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/statfs.h>
  37 #include <linux/compat.h>
  38 #include <linux/bit_spinlock.h>
  39 #include <linux/security.h>
  40 #include <linux/xattr.h>
  41 #include <linux/vmalloc.h>
  42 #include <linux/slab.h>
  43 #include <linux/blkdev.h>
  44 #include "compat.h"
  45 #include "ctree.h"
  46 #include "disk-io.h"
  47 #include "transaction.h"
  48 #include "btrfs_inode.h"
  49 #include "ioctl.h"
  50 #include "print-tree.h"
  51 #include "volumes.h"
  52 #include "locking.h"
  53 #include "inode-map.h"
  54 #include "backref.h"
  55
  56 /* Mask out flags that are inappropriate for the given type of inode. */
  57 static inline __u32 btrfs_mask_flags(umode_t mode, __u32 flags)
  58 {
  59         if (S_ISDIR(mode))
  60                 return flags;
  61         else if (S_ISREG(mode))
  62                 return flags & ~FS_DIRSYNC_FL;
  63         else
  64                 return flags & (FS_NODUMP_FL | FS_NOATIME_FL);
  65 }
  66
  67 /*
  68  * Export inode flags to the format expected by the FS_IOC_GETFLAGS ioctl.
  69  */
  70 static unsigned int btrfs_flags_to_ioctl(unsigned int flags)
  71 {
  72         unsigned int iflags = 0;
  73
  74         if (flags & BTRFS_INODE_SYNC)
  75                 iflags |= FS_SYNC_FL;
  76         if (flags & BTRFS_INODE_IMMUTABLE)
  77                 iflags |= FS_IMMUTABLE_FL;
  78         if (flags & BTRFS_INODE_APPEND)
  79                 iflags |= FS_APPEND_FL;
  80         if (flags & BTRFS_INODE_NODUMP)
  81                 iflags |= FS_NODUMP_FL;
  82         if (flags & BTRFS_INODE_NOATIME)
  83                 iflags |= FS_NOATIME_FL;
  84         if (flags & BTRFS_INODE_DIRSYNC)
  85                 iflags |= FS_DIRSYNC_FL;
  86         if (flags & BTRFS_INODE_NODATACOW)
  87                 iflags |= FS_NOCOW_FL;
  88
  89         if ((flags & BTRFS_INODE_COMPRESS) && !(flags & BTRFS_INODE_NOCOMPRESS))
  90                 iflags |= FS_COMPR_FL;
  91         else if (flags & BTRFS_INODE_NOCOMPRESS)
  92                 iflags |= FS_NOCOMP_FL;
  93
  94         return iflags;
  95 }
  96
  97 /*
  98  * Update inode->i_flags based on the btrfs internal flags.
  99  */
 100 void btrfs_update_iflags(struct inode *inode)
 101 {
 102         struct btrfs_inode *ip = BTRFS_I(inode);
 103
 104         inode->i_flags &= ~(S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC);
 105
 106         if (ip->flags & BTRFS_INODE_SYNC)
 107                 inode->i_flags |= S_SYNC;
 108         if (ip->flags & BTRFS_INODE_IMMUTABLE)
 109                 inode->i_flags |= S_IMMUTABLE;
 110         if (ip->flags & BTRFS_INODE_APPEND)
 111                 inode->i_flags |= S_APPEND;
 112         if (ip->flags & BTRFS_INODE_NOATIME)
 113                 inode->i_flags |= S_NOATIME;
 114         if (ip->flags & BTRFS_INODE_DIRSYNC)
 115                 inode->i_flags |= S_DIRSYNC;
 116 }
 117
 118 /*
 119  * Inherit flags from the parent inode.
 120  *
 121  * Currently only the compression flags and the cow flags are inherited.
 122  */
 123 void btrfs_inherit_iflags(struct inode *inode, struct inode *dir)
 124 {
 125         unsigned int flags;
 126
 127         if (!dir)
 128                 return;
 129
 130         flags = BTRFS_I(dir)->flags;
 131
 132         if (flags & BTRFS_INODE_NOCOMPRESS) {
 133                 BTRFS_I(inode)->flags &= ~BTRFS_INODE_COMPRESS;
 134                 BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS;
 135         } else if (flags & BTRFS_INODE_COMPRESS) {
 136                 BTRFS_I(inode)->flags &= ~BTRFS_INODE_NOCOMPRESS;
 137                 BTRFS_I(inode)->flags |= BTRFS_INODE_COMPRESS;
 138         }
 139
 140         if (flags & BTRFS_INODE_NODATACOW)
 141                 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATACOW;
 142
 143         btrfs_update_iflags(inode);
 144 }
 145
 146 static int btrfs_ioctl_getflags(struct file *file, void __user *arg)
 147 {
 148         struct btrfs_inode *ip = BTRFS_I(file->f_path.dentry->d_inode);
 149         unsigned int flags = btrfs_flags_to_ioctl(ip->flags);
 150
 151         if (copy_to_user(arg, &flags, sizeof(flags)))
 152                 return -EFAULT;
 153         return 0;
 154 }
 155
 156 static int check_flags(unsigned int flags)
 157 {
 158         if (flags & ~(FS_IMMUTABLE_FL | FS_APPEND_FL | \
 159                       FS_NOATIME_FL | FS_NODUMP_FL | \
 160                       FS_SYNC_FL | FS_DIRSYNC_FL | \
 161                       FS_NOCOMP_FL | FS_COMPR_FL |
 162                       FS_NOCOW_FL))
 163                 return -EOPNOTSUPP;
 164
 165         if ((flags & FS_NOCOMP_FL) && (flags & FS_COMPR_FL))
 166                 return -EINVAL;
 167
 168         return 0;
 169 }
 170
 171 static int btrfs_ioctl_setflags(struct file *file, void __user *arg)
 172 {
 173         struct inode *inode = file->f_path.dentry->d_inode;
 174         struct btrfs_inode *ip = BTRFS_I(inode);
 175         struct btrfs_root *root = ip->root;
 176         struct btrfs_trans_handle *trans;
 177         unsigned int flags, oldflags;
 178         int ret;
 179
 180         if (btrfs_root_readonly(root))
 181                 return -EROFS;
 182
 183         if (copy_from_user(&flags, arg, sizeof(flags)))
 184                 return -EFAULT;
 185
 186         ret = check_flags(flags);
 187         if (ret)
 188                 return ret;
 189
 190         if (!inode_owner_or_capable(inode))
 191                 return -EACCES;
 192
 193         mutex_lock(&inode->i_mutex);
 194
 195         flags = btrfs_mask_flags(inode->i_mode, flags);
 196         oldflags = btrfs_flags_to_ioctl(ip->flags);
 197         if ((flags ^ oldflags) & (FS_APPEND_FL | FS_IMMUTABLE_FL)) {
 198                 if (!capable(CAP_LINUX_IMMUTABLE)) {
 199                         ret = -EPERM;
 200                         goto out_unlock;
 201                 }
 202         }
 203
 204         ret = mnt_want_write(file->f_path.mnt);
 205         if (ret)
 206                 goto out_unlock;
 207
 208         if (flags & FS_SYNC_FL)
 209                 ip->flags |= BTRFS_INODE_SYNC;
 210         else
 211                 ip->flags &= ~BTRFS_INODE_SYNC;
 212         if (flags & FS_IMMUTABLE_FL)
 213                 ip->flags |= BTRFS_INODE_IMMUTABLE;
 214         else
 215                 ip->flags &= ~BTRFS_INODE_IMMUTABLE;
 216         if (flags & FS_APPEND_FL)
 217                 ip->flags |= BTRFS_INODE_APPEND;
 218         else
 219                 ip->flags &= ~BTRFS_INODE_APPEND;
 220         if (flags & FS_NODUMP_FL)
 221                 ip->flags |= BTRFS_INODE_NODUMP;
 222         else
 223                 ip->flags &= ~BTRFS_INODE_NODUMP;
 224         if (flags & FS_NOATIME_FL)
 225                 ip->flags |= BTRFS_INODE_NOATIME;
 226         else
 227                 ip->flags &= ~BTRFS_INODE_NOATIME;
 228         if (flags & FS_DIRSYNC_FL)
 229                 ip->flags |= BTRFS_INODE_DIRSYNC;
 230         else
 231                 ip->flags &= ~BTRFS_INODE_DIRSYNC;
 232         if (flags & FS_NOCOW_FL)
 233                 ip->flags |= BTRFS_INODE_NODATACOW;
 234         else
 235                 ip->flags &= ~BTRFS_INODE_NODATACOW;
 236
 237         /*
 238          * The COMPRESS flag can only be changed by users, while the NOCOMPRESS
 239          * flag may be changed automatically if compression code won't make
 240          * things smaller.
 241          */
 242         if (flags & FS_NOCOMP_FL) {
 243                 ip->flags &= ~BTRFS_INODE_COMPRESS;
 244                 ip->flags |= BTRFS_INODE_NOCOMPRESS;
 245         } else if (flags & FS_COMPR_FL) {
 246                 ip->flags |= BTRFS_INODE_COMPRESS;
 247                 ip->flags &= ~BTRFS_INODE_NOCOMPRESS;
 248         } else {
 249                 ip->flags &= ~(BTRFS_INODE_COMPRESS | BTRFS_INODE_NOCOMPRESS);
 250         }
 251
 252         trans = btrfs_join_transaction(root);
 253         BUG_ON(IS_ERR(trans));
 254
 255         ret = btrfs_update_inode(trans, root, inode);
 256         BUG_ON(ret);
 257
 258         btrfs_update_iflags(inode);
 259         inode->i_ctime = CURRENT_TIME;
 260         btrfs_end_transaction(trans, root);
 261
 262         mnt_drop_write(file->f_path.mnt);
 263
 264         ret = 0;
 265  out_unlock:
 266         mutex_unlock(&inode->i_mutex);
 267         return ret;
 268 }
 269
 270 static int btrfs_ioctl_getversion(struct file *file, int __user *arg)
 271 {
 272         struct inode *inode = file->f_path.dentry->d_inode;
 273
 274         return put_user(inode->i_generation, arg);
 275 }
 276
 277 static noinline int btrfs_ioctl_fitrim(struct file *file, void __user *arg)
 278 {
 279         struct btrfs_root *root = fdentry(file)->d_sb->s_fs_info;
 280         struct btrfs_fs_info *fs_info = root->fs_info;
 281         struct btrfs_device *device;
 282         struct request_queue *q;
 283         struct fstrim_range range;
 284         u64 minlen = ULLONG_MAX;
 285         u64 num_devices = 0;
 286         u64 total_bytes = btrfs_super_total_bytes(root->fs_info->super_copy);
 287         int ret;
 288
 289         if (!capable(CAP_SYS_ADMIN))
 290                 return -EPERM;
 291
 292         rcu_read_lock();
 293         list_for_each_entry_rcu(device, &fs_info->fs_devices->devices,
 294                                 dev_list) {
 295                 if (!device->bdev)
 296                         continue;
 297                 q = bdev_get_queue(device->bdev);
 298                 if (blk_queue_discard(q)) {
 299                         num_devices++;
 300                         minlen = min((u64)q->limits.discard_granularity,
 301                                      minlen);
 302                 }
 303         }
 304         rcu_read_unlock();
 305
 306         if (!num_devices)
 307                 return -EOPNOTSUPP;
 308         if (copy_from_user(&range, arg, sizeof(range)))
 309                 return -EFAULT;
 310         if (range.start > total_bytes)
 311                 return -EINVAL;
 312
 313         range.len = min(range.len, total_bytes - range.start);
 314         range.minlen = max(range.minlen, minlen);
 315         ret = btrfs_trim_fs(root, &range);
 316         if (ret < 0)
 317                 return ret;
 318
 319         if (copy_to_user(arg, &range, sizeof(range)))
 320                 return -EFAULT;
 321
 322         return 0;
 323 }
 324
 325 static noinline int create_subvol(struct btrfs_root *root,
 326                                   struct dentry *dentry,
 327                                   char *name, int namelen,
 328                                   u64 *async_transid)
 329 {
 330         struct btrfs_trans_handle *trans;
 331         struct btrfs_key key;
 332         struct btrfs_root_item root_item;
 333         struct btrfs_inode_item *inode_item;
 334         struct extent_buffer *leaf;
 335         struct btrfs_root *new_root;
 336         struct dentry *parent = dentry->d_parent;
 337         struct inode *dir;
 338         int ret;
 339         int err;
 340         u64 objectid;
 341         u64 new_dirid = BTRFS_FIRST_FREE_OBJECTID;
 342         u64 index = 0;
 343
 344         ret = btrfs_find_free_objectid(root->fs_info->tree_root, &objectid);
 345         if (ret)
 346                 return ret;
 347
 348         dir = parent->d_inode;
 349
 350         /*
 351          * 1 - inode item
 352          * 2 - refs
 353          * 1 - root item
 354          * 2 - dir items
 355          */
 356         trans = btrfs_start_transaction(root, 6);
 357         if (IS_ERR(trans))
 358                 return PTR_ERR(trans);
 359
 360         leaf = btrfs_alloc_free_block(trans, root, root->leafsize,
 361                                       0, objectid, NULL, 0, 0, 0);
 362         if (IS_ERR(leaf)) {
 363                 ret = PTR_ERR(leaf);
 364                 goto fail;
 365         }
 366
 367         memset_extent_buffer(leaf, 0, 0, sizeof(struct btrfs_header));
 368         btrfs_set_header_bytenr(leaf, leaf->start);
 369         btrfs_set_header_generation(leaf, trans->transid);
 370         btrfs_set_header_backref_rev(leaf, BTRFS_MIXED_BACKREF_REV);
 371         btrfs_set_header_owner(leaf, objectid);
 372
 373         write_extent_buffer(leaf, root->fs_info->fsid,
 374                             (unsigned long)btrfs_header_fsid(leaf),
 375                             BTRFS_FSID_SIZE);
 376         write_extent_buffer(leaf, root->fs_info->chunk_tree_uuid,
 377                             (unsigned long)btrfs_header_chunk_tree_uuid(leaf),
 378                             BTRFS_UUID_SIZE);
 379         btrfs_mark_buffer_dirty(leaf);
 380
 381         inode_item = &root_item.inode;
 382         memset(inode_item, 0, sizeof(*inode_item));
 383         inode_item->generation = cpu_to_le64(1);
 384         inode_item->size = cpu_to_le64(3);
 385         inode_item->nlink = cpu_to_le32(1);
 386         inode_item->nbytes = cpu_to_le64(root->leafsize);
 387         inode_item->mode = cpu_to_le32(S_IFDIR | 0755);
 388
 389         root_item.flags = 0;
 390         root_item.byte_limit = 0;
 391         inode_item->flags = cpu_to_le64(BTRFS_INODE_ROOT_ITEM_INIT);
 392
 393         btrfs_set_root_bytenr(&root_item, leaf->start);
 394         btrfs_set_root_generation(&root_item, trans->transid);
 395         btrfs_set_root_level(&root_item, 0);
 396         btrfs_set_root_refs(&root_item, 1);
 397         btrfs_set_root_used(&root_item, leaf->len);
 398         btrfs_set_root_last_snapshot(&root_item, 0);
 399
 400         memset(&root_item.drop_progress, 0, sizeof(root_item.drop_progress));
 401         root_item.drop_level = 0;
 402
 403         btrfs_tree_unlock(leaf);
 404         free_extent_buffer(leaf);
 405         leaf = NULL;
 406
 407         btrfs_set_root_dirid(&root_item, new_dirid);
 408
 409         key.objectid = objectid;
 410         key.offset = 0;
 411         btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
 412         ret = btrfs_insert_root(trans, root->fs_info->tree_root, &key,
 413                                 &root_item);
 414         if (ret)
 415                 goto fail;
 416
 417         key.offset = (u64)-1;
 418         new_root = btrfs_read_fs_root_no_name(root->fs_info, &key);
 419         BUG_ON(IS_ERR(new_root));
 420
 421         btrfs_record_root_in_trans(trans, new_root);
 422
 423         ret = btrfs_create_subvol_root(trans, new_root, new_dirid);
 424         /*
 425          * insert the directory item
 426          */
 427         ret = btrfs_set_inode_index(dir, &index);
 428         BUG_ON(ret);
 429
 430         ret = btrfs_insert_dir_item(trans, root,
 431                                     name, namelen, dir, &key,
 432                                     BTRFS_FT_DIR, index);
 433         if (ret)
 434                 goto fail;
 435
 436         btrfs_i_size_write(dir, dir->i_size + namelen * 2);
 437         ret = btrfs_update_inode(trans, root, dir);
 438         BUG_ON(ret);
 439
 440         ret = btrfs_add_root_ref(trans, root->fs_info->tree_root,
 441                                  objectid, root->root_key.objectid,
 442                                  btrfs_ino(dir), index, name, namelen);
 443
 444         BUG_ON(ret);
 445
 446         d_instantiate(dentry, btrfs_lookup_dentry(dir, dentry));
 447 fail:
 448         if (async_transid) {
 449                 *async_transid = trans->transid;
 450                 err = btrfs_commit_transaction_async(trans, root, 1);
 451         } else {
 452                 err = btrfs_commit_transaction(trans, root);
 453         }
 454         if (err && !ret)
 455                 ret = err;
 456         return ret;
 457 }
 458
 459 static int create_snapshot(struct btrfs_root *root, struct dentry *dentry,
 460                            char *name, int namelen, u64 *async_transid,
 461                            bool readonly)
 462 {
 463         struct inode *inode;
 464         struct btrfs_pending_snapshot *pending_snapshot;
 465         struct btrfs_trans_handle *trans;
 466         int ret;
 467
 468         if (!root->ref_cows)
 469                 return -EINVAL;
 470
 471         pending_snapshot = kzalloc(sizeof(*pending_snapshot), GFP_NOFS);
 472         if (!pending_snapshot)
 473                 return -ENOMEM;
 474
 475         btrfs_init_block_rsv(&pending_snapshot->block_rsv);
 476         pending_snapshot->dentry = dentry;
 477         pending_snapshot->root = root;
 478         pending_snapshot->readonly = readonly;
 479
 480         trans = btrfs_start_transaction(root->fs_info->extent_root, 5);
 481         if (IS_ERR(trans)) {
 482                 ret = PTR_ERR(trans);
 483                 goto fail;
 484         }
 485
 486         ret = btrfs_snap_reserve_metadata(trans, pending_snapshot);
 487         BUG_ON(ret);
 488
 489         spin_lock(&root->fs_info->trans_lock);
 490         list_add(&pending_snapshot->list,
 491                  &trans->transaction->pending_snapshots);
 492         spin_unlock(&root->fs_info->trans_lock);
 493         if (async_transid) {
 494                 *async_transid = trans->transid;
 495                 ret = btrfs_commit_transaction_async(trans,
 496                                      root->fs_info->extent_root, 1);
 497         } else {
 498                 ret = btrfs_commit_transaction(trans,
 499                                                root->fs_info->extent_root);
 500         }
 501         BUG_ON(ret);
 502
 503         ret = pending_snapshot->error;
 504         if (ret)
 505                 goto fail;
 506
 507         ret = btrfs_orphan_cleanup(pending_snapshot->snap);
 508         if (ret)
 509                 goto fail;
 510
 511         inode = btrfs_lookup_dentry(dentry->d_parent->d_inode, dentry);
 512         if (IS_ERR(inode)) {
 513                 ret = PTR_ERR(inode);
 514                 goto fail;
 515         }
 516         BUG_ON(!inode);
 517         d_instantiate(dentry, inode);
 518         ret = 0;
 519 fail:
 520         kfree(pending_snapshot);
 521         return ret;
 522 }
 523
 524 /*  copy of check_sticky in fs/namei.c()
 525 * It's inline, so penalty for filesystems that don't use sticky bit is
 526 * minimal.
 527 */
 528 static inline int btrfs_check_sticky(struct inode *dir, struct inode *inode)
 529 {
 530         uid_t fsuid = current_fsuid();
 531
 532         if (!(dir->i_mode & S_ISVTX))
 533                 return 0;
 534         if (inode->i_uid == fsuid)
 535                 return 0;
 536         if (dir->i_uid == fsuid)
 537                 return 0;
 538         return !capable(CAP_FOWNER);
 539 }
 540
 541 /*  copy of may_delete in fs/namei.c()
 542  *      Check whether we can remove a link victim from directory dir, check
 543  *  whether the type of victim is right.
 544  *  1. We can't do it if dir is read-only (done in permission())
 545  *  2. We should have write and exec permissions on dir
 546  *  3. We can't remove anything from append-only dir
 547  *  4. We can't do anything with immutable dir (done in permission())
 548  *  5. If the sticky bit on dir is set we should either
 549  *      a. be owner of dir, or
 550  *      b. be owner of victim, or
 551  *      c. have CAP_FOWNER capability
 552  *  6. If the victim is append-only or immutable we can't do antyhing with
 553  *     links pointing to it.
 554  *  7. If we were asked to remove a directory and victim isn't one - ENOTDIR.
 555  *  8. If we were asked to remove a non-directory and victim isn't one - EISDIR.
 556  *  9. We can't remove a root or mountpoint.
 557  * 10. We don't allow removal of NFS sillyrenamed files; it's handled by
 558  *     nfs_async_unlink().
 559  */
 560
 561 static int btrfs_may_delete(struct inode *dir,struct dentry *victim,int isdir)
 562 {
 563         int error;
 564
 565         if (!victim->d_inode)
 566                 return -ENOENT;
 567
 568         BUG_ON(victim->d_parent->d_inode != dir);
 569         audit_inode_child(victim, dir);
 570
 571         error = inode_permission(dir, MAY_WRITE | MAY_EXEC);
 572         if (error)
 573                 return error;
 574         if (IS_APPEND(dir))
 575                 return -EPERM;
 576         if (btrfs_check_sticky(dir, victim->d_inode)||
 577                 IS_APPEND(victim->d_inode)||
 578             IS_IMMUTABLE(victim->d_inode) || IS_SWAPFILE(victim->d_inode))
 579                 return -EPERM;
 580         if (isdir) {
 581                 if (!S_ISDIR(victim->d_inode->i_mode))
 582                         return -ENOTDIR;
 583                 if (IS_ROOT(victim))
 584                         return -EBUSY;
 585         } else if (S_ISDIR(victim->d_inode->i_mode))
 586                 return -EISDIR;
 587         if (IS_DEADDIR(dir))
 588                 return -ENOENT;
 589         if (victim->d_flags & DCACHE_NFSFS_RENAMED)
 590                 return -EBUSY;
 591         return 0;
 592 }
 593
 594 /* copy of may_create in fs/namei.c() */
 595 static inline int btrfs_may_create(struct inode *dir, struct dentry *child)
 596 {
 597         if (child->d_inode)
 598                 return -EEXIST;
 599         if (IS_DEADDIR(dir))
 600                 return -ENOENT;
 601         return inode_permission(dir, MAY_WRITE | MAY_EXEC);
 602 }
 603
 604 /*
 605  * Create a new subvolume below @parent.  This is largely modeled after
 606  * sys_mkdirat and vfs_mkdir, but we only do a single component lookup
 607  * inside this filesystem so it's quite a bit simpler.
 608  */
 609 static noinline int btrfs_mksubvol(struct path *parent,
 610                                    char *name, int namelen,
 611                                    struct btrfs_root *snap_src,
 612                                    u64 *async_transid, bool readonly)
 613 {
 614         struct inode *dir  = parent->dentry->d_inode;
 615         struct dentry *dentry;
 616         int error;
 617
 618         mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
 619
 620         dentry = lookup_one_len(name, parent->dentry, namelen);
 621         error = PTR_ERR(dentry);
 622         if (IS_ERR(dentry))
 623                 goto out_unlock;
 624
 625         error = -EEXIST;
 626         if (dentry->d_inode)
 627                 goto out_dput;
 628
 629         error = mnt_want_write(parent->mnt);
 630         if (error)
 631                 goto out_dput;
 632
 633         error = btrfs_may_create(dir, dentry);
 634         if (error)
 635                 goto out_drop_write;
 636
 637         down_read(&BTRFS_I(dir)->root->fs_info->subvol_sem);
 638
 639         if (btrfs_root_refs(&BTRFS_I(dir)->root->root_item) == 0)
 640                 goto out_up_read;
 641
 642         if (snap_src) {
 643                 error = create_snapshot(snap_src, dentry,
 644                                         name, namelen, async_transid, readonly);
 645         } else {
 646                 error = create_subvol(BTRFS_I(dir)->root, dentry,
 647                                       name, namelen, async_transid);
 648         }
 649         if (!error)
 650                 fsnotify_mkdir(dir, dentry);
 651 out_up_read:
 652         up_read(&BTRFS_I(dir)->root->fs_info->subvol_sem);
 653 out_drop_write:
 654         mnt_drop_write(parent->mnt);
 655 out_dput:
 656         dput(dentry);
 657 out_unlock:
 658         mutex_unlock(&dir->i_mutex);
 659         return error;
 660 }
 661
 662 /*
 663  * When we're defragging a range, we don't want to kick it off again
 664  * if it is really just waiting for delalloc to send it down.
 665  * If we find a nice big extent or delalloc range for the bytes in the
 666  * file you want to defrag, we return 0 to let you know to skip this
 667  * part of the file
 668  */
 669 static int check_defrag_in_cache(struct inode *inode, u64 offset, int thresh)
 670 {
 671         struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
 672         struct extent_map *em = NULL;
 673         struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
 674         u64 end;
 675
 676         read_lock(&em_tree->lock);
 677         em = lookup_extent_mapping(em_tree, offset, PAGE_CACHE_SIZE);
 678         read_unlock(&em_tree->lock);
 679
 680         if (em) {
 681                 end = extent_map_end(em);
 682                 free_extent_map(em);
 683                 if (end - offset > thresh)
 684                         return 0;
 685         }
 686         /* if we already have a nice delalloc here, just stop */
 687         thresh /= 2;
 688         end = count_range_bits(io_tree, &offset, offset + thresh,
 689                                thresh, EXTENT_DELALLOC, 1);
 690         if (end >= thresh)
 691                 return 0;
 692         return 1;
 693 }
 694
 695 /*
 696  * helper function to walk through a file and find extents
 697  * newer than a specific transid, and smaller than thresh.
 698  *
 699  * This is used by the defragging code to find new and small
 700  * extents
 701  */
 702 static int find_new_extents(struct btrfs_root *root,
 703                             struct inode *inode, u64 newer_than,
 704                             u64 *off, int thresh)
 705 {
 706         struct btrfs_path *path;
 707         struct btrfs_key min_key;
 708         struct btrfs_key max_key;
 709         struct extent_buffer *leaf;
 710         struct btrfs_file_extent_item *extent;
 711         int type;
 712         int ret;
 713         u64 ino = btrfs_ino(inode);
 714
 715         path = btrfs_alloc_path();
 716         if (!path)
 717                 return -ENOMEM;
 718
 719         min_key.objectid = ino;
 720         min_key.type = BTRFS_EXTENT_DATA_KEY;
 721         min_key.offset = *off;
 722
 723         max_key.objectid = ino;
 724         max_key.type = (u8)-1;
 725         max_key.offset = (u64)-1;
 726
 727         path->keep_locks = 1;
 728
 729         while(1) {
 730                 ret = btrfs_search_forward(root, &min_key, &max_key,
 731                                            path, 0, newer_than);
 732                 if (ret != 0)
 733                         goto none;
 734                 if (min_key.objectid != ino)
 735                         goto none;
 736                 if (min_key.type != BTRFS_EXTENT_DATA_KEY)
 737                         goto none;
 738
 739                 leaf = path->nodes[0];
 740                 extent = btrfs_item_ptr(leaf, path->slots[0],
 741                                         struct btrfs_file_extent_item);
 742
 743                 type = btrfs_file_extent_type(leaf, extent);
 744                 if (type == BTRFS_FILE_EXTENT_REG &&
 745                     btrfs_file_extent_num_bytes(leaf, extent) < thresh &&
 746                     check_defrag_in_cache(inode, min_key.offset, thresh)) {
 747                         *off = min_key.offset;
 748                         btrfs_free_path(path);
 749                         return 0;
 750                 }
 751
 752                 if (min_key.offset == (u64)-1)
 753                         goto none;
 754
 755                 min_key.offset++;
 756                 btrfs_release_path(path);
 757         }
 758 none:
 759         btrfs_free_path(path);
 760         return -ENOENT;
 761 }
 762
 763 static int should_defrag_range(struct inode *inode, u64 start, u64 len,
 764                                int thresh, u64 *last_len, u64 *skip,
 765                                u64 *defrag_end)
 766 {
 767         struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
 768         struct extent_map *em = NULL;
 769         struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
 770         int ret = 1;
 771
 772         /*
 773          * make sure that once we start defragging an extent, we keep on
 774          * defragging it
 775          */
 776         if (start < *defrag_end)
 777                 return 1;
 778
 779         *skip = 0;
 780
 781         /*
 782          * hopefully we have this extent in the tree already, try without
 783          * the full extent lock
 784          */
 785         read_lock(&em_tree->lock);
 786         em = lookup_extent_mapping(em_tree, start, len);
 787         read_unlock(&em_tree->lock);
 788
 789         if (!em) {
 790                 /* get the big lock and read metadata off disk */
 791                 lock_extent(io_tree, start, start + len - 1, GFP_NOFS);
 792                 em = btrfs_get_extent(inode, NULL, 0, start, len, 0);
 793                 unlock_extent(io_tree, start, start + len - 1, GFP_NOFS);
 794
 795                 if (IS_ERR(em))
 796                         return 0;
 797         }
 798
 799         /* this will cover holes, and inline extents */
 800         if (em->block_start >= EXTENT_MAP_LAST_BYTE)
 801                 ret = 0;
 802
 803         /*
 804          * we hit a real extent, if it is big don't bother defragging it again
 805          */
 806         if ((*last_len == 0 || *last_len >= thresh) && em->len >= thresh)
 807                 ret = 0;
 808
 809         /*
 810          * last_len ends up being a counter of how many bytes we've defragged.
 811          * every time we choose not to defrag an extent, we reset *last_len
 812          * so that the next tiny extent will force a defrag.
 813          *
 814          * The end result of this is that tiny extents before a single big
 815          * extent will force at least part of that big extent to be defragged.
 816          */
 817         if (ret) {
 818                 *defrag_end = extent_map_end(em);
 819         } else {
 820                 *last_len = 0;
 821                 *skip = extent_map_end(em);
 822                 *defrag_end = 0;
 823         }
 824
 825         free_extent_map(em);
 826         return ret;
 827 }
 828
 829 /*
 830  * it doesn't do much good to defrag one or two pages
 831  * at a time.  This pulls in a nice chunk of pages
 832  * to COW and defrag.
 833  *
 834  * It also makes sure the delalloc code has enough
 835  * dirty data to avoid making new small extents as part
 836  * of the defrag
 837  *
 838  * It's a good idea to start RA on this range
 839  * before calling this.
 840  */
 841 static int cluster_pages_for_defrag(struct inode *inode,
 842                                     struct page **pages,
 843                                     unsigned long start_index,
 844                                     int num_pages)
 845 {
 846         unsigned long file_end;
 847         u64 isize = i_size_read(inode);
 848         u64 page_start;
 849         u64 page_end;
 850         int ret;
 851         int i;
 852         int i_done;
 853         struct btrfs_ordered_extent *ordered;
 854         struct extent_state *cached_state = NULL;
 855         gfp_t mask = btrfs_alloc_write_mask(inode->i_mapping);
 856
 857         if (isize == 0)
 858                 return 0;
 859         file_end = (isize - 1) >> PAGE_CACHE_SHIFT;
 860
 861         ret = btrfs_delalloc_reserve_space(inode,
 862                                            num_pages << PAGE_CACHE_SHIFT);
 863         if (ret)
 864                 return ret;
 865 again:
 866         ret = 0;
 867         i_done = 0;
 868
 869         /* step one, lock all the pages */
 870         for (i = 0; i < num_pages; i++) {
 871                 struct page *page;
 872                 page = find_or_create_page(inode->i_mapping,
 873                                             start_index + i, mask);
 874                 if (!page)
 875                         break;
 876
 877                 if (!PageUptodate(page)) {
 878                         btrfs_readpage(NULL, page);
 879                         lock_page(page);
 880                         if (!PageUptodate(page)) {
 881                                 unlock_page(page);
 882                                 page_cache_release(page);
 883                                 ret = -EIO;
 884                                 break;
 885                         }
 886                 }
 887                 isize = i_size_read(inode);
 888                 file_end = (isize - 1) >> PAGE_CACHE_SHIFT;
 889                 if (!isize || page->index > file_end ||
 890                     page->mapping != inode->i_mapping) {
 891                         /* whoops, we blew past eof, skip this page */
 892                         unlock_page(page);
 893                         page_cache_release(page);
 894                         break;
 895                 }
 896                 pages[i] = page;
 897                 i_done++;
 898         }
 899         if (!i_done || ret)
 900                 goto out;
 901
 902         if (!(inode->i_sb->s_flags & MS_ACTIVE))
 903                 goto out;
 904
 905         /*
 906          * so now we have a nice long stream of locked
 907          * and up to date pages, lets wait on them
 908          */
 909         for (i = 0; i < i_done; i++)
 910                 wait_on_page_writeback(pages[i]);
 911
 912         page_start = page_offset(pages[0]);
 913         page_end = page_offset(pages[i_done - 1]) + PAGE_CACHE_SIZE;
 914
 915         lock_extent_bits(&BTRFS_I(inode)->io_tree,
 916                          page_start, page_end - 1, 0, &cached_state,
 917                          GFP_NOFS);
 918         ordered = btrfs_lookup_first_ordered_extent(inode, page_end - 1);
 919         if (ordered &&
 920             ordered->file_offset + ordered->len > page_start &&
 921             ordered->file_offset < page_end) {
 922                 btrfs_put_ordered_extent(ordered);
 923                 unlock_extent_cached(&BTRFS_I(inode)->io_tree,
 924                                      page_start, page_end - 1,
 925                                      &cached_state, GFP_NOFS);
 926                 for (i = 0; i < i_done; i++) {
 927                         unlock_page(pages[i]);
 928                         page_cache_release(pages[i]);
 929                 }
 930                 btrfs_wait_ordered_range(inode, page_start,
 931                                          page_end - page_start);
 932                 goto again;
 933         }
 934         if (ordered)
 935                 btrfs_put_ordered_extent(ordered);
 936
 937         clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start,
 938                           page_end - 1, EXTENT_DIRTY | EXTENT_DELALLOC |
 939                           EXTENT_DO_ACCOUNTING, 0, 0, &cached_state,
 940                           GFP_NOFS);
 941
 942         if (i_done != num_pages) {
 943                 spin_lock(&BTRFS_I(inode)->lock);
 944                 BTRFS_I(inode)->outstanding_extents++;
 945                 spin_unlock(&BTRFS_I(inode)->lock);
 946                 btrfs_delalloc_release_space(inode,
 947                                      (num_pages - i_done) << PAGE_CACHE_SHIFT);
 948         }
 949
 950
 951         btrfs_set_extent_delalloc(inode, page_start, page_end - 1,
 952                                   &cached_state);
 953
 954         unlock_extent_cached(&BTRFS_I(inode)->io_tree,
 955                              page_start, page_end - 1, &cached_state,
 956                              GFP_NOFS);
 957
 958         for (i = 0; i < i_done; i++) {
 959                 clear_page_dirty_for_io(pages[i]);
 960                 ClearPageChecked(pages[i]);
 961                 set_page_extent_mapped(pages[i]);
 962                 set_page_dirty(pages[i]);
 963                 unlock_page(pages[i]);
 964                 page_cache_release(pages[i]);
 965         }
 966         return i_done;
 967 out:
 968         for (i = 0; i < i_done; i++) {
 969                 unlock_page(pages[i]);
 970                 page_cache_release(pages[i]);
 971         }
 972         btrfs_delalloc_release_space(inode, num_pages << PAGE_CACHE_SHIFT);
 973         return ret;
 974
 975 }
 976
 977 int btrfs_defrag_file(struct inode *inode, struct file *file,
 978                       struct btrfs_ioctl_defrag_range_args *range,
 979                       u64 newer_than, unsigned long max_to_defrag)
 980 {
 981         struct btrfs_root *root = BTRFS_I(inode)->root;
 982         struct btrfs_super_block *disk_super;
 983         struct file_ra_state *ra = NULL;
 984         unsigned long last_index;
 985         u64 isize = i_size_read(inode);
 986         u64 features;
 987         u64 last_len = 0;
 988         u64 skip = 0;
 989         u64 defrag_end = 0;
 990         u64 newer_off = range->start;
 991         unsigned long i;
 992         unsigned long ra_index = 0;
 993         int ret;
 994         int defrag_count = 0;
 995         int compress_type = BTRFS_COMPRESS_ZLIB;
 996         int extent_thresh = range->extent_thresh;
 997         int max_cluster = (256 * 1024) >> PAGE_CACHE_SHIFT;
 998         int cluster = max_cluster;
 999         u64 new_align = ~((u64)128 * 1024 - 1);
1000         struct page **pages = NULL;
1001
1002         if (extent_thresh == 0)
1003                 extent_thresh = 256 * 1024;
1004
1005         if (range->flags & BTRFS_DEFRAG_RANGE_COMPRESS) {
1006                 if (range->compress_type > BTRFS_COMPRESS_TYPES)
1007                         return -EINVAL;
1008                 if (range->compress_type)
1009                         compress_type = range->compress_type;
1010         }
1011
1012         if (isize == 0)
1013                 return 0;
1014
1015         /*
1016          * if we were not given a file, allocate a readahead
1017          * context
1018          */
1019         if (!file) {
1020                 ra = kzalloc(sizeof(*ra), GFP_NOFS);
1021                 if (!ra)
1022                         return -ENOMEM;
1023                 file_ra_state_init(ra, inode->i_mapping);
1024         } else {
1025                 ra = &file->f_ra;
1026         }
1027
1028         pages = kmalloc(sizeof(struct page *) * max_cluster,
1029                         GFP_NOFS);
1030         if (!pages) {
1031                 ret = -ENOMEM;
1032                 goto out_ra;
1033         }
1034
1035         /* find the last page to defrag */
1036         if (range->start + range->len > range->start) {
1037                 last_index = min_t(u64, isize - 1,
1038                          range->start + range->len - 1) >> PAGE_CACHE_SHIFT;
1039         } else {
1040                 last_index = (isize - 1) >> PAGE_CACHE_SHIFT;
1041         }
1042
1043         if (newer_than) {
1044                 ret = find_new_extents(root, inode, newer_than,
1045                                        &newer_off, 64 * 1024);
1046                 if (!ret) {
1047                         range->start = newer_off;
1048                         /*
1049                          * we always align our defrag to help keep
1050                          * the extents in the file evenly spaced
1051                          */
1052                         i = (newer_off & new_align) >> PAGE_CACHE_SHIFT;
1053                 } else
1054                         goto out_ra;
1055         } else {
1056                 i = range->start >> PAGE_CACHE_SHIFT;
1057         }
1058         if (!max_to_defrag)
1059                 max_to_defrag = last_index;
1060
1061         /*
1062          * make writeback starts from i, so the defrag range can be
1063          * written sequentially.
1064          */
1065         if (i < inode->i_mapping->writeback_index)
1066                 inode->i_mapping->writeback_index = i;
1067
1068         while (i <= last_index && defrag_count < max_to_defrag &&
1069                (i < (i_size_read(inode) + PAGE_CACHE_SIZE - 1) >>
1070                 PAGE_CACHE_SHIFT)) {
1071                 /*
1072                  * make sure we stop running if someone unmounts
1073                  * the FS
1074                  */
1075                 if (!(inode->i_sb->s_flags & MS_ACTIVE))
1076                         break;
1077
1078                 if (!newer_than &&
1079                     !should_defrag_range(inode, (u64)i << PAGE_CACHE_SHIFT,
1080                                         PAGE_CACHE_SIZE,
1081                                         extent_thresh,
1082                                         &last_len, &skip,
1083                                         &defrag_end)) {
1084                         unsigned long next;
1085                         /*
1086                          * the should_defrag function tells us how much to skip
1087                          * bump our counter by the suggested amount
1088                          */
1089                         next = (skip + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
1090                         i = max(i + 1, next);
1091                         continue;
1092                 }
1093
1094                 if (!newer_than) {
1095                         cluster = (PAGE_CACHE_ALIGN(defrag_end) >>
1096                                    PAGE_CACHE_SHIFT) - i;
1097                         cluster = min(cluster, max_cluster);
1098                 } else {
1099                         cluster = max_cluster;
1100                 }
1101
1102                 if (range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)
1103                         BTRFS_I(inode)->force_compress = compress_type;
1104
1105                 if (i + cluster > ra_index) {
1106                         ra_index = max(i, ra_index);
1107                         btrfs_force_ra(inode->i_mapping, ra, file, ra_index,
1108                                        cluster);
1109                         ra_index += max_cluster;
1110                 }
1111
1112                 ret = cluster_pages_for_defrag(inode, pages, i, cluster);
1113                 if (ret < 0)
1114                         goto out_ra;
1115
1116                 defrag_count += ret;
1117                 balance_dirty_pages_ratelimited_nr(inode->i_mapping, ret);
1118
1119                 if (newer_than) {
1120                         if (newer_off == (u64)-1)
1121                                 break;
1122
1123                         newer_off = max(newer_off + 1,
1124                                         (u64)i << PAGE_CACHE_SHIFT);
1125
1126                         ret = find_new_extents(root, inode,
1127                                                newer_than, &newer_off,
1128                                                64 * 1024);
1129                         if (!ret) {
1130                                 range->start = newer_off;
1131                                 i = (newer_off & new_align) >> PAGE_CACHE_SHIFT;
1132                         } else {
1133                                 break;
1134                         }
1135                 } else {
1136                         if (ret > 0) {
1137                                 i += ret;
1138                                 last_len += ret << PAGE_CACHE_SHIFT;
1139                         } else {
1140                                 i++;
1141                                 last_len = 0;
1142                         }
1143                 }
1144         }
1145
1146         if ((range->flags & BTRFS_DEFRAG_RANGE_START_IO))
1147                 filemap_flush(inode->i_mapping);
1148
1149         if ((range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)) {
1150                 /* the filemap_flush will queue IO into the worker threads, but
1151                  * we have to make sure the IO is actually started and that
1152                  * ordered extents get created before we return
1153                  */
1154                 atomic_inc(&root->fs_info->async_submit_draining);
1155                 while (atomic_read(&root->fs_info->nr_async_submits) ||
1156                       atomic_read(&root->fs_info->async_delalloc_pages)) {
1157                         wait_event(root->fs_info->async_submit_wait,
1158                            (atomic_read(&root->fs_info->nr_async_submits) == 0 &&
1159                             atomic_read(&root->fs_info->async_delalloc_pages) == 0));
1160                 }
1161                 atomic_dec(&root->fs_info->async_submit_draining);
1162
1163                 mutex_lock(&inode->i_mutex);
1164                 BTRFS_I(inode)->force_compress = BTRFS_COMPRESS_NONE;
1165                 mutex_unlock(&inode->i_mutex);
1166         }
1167
1168         disk_super = root->fs_info->super_copy;
1169         features = btrfs_super_incompat_flags(disk_super);
1170         if (range->compress_type == BTRFS_COMPRESS_LZO) {
1171                 features |= BTRFS_FEATURE_INCOMPAT_COMPRESS_LZO;
1172                 btrfs_set_super_incompat_flags(disk_super, features);
1173         }
1174
1175         ret = defrag_count;
1176
1177 out_ra:
1178         if (!file)
1179                 kfree(ra);
1180         kfree(pages);
1181         return ret;
1182 }
1183
1184 static noinline int btrfs_ioctl_resize(struct btrfs_root *root,
1185                                         void __user *arg)
1186 {
1187         u64 new_size;
1188         u64 old_size;
1189         u64 devid = 1;
1190         struct btrfs_ioctl_vol_args *vol_args;
1191         struct btrfs_trans_handle *trans;
1192         struct btrfs_device *device = NULL;
1193         char *sizestr;
1194         char *devstr = NULL;
1195         int ret = 0;
1196         int mod = 0;
1197
1198         if (root->fs_info->sb->s_flags & MS_RDONLY)
1199                 return -EROFS;
1200
1201         if (!capable(CAP_SYS_ADMIN))
1202                 return -EPERM;
1203
1204         vol_args = memdup_user(arg, sizeof(*vol_args));
1205         if (IS_ERR(vol_args))
1206                 return PTR_ERR(vol_args);
1207
1208         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1209
1210         mutex_lock(&root->fs_info->volume_mutex);
1211         sizestr = vol_args->name;
1212         devstr = strchr(sizestr, ':');
1213         if (devstr) {
1214                 char *end;
1215                 sizestr = devstr + 1;
1216                 *devstr = '\0';
1217                 devstr = vol_args->name;
1218                 devid = simple_strtoull(devstr, &end, 10);
1219                 printk(KERN_INFO "btrfs: resizing devid %llu\n",
1220                        (unsigned long long)devid);
1221         }
1222         device = btrfs_find_device(root, devid, NULL, NULL);
1223         if (!device) {
1224                 printk(KERN_INFO "btrfs: resizer unable to find device %llu\n",
1225                        (unsigned long long)devid);
1226                 ret = -EINVAL;
1227                 goto out_unlock;
1228         }
1229         if (!strcmp(sizestr, "max"))
1230                 new_size = device->bdev->bd_inode->i_size;
1231         else {
1232                 if (sizestr[0] == '-') {
1233                         mod = -1;
1234                         sizestr++;
1235                 } else if (sizestr[0] == '+') {
1236                         mod = 1;
1237                         sizestr++;
1238                 }
1239                 new_size = memparse(sizestr, NULL);
1240                 if (new_size == 0) {
1241                         ret = -EINVAL;
1242                         goto out_unlock;
1243                 }
1244         }
1245
1246         old_size = device->total_bytes;
1247
1248         if (mod < 0) {
1249                 if (new_size > old_size) {
1250                         ret = -EINVAL;
1251                         goto out_unlock;
1252                 }
1253                 new_size = old_size - new_size;
1254         } else if (mod > 0) {
1255                 new_size = old_size + new_size;
1256         }
1257
1258         if (new_size < 256 * 1024 * 1024) {
1259                 ret = -EINVAL;
1260                 goto out_unlock;
1261         }
1262         if (new_size > device->bdev->bd_inode->i_size) {
1263                 ret = -EFBIG;
1264                 goto out_unlock;
1265         }
1266
1267         do_div(new_size, root->sectorsize);
1268         new_size *= root->sectorsize;
1269
1270         printk(KERN_INFO "btrfs: new size for %s is %llu\n",
1271                 device->name, (unsigned long long)new_size);
1272
1273         if (new_size > old_size) {
1274                 trans = btrfs_start_transaction(root, 0);
1275                 if (IS_ERR(trans)) {
1276                         ret = PTR_ERR(trans);
1277                         goto out_unlock;
1278                 }
1279                 ret = btrfs_grow_device(trans, device, new_size);
1280                 btrfs_commit_transaction(trans, root);
1281         } else if (new_size < old_size) {
1282                 ret = btrfs_shrink_device(device, new_size);
1283         }
1284
1285 out_unlock:
1286         mutex_unlock(&root->fs_info->volume_mutex);
1287         kfree(vol_args);
1288         return ret;
1289 }
1290
1291 static noinline int btrfs_ioctl_snap_create_transid(struct file *file,
1292                                                     char *name,
1293                                                     unsigned long fd,
1294                                                     int subvol,
1295                                                     u64 *transid,
1296                                                     bool readonly)
1297 {
1298         struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root;
1299         struct file *src_file;
1300         int namelen;
1301         int ret = 0;
1302
1303         if (root->fs_info->sb->s_flags & MS_RDONLY)
1304                 return -EROFS;
1305
1306         namelen = strlen(name);
1307         if (strchr(name, '/')) {
1308                 ret = -EINVAL;
1309                 goto out;
1310         }
1311
1312         if (subvol) {
1313                 ret = btrfs_mksubvol(&file->f_path, name, namelen,
1314                                      NULL, transid, readonly);
1315         } else {
1316                 struct inode *src_inode;
1317                 src_file = fget(fd);
1318                 if (!src_file) {
1319                         ret = -EINVAL;
1320                         goto out;
1321                 }
1322
1323                 src_inode = src_file->f_path.dentry->d_inode;
1324                 if (src_inode->i_sb != file->f_path.dentry->d_inode->i_sb) {
1325                         printk(KERN_INFO "btrfs: Snapshot src from "
1326                                "another FS\n");
1327                         ret = -EINVAL;
1328                         fput(src_file);
1329                         goto out;
1330                 }
1331                 ret = btrfs_mksubvol(&file->f_path, name, namelen,
1332                                      BTRFS_I(src_inode)->root,
1333                                      transid, readonly);
1334                 fput(src_file);
1335         }
1336 out:
1337         return ret;
1338 }
1339
1340 static noinline int btrfs_ioctl_snap_create(struct file *file,
1341                                             void __user *arg, int subvol)
1342 {
1343         struct btrfs_ioctl_vol_args *vol_args;
1344         int ret;
1345
1346         vol_args = memdup_user(arg, sizeof(*vol_args));
1347         if (IS_ERR(vol_args))
1348                 return PTR_ERR(vol_args);
1349         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1350
1351         ret = btrfs_ioctl_snap_create_transid(file, vol_args->name,
1352                                               vol_args->fd, subvol,
1353                                               NULL, false);
1354
1355         kfree(vol_args);
1356         return ret;
1357 }
1358
1359 static noinline int btrfs_ioctl_snap_create_v2(struct file *file,
1360                                                void __user *arg, int subvol)
1361 {
1362         struct btrfs_ioctl_vol_args_v2 *vol_args;
1363         int ret;
1364         u64 transid = 0;
1365         u64 *ptr = NULL;
1366         bool readonly = false;
1367
1368         vol_args = memdup_user(arg, sizeof(*vol_args));
1369         if (IS_ERR(vol_args))
1370                 return PTR_ERR(vol_args);
1371         vol_args->name[BTRFS_SUBVOL_NAME_MAX] = '\0';
1372
1373         if (vol_args->flags &
1374             ~(BTRFS_SUBVOL_CREATE_ASYNC | BTRFS_SUBVOL_RDONLY)) {
1375                 ret = -EOPNOTSUPP;
1376                 goto out;
1377         }
1378
1379         if (vol_args->flags & BTRFS_SUBVOL_CREATE_ASYNC)
1380                 ptr = &transid;
1381         if (vol_args->flags & BTRFS_SUBVOL_RDONLY)
1382                 readonly = true;
1383
1384         ret = btrfs_ioctl_snap_create_transid(file, vol_args->name,
1385                                               vol_args->fd, subvol,
1386                                               ptr, readonly);
1387
1388         if (ret == 0 && ptr &&
1389             copy_to_user(arg +
1390                          offsetof(struct btrfs_ioctl_vol_args_v2,
1391                                   transid), ptr, sizeof(*ptr)))
1392                 ret = -EFAULT;
1393 out:
1394         kfree(vol_args);
1395         return ret;
1396 }
1397
1398 static noinline int btrfs_ioctl_subvol_getflags(struct file *file,
1399                                                 void __user *arg)
1400 {
1401         struct inode *inode = fdentry(file)->d_inode;
1402         struct btrfs_root *root = BTRFS_I(inode)->root;
1403         int ret = 0;
1404         u64 flags = 0;
1405
1406         if (btrfs_ino(inode) != BTRFS_FIRST_FREE_OBJECTID)
1407                 return -EINVAL;
1408
1409         down_read(&root->fs_info->subvol_sem);
1410         if (btrfs_root_readonly(root))
1411                 flags |= BTRFS_SUBVOL_RDONLY;
1412         up_read(&root->fs_info->subvol_sem);
1413
1414         if (copy_to_user(arg, &flags, sizeof(flags)))
1415                 ret = -EFAULT;
1416
1417         return ret;
1418 }
1419
1420 static noinline int btrfs_ioctl_subvol_setflags(struct file *file,
1421                                               void __user *arg)
1422 {
1423         struct inode *inode = fdentry(file)->d_inode;
1424         struct btrfs_root *root = BTRFS_I(inode)->root;
1425         struct btrfs_trans_handle *trans;
1426         u64 root_flags;
1427         u64 flags;
1428         int ret = 0;
1429
1430         if (root->fs_info->sb->s_flags & MS_RDONLY)
1431                 return -EROFS;
1432
1433         if (btrfs_ino(inode) != BTRFS_FIRST_FREE_OBJECTID)
1434                 return -EINVAL;
1435
1436         if (copy_from_user(&flags, arg, sizeof(flags)))
1437                 return -EFAULT;
1438
1439         if (flags & BTRFS_SUBVOL_CREATE_ASYNC)
1440                 return -EINVAL;
1441
1442         if (flags & ~BTRFS_SUBVOL_RDONLY)
1443                 return -EOPNOTSUPP;
1444
1445         if (!inode_owner_or_capable(inode))
1446                 return -EACCES;
1447
1448         down_write(&root->fs_info->subvol_sem);
1449
1450         /* nothing to do */
1451         if (!!(flags & BTRFS_SUBVOL_RDONLY) == btrfs_root_readonly(root))
1452                 goto out;
1453
1454         root_flags = btrfs_root_flags(&root->root_item);
1455         if (flags & BTRFS_SUBVOL_RDONLY)
1456                 btrfs_set_root_flags(&root->root_item,
1457                                      root_flags | BTRFS_ROOT_SUBVOL_RDONLY);
1458         else
1459                 btrfs_set_root_flags(&root->root_item,
1460                                      root_flags & ~BTRFS_ROOT_SUBVOL_RDONLY);
1461
1462         trans = btrfs_start_transaction(root, 1);
1463         if (IS_ERR(trans)) {
1464                 ret = PTR_ERR(trans);
1465                 goto out_reset;
1466         }
1467
1468         ret = btrfs_update_root(trans, root->fs_info->tree_root,
1469                                 &root->root_key, &root->root_item);
1470
1471         btrfs_commit_transaction(trans, root);
1472 out_reset:
1473         if (ret)
1474                 btrfs_set_root_flags(&root->root_item, root_flags);
1475 out:
1476         up_write(&root->fs_info->subvol_sem);
1477         return ret;
1478 }
1479
1480 /*
1481  * helper to check if the subvolume references other subvolumes
1482  */
1483 static noinline int may_destroy_subvol(struct btrfs_root *root)
1484 {
1485         struct btrfs_path *path;
1486         struct btrfs_key key;
1487         int ret;
1488
1489         path = btrfs_alloc_path();
1490         if (!path)
1491                 return -ENOMEM;
1492
1493         key.objectid = root->root_key.objectid;
1494         key.type = BTRFS_ROOT_REF_KEY;
1495         key.offset = (u64)-1;
1496
1497         ret = btrfs_search_slot(NULL, root->fs_info->tree_root,
1498                                 &key, path, 0, 0);
1499         if (ret < 0)
1500                 goto out;
1501         BUG_ON(ret == 0);
1502
1503         ret = 0;
1504         if (path->slots[0] > 0) {
1505                 path->slots[0]--;
1506                 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
1507                 if (key.objectid == root->root_key.objectid &&
1508                     key.type == BTRFS_ROOT_REF_KEY)
1509                         ret = -ENOTEMPTY;
1510         }
1511 out:
1512         btrfs_free_path(path);
1513         return ret;
1514 }
1515
1516 static noinline int key_in_sk(struct btrfs_key *key,
1517                               struct btrfs_ioctl_search_key *sk)
1518 {
1519         struct btrfs_key test;
1520         int ret;
1521
1522         test.objectid = sk->min_objectid;
1523         test.type = sk->min_type;
1524         test.offset = sk->min_offset;
1525
1526         ret = btrfs_comp_cpu_keys(key, &test);
1527         if (ret < 0)
1528                 return 0;
1529
1530         test.objectid = sk->max_objectid;
1531         test.type = sk->max_type;
1532         test.offset = sk->max_offset;
1533
1534         ret = btrfs_comp_cpu_keys(key, &test);
1535         if (ret > 0)
1536                 return 0;
1537         return 1;
1538 }
1539
1540 static noinline int copy_to_sk(struct btrfs_root *root,
1541                                struct btrfs_path *path,
1542                                struct btrfs_key *key,
1543                                struct btrfs_ioctl_search_key *sk,
1544                                char *buf,
1545                                unsigned long *sk_offset,
1546                                int *num_found)
1547 {
1548         u64 found_transid;
1549         struct extent_buffer *leaf;
1550         struct btrfs_ioctl_search_header sh;
1551         unsigned long item_off;
1552         unsigned long item_len;
1553         int nritems;
1554         int i;
1555         int slot;
1556         int ret = 0;
1557
1558         leaf = path->nodes[0];
1559         slot = path->slots[0];
1560         nritems = btrfs_header_nritems(leaf);
1561
1562         if (btrfs_header_generation(leaf) > sk->max_transid) {
1563                 i = nritems;
1564                 goto advance_key;
1565         }
1566         found_transid = btrfs_header_generation(leaf);
1567
1568         for (i = slot; i < nritems; i++) {
1569                 item_off = btrfs_item_ptr_offset(leaf, i);
1570                 item_len = btrfs_item_size_nr(leaf, i);
1571
1572                 if (item_len > BTRFS_SEARCH_ARGS_BUFSIZE)
1573                         item_len = 0;
1574
1575                 if (sizeof(sh) + item_len + *sk_offset >
1576                     BTRFS_SEARCH_ARGS_BUFSIZE) {
1577                         ret = 1;
1578                         goto overflow;
1579                 }
1580
1581                 btrfs_item_key_to_cpu(leaf, key, i);
1582                 if (!key_in_sk(key, sk))
1583                         continue;
1584
1585                 sh.objectid = key->objectid;
1586                 sh.offset = key->offset;
1587                 sh.type = key->type;
1588                 sh.len = item_len;
1589                 sh.transid = found_transid;
1590
1591                 /* copy search result header */
1592                 memcpy(buf + *sk_offset, &sh, sizeof(sh));
1593                 *sk_offset += sizeof(sh);
1594
1595                 if (item_len) {
1596                         char *p = buf + *sk_offset;
1597                         /* copy the item */
1598                         read_extent_buffer(leaf, p,
1599                                            item_off, item_len);
1600                         *sk_offset += item_len;
1601                 }
1602                 (*num_found)++;
1603
1604                 if (*num_found >= sk->nr_items)
1605                         break;
1606         }
1607 advance_key:
1608         ret = 0;
1609         if (key->offset < (u64)-1 && key->offset < sk->max_offset)
1610                 key->offset++;
1611         else if (key->type < (u8)-1 && key->type < sk->max_type) {
1612                 key->offset = 0;
1613                 key->type++;
1614         } else if (key->objectid < (u64)-1 && key->objectid < sk->max_objectid) {
1615                 key->offset = 0;
1616                 key->type = 0;
1617                 key->objectid++;
1618         } else
1619                 ret = 1;
1620 overflow:
1621         return ret;
1622 }
1623
1624 static noinline int search_ioctl(struct inode *inode,
1625                                  struct btrfs_ioctl_search_args *args)
1626 {
1627         struct btrfs_root *root;
1628         struct btrfs_key key;
1629         struct btrfs_key max_key;
1630         struct btrfs_path *path;
1631         struct btrfs_ioctl_search_key *sk = &args->key;
1632         struct btrfs_fs_info *info = BTRFS_I(inode)->root->fs_info;
1633         int ret;
1634         int num_found = 0;
1635         unsigned long sk_offset = 0;
1636
1637         path = btrfs_alloc_path();
1638         if (!path)
1639                 return -ENOMEM;
1640
1641         if (sk->tree_id == 0) {
1642                 /* search the root of the inode that was passed */
1643                 root = BTRFS_I(inode)->root;
1644         } else {
1645                 key.objectid = sk->tree_id;
1646                 key.type = BTRFS_ROOT_ITEM_KEY;
1647                 key.offset = (u64)-1;
1648                 root = btrfs_read_fs_root_no_name(info, &key);
1649                 if (IS_ERR(root)) {
1650                         printk(KERN_ERR "could not find root %llu\n",
1651                                sk->tree_id);
1652                         btrfs_free_path(path);
1653                         return -ENOENT;
1654                 }
1655         }
1656
1657         key.objectid = sk->min_objectid;
1658         key.type = sk->min_type;
1659         key.offset = sk->min_offset;
1660
1661         max_key.objectid = sk->max_objectid;
1662         max_key.type = sk->max_type;
1663         max_key.offset = sk->max_offset;
1664
1665         path->keep_locks = 1;
1666
1667         while(1) {
1668                 ret = btrfs_search_forward(root, &key, &max_key, path, 0,
1669                                            sk->min_transid);
1670                 if (ret != 0) {
1671                         if (ret > 0)
1672                                 ret = 0;
1673                         goto err;
1674                 }
1675                 ret = copy_to_sk(root, path, &key, sk, args->buf,
1676                                  &sk_offset, &num_found);
1677                 btrfs_release_path(path);
1678                 if (ret || num_found >= sk->nr_items)
1679                         break;
1680
1681         }
1682         ret = 0;
1683 err:
1684         sk->nr_items = num_found;
1685         btrfs_free_path(path);
1686         return ret;
1687 }
1688
1689 static noinline int btrfs_ioctl_tree_search(struct file *file,
1690                                            void __user *argp)
1691 {
1692          struct btrfs_ioctl_search_args *args;
1693          struct inode *inode;
1694          int ret;
1695
1696         if (!capable(CAP_SYS_ADMIN))
1697                 return -EPERM;
1698
1699         args = memdup_user(argp, sizeof(*args));
1700         if (IS_ERR(args))
1701                 return PTR_ERR(args);
1702
1703         inode = fdentry(file)->d_inode;
1704         ret = search_ioctl(inode, args);
1705         if (ret == 0 && copy_to_user(argp, args, sizeof(*args)))
1706                 ret = -EFAULT;
1707         kfree(args);
1708         return ret;
1709 }
1710
1711 /*
1712  * Search INODE_REFs to identify path name of 'dirid' directory
1713  * in a 'tree_id' tree. and sets path name to 'name'.
1714  */
1715 static noinline int btrfs_search_path_in_tree(struct btrfs_fs_info *info,
1716                                 u64 tree_id, u64 dirid, char *name)
1717 {
1718         struct btrfs_root *root;
1719         struct btrfs_key key;
1720         char *ptr;
1721         int ret = -1;
1722         int slot;
1723         int len;
1724         int total_len = 0;
1725         struct btrfs_inode_ref *iref;
1726         struct extent_buffer *l;
1727         struct btrfs_path *path;
1728
1729         if (dirid == BTRFS_FIRST_FREE_OBJECTID) {
1730                 name[0]='\0';
1731                 return 0;
1732         }
1733
1734         path = btrfs_alloc_path();
1735         if (!path)
1736                 return -ENOMEM;
1737
1738         ptr = &name[BTRFS_INO_LOOKUP_PATH_MAX];
1739
1740         key.objectid = tree_id;
1741         key.type = BTRFS_ROOT_ITEM_KEY;
1742         key.offset = (u64)-1;
1743         root = btrfs_read_fs_root_no_name(info, &key);
1744         if (IS_ERR(root)) {
1745                 printk(KERN_ERR "could not find root %llu\n", tree_id);
1746                 ret = -ENOENT;
1747                 goto out;
1748         }
1749
1750         key.objectid = dirid;
1751         key.type = BTRFS_INODE_REF_KEY;
1752         key.offset = (u64)-1;
1753
1754         while(1) {
1755                 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1756                 if (ret < 0)
1757                         goto out;
1758
1759                 l = path->nodes[0];
1760                 slot = path->slots[0];
1761                 if (ret > 0 && slot > 0)
1762                         slot--;
1763                 btrfs_item_key_to_cpu(l, &key, slot);
1764
1765                 if (ret > 0 && (key.objectid != dirid ||
1766                                 key.type != BTRFS_INODE_REF_KEY)) {
1767                         ret = -ENOENT;
1768                         goto out;
1769                 }
1770
1771                 iref = btrfs_item_ptr(l, slot, struct btrfs_inode_ref);
1772                 len = btrfs_inode_ref_name_len(l, iref);
1773                 ptr -= len + 1;
1774                 total_len += len + 1;
1775                 if (ptr < name)
1776                         goto out;
1777
1778                 *(ptr + len) = '/';
1779                 read_extent_buffer(l, ptr,(unsigned long)(iref + 1), len);
1780
1781                 if (key.offset == BTRFS_FIRST_FREE_OBJECTID)
1782                         break;
1783
1784                 btrfs_release_path(path);
1785                 key.objectid = key.offset;
1786                 key.offset = (u64)-1;
1787                 dirid = key.objectid;
1788         }
1789         if (ptr < name)
1790                 goto out;
1791         memmove(name, ptr, total_len);
1792         name[total_len]='\0';
1793         ret = 0;
1794 out:
1795         btrfs_free_path(path);
1796         return ret;
1797 }
1798
1799 static noinline int btrfs_ioctl_ino_lookup(struct file *file,
1800                                            void __user *argp)
1801 {
1802          struct btrfs_ioctl_ino_lookup_args *args;
1803          struct inode *inode;
1804          int ret;
1805
1806         if (!capable(CAP_SYS_ADMIN))
1807                 return -EPERM;
1808
1809         args = memdup_user(argp, sizeof(*args));
1810         if (IS_ERR(args))
1811                 return PTR_ERR(args);
1812
1813         inode = fdentry(file)->d_inode;
1814
1815         if (args->treeid == 0)
1816                 args->treeid = BTRFS_I(inode)->root->root_key.objectid;
1817
1818         ret = btrfs_search_path_in_tree(BTRFS_I(inode)->root->fs_info,
1819                                         args->treeid, args->objectid,
1820                                         args->name);
1821
1822         if (ret == 0 && copy_to_user(argp, args, sizeof(*args)))
1823                 ret = -EFAULT;
1824
1825         kfree(args);
1826         return ret;
1827 }
1828
1829 static noinline int btrfs_ioctl_snap_destroy(struct file *file,
1830                                              void __user *arg)
1831 {
1832         struct dentry *parent = fdentry(file);
1833         struct dentry *dentry;
1834         struct inode *dir = parent->d_inode;
1835         struct inode *inode;
1836         struct btrfs_root *root = BTRFS_I(dir)->root;
1837         struct btrfs_root *dest = NULL;
1838         struct btrfs_ioctl_vol_args *vol_args;
1839         struct btrfs_trans_handle *trans;
1840         int namelen;
1841         int ret;
1842         int err = 0;
1843
1844         vol_args = memdup_user(arg, sizeof(*vol_args));
1845         if (IS_ERR(vol_args))
1846                 return PTR_ERR(vol_args);
1847
1848         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1849         namelen = strlen(vol_args->name);
1850         if (strchr(vol_args->name, '/') ||
1851             strncmp(vol_args->name, "..", namelen) == 0) {
1852                 err = -EINVAL;
1853                 goto out;
1854         }
1855
1856         err = mnt_want_write(file->f_path.mnt);
1857         if (err)
1858                 goto out;
1859
1860         mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
1861         dentry = lookup_one_len(vol_args->name, parent, namelen);
1862         if (IS_ERR(dentry)) {
1863                 err = PTR_ERR(dentry);
1864                 goto out_unlock_dir;
1865         }
1866
1867         if (!dentry->d_inode) {
1868                 err = -ENOENT;
1869                 goto out_dput;
1870         }
1871
1872         inode = dentry->d_inode;
1873         dest = BTRFS_I(inode)->root;
1874         if (!capable(CAP_SYS_ADMIN)){
1875                 /*
1876                  * Regular user.  Only allow this with a special mount
1877                  * option, when the user has write+exec access to the
1878                  * subvol root, and when rmdir(2) would have been
1879                  * allowed.
1880                  *
1881                  * Note that this is _not_ check that the subvol is
1882                  * empty or doesn't contain data that we wouldn't
1883                  * otherwise be able to delete.
1884                  *
1885                  * Users who want to delete empty subvols should try
1886                  * rmdir(2).
1887                  */
1888                 err = -EPERM;
1889                 if (!btrfs_test_opt(root, USER_SUBVOL_RM_ALLOWED))
1890                         goto out_dput;
1891
1892                 /*
1893                  * Do not allow deletion if the parent dir is the same
1894                  * as the dir to be deleted.  That means the ioctl
1895                  * must be called on the dentry referencing the root
1896                  * of the subvol, not a random directory contained
1897                  * within it.
1898                  */
1899                 err = -EINVAL;
1900                 if (root == dest)
1901                         goto out_dput;
1902
1903                 err = inode_permission(inode, MAY_WRITE | MAY_EXEC);
1904                 if (err)
1905                         goto out_dput;
1906
1907                 /* check if subvolume may be deleted by a non-root user */
1908                 err = btrfs_may_delete(dir, dentry, 1);
1909                 if (err)
1910                         goto out_dput;
1911         }
1912
1913         if (btrfs_ino(inode) != BTRFS_FIRST_FREE_OBJECTID) {
1914                 err = -EINVAL;
1915                 goto out_dput;
1916         }
1917
1918         mutex_lock(&inode->i_mutex);
1919         err = d_invalidate(dentry);
1920         if (err)
1921                 goto out_unlock;
1922
1923         down_write(&root->fs_info->subvol_sem);
1924
1925         err = may_destroy_subvol(dest);
1926         if (err)
1927                 goto out_up_write;
1928
1929         trans = btrfs_start_transaction(root, 0);
1930         if (IS_ERR(trans)) {
1931                 err = PTR_ERR(trans);
1932                 goto out_up_write;
1933         }
1934         trans->block_rsv = &root->fs_info->global_block_rsv;
1935
1936         ret = btrfs_unlink_subvol(trans, root, dir,
1937                                 dest->root_key.objectid,
1938                                 dentry->d_name.name,
1939                                 dentry->d_name.len);
1940         BUG_ON(ret);
1941
1942         btrfs_record_root_in_trans(trans, dest);
1943
1944         memset(&dest->root_item.drop_progress, 0,
1945                 sizeof(dest->root_item.drop_progress));
1946         dest->root_item.drop_level = 0;
1947         btrfs_set_root_refs(&dest->root_item, 0);
1948
1949         if (!xchg(&dest->orphan_item_inserted, 1)) {
1950                 ret = btrfs_insert_orphan_item(trans,
1951                                         root->fs_info->tree_root,
1952                                         dest->root_key.objectid);
1953                 BUG_ON(ret);
1954         }
1955
1956         ret = btrfs_end_transaction(trans, root);
1957         BUG_ON(ret);
1958         inode->i_flags |= S_DEAD;
1959 out_up_write:
1960         up_write(&root->fs_info->subvol_sem);
1961 out_unlock:
1962         mutex_unlock(&inode->i_mutex);
1963         if (!err) {
1964                 shrink_dcache_sb(root->fs_info->sb);
1965                 btrfs_invalidate_inodes(dest);
1966                 d_delete(dentry);
1967         }
1968 out_dput:
1969         dput(dentry);
1970 out_unlock_dir:
1971         mutex_unlock(&dir->i_mutex);
1972         mnt_drop_write(file->f_path.mnt);
1973 out:
1974         kfree(vol_args);
1975         return err;
1976 }
1977
1978 static int btrfs_ioctl_defrag(struct file *file, void __user *argp)
1979 {
1980         struct inode *inode = fdentry(file)->d_inode;
1981         struct btrfs_root *root = BTRFS_I(inode)->root;
1982         struct btrfs_ioctl_defrag_range_args *range;
1983         int ret;
1984
1985         if (btrfs_root_readonly(root))
1986                 return -EROFS;
1987
1988         ret = mnt_want_write(file->f_path.mnt);
1989         if (ret)
1990                 return ret;
1991
1992         switch (inode->i_mode & S_IFMT) {
1993         case S_IFDIR:
1994                 if (!capable(CAP_SYS_ADMIN)) {
1995                         ret = -EPERM;
1996                         goto out;
1997                 }
1998                 ret = btrfs_defrag_root(root, 0);
1999                 if (ret)
2000                         goto out;
2001                 ret = btrfs_defrag_root(root->fs_info->extent_root, 0);
2002                 break;
2003         case S_IFREG:
2004                 if (!(file->f_mode & FMODE_WRITE)) {
2005                         ret = -EINVAL;
2006                         goto out;
2007                 }
2008
2009                 range = kzalloc(sizeof(*range), GFP_KERNEL);
2010                 if (!range) {
2011                         ret = -ENOMEM;
2012                         goto out;
2013                 }
2014
2015                 if (argp) {
2016                         if (copy_from_user(range, argp,
2017                                            sizeof(*range))) {
2018                                 ret = -EFAULT;
2019                                 kfree(range);
2020                                 goto out;
2021                         }
2022                         /* compression requires us to start the IO */
2023                         if ((range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)) {
2024                                 range->flags |= BTRFS_DEFRAG_RANGE_START_IO;
2025                                 range->extent_thresh = (u32)-1;
2026                         }
2027                 } else {
2028                         /* the rest are all set to zero by kzalloc */
2029                         range->len = (u64)-1;
2030                 }
2031                 ret = btrfs_defrag_file(fdentry(file)->d_inode, file,
2032                                         range, 0, 0);
2033                 if (ret > 0)
2034                         ret = 0;
2035                 kfree(range);
2036                 break;
2037         default:
2038                 ret = -EINVAL;
2039         }
2040 out:
2041         mnt_drop_write(file->f_path.mnt);
2042         return ret;
2043 }
2044
2045 static long btrfs_ioctl_add_dev(struct btrfs_root *root, void __user *arg)
2046 {
2047         struct btrfs_ioctl_vol_args *vol_args;
2048         int ret;
2049
2050         if (!capable(CAP_SYS_ADMIN))
2051                 return -EPERM;
2052
2053         vol_args = memdup_user(arg, sizeof(*vol_args));
2054         if (IS_ERR(vol_args))
2055                 return PTR_ERR(vol_args);
2056
2057         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
2058         ret = btrfs_init_new_device(root, vol_args->name);
2059
2060         kfree(vol_args);
2061         return ret;
2062 }
2063
2064 static long btrfs_ioctl_rm_dev(struct btrfs_root *root, void __user *arg)
2065 {
2066         struct btrfs_ioctl_vol_args *vol_args;
2067         int ret;
2068
2069         if (!capable(CAP_SYS_ADMIN))
2070                 return -EPERM;
2071
2072         if (root->fs_info->sb->s_flags & MS_RDONLY)
2073                 return -EROFS;
2074
2075         vol_args = memdup_user(arg, sizeof(*vol_args));
2076         if (IS_ERR(vol_args))
2077                 return PTR_ERR(vol_args);
2078
2079         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
2080         ret = btrfs_rm_device(root, vol_args->name);
2081
2082         kfree(vol_args);
2083         return ret;
2084 }
2085
2086 static long btrfs_ioctl_fs_info(struct btrfs_root *root, void __user *arg)
2087 {
2088         struct btrfs_ioctl_fs_info_args *fi_args;
2089         struct btrfs_device *device;
2090         struct btrfs_device *next;
2091         struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
2092         int ret = 0;
2093
2094         if (!capable(CAP_SYS_ADMIN))
2095                 return -EPERM;
2096
2097         fi_args = kzalloc(sizeof(*fi_args), GFP_KERNEL);
2098         if (!fi_args)
2099                 return -ENOMEM;
2100
2101         fi_args->num_devices = fs_devices->num_devices;
2102         memcpy(&fi_args->fsid, root->fs_info->fsid, sizeof(fi_args->fsid));
2103
2104         mutex_lock(&fs_devices->device_list_mutex);
2105         list_for_each_entry_safe(device, next, &fs_devices->devices, dev_list) {
2106                 if (device->devid > fi_args->max_id)
2107                         fi_args->max_id = device->devid;
2108         }
2109         mutex_unlock(&fs_devices->device_list_mutex);
2110
2111         if (copy_to_user(arg, fi_args, sizeof(*fi_args)))
2112                 ret = -EFAULT;
2113
2114         kfree(fi_args);
2115         return ret;
2116 }
2117
2118 static long btrfs_ioctl_dev_info(struct btrfs_root *root, void __user *arg)
2119 {
2120         struct btrfs_ioctl_dev_info_args *di_args;
2121         struct btrfs_device *dev;
2122         struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
2123         int ret = 0;
2124         char *s_uuid = NULL;
2125         char empty_uuid[BTRFS_UUID_SIZE] = {0};
2126
2127         if (!capable(CAP_SYS_ADMIN))
2128                 return -EPERM;
2129
2130         di_args = memdup_user(arg, sizeof(*di_args));
2131         if (IS_ERR(di_args))
2132                 return PTR_ERR(di_args);
2133
2134         if (memcmp(empty_uuid, di_args->uuid, BTRFS_UUID_SIZE) != 0)
2135                 s_uuid = di_args->uuid;
2136
2137         mutex_lock(&fs_devices->device_list_mutex);
2138         dev = btrfs_find_device(root, di_args->devid, s_uuid, NULL);
2139         mutex_unlock(&fs_devices->device_list_mutex);
2140
2141         if (!dev) {
2142                 ret = -ENODEV;
2143                 goto out;
2144         }
2145
2146         di_args->devid = dev->devid;
2147         di_args->bytes_used = dev->bytes_used;
2148         di_args->total_bytes = dev->total_bytes;
2149         memcpy(di_args->uuid, dev->uuid, sizeof(di_args->uuid));
2150         strncpy(di_args->path, dev->name, sizeof(di_args->path));
2151
2152 out:
2153         if (ret == 0 && copy_to_user(arg, di_args, sizeof(*di_args)))
2154                 ret = -EFAULT;
2155
2156         kfree(di_args);
2157         return ret;
2158 }
2159
2160 static noinline long btrfs_ioctl_clone(struct file *file, unsigned long srcfd,
2161                                        u64 off, u64 olen, u64 destoff)
2162 {
2163         struct inode *inode = fdentry(file)->d_inode;
2164         struct btrfs_root *root = BTRFS_I(inode)->root;
2165         struct file *src_file;
2166         struct inode *src;
2167         struct btrfs_trans_handle *trans;
2168         struct btrfs_path *path;
2169         struct extent_buffer *leaf;
2170         char *buf;
2171         struct btrfs_key key;
2172         u32 nritems;
2173         int slot;
2174         int ret;
2175         u64 len = olen;
2176         u64 bs = root->fs_info->sb->s_blocksize;
2177         u64 hint_byte;
2178
2179         /*
2180          * TODO:
2181          * - split compressed inline extents.  annoying: we need to
2182          *   decompress into destination's address_space (the file offset
2183          *   may change, so source mapping won't do), then recompress (or
2184          *   otherwise reinsert) a subrange.
2185          * - allow ranges within the same file to be cloned (provided
2186          *   they don't overlap)?
2187          */
2188
2189         /* the destination must be opened for writing */
2190         if (!(file->f_mode & FMODE_WRITE) || (file->f_flags & O_APPEND))
2191                 return -EINVAL;
2192
2193         if (btrfs_root_readonly(root))
2194                 return -EROFS;
2195
2196         ret = mnt_want_write(file->f_path.mnt);
2197         if (ret)
2198                 return ret;
2199
2200         src_file = fget(srcfd);
2201         if (!src_file) {
2202                 ret = -EBADF;
2203                 goto out_drop_write;
2204         }
2205
2206         src = src_file->f_dentry->d_inode;
2207
2208         ret = -EINVAL;
2209         if (src == inode)
2210                 goto out_fput;
2211
2212         /* the src must be open for reading */
2213         if (!(src_file->f_mode & FMODE_READ))
2214                 goto out_fput;
2215
2216         /* don't make the dst file partly checksummed */
2217         if ((BTRFS_I(src)->flags & BTRFS_INODE_NODATASUM) !=
2218             (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM))
2219                 goto out_fput;
2220
2221         ret = -EISDIR;
2222         if (S_ISDIR(src->i_mode) || S_ISDIR(inode->i_mode))
2223                 goto out_fput;
2224
2225         ret = -EXDEV;
2226         if (src->i_sb != inode->i_sb || BTRFS_I(src)->root != root)
2227                 goto out_fput;
2228
2229         ret = -ENOMEM;
2230         buf = vmalloc(btrfs_level_size(root, 0));
2231         if (!buf)
2232                 goto out_fput;
2233
2234         path = btrfs_alloc_path();
2235         if (!path) {
2236                 vfree(buf);
2237                 goto out_fput;
2238         }
2239         path->reada = 2;
2240
2241         if (inode < src) {
2242                 mutex_lock_nested(&inode->i_mutex, I_MUTEX_PARENT);
2243                 mutex_lock_nested(&src->i_mutex, I_MUTEX_CHILD);
2244         } else {
2245                 mutex_lock_nested(&src->i_mutex, I_MUTEX_PARENT);
2246                 mutex_lock_nested(&inode->i_mutex, I_MUTEX_CHILD);
2247         }
2248
2249         /* determine range to clone */
2250         ret = -EINVAL;
2251         if (off + len > src->i_size || off + len < off)
2252                 goto out_unlock;
2253         if (len == 0)
2254                 olen = len = src->i_size - off;
2255         /* if we extend to eof, continue to block boundary */
2256         if (off + len == src->i_size)
2257                 len = ALIGN(src->i_size, bs) - off;
2258
2259         /* verify the end result is block aligned */
2260         if (!IS_ALIGNED(off, bs) || !IS_ALIGNED(off + len, bs) ||
2261             !IS_ALIGNED(destoff, bs))
2262                 goto out_unlock;
2263
2264         if (destoff > inode->i_size) {
2265                 ret = btrfs_cont_expand(inode, inode->i_size, destoff);
2266                 if (ret)
2267                         goto out_unlock;
2268         }
2269
2270         /* truncate page cache pages from target inode range */
2271         truncate_inode_pages_range(&inode->i_data, destoff,
2272                                    PAGE_CACHE_ALIGN(destoff + len) - 1);
2273
2274         /* do any pending delalloc/csum calc on src, one way or
2275            another, and lock file content */
2276         while (1) {
2277                 struct btrfs_ordered_extent *ordered;
2278                 lock_extent(&BTRFS_I(src)->io_tree, off, off+len, GFP_NOFS);
2279                 ordered = btrfs_lookup_first_ordered_extent(src, off+len);
2280                 if (!ordered &&
2281                     !test_range_bit(&BTRFS_I(src)->io_tree, off, off+len,
2282                                    EXTENT_DELALLOC, 0, NULL))
2283                         break;
2284                 unlock_extent(&BTRFS_I(src)->io_tree, off, off+len, GFP_NOFS);
2285                 if (ordered)
2286                         btrfs_put_ordered_extent(ordered);
2287                 btrfs_wait_ordered_range(src, off, len);
2288         }
2289
2290         /* clone data */
2291         key.objectid = btrfs_ino(src);
2292         key.type = BTRFS_EXTENT_DATA_KEY;
2293         key.offset = 0;
2294
2295         while (1) {
2296                 /*
2297                  * note the key will change type as we walk through the
2298                  * tree.
2299                  */
2300                 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2301                 if (ret < 0)
2302                         goto out;
2303
2304                 nritems = btrfs_header_nritems(path->nodes[0]);
2305                 if (path->slots[0] >= nritems) {
2306                         ret = btrfs_next_leaf(root, path);
2307                         if (ret < 0)
2308                                 goto out;
2309                         if (ret > 0)
2310                                 break;
2311                         nritems = btrfs_header_nritems(path->nodes[0]);
2312                 }
2313                 leaf = path->nodes[0];
2314                 slot = path->slots[0];
2315
2316                 btrfs_item_key_to_cpu(leaf, &key, slot);
2317                 if (btrfs_key_type(&key) > BTRFS_EXTENT_DATA_KEY ||
2318                     key.objectid != btrfs_ino(src))
2319                         break;
2320
2321                 if (btrfs_key_type(&key) == BTRFS_EXTENT_DATA_KEY) {
2322                         struct btrfs_file_extent_item *extent;
2323                         int type;
2324                         u32 size;
2325                         struct btrfs_key new_key;
2326                         u64 disko = 0, diskl = 0;
2327                         u64 datao = 0, datal = 0;
2328                         u8 comp;
2329                         u64 endoff;
2330
2331                         size = btrfs_item_size_nr(leaf, slot);
2332                         read_extent_buffer(leaf, buf,
2333                                            btrfs_item_ptr_offset(leaf, slot),
2334                                            size);
2335
2336                         extent = btrfs_item_ptr(leaf, slot,
2337                                                 struct btrfs_file_extent_item);
2338                         comp = btrfs_file_extent_compression(leaf, extent);
2339                         type = btrfs_file_extent_type(leaf, extent);
2340                         if (type == BTRFS_FILE_EXTENT_REG ||
2341                             type == BTRFS_FILE_EXTENT_PREALLOC) {
2342                                 disko = btrfs_file_extent_disk_bytenr(leaf,
2343                                                                       extent);
2344                                 diskl = btrfs_file_extent_disk_num_bytes(leaf,
2345                                                                  extent);
2346                                 datao = btrfs_file_extent_offset(leaf, extent);
2347                                 datal = btrfs_file_extent_num_bytes(leaf,
2348                                                                     extent);
2349                         } else if (type == BTRFS_FILE_EXTENT_INLINE) {
2350                                 /* take upper bound, may be compressed */
2351                                 datal = btrfs_file_extent_ram_bytes(leaf,
2352                                                                     extent);
2353                         }
2354                         btrfs_release_path(path);
2355
2356                         if (key.offset + datal <= off ||
2357                             key.offset >= off+len)
2358                                 goto next;
2359
2360                         memcpy(&new_key, &key, sizeof(new_key));
2361                         new_key.objectid = btrfs_ino(inode);
2362                         if (off <= key.offset)
2363                                 new_key.offset = key.offset + destoff - off;
2364                         else
2365                                 new_key.offset = destoff;
2366
2367                         /*
2368                          * 1 - adjusting old extent (we may have to split it)
2369                          * 1 - add new extent
2370                          * 1 - inode update
2371                          */
2372                         trans = btrfs_start_transaction(root, 3);
2373                         if (IS_ERR(trans)) {
2374                                 ret = PTR_ERR(trans);
2375                                 goto out;
2376                         }
2377
2378                         if (type == BTRFS_FILE_EXTENT_REG ||
2379                             type == BTRFS_FILE_EXTENT_PREALLOC) {
2380                                 /*
2381                                  *    a  | --- range to clone ---|  b
2382                                  * | ------------- extent ------------- |
2383                                  */
2384
2385                                 /* substract range b */
2386                                 if (key.offset + datal > off + len)
2387                                         datal = off + len - key.offset;
2388
2389                                 /* substract range a */
2390                                 if (off > key.offset) {
2391                                         datao += off - key.offset;
2392                                         datal -= off - key.offset;
2393                                 }
2394
2395                                 ret = btrfs_drop_extents(trans, inode,
2396                                                          new_key.offset,
2397                                                          new_key.offset + datal,
2398                                                          &hint_byte, 1);
2399                                 BUG_ON(ret);
2400
2401                                 ret = btrfs_insert_empty_item(trans, root, path,
2402                                                               &new_key, size);
2403                                 BUG_ON(ret);
2404
2405                                 leaf = path->nodes[0];
2406                                 slot = path->slots[0];
2407                                 write_extent_buffer(leaf, buf,
2408                                             btrfs_item_ptr_offset(leaf, slot),
2409                                             size);
2410
2411                                 extent = btrfs_item_ptr(leaf, slot,
2412                                                 struct btrfs_file_extent_item);
2413
2414                                 /* disko == 0 means it's a hole */
2415                                 if (!disko)
2416                                         datao = 0;
2417
2418                                 btrfs_set_file_extent_offset(leaf, extent,
2419                                                              datao);
2420                                 btrfs_set_file_extent_num_bytes(leaf, extent,
2421                                                                 datal);
2422                                 if (disko) {
2423                                         inode_add_bytes(inode, datal);
2424                                         ret = btrfs_inc_extent_ref(trans, root,
2425                                                         disko, diskl, 0,
2426                                                         root->root_key.objectid,
2427                                                         btrfs_ino(inode),
2428                                                         new_key.offset - datao);
2429                                         BUG_ON(ret);
2430                                 }
2431                         } else if (type == BTRFS_FILE_EXTENT_INLINE) {
2432                                 u64 skip = 0;
2433                                 u64 trim = 0;
2434                                 if (off > key.offset) {
2435                                         skip = off - key.offset;
2436                                         new_key.offset += skip;
2437                                 }
2438
2439                                 if (key.offset + datal > off+len)
2440                                         trim = key.offset + datal - (off+len);
2441
2442                                 if (comp && (skip || trim)) {
2443                                         ret = -EINVAL;
2444                                         btrfs_end_transaction(trans, root);
2445                                         goto out;
2446                                 }
2447                                 size -= skip + trim;
2448                                 datal -= skip + trim;
2449
2450                                 ret = btrfs_drop_extents(trans, inode,
2451                                                          new_key.offset,
2452                                                          new_key.offset + datal,
2453                                                          &hint_byte, 1);
2454                                 BUG_ON(ret);
2455
2456                                 ret = btrfs_insert_empty_item(trans, root, path,
2457                                                               &new_key, size);
2458                                 BUG_ON(ret);
2459
2460                                 if (skip) {
2461                                         u32 start =
2462                                           btrfs_file_extent_calc_inline_size(0);
2463                                         memmove(buf+start, buf+start+skip,
2464                                                 datal);
2465                                 }
2466
2467                                 leaf = path->nodes[0];
2468                                 slot = path->slots[0];
2469                                 write_extent_buffer(leaf, buf,
2470                                             btrfs_item_ptr_offset(leaf, slot),
2471                                             size);
2472                                 inode_add_bytes(inode, datal);
2473                         }
2474
2475                         btrfs_mark_buffer_dirty(leaf);
2476                         btrfs_release_path(path);
2477
2478                         inode->i_mtime = inode->i_ctime = CURRENT_TIME;
2479
2480                         /*
2481                          * we round up to the block size at eof when
2482                          * determining which extents to clone above,
2483                          * but shouldn't round up the file size
2484                          */
2485                         endoff = new_key.offset + datal;
2486                         if (endoff > destoff+olen)
2487                                 endoff = destoff+olen;
2488                         if (endoff > inode->i_size)
2489                                 btrfs_i_size_write(inode, endoff);
2490
2491                         ret = btrfs_update_inode(trans, root, inode);
2492                         BUG_ON(ret);
2493                         btrfs_end_transaction(trans, root);
2494                 }
2495 next:
2496                 btrfs_release_path(path);
2497                 key.offset++;
2498         }
2499         ret = 0;
2500 out:
2501         btrfs_release_path(path);
2502         unlock_extent(&BTRFS_I(src)->io_tree, off, off+len, GFP_NOFS);
2503 out_unlock:
2504         mutex_unlock(&src->i_mutex);
2505         mutex_unlock(&inode->i_mutex);
2506         vfree(buf);
2507         btrfs_free_path(path);
2508 out_fput:
2509         fput(src_file);
2510 out_drop_write:
2511         mnt_drop_write(file->f_path.mnt);
2512         return ret;
2513 }
2514
2515 static long btrfs_ioctl_clone_range(struct file *file, void __user *argp)
2516 {
2517         struct btrfs_ioctl_clone_range_args args;
2518
2519         if (copy_from_user(&args, argp, sizeof(args)))
2520                 return -EFAULT;
2521         return btrfs_ioctl_clone(file, args.src_fd, args.src_offset,
2522                                  args.src_length, args.dest_offset);
2523 }
2524
2525 /*
2526  * there are many ways the trans_start and trans_end ioctls can lead
2527  * to deadlocks.  They should only be used by applications that
2528  * basically own the machine, and have a very in depth understanding
2529  * of all the possible deadlocks and enospc problems.
2530  */
2531 static long btrfs_ioctl_trans_start(struct file *file)
2532 {
2533         struct inode *inode = fdentry(file)->d_inode;
2534         struct btrfs_root *root = BTRFS_I(inode)->root;
2535         struct btrfs_trans_handle *trans;
2536         int ret;
2537
2538         ret = -EPERM;
2539         if (!capable(CAP_SYS_ADMIN))
2540                 goto out;
2541
2542         ret = -EINPROGRESS;
2543         if (file->private_data)
2544                 goto out;
2545
2546         ret = -EROFS;
2547         if (btrfs_root_readonly(root))
2548                 goto out;
2549
2550         ret = mnt_want_write(file->f_path.mnt);
2551         if (ret)
2552                 goto out;
2553
2554         atomic_inc(&root->fs_info->open_ioctl_trans);
2555
2556         ret = -ENOMEM;
2557         trans = btrfs_start_ioctl_transaction(root);
2558         if (IS_ERR(trans))
2559                 goto out_drop;
2560
2561         file->private_data = trans;
2562         return 0;
2563
2564 out_drop:
2565         atomic_dec(&root->fs_info->open_ioctl_trans);
2566         mnt_drop_write(file->f_path.mnt);
2567 out:
2568         return ret;
2569 }
2570
2571 static long btrfs_ioctl_default_subvol(struct file *file, void __user *argp)
2572 {
2573         struct inode *inode = fdentry(file)->d_inode;
2574         struct btrfs_root *root = BTRFS_I(inode)->root;
2575         struct btrfs_root *new_root;
2576         struct btrfs_dir_item *di;
2577         struct btrfs_trans_handle *trans;
2578         struct btrfs_path *path;
2579         struct btrfs_key location;
2580         struct btrfs_disk_key disk_key;
2581         struct btrfs_super_block *disk_super;
2582         u64 features;
2583         u64 objectid = 0;
2584         u64 dir_id;
2585
2586         if (!capable(CAP_SYS_ADMIN))
2587                 return -EPERM;
2588
2589         if (copy_from_user(&objectid, argp, sizeof(objectid)))
2590                 return -EFAULT;
2591
2592         if (!objectid)
2593                 objectid = root->root_key.objectid;
2594
2595         location.objectid = objectid;
2596         location.type = BTRFS_ROOT_ITEM_KEY;
2597         location.offset = (u64)-1;
2598
2599         new_root = btrfs_read_fs_root_no_name(root->fs_info, &location);
2600         if (IS_ERR(new_root))
2601                 return PTR_ERR(new_root);
2602
2603         if (btrfs_root_refs(&new_root->root_item) == 0)
2604                 return -ENOENT;
2605
2606         path = btrfs_alloc_path();
2607         if (!path)
2608                 return -ENOMEM;
2609         path->leave_spinning = 1;
2610
2611         trans = btrfs_start_transaction(root, 1);
2612         if (IS_ERR(trans)) {
2613                 btrfs_free_path(path);
2614                 return PTR_ERR(trans);
2615         }
2616
2617         dir_id = btrfs_super_root_dir(root->fs_info->super_copy);
2618         di = btrfs_lookup_dir_item(trans, root->fs_info->tree_root, path,
2619                                    dir_id, "default", 7, 1);
2620         if (IS_ERR_OR_NULL(di)) {
2621                 btrfs_free_path(path);
2622                 btrfs_end_transaction(trans, root);
2623                 printk(KERN_ERR "Umm, you don't have the default dir item, "
2624                        "this isn't going to work\n");
2625                 return -ENOENT;
2626         }
2627
2628         btrfs_cpu_key_to_disk(&disk_key, &new_root->root_key);
2629         btrfs_set_dir_item_key(path->nodes[0], di, &disk_key);
2630         btrfs_mark_buffer_dirty(path->nodes[0]);
2631         btrfs_free_path(path);
2632
2633         disk_super = root->fs_info->super_copy;
2634         features = btrfs_super_incompat_flags(disk_super);
2635         if (!(features & BTRFS_FEATURE_INCOMPAT_DEFAULT_SUBVOL)) {
2636                 features |= BTRFS_FEATURE_INCOMPAT_DEFAULT_SUBVOL;
2637                 btrfs_set_super_incompat_flags(disk_super, features);
2638         }
2639         btrfs_end_transaction(trans, root);
2640
2641         return 0;
2642 }
2643
2644 static void get_block_group_info(struct list_head *groups_list,
2645                                  struct btrfs_ioctl_space_info *space)
2646 {
2647         struct btrfs_block_group_cache *block_group;
2648
2649         space->total_bytes = 0;
2650         space->used_bytes = 0;
2651         space->flags = 0;
2652         list_for_each_entry(block_group, groups_list, list) {
2653                 space->flags = block_group->flags;
2654                 space->total_bytes += block_group->key.offset;
2655                 space->used_bytes +=
2656                         btrfs_block_group_used(&block_group->item);
2657         }
2658 }
2659
2660 long btrfs_ioctl_space_info(struct btrfs_root *root, void __user *arg)
2661 {
2662         struct btrfs_ioctl_space_args space_args;
2663         struct btrfs_ioctl_space_info space;
2664         struct btrfs_ioctl_space_info *dest;
2665         struct btrfs_ioctl_space_info *dest_orig;
2666         struct btrfs_ioctl_space_info __user *user_dest;
2667         struct btrfs_space_info *info;
2668         u64 types[] = {BTRFS_BLOCK_GROUP_DATA,
2669                        BTRFS_BLOCK_GROUP_SYSTEM,
2670                        BTRFS_BLOCK_GROUP_METADATA,
2671                        BTRFS_BLOCK_GROUP_DATA | BTRFS_BLOCK_GROUP_METADATA};
2672         int num_types = 4;
2673         int alloc_size;
2674         int ret = 0;
2675         u64 slot_count = 0;
2676         int i, c;
2677
2678         if (copy_from_user(&space_args,
2679                            (struct btrfs_ioctl_space_args __user *)arg,
2680                            sizeof(space_args)))
2681                 return -EFAULT;
2682
2683         for (i = 0; i < num_types; i++) {
2684                 struct btrfs_space_info *tmp;
2685
2686                 info = NULL;
2687                 rcu_read_lock();
2688                 list_for_each_entry_rcu(tmp, &root->fs_info->space_info,
2689                                         list) {
2690                         if (tmp->flags == types[i]) {
2691                                 info = tmp;
2692                                 break;
2693                         }
2694                 }
2695                 rcu_read_unlock();
2696
2697                 if (!info)
2698                         continue;
2699
2700                 down_read(&info->groups_sem);
2701                 for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) {
2702                         if (!list_empty(&info->block_groups[c]))
2703                                 slot_count++;
2704                 }
2705                 up_read(&info->groups_sem);
2706         }
2707
2708         /* space_slots == 0 means they are asking for a count */
2709         if (space_args.space_slots == 0) {
2710                 space_args.total_spaces = slot_count;
2711                 goto out;
2712         }
2713
2714         slot_count = min_t(u64, space_args.space_slots, slot_count);
2715
2716         alloc_size = sizeof(*dest) * slot_count;
2717
2718         /* we generally have at most 6 or so space infos, one for each raid
2719          * level.  So, a whole page should be more than enough for everyone
2720          */
2721         if (alloc_size > PAGE_CACHE_SIZE)
2722                 return -ENOMEM;
2723
2724         space_args.total_spaces = 0;
2725         dest = kmalloc(alloc_size, GFP_NOFS);
2726         if (!dest)
2727                 return -ENOMEM;
2728         dest_orig = dest;
2729
2730         /* now we have a buffer to copy into */
2731         for (i = 0; i < num_types; i++) {
2732                 struct btrfs_space_info *tmp;
2733
2734                 if (!slot_count)
2735                         break;
2736
2737                 info = NULL;
2738                 rcu_read_lock();
2739                 list_for_each_entry_rcu(tmp, &root->fs_info->space_info,
2740                                         list) {
2741                         if (tmp->flags == types[i]) {
2742                                 info = tmp;
2743                                 break;
2744                         }
2745                 }
2746                 rcu_read_unlock();
2747
2748                 if (!info)
2749                         continue;
2750                 down_read(&info->groups_sem);
2751                 for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) {
2752                         if (!list_empty(&info->block_groups[c])) {
2753                                 get_block_group_info(&info->block_groups[c],
2754                                                      &space);
2755                                 memcpy(dest, &space, sizeof(space));
2756                                 dest++;
2757                                 space_args.total_spaces++;
2758                                 slot_count--;
2759                         }
2760                         if (!slot_count)
2761                                 break;
2762                 }
2763                 up_read(&info->groups_sem);
2764         }
2765
2766         user_dest = (struct btrfs_ioctl_space_info *)
2767                 (arg + sizeof(struct btrfs_ioctl_space_args));
2768
2769         if (copy_to_user(user_dest, dest_orig, alloc_size))
2770                 ret = -EFAULT;
2771
2772         kfree(dest_orig);
2773 out:
2774         if (ret == 0 && copy_to_user(arg, &space_args, sizeof(space_args)))
2775                 ret = -EFAULT;
2776
2777         return ret;
2778 }
2779
2780 /*
2781  * there are many ways the trans_start and trans_end ioctls can lead
2782  * to deadlocks.  They should only be used by applications that
2783  * basically own the machine, and have a very in depth understanding
2784  * of all the possible deadlocks and enospc problems.
2785  */
2786 long btrfs_ioctl_trans_end(struct file *file)
2787 {
2788         struct inode *inode = fdentry(file)->d_inode;
2789         struct btrfs_root *root = BTRFS_I(inode)->root;
2790         struct btrfs_trans_handle *trans;
2791
2792         trans = file->private_data;
2793         if (!trans)
2794                 return -EINVAL;
2795         file->private_data = NULL;
2796
2797         btrfs_end_transaction(trans, root);
2798
2799         atomic_dec(&root->fs_info->open_ioctl_trans);
2800
2801         mnt_drop_write(file->f_path.mnt);
2802         return 0;
2803 }
2804
2805 static noinline long btrfs_ioctl_start_sync(struct file *file, void __user *argp)
2806 {
2807         struct btrfs_root *root = BTRFS_I(file->f_dentry->d_inode)->root;
2808         struct btrfs_trans_handle *trans;
2809         u64 transid;
2810         int ret;
2811
2812         trans = btrfs_start_transaction(root, 0);
2813         if (IS_ERR(trans))
2814                 return PTR_ERR(trans);
2815         transid = trans->transid;
2816         ret = btrfs_commit_transaction_async(trans, root, 0);
2817         if (ret) {
2818                 btrfs_end_transaction(trans, root);
2819                 return ret;
2820         }
2821
2822         if (argp)
2823                 if (copy_to_user(argp, &transid, sizeof(transid)))
2824                         return -EFAULT;
2825         return 0;
2826 }
2827
2828 static noinline long btrfs_ioctl_wait_sync(struct file *file, void __user *argp)
2829 {
2830         struct btrfs_root *root = BTRFS_I(file->f_dentry->d_inode)->root;
2831         u64 transid;
2832
2833         if (argp) {
2834                 if (copy_from_user(&transid, argp, sizeof(transid)))
2835                         return -EFAULT;
2836         } else {
2837                 transid = 0;  /* current trans */
2838         }
2839         return btrfs_wait_for_commit(root, transid);
2840 }
2841
2842 static long btrfs_ioctl_scrub(struct btrfs_root *root, void __user *arg)
2843 {
2844         int ret;
2845         struct btrfs_ioctl_scrub_args *sa;
2846
2847         if (!capable(CAP_SYS_ADMIN))
2848                 return -EPERM;
2849
2850         sa = memdup_user(arg, sizeof(*sa));
2851         if (IS_ERR(sa))
2852                 return PTR_ERR(sa);
2853
2854         ret = btrfs_scrub_dev(root, sa->devid, sa->start, sa->end,
2855                               &sa->progress, sa->flags & BTRFS_SCRUB_READONLY);
2856
2857         if (copy_to_user(arg, sa, sizeof(*sa)))
2858                 ret = -EFAULT;
2859
2860         kfree(sa);
2861         return ret;
2862 }
2863
2864 static long btrfs_ioctl_scrub_cancel(struct btrfs_root *root, void __user *arg)
2865 {
2866         if (!capable(CAP_SYS_ADMIN))
2867                 return -EPERM;
2868
2869         return btrfs_scrub_cancel(root);
2870 }
2871
2872 static long btrfs_ioctl_scrub_progress(struct btrfs_root *root,
2873                                        void __user *arg)
2874 {
2875         struct btrfs_ioctl_scrub_args *sa;
2876         int ret;
2877
2878         if (!capable(CAP_SYS_ADMIN))
2879                 return -EPERM;
2880
2881         sa = memdup_user(arg, sizeof(*sa));
2882         if (IS_ERR(sa))
2883                 return PTR_ERR(sa);
2884
2885         ret = btrfs_scrub_progress(root, sa->devid, &sa->progress);
2886
2887         if (copy_to_user(arg, sa, sizeof(*sa)))
2888                 ret = -EFAULT;
2889
2890         kfree(sa);
2891         return ret;
2892 }
2893
2894 static long btrfs_ioctl_ino_to_path(struct btrfs_root *root, void __user *arg)
2895 {
2896         int ret = 0;
2897         int i;
2898         u64 rel_ptr;
2899         int size;
2900         struct btrfs_ioctl_ino_path_args *ipa = NULL;
2901         struct inode_fs_paths *ipath = NULL;
2902         struct btrfs_path *path;
2903
2904         if (!capable(CAP_SYS_ADMIN))
2905                 return -EPERM;
2906
2907         path = btrfs_alloc_path();
2908         if (!path) {
2909                 ret = -ENOMEM;
2910                 goto out;
2911         }
2912
2913         ipa = memdup_user(arg, sizeof(*ipa));
2914         if (IS_ERR(ipa)) {
2915                 ret = PTR_ERR(ipa);
2916                 ipa = NULL;
2917                 goto out;
2918         }
2919
2920         size = min_t(u32, ipa->size, 4096);
2921         ipath = init_ipath(size, root, path);
2922         if (IS_ERR(ipath)) {
2923                 ret = PTR_ERR(ipath);
2924                 ipath = NULL;
2925                 goto out;
2926         }
2927
2928         ret = paths_from_inode(ipa->inum, ipath);
2929         if (ret < 0)
2930                 goto out;
2931
2932         for (i = 0; i < ipath->fspath->elem_cnt; ++i) {
2933                 rel_ptr = ipath->fspath->val[i] -
2934                           (u64)(unsigned long)ipath->fspath->val;
2935                 ipath->fspath->val[i] = rel_ptr;
2936         }
2937
2938         ret = copy_to_user((void *)(unsigned long)ipa->fspath,
2939                            (void *)(unsigned long)ipath->fspath, size);
2940         if (ret) {
2941                 ret = -EFAULT;
2942                 goto out;
2943         }
2944
2945 out:
2946         btrfs_free_path(path);
2947         free_ipath(ipath);
2948         kfree(ipa);
2949
2950         return ret;
2951 }
2952
2953 static int build_ino_list(u64 inum, u64 offset, u64 root, void *ctx)
2954 {
2955         struct btrfs_data_container *inodes = ctx;
2956         const size_t c = 3 * sizeof(u64);
2957
2958         if (inodes->bytes_left >= c) {
2959                 inodes->bytes_left -= c;
2960                 inodes->val[inodes->elem_cnt] = inum;
2961                 inodes->val[inodes->elem_cnt + 1] = offset;
2962                 inodes->val[inodes->elem_cnt + 2] = root;
2963                 inodes->elem_cnt += 3;
2964         } else {
2965                 inodes->bytes_missing += c - inodes->bytes_left;
2966                 inodes->bytes_left = 0;
2967                 inodes->elem_missed += 3;
2968         }
2969
2970         return 0;
2971 }
2972
2973 static long btrfs_ioctl_logical_to_ino(struct btrfs_root *root,
2974                                         void __user *arg)
2975 {
2976         int ret = 0;
2977         int size;
2978         u64 extent_offset;
2979         struct btrfs_ioctl_logical_ino_args *loi;
2980         struct btrfs_data_container *inodes = NULL;
2981         struct btrfs_path *path = NULL;
2982         struct btrfs_key key;
2983
2984         if (!capable(CAP_SYS_ADMIN))
2985                 return -EPERM;
2986
2987         loi = memdup_user(arg, sizeof(*loi));
2988         if (IS_ERR(loi)) {
2989                 ret = PTR_ERR(loi);
2990                 loi = NULL;
2991                 goto out;
2992         }
2993
2994         path = btrfs_alloc_path();
2995         if (!path) {
2996                 ret = -ENOMEM;
2997                 goto out;
2998         }
2999
3000         size = min_t(u32, loi->size, 4096);
3001         inodes = init_data_container(size);
3002         if (IS_ERR(inodes)) {
3003                 ret = PTR_ERR(inodes);
3004                 inodes = NULL;
3005                 goto out;
3006         }
3007
3008         ret = extent_from_logical(root->fs_info, loi->logical, path, &key);
3009
3010         if (ret & BTRFS_EXTENT_FLAG_TREE_BLOCK)
3011                 ret = -ENOENT;
3012         if (ret < 0)
3013                 goto out;
3014
3015         extent_offset = loi->logical - key.objectid;
3016         ret = iterate_extent_inodes(root->fs_info, path, key.objectid,
3017                                         extent_offset, build_ino_list, inodes);
3018
3019         if (ret < 0)
3020                 goto out;
3021
3022         ret = copy_to_user((void *)(unsigned long)loi->inodes,
3023                            (void *)(unsigned long)inodes, size);
3024         if (ret)
3025                 ret = -EFAULT;
3026
3027 out:
3028         btrfs_free_path(path);
3029         kfree(inodes);
3030         kfree(loi);
3031
3032         return ret;
3033 }
3034
3035 long btrfs_ioctl(struct file *file, unsigned int
3036                 cmd, unsigned long arg)
3037 {
3038         struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root;
3039         void __user *argp = (void __user *)arg;
3040
3041         switch (cmd) {
3042         case FS_IOC_GETFLAGS:
3043                 return btrfs_ioctl_getflags(file, argp);
3044         case FS_IOC_SETFLAGS:
3045                 return btrfs_ioctl_setflags(file, argp);
3046         case FS_IOC_GETVERSION:
3047                 return btrfs_ioctl_getversion(file, argp);
3048         case FITRIM:
3049                 return btrfs_ioctl_fitrim(file, argp);
3050         case BTRFS_IOC_SNAP_CREATE:
3051                 return btrfs_ioctl_snap_create(file, argp, 0);
3052         case BTRFS_IOC_SNAP_CREATE_V2:
3053                 return btrfs_ioctl_snap_create_v2(file, argp, 0);
3054         case BTRFS_IOC_SUBVOL_CREATE:
3055                 return btrfs_ioctl_snap_create(file, argp, 1);
3056         case BTRFS_IOC_SNAP_DESTROY:
3057                 return btrfs_ioctl_snap_destroy(file, argp);
3058         case BTRFS_IOC_SUBVOL_GETFLAGS:
3059                 return btrfs_ioctl_subvol_getflags(file, argp);
3060         case BTRFS_IOC_SUBVOL_SETFLAGS:
3061                 return btrfs_ioctl_subvol_setflags(file, argp);
3062         case BTRFS_IOC_DEFAULT_SUBVOL:
3063                 return btrfs_ioctl_default_subvol(file, argp);
3064         case BTRFS_IOC_DEFRAG:
3065                 return btrfs_ioctl_defrag(file, NULL);
3066         case BTRFS_IOC_DEFRAG_RANGE:
3067                 return btrfs_ioctl_defrag(file, argp);
3068         case BTRFS_IOC_RESIZE:
3069                 return btrfs_ioctl_resize(root, argp);
3070         case BTRFS_IOC_ADD_DEV:
3071                 return btrfs_ioctl_add_dev(root, argp);
3072         case BTRFS_IOC_RM_DEV:
3073                 return btrfs_ioctl_rm_dev(root, argp);
3074         case BTRFS_IOC_FS_INFO:
3075                 return btrfs_ioctl_fs_info(root, argp);
3076         case BTRFS_IOC_DEV_INFO:
3077                 return btrfs_ioctl_dev_info(root, argp);
3078         case BTRFS_IOC_BALANCE:
3079                 return btrfs_balance(root->fs_info->dev_root);
3080         case BTRFS_IOC_CLONE:
3081                 return btrfs_ioctl_clone(file, arg, 0, 0, 0);
3082         case BTRFS_IOC_CLONE_RANGE:
3083                 return btrfs_ioctl_clone_range(file, argp);
3084         case BTRFS_IOC_TRANS_START:
3085                 return btrfs_ioctl_trans_start(file);
3086         case BTRFS_IOC_TRANS_END:
3087                 return btrfs_ioctl_trans_end(file);
3088         case BTRFS_IOC_TREE_SEARCH:
3089                 return btrfs_ioctl_tree_search(file, argp);
3090         case BTRFS_IOC_INO_LOOKUP:
3091                 return btrfs_ioctl_ino_lookup(file, argp);
3092         case BTRFS_IOC_INO_PATHS:
3093                 return btrfs_ioctl_ino_to_path(root, argp);
3094         case BTRFS_IOC_LOGICAL_INO:
3095                 return btrfs_ioctl_logical_to_ino(root, argp);
3096         case BTRFS_IOC_SPACE_INFO:
3097                 return btrfs_ioctl_space_info(root, argp);
3098         case BTRFS_IOC_SYNC:
3099                 btrfs_sync_fs(file->f_dentry->d_sb, 1);
3100                 return 0;
3101         case BTRFS_IOC_START_SYNC:
3102                 return btrfs_ioctl_start_sync(file, argp);
3103         case BTRFS_IOC_WAIT_SYNC:
3104                 return btrfs_ioctl_wait_sync(file, argp);
3105         case BTRFS_IOC_SCRUB:
3106                 return btrfs_ioctl_scrub(root, argp);
3107         case BTRFS_IOC_SCRUB_CANCEL:
3108                 return btrfs_ioctl_scrub_cancel(root, argp);
3109         case BTRFS_IOC_SCRUB_PROGRESS:
3110                 return btrfs_ioctl_scrub_progress(root, argp);
3111         }
3112
3113         return -ENOTTY;
3114 }