fs/btrfs/ioctl.c

   1 /*
   2  * Copyright (C) 2007 Oracle.  All rights reserved.
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public
   6  * License v2 as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  11  * General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public
  14  * License along with this program; if not, write to the
  15  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  16  * Boston, MA 021110-1307, USA.
  17  */
  18
  19 #include <linux/kernel.h>
  20 #include <linux/bio.h>
  21 #include <linux/buffer_head.h>
  22 #include <linux/file.h>
  23 #include <linux/fs.h>
  24 #include <linux/fsnotify.h>
  25 #include <linux/pagemap.h>
  26 #include <linux/highmem.h>
  27 #include <linux/time.h>
  28 #include <linux/init.h>
  29 #include <linux/string.h>
  30 #include <linux/backing-dev.h>
  31 #include <linux/mount.h>
  32 #include <linux/mpage.h>
  33 #include <linux/namei.h>
  34 #include <linux/swap.h>
  35 #include <linux/writeback.h>
  36 #include <linux/compat.h>
  37 #include <linux/bit_spinlock.h>
  38 #include <linux/security.h>
  39 #include <linux/xattr.h>
  40 #include <linux/mm.h>
  41 #include <linux/slab.h>
  42 #include <linux/blkdev.h>
  43 #include <linux/uuid.h>
  44 #include <linux/btrfs.h>
  45 #include <linux/uaccess.h>
  46 #include "ctree.h"
  47 #include "disk-io.h"
  48 #include "transaction.h"
  49 #include "btrfs_inode.h"
  50 #include "print-tree.h"
  51 #include "volumes.h"
  52 #include "locking.h"
  53 #include "inode-map.h"
  54 #include "backref.h"
  55 #include "rcu-string.h"
  56 #include "send.h"
  57 #include "dev-replace.h"
  58 #include "props.h"
  59 #include "sysfs.h"
  60 #include "qgroup.h"
  61 #include "tree-log.h"
  62 #include "compression.h"
  63
  64 #ifdef CONFIG_64BIT
  65 /* If we have a 32-bit userspace and 64-bit kernel, then the UAPI
  66  * structures are incorrect, as the timespec structure from userspace
  67  * is 4 bytes too small. We define these alternatives here to teach
  68  * the kernel about the 32-bit struct packing.
  69  */
  70 struct btrfs_ioctl_timespec_32 {
  71         __u64 sec;
  72         __u32 nsec;
  73 } __attribute__ ((__packed__));
  74
  75 struct btrfs_ioctl_received_subvol_args_32 {
  76         char    uuid[BTRFS_UUID_SIZE];  /* in */
  77         __u64   stransid;               /* in */
  78         __u64   rtransid;               /* out */
  79         struct btrfs_ioctl_timespec_32 stime; /* in */
  80         struct btrfs_ioctl_timespec_32 rtime; /* out */
  81         __u64   flags;                  /* in */
  82         __u64   reserved[16];           /* in */
  83 } __attribute__ ((__packed__));
  84
  85 #define BTRFS_IOC_SET_RECEIVED_SUBVOL_32 _IOWR(BTRFS_IOCTL_MAGIC, 37, \
  86                                 struct btrfs_ioctl_received_subvol_args_32)
  87 #endif
  88
  89
  90 static int btrfs_clone(struct inode *src, struct inode *inode,
  91                        u64 off, u64 olen, u64 olen_aligned, u64 destoff,
  92                        int no_time_update);
  93
  94 /* Mask out flags that are inappropriate for the given type of inode. */
  95 static inline __u32 btrfs_mask_flags(umode_t mode, __u32 flags)
  96 {
  97         if (S_ISDIR(mode))
  98                 return flags;
  99         else if (S_ISREG(mode))
 100                 return flags & ~FS_DIRSYNC_FL;
 101         else
 102                 return flags & (FS_NODUMP_FL | FS_NOATIME_FL);
 103 }
 104
 105 /*
 106  * Export inode flags to the format expected by the FS_IOC_GETFLAGS ioctl.
 107  */
 108 static unsigned int btrfs_flags_to_ioctl(unsigned int flags)
 109 {
 110         unsigned int iflags = 0;
 111
 112         if (flags & BTRFS_INODE_SYNC)
 113                 iflags |= FS_SYNC_FL;
 114         if (flags & BTRFS_INODE_IMMUTABLE)
 115                 iflags |= FS_IMMUTABLE_FL;
 116         if (flags & BTRFS_INODE_APPEND)
 117                 iflags |= FS_APPEND_FL;
 118         if (flags & BTRFS_INODE_NODUMP)
 119                 iflags |= FS_NODUMP_FL;
 120         if (flags & BTRFS_INODE_NOATIME)
 121                 iflags |= FS_NOATIME_FL;
 122         if (flags & BTRFS_INODE_DIRSYNC)
 123                 iflags |= FS_DIRSYNC_FL;
 124         if (flags & BTRFS_INODE_NODATACOW)
 125                 iflags |= FS_NOCOW_FL;
 126
 127         if (flags & BTRFS_INODE_NOCOMPRESS)
 128                 iflags |= FS_NOCOMP_FL;
 129         else if (flags & BTRFS_INODE_COMPRESS)
 130                 iflags |= FS_COMPR_FL;
 131
 132         return iflags;
 133 }
 134
 135 /*
 136  * Update inode->i_flags based on the btrfs internal flags.
 137  */
 138 void btrfs_update_iflags(struct inode *inode)
 139 {
 140         struct btrfs_inode *ip = BTRFS_I(inode);
 141         unsigned int new_fl = 0;
 142
 143         if (ip->flags & BTRFS_INODE_SYNC)
 144                 new_fl |= S_SYNC;
 145         if (ip->flags & BTRFS_INODE_IMMUTABLE)
 146                 new_fl |= S_IMMUTABLE;
 147         if (ip->flags & BTRFS_INODE_APPEND)
 148                 new_fl |= S_APPEND;
 149         if (ip->flags & BTRFS_INODE_NOATIME)
 150                 new_fl |= S_NOATIME;
 151         if (ip->flags & BTRFS_INODE_DIRSYNC)
 152                 new_fl |= S_DIRSYNC;
 153
 154         set_mask_bits(&inode->i_flags,
 155                       S_SYNC | S_APPEND | S_IMMUTABLE | S_NOATIME | S_DIRSYNC,
 156                       new_fl);
 157 }
 158
 159 static int btrfs_ioctl_getflags(struct file *file, void __user *arg)
 160 {
 161         struct btrfs_inode *ip = BTRFS_I(file_inode(file));
 162         unsigned int flags = btrfs_flags_to_ioctl(ip->flags);
 163
 164         if (copy_to_user(arg, &flags, sizeof(flags)))
 165                 return -EFAULT;
 166         return 0;
 167 }
 168
 169 static int check_flags(unsigned int flags)
 170 {
 171         if (flags & ~(FS_IMMUTABLE_FL | FS_APPEND_FL | \
 172                       FS_NOATIME_FL | FS_NODUMP_FL | \
 173                       FS_SYNC_FL | FS_DIRSYNC_FL | \
 174                       FS_NOCOMP_FL | FS_COMPR_FL |
 175                       FS_NOCOW_FL))
 176                 return -EOPNOTSUPP;
 177
 178         if ((flags & FS_NOCOMP_FL) && (flags & FS_COMPR_FL))
 179                 return -EINVAL;
 180
 181         return 0;
 182 }
 183
 184 static int btrfs_ioctl_setflags(struct file *file, void __user *arg)
 185 {
 186         struct inode *inode = file_inode(file);
 187         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
 188         struct btrfs_inode *ip = BTRFS_I(inode);
 189         struct btrfs_root *root = ip->root;
 190         struct btrfs_trans_handle *trans;
 191         unsigned int flags, oldflags;
 192         int ret;
 193         u64 ip_oldflags;
 194         unsigned int i_oldflags;
 195         umode_t mode;
 196
 197         if (!inode_owner_or_capable(inode))
 198                 return -EPERM;
 199
 200         if (btrfs_root_readonly(root))
 201                 return -EROFS;
 202
 203         if (copy_from_user(&flags, arg, sizeof(flags)))
 204                 return -EFAULT;
 205
 206         ret = check_flags(flags);
 207         if (ret)
 208                 return ret;
 209
 210         ret = mnt_want_write_file(file);
 211         if (ret)
 212                 return ret;
 213
 214         inode_lock(inode);
 215
 216         ip_oldflags = ip->flags;
 217         i_oldflags = inode->i_flags;
 218         mode = inode->i_mode;
 219
 220         flags = btrfs_mask_flags(inode->i_mode, flags);
 221         oldflags = btrfs_flags_to_ioctl(ip->flags);
 222         if ((flags ^ oldflags) & (FS_APPEND_FL | FS_IMMUTABLE_FL)) {
 223                 if (!capable(CAP_LINUX_IMMUTABLE)) {
 224                         ret = -EPERM;
 225                         goto out_unlock;
 226                 }
 227         }
 228
 229         if (flags & FS_SYNC_FL)
 230                 ip->flags |= BTRFS_INODE_SYNC;
 231         else
 232                 ip->flags &= ~BTRFS_INODE_SYNC;
 233         if (flags & FS_IMMUTABLE_FL)
 234                 ip->flags |= BTRFS_INODE_IMMUTABLE;
 235         else
 236                 ip->flags &= ~BTRFS_INODE_IMMUTABLE;
 237         if (flags & FS_APPEND_FL)
 238                 ip->flags |= BTRFS_INODE_APPEND;
 239         else
 240                 ip->flags &= ~BTRFS_INODE_APPEND;
 241         if (flags & FS_NODUMP_FL)
 242                 ip->flags |= BTRFS_INODE_NODUMP;
 243         else
 244                 ip->flags &= ~BTRFS_INODE_NODUMP;
 245         if (flags & FS_NOATIME_FL)
 246                 ip->flags |= BTRFS_INODE_NOATIME;
 247         else
 248                 ip->flags &= ~BTRFS_INODE_NOATIME;
 249         if (flags & FS_DIRSYNC_FL)
 250                 ip->flags |= BTRFS_INODE_DIRSYNC;
 251         else
 252                 ip->flags &= ~BTRFS_INODE_DIRSYNC;
 253         if (flags & FS_NOCOW_FL) {
 254                 if (S_ISREG(mode)) {
 255                         /*
 256                          * It's safe to turn csums off here, no extents exist.
 257                          * Otherwise we want the flag to reflect the real COW
 258                          * status of the file and will not set it.
 259                          */
 260                         if (inode->i_size == 0)
 261                                 ip->flags |= BTRFS_INODE_NODATACOW
 262                                            | BTRFS_INODE_NODATASUM;
 263                 } else {
 264                         ip->flags |= BTRFS_INODE_NODATACOW;
 265                 }
 266         } else {
 267                 /*
 268                  * Revert back under same assumptions as above
 269                  */
 270                 if (S_ISREG(mode)) {
 271                         if (inode->i_size == 0)
 272                                 ip->flags &= ~(BTRFS_INODE_NODATACOW
 273                                              | BTRFS_INODE_NODATASUM);
 274                 } else {
 275                         ip->flags &= ~BTRFS_INODE_NODATACOW;
 276                 }
 277         }
 278
 279         /*
 280          * The COMPRESS flag can only be changed by users, while the NOCOMPRESS
 281          * flag may be changed automatically if compression code won't make
 282          * things smaller.
 283          */
 284         if (flags & FS_NOCOMP_FL) {
 285                 ip->flags &= ~BTRFS_INODE_COMPRESS;
 286                 ip->flags |= BTRFS_INODE_NOCOMPRESS;
 287
 288                 ret = btrfs_set_prop(inode, "btrfs.compression", NULL, 0, 0);
 289                 if (ret && ret != -ENODATA)
 290                         goto out_drop;
 291         } else if (flags & FS_COMPR_FL) {
 292                 const char *comp;
 293
 294                 ip->flags |= BTRFS_INODE_COMPRESS;
 295                 ip->flags &= ~BTRFS_INODE_NOCOMPRESS;
 296
 297                 if (fs_info->compress_type == BTRFS_COMPRESS_LZO)
 298                         comp = "lzo";
 299                 else
 300                         comp = "zlib";
 301                 ret = btrfs_set_prop(inode, "btrfs.compression",
 302                                      comp, strlen(comp), 0);
 303                 if (ret)
 304                         goto out_drop;
 305
 306         } else {
 307                 ret = btrfs_set_prop(inode, "btrfs.compression", NULL, 0, 0);
 308                 if (ret && ret != -ENODATA)
 309                         goto out_drop;
 310                 ip->flags &= ~(BTRFS_INODE_COMPRESS | BTRFS_INODE_NOCOMPRESS);
 311         }
 312
 313         trans = btrfs_start_transaction(root, 1);
 314         if (IS_ERR(trans)) {
 315                 ret = PTR_ERR(trans);
 316                 goto out_drop;
 317         }
 318
 319         btrfs_update_iflags(inode);
 320         inode_inc_iversion(inode);
 321         inode->i_ctime = current_time(inode);
 322         ret = btrfs_update_inode(trans, root, inode);
 323
 324         btrfs_end_transaction(trans);
 325  out_drop:
 326         if (ret) {
 327                 ip->flags = ip_oldflags;
 328                 inode->i_flags = i_oldflags;
 329         }
 330
 331  out_unlock:
 332         inode_unlock(inode);
 333         mnt_drop_write_file(file);
 334         return ret;
 335 }
 336
 337 static int btrfs_ioctl_getversion(struct file *file, int __user *arg)
 338 {
 339         struct inode *inode = file_inode(file);
 340
 341         return put_user(inode->i_generation, arg);
 342 }
 343
 344 static noinline int btrfs_ioctl_fitrim(struct file *file, void __user *arg)
 345 {
 346         struct inode *inode = file_inode(file);
 347         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
 348         struct btrfs_device *device;
 349         struct request_queue *q;
 350         struct fstrim_range range;
 351         u64 minlen = ULLONG_MAX;
 352         u64 num_devices = 0;
 353         u64 total_bytes = btrfs_super_total_bytes(fs_info->super_copy);
 354         int ret;
 355
 356         if (!capable(CAP_SYS_ADMIN))
 357                 return -EPERM;
 358
 359         rcu_read_lock();
 360         list_for_each_entry_rcu(device, &fs_info->fs_devices->devices,
 361                                 dev_list) {
 362                 if (!device->bdev)
 363                         continue;
 364                 q = bdev_get_queue(device->bdev);
 365                 if (blk_queue_discard(q)) {
 366                         num_devices++;
 367                         minlen = min_t(u64, q->limits.discard_granularity,
 368                                      minlen);
 369                 }
 370         }
 371         rcu_read_unlock();
 372
 373         if (!num_devices)
 374                 return -EOPNOTSUPP;
 375         if (copy_from_user(&range, arg, sizeof(range)))
 376                 return -EFAULT;
 377         if (range.start > total_bytes ||
 378             range.len < fs_info->sb->s_blocksize)
 379                 return -EINVAL;
 380
 381         range.len = min(range.len, total_bytes - range.start);
 382         range.minlen = max(range.minlen, minlen);
 383         ret = btrfs_trim_fs(fs_info, &range);
 384         if (ret < 0)
 385                 return ret;
 386
 387         if (copy_to_user(arg, &range, sizeof(range)))
 388                 return -EFAULT;
 389
 390         return 0;
 391 }
 392
 393 int btrfs_is_empty_uuid(u8 *uuid)
 394 {
 395         int i;
 396
 397         for (i = 0; i < BTRFS_UUID_SIZE; i++) {
 398                 if (uuid[i])
 399                         return 0;
 400         }
 401         return 1;
 402 }
 403
 404 static noinline int create_subvol(struct inode *dir,
 405                                   struct dentry *dentry,
 406                                   const char *name, int namelen,
 407                                   u64 *async_transid,
 408                                   struct btrfs_qgroup_inherit *inherit)
 409 {
 410         struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
 411         struct btrfs_trans_handle *trans;
 412         struct btrfs_key key;
 413         struct btrfs_root_item *root_item;
 414         struct btrfs_inode_item *inode_item;
 415         struct extent_buffer *leaf;
 416         struct btrfs_root *root = BTRFS_I(dir)->root;
 417         struct btrfs_root *new_root;
 418         struct btrfs_block_rsv block_rsv;
 419         struct timespec cur_time = current_time(dir);
 420         struct inode *inode;
 421         int ret;
 422         int err;
 423         u64 objectid;
 424         u64 new_dirid = BTRFS_FIRST_FREE_OBJECTID;
 425         u64 index = 0;
 426         u64 qgroup_reserved;
 427         uuid_le new_uuid;
 428
 429         root_item = kzalloc(sizeof(*root_item), GFP_KERNEL);
 430         if (!root_item)
 431                 return -ENOMEM;
 432
 433         ret = btrfs_find_free_objectid(fs_info->tree_root, &objectid);
 434         if (ret)
 435                 goto fail_free;
 436
 437         /*
 438          * Don't create subvolume whose level is not zero. Or qgroup will be
 439          * screwed up since it assumes subvolume qgroup's level to be 0.
 440          */
 441         if (btrfs_qgroup_level(objectid)) {
 442                 ret = -ENOSPC;
 443                 goto fail_free;
 444         }
 445
 446         btrfs_init_block_rsv(&block_rsv, BTRFS_BLOCK_RSV_TEMP);
 447         /*
 448          * The same as the snapshot creation, please see the comment
 449          * of create_snapshot().
 450          */
 451         ret = btrfs_subvolume_reserve_metadata(root, &block_rsv,
 452                                                8, &qgroup_reserved, false);
 453         if (ret)
 454                 goto fail_free;
 455
 456         trans = btrfs_start_transaction(root, 0);
 457         if (IS_ERR(trans)) {
 458                 ret = PTR_ERR(trans);
 459                 btrfs_subvolume_release_metadata(fs_info, &block_rsv);
 460                 goto fail_free;
 461         }
 462         trans->block_rsv = &block_rsv;
 463         trans->bytes_reserved = block_rsv.size;
 464
 465         ret = btrfs_qgroup_inherit(trans, fs_info, 0, objectid, inherit);
 466         if (ret)
 467                 goto fail;
 468
 469         leaf = btrfs_alloc_tree_block(trans, root, 0, objectid, NULL, 0, 0, 0);
 470         if (IS_ERR(leaf)) {
 471                 ret = PTR_ERR(leaf);
 472                 goto fail;
 473         }
 474
 475         memzero_extent_buffer(leaf, 0, sizeof(struct btrfs_header));
 476         btrfs_set_header_bytenr(leaf, leaf->start);
 477         btrfs_set_header_generation(leaf, trans->transid);
 478         btrfs_set_header_backref_rev(leaf, BTRFS_MIXED_BACKREF_REV);
 479         btrfs_set_header_owner(leaf, objectid);
 480
 481         write_extent_buffer_fsid(leaf, fs_info->fsid);
 482         write_extent_buffer_chunk_tree_uuid(leaf, fs_info->chunk_tree_uuid);
 483         btrfs_mark_buffer_dirty(leaf);
 484
 485         inode_item = &root_item->inode;
 486         btrfs_set_stack_inode_generation(inode_item, 1);
 487         btrfs_set_stack_inode_size(inode_item, 3);
 488         btrfs_set_stack_inode_nlink(inode_item, 1);
 489         btrfs_set_stack_inode_nbytes(inode_item,
 490                                      fs_info->nodesize);
 491         btrfs_set_stack_inode_mode(inode_item, S_IFDIR | 0755);
 492
 493         btrfs_set_root_flags(root_item, 0);
 494         btrfs_set_root_limit(root_item, 0);
 495         btrfs_set_stack_inode_flags(inode_item, BTRFS_INODE_ROOT_ITEM_INIT);
 496
 497         btrfs_set_root_bytenr(root_item, leaf->start);
 498         btrfs_set_root_generation(root_item, trans->transid);
 499         btrfs_set_root_level(root_item, 0);
 500         btrfs_set_root_refs(root_item, 1);
 501         btrfs_set_root_used(root_item, leaf->len);
 502         btrfs_set_root_last_snapshot(root_item, 0);
 503
 504         btrfs_set_root_generation_v2(root_item,
 505                         btrfs_root_generation(root_item));
 506         uuid_le_gen(&new_uuid);
 507         memcpy(root_item->uuid, new_uuid.b, BTRFS_UUID_SIZE);
 508         btrfs_set_stack_timespec_sec(&root_item->otime, cur_time.tv_sec);
 509         btrfs_set_stack_timespec_nsec(&root_item->otime, cur_time.tv_nsec);
 510         root_item->ctime = root_item->otime;
 511         btrfs_set_root_ctransid(root_item, trans->transid);
 512         btrfs_set_root_otransid(root_item, trans->transid);
 513
 514         btrfs_tree_unlock(leaf);
 515         free_extent_buffer(leaf);
 516         leaf = NULL;
 517
 518         btrfs_set_root_dirid(root_item, new_dirid);
 519
 520         key.objectid = objectid;
 521         key.offset = 0;
 522         key.type = BTRFS_ROOT_ITEM_KEY;
 523         ret = btrfs_insert_root(trans, fs_info->tree_root, &key,
 524                                 root_item);
 525         if (ret)
 526                 goto fail;
 527
 528         key.offset = (u64)-1;
 529         new_root = btrfs_read_fs_root_no_name(fs_info, &key);
 530         if (IS_ERR(new_root)) {
 531                 ret = PTR_ERR(new_root);
 532                 btrfs_abort_transaction(trans, ret);
 533                 goto fail;
 534         }
 535
 536         btrfs_record_root_in_trans(trans, new_root);
 537
 538         ret = btrfs_create_subvol_root(trans, new_root, root, new_dirid);
 539         if (ret) {
 540                 /* We potentially lose an unused inode item here */
 541                 btrfs_abort_transaction(trans, ret);
 542                 goto fail;
 543         }
 544
 545         mutex_lock(&new_root->objectid_mutex);
 546         new_root->highest_objectid = new_dirid;
 547         mutex_unlock(&new_root->objectid_mutex);
 548
 549         /*
 550          * insert the directory item
 551          */
 552         ret = btrfs_set_inode_index(BTRFS_I(dir), &index);
 553         if (ret) {
 554                 btrfs_abort_transaction(trans, ret);
 555                 goto fail;
 556         }
 557
 558         ret = btrfs_insert_dir_item(trans, root,
 559                                     name, namelen, BTRFS_I(dir), &key,
 560                                     BTRFS_FT_DIR, index);
 561         if (ret) {
 562                 btrfs_abort_transaction(trans, ret);
 563                 goto fail;
 564         }
 565
 566         btrfs_i_size_write(BTRFS_I(dir), dir->i_size + namelen * 2);
 567         ret = btrfs_update_inode(trans, root, dir);
 568         BUG_ON(ret);
 569
 570         ret = btrfs_add_root_ref(trans, fs_info,
 571                                  objectid, root->root_key.objectid,
 572                                  btrfs_ino(BTRFS_I(dir)), index, name, namelen);
 573         BUG_ON(ret);
 574
 575         ret = btrfs_uuid_tree_add(trans, fs_info, root_item->uuid,
 576                                   BTRFS_UUID_KEY_SUBVOL, objectid);
 577         if (ret)
 578                 btrfs_abort_transaction(trans, ret);
 579
 580 fail:
 581         kfree(root_item);
 582         trans->block_rsv = NULL;
 583         trans->bytes_reserved = 0;
 584         btrfs_subvolume_release_metadata(fs_info, &block_rsv);
 585
 586         if (async_transid) {
 587                 *async_transid = trans->transid;
 588                 err = btrfs_commit_transaction_async(trans, 1);
 589                 if (err)
 590                         err = btrfs_commit_transaction(trans);
 591         } else {
 592                 err = btrfs_commit_transaction(trans);
 593         }
 594         if (err && !ret)
 595                 ret = err;
 596
 597         if (!ret) {
 598                 inode = btrfs_lookup_dentry(dir, dentry);
 599                 if (IS_ERR(inode))
 600                         return PTR_ERR(inode);
 601                 d_instantiate(dentry, inode);
 602         }
 603         return ret;
 604
 605 fail_free:
 606         kfree(root_item);
 607         return ret;
 608 }
 609
 610 static void btrfs_wait_for_no_snapshotting_writes(struct btrfs_root *root)
 611 {
 612         s64 writers;
 613         DEFINE_WAIT(wait);
 614
 615         do {
 616                 prepare_to_wait(&root->subv_writers->wait, &wait,
 617                                 TASK_UNINTERRUPTIBLE);
 618
 619                 writers = percpu_counter_sum(&root->subv_writers->counter);
 620                 if (writers)
 621                         schedule();
 622
 623                 finish_wait(&root->subv_writers->wait, &wait);
 624         } while (writers);
 625 }
 626
 627 static int create_snapshot(struct btrfs_root *root, struct inode *dir,
 628                            struct dentry *dentry,
 629                            u64 *async_transid, bool readonly,
 630                            struct btrfs_qgroup_inherit *inherit)
 631 {
 632         struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
 633         struct inode *inode;
 634         struct btrfs_pending_snapshot *pending_snapshot;
 635         struct btrfs_trans_handle *trans;
 636         int ret;
 637
 638         if (!test_bit(BTRFS_ROOT_REF_COWS, &root->state))
 639                 return -EINVAL;
 640
 641         pending_snapshot = kzalloc(sizeof(*pending_snapshot), GFP_KERNEL);
 642         if (!pending_snapshot)
 643                 return -ENOMEM;
 644
 645         pending_snapshot->root_item = kzalloc(sizeof(struct btrfs_root_item),
 646                         GFP_KERNEL);
 647         pending_snapshot->path = btrfs_alloc_path();
 648         if (!pending_snapshot->root_item || !pending_snapshot->path) {
 649                 ret = -ENOMEM;
 650                 goto free_pending;
 651         }
 652
 653         atomic_inc(&root->will_be_snapshotted);
 654         smp_mb__after_atomic();
 655         btrfs_wait_for_no_snapshotting_writes(root);
 656
 657         ret = btrfs_start_delalloc_inodes(root, 0);
 658         if (ret)
 659                 goto dec_and_free;
 660
 661         btrfs_wait_ordered_extents(root, U64_MAX, 0, (u64)-1);
 662
 663         btrfs_init_block_rsv(&pending_snapshot->block_rsv,
 664                              BTRFS_BLOCK_RSV_TEMP);
 665         /*
 666          * 1 - parent dir inode
 667          * 2 - dir entries
 668          * 1 - root item
 669          * 2 - root ref/backref
 670          * 1 - root of snapshot
 671          * 1 - UUID item
 672          */
 673         ret = btrfs_subvolume_reserve_metadata(BTRFS_I(dir)->root,
 674                                         &pending_snapshot->block_rsv, 8,
 675                                         &pending_snapshot->qgroup_reserved,
 676                                         false);
 677         if (ret)
 678                 goto dec_and_free;
 679
 680         pending_snapshot->dentry = dentry;
 681         pending_snapshot->root = root;
 682         pending_snapshot->readonly = readonly;
 683         pending_snapshot->dir = dir;
 684         pending_snapshot->inherit = inherit;
 685
 686         trans = btrfs_start_transaction(root, 0);
 687         if (IS_ERR(trans)) {
 688                 ret = PTR_ERR(trans);
 689                 goto fail;
 690         }
 691
 692         spin_lock(&fs_info->trans_lock);
 693         list_add(&pending_snapshot->list,
 694                  &trans->transaction->pending_snapshots);
 695         spin_unlock(&fs_info->trans_lock);
 696         if (async_transid) {
 697                 *async_transid = trans->transid;
 698                 ret = btrfs_commit_transaction_async(trans, 1);
 699                 if (ret)
 700                         ret = btrfs_commit_transaction(trans);
 701         } else {
 702                 ret = btrfs_commit_transaction(trans);
 703         }
 704         if (ret)
 705                 goto fail;
 706
 707         ret = pending_snapshot->error;
 708         if (ret)
 709                 goto fail;
 710
 711         ret = btrfs_orphan_cleanup(pending_snapshot->snap);
 712         if (ret)
 713                 goto fail;
 714
 715         inode = btrfs_lookup_dentry(d_inode(dentry->d_parent), dentry);
 716         if (IS_ERR(inode)) {
 717                 ret = PTR_ERR(inode);
 718                 goto fail;
 719         }
 720
 721         d_instantiate(dentry, inode);
 722         ret = 0;
 723 fail:
 724         btrfs_subvolume_release_metadata(fs_info, &pending_snapshot->block_rsv);
 725 dec_and_free:
 726         if (atomic_dec_and_test(&root->will_be_snapshotted))
 727                 wake_up_atomic_t(&root->will_be_snapshotted);
 728 free_pending:
 729         kfree(pending_snapshot->root_item);
 730         btrfs_free_path(pending_snapshot->path);
 731         kfree(pending_snapshot);
 732
 733         return ret;
 734 }
 735
 736 /*  copy of may_delete in fs/namei.c()
 737  *      Check whether we can remove a link victim from directory dir, check
 738  *  whether the type of victim is right.
 739  *  1. We can't do it if dir is read-only (done in permission())
 740  *  2. We should have write and exec permissions on dir
 741  *  3. We can't remove anything from append-only dir
 742  *  4. We can't do anything with immutable dir (done in permission())
 743  *  5. If the sticky bit on dir is set we should either
 744  *      a. be owner of dir, or
 745  *      b. be owner of victim, or
 746  *      c. have CAP_FOWNER capability
 747  *  6. If the victim is append-only or immutable we can't do anything with
 748  *     links pointing to it.
 749  *  7. If we were asked to remove a directory and victim isn't one - ENOTDIR.
 750  *  8. If we were asked to remove a non-directory and victim isn't one - EISDIR.
 751  *  9. We can't remove a root or mountpoint.
 752  * 10. We don't allow removal of NFS sillyrenamed files; it's handled by
 753  *     nfs_async_unlink().
 754  */
 755
 756 static int btrfs_may_delete(struct inode *dir, struct dentry *victim, int isdir)
 757 {
 758         int error;
 759
 760         if (d_really_is_negative(victim))
 761                 return -ENOENT;
 762
 763         BUG_ON(d_inode(victim->d_parent) != dir);
 764         audit_inode_child(dir, victim, AUDIT_TYPE_CHILD_DELETE);
 765
 766         error = inode_permission(dir, MAY_WRITE | MAY_EXEC);
 767         if (error)
 768                 return error;
 769         if (IS_APPEND(dir))
 770                 return -EPERM;
 771         if (check_sticky(dir, d_inode(victim)) || IS_APPEND(d_inode(victim)) ||
 772             IS_IMMUTABLE(d_inode(victim)) || IS_SWAPFILE(d_inode(victim)))
 773                 return -EPERM;
 774         if (isdir) {
 775                 if (!d_is_dir(victim))
 776                         return -ENOTDIR;
 777                 if (IS_ROOT(victim))
 778                         return -EBUSY;
 779         } else if (d_is_dir(victim))
 780                 return -EISDIR;
 781         if (IS_DEADDIR(dir))
 782                 return -ENOENT;
 783         if (victim->d_flags & DCACHE_NFSFS_RENAMED)
 784                 return -EBUSY;
 785         return 0;
 786 }
 787
 788 /* copy of may_create in fs/namei.c() */
 789 static inline int btrfs_may_create(struct inode *dir, struct dentry *child)
 790 {
 791         if (d_really_is_positive(child))
 792                 return -EEXIST;
 793         if (IS_DEADDIR(dir))
 794                 return -ENOENT;
 795         return inode_permission(dir, MAY_WRITE | MAY_EXEC);
 796 }
 797
 798 /*
 799  * Create a new subvolume below @parent.  This is largely modeled after
 800  * sys_mkdirat and vfs_mkdir, but we only do a single component lookup
 801  * inside this filesystem so it's quite a bit simpler.
 802  */
 803 static noinline int btrfs_mksubvol(const struct path *parent,
 804                                    const char *name, int namelen,
 805                                    struct btrfs_root *snap_src,
 806                                    u64 *async_transid, bool readonly,
 807                                    struct btrfs_qgroup_inherit *inherit)
 808 {
 809         struct inode *dir = d_inode(parent->dentry);
 810         struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
 811         struct dentry *dentry;
 812         int error;
 813
 814         error = down_write_killable_nested(&dir->i_rwsem, I_MUTEX_PARENT);
 815         if (error == -EINTR)
 816                 return error;
 817
 818         dentry = lookup_one_len(name, parent->dentry, namelen);
 819         error = PTR_ERR(dentry);
 820         if (IS_ERR(dentry))
 821                 goto out_unlock;
 822
 823         error = btrfs_may_create(dir, dentry);
 824         if (error)
 825                 goto out_dput;
 826
 827         /*
 828          * even if this name doesn't exist, we may get hash collisions.
 829          * check for them now when we can safely fail
 830          */
 831         error = btrfs_check_dir_item_collision(BTRFS_I(dir)->root,
 832                                                dir->i_ino, name,
 833                                                namelen);
 834         if (error)
 835                 goto out_dput;
 836
 837         down_read(&fs_info->subvol_sem);
 838
 839         if (btrfs_root_refs(&BTRFS_I(dir)->root->root_item) == 0)
 840                 goto out_up_read;
 841
 842         if (snap_src) {
 843                 error = create_snapshot(snap_src, dir, dentry,
 844                                         async_transid, readonly, inherit);
 845         } else {
 846                 error = create_subvol(dir, dentry, name, namelen,
 847                                       async_transid, inherit);
 848         }
 849         if (!error)
 850                 fsnotify_mkdir(dir, dentry);
 851 out_up_read:
 852         up_read(&fs_info->subvol_sem);
 853 out_dput:
 854         dput(dentry);
 855 out_unlock:
 856         inode_unlock(dir);
 857         return error;
 858 }
 859
 860 /*
 861  * When we're defragging a range, we don't want to kick it off again
 862  * if it is really just waiting for delalloc to send it down.
 863  * If we find a nice big extent or delalloc range for the bytes in the
 864  * file you want to defrag, we return 0 to let you know to skip this
 865  * part of the file
 866  */
 867 static int check_defrag_in_cache(struct inode *inode, u64 offset, u32 thresh)
 868 {
 869         struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
 870         struct extent_map *em = NULL;
 871         struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
 872         u64 end;
 873
 874         read_lock(&em_tree->lock);
 875         em = lookup_extent_mapping(em_tree, offset, PAGE_SIZE);
 876         read_unlock(&em_tree->lock);
 877
 878         if (em) {
 879                 end = extent_map_end(em);
 880                 free_extent_map(em);
 881                 if (end - offset > thresh)
 882                         return 0;
 883         }
 884         /* if we already have a nice delalloc here, just stop */
 885         thresh /= 2;
 886         end = count_range_bits(io_tree, &offset, offset + thresh,
 887                                thresh, EXTENT_DELALLOC, 1);
 888         if (end >= thresh)
 889                 return 0;
 890         return 1;
 891 }
 892
 893 /*
 894  * helper function to walk through a file and find extents
 895  * newer than a specific transid, and smaller than thresh.
 896  *
 897  * This is used by the defragging code to find new and small
 898  * extents
 899  */
 900 static int find_new_extents(struct btrfs_root *root,
 901                             struct inode *inode, u64 newer_than,
 902                             u64 *off, u32 thresh)
 903 {
 904         struct btrfs_path *path;
 905         struct btrfs_key min_key;
 906         struct extent_buffer *leaf;
 907         struct btrfs_file_extent_item *extent;
 908         int type;
 909         int ret;
 910         u64 ino = btrfs_ino(BTRFS_I(inode));
 911
 912         path = btrfs_alloc_path();
 913         if (!path)
 914                 return -ENOMEM;
 915
 916         min_key.objectid = ino;
 917         min_key.type = BTRFS_EXTENT_DATA_KEY;
 918         min_key.offset = *off;
 919
 920         while (1) {
 921                 ret = btrfs_search_forward(root, &min_key, path, newer_than);
 922                 if (ret != 0)
 923                         goto none;
 924 process_slot:
 925                 if (min_key.objectid != ino)
 926                         goto none;
 927                 if (min_key.type != BTRFS_EXTENT_DATA_KEY)
 928                         goto none;
 929
 930                 leaf = path->nodes[0];
 931                 extent = btrfs_item_ptr(leaf, path->slots[0],
 932                                         struct btrfs_file_extent_item);
 933
 934                 type = btrfs_file_extent_type(leaf, extent);
 935                 if (type == BTRFS_FILE_EXTENT_REG &&
 936                     btrfs_file_extent_num_bytes(leaf, extent) < thresh &&
 937                     check_defrag_in_cache(inode, min_key.offset, thresh)) {
 938                         *off = min_key.offset;
 939                         btrfs_free_path(path);
 940                         return 0;
 941                 }
 942
 943                 path->slots[0]++;
 944                 if (path->slots[0] < btrfs_header_nritems(leaf)) {
 945                         btrfs_item_key_to_cpu(leaf, &min_key, path->slots[0]);
 946                         goto process_slot;
 947                 }
 948
 949                 if (min_key.offset == (u64)-1)
 950                         goto none;
 951
 952                 min_key.offset++;
 953                 btrfs_release_path(path);
 954         }
 955 none:
 956         btrfs_free_path(path);
 957         return -ENOENT;
 958 }
 959
 960 static struct extent_map *defrag_lookup_extent(struct inode *inode, u64 start)
 961 {
 962         struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
 963         struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
 964         struct extent_map *em;
 965         u64 len = PAGE_SIZE;
 966
 967         /*
 968          * hopefully we have this extent in the tree already, try without
 969          * the full extent lock
 970          */
 971         read_lock(&em_tree->lock);
 972         em = lookup_extent_mapping(em_tree, start, len);
 973         read_unlock(&em_tree->lock);
 974
 975         if (!em) {
 976                 struct extent_state *cached = NULL;
 977                 u64 end = start + len - 1;
 978
 979                 /* get the big lock and read metadata off disk */
 980                 lock_extent_bits(io_tree, start, end, &cached);
 981                 em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, start, len, 0);
 982                 unlock_extent_cached(io_tree, start, end, &cached, GFP_NOFS);
 983
 984                 if (IS_ERR(em))
 985                         return NULL;
 986         }
 987
 988         return em;
 989 }
 990
 991 static bool defrag_check_next_extent(struct inode *inode, struct extent_map *em)
 992 {
 993         struct extent_map *next;
 994         bool ret = true;
 995
 996         /* this is the last extent */
 997         if (em->start + em->len >= i_size_read(inode))
 998                 return false;
 999
1000         next = defrag_lookup_extent(inode, em->start + em->len);
1001         if (!next || next->block_start >= EXTENT_MAP_LAST_BYTE)
1002                 ret = false;
1003         else if ((em->block_start + em->block_len == next->block_start) &&
1004                  (em->block_len > SZ_128K && next->block_len > SZ_128K))
1005                 ret = false;
1006
1007         free_extent_map(next);
1008         return ret;
1009 }
1010
1011 static int should_defrag_range(struct inode *inode, u64 start, u32 thresh,
1012                                u64 *last_len, u64 *skip, u64 *defrag_end,
1013                                int compress)
1014 {
1015         struct extent_map *em;
1016         int ret = 1;
1017         bool next_mergeable = true;
1018         bool prev_mergeable = true;
1019
1020         /*
1021          * make sure that once we start defragging an extent, we keep on
1022          * defragging it
1023          */
1024         if (start < *defrag_end)
1025                 return 1;
1026
1027         *skip = 0;
1028
1029         em = defrag_lookup_extent(inode, start);
1030         if (!em)
1031                 return 0;
1032
1033         /* this will cover holes, and inline extents */
1034         if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
1035                 ret = 0;
1036                 goto out;
1037         }
1038
1039         if (!*defrag_end)
1040                 prev_mergeable = false;
1041
1042         next_mergeable = defrag_check_next_extent(inode, em);
1043         /*
1044          * we hit a real extent, if it is big or the next extent is not a
1045          * real extent, don't bother defragging it
1046          */
1047         if (!compress && (*last_len == 0 || *last_len >= thresh) &&
1048             (em->len >= thresh || (!next_mergeable && !prev_mergeable)))
1049                 ret = 0;
1050 out:
1051         /*
1052          * last_len ends up being a counter of how many bytes we've defragged.
1053          * every time we choose not to defrag an extent, we reset *last_len
1054          * so that the next tiny extent will force a defrag.
1055          *
1056          * The end result of this is that tiny extents before a single big
1057          * extent will force at least part of that big extent to be defragged.
1058          */
1059         if (ret) {
1060                 *defrag_end = extent_map_end(em);
1061         } else {
1062                 *last_len = 0;
1063                 *skip = extent_map_end(em);
1064                 *defrag_end = 0;
1065         }
1066
1067         free_extent_map(em);
1068         return ret;
1069 }
1070
1071 /*
1072  * it doesn't do much good to defrag one or two pages
1073  * at a time.  This pulls in a nice chunk of pages
1074  * to COW and defrag.
1075  *
1076  * It also makes sure the delalloc code has enough
1077  * dirty data to avoid making new small extents as part
1078  * of the defrag
1079  *
1080  * It's a good idea to start RA on this range
1081  * before calling this.
1082  */
1083 static int cluster_pages_for_defrag(struct inode *inode,
1084                                     struct page **pages,
1085                                     unsigned long start_index,
1086                                     unsigned long num_pages)
1087 {
1088         unsigned long file_end;
1089         u64 isize = i_size_read(inode);
1090         u64 page_start;
1091         u64 page_end;
1092         u64 page_cnt;
1093         int ret;
1094         int i;
1095         int i_done;
1096         struct btrfs_ordered_extent *ordered;
1097         struct extent_state *cached_state = NULL;
1098         struct extent_io_tree *tree;
1099         struct extent_changeset *data_reserved = NULL;
1100         gfp_t mask = btrfs_alloc_write_mask(inode->i_mapping);
1101
1102         file_end = (isize - 1) >> PAGE_SHIFT;
1103         if (!isize || start_index > file_end)
1104                 return 0;
1105
1106         page_cnt = min_t(u64, (u64)num_pages, (u64)file_end - start_index + 1);
1107
1108         ret = btrfs_delalloc_reserve_space(inode, &data_reserved,
1109                         start_index << PAGE_SHIFT,
1110                         page_cnt << PAGE_SHIFT);
1111         if (ret)
1112                 return ret;
1113         i_done = 0;
1114         tree = &BTRFS_I(inode)->io_tree;
1115
1116         /* step one, lock all the pages */
1117         for (i = 0; i < page_cnt; i++) {
1118                 struct page *page;
1119 again:
1120                 page = find_or_create_page(inode->i_mapping,
1121                                            start_index + i, mask);
1122                 if (!page)
1123                         break;
1124
1125                 page_start = page_offset(page);
1126                 page_end = page_start + PAGE_SIZE - 1;
1127                 while (1) {
1128                         lock_extent_bits(tree, page_start, page_end,
1129                                          &cached_state);
1130                         ordered = btrfs_lookup_ordered_extent(inode,
1131                                                               page_start);
1132                         unlock_extent_cached(tree, page_start, page_end,
1133                                              &cached_state, GFP_NOFS);
1134                         if (!ordered)
1135                                 break;
1136
1137                         unlock_page(page);
1138                         btrfs_start_ordered_extent(inode, ordered, 1);
1139                         btrfs_put_ordered_extent(ordered);
1140                         lock_page(page);
1141                         /*
1142                          * we unlocked the page above, so we need check if
1143                          * it was released or not.
1144                          */
1145                         if (page->mapping != inode->i_mapping) {
1146                                 unlock_page(page);
1147                                 put_page(page);
1148                                 goto again;
1149                         }
1150                 }
1151
1152                 if (!PageUptodate(page)) {
1153                         btrfs_readpage(NULL, page);
1154                         lock_page(page);
1155                         if (!PageUptodate(page)) {
1156                                 unlock_page(page);
1157                                 put_page(page);
1158                                 ret = -EIO;
1159                                 break;
1160                         }
1161                 }
1162
1163                 if (page->mapping != inode->i_mapping) {
1164                         unlock_page(page);
1165                         put_page(page);
1166                         goto again;
1167                 }
1168
1169                 pages[i] = page;
1170                 i_done++;
1171         }
1172         if (!i_done || ret)
1173                 goto out;
1174
1175         if (!(inode->i_sb->s_flags & MS_ACTIVE))
1176                 goto out;
1177
1178         /*
1179          * so now we have a nice long stream of locked
1180          * and up to date pages, lets wait on them
1181          */
1182         for (i = 0; i < i_done; i++)
1183                 wait_on_page_writeback(pages[i]);
1184
1185         page_start = page_offset(pages[0]);
1186         page_end = page_offset(pages[i_done - 1]) + PAGE_SIZE;
1187
1188         lock_extent_bits(&BTRFS_I(inode)->io_tree,
1189                          page_start, page_end - 1, &cached_state);
1190         clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start,
1191                           page_end - 1, EXTENT_DIRTY | EXTENT_DELALLOC |
1192                           EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG, 0, 0,
1193                           &cached_state, GFP_NOFS);
1194
1195         if (i_done != page_cnt) {
1196                 spin_lock(&BTRFS_I(inode)->lock);
1197                 BTRFS_I(inode)->outstanding_extents++;
1198                 spin_unlock(&BTRFS_I(inode)->lock);
1199                 btrfs_delalloc_release_space(inode, data_reserved,
1200                                 start_index << PAGE_SHIFT,
1201                                 (page_cnt - i_done) << PAGE_SHIFT);
1202         }
1203
1204
1205         set_extent_defrag(&BTRFS_I(inode)->io_tree, page_start, page_end - 1,
1206                           &cached_state);
1207
1208         unlock_extent_cached(&BTRFS_I(inode)->io_tree,
1209                              page_start, page_end - 1, &cached_state,
1210                              GFP_NOFS);
1211
1212         for (i = 0; i < i_done; i++) {
1213                 clear_page_dirty_for_io(pages[i]);
1214                 ClearPageChecked(pages[i]);
1215                 set_page_extent_mapped(pages[i]);
1216                 set_page_dirty(pages[i]);
1217                 unlock_page(pages[i]);
1218                 put_page(pages[i]);
1219         }
1220         extent_changeset_free(data_reserved);
1221         return i_done;
1222 out:
1223         for (i = 0; i < i_done; i++) {
1224                 unlock_page(pages[i]);
1225                 put_page(pages[i]);
1226         }
1227         btrfs_delalloc_release_space(inode, data_reserved,
1228                         start_index << PAGE_SHIFT,
1229                         page_cnt << PAGE_SHIFT);
1230         extent_changeset_free(data_reserved);
1231         return ret;
1232
1233 }
1234
1235 int btrfs_defrag_file(struct inode *inode, struct file *file,
1236                       struct btrfs_ioctl_defrag_range_args *range,
1237                       u64 newer_than, unsigned long max_to_defrag)
1238 {
1239         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1240         struct btrfs_root *root = BTRFS_I(inode)->root;
1241         struct file_ra_state *ra = NULL;
1242         unsigned long last_index;
1243         u64 isize = i_size_read(inode);
1244         u64 last_len = 0;
1245         u64 skip = 0;
1246         u64 defrag_end = 0;
1247         u64 newer_off = range->start;
1248         unsigned long i;
1249         unsigned long ra_index = 0;
1250         int ret;
1251         int defrag_count = 0;
1252         int compress_type = BTRFS_COMPRESS_ZLIB;
1253         u32 extent_thresh = range->extent_thresh;
1254         unsigned long max_cluster = SZ_256K >> PAGE_SHIFT;
1255         unsigned long cluster = max_cluster;
1256         u64 new_align = ~((u64)SZ_128K - 1);
1257         struct page **pages = NULL;
1258         bool do_compress = range->flags & BTRFS_DEFRAG_RANGE_COMPRESS;
1259
1260         if (isize == 0)
1261                 return 0;
1262
1263         if (range->start >= isize)
1264                 return -EINVAL;
1265
1266         if (do_compress) {
1267                 if (range->compress_type > BTRFS_COMPRESS_TYPES)
1268                         return -EINVAL;
1269                 if (range->compress_type)
1270                         compress_type = range->compress_type;
1271         }
1272
1273         if (extent_thresh == 0)
1274                 extent_thresh = SZ_256K;
1275
1276         /*
1277          * If we were not given a file, allocate a readahead context. As
1278          * readahead is just an optimization, defrag will work without it so
1279          * we don't error out.
1280          */
1281         if (!file) {
1282                 ra = kzalloc(sizeof(*ra), GFP_KERNEL);
1283                 if (ra)
1284                         file_ra_state_init(ra, inode->i_mapping);
1285         } else {
1286                 ra = &file->f_ra;
1287         }
1288
1289         pages = kmalloc_array(max_cluster, sizeof(struct page *), GFP_KERNEL);
1290         if (!pages) {
1291                 ret = -ENOMEM;
1292                 goto out_ra;
1293         }
1294
1295         /* find the last page to defrag */
1296         if (range->start + range->len > range->start) {
1297                 last_index = min_t(u64, isize - 1,
1298                          range->start + range->len - 1) >> PAGE_SHIFT;
1299         } else {
1300                 last_index = (isize - 1) >> PAGE_SHIFT;
1301         }
1302
1303         if (newer_than) {
1304                 ret = find_new_extents(root, inode, newer_than,
1305                                        &newer_off, SZ_64K);
1306                 if (!ret) {
1307                         range->start = newer_off;
1308                         /*
1309                          * we always align our defrag to help keep
1310                          * the extents in the file evenly spaced
1311                          */
1312                         i = (newer_off & new_align) >> PAGE_SHIFT;
1313                 } else
1314                         goto out_ra;
1315         } else {
1316                 i = range->start >> PAGE_SHIFT;
1317         }
1318         if (!max_to_defrag)
1319                 max_to_defrag = last_index - i + 1;
1320
1321         /*
1322          * make writeback starts from i, so the defrag range can be
1323          * written sequentially.
1324          */
1325         if (i < inode->i_mapping->writeback_index)
1326                 inode->i_mapping->writeback_index = i;
1327
1328         while (i <= last_index && defrag_count < max_to_defrag &&
1329                (i < DIV_ROUND_UP(i_size_read(inode), PAGE_SIZE))) {
1330                 /*
1331                  * make sure we stop running if someone unmounts
1332                  * the FS
1333                  */
1334                 if (!(inode->i_sb->s_flags & MS_ACTIVE))
1335                         break;
1336
1337                 if (btrfs_defrag_cancelled(fs_info)) {
1338                         btrfs_debug(fs_info, "defrag_file cancelled");
1339                         ret = -EAGAIN;
1340                         break;
1341                 }
1342
1343                 if (!should_defrag_range(inode, (u64)i << PAGE_SHIFT,
1344                                          extent_thresh, &last_len, &skip,
1345                                          &defrag_end, do_compress)){
1346                         unsigned long next;
1347                         /*
1348                          * the should_defrag function tells us how much to skip
1349                          * bump our counter by the suggested amount
1350                          */
1351                         next = DIV_ROUND_UP(skip, PAGE_SIZE);
1352                         i = max(i + 1, next);
1353                         continue;
1354                 }
1355
1356                 if (!newer_than) {
1357                         cluster = (PAGE_ALIGN(defrag_end) >>
1358                                    PAGE_SHIFT) - i;
1359                         cluster = min(cluster, max_cluster);
1360                 } else {
1361                         cluster = max_cluster;
1362                 }
1363
1364                 if (i + cluster > ra_index) {
1365                         ra_index = max(i, ra_index);
1366                         if (ra)
1367                                 page_cache_sync_readahead(inode->i_mapping, ra,
1368                                                 file, ra_index, cluster);
1369                         ra_index += cluster;
1370                 }
1371
1372                 inode_lock(inode);
1373                 if (do_compress)
1374                         BTRFS_I(inode)->defrag_compress = compress_type;
1375                 ret = cluster_pages_for_defrag(inode, pages, i, cluster);
1376                 if (ret < 0) {
1377                         inode_unlock(inode);
1378                         goto out_ra;
1379                 }
1380
1381                 defrag_count += ret;
1382                 balance_dirty_pages_ratelimited(inode->i_mapping);
1383                 inode_unlock(inode);
1384
1385                 if (newer_than) {
1386                         if (newer_off == (u64)-1)
1387                                 break;
1388
1389                         if (ret > 0)
1390                                 i += ret;
1391
1392                         newer_off = max(newer_off + 1,
1393                                         (u64)i << PAGE_SHIFT);
1394
1395                         ret = find_new_extents(root, inode, newer_than,
1396                                                &newer_off, SZ_64K);
1397                         if (!ret) {
1398                                 range->start = newer_off;
1399                                 i = (newer_off & new_align) >> PAGE_SHIFT;
1400                         } else {
1401                                 break;
1402                         }
1403                 } else {
1404                         if (ret > 0) {
1405                                 i += ret;
1406                                 last_len += ret << PAGE_SHIFT;
1407                         } else {
1408                                 i++;
1409                                 last_len = 0;
1410                         }
1411                 }
1412         }
1413
1414         if ((range->flags & BTRFS_DEFRAG_RANGE_START_IO)) {
1415                 filemap_flush(inode->i_mapping);
1416                 if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
1417                              &BTRFS_I(inode)->runtime_flags))
1418                         filemap_flush(inode->i_mapping);
1419         }
1420
1421         if (do_compress) {
1422                 /* the filemap_flush will queue IO into the worker threads, but
1423                  * we have to make sure the IO is actually started and that
1424                  * ordered extents get created before we return
1425                  */
1426                 atomic_inc(&fs_info->async_submit_draining);
1427                 while (atomic_read(&fs_info->nr_async_submits) ||
1428                        atomic_read(&fs_info->async_delalloc_pages)) {
1429                         wait_event(fs_info->async_submit_wait,
1430                                    (atomic_read(&fs_info->nr_async_submits) == 0 &&
1431                                     atomic_read(&fs_info->async_delalloc_pages) == 0));
1432                 }
1433                 atomic_dec(&fs_info->async_submit_draining);
1434         }
1435
1436         if (range->compress_type == BTRFS_COMPRESS_LZO) {
1437                 btrfs_set_fs_incompat(fs_info, COMPRESS_LZO);
1438         }
1439
1440         ret = defrag_count;
1441
1442 out_ra:
1443         if (do_compress) {
1444                 inode_lock(inode);
1445                 BTRFS_I(inode)->defrag_compress = BTRFS_COMPRESS_NONE;
1446                 inode_unlock(inode);
1447         }
1448         if (!file)
1449                 kfree(ra);
1450         kfree(pages);
1451         return ret;
1452 }
1453
1454 static noinline int btrfs_ioctl_resize(struct file *file,
1455                                         void __user *arg)
1456 {
1457         struct inode *inode = file_inode(file);
1458         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1459         u64 new_size;
1460         u64 old_size;
1461         u64 devid = 1;
1462         struct btrfs_root *root = BTRFS_I(inode)->root;
1463         struct btrfs_ioctl_vol_args *vol_args;
1464         struct btrfs_trans_handle *trans;
1465         struct btrfs_device *device = NULL;
1466         char *sizestr;
1467         char *retptr;
1468         char *devstr = NULL;
1469         int ret = 0;
1470         int mod = 0;
1471
1472         if (!capable(CAP_SYS_ADMIN))
1473                 return -EPERM;
1474
1475         ret = mnt_want_write_file(file);
1476         if (ret)
1477                 return ret;
1478
1479         if (test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags)) {
1480                 mnt_drop_write_file(file);
1481                 return BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
1482         }
1483
1484         mutex_lock(&fs_info->volume_mutex);
1485         vol_args = memdup_user(arg, sizeof(*vol_args));
1486         if (IS_ERR(vol_args)) {
1487                 ret = PTR_ERR(vol_args);
1488                 goto out;
1489         }
1490
1491         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1492
1493         sizestr = vol_args->name;
1494         devstr = strchr(sizestr, ':');
1495         if (devstr) {
1496                 sizestr = devstr + 1;
1497                 *devstr = '\0';
1498                 devstr = vol_args->name;
1499                 ret = kstrtoull(devstr, 10, &devid);
1500                 if (ret)
1501                         goto out_free;
1502                 if (!devid) {
1503                         ret = -EINVAL;
1504                         goto out_free;
1505                 }
1506                 btrfs_info(fs_info, "resizing devid %llu", devid);
1507         }
1508
1509         device = btrfs_find_device(fs_info, devid, NULL, NULL);
1510         if (!device) {
1511                 btrfs_info(fs_info, "resizer unable to find device %llu",
1512                            devid);
1513                 ret = -ENODEV;
1514                 goto out_free;
1515         }
1516
1517         if (!device->writeable) {
1518                 btrfs_info(fs_info,
1519                            "resizer unable to apply on readonly device %llu",
1520                        devid);
1521                 ret = -EPERM;
1522                 goto out_free;
1523         }
1524
1525         if (!strcmp(sizestr, "max"))
1526                 new_size = device->bdev->bd_inode->i_size;
1527         else {
1528                 if (sizestr[0] == '-') {
1529                         mod = -1;
1530                         sizestr++;
1531                 } else if (sizestr[0] == '+') {
1532                         mod = 1;
1533                         sizestr++;
1534                 }
1535                 new_size = memparse(sizestr, &retptr);
1536                 if (*retptr != '\0' || new_size == 0) {
1537                         ret = -EINVAL;
1538                         goto out_free;
1539                 }
1540         }
1541
1542         if (device->is_tgtdev_for_dev_replace) {
1543                 ret = -EPERM;
1544                 goto out_free;
1545         }
1546
1547         old_size = btrfs_device_get_total_bytes(device);
1548
1549         if (mod < 0) {
1550                 if (new_size > old_size) {
1551                         ret = -EINVAL;
1552                         goto out_free;
1553                 }
1554                 new_size = old_size - new_size;
1555         } else if (mod > 0) {
1556                 if (new_size > ULLONG_MAX - old_size) {
1557                         ret = -ERANGE;
1558                         goto out_free;
1559                 }
1560                 new_size = old_size + new_size;
1561         }
1562
1563         if (new_size < SZ_256M) {
1564                 ret = -EINVAL;
1565                 goto out_free;
1566         }
1567         if (new_size > device->bdev->bd_inode->i_size) {
1568                 ret = -EFBIG;
1569                 goto out_free;
1570         }
1571
1572         new_size = round_down(new_size, fs_info->sectorsize);
1573
1574         btrfs_info_in_rcu(fs_info, "new size for %s is %llu",
1575                           rcu_str_deref(device->name), new_size);
1576
1577         if (new_size > old_size) {
1578                 trans = btrfs_start_transaction(root, 0);
1579                 if (IS_ERR(trans)) {
1580                         ret = PTR_ERR(trans);
1581                         goto out_free;
1582                 }
1583                 ret = btrfs_grow_device(trans, device, new_size);
1584                 btrfs_commit_transaction(trans);
1585         } else if (new_size < old_size) {
1586                 ret = btrfs_shrink_device(device, new_size);
1587         } /* equal, nothing need to do */
1588
1589 out_free:
1590         kfree(vol_args);
1591 out:
1592         mutex_unlock(&fs_info->volume_mutex);
1593         clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
1594         mnt_drop_write_file(file);
1595         return ret;
1596 }
1597
1598 static noinline int btrfs_ioctl_snap_create_transid(struct file *file,
1599                                 const char *name, unsigned long fd, int subvol,
1600                                 u64 *transid, bool readonly,
1601                                 struct btrfs_qgroup_inherit *inherit)
1602 {
1603         int namelen;
1604         int ret = 0;
1605
1606         if (!S_ISDIR(file_inode(file)->i_mode))
1607                 return -ENOTDIR;
1608
1609         ret = mnt_want_write_file(file);
1610         if (ret)
1611                 goto out;
1612
1613         namelen = strlen(name);
1614         if (strchr(name, '/')) {
1615                 ret = -EINVAL;
1616                 goto out_drop_write;
1617         }
1618
1619         if (name[0] == '.' &&
1620            (namelen == 1 || (name[1] == '.' && namelen == 2))) {
1621                 ret = -EEXIST;
1622                 goto out_drop_write;
1623         }
1624
1625         if (subvol) {
1626                 ret = btrfs_mksubvol(&file->f_path, name, namelen,
1627                                      NULL, transid, readonly, inherit);
1628         } else {
1629                 struct fd src = fdget(fd);
1630                 struct inode *src_inode;
1631                 if (!src.file) {
1632                         ret = -EINVAL;
1633                         goto out_drop_write;
1634                 }
1635
1636                 src_inode = file_inode(src.file);
1637                 if (src_inode->i_sb != file_inode(file)->i_sb) {
1638                         btrfs_info(BTRFS_I(file_inode(file))->root->fs_info,
1639                                    "Snapshot src from another FS");
1640                         ret = -EXDEV;
1641                 } else if (!inode_owner_or_capable(src_inode)) {
1642                         /*
1643                          * Subvolume creation is not restricted, but snapshots
1644                          * are limited to own subvolumes only
1645                          */
1646                         ret = -EPERM;
1647                 } else {
1648                         ret = btrfs_mksubvol(&file->f_path, name, namelen,
1649                                              BTRFS_I(src_inode)->root,
1650                                              transid, readonly, inherit);
1651                 }
1652                 fdput(src);
1653         }
1654 out_drop_write:
1655         mnt_drop_write_file(file);
1656 out:
1657         return ret;
1658 }
1659
1660 static noinline int btrfs_ioctl_snap_create(struct file *file,
1661                                             void __user *arg, int subvol)
1662 {
1663         struct btrfs_ioctl_vol_args *vol_args;
1664         int ret;
1665
1666         if (!S_ISDIR(file_inode(file)->i_mode))
1667                 return -ENOTDIR;
1668
1669         vol_args = memdup_user(arg, sizeof(*vol_args));
1670         if (IS_ERR(vol_args))
1671                 return PTR_ERR(vol_args);
1672         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1673
1674         ret = btrfs_ioctl_snap_create_transid(file, vol_args->name,
1675                                               vol_args->fd, subvol,
1676                                               NULL, false, NULL);
1677
1678         kfree(vol_args);
1679         return ret;
1680 }
1681
1682 static noinline int btrfs_ioctl_snap_create_v2(struct file *file,
1683                                                void __user *arg, int subvol)
1684 {
1685         struct btrfs_ioctl_vol_args_v2 *vol_args;
1686         int ret;
1687         u64 transid = 0;
1688         u64 *ptr = NULL;
1689         bool readonly = false;
1690         struct btrfs_qgroup_inherit *inherit = NULL;
1691
1692         if (!S_ISDIR(file_inode(file)->i_mode))
1693                 return -ENOTDIR;
1694
1695         vol_args = memdup_user(arg, sizeof(*vol_args));
1696         if (IS_ERR(vol_args))
1697                 return PTR_ERR(vol_args);
1698         vol_args->name[BTRFS_SUBVOL_NAME_MAX] = '\0';
1699
1700         if (vol_args->flags &
1701             ~(BTRFS_SUBVOL_CREATE_ASYNC | BTRFS_SUBVOL_RDONLY |
1702               BTRFS_SUBVOL_QGROUP_INHERIT)) {
1703                 ret = -EOPNOTSUPP;
1704                 goto free_args;
1705         }
1706
1707         if (vol_args->flags & BTRFS_SUBVOL_CREATE_ASYNC)
1708                 ptr = &transid;
1709         if (vol_args->flags & BTRFS_SUBVOL_RDONLY)
1710                 readonly = true;
1711         if (vol_args->flags & BTRFS_SUBVOL_QGROUP_INHERIT) {
1712                 if (vol_args->size > PAGE_SIZE) {
1713                         ret = -EINVAL;
1714                         goto free_args;
1715                 }
1716                 inherit = memdup_user(vol_args->qgroup_inherit, vol_args->size);
1717                 if (IS_ERR(inherit)) {
1718                         ret = PTR_ERR(inherit);
1719                         goto free_args;
1720                 }
1721         }
1722
1723         ret = btrfs_ioctl_snap_create_transid(file, vol_args->name,
1724                                               vol_args->fd, subvol, ptr,
1725                                               readonly, inherit);
1726         if (ret)
1727                 goto free_inherit;
1728
1729         if (ptr && copy_to_user(arg +
1730                                 offsetof(struct btrfs_ioctl_vol_args_v2,
1731                                         transid),
1732                                 ptr, sizeof(*ptr)))
1733                 ret = -EFAULT;
1734
1735 free_inherit:
1736         kfree(inherit);
1737 free_args:
1738         kfree(vol_args);
1739         return ret;
1740 }
1741
1742 static noinline int btrfs_ioctl_subvol_getflags(struct file *file,
1743                                                 void __user *arg)
1744 {
1745         struct inode *inode = file_inode(file);
1746         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1747         struct btrfs_root *root = BTRFS_I(inode)->root;
1748         int ret = 0;
1749         u64 flags = 0;
1750
1751         if (btrfs_ino(BTRFS_I(inode)) != BTRFS_FIRST_FREE_OBJECTID)
1752                 return -EINVAL;
1753
1754         down_read(&fs_info->subvol_sem);
1755         if (btrfs_root_readonly(root))
1756                 flags |= BTRFS_SUBVOL_RDONLY;
1757         up_read(&fs_info->subvol_sem);
1758
1759         if (copy_to_user(arg, &flags, sizeof(flags)))
1760                 ret = -EFAULT;
1761
1762         return ret;
1763 }
1764
1765 static noinline int btrfs_ioctl_subvol_setflags(struct file *file,
1766                                               void __user *arg)
1767 {
1768         struct inode *inode = file_inode(file);
1769         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1770         struct btrfs_root *root = BTRFS_I(inode)->root;
1771         struct btrfs_trans_handle *trans;
1772         u64 root_flags;
1773         u64 flags;
1774         int ret = 0;
1775
1776         if (!inode_owner_or_capable(inode))
1777                 return -EPERM;
1778
1779         ret = mnt_want_write_file(file);
1780         if (ret)
1781                 goto out;
1782
1783         if (btrfs_ino(BTRFS_I(inode)) != BTRFS_FIRST_FREE_OBJECTID) {
1784                 ret = -EINVAL;
1785                 goto out_drop_write;
1786         }
1787
1788         if (copy_from_user(&flags, arg, sizeof(flags))) {
1789                 ret = -EFAULT;
1790                 goto out_drop_write;
1791         }
1792
1793         if (flags & BTRFS_SUBVOL_CREATE_ASYNC) {
1794                 ret = -EINVAL;
1795                 goto out_drop_write;
1796         }
1797
1798         if (flags & ~BTRFS_SUBVOL_RDONLY) {
1799                 ret = -EOPNOTSUPP;
1800                 goto out_drop_write;
1801         }
1802
1803         down_write(&fs_info->subvol_sem);
1804
1805         /* nothing to do */
1806         if (!!(flags & BTRFS_SUBVOL_RDONLY) == btrfs_root_readonly(root))
1807                 goto out_drop_sem;
1808
1809         root_flags = btrfs_root_flags(&root->root_item);
1810         if (flags & BTRFS_SUBVOL_RDONLY) {
1811                 btrfs_set_root_flags(&root->root_item,
1812                                      root_flags | BTRFS_ROOT_SUBVOL_RDONLY);
1813         } else {
1814                 /*
1815                  * Block RO -> RW transition if this subvolume is involved in
1816                  * send
1817                  */
1818                 spin_lock(&root->root_item_lock);
1819                 if (root->send_in_progress == 0) {
1820                         btrfs_set_root_flags(&root->root_item,
1821                                      root_flags & ~BTRFS_ROOT_SUBVOL_RDONLY);
1822                         spin_unlock(&root->root_item_lock);
1823                 } else {
1824                         spin_unlock(&root->root_item_lock);
1825                         btrfs_warn(fs_info,
1826                                    "Attempt to set subvolume %llu read-write during send",
1827                                    root->root_key.objectid);
1828                         ret = -EPERM;
1829                         goto out_drop_sem;
1830                 }
1831         }
1832
1833         trans = btrfs_start_transaction(root, 1);
1834         if (IS_ERR(trans)) {
1835                 ret = PTR_ERR(trans);
1836                 goto out_reset;
1837         }
1838
1839         ret = btrfs_update_root(trans, fs_info->tree_root,
1840                                 &root->root_key, &root->root_item);
1841
1842         btrfs_commit_transaction(trans);
1843 out_reset:
1844         if (ret)
1845                 btrfs_set_root_flags(&root->root_item, root_flags);
1846 out_drop_sem:
1847         up_write(&fs_info->subvol_sem);
1848 out_drop_write:
1849         mnt_drop_write_file(file);
1850 out:
1851         return ret;
1852 }
1853
1854 /*
1855  * helper to check if the subvolume references other subvolumes
1856  */
1857 static noinline int may_destroy_subvol(struct btrfs_root *root)
1858 {
1859         struct btrfs_fs_info *fs_info = root->fs_info;
1860         struct btrfs_path *path;
1861         struct btrfs_dir_item *di;
1862         struct btrfs_key key;
1863         u64 dir_id;
1864         int ret;
1865
1866         path = btrfs_alloc_path();
1867         if (!path)
1868                 return -ENOMEM;
1869
1870         /* Make sure this root isn't set as the default subvol */
1871         dir_id = btrfs_super_root_dir(fs_info->super_copy);
1872         di = btrfs_lookup_dir_item(NULL, fs_info->tree_root, path,
1873                                    dir_id, "default", 7, 0);
1874         if (di && !IS_ERR(di)) {
1875                 btrfs_dir_item_key_to_cpu(path->nodes[0], di, &key);
1876                 if (key.objectid == root->root_key.objectid) {
1877                         ret = -EPERM;
1878                         btrfs_err(fs_info,
1879                                   "deleting default subvolume %llu is not allowed",
1880                                   key.objectid);
1881                         goto out;
1882                 }
1883                 btrfs_release_path(path);
1884         }
1885
1886         key.objectid = root->root_key.objectid;
1887         key.type = BTRFS_ROOT_REF_KEY;
1888         key.offset = (u64)-1;
1889
1890         ret = btrfs_search_slot(NULL, fs_info->tree_root, &key, path, 0, 0);
1891         if (ret < 0)
1892                 goto out;
1893         BUG_ON(ret == 0);
1894
1895         ret = 0;
1896         if (path->slots[0] > 0) {
1897                 path->slots[0]--;
1898                 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
1899                 if (key.objectid == root->root_key.objectid &&
1900                     key.type == BTRFS_ROOT_REF_KEY)
1901                         ret = -ENOTEMPTY;
1902         }
1903 out:
1904         btrfs_free_path(path);
1905         return ret;
1906 }
1907
1908 static noinline int key_in_sk(struct btrfs_key *key,
1909                               struct btrfs_ioctl_search_key *sk)
1910 {
1911         struct btrfs_key test;
1912         int ret;
1913
1914         test.objectid = sk->min_objectid;
1915         test.type = sk->min_type;
1916         test.offset = sk->min_offset;
1917
1918         ret = btrfs_comp_cpu_keys(key, &test);
1919         if (ret < 0)
1920                 return 0;
1921
1922         test.objectid = sk->max_objectid;
1923         test.type = sk->max_type;
1924         test.offset = sk->max_offset;
1925
1926         ret = btrfs_comp_cpu_keys(key, &test);
1927         if (ret > 0)
1928                 return 0;
1929         return 1;
1930 }
1931
1932 static noinline int copy_to_sk(struct btrfs_path *path,
1933                                struct btrfs_key *key,
1934                                struct btrfs_ioctl_search_key *sk,
1935                                size_t *buf_size,
1936                                char __user *ubuf,
1937                                unsigned long *sk_offset,
1938                                int *num_found)
1939 {
1940         u64 found_transid;
1941         struct extent_buffer *leaf;
1942         struct btrfs_ioctl_search_header sh;
1943         struct btrfs_key test;
1944         unsigned long item_off;
1945         unsigned long item_len;
1946         int nritems;
1947         int i;
1948         int slot;
1949         int ret = 0;
1950
1951         leaf = path->nodes[0];
1952         slot = path->slots[0];
1953         nritems = btrfs_header_nritems(leaf);
1954
1955         if (btrfs_header_generation(leaf) > sk->max_transid) {
1956                 i = nritems;
1957                 goto advance_key;
1958         }
1959         found_transid = btrfs_header_generation(leaf);
1960
1961         for (i = slot; i < nritems; i++) {
1962                 item_off = btrfs_item_ptr_offset(leaf, i);
1963                 item_len = btrfs_item_size_nr(leaf, i);
1964
1965                 btrfs_item_key_to_cpu(leaf, key, i);
1966                 if (!key_in_sk(key, sk))
1967                         continue;
1968
1969                 if (sizeof(sh) + item_len > *buf_size) {
1970                         if (*num_found) {
1971                                 ret = 1;
1972                                 goto out;
1973                         }
1974
1975                         /*
1976                          * return one empty item back for v1, which does not
1977                          * handle -EOVERFLOW
1978                          */
1979
1980                         *buf_size = sizeof(sh) + item_len;
1981                         item_len = 0;
1982                         ret = -EOVERFLOW;
1983                 }
1984
1985                 if (sizeof(sh) + item_len + *sk_offset > *buf_size) {
1986                         ret = 1;
1987                         goto out;
1988                 }
1989
1990                 sh.objectid = key->objectid;
1991                 sh.offset = key->offset;
1992                 sh.type = key->type;
1993                 sh.len = item_len;
1994                 sh.transid = found_transid;
1995
1996                 /* copy search result header */
1997                 if (copy_to_user(ubuf + *sk_offset, &sh, sizeof(sh))) {
1998                         ret = -EFAULT;
1999                         goto out;
2000                 }
2001
2002                 *sk_offset += sizeof(sh);
2003
2004                 if (item_len) {
2005                         char __user *up = ubuf + *sk_offset;
2006                         /* copy the item */
2007                         if (read_extent_buffer_to_user(leaf, up,
2008                                                        item_off, item_len)) {
2009                                 ret = -EFAULT;
2010                                 goto out;
2011                         }
2012
2013                         *sk_offset += item_len;
2014                 }
2015                 (*num_found)++;
2016
2017                 if (ret) /* -EOVERFLOW from above */
2018                         goto out;
2019
2020                 if (*num_found >= sk->nr_items) {
2021                         ret = 1;
2022                         goto out;
2023                 }
2024         }
2025 advance_key:
2026         ret = 0;
2027         test.objectid = sk->max_objectid;
2028         test.type = sk->max_type;
2029         test.offset = sk->max_offset;
2030         if (btrfs_comp_cpu_keys(key, &test) >= 0)
2031                 ret = 1;
2032         else if (key->offset < (u64)-1)
2033                 key->offset++;
2034         else if (key->type < (u8)-1) {
2035                 key->offset = 0;
2036                 key->type++;
2037         } else if (key->objectid < (u64)-1) {
2038                 key->offset = 0;
2039                 key->type = 0;
2040                 key->objectid++;
2041         } else
2042                 ret = 1;
2043 out:
2044         /*
2045          *  0: all items from this leaf copied, continue with next
2046          *  1: * more items can be copied, but unused buffer is too small
2047          *     * all items were found
2048          *     Either way, it will stops the loop which iterates to the next
2049          *     leaf
2050          *  -EOVERFLOW: item was to large for buffer
2051          *  -EFAULT: could not copy extent buffer back to userspace
2052          */
2053         return ret;
2054 }
2055
2056 static noinline int search_ioctl(struct inode *inode,
2057                                  struct btrfs_ioctl_search_key *sk,
2058                                  size_t *buf_size,
2059                                  char __user *ubuf)
2060 {
2061         struct btrfs_fs_info *info = btrfs_sb(inode->i_sb);
2062         struct btrfs_root *root;
2063         struct btrfs_key key;
2064         struct btrfs_path *path;
2065         int ret;
2066         int num_found = 0;
2067         unsigned long sk_offset = 0;
2068
2069         if (*buf_size < sizeof(struct btrfs_ioctl_search_header)) {
2070                 *buf_size = sizeof(struct btrfs_ioctl_search_header);
2071                 return -EOVERFLOW;
2072         }
2073
2074         path = btrfs_alloc_path();
2075         if (!path)
2076                 return -ENOMEM;
2077
2078         if (sk->tree_id == 0) {
2079                 /* search the root of the inode that was passed */
2080                 root = BTRFS_I(inode)->root;
2081         } else {
2082                 key.objectid = sk->tree_id;
2083                 key.type = BTRFS_ROOT_ITEM_KEY;
2084                 key.offset = (u64)-1;
2085                 root = btrfs_read_fs_root_no_name(info, &key);
2086                 if (IS_ERR(root)) {
2087                         btrfs_free_path(path);
2088                         return -ENOENT;
2089                 }
2090         }
2091
2092         key.objectid = sk->min_objectid;
2093         key.type = sk->min_type;
2094         key.offset = sk->min_offset;
2095
2096         while (1) {
2097                 ret = btrfs_search_forward(root, &key, path, sk->min_transid);
2098                 if (ret != 0) {
2099                         if (ret > 0)
2100                                 ret = 0;
2101                         goto err;
2102                 }
2103                 ret = copy_to_sk(path, &key, sk, buf_size, ubuf,
2104                                  &sk_offset, &num_found);
2105                 btrfs_release_path(path);
2106                 if (ret)
2107                         break;
2108
2109         }
2110         if (ret > 0)
2111                 ret = 0;
2112 err:
2113         sk->nr_items = num_found;
2114         btrfs_free_path(path);
2115         return ret;
2116 }
2117
2118 static noinline int btrfs_ioctl_tree_search(struct file *file,
2119                                            void __user *argp)
2120 {
2121         struct btrfs_ioctl_search_args __user *uargs;
2122         struct btrfs_ioctl_search_key sk;
2123         struct inode *inode;
2124         int ret;
2125         size_t buf_size;
2126
2127         if (!capable(CAP_SYS_ADMIN))
2128                 return -EPERM;
2129
2130         uargs = (struct btrfs_ioctl_search_args __user *)argp;
2131
2132         if (copy_from_user(&sk, &uargs->key, sizeof(sk)))
2133                 return -EFAULT;
2134
2135         buf_size = sizeof(uargs->buf);
2136
2137         inode = file_inode(file);
2138         ret = search_ioctl(inode, &sk, &buf_size, uargs->buf);
2139
2140         /*
2141          * In the origin implementation an overflow is handled by returning a
2142          * search header with a len of zero, so reset ret.
2143          */
2144         if (ret == -EOVERFLOW)
2145                 ret = 0;
2146
2147         if (ret == 0 && copy_to_user(&uargs->key, &sk, sizeof(sk)))
2148                 ret = -EFAULT;
2149         return ret;
2150 }
2151
2152 static noinline int btrfs_ioctl_tree_search_v2(struct file *file,
2153                                                void __user *argp)
2154 {
2155         struct btrfs_ioctl_search_args_v2 __user *uarg;
2156         struct btrfs_ioctl_search_args_v2 args;
2157         struct inode *inode;
2158         int ret;
2159         size_t buf_size;
2160         const size_t buf_limit = SZ_16M;
2161
2162         if (!capable(CAP_SYS_ADMIN))
2163                 return -EPERM;
2164
2165         /* copy search header and buffer size */
2166         uarg = (struct btrfs_ioctl_search_args_v2 __user *)argp;
2167         if (copy_from_user(&args, uarg, sizeof(args)))
2168                 return -EFAULT;
2169
2170         buf_size = args.buf_size;
2171
2172         /* limit result size to 16MB */
2173         if (buf_size > buf_limit)
2174                 buf_size = buf_limit;
2175
2176         inode = file_inode(file);
2177         ret = search_ioctl(inode, &args.key, &buf_size,
2178                            (char *)(&uarg->buf[0]));
2179         if (ret == 0 && copy_to_user(&uarg->key, &args.key, sizeof(args.key)))
2180                 ret = -EFAULT;
2181         else if (ret == -EOVERFLOW &&
2182                 copy_to_user(&uarg->buf_size, &buf_size, sizeof(buf_size)))
2183                 ret = -EFAULT;
2184
2185         return ret;
2186 }
2187
2188 /*
2189  * Search INODE_REFs to identify path name of 'dirid' directory
2190  * in a 'tree_id' tree. and sets path name to 'name'.
2191  */
2192 static noinline int btrfs_search_path_in_tree(struct btrfs_fs_info *info,
2193                                 u64 tree_id, u64 dirid, char *name)
2194 {
2195         struct btrfs_root *root;
2196         struct btrfs_key key;
2197         char *ptr;
2198         int ret = -1;
2199         int slot;
2200         int len;
2201         int total_len = 0;
2202         struct btrfs_inode_ref *iref;
2203         struct extent_buffer *l;
2204         struct btrfs_path *path;
2205
2206         if (dirid == BTRFS_FIRST_FREE_OBJECTID) {
2207                 name[0]='\0';
2208                 return 0;
2209         }
2210
2211         path = btrfs_alloc_path();
2212         if (!path)
2213                 return -ENOMEM;
2214
2215         ptr = &name[BTRFS_INO_LOOKUP_PATH_MAX];
2216
2217         key.objectid = tree_id;
2218         key.type = BTRFS_ROOT_ITEM_KEY;
2219         key.offset = (u64)-1;
2220         root = btrfs_read_fs_root_no_name(info, &key);
2221         if (IS_ERR(root)) {
2222                 btrfs_err(info, "could not find root %llu", tree_id);
2223                 ret = -ENOENT;
2224                 goto out;
2225         }
2226
2227         key.objectid = dirid;
2228         key.type = BTRFS_INODE_REF_KEY;
2229         key.offset = (u64)-1;
2230
2231         while (1) {
2232                 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2233                 if (ret < 0)
2234                         goto out;
2235                 else if (ret > 0) {
2236                         ret = btrfs_previous_item(root, path, dirid,
2237                                                   BTRFS_INODE_REF_KEY);
2238                         if (ret < 0)
2239                                 goto out;
2240                         else if (ret > 0) {
2241                                 ret = -ENOENT;
2242                                 goto out;
2243                         }
2244                 }
2245
2246                 l = path->nodes[0];
2247                 slot = path->slots[0];
2248                 btrfs_item_key_to_cpu(l, &key, slot);
2249
2250                 iref = btrfs_item_ptr(l, slot, struct btrfs_inode_ref);
2251                 len = btrfs_inode_ref_name_len(l, iref);
2252                 ptr -= len + 1;
2253                 total_len += len + 1;
2254                 if (ptr < name) {
2255                         ret = -ENAMETOOLONG;
2256                         goto out;
2257                 }
2258
2259                 *(ptr + len) = '/';
2260                 read_extent_buffer(l, ptr, (unsigned long)(iref + 1), len);
2261
2262                 if (key.offset == BTRFS_FIRST_FREE_OBJECTID)
2263                         break;
2264
2265                 btrfs_release_path(path);
2266                 key.objectid = key.offset;
2267                 key.offset = (u64)-1;
2268                 dirid = key.objectid;
2269         }
2270         memmove(name, ptr, total_len);
2271         name[total_len] = '\0';
2272         ret = 0;
2273 out:
2274         btrfs_free_path(path);
2275         return ret;
2276 }
2277
2278 static noinline int btrfs_ioctl_ino_lookup(struct file *file,
2279                                            void __user *argp)
2280 {
2281          struct btrfs_ioctl_ino_lookup_args *args;
2282          struct inode *inode;
2283         int ret = 0;
2284
2285         args = memdup_user(argp, sizeof(*args));
2286         if (IS_ERR(args))
2287                 return PTR_ERR(args);
2288
2289         inode = file_inode(file);
2290
2291         /*
2292          * Unprivileged query to obtain the containing subvolume root id. The
2293          * path is reset so it's consistent with btrfs_search_path_in_tree.
2294          */
2295         if (args->treeid == 0)
2296                 args->treeid = BTRFS_I(inode)->root->root_key.objectid;
2297
2298         if (args->objectid == BTRFS_FIRST_FREE_OBJECTID) {
2299                 args->name[0] = 0;
2300                 goto out;
2301         }
2302
2303         if (!capable(CAP_SYS_ADMIN)) {
2304                 ret = -EPERM;
2305                 goto out;
2306         }
2307
2308         ret = btrfs_search_path_in_tree(BTRFS_I(inode)->root->fs_info,
2309                                         args->treeid, args->objectid,
2310                                         args->name);
2311
2312 out:
2313         if (ret == 0 && copy_to_user(argp, args, sizeof(*args)))
2314                 ret = -EFAULT;
2315
2316         kfree(args);
2317         return ret;
2318 }
2319
2320 static noinline int btrfs_ioctl_snap_destroy(struct file *file,
2321                                              void __user *arg)
2322 {
2323         struct dentry *parent = file->f_path.dentry;
2324         struct btrfs_fs_info *fs_info = btrfs_sb(parent->d_sb);
2325         struct dentry *dentry;
2326         struct inode *dir = d_inode(parent);
2327         struct inode *inode;
2328         struct btrfs_root *root = BTRFS_I(dir)->root;
2329         struct btrfs_root *dest = NULL;
2330         struct btrfs_ioctl_vol_args *vol_args;
2331         struct btrfs_trans_handle *trans;
2332         struct btrfs_block_rsv block_rsv;
2333         u64 root_flags;
2334         u64 qgroup_reserved;
2335         int namelen;
2336         int ret;
2337         int err = 0;
2338
2339         if (!S_ISDIR(dir->i_mode))
2340                 return -ENOTDIR;
2341
2342         vol_args = memdup_user(arg, sizeof(*vol_args));
2343         if (IS_ERR(vol_args))
2344                 return PTR_ERR(vol_args);
2345
2346         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
2347         namelen = strlen(vol_args->name);
2348         if (strchr(vol_args->name, '/') ||
2349             strncmp(vol_args->name, "..", namelen) == 0) {
2350                 err = -EINVAL;
2351                 goto out;
2352         }
2353
2354         err = mnt_want_write_file(file);
2355         if (err)
2356                 goto out;
2357
2358
2359         err = down_write_killable_nested(&dir->i_rwsem, I_MUTEX_PARENT);
2360         if (err == -EINTR)
2361                 goto out_drop_write;
2362         dentry = lookup_one_len(vol_args->name, parent, namelen);
2363         if (IS_ERR(dentry)) {
2364                 err = PTR_ERR(dentry);
2365                 goto out_unlock_dir;
2366         }
2367
2368         if (d_really_is_negative(dentry)) {
2369                 err = -ENOENT;
2370                 goto out_dput;
2371         }
2372
2373         inode = d_inode(dentry);
2374         dest = BTRFS_I(inode)->root;
2375         if (!capable(CAP_SYS_ADMIN)) {
2376                 /*
2377                  * Regular user.  Only allow this with a special mount
2378                  * option, when the user has write+exec access to the
2379                  * subvol root, and when rmdir(2) would have been
2380                  * allowed.
2381                  *
2382                  * Note that this is _not_ check that the subvol is
2383                  * empty or doesn't contain data that we wouldn't
2384                  * otherwise be able to delete.
2385                  *
2386                  * Users who want to delete empty subvols should try
2387                  * rmdir(2).
2388                  */
2389                 err = -EPERM;
2390                 if (!btrfs_test_opt(fs_info, USER_SUBVOL_RM_ALLOWED))
2391                         goto out_dput;
2392
2393                 /*
2394                  * Do not allow deletion if the parent dir is the same
2395                  * as the dir to be deleted.  That means the ioctl
2396                  * must be called on the dentry referencing the root
2397                  * of the subvol, not a random directory contained
2398                  * within it.
2399                  */
2400                 err = -EINVAL;
2401                 if (root == dest)
2402                         goto out_dput;
2403
2404                 err = inode_permission(inode, MAY_WRITE | MAY_EXEC);
2405                 if (err)
2406                         goto out_dput;
2407         }
2408
2409         /* check if subvolume may be deleted by a user */
2410         err = btrfs_may_delete(dir, dentry, 1);
2411         if (err)
2412                 goto out_dput;
2413
2414         if (btrfs_ino(BTRFS_I(inode)) != BTRFS_FIRST_FREE_OBJECTID) {
2415                 err = -EINVAL;
2416                 goto out_dput;
2417         }
2418
2419         inode_lock(inode);
2420
2421         /*
2422          * Don't allow to delete a subvolume with send in progress. This is
2423          * inside the i_mutex so the error handling that has to drop the bit
2424          * again is not run concurrently.
2425          */
2426         spin_lock(&dest->root_item_lock);
2427         root_flags = btrfs_root_flags(&dest->root_item);
2428         if (dest->send_in_progress == 0) {
2429                 btrfs_set_root_flags(&dest->root_item,
2430                                 root_flags | BTRFS_ROOT_SUBVOL_DEAD);
2431                 spin_unlock(&dest->root_item_lock);
2432         } else {
2433                 spin_unlock(&dest->root_item_lock);
2434                 btrfs_warn(fs_info,
2435                            "Attempt to delete subvolume %llu during send",
2436                            dest->root_key.objectid);
2437                 err = -EPERM;
2438                 goto out_unlock_inode;
2439         }
2440
2441         down_write(&fs_info->subvol_sem);
2442
2443         err = may_destroy_subvol(dest);
2444         if (err)
2445                 goto out_up_write;
2446
2447         btrfs_init_block_rsv(&block_rsv, BTRFS_BLOCK_RSV_TEMP);
2448         /*
2449          * One for dir inode, two for dir entries, two for root
2450          * ref/backref.
2451          */
2452         err = btrfs_subvolume_reserve_metadata(root, &block_rsv,
2453                                                5, &qgroup_reserved, true);
2454         if (err)
2455                 goto out_up_write;
2456
2457         trans = btrfs_start_transaction(root, 0);
2458         if (IS_ERR(trans)) {
2459                 err = PTR_ERR(trans);
2460                 goto out_release;
2461         }
2462         trans->block_rsv = &block_rsv;
2463         trans->bytes_reserved = block_rsv.size;
2464
2465         btrfs_record_snapshot_destroy(trans, BTRFS_I(dir));
2466
2467         ret = btrfs_unlink_subvol(trans, root, dir,
2468                                 dest->root_key.objectid,
2469                                 dentry->d_name.name,
2470                                 dentry->d_name.len);
2471         if (ret) {
2472                 err = ret;
2473                 btrfs_abort_transaction(trans, ret);
2474                 goto out_end_trans;
2475         }
2476
2477         btrfs_record_root_in_trans(trans, dest);
2478
2479         memset(&dest->root_item.drop_progress, 0,
2480                 sizeof(dest->root_item.drop_progress));
2481         dest->root_item.drop_level = 0;
2482         btrfs_set_root_refs(&dest->root_item, 0);
2483
2484         if (!test_and_set_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &dest->state)) {
2485                 ret = btrfs_insert_orphan_item(trans,
2486                                         fs_info->tree_root,
2487                                         dest->root_key.objectid);
2488                 if (ret) {
2489                         btrfs_abort_transaction(trans, ret);
2490                         err = ret;
2491                         goto out_end_trans;
2492                 }
2493         }
2494
2495         ret = btrfs_uuid_tree_rem(trans, fs_info, dest->root_item.uuid,
2496                                   BTRFS_UUID_KEY_SUBVOL,
2497                                   dest->root_key.objectid);
2498         if (ret && ret != -ENOENT) {
2499                 btrfs_abort_transaction(trans, ret);
2500                 err = ret;
2501                 goto out_end_trans;
2502         }
2503         if (!btrfs_is_empty_uuid(dest->root_item.received_uuid)) {
2504                 ret = btrfs_uuid_tree_rem(trans, fs_info,
2505                                           dest->root_item.received_uuid,
2506                                           BTRFS_UUID_KEY_RECEIVED_SUBVOL,
2507                                           dest->root_key.objectid);
2508                 if (ret && ret != -ENOENT) {
2509                         btrfs_abort_transaction(trans, ret);
2510                         err = ret;
2511                         goto out_end_trans;
2512                 }
2513         }
2514
2515 out_end_trans:
2516         trans->block_rsv = NULL;
2517         trans->bytes_reserved = 0;
2518         ret = btrfs_end_transaction(trans);
2519         if (ret && !err)
2520                 err = ret;
2521         inode->i_flags |= S_DEAD;
2522 out_release:
2523         btrfs_subvolume_release_metadata(fs_info, &block_rsv);
2524 out_up_write:
2525         up_write(&fs_info->subvol_sem);
2526         if (err) {
2527                 spin_lock(&dest->root_item_lock);
2528                 root_flags = btrfs_root_flags(&dest->root_item);
2529                 btrfs_set_root_flags(&dest->root_item,
2530                                 root_flags & ~BTRFS_ROOT_SUBVOL_DEAD);
2531                 spin_unlock(&dest->root_item_lock);
2532         }
2533 out_unlock_inode:
2534         inode_unlock(inode);
2535         if (!err) {
2536                 d_invalidate(dentry);
2537                 btrfs_invalidate_inodes(dest);
2538                 d_delete(dentry);
2539                 ASSERT(dest->send_in_progress == 0);
2540
2541                 /* the last ref */
2542                 if (dest->ino_cache_inode) {
2543                         iput(dest->ino_cache_inode);
2544                         dest->ino_cache_inode = NULL;
2545                 }
2546         }
2547 out_dput:
2548         dput(dentry);
2549 out_unlock_dir:
2550         inode_unlock(dir);
2551 out_drop_write:
2552         mnt_drop_write_file(file);
2553 out:
2554         kfree(vol_args);
2555         return err;
2556 }
2557
2558 static int btrfs_ioctl_defrag(struct file *file, void __user *argp)
2559 {
2560         struct inode *inode = file_inode(file);
2561         struct btrfs_root *root = BTRFS_I(inode)->root;
2562         struct btrfs_ioctl_defrag_range_args *range;
2563         int ret;
2564
2565         ret = mnt_want_write_file(file);
2566         if (ret)
2567                 return ret;
2568
2569         if (btrfs_root_readonly(root)) {
2570                 ret = -EROFS;
2571                 goto out;
2572         }
2573
2574         switch (inode->i_mode & S_IFMT) {
2575         case S_IFDIR:
2576                 if (!capable(CAP_SYS_ADMIN)) {
2577                         ret = -EPERM;
2578                         goto out;
2579                 }
2580                 ret = btrfs_defrag_root(root);
2581                 break;
2582         case S_IFREG:
2583                 if (!(file->f_mode & FMODE_WRITE)) {
2584                         ret = -EINVAL;
2585                         goto out;
2586                 }
2587
2588                 range = kzalloc(sizeof(*range), GFP_KERNEL);
2589                 if (!range) {
2590                         ret = -ENOMEM;
2591                         goto out;
2592                 }
2593
2594                 if (argp) {
2595                         if (copy_from_user(range, argp,
2596                                            sizeof(*range))) {
2597                                 ret = -EFAULT;
2598                                 kfree(range);
2599                                 goto out;
2600                         }
2601                         /* compression requires us to start the IO */
2602                         if ((range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)) {
2603                                 range->flags |= BTRFS_DEFRAG_RANGE_START_IO;
2604                                 range->extent_thresh = (u32)-1;
2605                         }
2606                 } else {
2607                         /* the rest are all set to zero by kzalloc */
2608                         range->len = (u64)-1;
2609                 }
2610                 ret = btrfs_defrag_file(file_inode(file), file,
2611                                         range, 0, 0);
2612                 if (ret > 0)
2613                         ret = 0;
2614                 kfree(range);
2615                 break;
2616         default:
2617                 ret = -EINVAL;
2618         }
2619 out:
2620         mnt_drop_write_file(file);
2621         return ret;
2622 }
2623
2624 static long btrfs_ioctl_add_dev(struct btrfs_fs_info *fs_info, void __user *arg)
2625 {
2626         struct btrfs_ioctl_vol_args *vol_args;
2627         int ret;
2628
2629         if (!capable(CAP_SYS_ADMIN))
2630                 return -EPERM;
2631
2632         if (test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags))
2633                 return BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
2634
2635         mutex_lock(&fs_info->volume_mutex);
2636         vol_args = memdup_user(arg, sizeof(*vol_args));
2637         if (IS_ERR(vol_args)) {
2638                 ret = PTR_ERR(vol_args);
2639                 goto out;
2640         }
2641
2642         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
2643         ret = btrfs_init_new_device(fs_info, vol_args->name);
2644
2645         if (!ret)
2646                 btrfs_info(fs_info, "disk added %s", vol_args->name);
2647
2648         kfree(vol_args);
2649 out:
2650         mutex_unlock(&fs_info->volume_mutex);
2651         clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
2652         return ret;
2653 }
2654
2655 static long btrfs_ioctl_rm_dev_v2(struct file *file, void __user *arg)
2656 {
2657         struct inode *inode = file_inode(file);
2658         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2659         struct btrfs_ioctl_vol_args_v2 *vol_args;
2660         int ret;
2661
2662         if (!capable(CAP_SYS_ADMIN))
2663                 return -EPERM;
2664
2665         ret = mnt_want_write_file(file);
2666         if (ret)
2667                 return ret;
2668
2669         vol_args = memdup_user(arg, sizeof(*vol_args));
2670         if (IS_ERR(vol_args)) {
2671                 ret = PTR_ERR(vol_args);
2672                 goto err_drop;
2673         }
2674
2675         /* Check for compatibility reject unknown flags */
2676         if (vol_args->flags & ~BTRFS_VOL_ARG_V2_FLAGS_SUPPORTED)
2677                 return -EOPNOTSUPP;
2678
2679         if (test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags)) {
2680                 ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
2681                 goto out;
2682         }
2683
2684         mutex_lock(&fs_info->volume_mutex);
2685         if (vol_args->flags & BTRFS_DEVICE_SPEC_BY_ID) {
2686                 ret = btrfs_rm_device(fs_info, NULL, vol_args->devid);
2687         } else {
2688                 vol_args->name[BTRFS_SUBVOL_NAME_MAX] = '\0';
2689                 ret = btrfs_rm_device(fs_info, vol_args->name, 0);
2690         }
2691         mutex_unlock(&fs_info->volume_mutex);
2692         clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
2693
2694         if (!ret) {
2695                 if (vol_args->flags & BTRFS_DEVICE_SPEC_BY_ID)
2696                         btrfs_info(fs_info, "device deleted: id %llu",
2697                                         vol_args->devid);
2698                 else
2699                         btrfs_info(fs_info, "device deleted: %s",
2700                                         vol_args->name);
2701         }
2702 out:
2703         kfree(vol_args);
2704 err_drop:
2705         mnt_drop_write_file(file);
2706         return ret;
2707 }
2708
2709 static long btrfs_ioctl_rm_dev(struct file *file, void __user *arg)
2710 {
2711         struct inode *inode = file_inode(file);
2712         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2713         struct btrfs_ioctl_vol_args *vol_args;
2714         int ret;
2715
2716         if (!capable(CAP_SYS_ADMIN))
2717                 return -EPERM;
2718
2719         ret = mnt_want_write_file(file);
2720         if (ret)
2721                 return ret;
2722
2723         if (test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags)) {
2724                 ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
2725                 goto out_drop_write;
2726         }
2727
2728         vol_args = memdup_user(arg, sizeof(*vol_args));
2729         if (IS_ERR(vol_args)) {
2730                 ret = PTR_ERR(vol_args);
2731                 goto out;
2732         }
2733
2734         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
2735         mutex_lock(&fs_info->volume_mutex);
2736         ret = btrfs_rm_device(fs_info, vol_args->name, 0);
2737         mutex_unlock(&fs_info->volume_mutex);
2738
2739         if (!ret)
2740                 btrfs_info(fs_info, "disk deleted %s", vol_args->name);
2741         kfree(vol_args);
2742 out:
2743         clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
2744 out_drop_write:
2745         mnt_drop_write_file(file);
2746
2747         return ret;
2748 }
2749
2750 static long btrfs_ioctl_fs_info(struct btrfs_fs_info *fs_info,
2751                                 void __user *arg)
2752 {
2753         struct btrfs_ioctl_fs_info_args *fi_args;
2754         struct btrfs_device *device;
2755         struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
2756         int ret = 0;
2757
2758         fi_args = kzalloc(sizeof(*fi_args), GFP_KERNEL);
2759         if (!fi_args)
2760                 return -ENOMEM;
2761
2762         mutex_lock(&fs_devices->device_list_mutex);
2763         fi_args->num_devices = fs_devices->num_devices;
2764         memcpy(&fi_args->fsid, fs_info->fsid, sizeof(fi_args->fsid));
2765
2766         list_for_each_entry(device, &fs_devices->devices, dev_list) {
2767                 if (device->devid > fi_args->max_id)
2768                         fi_args->max_id = device->devid;
2769         }
2770         mutex_unlock(&fs_devices->device_list_mutex);
2771
2772         fi_args->nodesize = fs_info->super_copy->nodesize;
2773         fi_args->sectorsize = fs_info->super_copy->sectorsize;
2774         fi_args->clone_alignment = fs_info->super_copy->sectorsize;
2775
2776         if (copy_to_user(arg, fi_args, sizeof(*fi_args)))
2777                 ret = -EFAULT;
2778
2779         kfree(fi_args);
2780         return ret;
2781 }
2782
2783 static long btrfs_ioctl_dev_info(struct btrfs_fs_info *fs_info,
2784                                  void __user *arg)
2785 {
2786         struct btrfs_ioctl_dev_info_args *di_args;
2787         struct btrfs_device *dev;
2788         struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
2789         int ret = 0;
2790         char *s_uuid = NULL;
2791
2792         di_args = memdup_user(arg, sizeof(*di_args));
2793         if (IS_ERR(di_args))
2794                 return PTR_ERR(di_args);
2795
2796         if (!btrfs_is_empty_uuid(di_args->uuid))
2797                 s_uuid = di_args->uuid;
2798
2799         mutex_lock(&fs_devices->device_list_mutex);
2800         dev = btrfs_find_device(fs_info, di_args->devid, s_uuid, NULL);
2801
2802         if (!dev) {
2803                 ret = -ENODEV;
2804                 goto out;
2805         }
2806
2807         di_args->devid = dev->devid;
2808         di_args->bytes_used = btrfs_device_get_bytes_used(dev);
2809         di_args->total_bytes = btrfs_device_get_total_bytes(dev);
2810         memcpy(di_args->uuid, dev->uuid, sizeof(di_args->uuid));
2811         if (dev->name) {
2812                 struct rcu_string *name;
2813
2814                 rcu_read_lock();
2815                 name = rcu_dereference(dev->name);
2816                 strncpy(di_args->path, name->str, sizeof(di_args->path));
2817                 rcu_read_unlock();
2818                 di_args->path[sizeof(di_args->path) - 1] = 0;
2819         } else {
2820                 di_args->path[0] = '\0';
2821         }
2822
2823 out:
2824         mutex_unlock(&fs_devices->device_list_mutex);
2825         if (ret == 0 && copy_to_user(arg, di_args, sizeof(*di_args)))
2826                 ret = -EFAULT;
2827
2828         kfree(di_args);
2829         return ret;
2830 }
2831
2832 static struct page *extent_same_get_page(struct inode *inode, pgoff_t index)
2833 {
2834         struct page *page;
2835
2836         page = grab_cache_page(inode->i_mapping, index);
2837         if (!page)
2838                 return ERR_PTR(-ENOMEM);
2839
2840         if (!PageUptodate(page)) {
2841                 int ret;
2842
2843                 ret = btrfs_readpage(NULL, page);
2844                 if (ret)
2845                         return ERR_PTR(ret);
2846                 lock_page(page);
2847                 if (!PageUptodate(page)) {
2848                         unlock_page(page);
2849                         put_page(page);
2850                         return ERR_PTR(-EIO);
2851                 }
2852                 if (page->mapping != inode->i_mapping) {
2853                         unlock_page(page);
2854                         put_page(page);
2855                         return ERR_PTR(-EAGAIN);
2856                 }
2857         }
2858
2859         return page;
2860 }
2861
2862 static int gather_extent_pages(struct inode *inode, struct page **pages,
2863                                int num_pages, u64 off)
2864 {
2865         int i;
2866         pgoff_t index = off >> PAGE_SHIFT;
2867
2868         for (i = 0; i < num_pages; i++) {
2869 again:
2870                 pages[i] = extent_same_get_page(inode, index + i);
2871                 if (IS_ERR(pages[i])) {
2872                         int err = PTR_ERR(pages[i]);
2873
2874                         if (err == -EAGAIN)
2875                                 goto again;
2876                         pages[i] = NULL;
2877                         return err;
2878                 }
2879         }
2880         return 0;
2881 }
2882
2883 static int lock_extent_range(struct inode *inode, u64 off, u64 len,
2884                              bool retry_range_locking)
2885 {
2886         /*
2887          * Do any pending delalloc/csum calculations on inode, one way or
2888          * another, and lock file content.
2889          * The locking order is:
2890          *
2891          *   1) pages
2892          *   2) range in the inode's io tree
2893          */
2894         while (1) {
2895                 struct btrfs_ordered_extent *ordered;
2896                 lock_extent(&BTRFS_I(inode)->io_tree, off, off + len - 1);
2897                 ordered = btrfs_lookup_first_ordered_extent(inode,
2898                                                             off + len - 1);
2899                 if ((!ordered ||
2900                      ordered->file_offset + ordered->len <= off ||
2901                      ordered->file_offset >= off + len) &&
2902                     !test_range_bit(&BTRFS_I(inode)->io_tree, off,
2903                                     off + len - 1, EXTENT_DELALLOC, 0, NULL)) {
2904                         if (ordered)
2905                                 btrfs_put_ordered_extent(ordered);
2906                         break;
2907                 }
2908                 unlock_extent(&BTRFS_I(inode)->io_tree, off, off + len - 1);
2909                 if (ordered)
2910                         btrfs_put_ordered_extent(ordered);
2911                 if (!retry_range_locking)
2912                         return -EAGAIN;
2913                 btrfs_wait_ordered_range(inode, off, len);
2914         }
2915         return 0;
2916 }
2917
2918 static void btrfs_double_inode_unlock(struct inode *inode1, struct inode *inode2)
2919 {
2920         inode_unlock(inode1);
2921         inode_unlock(inode2);
2922 }
2923
2924 static void btrfs_double_inode_lock(struct inode *inode1, struct inode *inode2)
2925 {
2926         if (inode1 < inode2)
2927                 swap(inode1, inode2);
2928
2929         inode_lock_nested(inode1, I_MUTEX_PARENT);
2930         inode_lock_nested(inode2, I_MUTEX_CHILD);
2931 }
2932
2933 static void btrfs_double_extent_unlock(struct inode *inode1, u64 loff1,
2934                                       struct inode *inode2, u64 loff2, u64 len)
2935 {
2936         unlock_extent(&BTRFS_I(inode1)->io_tree, loff1, loff1 + len - 1);
2937         unlock_extent(&BTRFS_I(inode2)->io_tree, loff2, loff2 + len - 1);
2938 }
2939
2940 static int btrfs_double_extent_lock(struct inode *inode1, u64 loff1,
2941                                     struct inode *inode2, u64 loff2, u64 len,
2942                                     bool retry_range_locking)
2943 {
2944         int ret;
2945
2946         if (inode1 < inode2) {
2947                 swap(inode1, inode2);
2948                 swap(loff1, loff2);
2949         }
2950         ret = lock_extent_range(inode1, loff1, len, retry_range_locking);
2951         if (ret)
2952                 return ret;
2953         ret = lock_extent_range(inode2, loff2, len, retry_range_locking);
2954         if (ret)
2955                 unlock_extent(&BTRFS_I(inode1)->io_tree, loff1,
2956                               loff1 + len - 1);
2957         return ret;
2958 }
2959
2960 struct cmp_pages {
2961         int             num_pages;
2962         struct page     **src_pages;
2963         struct page     **dst_pages;
2964 };
2965
2966 static void btrfs_cmp_data_free(struct cmp_pages *cmp)
2967 {
2968         int i;
2969         struct page *pg;
2970
2971         for (i = 0; i < cmp->num_pages; i++) {
2972                 pg = cmp->src_pages[i];
2973                 if (pg) {
2974                         unlock_page(pg);
2975                         put_page(pg);
2976                 }
2977                 pg = cmp->dst_pages[i];
2978                 if (pg) {
2979                         unlock_page(pg);
2980                         put_page(pg);
2981                 }
2982         }
2983         kfree(cmp->src_pages);
2984         kfree(cmp->dst_pages);
2985 }
2986
2987 static int btrfs_cmp_data_prepare(struct inode *src, u64 loff,
2988                                   struct inode *dst, u64 dst_loff,
2989                                   u64 len, struct cmp_pages *cmp)
2990 {
2991         int ret;
2992         int num_pages = PAGE_ALIGN(len) >> PAGE_SHIFT;
2993         struct page **src_pgarr, **dst_pgarr;
2994
2995         /*
2996          * We must gather up all the pages before we initiate our
2997          * extent locking. We use an array for the page pointers. Size
2998          * of the array is bounded by len, which is in turn bounded by
2999          * BTRFS_MAX_DEDUPE_LEN.
3000          */
3001         src_pgarr = kcalloc(num_pages, sizeof(struct page *), GFP_KERNEL);
3002         dst_pgarr = kcalloc(num_pages, sizeof(struct page *), GFP_KERNEL);
3003         if (!src_pgarr || !dst_pgarr) {
3004                 kfree(src_pgarr);
3005                 kfree(dst_pgarr);
3006                 return -ENOMEM;
3007         }
3008         cmp->num_pages = num_pages;
3009         cmp->src_pages = src_pgarr;
3010         cmp->dst_pages = dst_pgarr;
3011
3012         /*
3013          * If deduping ranges in the same inode, locking rules make it mandatory
3014          * to always lock pages in ascending order to avoid deadlocks with
3015          * concurrent tasks (such as starting writeback/delalloc).
3016          */
3017         if (src == dst && dst_loff < loff) {
3018                 swap(src_pgarr, dst_pgarr);
3019                 swap(loff, dst_loff);
3020         }
3021
3022         ret = gather_extent_pages(src, src_pgarr, cmp->num_pages, loff);
3023         if (ret)
3024                 goto out;
3025
3026         ret = gather_extent_pages(dst, dst_pgarr, cmp->num_pages, dst_loff);
3027
3028 out:
3029         if (ret)
3030                 btrfs_cmp_data_free(cmp);
3031         return 0;
3032 }
3033
3034 static int btrfs_cmp_data(u64 len, struct cmp_pages *cmp)
3035 {
3036         int ret = 0;
3037         int i;
3038         struct page *src_page, *dst_page;
3039         unsigned int cmp_len = PAGE_SIZE;
3040         void *addr, *dst_addr;
3041
3042         i = 0;
3043         while (len) {
3044                 if (len < PAGE_SIZE)
3045                         cmp_len = len;
3046
3047                 BUG_ON(i >= cmp->num_pages);
3048
3049                 src_page = cmp->src_pages[i];
3050                 dst_page = cmp->dst_pages[i];
3051                 ASSERT(PageLocked(src_page));
3052                 ASSERT(PageLocked(dst_page));
3053
3054                 addr = kmap_atomic(src_page);
3055                 dst_addr = kmap_atomic(dst_page);
3056
3057                 flush_dcache_page(src_page);
3058                 flush_dcache_page(dst_page);
3059
3060                 if (memcmp(addr, dst_addr, cmp_len))
3061                         ret = -EBADE;
3062
3063                 kunmap_atomic(addr);
3064                 kunmap_atomic(dst_addr);
3065
3066                 if (ret)
3067                         break;
3068
3069                 len -= cmp_len;
3070                 i++;
3071         }
3072
3073         return ret;
3074 }
3075
3076 static int extent_same_check_offsets(struct inode *inode, u64 off, u64 *plen,
3077                                      u64 olen)
3078 {
3079         u64 len = *plen;
3080         u64 bs = BTRFS_I(inode)->root->fs_info->sb->s_blocksize;
3081
3082         if (off + olen > inode->i_size || off + olen < off)
3083                 return -EINVAL;
3084
3085         /* if we extend to eof, continue to block boundary */
3086         if (off + len == inode->i_size)
3087                 *plen = len = ALIGN(inode->i_size, bs) - off;
3088
3089         /* Check that we are block aligned - btrfs_clone() requires this */
3090         if (!IS_ALIGNED(off, bs) || !IS_ALIGNED(off + len, bs))
3091                 return -EINVAL;
3092
3093         return 0;
3094 }
3095
3096 static int btrfs_extent_same(struct inode *src, u64 loff, u64 olen,
3097                              struct inode *dst, u64 dst_loff)
3098 {
3099         int ret;
3100         u64 len = olen;
3101         struct cmp_pages cmp;
3102         bool same_inode = (src == dst);
3103         u64 same_lock_start = 0;
3104         u64 same_lock_len = 0;
3105
3106         if (len == 0)
3107                 return 0;
3108
3109         if (same_inode)
3110                 inode_lock(src);
3111         else
3112                 btrfs_double_inode_lock(src, dst);
3113
3114         ret = extent_same_check_offsets(src, loff, &len, olen);
3115         if (ret)
3116                 goto out_unlock;
3117
3118         ret = extent_same_check_offsets(dst, dst_loff, &len, olen);
3119         if (ret)
3120                 goto out_unlock;
3121
3122         if (same_inode) {
3123                 /*
3124                  * Single inode case wants the same checks, except we
3125                  * don't want our length pushed out past i_size as
3126                  * comparing that data range makes no sense.
3127                  *
3128                  * extent_same_check_offsets() will do this for an
3129                  * unaligned length at i_size, so catch it here and
3130                  * reject the request.
3131                  *
3132                  * This effectively means we require aligned extents
3133                  * for the single-inode case, whereas the other cases
3134                  * allow an unaligned length so long as it ends at
3135                  * i_size.
3136                  */
3137                 if (len != olen) {
3138                         ret = -EINVAL;
3139                         goto out_unlock;
3140                 }
3141
3142                 /* Check for overlapping ranges */
3143                 if (dst_loff + len > loff && dst_loff < loff + len) {
3144                         ret = -EINVAL;
3145                         goto out_unlock;
3146                 }
3147
3148                 same_lock_start = min_t(u64, loff, dst_loff);
3149                 same_lock_len = max_t(u64, loff, dst_loff) + len - same_lock_start;
3150         }
3151
3152         /* don't make the dst file partly checksummed */
3153         if ((BTRFS_I(src)->flags & BTRFS_INODE_NODATASUM) !=
3154             (BTRFS_I(dst)->flags & BTRFS_INODE_NODATASUM)) {
3155                 ret = -EINVAL;
3156                 goto out_unlock;
3157         }
3158
3159 again:
3160         ret = btrfs_cmp_data_prepare(src, loff, dst, dst_loff, olen, &cmp);
3161         if (ret)
3162                 goto out_unlock;
3163
3164         if (same_inode)
3165                 ret = lock_extent_range(src, same_lock_start, same_lock_len,
3166                                         false);
3167         else
3168                 ret = btrfs_double_extent_lock(src, loff, dst, dst_loff, len,
3169                                                false);
3170         /*
3171          * If one of the inodes has dirty pages in the respective range or
3172          * ordered extents, we need to flush dellaloc and wait for all ordered
3173          * extents in the range. We must unlock the pages and the ranges in the
3174          * io trees to avoid deadlocks when flushing delalloc (requires locking
3175          * pages) and when waiting for ordered extents to complete (they require
3176          * range locking).
3177          */
3178         if (ret == -EAGAIN) {
3179                 /*
3180                  * Ranges in the io trees already unlocked. Now unlock all
3181                  * pages before waiting for all IO to complete.
3182                  */
3183                 btrfs_cmp_data_free(&cmp);
3184                 if (same_inode) {
3185                         btrfs_wait_ordered_range(src, same_lock_start,
3186                                                  same_lock_len);
3187                 } else {
3188                         btrfs_wait_ordered_range(src, loff, len);
3189                         btrfs_wait_ordered_range(dst, dst_loff, len);
3190                 }
3191                 goto again;
3192         }
3193         ASSERT(ret == 0);
3194         if (WARN_ON(ret)) {
3195                 /* ranges in the io trees already unlocked */
3196                 btrfs_cmp_data_free(&cmp);
3197                 return ret;
3198         }
3199
3200         /* pass original length for comparison so we stay within i_size */
3201         ret = btrfs_cmp_data(olen, &cmp);
3202         if (ret == 0)
3203                 ret = btrfs_clone(src, dst, loff, olen, len, dst_loff, 1);
3204
3205         if (same_inode)
3206                 unlock_extent(&BTRFS_I(src)->io_tree, same_lock_start,
3207                               same_lock_start + same_lock_len - 1);
3208         else
3209                 btrfs_double_extent_unlock(src, loff, dst, dst_loff, len);
3210
3211         btrfs_cmp_data_free(&cmp);
3212 out_unlock:
3213         if (same_inode)
3214                 inode_unlock(src);
3215         else
3216                 btrfs_double_inode_unlock(src, dst);
3217
3218         return ret;
3219 }
3220
3221 #define BTRFS_MAX_DEDUPE_LEN    SZ_16M
3222
3223 ssize_t btrfs_dedupe_file_range(struct file *src_file, u64 loff, u64 olen,
3224                                 struct file *dst_file, u64 dst_loff)
3225 {
3226         struct inode *src = file_inode(src_file);
3227         struct inode *dst = file_inode(dst_file);
3228         u64 bs = BTRFS_I(src)->root->fs_info->sb->s_blocksize;
3229         ssize_t res;
3230
3231         if (olen > BTRFS_MAX_DEDUPE_LEN)
3232                 olen = BTRFS_MAX_DEDUPE_LEN;
3233
3234         if (WARN_ON_ONCE(bs < PAGE_SIZE)) {
3235                 /*
3236                  * Btrfs does not support blocksize < page_size. As a
3237                  * result, btrfs_cmp_data() won't correctly handle
3238                  * this situation without an update.
3239                  */
3240                 return -EINVAL;
3241         }
3242
3243         res = btrfs_extent_same(src, loff, olen, dst, dst_loff);
3244         if (res)
3245                 return res;
3246         return olen;
3247 }
3248
3249 static int clone_finish_inode_update(struct btrfs_trans_handle *trans,
3250                                      struct inode *inode,
3251                                      u64 endoff,
3252                                      const u64 destoff,
3253                                      const u64 olen,
3254                                      int no_time_update)
3255 {
3256         struct btrfs_root *root = BTRFS_I(inode)->root;
3257         int ret;
3258
3259         inode_inc_iversion(inode);
3260         if (!no_time_update)
3261                 inode->i_mtime = inode->i_ctime = current_time(inode);
3262         /*
3263          * We round up to the block size at eof when determining which
3264          * extents to clone above, but shouldn't round up the file size.
3265          */
3266         if (endoff > destoff + olen)
3267                 endoff = destoff + olen;
3268         if (endoff > inode->i_size)
3269                 btrfs_i_size_write(BTRFS_I(inode), endoff);
3270
3271         ret = btrfs_update_inode(trans, root, inode);
3272         if (ret) {
3273                 btrfs_abort_transaction(trans, ret);
3274                 btrfs_end_transaction(trans);
3275                 goto out;
3276         }
3277         ret = btrfs_end_transaction(trans);
3278 out:
3279         return ret;
3280 }
3281
3282 static void clone_update_extent_map(struct btrfs_inode *inode,
3283                                     const struct btrfs_trans_handle *trans,
3284                                     const struct btrfs_path *path,
3285                                     const u64 hole_offset,
3286                                     const u64 hole_len)
3287 {
3288         struct extent_map_tree *em_tree = &inode->extent_tree;
3289         struct extent_map *em;
3290         int ret;
3291
3292         em = alloc_extent_map();
3293         if (!em) {
3294                 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &inode->runtime_flags);
3295                 return;
3296         }
3297
3298         if (path) {
3299                 struct btrfs_file_extent_item *fi;
3300
3301                 fi = btrfs_item_ptr(path->nodes[0], path->slots[0],
3302                                     struct btrfs_file_extent_item);
3303                 btrfs_extent_item_to_extent_map(inode, path, fi, false, em);
3304                 em->generation = -1;
3305                 if (btrfs_file_extent_type(path->nodes[0], fi) ==
3306                     BTRFS_FILE_EXTENT_INLINE)
3307                         set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
3308                                         &inode->runtime_flags);
3309         } else {
3310                 em->start = hole_offset;
3311                 em->len = hole_len;
3312                 em->ram_bytes = em->len;
3313                 em->orig_start = hole_offset;
3314                 em->block_start = EXTENT_MAP_HOLE;
3315                 em->block_len = 0;
3316                 em->orig_block_len = 0;
3317                 em->compress_type = BTRFS_COMPRESS_NONE;
3318                 em->generation = trans->transid;
3319         }
3320
3321         while (1) {
3322                 write_lock(&em_tree->lock);
3323                 ret = add_extent_mapping(em_tree, em, 1);
3324                 write_unlock(&em_tree->lock);
3325                 if (ret != -EEXIST) {
3326                         free_extent_map(em);
3327                         break;
3328                 }
3329                 btrfs_drop_extent_cache(inode, em->start,
3330                                         em->start + em->len - 1, 0);
3331         }
3332
3333         if (ret)
3334                 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &inode->runtime_flags);
3335 }
3336
3337 /*
3338  * Make sure we do not end up inserting an inline extent into a file that has
3339  * already other (non-inline) extents. If a file has an inline extent it can
3340  * not have any other extents and the (single) inline extent must start at the
3341  * file offset 0. Failing to respect these rules will lead to file corruption,
3342  * resulting in EIO errors on read/write operations, hitting BUG_ON's in mm, etc
3343  *
3344  * We can have extents that have been already written to disk or we can have
3345  * dirty ranges still in delalloc, in which case the extent maps and items are
3346  * created only when we run delalloc, and the delalloc ranges might fall outside
3347  * the range we are currently locking in the inode's io tree. So we check the
3348  * inode's i_size because of that (i_size updates are done while holding the
3349  * i_mutex, which we are holding here).
3350  * We also check to see if the inode has a size not greater than "datal" but has
3351  * extents beyond it, due to an fallocate with FALLOC_FL_KEEP_SIZE (and we are
3352  * protected against such concurrent fallocate calls by the i_mutex).
3353  *
3354  * If the file has no extents but a size greater than datal, do not allow the
3355  * copy because we would need turn the inline extent into a non-inline one (even
3356  * with NO_HOLES enabled). If we find our destination inode only has one inline
3357  * extent, just overwrite it with the source inline extent if its size is less
3358  * than the source extent's size, or we could copy the source inline extent's
3359  * data into the destination inode's inline extent if the later is greater then
3360  * the former.
3361  */
3362 static int clone_copy_inline_extent(struct inode *dst,
3363                                     struct btrfs_trans_handle *trans,
3364                                     struct btrfs_path *path,
3365                                     struct btrfs_key *new_key,
3366                                     const u64 drop_start,
3367                                     const u64 datal,
3368                                     const u64 skip,
3369                                     const u64 size,
3370                                     char *inline_data)
3371 {
3372         struct btrfs_fs_info *fs_info = btrfs_sb(dst->i_sb);
3373         struct btrfs_root *root = BTRFS_I(dst)->root;
3374         const u64 aligned_end = ALIGN(new_key->offset + datal,
3375                                       fs_info->sectorsize);
3376         int ret;
3377         struct btrfs_key key;
3378
3379         if (new_key->offset > 0)
3380                 return -EOPNOTSUPP;
3381
3382         key.objectid = btrfs_ino(BTRFS_I(dst));
3383         key.type = BTRFS_EXTENT_DATA_KEY;
3384         key.offset = 0;
3385         ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3386         if (ret < 0) {
3387                 return ret;
3388         } else if (ret > 0) {
3389                 if (path->slots[0] >= btrfs_header_nritems(path->nodes[0])) {
3390                         ret = btrfs_next_leaf(root, path);
3391                         if (ret < 0)
3392                                 return ret;
3393                         else if (ret > 0)
3394                                 goto copy_inline_extent;
3395                 }
3396                 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
3397                 if (key.objectid == btrfs_ino(BTRFS_I(dst)) &&
3398                     key.type == BTRFS_EXTENT_DATA_KEY) {
3399                         ASSERT(key.offset > 0);
3400                         return -EOPNOTSUPP;
3401                 }
3402         } else if (i_size_read(dst) <= datal) {
3403                 struct btrfs_file_extent_item *ei;
3404                 u64 ext_len;
3405
3406                 /*
3407                  * If the file size is <= datal, make sure there are no other
3408                  * extents following (can happen do to an fallocate call with
3409                  * the flag FALLOC_FL_KEEP_SIZE).
3410                  */
3411                 ei = btrfs_item_ptr(path->nodes[0], path->slots[0],
3412                                     struct btrfs_file_extent_item);
3413                 /*
3414                  * If it's an inline extent, it can not have other extents
3415                  * following it.
3416                  */
3417                 if (btrfs_file_extent_type(path->nodes[0], ei) ==
3418                     BTRFS_FILE_EXTENT_INLINE)
3419                         goto copy_inline_extent;
3420
3421                 ext_len = btrfs_file_extent_num_bytes(path->nodes[0], ei);
3422                 if (ext_len > aligned_end)
3423                         return -EOPNOTSUPP;
3424
3425                 ret = btrfs_next_item(root, path);
3426                 if (ret < 0) {
3427                         return ret;
3428                 } else if (ret == 0) {
3429                         btrfs_item_key_to_cpu(path->nodes[0], &key,
3430                                               path->slots[0]);
3431                         if (key.objectid == btrfs_ino(BTRFS_I(dst)) &&
3432                             key.type == BTRFS_EXTENT_DATA_KEY)
3433                                 return -EOPNOTSUPP;
3434                 }
3435         }
3436
3437 copy_inline_extent:
3438         /*
3439          * We have no extent items, or we have an extent at offset 0 which may
3440          * or may not be inlined. All these cases are dealt the same way.
3441          */
3442         if (i_size_read(dst) > datal) {
3443                 /*
3444                  * If the destination inode has an inline extent...
3445                  * This would require copying the data from the source inline
3446                  * extent into the beginning of the destination's inline extent.
3447                  * But this is really complex, both extents can be compressed
3448                  * or just one of them, which would require decompressing and
3449                  * re-compressing data (which could increase the new compressed
3450                  * size, not allowing the compressed data to fit anymore in an
3451                  * inline extent).
3452                  * So just don't support this case for now (it should be rare,
3453                  * we are not really saving space when cloning inline extents).
3454                  */
3455                 return -EOPNOTSUPP;
3456         }
3457
3458         btrfs_release_path(path);
3459         ret = btrfs_drop_extents(trans, root, dst, drop_start, aligned_end, 1);
3460         if (ret)
3461                 return ret;
3462         ret = btrfs_insert_empty_item(trans, root, path, new_key, size);
3463         if (ret)
3464                 return ret;
3465
3466         if (skip) {
3467                 const u32 start = btrfs_file_extent_calc_inline_size(0);
3468
3469                 memmove(inline_data + start, inline_data + start + skip, datal);
3470         }
3471
3472         write_extent_buffer(path->nodes[0], inline_data,
3473                             btrfs_item_ptr_offset(path->nodes[0],
3474                                                   path->slots[0]),
3475                             size);
3476         inode_add_bytes(dst, datal);
3477
3478         return 0;
3479 }
3480
3481 /**
3482  * btrfs_clone() - clone a range from inode file to another
3483  *
3484  * @src: Inode to clone from
3485  * @inode: Inode to clone to
3486  * @off: Offset within source to start clone from
3487  * @olen: Original length, passed by user, of range to clone
3488  * @olen_aligned: Block-aligned value of olen
3489  * @destoff: Offset within @inode to start clone
3490  * @no_time_update: Whether to update mtime/ctime on the target inode
3491  */
3492 static int btrfs_clone(struct inode *src, struct inode *inode,
3493                        const u64 off, const u64 olen, const u64 olen_aligned,
3494                        const u64 destoff, int no_time_update)
3495 {
3496         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3497         struct btrfs_root *root = BTRFS_I(inode)->root;
3498         struct btrfs_path *path = NULL;
3499         struct extent_buffer *leaf;
3500         struct btrfs_trans_handle *trans;
3501         char *buf = NULL;
3502         struct btrfs_key key;
3503         u32 nritems;
3504         int slot;
3505         int ret;
3506         const u64 len = olen_aligned;
3507         u64 last_dest_end = destoff;
3508
3509         ret = -ENOMEM;
3510         buf = kvmalloc(fs_info->nodesize, GFP_KERNEL);
3511         if (!buf)
3512                 return ret;
3513
3514         path = btrfs_alloc_path();
3515         if (!path) {
3516                 kvfree(buf);
3517                 return ret;
3518         }
3519
3520         path->reada = READA_FORWARD;
3521         /* clone data */
3522         key.objectid = btrfs_ino(BTRFS_I(src));
3523         key.type = BTRFS_EXTENT_DATA_KEY;
3524         key.offset = off;
3525
3526         while (1) {
3527                 u64 next_key_min_offset = key.offset + 1;
3528
3529                 /*
3530                  * note the key will change type as we walk through the
3531                  * tree.
3532                  */
3533                 path->leave_spinning = 1;
3534                 ret = btrfs_search_slot(NULL, BTRFS_I(src)->root, &key, path,
3535                                 0, 0);
3536                 if (ret < 0)
3537                         goto out;
3538                 /*
3539                  * First search, if no extent item that starts at offset off was
3540                  * found but the previous item is an extent item, it's possible
3541                  * it might overlap our target range, therefore process it.
3542                  */
3543                 if (key.offset == off && ret > 0 && path->slots[0] > 0) {
3544                         btrfs_item_key_to_cpu(path->nodes[0], &key,
3545                                               path->slots[0] - 1);
3546                         if (key.type == BTRFS_EXTENT_DATA_KEY)
3547                                 path->slots[0]--;
3548                 }
3549
3550                 nritems = btrfs_header_nritems(path->nodes[0]);
3551 process_slot:
3552                 if (path->slots[0] >= nritems) {
3553                         ret = btrfs_next_leaf(BTRFS_I(src)->root, path);
3554                         if (ret < 0)
3555                                 goto out;
3556                         if (ret > 0)
3557                                 break;
3558                         nritems = btrfs_header_nritems(path->nodes[0]);
3559                 }
3560                 leaf = path->nodes[0];
3561                 slot = path->slots[0];
3562
3563                 btrfs_item_key_to_cpu(leaf, &key, slot);
3564                 if (key.type > BTRFS_EXTENT_DATA_KEY ||
3565                     key.objectid != btrfs_ino(BTRFS_I(src)))
3566                         break;
3567
3568                 if (key.type == BTRFS_EXTENT_DATA_KEY) {
3569                         struct btrfs_file_extent_item *extent;
3570                         int type;
3571                         u32 size;
3572                         struct btrfs_key new_key;
3573                         u64 disko = 0, diskl = 0;
3574                         u64 datao = 0, datal = 0;
3575                         u8 comp;
3576                         u64 drop_start;
3577
3578                         extent = btrfs_item_ptr(leaf, slot,
3579                                                 struct btrfs_file_extent_item);
3580                         comp = btrfs_file_extent_compression(leaf, extent);
3581                         type = btrfs_file_extent_type(leaf, extent);
3582                         if (type == BTRFS_FILE_EXTENT_REG ||
3583                             type == BTRFS_FILE_EXTENT_PREALLOC) {
3584                                 disko = btrfs_file_extent_disk_bytenr(leaf,
3585                                                                       extent);
3586                                 diskl = btrfs_file_extent_disk_num_bytes(leaf,
3587                                                                  extent);
3588                                 datao = btrfs_file_extent_offset(leaf, extent);
3589                                 datal = btrfs_file_extent_num_bytes(leaf,
3590                                                                     extent);
3591                         } else if (type == BTRFS_FILE_EXTENT_INLINE) {
3592                                 /* take upper bound, may be compressed */
3593                                 datal = btrfs_file_extent_ram_bytes(leaf,
3594                                                                     extent);
3595                         }
3596
3597                         /*
3598                          * The first search might have left us at an extent
3599                          * item that ends before our target range's start, can
3600                          * happen if we have holes and NO_HOLES feature enabled.
3601                          */
3602                         if (key.offset + datal <= off) {
3603                                 path->slots[0]++;
3604                                 goto process_slot;
3605                         } else if (key.offset >= off + len) {
3606                                 break;
3607                         }
3608                         next_key_min_offset = key.offset + datal;
3609                         size = btrfs_item_size_nr(leaf, slot);
3610                         read_extent_buffer(leaf, buf,
3611                                            btrfs_item_ptr_offset(leaf, slot),
3612                                            size);
3613
3614                         btrfs_release_path(path);
3615                         path->leave_spinning = 0;
3616
3617                         memcpy(&new_key, &key, sizeof(new_key));
3618                         new_key.objectid = btrfs_ino(BTRFS_I(inode));
3619                         if (off <= key.offset)
3620                                 new_key.offset = key.offset + destoff - off;
3621                         else
3622                                 new_key.offset = destoff;
3623
3624                         /*
3625                          * Deal with a hole that doesn't have an extent item
3626                          * that represents it (NO_HOLES feature enabled).
3627                          * This hole is either in the middle of the cloning
3628                          * range or at the beginning (fully overlaps it or
3629                          * partially overlaps it).
3630                          */
3631                         if (new_key.offset != last_dest_end)
3632                                 drop_start = last_dest_end;
3633                         else
3634                                 drop_start = new_key.offset;
3635
3636                         /*
3637                          * 1 - adjusting old extent (we may have to split it)
3638                          * 1 - add new extent
3639                          * 1 - inode update
3640                          */
3641                         trans = btrfs_start_transaction(root, 3);
3642                         if (IS_ERR(trans)) {
3643                                 ret = PTR_ERR(trans);
3644                                 goto out;
3645                         }
3646
3647                         if (type == BTRFS_FILE_EXTENT_REG ||
3648                             type == BTRFS_FILE_EXTENT_PREALLOC) {
3649                                 /*
3650                                  *    a  | --- range to clone ---|  b
3651                                  * | ------------- extent ------------- |
3652                                  */
3653
3654                                 /* subtract range b */
3655                                 if (key.offset + datal > off + len)
3656                                         datal = off + len - key.offset;
3657
3658                                 /* subtract range a */
3659                                 if (off > key.offset) {
3660                                         datao += off - key.offset;
3661                                         datal -= off - key.offset;
3662                                 }
3663
3664                                 ret = btrfs_drop_extents(trans, root, inode,
3665                                                          drop_start,
3666                                                          new_key.offset + datal,
3667                                                          1);
3668                                 if (ret) {
3669                                         if (ret != -EOPNOTSUPP)
3670                                                 btrfs_abort_transaction(trans,
3671                                                                         ret);
3672                                         btrfs_end_transaction(trans);
3673                                         goto out;
3674                                 }
3675
3676                                 ret = btrfs_insert_empty_item(trans, root, path,
3677                                                               &new_key, size);
3678                                 if (ret) {
3679                                         btrfs_abort_transaction(trans, ret);
3680                                         btrfs_end_transaction(trans);
3681                                         goto out;
3682                                 }
3683
3684                                 leaf = path->nodes[0];
3685                                 slot = path->slots[0];
3686                                 write_extent_buffer(leaf, buf,
3687                                             btrfs_item_ptr_offset(leaf, slot),
3688                                             size);
3689
3690                                 extent = btrfs_item_ptr(leaf, slot,
3691                                                 struct btrfs_file_extent_item);
3692
3693                                 /* disko == 0 means it's a hole */
3694                                 if (!disko)
3695                                         datao = 0;
3696
3697                                 btrfs_set_file_extent_offset(leaf, extent,
3698                                                              datao);
3699                                 btrfs_set_file_extent_num_bytes(leaf, extent,
3700                                                                 datal);
3701
3702                                 if (disko) {
3703                                         inode_add_bytes(inode, datal);
3704                                         ret = btrfs_inc_extent_ref(trans,
3705                                                         fs_info,
3706                                                         disko, diskl, 0,
3707                                                         root->root_key.objectid,
3708                                                         btrfs_ino(BTRFS_I(inode)),
3709                                                         new_key.offset - datao);
3710                                         if (ret) {
3711                                                 btrfs_abort_transaction(trans,
3712                                                                         ret);
3713                                                 btrfs_end_transaction(trans);
3714                                                 goto out;
3715
3716                                         }
3717                                 }
3718                         } else if (type == BTRFS_FILE_EXTENT_INLINE) {
3719                                 u64 skip = 0;
3720                                 u64 trim = 0;
3721
3722                                 if (off > key.offset) {
3723                                         skip = off - key.offset;
3724                                         new_key.offset += skip;
3725                                 }
3726
3727                                 if (key.offset + datal > off + len)
3728                                         trim = key.offset + datal - (off + len);
3729
3730                                 if (comp && (skip || trim)) {
3731                                         ret = -EINVAL;
3732                                         btrfs_end_transaction(trans);
3733                                         goto out;
3734                                 }
3735                                 size -= skip + trim;
3736                                 datal -= skip + trim;
3737
3738                                 ret = clone_copy_inline_extent(inode,
3739                                                                trans, path,
3740                                                                &new_key,
3741                                                                drop_start,
3742                                                                datal,
3743                                                                skip, size, buf);
3744                                 if (ret) {
3745                                         if (ret != -EOPNOTSUPP)
3746                                                 btrfs_abort_transaction(trans,
3747                                                                         ret);
3748                                         btrfs_end_transaction(trans);
3749                                         goto out;
3750                                 }
3751                                 leaf = path->nodes[0];
3752                                 slot = path->slots[0];
3753                         }
3754
3755                         /* If we have an implicit hole (NO_HOLES feature). */
3756                         if (drop_start < new_key.offset)
3757                                 clone_update_extent_map(BTRFS_I(inode), trans,
3758                                                 NULL, drop_start,
3759                                                 new_key.offset - drop_start);
3760
3761                         clone_update_extent_map(BTRFS_I(inode), trans,
3762                                         path, 0, 0);
3763
3764                         btrfs_mark_buffer_dirty(leaf);
3765                         btrfs_release_path(path);
3766
3767                         last_dest_end = ALIGN(new_key.offset + datal,
3768                                               fs_info->sectorsize);
3769                         ret = clone_finish_inode_update(trans, inode,
3770                                                         last_dest_end,
3771                                                         destoff, olen,
3772                                                         no_time_update);
3773                         if (ret)
3774                                 goto out;
3775                         if (new_key.offset + datal >= destoff + len)
3776                                 break;
3777                 }
3778                 btrfs_release_path(path);
3779                 key.offset = next_key_min_offset;
3780
3781                 if (fatal_signal_pending(current)) {
3782                         ret = -EINTR;
3783                         goto out;
3784                 }
3785         }
3786         ret = 0;
3787
3788         if (last_dest_end < destoff + len) {
3789                 /*
3790                  * We have an implicit hole (NO_HOLES feature is enabled) that
3791                  * fully or partially overlaps our cloning range at its end.
3792                  */
3793                 btrfs_release_path(path);
3794
3795                 /*
3796                  * 1 - remove extent(s)
3797                  * 1 - inode update
3798                  */
3799                 trans = btrfs_start_transaction(root, 2);
3800                 if (IS_ERR(trans)) {
3801                         ret = PTR_ERR(trans);
3802                         goto out;
3803                 }
3804                 ret = btrfs_drop_extents(trans, root, inode,
3805                                          last_dest_end, destoff + len, 1);
3806                 if (ret) {
3807                         if (ret != -EOPNOTSUPP)
3808                                 btrfs_abort_transaction(trans, ret);
3809                         btrfs_end_transaction(trans);
3810                         goto out;
3811                 }
3812                 clone_update_extent_map(BTRFS_I(inode), trans, NULL,
3813                                 last_dest_end,
3814                                 destoff + len - last_dest_end);
3815                 ret = clone_finish_inode_update(trans, inode, destoff + len,
3816                                                 destoff, olen, no_time_update);
3817         }
3818
3819 out:
3820         btrfs_free_path(path);
3821         kvfree(buf);
3822         return ret;
3823 }
3824
3825 static noinline int btrfs_clone_files(struct file *file, struct file *file_src,
3826                                         u64 off, u64 olen, u64 destoff)
3827 {
3828         struct inode *inode = file_inode(file);
3829         struct inode *src = file_inode(file_src);
3830         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3831         struct btrfs_root *root = BTRFS_I(inode)->root;
3832         int ret;
3833         u64 len = olen;
3834         u64 bs = fs_info->sb->s_blocksize;
3835         int same_inode = src == inode;
3836
3837         /*
3838          * TODO:
3839          * - split compressed inline extents.  annoying: we need to
3840          *   decompress into destination's address_space (the file offset
3841          *   may change, so source mapping won't do), then recompress (or
3842          *   otherwise reinsert) a subrange.
3843          *
3844          * - split destination inode's inline extents.  The inline extents can
3845          *   be either compressed or non-compressed.
3846          */
3847
3848         if (btrfs_root_readonly(root))
3849                 return -EROFS;
3850
3851         if (file_src->f_path.mnt != file->f_path.mnt ||
3852             src->i_sb != inode->i_sb)
3853                 return -EXDEV;
3854
3855         /* don't make the dst file partly checksummed */
3856         if ((BTRFS_I(src)->flags & BTRFS_INODE_NODATASUM) !=
3857             (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM))
3858                 return -EINVAL;
3859
3860         if (S_ISDIR(src->i_mode) || S_ISDIR(inode->i_mode))
3861                 return -EISDIR;
3862
3863         if (!same_inode) {
3864                 btrfs_double_inode_lock(src, inode);
3865         } else {
3866                 inode_lock(src);
3867         }
3868
3869         /* determine range to clone */
3870         ret = -EINVAL;
3871         if (off + len > src->i_size || off + len < off)
3872                 goto out_unlock;
3873         if (len == 0)
3874                 olen = len = src->i_size - off;
3875         /* if we extend to eof, continue to block boundary */
3876         if (off + len == src->i_size)
3877                 len = ALIGN(src->i_size, bs) - off;
3878
3879         if (len == 0) {
3880                 ret = 0;
3881                 goto out_unlock;
3882         }
3883
3884         /* verify the end result is block aligned */
3885         if (!IS_ALIGNED(off, bs) || !IS_ALIGNED(off + len, bs) ||
3886             !IS_ALIGNED(destoff, bs))
3887                 goto out_unlock;
3888
3889         /* verify if ranges are overlapped within the same file */
3890         if (same_inode) {
3891                 if (destoff + len > off && destoff < off + len)
3892                         goto out_unlock;
3893         }
3894
3895         if (destoff > inode->i_size) {
3896                 ret = btrfs_cont_expand(inode, inode->i_size, destoff);
3897                 if (ret)
3898                         goto out_unlock;
3899         }
3900
3901         /*
3902          * Lock the target range too. Right after we replace the file extent
3903          * items in the fs tree (which now point to the cloned data), we might
3904          * have a worker replace them with extent items relative to a write
3905          * operation that was issued before this clone operation (i.e. confront
3906          * with inode.c:btrfs_finish_ordered_io).
3907          */
3908         if (same_inode) {
3909                 u64 lock_start = min_t(u64, off, destoff);
3910                 u64 lock_len = max_t(u64, off, destoff) + len - lock_start;
3911
3912                 ret = lock_extent_range(src, lock_start, lock_len, true);
3913         } else {
3914                 ret = btrfs_double_extent_lock(src, off, inode, destoff, len,
3915                                                true);
3916         }
3917         ASSERT(ret == 0);
3918         if (WARN_ON(ret)) {
3919                 /* ranges in the io trees already unlocked */
3920                 goto out_unlock;
3921         }
3922
3923         ret = btrfs_clone(src, inode, off, olen, len, destoff, 0);
3924
3925         if (same_inode) {
3926                 u64 lock_start = min_t(u64, off, destoff);
3927                 u64 lock_end = max_t(u64, off, destoff) + len - 1;
3928
3929                 unlock_extent(&BTRFS_I(src)->io_tree, lock_start, lock_end);
3930         } else {
3931                 btrfs_double_extent_unlock(src, off, inode, destoff, len);
3932         }
3933         /*
3934          * Truncate page cache pages so that future reads will see the cloned
3935          * data immediately and not the previous data.
3936          */
3937         truncate_inode_pages_range(&inode->i_data,
3938                                 round_down(destoff, PAGE_SIZE),
3939                                 round_up(destoff + len, PAGE_SIZE) - 1);
3940 out_unlock:
3941         if (!same_inode)
3942                 btrfs_double_inode_unlock(src, inode);
3943         else
3944                 inode_unlock(src);
3945         return ret;
3946 }
3947
3948 int btrfs_clone_file_range(struct file *src_file, loff_t off,
3949                 struct file *dst_file, loff_t destoff, u64 len)
3950 {
3951         return btrfs_clone_files(dst_file, src_file, off, len, destoff);
3952 }
3953
3954 /*
3955  * there are many ways the trans_start and trans_end ioctls can lead
3956  * to deadlocks.  They should only be used by applications that
3957  * basically own the machine, and have a very in depth understanding
3958  * of all the possible deadlocks and enospc problems.
3959  */
3960 static long btrfs_ioctl_trans_start(struct file *file)
3961 {
3962         struct inode *inode = file_inode(file);
3963         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3964         struct btrfs_root *root = BTRFS_I(inode)->root;
3965         struct btrfs_trans_handle *trans;
3966         struct btrfs_file_private *private;
3967         int ret;
3968         static bool warned = false;
3969
3970         ret = -EPERM;
3971         if (!capable(CAP_SYS_ADMIN))
3972                 goto out;
3973
3974         if (!warned) {
3975                 btrfs_warn(fs_info,
3976                         "Userspace transaction mechanism is considered "
3977                         "deprecated and slated to be removed in 4.17. "
3978                         "If you have a valid use case please "
3979                         "speak up on the mailing list");
3980                 WARN_ON(1);
3981                 warned = true;
3982         }
3983
3984         ret = -EINPROGRESS;
3985         private = file->private_data;
3986         if (private && private->trans)
3987                 goto out;
3988         if (!private) {
3989                 private = kzalloc(sizeof(struct btrfs_file_private),
3990                                   GFP_KERNEL);
3991                 if (!private)
3992                         return -ENOMEM;
3993                 file->private_data = private;
3994         }
3995
3996         ret = -EROFS;
3997         if (btrfs_root_readonly(root))
3998                 goto out;
3999
4000         ret = mnt_want_write_file(file);
4001         if (ret)
4002                 goto out;
4003
4004         atomic_inc(&fs_info->open_ioctl_trans);
4005
4006         ret = -ENOMEM;
4007         trans = btrfs_start_ioctl_transaction(root);
4008         if (IS_ERR(trans))
4009                 goto out_drop;
4010
4011         private->trans = trans;
4012         return 0;
4013
4014 out_drop:
4015         atomic_dec(&fs_info->open_ioctl_trans);
4016         mnt_drop_write_file(file);
4017 out:
4018         return ret;
4019 }
4020
4021 static long btrfs_ioctl_default_subvol(struct file *file, void __user *argp)
4022 {
4023         struct inode *inode = file_inode(file);
4024         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4025         struct btrfs_root *root = BTRFS_I(inode)->root;
4026         struct btrfs_root *new_root;
4027         struct btrfs_dir_item *di;
4028         struct btrfs_trans_handle *trans;
4029         struct btrfs_path *path;
4030         struct btrfs_key location;
4031         struct btrfs_disk_key disk_key;
4032         u64 objectid = 0;
4033         u64 dir_id;
4034         int ret;
4035
4036         if (!capable(CAP_SYS_ADMIN))
4037                 return -EPERM;
4038
4039         ret = mnt_want_write_file(file);
4040         if (ret)
4041                 return ret;
4042
4043         if (copy_from_user(&objectid, argp, sizeof(objectid))) {
4044                 ret = -EFAULT;
4045                 goto out;
4046         }
4047
4048         if (!objectid)
4049                 objectid = BTRFS_FS_TREE_OBJECTID;
4050
4051         location.objectid = objectid;
4052         location.type = BTRFS_ROOT_ITEM_KEY;
4053         location.offset = (u64)-1;
4054
4055         new_root = btrfs_read_fs_root_no_name(fs_info, &location);
4056         if (IS_ERR(new_root)) {
4057                 ret = PTR_ERR(new_root);
4058                 goto out;
4059         }
4060
4061         path = btrfs_alloc_path();
4062         if (!path) {
4063                 ret = -ENOMEM;
4064                 goto out;
4065         }
4066         path->leave_spinning = 1;
4067
4068         trans = btrfs_start_transaction(root, 1);
4069         if (IS_ERR(trans)) {
4070                 btrfs_free_path(path);
4071                 ret = PTR_ERR(trans);
4072                 goto out;
4073         }
4074
4075         dir_id = btrfs_super_root_dir(fs_info->super_copy);
4076         di = btrfs_lookup_dir_item(trans, fs_info->tree_root, path,
4077                                    dir_id, "default", 7, 1);
4078         if (IS_ERR_OR_NULL(di)) {
4079                 btrfs_free_path(path);
4080                 btrfs_end_transaction(trans);
4081                 btrfs_err(fs_info,
4082                           "Umm, you don't have the default diritem, this isn't going to work");
4083                 ret = -ENOENT;
4084                 goto out;
4085         }
4086
4087         btrfs_cpu_key_to_disk(&disk_key, &new_root->root_key);
4088         btrfs_set_dir_item_key(path->nodes[0], di, &disk_key);
4089         btrfs_mark_buffer_dirty(path->nodes[0]);
4090         btrfs_free_path(path);
4091
4092         btrfs_set_fs_incompat(fs_info, DEFAULT_SUBVOL);
4093         btrfs_end_transaction(trans);
4094 out:
4095         mnt_drop_write_file(file);
4096         return ret;
4097 }
4098
4099 void btrfs_get_block_group_info(struct list_head *groups_list,
4100                                 struct btrfs_ioctl_space_info *space)
4101 {
4102         struct btrfs_block_group_cache *block_group;
4103
4104         space->total_bytes = 0;
4105         space->used_bytes = 0;
4106         space->flags = 0;
4107         list_for_each_entry(block_group, groups_list, list) {
4108                 space->flags = block_group->flags;
4109                 space->total_bytes += block_group->key.offset;
4110                 space->used_bytes +=
4111                         btrfs_block_group_used(&block_group->item);
4112         }
4113 }
4114
4115 static long btrfs_ioctl_space_info(struct btrfs_fs_info *fs_info,
4116                                    void __user *arg)
4117 {
4118         struct btrfs_ioctl_space_args space_args;
4119         struct btrfs_ioctl_space_info space;
4120         struct btrfs_ioctl_space_info *dest;
4121         struct btrfs_ioctl_space_info *dest_orig;
4122         struct btrfs_ioctl_space_info __user *user_dest;
4123         struct btrfs_space_info *info;
4124         u64 types[] = {BTRFS_BLOCK_GROUP_DATA,
4125                        BTRFS_BLOCK_GROUP_SYSTEM,
4126                        BTRFS_BLOCK_GROUP_METADATA,
4127                        BTRFS_BLOCK_GROUP_DATA | BTRFS_BLOCK_GROUP_METADATA};
4128         int num_types = 4;
4129         int alloc_size;
4130         int ret = 0;
4131         u64 slot_count = 0;
4132         int i, c;
4133
4134         if (copy_from_user(&space_args,
4135                            (struct btrfs_ioctl_space_args __user *)arg,
4136                            sizeof(space_args)))
4137                 return -EFAULT;
4138
4139         for (i = 0; i < num_types; i++) {
4140                 struct btrfs_space_info *tmp;
4141
4142                 info = NULL;
4143                 rcu_read_lock();
4144                 list_for_each_entry_rcu(tmp, &fs_info->space_info,
4145                                         list) {
4146                         if (tmp->flags == types[i]) {
4147                                 info = tmp;
4148                                 break;
4149                         }
4150                 }
4151                 rcu_read_unlock();
4152
4153                 if (!info)
4154                         continue;
4155
4156                 down_read(&info->groups_sem);
4157                 for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) {
4158                         if (!list_empty(&info->block_groups[c]))
4159                                 slot_count++;
4160                 }
4161                 up_read(&info->groups_sem);
4162         }
4163
4164         /*
4165          * Global block reserve, exported as a space_info
4166          */
4167         slot_count++;
4168
4169         /* space_slots == 0 means they are asking for a count */
4170         if (space_args.space_slots == 0) {
4171                 space_args.total_spaces = slot_count;
4172                 goto out;
4173         }
4174
4175         slot_count = min_t(u64, space_args.space_slots, slot_count);
4176
4177         alloc_size = sizeof(*dest) * slot_count;
4178
4179         /* we generally have at most 6 or so space infos, one for each raid
4180          * level.  So, a whole page should be more than enough for everyone
4181          */
4182         if (alloc_size > PAGE_SIZE)
4183                 return -ENOMEM;
4184
4185         space_args.total_spaces = 0;
4186         dest = kmalloc(alloc_size, GFP_KERNEL);
4187         if (!dest)
4188                 return -ENOMEM;
4189         dest_orig = dest;
4190
4191         /* now we have a buffer to copy into */
4192         for (i = 0; i < num_types; i++) {
4193                 struct btrfs_space_info *tmp;
4194
4195                 if (!slot_count)
4196                         break;
4197
4198                 info = NULL;
4199                 rcu_read_lock();
4200                 list_for_each_entry_rcu(tmp, &fs_info->space_info,
4201                                         list) {
4202                         if (tmp->flags == types[i]) {
4203                                 info = tmp;
4204                                 break;
4205                         }
4206                 }
4207                 rcu_read_unlock();
4208
4209                 if (!info)
4210                         continue;
4211                 down_read(&info->groups_sem);
4212                 for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) {
4213                         if (!list_empty(&info->block_groups[c])) {
4214                                 btrfs_get_block_group_info(
4215                                         &info->block_groups[c], &space);
4216                                 memcpy(dest, &space, sizeof(space));
4217                                 dest++;
4218                                 space_args.total_spaces++;
4219                                 slot_count--;
4220                         }
4221                         if (!slot_count)
4222                                 break;
4223                 }
4224                 up_read(&info->groups_sem);
4225         }
4226
4227         /*
4228          * Add global block reserve
4229          */
4230         if (slot_count) {
4231                 struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
4232
4233                 spin_lock(&block_rsv->lock);
4234                 space.total_bytes = block_rsv->size;
4235                 space.used_bytes = block_rsv->size - block_rsv->reserved;
4236                 spin_unlock(&block_rsv->lock);
4237                 space.flags = BTRFS_SPACE_INFO_GLOBAL_RSV;
4238                 memcpy(dest, &space, sizeof(space));
4239                 space_args.total_spaces++;
4240         }
4241
4242         user_dest = (struct btrfs_ioctl_space_info __user *)
4243                 (arg + sizeof(struct btrfs_ioctl_space_args));
4244
4245         if (copy_to_user(user_dest, dest_orig, alloc_size))
4246                 ret = -EFAULT;
4247
4248         kfree(dest_orig);
4249 out:
4250         if (ret == 0 && copy_to_user(arg, &space_args, sizeof(space_args)))
4251                 ret = -EFAULT;
4252
4253         return ret;
4254 }
4255
4256 /*
4257  * there are many ways the trans_start and trans_end ioctls can lead
4258  * to deadlocks.  They should only be used by applications that
4259  * basically own the machine, and have a very in depth understanding
4260  * of all the possible deadlocks and enospc problems.
4261  */
4262 long btrfs_ioctl_trans_end(struct file *file)
4263 {
4264         struct inode *inode = file_inode(file);
4265         struct btrfs_root *root = BTRFS_I(inode)->root;
4266         struct btrfs_file_private *private = file->private_data;
4267
4268         if (!private || !private->trans)
4269                 return -EINVAL;
4270
4271         btrfs_end_transaction(private->trans);
4272         private->trans = NULL;
4273
4274         atomic_dec(&root->fs_info->open_ioctl_trans);
4275
4276         mnt_drop_write_file(file);
4277         return 0;
4278 }
4279
4280 static noinline long btrfs_ioctl_start_sync(struct btrfs_root *root,
4281                                             void __user *argp)
4282 {
4283         struct btrfs_trans_handle *trans;
4284         u64 transid;
4285         int ret;
4286
4287         trans = btrfs_attach_transaction_barrier(root);
4288         if (IS_ERR(trans)) {
4289                 if (PTR_ERR(trans) != -ENOENT)
4290                         return PTR_ERR(trans);
4291
4292                 /* No running transaction, don't bother */
4293                 transid = root->fs_info->last_trans_committed;
4294                 goto out;
4295         }
4296         transid = trans->transid;
4297         ret = btrfs_commit_transaction_async(trans, 0);
4298         if (ret) {
4299                 btrfs_end_transaction(trans);
4300                 return ret;
4301         }
4302 out:
4303         if (argp)
4304                 if (copy_to_user(argp, &transid, sizeof(transid)))
4305                         return -EFAULT;
4306         return 0;
4307 }
4308
4309 static noinline long btrfs_ioctl_wait_sync(struct btrfs_fs_info *fs_info,
4310                                            void __user *argp)
4311 {
4312         u64 transid;
4313
4314         if (argp) {
4315                 if (copy_from_user(&transid, argp, sizeof(transid)))
4316                         return -EFAULT;
4317         } else {
4318                 transid = 0;  /* current trans */
4319         }
4320         return btrfs_wait_for_commit(fs_info, transid);
4321 }
4322
4323 static long btrfs_ioctl_scrub(struct file *file, void __user *arg)
4324 {
4325         struct btrfs_fs_info *fs_info = btrfs_sb(file_inode(file)->i_sb);
4326         struct btrfs_ioctl_scrub_args *sa;
4327         int ret;
4328
4329         if (!capable(CAP_SYS_ADMIN))
4330                 return -EPERM;
4331
4332         sa = memdup_user(arg, sizeof(*sa));
4333         if (IS_ERR(sa))
4334                 return PTR_ERR(sa);
4335
4336         if (!(sa->flags & BTRFS_SCRUB_READONLY)) {
4337                 ret = mnt_want_write_file(file);
4338                 if (ret)
4339                         goto out;
4340         }
4341
4342         ret = btrfs_scrub_dev(fs_info, sa->devid, sa->start, sa->end,
4343                               &sa->progress, sa->flags & BTRFS_SCRUB_READONLY,
4344                               0);
4345
4346         if (copy_to_user(arg, sa, sizeof(*sa)))
4347                 ret = -EFAULT;
4348
4349         if (!(sa->flags & BTRFS_SCRUB_READONLY))
4350                 mnt_drop_write_file(file);
4351 out:
4352         kfree(sa);
4353         return ret;
4354 }
4355
4356 static long btrfs_ioctl_scrub_cancel(struct btrfs_fs_info *fs_info)
4357 {
4358         if (!capable(CAP_SYS_ADMIN))
4359                 return -EPERM;
4360
4361         return btrfs_scrub_cancel(fs_info);
4362 }
4363
4364 static long btrfs_ioctl_scrub_progress(struct btrfs_fs_info *fs_info,
4365                                        void __user *arg)
4366 {
4367         struct btrfs_ioctl_scrub_args *sa;
4368         int ret;
4369
4370         if (!capable(CAP_SYS_ADMIN))
4371                 return -EPERM;
4372
4373         sa = memdup_user(arg, sizeof(*sa));
4374         if (IS_ERR(sa))
4375                 return PTR_ERR(sa);
4376
4377         ret = btrfs_scrub_progress(fs_info, sa->devid, &sa->progress);
4378
4379         if (copy_to_user(arg, sa, sizeof(*sa)))
4380                 ret = -EFAULT;
4381
4382         kfree(sa);
4383         return ret;
4384 }
4385
4386 static long btrfs_ioctl_get_dev_stats(struct btrfs_fs_info *fs_info,
4387                                       void __user *arg)
4388 {
4389         struct btrfs_ioctl_get_dev_stats *sa;
4390         int ret;
4391
4392         sa = memdup_user(arg, sizeof(*sa));
4393         if (IS_ERR(sa))
4394                 return PTR_ERR(sa);
4395
4396         if ((sa->flags & BTRFS_DEV_STATS_RESET) && !capable(CAP_SYS_ADMIN)) {
4397                 kfree(sa);
4398                 return -EPERM;
4399         }
4400
4401         ret = btrfs_get_dev_stats(fs_info, sa);
4402
4403         if (copy_to_user(arg, sa, sizeof(*sa)))
4404                 ret = -EFAULT;
4405
4406         kfree(sa);
4407         return ret;
4408 }
4409
4410 static long btrfs_ioctl_dev_replace(struct btrfs_fs_info *fs_info,
4411                                     void __user *arg)
4412 {
4413         struct btrfs_ioctl_dev_replace_args *p;
4414         int ret;
4415
4416         if (!capable(CAP_SYS_ADMIN))
4417                 return -EPERM;
4418
4419         p = memdup_user(arg, sizeof(*p));
4420         if (IS_ERR(p))
4421                 return PTR_ERR(p);
4422
4423         switch (p->cmd) {
4424         case BTRFS_IOCTL_DEV_REPLACE_CMD_START:
4425                 if (fs_info->sb->s_flags & MS_RDONLY) {
4426                         ret = -EROFS;
4427                         goto out;
4428                 }
4429                 if (test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags)) {
4430                         ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
4431                 } else {
4432                         ret = btrfs_dev_replace_by_ioctl(fs_info, p);
4433                         clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
4434                 }
4435                 break;
4436         case BTRFS_IOCTL_DEV_REPLACE_CMD_STATUS:
4437                 btrfs_dev_replace_status(fs_info, p);
4438                 ret = 0;
4439                 break;
4440         case BTRFS_IOCTL_DEV_REPLACE_CMD_CANCEL:
4441                 ret = btrfs_dev_replace_cancel(fs_info, p);
4442                 break;
4443         default:
4444                 ret = -EINVAL;
4445                 break;
4446         }
4447
4448         if (copy_to_user(arg, p, sizeof(*p)))
4449                 ret = -EFAULT;
4450 out:
4451         kfree(p);
4452         return ret;
4453 }
4454
4455 static long btrfs_ioctl_ino_to_path(struct btrfs_root *root, void __user *arg)
4456 {
4457         int ret = 0;
4458         int i;
4459         u64 rel_ptr;
4460         int size;
4461         struct btrfs_ioctl_ino_path_args *ipa = NULL;
4462         struct inode_fs_paths *ipath = NULL;
4463         struct btrfs_path *path;
4464
4465         if (!capable(CAP_DAC_READ_SEARCH))
4466                 return -EPERM;
4467
4468         path = btrfs_alloc_path();
4469         if (!path) {
4470                 ret = -ENOMEM;
4471                 goto out;
4472         }
4473
4474         ipa = memdup_user(arg, sizeof(*ipa));
4475         if (IS_ERR(ipa)) {
4476                 ret = PTR_ERR(ipa);
4477                 ipa = NULL;
4478                 goto out;
4479         }
4480
4481         size = min_t(u32, ipa->size, 4096);
4482         ipath = init_ipath(size, root, path);
4483         if (IS_ERR(ipath)) {
4484                 ret = PTR_ERR(ipath);
4485                 ipath = NULL;
4486                 goto out;
4487         }
4488
4489         ret = paths_from_inode(ipa->inum, ipath);
4490         if (ret < 0)
4491                 goto out;
4492
4493         for (i = 0; i < ipath->fspath->elem_cnt; ++i) {
4494                 rel_ptr = ipath->fspath->val[i] -
4495                           (u64)(unsigned long)ipath->fspath->val;
4496                 ipath->fspath->val[i] = rel_ptr;
4497         }
4498
4499         ret = copy_to_user((void *)(unsigned long)ipa->fspath,
4500                            (void *)(unsigned long)ipath->fspath, size);
4501         if (ret) {
4502                 ret = -EFAULT;
4503                 goto out;
4504         }
4505
4506 out:
4507         btrfs_free_path(path);
4508         free_ipath(ipath);
4509         kfree(ipa);
4510
4511         return ret;
4512 }
4513
4514 static int build_ino_list(u64 inum, u64 offset, u64 root, void *ctx)
4515 {
4516         struct btrfs_data_container *inodes = ctx;
4517         const size_t c = 3 * sizeof(u64);
4518
4519         if (inodes->bytes_left >= c) {
4520                 inodes->bytes_left -= c;
4521                 inodes->val[inodes->elem_cnt] = inum;
4522                 inodes->val[inodes->elem_cnt + 1] = offset;
4523                 inodes->val[inodes->elem_cnt + 2] = root;
4524                 inodes->elem_cnt += 3;
4525         } else {
4526                 inodes->bytes_missing += c - inodes->bytes_left;
4527                 inodes->bytes_left = 0;
4528                 inodes->elem_missed += 3;
4529         }
4530
4531         return 0;
4532 }
4533
4534 static long btrfs_ioctl_logical_to_ino(struct btrfs_fs_info *fs_info,
4535                                         void __user *arg)
4536 {
4537         int ret = 0;
4538         int size;
4539         struct btrfs_ioctl_logical_ino_args *loi;
4540         struct btrfs_data_container *inodes = NULL;
4541         struct btrfs_path *path = NULL;
4542
4543         if (!capable(CAP_SYS_ADMIN))
4544                 return -EPERM;
4545
4546         loi = memdup_user(arg, sizeof(*loi));
4547         if (IS_ERR(loi))
4548                 return PTR_ERR(loi);
4549
4550         path = btrfs_alloc_path();
4551         if (!path) {
4552                 ret = -ENOMEM;
4553                 goto out;
4554         }
4555
4556         size = min_t(u32, loi->size, SZ_64K);
4557         inodes = init_data_container(size);
4558         if (IS_ERR(inodes)) {
4559                 ret = PTR_ERR(inodes);
4560                 inodes = NULL;
4561                 goto out;
4562         }
4563
4564         ret = iterate_inodes_from_logical(loi->logical, fs_info, path,
4565                                           build_ino_list, inodes);
4566         if (ret == -EINVAL)
4567                 ret = -ENOENT;
4568         if (ret < 0)
4569                 goto out;
4570
4571         ret = copy_to_user((void *)(unsigned long)loi->inodes,
4572                            (void *)(unsigned long)inodes, size);
4573         if (ret)
4574                 ret = -EFAULT;
4575
4576 out:
4577         btrfs_free_path(path);
4578         kvfree(inodes);
4579         kfree(loi);
4580
4581         return ret;
4582 }
4583
4584 void update_ioctl_balance_args(struct btrfs_fs_info *fs_info, int lock,
4585                                struct btrfs_ioctl_balance_args *bargs)
4586 {
4587         struct btrfs_balance_control *bctl = fs_info->balance_ctl;
4588
4589         bargs->flags = bctl->flags;
4590
4591         if (atomic_read(&fs_info->balance_running))
4592                 bargs->state |= BTRFS_BALANCE_STATE_RUNNING;
4593         if (atomic_read(&fs_info->balance_pause_req))
4594                 bargs->state |= BTRFS_BALANCE_STATE_PAUSE_REQ;
4595         if (atomic_read(&fs_info->balance_cancel_req))
4596                 bargs->state |= BTRFS_BALANCE_STATE_CANCEL_REQ;
4597
4598         memcpy(&bargs->data, &bctl->data, sizeof(bargs->data));
4599         memcpy(&bargs->meta, &bctl->meta, sizeof(bargs->meta));
4600         memcpy(&bargs->sys, &bctl->sys, sizeof(bargs->sys));
4601
4602         if (lock) {
4603                 spin_lock(&fs_info->balance_lock);
4604                 memcpy(&bargs->stat, &bctl->stat, sizeof(bargs->stat));
4605                 spin_unlock(&fs_info->balance_lock);
4606         } else {
4607                 memcpy(&bargs->stat, &bctl->stat, sizeof(bargs->stat));
4608         }
4609 }
4610
4611 static long btrfs_ioctl_balance(struct file *file, void __user *arg)
4612 {
4613         struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
4614         struct btrfs_fs_info *fs_info = root->fs_info;
4615         struct btrfs_ioctl_balance_args *bargs;
4616         struct btrfs_balance_control *bctl;
4617         bool need_unlock; /* for mut. excl. ops lock */
4618         int ret;
4619
4620         if (!capable(CAP_SYS_ADMIN))
4621                 return -EPERM;
4622
4623         ret = mnt_want_write_file(file);
4624         if (ret)
4625                 return ret;
4626
4627 again:
4628         if (!test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags)) {
4629                 mutex_lock(&fs_info->volume_mutex);
4630                 mutex_lock(&fs_info->balance_mutex);
4631                 need_unlock = true;
4632                 goto locked;
4633         }
4634
4635         /*
4636          * mut. excl. ops lock is locked.  Three possibilities:
4637          *   (1) some other op is running
4638          *   (2) balance is running
4639          *   (3) balance is paused -- special case (think resume)
4640          */
4641         mutex_lock(&fs_info->balance_mutex);
4642         if (fs_info->balance_ctl) {
4643                 /* this is either (2) or (3) */
4644                 if (!atomic_read(&fs_info->balance_running)) {
4645                         mutex_unlock(&fs_info->balance_mutex);
4646                         if (!mutex_trylock(&fs_info->volume_mutex))
4647                                 goto again;
4648                         mutex_lock(&fs_info->balance_mutex);
4649
4650                         if (fs_info->balance_ctl &&
4651                             !atomic_read(&fs_info->balance_running)) {
4652                                 /* this is (3) */
4653                                 need_unlock = false;
4654                                 goto locked;
4655                         }
4656
4657                         mutex_unlock(&fs_info->balance_mutex);
4658                         mutex_unlock(&fs_info->volume_mutex);
4659                         goto again;
4660                 } else {
4661                         /* this is (2) */
4662                         mutex_unlock(&fs_info->balance_mutex);
4663                         ret = -EINPROGRESS;
4664                         goto out;
4665                 }
4666         } else {
4667                 /* this is (1) */
4668                 mutex_unlock(&fs_info->balance_mutex);
4669                 ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
4670                 goto out;
4671         }
4672
4673 locked:
4674         BUG_ON(!test_bit(BTRFS_FS_EXCL_OP, &fs_info->flags));
4675
4676         if (arg) {
4677                 bargs = memdup_user(arg, sizeof(*bargs));
4678                 if (IS_ERR(bargs)) {
4679                         ret = PTR_ERR(bargs);
4680                         goto out_unlock;
4681                 }
4682
4683                 if (bargs->flags & BTRFS_BALANCE_RESUME) {
4684                         if (!fs_info->balance_ctl) {
4685                                 ret = -ENOTCONN;
4686                                 goto out_bargs;
4687                         }
4688
4689                         bctl = fs_info->balance_ctl;
4690                         spin_lock(&fs_info->balance_lock);
4691                         bctl->flags |= BTRFS_BALANCE_RESUME;
4692                         spin_unlock(&fs_info->balance_lock);
4693
4694                         goto do_balance;
4695                 }
4696         } else {
4697                 bargs = NULL;
4698         }
4699
4700         if (fs_info->balance_ctl) {
4701                 ret = -EINPROGRESS;
4702                 goto out_bargs;
4703         }
4704
4705         bctl = kzalloc(sizeof(*bctl), GFP_KERNEL);
4706         if (!bctl) {
4707                 ret = -ENOMEM;
4708                 goto out_bargs;
4709         }
4710
4711         bctl->fs_info = fs_info;
4712         if (arg) {
4713                 memcpy(&bctl->data, &bargs->data, sizeof(bctl->data));
4714                 memcpy(&bctl->meta, &bargs->meta, sizeof(bctl->meta));
4715                 memcpy(&bctl->sys, &bargs->sys, sizeof(bctl->sys));
4716
4717                 bctl->flags = bargs->flags;
4718         } else {
4719                 /* balance everything - no filters */
4720                 bctl->flags |= BTRFS_BALANCE_TYPE_MASK;
4721         }
4722
4723         if (bctl->flags & ~(BTRFS_BALANCE_ARGS_MASK | BTRFS_BALANCE_TYPE_MASK)) {
4724                 ret = -EINVAL;
4725                 goto out_bctl;
4726         }
4727
4728 do_balance:
4729         /*
4730          * Ownership of bctl and filesystem flag BTRFS_FS_EXCL_OP
4731          * goes to to btrfs_balance.  bctl is freed in __cancel_balance,
4732          * or, if restriper was paused all the way until unmount, in
4733          * free_fs_info.  The flag is cleared in __cancel_balance.
4734          */
4735         need_unlock = false;
4736
4737         ret = btrfs_balance(bctl, bargs);
4738         bctl = NULL;
4739
4740         if (arg) {
4741                 if (copy_to_user(arg, bargs, sizeof(*bargs)))
4742                         ret = -EFAULT;
4743         }
4744
4745 out_bctl:
4746         kfree(bctl);
4747 out_bargs:
4748         kfree(bargs);
4749 out_unlock:
4750         mutex_unlock(&fs_info->balance_mutex);
4751         mutex_unlock(&fs_info->volume_mutex);
4752         if (need_unlock)
4753                 clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
4754 out:
4755         mnt_drop_write_file(file);
4756         return ret;
4757 }
4758
4759 static long btrfs_ioctl_balance_ctl(struct btrfs_fs_info *fs_info, int cmd)
4760 {
4761         if (!capable(CAP_SYS_ADMIN))
4762                 return -EPERM;
4763
4764         switch (cmd) {
4765         case BTRFS_BALANCE_CTL_PAUSE:
4766                 return btrfs_pause_balance(fs_info);
4767         case BTRFS_BALANCE_CTL_CANCEL:
4768                 return btrfs_cancel_balance(fs_info);
4769         }
4770
4771         return -EINVAL;
4772 }
4773
4774 static long btrfs_ioctl_balance_progress(struct btrfs_fs_info *fs_info,
4775                                          void __user *arg)
4776 {
4777         struct btrfs_ioctl_balance_args *bargs;
4778         int ret = 0;
4779
4780         if (!capable(CAP_SYS_ADMIN))
4781                 return -EPERM;
4782
4783         mutex_lock(&fs_info->balance_mutex);
4784         if (!fs_info->balance_ctl) {
4785                 ret = -ENOTCONN;
4786                 goto out;
4787         }
4788
4789         bargs = kzalloc(sizeof(*bargs), GFP_KERNEL);
4790         if (!bargs) {
4791                 ret = -ENOMEM;
4792                 goto out;
4793         }
4794
4795         update_ioctl_balance_args(fs_info, 1, bargs);
4796
4797         if (copy_to_user(arg, bargs, sizeof(*bargs)))
4798                 ret = -EFAULT;
4799
4800         kfree(bargs);
4801 out:
4802         mutex_unlock(&fs_info->balance_mutex);
4803         return ret;
4804 }
4805
4806 static long btrfs_ioctl_quota_ctl(struct file *file, void __user *arg)
4807 {
4808         struct inode *inode = file_inode(file);
4809         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4810         struct btrfs_ioctl_quota_ctl_args *sa;
4811         struct btrfs_trans_handle *trans = NULL;
4812         int ret;
4813         int err;
4814
4815         if (!capable(CAP_SYS_ADMIN))
4816                 return -EPERM;
4817
4818         ret = mnt_want_write_file(file);
4819         if (ret)
4820                 return ret;
4821
4822         sa = memdup_user(arg, sizeof(*sa));
4823         if (IS_ERR(sa)) {
4824                 ret = PTR_ERR(sa);
4825                 goto drop_write;
4826         }
4827
4828         down_write(&fs_info->subvol_sem);
4829         trans = btrfs_start_transaction(fs_info->tree_root, 2);
4830         if (IS_ERR(trans)) {
4831                 ret = PTR_ERR(trans);
4832                 goto out;
4833         }
4834
4835         switch (sa->cmd) {
4836         case BTRFS_QUOTA_CTL_ENABLE:
4837                 ret = btrfs_quota_enable(trans, fs_info);
4838                 break;
4839         case BTRFS_QUOTA_CTL_DISABLE:
4840                 ret = btrfs_quota_disable(trans, fs_info);
4841                 break;
4842         default:
4843                 ret = -EINVAL;
4844                 break;
4845         }
4846
4847         err = btrfs_commit_transaction(trans);
4848         if (err && !ret)
4849                 ret = err;
4850 out:
4851         kfree(sa);
4852         up_write(&fs_info->subvol_sem);
4853 drop_write:
4854         mnt_drop_write_file(file);
4855         return ret;
4856 }
4857
4858 static long btrfs_ioctl_qgroup_assign(struct file *file, void __user *arg)
4859 {
4860         struct inode *inode = file_inode(file);
4861         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4862         struct btrfs_root *root = BTRFS_I(inode)->root;
4863         struct btrfs_ioctl_qgroup_assign_args *sa;
4864         struct btrfs_trans_handle *trans;
4865         int ret;
4866         int err;
4867
4868         if (!capable(CAP_SYS_ADMIN))
4869                 return -EPERM;
4870
4871         ret = mnt_want_write_file(file);
4872         if (ret)
4873                 return ret;
4874
4875         sa = memdup_user(arg, sizeof(*sa));
4876         if (IS_ERR(sa)) {
4877                 ret = PTR_ERR(sa);
4878                 goto drop_write;
4879         }
4880
4881         trans = btrfs_join_transaction(root);
4882         if (IS_ERR(trans)) {
4883                 ret = PTR_ERR(trans);
4884                 goto out;
4885         }
4886
4887         if (sa->assign) {
4888                 ret = btrfs_add_qgroup_relation(trans, fs_info,
4889                                                 sa->src, sa->dst);
4890         } else {
4891                 ret = btrfs_del_qgroup_relation(trans, fs_info,
4892                                                 sa->src, sa->dst);
4893         }
4894
4895         /* update qgroup status and info */
4896         err = btrfs_run_qgroups(trans, fs_info);
4897         if (err < 0)
4898                 btrfs_handle_fs_error(fs_info, err,
4899                                       "failed to update qgroup status and info");
4900         err = btrfs_end_transaction(trans);
4901         if (err && !ret)
4902                 ret = err;
4903
4904 out:
4905         kfree(sa);
4906 drop_write:
4907         mnt_drop_write_file(file);
4908         return ret;
4909 }
4910
4911 static long btrfs_ioctl_qgroup_create(struct file *file, void __user *arg)
4912 {
4913         struct inode *inode = file_inode(file);
4914         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4915         struct btrfs_root *root = BTRFS_I(inode)->root;
4916         struct btrfs_ioctl_qgroup_create_args *sa;
4917         struct btrfs_trans_handle *trans;
4918         int ret;
4919         int err;
4920
4921         if (!capable(CAP_SYS_ADMIN))
4922                 return -EPERM;
4923
4924         ret = mnt_want_write_file(file);
4925         if (ret)
4926                 return ret;
4927
4928         sa = memdup_user(arg, sizeof(*sa));
4929         if (IS_ERR(sa)) {
4930                 ret = PTR_ERR(sa);
4931                 goto drop_write;
4932         }
4933
4934         if (!sa->qgroupid) {
4935                 ret = -EINVAL;
4936                 goto out;
4937         }
4938
4939         trans = btrfs_join_transaction(root);
4940         if (IS_ERR(trans)) {
4941                 ret = PTR_ERR(trans);
4942                 goto out;
4943         }
4944
4945         if (sa->create) {
4946                 ret = btrfs_create_qgroup(trans, fs_info, sa->qgroupid);
4947         } else {
4948                 ret = btrfs_remove_qgroup(trans, fs_info, sa->qgroupid);
4949         }
4950
4951         err = btrfs_end_transaction(trans);
4952         if (err && !ret)
4953                 ret = err;
4954
4955 out:
4956         kfree(sa);
4957 drop_write:
4958         mnt_drop_write_file(file);
4959         return ret;
4960 }
4961
4962 static long btrfs_ioctl_qgroup_limit(struct file *file, void __user *arg)
4963 {
4964         struct inode *inode = file_inode(file);
4965         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4966         struct btrfs_root *root = BTRFS_I(inode)->root;
4967         struct btrfs_ioctl_qgroup_limit_args *sa;
4968         struct btrfs_trans_handle *trans;
4969         int ret;
4970         int err;
4971         u64 qgroupid;
4972
4973         if (!capable(CAP_SYS_ADMIN))
4974                 return -EPERM;
4975
4976         ret = mnt_want_write_file(file);
4977         if (ret)
4978                 return ret;
4979
4980         sa = memdup_user(arg, sizeof(*sa));
4981         if (IS_ERR(sa)) {
4982                 ret = PTR_ERR(sa);
4983                 goto drop_write;
4984         }
4985
4986         trans = btrfs_join_transaction(root);
4987         if (IS_ERR(trans)) {
4988                 ret = PTR_ERR(trans);
4989                 goto out;
4990         }
4991
4992         qgroupid = sa->qgroupid;
4993         if (!qgroupid) {
4994                 /* take the current subvol as qgroup */
4995                 qgroupid = root->root_key.objectid;
4996         }
4997
4998         ret = btrfs_limit_qgroup(trans, fs_info, qgroupid, &sa->lim);
4999
5000         err = btrfs_end_transaction(trans);
5001         if (err && !ret)
5002                 ret = err;
5003
5004 out:
5005         kfree(sa);
5006 drop_write:
5007         mnt_drop_write_file(file);
5008         return ret;
5009 }
5010
5011 static long btrfs_ioctl_quota_rescan(struct file *file, void __user *arg)
5012 {
5013         struct inode *inode = file_inode(file);
5014         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5015         struct btrfs_ioctl_quota_rescan_args *qsa;
5016         int ret;
5017
5018         if (!capable(CAP_SYS_ADMIN))
5019                 return -EPERM;
5020
5021         ret = mnt_want_write_file(file);
5022         if (ret)
5023                 return ret;
5024
5025         qsa = memdup_user(arg, sizeof(*qsa));
5026         if (IS_ERR(qsa)) {
5027                 ret = PTR_ERR(qsa);
5028                 goto drop_write;
5029         }
5030
5031         if (qsa->flags) {
5032                 ret = -EINVAL;
5033                 goto out;
5034         }
5035
5036         ret = btrfs_qgroup_rescan(fs_info);
5037
5038 out:
5039         kfree(qsa);
5040 drop_write:
5041         mnt_drop_write_file(file);
5042         return ret;
5043 }
5044
5045 static long btrfs_ioctl_quota_rescan_status(struct file *file, void __user *arg)
5046 {
5047         struct inode *inode = file_inode(file);
5048         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5049         struct btrfs_ioctl_quota_rescan_args *qsa;
5050         int ret = 0;
5051
5052         if (!capable(CAP_SYS_ADMIN))
5053                 return -EPERM;
5054
5055         qsa = kzalloc(sizeof(*qsa), GFP_KERNEL);
5056         if (!qsa)
5057                 return -ENOMEM;
5058
5059         if (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN) {
5060                 qsa->flags = 1;
5061                 qsa->progress = fs_info->qgroup_rescan_progress.objectid;
5062         }
5063
5064         if (copy_to_user(arg, qsa, sizeof(*qsa)))
5065                 ret = -EFAULT;
5066
5067         kfree(qsa);
5068         return ret;
5069 }
5070
5071 static long btrfs_ioctl_quota_rescan_wait(struct file *file, void __user *arg)
5072 {
5073         struct inode *inode = file_inode(file);
5074         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5075
5076         if (!capable(CAP_SYS_ADMIN))
5077                 return -EPERM;
5078
5079         return btrfs_qgroup_wait_for_completion(fs_info, true);
5080 }
5081
5082 static long _btrfs_ioctl_set_received_subvol(struct file *file,
5083                                             struct btrfs_ioctl_received_subvol_args *sa)
5084 {
5085         struct inode *inode = file_inode(file);
5086         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5087         struct btrfs_root *root = BTRFS_I(inode)->root;
5088         struct btrfs_root_item *root_item = &root->root_item;
5089         struct btrfs_trans_handle *trans;
5090         struct timespec ct = current_time(inode);
5091         int ret = 0;
5092         int received_uuid_changed;
5093
5094         if (!inode_owner_or_capable(inode))
5095                 return -EPERM;
5096
5097         ret = mnt_want_write_file(file);
5098         if (ret < 0)
5099                 return ret;
5100
5101         down_write(&fs_info->subvol_sem);
5102
5103         if (btrfs_ino(BTRFS_I(inode)) != BTRFS_FIRST_FREE_OBJECTID) {
5104                 ret = -EINVAL;
5105                 goto out;
5106         }
5107
5108         if (btrfs_root_readonly(root)) {
5109                 ret = -EROFS;
5110                 goto out;
5111         }
5112
5113         /*
5114          * 1 - root item
5115          * 2 - uuid items (received uuid + subvol uuid)
5116          */
5117         trans = btrfs_start_transaction(root, 3);
5118         if (IS_ERR(trans)) {
5119                 ret = PTR_ERR(trans);
5120                 trans = NULL;
5121                 goto out;
5122         }
5123
5124         sa->rtransid = trans->transid;
5125         sa->rtime.sec = ct.tv_sec;
5126         sa->rtime.nsec = ct.tv_nsec;
5127
5128         received_uuid_changed = memcmp(root_item->received_uuid, sa->uuid,
5129                                        BTRFS_UUID_SIZE);
5130         if (received_uuid_changed &&
5131             !btrfs_is_empty_uuid(root_item->received_uuid))
5132                 btrfs_uuid_tree_rem(trans, fs_info, root_item->received_uuid,
5133                                     BTRFS_UUID_KEY_RECEIVED_SUBVOL,
5134                                     root->root_key.objectid);
5135         memcpy(root_item->received_uuid, sa->uuid, BTRFS_UUID_SIZE);
5136         btrfs_set_root_stransid(root_item, sa->stransid);
5137         btrfs_set_root_rtransid(root_item, sa->rtransid);
5138         btrfs_set_stack_timespec_sec(&root_item->stime, sa->stime.sec);
5139         btrfs_set_stack_timespec_nsec(&root_item->stime, sa->stime.nsec);
5140         btrfs_set_stack_timespec_sec(&root_item->rtime, sa->rtime.sec);
5141         btrfs_set_stack_timespec_nsec(&root_item->rtime, sa->rtime.nsec);
5142
5143         ret = btrfs_update_root(trans, fs_info->tree_root,
5144                                 &root->root_key, &root->root_item);
5145         if (ret < 0) {
5146                 btrfs_end_transaction(trans);
5147                 goto out;
5148         }
5149         if (received_uuid_changed && !btrfs_is_empty_uuid(sa->uuid)) {
5150                 ret = btrfs_uuid_tree_add(trans, fs_info, sa->uuid,
5151                                           BTRFS_UUID_KEY_RECEIVED_SUBVOL,
5152                                           root->root_key.objectid);
5153                 if (ret < 0 && ret != -EEXIST) {
5154                         btrfs_abort_transaction(trans, ret);
5155                         goto out;
5156                 }
5157         }
5158         ret = btrfs_commit_transaction(trans);
5159         if (ret < 0) {
5160                 btrfs_abort_transaction(trans, ret);
5161                 goto out;
5162         }
5163
5164 out:
5165         up_write(&fs_info->subvol_sem);
5166         mnt_drop_write_file(file);
5167         return ret;
5168 }
5169
5170 #ifdef CONFIG_64BIT
5171 static long btrfs_ioctl_set_received_subvol_32(struct file *file,
5172                                                 void __user *arg)
5173 {
5174         struct btrfs_ioctl_received_subvol_args_32 *args32 = NULL;
5175         struct btrfs_ioctl_received_subvol_args *args64 = NULL;
5176         int ret = 0;
5177
5178         args32 = memdup_user(arg, sizeof(*args32));
5179         if (IS_ERR(args32))
5180                 return PTR_ERR(args32);
5181
5182         args64 = kmalloc(sizeof(*args64), GFP_KERNEL);
5183         if (!args64) {
5184                 ret = -ENOMEM;
5185                 goto out;
5186         }
5187
5188         memcpy(args64->uuid, args32->uuid, BTRFS_UUID_SIZE);
5189         args64->stransid = args32->stransid;
5190         args64->rtransid = args32->rtransid;
5191         args64->stime.sec = args32->stime.sec;
5192         args64->stime.nsec = args32->stime.nsec;
5193         args64->rtime.sec = args32->rtime.sec;
5194         args64->rtime.nsec = args32->rtime.nsec;
5195         args64->flags = args32->flags;
5196
5197         ret = _btrfs_ioctl_set_received_subvol(file, args64);
5198         if (ret)
5199                 goto out;
5200
5201         memcpy(args32->uuid, args64->uuid, BTRFS_UUID_SIZE);
5202         args32->stransid = args64->stransid;
5203         args32->rtransid = args64->rtransid;
5204         args32->stime.sec = args64->stime.sec;
5205         args32->stime.nsec = args64->stime.nsec;
5206         args32->rtime.sec = args64->rtime.sec;
5207         args32->rtime.nsec = args64->rtime.nsec;
5208         args32->flags = args64->flags;
5209
5210         ret = copy_to_user(arg, args32, sizeof(*args32));
5211         if (ret)
5212                 ret = -EFAULT;
5213
5214 out:
5215         kfree(args32);
5216         kfree(args64);
5217         return ret;
5218 }
5219 #endif
5220
5221 static long btrfs_ioctl_set_received_subvol(struct file *file,
5222                                             void __user *arg)
5223 {
5224         struct btrfs_ioctl_received_subvol_args *sa = NULL;
5225         int ret = 0;
5226
5227         sa = memdup_user(arg, sizeof(*sa));
5228         if (IS_ERR(sa))
5229                 return PTR_ERR(sa);
5230
5231         ret = _btrfs_ioctl_set_received_subvol(file, sa);
5232
5233         if (ret)
5234                 goto out;
5235
5236         ret = copy_to_user(arg, sa, sizeof(*sa));
5237         if (ret)
5238                 ret = -EFAULT;
5239
5240 out:
5241         kfree(sa);
5242         return ret;
5243 }
5244
5245 static int btrfs_ioctl_get_fslabel(struct file *file, void __user *arg)
5246 {
5247         struct inode *inode = file_inode(file);
5248         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5249         size_t len;
5250         int ret;
5251         char label[BTRFS_LABEL_SIZE];
5252
5253         spin_lock(&fs_info->super_lock);
5254         memcpy(label, fs_info->super_copy->label, BTRFS_LABEL_SIZE);
5255         spin_unlock(&fs_info->super_lock);
5256
5257         len = strnlen(label, BTRFS_LABEL_SIZE);
5258
5259         if (len == BTRFS_LABEL_SIZE) {
5260                 btrfs_warn(fs_info,
5261                            "label is too long, return the first %zu bytes",
5262                            --len);
5263         }
5264
5265         ret = copy_to_user(arg, label, len);
5266
5267         return ret ? -EFAULT : 0;
5268 }
5269
5270 static int btrfs_ioctl_set_fslabel(struct file *file, void __user *arg)
5271 {
5272         struct inode *inode = file_inode(file);
5273         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5274         struct btrfs_root *root = BTRFS_I(inode)->root;
5275         struct btrfs_super_block *super_block = fs_info->super_copy;
5276         struct btrfs_trans_handle *trans;
5277         char label[BTRFS_LABEL_SIZE];
5278         int ret;
5279
5280         if (!capable(CAP_SYS_ADMIN))
5281                 return -EPERM;
5282
5283         if (copy_from_user(label, arg, sizeof(label)))
5284                 return -EFAULT;
5285
5286         if (strnlen(label, BTRFS_LABEL_SIZE) == BTRFS_LABEL_SIZE) {
5287                 btrfs_err(fs_info,
5288                           "unable to set label with more than %d bytes",
5289                           BTRFS_LABEL_SIZE - 1);
5290                 return -EINVAL;
5291         }
5292
5293         ret = mnt_want_write_file(file);
5294         if (ret)
5295                 return ret;
5296
5297         trans = btrfs_start_transaction(root, 0);
5298         if (IS_ERR(trans)) {
5299                 ret = PTR_ERR(trans);
5300                 goto out_unlock;
5301         }
5302
5303         spin_lock(&fs_info->super_lock);
5304         strcpy(super_block->label, label);
5305         spin_unlock(&fs_info->super_lock);
5306         ret = btrfs_commit_transaction(trans);
5307
5308 out_unlock:
5309         mnt_drop_write_file(file);
5310         return ret;
5311 }
5312
5313 #define INIT_FEATURE_FLAGS(suffix) \
5314         { .compat_flags = BTRFS_FEATURE_COMPAT_##suffix, \
5315           .compat_ro_flags = BTRFS_FEATURE_COMPAT_RO_##suffix, \
5316           .incompat_flags = BTRFS_FEATURE_INCOMPAT_##suffix }
5317
5318 int btrfs_ioctl_get_supported_features(void __user *arg)
5319 {
5320         static const struct btrfs_ioctl_feature_flags features[3] = {
5321                 INIT_FEATURE_FLAGS(SUPP),
5322                 INIT_FEATURE_FLAGS(SAFE_SET),
5323                 INIT_FEATURE_FLAGS(SAFE_CLEAR)
5324         };
5325
5326         if (copy_to_user(arg, &features, sizeof(features)))
5327                 return -EFAULT;
5328
5329         return 0;
5330 }
5331
5332 static int btrfs_ioctl_get_features(struct file *file, void __user *arg)
5333 {
5334         struct inode *inode = file_inode(file);
5335         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5336         struct btrfs_super_block *super_block = fs_info->super_copy;
5337         struct btrfs_ioctl_feature_flags features;
5338
5339         features.compat_flags = btrfs_super_compat_flags(super_block);
5340         features.compat_ro_flags = btrfs_super_compat_ro_flags(super_block);
5341         features.incompat_flags = btrfs_super_incompat_flags(super_block);
5342
5343         if (copy_to_user(arg, &features, sizeof(features)))
5344                 return -EFAULT;
5345
5346         return 0;
5347 }
5348
5349 static int check_feature_bits(struct btrfs_fs_info *fs_info,
5350                               enum btrfs_feature_set set,
5351                               u64 change_mask, u64 flags, u64 supported_flags,
5352                               u64 safe_set, u64 safe_clear)
5353 {
5354         const char *type = btrfs_feature_set_names[set];
5355         char *names;
5356         u64 disallowed, unsupported;
5357         u64 set_mask = flags & change_mask;
5358         u64 clear_mask = ~flags & change_mask;
5359
5360         unsupported = set_mask & ~supported_flags;
5361         if (unsupported) {
5362                 names = btrfs_printable_features(set, unsupported);
5363                 if (names) {
5364                         btrfs_warn(fs_info,
5365                                    "this kernel does not support the %s feature bit%s",
5366                                    names, strchr(names, ',') ? "s" : "");
5367                         kfree(names);
5368                 } else
5369                         btrfs_warn(fs_info,
5370                                    "this kernel does not support %s bits 0x%llx",
5371                                    type, unsupported);
5372                 return -EOPNOTSUPP;
5373         }
5374
5375         disallowed = set_mask & ~safe_set;
5376         if (disallowed) {
5377                 names = btrfs_printable_features(set, disallowed);
5378                 if (names) {
5379                         btrfs_warn(fs_info,
5380                                    "can't set the %s feature bit%s while mounted",
5381                                    names, strchr(names, ',') ? "s" : "");
5382                         kfree(names);
5383                 } else
5384                         btrfs_warn(fs_info,
5385                                    "can't set %s bits 0x%llx while mounted",
5386                                    type, disallowed);
5387                 return -EPERM;
5388         }
5389
5390         disallowed = clear_mask & ~safe_clear;
5391         if (disallowed) {
5392                 names = btrfs_printable_features(set, disallowed);
5393                 if (names) {
5394                         btrfs_warn(fs_info,
5395                                    "can't clear the %s feature bit%s while mounted",
5396                                    names, strchr(names, ',') ? "s" : "");
5397                         kfree(names);
5398                 } else
5399                         btrfs_warn(fs_info,
5400                                    "can't clear %s bits 0x%llx while mounted",
5401                                    type, disallowed);
5402                 return -EPERM;
5403         }
5404
5405         return 0;
5406 }
5407
5408 #define check_feature(fs_info, change_mask, flags, mask_base)   \
5409 check_feature_bits(fs_info, FEAT_##mask_base, change_mask, flags,       \
5410                    BTRFS_FEATURE_ ## mask_base ## _SUPP,        \
5411                    BTRFS_FEATURE_ ## mask_base ## _SAFE_SET,    \
5412                    BTRFS_FEATURE_ ## mask_base ## _SAFE_CLEAR)
5413
5414 static int btrfs_ioctl_set_features(struct file *file, void __user *arg)
5415 {
5416         struct inode *inode = file_inode(file);
5417         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5418         struct btrfs_root *root = BTRFS_I(inode)->root;
5419         struct btrfs_super_block *super_block = fs_info->super_copy;
5420         struct btrfs_ioctl_feature_flags flags[2];
5421         struct btrfs_trans_handle *trans;
5422         u64 newflags;
5423         int ret;
5424
5425         if (!capable(CAP_SYS_ADMIN))
5426                 return -EPERM;
5427
5428         if (copy_from_user(flags, arg, sizeof(flags)))
5429                 return -EFAULT;
5430
5431         /* Nothing to do */
5432         if (!flags[0].compat_flags && !flags[0].compat_ro_flags &&
5433             !flags[0].incompat_flags)
5434                 return 0;
5435
5436         ret = check_feature(fs_info, flags[0].compat_flags,
5437                             flags[1].compat_flags, COMPAT);
5438         if (ret)
5439                 return ret;
5440
5441         ret = check_feature(fs_info, flags[0].compat_ro_flags,
5442                             flags[1].compat_ro_flags, COMPAT_RO);
5443         if (ret)
5444                 return ret;
5445
5446         ret = check_feature(fs_info, flags[0].incompat_flags,
5447                             flags[1].incompat_flags, INCOMPAT);
5448         if (ret)
5449                 return ret;
5450
5451         ret = mnt_want_write_file(file);
5452         if (ret)
5453                 return ret;
5454
5455         trans = btrfs_start_transaction(root, 0);
5456         if (IS_ERR(trans)) {
5457                 ret = PTR_ERR(trans);
5458                 goto out_drop_write;
5459         }
5460
5461         spin_lock(&fs_info->super_lock);
5462         newflags = btrfs_super_compat_flags(super_block);
5463         newflags |= flags[0].compat_flags & flags[1].compat_flags;
5464         newflags &= ~(flags[0].compat_flags & ~flags[1].compat_flags);
5465         btrfs_set_super_compat_flags(super_block, newflags);
5466
5467         newflags = btrfs_super_compat_ro_flags(super_block);
5468         newflags |= flags[0].compat_ro_flags & flags[1].compat_ro_flags;
5469         newflags &= ~(flags[0].compat_ro_flags & ~flags[1].compat_ro_flags);
5470         btrfs_set_super_compat_ro_flags(super_block, newflags);
5471
5472         newflags = btrfs_super_incompat_flags(super_block);
5473         newflags |= flags[0].incompat_flags & flags[1].incompat_flags;
5474         newflags &= ~(flags[0].incompat_flags & ~flags[1].incompat_flags);
5475         btrfs_set_super_incompat_flags(super_block, newflags);
5476         spin_unlock(&fs_info->super_lock);
5477
5478         ret = btrfs_commit_transaction(trans);
5479 out_drop_write:
5480         mnt_drop_write_file(file);
5481
5482         return ret;
5483 }
5484
5485 long btrfs_ioctl(struct file *file, unsigned int
5486                 cmd, unsigned long arg)
5487 {
5488         struct inode *inode = file_inode(file);
5489         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5490         struct btrfs_root *root = BTRFS_I(inode)->root;
5491         void __user *argp = (void __user *)arg;
5492
5493         switch (cmd) {
5494         case FS_IOC_GETFLAGS:
5495                 return btrfs_ioctl_getflags(file, argp);
5496         case FS_IOC_SETFLAGS:
5497                 return btrfs_ioctl_setflags(file, argp);
5498         case FS_IOC_GETVERSION:
5499                 return btrfs_ioctl_getversion(file, argp);
5500         case FITRIM:
5501                 return btrfs_ioctl_fitrim(file, argp);
5502         case BTRFS_IOC_SNAP_CREATE:
5503                 return btrfs_ioctl_snap_create(file, argp, 0);
5504         case BTRFS_IOC_SNAP_CREATE_V2:
5505                 return btrfs_ioctl_snap_create_v2(file, argp, 0);
5506         case BTRFS_IOC_SUBVOL_CREATE:
5507                 return btrfs_ioctl_snap_create(file, argp, 1);
5508         case BTRFS_IOC_SUBVOL_CREATE_V2:
5509                 return btrfs_ioctl_snap_create_v2(file, argp, 1);
5510         case BTRFS_IOC_SNAP_DESTROY:
5511                 return btrfs_ioctl_snap_destroy(file, argp);
5512         case BTRFS_IOC_SUBVOL_GETFLAGS:
5513                 return btrfs_ioctl_subvol_getflags(file, argp);
5514         case BTRFS_IOC_SUBVOL_SETFLAGS:
5515                 return btrfs_ioctl_subvol_setflags(file, argp);
5516         case BTRFS_IOC_DEFAULT_SUBVOL:
5517                 return btrfs_ioctl_default_subvol(file, argp);
5518         case BTRFS_IOC_DEFRAG:
5519                 return btrfs_ioctl_defrag(file, NULL);
5520         case BTRFS_IOC_DEFRAG_RANGE:
5521                 return btrfs_ioctl_defrag(file, argp);
5522         case BTRFS_IOC_RESIZE:
5523                 return btrfs_ioctl_resize(file, argp);
5524         case BTRFS_IOC_ADD_DEV:
5525                 return btrfs_ioctl_add_dev(fs_info, argp);
5526         case BTRFS_IOC_RM_DEV:
5527                 return btrfs_ioctl_rm_dev(file, argp);
5528         case BTRFS_IOC_RM_DEV_V2:
5529                 return btrfs_ioctl_rm_dev_v2(file, argp);
5530         case BTRFS_IOC_FS_INFO:
5531                 return btrfs_ioctl_fs_info(fs_info, argp);
5532         case BTRFS_IOC_DEV_INFO:
5533                 return btrfs_ioctl_dev_info(fs_info, argp);
5534         case BTRFS_IOC_BALANCE:
5535                 return btrfs_ioctl_balance(file, NULL);
5536         case BTRFS_IOC_TRANS_START:
5537                 return btrfs_ioctl_trans_start(file);
5538         case BTRFS_IOC_TRANS_END:
5539                 return btrfs_ioctl_trans_end(file);
5540         case BTRFS_IOC_TREE_SEARCH:
5541                 return btrfs_ioctl_tree_search(file, argp);
5542         case BTRFS_IOC_TREE_SEARCH_V2:
5543                 return btrfs_ioctl_tree_search_v2(file, argp);
5544         case BTRFS_IOC_INO_LOOKUP:
5545                 return btrfs_ioctl_ino_lookup(file, argp);
5546         case BTRFS_IOC_INO_PATHS:
5547                 return btrfs_ioctl_ino_to_path(root, argp);
5548         case BTRFS_IOC_LOGICAL_INO:
5549                 return btrfs_ioctl_logical_to_ino(fs_info, argp);
5550         case BTRFS_IOC_SPACE_INFO:
5551                 return btrfs_ioctl_space_info(fs_info, argp);
5552         case BTRFS_IOC_SYNC: {
5553                 int ret;
5554
5555                 ret = btrfs_start_delalloc_roots(fs_info, 0, -1);
5556                 if (ret)
5557                         return ret;
5558                 ret = btrfs_sync_fs(inode->i_sb, 1);
5559                 /*
5560                  * The transaction thread may want to do more work,
5561                  * namely it pokes the cleaner kthread that will start
5562                  * processing uncleaned subvols.
5563                  */
5564                 wake_up_process(fs_info->transaction_kthread);
5565                 return ret;
5566         }
5567         case BTRFS_IOC_START_SYNC:
5568                 return btrfs_ioctl_start_sync(root, argp);
5569         case BTRFS_IOC_WAIT_SYNC:
5570                 return btrfs_ioctl_wait_sync(fs_info, argp);
5571         case BTRFS_IOC_SCRUB:
5572                 return btrfs_ioctl_scrub(file, argp);
5573         case BTRFS_IOC_SCRUB_CANCEL:
5574                 return btrfs_ioctl_scrub_cancel(fs_info);
5575         case BTRFS_IOC_SCRUB_PROGRESS:
5576                 return btrfs_ioctl_scrub_progress(fs_info, argp);
5577         case BTRFS_IOC_BALANCE_V2:
5578                 return btrfs_ioctl_balance(file, argp);
5579         case BTRFS_IOC_BALANCE_CTL:
5580                 return btrfs_ioctl_balance_ctl(fs_info, arg);
5581         case BTRFS_IOC_BALANCE_PROGRESS:
5582                 return btrfs_ioctl_balance_progress(fs_info, argp);
5583         case BTRFS_IOC_SET_RECEIVED_SUBVOL:
5584                 return btrfs_ioctl_set_received_subvol(file, argp);
5585 #ifdef CONFIG_64BIT
5586         case BTRFS_IOC_SET_RECEIVED_SUBVOL_32:
5587                 return btrfs_ioctl_set_received_subvol_32(file, argp);
5588 #endif
5589         case BTRFS_IOC_SEND:
5590                 return btrfs_ioctl_send(file, argp);
5591         case BTRFS_IOC_GET_DEV_STATS:
5592                 return btrfs_ioctl_get_dev_stats(fs_info, argp);
5593         case BTRFS_IOC_QUOTA_CTL:
5594                 return btrfs_ioctl_quota_ctl(file, argp);
5595         case BTRFS_IOC_QGROUP_ASSIGN:
5596                 return btrfs_ioctl_qgroup_assign(file, argp);
5597         case BTRFS_IOC_QGROUP_CREATE:
5598                 return btrfs_ioctl_qgroup_create(file, argp);
5599         case BTRFS_IOC_QGROUP_LIMIT:
5600                 return btrfs_ioctl_qgroup_limit(file, argp);
5601         case BTRFS_IOC_QUOTA_RESCAN:
5602                 return btrfs_ioctl_quota_rescan(file, argp);
5603         case BTRFS_IOC_QUOTA_RESCAN_STATUS:
5604                 return btrfs_ioctl_quota_rescan_status(file, argp);
5605         case BTRFS_IOC_QUOTA_RESCAN_WAIT:
5606                 return btrfs_ioctl_quota_rescan_wait(file, argp);
5607         case BTRFS_IOC_DEV_REPLACE:
5608                 return btrfs_ioctl_dev_replace(fs_info, argp);
5609         case BTRFS_IOC_GET_FSLABEL:
5610                 return btrfs_ioctl_get_fslabel(file, argp);
5611         case BTRFS_IOC_SET_FSLABEL:
5612                 return btrfs_ioctl_set_fslabel(file, argp);
5613         case BTRFS_IOC_GET_SUPPORTED_FEATURES:
5614                 return btrfs_ioctl_get_supported_features(argp);
5615         case BTRFS_IOC_GET_FEATURES:
5616                 return btrfs_ioctl_get_features(file, argp);
5617         case BTRFS_IOC_SET_FEATURES:
5618                 return btrfs_ioctl_set_features(file, argp);
5619         }
5620
5621         return -ENOTTY;
5622 }
5623
5624 #ifdef CONFIG_COMPAT
5625 long btrfs_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
5626 {
5627         /*
5628          * These all access 32-bit values anyway so no further
5629          * handling is necessary.
5630          */
5631         switch (cmd) {
5632         case FS_IOC32_GETFLAGS:
5633                 cmd = FS_IOC_GETFLAGS;
5634                 break;
5635         case FS_IOC32_SETFLAGS:
5636                 cmd = FS_IOC_SETFLAGS;
5637                 break;
5638         case FS_IOC32_GETVERSION:
5639                 cmd = FS_IOC_GETVERSION;
5640                 break;
5641         }
5642
5643         return btrfs_ioctl(file, cmd, (unsigned long) compat_ptr(arg));
5644 }
5645 #endif