fs/btrfs/ioctl.c

   1 /*
   2  * Copyright (C) 2007 Oracle.  All rights reserved.
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public
   6  * License v2 as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  11  * General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public
  14  * License along with this program; if not, write to the
  15  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  16  * Boston, MA 021110-1307, USA.
  17  */
  18
  19 #include <linux/kernel.h>
  20 #include <linux/bio.h>
  21 #include <linux/buffer_head.h>
  22 #include <linux/file.h>
  23 #include <linux/fs.h>
  24 #include <linux/fsnotify.h>
  25 #include <linux/pagemap.h>
  26 #include <linux/highmem.h>
  27 #include <linux/time.h>
  28 #include <linux/init.h>
  29 #include <linux/string.h>
  30 #include <linux/backing-dev.h>
  31 #include <linux/mount.h>
  32 #include <linux/mpage.h>
  33 #include <linux/namei.h>
  34 #include <linux/swap.h>
  35 #include <linux/writeback.h>
  36 #include <linux/statfs.h>
  37 #include <linux/compat.h>
  38 #include <linux/bit_spinlock.h>
  39 #include <linux/security.h>
  40 #include <linux/xattr.h>
  41 #include <linux/vmalloc.h>
  42 #include <linux/slab.h>
  43 #include <linux/blkdev.h>
  44 #include <linux/uuid.h>
  45 #include "compat.h"
  46 #include "ctree.h"
  47 #include "disk-io.h"
  48 #include "transaction.h"
  49 #include "btrfs_inode.h"
  50 #include "ioctl.h"
  51 #include "print-tree.h"
  52 #include "volumes.h"
  53 #include "locking.h"
  54 #include "inode-map.h"
  55 #include "backref.h"
  56 #include "rcu-string.h"
  57 #include "send.h"
  58
  59 /* Mask out flags that are inappropriate for the given type of inode. */
  60 static inline __u32 btrfs_mask_flags(umode_t mode, __u32 flags)
  61 {
  62         if (S_ISDIR(mode))
  63                 return flags;
  64         else if (S_ISREG(mode))
  65                 return flags & ~FS_DIRSYNC_FL;
  66         else
  67                 return flags & (FS_NODUMP_FL | FS_NOATIME_FL);
  68 }
  69
  70 /*
  71  * Export inode flags to the format expected by the FS_IOC_GETFLAGS ioctl.
  72  */
  73 static unsigned int btrfs_flags_to_ioctl(unsigned int flags)
  74 {
  75         unsigned int iflags = 0;
  76
  77         if (flags & BTRFS_INODE_SYNC)
  78                 iflags |= FS_SYNC_FL;
  79         if (flags & BTRFS_INODE_IMMUTABLE)
  80                 iflags |= FS_IMMUTABLE_FL;
  81         if (flags & BTRFS_INODE_APPEND)
  82                 iflags |= FS_APPEND_FL;
  83         if (flags & BTRFS_INODE_NODUMP)
  84                 iflags |= FS_NODUMP_FL;
  85         if (flags & BTRFS_INODE_NOATIME)
  86                 iflags |= FS_NOATIME_FL;
  87         if (flags & BTRFS_INODE_DIRSYNC)
  88                 iflags |= FS_DIRSYNC_FL;
  89         if (flags & BTRFS_INODE_NODATACOW)
  90                 iflags |= FS_NOCOW_FL;
  91
  92         if ((flags & BTRFS_INODE_COMPRESS) && !(flags & BTRFS_INODE_NOCOMPRESS))
  93                 iflags |= FS_COMPR_FL;
  94         else if (flags & BTRFS_INODE_NOCOMPRESS)
  95                 iflags |= FS_NOCOMP_FL;
  96
  97         return iflags;
  98 }
  99
 100 /*
 101  * Update inode->i_flags based on the btrfs internal flags.
 102  */
 103 void btrfs_update_iflags(struct inode *inode)
 104 {
 105         struct btrfs_inode *ip = BTRFS_I(inode);
 106
 107         inode->i_flags &= ~(S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC);
 108
 109         if (ip->flags & BTRFS_INODE_SYNC)
 110                 inode->i_flags |= S_SYNC;
 111         if (ip->flags & BTRFS_INODE_IMMUTABLE)
 112                 inode->i_flags |= S_IMMUTABLE;
 113         if (ip->flags & BTRFS_INODE_APPEND)
 114                 inode->i_flags |= S_APPEND;
 115         if (ip->flags & BTRFS_INODE_NOATIME)
 116                 inode->i_flags |= S_NOATIME;
 117         if (ip->flags & BTRFS_INODE_DIRSYNC)
 118                 inode->i_flags |= S_DIRSYNC;
 119 }
 120
 121 /*
 122  * Inherit flags from the parent inode.
 123  *
 124  * Currently only the compression flags and the cow flags are inherited.
 125  */
 126 void btrfs_inherit_iflags(struct inode *inode, struct inode *dir)
 127 {
 128         unsigned int flags;
 129
 130         if (!dir)
 131                 return;
 132
 133         flags = BTRFS_I(dir)->flags;
 134
 135         if (flags & BTRFS_INODE_NOCOMPRESS) {
 136                 BTRFS_I(inode)->flags &= ~BTRFS_INODE_COMPRESS;
 137                 BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS;
 138         } else if (flags & BTRFS_INODE_COMPRESS) {
 139                 BTRFS_I(inode)->flags &= ~BTRFS_INODE_NOCOMPRESS;
 140                 BTRFS_I(inode)->flags |= BTRFS_INODE_COMPRESS;
 141         }
 142
 143         if (flags & BTRFS_INODE_NODATACOW)
 144                 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATACOW;
 145
 146         btrfs_update_iflags(inode);
 147 }
 148
 149 static int btrfs_ioctl_getflags(struct file *file, void __user *arg)
 150 {
 151         struct btrfs_inode *ip = BTRFS_I(file->f_path.dentry->d_inode);
 152         unsigned int flags = btrfs_flags_to_ioctl(ip->flags);
 153
 154         if (copy_to_user(arg, &flags, sizeof(flags)))
 155                 return -EFAULT;
 156         return 0;
 157 }
 158
 159 static int check_flags(unsigned int flags)
 160 {
 161         if (flags & ~(FS_IMMUTABLE_FL | FS_APPEND_FL | \
 162                       FS_NOATIME_FL | FS_NODUMP_FL | \
 163                       FS_SYNC_FL | FS_DIRSYNC_FL | \
 164                       FS_NOCOMP_FL | FS_COMPR_FL |
 165                       FS_NOCOW_FL))
 166                 return -EOPNOTSUPP;
 167
 168         if ((flags & FS_NOCOMP_FL) && (flags & FS_COMPR_FL))
 169                 return -EINVAL;
 170
 171         return 0;
 172 }
 173
 174 static int btrfs_ioctl_setflags(struct file *file, void __user *arg)
 175 {
 176         struct inode *inode = file->f_path.dentry->d_inode;
 177         struct btrfs_inode *ip = BTRFS_I(inode);
 178         struct btrfs_root *root = ip->root;
 179         struct btrfs_trans_handle *trans;
 180         unsigned int flags, oldflags;
 181         int ret;
 182         u64 ip_oldflags;
 183         unsigned int i_oldflags;
 184
 185         if (btrfs_root_readonly(root))
 186                 return -EROFS;
 187
 188         if (copy_from_user(&flags, arg, sizeof(flags)))
 189                 return -EFAULT;
 190
 191         ret = check_flags(flags);
 192         if (ret)
 193                 return ret;
 194
 195         if (!inode_owner_or_capable(inode))
 196                 return -EACCES;
 197
 198         ret = mnt_want_write_file(file);
 199         if (ret)
 200                 return ret;
 201
 202         mutex_lock(&inode->i_mutex);
 203
 204         ip_oldflags = ip->flags;
 205         i_oldflags = inode->i_flags;
 206
 207         flags = btrfs_mask_flags(inode->i_mode, flags);
 208         oldflags = btrfs_flags_to_ioctl(ip->flags);
 209         if ((flags ^ oldflags) & (FS_APPEND_FL | FS_IMMUTABLE_FL)) {
 210                 if (!capable(CAP_LINUX_IMMUTABLE)) {
 211                         ret = -EPERM;
 212                         goto out_unlock;
 213                 }
 214         }
 215
 216         if (flags & FS_SYNC_FL)
 217                 ip->flags |= BTRFS_INODE_SYNC;
 218         else
 219                 ip->flags &= ~BTRFS_INODE_SYNC;
 220         if (flags & FS_IMMUTABLE_FL)
 221                 ip->flags |= BTRFS_INODE_IMMUTABLE;
 222         else
 223                 ip->flags &= ~BTRFS_INODE_IMMUTABLE;
 224         if (flags & FS_APPEND_FL)
 225                 ip->flags |= BTRFS_INODE_APPEND;
 226         else
 227                 ip->flags &= ~BTRFS_INODE_APPEND;
 228         if (flags & FS_NODUMP_FL)
 229                 ip->flags |= BTRFS_INODE_NODUMP;
 230         else
 231                 ip->flags &= ~BTRFS_INODE_NODUMP;
 232         if (flags & FS_NOATIME_FL)
 233                 ip->flags |= BTRFS_INODE_NOATIME;
 234         else
 235                 ip->flags &= ~BTRFS_INODE_NOATIME;
 236         if (flags & FS_DIRSYNC_FL)
 237                 ip->flags |= BTRFS_INODE_DIRSYNC;
 238         else
 239                 ip->flags &= ~BTRFS_INODE_DIRSYNC;
 240         if (flags & FS_NOCOW_FL)
 241                 ip->flags |= BTRFS_INODE_NODATACOW;
 242         else
 243                 ip->flags &= ~BTRFS_INODE_NODATACOW;
 244
 245         /*
 246          * The COMPRESS flag can only be changed by users, while the NOCOMPRESS
 247          * flag may be changed automatically if compression code won't make
 248          * things smaller.
 249          */
 250         if (flags & FS_NOCOMP_FL) {
 251                 ip->flags &= ~BTRFS_INODE_COMPRESS;
 252                 ip->flags |= BTRFS_INODE_NOCOMPRESS;
 253         } else if (flags & FS_COMPR_FL) {
 254                 ip->flags |= BTRFS_INODE_COMPRESS;
 255                 ip->flags &= ~BTRFS_INODE_NOCOMPRESS;
 256         } else {
 257                 ip->flags &= ~(BTRFS_INODE_COMPRESS | BTRFS_INODE_NOCOMPRESS);
 258         }
 259
 260         trans = btrfs_start_transaction(root, 1);
 261         if (IS_ERR(trans)) {
 262                 ret = PTR_ERR(trans);
 263                 goto out_drop;
 264         }
 265
 266         btrfs_update_iflags(inode);
 267         inode_inc_iversion(inode);
 268         inode->i_ctime = CURRENT_TIME;
 269         ret = btrfs_update_inode(trans, root, inode);
 270
 271         btrfs_end_transaction(trans, root);
 272  out_drop:
 273         if (ret) {
 274                 ip->flags = ip_oldflags;
 275                 inode->i_flags = i_oldflags;
 276         }
 277
 278  out_unlock:
 279         mutex_unlock(&inode->i_mutex);
 280         mnt_drop_write_file(file);
 281         return ret;
 282 }
 283
 284 static int btrfs_ioctl_getversion(struct file *file, int __user *arg)
 285 {
 286         struct inode *inode = file->f_path.dentry->d_inode;
 287
 288         return put_user(inode->i_generation, arg);
 289 }
 290
 291 static noinline int btrfs_ioctl_fitrim(struct file *file, void __user *arg)
 292 {
 293         struct btrfs_fs_info *fs_info = btrfs_sb(fdentry(file)->d_sb);
 294         struct btrfs_device *device;
 295         struct request_queue *q;
 296         struct fstrim_range range;
 297         u64 minlen = ULLONG_MAX;
 298         u64 num_devices = 0;
 299         u64 total_bytes = btrfs_super_total_bytes(fs_info->super_copy);
 300         int ret;
 301
 302         if (!capable(CAP_SYS_ADMIN))
 303                 return -EPERM;
 304
 305         rcu_read_lock();
 306         list_for_each_entry_rcu(device, &fs_info->fs_devices->devices,
 307                                 dev_list) {
 308                 if (!device->bdev)
 309                         continue;
 310                 q = bdev_get_queue(device->bdev);
 311                 if (blk_queue_discard(q)) {
 312                         num_devices++;
 313                         minlen = min((u64)q->limits.discard_granularity,
 314                                      minlen);
 315                 }
 316         }
 317         rcu_read_unlock();
 318
 319         if (!num_devices)
 320                 return -EOPNOTSUPP;
 321         if (copy_from_user(&range, arg, sizeof(range)))
 322                 return -EFAULT;
 323         if (range.start > total_bytes)
 324                 return -EINVAL;
 325
 326         range.len = min(range.len, total_bytes - range.start);
 327         range.minlen = max(range.minlen, minlen);
 328         ret = btrfs_trim_fs(fs_info->tree_root, &range);
 329         if (ret < 0)
 330                 return ret;
 331
 332         if (copy_to_user(arg, &range, sizeof(range)))
 333                 return -EFAULT;
 334
 335         return 0;
 336 }
 337
 338 static noinline int create_subvol(struct btrfs_root *root,
 339                                   struct dentry *dentry,
 340                                   char *name, int namelen,
 341                                   u64 *async_transid,
 342                                   struct btrfs_qgroup_inherit **inherit)
 343 {
 344         struct btrfs_trans_handle *trans;
 345         struct btrfs_key key;
 346         struct btrfs_root_item root_item;
 347         struct btrfs_inode_item *inode_item;
 348         struct extent_buffer *leaf;
 349         struct btrfs_root *new_root;
 350         struct dentry *parent = dentry->d_parent;
 351         struct inode *dir;
 352         struct timespec cur_time = CURRENT_TIME;
 353         int ret;
 354         int err;
 355         u64 objectid;
 356         u64 new_dirid = BTRFS_FIRST_FREE_OBJECTID;
 357         u64 index = 0;
 358         uuid_le new_uuid;
 359
 360         ret = btrfs_find_free_objectid(root->fs_info->tree_root, &objectid);
 361         if (ret)
 362                 return ret;
 363
 364         dir = parent->d_inode;
 365
 366         /*
 367          * 1 - inode item
 368          * 2 - refs
 369          * 1 - root item
 370          * 2 - dir items
 371          */
 372         trans = btrfs_start_transaction(root, 6);
 373         if (IS_ERR(trans))
 374                 return PTR_ERR(trans);
 375
 376         ret = btrfs_qgroup_inherit(trans, root->fs_info, 0, objectid,
 377                                    inherit ? *inherit : NULL);
 378         if (ret)
 379                 goto fail;
 380
 381         leaf = btrfs_alloc_free_block(trans, root, root->leafsize,
 382                                       0, objectid, NULL, 0, 0, 0);
 383         if (IS_ERR(leaf)) {
 384                 ret = PTR_ERR(leaf);
 385                 goto fail;
 386         }
 387
 388         memset_extent_buffer(leaf, 0, 0, sizeof(struct btrfs_header));
 389         btrfs_set_header_bytenr(leaf, leaf->start);
 390         btrfs_set_header_generation(leaf, trans->transid);
 391         btrfs_set_header_backref_rev(leaf, BTRFS_MIXED_BACKREF_REV);
 392         btrfs_set_header_owner(leaf, objectid);
 393
 394         write_extent_buffer(leaf, root->fs_info->fsid,
 395                             (unsigned long)btrfs_header_fsid(leaf),
 396                             BTRFS_FSID_SIZE);
 397         write_extent_buffer(leaf, root->fs_info->chunk_tree_uuid,
 398                             (unsigned long)btrfs_header_chunk_tree_uuid(leaf),
 399                             BTRFS_UUID_SIZE);
 400         btrfs_mark_buffer_dirty(leaf);
 401
 402         memset(&root_item, 0, sizeof(root_item));
 403
 404         inode_item = &root_item.inode;
 405         inode_item->generation = cpu_to_le64(1);
 406         inode_item->size = cpu_to_le64(3);
 407         inode_item->nlink = cpu_to_le32(1);
 408         inode_item->nbytes = cpu_to_le64(root->leafsize);
 409         inode_item->mode = cpu_to_le32(S_IFDIR | 0755);
 410
 411         root_item.flags = 0;
 412         root_item.byte_limit = 0;
 413         inode_item->flags = cpu_to_le64(BTRFS_INODE_ROOT_ITEM_INIT);
 414
 415         btrfs_set_root_bytenr(&root_item, leaf->start);
 416         btrfs_set_root_generation(&root_item, trans->transid);
 417         btrfs_set_root_level(&root_item, 0);
 418         btrfs_set_root_refs(&root_item, 1);
 419         btrfs_set_root_used(&root_item, leaf->len);
 420         btrfs_set_root_last_snapshot(&root_item, 0);
 421
 422         btrfs_set_root_generation_v2(&root_item,
 423                         btrfs_root_generation(&root_item));
 424         uuid_le_gen(&new_uuid);
 425         memcpy(root_item.uuid, new_uuid.b, BTRFS_UUID_SIZE);
 426         root_item.otime.sec = cpu_to_le64(cur_time.tv_sec);
 427         root_item.otime.nsec = cpu_to_le64(cur_time.tv_nsec);
 428         root_item.ctime = root_item.otime;
 429         btrfs_set_root_ctransid(&root_item, trans->transid);
 430         btrfs_set_root_otransid(&root_item, trans->transid);
 431
 432         btrfs_tree_unlock(leaf);
 433         free_extent_buffer(leaf);
 434         leaf = NULL;
 435
 436         btrfs_set_root_dirid(&root_item, new_dirid);
 437
 438         key.objectid = objectid;
 439         key.offset = 0;
 440         btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
 441         ret = btrfs_insert_root(trans, root->fs_info->tree_root, &key,
 442                                 &root_item);
 443         if (ret)
 444                 goto fail;
 445
 446         key.offset = (u64)-1;
 447         new_root = btrfs_read_fs_root_no_name(root->fs_info, &key);
 448         if (IS_ERR(new_root)) {
 449                 btrfs_abort_transaction(trans, root, PTR_ERR(new_root));
 450                 ret = PTR_ERR(new_root);
 451                 goto fail;
 452         }
 453
 454         btrfs_record_root_in_trans(trans, new_root);
 455
 456         ret = btrfs_create_subvol_root(trans, new_root, new_dirid);
 457         if (ret) {
 458                 /* We potentially lose an unused inode item here */
 459                 btrfs_abort_transaction(trans, root, ret);
 460                 goto fail;
 461         }
 462
 463         /*
 464          * insert the directory item
 465          */
 466         ret = btrfs_set_inode_index(dir, &index);
 467         if (ret) {
 468                 btrfs_abort_transaction(trans, root, ret);
 469                 goto fail;
 470         }
 471
 472         ret = btrfs_insert_dir_item(trans, root,
 473                                     name, namelen, dir, &key,
 474                                     BTRFS_FT_DIR, index);
 475         if (ret) {
 476                 btrfs_abort_transaction(trans, root, ret);
 477                 goto fail;
 478         }
 479
 480         btrfs_i_size_write(dir, dir->i_size + namelen * 2);
 481         ret = btrfs_update_inode(trans, root, dir);
 482         BUG_ON(ret);
 483
 484         ret = btrfs_add_root_ref(trans, root->fs_info->tree_root,
 485                                  objectid, root->root_key.objectid,
 486                                  btrfs_ino(dir), index, name, namelen);
 487
 488         BUG_ON(ret);
 489
 490         d_instantiate(dentry, btrfs_lookup_dentry(dir, dentry));
 491 fail:
 492         if (async_transid) {
 493                 *async_transid = trans->transid;
 494                 err = btrfs_commit_transaction_async(trans, root, 1);
 495         } else {
 496                 err = btrfs_commit_transaction(trans, root);
 497         }
 498         if (err && !ret)
 499                 ret = err;
 500         return ret;
 501 }
 502
 503 static int create_snapshot(struct btrfs_root *root, struct dentry *dentry,
 504                            char *name, int namelen, u64 *async_transid,
 505                            bool readonly, struct btrfs_qgroup_inherit **inherit)
 506 {
 507         struct inode *inode;
 508         struct btrfs_pending_snapshot *pending_snapshot;
 509         struct btrfs_trans_handle *trans;
 510         int ret;
 511
 512         if (!root->ref_cows)
 513                 return -EINVAL;
 514
 515         pending_snapshot = kzalloc(sizeof(*pending_snapshot), GFP_NOFS);
 516         if (!pending_snapshot)
 517                 return -ENOMEM;
 518
 519         btrfs_init_block_rsv(&pending_snapshot->block_rsv);
 520         pending_snapshot->dentry = dentry;
 521         pending_snapshot->root = root;
 522         pending_snapshot->readonly = readonly;
 523         if (inherit) {
 524                 pending_snapshot->inherit = *inherit;
 525                 *inherit = NULL;        /* take responsibility to free it */
 526         }
 527
 528         trans = btrfs_start_transaction(root->fs_info->extent_root, 5);
 529         if (IS_ERR(trans)) {
 530                 ret = PTR_ERR(trans);
 531                 goto fail;
 532         }
 533
 534         ret = btrfs_snap_reserve_metadata(trans, pending_snapshot);
 535         BUG_ON(ret);
 536
 537         spin_lock(&root->fs_info->trans_lock);
 538         list_add(&pending_snapshot->list,
 539                  &trans->transaction->pending_snapshots);
 540         spin_unlock(&root->fs_info->trans_lock);
 541         if (async_transid) {
 542                 *async_transid = trans->transid;
 543                 ret = btrfs_commit_transaction_async(trans,
 544                                      root->fs_info->extent_root, 1);
 545         } else {
 546                 ret = btrfs_commit_transaction(trans,
 547                                                root->fs_info->extent_root);
 548         }
 549         BUG_ON(ret);
 550
 551         ret = pending_snapshot->error;
 552         if (ret)
 553                 goto fail;
 554
 555         ret = btrfs_orphan_cleanup(pending_snapshot->snap);
 556         if (ret)
 557                 goto fail;
 558
 559         inode = btrfs_lookup_dentry(dentry->d_parent->d_inode, dentry);
 560         if (IS_ERR(inode)) {
 561                 ret = PTR_ERR(inode);
 562                 goto fail;
 563         }
 564         BUG_ON(!inode);
 565         d_instantiate(dentry, inode);
 566         ret = 0;
 567 fail:
 568         kfree(pending_snapshot);
 569         return ret;
 570 }
 571
 572 /*  copy of check_sticky in fs/namei.c()
 573 * It's inline, so penalty for filesystems that don't use sticky bit is
 574 * minimal.
 575 */
 576 static inline int btrfs_check_sticky(struct inode *dir, struct inode *inode)
 577 {
 578         uid_t fsuid = current_fsuid();
 579
 580         if (!(dir->i_mode & S_ISVTX))
 581                 return 0;
 582         if (inode->i_uid == fsuid)
 583                 return 0;
 584         if (dir->i_uid == fsuid)
 585                 return 0;
 586         return !capable(CAP_FOWNER);
 587 }
 588
 589 /*  copy of may_delete in fs/namei.c()
 590  *      Check whether we can remove a link victim from directory dir, check
 591  *  whether the type of victim is right.
 592  *  1. We can't do it if dir is read-only (done in permission())
 593  *  2. We should have write and exec permissions on dir
 594  *  3. We can't remove anything from append-only dir
 595  *  4. We can't do anything with immutable dir (done in permission())
 596  *  5. If the sticky bit on dir is set we should either
 597  *      a. be owner of dir, or
 598  *      b. be owner of victim, or
 599  *      c. have CAP_FOWNER capability
 600  *  6. If the victim is append-only or immutable we can't do antyhing with
 601  *     links pointing to it.
 602  *  7. If we were asked to remove a directory and victim isn't one - ENOTDIR.
 603  *  8. If we were asked to remove a non-directory and victim isn't one - EISDIR.
 604  *  9. We can't remove a root or mountpoint.
 605  * 10. We don't allow removal of NFS sillyrenamed files; it's handled by
 606  *     nfs_async_unlink().
 607  */
 608
 609 static int btrfs_may_delete(struct inode *dir,struct dentry *victim,int isdir)
 610 {
 611         int error;
 612
 613         if (!victim->d_inode)
 614                 return -ENOENT;
 615
 616         BUG_ON(victim->d_parent->d_inode != dir);
 617         audit_inode_child(victim, dir);
 618
 619         error = inode_permission(dir, MAY_WRITE | MAY_EXEC);
 620         if (error)
 621                 return error;
 622         if (IS_APPEND(dir))
 623                 return -EPERM;
 624         if (btrfs_check_sticky(dir, victim->d_inode)||
 625                 IS_APPEND(victim->d_inode)||
 626             IS_IMMUTABLE(victim->d_inode) || IS_SWAPFILE(victim->d_inode))
 627                 return -EPERM;
 628         if (isdir) {
 629                 if (!S_ISDIR(victim->d_inode->i_mode))
 630                         return -ENOTDIR;
 631                 if (IS_ROOT(victim))
 632                         return -EBUSY;
 633         } else if (S_ISDIR(victim->d_inode->i_mode))
 634                 return -EISDIR;
 635         if (IS_DEADDIR(dir))
 636                 return -ENOENT;
 637         if (victim->d_flags & DCACHE_NFSFS_RENAMED)
 638                 return -EBUSY;
 639         return 0;
 640 }
 641
 642 /* copy of may_create in fs/namei.c() */
 643 static inline int btrfs_may_create(struct inode *dir, struct dentry *child)
 644 {
 645         if (child->d_inode)
 646                 return -EEXIST;
 647         if (IS_DEADDIR(dir))
 648                 return -ENOENT;
 649         return inode_permission(dir, MAY_WRITE | MAY_EXEC);
 650 }
 651
 652 /*
 653  * Create a new subvolume below @parent.  This is largely modeled after
 654  * sys_mkdirat and vfs_mkdir, but we only do a single component lookup
 655  * inside this filesystem so it's quite a bit simpler.
 656  */
 657 static noinline int btrfs_mksubvol(struct path *parent,
 658                                    char *name, int namelen,
 659                                    struct btrfs_root *snap_src,
 660                                    u64 *async_transid, bool readonly,
 661                                    struct btrfs_qgroup_inherit **inherit)
 662 {
 663         struct inode *dir  = parent->dentry->d_inode;
 664         struct dentry *dentry;
 665         int error;
 666
 667         mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
 668
 669         dentry = lookup_one_len(name, parent->dentry, namelen);
 670         error = PTR_ERR(dentry);
 671         if (IS_ERR(dentry))
 672                 goto out_unlock;
 673
 674         error = -EEXIST;
 675         if (dentry->d_inode)
 676                 goto out_dput;
 677
 678         error = btrfs_may_create(dir, dentry);
 679         if (error)
 680                 goto out_dput;
 681
 682         down_read(&BTRFS_I(dir)->root->fs_info->subvol_sem);
 683
 684         if (btrfs_root_refs(&BTRFS_I(dir)->root->root_item) == 0)
 685                 goto out_up_read;
 686
 687         if (snap_src) {
 688                 error = create_snapshot(snap_src, dentry, name, namelen,
 689                                         async_transid, readonly, inherit);
 690         } else {
 691                 error = create_subvol(BTRFS_I(dir)->root, dentry,
 692                                       name, namelen, async_transid, inherit);
 693         }
 694         if (!error)
 695                 fsnotify_mkdir(dir, dentry);
 696 out_up_read:
 697         up_read(&BTRFS_I(dir)->root->fs_info->subvol_sem);
 698 out_dput:
 699         dput(dentry);
 700 out_unlock:
 701         mutex_unlock(&dir->i_mutex);
 702         return error;
 703 }
 704
 705 /*
 706  * When we're defragging a range, we don't want to kick it off again
 707  * if it is really just waiting for delalloc to send it down.
 708  * If we find a nice big extent or delalloc range for the bytes in the
 709  * file you want to defrag, we return 0 to let you know to skip this
 710  * part of the file
 711  */
 712 static int check_defrag_in_cache(struct inode *inode, u64 offset, int thresh)
 713 {
 714         struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
 715         struct extent_map *em = NULL;
 716         struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
 717         u64 end;
 718
 719         read_lock(&em_tree->lock);
 720         em = lookup_extent_mapping(em_tree, offset, PAGE_CACHE_SIZE);
 721         read_unlock(&em_tree->lock);
 722
 723         if (em) {
 724                 end = extent_map_end(em);
 725                 free_extent_map(em);
 726                 if (end - offset > thresh)
 727                         return 0;
 728         }
 729         /* if we already have a nice delalloc here, just stop */
 730         thresh /= 2;
 731         end = count_range_bits(io_tree, &offset, offset + thresh,
 732                                thresh, EXTENT_DELALLOC, 1);
 733         if (end >= thresh)
 734                 return 0;
 735         return 1;
 736 }
 737
 738 /*
 739  * helper function to walk through a file and find extents
 740  * newer than a specific transid, and smaller than thresh.
 741  *
 742  * This is used by the defragging code to find new and small
 743  * extents
 744  */
 745 static int find_new_extents(struct btrfs_root *root,
 746                             struct inode *inode, u64 newer_than,
 747                             u64 *off, int thresh)
 748 {
 749         struct btrfs_path *path;
 750         struct btrfs_key min_key;
 751         struct btrfs_key max_key;
 752         struct extent_buffer *leaf;
 753         struct btrfs_file_extent_item *extent;
 754         int type;
 755         int ret;
 756         u64 ino = btrfs_ino(inode);
 757
 758         path = btrfs_alloc_path();
 759         if (!path)
 760                 return -ENOMEM;
 761
 762         min_key.objectid = ino;
 763         min_key.type = BTRFS_EXTENT_DATA_KEY;
 764         min_key.offset = *off;
 765
 766         max_key.objectid = ino;
 767         max_key.type = (u8)-1;
 768         max_key.offset = (u64)-1;
 769
 770         path->keep_locks = 1;
 771
 772         while(1) {
 773                 ret = btrfs_search_forward(root, &min_key, &max_key,
 774                                            path, 0, newer_than);
 775                 if (ret != 0)
 776                         goto none;
 777                 if (min_key.objectid != ino)
 778                         goto none;
 779                 if (min_key.type != BTRFS_EXTENT_DATA_KEY)
 780                         goto none;
 781
 782                 leaf = path->nodes[0];
 783                 extent = btrfs_item_ptr(leaf, path->slots[0],
 784                                         struct btrfs_file_extent_item);
 785
 786                 type = btrfs_file_extent_type(leaf, extent);
 787                 if (type == BTRFS_FILE_EXTENT_REG &&
 788                     btrfs_file_extent_num_bytes(leaf, extent) < thresh &&
 789                     check_defrag_in_cache(inode, min_key.offset, thresh)) {
 790                         *off = min_key.offset;
 791                         btrfs_free_path(path);
 792                         return 0;
 793                 }
 794
 795                 if (min_key.offset == (u64)-1)
 796                         goto none;
 797
 798                 min_key.offset++;
 799                 btrfs_release_path(path);
 800         }
 801 none:
 802         btrfs_free_path(path);
 803         return -ENOENT;
 804 }
 805
 806 static struct extent_map *defrag_lookup_extent(struct inode *inode, u64 start)
 807 {
 808         struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
 809         struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
 810         struct extent_map *em;
 811         u64 len = PAGE_CACHE_SIZE;
 812
 813         /*
 814          * hopefully we have this extent in the tree already, try without
 815          * the full extent lock
 816          */
 817         read_lock(&em_tree->lock);
 818         em = lookup_extent_mapping(em_tree, start, len);
 819         read_unlock(&em_tree->lock);
 820
 821         if (!em) {
 822                 /* get the big lock and read metadata off disk */
 823                 lock_extent(io_tree, start, start + len - 1);
 824                 em = btrfs_get_extent(inode, NULL, 0, start, len, 0);
 825                 unlock_extent(io_tree, start, start + len - 1);
 826
 827                 if (IS_ERR(em))
 828                         return NULL;
 829         }
 830
 831         return em;
 832 }
 833
 834 static bool defrag_check_next_extent(struct inode *inode, struct extent_map *em)
 835 {
 836         struct extent_map *next;
 837         bool ret = true;
 838
 839         /* this is the last extent */
 840         if (em->start + em->len >= i_size_read(inode))
 841                 return false;
 842
 843         next = defrag_lookup_extent(inode, em->start + em->len);
 844         if (!next || next->block_start >= EXTENT_MAP_LAST_BYTE)
 845                 ret = false;
 846
 847         free_extent_map(next);
 848         return ret;
 849 }
 850
 851 static int should_defrag_range(struct inode *inode, u64 start, int thresh,
 852                                u64 *last_len, u64 *skip, u64 *defrag_end,
 853                                int compress)
 854 {
 855         struct extent_map *em;
 856         int ret = 1;
 857         bool next_mergeable = true;
 858
 859         /*
 860          * make sure that once we start defragging an extent, we keep on
 861          * defragging it
 862          */
 863         if (start < *defrag_end)
 864                 return 1;
 865
 866         *skip = 0;
 867
 868         em = defrag_lookup_extent(inode, start);
 869         if (!em)
 870                 return 0;
 871
 872         /* this will cover holes, and inline extents */
 873         if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
 874                 ret = 0;
 875                 goto out;
 876         }
 877
 878         next_mergeable = defrag_check_next_extent(inode, em);
 879
 880         /*
 881          * we hit a real extent, if it is big or the next extent is not a
 882          * real extent, don't bother defragging it
 883          */
 884         if (!compress && (*last_len == 0 || *last_len >= thresh) &&
 885             (em->len >= thresh || !next_mergeable))
 886                 ret = 0;
 887 out:
 888         /*
 889          * last_len ends up being a counter of how many bytes we've defragged.
 890          * every time we choose not to defrag an extent, we reset *last_len
 891          * so that the next tiny extent will force a defrag.
 892          *
 893          * The end result of this is that tiny extents before a single big
 894          * extent will force at least part of that big extent to be defragged.
 895          */
 896         if (ret) {
 897                 *defrag_end = extent_map_end(em);
 898         } else {
 899                 *last_len = 0;
 900                 *skip = extent_map_end(em);
 901                 *defrag_end = 0;
 902         }
 903
 904         free_extent_map(em);
 905         return ret;
 906 }
 907
 908 /*
 909  * it doesn't do much good to defrag one or two pages
 910  * at a time.  This pulls in a nice chunk of pages
 911  * to COW and defrag.
 912  *
 913  * It also makes sure the delalloc code has enough
 914  * dirty data to avoid making new small extents as part
 915  * of the defrag
 916  *
 917  * It's a good idea to start RA on this range
 918  * before calling this.
 919  */
 920 static int cluster_pages_for_defrag(struct inode *inode,
 921                                     struct page **pages,
 922                                     unsigned long start_index,
 923                                     int num_pages)
 924 {
 925         unsigned long file_end;
 926         u64 isize = i_size_read(inode);
 927         u64 page_start;
 928         u64 page_end;
 929         u64 page_cnt;
 930         int ret;
 931         int i;
 932         int i_done;
 933         struct btrfs_ordered_extent *ordered;
 934         struct extent_state *cached_state = NULL;
 935         struct extent_io_tree *tree;
 936         gfp_t mask = btrfs_alloc_write_mask(inode->i_mapping);
 937
 938         file_end = (isize - 1) >> PAGE_CACHE_SHIFT;
 939         if (!isize || start_index > file_end)
 940                 return 0;
 941
 942         page_cnt = min_t(u64, (u64)num_pages, (u64)file_end - start_index + 1);
 943
 944         ret = btrfs_delalloc_reserve_space(inode,
 945                                            page_cnt << PAGE_CACHE_SHIFT);
 946         if (ret)
 947                 return ret;
 948         i_done = 0;
 949         tree = &BTRFS_I(inode)->io_tree;
 950
 951         /* step one, lock all the pages */
 952         for (i = 0; i < page_cnt; i++) {
 953                 struct page *page;
 954 again:
 955                 page = find_or_create_page(inode->i_mapping,
 956                                            start_index + i, mask);
 957                 if (!page)
 958                         break;
 959
 960                 page_start = page_offset(page);
 961                 page_end = page_start + PAGE_CACHE_SIZE - 1;
 962                 while (1) {
 963                         lock_extent(tree, page_start, page_end);
 964                         ordered = btrfs_lookup_ordered_extent(inode,
 965                                                               page_start);
 966                         unlock_extent(tree, page_start, page_end);
 967                         if (!ordered)
 968                                 break;
 969
 970                         unlock_page(page);
 971                         btrfs_start_ordered_extent(inode, ordered, 1);
 972                         btrfs_put_ordered_extent(ordered);
 973                         lock_page(page);
 974                         /*
 975                          * we unlocked the page above, so we need check if
 976                          * it was released or not.
 977                          */
 978                         if (page->mapping != inode->i_mapping) {
 979                                 unlock_page(page);
 980                                 page_cache_release(page);
 981                                 goto again;
 982                         }
 983                 }
 984
 985                 if (!PageUptodate(page)) {
 986                         btrfs_readpage(NULL, page);
 987                         lock_page(page);
 988                         if (!PageUptodate(page)) {
 989                                 unlock_page(page);
 990                                 page_cache_release(page);
 991                                 ret = -EIO;
 992                                 break;
 993                         }
 994                 }
 995
 996                 if (page->mapping != inode->i_mapping) {
 997                         unlock_page(page);
 998                         page_cache_release(page);
 999                         goto again;
1000                 }
1001
1002                 pages[i] = page;
1003                 i_done++;
1004         }
1005         if (!i_done || ret)
1006                 goto out;
1007
1008         if (!(inode->i_sb->s_flags & MS_ACTIVE))
1009                 goto out;
1010
1011         /*
1012          * so now we have a nice long stream of locked
1013          * and up to date pages, lets wait on them
1014          */
1015         for (i = 0; i < i_done; i++)
1016                 wait_on_page_writeback(pages[i]);
1017
1018         page_start = page_offset(pages[0]);
1019         page_end = page_offset(pages[i_done - 1]) + PAGE_CACHE_SIZE;
1020
1021         lock_extent_bits(&BTRFS_I(inode)->io_tree,
1022                          page_start, page_end - 1, 0, &cached_state);
1023         clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start,
1024                           page_end - 1, EXTENT_DIRTY | EXTENT_DELALLOC |
1025                           EXTENT_DO_ACCOUNTING, 0, 0, &cached_state,
1026                           GFP_NOFS);
1027
1028         if (i_done != page_cnt) {
1029                 spin_lock(&BTRFS_I(inode)->lock);
1030                 BTRFS_I(inode)->outstanding_extents++;
1031                 spin_unlock(&BTRFS_I(inode)->lock);
1032                 btrfs_delalloc_release_space(inode,
1033                                      (page_cnt - i_done) << PAGE_CACHE_SHIFT);
1034         }
1035
1036
1037         btrfs_set_extent_delalloc(inode, page_start, page_end - 1,
1038                                   &cached_state);
1039
1040         unlock_extent_cached(&BTRFS_I(inode)->io_tree,
1041                              page_start, page_end - 1, &cached_state,
1042                              GFP_NOFS);
1043
1044         for (i = 0; i < i_done; i++) {
1045                 clear_page_dirty_for_io(pages[i]);
1046                 ClearPageChecked(pages[i]);
1047                 set_page_extent_mapped(pages[i]);
1048                 set_page_dirty(pages[i]);
1049                 unlock_page(pages[i]);
1050                 page_cache_release(pages[i]);
1051         }
1052         return i_done;
1053 out:
1054         for (i = 0; i < i_done; i++) {
1055                 unlock_page(pages[i]);
1056                 page_cache_release(pages[i]);
1057         }
1058         btrfs_delalloc_release_space(inode, page_cnt << PAGE_CACHE_SHIFT);
1059         return ret;
1060
1061 }
1062
1063 int btrfs_defrag_file(struct inode *inode, struct file *file,
1064                       struct btrfs_ioctl_defrag_range_args *range,
1065                       u64 newer_than, unsigned long max_to_defrag)
1066 {
1067         struct btrfs_root *root = BTRFS_I(inode)->root;
1068         struct file_ra_state *ra = NULL;
1069         unsigned long last_index;
1070         u64 isize = i_size_read(inode);
1071         u64 last_len = 0;
1072         u64 skip = 0;
1073         u64 defrag_end = 0;
1074         u64 newer_off = range->start;
1075         unsigned long i;
1076         unsigned long ra_index = 0;
1077         int ret;
1078         int defrag_count = 0;
1079         int compress_type = BTRFS_COMPRESS_ZLIB;
1080         int extent_thresh = range->extent_thresh;
1081         int max_cluster = (256 * 1024) >> PAGE_CACHE_SHIFT;
1082         int cluster = max_cluster;
1083         u64 new_align = ~((u64)128 * 1024 - 1);
1084         struct page **pages = NULL;
1085
1086         if (extent_thresh == 0)
1087                 extent_thresh = 256 * 1024;
1088
1089         if (range->flags & BTRFS_DEFRAG_RANGE_COMPRESS) {
1090                 if (range->compress_type > BTRFS_COMPRESS_TYPES)
1091                         return -EINVAL;
1092                 if (range->compress_type)
1093                         compress_type = range->compress_type;
1094         }
1095
1096         if (isize == 0)
1097                 return 0;
1098
1099         /*
1100          * if we were not given a file, allocate a readahead
1101          * context
1102          */
1103         if (!file) {
1104                 ra = kzalloc(sizeof(*ra), GFP_NOFS);
1105                 if (!ra)
1106                         return -ENOMEM;
1107                 file_ra_state_init(ra, inode->i_mapping);
1108         } else {
1109                 ra = &file->f_ra;
1110         }
1111
1112         pages = kmalloc(sizeof(struct page *) * max_cluster,
1113                         GFP_NOFS);
1114         if (!pages) {
1115                 ret = -ENOMEM;
1116                 goto out_ra;
1117         }
1118
1119         /* find the last page to defrag */
1120         if (range->start + range->len > range->start) {
1121                 last_index = min_t(u64, isize - 1,
1122                          range->start + range->len - 1) >> PAGE_CACHE_SHIFT;
1123         } else {
1124                 last_index = (isize - 1) >> PAGE_CACHE_SHIFT;
1125         }
1126
1127         if (newer_than) {
1128                 ret = find_new_extents(root, inode, newer_than,
1129                                        &newer_off, 64 * 1024);
1130                 if (!ret) {
1131                         range->start = newer_off;
1132                         /*
1133                          * we always align our defrag to help keep
1134                          * the extents in the file evenly spaced
1135                          */
1136                         i = (newer_off & new_align) >> PAGE_CACHE_SHIFT;
1137                 } else
1138                         goto out_ra;
1139         } else {
1140                 i = range->start >> PAGE_CACHE_SHIFT;
1141         }
1142         if (!max_to_defrag)
1143                 max_to_defrag = last_index + 1;
1144
1145         /*
1146          * make writeback starts from i, so the defrag range can be
1147          * written sequentially.
1148          */
1149         if (i < inode->i_mapping->writeback_index)
1150                 inode->i_mapping->writeback_index = i;
1151
1152         while (i <= last_index && defrag_count < max_to_defrag &&
1153                (i < (i_size_read(inode) + PAGE_CACHE_SIZE - 1) >>
1154                 PAGE_CACHE_SHIFT)) {
1155                 /*
1156                  * make sure we stop running if someone unmounts
1157                  * the FS
1158                  */
1159                 if (!(inode->i_sb->s_flags & MS_ACTIVE))
1160                         break;
1161
1162                 if (!should_defrag_range(inode, (u64)i << PAGE_CACHE_SHIFT,
1163                                          extent_thresh, &last_len, &skip,
1164                                          &defrag_end, range->flags &
1165                                          BTRFS_DEFRAG_RANGE_COMPRESS)) {
1166                         unsigned long next;
1167                         /*
1168                          * the should_defrag function tells us how much to skip
1169                          * bump our counter by the suggested amount
1170                          */
1171                         next = (skip + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
1172                         i = max(i + 1, next);
1173                         continue;
1174                 }
1175
1176                 if (!newer_than) {
1177                         cluster = (PAGE_CACHE_ALIGN(defrag_end) >>
1178                                    PAGE_CACHE_SHIFT) - i;
1179                         cluster = min(cluster, max_cluster);
1180                 } else {
1181                         cluster = max_cluster;
1182                 }
1183
1184                 if (range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)
1185                         BTRFS_I(inode)->force_compress = compress_type;
1186
1187                 if (i + cluster > ra_index) {
1188                         ra_index = max(i, ra_index);
1189                         btrfs_force_ra(inode->i_mapping, ra, file, ra_index,
1190                                        cluster);
1191                         ra_index += max_cluster;
1192                 }
1193
1194                 mutex_lock(&inode->i_mutex);
1195                 ret = cluster_pages_for_defrag(inode, pages, i, cluster);
1196                 if (ret < 0) {
1197                         mutex_unlock(&inode->i_mutex);
1198                         goto out_ra;
1199                 }
1200
1201                 defrag_count += ret;
1202                 balance_dirty_pages_ratelimited_nr(inode->i_mapping, ret);
1203                 mutex_unlock(&inode->i_mutex);
1204
1205                 if (newer_than) {
1206                         if (newer_off == (u64)-1)
1207                                 break;
1208
1209                         if (ret > 0)
1210                                 i += ret;
1211
1212                         newer_off = max(newer_off + 1,
1213                                         (u64)i << PAGE_CACHE_SHIFT);
1214
1215                         ret = find_new_extents(root, inode,
1216                                                newer_than, &newer_off,
1217                                                64 * 1024);
1218                         if (!ret) {
1219                                 range->start = newer_off;
1220                                 i = (newer_off & new_align) >> PAGE_CACHE_SHIFT;
1221                         } else {
1222                                 break;
1223                         }
1224                 } else {
1225                         if (ret > 0) {
1226                                 i += ret;
1227                                 last_len += ret << PAGE_CACHE_SHIFT;
1228                         } else {
1229                                 i++;
1230                                 last_len = 0;
1231                         }
1232                 }
1233         }
1234
1235         if ((range->flags & BTRFS_DEFRAG_RANGE_START_IO))
1236                 filemap_flush(inode->i_mapping);
1237
1238         if ((range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)) {
1239                 /* the filemap_flush will queue IO into the worker threads, but
1240                  * we have to make sure the IO is actually started and that
1241                  * ordered extents get created before we return
1242                  */
1243                 atomic_inc(&root->fs_info->async_submit_draining);
1244                 while (atomic_read(&root->fs_info->nr_async_submits) ||
1245                       atomic_read(&root->fs_info->async_delalloc_pages)) {
1246                         wait_event(root->fs_info->async_submit_wait,
1247                            (atomic_read(&root->fs_info->nr_async_submits) == 0 &&
1248                             atomic_read(&root->fs_info->async_delalloc_pages) == 0));
1249                 }
1250                 atomic_dec(&root->fs_info->async_submit_draining);
1251
1252                 mutex_lock(&inode->i_mutex);
1253                 BTRFS_I(inode)->force_compress = BTRFS_COMPRESS_NONE;
1254                 mutex_unlock(&inode->i_mutex);
1255         }
1256
1257         if (range->compress_type == BTRFS_COMPRESS_LZO) {
1258                 btrfs_set_fs_incompat(root->fs_info, COMPRESS_LZO);
1259         }
1260
1261         ret = defrag_count;
1262
1263 out_ra:
1264         if (!file)
1265                 kfree(ra);
1266         kfree(pages);
1267         return ret;
1268 }
1269
1270 static noinline int btrfs_ioctl_resize(struct btrfs_root *root,
1271                                         void __user *arg)
1272 {
1273         u64 new_size;
1274         u64 old_size;
1275         u64 devid = 1;
1276         struct btrfs_ioctl_vol_args *vol_args;
1277         struct btrfs_trans_handle *trans;
1278         struct btrfs_device *device = NULL;
1279         char *sizestr;
1280         char *devstr = NULL;
1281         int ret = 0;
1282         int mod = 0;
1283
1284         if (root->fs_info->sb->s_flags & MS_RDONLY)
1285                 return -EROFS;
1286
1287         if (!capable(CAP_SYS_ADMIN))
1288                 return -EPERM;
1289
1290         mutex_lock(&root->fs_info->volume_mutex);
1291         if (root->fs_info->balance_ctl) {
1292                 printk(KERN_INFO "btrfs: balance in progress\n");
1293                 ret = -EINVAL;
1294                 goto out;
1295         }
1296
1297         vol_args = memdup_user(arg, sizeof(*vol_args));
1298         if (IS_ERR(vol_args)) {
1299                 ret = PTR_ERR(vol_args);
1300                 goto out;
1301         }
1302
1303         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1304
1305         sizestr = vol_args->name;
1306         devstr = strchr(sizestr, ':');
1307         if (devstr) {
1308                 char *end;
1309                 sizestr = devstr + 1;
1310                 *devstr = '\0';
1311                 devstr = vol_args->name;
1312                 devid = simple_strtoull(devstr, &end, 10);
1313                 printk(KERN_INFO "btrfs: resizing devid %llu\n",
1314                        (unsigned long long)devid);
1315         }
1316         device = btrfs_find_device(root, devid, NULL, NULL);
1317         if (!device) {
1318                 printk(KERN_INFO "btrfs: resizer unable to find device %llu\n",
1319                        (unsigned long long)devid);
1320                 ret = -EINVAL;
1321                 goto out_free;
1322         }
1323         if (device->fs_devices && device->fs_devices->seeding) {
1324                 printk(KERN_INFO "btrfs: resizer unable to apply on "
1325                        "seeding device %llu\n",
1326                        (unsigned long long)devid);
1327                 ret = -EINVAL;
1328                 goto out_free;
1329         }
1330
1331         if (!strcmp(sizestr, "max"))
1332                 new_size = device->bdev->bd_inode->i_size;
1333         else {
1334                 if (sizestr[0] == '-') {
1335                         mod = -1;
1336                         sizestr++;
1337                 } else if (sizestr[0] == '+') {
1338                         mod = 1;
1339                         sizestr++;
1340                 }
1341                 new_size = memparse(sizestr, NULL);
1342                 if (new_size == 0) {
1343                         ret = -EINVAL;
1344                         goto out_free;
1345                 }
1346         }
1347
1348         old_size = device->total_bytes;
1349
1350         if (mod < 0) {
1351                 if (new_size > old_size) {
1352                         ret = -EINVAL;
1353                         goto out_free;
1354                 }
1355                 new_size = old_size - new_size;
1356         } else if (mod > 0) {
1357                 new_size = old_size + new_size;
1358         }
1359
1360         if (new_size < 256 * 1024 * 1024) {
1361                 ret = -EINVAL;
1362                 goto out_free;
1363         }
1364         if (new_size > device->bdev->bd_inode->i_size) {
1365                 ret = -EFBIG;
1366                 goto out_free;
1367         }
1368
1369         do_div(new_size, root->sectorsize);
1370         new_size *= root->sectorsize;
1371
1372         printk_in_rcu(KERN_INFO "btrfs: new size for %s is %llu\n",
1373                       rcu_str_deref(device->name),
1374                       (unsigned long long)new_size);
1375
1376         if (new_size > old_size) {
1377                 trans = btrfs_start_transaction(root, 0);
1378                 if (IS_ERR(trans)) {
1379                         ret = PTR_ERR(trans);
1380                         goto out_free;
1381                 }
1382                 ret = btrfs_grow_device(trans, device, new_size);
1383                 btrfs_commit_transaction(trans, root);
1384         } else if (new_size < old_size) {
1385                 ret = btrfs_shrink_device(device, new_size);
1386         }
1387
1388 out_free:
1389         kfree(vol_args);
1390 out:
1391         mutex_unlock(&root->fs_info->volume_mutex);
1392         return ret;
1393 }
1394
1395 static noinline int btrfs_ioctl_snap_create_transid(struct file *file,
1396                                 char *name, unsigned long fd, int subvol,
1397                                 u64 *transid, bool readonly,
1398                                 struct btrfs_qgroup_inherit **inherit)
1399 {
1400         struct file *src_file;
1401         int namelen;
1402         int ret = 0;
1403
1404         ret = mnt_want_write_file(file);
1405         if (ret)
1406                 goto out;
1407
1408         namelen = strlen(name);
1409         if (strchr(name, '/')) {
1410                 ret = -EINVAL;
1411                 goto out_drop_write;
1412         }
1413
1414         if (name[0] == '.' &&
1415            (namelen == 1 || (name[1] == '.' && namelen == 2))) {
1416                 ret = -EEXIST;
1417                 goto out_drop_write;
1418         }
1419
1420         if (subvol) {
1421                 ret = btrfs_mksubvol(&file->f_path, name, namelen,
1422                                      NULL, transid, readonly, inherit);
1423         } else {
1424                 struct inode *src_inode;
1425                 src_file = fget(fd);
1426                 if (!src_file) {
1427                         ret = -EINVAL;
1428                         goto out_drop_write;
1429                 }
1430
1431                 src_inode = src_file->f_path.dentry->d_inode;
1432                 if (src_inode->i_sb != file->f_path.dentry->d_inode->i_sb) {
1433                         printk(KERN_INFO "btrfs: Snapshot src from "
1434                                "another FS\n");
1435                         ret = -EINVAL;
1436                         fput(src_file);
1437                         goto out_drop_write;
1438                 }
1439                 ret = btrfs_mksubvol(&file->f_path, name, namelen,
1440                                      BTRFS_I(src_inode)->root,
1441                                      transid, readonly, inherit);
1442                 fput(src_file);
1443         }
1444 out_drop_write:
1445         mnt_drop_write_file(file);
1446 out:
1447         return ret;
1448 }
1449
1450 static noinline int btrfs_ioctl_snap_create(struct file *file,
1451                                             void __user *arg, int subvol)
1452 {
1453         struct btrfs_ioctl_vol_args *vol_args;
1454         int ret;
1455
1456         vol_args = memdup_user(arg, sizeof(*vol_args));
1457         if (IS_ERR(vol_args))
1458                 return PTR_ERR(vol_args);
1459         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1460
1461         ret = btrfs_ioctl_snap_create_transid(file, vol_args->name,
1462                                               vol_args->fd, subvol,
1463                                               NULL, false, NULL);
1464
1465         kfree(vol_args);
1466         return ret;
1467 }
1468
1469 static noinline int btrfs_ioctl_snap_create_v2(struct file *file,
1470                                                void __user *arg, int subvol)
1471 {
1472         struct btrfs_ioctl_vol_args_v2 *vol_args;
1473         int ret;
1474         u64 transid = 0;
1475         u64 *ptr = NULL;
1476         bool readonly = false;
1477         struct btrfs_qgroup_inherit *inherit = NULL;
1478
1479         vol_args = memdup_user(arg, sizeof(*vol_args));
1480         if (IS_ERR(vol_args))
1481                 return PTR_ERR(vol_args);
1482         vol_args->name[BTRFS_SUBVOL_NAME_MAX] = '\0';
1483
1484         if (vol_args->flags &
1485             ~(BTRFS_SUBVOL_CREATE_ASYNC | BTRFS_SUBVOL_RDONLY |
1486               BTRFS_SUBVOL_QGROUP_INHERIT)) {
1487                 ret = -EOPNOTSUPP;
1488                 goto out;
1489         }
1490
1491         if (vol_args->flags & BTRFS_SUBVOL_CREATE_ASYNC)
1492                 ptr = &transid;
1493         if (vol_args->flags & BTRFS_SUBVOL_RDONLY)
1494                 readonly = true;
1495         if (vol_args->flags & BTRFS_SUBVOL_QGROUP_INHERIT) {
1496                 if (vol_args->size > PAGE_CACHE_SIZE) {
1497                         ret = -EINVAL;
1498                         goto out;
1499                 }
1500                 inherit = memdup_user(vol_args->qgroup_inherit, vol_args->size);
1501                 if (IS_ERR(inherit)) {
1502                         ret = PTR_ERR(inherit);
1503                         goto out;
1504                 }
1505         }
1506
1507         ret = btrfs_ioctl_snap_create_transid(file, vol_args->name,
1508                                               vol_args->fd, subvol, ptr,
1509                                               readonly, &inherit);
1510
1511         if (ret == 0 && ptr &&
1512             copy_to_user(arg +
1513                          offsetof(struct btrfs_ioctl_vol_args_v2,
1514                                   transid), ptr, sizeof(*ptr)))
1515                 ret = -EFAULT;
1516 out:
1517         kfree(vol_args);
1518         kfree(inherit);
1519         return ret;
1520 }
1521
1522 static noinline int btrfs_ioctl_subvol_getflags(struct file *file,
1523                                                 void __user *arg)
1524 {
1525         struct inode *inode = fdentry(file)->d_inode;
1526         struct btrfs_root *root = BTRFS_I(inode)->root;
1527         int ret = 0;
1528         u64 flags = 0;
1529
1530         if (btrfs_ino(inode) != BTRFS_FIRST_FREE_OBJECTID)
1531                 return -EINVAL;
1532
1533         down_read(&root->fs_info->subvol_sem);
1534         if (btrfs_root_readonly(root))
1535                 flags |= BTRFS_SUBVOL_RDONLY;
1536         up_read(&root->fs_info->subvol_sem);
1537
1538         if (copy_to_user(arg, &flags, sizeof(flags)))
1539                 ret = -EFAULT;
1540
1541         return ret;
1542 }
1543
1544 static noinline int btrfs_ioctl_subvol_setflags(struct file *file,
1545                                               void __user *arg)
1546 {
1547         struct inode *inode = fdentry(file)->d_inode;
1548         struct btrfs_root *root = BTRFS_I(inode)->root;
1549         struct btrfs_trans_handle *trans;
1550         u64 root_flags;
1551         u64 flags;
1552         int ret = 0;
1553
1554         ret = mnt_want_write_file(file);
1555         if (ret)
1556                 goto out;
1557
1558         if (btrfs_ino(inode) != BTRFS_FIRST_FREE_OBJECTID) {
1559                 ret = -EINVAL;
1560                 goto out_drop_write;
1561         }
1562
1563         if (copy_from_user(&flags, arg, sizeof(flags))) {
1564                 ret = -EFAULT;
1565                 goto out_drop_write;
1566         }
1567
1568         if (flags & BTRFS_SUBVOL_CREATE_ASYNC) {
1569                 ret = -EINVAL;
1570                 goto out_drop_write;
1571         }
1572
1573         if (flags & ~BTRFS_SUBVOL_RDONLY) {
1574                 ret = -EOPNOTSUPP;
1575                 goto out_drop_write;
1576         }
1577
1578         if (!inode_owner_or_capable(inode)) {
1579                 ret = -EACCES;
1580                 goto out_drop_write;
1581         }
1582
1583         down_write(&root->fs_info->subvol_sem);
1584
1585         /* nothing to do */
1586         if (!!(flags & BTRFS_SUBVOL_RDONLY) == btrfs_root_readonly(root))
1587                 goto out_drop_sem;
1588
1589         root_flags = btrfs_root_flags(&root->root_item);
1590         if (flags & BTRFS_SUBVOL_RDONLY)
1591                 btrfs_set_root_flags(&root->root_item,
1592                                      root_flags | BTRFS_ROOT_SUBVOL_RDONLY);
1593         else
1594                 btrfs_set_root_flags(&root->root_item,
1595                                      root_flags & ~BTRFS_ROOT_SUBVOL_RDONLY);
1596
1597         trans = btrfs_start_transaction(root, 1);
1598         if (IS_ERR(trans)) {
1599                 ret = PTR_ERR(trans);
1600                 goto out_reset;
1601         }
1602
1603         ret = btrfs_update_root(trans, root->fs_info->tree_root,
1604                                 &root->root_key, &root->root_item);
1605
1606         btrfs_commit_transaction(trans, root);
1607 out_reset:
1608         if (ret)
1609                 btrfs_set_root_flags(&root->root_item, root_flags);
1610 out_drop_sem:
1611         up_write(&root->fs_info->subvol_sem);
1612 out_drop_write:
1613         mnt_drop_write_file(file);
1614 out:
1615         return ret;
1616 }
1617
1618 /*
1619  * helper to check if the subvolume references other subvolumes
1620  */
1621 static noinline int may_destroy_subvol(struct btrfs_root *root)
1622 {
1623         struct btrfs_path *path;
1624         struct btrfs_key key;
1625         int ret;
1626
1627         path = btrfs_alloc_path();
1628         if (!path)
1629                 return -ENOMEM;
1630
1631         key.objectid = root->root_key.objectid;
1632         key.type = BTRFS_ROOT_REF_KEY;
1633         key.offset = (u64)-1;
1634
1635         ret = btrfs_search_slot(NULL, root->fs_info->tree_root,
1636                                 &key, path, 0, 0);
1637         if (ret < 0)
1638                 goto out;
1639         BUG_ON(ret == 0);
1640
1641         ret = 0;
1642         if (path->slots[0] > 0) {
1643                 path->slots[0]--;
1644                 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
1645                 if (key.objectid == root->root_key.objectid &&
1646                     key.type == BTRFS_ROOT_REF_KEY)
1647                         ret = -ENOTEMPTY;
1648         }
1649 out:
1650         btrfs_free_path(path);
1651         return ret;
1652 }
1653
1654 static noinline int key_in_sk(struct btrfs_key *key,
1655                               struct btrfs_ioctl_search_key *sk)
1656 {
1657         struct btrfs_key test;
1658         int ret;
1659
1660         test.objectid = sk->min_objectid;
1661         test.type = sk->min_type;
1662         test.offset = sk->min_offset;
1663
1664         ret = btrfs_comp_cpu_keys(key, &test);
1665         if (ret < 0)
1666                 return 0;
1667
1668         test.objectid = sk->max_objectid;
1669         test.type = sk->max_type;
1670         test.offset = sk->max_offset;
1671
1672         ret = btrfs_comp_cpu_keys(key, &test);
1673         if (ret > 0)
1674                 return 0;
1675         return 1;
1676 }
1677
1678 static noinline int copy_to_sk(struct btrfs_root *root,
1679                                struct btrfs_path *path,
1680                                struct btrfs_key *key,
1681                                struct btrfs_ioctl_search_key *sk,
1682                                char *buf,
1683                                unsigned long *sk_offset,
1684                                int *num_found)
1685 {
1686         u64 found_transid;
1687         struct extent_buffer *leaf;
1688         struct btrfs_ioctl_search_header sh;
1689         unsigned long item_off;
1690         unsigned long item_len;
1691         int nritems;
1692         int i;
1693         int slot;
1694         int ret = 0;
1695
1696         leaf = path->nodes[0];
1697         slot = path->slots[0];
1698         nritems = btrfs_header_nritems(leaf);
1699
1700         if (btrfs_header_generation(leaf) > sk->max_transid) {
1701                 i = nritems;
1702                 goto advance_key;
1703         }
1704         found_transid = btrfs_header_generation(leaf);
1705
1706         for (i = slot; i < nritems; i++) {
1707                 item_off = btrfs_item_ptr_offset(leaf, i);
1708                 item_len = btrfs_item_size_nr(leaf, i);
1709
1710                 if (item_len > BTRFS_SEARCH_ARGS_BUFSIZE)
1711                         item_len = 0;
1712
1713                 if (sizeof(sh) + item_len + *sk_offset >
1714                     BTRFS_SEARCH_ARGS_BUFSIZE) {
1715                         ret = 1;
1716                         goto overflow;
1717                 }
1718
1719                 btrfs_item_key_to_cpu(leaf, key, i);
1720                 if (!key_in_sk(key, sk))
1721                         continue;
1722
1723                 sh.objectid = key->objectid;
1724                 sh.offset = key->offset;
1725                 sh.type = key->type;
1726                 sh.len = item_len;
1727                 sh.transid = found_transid;
1728
1729                 /* copy search result header */
1730                 memcpy(buf + *sk_offset, &sh, sizeof(sh));
1731                 *sk_offset += sizeof(sh);
1732
1733                 if (item_len) {
1734                         char *p = buf + *sk_offset;
1735                         /* copy the item */
1736                         read_extent_buffer(leaf, p,
1737                                            item_off, item_len);
1738                         *sk_offset += item_len;
1739                 }
1740                 (*num_found)++;
1741
1742                 if (*num_found >= sk->nr_items)
1743                         break;
1744         }
1745 advance_key:
1746         ret = 0;
1747         if (key->offset < (u64)-1 && key->offset < sk->max_offset)
1748                 key->offset++;
1749         else if (key->type < (u8)-1 && key->type < sk->max_type) {
1750                 key->offset = 0;
1751                 key->type++;
1752         } else if (key->objectid < (u64)-1 && key->objectid < sk->max_objectid) {
1753                 key->offset = 0;
1754                 key->type = 0;
1755                 key->objectid++;
1756         } else
1757                 ret = 1;
1758 overflow:
1759         return ret;
1760 }
1761
1762 static noinline int search_ioctl(struct inode *inode,
1763                                  struct btrfs_ioctl_search_args *args)
1764 {
1765         struct btrfs_root *root;
1766         struct btrfs_key key;
1767         struct btrfs_key max_key;
1768         struct btrfs_path *path;
1769         struct btrfs_ioctl_search_key *sk = &args->key;
1770         struct btrfs_fs_info *info = BTRFS_I(inode)->root->fs_info;
1771         int ret;
1772         int num_found = 0;
1773         unsigned long sk_offset = 0;
1774
1775         path = btrfs_alloc_path();
1776         if (!path)
1777                 return -ENOMEM;
1778
1779         if (sk->tree_id == 0) {
1780                 /* search the root of the inode that was passed */
1781                 root = BTRFS_I(inode)->root;
1782         } else {
1783                 key.objectid = sk->tree_id;
1784                 key.type = BTRFS_ROOT_ITEM_KEY;
1785                 key.offset = (u64)-1;
1786                 root = btrfs_read_fs_root_no_name(info, &key);
1787                 if (IS_ERR(root)) {
1788                         printk(KERN_ERR "could not find root %llu\n",
1789                                sk->tree_id);
1790                         btrfs_free_path(path);
1791                         return -ENOENT;
1792                 }
1793         }
1794
1795         key.objectid = sk->min_objectid;
1796         key.type = sk->min_type;
1797         key.offset = sk->min_offset;
1798
1799         max_key.objectid = sk->max_objectid;
1800         max_key.type = sk->max_type;
1801         max_key.offset = sk->max_offset;
1802
1803         path->keep_locks = 1;
1804
1805         while(1) {
1806                 ret = btrfs_search_forward(root, &key, &max_key, path, 0,
1807                                            sk->min_transid);
1808                 if (ret != 0) {
1809                         if (ret > 0)
1810                                 ret = 0;
1811                         goto err;
1812                 }
1813                 ret = copy_to_sk(root, path, &key, sk, args->buf,
1814                                  &sk_offset, &num_found);
1815                 btrfs_release_path(path);
1816                 if (ret || num_found >= sk->nr_items)
1817                         break;
1818
1819         }
1820         ret = 0;
1821 err:
1822         sk->nr_items = num_found;
1823         btrfs_free_path(path);
1824         return ret;
1825 }
1826
1827 static noinline int btrfs_ioctl_tree_search(struct file *file,
1828                                            void __user *argp)
1829 {
1830          struct btrfs_ioctl_search_args *args;
1831          struct inode *inode;
1832          int ret;
1833
1834         if (!capable(CAP_SYS_ADMIN))
1835                 return -EPERM;
1836
1837         args = memdup_user(argp, sizeof(*args));
1838         if (IS_ERR(args))
1839                 return PTR_ERR(args);
1840
1841         inode = fdentry(file)->d_inode;
1842         ret = search_ioctl(inode, args);
1843         if (ret == 0 && copy_to_user(argp, args, sizeof(*args)))
1844                 ret = -EFAULT;
1845         kfree(args);
1846         return ret;
1847 }
1848
1849 /*
1850  * Search INODE_REFs to identify path name of 'dirid' directory
1851  * in a 'tree_id' tree. and sets path name to 'name'.
1852  */
1853 static noinline int btrfs_search_path_in_tree(struct btrfs_fs_info *info,
1854                                 u64 tree_id, u64 dirid, char *name)
1855 {
1856         struct btrfs_root *root;
1857         struct btrfs_key key;
1858         char *ptr;
1859         int ret = -1;
1860         int slot;
1861         int len;
1862         int total_len = 0;
1863         struct btrfs_inode_ref *iref;
1864         struct extent_buffer *l;
1865         struct btrfs_path *path;
1866
1867         if (dirid == BTRFS_FIRST_FREE_OBJECTID) {
1868                 name[0]='\0';
1869                 return 0;
1870         }
1871
1872         path = btrfs_alloc_path();
1873         if (!path)
1874                 return -ENOMEM;
1875
1876         ptr = &name[BTRFS_INO_LOOKUP_PATH_MAX];
1877
1878         key.objectid = tree_id;
1879         key.type = BTRFS_ROOT_ITEM_KEY;
1880         key.offset = (u64)-1;
1881         root = btrfs_read_fs_root_no_name(info, &key);
1882         if (IS_ERR(root)) {
1883                 printk(KERN_ERR "could not find root %llu\n", tree_id);
1884                 ret = -ENOENT;
1885                 goto out;
1886         }
1887
1888         key.objectid = dirid;
1889         key.type = BTRFS_INODE_REF_KEY;
1890         key.offset = (u64)-1;
1891
1892         while(1) {
1893                 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1894                 if (ret < 0)
1895                         goto out;
1896
1897                 l = path->nodes[0];
1898                 slot = path->slots[0];
1899                 if (ret > 0 && slot > 0)
1900                         slot--;
1901                 btrfs_item_key_to_cpu(l, &key, slot);
1902
1903                 if (ret > 0 && (key.objectid != dirid ||
1904                                 key.type != BTRFS_INODE_REF_KEY)) {
1905                         ret = -ENOENT;
1906                         goto out;
1907                 }
1908
1909                 iref = btrfs_item_ptr(l, slot, struct btrfs_inode_ref);
1910                 len = btrfs_inode_ref_name_len(l, iref);
1911                 ptr -= len + 1;
1912                 total_len += len + 1;
1913                 if (ptr < name)
1914                         goto out;
1915
1916                 *(ptr + len) = '/';
1917                 read_extent_buffer(l, ptr,(unsigned long)(iref + 1), len);
1918
1919                 if (key.offset == BTRFS_FIRST_FREE_OBJECTID)
1920                         break;
1921
1922                 btrfs_release_path(path);
1923                 key.objectid = key.offset;
1924                 key.offset = (u64)-1;
1925                 dirid = key.objectid;
1926         }
1927         if (ptr < name)
1928                 goto out;
1929         memmove(name, ptr, total_len);
1930         name[total_len]='\0';
1931         ret = 0;
1932 out:
1933         btrfs_free_path(path);
1934         return ret;
1935 }
1936
1937 static noinline int btrfs_ioctl_ino_lookup(struct file *file,
1938                                            void __user *argp)
1939 {
1940          struct btrfs_ioctl_ino_lookup_args *args;
1941          struct inode *inode;
1942          int ret;
1943
1944         if (!capable(CAP_SYS_ADMIN))
1945                 return -EPERM;
1946
1947         args = memdup_user(argp, sizeof(*args));
1948         if (IS_ERR(args))
1949                 return PTR_ERR(args);
1950
1951         inode = fdentry(file)->d_inode;
1952
1953         if (args->treeid == 0)
1954                 args->treeid = BTRFS_I(inode)->root->root_key.objectid;
1955
1956         ret = btrfs_search_path_in_tree(BTRFS_I(inode)->root->fs_info,
1957                                         args->treeid, args->objectid,
1958                                         args->name);
1959
1960         if (ret == 0 && copy_to_user(argp, args, sizeof(*args)))
1961                 ret = -EFAULT;
1962
1963         kfree(args);
1964         return ret;
1965 }
1966
1967 static noinline int btrfs_ioctl_snap_destroy(struct file *file,
1968                                              void __user *arg)
1969 {
1970         struct dentry *parent = fdentry(file);
1971         struct dentry *dentry;
1972         struct inode *dir = parent->d_inode;
1973         struct inode *inode;
1974         struct btrfs_root *root = BTRFS_I(dir)->root;
1975         struct btrfs_root *dest = NULL;
1976         struct btrfs_ioctl_vol_args *vol_args;
1977         struct btrfs_trans_handle *trans;
1978         int namelen;
1979         int ret;
1980         int err = 0;
1981
1982         vol_args = memdup_user(arg, sizeof(*vol_args));
1983         if (IS_ERR(vol_args))
1984                 return PTR_ERR(vol_args);
1985
1986         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1987         namelen = strlen(vol_args->name);
1988         if (strchr(vol_args->name, '/') ||
1989             strncmp(vol_args->name, "..", namelen) == 0) {
1990                 err = -EINVAL;
1991                 goto out;
1992         }
1993
1994         err = mnt_want_write_file(file);
1995         if (err)
1996                 goto out;
1997
1998         mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
1999         dentry = lookup_one_len(vol_args->name, parent, namelen);
2000         if (IS_ERR(dentry)) {
2001                 err = PTR_ERR(dentry);
2002                 goto out_unlock_dir;
2003         }
2004
2005         if (!dentry->d_inode) {
2006                 err = -ENOENT;
2007                 goto out_dput;
2008         }
2009
2010         inode = dentry->d_inode;
2011         dest = BTRFS_I(inode)->root;
2012         if (!capable(CAP_SYS_ADMIN)){
2013                 /*
2014                  * Regular user.  Only allow this with a special mount
2015                  * option, when the user has write+exec access to the
2016                  * subvol root, and when rmdir(2) would have been
2017                  * allowed.
2018                  *
2019                  * Note that this is _not_ check that the subvol is
2020                  * empty or doesn't contain data that we wouldn't
2021                  * otherwise be able to delete.
2022                  *
2023                  * Users who want to delete empty subvols should try
2024                  * rmdir(2).
2025                  */
2026                 err = -EPERM;
2027                 if (!btrfs_test_opt(root, USER_SUBVOL_RM_ALLOWED))
2028                         goto out_dput;
2029
2030                 /*
2031                  * Do not allow deletion if the parent dir is the same
2032                  * as the dir to be deleted.  That means the ioctl
2033                  * must be called on the dentry referencing the root
2034                  * of the subvol, not a random directory contained
2035                  * within it.
2036                  */
2037                 err = -EINVAL;
2038                 if (root == dest)
2039                         goto out_dput;
2040
2041                 err = inode_permission(inode, MAY_WRITE | MAY_EXEC);
2042                 if (err)
2043                         goto out_dput;
2044
2045                 /* check if subvolume may be deleted by a non-root user */
2046                 err = btrfs_may_delete(dir, dentry, 1);
2047                 if (err)
2048                         goto out_dput;
2049         }
2050
2051         if (btrfs_ino(inode) != BTRFS_FIRST_FREE_OBJECTID) {
2052                 err = -EINVAL;
2053                 goto out_dput;
2054         }
2055
2056         mutex_lock(&inode->i_mutex);
2057         err = d_invalidate(dentry);
2058         if (err)
2059                 goto out_unlock;
2060
2061         down_write(&root->fs_info->subvol_sem);
2062
2063         err = may_destroy_subvol(dest);
2064         if (err)
2065                 goto out_up_write;
2066
2067         trans = btrfs_start_transaction(root, 0);
2068         if (IS_ERR(trans)) {
2069                 err = PTR_ERR(trans);
2070                 goto out_up_write;
2071         }
2072         trans->block_rsv = &root->fs_info->global_block_rsv;
2073
2074         ret = btrfs_unlink_subvol(trans, root, dir,
2075                                 dest->root_key.objectid,
2076                                 dentry->d_name.name,
2077                                 dentry->d_name.len);
2078         if (ret) {
2079                 err = ret;
2080                 btrfs_abort_transaction(trans, root, ret);
2081                 goto out_end_trans;
2082         }
2083
2084         btrfs_record_root_in_trans(trans, dest);
2085
2086         memset(&dest->root_item.drop_progress, 0,
2087                 sizeof(dest->root_item.drop_progress));
2088         dest->root_item.drop_level = 0;
2089         btrfs_set_root_refs(&dest->root_item, 0);
2090
2091         if (!xchg(&dest->orphan_item_inserted, 1)) {
2092                 ret = btrfs_insert_orphan_item(trans,
2093                                         root->fs_info->tree_root,
2094                                         dest->root_key.objectid);
2095                 if (ret) {
2096                         btrfs_abort_transaction(trans, root, ret);
2097                         err = ret;
2098                         goto out_end_trans;
2099                 }
2100         }
2101 out_end_trans:
2102         ret = btrfs_end_transaction(trans, root);
2103         if (ret && !err)
2104                 err = ret;
2105         inode->i_flags |= S_DEAD;
2106 out_up_write:
2107         up_write(&root->fs_info->subvol_sem);
2108 out_unlock:
2109         mutex_unlock(&inode->i_mutex);
2110         if (!err) {
2111                 shrink_dcache_sb(root->fs_info->sb);
2112                 btrfs_invalidate_inodes(dest);
2113                 d_delete(dentry);
2114         }
2115 out_dput:
2116         dput(dentry);
2117 out_unlock_dir:
2118         mutex_unlock(&dir->i_mutex);
2119         mnt_drop_write_file(file);
2120 out:
2121         kfree(vol_args);
2122         return err;
2123 }
2124
2125 static int btrfs_ioctl_defrag(struct file *file, void __user *argp)
2126 {
2127         struct inode *inode = fdentry(file)->d_inode;
2128         struct btrfs_root *root = BTRFS_I(inode)->root;
2129         struct btrfs_ioctl_defrag_range_args *range;
2130         int ret;
2131
2132         if (btrfs_root_readonly(root))
2133                 return -EROFS;
2134
2135         ret = mnt_want_write_file(file);
2136         if (ret)
2137                 return ret;
2138
2139         switch (inode->i_mode & S_IFMT) {
2140         case S_IFDIR:
2141                 if (!capable(CAP_SYS_ADMIN)) {
2142                         ret = -EPERM;
2143                         goto out;
2144                 }
2145                 ret = btrfs_defrag_root(root, 0);
2146                 if (ret)
2147                         goto out;
2148                 ret = btrfs_defrag_root(root->fs_info->extent_root, 0);
2149                 break;
2150         case S_IFREG:
2151                 if (!(file->f_mode & FMODE_WRITE)) {
2152                         ret = -EINVAL;
2153                         goto out;
2154                 }
2155
2156                 range = kzalloc(sizeof(*range), GFP_KERNEL);
2157                 if (!range) {
2158                         ret = -ENOMEM;
2159                         goto out;
2160                 }
2161
2162                 if (argp) {
2163                         if (copy_from_user(range, argp,
2164                                            sizeof(*range))) {
2165                                 ret = -EFAULT;
2166                                 kfree(range);
2167                                 goto out;
2168                         }
2169                         /* compression requires us to start the IO */
2170                         if ((range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)) {
2171                                 range->flags |= BTRFS_DEFRAG_RANGE_START_IO;
2172                                 range->extent_thresh = (u32)-1;
2173                         }
2174                 } else {
2175                         /* the rest are all set to zero by kzalloc */
2176                         range->len = (u64)-1;
2177                 }
2178                 ret = btrfs_defrag_file(fdentry(file)->d_inode, file,
2179                                         range, 0, 0);
2180                 if (ret > 0)
2181                         ret = 0;
2182                 kfree(range);
2183                 break;
2184         default:
2185                 ret = -EINVAL;
2186         }
2187 out:
2188         mnt_drop_write_file(file);
2189         return ret;
2190 }
2191
2192 static long btrfs_ioctl_add_dev(struct btrfs_root *root, void __user *arg)
2193 {
2194         struct btrfs_ioctl_vol_args *vol_args;
2195         int ret;
2196
2197         if (!capable(CAP_SYS_ADMIN))
2198                 return -EPERM;
2199
2200         mutex_lock(&root->fs_info->volume_mutex);
2201         if (root->fs_info->balance_ctl) {
2202                 printk(KERN_INFO "btrfs: balance in progress\n");
2203                 ret = -EINVAL;
2204                 goto out;
2205         }
2206
2207         vol_args = memdup_user(arg, sizeof(*vol_args));
2208         if (IS_ERR(vol_args)) {
2209                 ret = PTR_ERR(vol_args);
2210                 goto out;
2211         }
2212
2213         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
2214         ret = btrfs_init_new_device(root, vol_args->name);
2215
2216         kfree(vol_args);
2217 out:
2218         mutex_unlock(&root->fs_info->volume_mutex);
2219         return ret;
2220 }
2221
2222 static long btrfs_ioctl_rm_dev(struct btrfs_root *root, void __user *arg)
2223 {
2224         struct btrfs_ioctl_vol_args *vol_args;
2225         int ret;
2226
2227         if (!capable(CAP_SYS_ADMIN))
2228                 return -EPERM;
2229
2230         if (root->fs_info->sb->s_flags & MS_RDONLY)
2231                 return -EROFS;
2232
2233         mutex_lock(&root->fs_info->volume_mutex);
2234         if (root->fs_info->balance_ctl) {
2235                 printk(KERN_INFO "btrfs: balance in progress\n");
2236                 ret = -EINVAL;
2237                 goto out;
2238         }
2239
2240         vol_args = memdup_user(arg, sizeof(*vol_args));
2241         if (IS_ERR(vol_args)) {
2242                 ret = PTR_ERR(vol_args);
2243                 goto out;
2244         }
2245
2246         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
2247         ret = btrfs_rm_device(root, vol_args->name);
2248
2249         kfree(vol_args);
2250 out:
2251         mutex_unlock(&root->fs_info->volume_mutex);
2252         return ret;
2253 }
2254
2255 static long btrfs_ioctl_fs_info(struct btrfs_root *root, void __user *arg)
2256 {
2257         struct btrfs_ioctl_fs_info_args *fi_args;
2258         struct btrfs_device *device;
2259         struct btrfs_device *next;
2260         struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
2261         int ret = 0;
2262
2263         if (!capable(CAP_SYS_ADMIN))
2264                 return -EPERM;
2265
2266         fi_args = kzalloc(sizeof(*fi_args), GFP_KERNEL);
2267         if (!fi_args)
2268                 return -ENOMEM;
2269
2270         fi_args->num_devices = fs_devices->num_devices;
2271         memcpy(&fi_args->fsid, root->fs_info->fsid, sizeof(fi_args->fsid));
2272
2273         mutex_lock(&fs_devices->device_list_mutex);
2274         list_for_each_entry_safe(device, next, &fs_devices->devices, dev_list) {
2275                 if (device->devid > fi_args->max_id)
2276                         fi_args->max_id = device->devid;
2277         }
2278         mutex_unlock(&fs_devices->device_list_mutex);
2279
2280         if (copy_to_user(arg, fi_args, sizeof(*fi_args)))
2281                 ret = -EFAULT;
2282
2283         kfree(fi_args);
2284         return ret;
2285 }
2286
2287 static long btrfs_ioctl_dev_info(struct btrfs_root *root, void __user *arg)
2288 {
2289         struct btrfs_ioctl_dev_info_args *di_args;
2290         struct btrfs_device *dev;
2291         struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
2292         int ret = 0;
2293         char *s_uuid = NULL;
2294         char empty_uuid[BTRFS_UUID_SIZE] = {0};
2295
2296         if (!capable(CAP_SYS_ADMIN))
2297                 return -EPERM;
2298
2299         di_args = memdup_user(arg, sizeof(*di_args));
2300         if (IS_ERR(di_args))
2301                 return PTR_ERR(di_args);
2302
2303         if (memcmp(empty_uuid, di_args->uuid, BTRFS_UUID_SIZE) != 0)
2304                 s_uuid = di_args->uuid;
2305
2306         mutex_lock(&fs_devices->device_list_mutex);
2307         dev = btrfs_find_device(root, di_args->devid, s_uuid, NULL);
2308         mutex_unlock(&fs_devices->device_list_mutex);
2309
2310         if (!dev) {
2311                 ret = -ENODEV;
2312                 goto out;
2313         }
2314
2315         di_args->devid = dev->devid;
2316         di_args->bytes_used = dev->bytes_used;
2317         di_args->total_bytes = dev->total_bytes;
2318         memcpy(di_args->uuid, dev->uuid, sizeof(di_args->uuid));
2319         if (dev->name) {
2320                 struct rcu_string *name;
2321
2322                 rcu_read_lock();
2323                 name = rcu_dereference(dev->name);
2324                 strncpy(di_args->path, name->str, sizeof(di_args->path));
2325                 rcu_read_unlock();
2326                 di_args->path[sizeof(di_args->path) - 1] = 0;
2327         } else {
2328                 di_args->path[0] = '\0';
2329         }
2330
2331 out:
2332         if (ret == 0 && copy_to_user(arg, di_args, sizeof(*di_args)))
2333                 ret = -EFAULT;
2334
2335         kfree(di_args);
2336         return ret;
2337 }
2338
2339 static noinline long btrfs_ioctl_clone(struct file *file, unsigned long srcfd,
2340                                        u64 off, u64 olen, u64 destoff)
2341 {
2342         struct inode *inode = fdentry(file)->d_inode;
2343         struct btrfs_root *root = BTRFS_I(inode)->root;
2344         struct file *src_file;
2345         struct inode *src;
2346         struct btrfs_trans_handle *trans;
2347         struct btrfs_path *path;
2348         struct extent_buffer *leaf;
2349         char *buf;
2350         struct btrfs_key key;
2351         u32 nritems;
2352         int slot;
2353         int ret;
2354         u64 len = olen;
2355         u64 bs = root->fs_info->sb->s_blocksize;
2356         u64 hint_byte;
2357
2358         /*
2359          * TODO:
2360          * - split compressed inline extents.  annoying: we need to
2361          *   decompress into destination's address_space (the file offset
2362          *   may change, so source mapping won't do), then recompress (or
2363          *   otherwise reinsert) a subrange.
2364          * - allow ranges within the same file to be cloned (provided
2365          *   they don't overlap)?
2366          */
2367
2368         /* the destination must be opened for writing */
2369         if (!(file->f_mode & FMODE_WRITE) || (file->f_flags & O_APPEND))
2370                 return -EINVAL;
2371
2372         if (btrfs_root_readonly(root))
2373                 return -EROFS;
2374
2375         ret = mnt_want_write_file(file);
2376         if (ret)
2377                 return ret;
2378
2379         src_file = fget(srcfd);
2380         if (!src_file) {
2381                 ret = -EBADF;
2382                 goto out_drop_write;
2383         }
2384
2385         ret = -EXDEV;
2386         if (src_file->f_path.mnt != file->f_path.mnt)
2387                 goto out_fput;
2388
2389         src = src_file->f_dentry->d_inode;
2390
2391         ret = -EINVAL;
2392         if (src == inode)
2393                 goto out_fput;
2394
2395         /* the src must be open for reading */
2396         if (!(src_file->f_mode & FMODE_READ))
2397                 goto out_fput;
2398
2399         /* don't make the dst file partly checksummed */
2400         if ((BTRFS_I(src)->flags & BTRFS_INODE_NODATASUM) !=
2401             (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM))
2402                 goto out_fput;
2403
2404         ret = -EISDIR;
2405         if (S_ISDIR(src->i_mode) || S_ISDIR(inode->i_mode))
2406                 goto out_fput;
2407
2408         ret = -EXDEV;
2409         if (src->i_sb != inode->i_sb)
2410                 goto out_fput;
2411
2412         ret = -ENOMEM;
2413         buf = vmalloc(btrfs_level_size(root, 0));
2414         if (!buf)
2415                 goto out_fput;
2416
2417         path = btrfs_alloc_path();
2418         if (!path) {
2419                 vfree(buf);
2420                 goto out_fput;
2421         }
2422         path->reada = 2;
2423
2424         if (inode < src) {
2425                 mutex_lock_nested(&inode->i_mutex, I_MUTEX_PARENT);
2426                 mutex_lock_nested(&src->i_mutex, I_MUTEX_CHILD);
2427         } else {
2428                 mutex_lock_nested(&src->i_mutex, I_MUTEX_PARENT);
2429                 mutex_lock_nested(&inode->i_mutex, I_MUTEX_CHILD);
2430         }
2431
2432         /* determine range to clone */
2433         ret = -EINVAL;
2434         if (off + len > src->i_size || off + len < off)
2435                 goto out_unlock;
2436         if (len == 0)
2437                 olen = len = src->i_size - off;
2438         /* if we extend to eof, continue to block boundary */
2439         if (off + len == src->i_size)
2440                 len = ALIGN(src->i_size, bs) - off;
2441
2442         /* verify the end result is block aligned */
2443         if (!IS_ALIGNED(off, bs) || !IS_ALIGNED(off + len, bs) ||
2444             !IS_ALIGNED(destoff, bs))
2445                 goto out_unlock;
2446
2447         if (destoff > inode->i_size) {
2448                 ret = btrfs_cont_expand(inode, inode->i_size, destoff);
2449                 if (ret)
2450                         goto out_unlock;
2451         }
2452
2453         /* truncate page cache pages from target inode range */
2454         truncate_inode_pages_range(&inode->i_data, destoff,
2455                                    PAGE_CACHE_ALIGN(destoff + len) - 1);
2456
2457         /* do any pending delalloc/csum calc on src, one way or
2458            another, and lock file content */
2459         while (1) {
2460                 struct btrfs_ordered_extent *ordered;
2461                 lock_extent(&BTRFS_I(src)->io_tree, off, off+len);
2462                 ordered = btrfs_lookup_first_ordered_extent(src, off+len);
2463                 if (!ordered &&
2464                     !test_range_bit(&BTRFS_I(src)->io_tree, off, off+len,
2465                                    EXTENT_DELALLOC, 0, NULL))
2466                         break;
2467                 unlock_extent(&BTRFS_I(src)->io_tree, off, off+len);
2468                 if (ordered)
2469                         btrfs_put_ordered_extent(ordered);
2470                 btrfs_wait_ordered_range(src, off, len);
2471         }
2472
2473         /* clone data */
2474         key.objectid = btrfs_ino(src);
2475         key.type = BTRFS_EXTENT_DATA_KEY;
2476         key.offset = 0;
2477
2478         while (1) {
2479                 /*
2480                  * note the key will change type as we walk through the
2481                  * tree.
2482                  */
2483                 ret = btrfs_search_slot(NULL, BTRFS_I(src)->root, &key, path,
2484                                 0, 0);
2485                 if (ret < 0)
2486                         goto out;
2487
2488                 nritems = btrfs_header_nritems(path->nodes[0]);
2489                 if (path->slots[0] >= nritems) {
2490                         ret = btrfs_next_leaf(BTRFS_I(src)->root, path);
2491                         if (ret < 0)
2492                                 goto out;
2493                         if (ret > 0)
2494                                 break;
2495                         nritems = btrfs_header_nritems(path->nodes[0]);
2496                 }
2497                 leaf = path->nodes[0];
2498                 slot = path->slots[0];
2499
2500                 btrfs_item_key_to_cpu(leaf, &key, slot);
2501                 if (btrfs_key_type(&key) > BTRFS_EXTENT_DATA_KEY ||
2502                     key.objectid != btrfs_ino(src))
2503                         break;
2504
2505                 if (btrfs_key_type(&key) == BTRFS_EXTENT_DATA_KEY) {
2506                         struct btrfs_file_extent_item *extent;
2507                         int type;
2508                         u32 size;
2509                         struct btrfs_key new_key;
2510                         u64 disko = 0, diskl = 0;
2511                         u64 datao = 0, datal = 0;
2512                         u8 comp;
2513                         u64 endoff;
2514
2515                         size = btrfs_item_size_nr(leaf, slot);
2516                         read_extent_buffer(leaf, buf,
2517                                            btrfs_item_ptr_offset(leaf, slot),
2518                                            size);
2519
2520                         extent = btrfs_item_ptr(leaf, slot,
2521                                                 struct btrfs_file_extent_item);
2522                         comp = btrfs_file_extent_compression(leaf, extent);
2523                         type = btrfs_file_extent_type(leaf, extent);
2524                         if (type == BTRFS_FILE_EXTENT_REG ||
2525                             type == BTRFS_FILE_EXTENT_PREALLOC) {
2526                                 disko = btrfs_file_extent_disk_bytenr(leaf,
2527                                                                       extent);
2528                                 diskl = btrfs_file_extent_disk_num_bytes(leaf,
2529                                                                  extent);
2530                                 datao = btrfs_file_extent_offset(leaf, extent);
2531                                 datal = btrfs_file_extent_num_bytes(leaf,
2532                                                                     extent);
2533                         } else if (type == BTRFS_FILE_EXTENT_INLINE) {
2534                                 /* take upper bound, may be compressed */
2535                                 datal = btrfs_file_extent_ram_bytes(leaf,
2536                                                                     extent);
2537                         }
2538                         btrfs_release_path(path);
2539
2540                         if (key.offset + datal <= off ||
2541                             key.offset >= off+len)
2542                                 goto next;
2543
2544                         memcpy(&new_key, &key, sizeof(new_key));
2545                         new_key.objectid = btrfs_ino(inode);
2546                         if (off <= key.offset)
2547                                 new_key.offset = key.offset + destoff - off;
2548                         else
2549                                 new_key.offset = destoff;
2550
2551                         /*
2552                          * 1 - adjusting old extent (we may have to split it)
2553                          * 1 - add new extent
2554                          * 1 - inode update
2555                          */
2556                         trans = btrfs_start_transaction(root, 3);
2557                         if (IS_ERR(trans)) {
2558                                 ret = PTR_ERR(trans);
2559                                 goto out;
2560                         }
2561
2562                         if (type == BTRFS_FILE_EXTENT_REG ||
2563                             type == BTRFS_FILE_EXTENT_PREALLOC) {
2564                                 /*
2565                                  *    a  | --- range to clone ---|  b
2566                                  * | ------------- extent ------------- |
2567                                  */
2568
2569                                 /* substract range b */
2570                                 if (key.offset + datal > off + len)
2571                                         datal = off + len - key.offset;
2572
2573                                 /* substract range a */
2574                                 if (off > key.offset) {
2575                                         datao += off - key.offset;
2576                                         datal -= off - key.offset;
2577                                 }
2578
2579                                 ret = btrfs_drop_extents(trans, inode,
2580                                                          new_key.offset,
2581                                                          new_key.offset + datal,
2582                                                          &hint_byte, 1);
2583                                 if (ret) {
2584                                         btrfs_abort_transaction(trans, root,
2585                                                                 ret);
2586                                         btrfs_end_transaction(trans, root);
2587                                         goto out;
2588                                 }
2589
2590                                 ret = btrfs_insert_empty_item(trans, root, path,
2591                                                               &new_key, size);
2592                                 if (ret) {
2593                                         btrfs_abort_transaction(trans, root,
2594                                                                 ret);
2595                                         btrfs_end_transaction(trans, root);
2596                                         goto out;
2597                                 }
2598
2599                                 leaf = path->nodes[0];
2600                                 slot = path->slots[0];
2601                                 write_extent_buffer(leaf, buf,
2602                                             btrfs_item_ptr_offset(leaf, slot),
2603                                             size);
2604
2605                                 extent = btrfs_item_ptr(leaf, slot,
2606                                                 struct btrfs_file_extent_item);
2607
2608                                 /* disko == 0 means it's a hole */
2609                                 if (!disko)
2610                                         datao = 0;
2611
2612                                 btrfs_set_file_extent_offset(leaf, extent,
2613                                                              datao);
2614                                 btrfs_set_file_extent_num_bytes(leaf, extent,
2615                                                                 datal);
2616                                 if (disko) {
2617                                         inode_add_bytes(inode, datal);
2618                                         ret = btrfs_inc_extent_ref(trans, root,
2619                                                         disko, diskl, 0,
2620                                                         root->root_key.objectid,
2621                                                         btrfs_ino(inode),
2622                                                         new_key.offset - datao,
2623                                                         0);
2624                                         if (ret) {
2625                                                 btrfs_abort_transaction(trans,
2626                                                                         root,
2627                                                                         ret);
2628                                                 btrfs_end_transaction(trans,
2629                                                                       root);
2630                                                 goto out;
2631
2632                                         }
2633                                 }
2634                         } else if (type == BTRFS_FILE_EXTENT_INLINE) {
2635                                 u64 skip = 0;
2636                                 u64 trim = 0;
2637                                 if (off > key.offset) {
2638                                         skip = off - key.offset;
2639                                         new_key.offset += skip;
2640                                 }
2641
2642                                 if (key.offset + datal > off+len)
2643                                         trim = key.offset + datal - (off+len);
2644
2645                                 if (comp && (skip || trim)) {
2646                                         ret = -EINVAL;
2647                                         btrfs_end_transaction(trans, root);
2648                                         goto out;
2649                                 }
2650                                 size -= skip + trim;
2651                                 datal -= skip + trim;
2652
2653                                 ret = btrfs_drop_extents(trans, inode,
2654                                                          new_key.offset,
2655                                                          new_key.offset + datal,
2656                                                          &hint_byte, 1);
2657                                 if (ret) {
2658                                         btrfs_abort_transaction(trans, root,
2659                                                                 ret);
2660                                         btrfs_end_transaction(trans, root);
2661                                         goto out;
2662                                 }
2663
2664                                 ret = btrfs_insert_empty_item(trans, root, path,
2665                                                               &new_key, size);
2666                                 if (ret) {
2667                                         btrfs_abort_transaction(trans, root,
2668                                                                 ret);
2669                                         btrfs_end_transaction(trans, root);
2670                                         goto out;
2671                                 }
2672
2673                                 if (skip) {
2674                                         u32 start =
2675                                           btrfs_file_extent_calc_inline_size(0);
2676                                         memmove(buf+start, buf+start+skip,
2677                                                 datal);
2678                                 }
2679
2680                                 leaf = path->nodes[0];
2681                                 slot = path->slots[0];
2682                                 write_extent_buffer(leaf, buf,
2683                                             btrfs_item_ptr_offset(leaf, slot),
2684                                             size);
2685                                 inode_add_bytes(inode, datal);
2686                         }
2687
2688                         btrfs_mark_buffer_dirty(leaf);
2689                         btrfs_release_path(path);
2690
2691                         inode_inc_iversion(inode);
2692                         inode->i_mtime = inode->i_ctime = CURRENT_TIME;
2693
2694                         /*
2695                          * we round up to the block size at eof when
2696                          * determining which extents to clone above,
2697                          * but shouldn't round up the file size
2698                          */
2699                         endoff = new_key.offset + datal;
2700                         if (endoff > destoff+olen)
2701                                 endoff = destoff+olen;
2702                         if (endoff > inode->i_size)
2703                                 btrfs_i_size_write(inode, endoff);
2704
2705                         ret = btrfs_update_inode(trans, root, inode);
2706                         if (ret) {
2707                                 btrfs_abort_transaction(trans, root, ret);
2708                                 btrfs_end_transaction(trans, root);
2709                                 goto out;
2710                         }
2711                         ret = btrfs_end_transaction(trans, root);
2712                 }
2713 next:
2714                 btrfs_release_path(path);
2715                 key.offset++;
2716         }
2717         ret = 0;
2718 out:
2719         btrfs_release_path(path);
2720         unlock_extent(&BTRFS_I(src)->io_tree, off, off+len);
2721 out_unlock:
2722         mutex_unlock(&src->i_mutex);
2723         mutex_unlock(&inode->i_mutex);
2724         vfree(buf);
2725         btrfs_free_path(path);
2726 out_fput:
2727         fput(src_file);
2728 out_drop_write:
2729         mnt_drop_write_file(file);
2730         return ret;
2731 }
2732
2733 static long btrfs_ioctl_clone_range(struct file *file, void __user *argp)
2734 {
2735         struct btrfs_ioctl_clone_range_args args;
2736
2737         if (copy_from_user(&args, argp, sizeof(args)))
2738                 return -EFAULT;
2739         return btrfs_ioctl_clone(file, args.src_fd, args.src_offset,
2740                                  args.src_length, args.dest_offset);
2741 }
2742
2743 /*
2744  * there are many ways the trans_start and trans_end ioctls can lead
2745  * to deadlocks.  They should only be used by applications that
2746  * basically own the machine, and have a very in depth understanding
2747  * of all the possible deadlocks and enospc problems.
2748  */
2749 static long btrfs_ioctl_trans_start(struct file *file)
2750 {
2751         struct inode *inode = fdentry(file)->d_inode;
2752         struct btrfs_root *root = BTRFS_I(inode)->root;
2753         struct btrfs_trans_handle *trans;
2754         int ret;
2755
2756         ret = -EPERM;
2757         if (!capable(CAP_SYS_ADMIN))
2758                 goto out;
2759
2760         ret = -EINPROGRESS;
2761         if (file->private_data)
2762                 goto out;
2763
2764         ret = -EROFS;
2765         if (btrfs_root_readonly(root))
2766                 goto out;
2767
2768         ret = mnt_want_write_file(file);
2769         if (ret)
2770                 goto out;
2771
2772         atomic_inc(&root->fs_info->open_ioctl_trans);
2773
2774         ret = -ENOMEM;
2775         trans = btrfs_start_ioctl_transaction(root);
2776         if (IS_ERR(trans))
2777                 goto out_drop;
2778
2779         file->private_data = trans;
2780         return 0;
2781
2782 out_drop:
2783         atomic_dec(&root->fs_info->open_ioctl_trans);
2784         mnt_drop_write_file(file);
2785 out:
2786         return ret;
2787 }
2788
2789 static long btrfs_ioctl_default_subvol(struct file *file, void __user *argp)
2790 {
2791         struct inode *inode = fdentry(file)->d_inode;
2792         struct btrfs_root *root = BTRFS_I(inode)->root;
2793         struct btrfs_root *new_root;
2794         struct btrfs_dir_item *di;
2795         struct btrfs_trans_handle *trans;
2796         struct btrfs_path *path;
2797         struct btrfs_key location;
2798         struct btrfs_disk_key disk_key;
2799         u64 objectid = 0;
2800         u64 dir_id;
2801
2802         if (!capable(CAP_SYS_ADMIN))
2803                 return -EPERM;
2804
2805         if (copy_from_user(&objectid, argp, sizeof(objectid)))
2806                 return -EFAULT;
2807
2808         if (!objectid)
2809                 objectid = root->root_key.objectid;
2810
2811         location.objectid = objectid;
2812         location.type = BTRFS_ROOT_ITEM_KEY;
2813         location.offset = (u64)-1;
2814
2815         new_root = btrfs_read_fs_root_no_name(root->fs_info, &location);
2816         if (IS_ERR(new_root))
2817                 return PTR_ERR(new_root);
2818
2819         if (btrfs_root_refs(&new_root->root_item) == 0)
2820                 return -ENOENT;
2821
2822         path = btrfs_alloc_path();
2823         if (!path)
2824                 return -ENOMEM;
2825         path->leave_spinning = 1;
2826
2827         trans = btrfs_start_transaction(root, 1);
2828         if (IS_ERR(trans)) {
2829                 btrfs_free_path(path);
2830                 return PTR_ERR(trans);
2831         }
2832
2833         dir_id = btrfs_super_root_dir(root->fs_info->super_copy);
2834         di = btrfs_lookup_dir_item(trans, root->fs_info->tree_root, path,
2835                                    dir_id, "default", 7, 1);
2836         if (IS_ERR_OR_NULL(di)) {
2837                 btrfs_free_path(path);
2838                 btrfs_end_transaction(trans, root);
2839                 printk(KERN_ERR "Umm, you don't have the default dir item, "
2840                        "this isn't going to work\n");
2841                 return -ENOENT;
2842         }
2843
2844         btrfs_cpu_key_to_disk(&disk_key, &new_root->root_key);
2845         btrfs_set_dir_item_key(path->nodes[0], di, &disk_key);
2846         btrfs_mark_buffer_dirty(path->nodes[0]);
2847         btrfs_free_path(path);
2848
2849         btrfs_set_fs_incompat(root->fs_info, DEFAULT_SUBVOL);
2850         btrfs_end_transaction(trans, root);
2851
2852         return 0;
2853 }
2854
2855 static void get_block_group_info(struct list_head *groups_list,
2856                                  struct btrfs_ioctl_space_info *space)
2857 {
2858         struct btrfs_block_group_cache *block_group;
2859
2860         space->total_bytes = 0;
2861         space->used_bytes = 0;
2862         space->flags = 0;
2863         list_for_each_entry(block_group, groups_list, list) {
2864                 space->flags = block_group->flags;
2865                 space->total_bytes += block_group->key.offset;
2866                 space->used_bytes +=
2867                         btrfs_block_group_used(&block_group->item);
2868         }
2869 }
2870
2871 long btrfs_ioctl_space_info(struct btrfs_root *root, void __user *arg)
2872 {
2873         struct btrfs_ioctl_space_args space_args;
2874         struct btrfs_ioctl_space_info space;
2875         struct btrfs_ioctl_space_info *dest;
2876         struct btrfs_ioctl_space_info *dest_orig;
2877         struct btrfs_ioctl_space_info __user *user_dest;
2878         struct btrfs_space_info *info;
2879         u64 types[] = {BTRFS_BLOCK_GROUP_DATA,
2880                        BTRFS_BLOCK_GROUP_SYSTEM,
2881                        BTRFS_BLOCK_GROUP_METADATA,
2882                        BTRFS_BLOCK_GROUP_DATA | BTRFS_BLOCK_GROUP_METADATA};
2883         int num_types = 4;
2884         int alloc_size;
2885         int ret = 0;
2886         u64 slot_count = 0;
2887         int i, c;
2888
2889         if (copy_from_user(&space_args,
2890                            (struct btrfs_ioctl_space_args __user *)arg,
2891                            sizeof(space_args)))
2892                 return -EFAULT;
2893
2894         for (i = 0; i < num_types; i++) {
2895                 struct btrfs_space_info *tmp;
2896
2897                 info = NULL;
2898                 rcu_read_lock();
2899                 list_for_each_entry_rcu(tmp, &root->fs_info->space_info,
2900                                         list) {
2901                         if (tmp->flags == types[i]) {
2902                                 info = tmp;
2903                                 break;
2904                         }
2905                 }
2906                 rcu_read_unlock();
2907
2908                 if (!info)
2909                         continue;
2910
2911                 down_read(&info->groups_sem);
2912                 for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) {
2913                         if (!list_empty(&info->block_groups[c]))
2914                                 slot_count++;
2915                 }
2916                 up_read(&info->groups_sem);
2917         }
2918
2919         /* space_slots == 0 means they are asking for a count */
2920         if (space_args.space_slots == 0) {
2921                 space_args.total_spaces = slot_count;
2922                 goto out;
2923         }
2924
2925         slot_count = min_t(u64, space_args.space_slots, slot_count);
2926
2927         alloc_size = sizeof(*dest) * slot_count;
2928
2929         /* we generally have at most 6 or so space infos, one for each raid
2930          * level.  So, a whole page should be more than enough for everyone
2931          */
2932         if (alloc_size > PAGE_CACHE_SIZE)
2933                 return -ENOMEM;
2934
2935         space_args.total_spaces = 0;
2936         dest = kmalloc(alloc_size, GFP_NOFS);
2937         if (!dest)
2938                 return -ENOMEM;
2939         dest_orig = dest;
2940
2941         /* now we have a buffer to copy into */
2942         for (i = 0; i < num_types; i++) {
2943                 struct btrfs_space_info *tmp;
2944
2945                 if (!slot_count)
2946                         break;
2947
2948                 info = NULL;
2949                 rcu_read_lock();
2950                 list_for_each_entry_rcu(tmp, &root->fs_info->space_info,
2951                                         list) {
2952                         if (tmp->flags == types[i]) {
2953                                 info = tmp;
2954                                 break;
2955                         }
2956                 }
2957                 rcu_read_unlock();
2958
2959                 if (!info)
2960                         continue;
2961                 down_read(&info->groups_sem);
2962                 for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) {
2963                         if (!list_empty(&info->block_groups[c])) {
2964                                 get_block_group_info(&info->block_groups[c],
2965                                                      &space);
2966                                 memcpy(dest, &space, sizeof(space));
2967                                 dest++;
2968                                 space_args.total_spaces++;
2969                                 slot_count--;
2970                         }
2971                         if (!slot_count)
2972                                 break;
2973                 }
2974                 up_read(&info->groups_sem);
2975         }
2976
2977         user_dest = (struct btrfs_ioctl_space_info __user *)
2978                 (arg + sizeof(struct btrfs_ioctl_space_args));
2979
2980         if (copy_to_user(user_dest, dest_orig, alloc_size))
2981                 ret = -EFAULT;
2982
2983         kfree(dest_orig);
2984 out:
2985         if (ret == 0 && copy_to_user(arg, &space_args, sizeof(space_args)))
2986                 ret = -EFAULT;
2987
2988         return ret;
2989 }
2990
2991 /*
2992  * there are many ways the trans_start and trans_end ioctls can lead
2993  * to deadlocks.  They should only be used by applications that
2994  * basically own the machine, and have a very in depth understanding
2995  * of all the possible deadlocks and enospc problems.
2996  */
2997 long btrfs_ioctl_trans_end(struct file *file)
2998 {
2999         struct inode *inode = fdentry(file)->d_inode;
3000         struct btrfs_root *root = BTRFS_I(inode)->root;
3001         struct btrfs_trans_handle *trans;
3002
3003         trans = file->private_data;
3004         if (!trans)
3005                 return -EINVAL;
3006         file->private_data = NULL;
3007
3008         btrfs_end_transaction(trans, root);
3009
3010         atomic_dec(&root->fs_info->open_ioctl_trans);
3011
3012         mnt_drop_write_file(file);
3013         return 0;
3014 }
3015
3016 static noinline long btrfs_ioctl_start_sync(struct file *file, void __user *argp)
3017 {
3018         struct btrfs_root *root = BTRFS_I(file->f_dentry->d_inode)->root;
3019         struct btrfs_trans_handle *trans;
3020         u64 transid;
3021         int ret;
3022
3023         trans = btrfs_start_transaction(root, 0);
3024         if (IS_ERR(trans))
3025                 return PTR_ERR(trans);
3026         transid = trans->transid;
3027         ret = btrfs_commit_transaction_async(trans, root, 0);
3028         if (ret) {
3029                 btrfs_end_transaction(trans, root);
3030                 return ret;
3031         }
3032
3033         if (argp)
3034                 if (copy_to_user(argp, &transid, sizeof(transid)))
3035                         return -EFAULT;
3036         return 0;
3037 }
3038
3039 static noinline long btrfs_ioctl_wait_sync(struct file *file, void __user *argp)
3040 {
3041         struct btrfs_root *root = BTRFS_I(file->f_dentry->d_inode)->root;
3042         u64 transid;
3043
3044         if (argp) {
3045                 if (copy_from_user(&transid, argp, sizeof(transid)))
3046                         return -EFAULT;
3047         } else {
3048                 transid = 0;  /* current trans */
3049         }
3050         return btrfs_wait_for_commit(root, transid);
3051 }
3052
3053 static long btrfs_ioctl_scrub(struct btrfs_root *root, void __user *arg)
3054 {
3055         int ret;
3056         struct btrfs_ioctl_scrub_args *sa;
3057
3058         if (!capable(CAP_SYS_ADMIN))
3059                 return -EPERM;
3060
3061         sa = memdup_user(arg, sizeof(*sa));
3062         if (IS_ERR(sa))
3063                 return PTR_ERR(sa);
3064
3065         ret = btrfs_scrub_dev(root, sa->devid, sa->start, sa->end,
3066                               &sa->progress, sa->flags & BTRFS_SCRUB_READONLY);
3067
3068         if (copy_to_user(arg, sa, sizeof(*sa)))
3069                 ret = -EFAULT;
3070
3071         kfree(sa);
3072         return ret;
3073 }
3074
3075 static long btrfs_ioctl_scrub_cancel(struct btrfs_root *root, void __user *arg)
3076 {
3077         if (!capable(CAP_SYS_ADMIN))
3078                 return -EPERM;
3079
3080         return btrfs_scrub_cancel(root);
3081 }
3082
3083 static long btrfs_ioctl_scrub_progress(struct btrfs_root *root,
3084                                        void __user *arg)
3085 {
3086         struct btrfs_ioctl_scrub_args *sa;
3087         int ret;
3088
3089         if (!capable(CAP_SYS_ADMIN))
3090                 return -EPERM;
3091
3092         sa = memdup_user(arg, sizeof(*sa));
3093         if (IS_ERR(sa))
3094                 return PTR_ERR(sa);
3095
3096         ret = btrfs_scrub_progress(root, sa->devid, &sa->progress);
3097
3098         if (copy_to_user(arg, sa, sizeof(*sa)))
3099                 ret = -EFAULT;
3100
3101         kfree(sa);
3102         return ret;
3103 }
3104
3105 static long btrfs_ioctl_get_dev_stats(struct btrfs_root *root,
3106                                       void __user *arg)
3107 {
3108         struct btrfs_ioctl_get_dev_stats *sa;
3109         int ret;
3110
3111         sa = memdup_user(arg, sizeof(*sa));
3112         if (IS_ERR(sa))
3113                 return PTR_ERR(sa);
3114
3115         if ((sa->flags & BTRFS_DEV_STATS_RESET) && !capable(CAP_SYS_ADMIN)) {
3116                 kfree(sa);
3117                 return -EPERM;
3118         }
3119
3120         ret = btrfs_get_dev_stats(root, sa);
3121
3122         if (copy_to_user(arg, sa, sizeof(*sa)))
3123                 ret = -EFAULT;
3124
3125         kfree(sa);
3126         return ret;
3127 }
3128
3129 static long btrfs_ioctl_ino_to_path(struct btrfs_root *root, void __user *arg)
3130 {
3131         int ret = 0;
3132         int i;
3133         u64 rel_ptr;
3134         int size;
3135         struct btrfs_ioctl_ino_path_args *ipa = NULL;
3136         struct inode_fs_paths *ipath = NULL;
3137         struct btrfs_path *path;
3138
3139         if (!capable(CAP_SYS_ADMIN))
3140                 return -EPERM;
3141
3142         path = btrfs_alloc_path();
3143         if (!path) {
3144                 ret = -ENOMEM;
3145                 goto out;
3146         }
3147
3148         ipa = memdup_user(arg, sizeof(*ipa));
3149         if (IS_ERR(ipa)) {
3150                 ret = PTR_ERR(ipa);
3151                 ipa = NULL;
3152                 goto out;
3153         }
3154
3155         size = min_t(u32, ipa->size, 4096);
3156         ipath = init_ipath(size, root, path);
3157         if (IS_ERR(ipath)) {
3158                 ret = PTR_ERR(ipath);
3159                 ipath = NULL;
3160                 goto out;
3161         }
3162
3163         ret = paths_from_inode(ipa->inum, ipath);
3164         if (ret < 0)
3165                 goto out;
3166
3167         for (i = 0; i < ipath->fspath->elem_cnt; ++i) {
3168                 rel_ptr = ipath->fspath->val[i] -
3169                           (u64)(unsigned long)ipath->fspath->val;
3170                 ipath->fspath->val[i] = rel_ptr;
3171         }
3172
3173         ret = copy_to_user((void *)(unsigned long)ipa->fspath,
3174                            (void *)(unsigned long)ipath->fspath, size);
3175         if (ret) {
3176                 ret = -EFAULT;
3177                 goto out;
3178         }
3179
3180 out:
3181         btrfs_free_path(path);
3182         free_ipath(ipath);
3183         kfree(ipa);
3184
3185         return ret;
3186 }
3187
3188 static int build_ino_list(u64 inum, u64 offset, u64 root, void *ctx)
3189 {
3190         struct btrfs_data_container *inodes = ctx;
3191         const size_t c = 3 * sizeof(u64);
3192
3193         if (inodes->bytes_left >= c) {
3194                 inodes->bytes_left -= c;
3195                 inodes->val[inodes->elem_cnt] = inum;
3196                 inodes->val[inodes->elem_cnt + 1] = offset;
3197                 inodes->val[inodes->elem_cnt + 2] = root;
3198                 inodes->elem_cnt += 3;
3199         } else {
3200                 inodes->bytes_missing += c - inodes->bytes_left;
3201                 inodes->bytes_left = 0;
3202                 inodes->elem_missed += 3;
3203         }
3204
3205         return 0;
3206 }
3207
3208 static long btrfs_ioctl_logical_to_ino(struct btrfs_root *root,
3209                                         void __user *arg)
3210 {
3211         int ret = 0;
3212         int size;
3213         u64 extent_item_pos;
3214         struct btrfs_ioctl_logical_ino_args *loi;
3215         struct btrfs_data_container *inodes = NULL;
3216         struct btrfs_path *path = NULL;
3217         struct btrfs_key key;
3218
3219         if (!capable(CAP_SYS_ADMIN))
3220                 return -EPERM;
3221
3222         loi = memdup_user(arg, sizeof(*loi));
3223         if (IS_ERR(loi)) {
3224                 ret = PTR_ERR(loi);
3225                 loi = NULL;
3226                 goto out;
3227         }
3228
3229         path = btrfs_alloc_path();
3230         if (!path) {
3231                 ret = -ENOMEM;
3232                 goto out;
3233         }
3234
3235         size = min_t(u32, loi->size, 4096);
3236         inodes = init_data_container(size);
3237         if (IS_ERR(inodes)) {
3238                 ret = PTR_ERR(inodes);
3239                 inodes = NULL;
3240                 goto out;
3241         }
3242
3243         ret = extent_from_logical(root->fs_info, loi->logical, path, &key);
3244         btrfs_release_path(path);
3245
3246         if (ret & BTRFS_EXTENT_FLAG_TREE_BLOCK)
3247                 ret = -ENOENT;
3248         if (ret < 0)
3249                 goto out;
3250
3251         extent_item_pos = loi->logical - key.objectid;
3252         ret = iterate_extent_inodes(root->fs_info, key.objectid,
3253                                         extent_item_pos, 0, build_ino_list,
3254                                         inodes);
3255
3256         if (ret < 0)
3257                 goto out;
3258
3259         ret = copy_to_user((void *)(unsigned long)loi->inodes,
3260                            (void *)(unsigned long)inodes, size);
3261         if (ret)
3262                 ret = -EFAULT;
3263
3264 out:
3265         btrfs_free_path(path);
3266         kfree(inodes);
3267         kfree(loi);
3268
3269         return ret;
3270 }
3271
3272 void update_ioctl_balance_args(struct btrfs_fs_info *fs_info, int lock,
3273                                struct btrfs_ioctl_balance_args *bargs)
3274 {
3275         struct btrfs_balance_control *bctl = fs_info->balance_ctl;
3276
3277         bargs->flags = bctl->flags;
3278
3279         if (atomic_read(&fs_info->balance_running))
3280                 bargs->state |= BTRFS_BALANCE_STATE_RUNNING;
3281         if (atomic_read(&fs_info->balance_pause_req))
3282                 bargs->state |= BTRFS_BALANCE_STATE_PAUSE_REQ;
3283         if (atomic_read(&fs_info->balance_cancel_req))
3284                 bargs->state |= BTRFS_BALANCE_STATE_CANCEL_REQ;
3285
3286         memcpy(&bargs->data, &bctl->data, sizeof(bargs->data));
3287         memcpy(&bargs->meta, &bctl->meta, sizeof(bargs->meta));
3288         memcpy(&bargs->sys, &bctl->sys, sizeof(bargs->sys));
3289
3290         if (lock) {
3291                 spin_lock(&fs_info->balance_lock);
3292                 memcpy(&bargs->stat, &bctl->stat, sizeof(bargs->stat));
3293                 spin_unlock(&fs_info->balance_lock);
3294         } else {
3295                 memcpy(&bargs->stat, &bctl->stat, sizeof(bargs->stat));
3296         }
3297 }
3298
3299 static long btrfs_ioctl_balance(struct file *file, void __user *arg)
3300 {
3301         struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root;
3302         struct btrfs_fs_info *fs_info = root->fs_info;
3303         struct btrfs_ioctl_balance_args *bargs;
3304         struct btrfs_balance_control *bctl;
3305         int ret;
3306
3307         if (!capable(CAP_SYS_ADMIN))
3308                 return -EPERM;
3309
3310         ret = mnt_want_write_file(file);
3311         if (ret)
3312                 return ret;
3313
3314         mutex_lock(&fs_info->volume_mutex);
3315         mutex_lock(&fs_info->balance_mutex);
3316
3317         if (arg) {
3318                 bargs = memdup_user(arg, sizeof(*bargs));
3319                 if (IS_ERR(bargs)) {
3320                         ret = PTR_ERR(bargs);
3321                         goto out;
3322                 }
3323
3324                 if (bargs->flags & BTRFS_BALANCE_RESUME) {
3325                         if (!fs_info->balance_ctl) {
3326                                 ret = -ENOTCONN;
3327                                 goto out_bargs;
3328                         }
3329
3330                         bctl = fs_info->balance_ctl;
3331                         spin_lock(&fs_info->balance_lock);
3332                         bctl->flags |= BTRFS_BALANCE_RESUME;
3333                         spin_unlock(&fs_info->balance_lock);
3334
3335                         goto do_balance;
3336                 }
3337         } else {
3338                 bargs = NULL;
3339         }
3340
3341         if (fs_info->balance_ctl) {
3342                 ret = -EINPROGRESS;
3343                 goto out_bargs;
3344         }
3345
3346         bctl = kzalloc(sizeof(*bctl), GFP_NOFS);
3347         if (!bctl) {
3348                 ret = -ENOMEM;
3349                 goto out_bargs;
3350         }
3351
3352         bctl->fs_info = fs_info;
3353         if (arg) {
3354                 memcpy(&bctl->data, &bargs->data, sizeof(bctl->data));
3355                 memcpy(&bctl->meta, &bargs->meta, sizeof(bctl->meta));
3356                 memcpy(&bctl->sys, &bargs->sys, sizeof(bctl->sys));
3357
3358                 bctl->flags = bargs->flags;
3359         } else {
3360                 /* balance everything - no filters */
3361                 bctl->flags |= BTRFS_BALANCE_TYPE_MASK;
3362         }
3363
3364 do_balance:
3365         ret = btrfs_balance(bctl, bargs);
3366         /*
3367          * bctl is freed in __cancel_balance or in free_fs_info if
3368          * restriper was paused all the way until unmount
3369          */
3370         if (arg) {
3371                 if (copy_to_user(arg, bargs, sizeof(*bargs)))
3372                         ret = -EFAULT;
3373         }
3374
3375 out_bargs:
3376         kfree(bargs);
3377 out:
3378         mutex_unlock(&fs_info->balance_mutex);
3379         mutex_unlock(&fs_info->volume_mutex);
3380         mnt_drop_write_file(file);
3381         return ret;
3382 }
3383
3384 static long btrfs_ioctl_balance_ctl(struct btrfs_root *root, int cmd)
3385 {
3386         if (!capable(CAP_SYS_ADMIN))
3387                 return -EPERM;
3388
3389         switch (cmd) {
3390         case BTRFS_BALANCE_CTL_PAUSE:
3391                 return btrfs_pause_balance(root->fs_info);
3392         case BTRFS_BALANCE_CTL_CANCEL:
3393                 return btrfs_cancel_balance(root->fs_info);
3394         }
3395
3396         return -EINVAL;
3397 }
3398
3399 static long btrfs_ioctl_balance_progress(struct btrfs_root *root,
3400                                          void __user *arg)
3401 {
3402         struct btrfs_fs_info *fs_info = root->fs_info;
3403         struct btrfs_ioctl_balance_args *bargs;
3404         int ret = 0;
3405
3406         if (!capable(CAP_SYS_ADMIN))
3407                 return -EPERM;
3408
3409         mutex_lock(&fs_info->balance_mutex);
3410         if (!fs_info->balance_ctl) {
3411                 ret = -ENOTCONN;
3412                 goto out;
3413         }
3414
3415         bargs = kzalloc(sizeof(*bargs), GFP_NOFS);
3416         if (!bargs) {
3417                 ret = -ENOMEM;
3418                 goto out;
3419         }
3420
3421         update_ioctl_balance_args(fs_info, 1, bargs);
3422
3423         if (copy_to_user(arg, bargs, sizeof(*bargs)))
3424                 ret = -EFAULT;
3425
3426         kfree(bargs);
3427 out:
3428         mutex_unlock(&fs_info->balance_mutex);
3429         return ret;
3430 }
3431
3432 static long btrfs_ioctl_quota_ctl(struct btrfs_root *root, void __user *arg)
3433 {
3434         struct btrfs_ioctl_quota_ctl_args *sa;
3435         struct btrfs_trans_handle *trans = NULL;
3436         int ret;
3437         int err;
3438
3439         if (!capable(CAP_SYS_ADMIN))
3440                 return -EPERM;
3441
3442         if (root->fs_info->sb->s_flags & MS_RDONLY)
3443                 return -EROFS;
3444
3445         sa = memdup_user(arg, sizeof(*sa));
3446         if (IS_ERR(sa))
3447                 return PTR_ERR(sa);
3448
3449         if (sa->cmd != BTRFS_QUOTA_CTL_RESCAN) {
3450                 trans = btrfs_start_transaction(root, 2);
3451                 if (IS_ERR(trans)) {
3452                         ret = PTR_ERR(trans);
3453                         goto out;
3454                 }
3455         }
3456
3457         switch (sa->cmd) {
3458         case BTRFS_QUOTA_CTL_ENABLE:
3459                 ret = btrfs_quota_enable(trans, root->fs_info);
3460                 break;
3461         case BTRFS_QUOTA_CTL_DISABLE:
3462                 ret = btrfs_quota_disable(trans, root->fs_info);
3463                 break;
3464         case BTRFS_QUOTA_CTL_RESCAN:
3465                 ret = btrfs_quota_rescan(root->fs_info);
3466                 break;
3467         default:
3468                 ret = -EINVAL;
3469                 break;
3470         }
3471
3472         if (copy_to_user(arg, sa, sizeof(*sa)))
3473                 ret = -EFAULT;
3474
3475         if (trans) {
3476                 err = btrfs_commit_transaction(trans, root);
3477                 if (err && !ret)
3478                         ret = err;
3479         }
3480
3481 out:
3482         kfree(sa);
3483         return ret;
3484 }
3485
3486 static long btrfs_ioctl_qgroup_assign(struct btrfs_root *root, void __user *arg)
3487 {
3488         struct btrfs_ioctl_qgroup_assign_args *sa;
3489         struct btrfs_trans_handle *trans;
3490         int ret;
3491         int err;
3492
3493         if (!capable(CAP_SYS_ADMIN))
3494                 return -EPERM;
3495
3496         if (root->fs_info->sb->s_flags & MS_RDONLY)
3497                 return -EROFS;
3498
3499         sa = memdup_user(arg, sizeof(*sa));
3500         if (IS_ERR(sa))
3501                 return PTR_ERR(sa);
3502
3503         trans = btrfs_join_transaction(root);
3504         if (IS_ERR(trans)) {
3505                 ret = PTR_ERR(trans);
3506                 goto out;
3507         }
3508
3509         /* FIXME: check if the IDs really exist */
3510         if (sa->assign) {
3511                 ret = btrfs_add_qgroup_relation(trans, root->fs_info,
3512                                                 sa->src, sa->dst);
3513         } else {
3514                 ret = btrfs_del_qgroup_relation(trans, root->fs_info,
3515                                                 sa->src, sa->dst);
3516         }
3517
3518         err = btrfs_end_transaction(trans, root);
3519         if (err && !ret)
3520                 ret = err;
3521
3522 out:
3523         kfree(sa);
3524         return ret;
3525 }
3526
3527 static long btrfs_ioctl_qgroup_create(struct btrfs_root *root, void __user *arg)
3528 {
3529         struct btrfs_ioctl_qgroup_create_args *sa;
3530         struct btrfs_trans_handle *trans;
3531         int ret;
3532         int err;
3533
3534         if (!capable(CAP_SYS_ADMIN))
3535                 return -EPERM;
3536
3537         if (root->fs_info->sb->s_flags & MS_RDONLY)
3538                 return -EROFS;
3539
3540         sa = memdup_user(arg, sizeof(*sa));
3541         if (IS_ERR(sa))
3542                 return PTR_ERR(sa);
3543
3544         trans = btrfs_join_transaction(root);
3545         if (IS_ERR(trans)) {
3546                 ret = PTR_ERR(trans);
3547                 goto out;
3548         }
3549
3550         /* FIXME: check if the IDs really exist */
3551         if (sa->create) {
3552                 ret = btrfs_create_qgroup(trans, root->fs_info, sa->qgroupid,
3553                                           NULL);
3554         } else {
3555                 ret = btrfs_remove_qgroup(trans, root->fs_info, sa->qgroupid);
3556         }
3557
3558         err = btrfs_end_transaction(trans, root);
3559         if (err && !ret)
3560                 ret = err;
3561
3562 out:
3563         kfree(sa);
3564         return ret;
3565 }
3566
3567 static long btrfs_ioctl_qgroup_limit(struct btrfs_root *root, void __user *arg)
3568 {
3569         struct btrfs_ioctl_qgroup_limit_args *sa;
3570         struct btrfs_trans_handle *trans;
3571         int ret;
3572         int err;
3573         u64 qgroupid;
3574
3575         if (!capable(CAP_SYS_ADMIN))
3576                 return -EPERM;
3577
3578         if (root->fs_info->sb->s_flags & MS_RDONLY)
3579                 return -EROFS;
3580
3581         sa = memdup_user(arg, sizeof(*sa));
3582         if (IS_ERR(sa))
3583                 return PTR_ERR(sa);
3584
3585         trans = btrfs_join_transaction(root);
3586         if (IS_ERR(trans)) {
3587                 ret = PTR_ERR(trans);
3588                 goto out;
3589         }
3590
3591         qgroupid = sa->qgroupid;
3592         if (!qgroupid) {
3593                 /* take the current subvol as qgroup */
3594                 qgroupid = root->root_key.objectid;
3595         }
3596
3597         /* FIXME: check if the IDs really exist */
3598         ret = btrfs_limit_qgroup(trans, root->fs_info, qgroupid, &sa->lim);
3599
3600         err = btrfs_end_transaction(trans, root);
3601         if (err && !ret)
3602                 ret = err;
3603
3604 out:
3605         kfree(sa);
3606         return ret;
3607 }
3608
3609 static long btrfs_ioctl_set_received_subvol(struct file *file,
3610                                             void __user *arg)
3611 {
3612         struct btrfs_ioctl_received_subvol_args *sa = NULL;
3613         struct inode *inode = fdentry(file)->d_inode;
3614         struct btrfs_root *root = BTRFS_I(inode)->root;
3615         struct btrfs_root_item *root_item = &root->root_item;
3616         struct btrfs_trans_handle *trans;
3617         struct timespec ct = CURRENT_TIME;
3618         int ret = 0;
3619
3620         ret = mnt_want_write_file(file);
3621         if (ret < 0)
3622                 return ret;
3623
3624         down_write(&root->fs_info->subvol_sem);
3625
3626         if (btrfs_ino(inode) != BTRFS_FIRST_FREE_OBJECTID) {
3627                 ret = -EINVAL;
3628                 goto out;
3629         }
3630
3631         if (btrfs_root_readonly(root)) {
3632                 ret = -EROFS;
3633                 goto out;
3634         }
3635
3636         if (!inode_owner_or_capable(inode)) {
3637                 ret = -EACCES;
3638                 goto out;
3639         }
3640
3641         sa = memdup_user(arg, sizeof(*sa));
3642         if (IS_ERR(sa)) {
3643                 ret = PTR_ERR(sa);
3644                 sa = NULL;
3645                 goto out;
3646         }
3647
3648         trans = btrfs_start_transaction(root, 1);
3649         if (IS_ERR(trans)) {
3650                 ret = PTR_ERR(trans);
3651                 trans = NULL;
3652                 goto out;
3653         }
3654
3655         sa->rtransid = trans->transid;
3656         sa->rtime.sec = ct.tv_sec;
3657         sa->rtime.nsec = ct.tv_nsec;
3658
3659         memcpy(root_item->received_uuid, sa->uuid, BTRFS_UUID_SIZE);
3660         btrfs_set_root_stransid(root_item, sa->stransid);
3661         btrfs_set_root_rtransid(root_item, sa->rtransid);
3662         root_item->stime.sec = cpu_to_le64(sa->stime.sec);
3663         root_item->stime.nsec = cpu_to_le32(sa->stime.nsec);
3664         root_item->rtime.sec = cpu_to_le64(sa->rtime.sec);
3665         root_item->rtime.nsec = cpu_to_le32(sa->rtime.nsec);
3666
3667         ret = btrfs_update_root(trans, root->fs_info->tree_root,
3668                                 &root->root_key, &root->root_item);
3669         if (ret < 0) {
3670                 btrfs_end_transaction(trans, root);
3671                 trans = NULL;
3672                 goto out;
3673         } else {
3674                 ret = btrfs_commit_transaction(trans, root);
3675                 if (ret < 0)
3676                         goto out;
3677         }
3678
3679         ret = copy_to_user(arg, sa, sizeof(*sa));
3680         if (ret)
3681                 ret = -EFAULT;
3682
3683 out:
3684         kfree(sa);
3685         up_write(&root->fs_info->subvol_sem);
3686         mnt_drop_write_file(file);
3687         return ret;
3688 }
3689
3690 long btrfs_ioctl(struct file *file, unsigned int
3691                 cmd, unsigned long arg)
3692 {
3693         struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root;
3694         void __user *argp = (void __user *)arg;
3695
3696         switch (cmd) {
3697         case FS_IOC_GETFLAGS:
3698                 return btrfs_ioctl_getflags(file, argp);
3699         case FS_IOC_SETFLAGS:
3700                 return btrfs_ioctl_setflags(file, argp);
3701         case FS_IOC_GETVERSION:
3702                 return btrfs_ioctl_getversion(file, argp);
3703         case FITRIM:
3704                 return btrfs_ioctl_fitrim(file, argp);
3705         case BTRFS_IOC_SNAP_CREATE:
3706                 return btrfs_ioctl_snap_create(file, argp, 0);
3707         case BTRFS_IOC_SNAP_CREATE_V2:
3708                 return btrfs_ioctl_snap_create_v2(file, argp, 0);
3709         case BTRFS_IOC_SUBVOL_CREATE:
3710                 return btrfs_ioctl_snap_create(file, argp, 1);
3711         case BTRFS_IOC_SUBVOL_CREATE_V2:
3712                 return btrfs_ioctl_snap_create_v2(file, argp, 1);
3713         case BTRFS_IOC_SNAP_DESTROY:
3714                 return btrfs_ioctl_snap_destroy(file, argp);
3715         case BTRFS_IOC_SUBVOL_GETFLAGS:
3716                 return btrfs_ioctl_subvol_getflags(file, argp);
3717         case BTRFS_IOC_SUBVOL_SETFLAGS:
3718                 return btrfs_ioctl_subvol_setflags(file, argp);
3719         case BTRFS_IOC_DEFAULT_SUBVOL:
3720                 return btrfs_ioctl_default_subvol(file, argp);
3721         case BTRFS_IOC_DEFRAG:
3722                 return btrfs_ioctl_defrag(file, NULL);
3723         case BTRFS_IOC_DEFRAG_RANGE:
3724                 return btrfs_ioctl_defrag(file, argp);
3725         case BTRFS_IOC_RESIZE:
3726                 return btrfs_ioctl_resize(root, argp);
3727         case BTRFS_IOC_ADD_DEV:
3728                 return btrfs_ioctl_add_dev(root, argp);
3729         case BTRFS_IOC_RM_DEV:
3730                 return btrfs_ioctl_rm_dev(root, argp);
3731         case BTRFS_IOC_FS_INFO:
3732                 return btrfs_ioctl_fs_info(root, argp);
3733         case BTRFS_IOC_DEV_INFO:
3734                 return btrfs_ioctl_dev_info(root, argp);
3735         case BTRFS_IOC_BALANCE:
3736                 return btrfs_ioctl_balance(file, NULL);
3737         case BTRFS_IOC_CLONE:
3738                 return btrfs_ioctl_clone(file, arg, 0, 0, 0);
3739         case BTRFS_IOC_CLONE_RANGE:
3740                 return btrfs_ioctl_clone_range(file, argp);
3741         case BTRFS_IOC_TRANS_START:
3742                 return btrfs_ioctl_trans_start(file);
3743         case BTRFS_IOC_TRANS_END:
3744                 return btrfs_ioctl_trans_end(file);
3745         case BTRFS_IOC_TREE_SEARCH:
3746                 return btrfs_ioctl_tree_search(file, argp);
3747         case BTRFS_IOC_INO_LOOKUP:
3748                 return btrfs_ioctl_ino_lookup(file, argp);
3749         case BTRFS_IOC_INO_PATHS:
3750                 return btrfs_ioctl_ino_to_path(root, argp);
3751         case BTRFS_IOC_LOGICAL_INO:
3752                 return btrfs_ioctl_logical_to_ino(root, argp);
3753         case BTRFS_IOC_SPACE_INFO:
3754                 return btrfs_ioctl_space_info(root, argp);
3755         case BTRFS_IOC_SYNC:
3756                 btrfs_sync_fs(file->f_dentry->d_sb, 1);
3757                 return 0;
3758         case BTRFS_IOC_START_SYNC:
3759                 return btrfs_ioctl_start_sync(file, argp);
3760         case BTRFS_IOC_WAIT_SYNC:
3761                 return btrfs_ioctl_wait_sync(file, argp);
3762         case BTRFS_IOC_SCRUB:
3763                 return btrfs_ioctl_scrub(root, argp);
3764         case BTRFS_IOC_SCRUB_CANCEL:
3765                 return btrfs_ioctl_scrub_cancel(root, argp);
3766         case BTRFS_IOC_SCRUB_PROGRESS:
3767                 return btrfs_ioctl_scrub_progress(root, argp);
3768         case BTRFS_IOC_BALANCE_V2:
3769                 return btrfs_ioctl_balance(file, argp);
3770         case BTRFS_IOC_BALANCE_CTL:
3771                 return btrfs_ioctl_balance_ctl(root, arg);
3772         case BTRFS_IOC_BALANCE_PROGRESS:
3773                 return btrfs_ioctl_balance_progress(root, argp);
3774         case BTRFS_IOC_SET_RECEIVED_SUBVOL:
3775                 return btrfs_ioctl_set_received_subvol(file, argp);
3776         case BTRFS_IOC_SEND:
3777                 return btrfs_ioctl_send(file, argp);
3778         case BTRFS_IOC_GET_DEV_STATS:
3779                 return btrfs_ioctl_get_dev_stats(root, argp);
3780         case BTRFS_IOC_QUOTA_CTL:
3781                 return btrfs_ioctl_quota_ctl(root, argp);
3782         case BTRFS_IOC_QGROUP_ASSIGN:
3783                 return btrfs_ioctl_qgroup_assign(root, argp);
3784         case BTRFS_IOC_QGROUP_CREATE:
3785                 return btrfs_ioctl_qgroup_create(root, argp);
3786         case BTRFS_IOC_QGROUP_LIMIT:
3787                 return btrfs_ioctl_qgroup_limit(root, argp);
3788         }
3789
3790         return -ENOTTY;
3791 }