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 "compat.h"
  44 #include "ctree.h"
  45 #include "disk-io.h"
  46 #include "transaction.h"
  47 #include "btrfs_inode.h"
  48 #include "ioctl.h"
  49 #include "print-tree.h"
  50 #include "volumes.h"
  51 #include "locking.h"
  52
  53 /* Mask out flags that are inappropriate for the given type of inode. */
  54 static inline __u32 btrfs_mask_flags(umode_t mode, __u32 flags)
  55 {
  56         if (S_ISDIR(mode))
  57                 return flags;
  58         else if (S_ISREG(mode))
  59                 return flags & ~FS_DIRSYNC_FL;
  60         else
  61                 return flags & (FS_NODUMP_FL | FS_NOATIME_FL);
  62 }
  63
  64 /*
  65  * Export inode flags to the format expected by the FS_IOC_GETFLAGS ioctl.
  66  */
  67 static unsigned int btrfs_flags_to_ioctl(unsigned int flags)
  68 {
  69         unsigned int iflags = 0;
  70
  71         if (flags & BTRFS_INODE_SYNC)
  72                 iflags |= FS_SYNC_FL;
  73         if (flags & BTRFS_INODE_IMMUTABLE)
  74                 iflags |= FS_IMMUTABLE_FL;
  75         if (flags & BTRFS_INODE_APPEND)
  76                 iflags |= FS_APPEND_FL;
  77         if (flags & BTRFS_INODE_NODUMP)
  78                 iflags |= FS_NODUMP_FL;
  79         if (flags & BTRFS_INODE_NOATIME)
  80                 iflags |= FS_NOATIME_FL;
  81         if (flags & BTRFS_INODE_DIRSYNC)
  82                 iflags |= FS_DIRSYNC_FL;
  83
  84         return iflags;
  85 }
  86
  87 /*
  88  * Update inode->i_flags based on the btrfs internal flags.
  89  */
  90 void btrfs_update_iflags(struct inode *inode)
  91 {
  92         struct btrfs_inode *ip = BTRFS_I(inode);
  93
  94         inode->i_flags &= ~(S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC);
  95
  96         if (ip->flags & BTRFS_INODE_SYNC)
  97                 inode->i_flags |= S_SYNC;
  98         if (ip->flags & BTRFS_INODE_IMMUTABLE)
  99                 inode->i_flags |= S_IMMUTABLE;
 100         if (ip->flags & BTRFS_INODE_APPEND)
 101                 inode->i_flags |= S_APPEND;
 102         if (ip->flags & BTRFS_INODE_NOATIME)
 103                 inode->i_flags |= S_NOATIME;
 104         if (ip->flags & BTRFS_INODE_DIRSYNC)
 105                 inode->i_flags |= S_DIRSYNC;
 106 }
 107
 108 /*
 109  * Inherit flags from the parent inode.
 110  *
 111  * Unlike extN we don't have any flags we don't want to inherit currently.
 112  */
 113 void btrfs_inherit_iflags(struct inode *inode, struct inode *dir)
 114 {
 115         unsigned int flags;
 116
 117         if (!dir)
 118                 return;
 119
 120         flags = BTRFS_I(dir)->flags;
 121
 122         if (S_ISREG(inode->i_mode))
 123                 flags &= ~BTRFS_INODE_DIRSYNC;
 124         else if (!S_ISDIR(inode->i_mode))
 125                 flags &= (BTRFS_INODE_NODUMP | BTRFS_INODE_NOATIME);
 126
 127         BTRFS_I(inode)->flags = flags;
 128         btrfs_update_iflags(inode);
 129 }
 130
 131 static int btrfs_ioctl_getflags(struct file *file, void __user *arg)
 132 {
 133         struct btrfs_inode *ip = BTRFS_I(file->f_path.dentry->d_inode);
 134         unsigned int flags = btrfs_flags_to_ioctl(ip->flags);
 135
 136         if (copy_to_user(arg, &flags, sizeof(flags)))
 137                 return -EFAULT;
 138         return 0;
 139 }
 140
 141 static int btrfs_ioctl_setflags(struct file *file, void __user *arg)
 142 {
 143         struct inode *inode = file->f_path.dentry->d_inode;
 144         struct btrfs_inode *ip = BTRFS_I(inode);
 145         struct btrfs_root *root = ip->root;
 146         struct btrfs_trans_handle *trans;
 147         unsigned int flags, oldflags;
 148         int ret;
 149
 150         if (btrfs_root_readonly(root))
 151                 return -EROFS;
 152
 153         if (copy_from_user(&flags, arg, sizeof(flags)))
 154                 return -EFAULT;
 155
 156         if (flags & ~(FS_IMMUTABLE_FL | FS_APPEND_FL | \
 157                       FS_NOATIME_FL | FS_NODUMP_FL | \
 158                       FS_SYNC_FL | FS_DIRSYNC_FL))
 159                 return -EOPNOTSUPP;
 160
 161         if (!is_owner_or_cap(inode))
 162                 return -EACCES;
 163
 164         mutex_lock(&inode->i_mutex);
 165
 166         flags = btrfs_mask_flags(inode->i_mode, flags);
 167         oldflags = btrfs_flags_to_ioctl(ip->flags);
 168         if ((flags ^ oldflags) & (FS_APPEND_FL | FS_IMMUTABLE_FL)) {
 169                 if (!capable(CAP_LINUX_IMMUTABLE)) {
 170                         ret = -EPERM;
 171                         goto out_unlock;
 172                 }
 173         }
 174
 175         ret = mnt_want_write(file->f_path.mnt);
 176         if (ret)
 177                 goto out_unlock;
 178
 179         if (flags & FS_SYNC_FL)
 180                 ip->flags |= BTRFS_INODE_SYNC;
 181         else
 182                 ip->flags &= ~BTRFS_INODE_SYNC;
 183         if (flags & FS_IMMUTABLE_FL)
 184                 ip->flags |= BTRFS_INODE_IMMUTABLE;
 185         else
 186                 ip->flags &= ~BTRFS_INODE_IMMUTABLE;
 187         if (flags & FS_APPEND_FL)
 188                 ip->flags |= BTRFS_INODE_APPEND;
 189         else
 190                 ip->flags &= ~BTRFS_INODE_APPEND;
 191         if (flags & FS_NODUMP_FL)
 192                 ip->flags |= BTRFS_INODE_NODUMP;
 193         else
 194                 ip->flags &= ~BTRFS_INODE_NODUMP;
 195         if (flags & FS_NOATIME_FL)
 196                 ip->flags |= BTRFS_INODE_NOATIME;
 197         else
 198                 ip->flags &= ~BTRFS_INODE_NOATIME;
 199         if (flags & FS_DIRSYNC_FL)
 200                 ip->flags |= BTRFS_INODE_DIRSYNC;
 201         else
 202                 ip->flags &= ~BTRFS_INODE_DIRSYNC;
 203
 204
 205         trans = btrfs_join_transaction(root, 1);
 206         BUG_ON(IS_ERR(trans));
 207
 208         ret = btrfs_update_inode(trans, root, inode);
 209         BUG_ON(ret);
 210
 211         btrfs_update_iflags(inode);
 212         inode->i_ctime = CURRENT_TIME;
 213         btrfs_end_transaction(trans, root);
 214
 215         mnt_drop_write(file->f_path.mnt);
 216  out_unlock:
 217         mutex_unlock(&inode->i_mutex);
 218         return 0;
 219 }
 220
 221 static int btrfs_ioctl_getversion(struct file *file, int __user *arg)
 222 {
 223         struct inode *inode = file->f_path.dentry->d_inode;
 224
 225         return put_user(inode->i_generation, arg);
 226 }
 227
 228 static noinline int create_subvol(struct btrfs_root *root,
 229                                   struct dentry *dentry,
 230                                   char *name, int namelen,
 231                                   u64 *async_transid)
 232 {
 233         struct btrfs_trans_handle *trans;
 234         struct btrfs_key key;
 235         struct btrfs_root_item root_item;
 236         struct btrfs_inode_item *inode_item;
 237         struct extent_buffer *leaf;
 238         struct btrfs_root *new_root;
 239         struct dentry *parent = dget_parent(dentry);
 240         struct inode *dir;
 241         int ret;
 242         int err;
 243         u64 objectid;
 244         u64 new_dirid = BTRFS_FIRST_FREE_OBJECTID;
 245         u64 index = 0;
 246
 247         ret = btrfs_find_free_objectid(NULL, root->fs_info->tree_root,
 248                                        0, &objectid);
 249         if (ret) {
 250                 dput(parent);
 251                 return ret;
 252         }
 253
 254         dir = parent->d_inode;
 255
 256         /*
 257          * 1 - inode item
 258          * 2 - refs
 259          * 1 - root item
 260          * 2 - dir items
 261          */
 262         trans = btrfs_start_transaction(root, 6);
 263         if (IS_ERR(trans)) {
 264                 dput(parent);
 265                 return PTR_ERR(trans);
 266         }
 267
 268         leaf = btrfs_alloc_free_block(trans, root, root->leafsize,
 269                                       0, objectid, NULL, 0, 0, 0);
 270         if (IS_ERR(leaf)) {
 271                 ret = PTR_ERR(leaf);
 272                 goto fail;
 273         }
 274
 275         memset_extent_buffer(leaf, 0, 0, sizeof(struct btrfs_header));
 276         btrfs_set_header_bytenr(leaf, leaf->start);
 277         btrfs_set_header_generation(leaf, trans->transid);
 278         btrfs_set_header_backref_rev(leaf, BTRFS_MIXED_BACKREF_REV);
 279         btrfs_set_header_owner(leaf, objectid);
 280
 281         write_extent_buffer(leaf, root->fs_info->fsid,
 282                             (unsigned long)btrfs_header_fsid(leaf),
 283                             BTRFS_FSID_SIZE);
 284         write_extent_buffer(leaf, root->fs_info->chunk_tree_uuid,
 285                             (unsigned long)btrfs_header_chunk_tree_uuid(leaf),
 286                             BTRFS_UUID_SIZE);
 287         btrfs_mark_buffer_dirty(leaf);
 288
 289         inode_item = &root_item.inode;
 290         memset(inode_item, 0, sizeof(*inode_item));
 291         inode_item->generation = cpu_to_le64(1);
 292         inode_item->size = cpu_to_le64(3);
 293         inode_item->nlink = cpu_to_le32(1);
 294         inode_item->nbytes = cpu_to_le64(root->leafsize);
 295         inode_item->mode = cpu_to_le32(S_IFDIR | 0755);
 296
 297         btrfs_set_root_bytenr(&root_item, leaf->start);
 298         btrfs_set_root_generation(&root_item, trans->transid);
 299         btrfs_set_root_level(&root_item, 0);
 300         btrfs_set_root_refs(&root_item, 1);
 301         btrfs_set_root_used(&root_item, leaf->len);
 302         btrfs_set_root_last_snapshot(&root_item, 0);
 303
 304         memset(&root_item.drop_progress, 0, sizeof(root_item.drop_progress));
 305         root_item.drop_level = 0;
 306
 307         btrfs_tree_unlock(leaf);
 308         free_extent_buffer(leaf);
 309         leaf = NULL;
 310
 311         btrfs_set_root_dirid(&root_item, new_dirid);
 312
 313         key.objectid = objectid;
 314         key.offset = 0;
 315         btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
 316         ret = btrfs_insert_root(trans, root->fs_info->tree_root, &key,
 317                                 &root_item);
 318         if (ret)
 319                 goto fail;
 320
 321         key.offset = (u64)-1;
 322         new_root = btrfs_read_fs_root_no_name(root->fs_info, &key);
 323         BUG_ON(IS_ERR(new_root));
 324
 325         btrfs_record_root_in_trans(trans, new_root);
 326
 327         ret = btrfs_create_subvol_root(trans, new_root, new_dirid,
 328                                        BTRFS_I(dir)->block_group);
 329         /*
 330          * insert the directory item
 331          */
 332         ret = btrfs_set_inode_index(dir, &index);
 333         BUG_ON(ret);
 334
 335         ret = btrfs_insert_dir_item(trans, root,
 336                                     name, namelen, dir->i_ino, &key,
 337                                     BTRFS_FT_DIR, index);
 338         if (ret)
 339                 goto fail;
 340
 341         btrfs_i_size_write(dir, dir->i_size + namelen * 2);
 342         ret = btrfs_update_inode(trans, root, dir);
 343         BUG_ON(ret);
 344
 345         ret = btrfs_add_root_ref(trans, root->fs_info->tree_root,
 346                                  objectid, root->root_key.objectid,
 347                                  dir->i_ino, index, name, namelen);
 348
 349         BUG_ON(ret);
 350
 351         d_instantiate(dentry, btrfs_lookup_dentry(dir, dentry));
 352 fail:
 353         dput(parent);
 354         if (async_transid) {
 355                 *async_transid = trans->transid;
 356                 err = btrfs_commit_transaction_async(trans, root, 1);
 357         } else {
 358                 err = btrfs_commit_transaction(trans, root);
 359         }
 360         if (err && !ret)
 361                 ret = err;
 362         return ret;
 363 }
 364
 365 static int create_snapshot(struct btrfs_root *root, struct dentry *dentry,
 366                            char *name, int namelen, u64 *async_transid,
 367                            bool readonly)
 368 {
 369         struct inode *inode;
 370         struct dentry *parent;
 371         struct btrfs_pending_snapshot *pending_snapshot;
 372         struct btrfs_trans_handle *trans;
 373         int ret;
 374
 375         if (!root->ref_cows)
 376                 return -EINVAL;
 377
 378         pending_snapshot = kzalloc(sizeof(*pending_snapshot), GFP_NOFS);
 379         if (!pending_snapshot)
 380                 return -ENOMEM;
 381
 382         btrfs_init_block_rsv(&pending_snapshot->block_rsv);
 383         pending_snapshot->dentry = dentry;
 384         pending_snapshot->root = root;
 385         pending_snapshot->readonly = readonly;
 386
 387         trans = btrfs_start_transaction(root->fs_info->extent_root, 5);
 388         if (IS_ERR(trans)) {
 389                 ret = PTR_ERR(trans);
 390                 goto fail;
 391         }
 392
 393         ret = btrfs_snap_reserve_metadata(trans, pending_snapshot);
 394         BUG_ON(ret);
 395
 396         list_add(&pending_snapshot->list,
 397                  &trans->transaction->pending_snapshots);
 398         if (async_transid) {
 399                 *async_transid = trans->transid;
 400                 ret = btrfs_commit_transaction_async(trans,
 401                                      root->fs_info->extent_root, 1);
 402         } else {
 403                 ret = btrfs_commit_transaction(trans,
 404                                                root->fs_info->extent_root);
 405         }
 406         BUG_ON(ret);
 407
 408         ret = pending_snapshot->error;
 409         if (ret)
 410                 goto fail;
 411
 412         btrfs_orphan_cleanup(pending_snapshot->snap);
 413
 414         parent = dget_parent(dentry);
 415         inode = btrfs_lookup_dentry(parent->d_inode, dentry);
 416         dput(parent);
 417         if (IS_ERR(inode)) {
 418                 ret = PTR_ERR(inode);
 419                 goto fail;
 420         }
 421         BUG_ON(!inode);
 422         d_instantiate(dentry, inode);
 423         ret = 0;
 424 fail:
 425         kfree(pending_snapshot);
 426         return ret;
 427 }
 428
 429 /*  copy of check_sticky in fs/namei.c()
 430 * It's inline, so penalty for filesystems that don't use sticky bit is
 431 * minimal.
 432 */
 433 static inline int btrfs_check_sticky(struct inode *dir, struct inode *inode)
 434 {
 435         uid_t fsuid = current_fsuid();
 436
 437         if (!(dir->i_mode & S_ISVTX))
 438                 return 0;
 439         if (inode->i_uid == fsuid)
 440                 return 0;
 441         if (dir->i_uid == fsuid)
 442                 return 0;
 443         return !capable(CAP_FOWNER);
 444 }
 445
 446 /*  copy of may_delete in fs/namei.c()
 447  *      Check whether we can remove a link victim from directory dir, check
 448  *  whether the type of victim is right.
 449  *  1. We can't do it if dir is read-only (done in permission())
 450  *  2. We should have write and exec permissions on dir
 451  *  3. We can't remove anything from append-only dir
 452  *  4. We can't do anything with immutable dir (done in permission())
 453  *  5. If the sticky bit on dir is set we should either
 454  *      a. be owner of dir, or
 455  *      b. be owner of victim, or
 456  *      c. have CAP_FOWNER capability
 457  *  6. If the victim is append-only or immutable we can't do antyhing with
 458  *     links pointing to it.
 459  *  7. If we were asked to remove a directory and victim isn't one - ENOTDIR.
 460  *  8. If we were asked to remove a non-directory and victim isn't one - EISDIR.
 461  *  9. We can't remove a root or mountpoint.
 462  * 10. We don't allow removal of NFS sillyrenamed files; it's handled by
 463  *     nfs_async_unlink().
 464  */
 465
 466 static int btrfs_may_delete(struct inode *dir,struct dentry *victim,int isdir)
 467 {
 468         int error;
 469
 470         if (!victim->d_inode)
 471                 return -ENOENT;
 472
 473         BUG_ON(victim->d_parent->d_inode != dir);
 474         audit_inode_child(victim, dir);
 475
 476         error = inode_permission(dir, MAY_WRITE | MAY_EXEC);
 477         if (error)
 478                 return error;
 479         if (IS_APPEND(dir))
 480                 return -EPERM;
 481         if (btrfs_check_sticky(dir, victim->d_inode)||
 482                 IS_APPEND(victim->d_inode)||
 483             IS_IMMUTABLE(victim->d_inode) || IS_SWAPFILE(victim->d_inode))
 484                 return -EPERM;
 485         if (isdir) {
 486                 if (!S_ISDIR(victim->d_inode->i_mode))
 487                         return -ENOTDIR;
 488                 if (IS_ROOT(victim))
 489                         return -EBUSY;
 490         } else if (S_ISDIR(victim->d_inode->i_mode))
 491                 return -EISDIR;
 492         if (IS_DEADDIR(dir))
 493                 return -ENOENT;
 494         if (victim->d_flags & DCACHE_NFSFS_RENAMED)
 495                 return -EBUSY;
 496         return 0;
 497 }
 498
 499 /* copy of may_create in fs/namei.c() */
 500 static inline int btrfs_may_create(struct inode *dir, struct dentry *child)
 501 {
 502         if (child->d_inode)
 503                 return -EEXIST;
 504         if (IS_DEADDIR(dir))
 505                 return -ENOENT;
 506         return inode_permission(dir, MAY_WRITE | MAY_EXEC);
 507 }
 508
 509 /*
 510  * Create a new subvolume below @parent.  This is largely modeled after
 511  * sys_mkdirat and vfs_mkdir, but we only do a single component lookup
 512  * inside this filesystem so it's quite a bit simpler.
 513  */
 514 static noinline int btrfs_mksubvol(struct path *parent,
 515                                    char *name, int namelen,
 516                                    struct btrfs_root *snap_src,
 517                                    u64 *async_transid, bool readonly)
 518 {
 519         struct inode *dir  = parent->dentry->d_inode;
 520         struct dentry *dentry;
 521         int error;
 522
 523         mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
 524
 525         dentry = lookup_one_len(name, parent->dentry, namelen);
 526         error = PTR_ERR(dentry);
 527         if (IS_ERR(dentry))
 528                 goto out_unlock;
 529
 530         error = -EEXIST;
 531         if (dentry->d_inode)
 532                 goto out_dput;
 533
 534         error = mnt_want_write(parent->mnt);
 535         if (error)
 536                 goto out_dput;
 537
 538         error = btrfs_may_create(dir, dentry);
 539         if (error)
 540                 goto out_drop_write;
 541
 542         down_read(&BTRFS_I(dir)->root->fs_info->subvol_sem);
 543
 544         if (btrfs_root_refs(&BTRFS_I(dir)->root->root_item) == 0)
 545                 goto out_up_read;
 546
 547         if (snap_src) {
 548                 error = create_snapshot(snap_src, dentry,
 549                                         name, namelen, async_transid, readonly);
 550         } else {
 551                 error = create_subvol(BTRFS_I(dir)->root, dentry,
 552                                       name, namelen, async_transid);
 553         }
 554         if (!error)
 555                 fsnotify_mkdir(dir, dentry);
 556 out_up_read:
 557         up_read(&BTRFS_I(dir)->root->fs_info->subvol_sem);
 558 out_drop_write:
 559         mnt_drop_write(parent->mnt);
 560 out_dput:
 561         dput(dentry);
 562 out_unlock:
 563         mutex_unlock(&dir->i_mutex);
 564         return error;
 565 }
 566
 567 static int should_defrag_range(struct inode *inode, u64 start, u64 len,
 568                                int thresh, u64 *last_len, u64 *skip,
 569                                u64 *defrag_end)
 570 {
 571         struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
 572         struct extent_map *em = NULL;
 573         struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
 574         int ret = 1;
 575
 576
 577         if (thresh == 0)
 578                 thresh = 256 * 1024;
 579
 580         /*
 581          * make sure that once we start defragging and extent, we keep on
 582          * defragging it
 583          */
 584         if (start < *defrag_end)
 585                 return 1;
 586
 587         *skip = 0;
 588
 589         /*
 590          * hopefully we have this extent in the tree already, try without
 591          * the full extent lock
 592          */
 593         read_lock(&em_tree->lock);
 594         em = lookup_extent_mapping(em_tree, start, len);
 595         read_unlock(&em_tree->lock);
 596
 597         if (!em) {
 598                 /* get the big lock and read metadata off disk */
 599                 lock_extent(io_tree, start, start + len - 1, GFP_NOFS);
 600                 em = btrfs_get_extent(inode, NULL, 0, start, len, 0);
 601                 unlock_extent(io_tree, start, start + len - 1, GFP_NOFS);
 602
 603                 if (IS_ERR(em))
 604                         return 0;
 605         }
 606
 607         /* this will cover holes, and inline extents */
 608         if (em->block_start >= EXTENT_MAP_LAST_BYTE)
 609                 ret = 0;
 610
 611         /*
 612          * we hit a real extent, if it is big don't bother defragging it again
 613          */
 614         if ((*last_len == 0 || *last_len >= thresh) && em->len >= thresh)
 615                 ret = 0;
 616
 617         /*
 618          * last_len ends up being a counter of how many bytes we've defragged.
 619          * every time we choose not to defrag an extent, we reset *last_len
 620          * so that the next tiny extent will force a defrag.
 621          *
 622          * The end result of this is that tiny extents before a single big
 623          * extent will force at least part of that big extent to be defragged.
 624          */
 625         if (ret) {
 626                 *last_len += len;
 627                 *defrag_end = extent_map_end(em);
 628         } else {
 629                 *last_len = 0;
 630                 *skip = extent_map_end(em);
 631                 *defrag_end = 0;
 632         }
 633
 634         free_extent_map(em);
 635         return ret;
 636 }
 637
 638 static int btrfs_defrag_file(struct file *file,
 639                              struct btrfs_ioctl_defrag_range_args *range)
 640 {
 641         struct inode *inode = fdentry(file)->d_inode;
 642         struct btrfs_root *root = BTRFS_I(inode)->root;
 643         struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
 644         struct btrfs_ordered_extent *ordered;
 645         struct page *page;
 646         struct btrfs_super_block *disk_super;
 647         unsigned long last_index;
 648         unsigned long ra_pages = root->fs_info->bdi.ra_pages;
 649         unsigned long total_read = 0;
 650         u64 features;
 651         u64 page_start;
 652         u64 page_end;
 653         u64 last_len = 0;
 654         u64 skip = 0;
 655         u64 defrag_end = 0;
 656         unsigned long i;
 657         int ret;
 658         int compress_type = BTRFS_COMPRESS_ZLIB;
 659
 660         if (range->flags & BTRFS_DEFRAG_RANGE_COMPRESS) {
 661                 if (range->compress_type > BTRFS_COMPRESS_TYPES)
 662                         return -EINVAL;
 663                 if (range->compress_type)
 664                         compress_type = range->compress_type;
 665         }
 666
 667         if (inode->i_size == 0)
 668                 return 0;
 669
 670         if (range->start + range->len > range->start) {
 671                 last_index = min_t(u64, inode->i_size - 1,
 672                          range->start + range->len - 1) >> PAGE_CACHE_SHIFT;
 673         } else {
 674                 last_index = (inode->i_size - 1) >> PAGE_CACHE_SHIFT;
 675         }
 676
 677         i = range->start >> PAGE_CACHE_SHIFT;
 678         while (i <= last_index) {
 679                 if (!should_defrag_range(inode, (u64)i << PAGE_CACHE_SHIFT,
 680                                         PAGE_CACHE_SIZE,
 681                                         range->extent_thresh,
 682                                         &last_len, &skip,
 683                                         &defrag_end)) {
 684                         unsigned long next;
 685                         /*
 686                          * the should_defrag function tells us how much to skip
 687                          * bump our counter by the suggested amount
 688                          */
 689                         next = (skip + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
 690                         i = max(i + 1, next);
 691                         continue;
 692                 }
 693
 694                 if (total_read % ra_pages == 0) {
 695                         btrfs_force_ra(inode->i_mapping, &file->f_ra, file, i,
 696                                        min(last_index, i + ra_pages - 1));
 697                 }
 698                 total_read++;
 699                 mutex_lock(&inode->i_mutex);
 700                 if (range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)
 701                         BTRFS_I(inode)->force_compress = compress_type;
 702
 703                 ret  = btrfs_delalloc_reserve_space(inode, PAGE_CACHE_SIZE);
 704                 if (ret)
 705                         goto err_unlock;
 706 again:
 707                 if (inode->i_size == 0 ||
 708                     i > ((inode->i_size - 1) >> PAGE_CACHE_SHIFT)) {
 709                         ret = 0;
 710                         goto err_reservations;
 711                 }
 712
 713                 page = grab_cache_page(inode->i_mapping, i);
 714                 if (!page) {
 715                         ret = -ENOMEM;
 716                         goto err_reservations;
 717                 }
 718
 719                 if (!PageUptodate(page)) {
 720                         btrfs_readpage(NULL, page);
 721                         lock_page(page);
 722                         if (!PageUptodate(page)) {
 723                                 unlock_page(page);
 724                                 page_cache_release(page);
 725                                 ret = -EIO;
 726                                 goto err_reservations;
 727                         }
 728                 }
 729
 730                 if (page->mapping != inode->i_mapping) {
 731                         unlock_page(page);
 732                         page_cache_release(page);
 733                         goto again;
 734                 }
 735
 736                 wait_on_page_writeback(page);
 737
 738                 if (PageDirty(page)) {
 739                         btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE);
 740                         goto loop_unlock;
 741                 }
 742
 743                 page_start = (u64)page->index << PAGE_CACHE_SHIFT;
 744                 page_end = page_start + PAGE_CACHE_SIZE - 1;
 745                 lock_extent(io_tree, page_start, page_end, GFP_NOFS);
 746
 747                 ordered = btrfs_lookup_ordered_extent(inode, page_start);
 748                 if (ordered) {
 749                         unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
 750                         unlock_page(page);
 751                         page_cache_release(page);
 752                         btrfs_start_ordered_extent(inode, ordered, 1);
 753                         btrfs_put_ordered_extent(ordered);
 754                         goto again;
 755                 }
 756                 set_page_extent_mapped(page);
 757
 758                 /*
 759                  * this makes sure page_mkwrite is called on the
 760                  * page if it is dirtied again later
 761                  */
 762                 clear_page_dirty_for_io(page);
 763                 clear_extent_bits(&BTRFS_I(inode)->io_tree, page_start,
 764                                   page_end, EXTENT_DIRTY | EXTENT_DELALLOC |
 765                                   EXTENT_DO_ACCOUNTING, GFP_NOFS);
 766
 767                 btrfs_set_extent_delalloc(inode, page_start, page_end, NULL);
 768                 ClearPageChecked(page);
 769                 set_page_dirty(page);
 770                 unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
 771
 772 loop_unlock:
 773                 unlock_page(page);
 774                 page_cache_release(page);
 775                 mutex_unlock(&inode->i_mutex);
 776
 777                 balance_dirty_pages_ratelimited_nr(inode->i_mapping, 1);
 778                 i++;
 779         }
 780
 781         if ((range->flags & BTRFS_DEFRAG_RANGE_START_IO))
 782                 filemap_flush(inode->i_mapping);
 783
 784         if ((range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)) {
 785                 /* the filemap_flush will queue IO into the worker threads, but
 786                  * we have to make sure the IO is actually started and that
 787                  * ordered extents get created before we return
 788                  */
 789                 atomic_inc(&root->fs_info->async_submit_draining);
 790                 while (atomic_read(&root->fs_info->nr_async_submits) ||
 791                       atomic_read(&root->fs_info->async_delalloc_pages)) {
 792                         wait_event(root->fs_info->async_submit_wait,
 793                            (atomic_read(&root->fs_info->nr_async_submits) == 0 &&
 794                             atomic_read(&root->fs_info->async_delalloc_pages) == 0));
 795                 }
 796                 atomic_dec(&root->fs_info->async_submit_draining);
 797
 798                 mutex_lock(&inode->i_mutex);
 799                 BTRFS_I(inode)->force_compress = BTRFS_COMPRESS_NONE;
 800                 mutex_unlock(&inode->i_mutex);
 801         }
 802
 803         disk_super = &root->fs_info->super_copy;
 804         features = btrfs_super_incompat_flags(disk_super);
 805         if (range->compress_type == BTRFS_COMPRESS_LZO) {
 806                 features |= BTRFS_FEATURE_INCOMPAT_COMPRESS_LZO;
 807                 btrfs_set_super_incompat_flags(disk_super, features);
 808         }
 809
 810         return 0;
 811
 812 err_reservations:
 813         btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE);
 814 err_unlock:
 815         mutex_unlock(&inode->i_mutex);
 816         return ret;
 817 }
 818
 819 static noinline int btrfs_ioctl_resize(struct btrfs_root *root,
 820                                         void __user *arg)
 821 {
 822         u64 new_size;
 823         u64 old_size;
 824         u64 devid = 1;
 825         struct btrfs_ioctl_vol_args *vol_args;
 826         struct btrfs_trans_handle *trans;
 827         struct btrfs_device *device = NULL;
 828         char *sizestr;
 829         char *devstr = NULL;
 830         int ret = 0;
 831         int mod = 0;
 832
 833         if (root->fs_info->sb->s_flags & MS_RDONLY)
 834                 return -EROFS;
 835
 836         if (!capable(CAP_SYS_ADMIN))
 837                 return -EPERM;
 838
 839         vol_args = memdup_user(arg, sizeof(*vol_args));
 840         if (IS_ERR(vol_args))
 841                 return PTR_ERR(vol_args);
 842
 843         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
 844
 845         mutex_lock(&root->fs_info->volume_mutex);
 846         sizestr = vol_args->name;
 847         devstr = strchr(sizestr, ':');
 848         if (devstr) {
 849                 char *end;
 850                 sizestr = devstr + 1;
 851                 *devstr = '\0';
 852                 devstr = vol_args->name;
 853                 devid = simple_strtoull(devstr, &end, 10);
 854                 printk(KERN_INFO "resizing devid %llu\n",
 855                        (unsigned long long)devid);
 856         }
 857         device = btrfs_find_device(root, devid, NULL, NULL);
 858         if (!device) {
 859                 printk(KERN_INFO "resizer unable to find device %llu\n",
 860                        (unsigned long long)devid);
 861                 ret = -EINVAL;
 862                 goto out_unlock;
 863         }
 864         if (!strcmp(sizestr, "max"))
 865                 new_size = device->bdev->bd_inode->i_size;
 866         else {
 867                 if (sizestr[0] == '-') {
 868                         mod = -1;
 869                         sizestr++;
 870                 } else if (sizestr[0] == '+') {
 871                         mod = 1;
 872                         sizestr++;
 873                 }
 874                 new_size = memparse(sizestr, NULL);
 875                 if (new_size == 0) {
 876                         ret = -EINVAL;
 877                         goto out_unlock;
 878                 }
 879         }
 880
 881         old_size = device->total_bytes;
 882
 883         if (mod < 0) {
 884                 if (new_size > old_size) {
 885                         ret = -EINVAL;
 886                         goto out_unlock;
 887                 }
 888                 new_size = old_size - new_size;
 889         } else if (mod > 0) {
 890                 new_size = old_size + new_size;
 891         }
 892
 893         if (new_size < 256 * 1024 * 1024) {
 894                 ret = -EINVAL;
 895                 goto out_unlock;
 896         }
 897         if (new_size > device->bdev->bd_inode->i_size) {
 898                 ret = -EFBIG;
 899                 goto out_unlock;
 900         }
 901
 902         do_div(new_size, root->sectorsize);
 903         new_size *= root->sectorsize;
 904
 905         printk(KERN_INFO "new size for %s is %llu\n",
 906                 device->name, (unsigned long long)new_size);
 907
 908         if (new_size > old_size) {
 909                 trans = btrfs_start_transaction(root, 0);
 910                 if (IS_ERR(trans)) {
 911                         ret = PTR_ERR(trans);
 912                         goto out_unlock;
 913                 }
 914                 ret = btrfs_grow_device(trans, device, new_size);
 915                 btrfs_commit_transaction(trans, root);
 916         } else {
 917                 ret = btrfs_shrink_device(device, new_size);
 918         }
 919
 920 out_unlock:
 921         mutex_unlock(&root->fs_info->volume_mutex);
 922         kfree(vol_args);
 923         return ret;
 924 }
 925
 926 static noinline int btrfs_ioctl_snap_create_transid(struct file *file,
 927                                                     char *name,
 928                                                     unsigned long fd,
 929                                                     int subvol,
 930                                                     u64 *transid,
 931                                                     bool readonly)
 932 {
 933         struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root;
 934         struct file *src_file;
 935         int namelen;
 936         int ret = 0;
 937
 938         if (root->fs_info->sb->s_flags & MS_RDONLY)
 939                 return -EROFS;
 940
 941         namelen = strlen(name);
 942         if (strchr(name, '/')) {
 943                 ret = -EINVAL;
 944                 goto out;
 945         }
 946
 947         if (subvol) {
 948                 ret = btrfs_mksubvol(&file->f_path, name, namelen,
 949                                      NULL, transid, readonly);
 950         } else {
 951                 struct inode *src_inode;
 952                 src_file = fget(fd);
 953                 if (!src_file) {
 954                         ret = -EINVAL;
 955                         goto out;
 956                 }
 957
 958                 src_inode = src_file->f_path.dentry->d_inode;
 959                 if (src_inode->i_sb != file->f_path.dentry->d_inode->i_sb) {
 960                         printk(KERN_INFO "btrfs: Snapshot src from "
 961                                "another FS\n");
 962                         ret = -EINVAL;
 963                         fput(src_file);
 964                         goto out;
 965                 }
 966                 ret = btrfs_mksubvol(&file->f_path, name, namelen,
 967                                      BTRFS_I(src_inode)->root,
 968                                      transid, readonly);
 969                 fput(src_file);
 970         }
 971 out:
 972         return ret;
 973 }
 974
 975 static noinline int btrfs_ioctl_snap_create(struct file *file,
 976                                             void __user *arg, int subvol)
 977 {
 978         struct btrfs_ioctl_vol_args *vol_args;
 979         int ret;
 980
 981         vol_args = memdup_user(arg, sizeof(*vol_args));
 982         if (IS_ERR(vol_args))
 983                 return PTR_ERR(vol_args);
 984         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
 985
 986         ret = btrfs_ioctl_snap_create_transid(file, vol_args->name,
 987                                               vol_args->fd, subvol,
 988                                               NULL, false);
 989
 990         kfree(vol_args);
 991         return ret;
 992 }
 993
 994 static noinline int btrfs_ioctl_snap_create_v2(struct file *file,
 995                                                void __user *arg, int subvol)
 996 {
 997         struct btrfs_ioctl_vol_args_v2 *vol_args;
 998         int ret;
 999         u64 transid = 0;
1000         u64 *ptr = NULL;
1001         bool readonly = false;
1002
1003         vol_args = memdup_user(arg, sizeof(*vol_args));
1004         if (IS_ERR(vol_args))
1005                 return PTR_ERR(vol_args);
1006         vol_args->name[BTRFS_SUBVOL_NAME_MAX] = '\0';
1007
1008         if (vol_args->flags &
1009             ~(BTRFS_SUBVOL_CREATE_ASYNC | BTRFS_SUBVOL_RDONLY)) {
1010                 ret = -EOPNOTSUPP;
1011                 goto out;
1012         }
1013
1014         if (vol_args->flags & BTRFS_SUBVOL_CREATE_ASYNC)
1015                 ptr = &transid;
1016         if (vol_args->flags & BTRFS_SUBVOL_RDONLY)
1017                 readonly = true;
1018
1019         ret = btrfs_ioctl_snap_create_transid(file, vol_args->name,
1020                                               vol_args->fd, subvol,
1021                                               ptr, readonly);
1022
1023         if (ret == 0 && ptr &&
1024             copy_to_user(arg +
1025                          offsetof(struct btrfs_ioctl_vol_args_v2,
1026                                   transid), ptr, sizeof(*ptr)))
1027                 ret = -EFAULT;
1028 out:
1029         kfree(vol_args);
1030         return ret;
1031 }
1032
1033 static noinline int btrfs_ioctl_subvol_getflags(struct file *file,
1034                                                 void __user *arg)
1035 {
1036         struct inode *inode = fdentry(file)->d_inode;
1037         struct btrfs_root *root = BTRFS_I(inode)->root;
1038         int ret = 0;
1039         u64 flags = 0;
1040
1041         if (inode->i_ino != BTRFS_FIRST_FREE_OBJECTID)
1042                 return -EINVAL;
1043
1044         down_read(&root->fs_info->subvol_sem);
1045         if (btrfs_root_readonly(root))
1046                 flags |= BTRFS_SUBVOL_RDONLY;
1047         up_read(&root->fs_info->subvol_sem);
1048
1049         if (copy_to_user(arg, &flags, sizeof(flags)))
1050                 ret = -EFAULT;
1051
1052         return ret;
1053 }
1054
1055 static noinline int btrfs_ioctl_subvol_setflags(struct file *file,
1056                                               void __user *arg)
1057 {
1058         struct inode *inode = fdentry(file)->d_inode;
1059         struct btrfs_root *root = BTRFS_I(inode)->root;
1060         struct btrfs_trans_handle *trans;
1061         u64 root_flags;
1062         u64 flags;
1063         int ret = 0;
1064
1065         if (root->fs_info->sb->s_flags & MS_RDONLY)
1066                 return -EROFS;
1067
1068         if (inode->i_ino != BTRFS_FIRST_FREE_OBJECTID)
1069                 return -EINVAL;
1070
1071         if (copy_from_user(&flags, arg, sizeof(flags)))
1072                 return -EFAULT;
1073
1074         if (flags & BTRFS_SUBVOL_CREATE_ASYNC)
1075                 return -EINVAL;
1076
1077         if (flags & ~BTRFS_SUBVOL_RDONLY)
1078                 return -EOPNOTSUPP;
1079
1080         if (!is_owner_or_cap(inode))
1081                 return -EACCES;
1082
1083         down_write(&root->fs_info->subvol_sem);
1084
1085         /* nothing to do */
1086         if (!!(flags & BTRFS_SUBVOL_RDONLY) == btrfs_root_readonly(root))
1087                 goto out;
1088
1089         root_flags = btrfs_root_flags(&root->root_item);
1090         if (flags & BTRFS_SUBVOL_RDONLY)
1091                 btrfs_set_root_flags(&root->root_item,
1092                                      root_flags | BTRFS_ROOT_SUBVOL_RDONLY);
1093         else
1094                 btrfs_set_root_flags(&root->root_item,
1095                                      root_flags & ~BTRFS_ROOT_SUBVOL_RDONLY);
1096
1097         trans = btrfs_start_transaction(root, 1);
1098         if (IS_ERR(trans)) {
1099                 ret = PTR_ERR(trans);
1100                 goto out_reset;
1101         }
1102
1103         ret = btrfs_update_root(trans, root->fs_info->tree_root,
1104                                 &root->root_key, &root->root_item);
1105
1106         btrfs_commit_transaction(trans, root);
1107 out_reset:
1108         if (ret)
1109                 btrfs_set_root_flags(&root->root_item, root_flags);
1110 out:
1111         up_write(&root->fs_info->subvol_sem);
1112         return ret;
1113 }
1114
1115 /*
1116  * helper to check if the subvolume references other subvolumes
1117  */
1118 static noinline int may_destroy_subvol(struct btrfs_root *root)
1119 {
1120         struct btrfs_path *path;
1121         struct btrfs_key key;
1122         int ret;
1123
1124         path = btrfs_alloc_path();
1125         if (!path)
1126                 return -ENOMEM;
1127
1128         key.objectid = root->root_key.objectid;
1129         key.type = BTRFS_ROOT_REF_KEY;
1130         key.offset = (u64)-1;
1131
1132         ret = btrfs_search_slot(NULL, root->fs_info->tree_root,
1133                                 &key, path, 0, 0);
1134         if (ret < 0)
1135                 goto out;
1136         BUG_ON(ret == 0);
1137
1138         ret = 0;
1139         if (path->slots[0] > 0) {
1140                 path->slots[0]--;
1141                 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
1142                 if (key.objectid == root->root_key.objectid &&
1143                     key.type == BTRFS_ROOT_REF_KEY)
1144                         ret = -ENOTEMPTY;
1145         }
1146 out:
1147         btrfs_free_path(path);
1148         return ret;
1149 }
1150
1151 static noinline int key_in_sk(struct btrfs_key *key,
1152                               struct btrfs_ioctl_search_key *sk)
1153 {
1154         struct btrfs_key test;
1155         int ret;
1156
1157         test.objectid = sk->min_objectid;
1158         test.type = sk->min_type;
1159         test.offset = sk->min_offset;
1160
1161         ret = btrfs_comp_cpu_keys(key, &test);
1162         if (ret < 0)
1163                 return 0;
1164
1165         test.objectid = sk->max_objectid;
1166         test.type = sk->max_type;
1167         test.offset = sk->max_offset;
1168
1169         ret = btrfs_comp_cpu_keys(key, &test);
1170         if (ret > 0)
1171                 return 0;
1172         return 1;
1173 }
1174
1175 static noinline int copy_to_sk(struct btrfs_root *root,
1176                                struct btrfs_path *path,
1177                                struct btrfs_key *key,
1178                                struct btrfs_ioctl_search_key *sk,
1179                                char *buf,
1180                                unsigned long *sk_offset,
1181                                int *num_found)
1182 {
1183         u64 found_transid;
1184         struct extent_buffer *leaf;
1185         struct btrfs_ioctl_search_header sh;
1186         unsigned long item_off;
1187         unsigned long item_len;
1188         int nritems;
1189         int i;
1190         int slot;
1191         int found = 0;
1192         int ret = 0;
1193
1194         leaf = path->nodes[0];
1195         slot = path->slots[0];
1196         nritems = btrfs_header_nritems(leaf);
1197
1198         if (btrfs_header_generation(leaf) > sk->max_transid) {
1199                 i = nritems;
1200                 goto advance_key;
1201         }
1202         found_transid = btrfs_header_generation(leaf);
1203
1204         for (i = slot; i < nritems; i++) {
1205                 item_off = btrfs_item_ptr_offset(leaf, i);
1206                 item_len = btrfs_item_size_nr(leaf, i);
1207
1208                 if (item_len > BTRFS_SEARCH_ARGS_BUFSIZE)
1209                         item_len = 0;
1210
1211                 if (sizeof(sh) + item_len + *sk_offset >
1212                     BTRFS_SEARCH_ARGS_BUFSIZE) {
1213                         ret = 1;
1214                         goto overflow;
1215                 }
1216
1217                 btrfs_item_key_to_cpu(leaf, key, i);
1218                 if (!key_in_sk(key, sk))
1219                         continue;
1220
1221                 sh.objectid = key->objectid;
1222                 sh.offset = key->offset;
1223                 sh.type = key->type;
1224                 sh.len = item_len;
1225                 sh.transid = found_transid;
1226
1227                 /* copy search result header */
1228                 memcpy(buf + *sk_offset, &sh, sizeof(sh));
1229                 *sk_offset += sizeof(sh);
1230
1231                 if (item_len) {
1232                         char *p = buf + *sk_offset;
1233                         /* copy the item */
1234                         read_extent_buffer(leaf, p,
1235                                            item_off, item_len);
1236                         *sk_offset += item_len;
1237                 }
1238                 found++;
1239
1240                 if (*num_found >= sk->nr_items)
1241                         break;
1242         }
1243 advance_key:
1244         ret = 0;
1245         if (key->offset < (u64)-1 && key->offset < sk->max_offset)
1246                 key->offset++;
1247         else if (key->type < (u8)-1 && key->type < sk->max_type) {
1248                 key->offset = 0;
1249                 key->type++;
1250         } else if (key->objectid < (u64)-1 && key->objectid < sk->max_objectid) {
1251                 key->offset = 0;
1252                 key->type = 0;
1253                 key->objectid++;
1254         } else
1255                 ret = 1;
1256 overflow:
1257         *num_found += found;
1258         return ret;
1259 }
1260
1261 static noinline int search_ioctl(struct inode *inode,
1262                                  struct btrfs_ioctl_search_args *args)
1263 {
1264         struct btrfs_root *root;
1265         struct btrfs_key key;
1266         struct btrfs_key max_key;
1267         struct btrfs_path *path;
1268         struct btrfs_ioctl_search_key *sk = &args->key;
1269         struct btrfs_fs_info *info = BTRFS_I(inode)->root->fs_info;
1270         int ret;
1271         int num_found = 0;
1272         unsigned long sk_offset = 0;
1273
1274         path = btrfs_alloc_path();
1275         if (!path)
1276                 return -ENOMEM;
1277
1278         if (sk->tree_id == 0) {
1279                 /* search the root of the inode that was passed */
1280                 root = BTRFS_I(inode)->root;
1281         } else {
1282                 key.objectid = sk->tree_id;
1283                 key.type = BTRFS_ROOT_ITEM_KEY;
1284                 key.offset = (u64)-1;
1285                 root = btrfs_read_fs_root_no_name(info, &key);
1286                 if (IS_ERR(root)) {
1287                         printk(KERN_ERR "could not find root %llu\n",
1288                                sk->tree_id);
1289                         btrfs_free_path(path);
1290                         return -ENOENT;
1291                 }
1292         }
1293
1294         key.objectid = sk->min_objectid;
1295         key.type = sk->min_type;
1296         key.offset = sk->min_offset;
1297
1298         max_key.objectid = sk->max_objectid;
1299         max_key.type = sk->max_type;
1300         max_key.offset = sk->max_offset;
1301
1302         path->keep_locks = 1;
1303
1304         while(1) {
1305                 ret = btrfs_search_forward(root, &key, &max_key, path, 0,
1306                                            sk->min_transid);
1307                 if (ret != 0) {
1308                         if (ret > 0)
1309                                 ret = 0;
1310                         goto err;
1311                 }
1312                 ret = copy_to_sk(root, path, &key, sk, args->buf,
1313                                  &sk_offset, &num_found);
1314                 btrfs_release_path(root, path);
1315                 if (ret || num_found >= sk->nr_items)
1316                         break;
1317
1318         }
1319         ret = 0;
1320 err:
1321         sk->nr_items = num_found;
1322         btrfs_free_path(path);
1323         return ret;
1324 }
1325
1326 static noinline int btrfs_ioctl_tree_search(struct file *file,
1327                                            void __user *argp)
1328 {
1329          struct btrfs_ioctl_search_args *args;
1330          struct inode *inode;
1331          int ret;
1332
1333         if (!capable(CAP_SYS_ADMIN))
1334                 return -EPERM;
1335
1336         args = memdup_user(argp, sizeof(*args));
1337         if (IS_ERR(args))
1338                 return PTR_ERR(args);
1339
1340         inode = fdentry(file)->d_inode;
1341         ret = search_ioctl(inode, args);
1342         if (ret == 0 && copy_to_user(argp, args, sizeof(*args)))
1343                 ret = -EFAULT;
1344         kfree(args);
1345         return ret;
1346 }
1347
1348 /*
1349  * Search INODE_REFs to identify path name of 'dirid' directory
1350  * in a 'tree_id' tree. and sets path name to 'name'.
1351  */
1352 static noinline int btrfs_search_path_in_tree(struct btrfs_fs_info *info,
1353                                 u64 tree_id, u64 dirid, char *name)
1354 {
1355         struct btrfs_root *root;
1356         struct btrfs_key key;
1357         char *ptr;
1358         int ret = -1;
1359         int slot;
1360         int len;
1361         int total_len = 0;
1362         struct btrfs_inode_ref *iref;
1363         struct extent_buffer *l;
1364         struct btrfs_path *path;
1365
1366         if (dirid == BTRFS_FIRST_FREE_OBJECTID) {
1367                 name[0]='\0';
1368                 return 0;
1369         }
1370
1371         path = btrfs_alloc_path();
1372         if (!path)
1373                 return -ENOMEM;
1374
1375         ptr = &name[BTRFS_INO_LOOKUP_PATH_MAX];
1376
1377         key.objectid = tree_id;
1378         key.type = BTRFS_ROOT_ITEM_KEY;
1379         key.offset = (u64)-1;
1380         root = btrfs_read_fs_root_no_name(info, &key);
1381         if (IS_ERR(root)) {
1382                 printk(KERN_ERR "could not find root %llu\n", tree_id);
1383                 ret = -ENOENT;
1384                 goto out;
1385         }
1386
1387         key.objectid = dirid;
1388         key.type = BTRFS_INODE_REF_KEY;
1389         key.offset = (u64)-1;
1390
1391         while(1) {
1392                 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1393                 if (ret < 0)
1394                         goto out;
1395
1396                 l = path->nodes[0];
1397                 slot = path->slots[0];
1398                 if (ret > 0 && slot > 0)
1399                         slot--;
1400                 btrfs_item_key_to_cpu(l, &key, slot);
1401
1402                 if (ret > 0 && (key.objectid != dirid ||
1403                                 key.type != BTRFS_INODE_REF_KEY)) {
1404                         ret = -ENOENT;
1405                         goto out;
1406                 }
1407
1408                 iref = btrfs_item_ptr(l, slot, struct btrfs_inode_ref);
1409                 len = btrfs_inode_ref_name_len(l, iref);
1410                 ptr -= len + 1;
1411                 total_len += len + 1;
1412                 if (ptr < name)
1413                         goto out;
1414
1415                 *(ptr + len) = '/';
1416                 read_extent_buffer(l, ptr,(unsigned long)(iref + 1), len);
1417
1418                 if (key.offset == BTRFS_FIRST_FREE_OBJECTID)
1419                         break;
1420
1421                 btrfs_release_path(root, path);
1422                 key.objectid = key.offset;
1423                 key.offset = (u64)-1;
1424                 dirid = key.objectid;
1425
1426         }
1427         if (ptr < name)
1428                 goto out;
1429         memcpy(name, ptr, total_len);
1430         name[total_len]='\0';
1431         ret = 0;
1432 out:
1433         btrfs_free_path(path);
1434         return ret;
1435 }
1436
1437 static noinline int btrfs_ioctl_ino_lookup(struct file *file,
1438                                            void __user *argp)
1439 {
1440          struct btrfs_ioctl_ino_lookup_args *args;
1441          struct inode *inode;
1442          int ret;
1443
1444         if (!capable(CAP_SYS_ADMIN))
1445                 return -EPERM;
1446
1447         args = memdup_user(argp, sizeof(*args));
1448         if (IS_ERR(args))
1449                 return PTR_ERR(args);
1450
1451         inode = fdentry(file)->d_inode;
1452
1453         if (args->treeid == 0)
1454                 args->treeid = BTRFS_I(inode)->root->root_key.objectid;
1455
1456         ret = btrfs_search_path_in_tree(BTRFS_I(inode)->root->fs_info,
1457                                         args->treeid, args->objectid,
1458                                         args->name);
1459
1460         if (ret == 0 && copy_to_user(argp, args, sizeof(*args)))
1461                 ret = -EFAULT;
1462
1463         kfree(args);
1464         return ret;
1465 }
1466
1467 static noinline int btrfs_ioctl_snap_destroy(struct file *file,
1468                                              void __user *arg)
1469 {
1470         struct dentry *parent = fdentry(file);
1471         struct dentry *dentry;
1472         struct inode *dir = parent->d_inode;
1473         struct inode *inode;
1474         struct btrfs_root *root = BTRFS_I(dir)->root;
1475         struct btrfs_root *dest = NULL;
1476         struct btrfs_ioctl_vol_args *vol_args;
1477         struct btrfs_trans_handle *trans;
1478         int namelen;
1479         int ret;
1480         int err = 0;
1481
1482         vol_args = memdup_user(arg, sizeof(*vol_args));
1483         if (IS_ERR(vol_args))
1484                 return PTR_ERR(vol_args);
1485
1486         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1487         namelen = strlen(vol_args->name);
1488         if (strchr(vol_args->name, '/') ||
1489             strncmp(vol_args->name, "..", namelen) == 0) {
1490                 err = -EINVAL;
1491                 goto out;
1492         }
1493
1494         err = mnt_want_write(file->f_path.mnt);
1495         if (err)
1496                 goto out;
1497
1498         mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
1499         dentry = lookup_one_len(vol_args->name, parent, namelen);
1500         if (IS_ERR(dentry)) {
1501                 err = PTR_ERR(dentry);
1502                 goto out_unlock_dir;
1503         }
1504
1505         if (!dentry->d_inode) {
1506                 err = -ENOENT;
1507                 goto out_dput;
1508         }
1509
1510         inode = dentry->d_inode;
1511         dest = BTRFS_I(inode)->root;
1512         if (!capable(CAP_SYS_ADMIN)){
1513                 /*
1514                  * Regular user.  Only allow this with a special mount
1515                  * option, when the user has write+exec access to the
1516                  * subvol root, and when rmdir(2) would have been
1517                  * allowed.
1518                  *
1519                  * Note that this is _not_ check that the subvol is
1520                  * empty or doesn't contain data that we wouldn't
1521                  * otherwise be able to delete.
1522                  *
1523                  * Users who want to delete empty subvols should try
1524                  * rmdir(2).
1525                  */
1526                 err = -EPERM;
1527                 if (!btrfs_test_opt(root, USER_SUBVOL_RM_ALLOWED))
1528                         goto out_dput;
1529
1530                 /*
1531                  * Do not allow deletion if the parent dir is the same
1532                  * as the dir to be deleted.  That means the ioctl
1533                  * must be called on the dentry referencing the root
1534                  * of the subvol, not a random directory contained
1535                  * within it.
1536                  */
1537                 err = -EINVAL;
1538                 if (root == dest)
1539                         goto out_dput;
1540
1541                 err = inode_permission(inode, MAY_WRITE | MAY_EXEC);
1542                 if (err)
1543                         goto out_dput;
1544
1545                 /* check if subvolume may be deleted by a non-root user */
1546                 err = btrfs_may_delete(dir, dentry, 1);
1547                 if (err)
1548                         goto out_dput;
1549         }
1550
1551         if (inode->i_ino != BTRFS_FIRST_FREE_OBJECTID) {
1552                 err = -EINVAL;
1553                 goto out_dput;
1554         }
1555
1556         mutex_lock(&inode->i_mutex);
1557         err = d_invalidate(dentry);
1558         if (err)
1559                 goto out_unlock;
1560
1561         down_write(&root->fs_info->subvol_sem);
1562
1563         err = may_destroy_subvol(dest);
1564         if (err)
1565                 goto out_up_write;
1566
1567         trans = btrfs_start_transaction(root, 0);
1568         if (IS_ERR(trans)) {
1569                 err = PTR_ERR(trans);
1570                 goto out_up_write;
1571         }
1572         trans->block_rsv = &root->fs_info->global_block_rsv;
1573
1574         ret = btrfs_unlink_subvol(trans, root, dir,
1575                                 dest->root_key.objectid,
1576                                 dentry->d_name.name,
1577                                 dentry->d_name.len);
1578         BUG_ON(ret);
1579
1580         btrfs_record_root_in_trans(trans, dest);
1581
1582         memset(&dest->root_item.drop_progress, 0,
1583                 sizeof(dest->root_item.drop_progress));
1584         dest->root_item.drop_level = 0;
1585         btrfs_set_root_refs(&dest->root_item, 0);
1586
1587         if (!xchg(&dest->orphan_item_inserted, 1)) {
1588                 ret = btrfs_insert_orphan_item(trans,
1589                                         root->fs_info->tree_root,
1590                                         dest->root_key.objectid);
1591                 BUG_ON(ret);
1592         }
1593
1594         ret = btrfs_end_transaction(trans, root);
1595         BUG_ON(ret);
1596         inode->i_flags |= S_DEAD;
1597 out_up_write:
1598         up_write(&root->fs_info->subvol_sem);
1599 out_unlock:
1600         mutex_unlock(&inode->i_mutex);
1601         if (!err) {
1602                 shrink_dcache_sb(root->fs_info->sb);
1603                 btrfs_invalidate_inodes(dest);
1604                 d_delete(dentry);
1605         }
1606 out_dput:
1607         dput(dentry);
1608 out_unlock_dir:
1609         mutex_unlock(&dir->i_mutex);
1610         mnt_drop_write(file->f_path.mnt);
1611 out:
1612         kfree(vol_args);
1613         return err;
1614 }
1615
1616 static int btrfs_ioctl_defrag(struct file *file, void __user *argp)
1617 {
1618         struct inode *inode = fdentry(file)->d_inode;
1619         struct btrfs_root *root = BTRFS_I(inode)->root;
1620         struct btrfs_ioctl_defrag_range_args *range;
1621         int ret;
1622
1623         if (btrfs_root_readonly(root))
1624                 return -EROFS;
1625
1626         ret = mnt_want_write(file->f_path.mnt);
1627         if (ret)
1628                 return ret;
1629
1630         switch (inode->i_mode & S_IFMT) {
1631         case S_IFDIR:
1632                 if (!capable(CAP_SYS_ADMIN)) {
1633                         ret = -EPERM;
1634                         goto out;
1635                 }
1636                 ret = btrfs_defrag_root(root, 0);
1637                 if (ret)
1638                         goto out;
1639                 ret = btrfs_defrag_root(root->fs_info->extent_root, 0);
1640                 break;
1641         case S_IFREG:
1642                 if (!(file->f_mode & FMODE_WRITE)) {
1643                         ret = -EINVAL;
1644                         goto out;
1645                 }
1646
1647                 range = kzalloc(sizeof(*range), GFP_KERNEL);
1648                 if (!range) {
1649                         ret = -ENOMEM;
1650                         goto out;
1651                 }
1652
1653                 if (argp) {
1654                         if (copy_from_user(range, argp,
1655                                            sizeof(*range))) {
1656                                 ret = -EFAULT;
1657                                 kfree(range);
1658                                 goto out;
1659                         }
1660                         /* compression requires us to start the IO */
1661                         if ((range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)) {
1662                                 range->flags |= BTRFS_DEFRAG_RANGE_START_IO;
1663                                 range->extent_thresh = (u32)-1;
1664                         }
1665                 } else {
1666                         /* the rest are all set to zero by kzalloc */
1667                         range->len = (u64)-1;
1668                 }
1669                 ret = btrfs_defrag_file(file, range);
1670                 kfree(range);
1671                 break;
1672         default:
1673                 ret = -EINVAL;
1674         }
1675 out:
1676         mnt_drop_write(file->f_path.mnt);
1677         return ret;
1678 }
1679
1680 static long btrfs_ioctl_add_dev(struct btrfs_root *root, void __user *arg)
1681 {
1682         struct btrfs_ioctl_vol_args *vol_args;
1683         int ret;
1684
1685         if (!capable(CAP_SYS_ADMIN))
1686                 return -EPERM;
1687
1688         vol_args = memdup_user(arg, sizeof(*vol_args));
1689         if (IS_ERR(vol_args))
1690                 return PTR_ERR(vol_args);
1691
1692         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1693         ret = btrfs_init_new_device(root, vol_args->name);
1694
1695         kfree(vol_args);
1696         return ret;
1697 }
1698
1699 static long btrfs_ioctl_rm_dev(struct btrfs_root *root, void __user *arg)
1700 {
1701         struct btrfs_ioctl_vol_args *vol_args;
1702         int ret;
1703
1704         if (!capable(CAP_SYS_ADMIN))
1705                 return -EPERM;
1706
1707         if (root->fs_info->sb->s_flags & MS_RDONLY)
1708                 return -EROFS;
1709
1710         vol_args = memdup_user(arg, sizeof(*vol_args));
1711         if (IS_ERR(vol_args))
1712                 return PTR_ERR(vol_args);
1713
1714         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1715         ret = btrfs_rm_device(root, vol_args->name);
1716
1717         kfree(vol_args);
1718         return ret;
1719 }
1720
1721 static noinline long btrfs_ioctl_clone(struct file *file, unsigned long srcfd,
1722                                        u64 off, u64 olen, u64 destoff)
1723 {
1724         struct inode *inode = fdentry(file)->d_inode;
1725         struct btrfs_root *root = BTRFS_I(inode)->root;
1726         struct file *src_file;
1727         struct inode *src;
1728         struct btrfs_trans_handle *trans;
1729         struct btrfs_path *path;
1730         struct extent_buffer *leaf;
1731         char *buf;
1732         struct btrfs_key key;
1733         u32 nritems;
1734         int slot;
1735         int ret;
1736         u64 len = olen;
1737         u64 bs = root->fs_info->sb->s_blocksize;
1738         u64 hint_byte;
1739
1740         /*
1741          * TODO:
1742          * - split compressed inline extents.  annoying: we need to
1743          *   decompress into destination's address_space (the file offset
1744          *   may change, so source mapping won't do), then recompress (or
1745          *   otherwise reinsert) a subrange.
1746          * - allow ranges within the same file to be cloned (provided
1747          *   they don't overlap)?
1748          */
1749
1750         /* the destination must be opened for writing */
1751         if (!(file->f_mode & FMODE_WRITE) || (file->f_flags & O_APPEND))
1752                 return -EINVAL;
1753
1754         if (btrfs_root_readonly(root))
1755                 return -EROFS;
1756
1757         ret = mnt_want_write(file->f_path.mnt);
1758         if (ret)
1759                 return ret;
1760
1761         src_file = fget(srcfd);
1762         if (!src_file) {
1763                 ret = -EBADF;
1764                 goto out_drop_write;
1765         }
1766
1767         src = src_file->f_dentry->d_inode;
1768
1769         ret = -EINVAL;
1770         if (src == inode)
1771                 goto out_fput;
1772
1773         /* the src must be open for reading */
1774         if (!(src_file->f_mode & FMODE_READ))
1775                 goto out_fput;
1776
1777         ret = -EISDIR;
1778         if (S_ISDIR(src->i_mode) || S_ISDIR(inode->i_mode))
1779                 goto out_fput;
1780
1781         ret = -EXDEV;
1782         if (src->i_sb != inode->i_sb || BTRFS_I(src)->root != root)
1783                 goto out_fput;
1784
1785         ret = -ENOMEM;
1786         buf = vmalloc(btrfs_level_size(root, 0));
1787         if (!buf)
1788                 goto out_fput;
1789
1790         path = btrfs_alloc_path();
1791         if (!path) {
1792                 vfree(buf);
1793                 goto out_fput;
1794         }
1795         path->reada = 2;
1796
1797         if (inode < src) {
1798                 mutex_lock_nested(&inode->i_mutex, I_MUTEX_PARENT);
1799                 mutex_lock_nested(&src->i_mutex, I_MUTEX_CHILD);
1800         } else {
1801                 mutex_lock_nested(&src->i_mutex, I_MUTEX_PARENT);
1802                 mutex_lock_nested(&inode->i_mutex, I_MUTEX_CHILD);
1803         }
1804
1805         /* determine range to clone */
1806         ret = -EINVAL;
1807         if (off + len > src->i_size || off + len < off)
1808                 goto out_unlock;
1809         if (len == 0)
1810                 olen = len = src->i_size - off;
1811         /* if we extend to eof, continue to block boundary */
1812         if (off + len == src->i_size)
1813                 len = ALIGN(src->i_size, bs) - off;
1814
1815         /* verify the end result is block aligned */
1816         if (!IS_ALIGNED(off, bs) || !IS_ALIGNED(off + len, bs) ||
1817             !IS_ALIGNED(destoff, bs))
1818                 goto out_unlock;
1819
1820         /* do any pending delalloc/csum calc on src, one way or
1821            another, and lock file content */
1822         while (1) {
1823                 struct btrfs_ordered_extent *ordered;
1824                 lock_extent(&BTRFS_I(src)->io_tree, off, off+len, GFP_NOFS);
1825                 ordered = btrfs_lookup_first_ordered_extent(src, off+len);
1826                 if (!ordered &&
1827                     !test_range_bit(&BTRFS_I(src)->io_tree, off, off+len,
1828                                    EXTENT_DELALLOC, 0, NULL))
1829                         break;
1830                 unlock_extent(&BTRFS_I(src)->io_tree, off, off+len, GFP_NOFS);
1831                 if (ordered)
1832                         btrfs_put_ordered_extent(ordered);
1833                 btrfs_wait_ordered_range(src, off, len);
1834         }
1835
1836         /* clone data */
1837         key.objectid = src->i_ino;
1838         key.type = BTRFS_EXTENT_DATA_KEY;
1839         key.offset = 0;
1840
1841         while (1) {
1842                 /*
1843                  * note the key will change type as we walk through the
1844                  * tree.
1845                  */
1846                 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1847                 if (ret < 0)
1848                         goto out;
1849
1850                 nritems = btrfs_header_nritems(path->nodes[0]);
1851                 if (path->slots[0] >= nritems) {
1852                         ret = btrfs_next_leaf(root, path);
1853                         if (ret < 0)
1854                                 goto out;
1855                         if (ret > 0)
1856                                 break;
1857                         nritems = btrfs_header_nritems(path->nodes[0]);
1858                 }
1859                 leaf = path->nodes[0];
1860                 slot = path->slots[0];
1861
1862                 btrfs_item_key_to_cpu(leaf, &key, slot);
1863                 if (btrfs_key_type(&key) > BTRFS_EXTENT_DATA_KEY ||
1864                     key.objectid != src->i_ino)
1865                         break;
1866
1867                 if (btrfs_key_type(&key) == BTRFS_EXTENT_DATA_KEY) {
1868                         struct btrfs_file_extent_item *extent;
1869                         int type;
1870                         u32 size;
1871                         struct btrfs_key new_key;
1872                         u64 disko = 0, diskl = 0;
1873                         u64 datao = 0, datal = 0;
1874                         u8 comp;
1875                         u64 endoff;
1876
1877                         size = btrfs_item_size_nr(leaf, slot);
1878                         read_extent_buffer(leaf, buf,
1879                                            btrfs_item_ptr_offset(leaf, slot),
1880                                            size);
1881
1882                         extent = btrfs_item_ptr(leaf, slot,
1883                                                 struct btrfs_file_extent_item);
1884                         comp = btrfs_file_extent_compression(leaf, extent);
1885                         type = btrfs_file_extent_type(leaf, extent);
1886                         if (type == BTRFS_FILE_EXTENT_REG ||
1887                             type == BTRFS_FILE_EXTENT_PREALLOC) {
1888                                 disko = btrfs_file_extent_disk_bytenr(leaf,
1889                                                                       extent);
1890                                 diskl = btrfs_file_extent_disk_num_bytes(leaf,
1891                                                                  extent);
1892                                 datao = btrfs_file_extent_offset(leaf, extent);
1893                                 datal = btrfs_file_extent_num_bytes(leaf,
1894                                                                     extent);
1895                         } else if (type == BTRFS_FILE_EXTENT_INLINE) {
1896                                 /* take upper bound, may be compressed */
1897                                 datal = btrfs_file_extent_ram_bytes(leaf,
1898                                                                     extent);
1899                         }
1900                         btrfs_release_path(root, path);
1901
1902                         if (key.offset + datal <= off ||
1903                             key.offset >= off+len)
1904                                 goto next;
1905
1906                         memcpy(&new_key, &key, sizeof(new_key));
1907                         new_key.objectid = inode->i_ino;
1908                         if (off <= key.offset)
1909                                 new_key.offset = key.offset + destoff - off;
1910                         else
1911                                 new_key.offset = destoff;
1912
1913                         trans = btrfs_start_transaction(root, 1);
1914                         if (IS_ERR(trans)) {
1915                                 ret = PTR_ERR(trans);
1916                                 goto out;
1917                         }
1918
1919                         if (type == BTRFS_FILE_EXTENT_REG ||
1920                             type == BTRFS_FILE_EXTENT_PREALLOC) {
1921                                 if (off > key.offset) {
1922                                         datao += off - key.offset;
1923                                         datal -= off - key.offset;
1924                                 }
1925
1926                                 if (key.offset + datal > off + len)
1927                                         datal = off + len - key.offset;
1928
1929                                 ret = btrfs_drop_extents(trans, inode,
1930                                                          new_key.offset,
1931                                                          new_key.offset + datal,
1932                                                          &hint_byte, 1);
1933                                 BUG_ON(ret);
1934
1935                                 ret = btrfs_insert_empty_item(trans, root, path,
1936                                                               &new_key, size);
1937                                 BUG_ON(ret);
1938
1939                                 leaf = path->nodes[0];
1940                                 slot = path->slots[0];
1941                                 write_extent_buffer(leaf, buf,
1942                                             btrfs_item_ptr_offset(leaf, slot),
1943                                             size);
1944
1945                                 extent = btrfs_item_ptr(leaf, slot,
1946                                                 struct btrfs_file_extent_item);
1947
1948                                 /* disko == 0 means it's a hole */
1949                                 if (!disko)
1950                                         datao = 0;
1951
1952                                 btrfs_set_file_extent_offset(leaf, extent,
1953                                                              datao);
1954                                 btrfs_set_file_extent_num_bytes(leaf, extent,
1955                                                                 datal);
1956                                 if (disko) {
1957                                         inode_add_bytes(inode, datal);
1958                                         ret = btrfs_inc_extent_ref(trans, root,
1959                                                         disko, diskl, 0,
1960                                                         root->root_key.objectid,
1961                                                         inode->i_ino,
1962                                                         new_key.offset - datao);
1963                                         BUG_ON(ret);
1964                                 }
1965                         } else if (type == BTRFS_FILE_EXTENT_INLINE) {
1966                                 u64 skip = 0;
1967                                 u64 trim = 0;
1968                                 if (off > key.offset) {
1969                                         skip = off - key.offset;
1970                                         new_key.offset += skip;
1971                                 }
1972
1973                                 if (key.offset + datal > off+len)
1974                                         trim = key.offset + datal - (off+len);
1975
1976                                 if (comp && (skip || trim)) {
1977                                         ret = -EINVAL;
1978                                         btrfs_end_transaction(trans, root);
1979                                         goto out;
1980                                 }
1981                                 size -= skip + trim;
1982                                 datal -= skip + trim;
1983
1984                                 ret = btrfs_drop_extents(trans, inode,
1985                                                          new_key.offset,
1986                                                          new_key.offset + datal,
1987                                                          &hint_byte, 1);
1988                                 BUG_ON(ret);
1989
1990                                 ret = btrfs_insert_empty_item(trans, root, path,
1991                                                               &new_key, size);
1992                                 BUG_ON(ret);
1993
1994                                 if (skip) {
1995                                         u32 start =
1996                                           btrfs_file_extent_calc_inline_size(0);
1997                                         memmove(buf+start, buf+start+skip,
1998                                                 datal);
1999                                 }
2000
2001                                 leaf = path->nodes[0];
2002                                 slot = path->slots[0];
2003                                 write_extent_buffer(leaf, buf,
2004                                             btrfs_item_ptr_offset(leaf, slot),
2005                                             size);
2006                                 inode_add_bytes(inode, datal);
2007                         }
2008
2009                         btrfs_mark_buffer_dirty(leaf);
2010                         btrfs_release_path(root, path);
2011
2012                         inode->i_mtime = inode->i_ctime = CURRENT_TIME;
2013
2014                         /*
2015                          * we round up to the block size at eof when
2016                          * determining which extents to clone above,
2017                          * but shouldn't round up the file size
2018                          */
2019                         endoff = new_key.offset + datal;
2020                         if (endoff > destoff+olen)
2021                                 endoff = destoff+olen;
2022                         if (endoff > inode->i_size)
2023                                 btrfs_i_size_write(inode, endoff);
2024
2025                         BTRFS_I(inode)->flags = BTRFS_I(src)->flags;
2026                         ret = btrfs_update_inode(trans, root, inode);
2027                         BUG_ON(ret);
2028                         btrfs_end_transaction(trans, root);
2029                 }
2030 next:
2031                 btrfs_release_path(root, path);
2032                 key.offset++;
2033         }
2034         ret = 0;
2035 out:
2036         btrfs_release_path(root, path);
2037         unlock_extent(&BTRFS_I(src)->io_tree, off, off+len, GFP_NOFS);
2038 out_unlock:
2039         mutex_unlock(&src->i_mutex);
2040         mutex_unlock(&inode->i_mutex);
2041         vfree(buf);
2042         btrfs_free_path(path);
2043 out_fput:
2044         fput(src_file);
2045 out_drop_write:
2046         mnt_drop_write(file->f_path.mnt);
2047         return ret;
2048 }
2049
2050 static long btrfs_ioctl_clone_range(struct file *file, void __user *argp)
2051 {
2052         struct btrfs_ioctl_clone_range_args args;
2053
2054         if (copy_from_user(&args, argp, sizeof(args)))
2055                 return -EFAULT;
2056         return btrfs_ioctl_clone(file, args.src_fd, args.src_offset,
2057                                  args.src_length, args.dest_offset);
2058 }
2059
2060 /*
2061  * there are many ways the trans_start and trans_end ioctls can lead
2062  * to deadlocks.  They should only be used by applications that
2063  * basically own the machine, and have a very in depth understanding
2064  * of all the possible deadlocks and enospc problems.
2065  */
2066 static long btrfs_ioctl_trans_start(struct file *file)
2067 {
2068         struct inode *inode = fdentry(file)->d_inode;
2069         struct btrfs_root *root = BTRFS_I(inode)->root;
2070         struct btrfs_trans_handle *trans;
2071         int ret;
2072
2073         ret = -EPERM;
2074         if (!capable(CAP_SYS_ADMIN))
2075                 goto out;
2076
2077         ret = -EINPROGRESS;
2078         if (file->private_data)
2079                 goto out;
2080
2081         ret = -EROFS;
2082         if (btrfs_root_readonly(root))
2083                 goto out;
2084
2085         ret = mnt_want_write(file->f_path.mnt);
2086         if (ret)
2087                 goto out;
2088
2089         mutex_lock(&root->fs_info->trans_mutex);
2090         root->fs_info->open_ioctl_trans++;
2091         mutex_unlock(&root->fs_info->trans_mutex);
2092
2093         ret = -ENOMEM;
2094         trans = btrfs_start_ioctl_transaction(root, 0);
2095         if (IS_ERR(trans))
2096                 goto out_drop;
2097
2098         file->private_data = trans;
2099         return 0;
2100
2101 out_drop:
2102         mutex_lock(&root->fs_info->trans_mutex);
2103         root->fs_info->open_ioctl_trans--;
2104         mutex_unlock(&root->fs_info->trans_mutex);
2105         mnt_drop_write(file->f_path.mnt);
2106 out:
2107         return ret;
2108 }
2109
2110 static long btrfs_ioctl_default_subvol(struct file *file, void __user *argp)
2111 {
2112         struct inode *inode = fdentry(file)->d_inode;
2113         struct btrfs_root *root = BTRFS_I(inode)->root;
2114         struct btrfs_root *new_root;
2115         struct btrfs_dir_item *di;
2116         struct btrfs_trans_handle *trans;
2117         struct btrfs_path *path;
2118         struct btrfs_key location;
2119         struct btrfs_disk_key disk_key;
2120         struct btrfs_super_block *disk_super;
2121         u64 features;
2122         u64 objectid = 0;
2123         u64 dir_id;
2124
2125         if (!capable(CAP_SYS_ADMIN))
2126                 return -EPERM;
2127
2128         if (copy_from_user(&objectid, argp, sizeof(objectid)))
2129                 return -EFAULT;
2130
2131         if (!objectid)
2132                 objectid = root->root_key.objectid;
2133
2134         location.objectid = objectid;
2135         location.type = BTRFS_ROOT_ITEM_KEY;
2136         location.offset = (u64)-1;
2137
2138         new_root = btrfs_read_fs_root_no_name(root->fs_info, &location);
2139         if (IS_ERR(new_root))
2140                 return PTR_ERR(new_root);
2141
2142         if (btrfs_root_refs(&new_root->root_item) == 0)
2143                 return -ENOENT;
2144
2145         path = btrfs_alloc_path();
2146         if (!path)
2147                 return -ENOMEM;
2148         path->leave_spinning = 1;
2149
2150         trans = btrfs_start_transaction(root, 1);
2151         if (IS_ERR(trans)) {
2152                 btrfs_free_path(path);
2153                 return PTR_ERR(trans);
2154         }
2155
2156         dir_id = btrfs_super_root_dir(&root->fs_info->super_copy);
2157         di = btrfs_lookup_dir_item(trans, root->fs_info->tree_root, path,
2158                                    dir_id, "default", 7, 1);
2159         if (IS_ERR_OR_NULL(di)) {
2160                 btrfs_free_path(path);
2161                 btrfs_end_transaction(trans, root);
2162                 printk(KERN_ERR "Umm, you don't have the default dir item, "
2163                        "this isn't going to work\n");
2164                 return -ENOENT;
2165         }
2166
2167         btrfs_cpu_key_to_disk(&disk_key, &new_root->root_key);
2168         btrfs_set_dir_item_key(path->nodes[0], di, &disk_key);
2169         btrfs_mark_buffer_dirty(path->nodes[0]);
2170         btrfs_free_path(path);
2171
2172         disk_super = &root->fs_info->super_copy;
2173         features = btrfs_super_incompat_flags(disk_super);
2174         if (!(features & BTRFS_FEATURE_INCOMPAT_DEFAULT_SUBVOL)) {
2175                 features |= BTRFS_FEATURE_INCOMPAT_DEFAULT_SUBVOL;
2176                 btrfs_set_super_incompat_flags(disk_super, features);
2177         }
2178         btrfs_end_transaction(trans, root);
2179
2180         return 0;
2181 }
2182
2183 static void get_block_group_info(struct list_head *groups_list,
2184                                  struct btrfs_ioctl_space_info *space)
2185 {
2186         struct btrfs_block_group_cache *block_group;
2187
2188         space->total_bytes = 0;
2189         space->used_bytes = 0;
2190         space->flags = 0;
2191         list_for_each_entry(block_group, groups_list, list) {
2192                 space->flags = block_group->flags;
2193                 space->total_bytes += block_group->key.offset;
2194                 space->used_bytes +=
2195                         btrfs_block_group_used(&block_group->item);
2196         }
2197 }
2198
2199 long btrfs_ioctl_space_info(struct btrfs_root *root, void __user *arg)
2200 {
2201         struct btrfs_ioctl_space_args space_args;
2202         struct btrfs_ioctl_space_info space;
2203         struct btrfs_ioctl_space_info *dest;
2204         struct btrfs_ioctl_space_info *dest_orig;
2205         struct btrfs_ioctl_space_info *user_dest;
2206         struct btrfs_space_info *info;
2207         u64 types[] = {BTRFS_BLOCK_GROUP_DATA,
2208                        BTRFS_BLOCK_GROUP_SYSTEM,
2209                        BTRFS_BLOCK_GROUP_METADATA,
2210                        BTRFS_BLOCK_GROUP_DATA | BTRFS_BLOCK_GROUP_METADATA};
2211         int num_types = 4;
2212         int alloc_size;
2213         int ret = 0;
2214         u64 slot_count = 0;
2215         int i, c;
2216
2217         if (copy_from_user(&space_args,
2218                            (struct btrfs_ioctl_space_args __user *)arg,
2219                            sizeof(space_args)))
2220                 return -EFAULT;
2221
2222         for (i = 0; i < num_types; i++) {
2223                 struct btrfs_space_info *tmp;
2224
2225                 info = NULL;
2226                 rcu_read_lock();
2227                 list_for_each_entry_rcu(tmp, &root->fs_info->space_info,
2228                                         list) {
2229                         if (tmp->flags == types[i]) {
2230                                 info = tmp;
2231                                 break;
2232                         }
2233                 }
2234                 rcu_read_unlock();
2235
2236                 if (!info)
2237                         continue;
2238
2239                 down_read(&info->groups_sem);
2240                 for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) {
2241                         if (!list_empty(&info->block_groups[c]))
2242                                 slot_count++;
2243                 }
2244                 up_read(&info->groups_sem);
2245         }
2246
2247         /* space_slots == 0 means they are asking for a count */
2248         if (space_args.space_slots == 0) {
2249                 space_args.total_spaces = slot_count;
2250                 goto out;
2251         }
2252
2253         slot_count = min_t(u64, space_args.space_slots, slot_count);
2254
2255         alloc_size = sizeof(*dest) * slot_count;
2256
2257         /* we generally have at most 6 or so space infos, one for each raid
2258          * level.  So, a whole page should be more than enough for everyone
2259          */
2260         if (alloc_size > PAGE_CACHE_SIZE)
2261                 return -ENOMEM;
2262
2263         space_args.total_spaces = 0;
2264         dest = kmalloc(alloc_size, GFP_NOFS);
2265         if (!dest)
2266                 return -ENOMEM;
2267         dest_orig = dest;
2268
2269         /* now we have a buffer to copy into */
2270         for (i = 0; i < num_types; i++) {
2271                 struct btrfs_space_info *tmp;
2272
2273                 if (!slot_count)
2274                         break;
2275
2276                 info = NULL;
2277                 rcu_read_lock();
2278                 list_for_each_entry_rcu(tmp, &root->fs_info->space_info,
2279                                         list) {
2280                         if (tmp->flags == types[i]) {
2281                                 info = tmp;
2282                                 break;
2283                         }
2284                 }
2285                 rcu_read_unlock();
2286
2287                 if (!info)
2288                         continue;
2289                 down_read(&info->groups_sem);
2290                 for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) {
2291                         if (!list_empty(&info->block_groups[c])) {
2292                                 get_block_group_info(&info->block_groups[c],
2293                                                      &space);
2294                                 memcpy(dest, &space, sizeof(space));
2295                                 dest++;
2296                                 space_args.total_spaces++;
2297                                 slot_count--;
2298                         }
2299                         if (!slot_count)
2300                                 break;
2301                 }
2302                 up_read(&info->groups_sem);
2303         }
2304
2305         user_dest = (struct btrfs_ioctl_space_info *)
2306                 (arg + sizeof(struct btrfs_ioctl_space_args));
2307
2308         if (copy_to_user(user_dest, dest_orig, alloc_size))
2309                 ret = -EFAULT;
2310
2311         kfree(dest_orig);
2312 out:
2313         if (ret == 0 && copy_to_user(arg, &space_args, sizeof(space_args)))
2314                 ret = -EFAULT;
2315
2316         return ret;
2317 }
2318
2319 /*
2320  * there are many ways the trans_start and trans_end ioctls can lead
2321  * to deadlocks.  They should only be used by applications that
2322  * basically own the machine, and have a very in depth understanding
2323  * of all the possible deadlocks and enospc problems.
2324  */
2325 long btrfs_ioctl_trans_end(struct file *file)
2326 {
2327         struct inode *inode = fdentry(file)->d_inode;
2328         struct btrfs_root *root = BTRFS_I(inode)->root;
2329         struct btrfs_trans_handle *trans;
2330
2331         trans = file->private_data;
2332         if (!trans)
2333                 return -EINVAL;
2334         file->private_data = NULL;
2335
2336         btrfs_end_transaction(trans, root);
2337
2338         mutex_lock(&root->fs_info->trans_mutex);
2339         root->fs_info->open_ioctl_trans--;
2340         mutex_unlock(&root->fs_info->trans_mutex);
2341
2342         mnt_drop_write(file->f_path.mnt);
2343         return 0;
2344 }
2345
2346 static noinline long btrfs_ioctl_start_sync(struct file *file, void __user *argp)
2347 {
2348         struct btrfs_root *root = BTRFS_I(file->f_dentry->d_inode)->root;
2349         struct btrfs_trans_handle *trans;
2350         u64 transid;
2351
2352         trans = btrfs_start_transaction(root, 0);
2353         if (IS_ERR(trans))
2354                 return PTR_ERR(trans);
2355         transid = trans->transid;
2356         btrfs_commit_transaction_async(trans, root, 0);
2357
2358         if (argp)
2359                 if (copy_to_user(argp, &transid, sizeof(transid)))
2360                         return -EFAULT;
2361         return 0;
2362 }
2363
2364 static noinline long btrfs_ioctl_wait_sync(struct file *file, void __user *argp)
2365 {
2366         struct btrfs_root *root = BTRFS_I(file->f_dentry->d_inode)->root;
2367         u64 transid;
2368
2369         if (argp) {
2370                 if (copy_from_user(&transid, argp, sizeof(transid)))
2371                         return -EFAULT;
2372         } else {
2373                 transid = 0;  /* current trans */
2374         }
2375         return btrfs_wait_for_commit(root, transid);
2376 }
2377
2378 long btrfs_ioctl(struct file *file, unsigned int
2379                 cmd, unsigned long arg)
2380 {
2381         struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root;
2382         void __user *argp = (void __user *)arg;
2383
2384         switch (cmd) {
2385         case FS_IOC_GETFLAGS:
2386                 return btrfs_ioctl_getflags(file, argp);
2387         case FS_IOC_SETFLAGS:
2388                 return btrfs_ioctl_setflags(file, argp);
2389         case FS_IOC_GETVERSION:
2390                 return btrfs_ioctl_getversion(file, argp);
2391         case BTRFS_IOC_SNAP_CREATE:
2392                 return btrfs_ioctl_snap_create(file, argp, 0);
2393         case BTRFS_IOC_SNAP_CREATE_V2:
2394                 return btrfs_ioctl_snap_create_v2(file, argp, 0);
2395         case BTRFS_IOC_SUBVOL_CREATE:
2396                 return btrfs_ioctl_snap_create(file, argp, 1);
2397         case BTRFS_IOC_SNAP_DESTROY:
2398                 return btrfs_ioctl_snap_destroy(file, argp);
2399         case BTRFS_IOC_SUBVOL_GETFLAGS:
2400                 return btrfs_ioctl_subvol_getflags(file, argp);
2401         case BTRFS_IOC_SUBVOL_SETFLAGS:
2402                 return btrfs_ioctl_subvol_setflags(file, argp);
2403         case BTRFS_IOC_DEFAULT_SUBVOL:
2404                 return btrfs_ioctl_default_subvol(file, argp);
2405         case BTRFS_IOC_DEFRAG:
2406                 return btrfs_ioctl_defrag(file, NULL);
2407         case BTRFS_IOC_DEFRAG_RANGE:
2408                 return btrfs_ioctl_defrag(file, argp);
2409         case BTRFS_IOC_RESIZE:
2410                 return btrfs_ioctl_resize(root, argp);
2411         case BTRFS_IOC_ADD_DEV:
2412                 return btrfs_ioctl_add_dev(root, argp);
2413         case BTRFS_IOC_RM_DEV:
2414                 return btrfs_ioctl_rm_dev(root, argp);
2415         case BTRFS_IOC_BALANCE:
2416                 return btrfs_balance(root->fs_info->dev_root);
2417         case BTRFS_IOC_CLONE:
2418                 return btrfs_ioctl_clone(file, arg, 0, 0, 0);
2419         case BTRFS_IOC_CLONE_RANGE:
2420                 return btrfs_ioctl_clone_range(file, argp);
2421         case BTRFS_IOC_TRANS_START:
2422                 return btrfs_ioctl_trans_start(file);
2423         case BTRFS_IOC_TRANS_END:
2424                 return btrfs_ioctl_trans_end(file);
2425         case BTRFS_IOC_TREE_SEARCH:
2426                 return btrfs_ioctl_tree_search(file, argp);
2427         case BTRFS_IOC_INO_LOOKUP:
2428                 return btrfs_ioctl_ino_lookup(file, argp);
2429         case BTRFS_IOC_SPACE_INFO:
2430                 return btrfs_ioctl_space_info(root, argp);
2431         case BTRFS_IOC_SYNC:
2432                 btrfs_sync_fs(file->f_dentry->d_sb, 1);
2433                 return 0;
2434         case BTRFS_IOC_START_SYNC:
2435                 return btrfs_ioctl_start_sync(file, argp);
2436         case BTRFS_IOC_WAIT_SYNC:
2437                 return btrfs_ioctl_wait_sync(file, argp);
2438         }
2439
2440         return -ENOTTY;
2441 }