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 /*
 160  * Inherit flags from the parent inode.
 161  *
 162  * Currently only the compression flags and the cow flags are inherited.
 163  */
 164 void btrfs_inherit_iflags(struct inode *inode, struct inode *dir)
 165 {
 166         unsigned int flags;
 167
 168         if (!dir)
 169                 return;
 170
 171         flags = BTRFS_I(dir)->flags;
 172
 173         if (flags & BTRFS_INODE_NOCOMPRESS) {
 174                 BTRFS_I(inode)->flags &= ~BTRFS_INODE_COMPRESS;
 175                 BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS;
 176         } else if (flags & BTRFS_INODE_COMPRESS) {
 177                 BTRFS_I(inode)->flags &= ~BTRFS_INODE_NOCOMPRESS;
 178                 BTRFS_I(inode)->flags |= BTRFS_INODE_COMPRESS;
 179         }
 180
 181         if (flags & BTRFS_INODE_NODATACOW) {
 182                 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATACOW;
 183                 if (S_ISREG(inode->i_mode))
 184                         BTRFS_I(inode)->flags |= BTRFS_INODE_NODATASUM;
 185         }
 186
 187         btrfs_update_iflags(inode);
 188 }
 189
 190 static int btrfs_ioctl_getflags(struct file *file, void __user *arg)
 191 {
 192         struct btrfs_inode *ip = BTRFS_I(file_inode(file));
 193         unsigned int flags = btrfs_flags_to_ioctl(ip->flags);
 194
 195         if (copy_to_user(arg, &flags, sizeof(flags)))
 196                 return -EFAULT;
 197         return 0;
 198 }
 199
 200 static int check_flags(unsigned int flags)
 201 {
 202         if (flags & ~(FS_IMMUTABLE_FL | FS_APPEND_FL | \
 203                       FS_NOATIME_FL | FS_NODUMP_FL | \
 204                       FS_SYNC_FL | FS_DIRSYNC_FL | \
 205                       FS_NOCOMP_FL | FS_COMPR_FL |
 206                       FS_NOCOW_FL))
 207                 return -EOPNOTSUPP;
 208
 209         if ((flags & FS_NOCOMP_FL) && (flags & FS_COMPR_FL))
 210                 return -EINVAL;
 211
 212         return 0;
 213 }
 214
 215 static int btrfs_ioctl_setflags(struct file *file, void __user *arg)
 216 {
 217         struct inode *inode = file_inode(file);
 218         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
 219         struct btrfs_inode *ip = BTRFS_I(inode);
 220         struct btrfs_root *root = ip->root;
 221         struct btrfs_trans_handle *trans;
 222         unsigned int flags, oldflags;
 223         int ret;
 224         u64 ip_oldflags;
 225         unsigned int i_oldflags;
 226         umode_t mode;
 227
 228         if (!inode_owner_or_capable(inode))
 229                 return -EPERM;
 230
 231         if (btrfs_root_readonly(root))
 232                 return -EROFS;
 233
 234         if (copy_from_user(&flags, arg, sizeof(flags)))
 235                 return -EFAULT;
 236
 237         ret = check_flags(flags);
 238         if (ret)
 239                 return ret;
 240
 241         ret = mnt_want_write_file(file);
 242         if (ret)
 243                 return ret;
 244
 245         inode_lock(inode);
 246
 247         ip_oldflags = ip->flags;
 248         i_oldflags = inode->i_flags;
 249         mode = inode->i_mode;
 250
 251         flags = btrfs_mask_flags(inode->i_mode, flags);
 252         oldflags = btrfs_flags_to_ioctl(ip->flags);
 253         if ((flags ^ oldflags) & (FS_APPEND_FL | FS_IMMUTABLE_FL)) {
 254                 if (!capable(CAP_LINUX_IMMUTABLE)) {
 255                         ret = -EPERM;
 256                         goto out_unlock;
 257                 }
 258         }
 259
 260         if (flags & FS_SYNC_FL)
 261                 ip->flags |= BTRFS_INODE_SYNC;
 262         else
 263                 ip->flags &= ~BTRFS_INODE_SYNC;
 264         if (flags & FS_IMMUTABLE_FL)
 265                 ip->flags |= BTRFS_INODE_IMMUTABLE;
 266         else
 267                 ip->flags &= ~BTRFS_INODE_IMMUTABLE;
 268         if (flags & FS_APPEND_FL)
 269                 ip->flags |= BTRFS_INODE_APPEND;
 270         else
 271                 ip->flags &= ~BTRFS_INODE_APPEND;
 272         if (flags & FS_NODUMP_FL)
 273                 ip->flags |= BTRFS_INODE_NODUMP;
 274         else
 275                 ip->flags &= ~BTRFS_INODE_NODUMP;
 276         if (flags & FS_NOATIME_FL)
 277                 ip->flags |= BTRFS_INODE_NOATIME;
 278         else
 279                 ip->flags &= ~BTRFS_INODE_NOATIME;
 280         if (flags & FS_DIRSYNC_FL)
 281                 ip->flags |= BTRFS_INODE_DIRSYNC;
 282         else
 283                 ip->flags &= ~BTRFS_INODE_DIRSYNC;
 284         if (flags & FS_NOCOW_FL) {
 285                 if (S_ISREG(mode)) {
 286                         /*
 287                          * It's safe to turn csums off here, no extents exist.
 288                          * Otherwise we want the flag to reflect the real COW
 289                          * status of the file and will not set it.
 290                          */
 291                         if (inode->i_size == 0)
 292                                 ip->flags |= BTRFS_INODE_NODATACOW
 293                                            | BTRFS_INODE_NODATASUM;
 294                 } else {
 295                         ip->flags |= BTRFS_INODE_NODATACOW;
 296                 }
 297         } else {
 298                 /*
 299                  * Revert back under same assumptions as above
 300                  */
 301                 if (S_ISREG(mode)) {
 302                         if (inode->i_size == 0)
 303                                 ip->flags &= ~(BTRFS_INODE_NODATACOW
 304                                              | BTRFS_INODE_NODATASUM);
 305                 } else {
 306                         ip->flags &= ~BTRFS_INODE_NODATACOW;
 307                 }
 308         }
 309
 310         /*
 311          * The COMPRESS flag can only be changed by users, while the NOCOMPRESS
 312          * flag may be changed automatically if compression code won't make
 313          * things smaller.
 314          */
 315         if (flags & FS_NOCOMP_FL) {
 316                 ip->flags &= ~BTRFS_INODE_COMPRESS;
 317                 ip->flags |= BTRFS_INODE_NOCOMPRESS;
 318
 319                 ret = btrfs_set_prop(inode, "btrfs.compression", NULL, 0, 0);
 320                 if (ret && ret != -ENODATA)
 321                         goto out_drop;
 322         } else if (flags & FS_COMPR_FL) {
 323                 const char *comp;
 324
 325                 ip->flags |= BTRFS_INODE_COMPRESS;
 326                 ip->flags &= ~BTRFS_INODE_NOCOMPRESS;
 327
 328                 if (fs_info->compress_type == BTRFS_COMPRESS_LZO)
 329                         comp = "lzo";
 330                 else
 331                         comp = "zlib";
 332                 ret = btrfs_set_prop(inode, "btrfs.compression",
 333                                      comp, strlen(comp), 0);
 334                 if (ret)
 335                         goto out_drop;
 336
 337         } else {
 338                 ret = btrfs_set_prop(inode, "btrfs.compression", NULL, 0, 0);
 339                 if (ret && ret != -ENODATA)
 340                         goto out_drop;
 341                 ip->flags &= ~(BTRFS_INODE_COMPRESS | BTRFS_INODE_NOCOMPRESS);
 342         }
 343
 344         trans = btrfs_start_transaction(root, 1);
 345         if (IS_ERR(trans)) {
 346                 ret = PTR_ERR(trans);
 347                 goto out_drop;
 348         }
 349
 350         btrfs_update_iflags(inode);
 351         inode_inc_iversion(inode);
 352         inode->i_ctime = current_time(inode);
 353         ret = btrfs_update_inode(trans, root, inode);
 354
 355         btrfs_end_transaction(trans);
 356  out_drop:
 357         if (ret) {
 358                 ip->flags = ip_oldflags;
 359                 inode->i_flags = i_oldflags;
 360         }
 361
 362  out_unlock:
 363         inode_unlock(inode);
 364         mnt_drop_write_file(file);
 365         return ret;
 366 }
 367
 368 static int btrfs_ioctl_getversion(struct file *file, int __user *arg)
 369 {
 370         struct inode *inode = file_inode(file);
 371
 372         return put_user(inode->i_generation, arg);
 373 }
 374
 375 static noinline int btrfs_ioctl_fitrim(struct file *file, void __user *arg)
 376 {
 377         struct inode *inode = file_inode(file);
 378         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
 379         struct btrfs_device *device;
 380         struct request_queue *q;
 381         struct fstrim_range range;
 382         u64 minlen = ULLONG_MAX;
 383         u64 num_devices = 0;
 384         u64 total_bytes = btrfs_super_total_bytes(fs_info->super_copy);
 385         int ret;
 386
 387         if (!capable(CAP_SYS_ADMIN))
 388                 return -EPERM;
 389
 390         rcu_read_lock();
 391         list_for_each_entry_rcu(device, &fs_info->fs_devices->devices,
 392                                 dev_list) {
 393                 if (!device->bdev)
 394                         continue;
 395                 q = bdev_get_queue(device->bdev);
 396                 if (blk_queue_discard(q)) {
 397                         num_devices++;
 398                         minlen = min_t(u64, q->limits.discard_granularity,
 399                                      minlen);
 400                 }
 401         }
 402         rcu_read_unlock();
 403
 404         if (!num_devices)
 405                 return -EOPNOTSUPP;
 406         if (copy_from_user(&range, arg, sizeof(range)))
 407                 return -EFAULT;
 408         if (range.start > total_bytes ||
 409             range.len < fs_info->sb->s_blocksize)
 410                 return -EINVAL;
 411
 412         range.len = min(range.len, total_bytes - range.start);
 413         range.minlen = max(range.minlen, minlen);
 414         ret = btrfs_trim_fs(fs_info, &range);
 415         if (ret < 0)
 416                 return ret;
 417
 418         if (copy_to_user(arg, &range, sizeof(range)))
 419                 return -EFAULT;
 420
 421         return 0;
 422 }
 423
 424 int btrfs_is_empty_uuid(u8 *uuid)
 425 {
 426         int i;
 427
 428         for (i = 0; i < BTRFS_UUID_SIZE; i++) {
 429                 if (uuid[i])
 430                         return 0;
 431         }
 432         return 1;
 433 }
 434
 435 static noinline int create_subvol(struct inode *dir,
 436                                   struct dentry *dentry,
 437                                   const char *name, int namelen,
 438                                   u64 *async_transid,
 439                                   struct btrfs_qgroup_inherit *inherit)
 440 {
 441         struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
 442         struct btrfs_trans_handle *trans;
 443         struct btrfs_key key;
 444         struct btrfs_root_item *root_item;
 445         struct btrfs_inode_item *inode_item;
 446         struct extent_buffer *leaf;
 447         struct btrfs_root *root = BTRFS_I(dir)->root;
 448         struct btrfs_root *new_root;
 449         struct btrfs_block_rsv block_rsv;
 450         struct timespec cur_time = current_time(dir);
 451         struct inode *inode;
 452         int ret;
 453         int err;
 454         u64 objectid;
 455         u64 new_dirid = BTRFS_FIRST_FREE_OBJECTID;
 456         u64 index = 0;
 457         u64 qgroup_reserved;
 458         uuid_le new_uuid;
 459
 460         root_item = kzalloc(sizeof(*root_item), GFP_KERNEL);
 461         if (!root_item)
 462                 return -ENOMEM;
 463
 464         ret = btrfs_find_free_objectid(fs_info->tree_root, &objectid);
 465         if (ret)
 466                 goto fail_free;
 467
 468         /*
 469          * Don't create subvolume whose level is not zero. Or qgroup will be
 470          * screwed up since it assumes subvolume qgroup's level to be 0.
 471          */
 472         if (btrfs_qgroup_level(objectid)) {
 473                 ret = -ENOSPC;
 474                 goto fail_free;
 475         }
 476
 477         btrfs_init_block_rsv(&block_rsv, BTRFS_BLOCK_RSV_TEMP);
 478         /*
 479          * The same as the snapshot creation, please see the comment
 480          * of create_snapshot().
 481          */
 482         ret = btrfs_subvolume_reserve_metadata(root, &block_rsv,
 483                                                8, &qgroup_reserved, false);
 484         if (ret)
 485                 goto fail_free;
 486
 487         trans = btrfs_start_transaction(root, 0);
 488         if (IS_ERR(trans)) {
 489                 ret = PTR_ERR(trans);
 490                 btrfs_subvolume_release_metadata(fs_info, &block_rsv);
 491                 goto fail_free;
 492         }
 493         trans->block_rsv = &block_rsv;
 494         trans->bytes_reserved = block_rsv.size;
 495
 496         ret = btrfs_qgroup_inherit(trans, fs_info, 0, objectid, inherit);
 497         if (ret)
 498                 goto fail;
 499
 500         leaf = btrfs_alloc_tree_block(trans, root, 0, objectid, NULL, 0, 0, 0);
 501         if (IS_ERR(leaf)) {
 502                 ret = PTR_ERR(leaf);
 503                 goto fail;
 504         }
 505
 506         memzero_extent_buffer(leaf, 0, sizeof(struct btrfs_header));
 507         btrfs_set_header_bytenr(leaf, leaf->start);
 508         btrfs_set_header_generation(leaf, trans->transid);
 509         btrfs_set_header_backref_rev(leaf, BTRFS_MIXED_BACKREF_REV);
 510         btrfs_set_header_owner(leaf, objectid);
 511
 512         write_extent_buffer_fsid(leaf, fs_info->fsid);
 513         write_extent_buffer_chunk_tree_uuid(leaf, fs_info->chunk_tree_uuid);
 514         btrfs_mark_buffer_dirty(leaf);
 515
 516         inode_item = &root_item->inode;
 517         btrfs_set_stack_inode_generation(inode_item, 1);
 518         btrfs_set_stack_inode_size(inode_item, 3);
 519         btrfs_set_stack_inode_nlink(inode_item, 1);
 520         btrfs_set_stack_inode_nbytes(inode_item,
 521                                      fs_info->nodesize);
 522         btrfs_set_stack_inode_mode(inode_item, S_IFDIR | 0755);
 523
 524         btrfs_set_root_flags(root_item, 0);
 525         btrfs_set_root_limit(root_item, 0);
 526         btrfs_set_stack_inode_flags(inode_item, BTRFS_INODE_ROOT_ITEM_INIT);
 527
 528         btrfs_set_root_bytenr(root_item, leaf->start);
 529         btrfs_set_root_generation(root_item, trans->transid);
 530         btrfs_set_root_level(root_item, 0);
 531         btrfs_set_root_refs(root_item, 1);
 532         btrfs_set_root_used(root_item, leaf->len);
 533         btrfs_set_root_last_snapshot(root_item, 0);
 534
 535         btrfs_set_root_generation_v2(root_item,
 536                         btrfs_root_generation(root_item));
 537         uuid_le_gen(&new_uuid);
 538         memcpy(root_item->uuid, new_uuid.b, BTRFS_UUID_SIZE);
 539         btrfs_set_stack_timespec_sec(&root_item->otime, cur_time.tv_sec);
 540         btrfs_set_stack_timespec_nsec(&root_item->otime, cur_time.tv_nsec);
 541         root_item->ctime = root_item->otime;
 542         btrfs_set_root_ctransid(root_item, trans->transid);
 543         btrfs_set_root_otransid(root_item, trans->transid);
 544
 545         btrfs_tree_unlock(leaf);
 546         free_extent_buffer(leaf);
 547         leaf = NULL;
 548
 549         btrfs_set_root_dirid(root_item, new_dirid);
 550
 551         key.objectid = objectid;
 552         key.offset = 0;
 553         key.type = BTRFS_ROOT_ITEM_KEY;
 554         ret = btrfs_insert_root(trans, fs_info->tree_root, &key,
 555                                 root_item);
 556         if (ret)
 557                 goto fail;
 558
 559         key.offset = (u64)-1;
 560         new_root = btrfs_read_fs_root_no_name(fs_info, &key);
 561         if (IS_ERR(new_root)) {
 562                 ret = PTR_ERR(new_root);
 563                 btrfs_abort_transaction(trans, ret);
 564                 goto fail;
 565         }
 566
 567         btrfs_record_root_in_trans(trans, new_root);
 568
 569         ret = btrfs_create_subvol_root(trans, new_root, root, new_dirid);
 570         if (ret) {
 571                 /* We potentially lose an unused inode item here */
 572                 btrfs_abort_transaction(trans, ret);
 573                 goto fail;
 574         }
 575
 576         mutex_lock(&new_root->objectid_mutex);
 577         new_root->highest_objectid = new_dirid;
 578         mutex_unlock(&new_root->objectid_mutex);
 579
 580         /*
 581          * insert the directory item
 582          */
 583         ret = btrfs_set_inode_index(BTRFS_I(dir), &index);
 584         if (ret) {
 585                 btrfs_abort_transaction(trans, ret);
 586                 goto fail;
 587         }
 588
 589         ret = btrfs_insert_dir_item(trans, root,
 590                                     name, namelen, BTRFS_I(dir), &key,
 591                                     BTRFS_FT_DIR, index);
 592         if (ret) {
 593                 btrfs_abort_transaction(trans, ret);
 594                 goto fail;
 595         }
 596
 597         btrfs_i_size_write(BTRFS_I(dir), dir->i_size + namelen * 2);
 598         ret = btrfs_update_inode(trans, root, dir);
 599         BUG_ON(ret);
 600
 601         ret = btrfs_add_root_ref(trans, fs_info,
 602                                  objectid, root->root_key.objectid,
 603                                  btrfs_ino(BTRFS_I(dir)), index, name, namelen);
 604         BUG_ON(ret);
 605
 606         ret = btrfs_uuid_tree_add(trans, fs_info, root_item->uuid,
 607                                   BTRFS_UUID_KEY_SUBVOL, objectid);
 608         if (ret)
 609                 btrfs_abort_transaction(trans, ret);
 610
 611 fail:
 612         kfree(root_item);
 613         trans->block_rsv = NULL;
 614         trans->bytes_reserved = 0;
 615         btrfs_subvolume_release_metadata(fs_info, &block_rsv);
 616
 617         if (async_transid) {
 618                 *async_transid = trans->transid;
 619                 err = btrfs_commit_transaction_async(trans, 1);
 620                 if (err)
 621                         err = btrfs_commit_transaction(trans);
 622         } else {
 623                 err = btrfs_commit_transaction(trans);
 624         }
 625         if (err && !ret)
 626                 ret = err;
 627
 628         if (!ret) {
 629                 inode = btrfs_lookup_dentry(dir, dentry);
 630                 if (IS_ERR(inode))
 631                         return PTR_ERR(inode);
 632                 d_instantiate(dentry, inode);
 633         }
 634         return ret;
 635
 636 fail_free:
 637         kfree(root_item);
 638         return ret;
 639 }
 640
 641 static void btrfs_wait_for_no_snapshoting_writes(struct btrfs_root *root)
 642 {
 643         s64 writers;
 644         DEFINE_WAIT(wait);
 645
 646         do {
 647                 prepare_to_wait(&root->subv_writers->wait, &wait,
 648                                 TASK_UNINTERRUPTIBLE);
 649
 650                 writers = percpu_counter_sum(&root->subv_writers->counter);
 651                 if (writers)
 652                         schedule();
 653
 654                 finish_wait(&root->subv_writers->wait, &wait);
 655         } while (writers);
 656 }
 657
 658 static int create_snapshot(struct btrfs_root *root, struct inode *dir,
 659                            struct dentry *dentry,
 660                            u64 *async_transid, bool readonly,
 661                            struct btrfs_qgroup_inherit *inherit)
 662 {
 663         struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
 664         struct inode *inode;
 665         struct btrfs_pending_snapshot *pending_snapshot;
 666         struct btrfs_trans_handle *trans;
 667         int ret;
 668
 669         if (!test_bit(BTRFS_ROOT_REF_COWS, &root->state))
 670                 return -EINVAL;
 671
 672         pending_snapshot = kzalloc(sizeof(*pending_snapshot), GFP_KERNEL);
 673         if (!pending_snapshot)
 674                 return -ENOMEM;
 675
 676         pending_snapshot->root_item = kzalloc(sizeof(struct btrfs_root_item),
 677                         GFP_KERNEL);
 678         pending_snapshot->path = btrfs_alloc_path();
 679         if (!pending_snapshot->root_item || !pending_snapshot->path) {
 680                 ret = -ENOMEM;
 681                 goto free_pending;
 682         }
 683
 684         atomic_inc(&root->will_be_snapshoted);
 685         smp_mb__after_atomic();
 686         btrfs_wait_for_no_snapshoting_writes(root);
 687
 688         ret = btrfs_start_delalloc_inodes(root, 0);
 689         if (ret)
 690                 goto dec_and_free;
 691
 692         btrfs_wait_ordered_extents(root, U64_MAX, 0, (u64)-1);
 693
 694         btrfs_init_block_rsv(&pending_snapshot->block_rsv,
 695                              BTRFS_BLOCK_RSV_TEMP);
 696         /*
 697          * 1 - parent dir inode
 698          * 2 - dir entries
 699          * 1 - root item
 700          * 2 - root ref/backref
 701          * 1 - root of snapshot
 702          * 1 - UUID item
 703          */
 704         ret = btrfs_subvolume_reserve_metadata(BTRFS_I(dir)->root,
 705                                         &pending_snapshot->block_rsv, 8,
 706                                         &pending_snapshot->qgroup_reserved,
 707                                         false);
 708         if (ret)
 709                 goto dec_and_free;
 710
 711         pending_snapshot->dentry = dentry;
 712         pending_snapshot->root = root;
 713         pending_snapshot->readonly = readonly;
 714         pending_snapshot->dir = dir;
 715         pending_snapshot->inherit = inherit;
 716
 717         trans = btrfs_start_transaction(root, 0);
 718         if (IS_ERR(trans)) {
 719                 ret = PTR_ERR(trans);
 720                 goto fail;
 721         }
 722
 723         spin_lock(&fs_info->trans_lock);
 724         list_add(&pending_snapshot->list,
 725                  &trans->transaction->pending_snapshots);
 726         spin_unlock(&fs_info->trans_lock);
 727         if (async_transid) {
 728                 *async_transid = trans->transid;
 729                 ret = btrfs_commit_transaction_async(trans, 1);
 730                 if (ret)
 731                         ret = btrfs_commit_transaction(trans);
 732         } else {
 733                 ret = btrfs_commit_transaction(trans);
 734         }
 735         if (ret)
 736                 goto fail;
 737
 738         ret = pending_snapshot->error;
 739         if (ret)
 740                 goto fail;
 741
 742         ret = btrfs_orphan_cleanup(pending_snapshot->snap);
 743         if (ret)
 744                 goto fail;
 745
 746         inode = btrfs_lookup_dentry(d_inode(dentry->d_parent), dentry);
 747         if (IS_ERR(inode)) {
 748                 ret = PTR_ERR(inode);
 749                 goto fail;
 750         }
 751
 752         d_instantiate(dentry, inode);
 753         ret = 0;
 754 fail:
 755         btrfs_subvolume_release_metadata(fs_info, &pending_snapshot->block_rsv);
 756 dec_and_free:
 757         if (atomic_dec_and_test(&root->will_be_snapshoted))
 758                 wake_up_atomic_t(&root->will_be_snapshoted);
 759 free_pending:
 760         kfree(pending_snapshot->root_item);
 761         btrfs_free_path(pending_snapshot->path);
 762         kfree(pending_snapshot);
 763
 764         return ret;
 765 }
 766
 767 /*  copy of may_delete in fs/namei.c()
 768  *      Check whether we can remove a link victim from directory dir, check
 769  *  whether the type of victim is right.
 770  *  1. We can't do it if dir is read-only (done in permission())
 771  *  2. We should have write and exec permissions on dir
 772  *  3. We can't remove anything from append-only dir
 773  *  4. We can't do anything with immutable dir (done in permission())
 774  *  5. If the sticky bit on dir is set we should either
 775  *      a. be owner of dir, or
 776  *      b. be owner of victim, or
 777  *      c. have CAP_FOWNER capability
 778  *  6. If the victim is append-only or immutable we can't do anything with
 779  *     links pointing to it.
 780  *  7. If we were asked to remove a directory and victim isn't one - ENOTDIR.
 781  *  8. If we were asked to remove a non-directory and victim isn't one - EISDIR.
 782  *  9. We can't remove a root or mountpoint.
 783  * 10. We don't allow removal of NFS sillyrenamed files; it's handled by
 784  *     nfs_async_unlink().
 785  */
 786
 787 static int btrfs_may_delete(struct inode *dir, struct dentry *victim, int isdir)
 788 {
 789         int error;
 790
 791         if (d_really_is_negative(victim))
 792                 return -ENOENT;
 793
 794         BUG_ON(d_inode(victim->d_parent) != dir);
 795         audit_inode_child(dir, victim, AUDIT_TYPE_CHILD_DELETE);
 796
 797         error = inode_permission(dir, MAY_WRITE | MAY_EXEC);
 798         if (error)
 799                 return error;
 800         if (IS_APPEND(dir))
 801                 return -EPERM;
 802         if (check_sticky(dir, d_inode(victim)) || IS_APPEND(d_inode(victim)) ||
 803             IS_IMMUTABLE(d_inode(victim)) || IS_SWAPFILE(d_inode(victim)))
 804                 return -EPERM;
 805         if (isdir) {
 806                 if (!d_is_dir(victim))
 807                         return -ENOTDIR;
 808                 if (IS_ROOT(victim))
 809                         return -EBUSY;
 810         } else if (d_is_dir(victim))
 811                 return -EISDIR;
 812         if (IS_DEADDIR(dir))
 813                 return -ENOENT;
 814         if (victim->d_flags & DCACHE_NFSFS_RENAMED)
 815                 return -EBUSY;
 816         return 0;
 817 }
 818
 819 /* copy of may_create in fs/namei.c() */
 820 static inline int btrfs_may_create(struct inode *dir, struct dentry *child)
 821 {
 822         if (d_really_is_positive(child))
 823                 return -EEXIST;
 824         if (IS_DEADDIR(dir))
 825                 return -ENOENT;
 826         return inode_permission(dir, MAY_WRITE | MAY_EXEC);
 827 }
 828
 829 /*
 830  * Create a new subvolume below @parent.  This is largely modeled after
 831  * sys_mkdirat and vfs_mkdir, but we only do a single component lookup
 832  * inside this filesystem so it's quite a bit simpler.
 833  */
 834 static noinline int btrfs_mksubvol(const struct path *parent,
 835                                    const char *name, int namelen,
 836                                    struct btrfs_root *snap_src,
 837                                    u64 *async_transid, bool readonly,
 838                                    struct btrfs_qgroup_inherit *inherit)
 839 {
 840         struct inode *dir = d_inode(parent->dentry);
 841         struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
 842         struct dentry *dentry;
 843         int error;
 844
 845         error = down_write_killable_nested(&dir->i_rwsem, I_MUTEX_PARENT);
 846         if (error == -EINTR)
 847                 return error;
 848
 849         dentry = lookup_one_len(name, parent->dentry, namelen);
 850         error = PTR_ERR(dentry);
 851         if (IS_ERR(dentry))
 852                 goto out_unlock;
 853
 854         error = btrfs_may_create(dir, dentry);
 855         if (error)
 856                 goto out_dput;
 857
 858         /*
 859          * even if this name doesn't exist, we may get hash collisions.
 860          * check for them now when we can safely fail
 861          */
 862         error = btrfs_check_dir_item_collision(BTRFS_I(dir)->root,
 863                                                dir->i_ino, name,
 864                                                namelen);
 865         if (error)
 866                 goto out_dput;
 867
 868         down_read(&fs_info->subvol_sem);
 869
 870         if (btrfs_root_refs(&BTRFS_I(dir)->root->root_item) == 0)
 871                 goto out_up_read;
 872
 873         if (snap_src) {
 874                 error = create_snapshot(snap_src, dir, dentry,
 875                                         async_transid, readonly, inherit);
 876         } else {
 877                 error = create_subvol(dir, dentry, name, namelen,
 878                                       async_transid, inherit);
 879         }
 880         if (!error)
 881                 fsnotify_mkdir(dir, dentry);
 882 out_up_read:
 883         up_read(&fs_info->subvol_sem);
 884 out_dput:
 885         dput(dentry);
 886 out_unlock:
 887         inode_unlock(dir);
 888         return error;
 889 }
 890
 891 /*
 892  * When we're defragging a range, we don't want to kick it off again
 893  * if it is really just waiting for delalloc to send it down.
 894  * If we find a nice big extent or delalloc range for the bytes in the
 895  * file you want to defrag, we return 0 to let you know to skip this
 896  * part of the file
 897  */
 898 static int check_defrag_in_cache(struct inode *inode, u64 offset, u32 thresh)
 899 {
 900         struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
 901         struct extent_map *em = NULL;
 902         struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
 903         u64 end;
 904
 905         read_lock(&em_tree->lock);
 906         em = lookup_extent_mapping(em_tree, offset, PAGE_SIZE);
 907         read_unlock(&em_tree->lock);
 908
 909         if (em) {
 910                 end = extent_map_end(em);
 911                 free_extent_map(em);
 912                 if (end - offset > thresh)
 913                         return 0;
 914         }
 915         /* if we already have a nice delalloc here, just stop */
 916         thresh /= 2;
 917         end = count_range_bits(io_tree, &offset, offset + thresh,
 918                                thresh, EXTENT_DELALLOC, 1);
 919         if (end >= thresh)
 920                 return 0;
 921         return 1;
 922 }
 923
 924 /*
 925  * helper function to walk through a file and find extents
 926  * newer than a specific transid, and smaller than thresh.
 927  *
 928  * This is used by the defragging code to find new and small
 929  * extents
 930  */
 931 static int find_new_extents(struct btrfs_root *root,
 932                             struct inode *inode, u64 newer_than,
 933                             u64 *off, u32 thresh)
 934 {
 935         struct btrfs_path *path;
 936         struct btrfs_key min_key;
 937         struct extent_buffer *leaf;
 938         struct btrfs_file_extent_item *extent;
 939         int type;
 940         int ret;
 941         u64 ino = btrfs_ino(BTRFS_I(inode));
 942
 943         path = btrfs_alloc_path();
 944         if (!path)
 945                 return -ENOMEM;
 946
 947         min_key.objectid = ino;
 948         min_key.type = BTRFS_EXTENT_DATA_KEY;
 949         min_key.offset = *off;
 950
 951         while (1) {
 952                 ret = btrfs_search_forward(root, &min_key, path, newer_than);
 953                 if (ret != 0)
 954                         goto none;
 955 process_slot:
 956                 if (min_key.objectid != ino)
 957                         goto none;
 958                 if (min_key.type != BTRFS_EXTENT_DATA_KEY)
 959                         goto none;
 960
 961                 leaf = path->nodes[0];
 962                 extent = btrfs_item_ptr(leaf, path->slots[0],
 963                                         struct btrfs_file_extent_item);
 964
 965                 type = btrfs_file_extent_type(leaf, extent);
 966                 if (type == BTRFS_FILE_EXTENT_REG &&
 967                     btrfs_file_extent_num_bytes(leaf, extent) < thresh &&
 968                     check_defrag_in_cache(inode, min_key.offset, thresh)) {
 969                         *off = min_key.offset;
 970                         btrfs_free_path(path);
 971                         return 0;
 972                 }
 973
 974                 path->slots[0]++;
 975                 if (path->slots[0] < btrfs_header_nritems(leaf)) {
 976                         btrfs_item_key_to_cpu(leaf, &min_key, path->slots[0]);
 977                         goto process_slot;
 978                 }
 979
 980                 if (min_key.offset == (u64)-1)
 981                         goto none;
 982
 983                 min_key.offset++;
 984                 btrfs_release_path(path);
 985         }
 986 none:
 987         btrfs_free_path(path);
 988         return -ENOENT;
 989 }
 990
 991 static struct extent_map *defrag_lookup_extent(struct inode *inode, u64 start)
 992 {
 993         struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
 994         struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
 995         struct extent_map *em;
 996         u64 len = PAGE_SIZE;
 997
 998         /*
 999          * hopefully we have this extent in the tree already, try without
1000          * the full extent lock
1001          */
1002         read_lock(&em_tree->lock);
1003         em = lookup_extent_mapping(em_tree, start, len);
1004         read_unlock(&em_tree->lock);
1005
1006         if (!em) {
1007                 struct extent_state *cached = NULL;
1008                 u64 end = start + len - 1;
1009
1010                 /* get the big lock and read metadata off disk */
1011                 lock_extent_bits(io_tree, start, end, &cached);
1012                 em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, start, len, 0);
1013                 unlock_extent_cached(io_tree, start, end, &cached, GFP_NOFS);
1014
1015                 if (IS_ERR(em))
1016                         return NULL;
1017         }
1018
1019         return em;
1020 }
1021
1022 static bool defrag_check_next_extent(struct inode *inode, struct extent_map *em)
1023 {
1024         struct extent_map *next;
1025         bool ret = true;
1026
1027         /* this is the last extent */
1028         if (em->start + em->len >= i_size_read(inode))
1029                 return false;
1030
1031         next = defrag_lookup_extent(inode, em->start + em->len);
1032         if (!next || next->block_start >= EXTENT_MAP_LAST_BYTE)
1033                 ret = false;
1034         else if ((em->block_start + em->block_len == next->block_start) &&
1035                  (em->block_len > SZ_128K && next->block_len > SZ_128K))
1036                 ret = false;
1037
1038         free_extent_map(next);
1039         return ret;
1040 }
1041
1042 static int should_defrag_range(struct inode *inode, u64 start, u32 thresh,
1043                                u64 *last_len, u64 *skip, u64 *defrag_end,
1044                                int compress)
1045 {
1046         struct extent_map *em;
1047         int ret = 1;
1048         bool next_mergeable = true;
1049         bool prev_mergeable = true;
1050
1051         /*
1052          * make sure that once we start defragging an extent, we keep on
1053          * defragging it
1054          */
1055         if (start < *defrag_end)
1056                 return 1;
1057
1058         *skip = 0;
1059
1060         em = defrag_lookup_extent(inode, start);
1061         if (!em)
1062                 return 0;
1063
1064         /* this will cover holes, and inline extents */
1065         if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
1066                 ret = 0;
1067                 goto out;
1068         }
1069
1070         if (!*defrag_end)
1071                 prev_mergeable = false;
1072
1073         next_mergeable = defrag_check_next_extent(inode, em);
1074         /*
1075          * we hit a real extent, if it is big or the next extent is not a
1076          * real extent, don't bother defragging it
1077          */
1078         if (!compress && (*last_len == 0 || *last_len >= thresh) &&
1079             (em->len >= thresh || (!next_mergeable && !prev_mergeable)))
1080                 ret = 0;
1081 out:
1082         /*
1083          * last_len ends up being a counter of how many bytes we've defragged.
1084          * every time we choose not to defrag an extent, we reset *last_len
1085          * so that the next tiny extent will force a defrag.
1086          *
1087          * The end result of this is that tiny extents before a single big
1088          * extent will force at least part of that big extent to be defragged.
1089          */
1090         if (ret) {
1091                 *defrag_end = extent_map_end(em);
1092         } else {
1093                 *last_len = 0;
1094                 *skip = extent_map_end(em);
1095                 *defrag_end = 0;
1096         }
1097
1098         free_extent_map(em);
1099         return ret;
1100 }
1101
1102 /*
1103  * it doesn't do much good to defrag one or two pages
1104  * at a time.  This pulls in a nice chunk of pages
1105  * to COW and defrag.
1106  *
1107  * It also makes sure the delalloc code has enough
1108  * dirty data to avoid making new small extents as part
1109  * of the defrag
1110  *
1111  * It's a good idea to start RA on this range
1112  * before calling this.
1113  */
1114 static int cluster_pages_for_defrag(struct inode *inode,
1115                                     struct page **pages,
1116                                     unsigned long start_index,
1117                                     unsigned long num_pages)
1118 {
1119         unsigned long file_end;
1120         u64 isize = i_size_read(inode);
1121         u64 page_start;
1122         u64 page_end;
1123         u64 page_cnt;
1124         int ret;
1125         int i;
1126         int i_done;
1127         struct btrfs_ordered_extent *ordered;
1128         struct extent_state *cached_state = NULL;
1129         struct extent_io_tree *tree;
1130         struct extent_changeset *data_reserved = NULL;
1131         gfp_t mask = btrfs_alloc_write_mask(inode->i_mapping);
1132
1133         file_end = (isize - 1) >> PAGE_SHIFT;
1134         if (!isize || start_index > file_end)
1135                 return 0;
1136
1137         page_cnt = min_t(u64, (u64)num_pages, (u64)file_end - start_index + 1);
1138
1139         ret = btrfs_delalloc_reserve_space(inode, &data_reserved,
1140                         start_index << PAGE_SHIFT,
1141                         page_cnt << PAGE_SHIFT);
1142         if (ret)
1143                 return ret;
1144         i_done = 0;
1145         tree = &BTRFS_I(inode)->io_tree;
1146
1147         /* step one, lock all the pages */
1148         for (i = 0; i < page_cnt; i++) {
1149                 struct page *page;
1150 again:
1151                 page = find_or_create_page(inode->i_mapping,
1152                                            start_index + i, mask);
1153                 if (!page)
1154                         break;
1155
1156                 page_start = page_offset(page);
1157                 page_end = page_start + PAGE_SIZE - 1;
1158                 while (1) {
1159                         lock_extent_bits(tree, page_start, page_end,
1160                                          &cached_state);
1161                         ordered = btrfs_lookup_ordered_extent(inode,
1162                                                               page_start);
1163                         unlock_extent_cached(tree, page_start, page_end,
1164                                              &cached_state, GFP_NOFS);
1165                         if (!ordered)
1166                                 break;
1167
1168                         unlock_page(page);
1169                         btrfs_start_ordered_extent(inode, ordered, 1);
1170                         btrfs_put_ordered_extent(ordered);
1171                         lock_page(page);
1172                         /*
1173                          * we unlocked the page above, so we need check if
1174                          * it was released or not.
1175                          */
1176                         if (page->mapping != inode->i_mapping) {
1177                                 unlock_page(page);
1178                                 put_page(page);
1179                                 goto again;
1180                         }
1181                 }
1182
1183                 if (!PageUptodate(page)) {
1184                         btrfs_readpage(NULL, page);
1185                         lock_page(page);
1186                         if (!PageUptodate(page)) {
1187                                 unlock_page(page);
1188                                 put_page(page);
1189                                 ret = -EIO;
1190                                 break;
1191                         }
1192                 }
1193
1194                 if (page->mapping != inode->i_mapping) {
1195                         unlock_page(page);
1196                         put_page(page);
1197                         goto again;
1198                 }
1199
1200                 pages[i] = page;
1201                 i_done++;
1202         }
1203         if (!i_done || ret)
1204                 goto out;
1205
1206         if (!(inode->i_sb->s_flags & MS_ACTIVE))
1207                 goto out;
1208
1209         /*
1210          * so now we have a nice long stream of locked
1211          * and up to date pages, lets wait on them
1212          */
1213         for (i = 0; i < i_done; i++)
1214                 wait_on_page_writeback(pages[i]);
1215
1216         page_start = page_offset(pages[0]);
1217         page_end = page_offset(pages[i_done - 1]) + PAGE_SIZE;
1218
1219         lock_extent_bits(&BTRFS_I(inode)->io_tree,
1220                          page_start, page_end - 1, &cached_state);
1221         clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start,
1222                           page_end - 1, EXTENT_DIRTY | EXTENT_DELALLOC |
1223                           EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG, 0, 0,
1224                           &cached_state, GFP_NOFS);
1225
1226         if (i_done != page_cnt) {
1227                 spin_lock(&BTRFS_I(inode)->lock);
1228                 BTRFS_I(inode)->outstanding_extents++;
1229                 spin_unlock(&BTRFS_I(inode)->lock);
1230                 btrfs_delalloc_release_space(inode, data_reserved,
1231                                 start_index << PAGE_SHIFT,
1232                                 (page_cnt - i_done) << PAGE_SHIFT);
1233         }
1234
1235
1236         set_extent_defrag(&BTRFS_I(inode)->io_tree, page_start, page_end - 1,
1237                           &cached_state);
1238
1239         unlock_extent_cached(&BTRFS_I(inode)->io_tree,
1240                              page_start, page_end - 1, &cached_state,
1241                              GFP_NOFS);
1242
1243         for (i = 0; i < i_done; i++) {
1244                 clear_page_dirty_for_io(pages[i]);
1245                 ClearPageChecked(pages[i]);
1246                 set_page_extent_mapped(pages[i]);
1247                 set_page_dirty(pages[i]);
1248                 unlock_page(pages[i]);
1249                 put_page(pages[i]);
1250         }
1251         extent_changeset_free(data_reserved);
1252         return i_done;
1253 out:
1254         for (i = 0; i < i_done; i++) {
1255                 unlock_page(pages[i]);
1256                 put_page(pages[i]);
1257         }
1258         btrfs_delalloc_release_space(inode, data_reserved,
1259                         start_index << PAGE_SHIFT,
1260                         page_cnt << PAGE_SHIFT);
1261         extent_changeset_free(data_reserved);
1262         return ret;
1263
1264 }
1265
1266 int btrfs_defrag_file(struct inode *inode, struct file *file,
1267                       struct btrfs_ioctl_defrag_range_args *range,
1268                       u64 newer_than, unsigned long max_to_defrag)
1269 {
1270         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1271         struct btrfs_root *root = BTRFS_I(inode)->root;
1272         struct file_ra_state *ra = NULL;
1273         unsigned long last_index;
1274         u64 isize = i_size_read(inode);
1275         u64 last_len = 0;
1276         u64 skip = 0;
1277         u64 defrag_end = 0;
1278         u64 newer_off = range->start;
1279         unsigned long i;
1280         unsigned long ra_index = 0;
1281         int ret;
1282         int defrag_count = 0;
1283         int compress_type = BTRFS_COMPRESS_ZLIB;
1284         u32 extent_thresh = range->extent_thresh;
1285         unsigned long max_cluster = SZ_256K >> PAGE_SHIFT;
1286         unsigned long cluster = max_cluster;
1287         u64 new_align = ~((u64)SZ_128K - 1);
1288         struct page **pages = NULL;
1289
1290         if (isize == 0)
1291                 return 0;
1292
1293         if (range->start >= isize)
1294                 return -EINVAL;
1295
1296         if (range->flags & BTRFS_DEFRAG_RANGE_COMPRESS) {
1297                 if (range->compress_type > BTRFS_COMPRESS_TYPES)
1298                         return -EINVAL;
1299                 if (range->compress_type)
1300                         compress_type = range->compress_type;
1301         }
1302
1303         if (extent_thresh == 0)
1304                 extent_thresh = SZ_256K;
1305
1306         /*
1307          * if we were not given a file, allocate a readahead
1308          * context
1309          */
1310         if (!file) {
1311                 ra = kzalloc(sizeof(*ra), GFP_NOFS);
1312                 if (!ra)
1313                         return -ENOMEM;
1314                 file_ra_state_init(ra, inode->i_mapping);
1315         } else {
1316                 ra = &file->f_ra;
1317         }
1318
1319         pages = kmalloc_array(max_cluster, sizeof(struct page *),
1320                         GFP_NOFS);
1321         if (!pages) {
1322                 ret = -ENOMEM;
1323                 goto out_ra;
1324         }
1325
1326         /* find the last page to defrag */
1327         if (range->start + range->len > range->start) {
1328                 last_index = min_t(u64, isize - 1,
1329                          range->start + range->len - 1) >> PAGE_SHIFT;
1330         } else {
1331                 last_index = (isize - 1) >> PAGE_SHIFT;
1332         }
1333
1334         if (newer_than) {
1335                 ret = find_new_extents(root, inode, newer_than,
1336                                        &newer_off, SZ_64K);
1337                 if (!ret) {
1338                         range->start = newer_off;
1339                         /*
1340                          * we always align our defrag to help keep
1341                          * the extents in the file evenly spaced
1342                          */
1343                         i = (newer_off & new_align) >> PAGE_SHIFT;
1344                 } else
1345                         goto out_ra;
1346         } else {
1347                 i = range->start >> PAGE_SHIFT;
1348         }
1349         if (!max_to_defrag)
1350                 max_to_defrag = last_index - i + 1;
1351
1352         /*
1353          * make writeback starts from i, so the defrag range can be
1354          * written sequentially.
1355          */
1356         if (i < inode->i_mapping->writeback_index)
1357                 inode->i_mapping->writeback_index = i;
1358
1359         while (i <= last_index && defrag_count < max_to_defrag &&
1360                (i < DIV_ROUND_UP(i_size_read(inode), PAGE_SIZE))) {
1361                 /*
1362                  * make sure we stop running if someone unmounts
1363                  * the FS
1364                  */
1365                 if (!(inode->i_sb->s_flags & MS_ACTIVE))
1366                         break;
1367
1368                 if (btrfs_defrag_cancelled(fs_info)) {
1369                         btrfs_debug(fs_info, "defrag_file cancelled");
1370                         ret = -EAGAIN;
1371                         break;
1372                 }
1373
1374                 if (!should_defrag_range(inode, (u64)i << PAGE_SHIFT,
1375                                          extent_thresh, &last_len, &skip,
1376                                          &defrag_end, range->flags &
1377                                          BTRFS_DEFRAG_RANGE_COMPRESS)) {
1378                         unsigned long next;
1379                         /*
1380                          * the should_defrag function tells us how much to skip
1381                          * bump our counter by the suggested amount
1382                          */
1383                         next = DIV_ROUND_UP(skip, PAGE_SIZE);
1384                         i = max(i + 1, next);
1385                         continue;
1386                 }
1387
1388                 if (!newer_than) {
1389                         cluster = (PAGE_ALIGN(defrag_end) >>
1390                                    PAGE_SHIFT) - i;
1391                         cluster = min(cluster, max_cluster);
1392                 } else {
1393                         cluster = max_cluster;
1394                 }
1395
1396                 if (i + cluster > ra_index) {
1397                         ra_index = max(i, ra_index);
1398                         btrfs_force_ra(inode->i_mapping, ra, file, ra_index,
1399                                        cluster);
1400                         ra_index += cluster;
1401                 }
1402
1403                 inode_lock(inode);
1404                 if (range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)
1405                         BTRFS_I(inode)->force_compress = compress_type;
1406                 ret = cluster_pages_for_defrag(inode, pages, i, cluster);
1407                 if (ret < 0) {
1408                         inode_unlock(inode);
1409                         goto out_ra;
1410                 }
1411
1412                 defrag_count += ret;
1413                 balance_dirty_pages_ratelimited(inode->i_mapping);
1414                 inode_unlock(inode);
1415
1416                 if (newer_than) {
1417                         if (newer_off == (u64)-1)
1418                                 break;
1419
1420                         if (ret > 0)
1421                                 i += ret;
1422
1423                         newer_off = max(newer_off + 1,
1424                                         (u64)i << PAGE_SHIFT);
1425
1426                         ret = find_new_extents(root, inode, newer_than,
1427                                                &newer_off, SZ_64K);
1428                         if (!ret) {
1429                                 range->start = newer_off;
1430                                 i = (newer_off & new_align) >> PAGE_SHIFT;
1431                         } else {
1432                                 break;
1433                         }
1434                 } else {
1435                         if (ret > 0) {
1436                                 i += ret;
1437                                 last_len += ret << PAGE_SHIFT;
1438                         } else {
1439                                 i++;
1440                                 last_len = 0;
1441                         }
1442                 }
1443         }
1444
1445         if ((range->flags & BTRFS_DEFRAG_RANGE_START_IO)) {
1446                 filemap_flush(inode->i_mapping);
1447                 if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
1448                              &BTRFS_I(inode)->runtime_flags))
1449                         filemap_flush(inode->i_mapping);
1450         }
1451
1452         if ((range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)) {
1453                 /* the filemap_flush will queue IO into the worker threads, but
1454                  * we have to make sure the IO is actually started and that
1455                  * ordered extents get created before we return
1456                  */
1457                 atomic_inc(&fs_info->async_submit_draining);
1458                 while (atomic_read(&fs_info->nr_async_submits) ||
1459                        atomic_read(&fs_info->async_delalloc_pages)) {
1460                         wait_event(fs_info->async_submit_wait,
1461                                    (atomic_read(&fs_info->nr_async_submits) == 0 &&
1462                                     atomic_read(&fs_info->async_delalloc_pages) == 0));
1463                 }
1464                 atomic_dec(&fs_info->async_submit_draining);
1465         }
1466
1467         if (range->compress_type == BTRFS_COMPRESS_LZO) {
1468                 btrfs_set_fs_incompat(fs_info, COMPRESS_LZO);
1469         }
1470
1471         ret = defrag_count;
1472
1473 out_ra:
1474         if (range->flags & BTRFS_DEFRAG_RANGE_COMPRESS) {
1475                 inode_lock(inode);
1476                 BTRFS_I(inode)->force_compress = BTRFS_COMPRESS_NONE;
1477                 inode_unlock(inode);
1478         }
1479         if (!file)
1480                 kfree(ra);
1481         kfree(pages);
1482         return ret;
1483 }
1484
1485 static noinline int btrfs_ioctl_resize(struct file *file,
1486                                         void __user *arg)
1487 {
1488         struct inode *inode = file_inode(file);
1489         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1490         u64 new_size;
1491         u64 old_size;
1492         u64 devid = 1;
1493         struct btrfs_root *root = BTRFS_I(inode)->root;
1494         struct btrfs_ioctl_vol_args *vol_args;
1495         struct btrfs_trans_handle *trans;
1496         struct btrfs_device *device = NULL;
1497         char *sizestr;
1498         char *retptr;
1499         char *devstr = NULL;
1500         int ret = 0;
1501         int mod = 0;
1502
1503         if (!capable(CAP_SYS_ADMIN))
1504                 return -EPERM;
1505
1506         ret = mnt_want_write_file(file);
1507         if (ret)
1508                 return ret;
1509
1510         if (test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags)) {
1511                 mnt_drop_write_file(file);
1512                 return BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
1513         }
1514
1515         mutex_lock(&fs_info->volume_mutex);
1516         vol_args = memdup_user(arg, sizeof(*vol_args));
1517         if (IS_ERR(vol_args)) {
1518                 ret = PTR_ERR(vol_args);
1519                 goto out;
1520         }
1521
1522         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1523
1524         sizestr = vol_args->name;
1525         devstr = strchr(sizestr, ':');
1526         if (devstr) {
1527                 sizestr = devstr + 1;
1528                 *devstr = '\0';
1529                 devstr = vol_args->name;
1530                 ret = kstrtoull(devstr, 10, &devid);
1531                 if (ret)
1532                         goto out_free;
1533                 if (!devid) {
1534                         ret = -EINVAL;
1535                         goto out_free;
1536                 }
1537                 btrfs_info(fs_info, "resizing devid %llu", devid);
1538         }
1539
1540         device = btrfs_find_device(fs_info, devid, NULL, NULL);
1541         if (!device) {
1542                 btrfs_info(fs_info, "resizer unable to find device %llu",
1543                            devid);
1544                 ret = -ENODEV;
1545                 goto out_free;
1546         }
1547
1548         if (!device->writeable) {
1549                 btrfs_info(fs_info,
1550                            "resizer unable to apply on readonly device %llu",
1551                        devid);
1552                 ret = -EPERM;
1553                 goto out_free;
1554         }
1555
1556         if (!strcmp(sizestr, "max"))
1557                 new_size = device->bdev->bd_inode->i_size;
1558         else {
1559                 if (sizestr[0] == '-') {
1560                         mod = -1;
1561                         sizestr++;
1562                 } else if (sizestr[0] == '+') {
1563                         mod = 1;
1564                         sizestr++;
1565                 }
1566                 new_size = memparse(sizestr, &retptr);
1567                 if (*retptr != '\0' || new_size == 0) {
1568                         ret = -EINVAL;
1569                         goto out_free;
1570                 }
1571         }
1572
1573         if (device->is_tgtdev_for_dev_replace) {
1574                 ret = -EPERM;
1575                 goto out_free;
1576         }
1577
1578         old_size = btrfs_device_get_total_bytes(device);
1579
1580         if (mod < 0) {
1581                 if (new_size > old_size) {
1582                         ret = -EINVAL;
1583                         goto out_free;
1584                 }
1585                 new_size = old_size - new_size;
1586         } else if (mod > 0) {
1587                 if (new_size > ULLONG_MAX - old_size) {
1588                         ret = -ERANGE;
1589                         goto out_free;
1590                 }
1591                 new_size = old_size + new_size;
1592         }
1593
1594         if (new_size < SZ_256M) {
1595                 ret = -EINVAL;
1596                 goto out_free;
1597         }
1598         if (new_size > device->bdev->bd_inode->i_size) {
1599                 ret = -EFBIG;
1600                 goto out_free;
1601         }
1602
1603         new_size = div_u64(new_size, fs_info->sectorsize);
1604         new_size *= fs_info->sectorsize;
1605
1606         btrfs_info_in_rcu(fs_info, "new size for %s is %llu",
1607                           rcu_str_deref(device->name), new_size);
1608
1609         if (new_size > old_size) {
1610                 trans = btrfs_start_transaction(root, 0);
1611                 if (IS_ERR(trans)) {
1612                         ret = PTR_ERR(trans);
1613                         goto out_free;
1614                 }
1615                 ret = btrfs_grow_device(trans, device, new_size);
1616                 btrfs_commit_transaction(trans);
1617         } else if (new_size < old_size) {
1618                 ret = btrfs_shrink_device(device, new_size);
1619         } /* equal, nothing need to do */
1620
1621 out_free:
1622         kfree(vol_args);
1623 out:
1624         mutex_unlock(&fs_info->volume_mutex);
1625         clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
1626         mnt_drop_write_file(file);
1627         return ret;
1628 }
1629
1630 static noinline int btrfs_ioctl_snap_create_transid(struct file *file,
1631                                 const char *name, unsigned long fd, int subvol,
1632                                 u64 *transid, bool readonly,
1633                                 struct btrfs_qgroup_inherit *inherit)
1634 {
1635         int namelen;
1636         int ret = 0;
1637
1638         if (!S_ISDIR(file_inode(file)->i_mode))
1639                 return -ENOTDIR;
1640
1641         ret = mnt_want_write_file(file);
1642         if (ret)
1643                 goto out;
1644
1645         namelen = strlen(name);
1646         if (strchr(name, '/')) {
1647                 ret = -EINVAL;
1648                 goto out_drop_write;
1649         }
1650
1651         if (name[0] == '.' &&
1652            (namelen == 1 || (name[1] == '.' && namelen == 2))) {
1653                 ret = -EEXIST;
1654                 goto out_drop_write;
1655         }
1656
1657         if (subvol) {
1658                 ret = btrfs_mksubvol(&file->f_path, name, namelen,
1659                                      NULL, transid, readonly, inherit);
1660         } else {
1661                 struct fd src = fdget(fd);
1662                 struct inode *src_inode;
1663                 if (!src.file) {
1664                         ret = -EINVAL;
1665                         goto out_drop_write;
1666                 }
1667
1668                 src_inode = file_inode(src.file);
1669                 if (src_inode->i_sb != file_inode(file)->i_sb) {
1670                         btrfs_info(BTRFS_I(file_inode(file))->root->fs_info,
1671                                    "Snapshot src from another FS");
1672                         ret = -EXDEV;
1673                 } else if (!inode_owner_or_capable(src_inode)) {
1674                         /*
1675                          * Subvolume creation is not restricted, but snapshots
1676                          * are limited to own subvolumes only
1677                          */
1678                         ret = -EPERM;
1679                 } else {
1680                         ret = btrfs_mksubvol(&file->f_path, name, namelen,
1681                                              BTRFS_I(src_inode)->root,
1682                                              transid, readonly, inherit);
1683                 }
1684                 fdput(src);
1685         }
1686 out_drop_write:
1687         mnt_drop_write_file(file);
1688 out:
1689         return ret;
1690 }
1691
1692 static noinline int btrfs_ioctl_snap_create(struct file *file,
1693                                             void __user *arg, int subvol)
1694 {
1695         struct btrfs_ioctl_vol_args *vol_args;
1696         int ret;
1697
1698         if (!S_ISDIR(file_inode(file)->i_mode))
1699                 return -ENOTDIR;
1700
1701         vol_args = memdup_user(arg, sizeof(*vol_args));
1702         if (IS_ERR(vol_args))
1703                 return PTR_ERR(vol_args);
1704         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1705
1706         ret = btrfs_ioctl_snap_create_transid(file, vol_args->name,
1707                                               vol_args->fd, subvol,
1708                                               NULL, false, NULL);
1709
1710         kfree(vol_args);
1711         return ret;
1712 }
1713
1714 static noinline int btrfs_ioctl_snap_create_v2(struct file *file,
1715                                                void __user *arg, int subvol)
1716 {
1717         struct btrfs_ioctl_vol_args_v2 *vol_args;
1718         int ret;
1719         u64 transid = 0;
1720         u64 *ptr = NULL;
1721         bool readonly = false;
1722         struct btrfs_qgroup_inherit *inherit = NULL;
1723
1724         if (!S_ISDIR(file_inode(file)->i_mode))
1725                 return -ENOTDIR;
1726
1727         vol_args = memdup_user(arg, sizeof(*vol_args));
1728         if (IS_ERR(vol_args))
1729                 return PTR_ERR(vol_args);
1730         vol_args->name[BTRFS_SUBVOL_NAME_MAX] = '\0';
1731
1732         if (vol_args->flags &
1733             ~(BTRFS_SUBVOL_CREATE_ASYNC | BTRFS_SUBVOL_RDONLY |
1734               BTRFS_SUBVOL_QGROUP_INHERIT)) {
1735                 ret = -EOPNOTSUPP;
1736                 goto free_args;
1737         }
1738
1739         if (vol_args->flags & BTRFS_SUBVOL_CREATE_ASYNC)
1740                 ptr = &transid;
1741         if (vol_args->flags & BTRFS_SUBVOL_RDONLY)
1742                 readonly = true;
1743         if (vol_args->flags & BTRFS_SUBVOL_QGROUP_INHERIT) {
1744                 if (vol_args->size > PAGE_SIZE) {
1745                         ret = -EINVAL;
1746                         goto free_args;
1747                 }
1748                 inherit = memdup_user(vol_args->qgroup_inherit, vol_args->size);
1749                 if (IS_ERR(inherit)) {
1750                         ret = PTR_ERR(inherit);
1751                         goto free_args;
1752                 }
1753         }
1754
1755         ret = btrfs_ioctl_snap_create_transid(file, vol_args->name,
1756                                               vol_args->fd, subvol, ptr,
1757                                               readonly, inherit);
1758         if (ret)
1759                 goto free_inherit;
1760
1761         if (ptr && copy_to_user(arg +
1762                                 offsetof(struct btrfs_ioctl_vol_args_v2,
1763                                         transid),
1764                                 ptr, sizeof(*ptr)))
1765                 ret = -EFAULT;
1766
1767 free_inherit:
1768         kfree(inherit);
1769 free_args:
1770         kfree(vol_args);
1771         return ret;
1772 }
1773
1774 static noinline int btrfs_ioctl_subvol_getflags(struct file *file,
1775                                                 void __user *arg)
1776 {
1777         struct inode *inode = file_inode(file);
1778         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1779         struct btrfs_root *root = BTRFS_I(inode)->root;
1780         int ret = 0;
1781         u64 flags = 0;
1782
1783         if (btrfs_ino(BTRFS_I(inode)) != BTRFS_FIRST_FREE_OBJECTID)
1784                 return -EINVAL;
1785
1786         down_read(&fs_info->subvol_sem);
1787         if (btrfs_root_readonly(root))
1788                 flags |= BTRFS_SUBVOL_RDONLY;
1789         up_read(&fs_info->subvol_sem);
1790
1791         if (copy_to_user(arg, &flags, sizeof(flags)))
1792                 ret = -EFAULT;
1793
1794         return ret;
1795 }
1796
1797 static noinline int btrfs_ioctl_subvol_setflags(struct file *file,
1798                                               void __user *arg)
1799 {
1800         struct inode *inode = file_inode(file);
1801         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1802         struct btrfs_root *root = BTRFS_I(inode)->root;
1803         struct btrfs_trans_handle *trans;
1804         u64 root_flags;
1805         u64 flags;
1806         int ret = 0;
1807
1808         if (!inode_owner_or_capable(inode))
1809                 return -EPERM;
1810
1811         ret = mnt_want_write_file(file);
1812         if (ret)
1813                 goto out;
1814
1815         if (btrfs_ino(BTRFS_I(inode)) != BTRFS_FIRST_FREE_OBJECTID) {
1816                 ret = -EINVAL;
1817                 goto out_drop_write;
1818         }
1819
1820         if (copy_from_user(&flags, arg, sizeof(flags))) {
1821                 ret = -EFAULT;
1822                 goto out_drop_write;
1823         }
1824
1825         if (flags & BTRFS_SUBVOL_CREATE_ASYNC) {
1826                 ret = -EINVAL;
1827                 goto out_drop_write;
1828         }
1829
1830         if (flags & ~BTRFS_SUBVOL_RDONLY) {
1831                 ret = -EOPNOTSUPP;
1832                 goto out_drop_write;
1833         }
1834
1835         down_write(&fs_info->subvol_sem);
1836
1837         /* nothing to do */
1838         if (!!(flags & BTRFS_SUBVOL_RDONLY) == btrfs_root_readonly(root))
1839                 goto out_drop_sem;
1840
1841         root_flags = btrfs_root_flags(&root->root_item);
1842         if (flags & BTRFS_SUBVOL_RDONLY) {
1843                 btrfs_set_root_flags(&root->root_item,
1844                                      root_flags | BTRFS_ROOT_SUBVOL_RDONLY);
1845         } else {
1846                 /*
1847                  * Block RO -> RW transition if this subvolume is involved in
1848                  * send
1849                  */
1850                 spin_lock(&root->root_item_lock);
1851                 if (root->send_in_progress == 0) {
1852                         btrfs_set_root_flags(&root->root_item,
1853                                      root_flags & ~BTRFS_ROOT_SUBVOL_RDONLY);
1854                         spin_unlock(&root->root_item_lock);
1855                 } else {
1856                         spin_unlock(&root->root_item_lock);
1857                         btrfs_warn(fs_info,
1858                                    "Attempt to set subvolume %llu read-write during send",
1859                                    root->root_key.objectid);
1860                         ret = -EPERM;
1861                         goto out_drop_sem;
1862                 }
1863         }
1864
1865         trans = btrfs_start_transaction(root, 1);
1866         if (IS_ERR(trans)) {
1867                 ret = PTR_ERR(trans);
1868                 goto out_reset;
1869         }
1870
1871         ret = btrfs_update_root(trans, fs_info->tree_root,
1872                                 &root->root_key, &root->root_item);
1873
1874         btrfs_commit_transaction(trans);
1875 out_reset:
1876         if (ret)
1877                 btrfs_set_root_flags(&root->root_item, root_flags);
1878 out_drop_sem:
1879         up_write(&fs_info->subvol_sem);
1880 out_drop_write:
1881         mnt_drop_write_file(file);
1882 out:
1883         return ret;
1884 }
1885
1886 /*
1887  * helper to check if the subvolume references other subvolumes
1888  */
1889 static noinline int may_destroy_subvol(struct btrfs_root *root)
1890 {
1891         struct btrfs_fs_info *fs_info = root->fs_info;
1892         struct btrfs_path *path;
1893         struct btrfs_dir_item *di;
1894         struct btrfs_key key;
1895         u64 dir_id;
1896         int ret;
1897
1898         path = btrfs_alloc_path();
1899         if (!path)
1900                 return -ENOMEM;
1901
1902         /* Make sure this root isn't set as the default subvol */
1903         dir_id = btrfs_super_root_dir(fs_info->super_copy);
1904         di = btrfs_lookup_dir_item(NULL, fs_info->tree_root, path,
1905                                    dir_id, "default", 7, 0);
1906         if (di && !IS_ERR(di)) {
1907                 btrfs_dir_item_key_to_cpu(path->nodes[0], di, &key);
1908                 if (key.objectid == root->root_key.objectid) {
1909                         ret = -EPERM;
1910                         btrfs_err(fs_info,
1911                                   "deleting default subvolume %llu is not allowed",
1912                                   key.objectid);
1913                         goto out;
1914                 }
1915                 btrfs_release_path(path);
1916         }
1917
1918         key.objectid = root->root_key.objectid;
1919         key.type = BTRFS_ROOT_REF_KEY;
1920         key.offset = (u64)-1;
1921
1922         ret = btrfs_search_slot(NULL, fs_info->tree_root, &key, path, 0, 0);
1923         if (ret < 0)
1924                 goto out;
1925         BUG_ON(ret == 0);
1926
1927         ret = 0;
1928         if (path->slots[0] > 0) {
1929                 path->slots[0]--;
1930                 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
1931                 if (key.objectid == root->root_key.objectid &&
1932                     key.type == BTRFS_ROOT_REF_KEY)
1933                         ret = -ENOTEMPTY;
1934         }
1935 out:
1936         btrfs_free_path(path);
1937         return ret;
1938 }
1939
1940 static noinline int key_in_sk(struct btrfs_key *key,
1941                               struct btrfs_ioctl_search_key *sk)
1942 {
1943         struct btrfs_key test;
1944         int ret;
1945
1946         test.objectid = sk->min_objectid;
1947         test.type = sk->min_type;
1948         test.offset = sk->min_offset;
1949
1950         ret = btrfs_comp_cpu_keys(key, &test);
1951         if (ret < 0)
1952                 return 0;
1953
1954         test.objectid = sk->max_objectid;
1955         test.type = sk->max_type;
1956         test.offset = sk->max_offset;
1957
1958         ret = btrfs_comp_cpu_keys(key, &test);
1959         if (ret > 0)
1960                 return 0;
1961         return 1;
1962 }
1963
1964 static noinline int copy_to_sk(struct btrfs_path *path,
1965                                struct btrfs_key *key,
1966                                struct btrfs_ioctl_search_key *sk,
1967                                size_t *buf_size,
1968                                char __user *ubuf,
1969                                unsigned long *sk_offset,
1970                                int *num_found)
1971 {
1972         u64 found_transid;
1973         struct extent_buffer *leaf;
1974         struct btrfs_ioctl_search_header sh;
1975         struct btrfs_key test;
1976         unsigned long item_off;
1977         unsigned long item_len;
1978         int nritems;
1979         int i;
1980         int slot;
1981         int ret = 0;
1982
1983         leaf = path->nodes[0];
1984         slot = path->slots[0];
1985         nritems = btrfs_header_nritems(leaf);
1986
1987         if (btrfs_header_generation(leaf) > sk->max_transid) {
1988                 i = nritems;
1989                 goto advance_key;
1990         }
1991         found_transid = btrfs_header_generation(leaf);
1992
1993         for (i = slot; i < nritems; i++) {
1994                 item_off = btrfs_item_ptr_offset(leaf, i);
1995                 item_len = btrfs_item_size_nr(leaf, i);
1996
1997                 btrfs_item_key_to_cpu(leaf, key, i);
1998                 if (!key_in_sk(key, sk))
1999                         continue;
2000
2001                 if (sizeof(sh) + item_len > *buf_size) {
2002                         if (*num_found) {
2003                                 ret = 1;
2004                                 goto out;
2005                         }
2006
2007                         /*
2008                          * return one empty item back for v1, which does not
2009                          * handle -EOVERFLOW
2010                          */
2011
2012                         *buf_size = sizeof(sh) + item_len;
2013                         item_len = 0;
2014                         ret = -EOVERFLOW;
2015                 }
2016
2017                 if (sizeof(sh) + item_len + *sk_offset > *buf_size) {
2018                         ret = 1;
2019                         goto out;
2020                 }
2021
2022                 sh.objectid = key->objectid;
2023                 sh.offset = key->offset;
2024                 sh.type = key->type;
2025                 sh.len = item_len;
2026                 sh.transid = found_transid;
2027
2028                 /* copy search result header */
2029                 if (copy_to_user(ubuf + *sk_offset, &sh, sizeof(sh))) {
2030                         ret = -EFAULT;
2031                         goto out;
2032                 }
2033
2034                 *sk_offset += sizeof(sh);
2035
2036                 if (item_len) {
2037                         char __user *up = ubuf + *sk_offset;
2038                         /* copy the item */
2039                         if (read_extent_buffer_to_user(leaf, up,
2040                                                        item_off, item_len)) {
2041                                 ret = -EFAULT;
2042                                 goto out;
2043                         }
2044
2045                         *sk_offset += item_len;
2046                 }
2047                 (*num_found)++;
2048
2049                 if (ret) /* -EOVERFLOW from above */
2050                         goto out;
2051
2052                 if (*num_found >= sk->nr_items) {
2053                         ret = 1;
2054                         goto out;
2055                 }
2056         }
2057 advance_key:
2058         ret = 0;
2059         test.objectid = sk->max_objectid;
2060         test.type = sk->max_type;
2061         test.offset = sk->max_offset;
2062         if (btrfs_comp_cpu_keys(key, &test) >= 0)
2063                 ret = 1;
2064         else if (key->offset < (u64)-1)
2065                 key->offset++;
2066         else if (key->type < (u8)-1) {
2067                 key->offset = 0;
2068                 key->type++;
2069         } else if (key->objectid < (u64)-1) {
2070                 key->offset = 0;
2071                 key->type = 0;
2072                 key->objectid++;
2073         } else
2074                 ret = 1;
2075 out:
2076         /*
2077          *  0: all items from this leaf copied, continue with next
2078          *  1: * more items can be copied, but unused buffer is too small
2079          *     * all items were found
2080          *     Either way, it will stops the loop which iterates to the next
2081          *     leaf
2082          *  -EOVERFLOW: item was to large for buffer
2083          *  -EFAULT: could not copy extent buffer back to userspace
2084          */
2085         return ret;
2086 }
2087
2088 static noinline int search_ioctl(struct inode *inode,
2089                                  struct btrfs_ioctl_search_key *sk,
2090                                  size_t *buf_size,
2091                                  char __user *ubuf)
2092 {
2093         struct btrfs_fs_info *info = btrfs_sb(inode->i_sb);
2094         struct btrfs_root *root;
2095         struct btrfs_key key;
2096         struct btrfs_path *path;
2097         int ret;
2098         int num_found = 0;
2099         unsigned long sk_offset = 0;
2100
2101         if (*buf_size < sizeof(struct btrfs_ioctl_search_header)) {
2102                 *buf_size = sizeof(struct btrfs_ioctl_search_header);
2103                 return -EOVERFLOW;
2104         }
2105
2106         path = btrfs_alloc_path();
2107         if (!path)
2108                 return -ENOMEM;
2109
2110         if (sk->tree_id == 0) {
2111                 /* search the root of the inode that was passed */
2112                 root = BTRFS_I(inode)->root;
2113         } else {
2114                 key.objectid = sk->tree_id;
2115                 key.type = BTRFS_ROOT_ITEM_KEY;
2116                 key.offset = (u64)-1;
2117                 root = btrfs_read_fs_root_no_name(info, &key);
2118                 if (IS_ERR(root)) {
2119                         btrfs_free_path(path);
2120                         return -ENOENT;
2121                 }
2122         }
2123
2124         key.objectid = sk->min_objectid;
2125         key.type = sk->min_type;
2126         key.offset = sk->min_offset;
2127
2128         while (1) {
2129                 ret = btrfs_search_forward(root, &key, path, sk->min_transid);
2130                 if (ret != 0) {
2131                         if (ret > 0)
2132                                 ret = 0;
2133                         goto err;
2134                 }
2135                 ret = copy_to_sk(path, &key, sk, buf_size, ubuf,
2136                                  &sk_offset, &num_found);
2137                 btrfs_release_path(path);
2138                 if (ret)
2139                         break;
2140
2141         }
2142         if (ret > 0)
2143                 ret = 0;
2144 err:
2145         sk->nr_items = num_found;
2146         btrfs_free_path(path);
2147         return ret;
2148 }
2149
2150 static noinline int btrfs_ioctl_tree_search(struct file *file,
2151                                            void __user *argp)
2152 {
2153         struct btrfs_ioctl_search_args __user *uargs;
2154         struct btrfs_ioctl_search_key sk;
2155         struct inode *inode;
2156         int ret;
2157         size_t buf_size;
2158
2159         if (!capable(CAP_SYS_ADMIN))
2160                 return -EPERM;
2161
2162         uargs = (struct btrfs_ioctl_search_args __user *)argp;
2163
2164         if (copy_from_user(&sk, &uargs->key, sizeof(sk)))
2165                 return -EFAULT;
2166
2167         buf_size = sizeof(uargs->buf);
2168
2169         inode = file_inode(file);
2170         ret = search_ioctl(inode, &sk, &buf_size, uargs->buf);
2171
2172         /*
2173          * In the origin implementation an overflow is handled by returning a
2174          * search header with a len of zero, so reset ret.
2175          */
2176         if (ret == -EOVERFLOW)
2177                 ret = 0;
2178
2179         if (ret == 0 && copy_to_user(&uargs->key, &sk, sizeof(sk)))
2180                 ret = -EFAULT;
2181         return ret;
2182 }
2183
2184 static noinline int btrfs_ioctl_tree_search_v2(struct file *file,
2185                                                void __user *argp)
2186 {
2187         struct btrfs_ioctl_search_args_v2 __user *uarg;
2188         struct btrfs_ioctl_search_args_v2 args;
2189         struct inode *inode;
2190         int ret;
2191         size_t buf_size;
2192         const size_t buf_limit = SZ_16M;
2193
2194         if (!capable(CAP_SYS_ADMIN))
2195                 return -EPERM;
2196
2197         /* copy search header and buffer size */
2198         uarg = (struct btrfs_ioctl_search_args_v2 __user *)argp;
2199         if (copy_from_user(&args, uarg, sizeof(args)))
2200                 return -EFAULT;
2201
2202         buf_size = args.buf_size;
2203
2204         if (buf_size < sizeof(struct btrfs_ioctl_search_header))
2205                 return -EOVERFLOW;
2206
2207         /* limit result size to 16MB */
2208         if (buf_size > buf_limit)
2209                 buf_size = buf_limit;
2210
2211         inode = file_inode(file);
2212         ret = search_ioctl(inode, &args.key, &buf_size,
2213                            (char *)(&uarg->buf[0]));
2214         if (ret == 0 && copy_to_user(&uarg->key, &args.key, sizeof(args.key)))
2215                 ret = -EFAULT;
2216         else if (ret == -EOVERFLOW &&
2217                 copy_to_user(&uarg->buf_size, &buf_size, sizeof(buf_size)))
2218                 ret = -EFAULT;
2219
2220         return ret;
2221 }
2222
2223 /*
2224  * Search INODE_REFs to identify path name of 'dirid' directory
2225  * in a 'tree_id' tree. and sets path name to 'name'.
2226  */
2227 static noinline int btrfs_search_path_in_tree(struct btrfs_fs_info *info,
2228                                 u64 tree_id, u64 dirid, char *name)
2229 {
2230         struct btrfs_root *root;
2231         struct btrfs_key key;
2232         char *ptr;
2233         int ret = -1;
2234         int slot;
2235         int len;
2236         int total_len = 0;
2237         struct btrfs_inode_ref *iref;
2238         struct extent_buffer *l;
2239         struct btrfs_path *path;
2240
2241         if (dirid == BTRFS_FIRST_FREE_OBJECTID) {
2242                 name[0]='\0';
2243                 return 0;
2244         }
2245
2246         path = btrfs_alloc_path();
2247         if (!path)
2248                 return -ENOMEM;
2249
2250         ptr = &name[BTRFS_INO_LOOKUP_PATH_MAX];
2251
2252         key.objectid = tree_id;
2253         key.type = BTRFS_ROOT_ITEM_KEY;
2254         key.offset = (u64)-1;
2255         root = btrfs_read_fs_root_no_name(info, &key);
2256         if (IS_ERR(root)) {
2257                 btrfs_err(info, "could not find root %llu", tree_id);
2258                 ret = -ENOENT;
2259                 goto out;
2260         }
2261
2262         key.objectid = dirid;
2263         key.type = BTRFS_INODE_REF_KEY;
2264         key.offset = (u64)-1;
2265
2266         while (1) {
2267                 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2268                 if (ret < 0)
2269                         goto out;
2270                 else if (ret > 0) {
2271                         ret = btrfs_previous_item(root, path, dirid,
2272                                                   BTRFS_INODE_REF_KEY);
2273                         if (ret < 0)
2274                                 goto out;
2275                         else if (ret > 0) {
2276                                 ret = -ENOENT;
2277                                 goto out;
2278                         }
2279                 }
2280
2281                 l = path->nodes[0];
2282                 slot = path->slots[0];
2283                 btrfs_item_key_to_cpu(l, &key, slot);
2284
2285                 iref = btrfs_item_ptr(l, slot, struct btrfs_inode_ref);
2286                 len = btrfs_inode_ref_name_len(l, iref);
2287                 ptr -= len + 1;
2288                 total_len += len + 1;
2289                 if (ptr < name) {
2290                         ret = -ENAMETOOLONG;
2291                         goto out;
2292                 }
2293
2294                 *(ptr + len) = '/';
2295                 read_extent_buffer(l, ptr, (unsigned long)(iref + 1), len);
2296
2297                 if (key.offset == BTRFS_FIRST_FREE_OBJECTID)
2298                         break;
2299
2300                 btrfs_release_path(path);
2301                 key.objectid = key.offset;
2302                 key.offset = (u64)-1;
2303                 dirid = key.objectid;
2304         }
2305         memmove(name, ptr, total_len);
2306         name[total_len] = '\0';
2307         ret = 0;
2308 out:
2309         btrfs_free_path(path);
2310         return ret;
2311 }
2312
2313 static noinline int btrfs_ioctl_ino_lookup(struct file *file,
2314                                            void __user *argp)
2315 {
2316          struct btrfs_ioctl_ino_lookup_args *args;
2317          struct inode *inode;
2318         int ret = 0;
2319
2320         args = memdup_user(argp, sizeof(*args));
2321         if (IS_ERR(args))
2322                 return PTR_ERR(args);
2323
2324         inode = file_inode(file);
2325
2326         /*
2327          * Unprivileged query to obtain the containing subvolume root id. The
2328          * path is reset so it's consistent with btrfs_search_path_in_tree.
2329          */
2330         if (args->treeid == 0)
2331                 args->treeid = BTRFS_I(inode)->root->root_key.objectid;
2332
2333         if (args->objectid == BTRFS_FIRST_FREE_OBJECTID) {
2334                 args->name[0] = 0;
2335                 goto out;
2336         }
2337
2338         if (!capable(CAP_SYS_ADMIN)) {
2339                 ret = -EPERM;
2340                 goto out;
2341         }
2342
2343         ret = btrfs_search_path_in_tree(BTRFS_I(inode)->root->fs_info,
2344                                         args->treeid, args->objectid,
2345                                         args->name);
2346
2347 out:
2348         if (ret == 0 && copy_to_user(argp, args, sizeof(*args)))
2349                 ret = -EFAULT;
2350
2351         kfree(args);
2352         return ret;
2353 }
2354
2355 static noinline int btrfs_ioctl_snap_destroy(struct file *file,
2356                                              void __user *arg)
2357 {
2358         struct dentry *parent = file->f_path.dentry;
2359         struct btrfs_fs_info *fs_info = btrfs_sb(parent->d_sb);
2360         struct dentry *dentry;
2361         struct inode *dir = d_inode(parent);
2362         struct inode *inode;
2363         struct btrfs_root *root = BTRFS_I(dir)->root;
2364         struct btrfs_root *dest = NULL;
2365         struct btrfs_ioctl_vol_args *vol_args;
2366         struct btrfs_trans_handle *trans;
2367         struct btrfs_block_rsv block_rsv;
2368         u64 root_flags;
2369         u64 qgroup_reserved;
2370         int namelen;
2371         int ret;
2372         int err = 0;
2373
2374         if (!S_ISDIR(dir->i_mode))
2375                 return -ENOTDIR;
2376
2377         vol_args = memdup_user(arg, sizeof(*vol_args));
2378         if (IS_ERR(vol_args))
2379                 return PTR_ERR(vol_args);
2380
2381         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
2382         namelen = strlen(vol_args->name);
2383         if (strchr(vol_args->name, '/') ||
2384             strncmp(vol_args->name, "..", namelen) == 0) {
2385                 err = -EINVAL;
2386                 goto out;
2387         }
2388
2389         err = mnt_want_write_file(file);
2390         if (err)
2391                 goto out;
2392
2393
2394         err = down_write_killable_nested(&dir->i_rwsem, I_MUTEX_PARENT);
2395         if (err == -EINTR)
2396                 goto out_drop_write;
2397         dentry = lookup_one_len(vol_args->name, parent, namelen);
2398         if (IS_ERR(dentry)) {
2399                 err = PTR_ERR(dentry);
2400                 goto out_unlock_dir;
2401         }
2402
2403         if (d_really_is_negative(dentry)) {
2404                 err = -ENOENT;
2405                 goto out_dput;
2406         }
2407
2408         inode = d_inode(dentry);
2409         dest = BTRFS_I(inode)->root;
2410         if (!capable(CAP_SYS_ADMIN)) {
2411                 /*
2412                  * Regular user.  Only allow this with a special mount
2413                  * option, when the user has write+exec access to the
2414                  * subvol root, and when rmdir(2) would have been
2415                  * allowed.
2416                  *
2417                  * Note that this is _not_ check that the subvol is
2418                  * empty or doesn't contain data that we wouldn't
2419                  * otherwise be able to delete.
2420                  *
2421                  * Users who want to delete empty subvols should try
2422                  * rmdir(2).
2423                  */
2424                 err = -EPERM;
2425                 if (!btrfs_test_opt(fs_info, USER_SUBVOL_RM_ALLOWED))
2426                         goto out_dput;
2427
2428                 /*
2429                  * Do not allow deletion if the parent dir is the same
2430                  * as the dir to be deleted.  That means the ioctl
2431                  * must be called on the dentry referencing the root
2432                  * of the subvol, not a random directory contained
2433                  * within it.
2434                  */
2435                 err = -EINVAL;
2436                 if (root == dest)
2437                         goto out_dput;
2438
2439                 err = inode_permission(inode, MAY_WRITE | MAY_EXEC);
2440                 if (err)
2441                         goto out_dput;
2442         }
2443
2444         /* check if subvolume may be deleted by a user */
2445         err = btrfs_may_delete(dir, dentry, 1);
2446         if (err)
2447                 goto out_dput;
2448
2449         if (btrfs_ino(BTRFS_I(inode)) != BTRFS_FIRST_FREE_OBJECTID) {
2450                 err = -EINVAL;
2451                 goto out_dput;
2452         }
2453
2454         inode_lock(inode);
2455
2456         /*
2457          * Don't allow to delete a subvolume with send in progress. This is
2458          * inside the i_mutex so the error handling that has to drop the bit
2459          * again is not run concurrently.
2460          */
2461         spin_lock(&dest->root_item_lock);
2462         root_flags = btrfs_root_flags(&dest->root_item);
2463         if (dest->send_in_progress == 0) {
2464                 btrfs_set_root_flags(&dest->root_item,
2465                                 root_flags | BTRFS_ROOT_SUBVOL_DEAD);
2466                 spin_unlock(&dest->root_item_lock);
2467         } else {
2468                 spin_unlock(&dest->root_item_lock);
2469                 btrfs_warn(fs_info,
2470                            "Attempt to delete subvolume %llu during send",
2471                            dest->root_key.objectid);
2472                 err = -EPERM;
2473                 goto out_unlock_inode;
2474         }
2475
2476         down_write(&fs_info->subvol_sem);
2477
2478         err = may_destroy_subvol(dest);
2479         if (err)
2480                 goto out_up_write;
2481
2482         btrfs_init_block_rsv(&block_rsv, BTRFS_BLOCK_RSV_TEMP);
2483         /*
2484          * One for dir inode, two for dir entries, two for root
2485          * ref/backref.
2486          */
2487         err = btrfs_subvolume_reserve_metadata(root, &block_rsv,
2488                                                5, &qgroup_reserved, true);
2489         if (err)
2490                 goto out_up_write;
2491
2492         trans = btrfs_start_transaction(root, 0);
2493         if (IS_ERR(trans)) {
2494                 err = PTR_ERR(trans);
2495                 goto out_release;
2496         }
2497         trans->block_rsv = &block_rsv;
2498         trans->bytes_reserved = block_rsv.size;
2499
2500         btrfs_record_snapshot_destroy(trans, BTRFS_I(dir));
2501
2502         ret = btrfs_unlink_subvol(trans, root, dir,
2503                                 dest->root_key.objectid,
2504                                 dentry->d_name.name,
2505                                 dentry->d_name.len);
2506         if (ret) {
2507                 err = ret;
2508                 btrfs_abort_transaction(trans, ret);
2509                 goto out_end_trans;
2510         }
2511
2512         btrfs_record_root_in_trans(trans, dest);
2513
2514         memset(&dest->root_item.drop_progress, 0,
2515                 sizeof(dest->root_item.drop_progress));
2516         dest->root_item.drop_level = 0;
2517         btrfs_set_root_refs(&dest->root_item, 0);
2518
2519         if (!test_and_set_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &dest->state)) {
2520                 ret = btrfs_insert_orphan_item(trans,
2521                                         fs_info->tree_root,
2522                                         dest->root_key.objectid);
2523                 if (ret) {
2524                         btrfs_abort_transaction(trans, ret);
2525                         err = ret;
2526                         goto out_end_trans;
2527                 }
2528         }
2529
2530         ret = btrfs_uuid_tree_rem(trans, fs_info, dest->root_item.uuid,
2531                                   BTRFS_UUID_KEY_SUBVOL,
2532                                   dest->root_key.objectid);
2533         if (ret && ret != -ENOENT) {
2534                 btrfs_abort_transaction(trans, ret);
2535                 err = ret;
2536                 goto out_end_trans;
2537         }
2538         if (!btrfs_is_empty_uuid(dest->root_item.received_uuid)) {
2539                 ret = btrfs_uuid_tree_rem(trans, fs_info,
2540                                           dest->root_item.received_uuid,
2541                                           BTRFS_UUID_KEY_RECEIVED_SUBVOL,
2542                                           dest->root_key.objectid);
2543                 if (ret && ret != -ENOENT) {
2544                         btrfs_abort_transaction(trans, ret);
2545                         err = ret;
2546                         goto out_end_trans;
2547                 }
2548         }
2549
2550 out_end_trans:
2551         trans->block_rsv = NULL;
2552         trans->bytes_reserved = 0;
2553         ret = btrfs_end_transaction(trans);
2554         if (ret && !err)
2555                 err = ret;
2556         inode->i_flags |= S_DEAD;
2557 out_release:
2558         btrfs_subvolume_release_metadata(fs_info, &block_rsv);
2559 out_up_write:
2560         up_write(&fs_info->subvol_sem);
2561         if (err) {
2562                 spin_lock(&dest->root_item_lock);
2563                 root_flags = btrfs_root_flags(&dest->root_item);
2564                 btrfs_set_root_flags(&dest->root_item,
2565                                 root_flags & ~BTRFS_ROOT_SUBVOL_DEAD);
2566                 spin_unlock(&dest->root_item_lock);
2567         }
2568 out_unlock_inode:
2569         inode_unlock(inode);
2570         if (!err) {
2571                 d_invalidate(dentry);
2572                 btrfs_invalidate_inodes(dest);
2573                 d_delete(dentry);
2574                 ASSERT(dest->send_in_progress == 0);
2575
2576                 /* the last ref */
2577                 if (dest->ino_cache_inode) {
2578                         iput(dest->ino_cache_inode);
2579                         dest->ino_cache_inode = NULL;
2580                 }
2581         }
2582 out_dput:
2583         dput(dentry);
2584 out_unlock_dir:
2585         inode_unlock(dir);
2586 out_drop_write:
2587         mnt_drop_write_file(file);
2588 out:
2589         kfree(vol_args);
2590         return err;
2591 }
2592
2593 static int btrfs_ioctl_defrag(struct file *file, void __user *argp)
2594 {
2595         struct inode *inode = file_inode(file);
2596         struct btrfs_root *root = BTRFS_I(inode)->root;
2597         struct btrfs_ioctl_defrag_range_args *range;
2598         int ret;
2599
2600         ret = mnt_want_write_file(file);
2601         if (ret)
2602                 return ret;
2603
2604         if (btrfs_root_readonly(root)) {
2605                 ret = -EROFS;
2606                 goto out;
2607         }
2608
2609         switch (inode->i_mode & S_IFMT) {
2610         case S_IFDIR:
2611                 if (!capable(CAP_SYS_ADMIN)) {
2612                         ret = -EPERM;
2613                         goto out;
2614                 }
2615                 ret = btrfs_defrag_root(root);
2616                 break;
2617         case S_IFREG:
2618                 if (!(file->f_mode & FMODE_WRITE)) {
2619                         ret = -EINVAL;
2620                         goto out;
2621                 }
2622
2623                 range = kzalloc(sizeof(*range), GFP_KERNEL);
2624                 if (!range) {
2625                         ret = -ENOMEM;
2626                         goto out;
2627                 }
2628
2629                 if (argp) {
2630                         if (copy_from_user(range, argp,
2631                                            sizeof(*range))) {
2632                                 ret = -EFAULT;
2633                                 kfree(range);
2634                                 goto out;
2635                         }
2636                         /* compression requires us to start the IO */
2637                         if ((range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)) {
2638                                 range->flags |= BTRFS_DEFRAG_RANGE_START_IO;
2639                                 range->extent_thresh = (u32)-1;
2640                         }
2641                 } else {
2642                         /* the rest are all set to zero by kzalloc */
2643                         range->len = (u64)-1;
2644                 }
2645                 ret = btrfs_defrag_file(file_inode(file), file,
2646                                         range, 0, 0);
2647                 if (ret > 0)
2648                         ret = 0;
2649                 kfree(range);
2650                 break;
2651         default:
2652                 ret = -EINVAL;
2653         }
2654 out:
2655         mnt_drop_write_file(file);
2656         return ret;
2657 }
2658
2659 static long btrfs_ioctl_add_dev(struct btrfs_fs_info *fs_info, void __user *arg)
2660 {
2661         struct btrfs_ioctl_vol_args *vol_args;
2662         int ret;
2663
2664         if (!capable(CAP_SYS_ADMIN))
2665                 return -EPERM;
2666
2667         if (test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags))
2668                 return BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
2669
2670         mutex_lock(&fs_info->volume_mutex);
2671         vol_args = memdup_user(arg, sizeof(*vol_args));
2672         if (IS_ERR(vol_args)) {
2673                 ret = PTR_ERR(vol_args);
2674                 goto out;
2675         }
2676
2677         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
2678         ret = btrfs_init_new_device(fs_info, vol_args->name);
2679
2680         if (!ret)
2681                 btrfs_info(fs_info, "disk added %s", vol_args->name);
2682
2683         kfree(vol_args);
2684 out:
2685         mutex_unlock(&fs_info->volume_mutex);
2686         clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
2687         return ret;
2688 }
2689
2690 static long btrfs_ioctl_rm_dev_v2(struct file *file, void __user *arg)
2691 {
2692         struct inode *inode = file_inode(file);
2693         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2694         struct btrfs_ioctl_vol_args_v2 *vol_args;
2695         int ret;
2696
2697         if (!capable(CAP_SYS_ADMIN))
2698                 return -EPERM;
2699
2700         ret = mnt_want_write_file(file);
2701         if (ret)
2702                 return ret;
2703
2704         vol_args = memdup_user(arg, sizeof(*vol_args));
2705         if (IS_ERR(vol_args)) {
2706                 ret = PTR_ERR(vol_args);
2707                 goto err_drop;
2708         }
2709
2710         /* Check for compatibility reject unknown flags */
2711         if (vol_args->flags & ~BTRFS_VOL_ARG_V2_FLAGS_SUPPORTED)
2712                 return -EOPNOTSUPP;
2713
2714         if (test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags)) {
2715                 ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
2716                 goto out;
2717         }
2718
2719         mutex_lock(&fs_info->volume_mutex);
2720         if (vol_args->flags & BTRFS_DEVICE_SPEC_BY_ID) {
2721                 ret = btrfs_rm_device(fs_info, NULL, vol_args->devid);
2722         } else {
2723                 vol_args->name[BTRFS_SUBVOL_NAME_MAX] = '\0';
2724                 ret = btrfs_rm_device(fs_info, vol_args->name, 0);
2725         }
2726         mutex_unlock(&fs_info->volume_mutex);
2727         clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
2728
2729         if (!ret) {
2730                 if (vol_args->flags & BTRFS_DEVICE_SPEC_BY_ID)
2731                         btrfs_info(fs_info, "device deleted: id %llu",
2732                                         vol_args->devid);
2733                 else
2734                         btrfs_info(fs_info, "device deleted: %s",
2735                                         vol_args->name);
2736         }
2737 out:
2738         kfree(vol_args);
2739 err_drop:
2740         mnt_drop_write_file(file);
2741         return ret;
2742 }
2743
2744 static long btrfs_ioctl_rm_dev(struct file *file, void __user *arg)
2745 {
2746         struct inode *inode = file_inode(file);
2747         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2748         struct btrfs_ioctl_vol_args *vol_args;
2749         int ret;
2750
2751         if (!capable(CAP_SYS_ADMIN))
2752                 return -EPERM;
2753
2754         ret = mnt_want_write_file(file);
2755         if (ret)
2756                 return ret;
2757
2758         if (test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags)) {
2759                 ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
2760                 goto out_drop_write;
2761         }
2762
2763         vol_args = memdup_user(arg, sizeof(*vol_args));
2764         if (IS_ERR(vol_args)) {
2765                 ret = PTR_ERR(vol_args);
2766                 goto out;
2767         }
2768
2769         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
2770         mutex_lock(&fs_info->volume_mutex);
2771         ret = btrfs_rm_device(fs_info, vol_args->name, 0);
2772         mutex_unlock(&fs_info->volume_mutex);
2773
2774         if (!ret)
2775                 btrfs_info(fs_info, "disk deleted %s", vol_args->name);
2776         kfree(vol_args);
2777 out:
2778         clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
2779 out_drop_write:
2780         mnt_drop_write_file(file);
2781
2782         return ret;
2783 }
2784
2785 static long btrfs_ioctl_fs_info(struct btrfs_fs_info *fs_info,
2786                                 void __user *arg)
2787 {
2788         struct btrfs_ioctl_fs_info_args *fi_args;
2789         struct btrfs_device *device;
2790         struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
2791         int ret = 0;
2792
2793         fi_args = kzalloc(sizeof(*fi_args), GFP_KERNEL);
2794         if (!fi_args)
2795                 return -ENOMEM;
2796
2797         mutex_lock(&fs_devices->device_list_mutex);
2798         fi_args->num_devices = fs_devices->num_devices;
2799         memcpy(&fi_args->fsid, fs_info->fsid, sizeof(fi_args->fsid));
2800
2801         list_for_each_entry(device, &fs_devices->devices, dev_list) {
2802                 if (device->devid > fi_args->max_id)
2803                         fi_args->max_id = device->devid;
2804         }
2805         mutex_unlock(&fs_devices->device_list_mutex);
2806
2807         fi_args->nodesize = fs_info->super_copy->nodesize;
2808         fi_args->sectorsize = fs_info->super_copy->sectorsize;
2809         fi_args->clone_alignment = fs_info->super_copy->sectorsize;
2810
2811         if (copy_to_user(arg, fi_args, sizeof(*fi_args)))
2812                 ret = -EFAULT;
2813
2814         kfree(fi_args);
2815         return ret;
2816 }
2817
2818 static long btrfs_ioctl_dev_info(struct btrfs_fs_info *fs_info,
2819                                  void __user *arg)
2820 {
2821         struct btrfs_ioctl_dev_info_args *di_args;
2822         struct btrfs_device *dev;
2823         struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
2824         int ret = 0;
2825         char *s_uuid = NULL;
2826
2827         di_args = memdup_user(arg, sizeof(*di_args));
2828         if (IS_ERR(di_args))
2829                 return PTR_ERR(di_args);
2830
2831         if (!btrfs_is_empty_uuid(di_args->uuid))
2832                 s_uuid = di_args->uuid;
2833
2834         mutex_lock(&fs_devices->device_list_mutex);
2835         dev = btrfs_find_device(fs_info, di_args->devid, s_uuid, NULL);
2836
2837         if (!dev) {
2838                 ret = -ENODEV;
2839                 goto out;
2840         }
2841
2842         di_args->devid = dev->devid;
2843         di_args->bytes_used = btrfs_device_get_bytes_used(dev);
2844         di_args->total_bytes = btrfs_device_get_total_bytes(dev);
2845         memcpy(di_args->uuid, dev->uuid, sizeof(di_args->uuid));
2846         if (dev->name) {
2847                 struct rcu_string *name;
2848
2849                 rcu_read_lock();
2850                 name = rcu_dereference(dev->name);
2851                 strncpy(di_args->path, name->str, sizeof(di_args->path));
2852                 rcu_read_unlock();
2853                 di_args->path[sizeof(di_args->path) - 1] = 0;
2854         } else {
2855                 di_args->path[0] = '\0';
2856         }
2857
2858 out:
2859         mutex_unlock(&fs_devices->device_list_mutex);
2860         if (ret == 0 && copy_to_user(arg, di_args, sizeof(*di_args)))
2861                 ret = -EFAULT;
2862
2863         kfree(di_args);
2864         return ret;
2865 }
2866
2867 static struct page *extent_same_get_page(struct inode *inode, pgoff_t index)
2868 {
2869         struct page *page;
2870
2871         page = grab_cache_page(inode->i_mapping, index);
2872         if (!page)
2873                 return ERR_PTR(-ENOMEM);
2874
2875         if (!PageUptodate(page)) {
2876                 int ret;
2877
2878                 ret = btrfs_readpage(NULL, page);
2879                 if (ret)
2880                         return ERR_PTR(ret);
2881                 lock_page(page);
2882                 if (!PageUptodate(page)) {
2883                         unlock_page(page);
2884                         put_page(page);
2885                         return ERR_PTR(-EIO);
2886                 }
2887                 if (page->mapping != inode->i_mapping) {
2888                         unlock_page(page);
2889                         put_page(page);
2890                         return ERR_PTR(-EAGAIN);
2891                 }
2892         }
2893
2894         return page;
2895 }
2896
2897 static int gather_extent_pages(struct inode *inode, struct page **pages,
2898                                int num_pages, u64 off)
2899 {
2900         int i;
2901         pgoff_t index = off >> PAGE_SHIFT;
2902
2903         for (i = 0; i < num_pages; i++) {
2904 again:
2905                 pages[i] = extent_same_get_page(inode, index + i);
2906                 if (IS_ERR(pages[i])) {
2907                         int err = PTR_ERR(pages[i]);
2908
2909                         if (err == -EAGAIN)
2910                                 goto again;
2911                         pages[i] = NULL;
2912                         return err;
2913                 }
2914         }
2915         return 0;
2916 }
2917
2918 static int lock_extent_range(struct inode *inode, u64 off, u64 len,
2919                              bool retry_range_locking)
2920 {
2921         /*
2922          * Do any pending delalloc/csum calculations on inode, one way or
2923          * another, and lock file content.
2924          * The locking order is:
2925          *
2926          *   1) pages
2927          *   2) range in the inode's io tree
2928          */
2929         while (1) {
2930                 struct btrfs_ordered_extent *ordered;
2931                 lock_extent(&BTRFS_I(inode)->io_tree, off, off + len - 1);
2932                 ordered = btrfs_lookup_first_ordered_extent(inode,
2933                                                             off + len - 1);
2934                 if ((!ordered ||
2935                      ordered->file_offset + ordered->len <= off ||
2936                      ordered->file_offset >= off + len) &&
2937                     !test_range_bit(&BTRFS_I(inode)->io_tree, off,
2938                                     off + len - 1, EXTENT_DELALLOC, 0, NULL)) {
2939                         if (ordered)
2940                                 btrfs_put_ordered_extent(ordered);
2941                         break;
2942                 }
2943                 unlock_extent(&BTRFS_I(inode)->io_tree, off, off + len - 1);
2944                 if (ordered)
2945                         btrfs_put_ordered_extent(ordered);
2946                 if (!retry_range_locking)
2947                         return -EAGAIN;
2948                 btrfs_wait_ordered_range(inode, off, len);
2949         }
2950         return 0;
2951 }
2952
2953 static void btrfs_double_inode_unlock(struct inode *inode1, struct inode *inode2)
2954 {
2955         inode_unlock(inode1);
2956         inode_unlock(inode2);
2957 }
2958
2959 static void btrfs_double_inode_lock(struct inode *inode1, struct inode *inode2)
2960 {
2961         if (inode1 < inode2)
2962                 swap(inode1, inode2);
2963
2964         inode_lock_nested(inode1, I_MUTEX_PARENT);
2965         inode_lock_nested(inode2, I_MUTEX_CHILD);
2966 }
2967
2968 static void btrfs_double_extent_unlock(struct inode *inode1, u64 loff1,
2969                                       struct inode *inode2, u64 loff2, u64 len)
2970 {
2971         unlock_extent(&BTRFS_I(inode1)->io_tree, loff1, loff1 + len - 1);
2972         unlock_extent(&BTRFS_I(inode2)->io_tree, loff2, loff2 + len - 1);
2973 }
2974
2975 static int btrfs_double_extent_lock(struct inode *inode1, u64 loff1,
2976                                     struct inode *inode2, u64 loff2, u64 len,
2977                                     bool retry_range_locking)
2978 {
2979         int ret;
2980
2981         if (inode1 < inode2) {
2982                 swap(inode1, inode2);
2983                 swap(loff1, loff2);
2984         }
2985         ret = lock_extent_range(inode1, loff1, len, retry_range_locking);
2986         if (ret)
2987                 return ret;
2988         ret = lock_extent_range(inode2, loff2, len, retry_range_locking);
2989         if (ret)
2990                 unlock_extent(&BTRFS_I(inode1)->io_tree, loff1,
2991                               loff1 + len - 1);
2992         return ret;
2993 }
2994
2995 struct cmp_pages {
2996         int             num_pages;
2997         struct page     **src_pages;
2998         struct page     **dst_pages;
2999 };
3000
3001 static void btrfs_cmp_data_free(struct cmp_pages *cmp)
3002 {
3003         int i;
3004         struct page *pg;
3005
3006         for (i = 0; i < cmp->num_pages; i++) {
3007                 pg = cmp->src_pages[i];
3008                 if (pg) {
3009                         unlock_page(pg);
3010                         put_page(pg);
3011                 }
3012                 pg = cmp->dst_pages[i];
3013                 if (pg) {
3014                         unlock_page(pg);
3015                         put_page(pg);
3016                 }
3017         }
3018         kfree(cmp->src_pages);
3019         kfree(cmp->dst_pages);
3020 }
3021
3022 static int btrfs_cmp_data_prepare(struct inode *src, u64 loff,
3023                                   struct inode *dst, u64 dst_loff,
3024                                   u64 len, struct cmp_pages *cmp)
3025 {
3026         int ret;
3027         int num_pages = PAGE_ALIGN(len) >> PAGE_SHIFT;
3028         struct page **src_pgarr, **dst_pgarr;
3029
3030         /*
3031          * We must gather up all the pages before we initiate our
3032          * extent locking. We use an array for the page pointers. Size
3033          * of the array is bounded by len, which is in turn bounded by
3034          * BTRFS_MAX_DEDUPE_LEN.
3035          */
3036         src_pgarr = kcalloc(num_pages, sizeof(struct page *), GFP_KERNEL);
3037         dst_pgarr = kcalloc(num_pages, sizeof(struct page *), GFP_KERNEL);
3038         if (!src_pgarr || !dst_pgarr) {
3039                 kfree(src_pgarr);
3040                 kfree(dst_pgarr);
3041                 return -ENOMEM;
3042         }
3043         cmp->num_pages = num_pages;
3044         cmp->src_pages = src_pgarr;
3045         cmp->dst_pages = dst_pgarr;
3046
3047         /*
3048          * If deduping ranges in the same inode, locking rules make it mandatory
3049          * to always lock pages in ascending order to avoid deadlocks with
3050          * concurrent tasks (such as starting writeback/delalloc).
3051          */
3052         if (src == dst && dst_loff < loff) {
3053                 swap(src_pgarr, dst_pgarr);
3054                 swap(loff, dst_loff);
3055         }
3056
3057         ret = gather_extent_pages(src, src_pgarr, cmp->num_pages, loff);
3058         if (ret)
3059                 goto out;
3060
3061         ret = gather_extent_pages(dst, dst_pgarr, cmp->num_pages, dst_loff);
3062
3063 out:
3064         if (ret)
3065                 btrfs_cmp_data_free(cmp);
3066         return 0;
3067 }
3068
3069 static int btrfs_cmp_data(u64 len, struct cmp_pages *cmp)
3070 {
3071         int ret = 0;
3072         int i;
3073         struct page *src_page, *dst_page;
3074         unsigned int cmp_len = PAGE_SIZE;
3075         void *addr, *dst_addr;
3076
3077         i = 0;
3078         while (len) {
3079                 if (len < PAGE_SIZE)
3080                         cmp_len = len;
3081
3082                 BUG_ON(i >= cmp->num_pages);
3083
3084                 src_page = cmp->src_pages[i];
3085                 dst_page = cmp->dst_pages[i];
3086                 ASSERT(PageLocked(src_page));
3087                 ASSERT(PageLocked(dst_page));
3088
3089                 addr = kmap_atomic(src_page);
3090                 dst_addr = kmap_atomic(dst_page);
3091
3092                 flush_dcache_page(src_page);
3093                 flush_dcache_page(dst_page);
3094
3095                 if (memcmp(addr, dst_addr, cmp_len))
3096                         ret = -EBADE;
3097
3098                 kunmap_atomic(addr);
3099                 kunmap_atomic(dst_addr);
3100
3101                 if (ret)
3102                         break;
3103
3104                 len -= cmp_len;
3105                 i++;
3106         }
3107
3108         return ret;
3109 }
3110
3111 static int extent_same_check_offsets(struct inode *inode, u64 off, u64 *plen,
3112                                      u64 olen)
3113 {
3114         u64 len = *plen;
3115         u64 bs = BTRFS_I(inode)->root->fs_info->sb->s_blocksize;
3116
3117         if (off + olen > inode->i_size || off + olen < off)
3118                 return -EINVAL;
3119
3120         /* if we extend to eof, continue to block boundary */
3121         if (off + len == inode->i_size)
3122                 *plen = len = ALIGN(inode->i_size, bs) - off;
3123
3124         /* Check that we are block aligned - btrfs_clone() requires this */
3125         if (!IS_ALIGNED(off, bs) || !IS_ALIGNED(off + len, bs))
3126                 return -EINVAL;
3127
3128         return 0;
3129 }
3130
3131 static int btrfs_extent_same(struct inode *src, u64 loff, u64 olen,
3132                              struct inode *dst, u64 dst_loff)
3133 {
3134         int ret;
3135         u64 len = olen;
3136         struct cmp_pages cmp;
3137         bool same_inode = (src == dst);
3138         u64 same_lock_start = 0;
3139         u64 same_lock_len = 0;
3140
3141         if (len == 0)
3142                 return 0;
3143
3144         if (same_inode)
3145                 inode_lock(src);
3146         else
3147                 btrfs_double_inode_lock(src, dst);
3148
3149         ret = extent_same_check_offsets(src, loff, &len, olen);
3150         if (ret)
3151                 goto out_unlock;
3152
3153         ret = extent_same_check_offsets(dst, dst_loff, &len, olen);
3154         if (ret)
3155                 goto out_unlock;
3156
3157         if (same_inode) {
3158                 /*
3159                  * Single inode case wants the same checks, except we
3160                  * don't want our length pushed out past i_size as
3161                  * comparing that data range makes no sense.
3162                  *
3163                  * extent_same_check_offsets() will do this for an
3164                  * unaligned length at i_size, so catch it here and
3165                  * reject the request.
3166                  *
3167                  * This effectively means we require aligned extents
3168                  * for the single-inode case, whereas the other cases
3169                  * allow an unaligned length so long as it ends at
3170                  * i_size.
3171                  */
3172                 if (len != olen) {
3173                         ret = -EINVAL;
3174                         goto out_unlock;
3175                 }
3176
3177                 /* Check for overlapping ranges */
3178                 if (dst_loff + len > loff && dst_loff < loff + len) {
3179                         ret = -EINVAL;
3180                         goto out_unlock;
3181                 }
3182
3183                 same_lock_start = min_t(u64, loff, dst_loff);
3184                 same_lock_len = max_t(u64, loff, dst_loff) + len - same_lock_start;
3185         }
3186
3187         /* don't make the dst file partly checksummed */
3188         if ((BTRFS_I(src)->flags & BTRFS_INODE_NODATASUM) !=
3189             (BTRFS_I(dst)->flags & BTRFS_INODE_NODATASUM)) {
3190                 ret = -EINVAL;
3191                 goto out_unlock;
3192         }
3193
3194 again:
3195         ret = btrfs_cmp_data_prepare(src, loff, dst, dst_loff, olen, &cmp);
3196         if (ret)
3197                 goto out_unlock;
3198
3199         if (same_inode)
3200                 ret = lock_extent_range(src, same_lock_start, same_lock_len,
3201                                         false);
3202         else
3203                 ret = btrfs_double_extent_lock(src, loff, dst, dst_loff, len,
3204                                                false);
3205         /*
3206          * If one of the inodes has dirty pages in the respective range or
3207          * ordered extents, we need to flush dellaloc and wait for all ordered
3208          * extents in the range. We must unlock the pages and the ranges in the
3209          * io trees to avoid deadlocks when flushing delalloc (requires locking
3210          * pages) and when waiting for ordered extents to complete (they require
3211          * range locking).
3212          */
3213         if (ret == -EAGAIN) {
3214                 /*
3215                  * Ranges in the io trees already unlocked. Now unlock all
3216                  * pages before waiting for all IO to complete.
3217                  */
3218                 btrfs_cmp_data_free(&cmp);
3219                 if (same_inode) {
3220                         btrfs_wait_ordered_range(src, same_lock_start,
3221                                                  same_lock_len);
3222                 } else {
3223                         btrfs_wait_ordered_range(src, loff, len);
3224                         btrfs_wait_ordered_range(dst, dst_loff, len);
3225                 }
3226                 goto again;
3227         }
3228         ASSERT(ret == 0);
3229         if (WARN_ON(ret)) {
3230                 /* ranges in the io trees already unlocked */
3231                 btrfs_cmp_data_free(&cmp);
3232                 return ret;
3233         }
3234
3235         /* pass original length for comparison so we stay within i_size */
3236         ret = btrfs_cmp_data(olen, &cmp);
3237         if (ret == 0)
3238                 ret = btrfs_clone(src, dst, loff, olen, len, dst_loff, 1);
3239
3240         if (same_inode)
3241                 unlock_extent(&BTRFS_I(src)->io_tree, same_lock_start,
3242                               same_lock_start + same_lock_len - 1);
3243         else
3244                 btrfs_double_extent_unlock(src, loff, dst, dst_loff, len);
3245
3246         btrfs_cmp_data_free(&cmp);
3247 out_unlock:
3248         if (same_inode)
3249                 inode_unlock(src);
3250         else
3251                 btrfs_double_inode_unlock(src, dst);
3252
3253         return ret;
3254 }
3255
3256 #define BTRFS_MAX_DEDUPE_LEN    SZ_16M
3257
3258 ssize_t btrfs_dedupe_file_range(struct file *src_file, u64 loff, u64 olen,
3259                                 struct file *dst_file, u64 dst_loff)
3260 {
3261         struct inode *src = file_inode(src_file);
3262         struct inode *dst = file_inode(dst_file);
3263         u64 bs = BTRFS_I(src)->root->fs_info->sb->s_blocksize;
3264         ssize_t res;
3265
3266         if (olen > BTRFS_MAX_DEDUPE_LEN)
3267                 olen = BTRFS_MAX_DEDUPE_LEN;
3268
3269         if (WARN_ON_ONCE(bs < PAGE_SIZE)) {
3270                 /*
3271                  * Btrfs does not support blocksize < page_size. As a
3272                  * result, btrfs_cmp_data() won't correctly handle
3273                  * this situation without an update.
3274                  */
3275                 return -EINVAL;
3276         }
3277
3278         res = btrfs_extent_same(src, loff, olen, dst, dst_loff);
3279         if (res)
3280                 return res;
3281         return olen;
3282 }
3283
3284 static int clone_finish_inode_update(struct btrfs_trans_handle *trans,
3285                                      struct inode *inode,
3286                                      u64 endoff,
3287                                      const u64 destoff,
3288                                      const u64 olen,
3289                                      int no_time_update)
3290 {
3291         struct btrfs_root *root = BTRFS_I(inode)->root;
3292         int ret;
3293
3294         inode_inc_iversion(inode);
3295         if (!no_time_update)
3296                 inode->i_mtime = inode->i_ctime = current_time(inode);
3297         /*
3298          * We round up to the block size at eof when determining which
3299          * extents to clone above, but shouldn't round up the file size.
3300          */
3301         if (endoff > destoff + olen)
3302                 endoff = destoff + olen;
3303         if (endoff > inode->i_size)
3304                 btrfs_i_size_write(BTRFS_I(inode), endoff);
3305
3306         ret = btrfs_update_inode(trans, root, inode);
3307         if (ret) {
3308                 btrfs_abort_transaction(trans, ret);
3309                 btrfs_end_transaction(trans);
3310                 goto out;
3311         }
3312         ret = btrfs_end_transaction(trans);
3313 out:
3314         return ret;
3315 }
3316
3317 static void clone_update_extent_map(struct btrfs_inode *inode,
3318                                     const struct btrfs_trans_handle *trans,
3319                                     const struct btrfs_path *path,
3320                                     const u64 hole_offset,
3321                                     const u64 hole_len)
3322 {
3323         struct extent_map_tree *em_tree = &inode->extent_tree;
3324         struct extent_map *em;
3325         int ret;
3326
3327         em = alloc_extent_map();
3328         if (!em) {
3329                 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &inode->runtime_flags);
3330                 return;
3331         }
3332
3333         if (path) {
3334                 struct btrfs_file_extent_item *fi;
3335
3336                 fi = btrfs_item_ptr(path->nodes[0], path->slots[0],
3337                                     struct btrfs_file_extent_item);
3338                 btrfs_extent_item_to_extent_map(inode, path, fi, false, em);
3339                 em->generation = -1;
3340                 if (btrfs_file_extent_type(path->nodes[0], fi) ==
3341                     BTRFS_FILE_EXTENT_INLINE)
3342                         set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
3343                                         &inode->runtime_flags);
3344         } else {
3345                 em->start = hole_offset;
3346                 em->len = hole_len;
3347                 em->ram_bytes = em->len;
3348                 em->orig_start = hole_offset;
3349                 em->block_start = EXTENT_MAP_HOLE;
3350                 em->block_len = 0;
3351                 em->orig_block_len = 0;
3352                 em->compress_type = BTRFS_COMPRESS_NONE;
3353                 em->generation = trans->transid;
3354         }
3355
3356         while (1) {
3357                 write_lock(&em_tree->lock);
3358                 ret = add_extent_mapping(em_tree, em, 1);
3359                 write_unlock(&em_tree->lock);
3360                 if (ret != -EEXIST) {
3361                         free_extent_map(em);
3362                         break;
3363                 }
3364                 btrfs_drop_extent_cache(inode, em->start,
3365                                         em->start + em->len - 1, 0);
3366         }
3367
3368         if (ret)
3369                 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &inode->runtime_flags);
3370 }
3371
3372 /*
3373  * Make sure we do not end up inserting an inline extent into a file that has
3374  * already other (non-inline) extents. If a file has an inline extent it can
3375  * not have any other extents and the (single) inline extent must start at the
3376  * file offset 0. Failing to respect these rules will lead to file corruption,
3377  * resulting in EIO errors on read/write operations, hitting BUG_ON's in mm, etc
3378  *
3379  * We can have extents that have been already written to disk or we can have
3380  * dirty ranges still in delalloc, in which case the extent maps and items are
3381  * created only when we run delalloc, and the delalloc ranges might fall outside
3382  * the range we are currently locking in the inode's io tree. So we check the
3383  * inode's i_size because of that (i_size updates are done while holding the
3384  * i_mutex, which we are holding here).
3385  * We also check to see if the inode has a size not greater than "datal" but has
3386  * extents beyond it, due to an fallocate with FALLOC_FL_KEEP_SIZE (and we are
3387  * protected against such concurrent fallocate calls by the i_mutex).
3388  *
3389  * If the file has no extents but a size greater than datal, do not allow the
3390  * copy because we would need turn the inline extent into a non-inline one (even
3391  * with NO_HOLES enabled). If we find our destination inode only has one inline
3392  * extent, just overwrite it with the source inline extent if its size is less
3393  * than the source extent's size, or we could copy the source inline extent's
3394  * data into the destination inode's inline extent if the later is greater then
3395  * the former.
3396  */
3397 static int clone_copy_inline_extent(struct inode *dst,
3398                                     struct btrfs_trans_handle *trans,
3399                                     struct btrfs_path *path,
3400                                     struct btrfs_key *new_key,
3401                                     const u64 drop_start,
3402                                     const u64 datal,
3403                                     const u64 skip,
3404                                     const u64 size,
3405                                     char *inline_data)
3406 {
3407         struct btrfs_fs_info *fs_info = btrfs_sb(dst->i_sb);
3408         struct btrfs_root *root = BTRFS_I(dst)->root;
3409         const u64 aligned_end = ALIGN(new_key->offset + datal,
3410                                       fs_info->sectorsize);
3411         int ret;
3412         struct btrfs_key key;
3413
3414         if (new_key->offset > 0)
3415                 return -EOPNOTSUPP;
3416
3417         key.objectid = btrfs_ino(BTRFS_I(dst));
3418         key.type = BTRFS_EXTENT_DATA_KEY;
3419         key.offset = 0;
3420         ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3421         if (ret < 0) {
3422                 return ret;
3423         } else if (ret > 0) {
3424                 if (path->slots[0] >= btrfs_header_nritems(path->nodes[0])) {
3425                         ret = btrfs_next_leaf(root, path);
3426                         if (ret < 0)
3427                                 return ret;
3428                         else if (ret > 0)
3429                                 goto copy_inline_extent;
3430                 }
3431                 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
3432                 if (key.objectid == btrfs_ino(BTRFS_I(dst)) &&
3433                     key.type == BTRFS_EXTENT_DATA_KEY) {
3434                         ASSERT(key.offset > 0);
3435                         return -EOPNOTSUPP;
3436                 }
3437         } else if (i_size_read(dst) <= datal) {
3438                 struct btrfs_file_extent_item *ei;
3439                 u64 ext_len;
3440
3441                 /*
3442                  * If the file size is <= datal, make sure there are no other
3443                  * extents following (can happen do to an fallocate call with
3444                  * the flag FALLOC_FL_KEEP_SIZE).
3445                  */
3446                 ei = btrfs_item_ptr(path->nodes[0], path->slots[0],
3447                                     struct btrfs_file_extent_item);
3448                 /*
3449                  * If it's an inline extent, it can not have other extents
3450                  * following it.
3451                  */
3452                 if (btrfs_file_extent_type(path->nodes[0], ei) ==
3453                     BTRFS_FILE_EXTENT_INLINE)
3454                         goto copy_inline_extent;
3455
3456                 ext_len = btrfs_file_extent_num_bytes(path->nodes[0], ei);
3457                 if (ext_len > aligned_end)
3458                         return -EOPNOTSUPP;
3459
3460                 ret = btrfs_next_item(root, path);
3461                 if (ret < 0) {
3462                         return ret;
3463                 } else if (ret == 0) {
3464                         btrfs_item_key_to_cpu(path->nodes[0], &key,
3465                                               path->slots[0]);
3466                         if (key.objectid == btrfs_ino(BTRFS_I(dst)) &&
3467                             key.type == BTRFS_EXTENT_DATA_KEY)
3468                                 return -EOPNOTSUPP;
3469                 }
3470         }
3471
3472 copy_inline_extent:
3473         /*
3474          * We have no extent items, or we have an extent at offset 0 which may
3475          * or may not be inlined. All these cases are dealt the same way.
3476          */
3477         if (i_size_read(dst) > datal) {
3478                 /*
3479                  * If the destination inode has an inline extent...
3480                  * This would require copying the data from the source inline
3481                  * extent into the beginning of the destination's inline extent.
3482                  * But this is really complex, both extents can be compressed
3483                  * or just one of them, which would require decompressing and
3484                  * re-compressing data (which could increase the new compressed
3485                  * size, not allowing the compressed data to fit anymore in an
3486                  * inline extent).
3487                  * So just don't support this case for now (it should be rare,
3488                  * we are not really saving space when cloning inline extents).
3489                  */
3490                 return -EOPNOTSUPP;
3491         }
3492
3493         btrfs_release_path(path);
3494         ret = btrfs_drop_extents(trans, root, dst, drop_start, aligned_end, 1);
3495         if (ret)
3496                 return ret;
3497         ret = btrfs_insert_empty_item(trans, root, path, new_key, size);
3498         if (ret)
3499                 return ret;
3500
3501         if (skip) {
3502                 const u32 start = btrfs_file_extent_calc_inline_size(0);
3503
3504                 memmove(inline_data + start, inline_data + start + skip, datal);
3505         }
3506
3507         write_extent_buffer(path->nodes[0], inline_data,
3508                             btrfs_item_ptr_offset(path->nodes[0],
3509                                                   path->slots[0]),
3510                             size);
3511         inode_add_bytes(dst, datal);
3512
3513         return 0;
3514 }
3515
3516 /**
3517  * btrfs_clone() - clone a range from inode file to another
3518  *
3519  * @src: Inode to clone from
3520  * @inode: Inode to clone to
3521  * @off: Offset within source to start clone from
3522  * @olen: Original length, passed by user, of range to clone
3523  * @olen_aligned: Block-aligned value of olen
3524  * @destoff: Offset within @inode to start clone
3525  * @no_time_update: Whether to update mtime/ctime on the target inode
3526  */
3527 static int btrfs_clone(struct inode *src, struct inode *inode,
3528                        const u64 off, const u64 olen, const u64 olen_aligned,
3529                        const u64 destoff, int no_time_update)
3530 {
3531         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3532         struct btrfs_root *root = BTRFS_I(inode)->root;
3533         struct btrfs_path *path = NULL;
3534         struct extent_buffer *leaf;
3535         struct btrfs_trans_handle *trans;
3536         char *buf = NULL;
3537         struct btrfs_key key;
3538         u32 nritems;
3539         int slot;
3540         int ret;
3541         const u64 len = olen_aligned;
3542         u64 last_dest_end = destoff;
3543
3544         ret = -ENOMEM;
3545         buf = kvmalloc(fs_info->nodesize, GFP_KERNEL);
3546         if (!buf)
3547                 return ret;
3548
3549         path = btrfs_alloc_path();
3550         if (!path) {
3551                 kvfree(buf);
3552                 return ret;
3553         }
3554
3555         path->reada = READA_FORWARD;
3556         /* clone data */
3557         key.objectid = btrfs_ino(BTRFS_I(src));
3558         key.type = BTRFS_EXTENT_DATA_KEY;
3559         key.offset = off;
3560
3561         while (1) {
3562                 u64 next_key_min_offset = key.offset + 1;
3563
3564                 /*
3565                  * note the key will change type as we walk through the
3566                  * tree.
3567                  */
3568                 path->leave_spinning = 1;
3569                 ret = btrfs_search_slot(NULL, BTRFS_I(src)->root, &key, path,
3570                                 0, 0);
3571                 if (ret < 0)
3572                         goto out;
3573                 /*
3574                  * First search, if no extent item that starts at offset off was
3575                  * found but the previous item is an extent item, it's possible
3576                  * it might overlap our target range, therefore process it.
3577                  */
3578                 if (key.offset == off && ret > 0 && path->slots[0] > 0) {
3579                         btrfs_item_key_to_cpu(path->nodes[0], &key,
3580                                               path->slots[0] - 1);
3581                         if (key.type == BTRFS_EXTENT_DATA_KEY)
3582                                 path->slots[0]--;
3583                 }
3584
3585                 nritems = btrfs_header_nritems(path->nodes[0]);
3586 process_slot:
3587                 if (path->slots[0] >= nritems) {
3588                         ret = btrfs_next_leaf(BTRFS_I(src)->root, path);
3589                         if (ret < 0)
3590                                 goto out;
3591                         if (ret > 0)
3592                                 break;
3593                         nritems = btrfs_header_nritems(path->nodes[0]);
3594                 }
3595                 leaf = path->nodes[0];
3596                 slot = path->slots[0];
3597
3598                 btrfs_item_key_to_cpu(leaf, &key, slot);
3599                 if (key.type > BTRFS_EXTENT_DATA_KEY ||
3600                     key.objectid != btrfs_ino(BTRFS_I(src)))
3601                         break;
3602
3603                 if (key.type == BTRFS_EXTENT_DATA_KEY) {
3604                         struct btrfs_file_extent_item *extent;
3605                         int type;
3606                         u32 size;
3607                         struct btrfs_key new_key;
3608                         u64 disko = 0, diskl = 0;
3609                         u64 datao = 0, datal = 0;
3610                         u8 comp;
3611                         u64 drop_start;
3612
3613                         extent = btrfs_item_ptr(leaf, slot,
3614                                                 struct btrfs_file_extent_item);
3615                         comp = btrfs_file_extent_compression(leaf, extent);
3616                         type = btrfs_file_extent_type(leaf, extent);
3617                         if (type == BTRFS_FILE_EXTENT_REG ||
3618                             type == BTRFS_FILE_EXTENT_PREALLOC) {
3619                                 disko = btrfs_file_extent_disk_bytenr(leaf,
3620                                                                       extent);
3621                                 diskl = btrfs_file_extent_disk_num_bytes(leaf,
3622                                                                  extent);
3623                                 datao = btrfs_file_extent_offset(leaf, extent);
3624                                 datal = btrfs_file_extent_num_bytes(leaf,
3625                                                                     extent);
3626                         } else if (type == BTRFS_FILE_EXTENT_INLINE) {
3627                                 /* take upper bound, may be compressed */
3628                                 datal = btrfs_file_extent_ram_bytes(leaf,
3629                                                                     extent);
3630                         }
3631
3632                         /*
3633                          * The first search might have left us at an extent
3634                          * item that ends before our target range's start, can
3635                          * happen if we have holes and NO_HOLES feature enabled.
3636                          */
3637                         if (key.offset + datal <= off) {
3638                                 path->slots[0]++;
3639                                 goto process_slot;
3640                         } else if (key.offset >= off + len) {
3641                                 break;
3642                         }
3643                         next_key_min_offset = key.offset + datal;
3644                         size = btrfs_item_size_nr(leaf, slot);
3645                         read_extent_buffer(leaf, buf,
3646                                            btrfs_item_ptr_offset(leaf, slot),
3647                                            size);
3648
3649                         btrfs_release_path(path);
3650                         path->leave_spinning = 0;
3651
3652                         memcpy(&new_key, &key, sizeof(new_key));
3653                         new_key.objectid = btrfs_ino(BTRFS_I(inode));
3654                         if (off <= key.offset)
3655                                 new_key.offset = key.offset + destoff - off;
3656                         else
3657                                 new_key.offset = destoff;
3658
3659                         /*
3660                          * Deal with a hole that doesn't have an extent item
3661                          * that represents it (NO_HOLES feature enabled).
3662                          * This hole is either in the middle of the cloning
3663                          * range or at the beginning (fully overlaps it or
3664                          * partially overlaps it).
3665                          */
3666                         if (new_key.offset != last_dest_end)
3667                                 drop_start = last_dest_end;
3668                         else
3669                                 drop_start = new_key.offset;
3670
3671                         /*
3672                          * 1 - adjusting old extent (we may have to split it)
3673                          * 1 - add new extent
3674                          * 1 - inode update
3675                          */
3676                         trans = btrfs_start_transaction(root, 3);
3677                         if (IS_ERR(trans)) {
3678                                 ret = PTR_ERR(trans);
3679                                 goto out;
3680                         }
3681
3682                         if (type == BTRFS_FILE_EXTENT_REG ||
3683                             type == BTRFS_FILE_EXTENT_PREALLOC) {
3684                                 /*
3685                                  *    a  | --- range to clone ---|  b
3686                                  * | ------------- extent ------------- |
3687                                  */
3688
3689                                 /* subtract range b */
3690                                 if (key.offset + datal > off + len)
3691                                         datal = off + len - key.offset;
3692
3693                                 /* subtract range a */
3694                                 if (off > key.offset) {
3695                                         datao += off - key.offset;
3696                                         datal -= off - key.offset;
3697                                 }
3698
3699                                 ret = btrfs_drop_extents(trans, root, inode,
3700                                                          drop_start,
3701                                                          new_key.offset + datal,
3702                                                          1);
3703                                 if (ret) {
3704                                         if (ret != -EOPNOTSUPP)
3705                                                 btrfs_abort_transaction(trans,
3706                                                                         ret);
3707                                         btrfs_end_transaction(trans);
3708                                         goto out;
3709                                 }
3710
3711                                 ret = btrfs_insert_empty_item(trans, root, path,
3712                                                               &new_key, size);
3713                                 if (ret) {
3714                                         btrfs_abort_transaction(trans, ret);
3715                                         btrfs_end_transaction(trans);
3716                                         goto out;
3717                                 }
3718
3719                                 leaf = path->nodes[0];
3720                                 slot = path->slots[0];
3721                                 write_extent_buffer(leaf, buf,
3722                                             btrfs_item_ptr_offset(leaf, slot),
3723                                             size);
3724
3725                                 extent = btrfs_item_ptr(leaf, slot,
3726                                                 struct btrfs_file_extent_item);
3727
3728                                 /* disko == 0 means it's a hole */
3729                                 if (!disko)
3730                                         datao = 0;
3731
3732                                 btrfs_set_file_extent_offset(leaf, extent,
3733                                                              datao);
3734                                 btrfs_set_file_extent_num_bytes(leaf, extent,
3735                                                                 datal);
3736
3737                                 if (disko) {
3738                                         inode_add_bytes(inode, datal);
3739                                         ret = btrfs_inc_extent_ref(trans,
3740                                                         fs_info,
3741                                                         disko, diskl, 0,
3742                                                         root->root_key.objectid,
3743                                                         btrfs_ino(BTRFS_I(inode)),
3744                                                         new_key.offset - datao);
3745                                         if (ret) {
3746                                                 btrfs_abort_transaction(trans,
3747                                                                         ret);
3748                                                 btrfs_end_transaction(trans);
3749                                                 goto out;
3750
3751                                         }
3752                                 }
3753                         } else if (type == BTRFS_FILE_EXTENT_INLINE) {
3754                                 u64 skip = 0;
3755                                 u64 trim = 0;
3756
3757                                 if (off > key.offset) {
3758                                         skip = off - key.offset;
3759                                         new_key.offset += skip;
3760                                 }
3761
3762                                 if (key.offset + datal > off + len)
3763                                         trim = key.offset + datal - (off + len);
3764
3765                                 if (comp && (skip || trim)) {
3766                                         ret = -EINVAL;
3767                                         btrfs_end_transaction(trans);
3768                                         goto out;
3769                                 }
3770                                 size -= skip + trim;
3771                                 datal -= skip + trim;
3772
3773                                 ret = clone_copy_inline_extent(inode,
3774                                                                trans, path,
3775                                                                &new_key,
3776                                                                drop_start,
3777                                                                datal,
3778                                                                skip, size, buf);
3779                                 if (ret) {
3780                                         if (ret != -EOPNOTSUPP)
3781                                                 btrfs_abort_transaction(trans,
3782                                                                         ret);
3783                                         btrfs_end_transaction(trans);
3784                                         goto out;
3785                                 }
3786                                 leaf = path->nodes[0];
3787                                 slot = path->slots[0];
3788                         }
3789
3790                         /* If we have an implicit hole (NO_HOLES feature). */
3791                         if (drop_start < new_key.offset)
3792                                 clone_update_extent_map(BTRFS_I(inode), trans,
3793                                                 NULL, drop_start,
3794                                                 new_key.offset - drop_start);
3795
3796                         clone_update_extent_map(BTRFS_I(inode), trans,
3797                                         path, 0, 0);
3798
3799                         btrfs_mark_buffer_dirty(leaf);
3800                         btrfs_release_path(path);
3801
3802                         last_dest_end = ALIGN(new_key.offset + datal,
3803                                               fs_info->sectorsize);
3804                         ret = clone_finish_inode_update(trans, inode,
3805                                                         last_dest_end,
3806                                                         destoff, olen,
3807                                                         no_time_update);
3808                         if (ret)
3809                                 goto out;
3810                         if (new_key.offset + datal >= destoff + len)
3811                                 break;
3812                 }
3813                 btrfs_release_path(path);
3814                 key.offset = next_key_min_offset;
3815
3816                 if (fatal_signal_pending(current)) {
3817                         ret = -EINTR;
3818                         goto out;
3819                 }
3820         }
3821         ret = 0;
3822
3823         if (last_dest_end < destoff + len) {
3824                 /*
3825                  * We have an implicit hole (NO_HOLES feature is enabled) that
3826                  * fully or partially overlaps our cloning range at its end.
3827                  */
3828                 btrfs_release_path(path);
3829
3830                 /*
3831                  * 1 - remove extent(s)
3832                  * 1 - inode update
3833                  */
3834                 trans = btrfs_start_transaction(root, 2);
3835                 if (IS_ERR(trans)) {
3836                         ret = PTR_ERR(trans);
3837                         goto out;
3838                 }
3839                 ret = btrfs_drop_extents(trans, root, inode,
3840                                          last_dest_end, destoff + len, 1);
3841                 if (ret) {
3842                         if (ret != -EOPNOTSUPP)
3843                                 btrfs_abort_transaction(trans, ret);
3844                         btrfs_end_transaction(trans);
3845                         goto out;
3846                 }
3847                 clone_update_extent_map(BTRFS_I(inode), trans, NULL,
3848                                 last_dest_end,
3849                                 destoff + len - last_dest_end);
3850                 ret = clone_finish_inode_update(trans, inode, destoff + len,
3851                                                 destoff, olen, no_time_update);
3852         }
3853
3854 out:
3855         btrfs_free_path(path);
3856         kvfree(buf);
3857         return ret;
3858 }
3859
3860 static noinline int btrfs_clone_files(struct file *file, struct file *file_src,
3861                                         u64 off, u64 olen, u64 destoff)
3862 {
3863         struct inode *inode = file_inode(file);
3864         struct inode *src = file_inode(file_src);
3865         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3866         struct btrfs_root *root = BTRFS_I(inode)->root;
3867         int ret;
3868         u64 len = olen;
3869         u64 bs = fs_info->sb->s_blocksize;
3870         int same_inode = src == inode;
3871
3872         /*
3873          * TODO:
3874          * - split compressed inline extents.  annoying: we need to
3875          *   decompress into destination's address_space (the file offset
3876          *   may change, so source mapping won't do), then recompress (or
3877          *   otherwise reinsert) a subrange.
3878          *
3879          * - split destination inode's inline extents.  The inline extents can
3880          *   be either compressed or non-compressed.
3881          */
3882
3883         if (btrfs_root_readonly(root))
3884                 return -EROFS;
3885
3886         if (file_src->f_path.mnt != file->f_path.mnt ||
3887             src->i_sb != inode->i_sb)
3888                 return -EXDEV;
3889
3890         /* don't make the dst file partly checksummed */
3891         if ((BTRFS_I(src)->flags & BTRFS_INODE_NODATASUM) !=
3892             (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM))
3893                 return -EINVAL;
3894
3895         if (S_ISDIR(src->i_mode) || S_ISDIR(inode->i_mode))
3896                 return -EISDIR;
3897
3898         if (!same_inode) {
3899                 btrfs_double_inode_lock(src, inode);
3900         } else {
3901                 inode_lock(src);
3902         }
3903
3904         /* determine range to clone */
3905         ret = -EINVAL;
3906         if (off + len > src->i_size || off + len < off)
3907                 goto out_unlock;
3908         if (len == 0)
3909                 olen = len = src->i_size - off;
3910         /* if we extend to eof, continue to block boundary */
3911         if (off + len == src->i_size)
3912                 len = ALIGN(src->i_size, bs) - off;
3913
3914         if (len == 0) {
3915                 ret = 0;
3916                 goto out_unlock;
3917         }
3918
3919         /* verify the end result is block aligned */
3920         if (!IS_ALIGNED(off, bs) || !IS_ALIGNED(off + len, bs) ||
3921             !IS_ALIGNED(destoff, bs))
3922                 goto out_unlock;
3923
3924         /* verify if ranges are overlapped within the same file */
3925         if (same_inode) {
3926                 if (destoff + len > off && destoff < off + len)
3927                         goto out_unlock;
3928         }
3929
3930         if (destoff > inode->i_size) {
3931                 ret = btrfs_cont_expand(inode, inode->i_size, destoff);
3932                 if (ret)
3933                         goto out_unlock;
3934         }
3935
3936         /*
3937          * Lock the target range too. Right after we replace the file extent
3938          * items in the fs tree (which now point to the cloned data), we might
3939          * have a worker replace them with extent items relative to a write
3940          * operation that was issued before this clone operation (i.e. confront
3941          * with inode.c:btrfs_finish_ordered_io).
3942          */
3943         if (same_inode) {
3944                 u64 lock_start = min_t(u64, off, destoff);
3945                 u64 lock_len = max_t(u64, off, destoff) + len - lock_start;
3946
3947                 ret = lock_extent_range(src, lock_start, lock_len, true);
3948         } else {
3949                 ret = btrfs_double_extent_lock(src, off, inode, destoff, len,
3950                                                true);
3951         }
3952         ASSERT(ret == 0);
3953         if (WARN_ON(ret)) {
3954                 /* ranges in the io trees already unlocked */
3955                 goto out_unlock;
3956         }
3957
3958         ret = btrfs_clone(src, inode, off, olen, len, destoff, 0);
3959
3960         if (same_inode) {
3961                 u64 lock_start = min_t(u64, off, destoff);
3962                 u64 lock_end = max_t(u64, off, destoff) + len - 1;
3963
3964                 unlock_extent(&BTRFS_I(src)->io_tree, lock_start, lock_end);
3965         } else {
3966                 btrfs_double_extent_unlock(src, off, inode, destoff, len);
3967         }
3968         /*
3969          * Truncate page cache pages so that future reads will see the cloned
3970          * data immediately and not the previous data.
3971          */
3972         truncate_inode_pages_range(&inode->i_data,
3973                                 round_down(destoff, PAGE_SIZE),
3974                                 round_up(destoff + len, PAGE_SIZE) - 1);
3975 out_unlock:
3976         if (!same_inode)
3977                 btrfs_double_inode_unlock(src, inode);
3978         else
3979                 inode_unlock(src);
3980         return ret;
3981 }
3982
3983 int btrfs_clone_file_range(struct file *src_file, loff_t off,
3984                 struct file *dst_file, loff_t destoff, u64 len)
3985 {
3986         return btrfs_clone_files(dst_file, src_file, off, len, destoff);
3987 }
3988
3989 /*
3990  * there are many ways the trans_start and trans_end ioctls can lead
3991  * to deadlocks.  They should only be used by applications that
3992  * basically own the machine, and have a very in depth understanding
3993  * of all the possible deadlocks and enospc problems.
3994  */
3995 static long btrfs_ioctl_trans_start(struct file *file)
3996 {
3997         struct inode *inode = file_inode(file);
3998         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3999         struct btrfs_root *root = BTRFS_I(inode)->root;
4000         struct btrfs_trans_handle *trans;
4001         int ret;
4002
4003         ret = -EPERM;
4004         if (!capable(CAP_SYS_ADMIN))
4005                 goto out;
4006
4007         ret = -EINPROGRESS;
4008         if (file->private_data)
4009                 goto out;
4010
4011         ret = -EROFS;
4012         if (btrfs_root_readonly(root))
4013                 goto out;
4014
4015         ret = mnt_want_write_file(file);
4016         if (ret)
4017                 goto out;
4018
4019         atomic_inc(&fs_info->open_ioctl_trans);
4020
4021         ret = -ENOMEM;
4022         trans = btrfs_start_ioctl_transaction(root);
4023         if (IS_ERR(trans))
4024                 goto out_drop;
4025
4026         file->private_data = trans;
4027         return 0;
4028
4029 out_drop:
4030         atomic_dec(&fs_info->open_ioctl_trans);
4031         mnt_drop_write_file(file);
4032 out:
4033         return ret;
4034 }
4035
4036 static long btrfs_ioctl_default_subvol(struct file *file, void __user *argp)
4037 {
4038         struct inode *inode = file_inode(file);
4039         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4040         struct btrfs_root *root = BTRFS_I(inode)->root;
4041         struct btrfs_root *new_root;
4042         struct btrfs_dir_item *di;
4043         struct btrfs_trans_handle *trans;
4044         struct btrfs_path *path;
4045         struct btrfs_key location;
4046         struct btrfs_disk_key disk_key;
4047         u64 objectid = 0;
4048         u64 dir_id;
4049         int ret;
4050
4051         if (!capable(CAP_SYS_ADMIN))
4052                 return -EPERM;
4053
4054         ret = mnt_want_write_file(file);
4055         if (ret)
4056                 return ret;
4057
4058         if (copy_from_user(&objectid, argp, sizeof(objectid))) {
4059                 ret = -EFAULT;
4060                 goto out;
4061         }
4062
4063         if (!objectid)
4064                 objectid = BTRFS_FS_TREE_OBJECTID;
4065
4066         location.objectid = objectid;
4067         location.type = BTRFS_ROOT_ITEM_KEY;
4068         location.offset = (u64)-1;
4069
4070         new_root = btrfs_read_fs_root_no_name(fs_info, &location);
4071         if (IS_ERR(new_root)) {
4072                 ret = PTR_ERR(new_root);
4073                 goto out;
4074         }
4075
4076         path = btrfs_alloc_path();
4077         if (!path) {
4078                 ret = -ENOMEM;
4079                 goto out;
4080         }
4081         path->leave_spinning = 1;
4082
4083         trans = btrfs_start_transaction(root, 1);
4084         if (IS_ERR(trans)) {
4085                 btrfs_free_path(path);
4086                 ret = PTR_ERR(trans);
4087                 goto out;
4088         }
4089
4090         dir_id = btrfs_super_root_dir(fs_info->super_copy);
4091         di = btrfs_lookup_dir_item(trans, fs_info->tree_root, path,
4092                                    dir_id, "default", 7, 1);
4093         if (IS_ERR_OR_NULL(di)) {
4094                 btrfs_free_path(path);
4095                 btrfs_end_transaction(trans);
4096                 btrfs_err(fs_info,
4097                           "Umm, you don't have the default diritem, this isn't going to work");
4098                 ret = -ENOENT;
4099                 goto out;
4100         }
4101
4102         btrfs_cpu_key_to_disk(&disk_key, &new_root->root_key);
4103         btrfs_set_dir_item_key(path->nodes[0], di, &disk_key);
4104         btrfs_mark_buffer_dirty(path->nodes[0]);
4105         btrfs_free_path(path);
4106
4107         btrfs_set_fs_incompat(fs_info, DEFAULT_SUBVOL);
4108         btrfs_end_transaction(trans);
4109 out:
4110         mnt_drop_write_file(file);
4111         return ret;
4112 }
4113
4114 void btrfs_get_block_group_info(struct list_head *groups_list,
4115                                 struct btrfs_ioctl_space_info *space)
4116 {
4117         struct btrfs_block_group_cache *block_group;
4118
4119         space->total_bytes = 0;
4120         space->used_bytes = 0;
4121         space->flags = 0;
4122         list_for_each_entry(block_group, groups_list, list) {
4123                 space->flags = block_group->flags;
4124                 space->total_bytes += block_group->key.offset;
4125                 space->used_bytes +=
4126                         btrfs_block_group_used(&block_group->item);
4127         }
4128 }
4129
4130 static long btrfs_ioctl_space_info(struct btrfs_fs_info *fs_info,
4131                                    void __user *arg)
4132 {
4133         struct btrfs_ioctl_space_args space_args;
4134         struct btrfs_ioctl_space_info space;
4135         struct btrfs_ioctl_space_info *dest;
4136         struct btrfs_ioctl_space_info *dest_orig;
4137         struct btrfs_ioctl_space_info __user *user_dest;
4138         struct btrfs_space_info *info;
4139         u64 types[] = {BTRFS_BLOCK_GROUP_DATA,
4140                        BTRFS_BLOCK_GROUP_SYSTEM,
4141                        BTRFS_BLOCK_GROUP_METADATA,
4142                        BTRFS_BLOCK_GROUP_DATA | BTRFS_BLOCK_GROUP_METADATA};
4143         int num_types = 4;
4144         int alloc_size;
4145         int ret = 0;
4146         u64 slot_count = 0;
4147         int i, c;
4148
4149         if (copy_from_user(&space_args,
4150                            (struct btrfs_ioctl_space_args __user *)arg,
4151                            sizeof(space_args)))
4152                 return -EFAULT;
4153
4154         for (i = 0; i < num_types; i++) {
4155                 struct btrfs_space_info *tmp;
4156
4157                 info = NULL;
4158                 rcu_read_lock();
4159                 list_for_each_entry_rcu(tmp, &fs_info->space_info,
4160                                         list) {
4161                         if (tmp->flags == types[i]) {
4162                                 info = tmp;
4163                                 break;
4164                         }
4165                 }
4166                 rcu_read_unlock();
4167
4168                 if (!info)
4169                         continue;
4170
4171                 down_read(&info->groups_sem);
4172                 for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) {
4173                         if (!list_empty(&info->block_groups[c]))
4174                                 slot_count++;
4175                 }
4176                 up_read(&info->groups_sem);
4177         }
4178
4179         /*
4180          * Global block reserve, exported as a space_info
4181          */
4182         slot_count++;
4183
4184         /* space_slots == 0 means they are asking for a count */
4185         if (space_args.space_slots == 0) {
4186                 space_args.total_spaces = slot_count;
4187                 goto out;
4188         }
4189
4190         slot_count = min_t(u64, space_args.space_slots, slot_count);
4191
4192         alloc_size = sizeof(*dest) * slot_count;
4193
4194         /* we generally have at most 6 or so space infos, one for each raid
4195          * level.  So, a whole page should be more than enough for everyone
4196          */
4197         if (alloc_size > PAGE_SIZE)
4198                 return -ENOMEM;
4199
4200         space_args.total_spaces = 0;
4201         dest = kmalloc(alloc_size, GFP_KERNEL);
4202         if (!dest)
4203                 return -ENOMEM;
4204         dest_orig = dest;
4205
4206         /* now we have a buffer to copy into */
4207         for (i = 0; i < num_types; i++) {
4208                 struct btrfs_space_info *tmp;
4209
4210                 if (!slot_count)
4211                         break;
4212
4213                 info = NULL;
4214                 rcu_read_lock();
4215                 list_for_each_entry_rcu(tmp, &fs_info->space_info,
4216                                         list) {
4217                         if (tmp->flags == types[i]) {
4218                                 info = tmp;
4219                                 break;
4220                         }
4221                 }
4222                 rcu_read_unlock();
4223
4224                 if (!info)
4225                         continue;
4226                 down_read(&info->groups_sem);
4227                 for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) {
4228                         if (!list_empty(&info->block_groups[c])) {
4229                                 btrfs_get_block_group_info(
4230                                         &info->block_groups[c], &space);
4231                                 memcpy(dest, &space, sizeof(space));
4232                                 dest++;
4233                                 space_args.total_spaces++;
4234                                 slot_count--;
4235                         }
4236                         if (!slot_count)
4237                                 break;
4238                 }
4239                 up_read(&info->groups_sem);
4240         }
4241
4242         /*
4243          * Add global block reserve
4244          */
4245         if (slot_count) {
4246                 struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
4247
4248                 spin_lock(&block_rsv->lock);
4249                 space.total_bytes = block_rsv->size;
4250                 space.used_bytes = block_rsv->size - block_rsv->reserved;
4251                 spin_unlock(&block_rsv->lock);
4252                 space.flags = BTRFS_SPACE_INFO_GLOBAL_RSV;
4253                 memcpy(dest, &space, sizeof(space));
4254                 space_args.total_spaces++;
4255         }
4256
4257         user_dest = (struct btrfs_ioctl_space_info __user *)
4258                 (arg + sizeof(struct btrfs_ioctl_space_args));
4259
4260         if (copy_to_user(user_dest, dest_orig, alloc_size))
4261                 ret = -EFAULT;
4262
4263         kfree(dest_orig);
4264 out:
4265         if (ret == 0 && copy_to_user(arg, &space_args, sizeof(space_args)))
4266                 ret = -EFAULT;
4267
4268         return ret;
4269 }
4270
4271 /*
4272  * there are many ways the trans_start and trans_end ioctls can lead
4273  * to deadlocks.  They should only be used by applications that
4274  * basically own the machine, and have a very in depth understanding
4275  * of all the possible deadlocks and enospc problems.
4276  */
4277 long btrfs_ioctl_trans_end(struct file *file)
4278 {
4279         struct inode *inode = file_inode(file);
4280         struct btrfs_root *root = BTRFS_I(inode)->root;
4281         struct btrfs_trans_handle *trans;
4282
4283         trans = file->private_data;
4284         if (!trans)
4285                 return -EINVAL;
4286         file->private_data = NULL;
4287
4288         btrfs_end_transaction(trans);
4289
4290         atomic_dec(&root->fs_info->open_ioctl_trans);
4291
4292         mnt_drop_write_file(file);
4293         return 0;
4294 }
4295
4296 static noinline long btrfs_ioctl_start_sync(struct btrfs_root *root,
4297                                             void __user *argp)
4298 {
4299         struct btrfs_trans_handle *trans;
4300         u64 transid;
4301         int ret;
4302
4303         trans = btrfs_attach_transaction_barrier(root);
4304         if (IS_ERR(trans)) {
4305                 if (PTR_ERR(trans) != -ENOENT)
4306                         return PTR_ERR(trans);
4307
4308                 /* No running transaction, don't bother */
4309                 transid = root->fs_info->last_trans_committed;
4310                 goto out;
4311         }
4312         transid = trans->transid;
4313         ret = btrfs_commit_transaction_async(trans, 0);
4314         if (ret) {
4315                 btrfs_end_transaction(trans);
4316                 return ret;
4317         }
4318 out:
4319         if (argp)
4320                 if (copy_to_user(argp, &transid, sizeof(transid)))
4321                         return -EFAULT;
4322         return 0;
4323 }
4324
4325 static noinline long btrfs_ioctl_wait_sync(struct btrfs_fs_info *fs_info,
4326                                            void __user *argp)
4327 {
4328         u64 transid;
4329
4330         if (argp) {
4331                 if (copy_from_user(&transid, argp, sizeof(transid)))
4332                         return -EFAULT;
4333         } else {
4334                 transid = 0;  /* current trans */
4335         }
4336         return btrfs_wait_for_commit(fs_info, transid);
4337 }
4338
4339 static long btrfs_ioctl_scrub(struct file *file, void __user *arg)
4340 {
4341         struct btrfs_fs_info *fs_info = btrfs_sb(file_inode(file)->i_sb);
4342         struct btrfs_ioctl_scrub_args *sa;
4343         int ret;
4344
4345         if (!capable(CAP_SYS_ADMIN))
4346                 return -EPERM;
4347
4348         sa = memdup_user(arg, sizeof(*sa));
4349         if (IS_ERR(sa))
4350                 return PTR_ERR(sa);
4351
4352         if (!(sa->flags & BTRFS_SCRUB_READONLY)) {
4353                 ret = mnt_want_write_file(file);
4354                 if (ret)
4355                         goto out;
4356         }
4357
4358         ret = btrfs_scrub_dev(fs_info, sa->devid, sa->start, sa->end,
4359                               &sa->progress, sa->flags & BTRFS_SCRUB_READONLY,
4360                               0);
4361
4362         if (copy_to_user(arg, sa, sizeof(*sa)))
4363                 ret = -EFAULT;
4364
4365         if (!(sa->flags & BTRFS_SCRUB_READONLY))
4366                 mnt_drop_write_file(file);
4367 out:
4368         kfree(sa);
4369         return ret;
4370 }
4371
4372 static long btrfs_ioctl_scrub_cancel(struct btrfs_fs_info *fs_info)
4373 {
4374         if (!capable(CAP_SYS_ADMIN))
4375                 return -EPERM;
4376
4377         return btrfs_scrub_cancel(fs_info);
4378 }
4379
4380 static long btrfs_ioctl_scrub_progress(struct btrfs_fs_info *fs_info,
4381                                        void __user *arg)
4382 {
4383         struct btrfs_ioctl_scrub_args *sa;
4384         int ret;
4385
4386         if (!capable(CAP_SYS_ADMIN))
4387                 return -EPERM;
4388
4389         sa = memdup_user(arg, sizeof(*sa));
4390         if (IS_ERR(sa))
4391                 return PTR_ERR(sa);
4392
4393         ret = btrfs_scrub_progress(fs_info, sa->devid, &sa->progress);
4394
4395         if (copy_to_user(arg, sa, sizeof(*sa)))
4396                 ret = -EFAULT;
4397
4398         kfree(sa);
4399         return ret;
4400 }
4401
4402 static long btrfs_ioctl_get_dev_stats(struct btrfs_fs_info *fs_info,
4403                                       void __user *arg)
4404 {
4405         struct btrfs_ioctl_get_dev_stats *sa;
4406         int ret;
4407
4408         sa = memdup_user(arg, sizeof(*sa));
4409         if (IS_ERR(sa))
4410                 return PTR_ERR(sa);
4411
4412         if ((sa->flags & BTRFS_DEV_STATS_RESET) && !capable(CAP_SYS_ADMIN)) {
4413                 kfree(sa);
4414                 return -EPERM;
4415         }
4416
4417         ret = btrfs_get_dev_stats(fs_info, sa);
4418
4419         if (copy_to_user(arg, sa, sizeof(*sa)))
4420                 ret = -EFAULT;
4421
4422         kfree(sa);
4423         return ret;
4424 }
4425
4426 static long btrfs_ioctl_dev_replace(struct btrfs_fs_info *fs_info,
4427                                     void __user *arg)
4428 {
4429         struct btrfs_ioctl_dev_replace_args *p;
4430         int ret;
4431
4432         if (!capable(CAP_SYS_ADMIN))
4433                 return -EPERM;
4434
4435         p = memdup_user(arg, sizeof(*p));
4436         if (IS_ERR(p))
4437                 return PTR_ERR(p);
4438
4439         switch (p->cmd) {
4440         case BTRFS_IOCTL_DEV_REPLACE_CMD_START:
4441                 if (fs_info->sb->s_flags & MS_RDONLY) {
4442                         ret = -EROFS;
4443                         goto out;
4444                 }
4445                 if (test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags)) {
4446                         ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
4447                 } else {
4448                         ret = btrfs_dev_replace_by_ioctl(fs_info, p);
4449                         clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
4450                 }
4451                 break;
4452         case BTRFS_IOCTL_DEV_REPLACE_CMD_STATUS:
4453                 btrfs_dev_replace_status(fs_info, p);
4454                 ret = 0;
4455                 break;
4456         case BTRFS_IOCTL_DEV_REPLACE_CMD_CANCEL:
4457                 ret = btrfs_dev_replace_cancel(fs_info, p);
4458                 break;
4459         default:
4460                 ret = -EINVAL;
4461                 break;
4462         }
4463
4464         if (copy_to_user(arg, p, sizeof(*p)))
4465                 ret = -EFAULT;
4466 out:
4467         kfree(p);
4468         return ret;
4469 }
4470
4471 static long btrfs_ioctl_ino_to_path(struct btrfs_root *root, void __user *arg)
4472 {
4473         int ret = 0;
4474         int i;
4475         u64 rel_ptr;
4476         int size;
4477         struct btrfs_ioctl_ino_path_args *ipa = NULL;
4478         struct inode_fs_paths *ipath = NULL;
4479         struct btrfs_path *path;
4480
4481         if (!capable(CAP_DAC_READ_SEARCH))
4482                 return -EPERM;
4483
4484         path = btrfs_alloc_path();
4485         if (!path) {
4486                 ret = -ENOMEM;
4487                 goto out;
4488         }
4489
4490         ipa = memdup_user(arg, sizeof(*ipa));
4491         if (IS_ERR(ipa)) {
4492                 ret = PTR_ERR(ipa);
4493                 ipa = NULL;
4494                 goto out;
4495         }
4496
4497         size = min_t(u32, ipa->size, 4096);
4498         ipath = init_ipath(size, root, path);
4499         if (IS_ERR(ipath)) {
4500                 ret = PTR_ERR(ipath);
4501                 ipath = NULL;
4502                 goto out;
4503         }
4504
4505         ret = paths_from_inode(ipa->inum, ipath);
4506         if (ret < 0)
4507                 goto out;
4508
4509         for (i = 0; i < ipath->fspath->elem_cnt; ++i) {
4510                 rel_ptr = ipath->fspath->val[i] -
4511                           (u64)(unsigned long)ipath->fspath->val;
4512                 ipath->fspath->val[i] = rel_ptr;
4513         }
4514
4515         ret = copy_to_user((void *)(unsigned long)ipa->fspath,
4516                            (void *)(unsigned long)ipath->fspath, size);
4517         if (ret) {
4518                 ret = -EFAULT;
4519                 goto out;
4520         }
4521
4522 out:
4523         btrfs_free_path(path);
4524         free_ipath(ipath);
4525         kfree(ipa);
4526
4527         return ret;
4528 }
4529
4530 static int build_ino_list(u64 inum, u64 offset, u64 root, void *ctx)
4531 {
4532         struct btrfs_data_container *inodes = ctx;
4533         const size_t c = 3 * sizeof(u64);
4534
4535         if (inodes->bytes_left >= c) {
4536                 inodes->bytes_left -= c;
4537                 inodes->val[inodes->elem_cnt] = inum;
4538                 inodes->val[inodes->elem_cnt + 1] = offset;
4539                 inodes->val[inodes->elem_cnt + 2] = root;
4540                 inodes->elem_cnt += 3;
4541         } else {
4542                 inodes->bytes_missing += c - inodes->bytes_left;
4543                 inodes->bytes_left = 0;
4544                 inodes->elem_missed += 3;
4545         }
4546
4547         return 0;
4548 }
4549
4550 static long btrfs_ioctl_logical_to_ino(struct btrfs_fs_info *fs_info,
4551                                         void __user *arg)
4552 {
4553         int ret = 0;
4554         int size;
4555         struct btrfs_ioctl_logical_ino_args *loi;
4556         struct btrfs_data_container *inodes = NULL;
4557         struct btrfs_path *path = NULL;
4558
4559         if (!capable(CAP_SYS_ADMIN))
4560                 return -EPERM;
4561
4562         loi = memdup_user(arg, sizeof(*loi));
4563         if (IS_ERR(loi))
4564                 return PTR_ERR(loi);
4565
4566         path = btrfs_alloc_path();
4567         if (!path) {
4568                 ret = -ENOMEM;
4569                 goto out;
4570         }
4571
4572         size = min_t(u32, loi->size, SZ_64K);
4573         inodes = init_data_container(size);
4574         if (IS_ERR(inodes)) {
4575                 ret = PTR_ERR(inodes);
4576                 inodes = NULL;
4577                 goto out;
4578         }
4579
4580         ret = iterate_inodes_from_logical(loi->logical, fs_info, path,
4581                                           build_ino_list, inodes);
4582         if (ret == -EINVAL)
4583                 ret = -ENOENT;
4584         if (ret < 0)
4585                 goto out;
4586
4587         ret = copy_to_user((void *)(unsigned long)loi->inodes,
4588                            (void *)(unsigned long)inodes, size);
4589         if (ret)
4590                 ret = -EFAULT;
4591
4592 out:
4593         btrfs_free_path(path);
4594         kvfree(inodes);
4595         kfree(loi);
4596
4597         return ret;
4598 }
4599
4600 void update_ioctl_balance_args(struct btrfs_fs_info *fs_info, int lock,
4601                                struct btrfs_ioctl_balance_args *bargs)
4602 {
4603         struct btrfs_balance_control *bctl = fs_info->balance_ctl;
4604
4605         bargs->flags = bctl->flags;
4606
4607         if (atomic_read(&fs_info->balance_running))
4608                 bargs->state |= BTRFS_BALANCE_STATE_RUNNING;
4609         if (atomic_read(&fs_info->balance_pause_req))
4610                 bargs->state |= BTRFS_BALANCE_STATE_PAUSE_REQ;
4611         if (atomic_read(&fs_info->balance_cancel_req))
4612                 bargs->state |= BTRFS_BALANCE_STATE_CANCEL_REQ;
4613
4614         memcpy(&bargs->data, &bctl->data, sizeof(bargs->data));
4615         memcpy(&bargs->meta, &bctl->meta, sizeof(bargs->meta));
4616         memcpy(&bargs->sys, &bctl->sys, sizeof(bargs->sys));
4617
4618         if (lock) {
4619                 spin_lock(&fs_info->balance_lock);
4620                 memcpy(&bargs->stat, &bctl->stat, sizeof(bargs->stat));
4621                 spin_unlock(&fs_info->balance_lock);
4622         } else {
4623                 memcpy(&bargs->stat, &bctl->stat, sizeof(bargs->stat));
4624         }
4625 }
4626
4627 static long btrfs_ioctl_balance(struct file *file, void __user *arg)
4628 {
4629         struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
4630         struct btrfs_fs_info *fs_info = root->fs_info;
4631         struct btrfs_ioctl_balance_args *bargs;
4632         struct btrfs_balance_control *bctl;
4633         bool need_unlock; /* for mut. excl. ops lock */
4634         int ret;
4635
4636         if (!capable(CAP_SYS_ADMIN))
4637                 return -EPERM;
4638
4639         ret = mnt_want_write_file(file);
4640         if (ret)
4641                 return ret;
4642
4643 again:
4644         if (!test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags)) {
4645                 mutex_lock(&fs_info->volume_mutex);
4646                 mutex_lock(&fs_info->balance_mutex);
4647                 need_unlock = true;
4648                 goto locked;
4649         }
4650
4651         /*
4652          * mut. excl. ops lock is locked.  Three possibilities:
4653          *   (1) some other op is running
4654          *   (2) balance is running
4655          *   (3) balance is paused -- special case (think resume)
4656          */
4657         mutex_lock(&fs_info->balance_mutex);
4658         if (fs_info->balance_ctl) {
4659                 /* this is either (2) or (3) */
4660                 if (!atomic_read(&fs_info->balance_running)) {
4661                         mutex_unlock(&fs_info->balance_mutex);
4662                         if (!mutex_trylock(&fs_info->volume_mutex))
4663                                 goto again;
4664                         mutex_lock(&fs_info->balance_mutex);
4665
4666                         if (fs_info->balance_ctl &&
4667                             !atomic_read(&fs_info->balance_running)) {
4668                                 /* this is (3) */
4669                                 need_unlock = false;
4670                                 goto locked;
4671                         }
4672
4673                         mutex_unlock(&fs_info->balance_mutex);
4674                         mutex_unlock(&fs_info->volume_mutex);
4675                         goto again;
4676                 } else {
4677                         /* this is (2) */
4678                         mutex_unlock(&fs_info->balance_mutex);
4679                         ret = -EINPROGRESS;
4680                         goto out;
4681                 }
4682         } else {
4683                 /* this is (1) */
4684                 mutex_unlock(&fs_info->balance_mutex);
4685                 ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
4686                 goto out;
4687         }
4688
4689 locked:
4690         BUG_ON(!test_bit(BTRFS_FS_EXCL_OP, &fs_info->flags));
4691
4692         if (arg) {
4693                 bargs = memdup_user(arg, sizeof(*bargs));
4694                 if (IS_ERR(bargs)) {
4695                         ret = PTR_ERR(bargs);
4696                         goto out_unlock;
4697                 }
4698
4699                 if (bargs->flags & BTRFS_BALANCE_RESUME) {
4700                         if (!fs_info->balance_ctl) {
4701                                 ret = -ENOTCONN;
4702                                 goto out_bargs;
4703                         }
4704
4705                         bctl = fs_info->balance_ctl;
4706                         spin_lock(&fs_info->balance_lock);
4707                         bctl->flags |= BTRFS_BALANCE_RESUME;
4708                         spin_unlock(&fs_info->balance_lock);
4709
4710                         goto do_balance;
4711                 }
4712         } else {
4713                 bargs = NULL;
4714         }
4715
4716         if (fs_info->balance_ctl) {
4717                 ret = -EINPROGRESS;
4718                 goto out_bargs;
4719         }
4720
4721         bctl = kzalloc(sizeof(*bctl), GFP_KERNEL);
4722         if (!bctl) {
4723                 ret = -ENOMEM;
4724                 goto out_bargs;
4725         }
4726
4727         bctl->fs_info = fs_info;
4728         if (arg) {
4729                 memcpy(&bctl->data, &bargs->data, sizeof(bctl->data));
4730                 memcpy(&bctl->meta, &bargs->meta, sizeof(bctl->meta));
4731                 memcpy(&bctl->sys, &bargs->sys, sizeof(bctl->sys));
4732
4733                 bctl->flags = bargs->flags;
4734         } else {
4735                 /* balance everything - no filters */
4736                 bctl->flags |= BTRFS_BALANCE_TYPE_MASK;
4737         }
4738
4739         if (bctl->flags & ~(BTRFS_BALANCE_ARGS_MASK | BTRFS_BALANCE_TYPE_MASK)) {
4740                 ret = -EINVAL;
4741                 goto out_bctl;
4742         }
4743
4744 do_balance:
4745         /*
4746          * Ownership of bctl and filesystem flag BTRFS_FS_EXCL_OP
4747          * goes to to btrfs_balance.  bctl is freed in __cancel_balance,
4748          * or, if restriper was paused all the way until unmount, in
4749          * free_fs_info.  The flag is cleared in __cancel_balance.
4750          */
4751         need_unlock = false;
4752
4753         ret = btrfs_balance(bctl, bargs);
4754         bctl = NULL;
4755
4756         if (arg) {
4757                 if (copy_to_user(arg, bargs, sizeof(*bargs)))
4758                         ret = -EFAULT;
4759         }
4760
4761 out_bctl:
4762         kfree(bctl);
4763 out_bargs:
4764         kfree(bargs);
4765 out_unlock:
4766         mutex_unlock(&fs_info->balance_mutex);
4767         mutex_unlock(&fs_info->volume_mutex);
4768         if (need_unlock)
4769                 clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
4770 out:
4771         mnt_drop_write_file(file);
4772         return ret;
4773 }
4774
4775 static long btrfs_ioctl_balance_ctl(struct btrfs_fs_info *fs_info, int cmd)
4776 {
4777         if (!capable(CAP_SYS_ADMIN))
4778                 return -EPERM;
4779
4780         switch (cmd) {
4781         case BTRFS_BALANCE_CTL_PAUSE:
4782                 return btrfs_pause_balance(fs_info);
4783         case BTRFS_BALANCE_CTL_CANCEL:
4784                 return btrfs_cancel_balance(fs_info);
4785         }
4786
4787         return -EINVAL;
4788 }
4789
4790 static long btrfs_ioctl_balance_progress(struct btrfs_fs_info *fs_info,
4791                                          void __user *arg)
4792 {
4793         struct btrfs_ioctl_balance_args *bargs;
4794         int ret = 0;
4795
4796         if (!capable(CAP_SYS_ADMIN))
4797                 return -EPERM;
4798
4799         mutex_lock(&fs_info->balance_mutex);
4800         if (!fs_info->balance_ctl) {
4801                 ret = -ENOTCONN;
4802                 goto out;
4803         }
4804
4805         bargs = kzalloc(sizeof(*bargs), GFP_KERNEL);
4806         if (!bargs) {
4807                 ret = -ENOMEM;
4808                 goto out;
4809         }
4810
4811         update_ioctl_balance_args(fs_info, 1, bargs);
4812
4813         if (copy_to_user(arg, bargs, sizeof(*bargs)))
4814                 ret = -EFAULT;
4815
4816         kfree(bargs);
4817 out:
4818         mutex_unlock(&fs_info->balance_mutex);
4819         return ret;
4820 }
4821
4822 static long btrfs_ioctl_quota_ctl(struct file *file, void __user *arg)
4823 {
4824         struct inode *inode = file_inode(file);
4825         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4826         struct btrfs_ioctl_quota_ctl_args *sa;
4827         struct btrfs_trans_handle *trans = NULL;
4828         int ret;
4829         int err;
4830
4831         if (!capable(CAP_SYS_ADMIN))
4832                 return -EPERM;
4833
4834         ret = mnt_want_write_file(file);
4835         if (ret)
4836                 return ret;
4837
4838         sa = memdup_user(arg, sizeof(*sa));
4839         if (IS_ERR(sa)) {
4840                 ret = PTR_ERR(sa);
4841                 goto drop_write;
4842         }
4843
4844         down_write(&fs_info->subvol_sem);
4845         trans = btrfs_start_transaction(fs_info->tree_root, 2);
4846         if (IS_ERR(trans)) {
4847                 ret = PTR_ERR(trans);
4848                 goto out;
4849         }
4850
4851         switch (sa->cmd) {
4852         case BTRFS_QUOTA_CTL_ENABLE:
4853                 ret = btrfs_quota_enable(trans, fs_info);
4854                 break;
4855         case BTRFS_QUOTA_CTL_DISABLE:
4856                 ret = btrfs_quota_disable(trans, fs_info);
4857                 break;
4858         default:
4859                 ret = -EINVAL;
4860                 break;
4861         }
4862
4863         err = btrfs_commit_transaction(trans);
4864         if (err && !ret)
4865                 ret = err;
4866 out:
4867         kfree(sa);
4868         up_write(&fs_info->subvol_sem);
4869 drop_write:
4870         mnt_drop_write_file(file);
4871         return ret;
4872 }
4873
4874 static long btrfs_ioctl_qgroup_assign(struct file *file, void __user *arg)
4875 {
4876         struct inode *inode = file_inode(file);
4877         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4878         struct btrfs_root *root = BTRFS_I(inode)->root;
4879         struct btrfs_ioctl_qgroup_assign_args *sa;
4880         struct btrfs_trans_handle *trans;
4881         int ret;
4882         int err;
4883
4884         if (!capable(CAP_SYS_ADMIN))
4885                 return -EPERM;
4886
4887         ret = mnt_want_write_file(file);
4888         if (ret)
4889                 return ret;
4890
4891         sa = memdup_user(arg, sizeof(*sa));
4892         if (IS_ERR(sa)) {
4893                 ret = PTR_ERR(sa);
4894                 goto drop_write;
4895         }
4896
4897         trans = btrfs_join_transaction(root);
4898         if (IS_ERR(trans)) {
4899                 ret = PTR_ERR(trans);
4900                 goto out;
4901         }
4902
4903         if (sa->assign) {
4904                 ret = btrfs_add_qgroup_relation(trans, fs_info,
4905                                                 sa->src, sa->dst);
4906         } else {
4907                 ret = btrfs_del_qgroup_relation(trans, fs_info,
4908                                                 sa->src, sa->dst);
4909         }
4910
4911         /* update qgroup status and info */
4912         err = btrfs_run_qgroups(trans, fs_info);
4913         if (err < 0)
4914                 btrfs_handle_fs_error(fs_info, err,
4915                                       "failed to update qgroup status and info");
4916         err = btrfs_end_transaction(trans);
4917         if (err && !ret)
4918                 ret = err;
4919
4920 out:
4921         kfree(sa);
4922 drop_write:
4923         mnt_drop_write_file(file);
4924         return ret;
4925 }
4926
4927 static long btrfs_ioctl_qgroup_create(struct file *file, void __user *arg)
4928 {
4929         struct inode *inode = file_inode(file);
4930         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4931         struct btrfs_root *root = BTRFS_I(inode)->root;
4932         struct btrfs_ioctl_qgroup_create_args *sa;
4933         struct btrfs_trans_handle *trans;
4934         int ret;
4935         int err;
4936
4937         if (!capable(CAP_SYS_ADMIN))
4938                 return -EPERM;
4939
4940         ret = mnt_want_write_file(file);
4941         if (ret)
4942                 return ret;
4943
4944         sa = memdup_user(arg, sizeof(*sa));
4945         if (IS_ERR(sa)) {
4946                 ret = PTR_ERR(sa);
4947                 goto drop_write;
4948         }
4949
4950         if (!sa->qgroupid) {
4951                 ret = -EINVAL;
4952                 goto out;
4953         }
4954
4955         trans = btrfs_join_transaction(root);
4956         if (IS_ERR(trans)) {
4957                 ret = PTR_ERR(trans);
4958                 goto out;
4959         }
4960
4961         if (sa->create) {
4962                 ret = btrfs_create_qgroup(trans, fs_info, sa->qgroupid);
4963         } else {
4964                 ret = btrfs_remove_qgroup(trans, fs_info, sa->qgroupid);
4965         }
4966
4967         err = btrfs_end_transaction(trans);
4968         if (err && !ret)
4969                 ret = err;
4970
4971 out:
4972         kfree(sa);
4973 drop_write:
4974         mnt_drop_write_file(file);
4975         return ret;
4976 }
4977
4978 static long btrfs_ioctl_qgroup_limit(struct file *file, void __user *arg)
4979 {
4980         struct inode *inode = file_inode(file);
4981         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4982         struct btrfs_root *root = BTRFS_I(inode)->root;
4983         struct btrfs_ioctl_qgroup_limit_args *sa;
4984         struct btrfs_trans_handle *trans;
4985         int ret;
4986         int err;
4987         u64 qgroupid;
4988
4989         if (!capable(CAP_SYS_ADMIN))
4990                 return -EPERM;
4991
4992         ret = mnt_want_write_file(file);
4993         if (ret)
4994                 return ret;
4995
4996         sa = memdup_user(arg, sizeof(*sa));
4997         if (IS_ERR(sa)) {
4998                 ret = PTR_ERR(sa);
4999                 goto drop_write;
5000         }
5001
5002         trans = btrfs_join_transaction(root);
5003         if (IS_ERR(trans)) {
5004                 ret = PTR_ERR(trans);
5005                 goto out;
5006         }
5007
5008         qgroupid = sa->qgroupid;
5009         if (!qgroupid) {
5010                 /* take the current subvol as qgroup */
5011                 qgroupid = root->root_key.objectid;
5012         }
5013
5014         ret = btrfs_limit_qgroup(trans, fs_info, qgroupid, &sa->lim);
5015
5016         err = btrfs_end_transaction(trans);
5017         if (err && !ret)
5018                 ret = err;
5019
5020 out:
5021         kfree(sa);
5022 drop_write:
5023         mnt_drop_write_file(file);
5024         return ret;
5025 }
5026
5027 static long btrfs_ioctl_quota_rescan(struct file *file, void __user *arg)
5028 {
5029         struct inode *inode = file_inode(file);
5030         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5031         struct btrfs_ioctl_quota_rescan_args *qsa;
5032         int ret;
5033
5034         if (!capable(CAP_SYS_ADMIN))
5035                 return -EPERM;
5036
5037         ret = mnt_want_write_file(file);
5038         if (ret)
5039                 return ret;
5040
5041         qsa = memdup_user(arg, sizeof(*qsa));
5042         if (IS_ERR(qsa)) {
5043                 ret = PTR_ERR(qsa);
5044                 goto drop_write;
5045         }
5046
5047         if (qsa->flags) {
5048                 ret = -EINVAL;
5049                 goto out;
5050         }
5051
5052         ret = btrfs_qgroup_rescan(fs_info);
5053
5054 out:
5055         kfree(qsa);
5056 drop_write:
5057         mnt_drop_write_file(file);
5058         return ret;
5059 }
5060
5061 static long btrfs_ioctl_quota_rescan_status(struct file *file, void __user *arg)
5062 {
5063         struct inode *inode = file_inode(file);
5064         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5065         struct btrfs_ioctl_quota_rescan_args *qsa;
5066         int ret = 0;
5067
5068         if (!capable(CAP_SYS_ADMIN))
5069                 return -EPERM;
5070
5071         qsa = kzalloc(sizeof(*qsa), GFP_KERNEL);
5072         if (!qsa)
5073                 return -ENOMEM;
5074
5075         if (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN) {
5076                 qsa->flags = 1;
5077                 qsa->progress = fs_info->qgroup_rescan_progress.objectid;
5078         }
5079
5080         if (copy_to_user(arg, qsa, sizeof(*qsa)))
5081                 ret = -EFAULT;
5082
5083         kfree(qsa);
5084         return ret;
5085 }
5086
5087 static long btrfs_ioctl_quota_rescan_wait(struct file *file, void __user *arg)
5088 {
5089         struct inode *inode = file_inode(file);
5090         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5091
5092         if (!capable(CAP_SYS_ADMIN))
5093                 return -EPERM;
5094
5095         return btrfs_qgroup_wait_for_completion(fs_info, true);
5096 }
5097
5098 static long _btrfs_ioctl_set_received_subvol(struct file *file,
5099                                             struct btrfs_ioctl_received_subvol_args *sa)
5100 {
5101         struct inode *inode = file_inode(file);
5102         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5103         struct btrfs_root *root = BTRFS_I(inode)->root;
5104         struct btrfs_root_item *root_item = &root->root_item;
5105         struct btrfs_trans_handle *trans;
5106         struct timespec ct = current_time(inode);
5107         int ret = 0;
5108         int received_uuid_changed;
5109
5110         if (!inode_owner_or_capable(inode))
5111                 return -EPERM;
5112
5113         ret = mnt_want_write_file(file);
5114         if (ret < 0)
5115                 return ret;
5116
5117         down_write(&fs_info->subvol_sem);
5118
5119         if (btrfs_ino(BTRFS_I(inode)) != BTRFS_FIRST_FREE_OBJECTID) {
5120                 ret = -EINVAL;
5121                 goto out;
5122         }
5123
5124         if (btrfs_root_readonly(root)) {
5125                 ret = -EROFS;
5126                 goto out;
5127         }
5128
5129         /*
5130          * 1 - root item
5131          * 2 - uuid items (received uuid + subvol uuid)
5132          */
5133         trans = btrfs_start_transaction(root, 3);
5134         if (IS_ERR(trans)) {
5135                 ret = PTR_ERR(trans);
5136                 trans = NULL;
5137                 goto out;
5138         }
5139
5140         sa->rtransid = trans->transid;
5141         sa->rtime.sec = ct.tv_sec;
5142         sa->rtime.nsec = ct.tv_nsec;
5143
5144         received_uuid_changed = memcmp(root_item->received_uuid, sa->uuid,
5145                                        BTRFS_UUID_SIZE);
5146         if (received_uuid_changed &&
5147             !btrfs_is_empty_uuid(root_item->received_uuid))
5148                 btrfs_uuid_tree_rem(trans, fs_info, root_item->received_uuid,
5149                                     BTRFS_UUID_KEY_RECEIVED_SUBVOL,
5150                                     root->root_key.objectid);
5151         memcpy(root_item->received_uuid, sa->uuid, BTRFS_UUID_SIZE);
5152         btrfs_set_root_stransid(root_item, sa->stransid);
5153         btrfs_set_root_rtransid(root_item, sa->rtransid);
5154         btrfs_set_stack_timespec_sec(&root_item->stime, sa->stime.sec);
5155         btrfs_set_stack_timespec_nsec(&root_item->stime, sa->stime.nsec);
5156         btrfs_set_stack_timespec_sec(&root_item->rtime, sa->rtime.sec);
5157         btrfs_set_stack_timespec_nsec(&root_item->rtime, sa->rtime.nsec);
5158
5159         ret = btrfs_update_root(trans, fs_info->tree_root,
5160                                 &root->root_key, &root->root_item);
5161         if (ret < 0) {
5162                 btrfs_end_transaction(trans);
5163                 goto out;
5164         }
5165         if (received_uuid_changed && !btrfs_is_empty_uuid(sa->uuid)) {
5166                 ret = btrfs_uuid_tree_add(trans, fs_info, sa->uuid,
5167                                           BTRFS_UUID_KEY_RECEIVED_SUBVOL,
5168                                           root->root_key.objectid);
5169                 if (ret < 0 && ret != -EEXIST) {
5170                         btrfs_abort_transaction(trans, ret);
5171                         goto out;
5172                 }
5173         }
5174         ret = btrfs_commit_transaction(trans);
5175         if (ret < 0) {
5176                 btrfs_abort_transaction(trans, ret);
5177                 goto out;
5178         }
5179
5180 out:
5181         up_write(&fs_info->subvol_sem);
5182         mnt_drop_write_file(file);
5183         return ret;
5184 }
5185
5186 #ifdef CONFIG_64BIT
5187 static long btrfs_ioctl_set_received_subvol_32(struct file *file,
5188                                                 void __user *arg)
5189 {
5190         struct btrfs_ioctl_received_subvol_args_32 *args32 = NULL;
5191         struct btrfs_ioctl_received_subvol_args *args64 = NULL;
5192         int ret = 0;
5193
5194         args32 = memdup_user(arg, sizeof(*args32));
5195         if (IS_ERR(args32))
5196                 return PTR_ERR(args32);
5197
5198         args64 = kmalloc(sizeof(*args64), GFP_KERNEL);
5199         if (!args64) {
5200                 ret = -ENOMEM;
5201                 goto out;
5202         }
5203
5204         memcpy(args64->uuid, args32->uuid, BTRFS_UUID_SIZE);
5205         args64->stransid = args32->stransid;
5206         args64->rtransid = args32->rtransid;
5207         args64->stime.sec = args32->stime.sec;
5208         args64->stime.nsec = args32->stime.nsec;
5209         args64->rtime.sec = args32->rtime.sec;
5210         args64->rtime.nsec = args32->rtime.nsec;
5211         args64->flags = args32->flags;
5212
5213         ret = _btrfs_ioctl_set_received_subvol(file, args64);
5214         if (ret)
5215                 goto out;
5216
5217         memcpy(args32->uuid, args64->uuid, BTRFS_UUID_SIZE);
5218         args32->stransid = args64->stransid;
5219         args32->rtransid = args64->rtransid;
5220         args32->stime.sec = args64->stime.sec;
5221         args32->stime.nsec = args64->stime.nsec;
5222         args32->rtime.sec = args64->rtime.sec;
5223         args32->rtime.nsec = args64->rtime.nsec;
5224         args32->flags = args64->flags;
5225
5226         ret = copy_to_user(arg, args32, sizeof(*args32));
5227         if (ret)
5228                 ret = -EFAULT;
5229
5230 out:
5231         kfree(args32);
5232         kfree(args64);
5233         return ret;
5234 }
5235 #endif
5236
5237 static long btrfs_ioctl_set_received_subvol(struct file *file,
5238                                             void __user *arg)
5239 {
5240         struct btrfs_ioctl_received_subvol_args *sa = NULL;
5241         int ret = 0;
5242
5243         sa = memdup_user(arg, sizeof(*sa));
5244         if (IS_ERR(sa))
5245                 return PTR_ERR(sa);
5246
5247         ret = _btrfs_ioctl_set_received_subvol(file, sa);
5248
5249         if (ret)
5250                 goto out;
5251
5252         ret = copy_to_user(arg, sa, sizeof(*sa));
5253         if (ret)
5254                 ret = -EFAULT;
5255
5256 out:
5257         kfree(sa);
5258         return ret;
5259 }
5260
5261 static int btrfs_ioctl_get_fslabel(struct file *file, void __user *arg)
5262 {
5263         struct inode *inode = file_inode(file);
5264         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5265         size_t len;
5266         int ret;
5267         char label[BTRFS_LABEL_SIZE];
5268
5269         spin_lock(&fs_info->super_lock);
5270         memcpy(label, fs_info->super_copy->label, BTRFS_LABEL_SIZE);
5271         spin_unlock(&fs_info->super_lock);
5272
5273         len = strnlen(label, BTRFS_LABEL_SIZE);
5274
5275         if (len == BTRFS_LABEL_SIZE) {
5276                 btrfs_warn(fs_info,
5277                            "label is too long, return the first %zu bytes",
5278                            --len);
5279         }
5280
5281         ret = copy_to_user(arg, label, len);
5282
5283         return ret ? -EFAULT : 0;
5284 }
5285
5286 static int btrfs_ioctl_set_fslabel(struct file *file, void __user *arg)
5287 {
5288         struct inode *inode = file_inode(file);
5289         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5290         struct btrfs_root *root = BTRFS_I(inode)->root;
5291         struct btrfs_super_block *super_block = fs_info->super_copy;
5292         struct btrfs_trans_handle *trans;
5293         char label[BTRFS_LABEL_SIZE];
5294         int ret;
5295
5296         if (!capable(CAP_SYS_ADMIN))
5297                 return -EPERM;
5298
5299         if (copy_from_user(label, arg, sizeof(label)))
5300                 return -EFAULT;
5301
5302         if (strnlen(label, BTRFS_LABEL_SIZE) == BTRFS_LABEL_SIZE) {
5303                 btrfs_err(fs_info,
5304                           "unable to set label with more than %d bytes",
5305                           BTRFS_LABEL_SIZE - 1);
5306                 return -EINVAL;
5307         }
5308
5309         ret = mnt_want_write_file(file);
5310         if (ret)
5311                 return ret;
5312
5313         trans = btrfs_start_transaction(root, 0);
5314         if (IS_ERR(trans)) {
5315                 ret = PTR_ERR(trans);
5316                 goto out_unlock;
5317         }
5318
5319         spin_lock(&fs_info->super_lock);
5320         strcpy(super_block->label, label);
5321         spin_unlock(&fs_info->super_lock);
5322         ret = btrfs_commit_transaction(trans);
5323
5324 out_unlock:
5325         mnt_drop_write_file(file);
5326         return ret;
5327 }
5328
5329 #define INIT_FEATURE_FLAGS(suffix) \
5330         { .compat_flags = BTRFS_FEATURE_COMPAT_##suffix, \
5331           .compat_ro_flags = BTRFS_FEATURE_COMPAT_RO_##suffix, \
5332           .incompat_flags = BTRFS_FEATURE_INCOMPAT_##suffix }
5333
5334 int btrfs_ioctl_get_supported_features(void __user *arg)
5335 {
5336         static const struct btrfs_ioctl_feature_flags features[3] = {
5337                 INIT_FEATURE_FLAGS(SUPP),
5338                 INIT_FEATURE_FLAGS(SAFE_SET),
5339                 INIT_FEATURE_FLAGS(SAFE_CLEAR)
5340         };
5341
5342         if (copy_to_user(arg, &features, sizeof(features)))
5343                 return -EFAULT;
5344
5345         return 0;
5346 }
5347
5348 static int btrfs_ioctl_get_features(struct file *file, void __user *arg)
5349 {
5350         struct inode *inode = file_inode(file);
5351         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5352         struct btrfs_super_block *super_block = fs_info->super_copy;
5353         struct btrfs_ioctl_feature_flags features;
5354
5355         features.compat_flags = btrfs_super_compat_flags(super_block);
5356         features.compat_ro_flags = btrfs_super_compat_ro_flags(super_block);
5357         features.incompat_flags = btrfs_super_incompat_flags(super_block);
5358
5359         if (copy_to_user(arg, &features, sizeof(features)))
5360                 return -EFAULT;
5361
5362         return 0;
5363 }
5364
5365 static int check_feature_bits(struct btrfs_fs_info *fs_info,
5366                               enum btrfs_feature_set set,
5367                               u64 change_mask, u64 flags, u64 supported_flags,
5368                               u64 safe_set, u64 safe_clear)
5369 {
5370         const char *type = btrfs_feature_set_names[set];
5371         char *names;
5372         u64 disallowed, unsupported;
5373         u64 set_mask = flags & change_mask;
5374         u64 clear_mask = ~flags & change_mask;
5375
5376         unsupported = set_mask & ~supported_flags;
5377         if (unsupported) {
5378                 names = btrfs_printable_features(set, unsupported);
5379                 if (names) {
5380                         btrfs_warn(fs_info,
5381                                    "this kernel does not support the %s feature bit%s",
5382                                    names, strchr(names, ',') ? "s" : "");
5383                         kfree(names);
5384                 } else
5385                         btrfs_warn(fs_info,
5386                                    "this kernel does not support %s bits 0x%llx",
5387                                    type, unsupported);
5388                 return -EOPNOTSUPP;
5389         }
5390
5391         disallowed = set_mask & ~safe_set;
5392         if (disallowed) {
5393                 names = btrfs_printable_features(set, disallowed);
5394                 if (names) {
5395                         btrfs_warn(fs_info,
5396                                    "can't set the %s feature bit%s while mounted",
5397                                    names, strchr(names, ',') ? "s" : "");
5398                         kfree(names);
5399                 } else
5400                         btrfs_warn(fs_info,
5401                                    "can't set %s bits 0x%llx while mounted",
5402                                    type, disallowed);
5403                 return -EPERM;
5404         }
5405
5406         disallowed = clear_mask & ~safe_clear;
5407         if (disallowed) {
5408                 names = btrfs_printable_features(set, disallowed);
5409                 if (names) {
5410                         btrfs_warn(fs_info,
5411                                    "can't clear the %s feature bit%s while mounted",
5412                                    names, strchr(names, ',') ? "s" : "");
5413                         kfree(names);
5414                 } else
5415                         btrfs_warn(fs_info,
5416                                    "can't clear %s bits 0x%llx while mounted",
5417                                    type, disallowed);
5418                 return -EPERM;
5419         }
5420
5421         return 0;
5422 }
5423
5424 #define check_feature(fs_info, change_mask, flags, mask_base)   \
5425 check_feature_bits(fs_info, FEAT_##mask_base, change_mask, flags,       \
5426                    BTRFS_FEATURE_ ## mask_base ## _SUPP,        \
5427                    BTRFS_FEATURE_ ## mask_base ## _SAFE_SET,    \
5428                    BTRFS_FEATURE_ ## mask_base ## _SAFE_CLEAR)
5429
5430 static int btrfs_ioctl_set_features(struct file *file, void __user *arg)
5431 {
5432         struct inode *inode = file_inode(file);
5433         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5434         struct btrfs_root *root = BTRFS_I(inode)->root;
5435         struct btrfs_super_block *super_block = fs_info->super_copy;
5436         struct btrfs_ioctl_feature_flags flags[2];
5437         struct btrfs_trans_handle *trans;
5438         u64 newflags;
5439         int ret;
5440
5441         if (!capable(CAP_SYS_ADMIN))
5442                 return -EPERM;
5443
5444         if (copy_from_user(flags, arg, sizeof(flags)))
5445                 return -EFAULT;
5446
5447         /* Nothing to do */
5448         if (!flags[0].compat_flags && !flags[0].compat_ro_flags &&
5449             !flags[0].incompat_flags)
5450                 return 0;
5451
5452         ret = check_feature(fs_info, flags[0].compat_flags,
5453                             flags[1].compat_flags, COMPAT);
5454         if (ret)
5455                 return ret;
5456
5457         ret = check_feature(fs_info, flags[0].compat_ro_flags,
5458                             flags[1].compat_ro_flags, COMPAT_RO);
5459         if (ret)
5460                 return ret;
5461
5462         ret = check_feature(fs_info, flags[0].incompat_flags,
5463                             flags[1].incompat_flags, INCOMPAT);
5464         if (ret)
5465                 return ret;
5466
5467         ret = mnt_want_write_file(file);
5468         if (ret)
5469                 return ret;
5470
5471         trans = btrfs_start_transaction(root, 0);
5472         if (IS_ERR(trans)) {
5473                 ret = PTR_ERR(trans);
5474                 goto out_drop_write;
5475         }
5476
5477         spin_lock(&fs_info->super_lock);
5478         newflags = btrfs_super_compat_flags(super_block);
5479         newflags |= flags[0].compat_flags & flags[1].compat_flags;
5480         newflags &= ~(flags[0].compat_flags & ~flags[1].compat_flags);
5481         btrfs_set_super_compat_flags(super_block, newflags);
5482
5483         newflags = btrfs_super_compat_ro_flags(super_block);
5484         newflags |= flags[0].compat_ro_flags & flags[1].compat_ro_flags;
5485         newflags &= ~(flags[0].compat_ro_flags & ~flags[1].compat_ro_flags);
5486         btrfs_set_super_compat_ro_flags(super_block, newflags);
5487
5488         newflags = btrfs_super_incompat_flags(super_block);
5489         newflags |= flags[0].incompat_flags & flags[1].incompat_flags;
5490         newflags &= ~(flags[0].incompat_flags & ~flags[1].incompat_flags);
5491         btrfs_set_super_incompat_flags(super_block, newflags);
5492         spin_unlock(&fs_info->super_lock);
5493
5494         ret = btrfs_commit_transaction(trans);
5495 out_drop_write:
5496         mnt_drop_write_file(file);
5497
5498         return ret;
5499 }
5500
5501 long btrfs_ioctl(struct file *file, unsigned int
5502                 cmd, unsigned long arg)
5503 {
5504         struct inode *inode = file_inode(file);
5505         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5506         struct btrfs_root *root = BTRFS_I(inode)->root;
5507         void __user *argp = (void __user *)arg;
5508
5509         switch (cmd) {
5510         case FS_IOC_GETFLAGS:
5511                 return btrfs_ioctl_getflags(file, argp);
5512         case FS_IOC_SETFLAGS:
5513                 return btrfs_ioctl_setflags(file, argp);
5514         case FS_IOC_GETVERSION:
5515                 return btrfs_ioctl_getversion(file, argp);
5516         case FITRIM:
5517                 return btrfs_ioctl_fitrim(file, argp);
5518         case BTRFS_IOC_SNAP_CREATE:
5519                 return btrfs_ioctl_snap_create(file, argp, 0);
5520         case BTRFS_IOC_SNAP_CREATE_V2:
5521                 return btrfs_ioctl_snap_create_v2(file, argp, 0);
5522         case BTRFS_IOC_SUBVOL_CREATE:
5523                 return btrfs_ioctl_snap_create(file, argp, 1);
5524         case BTRFS_IOC_SUBVOL_CREATE_V2:
5525                 return btrfs_ioctl_snap_create_v2(file, argp, 1);
5526         case BTRFS_IOC_SNAP_DESTROY:
5527                 return btrfs_ioctl_snap_destroy(file, argp);
5528         case BTRFS_IOC_SUBVOL_GETFLAGS:
5529                 return btrfs_ioctl_subvol_getflags(file, argp);
5530         case BTRFS_IOC_SUBVOL_SETFLAGS:
5531                 return btrfs_ioctl_subvol_setflags(file, argp);
5532         case BTRFS_IOC_DEFAULT_SUBVOL:
5533                 return btrfs_ioctl_default_subvol(file, argp);
5534         case BTRFS_IOC_DEFRAG:
5535                 return btrfs_ioctl_defrag(file, NULL);
5536         case BTRFS_IOC_DEFRAG_RANGE:
5537                 return btrfs_ioctl_defrag(file, argp);
5538         case BTRFS_IOC_RESIZE:
5539                 return btrfs_ioctl_resize(file, argp);
5540         case BTRFS_IOC_ADD_DEV:
5541                 return btrfs_ioctl_add_dev(fs_info, argp);
5542         case BTRFS_IOC_RM_DEV:
5543                 return btrfs_ioctl_rm_dev(file, argp);
5544         case BTRFS_IOC_RM_DEV_V2:
5545                 return btrfs_ioctl_rm_dev_v2(file, argp);
5546         case BTRFS_IOC_FS_INFO:
5547                 return btrfs_ioctl_fs_info(fs_info, argp);
5548         case BTRFS_IOC_DEV_INFO:
5549                 return btrfs_ioctl_dev_info(fs_info, argp);
5550         case BTRFS_IOC_BALANCE:
5551                 return btrfs_ioctl_balance(file, NULL);
5552         case BTRFS_IOC_TRANS_START:
5553                 return btrfs_ioctl_trans_start(file);
5554         case BTRFS_IOC_TRANS_END:
5555                 return btrfs_ioctl_trans_end(file);
5556         case BTRFS_IOC_TREE_SEARCH:
5557                 return btrfs_ioctl_tree_search(file, argp);
5558         case BTRFS_IOC_TREE_SEARCH_V2:
5559                 return btrfs_ioctl_tree_search_v2(file, argp);
5560         case BTRFS_IOC_INO_LOOKUP:
5561                 return btrfs_ioctl_ino_lookup(file, argp);
5562         case BTRFS_IOC_INO_PATHS:
5563                 return btrfs_ioctl_ino_to_path(root, argp);
5564         case BTRFS_IOC_LOGICAL_INO:
5565                 return btrfs_ioctl_logical_to_ino(fs_info, argp);
5566         case BTRFS_IOC_SPACE_INFO:
5567                 return btrfs_ioctl_space_info(fs_info, argp);
5568         case BTRFS_IOC_SYNC: {
5569                 int ret;
5570
5571                 ret = btrfs_start_delalloc_roots(fs_info, 0, -1);
5572                 if (ret)
5573                         return ret;
5574                 ret = btrfs_sync_fs(inode->i_sb, 1);
5575                 /*
5576                  * The transaction thread may want to do more work,
5577                  * namely it pokes the cleaner kthread that will start
5578                  * processing uncleaned subvols.
5579                  */
5580                 wake_up_process(fs_info->transaction_kthread);
5581                 return ret;
5582         }
5583         case BTRFS_IOC_START_SYNC:
5584                 return btrfs_ioctl_start_sync(root, argp);
5585         case BTRFS_IOC_WAIT_SYNC:
5586                 return btrfs_ioctl_wait_sync(fs_info, argp);
5587         case BTRFS_IOC_SCRUB:
5588                 return btrfs_ioctl_scrub(file, argp);
5589         case BTRFS_IOC_SCRUB_CANCEL:
5590                 return btrfs_ioctl_scrub_cancel(fs_info);
5591         case BTRFS_IOC_SCRUB_PROGRESS:
5592                 return btrfs_ioctl_scrub_progress(fs_info, argp);
5593         case BTRFS_IOC_BALANCE_V2:
5594                 return btrfs_ioctl_balance(file, argp);
5595         case BTRFS_IOC_BALANCE_CTL:
5596                 return btrfs_ioctl_balance_ctl(fs_info, arg);
5597         case BTRFS_IOC_BALANCE_PROGRESS:
5598                 return btrfs_ioctl_balance_progress(fs_info, argp);
5599         case BTRFS_IOC_SET_RECEIVED_SUBVOL:
5600                 return btrfs_ioctl_set_received_subvol(file, argp);
5601 #ifdef CONFIG_64BIT
5602         case BTRFS_IOC_SET_RECEIVED_SUBVOL_32:
5603                 return btrfs_ioctl_set_received_subvol_32(file, argp);
5604 #endif
5605         case BTRFS_IOC_SEND:
5606                 return btrfs_ioctl_send(file, argp);
5607         case BTRFS_IOC_GET_DEV_STATS:
5608                 return btrfs_ioctl_get_dev_stats(fs_info, argp);
5609         case BTRFS_IOC_QUOTA_CTL:
5610                 return btrfs_ioctl_quota_ctl(file, argp);
5611         case BTRFS_IOC_QGROUP_ASSIGN:
5612                 return btrfs_ioctl_qgroup_assign(file, argp);
5613         case BTRFS_IOC_QGROUP_CREATE:
5614                 return btrfs_ioctl_qgroup_create(file, argp);
5615         case BTRFS_IOC_QGROUP_LIMIT:
5616                 return btrfs_ioctl_qgroup_limit(file, argp);
5617         case BTRFS_IOC_QUOTA_RESCAN:
5618                 return btrfs_ioctl_quota_rescan(file, argp);
5619         case BTRFS_IOC_QUOTA_RESCAN_STATUS:
5620                 return btrfs_ioctl_quota_rescan_status(file, argp);
5621         case BTRFS_IOC_QUOTA_RESCAN_WAIT:
5622                 return btrfs_ioctl_quota_rescan_wait(file, argp);
5623         case BTRFS_IOC_DEV_REPLACE:
5624                 return btrfs_ioctl_dev_replace(fs_info, argp);
5625         case BTRFS_IOC_GET_FSLABEL:
5626                 return btrfs_ioctl_get_fslabel(file, argp);
5627         case BTRFS_IOC_SET_FSLABEL:
5628                 return btrfs_ioctl_set_fslabel(file, argp);
5629         case BTRFS_IOC_GET_SUPPORTED_FEATURES:
5630                 return btrfs_ioctl_get_supported_features(argp);
5631         case BTRFS_IOC_GET_FEATURES:
5632                 return btrfs_ioctl_get_features(file, argp);
5633         case BTRFS_IOC_SET_FEATURES:
5634                 return btrfs_ioctl_set_features(file, argp);
5635         }
5636
5637         return -ENOTTY;
5638 }
5639
5640 #ifdef CONFIG_COMPAT
5641 long btrfs_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
5642 {
5643         /*
5644          * These all access 32-bit values anyway so no further
5645          * handling is necessary.
5646          */
5647         switch (cmd) {
5648         case FS_IOC32_GETFLAGS:
5649                 cmd = FS_IOC_GETFLAGS;
5650                 break;
5651         case FS_IOC32_SETFLAGS:
5652                 cmd = FS_IOC_SETFLAGS;
5653                 break;
5654         case FS_IOC32_GETVERSION:
5655                 cmd = FS_IOC_GETVERSION;
5656                 break;
5657         }
5658
5659         return btrfs_ioctl(file, cmd, (unsigned long) compat_ptr(arg));
5660 }
5661 #endif