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