tree_root, path,
1877                                    dir_id, "default", 7, 0);
1878         if (di && !IS_ERR(di)) {
1879                 btrfs_dir_item_key_to_cpu(path->nodes[0], di, &key);
1880                 if (key.objectid == root->root_key.objectid) {
1881                         ret = -EPERM;
1882                         btrfs_err(fs_info,
1883                                   "deleting default subvolume %llu is not allowed",
1884                                   key.objectid);
1885                         goto out;
1886                 }
1887                 btrfs_release_path(path);
1888         }
1889
1890         key.objectid = root->root_key.objectid;
1891         key.type = BTRFS_ROOT_REF_KEY;
1892         key.offset = (u64)-1;
1893
1894         ret = btrfs_search_slot(NULL, fs_info->tree_root, &key, path, 0, 0);
1895         if (ret < 0)
1896                 goto out;
1897         BUG_ON(ret == 0);
1898
1899         ret = 0;
1900         if (path->slots[0] > 0) {
1901                 path->slots[0]--;
1902                 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
1903                 if (key.objectid == root->root_key.objectid &&
1904                     key.type == BTRFS_ROOT_REF_KEY)
1905                         ret = -ENOTEMPTY;
1906         }
1907 out:
1908         btrfs_free_path(path);
1909         return ret;
1910 }
1911
1912 static noinline int key_in_sk(struct btrfs_key *key,
1913                               struct btrfs_ioctl_search_key *sk)
1914 {
1915         struct btrfs_key test;
1916         int ret;
1917
1918         test.objectid = sk->min_objectid;
1919         test.type = sk->min_type;
1920         test.offset = sk->min_offset;
1921
1922         ret = btrfs_comp_cpu_keys(key, &test);
1923         if (ret < 0)
1924                 return 0;
1925
1926         test.objectid = sk->max_objectid;
1927         test.type = sk->max_type;
1928         test.offset = sk->max_offset;
1929
1930         ret = btrfs_comp_cpu_keys(key, &test);
1931         if (ret > 0)
1932                 return 0;
1933         return 1;
1934 }
1935
1936 static noinline int copy_to_sk(struct btrfs_path *path,
1937                                struct btrfs_key *key,
1938                                struct btrfs_ioctl_search_key *sk,
1939                                size_t *buf_size,
1940                                char __user *ubuf,
1941                                unsigned long *sk_offset,
1942                                int *num_found)
1943 {
1944         u64 found_transid;
1945         struct extent_buffer *leaf;
1946         struct btrfs_ioctl_search_header sh;
1947         struct btrfs_key test;
1948         unsigned long item_off;
1949         unsigned long item_len;
1950         int nritems;
1951         int i;
1952         int slot;
1953         int ret = 0;
1954
1955         leaf = path->nodes[0];
1956         slot = path->slots[0];
1957         nritems = btrfs_header_nritems(leaf);
1958
1959         if (btrfs_header_generation(leaf) > sk->max_transid) {
1960                 i = nritems;
1961                 goto advance_key;
1962         }
1963         found_transid = btrfs_header_generation(leaf);
1964
1965         for (i = slot; i < nritems; i++) {
1966                 item_off = btrfs_item_ptr_offset(leaf, i);
1967                 item_len = btrfs_item_size_nr(leaf, i);
1968
1969                 btrfs_item_key_to_cpu(leaf, key, i);
1970                 if (!key_in_sk(key, sk))
1971                         continue;
1972
1973                 if (sizeof(sh) + item_len > *buf_size) {
1974                         if (*num_found) {
1975                                 ret = 1;
1976                                 goto out;
1977                         }
1978
1979                         /*
1980                          * return one empty item back for v1, which does not
1981                          * handle -EOVERFLOW
1982                          */
1983
1984                         *buf_size = sizeof(sh) + item_len;
1985                         item_len = 0;
1986                         ret = -EOVERFLOW;
1987                 }
1988
1989                 if (sizeof(sh) + item_len + *sk_offset > *buf_size) {
1990                         ret = 1;
1991                         goto out;
1992                 }
1993
1994                 sh.objectid = key->objectid;
1995                 sh.offset = key->offset;
1996                 sh.type = key->type;
1997                 sh.len = item_len;
1998                 sh.transid = found_transid;
1999
2000                 /* copy search result header */
2001                 if (copy_to_user(ubuf + *sk_offset, &sh, sizeof(sh))) {
2002                         ret = -EFAULT;
2003                         goto out;
2004                 }
2005
2006                 *sk_offset += sizeof(sh);
2007
2008                 if (item_len) {
2009                         char __user *up = ubuf + *sk_offset;
2010                         /* copy the item */
2011                         if (read_extent_buffer_to_user(leaf, up,
2012                                                        item_off, item_len)) {
2013                                 ret = -EFAULT;
2014                                 goto out;
2015                         }
2016
2017                         *sk_offset += item_len;
2018                 }
2019                 (*num_found)++;
2020
2021                 if (ret) /* -EOVERFLOW from above */
2022                         goto out;
2023
2024                 if (*num_found >= sk->nr_items) {
2025                         ret = 1;
2026                         goto out;
2027                 }
2028         }
2029 advance_key:
2030         ret = 0;
2031         test.objectid = sk->max_objectid;
2032         test.type = sk->max_type;
2033         test.offset = sk->max_offset;
2034         if (btrfs_comp_cpu_keys(key, &test) >= 0)
2035                 ret = 1;
2036         else if (key->offset < (u64)-1)
2037                 key->offset++;
2038         else if (key->type < (u8)-1) {
2039                 key->offset = 0;
2040                 key->type++;
2041         } else if (key->objectid < (u64)-1) {
2042                 key->offset = 0;
2043                 key->type = 0;
2044                 key->objectid++;
2045         } else
2046                 ret = 1;
2047 out:
2048         /*
2049          *  0: all items from this leaf copied, continue with next
2050          *  1: * more items can be copied, but unused buffer is too small
2051          *     * all items were found
2052          *     Either way, it will stops the loop which iterates to the next
2053          *     leaf
2054          *  -EOVERFLOW: item was to large for buffer
2055          *  -EFAULT: could not copy extent buffer back to userspace
2056          */
2057         return ret;
2058 }
2059
2060 static noinline int search_ioctl(struct inode *inode,
2061                                  struct btrfs_ioctl_search_key *sk,
2062                                  size_t *buf_size,
2063                                  char __user *ubuf)
2064 {
2065         struct btrfs_fs_info *info = btrfs_sb(inode->i_sb);
2066         struct btrfs_root *root;
2067         struct btrfs_key key;
2068         struct btrfs_path *path;
2069         int ret;
2070         int num_found = 0;
2071         unsigned long sk_offset = 0;
2072
2073         if (*buf_size < sizeof(struct btrfs_ioctl_search_header)) {
2074                 *buf_size = sizeof(struct btrfs_ioctl_search_header);
2075                 return -EOVERFLOW;
2076         }
2077
2078         path = btrfs_alloc_path();
2079         if (!path)
2080                 return -ENOMEM;
2081
2082         if (sk->tree_id == 0) {
2083                 /* search the root of the inode that was passed */
2084                 root = BTRFS_I(inode)->root;
2085         } else {
2086                 key.objectid = sk->tree_id;
2087                 key.type = BTRFS_ROOT_ITEM_KEY;
2088                 key.offset = (u64)-1;
2089                 root = btrfs_read_fs_root_no_name(info, &key);
2090                 if (IS_ERR(root)) {
2091                         btrfs_free_path(path);
2092                         return -ENOENT;
2093                 }
2094         }
2095
2096         key.objectid = sk->min_objectid;
2097         key.type = sk->min_type;
2098         key.offset = sk->min_offset;
2099
2100         while (1) {
2101                 ret = btrfs_search_forward(root, &key, path, sk->min_transid);
2102                 if (ret != 0) {
2103                         if (ret > 0)
2104                                 ret = 0;
2105                         goto err;
2106                 }
2107                 ret = copy_to_sk(path, &key, sk, buf_size, ubuf,
2108                                  &sk_offset, &num_found);
2109                 btrfs_release_path(path);
2110                 if (ret)
2111                         break;
2112
2113         }
2114         if (ret > 0)
2115                 ret = 0;
2116 err:
2117         sk->nr_items = num_found;
2118         btrfs_free_path(path);
2119         return ret;
2120 }
2121
2122 static noinline int btrfs_ioctl_tree_search(struct file *file,
2123                                            void __user *argp)
2124 {
2125         struct btrfs_ioctl_search_args __user *uargs;
2126         struct btrfs_ioctl_search_key sk;
2127         struct inode *inode;
2128         int ret;
2129         size_t buf_size;
2130
2131         if (!capable(CAP_SYS_ADMIN))
2132                 return -EPERM;
2133
2134         uargs = (struct btrfs_ioctl_search_args __user *)argp;
2135
2136         if (copy_from_user(&sk, &uargs->key, sizeof(sk)))
2137                 return -EFAULT;
2138
2139         buf_size = sizeof(uargs->buf);
2140
2141         inode = file_inode(file);
2142         ret = search_ioctl(inode, &sk, &buf_size, uargs->buf);
2143
2144         /*
2145          * In the origin implementation an overflow is handled by returning a
2146          * search header with a len of zero, so reset ret.
2147          */
2148         if (ret == -EOVERFLOW)
2149                 ret = 0;
2150
2151         if (ret == 0 && copy_to_user(&uargs->key, &sk, sizeof(sk)))
2152                 ret = -EFAULT;
2153         return ret;
2154 }
2155
2156 static noinline int btrfs_ioctl_tree_search_v2(struct file *file,
2157                                                void __user *argp)
2158 {
2159         struct btrfs_ioctl_search_args_v2 __user *uarg;
2160         struct btrfs_ioctl_search_args_v2 args;
2161         struct inode *inode;
2162         int ret;
2163         size_t buf_size;
2164         const size_t buf_limit = SZ_16M;
2165
2166         if (!capable(CAP_SYS_ADMIN))
2167                 return -EPERM;
2168
2169         /* copy search header and buffer size */
2170         uarg = (struct btrfs_ioctl_search_args_v2 __user *)argp;
2171         if (copy_from_user(&args, uarg, sizeof(args)))
2172                 return -EFAULT;
2173
2174         buf_size = args.buf_size;
2175
2176         /* limit result size to 16MB */
2177         if (buf_size > buf_limit)
2178                 buf_size = buf_limit;
2179
2180         inode = file_inode(file);
2181         ret = search_ioctl(inode, &args.key, &buf_size,
2182                            (char *)(&uarg->buf[0]));
2183         if (ret == 0 && copy_to_user(&uarg->key, &args.key, sizeof(args.key)))
2184                 ret = -EFAULT;
2185         else if (ret == -EOVERFLOW &&
2186                 copy_to_user(&uarg->buf_size, &buf_size, sizeof(buf_size)))
2187                 ret = -EFAULT;
2188
2189         return ret;
2190 }
2191
2192 /*
2193  * Search INODE_REFs to identify path name of 'dirid' directory
2194  * in a 'tree_id' tree. and sets path name to 'name'.
2195  */
2196 static noinline int btrfs_search_path_in_tree(struct btrfs_fs_info *info,
2197                                 u64 tree_id, u64 dirid, char *name)
2198 {
2199         struct btrfs_root *root;
2200         struct btrfs_key key;
2201         char *ptr;
2202         int ret = -1;
2203         int slot;
2204         int len;
2205         int total_len = 0;
2206         struct btrfs_inode_ref *iref;
2207         struct extent_buffer *l;
2208         struct btrfs_path *path;
2209
2210         if (dirid == BTRFS_FIRST_FREE_OBJECTID) {
2211                 name[0]='\0';
2212                 return 0;
2213         }
2214
2215         path = btrfs_alloc_path();
2216         if (!path)
2217                 return -ENOMEM;
2218
2219         ptr = &name[BTRFS_INO_LOOKUP_PATH_MAX];
2220
2221         key.objectid = tree_id;
2222         key.type = BTRFS_ROOT_ITEM_KEY;
2223         key.offset = (u64)-1;
2224         root = btrfs_read_fs_root_no_name(info, &key);
2225         if (IS_ERR(root)) {
2226                 btrfs_err(info, "could not find root %llu", tree_id);
2227                 ret = -ENOENT;
2228                 goto out;
2229         }
2230
2231         key.objectid = dirid;
2232         key.type = BTRFS_INODE_REF_KEY;
2233         key.offset = (u64)-1;
2234
2235         while (1) {
2236                 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2237                 if (ret < 0)
2238                         goto out;
2239                 else if (ret > 0) {
2240                         ret = btrfs_previous_item(root, path, dirid,
2241                                                   BTRFS_INODE_REF_KEY);
2242                         if (ret < 0)
2243                                 goto out;
2244                         else if (ret > 0) {
2245                                 ret = -ENOENT;
2246                                 goto out;
2247                         }
2248                 }
2249
2250                 l = path->nodes[0];
2251                 slot = path->slots[0];
2252                 btrfs_item_key_to_cpu(l, &key, slot);
2253
2254                 iref = btrfs_item_ptr(l, slot, struct btrfs_inode_ref);
2255                 len = btrfs_inode_ref_name_len(l, iref);
2256                 ptr -= len + 1;
2257                 total_len += len + 1;
2258                 if (ptr < name) {
2259                         ret = -ENAMETOOLONG;
2260                         goto out;
2261                 }
2262
2263                 *(ptr + len) = '/';
2264                 read_extent_buffer(l, ptr, (unsigned long)(iref + 1), len);
2265
2266                 if (key.offset == BTRFS_FIRST_FREE_OBJECTID)
2267                         break;
2268
2269                 btrfs_release_path(path);
2270                 key.objectid = key.offset;
2271                 key.offset = (u64)-1;
2272                 dirid = key.objectid;
2273         }
2274         memmove(name, ptr, total_len);
2275         name[total_len] = '\0';
2276         ret = 0;
2277 out:
2278         btrfs_free_path(path);
2279         return ret;
2280 }
2281
2282 static noinline int btrfs_ioctl_ino_lookup(struct file *file,
2283                                            void __user *argp)
2284 {
2285          struct btrfs_ioctl_ino_lookup_args *args;
2286          struct inode *inode;
2287         int ret = 0;
2288
2289         args = memdup_user(argp, sizeof(*args));
2290         if (IS_ERR(args))
2291                 return PTR_ERR(args);
2292
2293         inode = file_inode(file);
2294
2295         /*
2296          * Unprivileged query to obtain the containing subvolume root id. The
2297          * path is reset so it's consistent with btrfs_search_path_in_tree.
2298          */
2299         if (args->treeid == 0)
2300                 args->treeid = BTRFS_I(inode)->root->root_key.objectid;
2301
2302         if (args->objectid == BTRFS_FIRST_FREE_OBJECTID) {
2303                 args->name[0] = 0;
2304                 goto out;
2305         }
2306
2307         if (!capable(CAP_SYS_ADMIN)) {
2308                 ret = -EPERM;
2309                 goto out;
2310         }
2311
2312         ret = btrfs_search_path_in_tree(BTRFS_I(inode)->root->fs_info,
2313                                         args->treeid, args->objectid,
2314                                         args->name);
2315
2316 out:
2317         if (ret == 0 && copy_to_user(argp, args, sizeof(*args)))
2318                 ret = -EFAULT;
2319
2320         kfree(args);
2321         return ret;
2322 }
2323
2324 static noinline int btrfs_ioctl_snap_destroy(struct file *file,
2325                                              void __user *arg)
2326 {
2327         struct dentry *parent = file->f_path.dentry;
2328         struct btrfs_fs_info *fs_info = btrfs_sb(parent->d_sb);
2329         struct dentry *dentry;
2330         struct inode *dir = d_inode(parent);
2331         struct inode *inode;
2332         struct btrfs_root *root = BTRFS_I(dir)->root;
2333         struct btrfs_root *dest = NULL;
2334         struct btrfs_ioctl_vol_args *vol_args;
2335         struct btrfs_trans_handle *trans;
2336         struct btrfs_block_rsv block_rsv;
2337         u64 root_flags;
2338         u64 qgroup_reserved;
2339         int namelen;
2340         int ret;
2341         int err = 0;
2342
2343         if (!S_ISDIR(dir->i_mode))
2344                 return -ENOTDIR;
2345
2346         vol_args = memdup_user(arg, sizeof(*vol_args));
2347         if (IS_ERR(vol_args))
2348                 return PTR_ERR(vol_args);
2349
2350         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
2351         namelen = strlen(vol_args->name);
2352         if (strchr(vol_args->name, '/') ||
2353             strncmp(vol_args->name, "..", namelen) == 0) {
2354                 err = -EINVAL;
2355                 goto out;
2356         }
2357
2358         err = mnt_want_write_file(file);
2359         if (err)
2360                 goto out;
2361
2362
2363         err = down_write_killable_nested(&dir->i_rwsem, I_MUTEX_PARENT);
2364         if (err == -EINTR)
2365                 goto out_drop_write;
2366         dentry = lookup_one_len(vol_args->name, parent, namelen);
2367         if (IS_ERR(dentry)) {
2368                 err = PTR_ERR(dentry);
2369                 goto out_unlock_dir;
2370         }
2371
2372         if (d_really_is_negative(dentry)) {
2373                 err = -ENOENT;
2374                 goto out_dput;
2375         }
2376
2377         inode = d_inode(dentry);
2378         dest = BTRFS_I(inode)->root;
2379         if (!capable(CAP_SYS_ADMIN)) {
2380                 /*
2381                  * Regular user.  Only allow this with a special mount
2382                  * option, when the user has write+exec access to the
2383                  * subvol root, and when rmdir(2) would have been
2384                  * allowed.
2385                  *
2386                  * Note that this is _not_ check that the subvol is
2387                  * empty or doesn't contain data that we wouldn't
2388                  * otherwise be able to delete.
2389                  *
2390                  * Users who want to delete empty subvols should try
2391                  * rmdir(2).
2392                  */
2393                 err = -EPERM;
2394                 if (!btrfs_test_opt(fs_info, USER_SUBVOL_RM_ALLOWED))
2395                         goto out_dput;
2396
2397                 /*
2398                  * Do not allow deletion if the parent dir is the same
2399                  * as the dir to be deleted.  That means the ioctl
2400                  * must be called on the dentry referencing the root
2401                  * of the subvol, not a random directory contained
2402                  * within it.
2403                  */
2404                 err = -EINVAL;
2405                 if (root == dest)
2406                         goto out_dput;
2407
2408                 err = inode_permission(inode, MAY_WRITE | MAY_EXEC);
2409                 if (err)
2410                         goto out_dput;
2411         }
2412
2413         /* check if subvolume may be deleted by a user */
2414         err = btrfs_may_delete(dir, dentry, 1);
2415         if (err)
2416                 goto out_dput;
2417
2418         if (btrfs_ino(BTRFS_I(inode)) != BTRFS_FIRST_FREE_OBJECTID) {
2419                 err = -EINVAL;
2420                 goto out_dput;
2421         }
2422
2423         inode_lock(inode);
2424
2425         /*
2426          * Don't allow to delete a subvolume with send in progress. This is
2427          * inside the i_mutex so the error handling that has to drop the bit
2428          * again is not run concurrently.
2429          */
2430         spin_lock(&dest->root_item_lock);
2431         root_flags = btrfs_root_flags(&dest->root_item);
2432         if (dest->send_in_progress == 0) {
2433                 btrfs_set_root_flags(&dest->root_item,
2434                                 root_flags | BTRFS_ROOT_SUBVOL_DEAD);
2435                 spin_unlock(&dest->root_item_lock);
2436         } else {
2437                 spin_unlock(&dest->root_item_lock);
2438                 btrfs_warn(fs_info,
2439                            "Attempt to delete subvolume %llu during send",
2440                            dest->root_key.objectid);
2441                 err = -EPERM;
2442                 goto out_unlock_inode;
2443         }
2444
2445         down_write(&fs_info->subvol_sem);
2446
2447         err = may_destroy_subvol(dest);
2448         if (err)
2449                 goto out_up_write;
2450
2451         btrfs_init_block_rsv(&block_rsv, BTRFS_BLOCK_RSV_TEMP);
2452         /*
2453          * One for dir inode, two for dir entries, two for root
2454          * ref/backref.
2455          */
2456         err = btrfs_subvolume_reserve_metadata(root, &block_rsv,
2457                                                5, &qgroup_reserved, true);
2458         if (err)
2459                 goto out_up_write;
2460
2461         trans = btrfs_start_transaction(root, 0);
2462         if (IS_ERR(trans)) {
2463                 err = PTR_ERR(trans);
2464                 goto out_release;
2465         }
2466         trans->block_rsv = &block_rsv;
2467         trans->bytes_reserved = block_rsv.size;
2468
2469         btrfs_record_snapshot_destroy(trans, BTRFS_I(dir));
2470
2471         ret = btrfs_unlink_subvol(trans, root, dir,
2472                                 dest->root_key.objectid,
2473                                 dentry->d_name.name,
2474                                 dentry->d_name.len);
2475         if (ret) {
2476                 err = ret;
2477                 btrfs_abort_transaction(trans, ret);
2478                 goto out_end_trans;
2479         }
2480
2481         btrfs_record_root_in_trans(trans, dest);
2482
2483         memset(&dest->root_item.drop_progress, 0,
2484                 sizeof(dest->root_item.drop_progress));
2485         dest->root_item.drop_level = 0;
2486         btrfs_set_root_refs(&dest->root_item, 0);
2487
2488         if (!test_and_set_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &dest->state)) {
2489                 ret = btrfs_insert_orphan_item(trans,
2490                                         fs_info->tree_root,
2491                                         dest->root_key.objectid);
2492                 if (ret) {
2493                         btrfs_abort_transaction(trans, ret);
2494                         err = ret;
2495                         goto out_end_trans;
2496                 }
2497         }
2498
2499         ret = btrfs_uuid_tree_rem(trans, fs_info, dest->root_item.uuid,
2500                                   BTRFS_UUID_KEY_SUBVOL,
2501                                   dest->root_key.objectid);
2502         if (ret && ret != -ENOENT) {
2503                 btrfs_abort_transaction(trans, ret);
2504                 err = ret;
2505                 goto out_end_trans;
2506         }
2507         if (!btrfs_is_empty_uuid(dest->root_item.received_uuid)) {
2508                 ret = btrfs_uuid_tree_rem(trans, fs_info,
2509                                           dest->root_item.received_uuid,
2510                                           BTRFS_UUID_KEY_RECEIVED_SUBVOL,
2511                                           dest->root_key.objectid);
2512                 if (ret && ret != -ENOENT) {
2513                         btrfs_abort_transaction(trans, ret);
2514                         err = ret;
2515                         goto out_end_trans;
2516                 }
2517         }
2518
2519 out_end_trans:
2520         trans->block_rsv = NULL;
2521         trans->bytes_reserved = 0;
2522         ret = btrfs_end_transaction(trans);
2523         if (ret && !err)
2524                 err = ret;
2525         inode->i_flags |= S_DEAD;
2526 out_release:
2527         btrfs_subvolume_release_metadata(fs_info, &block_rsv);
2528 out_up_write:
2529         up_write(&fs_info->subvol_sem);
2530         if (err) {
2531                 spin_lock(&dest->root_item_lock);
2532                 root_flags = btrfs_root_flags(&dest->root_item);
2533                 btrfs_set_root_flags(&dest->root_item,
2534                                 root_flags & ~BTRFS_ROOT_SUBVOL_DEAD);
2535                 spin_unlock(&dest->root_item_lock);
2536         }
2537 out_unlock_inode:
2538         inode_unlock(inode);
2539         if (!err) {
2540                 d_invalidate(dentry);
2541                 btrfs_invalidate_inodes(dest);
2542                 d_delete(dentry);
2543                 ASSERT(dest->send_in_progress == 0);
2544
2545                 /* the last ref */
2546                 if (dest->ino_cache_inode) {
2547                         iput(dest->ino_cache_inode);
2548                         dest->ino_cache_inode = NULL;
2549                 }
2550         }
2551 out_dput:
2552         dput(dentry);
2553 out_unlock_dir:
2554         inode_unlock(dir);
2555 out_drop_write:
2556         mnt_drop_write_file(file);
2557 out:
2558         kfree(vol_args);
2559         return err;
2560 }
2561
2562 static int btrfs_ioctl_defrag(struct file *file, void __user *argp)
2563 {
2564         struct inode *inode = file_inode(file);
2565         struct btrfs_root *root = BTRFS_I(inode)->root;
2566         struct btrfs_ioctl_defrag_range_args *range;
2567         int ret;
2568
2569         ret = mnt_want_write_file(file);
2570         if (ret)
2571                 return ret;
2572
2573         if (btrfs_root_readonly(root)) {
2574                 ret = -EROFS;
2575                 goto out;
2576         }
2577
2578         switch (inode->i_mode & S_IFMT) {
2579         case S_IFDIR:
2580                 if (!capable(CAP_SYS_ADMIN)) {
2581                         ret = -EPERM;
2582                         goto out;
2583                 }
2584                 ret = btrfs_defrag_root(root);
2585                 break;
2586         case S_IFREG:
2587                 if (!(file->f_mode & FMODE_WRITE)) {
2588                         ret = -EINVAL;
2589                         goto out;
2590                 }
2591
2592                 range = kzalloc(sizeof(*range), GFP_KERNEL);
2593                 if (!range) {
2594                         ret = -ENOMEM;
2595                         goto out;
2596                 }
2597
2598                 if (argp) {
2599                         if (copy_from_user(range, argp,
2600                                            sizeof(*range))) {
2601                                 ret = -EFAULT;
2602                                 kfree(range);
2603                                 goto out;
2604                         }
2605                         /* compression requires us to start the IO */
2606                         if ((range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)) {
2607                                 range->flags |= BTRFS_DEFRAG_RANGE_START_IO;
2608                                 range->extent_thresh = (u32)-1;
2609                         }
2610                 } else {
2611                         /* the rest are all set to zero by kzalloc */
2612                         range->len = (u64)-1;
2613                 }
2614                 ret = btrfs_defrag_file(file_inode(file), file,
2615                                         range, 0, 0);
2616                 if (ret > 0)
2617                         ret = 0;
2618                 kfree(range);
2619                 break;
2620         default:
2621                 ret = -EINVAL;
2622         }
2623 out:
2624         mnt_drop_write_file(file);
2625         return ret;
2626 }
2627
2628 static long btrfs_ioctl_add_dev(struct btrfs_fs_info *fs_info, void __user *arg)
2629 {
2630         struct btrfs_ioctl_vol_args *vol_args;
2631         int ret;
2632
2633         if (!capable(CAP_SYS_ADMIN))
2634                 return -EPERM;
2635
2636         if (test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags))
2637                 return BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
2638
2639         mutex_lock(&fs_info->volume_mutex);
2640         vol_args = memdup_user(arg, sizeof(*vol_args));
2641         if (IS_ERR(vol_args)) {
2642                 ret = PTR_ERR(vol_args);
2643                 goto out;
2644         }
2645
2646         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
2647         ret = btrfs_init_new_device(fs_info, vol_args->name);
2648
2649         if (!ret)
2650                 btrfs_info(fs_info, "disk added %s", vol_args->name);
2651
2652         kfree(vol_args);
2653 out:
2654         mutex_unlock(&fs_info->volume_mutex);
2655         clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
2656         return ret;
2657 }
2658
2659 static long btrfs_ioctl_rm_dev_v2(struct file *file, void __user *arg)
2660 {
2661         struct inode *inode = file_inode(file);
2662         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2663         struct btrfs_ioctl_vol_args_v2 *vol_args;
2664         int ret;
2665
2666         if (!capable(CAP_SYS_ADMIN))
2667                 return -EPERM;
2668
2669         ret = mnt_want_write_file(file);
2670         if (ret)
2671                 return ret;
2672
2673         vol_args = memdup_user(arg, sizeof(*vol_args));
2674         if (IS_ERR(vol_args)) {
2675                 ret = PTR_ERR(vol_args);
2676                 goto err_drop;
2677         }
2678
2679         /* Check for compatibility reject unknown flags */
2680         if (vol_args->flags & ~BTRFS_VOL_ARG_V2_FLAGS_SUPPORTED)
2681                 return -EOPNOTSUPP;
2682
2683         if (test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags)) {
2684                 ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
2685                 goto out;
2686         }
2687
2688         mutex_lock(&fs_info->volume_mutex);
2689         if (vol_args->flags & BTRFS_DEVICE_SPEC_BY_ID) {
2690                 ret = btrfs_rm_device(fs_info, NULL, vol_args->devid);
2691         } else {
2692                 vol_args->name[BTRFS_SUBVOL_NAME_MAX] = '\0';
2693                 ret = btrfs_rm_device(fs_info, vol_args->name, 0);
2694         }
2695         mutex_unlock(&fs_info->volume_mutex);
2696         clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
2697
2698         if (!ret) {
2699                 if (vol_args->flags & BTRFS_DEVICE_SPEC_BY_ID)
2700                         btrfs_info(fs_info, "device deleted: id %llu",
2701                                         vol_args->devid);
2702                 else
2703                         btrfs_info(fs_info, "device deleted: %s",
2704                                         vol_args->name);
2705         }
2706 out:
2707         kfree(vol_args);
2708 err_drop:
2709         mnt_drop_write_file(file);
2710         return ret;
2711 }
2712
2713 static long btrfs_ioctl_rm_dev(struct file *file, void __user *arg)
2714 {
2715         struct inode *inode = file_inode(file);
2716         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2717         struct btrfs_ioctl_vol_args *vol_args;
2718         int ret;
2719
2720         if (!capable(CAP_SYS_ADMIN))
2721                 return -EPERM;
2722
2723         ret = mnt_want_write_file(file);
2724         if (ret)
2725                 return ret;
2726
2727         if (test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags)) {
2728                 ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
2729                 goto out_drop_write;
2730         }
2731
2732         vol_args = memdup_user(arg, sizeof(*vol_args));
2733         if (IS_ERR(vol_args)) {
2734                 ret = PTR_ERR(vol_args);
2735                 goto out;
2736         }
2737
2738         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
2739         mutex_lock(&fs_info->volume_mutex);
2740         ret = btrfs_rm_device(fs_info, vol_args->name, 0);
2741         mutex_unlock(&fs_info->volume_mutex);
2742
2743         if (!ret)
2744                 btrfs_info(fs_info, "disk deleted %s", vol_args->name);
2745         kfree(vol_args);
2746 out:
2747         clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
2748 out_drop_write:
2749         mnt_drop_write_file(file);
2750
2751         return ret;
2752 }
2753
2754 static long btrfs_ioctl_fs_info(struct btrfs_fs_info *fs_info,
2755                                 void __user *arg)
2756 {
2757         struct btrfs_ioctl_fs_info_args *fi_args;
2758         struct btrfs_device *device;
2759         struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
2760         int ret = 0;
2761
2762         fi_args = kzalloc(sizeof(*fi_args), GFP_KERNEL);
2763         if (!fi_args)
2764                 return -ENOMEM;
2765
2766         mutex_lock(&fs_devices->device_list_mutex);
2767         fi_args->num_devices = fs_devices->num_devices;
2768         memcpy(&fi_args->fsid, fs_info->fsid, sizeof(fi_args->fsid));
2769
2770         list_for_each_entry(device, &fs_devices->devices, dev_list) {
2771                 if (device->devid > fi_args->max_id)
2772                         fi_args->max_id = device->devid;
2773         }
2774         mutex_unlock(&fs_devices->device_list_mutex);
2775
2776         fi_args->nodesize = fs_info->nodesize;
2777         fi_args->sectorsize = fs_info->sectorsize;
2778         fi_args->clone_alignment = fs_info->sectorsize;
2779
2780         if (copy_to_user(arg, fi_args, sizeof(*fi_args)))
2781                 ret = -EFAULT;
2782
2783         kfree(fi_args);
2784         return ret;
2785 }
2786
2787 static long btrfs_ioctl_dev_info(struct btrfs_fs_info *fs_info,
2788                                  void __user *arg)
2789 {
2790         struct btrfs_ioctl_dev_info_args *di_args;
2791         struct btrfs_device *dev;
2792         struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
2793         int ret = 0;
2794         char *s_uuid = NULL;
2795
2796         di_args = memdup_user(arg, sizeof(*di_args));
2797         if (IS_ERR(di_args))
2798                 return PTR_ERR(di_args);
2799
2800         if (!btrfs_is_empty_uuid(di_args->uuid))
2801                 s_uuid = di_args->uuid;
2802
2803         mutex_lock(&fs_devices->device_list_mutex);
2804         dev = btrfs_find_device(fs_info, di_args->devid, s_uuid, NULL);
2805
2806         if (!dev) {
2807                 ret = -ENODEV;
2808                 goto out;
2809         }
2810
2811         di_args->devid = dev->devid;
2812         di_args->bytes_used = btrfs_device_get_bytes_used(dev);
2813         di_args->total_bytes = btrfs_device_get_total_bytes(dev);
2814         memcpy(di_args->uuid, dev->uuid, sizeof(di_args->uuid));
2815         if (dev->name) {
2816                 struct rcu_string *name;
2817
2818                 rcu_read_lock();
2819                 name = rcu_dereference(dev->name);
2820                 strncpy(di_args->path, name->str, sizeof(di_args->path));
2821                 rcu_read_unlock();
2822                 di_args->path[sizeof(di_args->path) - 1] = 0;
2823         } else {
2824                 di_args->path[0] = '\0';
2825         }
2826
2827 out:
2828         mutex_unlock(&fs_devices->device_list_mutex);
2829         if (ret == 0 && copy_to_user(arg, di_args, sizeof(*di_args)))
2830                 ret = -EFAULT;
2831
2832         kfree(di_args);
2833         return ret;
2834 }
2835
2836 static struct page *extent_same_get_page(struct inode *inode, pgoff_t index)
2837 {
2838         struct page *page;
2839
2840         page = grab_cache_page(inode->i_mapping, index);
2841         if (!page)
2842                 return ERR_PTR(-ENOMEM);
2843
2844         if (!PageUptodate(page)) {
2845                 int ret;
2846
2847                 ret = btrfs_readpage(NULL, page);
2848                 if (ret)
2849                         return ERR_PTR(ret);
2850                 lock_page(page);
2851                 if (!PageUptodate(page)) {
2852                         unlock_page(page);
2853                         put_page(page);
2854                         return ERR_PTR(-EIO);
2855                 }
2856                 if (page->mapping != inode->i_mapping) {
2857                         unlock_page(page);
2858                         put_page(page);
2859                         return ERR_PTR(-EAGAIN);
2860                 }
2861         }
2862
2863         return page;
2864 }
2865
2866 static int gather_extent_pages(struct inode *inode, struct page **pages,
2867                                int num_pages, u64 off)
2868 {
2869         int i;
2870         pgoff_t index = off >> PAGE_SHIFT;
2871
2872         for (i = 0; i < num_pages; i++) {
2873 again:
2874                 pages[i] = extent_same_get_page(inode, index + i);
2875                 if (IS_ERR(pages[i])) {
2876                         int err = PTR_ERR(pages[i]);
2877
2878                         if (err == -EAGAIN)
2879                                 goto again;
2880                         pages[i] = NULL;
2881                         return err;
2882                 }
2883         }
2884         return 0;
2885 }
2886
2887 static int lock_extent_range(struct inode *inode, u64 off, u64 len,
2888                              bool retry_range_locking)
2889 {
2890         /*
2891          * Do any pending delalloc/csum calculations on inode, one way or
2892          * another, and lock file content.
2893          * The locking order is:
2894          *
2895          *   1) pages
2896          *   2) range in the inode's io tree
2897          */
2898         while (1) {
2899                 struct btrfs_ordered_extent *ordered;
2900                 lock_extent(&BTRFS_I(inode)->io_tree, off, off + len - 1);
2901                 ordered = btrfs_lookup_first_ordered_extent(inode,
2902                                                             off + len - 1);
2903                 if ((!ordered ||
2904                      ordered->file_offset + ordered->len <= off ||
2905                      ordered->file_offset >= off + len) &&
2906                     !test_range_bit(&BTRFS_I(inode)->io_tree, off,
2907                                     off + len - 1, EXTENT_DELALLOC, 0, NULL)) {
2908                         if (ordered)
2909                                 btrfs_put_ordered_extent(ordered);
2910                         break;
2911                 }
2912                 unlock_extent(&BTRFS_I(inode)->io_tree, off, off + len - 1);
2913                 if (ordered)
2914                         btrfs_put_ordered_extent(ordered);
2915                 if (!retry_range_locking)
2916                         return -EAGAIN;
2917                 btrfs_wait_ordered_range(inode, off, len);
2918         }
2919         return 0;
2920 }
2921
2922 static void btrfs_double_inode_unlock(struct inode *inode1, struct inode *inode2)
2923 {
2924         inode_unlock(inode1);
2925         inode_unlock(inode2);
2926 }
2927
2928 static void btrfs_double_inode_lock(struct inode *inode1, struct inode *inode2)
2929 {
2930         if (inode1 < inode2)
2931                 swap(inode1, inode2);
2932
2933         inode_lock_nested(inode1, I_MUTEX_PARENT);
2934         inode_lock_nested(inode2, I_MUTEX_CHILD);
2935 }
2936
2937 static void btrfs_double_extent_unlock(struct inode *inode1, u64 loff1,
2938                                       struct inode *inode2, u64 loff2, u64 len)
2939 {
2940         unlock_extent(&BTRFS_I(inode1)->io_tree, loff1, loff1 + len - 1);
2941         unlock_extent(&BTRFS_I(inode2)->io_tree, loff2, loff2 + len - 1);
2942 }
2943
2944 static int btrfs_double_extent_lock(struct inode *inode1, u64 loff1,
2945                                     struct inode *inode2, u64 loff2, u64 len,
2946                                     bool retry_range_locking)
2947 {
2948         int ret;
2949
2950         if (inode1 < inode2) {
2951                 swap(inode1, inode2);
2952                 swap(loff1, loff2);
2953         }
2954         ret = lock_extent_range(inode1, loff1, len, retry_range_locking);
2955         if (ret)
2956                 return ret;
2957         ret = lock_extent_range(inode2, loff2, len, retry_range_locking);
2958         if (ret)
2959                 unlock_extent(&BTRFS_I(inode1)->io_tree, loff1,
2960                               loff1 + len - 1);
2961         return ret;
2962 }
2963
2964 struct cmp_pages {
2965         int             num_pages;
2966         struct page     **src_pages;
2967         struct page     **dst_pages;
2968 };
2969
2970 static void btrfs_cmp_data_free(struct cmp_pages *cmp)
2971 {
2972         int i;
2973         struct page *pg;
2974
2975         for (i = 0; i < cmp->num_pages; i++) {
2976                 pg = cmp->src_pages[i];
2977                 if (pg) {
2978                         unlock_page(pg);
2979                         put_page(pg);
2980                 }
2981                 pg = cmp->dst_pages[i];
2982                 if (pg) {
2983                         unlock_page(pg);
2984                         put_page(pg);
2985                 }
2986         }
2987         kfree(cmp->src_pages);
2988         kfree(cmp->dst_pages);
2989 }
2990
2991 static int btrfs_cmp_data_prepare(struct inode *src, u64 loff,
2992                                   struct inode *dst, u64 dst_loff,
2993                                   u64 len, struct cmp_pages *cmp)
2994 {
2995         int ret;
2996         int num_pages = PAGE_ALIGN(len) >> PAGE_SHIFT;
2997         struct page **src_pgarr, **dst_pgarr;
2998
2999         /*
3000          * We must gather up all the pages before we initiate our
3001          * extent locking. We use an array for the page pointers. Size
3002          * of the array is bounded by len, which is in turn bounded by
3003          * BTRFS_MAX_DEDUPE_LEN.
3004          */
3005         src_pgarr = kcalloc(num_pages, sizeof(struct page *), GFP_KERNEL);
3006         dst_pgarr = kcalloc(num_pages, sizeof(struct page *), GFP_KERNEL);
3007         if (!src_pgarr || !dst_pgarr) {
3008                 kfree(src_pgarr);
3009                 kfree(dst_pgarr);
3010                 return -ENOMEM;
3011         }
3012         cmp->num_pages = num_pages;
3013         cmp->src_pages = src_pgarr;
3014         cmp->dst_pages = dst_pgarr;
3015
3016         /*
3017          * If deduping ranges in the same inode, locking rules make it mandatory
3018          * to always lock pages in ascending order to avoid deadlocks with
3019          * concurrent tasks (such as starting writeback/delalloc).
3020          */
3021         if (src == dst && dst_loff < loff) {
3022                 swap(src_pgarr, dst_pgarr);
3023                 swap(loff, dst_loff);
3024         }
3025
3026         ret = gather_extent_pages(src, src_pgarr, cmp->num_pages, loff);
3027         if (ret)
3028                 goto out;
3029
3030         ret = gather_extent_pages(dst, dst_pgarr, cmp->num_pages, dst_loff);
3031
3032 out:
3033         if (ret)
3034                 btrfs_cmp_data_free(cmp);
3035         return ret;
3036 }
3037
3038 static int btrfs_cmp_data(u64 len, struct cmp_pages *cmp)
3039 {
3040         int ret = 0;
3041         int i;
3042         struct page *src_page, *dst_page;
3043         unsigned int cmp_len = PAGE_SIZE;
3044         void *addr, *dst_addr;
3045
3046         i = 0;
3047         while (len) {
3048                 if (len < PAGE_SIZE)
3049                         cmp_len = len;
3050
3051                 BUG_ON(i >= cmp->num_pages);
3052
3053                 src_page = cmp->src_pages[i];
3054                 dst_page = cmp->dst_pages[i];
3055                 ASSERT(PageLocked(src_page));
3056                 ASSERT(PageLocked(dst_page));
3057
3058                 addr = kmap_atomic(src_page);
3059                 dst_addr = kmap_atomic(dst_page);
3060
3061                 flush_dcache_page(src_page);
3062                 flush_dcache_page(dst_page);
3063
3064                 if (memcmp(addr, dst_addr, cmp_len))
3065                         ret = -EBADE;
3066
3067                 kunmap_atomic(addr);
3068                 kunmap_atomic(dst_addr);
3069
3070                 if (ret)
3071                         break;
3072
3073                 len -= cmp_len;
3074                 i++;
3075         }
3076
3077         return ret;
3078 }
3079
3080 static int extent_same_check_offsets(struct inode *inode, u64 off, u64 *plen,
3081                                      u64 olen)
3082 {
3083         u64 len = *plen;
3084         u64 bs = BTRFS_I(inode)->root->fs_info->sb->s_blocksize;
3085
3086         if (off + olen > inode->i_size || off + olen < off)
3087                 return -EINVAL;
3088
3089         /* if we extend to eof, continue to block boundary */
3090         if (off + len == inode->i_size)
3091                 *plen = len = ALIGN(inode->i_size, bs) - off;
3092
3093         /* Check that we are block aligned - btrfs_clone() requires this */
3094         if (!IS_ALIGNED(off, bs) || !IS_ALIGNED(off + len, bs))
3095                 return -EINVAL;
3096
3097         return 0;
3098 }
3099
3100 static int btrfs_extent_same(struct inode *src, u64 loff, u64 olen,
3101                              struct inode *dst, u64 dst_loff)
3102 {
3103         int ret;
3104         u64 len = olen;
3105         struct cmp_pages cmp;
3106         bool same_inode = (src == dst);
3107         u64 same_lock_start = 0;
3108         u64 same_lock_len = 0;
3109
3110         if (len == 0)
3111                 return 0;
3112
3113         if (same_inode)
3114                 inode_lock(src);
3115         else
3116                 btrfs_double_inode_lock(src, dst);
3117
3118         ret = extent_same_check_offsets(src, loff, &len, olen);
3119         if (ret)
3120                 goto out_unlock;
3121
3122         ret = extent_same_check_offsets(dst, dst_loff, &len, olen);
3123         if (ret)
3124                 goto out_unlock;
3125
3126         if (same_inode) {
3127                 /*
3128                  * Single inode case wants the same checks, except we
3129                  * don't want our length pushed out past i_size as
3130                  * comparing that data range makes no sense.
3131                  *
3132                  * extent_same_check_offsets() will do this for an
3133                  * unaligned length at i_size, so catch it here and
3134                  * reject the request.
3135                  *
3136                  * This effectively means we require aligned extents
3137                  * for the single-inode case, whereas the other cases
3138                  * allow an unaligned length so long as it ends at
3139                  * i_size.
3140                  */
3141                 if (len != olen) {
3142                         ret = -EINVAL;
3143                         goto out_unlock;
3144                 }
3145
3146                 /* Check for overlapping ranges */
3147                 if (dst_loff + len > loff && dst_loff < loff + len) {
3148                         ret = -EINVAL;
3149                         goto out_unlock;
3150                 }
3151
3152                 same_lock_start = min_t(u64, loff, dst_loff);
3153                 same_lock_len = max_t(u64, loff, dst_loff) + len - same_lock_start;
3154         }
3155
3156         /* don't make the dst file partly checksummed */
3157         if ((BTRFS_I(src)->flags & BTRFS_INODE_NODATASUM) !=
3158             (BTRFS_I(dst)->flags & BTRFS_INODE_NODATASUM)) {
3159                 ret = -EINVAL;
3160                 goto out_unlock;
3161         }
3162
3163 again:
3164         ret = btrfs_cmp_data_prepare(src, loff, dst, dst_loff, olen, &cmp);
3165         if (ret)
3166                 goto out_unlock;
3167
3168         if (same_inode)
3169                 ret = lock_extent_range(src, same_lock_start, same_lock_len,
3170                                         false);
3171         else
3172                 ret = btrfs_double_extent_lock(src, loff, dst, dst_loff, len,
3173                                                false);
3174         /*
3175          * If one of the inodes has dirty pages in the respective range or
3176          * ordered extents, we need to flush dellaloc and wait for all ordered
3177          * extents in the range. We must unlock the pages and the ranges in the
3178          * io trees to avoid deadlocks when flushing delalloc (requires locking
3179          * pages) and when waiting for ordered extents to complete (they require
3180          * range locking).
3181          */
3182         if (ret == -EAGAIN) {
3183                 /*
3184                  * Ranges in the io trees already unlocked. Now unlock all
3185                  * pages before waiting for all IO to complete.
3186                  */
3187                 btrfs_cmp_data_free(&cmp);
3188                 if (same_inode) {
3189                         btrfs_wait_ordered_range(src, same_lock_start,
3190                                                  same_lock_len);
3191                 } else {
3192                         btrfs_wait_ordered_range(src, loff, len);
3193                         btrfs_wait_ordered_range(dst, dst_loff, len);
3194                 }
3195                 goto again;
3196         }
3197         ASSERT(ret == 0);
3198         if (WARN_ON(ret)) {
3199                 /* ranges in the io trees already unlocked */
3200                 btrfs_cmp_data_free(&cmp);
3201                 return ret;
3202         }
3203
3204         /* pass original length for comparison so we stay within i_size */
3205         ret = btrfs_cmp_data(olen, &cmp);
3206         if (ret == 0)
3207                 ret = btrfs_clone(src, dst, loff, olen, len, dst_loff, 1);
3208
3209         if (same_inode)
3210                 unlock_extent(&BTRFS_I(src)->io_tree, same_lock_start,
3211                               same_lock_start + same_lock_len - 1);
3212         else
3213                 btrfs_double_extent_unlock(src, loff, dst, dst_loff, len);
3214
3215         btrfs_cmp_data_free(&cmp);
3216 out_unlock:
3217         if (same_inode)
3218                 inode_unlock(src);
3219         else
3220                 btrfs_double_inode_unlock(src, dst);
3221
3222         return ret;
3223 }
3224
3225 #define BTRFS_MAX_DEDUPE_LEN    SZ_16M
3226
3227 ssize_t btrfs_dedupe_file_range(struct file *src_file, u64 loff, u64 olen,
3228                                 struct file *dst_file, u64 dst_loff)
3229 {
3230         struct inode *src = file_inode(src_file);
3231         struct inode *dst = file_inode(dst_file);
3232         u64 bs = BTRFS_I(src)->root->fs_info->sb->s_blocksize;
3233         ssize_t res;
3234
3235         if (olen > BTRFS_MAX_DEDUPE_LEN)
3236                 olen = BTRFS_MAX_DEDUPE_LEN;
3237
3238         if (WARN_ON_ONCE(bs < PAGE_SIZE)) {
3239                 /*
3240                  * Btrfs does not support blocksize < page_size. As a
3241                  * result, btrfs_cmp_data() won't correctly handle
3242                  * this situation without an update.
3243                  */
3244                 return -EINVAL;
3245         }
3246
3247         res = btrfs_extent_same(src, loff, olen, dst, dst_loff);
3248         if (res)
3249                 return res;
3250         return olen;
3251 }
3252
3253 static int clone_finish_inode_update(struct btrfs_trans_handle *trans,
3254                                      struct inode *inode,
3255                                      u64 endoff,
3256                                      const u64 destoff,
3257                                      const u64 olen,
3258                                      int no_time_update)
3259 {
3260         struct btrfs_root *root = BTRFS_I(inode)->root;
3261         int ret;
3262
3263         inode_inc_iversion(inode);
3264         if (!no_time_update)
3265                 inode->i_mtime = inode->i_ctime = current_time(inode);
3266         /*
3267          * We round up to the block size at eof when determining which
3268          * extents to clone above, but shouldn't round up the file size.
3269          */
3270         if (endoff > destoff + olen)
3271                 endoff = destoff + olen;
3272         if (endoff > inode->i_size)
3273                 btrfs_i_size_write(BTRFS_I(inode), endoff);
3274
3275         ret = btrfs_update_inode(trans, root, inode);
3276         if (ret) {
3277                 btrfs_abort_transaction(trans, ret);
3278                 btrfs_end_transaction(trans);
3279                 goto out;
3280         }
3281         ret = btrfs_end_transaction(trans);
3282 out:
3283         return ret;
3284 }
3285
3286 static void clone_update_extent_map(struct btrfs_inode *inode,
3287                                     const struct btrfs_trans_handle *trans,
3288                                     const struct btrfs_path *path,
3289                                     const u64 hole_offset,
3290                                     const u64 hole_len)
3291 {
3292         struct extent_map_tree *em_tree = &inode->extent_tree;
3293         struct extent_map *em;
3294         int ret;
3295
3296         em = alloc_extent_map();
3297         if (!em) {
3298                 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &inode->runtime_flags);
3299                 return;
3300         }
3301
3302         if (path) {
3303                 struct btrfs_file_extent_item *fi;
3304
3305                 fi = btrfs_item_ptr(path->nodes[0], path->slots[0],
3306                                     struct btrfs_file_extent_item);
3307                 btrfs_extent_item_to_extent_map(inode, path, fi, false, em);
3308                 em->generation = -1;
3309                 if (btrfs_file_extent_type(path->nodes[0], fi) ==
3310                     BTRFS_FILE_EXTENT_INLINE)
3311                         set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
3312                                         &inode->runtime_flags);
3313         } else {
3314                 em->start = hole_offset;
3315                 em->len = hole_len;
3316                 em->ram_bytes = em->len;
3317                 em->orig_start = hole_offset;
3318                 em->block_start = EXTENT_MAP_HOLE;
3319                 em->block_len = 0;
3320                 em->orig_block_len = 0;
3321                 em->compress_type = BTRFS_COMPRESS_NONE;
3322                 em->generation = trans->transid;
3323         }
3324
3325         while (1) {
3326                 write_lock(&em_tree->lock);
3327                 ret = add_extent_mapping(em_tree, em, 1);
3328                 write_unlock(&em_tree->lock);
3329                 if (ret != -EEXIST) {
3330                         free_extent_map(em);
3331                         break;
3332                 }
3333                 btrfs_drop_extent_cache(inode, em->start,
3334                                         em->start + em->len - 1, 0);
3335         }
3336
3337         if (ret)
3338                 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &inode->runtime_flags);
3339 }
3340
3341 /*
3342  * Make sure we do not end up inserting an inline extent into a file that has
3343  * already other (non-inline) extents. If a file has an inline extent it can
3344  * not have any other extents and the (single) inline extent must start at the
3345  * file offset 0. Failing to respect these rules will lead to file corruption,
3346  * resulting in EIO errors on read/write operations, hitting BUG_ON's in mm, etc
3347  *
3348  * We can have extents that have been already written to disk or we can have
3349  * dirty ranges still in delalloc, in which case the extent maps and items are
3350  * created only when we run delalloc, and the delalloc ranges might fall outside
3351  * the range we are currently locking in the inode's io tree. So we check the
3352  * inode's i_size because of that (i_size updates are done while holding the
3353  * i_mutex, which we are holding here).
3354  * We also check to see if the inode has a size not greater than "datal" but has
3355  * extents beyond it, due to an fallocate with FALLOC_FL_KEEP_SIZE (and we are
3356  * protected against such concurrent fallocate calls by the i_mutex).
3357  *
3358  * If the file has no extents but a size greater than datal, do not allow the
3359  * copy because we would need turn the inline extent into a non-inline one (even
3360  * with NO_HOLES enabled). If we find our destination inode only has one inline
3361  * extent, just overwrite it with the source inline extent if its size is less
3362  * than the source extent's size, or we could copy the source inline extent's
3363  * data into the destination inode's inline extent if the later is greater then
3364  * the former.
3365  */
3366 static int clone_copy_inline_extent(struct inode *dst,
3367                                     struct btrfs_trans_handle *trans,
3368                                     struct btrfs_path *path,
3369                                     struct btrfs_key *new_key,
3370                                     const u64 drop_start,
3371                                     const u64 datal,
3372                                     const u64 skip,
3373                                     const u64 size,
3374                                     char *inline_data)
3375 {
3376         struct btrfs_fs_info *fs_info = btrfs_sb(dst->i_sb);
3377         struct btrfs_root *root = BTRFS_I(dst)->root;
3378         const u64 aligned_end = ALIGN(new_key->offset + datal,
3379                                       fs_info->sectorsize);
3380         int ret;
3381         struct btrfs_key key;
3382
3383         if (new_key->offset > 0)
3384                 return -EOPNOTSUPP;
3385
3386         key.objectid = btrfs_ino(BTRFS_I(dst));
3387         key.type = BTRFS_EXTENT_DATA_KEY;
3388         key.offset = 0;
3389         ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3390         if (ret < 0) {
3391                 return ret;
3392         } else if (ret > 0) {
3393                 if (path->slots[0] >= btrfs_header_nritems(path->nodes[0])) {
3394                         ret = btrfs_next_leaf(root, path);
3395                         if (ret < 0)
3396                                 return ret;
3397                         else if (ret > 0)
3398                                 goto copy_inline_extent;
3399                 }
3400                 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
3401                 if (key.objectid == btrfs_ino(BTRFS_I(dst)) &&
3402                     key.type == BTRFS_EXTENT_DATA_KEY) {
3403                         ASSERT(key.offset > 0);
3404                         return -EOPNOTSUPP;
3405                 }
3406         } else if (i_size_read(dst) <= datal) {
3407                 struct btrfs_file_extent_item *ei;
3408                 u64 ext_len;
3409
3410                 /*
3411                  * If the file size is <= datal, make sure there are no other
3412                  * extents following (can happen do to an fallocate call with
3413                  * the flag FALLOC_FL_KEEP_SIZE).
3414                  */
3415                 ei = btrfs_item_ptr(path->nodes[0], path->slots[0],
3416                                     struct btrfs_file_extent_item);
3417                 /*
3418                  * If it's an inline extent, it can not have other extents
3419                  * following it.
3420                  */
3421                 if (btrfs_file_extent_type(path->nodes[0], ei) ==
3422                     BTRFS_FILE_EXTENT_INLINE)
3423                         goto copy_inline_extent;
3424
3425                 ext_len = btrfs_file_extent_num_bytes(path->nodes[0], ei);
3426                 if (ext_len > aligned_end)
3427                         return -EOPNOTSUPP;
3428
3429                 ret = btrfs_next_item(root, path);
3430                 if (ret < 0) {
3431                         return ret;
3432                 } else if (ret == 0) {
3433                         btrfs_item_key_to_cpu(path->nodes[0], &key,
3434                                               path->slots[0]);
3435                         if (key.objectid == btrfs_ino(BTRFS_I(dst)) &&
3436                             key.type == BTRFS_EXTENT_DATA_KEY)
3437                                 return -EOPNOTSUPP;
3438                 }
3439         }
3440
3441 copy_inline_extent:
3442         /*
3443          * We have no extent items, or we have an extent at offset 0 which may
3444          * or may not be inlined. All these cases are dealt the same way.
3445          */
3446         if (i_size_read(dst) > datal) {
3447                 /*
3448                  * If the destination inode has an inline extent...
3449                  * This would require copying the data from the source inline
3450                  * extent into the beginning of the destination's inline extent.
3451                  * But this is really complex, both extents can be compressed
3452                  * or just one of them, which would require decompressing and
3453                  * re-compressing data (which could increase the new compressed
3454                  * size, not allowing the compressed data to fit anymore in an
3455                  * inline extent).
3456                  * So just don't support this case for now (it should be rare,
3457                  * we are not really saving space when cloning inline extents).
3458                  */
3459                 return -EOPNOTSUPP;
3460         }
3461
3462         btrfs_release_path(path);
3463         ret = btrfs_drop_extents(trans, root, dst, drop_start, aligned_end, 1);
3464         if (ret)
3465                 return ret;
3466         ret = btrfs_insert_empty_item(trans, root, path, new_key, size);
3467         if (ret)
3468                 return ret;
3469
3470         if (skip) {
3471                 const u32 start = btrfs_file_extent_calc_inline_size(0);
3472
3473                 memmove(inline_data + start, inline_data + start + skip, datal);
3474         }
3475
3476         write_extent_buffer(path->nodes[0], inline_data,
3477                             btrfs_item_ptr_offset(path->nodes[0],
3478                                                   path->slots[0]),
3479                             size);
3480         inode_add_bytes(dst, datal);
3481
3482         return 0;
3483 }
3484
3485 /**
3486  * btrfs_clone() - clone a range from inode file to another
3487  *
3488  * @src: Inode to clone from
3489  * @inode: Inode to clone to
3490  * @off: Offset within source to start clone from
3491  * @olen: Original length, passed by user, of range to clone
3492  * @olen_aligned: Block-aligned value of olen
3493  * @destoff: Offset within @inode to start clone
3494  * @no_time_update: Whether to update mtime/ctime on the target inode
3495  */
3496 static int btrfs_clone(struct inode *src, struct inode *inode,
3497                        const u64 off, const u64 olen, const u64 olen_aligned,
3498                        const u64 destoff, int no_time_update)
3499 {
3500         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3501         struct btrfs_root *root = BTRFS_I(inode)->root;
3502         struct btrfs_path *path = NULL;
3503         struct extent_buffer *leaf;
3504         struct btrfs_trans_handle *trans;
3505         char *buf = NULL;
3506         struct btrfs_key key;
3507         u32 nritems;
3508         int slot;
3509         int ret;
3510         const u64 len = olen_aligned;
3511         u64 last_dest_end = destoff;
3512
3513         ret = -ENOMEM;
3514         buf = kvmalloc(fs_info->nodesize, GFP_KERNEL);
3515         if (!buf)
3516                 return ret;
3517
3518         path = btrfs_alloc_path();
3519         if (!path) {
3520                 kvfree(buf);
3521                 return ret;
3522         }
3523
3524         path->reada = READA_FORWARD;
3525         /* clone data */
3526         key.objectid = btrfs_ino(BTRFS_I(src));
3527         key.type = BTRFS_EXTENT_DATA_KEY;
3528         key.offset = off;
3529
3530         while (1) {
3531                 u64 next_key_min_offset = key.offset + 1;
3532
3533                 /*
3534                  * note the key will change type as we walk through the
3535                  * tree.
3536                  */
3537                 path->leave_spinning = 1;
3538                 ret = btrfs_search_slot(NULL, BTRFS_I(src)->root, &key, path,
3539                                 0, 0);
3540                 if (ret < 0)
3541                         goto out;
3542                 /*
3543                  * First search, if no extent item that starts at offset off was
3544                  * found but the previous item is an extent item, it's possible
3545                  * it might overlap our target range, therefore process it.
3546                  */
3547                 if (key.offset == off && ret > 0 && path->slots[0] > 0) {
3548                         btrfs_item_key_to_cpu(path->nodes[0], &key,
3549                                               path->slots[0] - 1);
3550                         if (key.type == BTRFS_EXTENT_DATA_KEY)
3551                                 path->slots[0]--;
3552                 }
3553
3554                 nritems = btrfs_header_nritems(path->nodes[0]);
3555 process_slot:
3556                 if (path->slots[0] >= nritems) {
3557                         ret = btrfs_next_leaf(BTRFS_I(src)->root, path);
3558                         if (ret < 0)
3559                                 goto out;
3560                         if (ret > 0)
3561                                 break;
3562                         nritems = btrfs_header_nritems(path->nodes[0]);
3563                 }
3564                 leaf = path->nodes[0];
3565                 slot = path->slots[0];
3566
3567                 btrfs_item_key_to_cpu(leaf, &key, slot);
3568                 if (key.type > BTRFS_EXTENT_DATA_KEY ||
3569                     key.objectid != btrfs_ino(BTRFS_I(src)))
3570                         break;
3571
3572                 if (key.type == BTRFS_EXTENT_DATA_KEY) {
3573                         struct btrfs_file_extent_item *extent;
3574                         int type;
3575                         u32 size;
3576                         struct btrfs_key new_key;
3577                         u64 disko = 0, diskl = 0;
3578                         u64 datao = 0, datal = 0;
3579                         u8 comp;
3580                         u64 drop_start;
3581
3582                         extent = btrfs_item_ptr(leaf, slot,
3583                                                 struct btrfs_file_extent_item);
3584                         comp = btrfs_file_extent_compression(leaf, extent);
3585                         type = btrfs_file_extent_type(leaf, extent);
3586                         if (type == BTRFS_FILE_EXTENT_REG ||
3587                             type == BTRFS_FILE_EXTENT_PREALLOC) {
3588                                 disko = btrfs_file_extent_disk_bytenr(leaf,
3589                                                                       extent);
3590                                 diskl = btrfs_file_extent_disk_num_bytes(leaf,
3591                                                                  extent);
3592                                 datao = btrfs_file_extent_offset(leaf, extent);
3593                                 datal = btrfs_file_extent_num_bytes(leaf,
3594                                                                     extent);
3595                         } else if (type == BTRFS_FILE_EXTENT_INLINE) {
3596                                 /* take upper bound, may be compressed */
3597                                 datal = btrfs_file_extent_ram_bytes(leaf,
3598                                                                     extent);
3599                         }
3600
3601                         /*
3602                          * The first search might have left us at an extent
3603                          * item that ends before our target range's start, can
3604                          * happen if we have holes and NO_HOLES feature enabled.
3605                          */
3606                         if (key.offset + datal <= off) {
3607                                 path->slots[0]++;
3608                                 goto process_slot;
3609                         } else if (key.offset >= off + len) {
3610                                 break;
3611                         }
3612                         next_key_min_offset = key.offset + datal;
3613                         size = btrfs_item_size_nr(leaf, slot);
3614                         read_extent_buffer(leaf, buf,
3615                                            btrfs_item_ptr_offset(leaf, slot),
3616                                            size);
3617
3618                         btrfs_release_path(path);
3619                         path->leave_spinning = 0;
3620
3621                         memcpy(&new_key, &key, sizeof(new_key));
3622                         new_key.objectid = btrfs_ino(BTRFS_I(inode));
3623                         if (off <= key.offset)
3624                                 new_key.offset = key.offset + destoff - off;
3625                         else
3626                                 new_key.offset = destoff;
3627
3628                         /*
3629                          * Deal with a hole that doesn't have an extent item
3630                          * that represents it (NO_HOLES feature enabled).
3631                          * This hole is either in the middle of the cloning
3632                          * range or at the beginning (fully overlaps it or
3633                          * partially overlaps it).
3634                          */
3635                         if (new_key.offset != last_dest_end)
3636                                 drop_start = last_dest_end;
3637                         else
3638                                 drop_start = new_key.offset;
3639
3640                         /*
3641                          * 1 - adjusting old extent (we may have to split it)
3642                          * 1 - add new extent
3643                          * 1 - inode update
3644                          */
3645                         trans = btrfs_start_transaction(root, 3);
3646                         if (IS_ERR(trans)) {
3647                                 ret = PTR_ERR(trans);
3648                                 goto out;
3649                         }
3650
3651                         if (type == BTRFS_FILE_EXTENT_REG ||
3652                             type == BTRFS_FILE_EXTENT_PREALLOC) {
3653                                 /*
3654                                  *    a  | --- range to clone ---|  b
3655                                  * | ------------- extent ------------- |
3656                                  */
3657
3658                                 /* subtract range b */
3659                                 if (key.offset + datal > off + len)
3660                                         datal = off + len - key.offset;
3661
3662                                 /* subtract range a */
3663                                 if (off > key.offset) {
3664                                         datao += off - key.offset;
3665                                         datal -= off - key.offset;
3666                                 }
3667
3668                                 ret = btrfs_drop_extents(trans, root, inode,
3669                                                          drop_start,
3670                                                          new_key.offset + datal,
3671                                                          1);
3672                                 if (ret) {
3673                                         if (ret != -EOPNOTSUPP)
3674                                                 btrfs_abort_transaction(trans,
3675                                                                         ret);
3676                                         btrfs_end_transaction(trans);
3677                                         goto out;
3678                                 }
3679
3680                                 ret = btrfs_insert_empty_item(trans, root, path,
3681                                                               &new_key, size);
3682                                 if (ret) {
3683                                         btrfs_abort_transaction(trans, ret);
3684                                         btrfs_end_transaction(trans);
3685                                         goto out;
3686                                 }
3687
3688                                 leaf = path->nodes[0];
3689                                 slot = path->slots[0];
3690                                 write_extent_buffer(leaf, buf,
3691                                             btrfs_item_ptr_offset(leaf, slot),
3692                                             size);
3693
3694                                 extent = btrfs_item_ptr(leaf, slot,
3695                                                 struct btrfs_file_extent_item);
3696
3697                                 /* disko == 0 means it's a hole */
3698                                 if (!disko)
3699                                         datao = 0;
3700
3701                                 btrfs_set_file_extent_offset(leaf, extent,
3702                                                              datao);
3703                                 btrfs_set_file_extent_num_bytes(leaf, extent,
3704                                                                 datal);
3705
3706                                 if (disko) {
3707                                         inode_add_bytes(inode, datal);
3708                                         ret = btrfs_inc_extent_ref(trans,
3709                                                         fs_info,
3710                                                         disko, diskl, 0,
3711                                                         root->root_key.objectid,
3712                                                         btrfs_ino(BTRFS_I(inode)),
3713                                                         new_key.offset - datao);
3714                                         if (ret) {
3715                                                 btrfs_abort_transaction(trans,
3716                                                                         ret);
3717                                                 btrfs_end_transaction(trans);
3718                                                 goto out;
3719
3720                                         }
3721                                 }
3722                         } else if (type == BTRFS_FILE_EXTENT_INLINE) {
3723                                 u64 skip = 0;
3724                                 u64 trim = 0;
3725
3726                                 if (off > key.offset) {
3727                                         skip = off - key.offset;
3728                                         new_key.offset += skip;
3729                                 }
3730
3731                                 if (key.offset + datal > off + len)
3732                                         trim = key.offset + datal - (off + len);
3733
3734                                 if (comp && (skip || trim)) {
3735                                         ret = -EINVAL;
3736                                         btrfs_end_transaction(trans);
3737                                         goto out;
3738                                 }
3739                                 size -= skip + trim;
3740                                 datal -= skip + trim;
3741
3742                                 ret = clone_copy_inline_extent(inode,
3743                                                                trans, path,
3744                                                                &new_key,
3745                                                                drop_start,
3746                                                                datal,
3747                                                                skip, size, buf);
3748                                 if (ret) {
3749                                         if (ret != -EOPNOTSUPP)
3750                                                 btrfs_abort_transaction(trans,
3751                                                                         ret);
3752                                         btrfs_end_transaction(trans);
3753                                         goto out;
3754                                 }
3755                                 leaf = path->nodes[0];
3756                                 slot = path->slots[0];
3757                         }
3758
3759                         /* If we have an implicit hole (NO_HOLES feature). */
3760                         if (drop_start < new_key.offset)
3761                                 clone_update_extent_map(BTRFS_I(inode), trans,
3762                                                 NULL, drop_start,
3763                                                 new_key.offset - drop_start);
3764
3765                         clone_update_extent_map(BTRFS_I(inode), trans,
3766                                         path, 0, 0);
3767
3768                         btrfs_mark_buffer_dirty(leaf);
3769                         btrfs_release_path(path);
3770
3771                         last_dest_end = ALIGN(new_key.offset + datal,
3772                                               fs_info->sectorsize);
3773                         ret = clone_finish_inode_update(trans, inode,
3774                                                         last_dest_end,
3775                                                         destoff, olen,
3776                                                         no_time_update);
3777                         if (ret)
3778                                 goto out;
3779                         if (new_key.offset + datal >= destoff + len)
3780                                 break;
3781                 }
3782                 btrfs_release_path(path);
3783                 key.offset = next_key_min_offset;
3784
3785                 if (fatal_signal_pending(current)) {
3786                         ret = -EINTR;
3787                         goto out;
3788                 }
3789         }
3790         ret = 0;
3791
3792         if (last_dest_end < destoff + len) {
3793                 /*
3794                  * We have an implicit hole (NO_HOLES feature is enabled) that
3795                  * fully or partially overlaps our cloning range at its end.
3796                  */
3797                 btrfs_release_path(path);
3798
3799                 /*
3800                  * 1 - remove extent(s)
3801                  * 1 - inode update
3802                  */
3803                 trans = btrfs_start_transaction(root, 2);
3804                 if (IS_ERR(trans)) {
3805                         ret = PTR_ERR(trans);
3806                         goto out;
3807                 }
3808                 ret = btrfs_drop_extents(trans, root, inode,
3809                                          last_dest_end, destoff + len, 1);
3810                 if (ret) {
3811                         if (ret != -EOPNOTSUPP)
3812                                 btrfs_abort_transaction(trans, ret);
3813                         btrfs_end_transaction(trans);
3814                         goto out;
3815                 }
3816                 clone_update_extent_map(BTRFS_I(inode), trans, NULL,
3817                                 last_dest_end,
3818                                 destoff + len - last_dest_end);
3819                 ret = clone_finish_inode_update(trans, inode, destoff + len,
3820                                                 destoff, olen, no_time_update);
3821         }
3822
3823 out:
3824         btrfs_free_path(path);
3825         kvfree(buf);
3826         return ret;
3827 }
3828
3829 static noinline int btrfs_clone_files(struct file *file, struct file *file_src,
3830                                         u64 off, u64 olen, u64 destoff)
3831 {
3832         struct inode *inode = file_inode(file);
3833         struct inode *src = file_inode(file_src);
3834         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3835         struct btrfs_root *root = BTRFS_I(inode)->root;
3836         int ret;
3837         u64 len = olen;
3838         u64 bs = fs_info->sb->s_blocksize;
3839         int same_inode = src == inode;
3840
3841         /*
3842          * TODO:
3843          * - split compressed inline extents.  annoying: we need to
3844          *   decompress into destination's address_space (the file offset
3845          *   may change, so source mapping won't do), then recompress (or
3846          *   otherwise reinsert) a subrange.
3847          *
3848          * - split destination inode's inline extents.  The inline extents can
3849          *   be either compressed or non-compressed.
3850          */
3851
3852         if (btrfs_root_readonly(root))
3853                 return -EROFS;
3854
3855         if (file_src->f_path.mnt != file->f_path.mnt ||
3856             src->i_sb != inode->i_sb)
3857                 return -EXDEV;
3858
3859         /* don't make the dst file partly checksummed */
3860         if ((BTRFS_I(src)->flags & BTRFS_INODE_NODATASUM) !=
3861             (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM))
3862                 return -EINVAL;
3863
3864         if (S_ISDIR(src->i_mode) || S_ISDIR(inode->i_mode))
3865                 return -EISDIR;
3866
3867         if (!same_inode) {
3868                 btrfs_double_inode_lock(src, inode);
3869         } else {
3870                 inode_lock(src);
3871         }
3872
3873         /* determine range to clone */
3874         ret = -EINVAL;
3875         if (off + len > src->i_size || off + len < off)
3876                 goto out_unlock;
3877         if (len == 0)
3878                 olen = len = src->i_size - off;
3879         /* if we extend to eof, continue to block boundary */
3880         if (off + len == src->i_size)
3881                 len = ALIGN(src->i_size, bs) - off;
3882
3883         if (len == 0) {
3884                 ret = 0;
3885                 goto out_unlock;
3886         }
3887
3888         /* verify the end result is block aligned */
3889         if (!IS_ALIGNED(off, bs) || !IS_ALIGNED(off + len, bs) ||
3890             !IS_ALIGNED(destoff, bs))
3891                 goto out_unlock;
3892
3893         /* verify if ranges are overlapped within the same file */
3894         if (same_inode) {
3895                 if (destoff + len > off && destoff < off + len)
3896                         goto out_unlock;
3897         }
3898
3899         if (destoff > inode->i_size) {
3900                 ret = btrfs_cont_expand(inode, inode->i_size, destoff);
3901                 if (ret)
3902                         goto out_unlock;
3903         }
3904
3905         /*
3906          * Lock the target range too. Right after we replace the file extent
3907          * items in the fs tree (which now point to the cloned data), we might
3908          * have a worker replace them with extent items relative to a write
3909          * operation that was issued before this clone operation (i.e. confront
3910          * with inode.c:btrfs_finish_ordered_io).
3911          */
3912         if (same_inode) {
3913                 u64 lock_start = min_t(u64, off, destoff);
3914                 u64 lock_len = max_t(u64, off, destoff) + len - lock_start;
3915
3916                 ret = lock_extent_range(src, lock_start, lock_len, true);
3917         } else {
3918                 ret = btrfs_double_extent_lock(src, off, inode, destoff, len,
3919                                                true);
3920         }
3921         ASSERT(ret == 0);
3922         if (WARN_ON(ret)) {
3923                 /* ranges in the io trees already unlocked */
3924                 goto out_unlock;
3925         }
3926
3927         ret = btrfs_clone(src, inode, off, olen, len, destoff, 0);
3928
3929         if (same_inode) {
3930                 u64 lock_start = min_t(u64, off, destoff);
3931                 u64 lock_end = max_t(u64, off, destoff) + len - 1;
3932
3933                 unlock_extent(&BTRFS_I(src)->io_tree, lock_start, lock_end);
3934         } else {
3935                 btrfs_double_extent_unlock(src, off, inode, destoff, len);
3936         }
3937         /*
3938          * Truncate page cache pages so that future reads will see the cloned
3939          * data immediately and not the previous data.
3940          */
3941         truncate_inode_pages_range(&inode->i_data,
3942                                 round_down(destoff, PAGE_SIZE),
3943                                 round_up(destoff + len, PAGE_SIZE) - 1);
3944 out_unlock:
3945         if (!same_inode)
3946                 btrfs_double_inode_unlock(src, inode);
3947         else
3948                 inode_unlock(src);
3949         return ret;
3950 }
3951
3952 int btrfs_clone_file_range(struct file *src_file, loff_t off,
3953                 struct file *dst_file, loff_t destoff, u64 len)
3954 {
3955         return btrfs_clone_files(dst_file, src_file, off, len, destoff);
3956 }
3957
3958 /*
3959  * there are many ways the trans_start and trans_end ioctls can lead
3960  * to deadlocks.  They should only be used by applications that
3961  * basically own the machine, and have a very in depth understanding
3962  * of all the possible deadlocks and enospc problems.
3963  */
3964 static long btrfs_ioctl_trans_start(struct file *file)
3965 {
3966         struct inode *inode = file_inode(file);
3967         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3968         struct btrfs_root *root = BTRFS_I(inode)->root;
3969         struct btrfs_trans_handle *trans;
3970         struct btrfs_file_private *private;
3971         int ret;
3972         static bool warned = false;
3973
3974         ret = -EPERM;
3975         if (!capable(CAP_SYS_ADMIN))
3976                 goto out;
3977
3978         if (!warned) {
3979                 btrfs_warn(fs_info,
3980                         "Userspace transaction mechanism is considered "
3981                         "deprecated and slated to be removed in 4.17. "
3982                         "If you have a valid use case please "
3983                         "speak up on the mailing list");
3984                 WARN_ON(1);
3985                 warned = true;
3986         }
3987
3988         ret = -EINPROGRESS;
3989         private = file->private_data;
3990         if (private && private->trans)
3991                 goto out;
3992         if (!private) {
3993                 private = kzalloc(sizeof(struct btrfs_file_private),
3994                                   GFP_KERNEL);
3995                 if (!private)
3996                         return -ENOMEM;
3997                 file->private_data = private;
3998         }
3999
4000         ret = -EROFS;
4001         if (btrfs_root_readonly(root))
4002                 goto out;
4003
4004         ret = mnt_want_write_file(file);
4005         if (ret)
4006                 goto out;
4007
4008         atomic_inc(&fs_info->open_ioctl_trans);
4009
4010         ret = -ENOMEM;
4011         trans = btrfs_start_ioctl_transaction(root);
4012         if (IS_ERR(trans))
4013                 goto out_drop;
4014
4015         private->trans = trans;
4016         return 0;
4017
4018 out_drop:
4019         atomic_dec(&fs_info->open_ioctl_trans);
4020         mnt_drop_write_file(file);
4021 out:
4022         return ret;
4023 }
4024
4025 static long btrfs_ioctl_default_subvol(struct file *file, void __user *argp)
4026 {
4027         struct inode *inode = file_inode(file);
4028         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4029         struct btrfs_root *root = BTRFS_I(inode)->root;
4030         struct btrfs_root *new_root;
4031         struct btrfs_dir_item *di;
4032         struct btrfs_trans_handle *trans;
4033         struct btrfs_path *path;
4034         struct btrfs_key location;
4035         struct btrfs_disk_key disk_key;
4036         u64 objectid = 0;
4037         u64 dir_id;
4038         int ret;
4039
4040         if (!capable(CAP_SYS_ADMIN))
4041                 return -EPERM;
4042
4043         ret = mnt_want_write_file(file);
4044         if (ret)
4045                 return ret;
4046
4047         if (copy_from_user(&objectid, argp, sizeof(objectid))) {
4048                 ret = -EFAULT;
4049                 goto out;
4050         }
4051
4052         if (!objectid)
4053                 objectid = BTRFS_FS_TREE_OBJECTID;
4054
4055         location.objectid = objectid;
4056         location.type = BTRFS_ROOT_ITEM_KEY;
4057         location.offset = (u64)-1;
4058
4059         new_root = btrfs_read_fs_root_no_name(fs_info, &location);
4060         if (IS_ERR(new_root)) {
4061                 ret = PTR_ERR(new_root);
4062                 goto out;
4063         }
4064         if (!is_fstree(new_root->objectid)) {
4065                 ret = -ENOENT;
4066                 goto out;
4067         }
4068
4069         path = btrfs_alloc_path();
4070         if (!path) {
4071                 ret = -ENOMEM;
4072                 goto out;
4073         }
4074         path->leave_spinning = 1;
4075
4076         trans = btrfs_start_transaction(root, 1);
4077         if (IS_ERR(trans)) {
4078                 btrfs_free_path(path);
4079                 ret = PTR_ERR(trans);
4080                 goto out;
4081         }
4082
4083         dir_id = btrfs_super_root_dir(fs_info->super_copy);
4084         di = btrfs_lookup_dir_item(trans, fs_info->tree_root, path,
4085                                    dir_id, "default", 7, 1);
4086         if (IS_ERR_OR_NULL(di)) {
4087                 btrfs_free_path(path);
4088                 btrfs_end_transaction(trans);
4089                 btrfs_err(fs_info,
4090                           "Umm, you don't have the default diritem, this isn't going to work");
4091                 ret = -ENOENT;
4092                 goto out;
4093         }
4094
4095         btrfs_cpu_key_to_disk(&disk_key, &new_root->root_key);
4096         btrfs_set_dir_item_key(path->nodes[0], di, &disk_key);
4097         btrfs_mark_buffer_dirty(path->nodes[0]);
4098         btrfs_free_path(path);
4099
4100         btrfs_set_fs_incompat(fs_info, DEFAULT_SUBVOL);
4101         btrfs_end_transaction(trans);
4102 out:
4103         mnt_drop_write_file(file);
4104         return ret;
4105 }
4106
4107 void btrfs_get_block_group_info(struct list_head *groups_list,
4108                                 struct btrfs_ioctl_space_info *space)
4109 {
4110         struct btrfs_block_group_cache *block_group;
4111
4112         space->total_bytes = 0;
4113         space->used_bytes = 0;
4114         space->flags = 0;
4115         list_for_each_entry(block_group, groups_list, list) {
4116                 space->flags = block_group->flags;
4117                 space->total_bytes += block_group->key.offset;
4118                 space->used_bytes +=
4119                         btrfs_block_group_used(&block_group->item);
4120         }
4121 }
4122
4123 static long btrfs_ioctl_space_info(struct btrfs_fs_info *fs_info,
4124                                    void __user *arg)
4125 {
4126         struct btrfs_ioctl_space_args space_args;
4127         struct btrfs_ioctl_space_info space;
4128         struct btrfs_ioctl_space_info *dest;
4129         struct btrfs_ioctl_space_info *dest_orig;
4130         struct btrfs_ioctl_space_info __user *user_dest;
4131         struct btrfs_space_info *info;
4132         u64 types[] = {BTRFS_BLOCK_GROUP_DATA,
4133                        BTRFS_BLOCK_GROUP_SYSTEM,
4134                        BTRFS_BLOCK_GROUP_METADATA,
4135                        BTRFS_BLOCK_GROUP_DATA | BTRFS_BLOCK_GROUP_METADATA};
4136         int num_types = 4;
4137         int alloc_size;
4138         int ret = 0;
4139         u64 slot_count = 0;
4140         int i, c;
4141
4142         if (copy_from_user(&space_args,
4143                            (struct btrfs_ioctl_space_args __user *)arg,
4144                            sizeof(space_args)))
4145                 return -EFAULT;
4146
4147         for (i = 0; i < num_types; i++) {
4148                 struct btrfs_space_info *tmp;
4149
4150                 info = NULL;
4151                 rcu_read_lock();
4152                 list_for_each_entry_rcu(tmp, &fs_info->space_info,
4153                                         list) {
4154                         if (tmp->flags == types[i]) {
4155                                 info = tmp;
4156                                 break;
4157                         }
4158                 }
4159                 rcu_read_unlock();
4160
4161                 if (!info)
4162                         continue;
4163
4164                 down_read(&info->groups_sem);
4165                 for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) {
4166                         if (!list_empty(&info->block_groups[c]))
4167                                 slot_count++;
4168                 }
4169                 up_read(&info->groups_sem);
4170         }
4171
4172         /*
4173          * Global block reserve, exported as a space_info
4174          */
4175         slot_count++;
4176
4177         /* space_slots == 0 means they are asking for a count */
4178         if (space_args.space_slots == 0) {
4179                 space_args.total_spaces = slot_count;
4180                 goto out;
4181         }
4182
4183         slot_count = min_t(u64, space_args.space_slots, slot_count);
4184
4185         alloc_size = sizeof(*dest) * slot_count;
4186
4187         /* we generally have at most 6 or so space infos, one for each raid
4188          * level.  So, a whole page should be more than enough for everyone
4189          */
4190         if (alloc_size > PAGE_SIZE)
4191                 return -ENOMEM;
4192
4193         space_args.total_spaces = 0;
4194         dest = kmalloc(alloc_size, GFP_KERNEL);
4195         if (!dest)
4196                 return -ENOMEM;
4197         dest_orig = dest;
4198
4199         /* now we have a buffer to copy into */
4200         for (i = 0; i < num_types; i++) {
4201                 struct btrfs_space_info *tmp;
4202
4203                 if (!slot_count)
4204                         break;
4205
4206                 info = NULL;
4207                 rcu_read_lock();
4208                 list_for_each_entry_rcu(tmp, &fs_info->space_info,
4209                                         list) {
4210                         if (tmp->flags == types[i]) {
4211                                 info = tmp;
4212                                 break;
4213                         }
4214                 }
4215                 rcu_read_unlock();
4216
4217                 if (!info)
4218                         continue;
4219                 down_read(&info->groups_sem);
4220                 for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) {
4221                         if (!list_empty(&info->block_groups[c])) {
4222                                 btrfs_get_block_group_info(
4223                                         &info->block_groups[c], &space);
4224                                 memcpy(dest, &space, sizeof(space));
4225                                 dest++;
4226                                 space_args.total_spaces++;
4227                                 slot_count--;
4228                         }
4229                         if (!slot_count)
4230                                 break;
4231                 }
4232                 up_read(&info->groups_sem);
4233         }
4234
4235         /*
4236          * Add global block reserve
4237          */
4238         if (slot_count) {
4239                 struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
4240
4241                 spin_lock(&block_rsv->lock);
4242                 space.total_bytes = block_rsv->size;
4243                 space.used_bytes = block_rsv->size - block_rsv->reserved;
4244                 spin_unlock(&block_rsv->lock);
4245                 space.flags = BTRFS_SPACE_INFO_GLOBAL_RSV;
4246                 memcpy(dest, &space, sizeof(space));
4247                 space_args.total_spaces++;
4248         }
4249
4250         user_dest = (struct btrfs_ioctl_space_info __user *)
4251                 (arg + sizeof(struct btrfs_ioctl_space_args));
4252
4253         if (copy_to_user(user_dest, dest_orig, alloc_size))
4254                 ret = -EFAULT;
4255
4256         kfree(dest_orig);
4257 out:
4258         if (ret == 0 && copy_to_user(arg, &space_args, sizeof(space_args)))
4259                 ret = -EFAULT;
4260
4261         return ret;
4262 }
4263
4264 /*
4265  * there are many ways the trans_start and trans_end ioctls can lead
4266  * to deadlocks.  They should only be used by applications that
4267  * basically own the machine, and have a very in depth understanding
4268  * of all the possible deadlocks and enospc problems.
4269  */
4270 long btrfs_ioctl_trans_end(struct file *file)
4271 {
4272         struct inode *inode = file_inode(file);
4273         struct btrfs_root *root = BTRFS_I(inode)->root;
4274         struct btrfs_file_private *private = file->private_data;
4275
4276         if (!private || !private->trans)
4277                 return -EINVAL;
4278
4279         btrfs_end_transaction(private->trans);
4280         private->trans = NULL;
4281
4282         atomic_dec(&root->fs_info->open_ioctl_trans);
4283
4284         mnt_drop_write_file(file);
4285         return 0;
4286 }
4287
4288 static noinline long btrfs_ioctl_start_sync(struct btrfs_root *root,
4289                                             void __user *argp)
4290 {
4291         struct btrfs_trans_handle *trans;
4292         u64 transid;
4293         int ret;
4294
4295         trans = btrfs_attach_transaction_barrier(root);
4296         if (IS_ERR(trans)) {
4297                 if (PTR_ERR(trans) != -ENOENT)
4298                         return PTR_ERR(trans);
4299
4300                 /* No running transaction, don't bother */
4301                 transid = root->fs_info->last_trans_committed;
4302                 goto out;
4303         }
4304         transid = trans->transid;
4305         ret = btrfs_commit_transaction_async(trans, 0);
4306         if (ret) {
4307                 btrfs_end_transaction(trans);
4308                 return ret;
4309         }
4310 out:
4311         if (argp)
4312                 if (copy_to_user(argp, &transid, sizeof(transid)))
4313                         return -EFAULT;
4314         return 0;
4315 }
4316
4317 static noinline long btrfs_ioctl_wait_sync(struct btrfs_fs_info *fs_info,
4318                                            void __user *argp)
4319 {
4320         u64 transid;
4321
4322         if (argp) {
4323                 if (copy_from_user(&transid, argp, sizeof(transid)))
4324                         return -EFAULT;
4325         } else {
4326                 transid = 0;  /* current trans */
4327         }
4328         return btrfs_wait_for_commit(fs_info, transid);
4329 }
4330
4331 static long btrfs_ioctl_scrub(struct file *file, void __user *arg)
4332 {
4333         struct btrfs_fs_info *fs_info = btrfs_sb(file_inode(file)->i_sb);
4334         struct btrfs_ioctl_scrub_args *sa;
4335         int ret;
4336
4337         if (!capable(CAP_SYS_ADMIN))
4338                 return -EPERM;
4339
4340         sa = memdup_user(arg, sizeof(*sa));
4341         if (IS_ERR(sa))
4342                 return PTR_ERR(sa);
4343
4344         if (!(sa->flags & BTRFS_SCRUB_READONLY)) {
4345                 ret = mnt_want_write_file(file);
4346                 if (ret)
4347                         goto out;
4348         }
4349
4350         ret = btrfs_scrub_dev(fs_info, sa->devid, sa->start, sa->end,
4351                               &sa->progress, sa->flags & BTRFS_SCRUB_READONLY,
4352                               0);
4353
4354         if (copy_to_user(arg, sa, sizeof(*sa)))
4355                 ret = -EFAULT;
4356
4357         if (!(sa->flags & BTRFS_SCRUB_READONLY))
4358                 mnt_drop_write_file(file);
4359 out:
4360         kfree(sa);
4361         return ret;
4362 }
4363
4364 static long btrfs_ioctl_scrub_cancel(struct btrfs_fs_info *fs_info)
4365 {
4366         if (!capable(CAP_SYS_ADMIN))
4367                 return -EPERM;
4368
4369         return btrfs_scrub_cancel(fs_info);
4370 }
4371
4372 static long btrfs_ioctl_scrub_progress(struct btrfs_fs_info *fs_info,
4373                                        void __user *arg)
4374 {
4375         struct btrfs_ioctl_scrub_args *sa;
4376         int ret;
4377
4378         if (!capable(CAP_SYS_ADMIN))
4379                 return -EPERM;
4380
4381         sa = memdup_user(arg, sizeof(*sa));
4382         if (IS_ERR(sa))
4383                 return PTR_ERR(sa);
4384
4385         ret = btrfs_scrub_progress(fs_info, sa->devid, &sa->progress);
4386
4387         if (copy_to_user(arg, sa, sizeof(*sa)))
4388                 ret = -EFAULT;
4389
4390         kfree(sa);
4391         return ret;
4392 }
4393
4394 static long btrfs_ioctl_get_dev_stats(struct btrfs_fs_info *fs_info,
4395                                       void __user *arg)
4396 {
4397         struct btrfs_ioctl_get_dev_stats *sa;
4398         int ret;
4399
4400         sa = memdup_user(arg, sizeof(*sa));
4401         if (IS_ERR(sa))
4402                 return PTR_ERR(sa);
4403
4404         if ((sa->flags & BTRFS_DEV_STATS_RESET) && !capable(CAP_SYS_ADMIN)) {
4405                 kfree(sa);
4406                 return -EPERM;
4407         }
4408
4409         ret = btrfs_get_dev_stats(fs_info, sa);
4410
4411         if (copy_to_user(arg, sa, sizeof(*sa)))
4412                 ret = -EFAULT;
4413
4414         kfree(sa);
4415         return ret;
4416 }
4417
4418 static long btrfs_ioctl_dev_replace(struct btrfs_fs_info *fs_info,
4419                                     void __user *arg)
4420 {
4421         struct btrfs_ioctl_dev_replace_args *p;
4422         int ret;
4423
4424         if (!capable(CAP_SYS_ADMIN))
4425                 return -EPERM;
4426
4427         p = memdup_user(arg, sizeof(*p));
4428         if (IS_ERR(p))
4429                 return PTR_ERR(p);
4430
4431         switch (p->cmd) {
4432         case BTRFS_IOCTL_DEV_REPLACE_CMD_START:
4433                 if (sb_rdonly(fs_info->sb)) {
4434                         ret = -EROFS;
4435                         goto out;
4436                 }
4437                 if (test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags)) {
4438                         ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
4439                 } else {
4440                         ret = btrfs_dev_replace_by_ioctl(fs_info, p);
4441                         clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
4442                 }
4443                 break;
4444         case BTRFS_IOCTL_DEV_REPLACE_CMD_STATUS:
4445                 btrfs_dev_replace_status(fs_info, p);
4446                 ret = 0;
4447                 break;
4448         case BTRFS_IOCTL_DEV_REPLACE_CMD_CANCEL:
4449                 ret = btrfs_dev_replace_cancel(fs_info, p);
4450                 break;
4451         default:
4452                 ret = -EINVAL;
4453                 break;
4454         }
4455
4456         if (copy_to_user(arg, p, sizeof(*p)))
4457                 ret = -EFAULT;
4458 out:
4459         kfree(p);
4460         return ret;
4461 }
4462
4463 static long btrfs_ioctl_ino_to_path(struct btrfs_root *root, void __user *arg)
4464 {
4465         int ret = 0;
4466         int i;
4467         u64 rel_ptr;
4468         int size;
4469         struct btrfs_ioctl_ino_path_args *ipa = NULL;
4470         struct inode_fs_paths *ipath = NULL;
4471         struct btrfs_path *path;
4472
4473         if (!capable(CAP_DAC_READ_SEARCH))
4474                 return -EPERM;
4475
4476         path = btrfs_alloc_path();
4477         if (!path) {
4478                 ret = -ENOMEM;
4479                 goto out;
4480         }
4481
4482         ipa = memdup_user(arg, sizeof(*ipa));
4483         if (IS_ERR(ipa)) {
4484                 ret = PTR_ERR(ipa);
4485                 ipa = NULL;
4486                 goto out;
4487         }
4488
4489         size = min_t(u32, ipa->size, 4096);
4490         ipath = init_ipath(size, root, path);
4491         if (IS_ERR(ipath)) {
4492                 ret = PTR_ERR(ipath);
4493                 ipath = NULL;
4494                 goto out;
4495         }
4496
4497         ret = paths_from_inode(ipa->inum, ipath);
4498         if (ret < 0)
4499                 goto out;
4500
4501         for (i = 0; i < ipath->fspath->elem_cnt; ++i) {
4502                 rel_ptr = ipath->fspath->val[i] -
4503                           (u64)(unsigned long)ipath->fspath->val;
4504                 ipath->fspath->val[i] = rel_ptr;
4505         }
4506
4507         ret = copy_to_user((void *)(unsigned long)ipa->fspath,
4508                            (void *)(unsigned long)ipath->fspath, size);
4509         if (ret) {
4510                 ret = -EFAULT;
4511                 goto out;
4512         }
4513
4514 out:
4515         btrfs_free_path(path);
4516         free_ipath(ipath);
4517         kfree(ipa);
4518
4519         return ret;
4520 }
4521
4522 static int build_ino_list(u64 inum, u64 offset, u64 root, void *ctx)
4523 {
4524         struct btrfs_data_container *inodes = ctx;
4525         const size_t c = 3 * sizeof(u64);
4526
4527         if (inodes->bytes_left >= c) {
4528                 inodes->bytes_left -= c;
4529                 inodes->val[inodes->elem_cnt] = inum;
4530                 inodes->val[inodes->elem_cnt + 1] = offset;
4531                 inodes->val[inodes->elem_cnt + 2] = root;
4532                 inodes->elem_cnt += 3;
4533         } else {
4534                 inodes->bytes_missing += c - inodes->bytes_left;
4535                 inodes->bytes_left = 0;
4536                 inodes->elem_missed += 3;
4537         }
4538
4539         return 0;
4540 }
4541
4542 static long btrfs_ioctl_logical_to_ino(struct btrfs_fs_info *fs_info,
4543                                         void __user *arg)
4544 {
4545         int ret = 0;
4546         int size;
4547         struct btrfs_ioctl_logical_ino_args *loi;
4548         struct btrfs_data_container *inodes = NULL;
4549         struct btrfs_path *path = NULL;
4550
4551         if (!capable(CAP_SYS_ADMIN))
4552                 return -EPERM;
4553
4554         loi = memdup_user(arg, sizeof(*loi));
4555         if (IS_ERR(loi))
4556                 return PTR_ERR(loi);
4557
4558         path = btrfs_alloc_path();
4559         if (!path) {
4560                 ret = -ENOMEM;
4561                 goto out;
4562         }
4563
4564         size = min_t(u32, loi->size, SZ_64K);
4565         inodes = init_data_container(size);
4566         if (IS_ERR(inodes)) {
4567                 ret = PTR_ERR(inodes);
4568                 inodes = NULL;
4569                 goto out;
4570         }
4571
4572         ret = iterate_inodes_from_logical(loi->logical, fs_info, path,
4573                                           build_ino_list, inodes);
4574         if (ret == -EINVAL)
4575                 ret = -ENOENT;
4576         if (ret < 0)
4577                 goto out;
4578
4579         ret = copy_to_user((void *)(unsigned long)loi->inodes,
4580                            (void *)(unsigned long)inodes, size);
4581         if (ret)
4582                 ret = -EFAULT;
4583
4584 out:
4585         btrfs_free_path(path);
4586         kvfree(inodes);
4587         kfree(loi);
4588
4589         return ret;
4590 }
4591
4592 void update_ioctl_balance_args(struct btrfs_fs_info *fs_info, int lock,
4593                                struct btrfs_ioctl_balance_args *bargs)
4594 {
4595         struct btrfs_balance_control *bctl = fs_info->balance_ctl;
4596
4597         bargs->flags = bctl->flags;
4598
4599         if (atomic_read(&fs_info->balance_running))
4600                 bargs->state |= BTRFS_BALANCE_STATE_RUNNING;
4601         if (atomic_read(&fs_info->balance_pause_req))
4602                 bargs->state |= BTRFS_BALANCE_STATE_PAUSE_REQ;
4603         if (atomic_read(&fs_info->balance_cancel_req))
4604                 bargs->state |= BTRFS_BALANCE_STATE_CANCEL_REQ;
4605
4606         memcpy(&bargs->data, &bctl->data, sizeof(bargs->data));
4607         memcpy(&bargs->meta, &bctl->meta, sizeof(bargs->meta));
4608         memcpy(&bargs->sys, &bctl->sys, sizeof(bargs->sys));
4609
4610         if (lock) {
4611                 spin_lock(&fs_info->balance_lock);
4612                 memcpy(&bargs->stat, &bctl->stat, sizeof(bargs->stat));
4613                 spin_unlock(&fs_info->balance_lock);
4614         } else {
4615                 memcpy(&bargs->stat, &bctl->stat, sizeof(bargs->stat));
4616         }
4617 }
4618
4619 static long btrfs_ioctl_balance(struct file *file, void __user *arg)
4620 {
4621         struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
4622         struct btrfs_fs_info *fs_info = root->fs_info;
4623         struct btrfs_ioctl_balance_args *bargs;
4624         struct btrfs_balance_control *bctl;
4625         bool need_unlock; /* for mut. excl. ops lock */
4626         int ret;
4627
4628         if (!capable(CAP_SYS_ADMIN))
4629                 return -EPERM;
4630
4631         ret = mnt_want_write_file(file);
4632         if (ret)
4633                 return ret;
4634
4635 again:
4636         if (!test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags)) {
4637                 mutex_lock(&fs_info->volume_mutex);
4638                 mutex_lock(&fs_info->balance_mutex);
4639                 need_unlock = true;
4640                 goto locked;
4641         }
4642
4643         /*
4644          * mut. excl. ops lock is locked.  Three possibilities:
4645          *   (1) some other op is running
4646          *   (2) balance is running
4647          *   (3) balance is paused -- special case (think resume)
4648          */
4649         mutex_lock(&fs_info->balance_mutex);
4650         if (fs_info->balance_ctl) {
4651                 /* this is either (2) or (3) */
4652                 if (!atomic_read(&fs_info->balance_running)) {
4653                         mutex_unlock(&fs_info->balance_mutex);
4654                         if (!mutex_trylock(&fs_info->volume_mutex))
4655                                 goto again;
4656                         mutex_lock(&fs_info->balance_mutex);
4657
4658                         if (fs_info->balance_ctl &&
4659                             !atomic_read(&fs_info->balance_running)) {
4660                                 /* this is (3) */
4661                                 need_unlock = false;
4662                                 goto locked;
4663                         }
4664
4665                         mutex_unlock(&fs_info->balance_mutex);
4666                         mutex_unlock(&fs_info->volume_mutex);
4667                         goto again;
4668                 } else {
4669                         /* this is (2) */
4670                         mutex_unlock(&fs_info->balance_mutex);
4671                         ret = -EINPROGRESS;
4672                         goto out;
4673                 }
4674         } else {
4675                 /* this is (1) */
4676                 mutex_unlock(&fs_info->balance_mutex);
4677                 ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
4678                 goto out;
4679         }
4680
4681 locked:
4682         BUG_ON(!test_bit(BTRFS_FS_EXCL_OP, &fs_info->flags));
4683
4684         if (arg) {
4685                 bargs = memdup_user(arg, sizeof(*bargs));
4686                 if (IS_ERR(bargs)) {
4687                         ret = PTR_ERR(bargs);
4688                         goto out_unlock;
4689                 }
4690
4691                 if (bargs->flags & BTRFS_BALANCE_RESUME) {
4692                         if (!fs_info->balance_ctl) {
4693                                 ret = -ENOTCONN;
4694                                 goto out_bargs;
4695                         }
4696
4697                         bctl = fs_info->balance_ctl;
4698                         spin_lock(&fs_info->balance_lock);
4699                         bctl->flags |= BTRFS_BALANCE_RESUME;
4700                         spin_unlock(&fs_info->balance_lock);
4701
4702                         goto do_balance;
4703                 }
4704         } else {
4705                 bargs = NULL;
4706         }
4707
4708         if (fs_info->balance_ctl) {
4709                 ret = -EINPROGRESS;
4710                 goto out_bargs;
4711         }
4712
4713         bctl = kzalloc(sizeof(*bctl), GFP_KERNEL);
4714         if (!bctl) {
4715                 ret = -ENOMEM;
4716                 goto out_bargs;
4717         }
4718
4719         bctl->fs_info = fs_info;
4720         if (arg) {
4721                 memcpy(&bctl->data, &bargs->data, sizeof(bctl->data));
4722                 memcpy(&bctl->meta, &bargs->meta, sizeof(bctl->meta));
4723                 memcpy(&bctl->sys, &bargs->sys, sizeof(bctl->sys));
4724
4725                 bctl->flags = bargs->flags;
4726         } else {
4727                 /* balance everything - no filters */
4728                 bctl->flags |= BTRFS_BALANCE_TYPE_MASK;
4729         }
4730
4731         if (bctl->flags & ~(BTRFS_BALANCE_ARGS_MASK | BTRFS_BALANCE_TYPE_MASK)) {
4732                 ret = -EINVAL;
4733                 goto out_bctl;
4734         }
4735
4736 do_balance:
4737         /*
4738          * Ownership of bctl and filesystem flag BTRFS_FS_EXCL_OP
4739          * goes to to btrfs_balance.  bctl is freed in __cancel_balance,
4740          * or, if restriper was paused all the way until unmount, in
4741          * free_fs_info.  The flag is cleared in __cancel_balance.
4742          */
4743         need_unlock = false;
4744
4745         ret = btrfs_balance(bctl, bargs);
4746         bctl = NULL;
4747
4748         if (arg) {
4749                 if (copy_to_user(arg, bargs, sizeof(*bargs)))
4750                         ret = -EFAULT;
4751         }
4752
4753 out_bctl:
4754         kfree(bctl);
4755 out_bargs:
4756         kfree(bargs);
4757 out_unlock:
4758         mutex_unlock(&fs_info->balance_mutex);
4759         mutex_unlock(&fs_info->volume_mutex);
4760         if (need_unlock)
4761                 clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
4762 out:
4763         mnt_drop_write_file(file);
4764         return ret;
4765 }
4766
4767 static long btrfs_ioctl_balance_ctl(struct btrfs_fs_info *fs_info, int cmd)
4768 {
4769         if (!capable(CAP_SYS_ADMIN))
4770                 return -EPERM;
4771
4772         switch (cmd) {
4773         case BTRFS_BALANCE_CTL_PAUSE:
4774                 return btrfs_pause_balance(fs_info);
4775         case BTRFS_BALANCE_CTL_CANCEL:
4776                 return btrfs_cancel_balance(fs_info);
4777         }
4778
4779         return -EINVAL;
4780 }
4781
4782 static long btrfs_ioctl_balance_progress(struct btrfs_fs_info *fs_info,
4783                                          void __user *arg)
4784 {
4785         struct btrfs_ioctl_balance_args *bargs;
4786         int ret = 0;
4787
4788         if (!capable(CAP_SYS_ADMIN))
4789                 return -EPERM;
4790
4791         mutex_lock(&fs_info->balance_mutex);
4792         if (!fs_info->balance_ctl) {
4793                 ret = -ENOTCONN;
4794                 goto out;
4795         }
4796
4797         bargs = kzalloc(sizeof(*bargs), GFP_KERNEL);
4798         if (!bargs) {
4799                 ret = -ENOMEM;
4800                 goto out;
4801         }
4802
4803         update_ioctl_balance_args(fs_info, 1, bargs);
4804
4805         if (copy_to_user(arg, bargs, sizeof(*bargs)))
4806                 ret = -EFAULT;
4807
4808         kfree(bargs);
4809 out:
4810         mutex_unlock(&fs_info->balance_mutex);
4811         return ret;
4812 }
4813
4814 static long btrfs_ioctl_quota_ctl(struct file *file, void __user *arg)
4815 {
4816         struct inode *inode = file_inode(file);
4817         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4818         struct btrfs_ioctl_quota_ctl_args *sa;
4819         struct btrfs_trans_handle *trans = NULL;
4820         int ret;
4821         int err;
4822
4823         if (!capable(CAP_SYS_ADMIN))
4824                 return -EPERM;
4825
4826         ret = mnt_want_write_file(file);
4827         if (ret)
4828                 return ret;
4829
4830         sa = memdup_user(arg, sizeof(*sa));
4831         if (IS_ERR(sa)) {
4832                 ret = PTR_ERR(sa);
4833                 goto drop_write;
4834         }
4835
4836         down_write(&fs_info->subvol_sem);
4837         trans = btrfs_start_transaction(fs_info->tree_root, 2);
4838         if (IS_ERR(trans)) {
4839                 ret = PTR_ERR(trans);
4840                 goto out;
4841         }
4842
4843         switch (sa->cmd) {
4844         case BTRFS_QUOTA_CTL_ENABLE:
4845                 ret = btrfs_quota_enable(trans, fs_info);
4846                 break;
4847         case BTRFS_QUOTA_CTL_DISABLE:
4848                 ret = btrfs_quota_disable(trans, fs_info);
4849                 break;
4850         default:
4851                 ret = -EINVAL;
4852                 break;
4853         }
4854
4855         err = btrfs_commit_transaction(trans);
4856         if (err && !ret)
4857                 ret = err;
4858 out:
4859         kfree(sa);
4860         up_write(&fs_info->subvol_sem);
4861 drop_write:
4862         mnt_drop_write_file(file);
4863         return ret;
4864 }
4865
4866 static long btrfs_ioctl_qgroup_assign(struct file *file, void __user *arg)
4867 {
4868         struct inode *inode = file_inode(file);
4869         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4870         struct btrfs_root *root = BTRFS_I(inode)->root;
4871         struct btrfs_ioctl_qgroup_assign_args *sa;
4872         struct btrfs_trans_handle *trans;
4873         int ret;
4874         int err;
4875
4876         if (!capable(CAP_SYS_ADMIN))
4877                 return -EPERM;
4878
4879         ret = mnt_want_write_file(file);
4880         if (ret)
4881                 return ret;
4882
4883         sa = memdup_user(arg, sizeof(*sa));
4884         if (IS_ERR(sa)) {
4885                 ret = PTR_ERR(sa);
4886                 goto drop_write;
4887         }
4888
4889         trans = btrfs_join_transaction(root);
4890         if (IS_ERR(trans)) {
4891                 ret = PTR_ERR(trans);
4892                 goto out;
4893         }
4894
4895         if (sa->assign) {
4896                 ret = btrfs_add_qgroup_relation(trans, fs_info,
4897                                                 sa->src, sa->dst);
4898         } else {
4899                 ret = btrfs_del_qgroup_relation(trans, fs_info,
4900                                                 sa->src, sa->dst);
4901         }
4902
4903         /* update qgroup status and info */
4904         err = btrfs_run_qgroups(trans, fs_info);
4905         if (err < 0)
4906                 btrfs_handle_fs_error(fs_info, err,
4907                                       "failed to update qgroup status and info");
4908         err = btrfs_end_transaction(trans);
4909         if (err && !ret)
4910                 ret = err;
4911
4912 out:
4913         kfree(sa);
4914 drop_write:
4915         mnt_drop_write_file(file);
4916         return ret;
4917 }
4918
4919 static long btrfs_ioctl_qgroup_create(struct file *file, void __user *arg)
4920 {
4921         struct inode *inode = file_inode(file);
4922         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4923         struct btrfs_root *root = BTRFS_I(inode)->root;
4924         struct btrfs_ioctl_qgroup_create_args *sa;
4925         struct btrfs_trans_handle *trans;
4926         int ret;
4927         int err;
4928
4929         if (!capable(CAP_SYS_ADMIN))
4930                 return -EPERM;
4931
4932         ret = mnt_want_write_file(file);
4933         if (ret)
4934                 return ret;
4935
4936         sa = memdup_user(arg, sizeof(*sa));
4937         if (IS_ERR(sa)) {
4938                 ret = PTR_ERR(sa);
4939                 goto drop_write;
4940         }
4941
4942         if (!sa->qgroupid) {
4943                 ret = -EINVAL;
4944                 goto out;
4945         }
4946
4947         trans = btrfs_join_transaction(root);
4948         if (IS_ERR(trans)) {
4949                 ret = PTR_ERR(trans);
4950                 goto out;
4951         }
4952
4953         if (sa->create) {
4954                 ret = btrfs_create_qgroup(trans, fs_info, sa->qgroupid);
4955         } else {
4956                 ret = btrfs_remove_qgroup(trans, fs_info, sa->qgroupid);
4957         }
4958
4959         err = btrfs_end_transaction(trans);
4960         if (err && !ret)
4961                 ret = err;
4962
4963 out:
4964         kfree(sa);
4965 drop_write:
4966         mnt_drop_write_file(file);
4967         return ret;
4968 }
4969
4970 static long btrfs_ioctl_qgroup_limit(struct file *file, void __user *arg)
4971 {
4972         struct inode *inode = file_inode(file);
4973         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4974         struct btrfs_root *root = BTRFS_I(inode)->root;
4975         struct btrfs_ioctl_qgroup_limit_args *sa;
4976         struct btrfs_trans_handle *trans;
4977         int ret;
4978         int err;
4979         u64 qgroupid;
4980
4981         if (!capable(CAP_SYS_ADMIN))
4982                 return -EPERM;
4983
4984         ret = mnt_want_write_file(file);
4985         if (ret)
4986                 return ret;
4987
4988         sa = memdup_user(arg, sizeof(*sa));
4989         if (IS_ERR(sa)) {
4990                 ret = PTR_ERR(sa);
4991                 goto drop_write;
4992         }
4993
4994         trans = btrfs_join_transaction(root);
4995         if (IS_ERR(trans)) {
4996                 ret = PTR_ERR(trans);
4997                 goto out;
4998         }
4999
5000         qgroupid = sa->qgroupid;
5001         if (!qgroupid) {
5002                 /* take the current subvol as qgroup */
5003                 qgroupid = root->root_key.objectid;
5004         }
5005
5006         ret = btrfs_limit_qgroup(trans, fs_info, qgroupid, &sa->lim);
5007
5008         err = btrfs_end_transaction(trans);
5009         if (err && !ret)
5010                 ret = err;
5011
5012 out:
5013         kfree(sa);
5014 drop_write:
5015         mnt_drop_write_file(file);
5016         return ret;
5017 }
5018
5019 static long btrfs_ioctl_quota_rescan(struct file *file, void __user *arg)
5020 {
5021         struct inode *inode = file_inode(file);
5022         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5023         struct btrfs_ioctl_quota_rescan_args *qsa;
5024         int ret;
5025
5026         if (!capable(CAP_SYS_ADMIN))
5027                 return -EPERM;
5028
5029         ret = mnt_want_write_file(file);
5030         if (ret)
5031                 return ret;
5032
5033         qsa = memdup_user(arg, sizeof(*qsa));
5034         if (IS_ERR(qsa)) {
5035                 ret = PTR_ERR(qsa);
5036                 goto drop_write;
5037         }
5038
5039         if (qsa->flags) {
5040                 ret = -EINVAL;
5041                 goto out;
5042         }
5043
5044         ret = btrfs_qgroup_rescan(fs_info);
5045
5046 out:
5047         kfree(qsa);
5048 drop_write:
5049         mnt_drop_write_file(file);
5050         return ret;
5051 }
5052
5053 static long btrfs_ioctl_quota_rescan_status(struct file *file, void __user *arg)
5054 {
5055         struct inode *inode = file_inode(file);
5056         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5057         struct btrfs_ioctl_quota_rescan_args *qsa;
5058         int ret = 0;
5059
5060         if (!capable(CAP_SYS_ADMIN))
5061                 return -EPERM;
5062
5063         qsa = kzalloc(sizeof(*qsa), GFP_KERNEL);
5064         if (!qsa)
5065                 return -ENOMEM;
5066
5067         if (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN) {
5068                 qsa->flags = 1;
5069                 qsa->progress = fs_info->qgroup_rescan_progress.objectid;
5070         }
5071
5072         if (copy_to_user(arg, qsa, sizeof(*qsa)))
5073                 ret = -EFAULT;
5074
5075         kfree(qsa);
5076         return ret;
5077 }
5078
5079 static long btrfs_ioctl_quota_rescan_wait(struct file *file, void __user *arg)
5080 {
5081         struct inode *inode = file_inode(file);
5082         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5083
5084         if (!capable(CAP_SYS_ADMIN))
5085                 return -EPERM;
5086
5087         return btrfs_qgroup_wait_for_completion(fs_info, true);
5088 }
5089
5090 static long _btrfs_ioctl_set_received_subvol(struct file *file,
5091                                             struct btrfs_ioctl_received_subvol_args *sa)
5092 {
5093         struct inode *inode = file_inode(file);
5094         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5095         struct btrfs_root *root = BTRFS_I(inode)->root;
5096         struct btrfs_root_item *root_item = &root->root_item;
5097         struct btrfs_trans_handle *trans;
5098         struct timespec ct = current_time(inode);
5099         int ret = 0;
5100         int received_uuid_changed;
5101
5102         if (!inode_owner_or_capable(inode))
5103                 return -EPERM;
5104
5105         ret = mnt_want_write_file(file);
5106         if (ret < 0)
5107                 return ret;
5108
5109         down_write(&fs_info->subvol_sem);
5110
5111         if (btrfs_ino(BTRFS_I(inode)) != BTRFS_FIRST_FREE_OBJECTID) {
5112                 ret = -EINVAL;
5113                 goto out;
5114         }
5115
5116         if (btrfs_root_readonly(root)) {
5117                 ret = -EROFS;
5118                 goto out;
5119         }
5120
5121         /*
5122          * 1 - root item
5123          * 2 - uuid items (received uuid + subvol uuid)
5124          */
5125         trans = btrfs_start_transaction(root, 3);
5126         if (IS_ERR(trans)) {
5127                 ret = PTR_ERR(trans);
5128                 trans = NULL;
5129                 goto out;
5130         }
5131
5132         sa->rtransid = trans->transid;
5133         sa->rtime.sec = ct.tv_sec;
5134         sa->rtime.nsec = ct.tv_nsec;
5135
5136         received_uuid_changed = memcmp(root_item->received_uuid, sa->uuid,
5137                                        BTRFS_UUID_SIZE);
5138         if (received_uuid_changed &&
5139             !btrfs_is_empty_uuid(root_item->received_uuid))
5140                 btrfs_uuid_tree_rem(trans, fs_info, root_item->received_uuid,
5141                                     BTRFS_UUID_KEY_RECEIVED_SUBVOL,
5142                                     root->root_key.objectid);
5143         memcpy(root_item->received_uuid, sa->uuid, BTRFS_UUID_SIZE);
5144         btrfs_set_root_stransid(root_item, sa->stransid);
5145         btrfs_set_root_rtransid(root_item, sa->rtransid);
5146         btrfs_set_stack_timespec_sec(&root_item->stime, sa->stime.sec);
5147         btrfs_set_stack_timespec_nsec(&root_item->stime, sa->stime.nsec);
5148         btrfs_set_stack_timespec_sec(&root_item->rtime, sa->rtime.sec);
5149         btrfs_set_stack_timespec_nsec(&root_item->rtime, sa->rtime.nsec);
5150
5151         ret = btrfs_update_root(trans, fs_info->tree_root,
5152                                 &root->root_key, &root->root_item);
5153         if (ret < 0) {
5154                 btrfs_end_transaction(trans);
5155                 goto out;
5156         }
5157         if (received_uuid_changed && !btrfs_is_empty_uuid(sa->uuid)) {
5158                 ret = btrfs_uuid_tree_add(trans, fs_info, sa->uuid,
5159                                           BTRFS_UUID_KEY_RECEIVED_SUBVOL,
5160                                           root->root_key.objectid);
5161                 if (ret < 0 && ret != -EEXIST) {
5162                         btrfs_abort_transaction(trans, ret);
5163                         goto out;
5164                 }
5165         }
5166         ret = btrfs_commit_transaction(trans);
5167         if (ret < 0) {
5168                 btrfs_abort_transaction(trans, ret);
5169                 goto out;
5170         }
5171
5172 out:
5173         up_write(&fs_info->subvol_sem);
5174         mnt_drop_write_file(file);
5175         return ret;
5176 }
5177
5178 #ifdef CONFIG_64BIT
5179 static long btrfs_ioctl_set_received_subvol_32(struct file *file,
5180                                                 void __user *arg)
5181 {
5182         struct btrfs_ioctl_received_subvol_args_32 *args32 = NULL;
5183         struct btrfs_ioctl_received_subvol_args *args64 = NULL;
5184         int ret = 0;
5185
5186         args32 = memdup_user(arg, sizeof(*args32));
5187         if (IS_ERR(args32))
5188                 return PTR_ERR(args32);
5189
5190         args64 = kmalloc(sizeof(*args64), GFP_KERNEL);
5191         if (!args64) {
5192                 ret = -ENOMEM;
5193                 goto out;
5194         }
5195
5196         memcpy(args64->uuid, args32->uuid, BTRFS_UUID_SIZE);
5197         args64->stransid = args32->stransid;
5198         args64->rtransid = args32->rtransid;
5199         args64->stime.sec = args32->stime.sec;
5200         args64->stime.nsec = args32->stime.nsec;
5201         args64->rtime.sec = args32->rtime.sec;
5202         args64->rtime.nsec = args32->rtime.nsec;
5203         args64->flags = args32->flags;
5204
5205         ret = _btrfs_ioctl_set_received_subvol(file, args64);
5206         if (ret)
5207                 goto out;
5208
5209         memcpy(args32->uuid, args64->uuid, BTRFS_UUID_SIZE);
5210         args32->stransid = args64->stransid;
5211         args32->rtransid = args64->rtransid;
5212         args32->stime.sec = args64->stime.sec;
5213         args32->stime.nsec = args64->stime.nsec;
5214         args32->rtime.sec = args64->rtime.sec;
5215         args32->rtime.nsec = args64->rtime.nsec;
5216         args32->flags = args64->flags;
5217
5218         ret = copy_to_user(arg, args32, sizeof(*args32));
5219         if (ret)
5220                 ret = -EFAULT;
5221
5222 out:
5223         kfree(args32);
5224         kfree(args64);
5225         return ret;
5226 }
5227 #endif
5228
5229 static long btrfs_ioctl_set_received_subvol(struct file *file,
5230                                             void __user *arg)
5231 {
5232         struct btrfs_ioctl_received_subvol_args *sa = NULL;
5233         int ret = 0;
5234
5235         sa = memdup_user(arg, sizeof(*sa));
5236         if (IS_ERR(sa))
5237                 return PTR_ERR(sa);
5238
5239         ret = _btrfs_ioctl_set_received_subvol(file, sa);
5240
5241         if (ret)
5242                 goto out;
5243
5244         ret = copy_to_user(arg, sa, sizeof(*sa));
5245         if (ret)
5246                 ret = -EFAULT;
5247
5248 out:
5249         kfree(sa);
5250         return ret;
5251 }
5252
5253 static int btrfs_ioctl_get_fslabel(struct file *file, void __user *arg)
5254 {
5255         struct inode *inode = file_inode(file);
5256         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5257         size_t len;
5258         int ret;
5259         char label[BTRFS_LABEL_SIZE];
5260
5261         spin_lock(&fs_info->super_lock);
5262         memcpy(label, fs_info->super_copy->label, BTRFS_LABEL_SIZE);
5263         spin_unlock(&fs_info->super_lock);
5264
5265         len = strnlen(label, BTRFS_LABEL_SIZE);
5266
5267         if (len == BTRFS_LABEL_SIZE) {
5268                 btrfs_warn(fs_info,
5269                            "label is too long, return the first %zu bytes",
5270                            --len);
5271         }
5272
5273         ret = copy_to_user(arg, label, len);
5274
5275         return ret ? -EFAULT : 0;
5276 }
5277
5278 static int btrfs_ioctl_set_fslabel(struct file *file, void __user *arg)
5279 {
5280         struct inode *inode = file_inode(file);
5281         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5282         struct btrfs_root *root = BTRFS_I(inode)->root;
5283         struct btrfs_super_block *super_block = fs_info->super_copy;
5284         struct btrfs_trans_handle *trans;
5285         char label[BTRFS_LABEL_SIZE];
5286         int ret;
5287
5288         if (!capable(CAP_SYS_ADMIN))
5289                 return -EPERM;
5290
5291         if (copy_from_user(label, arg, sizeof(label)))
5292                 return -EFAULT;
5293
5294         if (strnlen(label, BTRFS_LABEL_SIZE) == BTRFS_LABEL_SIZE) {
5295                 btrfs_err(fs_info,
5296                           "unable to set label with more than %d bytes",
5297                           BTRFS_LABEL_SIZE - 1);
5298                 return -EINVAL;
5299         }
5300
5301         ret = mnt_want_write_file(file);
5302         if (ret)
5303                 return ret;
5304
5305         trans = btrfs_start_transaction(root, 0);
5306         if (IS_ERR(trans)) {
5307                 ret = PTR_ERR(trans);
5308                 goto out_unlock;
5309         }
5310
5311         spin_lock(&fs_info->super_lock);
5312         strcpy(super_block->label, label);
5313         spin_unlock(&fs_info->super_lock);
5314         ret = btrfs_commit_transaction(trans);
5315
5316 out_unlock:
5317         mnt_drop_write_file(file);
5318         return ret;
5319 }
5320
5321 #define INIT_FEATURE_FLAGS(suffix) \
5322         { .compat_flags = BTRFS_FEATURE_COMPAT_##suffix, \
5323           .compat_ro_flags = BTRFS_FEATURE_COMPAT_RO_##suffix, \
5324           .incompat_flags = BTRFS_FEATURE_INCOMPAT_##suffix }
5325
5326 int btrfs_ioctl_get_supported_features(void __user *arg)
5327 {
5328         static const struct btrfs_ioctl_feature_flags features[3] = {
5329                 INIT_FEATURE_FLAGS(SUPP),
5330                 INIT_FEATURE_FLAGS(SAFE_SET),
5331                 INIT_FEATURE_FLAGS(SAFE_CLEAR)
5332         };
5333
5334         if (copy_to_user(arg, &features, sizeof(features)))
5335                 return -EFAULT;
5336
5337         return 0;
5338 }
5339
5340 static int btrfs_ioctl_get_features(struct file *file, void __user *arg)
5341 {
5342         struct inode *inode = file_inode(file);
5343         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5344         struct btrfs_super_block *super_block = fs_info->super_copy;
5345         struct btrfs_ioctl_feature_flags features;
5346
5347         features.compat_flags = btrfs_super_compat_flags(super_block);
5348         features.compat_ro_flags = btrfs_super_compat_ro_flags(super_block);
5349         features.incompat_flags = btrfs_super_incompat_flags(super_block);
5350
5351         if (copy_to_user(arg, &features, sizeof(features)))
5352                 return -EFAULT;
5353
5354         return 0;
5355 }
5356
5357 static int check_feature_bits(struct btrfs_fs_info *fs_info,
5358                               enum btrfs_feature_set set,
5359                               u64 change_mask, u64 flags, u64 supported_flags,
5360                               u64 safe_set, u64 safe_clear)
5361 {
5362         const char *type = btrfs_feature_set_names[set];
5363         char *names;
5364         u64 disallowed, unsupported;
5365         u64 set_mask = flags & change_mask;
5366         u64 clear_mask = ~flags & change_mask;
5367
5368         unsupported = set_mask & ~supported_flags;
5369         if (unsupported) {
5370                 names = btrfs_printable_features(set, unsupported);
5371                 if (names) {
5372                         btrfs_warn(fs_info,
5373                                    "this kernel does not support the %s feature bit%s",
5374                                    names, strchr(names, ',') ? "s" : "");
5375                         kfree(names);
5376                 } else
5377                         btrfs_warn(fs_info,
5378                                    "this kernel does not support %s bits 0x%llx",
5379                                    type, unsupported);
5380                 return -EOPNOTSUPP;
5381         }
5382
5383         disallowed = set_mask & ~safe_set;
5384         if (disallowed) {
5385                 names = btrfs_printable_features(set, disallowed);
5386                 if (names) {
5387                         btrfs_warn(fs_info,
5388                                    "can't set the %s feature bit%s while mounted",
5389                                    names, strchr(names, ',') ? "s" : "");
5390                         kfree(names);
5391                 } else
5392                         btrfs_warn(fs_info,
5393                                    "can't set %s bits 0x%llx while mounted",
5394                                    type, disallowed);
5395                 return -EPERM;
5396         }
5397
5398         disallowed = clear_mask & ~safe_clear;
5399         if (disallowed) {
5400                 names = btrfs_printable_features(set, disallowed);
5401                 if (names) {
5402                         btrfs_warn(fs_info,
5403                                    "can't clear the %s feature bit%s while mounted",
5404                                    names, strchr(names, ',') ? "s" : "");
5405                         kfree(names);
5406                 } else
5407                         btrfs_warn(fs_info,
5408                                    "can't clear %s bits 0x%llx while mounted",
5409                                    type, disallowed);
5410                 return -EPERM;
5411         }
5412
5413         return 0;
5414 }
5415
5416 #define check_feature(fs_info, change_mask, flags, mask_base)   \
5417 check_feature_bits(fs_info, FEAT_##mask_base, change_mask, flags,       \
5418                    BTRFS_FEATURE_ ## mask_base ## _SUPP,        \
5419                    BTRFS_FEATURE_ ## mask_base ## _SAFE_SET,    \
5420                    BTRFS_FEATURE_ ## mask_base ## _SAFE_CLEAR)
5421
5422 static int btrfs_ioctl_set_features(struct file *file, void __user *arg)
5423 {
5424         struct inode *inode = file_inode(file);
5425         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5426         struct btrfs_root *root = BTRFS_I(inode)->root;
5427         struct btrfs_super_block *super_block = fs_info->super_copy;
5428         struct btrfs_ioctl_feature_flags flags[2];
5429         struct btrfs_trans_handle *trans;
5430         u64 newflags;
5431         int ret;
5432
5433         if (!capable(CAP_SYS_ADMIN))
5434                 return -EPERM;
5435
5436         if (copy_from_user(flags, arg, sizeof(flags)))
5437                 return -EFAULT;
5438
5439         /* Nothing to do */
5440         if (!flags[0].compat_flags && !flags[0].compat_ro_flags &&
5441             !flags[0].incompat_flags)
5442                 return 0;
5443
5444         ret = check_feature(fs_info, flags[0].compat_flags,
5445                             flags[1].compat_flags, COMPAT);
5446         if (ret)
5447                 return ret;
5448
5449         ret = check_feature(fs_info, flags[0].compat_ro_flags,
5450                             flags[1].compat_ro_flags, COMPAT_RO);
5451         if (ret)
5452                 return ret;
5453
5454         ret = check_feature(fs_info, flags[0].incompat_flags,
5455                             flags[1].incompat_flags, INCOMPAT);
5456         if (ret)
5457                 return ret;
5458
5459         ret = mnt_want_write_file(file);
5460         if (ret)
5461                 return ret;
5462
5463         trans = btrfs_start_transaction(root, 0);
5464         if (IS_ERR(trans)) {
5465                 ret = PTR_ERR(trans);
5466                 goto out_drop_write;
5467         }
5468
5469         spin_lock(&fs_info->super_lock);
5470         newflags = btrfs_super_compat_flags(super_block);
5471         newflags |= flags[0].compat_flags & flags[1].compat_flags;
5472         newflags &= ~(flags[0].compat_flags & ~flags[1].compat_flags);
5473         btrfs_set_super_compat_flags(super_block, newflags);
5474
5475         newflags = btrfs_super_compat_ro_flags(super_block);
5476         newflags |= flags[0].compat_ro_flags & flags[1].compat_ro_flags;
5477         newflags &= ~(flags[0].compat_ro_flags & ~flags[1].compat_ro_flags);
5478         btrfs_set_super_compat_ro_flags(super_block, newflags);
5479
5480         newflags = btrfs_super_incompat_flags(super_block);
5481         newflags |= flags[0].incompat_flags & flags[1].incompat_flags;
5482         newflags &= ~(flags[0].incompat_flags & ~flags[1].incompat_flags);
5483         btrfs_set_super_incompat_flags(super_block, newflags);
5484         spin_unlock(&fs_info->super_lock);
5485
5486         ret = btrfs_commit_transaction(trans);
5487 out_drop_write:
5488         mnt_drop_write_file(file);
5489
5490         return ret;
5491 }
5492
5493 long btrfs_ioctl(struct file *file, unsigned int
5494                 cmd, unsigned long arg)
5495 {
5496         struct inode *inode = file_inode(file);
5497         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5498         struct btrfs_root *root = BTRFS_I(inode)->root;
5499         void __user *argp = (void __user *)arg;
5500
5501         switch (cmd) {
5502         case FS_IOC_GETFLAGS:
5503                 return btrfs_ioctl_getflags(file, argp);
5504         case FS_IOC_SETFLAGS:
5505                 return btrfs_ioctl_setflags(file, argp);
5506         case FS_IOC_GETVERSION:
5507                 return btrfs_ioctl_getversion(file, argp);
5508         case FITRIM:
5509                 return btrfs_ioctl_fitrim(file, argp);
5510         case BTRFS_IOC_SNAP_CREATE:
5511                 return btrfs_ioctl_snap_create(file, argp, 0);
5512         case BTRFS_IOC_SNAP_CREATE_V2:
5513                 return btrfs_ioctl_snap_create_v2(file, argp, 0);
5514         case BTRFS_IOC_SUBVOL_CREATE:
5515                 return btrfs_ioctl_snap_create(file, argp, 1);
5516         case BTRFS_IOC_SUBVOL_CREATE_V2:
5517                 return btrfs_ioctl_snap_create_v2(file, argp, 1);
5518         case BTRFS_IOC_SNAP_DESTROY:
5519                 return btrfs_ioctl_snap_destroy(file, argp);
5520         case BTRFS_IOC_SUBVOL_GETFLAGS:
5521                 return btrfs_ioctl_subvol_getflags(file, argp);
5522         case BTRFS_IOC_SUBVOL_SETFLAGS:
5523                 return btrfs_ioctl_subvol_setflags(file, argp);
5524         case BTRFS_IOC_DEFAULT_SUBVOL:
5525                 return btrfs_ioctl_default_subvol(file, argp);
5526         case BTRFS_IOC_DEFRAG:
5527                 return btrfs_ioctl_defrag(file, NULL);
5528         case BTRFS_IOC_DEFRAG_RANGE:
5529                 return btrfs_ioctl_defrag(file, argp);
5530         case BTRFS_IOC_RESIZE:
5531                 return btrfs_ioctl_resize(file, argp);
5532         case BTRFS_IOC_ADD_DEV:
5533                 return btrfs_ioctl_add_dev(fs_info, argp);
5534         case BTRFS_IOC_RM_DEV:
5535                 return btrfs_ioctl_rm_dev(file, argp);
5536         case BTRFS_IOC_RM_DEV_V2:
5537                 return btrfs_ioctl_rm_dev_v2(file, argp);
5538         case BTRFS_IOC_FS_INFO:
5539                 return btrfs_ioctl_fs_info(fs_info, argp);
5540         case BTRFS_IOC_DEV_INFO:
5541                 return btrfs_ioctl_dev_info(fs_info, argp);
5542         case BTRFS_IOC_BALANCE:
5543                 return btrfs_ioctl_balance(file, NULL);
5544         case BTRFS_IOC_TRANS_START:
5545                 return btrfs_ioctl_trans_start(file);
5546         case BTRFS_IOC_TRANS_END:
5547                 return btrfs_ioctl_trans_end(file);
5548         case BTRFS_IOC_TREE_SEARCH:
5549                 return btrfs_ioctl_tree_search(file, argp);
5550         case BTRFS_IOC_TREE_SEARCH_V2:
5551                 return btrfs_ioctl_tree_search_v2(file, argp);
5552         case BTRFS_IOC_INO_LOOKUP:
5553                 return btrfs_ioctl_ino_lookup(file, argp);
5554         case BTRFS_IOC_INO_PATHS:
5555                 return btrfs_ioctl_ino_to_path(root, argp);
5556         case BTRFS_IOC_LOGICAL_INO:
5557                 return btrfs_ioctl_logical_to_ino(fs_info, argp);
5558         case BTRFS_IOC_SPACE_INFO:
5559                 return btrfs_ioctl_space_info(fs_info, argp);
5560         case BTRFS_IOC_SYNC: {
5561                 int ret;
5562
5563                 ret = btrfs_start_delalloc_roots(fs_info, 0, -1);
5564                 if (ret)
5565                         return ret;
5566                 ret = btrfs_sync_fs(inode->i_sb, 1);
5567                 /*
5568                  * The transaction thread may want to do more work,
5569                  * namely it pokes the cleaner kthread that will start
5570                  * processing uncleaned subvols.
5571                  */
5572                 wake_up_process(fs_info->transaction_kthread);
5573                 return ret;
5574         }
5575         case BTRFS_IOC_START_SYNC:
5576                 return btrfs_ioctl_start_sync(root, argp);
5577         case BTRFS_IOC_WAIT_SYNC:
5578                 return btrfs_ioctl_wait_sync(fs_info, argp);
5579         case BTRFS_IOC_SCRUB:
5580                 return btrfs_ioctl_scrub(file, argp);
5581         case BTRFS_IOC_SCRUB_CANCEL:
5582                 return btrfs_ioctl_scrub_cancel(fs_info);
5583         case BTRFS_IOC_SCRUB_PROGRESS:
5584                 return btrfs_ioctl_scrub_progress(fs_info, argp);
5585         case BTRFS_IOC_BALANCE_V2:
5586                 return btrfs_ioctl_balance(file, argp);
5587         case BTRFS_IOC_BALANCE_CTL:
5588                 return btrfs_ioctl_balance_ctl(fs_info, arg);
5589         case BTRFS_IOC_BALANCE_PROGRESS:
5590                 return btrfs_ioctl_balance_progress(fs_info, argp);
5591         case BTRFS_IOC_SET_RECEIVED_SUBVOL:
5592                 return btrfs_ioctl_set_received_subvol(file, argp);
5593 #ifdef CONFIG_64BIT
5594         case BTRFS_IOC_SET_RECEIVED_SUBVOL_32:
5595                 return btrfs_ioctl_set_received_subvol_32(file, argp);
5596 #endif
5597         case BTRFS_IOC_SEND:
5598                 return btrfs_ioctl_send(file, argp);
5599         case BTRFS_IOC_GET_DEV_STATS:
5600                 return btrfs_ioctl_get_dev_stats(fs_info, argp);
5601         case BTRFS_IOC_QUOTA_CTL:
5602                 return btrfs_ioctl_quota_ctl(file, argp);
5603         case BTRFS_IOC_QGROUP_ASSIGN:
5604                 return btrfs_ioctl_qgroup_assign(file, argp);
5605         case BTRFS_IOC_QGROUP_CREATE:
5606                 return btrfs_ioctl_qgroup_create(file, argp);
5607         case BTRFS_IOC_QGROUP_LIMIT:
5608                 return btrfs_ioctl_qgroup_limit(file, argp);
5609         case BTRFS_IOC_QUOTA_RESCAN:
5610                 return btrfs_ioctl_quota_rescan(file, argp);
5611         case BTRFS_IOC_QUOTA_RESCAN_STATUS:
5612                 return btrfs_ioctl_quota_rescan_status(file, argp);
5613         case BTRFS_IOC_QUOTA_RESCAN_WAIT:
5614                 return btrfs_ioctl_quota_rescan_wait(file, argp);
5615         case BTRFS_IOC_DEV_REPLACE:
5616                 return btrfs_ioctl_dev_replace(fs_info, argp);
5617         case BTRFS_IOC_GET_FSLABEL:
5618                 return btrfs_ioctl_get_fslabel(file, argp);
5619         case BTRFS_IOC_SET_FSLABEL:
5620                 return btrfs_ioctl_set_fslabel(file, argp);
5621         case BTRFS_IOC_GET_SUPPORTED_FEATURES:
5622                 return btrfs_ioctl_get_supported_features(argp);
5623         case BTRFS_IOC_GET_FEATURES:
5624                 return btrfs_ioctl_get_features(file, argp);
5625         case BTRFS_IOC_SET_FEATURES:
5626                 return btrfs_ioctl_set_features(file, argp);
5627         }
5628
5629         return -ENOTTY;
5630 }
5631
5632 #ifdef CONFIG_COMPAT
5633 long btrfs_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
5634 {
5635         /*
5636          * These all access 32-bit values anyway so no further
5637          * handling is necessary.
5638          */
5639         switch (cmd) {
5640         case FS_IOC32_GETFLAGS:
5641                 cmd = FS_IOC_GETFLAGS;
5642                 break;
5643         case FS_IOC32_SETFLAGS:
5644                 cmd = FS_IOC_SETFLAGS;
5645                 break;
5646         case FS_IOC32_GETVERSION:
5647                 cmd = FS_IOC_GETVERSION;
5648                 break;
5649         }
5650
5651         return btrfs_ioctl(file, cmd, (unsigned long) compat_ptr(arg));
5652 }
5653 #endif