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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/blkdev.h>
20#include <linux/module.h>
21#include <linux/buffer_head.h>
22#include <linux/fs.h>
23#include <linux/pagemap.h>
24#include <linux/highmem.h>
25#include <linux/time.h>
26#include <linux/init.h>
27#include <linux/seq_file.h>
28#include <linux/string.h>
29#include <linux/backing-dev.h>
30#include <linux/mount.h>
31#include <linux/mpage.h>
32#include <linux/swap.h>
33#include <linux/writeback.h>
34#include <linux/statfs.h>
35#include <linux/compat.h>
36#include <linux/parser.h>
37#include <linux/ctype.h>
38#include <linux/namei.h>
39#include <linux/miscdevice.h>
40#include <linux/magic.h>
41#include <linux/slab.h>
42#include <linux/cleancache.h>
43#include "compat.h"
44#include "delayed-inode.h"
45#include "ctree.h"
46#include "disk-io.h"
47#include "transaction.h"
48#include "btrfs_inode.h"
49#include "ioctl.h"
50#include "print-tree.h"
51#include "xattr.h"
52#include "volumes.h"
53#include "version.h"
54#include "export.h"
55#include "compression.h"
56
57#define CREATE_TRACE_POINTS
58#include <trace/events/btrfs.h>
59
60static const struct super_operations btrfs_super_ops;
61
62static const char *btrfs_decode_error(struct btrfs_fs_info *fs_info, int errno,
63 char nbuf[16])
64{
65 char *errstr = NULL;
66
67 switch (errno) {
68 case -EIO:
69 errstr = "IO failure";
70 break;
71 case -ENOMEM:
72 errstr = "Out of memory";
73 break;
74 case -EROFS:
75 errstr = "Readonly filesystem";
76 break;
77 default:
78 if (nbuf) {
79 if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
80 errstr = nbuf;
81 }
82 break;
83 }
84
85 return errstr;
86}
87
88static void __save_error_info(struct btrfs_fs_info *fs_info)
89{
90 /*
91 * today we only save the error info into ram. Long term we'll
92 * also send it down to the disk
93 */
94 fs_info->fs_state = BTRFS_SUPER_FLAG_ERROR;
95}
96
97/* NOTE:
98 * We move write_super stuff at umount in order to avoid deadlock
99 * for umount hold all lock.
100 */
101static void save_error_info(struct btrfs_fs_info *fs_info)
102{
103 __save_error_info(fs_info);
104}
105
106/* btrfs handle error by forcing the filesystem readonly */
107static void btrfs_handle_error(struct btrfs_fs_info *fs_info)
108{
109 struct super_block *sb = fs_info->sb;
110
111 if (sb->s_flags & MS_RDONLY)
112 return;
113
114 if (fs_info->fs_state & BTRFS_SUPER_FLAG_ERROR) {
115 sb->s_flags |= MS_RDONLY;
116 printk(KERN_INFO "btrfs is forced readonly\n");
117 }
118}
119
120/*
121 * __btrfs_std_error decodes expected errors from the caller and
122 * invokes the approciate error response.
123 */
124void __btrfs_std_error(struct btrfs_fs_info *fs_info, const char *function,
125 unsigned int line, int errno)
126{
127 struct super_block *sb = fs_info->sb;
128 char nbuf[16];
129 const char *errstr;
130
131 /*
132 * Special case: if the error is EROFS, and we're already
133 * under MS_RDONLY, then it is safe here.
134 */
135 if (errno == -EROFS && (sb->s_flags & MS_RDONLY))
136 return;
137
138 errstr = btrfs_decode_error(fs_info, errno, nbuf);
139 printk(KERN_CRIT "BTRFS error (device %s) in %s:%d: %s\n",
140 sb->s_id, function, line, errstr);
141 save_error_info(fs_info);
142
143 btrfs_handle_error(fs_info);
144}
145
146static void btrfs_put_super(struct super_block *sb)
147{
148 struct btrfs_root *root = btrfs_sb(sb);
149 int ret;
150
151 ret = close_ctree(root);
152 sb->s_fs_info = NULL;
153
154 (void)ret; /* FIXME: need to fix VFS to return error? */
155}
156
157enum {
158 Opt_degraded, Opt_subvol, Opt_subvolid, Opt_device, Opt_nodatasum,
159 Opt_nodatacow, Opt_max_inline, Opt_alloc_start, Opt_nobarrier, Opt_ssd,
160 Opt_nossd, Opt_ssd_spread, Opt_thread_pool, Opt_noacl, Opt_compress,
161 Opt_compress_type, Opt_compress_force, Opt_compress_force_type,
162 Opt_notreelog, Opt_ratio, Opt_flushoncommit, Opt_discard,
163 Opt_space_cache, Opt_clear_cache, Opt_user_subvol_rm_allowed,
164 Opt_enospc_debug, Opt_subvolrootid, Opt_defrag,
165 Opt_inode_cache, Opt_err,
166};
167
168static match_table_t tokens = {
169 {Opt_degraded, "degraded"},
170 {Opt_subvol, "subvol=%s"},
171 {Opt_subvolid, "subvolid=%d"},
172 {Opt_device, "device=%s"},
173 {Opt_nodatasum, "nodatasum"},
174 {Opt_nodatacow, "nodatacow"},
175 {Opt_nobarrier, "nobarrier"},
176 {Opt_max_inline, "max_inline=%s"},
177 {Opt_alloc_start, "alloc_start=%s"},
178 {Opt_thread_pool, "thread_pool=%d"},
179 {Opt_compress, "compress"},
180 {Opt_compress_type, "compress=%s"},
181 {Opt_compress_force, "compress-force"},
182 {Opt_compress_force_type, "compress-force=%s"},
183 {Opt_ssd, "ssd"},
184 {Opt_ssd_spread, "ssd_spread"},
185 {Opt_nossd, "nossd"},
186 {Opt_noacl, "noacl"},
187 {Opt_notreelog, "notreelog"},
188 {Opt_flushoncommit, "flushoncommit"},
189 {Opt_ratio, "metadata_ratio=%d"},
190 {Opt_discard, "discard"},
191 {Opt_space_cache, "space_cache"},
192 {Opt_clear_cache, "clear_cache"},
193 {Opt_user_subvol_rm_allowed, "user_subvol_rm_allowed"},
194 {Opt_enospc_debug, "enospc_debug"},
195 {Opt_subvolrootid, "subvolrootid=%d"},
196 {Opt_defrag, "autodefrag"},
197 {Opt_inode_cache, "inode_cache"},
198 {Opt_err, NULL},
199};
200
201/*
202 * Regular mount options parser. Everything that is needed only when
203 * reading in a new superblock is parsed here.
204 */
205int btrfs_parse_options(struct btrfs_root *root, char *options)
206{
207 struct btrfs_fs_info *info = root->fs_info;
208 substring_t args[MAX_OPT_ARGS];
209 char *p, *num, *orig;
210 int intarg;
211 int ret = 0;
212 char *compress_type;
213 bool compress_force = false;
214
215 if (!options)
216 return 0;
217
218 /*
219 * strsep changes the string, duplicate it because parse_options
220 * gets called twice
221 */
222 options = kstrdup(options, GFP_NOFS);
223 if (!options)
224 return -ENOMEM;
225
226 orig = options;
227
228 while ((p = strsep(&options, ",")) != NULL) {
229 int token;
230 if (!*p)
231 continue;
232
233 token = match_token(p, tokens, args);
234 switch (token) {
235 case Opt_degraded:
236 printk(KERN_INFO "btrfs: allowing degraded mounts\n");
237 btrfs_set_opt(info->mount_opt, DEGRADED);
238 break;
239 case Opt_subvol:
240 case Opt_subvolid:
241 case Opt_subvolrootid:
242 case Opt_device:
243 /*
244 * These are parsed by btrfs_parse_early_options
245 * and can be happily ignored here.
246 */
247 break;
248 case Opt_nodatasum:
249 printk(KERN_INFO "btrfs: setting nodatasum\n");
250 btrfs_set_opt(info->mount_opt, NODATASUM);
251 break;
252 case Opt_nodatacow:
253 printk(KERN_INFO "btrfs: setting nodatacow\n");
254 btrfs_set_opt(info->mount_opt, NODATACOW);
255 btrfs_set_opt(info->mount_opt, NODATASUM);
256 break;
257 case Opt_compress_force:
258 case Opt_compress_force_type:
259 compress_force = true;
260 case Opt_compress:
261 case Opt_compress_type:
262 if (token == Opt_compress ||
263 token == Opt_compress_force ||
264 strcmp(args[0].from, "zlib") == 0) {
265 compress_type = "zlib";
266 info->compress_type = BTRFS_COMPRESS_ZLIB;
267 } else if (strcmp(args[0].from, "lzo") == 0) {
268 compress_type = "lzo";
269 info->compress_type = BTRFS_COMPRESS_LZO;
270 } else {
271 ret = -EINVAL;
272 goto out;
273 }
274
275 btrfs_set_opt(info->mount_opt, COMPRESS);
276 if (compress_force) {
277 btrfs_set_opt(info->mount_opt, FORCE_COMPRESS);
278 pr_info("btrfs: force %s compression\n",
279 compress_type);
280 } else
281 pr_info("btrfs: use %s compression\n",
282 compress_type);
283 break;
284 case Opt_ssd:
285 printk(KERN_INFO "btrfs: use ssd allocation scheme\n");
286 btrfs_set_opt(info->mount_opt, SSD);
287 break;
288 case Opt_ssd_spread:
289 printk(KERN_INFO "btrfs: use spread ssd "
290 "allocation scheme\n");
291 btrfs_set_opt(info->mount_opt, SSD);
292 btrfs_set_opt(info->mount_opt, SSD_SPREAD);
293 break;
294 case Opt_nossd:
295 printk(KERN_INFO "btrfs: not using ssd allocation "
296 "scheme\n");
297 btrfs_set_opt(info->mount_opt, NOSSD);
298 btrfs_clear_opt(info->mount_opt, SSD);
299 btrfs_clear_opt(info->mount_opt, SSD_SPREAD);
300 break;
301 case Opt_nobarrier:
302 printk(KERN_INFO "btrfs: turning off barriers\n");
303 btrfs_set_opt(info->mount_opt, NOBARRIER);
304 break;
305 case Opt_thread_pool:
306 intarg = 0;
307 match_int(&args[0], &intarg);
308 if (intarg) {
309 info->thread_pool_size = intarg;
310 printk(KERN_INFO "btrfs: thread pool %d\n",
311 info->thread_pool_size);
312 }
313 break;
314 case Opt_max_inline:
315 num = match_strdup(&args[0]);
316 if (num) {
317 info->max_inline = memparse(num, NULL);
318 kfree(num);
319
320 if (info->max_inline) {
321 info->max_inline = max_t(u64,
322 info->max_inline,
323 root->sectorsize);
324 }
325 printk(KERN_INFO "btrfs: max_inline at %llu\n",
326 (unsigned long long)info->max_inline);
327 }
328 break;
329 case Opt_alloc_start:
330 num = match_strdup(&args[0]);
331 if (num) {
332 info->alloc_start = memparse(num, NULL);
333 kfree(num);
334 printk(KERN_INFO
335 "btrfs: allocations start at %llu\n",
336 (unsigned long long)info->alloc_start);
337 }
338 break;
339 case Opt_noacl:
340 root->fs_info->sb->s_flags &= ~MS_POSIXACL;
341 break;
342 case Opt_notreelog:
343 printk(KERN_INFO "btrfs: disabling tree log\n");
344 btrfs_set_opt(info->mount_opt, NOTREELOG);
345 break;
346 case Opt_flushoncommit:
347 printk(KERN_INFO "btrfs: turning on flush-on-commit\n");
348 btrfs_set_opt(info->mount_opt, FLUSHONCOMMIT);
349 break;
350 case Opt_ratio:
351 intarg = 0;
352 match_int(&args[0], &intarg);
353 if (intarg) {
354 info->metadata_ratio = intarg;
355 printk(KERN_INFO "btrfs: metadata ratio %d\n",
356 info->metadata_ratio);
357 }
358 break;
359 case Opt_discard:
360 btrfs_set_opt(info->mount_opt, DISCARD);
361 break;
362 case Opt_space_cache:
363 printk(KERN_INFO "btrfs: enabling disk space caching\n");
364 btrfs_set_opt(info->mount_opt, SPACE_CACHE);
365 break;
366 case Opt_inode_cache:
367 printk(KERN_INFO "btrfs: enabling inode map caching\n");
368 btrfs_set_opt(info->mount_opt, INODE_MAP_CACHE);
369 break;
370 case Opt_clear_cache:
371 printk(KERN_INFO "btrfs: force clearing of disk cache\n");
372 btrfs_set_opt(info->mount_opt, CLEAR_CACHE);
373 break;
374 case Opt_user_subvol_rm_allowed:
375 btrfs_set_opt(info->mount_opt, USER_SUBVOL_RM_ALLOWED);
376 break;
377 case Opt_enospc_debug:
378 btrfs_set_opt(info->mount_opt, ENOSPC_DEBUG);
379 break;
380 case Opt_defrag:
381 printk(KERN_INFO "btrfs: enabling auto defrag");
382 btrfs_set_opt(info->mount_opt, AUTO_DEFRAG);
383 break;
384 case Opt_err:
385 printk(KERN_INFO "btrfs: unrecognized mount option "
386 "'%s'\n", p);
387 ret = -EINVAL;
388 goto out;
389 default:
390 break;
391 }
392 }
393out:
394 kfree(orig);
395 return ret;
396}
397
398/*
399 * Parse mount options that are required early in the mount process.
400 *
401 * All other options will be parsed on much later in the mount process and
402 * only when we need to allocate a new super block.
403 */
404static int btrfs_parse_early_options(const char *options, fmode_t flags,
405 void *holder, char **subvol_name, u64 *subvol_objectid,
406 u64 *subvol_rootid, struct btrfs_fs_devices **fs_devices)
407{
408 substring_t args[MAX_OPT_ARGS];
409 char *opts, *orig, *p;
410 int error = 0;
411 int intarg;
412
413 if (!options)
414 goto out;
415
416 /*
417 * strsep changes the string, duplicate it because parse_options
418 * gets called twice
419 */
420 opts = kstrdup(options, GFP_KERNEL);
421 if (!opts)
422 return -ENOMEM;
423 orig = opts;
424
425 while ((p = strsep(&opts, ",")) != NULL) {
426 int token;
427 if (!*p)
428 continue;
429
430 token = match_token(p, tokens, args);
431 switch (token) {
432 case Opt_subvol:
433 *subvol_name = match_strdup(&args[0]);
434 break;
435 case Opt_subvolid:
436 intarg = 0;
437 error = match_int(&args[0], &intarg);
438 if (!error) {
439 /* we want the original fs_tree */
440 if (!intarg)
441 *subvol_objectid =
442 BTRFS_FS_TREE_OBJECTID;
443 else
444 *subvol_objectid = intarg;
445 }
446 break;
447 case Opt_subvolrootid:
448 intarg = 0;
449 error = match_int(&args[0], &intarg);
450 if (!error) {
451 /* we want the original fs_tree */
452 if (!intarg)
453 *subvol_rootid =
454 BTRFS_FS_TREE_OBJECTID;
455 else
456 *subvol_rootid = intarg;
457 }
458 break;
459 case Opt_device:
460 error = btrfs_scan_one_device(match_strdup(&args[0]),
461 flags, holder, fs_devices);
462 if (error)
463 goto out_free_opts;
464 break;
465 default:
466 break;
467 }
468 }
469
470 out_free_opts:
471 kfree(orig);
472 out:
473 /*
474 * If no subvolume name is specified we use the default one. Allocate
475 * a copy of the string "." here so that code later in the
476 * mount path doesn't care if it's the default volume or another one.
477 */
478 if (!*subvol_name) {
479 *subvol_name = kstrdup(".", GFP_KERNEL);
480 if (!*subvol_name)
481 return -ENOMEM;
482 }
483 return error;
484}
485
486static struct dentry *get_default_root(struct super_block *sb,
487 u64 subvol_objectid)
488{
489 struct btrfs_root *root = sb->s_fs_info;
490 struct btrfs_root *new_root;
491 struct btrfs_dir_item *di;
492 struct btrfs_path *path;
493 struct btrfs_key location;
494 struct inode *inode;
495 struct dentry *dentry;
496 u64 dir_id;
497 int new = 0;
498
499 /*
500 * We have a specific subvol we want to mount, just setup location and
501 * go look up the root.
502 */
503 if (subvol_objectid) {
504 location.objectid = subvol_objectid;
505 location.type = BTRFS_ROOT_ITEM_KEY;
506 location.offset = (u64)-1;
507 goto find_root;
508 }
509
510 path = btrfs_alloc_path();
511 if (!path)
512 return ERR_PTR(-ENOMEM);
513 path->leave_spinning = 1;
514
515 /*
516 * Find the "default" dir item which points to the root item that we
517 * will mount by default if we haven't been given a specific subvolume
518 * to mount.
519 */
520 dir_id = btrfs_super_root_dir(&root->fs_info->super_copy);
521 di = btrfs_lookup_dir_item(NULL, root, path, dir_id, "default", 7, 0);
522 if (IS_ERR(di)) {
523 btrfs_free_path(path);
524 return ERR_CAST(di);
525 }
526 if (!di) {
527 /*
528 * Ok the default dir item isn't there. This is weird since
529 * it's always been there, but don't freak out, just try and
530 * mount to root most subvolume.
531 */
532 btrfs_free_path(path);
533 dir_id = BTRFS_FIRST_FREE_OBJECTID;
534 new_root = root->fs_info->fs_root;
535 goto setup_root;
536 }
537
538 btrfs_dir_item_key_to_cpu(path->nodes[0], di, &location);
539 btrfs_free_path(path);
540
541find_root:
542 new_root = btrfs_read_fs_root_no_name(root->fs_info, &location);
543 if (IS_ERR(new_root))
544 return ERR_CAST(new_root);
545
546 if (btrfs_root_refs(&new_root->root_item) == 0)
547 return ERR_PTR(-ENOENT);
548
549 dir_id = btrfs_root_dirid(&new_root->root_item);
550setup_root:
551 location.objectid = dir_id;
552 location.type = BTRFS_INODE_ITEM_KEY;
553 location.offset = 0;
554
555 inode = btrfs_iget(sb, &location, new_root, &new);
556 if (IS_ERR(inode))
557 return ERR_CAST(inode);
558
559 /*
560 * If we're just mounting the root most subvol put the inode and return
561 * a reference to the dentry. We will have already gotten a reference
562 * to the inode in btrfs_fill_super so we're good to go.
563 */
564 if (!new && sb->s_root->d_inode == inode) {
565 iput(inode);
566 return dget(sb->s_root);
567 }
568
569 if (new) {
570 const struct qstr name = { .name = "/", .len = 1 };
571
572 /*
573 * New inode, we need to make the dentry a sibling of s_root so
574 * everything gets cleaned up properly on unmount.
575 */
576 dentry = d_alloc(sb->s_root, &name);
577 if (!dentry) {
578 iput(inode);
579 return ERR_PTR(-ENOMEM);
580 }
581 d_splice_alias(inode, dentry);
582 } else {
583 /*
584 * We found the inode in cache, just find a dentry for it and
585 * put the reference to the inode we just got.
586 */
587 dentry = d_find_alias(inode);
588 iput(inode);
589 }
590
591 return dentry;
592}
593
594static int btrfs_fill_super(struct super_block *sb,
595 struct btrfs_fs_devices *fs_devices,
596 void *data, int silent)
597{
598 struct inode *inode;
599 struct dentry *root_dentry;
600 struct btrfs_root *tree_root;
601 struct btrfs_key key;
602 int err;
603
604 sb->s_maxbytes = MAX_LFS_FILESIZE;
605 sb->s_magic = BTRFS_SUPER_MAGIC;
606 sb->s_op = &btrfs_super_ops;
607 sb->s_d_op = &btrfs_dentry_operations;
608 sb->s_export_op = &btrfs_export_ops;
609 sb->s_xattr = btrfs_xattr_handlers;
610 sb->s_time_gran = 1;
611#ifdef CONFIG_BTRFS_FS_POSIX_ACL
612 sb->s_flags |= MS_POSIXACL;
613#endif
614
615 tree_root = open_ctree(sb, fs_devices, (char *)data);
616
617 if (IS_ERR(tree_root)) {
618 printk("btrfs: open_ctree failed\n");
619 return PTR_ERR(tree_root);
620 }
621 sb->s_fs_info = tree_root;
622
623 key.objectid = BTRFS_FIRST_FREE_OBJECTID;
624 key.type = BTRFS_INODE_ITEM_KEY;
625 key.offset = 0;
626 inode = btrfs_iget(sb, &key, tree_root->fs_info->fs_root, NULL);
627 if (IS_ERR(inode)) {
628 err = PTR_ERR(inode);
629 goto fail_close;
630 }
631
632 root_dentry = d_alloc_root(inode);
633 if (!root_dentry) {
634 iput(inode);
635 err = -ENOMEM;
636 goto fail_close;
637 }
638
639 sb->s_root = root_dentry;
640
641 save_mount_options(sb, data);
642 cleancache_init_fs(sb);
643 return 0;
644
645fail_close:
646 close_ctree(tree_root);
647 return err;
648}
649
650int btrfs_sync_fs(struct super_block *sb, int wait)
651{
652 struct btrfs_trans_handle *trans;
653 struct btrfs_root *root = btrfs_sb(sb);
654 int ret;
655
656 trace_btrfs_sync_fs(wait);
657
658 if (!wait) {
659 filemap_flush(root->fs_info->btree_inode->i_mapping);
660 return 0;
661 }
662
663 btrfs_start_delalloc_inodes(root, 0);
664 btrfs_wait_ordered_extents(root, 0, 0);
665
666 trans = btrfs_start_transaction(root, 0);
667 if (IS_ERR(trans))
668 return PTR_ERR(trans);
669 ret = btrfs_commit_transaction(trans, root);
670 return ret;
671}
672
673static int btrfs_show_options(struct seq_file *seq, struct vfsmount *vfs)
674{
675 struct btrfs_root *root = btrfs_sb(vfs->mnt_sb);
676 struct btrfs_fs_info *info = root->fs_info;
677 char *compress_type;
678
679 if (btrfs_test_opt(root, DEGRADED))
680 seq_puts(seq, ",degraded");
681 if (btrfs_test_opt(root, NODATASUM))
682 seq_puts(seq, ",nodatasum");
683 if (btrfs_test_opt(root, NODATACOW))
684 seq_puts(seq, ",nodatacow");
685 if (btrfs_test_opt(root, NOBARRIER))
686 seq_puts(seq, ",nobarrier");
687 if (info->max_inline != 8192 * 1024)
688 seq_printf(seq, ",max_inline=%llu",
689 (unsigned long long)info->max_inline);
690 if (info->alloc_start != 0)
691 seq_printf(seq, ",alloc_start=%llu",
692 (unsigned long long)info->alloc_start);
693 if (info->thread_pool_size != min_t(unsigned long,
694 num_online_cpus() + 2, 8))
695 seq_printf(seq, ",thread_pool=%d", info->thread_pool_size);
696 if (btrfs_test_opt(root, COMPRESS)) {
697 if (info->compress_type == BTRFS_COMPRESS_ZLIB)
698 compress_type = "zlib";
699 else
700 compress_type = "lzo";
701 if (btrfs_test_opt(root, FORCE_COMPRESS))
702 seq_printf(seq, ",compress-force=%s", compress_type);
703 else
704 seq_printf(seq, ",compress=%s", compress_type);
705 }
706 if (btrfs_test_opt(root, NOSSD))
707 seq_puts(seq, ",nossd");
708 if (btrfs_test_opt(root, SSD_SPREAD))
709 seq_puts(seq, ",ssd_spread");
710 else if (btrfs_test_opt(root, SSD))
711 seq_puts(seq, ",ssd");
712 if (btrfs_test_opt(root, NOTREELOG))
713 seq_puts(seq, ",notreelog");
714 if (btrfs_test_opt(root, FLUSHONCOMMIT))
715 seq_puts(seq, ",flushoncommit");
716 if (btrfs_test_opt(root, DISCARD))
717 seq_puts(seq, ",discard");
718 if (!(root->fs_info->sb->s_flags & MS_POSIXACL))
719 seq_puts(seq, ",noacl");
720 if (btrfs_test_opt(root, SPACE_CACHE))
721 seq_puts(seq, ",space_cache");
722 if (btrfs_test_opt(root, CLEAR_CACHE))
723 seq_puts(seq, ",clear_cache");
724 if (btrfs_test_opt(root, USER_SUBVOL_RM_ALLOWED))
725 seq_puts(seq, ",user_subvol_rm_allowed");
726 if (btrfs_test_opt(root, ENOSPC_DEBUG))
727 seq_puts(seq, ",enospc_debug");
728 if (btrfs_test_opt(root, AUTO_DEFRAG))
729 seq_puts(seq, ",autodefrag");
730 if (btrfs_test_opt(root, INODE_MAP_CACHE))
731 seq_puts(seq, ",inode_cache");
732 return 0;
733}
734
735static int btrfs_test_super(struct super_block *s, void *data)
736{
737 struct btrfs_root *test_root = data;
738 struct btrfs_root *root = btrfs_sb(s);
739
740 /*
741 * If this super block is going away, return false as it
742 * can't match as an existing super block.
743 */
744 if (!atomic_read(&s->s_active))
745 return 0;
746 return root->fs_info->fs_devices == test_root->fs_info->fs_devices;
747}
748
749static int btrfs_set_super(struct super_block *s, void *data)
750{
751 s->s_fs_info = data;
752
753 return set_anon_super(s, data);
754}
755
756
757/*
758 * Find a superblock for the given device / mount point.
759 *
760 * Note: This is based on get_sb_bdev from fs/super.c with a few additions
761 * for multiple device setup. Make sure to keep it in sync.
762 */
763static struct dentry *btrfs_mount(struct file_system_type *fs_type, int flags,
764 const char *device_name, void *data)
765{
766 struct block_device *bdev = NULL;
767 struct super_block *s;
768 struct dentry *root;
769 struct btrfs_fs_devices *fs_devices = NULL;
770 struct btrfs_root *tree_root = NULL;
771 struct btrfs_fs_info *fs_info = NULL;
772 fmode_t mode = FMODE_READ;
773 char *subvol_name = NULL;
774 u64 subvol_objectid = 0;
775 u64 subvol_rootid = 0;
776 int error = 0;
777
778 if (!(flags & MS_RDONLY))
779 mode |= FMODE_WRITE;
780
781 error = btrfs_parse_early_options(data, mode, fs_type,
782 &subvol_name, &subvol_objectid,
783 &subvol_rootid, &fs_devices);
784 if (error)
785 return ERR_PTR(error);
786
787 error = btrfs_scan_one_device(device_name, mode, fs_type, &fs_devices);
788 if (error)
789 goto error_free_subvol_name;
790
791 error = btrfs_open_devices(fs_devices, mode, fs_type);
792 if (error)
793 goto error_free_subvol_name;
794
795 if (!(flags & MS_RDONLY) && fs_devices->rw_devices == 0) {
796 error = -EACCES;
797 goto error_close_devices;
798 }
799
800 /*
801 * Setup a dummy root and fs_info for test/set super. This is because
802 * we don't actually fill this stuff out until open_ctree, but we need
803 * it for searching for existing supers, so this lets us do that and
804 * then open_ctree will properly initialize everything later.
805 */
806 fs_info = kzalloc(sizeof(struct btrfs_fs_info), GFP_NOFS);
807 tree_root = kzalloc(sizeof(struct btrfs_root), GFP_NOFS);
808 if (!fs_info || !tree_root) {
809 error = -ENOMEM;
810 goto error_close_devices;
811 }
812 fs_info->tree_root = tree_root;
813 fs_info->fs_devices = fs_devices;
814 tree_root->fs_info = fs_info;
815
816 bdev = fs_devices->latest_bdev;
817 s = sget(fs_type, btrfs_test_super, btrfs_set_super, tree_root);
818 if (IS_ERR(s))
819 goto error_s;
820
821 if (s->s_root) {
822 if ((flags ^ s->s_flags) & MS_RDONLY) {
823 deactivate_locked_super(s);
824 error = -EBUSY;
825 goto error_close_devices;
826 }
827
828 btrfs_close_devices(fs_devices);
829 kfree(fs_info);
830 kfree(tree_root);
831 } else {
832 char b[BDEVNAME_SIZE];
833
834 s->s_flags = flags | MS_NOSEC;
835 strlcpy(s->s_id, bdevname(bdev, b), sizeof(s->s_id));
836 error = btrfs_fill_super(s, fs_devices, data,
837 flags & MS_SILENT ? 1 : 0);
838 if (error) {
839 deactivate_locked_super(s);
840 goto error_free_subvol_name;
841 }
842
843 btrfs_sb(s)->fs_info->bdev_holder = fs_type;
844 s->s_flags |= MS_ACTIVE;
845 }
846
847 /* if they gave us a subvolume name bind mount into that */
848 if (strcmp(subvol_name, ".")) {
849 struct dentry *new_root;
850
851 root = get_default_root(s, subvol_rootid);
852 if (IS_ERR(root)) {
853 error = PTR_ERR(root);
854 deactivate_locked_super(s);
855 goto error_free_subvol_name;
856 }
857
858 mutex_lock(&root->d_inode->i_mutex);
859 new_root = lookup_one_len(subvol_name, root,
860 strlen(subvol_name));
861 mutex_unlock(&root->d_inode->i_mutex);
862
863 if (IS_ERR(new_root)) {
864 dput(root);
865 deactivate_locked_super(s);
866 error = PTR_ERR(new_root);
867 goto error_free_subvol_name;
868 }
869 if (!new_root->d_inode) {
870 dput(root);
871 dput(new_root);
872 deactivate_locked_super(s);
873 error = -ENXIO;
874 goto error_free_subvol_name;
875 }
876 dput(root);
877 root = new_root;
878 } else {
879 root = get_default_root(s, subvol_objectid);
880 if (IS_ERR(root)) {
881 error = PTR_ERR(root);
882 deactivate_locked_super(s);
883 goto error_free_subvol_name;
884 }
885 }
886
887 kfree(subvol_name);
888 return root;
889
890error_s:
891 error = PTR_ERR(s);
892error_close_devices:
893 btrfs_close_devices(fs_devices);
894 kfree(fs_info);
895 kfree(tree_root);
896error_free_subvol_name:
897 kfree(subvol_name);
898 return ERR_PTR(error);
899}
900
901static int btrfs_remount(struct super_block *sb, int *flags, char *data)
902{
903 struct btrfs_root *root = btrfs_sb(sb);
904 int ret;
905
906 ret = btrfs_parse_options(root, data);
907 if (ret)
908 return -EINVAL;
909
910 if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
911 return 0;
912
913 if (*flags & MS_RDONLY) {
914 sb->s_flags |= MS_RDONLY;
915
916 ret = btrfs_commit_super(root);
917 WARN_ON(ret);
918 } else {
919 if (root->fs_info->fs_devices->rw_devices == 0)
920 return -EACCES;
921
922 if (btrfs_super_log_root(&root->fs_info->super_copy) != 0)
923 return -EINVAL;
924
925 ret = btrfs_cleanup_fs_roots(root->fs_info);
926 WARN_ON(ret);
927
928 /* recover relocation */
929 ret = btrfs_recover_relocation(root);
930 WARN_ON(ret);
931
932 sb->s_flags &= ~MS_RDONLY;
933 }
934
935 return 0;
936}
937
938/* Used to sort the devices by max_avail(descending sort) */
939static int btrfs_cmp_device_free_bytes(const void *dev_info1,
940 const void *dev_info2)
941{
942 if (((struct btrfs_device_info *)dev_info1)->max_avail >
943 ((struct btrfs_device_info *)dev_info2)->max_avail)
944 return -1;
945 else if (((struct btrfs_device_info *)dev_info1)->max_avail <
946 ((struct btrfs_device_info *)dev_info2)->max_avail)
947 return 1;
948 else
949 return 0;
950}
951
952/*
953 * sort the devices by max_avail, in which max free extent size of each device
954 * is stored.(Descending Sort)
955 */
956static inline void btrfs_descending_sort_devices(
957 struct btrfs_device_info *devices,
958 size_t nr_devices)
959{
960 sort(devices, nr_devices, sizeof(struct btrfs_device_info),
961 btrfs_cmp_device_free_bytes, NULL);
962}
963
964/*
965 * The helper to calc the free space on the devices that can be used to store
966 * file data.
967 */
968static int btrfs_calc_avail_data_space(struct btrfs_root *root, u64 *free_bytes)
969{
970 struct btrfs_fs_info *fs_info = root->fs_info;
971 struct btrfs_device_info *devices_info;
972 struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
973 struct btrfs_device *device;
974 u64 skip_space;
975 u64 type;
976 u64 avail_space;
977 u64 used_space;
978 u64 min_stripe_size;
979 int min_stripes = 1;
980 int i = 0, nr_devices;
981 int ret;
982
983 nr_devices = fs_info->fs_devices->rw_devices;
984 BUG_ON(!nr_devices);
985
986 devices_info = kmalloc(sizeof(*devices_info) * nr_devices,
987 GFP_NOFS);
988 if (!devices_info)
989 return -ENOMEM;
990
991 /* calc min stripe number for data space alloction */
992 type = btrfs_get_alloc_profile(root, 1);
993 if (type & BTRFS_BLOCK_GROUP_RAID0)
994 min_stripes = 2;
995 else if (type & BTRFS_BLOCK_GROUP_RAID1)
996 min_stripes = 2;
997 else if (type & BTRFS_BLOCK_GROUP_RAID10)
998 min_stripes = 4;
999
1000 if (type & BTRFS_BLOCK_GROUP_DUP)
1001 min_stripe_size = 2 * BTRFS_STRIPE_LEN;
1002 else
1003 min_stripe_size = BTRFS_STRIPE_LEN;
1004
1005 list_for_each_entry(device, &fs_devices->alloc_list, dev_alloc_list) {
1006 if (!device->in_fs_metadata)
1007 continue;
1008
1009 avail_space = device->total_bytes - device->bytes_used;
1010
1011 /* align with stripe_len */
1012 do_div(avail_space, BTRFS_STRIPE_LEN);
1013 avail_space *= BTRFS_STRIPE_LEN;
1014
1015 /*
1016 * In order to avoid overwritting the superblock on the drive,
1017 * btrfs starts at an offset of at least 1MB when doing chunk
1018 * allocation.
1019 */
1020 skip_space = 1024 * 1024;
1021
1022 /* user can set the offset in fs_info->alloc_start. */
1023 if (fs_info->alloc_start + BTRFS_STRIPE_LEN <=
1024 device->total_bytes)
1025 skip_space = max(fs_info->alloc_start, skip_space);
1026
1027 /*
1028 * btrfs can not use the free space in [0, skip_space - 1],
1029 * we must subtract it from the total. In order to implement
1030 * it, we account the used space in this range first.
1031 */
1032 ret = btrfs_account_dev_extents_size(device, 0, skip_space - 1,
1033 &used_space);
1034 if (ret) {
1035 kfree(devices_info);
1036 return ret;
1037 }
1038
1039 /* calc the free space in [0, skip_space - 1] */
1040 skip_space -= used_space;
1041
1042 /*
1043 * we can use the free space in [0, skip_space - 1], subtract
1044 * it from the total.
1045 */
1046 if (avail_space && avail_space >= skip_space)
1047 avail_space -= skip_space;
1048 else
1049 avail_space = 0;
1050
1051 if (avail_space < min_stripe_size)
1052 continue;
1053
1054 devices_info[i].dev = device;
1055 devices_info[i].max_avail = avail_space;
1056
1057 i++;
1058 }
1059
1060 nr_devices = i;
1061
1062 btrfs_descending_sort_devices(devices_info, nr_devices);
1063
1064 i = nr_devices - 1;
1065 avail_space = 0;
1066 while (nr_devices >= min_stripes) {
1067 if (devices_info[i].max_avail >= min_stripe_size) {
1068 int j;
1069 u64 alloc_size;
1070
1071 avail_space += devices_info[i].max_avail * min_stripes;
1072 alloc_size = devices_info[i].max_avail;
1073 for (j = i + 1 - min_stripes; j <= i; j++)
1074 devices_info[j].max_avail -= alloc_size;
1075 }
1076 i--;
1077 nr_devices--;
1078 }
1079
1080 kfree(devices_info);
1081 *free_bytes = avail_space;
1082 return 0;
1083}
1084
1085static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf)
1086{
1087 struct btrfs_root *root = btrfs_sb(dentry->d_sb);
1088 struct btrfs_super_block *disk_super = &root->fs_info->super_copy;
1089 struct list_head *head = &root->fs_info->space_info;
1090 struct btrfs_space_info *found;
1091 u64 total_used = 0;
1092 u64 total_free_data = 0;
1093 int bits = dentry->d_sb->s_blocksize_bits;
1094 __be32 *fsid = (__be32 *)root->fs_info->fsid;
1095 int ret;
1096
1097 /* holding chunk_muext to avoid allocating new chunks */
1098 mutex_lock(&root->fs_info->chunk_mutex);
1099 rcu_read_lock();
1100 list_for_each_entry_rcu(found, head, list) {
1101 if (found->flags & BTRFS_BLOCK_GROUP_DATA) {
1102 total_free_data += found->disk_total - found->disk_used;
1103 total_free_data -=
1104 btrfs_account_ro_block_groups_free_space(found);
1105 }
1106
1107 total_used += found->disk_used;
1108 }
1109 rcu_read_unlock();
1110
1111 buf->f_namelen = BTRFS_NAME_LEN;
1112 buf->f_blocks = btrfs_super_total_bytes(disk_super) >> bits;
1113 buf->f_bfree = buf->f_blocks - (total_used >> bits);
1114 buf->f_bsize = dentry->d_sb->s_blocksize;
1115 buf->f_type = BTRFS_SUPER_MAGIC;
1116 buf->f_bavail = total_free_data;
1117 ret = btrfs_calc_avail_data_space(root, &total_free_data);
1118 if (ret) {
1119 mutex_unlock(&root->fs_info->chunk_mutex);
1120 return ret;
1121 }
1122 buf->f_bavail += total_free_data;
1123 buf->f_bavail = buf->f_bavail >> bits;
1124 mutex_unlock(&root->fs_info->chunk_mutex);
1125
1126 /* We treat it as constant endianness (it doesn't matter _which_)
1127 because we want the fsid to come out the same whether mounted
1128 on a big-endian or little-endian host */
1129 buf->f_fsid.val[0] = be32_to_cpu(fsid[0]) ^ be32_to_cpu(fsid[2]);
1130 buf->f_fsid.val[1] = be32_to_cpu(fsid[1]) ^ be32_to_cpu(fsid[3]);
1131 /* Mask in the root object ID too, to disambiguate subvols */
1132 buf->f_fsid.val[0] ^= BTRFS_I(dentry->d_inode)->root->objectid >> 32;
1133 buf->f_fsid.val[1] ^= BTRFS_I(dentry->d_inode)->root->objectid;
1134
1135 return 0;
1136}
1137
1138static struct file_system_type btrfs_fs_type = {
1139 .owner = THIS_MODULE,
1140 .name = "btrfs",
1141 .mount = btrfs_mount,
1142 .kill_sb = kill_anon_super,
1143 .fs_flags = FS_REQUIRES_DEV,
1144};
1145
1146/*
1147 * used by btrfsctl to scan devices when no FS is mounted
1148 */
1149static long btrfs_control_ioctl(struct file *file, unsigned int cmd,
1150 unsigned long arg)
1151{
1152 struct btrfs_ioctl_vol_args *vol;
1153 struct btrfs_fs_devices *fs_devices;
1154 int ret = -ENOTTY;
1155
1156 if (!capable(CAP_SYS_ADMIN))
1157 return -EPERM;
1158
1159 vol = memdup_user((void __user *)arg, sizeof(*vol));
1160 if (IS_ERR(vol))
1161 return PTR_ERR(vol);
1162
1163 switch (cmd) {
1164 case BTRFS_IOC_SCAN_DEV:
1165 ret = btrfs_scan_one_device(vol->name, FMODE_READ,
1166 &btrfs_fs_type, &fs_devices);
1167 break;
1168 }
1169
1170 kfree(vol);
1171 return ret;
1172}
1173
1174static int btrfs_freeze(struct super_block *sb)
1175{
1176 struct btrfs_root *root = btrfs_sb(sb);
1177 mutex_lock(&root->fs_info->transaction_kthread_mutex);
1178 mutex_lock(&root->fs_info->cleaner_mutex);
1179 return 0;
1180}
1181
1182static int btrfs_unfreeze(struct super_block *sb)
1183{
1184 struct btrfs_root *root = btrfs_sb(sb);
1185 mutex_unlock(&root->fs_info->cleaner_mutex);
1186 mutex_unlock(&root->fs_info->transaction_kthread_mutex);
1187 return 0;
1188}
1189
1190static const struct super_operations btrfs_super_ops = {
1191 .drop_inode = btrfs_drop_inode,
1192 .evict_inode = btrfs_evict_inode,
1193 .put_super = btrfs_put_super,
1194 .sync_fs = btrfs_sync_fs,
1195 .show_options = btrfs_show_options,
1196 .write_inode = btrfs_write_inode,
1197 .dirty_inode = btrfs_dirty_inode,
1198 .alloc_inode = btrfs_alloc_inode,
1199 .destroy_inode = btrfs_destroy_inode,
1200 .statfs = btrfs_statfs,
1201 .remount_fs = btrfs_remount,
1202 .freeze_fs = btrfs_freeze,
1203 .unfreeze_fs = btrfs_unfreeze,
1204};
1205
1206static const struct file_operations btrfs_ctl_fops = {
1207 .unlocked_ioctl = btrfs_control_ioctl,
1208 .compat_ioctl = btrfs_control_ioctl,
1209 .owner = THIS_MODULE,
1210 .llseek = noop_llseek,
1211};
1212
1213static struct miscdevice btrfs_misc = {
1214 .minor = BTRFS_MINOR,
1215 .name = "btrfs-control",
1216 .fops = &btrfs_ctl_fops
1217};
1218
1219MODULE_ALIAS_MISCDEV(BTRFS_MINOR);
1220MODULE_ALIAS("devname:btrfs-control");
1221
1222static int btrfs_interface_init(void)
1223{
1224 return misc_register(&btrfs_misc);
1225}
1226
1227static void btrfs_interface_exit(void)
1228{
1229 if (misc_deregister(&btrfs_misc) < 0)
1230 printk(KERN_INFO "misc_deregister failed for control device");
1231}
1232
1233static int __init init_btrfs_fs(void)
1234{
1235 int err;
1236
1237 err = btrfs_init_sysfs();
1238 if (err)
1239 return err;
1240
1241 err = btrfs_init_compress();
1242 if (err)
1243 goto free_sysfs;
1244
1245 err = btrfs_init_cachep();
1246 if (err)
1247 goto free_compress;
1248
1249 err = extent_io_init();
1250 if (err)
1251 goto free_cachep;
1252
1253 err = extent_map_init();
1254 if (err)
1255 goto free_extent_io;
1256
1257 err = btrfs_delayed_inode_init();
1258 if (err)
1259 goto free_extent_map;
1260
1261 err = btrfs_interface_init();
1262 if (err)
1263 goto free_delayed_inode;
1264
1265 err = register_filesystem(&btrfs_fs_type);
1266 if (err)
1267 goto unregister_ioctl;
1268
1269 printk(KERN_INFO "%s loaded\n", BTRFS_BUILD_VERSION);
1270 return 0;
1271
1272unregister_ioctl:
1273 btrfs_interface_exit();
1274free_delayed_inode:
1275 btrfs_delayed_inode_exit();
1276free_extent_map:
1277 extent_map_exit();
1278free_extent_io:
1279 extent_io_exit();
1280free_cachep:
1281 btrfs_destroy_cachep();
1282free_compress:
1283 btrfs_exit_compress();
1284free_sysfs:
1285 btrfs_exit_sysfs();
1286 return err;
1287}
1288
1289static void __exit exit_btrfs_fs(void)
1290{
1291 btrfs_destroy_cachep();
1292 btrfs_delayed_inode_exit();
1293 extent_map_exit();
1294 extent_io_exit();
1295 btrfs_interface_exit();
1296 unregister_filesystem(&btrfs_fs_type);
1297 btrfs_exit_sysfs();
1298 btrfs_cleanup_fs_uuids();
1299 btrfs_exit_compress();
1300}
1301
1302module_init(init_btrfs_fs)
1303module_exit(exit_btrfs_fs)
1304
1305MODULE_LICENSE("GPL");
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/blkdev.h>
20#include <linux/module.h>
21#include <linux/buffer_head.h>
22#include <linux/fs.h>
23#include <linux/pagemap.h>
24#include <linux/highmem.h>
25#include <linux/time.h>
26#include <linux/init.h>
27#include <linux/seq_file.h>
28#include <linux/string.h>
29#include <linux/backing-dev.h>
30#include <linux/mount.h>
31#include <linux/mpage.h>
32#include <linux/swap.h>
33#include <linux/writeback.h>
34#include <linux/statfs.h>
35#include <linux/compat.h>
36#include <linux/parser.h>
37#include <linux/ctype.h>
38#include <linux/namei.h>
39#include <linux/miscdevice.h>
40#include <linux/magic.h>
41#include <linux/slab.h>
42#include <linux/cleancache.h>
43#include <linux/ratelimit.h>
44#include "compat.h"
45#include "delayed-inode.h"
46#include "ctree.h"
47#include "disk-io.h"
48#include "transaction.h"
49#include "btrfs_inode.h"
50#include "ioctl.h"
51#include "print-tree.h"
52#include "xattr.h"
53#include "volumes.h"
54#include "version.h"
55#include "export.h"
56#include "compression.h"
57#include "rcu-string.h"
58
59#define CREATE_TRACE_POINTS
60#include <trace/events/btrfs.h>
61
62static const struct super_operations btrfs_super_ops;
63static struct file_system_type btrfs_fs_type;
64
65static const char *btrfs_decode_error(struct btrfs_fs_info *fs_info, int errno,
66 char nbuf[16])
67{
68 char *errstr = NULL;
69
70 switch (errno) {
71 case -EIO:
72 errstr = "IO failure";
73 break;
74 case -ENOMEM:
75 errstr = "Out of memory";
76 break;
77 case -EROFS:
78 errstr = "Readonly filesystem";
79 break;
80 case -EEXIST:
81 errstr = "Object already exists";
82 break;
83 default:
84 if (nbuf) {
85 if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
86 errstr = nbuf;
87 }
88 break;
89 }
90
91 return errstr;
92}
93
94static void __save_error_info(struct btrfs_fs_info *fs_info)
95{
96 /*
97 * today we only save the error info into ram. Long term we'll
98 * also send it down to the disk
99 */
100 fs_info->fs_state = BTRFS_SUPER_FLAG_ERROR;
101}
102
103/* NOTE:
104 * We move write_super stuff at umount in order to avoid deadlock
105 * for umount hold all lock.
106 */
107static void save_error_info(struct btrfs_fs_info *fs_info)
108{
109 __save_error_info(fs_info);
110}
111
112/* btrfs handle error by forcing the filesystem readonly */
113static void btrfs_handle_error(struct btrfs_fs_info *fs_info)
114{
115 struct super_block *sb = fs_info->sb;
116
117 if (sb->s_flags & MS_RDONLY)
118 return;
119
120 if (fs_info->fs_state & BTRFS_SUPER_FLAG_ERROR) {
121 sb->s_flags |= MS_RDONLY;
122 printk(KERN_INFO "btrfs is forced readonly\n");
123 __btrfs_scrub_cancel(fs_info);
124// WARN_ON(1);
125 }
126}
127
128/*
129 * __btrfs_std_error decodes expected errors from the caller and
130 * invokes the approciate error response.
131 */
132void __btrfs_std_error(struct btrfs_fs_info *fs_info, const char *function,
133 unsigned int line, int errno, const char *fmt, ...)
134{
135 struct super_block *sb = fs_info->sb;
136 char nbuf[16];
137 const char *errstr;
138 va_list args;
139 va_start(args, fmt);
140
141 /*
142 * Special case: if the error is EROFS, and we're already
143 * under MS_RDONLY, then it is safe here.
144 */
145 if (errno == -EROFS && (sb->s_flags & MS_RDONLY))
146 return;
147
148 errstr = btrfs_decode_error(fs_info, errno, nbuf);
149 if (fmt) {
150 struct va_format vaf = {
151 .fmt = fmt,
152 .va = &args,
153 };
154
155 printk(KERN_CRIT "BTRFS error (device %s) in %s:%d: %s (%pV)\n",
156 sb->s_id, function, line, errstr, &vaf);
157 } else {
158 printk(KERN_CRIT "BTRFS error (device %s) in %s:%d: %s\n",
159 sb->s_id, function, line, errstr);
160 }
161
162 /* Don't go through full error handling during mount */
163 if (sb->s_flags & MS_BORN) {
164 save_error_info(fs_info);
165 btrfs_handle_error(fs_info);
166 }
167 va_end(args);
168}
169
170const char *logtypes[] = {
171 "emergency",
172 "alert",
173 "critical",
174 "error",
175 "warning",
176 "notice",
177 "info",
178 "debug",
179};
180
181void btrfs_printk(struct btrfs_fs_info *fs_info, const char *fmt, ...)
182{
183 struct super_block *sb = fs_info->sb;
184 char lvl[4];
185 struct va_format vaf;
186 va_list args;
187 const char *type = logtypes[4];
188
189 va_start(args, fmt);
190
191 if (fmt[0] == '<' && isdigit(fmt[1]) && fmt[2] == '>') {
192 memcpy(lvl, fmt, 3);
193 lvl[3] = '\0';
194 fmt += 3;
195 type = logtypes[fmt[1] - '0'];
196 } else
197 *lvl = '\0';
198
199 vaf.fmt = fmt;
200 vaf.va = &args;
201 printk("%sBTRFS %s (device %s): %pV", lvl, type, sb->s_id, &vaf);
202}
203
204/*
205 * We only mark the transaction aborted and then set the file system read-only.
206 * This will prevent new transactions from starting or trying to join this
207 * one.
208 *
209 * This means that error recovery at the call site is limited to freeing
210 * any local memory allocations and passing the error code up without
211 * further cleanup. The transaction should complete as it normally would
212 * in the call path but will return -EIO.
213 *
214 * We'll complete the cleanup in btrfs_end_transaction and
215 * btrfs_commit_transaction.
216 */
217void __btrfs_abort_transaction(struct btrfs_trans_handle *trans,
218 struct btrfs_root *root, const char *function,
219 unsigned int line, int errno)
220{
221 WARN_ONCE(1, KERN_DEBUG "btrfs: Transaction aborted");
222 trans->aborted = errno;
223 /* Nothing used. The other threads that have joined this
224 * transaction may be able to continue. */
225 if (!trans->blocks_used) {
226 btrfs_printk(root->fs_info, "Aborting unused transaction.\n");
227 return;
228 }
229 trans->transaction->aborted = errno;
230 __btrfs_std_error(root->fs_info, function, line, errno, NULL);
231}
232/*
233 * __btrfs_panic decodes unexpected, fatal errors from the caller,
234 * issues an alert, and either panics or BUGs, depending on mount options.
235 */
236void __btrfs_panic(struct btrfs_fs_info *fs_info, const char *function,
237 unsigned int line, int errno, const char *fmt, ...)
238{
239 char nbuf[16];
240 char *s_id = "<unknown>";
241 const char *errstr;
242 struct va_format vaf = { .fmt = fmt };
243 va_list args;
244
245 if (fs_info)
246 s_id = fs_info->sb->s_id;
247
248 va_start(args, fmt);
249 vaf.va = &args;
250
251 errstr = btrfs_decode_error(fs_info, errno, nbuf);
252 if (fs_info->mount_opt & BTRFS_MOUNT_PANIC_ON_FATAL_ERROR)
253 panic(KERN_CRIT "BTRFS panic (device %s) in %s:%d: %pV (%s)\n",
254 s_id, function, line, &vaf, errstr);
255
256 printk(KERN_CRIT "BTRFS panic (device %s) in %s:%d: %pV (%s)\n",
257 s_id, function, line, &vaf, errstr);
258 va_end(args);
259 /* Caller calls BUG() */
260}
261
262static void btrfs_put_super(struct super_block *sb)
263{
264 (void)close_ctree(btrfs_sb(sb)->tree_root);
265 /* FIXME: need to fix VFS to return error? */
266 /* AV: return it _where_? ->put_super() can be triggered by any number
267 * of async events, up to and including delivery of SIGKILL to the
268 * last process that kept it busy. Or segfault in the aforementioned
269 * process... Whom would you report that to?
270 */
271}
272
273enum {
274 Opt_degraded, Opt_subvol, Opt_subvolid, Opt_device, Opt_nodatasum,
275 Opt_nodatacow, Opt_max_inline, Opt_alloc_start, Opt_nobarrier, Opt_ssd,
276 Opt_nossd, Opt_ssd_spread, Opt_thread_pool, Opt_noacl, Opt_compress,
277 Opt_compress_type, Opt_compress_force, Opt_compress_force_type,
278 Opt_notreelog, Opt_ratio, Opt_flushoncommit, Opt_discard,
279 Opt_space_cache, Opt_clear_cache, Opt_user_subvol_rm_allowed,
280 Opt_enospc_debug, Opt_subvolrootid, Opt_defrag, Opt_inode_cache,
281 Opt_no_space_cache, Opt_recovery, Opt_skip_balance,
282 Opt_check_integrity, Opt_check_integrity_including_extent_data,
283 Opt_check_integrity_print_mask, Opt_fatal_errors,
284 Opt_err,
285};
286
287static match_table_t tokens = {
288 {Opt_degraded, "degraded"},
289 {Opt_subvol, "subvol=%s"},
290 {Opt_subvolid, "subvolid=%d"},
291 {Opt_device, "device=%s"},
292 {Opt_nodatasum, "nodatasum"},
293 {Opt_nodatacow, "nodatacow"},
294 {Opt_nobarrier, "nobarrier"},
295 {Opt_max_inline, "max_inline=%s"},
296 {Opt_alloc_start, "alloc_start=%s"},
297 {Opt_thread_pool, "thread_pool=%d"},
298 {Opt_compress, "compress"},
299 {Opt_compress_type, "compress=%s"},
300 {Opt_compress_force, "compress-force"},
301 {Opt_compress_force_type, "compress-force=%s"},
302 {Opt_ssd, "ssd"},
303 {Opt_ssd_spread, "ssd_spread"},
304 {Opt_nossd, "nossd"},
305 {Opt_noacl, "noacl"},
306 {Opt_notreelog, "notreelog"},
307 {Opt_flushoncommit, "flushoncommit"},
308 {Opt_ratio, "metadata_ratio=%d"},
309 {Opt_discard, "discard"},
310 {Opt_space_cache, "space_cache"},
311 {Opt_clear_cache, "clear_cache"},
312 {Opt_user_subvol_rm_allowed, "user_subvol_rm_allowed"},
313 {Opt_enospc_debug, "enospc_debug"},
314 {Opt_subvolrootid, "subvolrootid=%d"},
315 {Opt_defrag, "autodefrag"},
316 {Opt_inode_cache, "inode_cache"},
317 {Opt_no_space_cache, "nospace_cache"},
318 {Opt_recovery, "recovery"},
319 {Opt_skip_balance, "skip_balance"},
320 {Opt_check_integrity, "check_int"},
321 {Opt_check_integrity_including_extent_data, "check_int_data"},
322 {Opt_check_integrity_print_mask, "check_int_print_mask=%d"},
323 {Opt_fatal_errors, "fatal_errors=%s"},
324 {Opt_err, NULL},
325};
326
327/*
328 * Regular mount options parser. Everything that is needed only when
329 * reading in a new superblock is parsed here.
330 * XXX JDM: This needs to be cleaned up for remount.
331 */
332int btrfs_parse_options(struct btrfs_root *root, char *options)
333{
334 struct btrfs_fs_info *info = root->fs_info;
335 substring_t args[MAX_OPT_ARGS];
336 char *p, *num, *orig = NULL;
337 u64 cache_gen;
338 int intarg;
339 int ret = 0;
340 char *compress_type;
341 bool compress_force = false;
342
343 cache_gen = btrfs_super_cache_generation(root->fs_info->super_copy);
344 if (cache_gen)
345 btrfs_set_opt(info->mount_opt, SPACE_CACHE);
346
347 if (!options)
348 goto out;
349
350 /*
351 * strsep changes the string, duplicate it because parse_options
352 * gets called twice
353 */
354 options = kstrdup(options, GFP_NOFS);
355 if (!options)
356 return -ENOMEM;
357
358 orig = options;
359
360 while ((p = strsep(&options, ",")) != NULL) {
361 int token;
362 if (!*p)
363 continue;
364
365 token = match_token(p, tokens, args);
366 switch (token) {
367 case Opt_degraded:
368 printk(KERN_INFO "btrfs: allowing degraded mounts\n");
369 btrfs_set_opt(info->mount_opt, DEGRADED);
370 break;
371 case Opt_subvol:
372 case Opt_subvolid:
373 case Opt_subvolrootid:
374 case Opt_device:
375 /*
376 * These are parsed by btrfs_parse_early_options
377 * and can be happily ignored here.
378 */
379 break;
380 case Opt_nodatasum:
381 printk(KERN_INFO "btrfs: setting nodatasum\n");
382 btrfs_set_opt(info->mount_opt, NODATASUM);
383 break;
384 case Opt_nodatacow:
385 printk(KERN_INFO "btrfs: setting nodatacow\n");
386 btrfs_set_opt(info->mount_opt, NODATACOW);
387 btrfs_set_opt(info->mount_opt, NODATASUM);
388 break;
389 case Opt_compress_force:
390 case Opt_compress_force_type:
391 compress_force = true;
392 case Opt_compress:
393 case Opt_compress_type:
394 if (token == Opt_compress ||
395 token == Opt_compress_force ||
396 strcmp(args[0].from, "zlib") == 0) {
397 compress_type = "zlib";
398 info->compress_type = BTRFS_COMPRESS_ZLIB;
399 } else if (strcmp(args[0].from, "lzo") == 0) {
400 compress_type = "lzo";
401 info->compress_type = BTRFS_COMPRESS_LZO;
402 } else {
403 ret = -EINVAL;
404 goto out;
405 }
406
407 btrfs_set_opt(info->mount_opt, COMPRESS);
408 if (compress_force) {
409 btrfs_set_opt(info->mount_opt, FORCE_COMPRESS);
410 pr_info("btrfs: force %s compression\n",
411 compress_type);
412 } else
413 pr_info("btrfs: use %s compression\n",
414 compress_type);
415 break;
416 case Opt_ssd:
417 printk(KERN_INFO "btrfs: use ssd allocation scheme\n");
418 btrfs_set_opt(info->mount_opt, SSD);
419 break;
420 case Opt_ssd_spread:
421 printk(KERN_INFO "btrfs: use spread ssd "
422 "allocation scheme\n");
423 btrfs_set_opt(info->mount_opt, SSD);
424 btrfs_set_opt(info->mount_opt, SSD_SPREAD);
425 break;
426 case Opt_nossd:
427 printk(KERN_INFO "btrfs: not using ssd allocation "
428 "scheme\n");
429 btrfs_set_opt(info->mount_opt, NOSSD);
430 btrfs_clear_opt(info->mount_opt, SSD);
431 btrfs_clear_opt(info->mount_opt, SSD_SPREAD);
432 break;
433 case Opt_nobarrier:
434 printk(KERN_INFO "btrfs: turning off barriers\n");
435 btrfs_set_opt(info->mount_opt, NOBARRIER);
436 break;
437 case Opt_thread_pool:
438 intarg = 0;
439 match_int(&args[0], &intarg);
440 if (intarg)
441 info->thread_pool_size = intarg;
442 break;
443 case Opt_max_inline:
444 num = match_strdup(&args[0]);
445 if (num) {
446 info->max_inline = memparse(num, NULL);
447 kfree(num);
448
449 if (info->max_inline) {
450 info->max_inline = max_t(u64,
451 info->max_inline,
452 root->sectorsize);
453 }
454 printk(KERN_INFO "btrfs: max_inline at %llu\n",
455 (unsigned long long)info->max_inline);
456 }
457 break;
458 case Opt_alloc_start:
459 num = match_strdup(&args[0]);
460 if (num) {
461 info->alloc_start = memparse(num, NULL);
462 kfree(num);
463 printk(KERN_INFO
464 "btrfs: allocations start at %llu\n",
465 (unsigned long long)info->alloc_start);
466 }
467 break;
468 case Opt_noacl:
469 root->fs_info->sb->s_flags &= ~MS_POSIXACL;
470 break;
471 case Opt_notreelog:
472 printk(KERN_INFO "btrfs: disabling tree log\n");
473 btrfs_set_opt(info->mount_opt, NOTREELOG);
474 break;
475 case Opt_flushoncommit:
476 printk(KERN_INFO "btrfs: turning on flush-on-commit\n");
477 btrfs_set_opt(info->mount_opt, FLUSHONCOMMIT);
478 break;
479 case Opt_ratio:
480 intarg = 0;
481 match_int(&args[0], &intarg);
482 if (intarg) {
483 info->metadata_ratio = intarg;
484 printk(KERN_INFO "btrfs: metadata ratio %d\n",
485 info->metadata_ratio);
486 }
487 break;
488 case Opt_discard:
489 btrfs_set_opt(info->mount_opt, DISCARD);
490 break;
491 case Opt_space_cache:
492 btrfs_set_opt(info->mount_opt, SPACE_CACHE);
493 break;
494 case Opt_no_space_cache:
495 printk(KERN_INFO "btrfs: disabling disk space caching\n");
496 btrfs_clear_opt(info->mount_opt, SPACE_CACHE);
497 break;
498 case Opt_inode_cache:
499 printk(KERN_INFO "btrfs: enabling inode map caching\n");
500 btrfs_set_opt(info->mount_opt, INODE_MAP_CACHE);
501 break;
502 case Opt_clear_cache:
503 printk(KERN_INFO "btrfs: force clearing of disk cache\n");
504 btrfs_set_opt(info->mount_opt, CLEAR_CACHE);
505 break;
506 case Opt_user_subvol_rm_allowed:
507 btrfs_set_opt(info->mount_opt, USER_SUBVOL_RM_ALLOWED);
508 break;
509 case Opt_enospc_debug:
510 btrfs_set_opt(info->mount_opt, ENOSPC_DEBUG);
511 break;
512 case Opt_defrag:
513 printk(KERN_INFO "btrfs: enabling auto defrag");
514 btrfs_set_opt(info->mount_opt, AUTO_DEFRAG);
515 break;
516 case Opt_recovery:
517 printk(KERN_INFO "btrfs: enabling auto recovery");
518 btrfs_set_opt(info->mount_opt, RECOVERY);
519 break;
520 case Opt_skip_balance:
521 btrfs_set_opt(info->mount_opt, SKIP_BALANCE);
522 break;
523#ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
524 case Opt_check_integrity_including_extent_data:
525 printk(KERN_INFO "btrfs: enabling check integrity"
526 " including extent data\n");
527 btrfs_set_opt(info->mount_opt,
528 CHECK_INTEGRITY_INCLUDING_EXTENT_DATA);
529 btrfs_set_opt(info->mount_opt, CHECK_INTEGRITY);
530 break;
531 case Opt_check_integrity:
532 printk(KERN_INFO "btrfs: enabling check integrity\n");
533 btrfs_set_opt(info->mount_opt, CHECK_INTEGRITY);
534 break;
535 case Opt_check_integrity_print_mask:
536 intarg = 0;
537 match_int(&args[0], &intarg);
538 if (intarg) {
539 info->check_integrity_print_mask = intarg;
540 printk(KERN_INFO "btrfs:"
541 " check_integrity_print_mask 0x%x\n",
542 info->check_integrity_print_mask);
543 }
544 break;
545#else
546 case Opt_check_integrity_including_extent_data:
547 case Opt_check_integrity:
548 case Opt_check_integrity_print_mask:
549 printk(KERN_ERR "btrfs: support for check_integrity*"
550 " not compiled in!\n");
551 ret = -EINVAL;
552 goto out;
553#endif
554 case Opt_fatal_errors:
555 if (strcmp(args[0].from, "panic") == 0)
556 btrfs_set_opt(info->mount_opt,
557 PANIC_ON_FATAL_ERROR);
558 else if (strcmp(args[0].from, "bug") == 0)
559 btrfs_clear_opt(info->mount_opt,
560 PANIC_ON_FATAL_ERROR);
561 else {
562 ret = -EINVAL;
563 goto out;
564 }
565 break;
566 case Opt_err:
567 printk(KERN_INFO "btrfs: unrecognized mount option "
568 "'%s'\n", p);
569 ret = -EINVAL;
570 goto out;
571 default:
572 break;
573 }
574 }
575out:
576 if (!ret && btrfs_test_opt(root, SPACE_CACHE))
577 printk(KERN_INFO "btrfs: disk space caching is enabled\n");
578 kfree(orig);
579 return ret;
580}
581
582/*
583 * Parse mount options that are required early in the mount process.
584 *
585 * All other options will be parsed on much later in the mount process and
586 * only when we need to allocate a new super block.
587 */
588static int btrfs_parse_early_options(const char *options, fmode_t flags,
589 void *holder, char **subvol_name, u64 *subvol_objectid,
590 u64 *subvol_rootid, struct btrfs_fs_devices **fs_devices)
591{
592 substring_t args[MAX_OPT_ARGS];
593 char *device_name, *opts, *orig, *p;
594 int error = 0;
595 int intarg;
596
597 if (!options)
598 return 0;
599
600 /*
601 * strsep changes the string, duplicate it because parse_options
602 * gets called twice
603 */
604 opts = kstrdup(options, GFP_KERNEL);
605 if (!opts)
606 return -ENOMEM;
607 orig = opts;
608
609 while ((p = strsep(&opts, ",")) != NULL) {
610 int token;
611 if (!*p)
612 continue;
613
614 token = match_token(p, tokens, args);
615 switch (token) {
616 case Opt_subvol:
617 kfree(*subvol_name);
618 *subvol_name = match_strdup(&args[0]);
619 break;
620 case Opt_subvolid:
621 intarg = 0;
622 error = match_int(&args[0], &intarg);
623 if (!error) {
624 /* we want the original fs_tree */
625 if (!intarg)
626 *subvol_objectid =
627 BTRFS_FS_TREE_OBJECTID;
628 else
629 *subvol_objectid = intarg;
630 }
631 break;
632 case Opt_subvolrootid:
633 intarg = 0;
634 error = match_int(&args[0], &intarg);
635 if (!error) {
636 /* we want the original fs_tree */
637 if (!intarg)
638 *subvol_rootid =
639 BTRFS_FS_TREE_OBJECTID;
640 else
641 *subvol_rootid = intarg;
642 }
643 break;
644 case Opt_device:
645 device_name = match_strdup(&args[0]);
646 if (!device_name) {
647 error = -ENOMEM;
648 goto out;
649 }
650 error = btrfs_scan_one_device(device_name,
651 flags, holder, fs_devices);
652 kfree(device_name);
653 if (error)
654 goto out;
655 break;
656 default:
657 break;
658 }
659 }
660
661out:
662 kfree(orig);
663 return error;
664}
665
666static struct dentry *get_default_root(struct super_block *sb,
667 u64 subvol_objectid)
668{
669 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
670 struct btrfs_root *root = fs_info->tree_root;
671 struct btrfs_root *new_root;
672 struct btrfs_dir_item *di;
673 struct btrfs_path *path;
674 struct btrfs_key location;
675 struct inode *inode;
676 u64 dir_id;
677 int new = 0;
678
679 /*
680 * We have a specific subvol we want to mount, just setup location and
681 * go look up the root.
682 */
683 if (subvol_objectid) {
684 location.objectid = subvol_objectid;
685 location.type = BTRFS_ROOT_ITEM_KEY;
686 location.offset = (u64)-1;
687 goto find_root;
688 }
689
690 path = btrfs_alloc_path();
691 if (!path)
692 return ERR_PTR(-ENOMEM);
693 path->leave_spinning = 1;
694
695 /*
696 * Find the "default" dir item which points to the root item that we
697 * will mount by default if we haven't been given a specific subvolume
698 * to mount.
699 */
700 dir_id = btrfs_super_root_dir(fs_info->super_copy);
701 di = btrfs_lookup_dir_item(NULL, root, path, dir_id, "default", 7, 0);
702 if (IS_ERR(di)) {
703 btrfs_free_path(path);
704 return ERR_CAST(di);
705 }
706 if (!di) {
707 /*
708 * Ok the default dir item isn't there. This is weird since
709 * it's always been there, but don't freak out, just try and
710 * mount to root most subvolume.
711 */
712 btrfs_free_path(path);
713 dir_id = BTRFS_FIRST_FREE_OBJECTID;
714 new_root = fs_info->fs_root;
715 goto setup_root;
716 }
717
718 btrfs_dir_item_key_to_cpu(path->nodes[0], di, &location);
719 btrfs_free_path(path);
720
721find_root:
722 new_root = btrfs_read_fs_root_no_name(fs_info, &location);
723 if (IS_ERR(new_root))
724 return ERR_CAST(new_root);
725
726 if (btrfs_root_refs(&new_root->root_item) == 0)
727 return ERR_PTR(-ENOENT);
728
729 dir_id = btrfs_root_dirid(&new_root->root_item);
730setup_root:
731 location.objectid = dir_id;
732 location.type = BTRFS_INODE_ITEM_KEY;
733 location.offset = 0;
734
735 inode = btrfs_iget(sb, &location, new_root, &new);
736 if (IS_ERR(inode))
737 return ERR_CAST(inode);
738
739 /*
740 * If we're just mounting the root most subvol put the inode and return
741 * a reference to the dentry. We will have already gotten a reference
742 * to the inode in btrfs_fill_super so we're good to go.
743 */
744 if (!new && sb->s_root->d_inode == inode) {
745 iput(inode);
746 return dget(sb->s_root);
747 }
748
749 return d_obtain_alias(inode);
750}
751
752static int btrfs_fill_super(struct super_block *sb,
753 struct btrfs_fs_devices *fs_devices,
754 void *data, int silent)
755{
756 struct inode *inode;
757 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
758 struct btrfs_key key;
759 int err;
760
761 sb->s_maxbytes = MAX_LFS_FILESIZE;
762 sb->s_magic = BTRFS_SUPER_MAGIC;
763 sb->s_op = &btrfs_super_ops;
764 sb->s_d_op = &btrfs_dentry_operations;
765 sb->s_export_op = &btrfs_export_ops;
766 sb->s_xattr = btrfs_xattr_handlers;
767 sb->s_time_gran = 1;
768#ifdef CONFIG_BTRFS_FS_POSIX_ACL
769 sb->s_flags |= MS_POSIXACL;
770#endif
771 sb->s_flags |= MS_I_VERSION;
772 err = open_ctree(sb, fs_devices, (char *)data);
773 if (err) {
774 printk("btrfs: open_ctree failed\n");
775 return err;
776 }
777
778 key.objectid = BTRFS_FIRST_FREE_OBJECTID;
779 key.type = BTRFS_INODE_ITEM_KEY;
780 key.offset = 0;
781 inode = btrfs_iget(sb, &key, fs_info->fs_root, NULL);
782 if (IS_ERR(inode)) {
783 err = PTR_ERR(inode);
784 goto fail_close;
785 }
786
787 sb->s_root = d_make_root(inode);
788 if (!sb->s_root) {
789 err = -ENOMEM;
790 goto fail_close;
791 }
792
793 save_mount_options(sb, data);
794 cleancache_init_fs(sb);
795 sb->s_flags |= MS_ACTIVE;
796 return 0;
797
798fail_close:
799 close_ctree(fs_info->tree_root);
800 return err;
801}
802
803int btrfs_sync_fs(struct super_block *sb, int wait)
804{
805 struct btrfs_trans_handle *trans;
806 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
807 struct btrfs_root *root = fs_info->tree_root;
808 int ret;
809
810 trace_btrfs_sync_fs(wait);
811
812 if (!wait) {
813 filemap_flush(fs_info->btree_inode->i_mapping);
814 return 0;
815 }
816
817 btrfs_wait_ordered_extents(root, 0, 0);
818
819 trans = btrfs_start_transaction(root, 0);
820 if (IS_ERR(trans))
821 return PTR_ERR(trans);
822 ret = btrfs_commit_transaction(trans, root);
823 return ret;
824}
825
826static int btrfs_show_options(struct seq_file *seq, struct dentry *dentry)
827{
828 struct btrfs_fs_info *info = btrfs_sb(dentry->d_sb);
829 struct btrfs_root *root = info->tree_root;
830 char *compress_type;
831
832 if (btrfs_test_opt(root, DEGRADED))
833 seq_puts(seq, ",degraded");
834 if (btrfs_test_opt(root, NODATASUM))
835 seq_puts(seq, ",nodatasum");
836 if (btrfs_test_opt(root, NODATACOW))
837 seq_puts(seq, ",nodatacow");
838 if (btrfs_test_opt(root, NOBARRIER))
839 seq_puts(seq, ",nobarrier");
840 if (info->max_inline != 8192 * 1024)
841 seq_printf(seq, ",max_inline=%llu",
842 (unsigned long long)info->max_inline);
843 if (info->alloc_start != 0)
844 seq_printf(seq, ",alloc_start=%llu",
845 (unsigned long long)info->alloc_start);
846 if (info->thread_pool_size != min_t(unsigned long,
847 num_online_cpus() + 2, 8))
848 seq_printf(seq, ",thread_pool=%d", info->thread_pool_size);
849 if (btrfs_test_opt(root, COMPRESS)) {
850 if (info->compress_type == BTRFS_COMPRESS_ZLIB)
851 compress_type = "zlib";
852 else
853 compress_type = "lzo";
854 if (btrfs_test_opt(root, FORCE_COMPRESS))
855 seq_printf(seq, ",compress-force=%s", compress_type);
856 else
857 seq_printf(seq, ",compress=%s", compress_type);
858 }
859 if (btrfs_test_opt(root, NOSSD))
860 seq_puts(seq, ",nossd");
861 if (btrfs_test_opt(root, SSD_SPREAD))
862 seq_puts(seq, ",ssd_spread");
863 else if (btrfs_test_opt(root, SSD))
864 seq_puts(seq, ",ssd");
865 if (btrfs_test_opt(root, NOTREELOG))
866 seq_puts(seq, ",notreelog");
867 if (btrfs_test_opt(root, FLUSHONCOMMIT))
868 seq_puts(seq, ",flushoncommit");
869 if (btrfs_test_opt(root, DISCARD))
870 seq_puts(seq, ",discard");
871 if (!(root->fs_info->sb->s_flags & MS_POSIXACL))
872 seq_puts(seq, ",noacl");
873 if (btrfs_test_opt(root, SPACE_CACHE))
874 seq_puts(seq, ",space_cache");
875 else
876 seq_puts(seq, ",nospace_cache");
877 if (btrfs_test_opt(root, CLEAR_CACHE))
878 seq_puts(seq, ",clear_cache");
879 if (btrfs_test_opt(root, USER_SUBVOL_RM_ALLOWED))
880 seq_puts(seq, ",user_subvol_rm_allowed");
881 if (btrfs_test_opt(root, ENOSPC_DEBUG))
882 seq_puts(seq, ",enospc_debug");
883 if (btrfs_test_opt(root, AUTO_DEFRAG))
884 seq_puts(seq, ",autodefrag");
885 if (btrfs_test_opt(root, INODE_MAP_CACHE))
886 seq_puts(seq, ",inode_cache");
887 if (btrfs_test_opt(root, SKIP_BALANCE))
888 seq_puts(seq, ",skip_balance");
889 if (btrfs_test_opt(root, PANIC_ON_FATAL_ERROR))
890 seq_puts(seq, ",fatal_errors=panic");
891 return 0;
892}
893
894static int btrfs_test_super(struct super_block *s, void *data)
895{
896 struct btrfs_fs_info *p = data;
897 struct btrfs_fs_info *fs_info = btrfs_sb(s);
898
899 return fs_info->fs_devices == p->fs_devices;
900}
901
902static int btrfs_set_super(struct super_block *s, void *data)
903{
904 int err = set_anon_super(s, data);
905 if (!err)
906 s->s_fs_info = data;
907 return err;
908}
909
910/*
911 * subvolumes are identified by ino 256
912 */
913static inline int is_subvolume_inode(struct inode *inode)
914{
915 if (inode && inode->i_ino == BTRFS_FIRST_FREE_OBJECTID)
916 return 1;
917 return 0;
918}
919
920/*
921 * This will strip out the subvol=%s argument for an argument string and add
922 * subvolid=0 to make sure we get the actual tree root for path walking to the
923 * subvol we want.
924 */
925static char *setup_root_args(char *args)
926{
927 unsigned len = strlen(args) + 2 + 1;
928 char *src, *dst, *buf;
929
930 /*
931 * We need the same args as before, but with this substitution:
932 * s!subvol=[^,]+!subvolid=0!
933 *
934 * Since the replacement string is up to 2 bytes longer than the
935 * original, allocate strlen(args) + 2 + 1 bytes.
936 */
937
938 src = strstr(args, "subvol=");
939 /* This shouldn't happen, but just in case.. */
940 if (!src)
941 return NULL;
942
943 buf = dst = kmalloc(len, GFP_NOFS);
944 if (!buf)
945 return NULL;
946
947 /*
948 * If the subvol= arg is not at the start of the string,
949 * copy whatever precedes it into buf.
950 */
951 if (src != args) {
952 *src++ = '\0';
953 strcpy(buf, args);
954 dst += strlen(args);
955 }
956
957 strcpy(dst, "subvolid=0");
958 dst += strlen("subvolid=0");
959
960 /*
961 * If there is a "," after the original subvol=... string,
962 * copy that suffix into our buffer. Otherwise, we're done.
963 */
964 src = strchr(src, ',');
965 if (src)
966 strcpy(dst, src);
967
968 return buf;
969}
970
971static struct dentry *mount_subvol(const char *subvol_name, int flags,
972 const char *device_name, char *data)
973{
974 struct dentry *root;
975 struct vfsmount *mnt;
976 char *newargs;
977
978 newargs = setup_root_args(data);
979 if (!newargs)
980 return ERR_PTR(-ENOMEM);
981 mnt = vfs_kern_mount(&btrfs_fs_type, flags, device_name,
982 newargs);
983 kfree(newargs);
984 if (IS_ERR(mnt))
985 return ERR_CAST(mnt);
986
987 root = mount_subtree(mnt, subvol_name);
988
989 if (!IS_ERR(root) && !is_subvolume_inode(root->d_inode)) {
990 struct super_block *s = root->d_sb;
991 dput(root);
992 root = ERR_PTR(-EINVAL);
993 deactivate_locked_super(s);
994 printk(KERN_ERR "btrfs: '%s' is not a valid subvolume\n",
995 subvol_name);
996 }
997
998 return root;
999}
1000
1001/*
1002 * Find a superblock for the given device / mount point.
1003 *
1004 * Note: This is based on get_sb_bdev from fs/super.c with a few additions
1005 * for multiple device setup. Make sure to keep it in sync.
1006 */
1007static struct dentry *btrfs_mount(struct file_system_type *fs_type, int flags,
1008 const char *device_name, void *data)
1009{
1010 struct block_device *bdev = NULL;
1011 struct super_block *s;
1012 struct dentry *root;
1013 struct btrfs_fs_devices *fs_devices = NULL;
1014 struct btrfs_fs_info *fs_info = NULL;
1015 fmode_t mode = FMODE_READ;
1016 char *subvol_name = NULL;
1017 u64 subvol_objectid = 0;
1018 u64 subvol_rootid = 0;
1019 int error = 0;
1020
1021 if (!(flags & MS_RDONLY))
1022 mode |= FMODE_WRITE;
1023
1024 error = btrfs_parse_early_options(data, mode, fs_type,
1025 &subvol_name, &subvol_objectid,
1026 &subvol_rootid, &fs_devices);
1027 if (error) {
1028 kfree(subvol_name);
1029 return ERR_PTR(error);
1030 }
1031
1032 if (subvol_name) {
1033 root = mount_subvol(subvol_name, flags, device_name, data);
1034 kfree(subvol_name);
1035 return root;
1036 }
1037
1038 error = btrfs_scan_one_device(device_name, mode, fs_type, &fs_devices);
1039 if (error)
1040 return ERR_PTR(error);
1041
1042 /*
1043 * Setup a dummy root and fs_info for test/set super. This is because
1044 * we don't actually fill this stuff out until open_ctree, but we need
1045 * it for searching for existing supers, so this lets us do that and
1046 * then open_ctree will properly initialize everything later.
1047 */
1048 fs_info = kzalloc(sizeof(struct btrfs_fs_info), GFP_NOFS);
1049 if (!fs_info)
1050 return ERR_PTR(-ENOMEM);
1051
1052 fs_info->fs_devices = fs_devices;
1053
1054 fs_info->super_copy = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_NOFS);
1055 fs_info->super_for_commit = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_NOFS);
1056 if (!fs_info->super_copy || !fs_info->super_for_commit) {
1057 error = -ENOMEM;
1058 goto error_fs_info;
1059 }
1060
1061 error = btrfs_open_devices(fs_devices, mode, fs_type);
1062 if (error)
1063 goto error_fs_info;
1064
1065 if (!(flags & MS_RDONLY) && fs_devices->rw_devices == 0) {
1066 error = -EACCES;
1067 goto error_close_devices;
1068 }
1069
1070 bdev = fs_devices->latest_bdev;
1071 s = sget(fs_type, btrfs_test_super, btrfs_set_super, fs_info);
1072 if (IS_ERR(s)) {
1073 error = PTR_ERR(s);
1074 goto error_close_devices;
1075 }
1076
1077 if (s->s_root) {
1078 btrfs_close_devices(fs_devices);
1079 free_fs_info(fs_info);
1080 if ((flags ^ s->s_flags) & MS_RDONLY)
1081 error = -EBUSY;
1082 } else {
1083 char b[BDEVNAME_SIZE];
1084
1085 s->s_flags = flags | MS_NOSEC;
1086 strlcpy(s->s_id, bdevname(bdev, b), sizeof(s->s_id));
1087 btrfs_sb(s)->bdev_holder = fs_type;
1088 error = btrfs_fill_super(s, fs_devices, data,
1089 flags & MS_SILENT ? 1 : 0);
1090 }
1091
1092 root = !error ? get_default_root(s, subvol_objectid) : ERR_PTR(error);
1093 if (IS_ERR(root))
1094 deactivate_locked_super(s);
1095
1096 return root;
1097
1098error_close_devices:
1099 btrfs_close_devices(fs_devices);
1100error_fs_info:
1101 free_fs_info(fs_info);
1102 return ERR_PTR(error);
1103}
1104
1105static void btrfs_set_max_workers(struct btrfs_workers *workers, int new_limit)
1106{
1107 spin_lock_irq(&workers->lock);
1108 workers->max_workers = new_limit;
1109 spin_unlock_irq(&workers->lock);
1110}
1111
1112static void btrfs_resize_thread_pool(struct btrfs_fs_info *fs_info,
1113 int new_pool_size, int old_pool_size)
1114{
1115 if (new_pool_size == old_pool_size)
1116 return;
1117
1118 fs_info->thread_pool_size = new_pool_size;
1119
1120 printk(KERN_INFO "btrfs: resize thread pool %d -> %d\n",
1121 old_pool_size, new_pool_size);
1122
1123 btrfs_set_max_workers(&fs_info->generic_worker, new_pool_size);
1124 btrfs_set_max_workers(&fs_info->workers, new_pool_size);
1125 btrfs_set_max_workers(&fs_info->delalloc_workers, new_pool_size);
1126 btrfs_set_max_workers(&fs_info->submit_workers, new_pool_size);
1127 btrfs_set_max_workers(&fs_info->caching_workers, new_pool_size);
1128 btrfs_set_max_workers(&fs_info->fixup_workers, new_pool_size);
1129 btrfs_set_max_workers(&fs_info->endio_workers, new_pool_size);
1130 btrfs_set_max_workers(&fs_info->endio_meta_workers, new_pool_size);
1131 btrfs_set_max_workers(&fs_info->endio_meta_write_workers, new_pool_size);
1132 btrfs_set_max_workers(&fs_info->endio_write_workers, new_pool_size);
1133 btrfs_set_max_workers(&fs_info->endio_freespace_worker, new_pool_size);
1134 btrfs_set_max_workers(&fs_info->delayed_workers, new_pool_size);
1135 btrfs_set_max_workers(&fs_info->readahead_workers, new_pool_size);
1136 btrfs_set_max_workers(&fs_info->scrub_workers, new_pool_size);
1137}
1138
1139static int btrfs_remount(struct super_block *sb, int *flags, char *data)
1140{
1141 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
1142 struct btrfs_root *root = fs_info->tree_root;
1143 unsigned old_flags = sb->s_flags;
1144 unsigned long old_opts = fs_info->mount_opt;
1145 unsigned long old_compress_type = fs_info->compress_type;
1146 u64 old_max_inline = fs_info->max_inline;
1147 u64 old_alloc_start = fs_info->alloc_start;
1148 int old_thread_pool_size = fs_info->thread_pool_size;
1149 unsigned int old_metadata_ratio = fs_info->metadata_ratio;
1150 int ret;
1151
1152 ret = btrfs_parse_options(root, data);
1153 if (ret) {
1154 ret = -EINVAL;
1155 goto restore;
1156 }
1157
1158 btrfs_resize_thread_pool(fs_info,
1159 fs_info->thread_pool_size, old_thread_pool_size);
1160
1161 if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
1162 return 0;
1163
1164 if (*flags & MS_RDONLY) {
1165 sb->s_flags |= MS_RDONLY;
1166
1167 ret = btrfs_commit_super(root);
1168 if (ret)
1169 goto restore;
1170 } else {
1171 if (fs_info->fs_devices->rw_devices == 0) {
1172 ret = -EACCES;
1173 goto restore;
1174 }
1175
1176 if (btrfs_super_log_root(fs_info->super_copy) != 0) {
1177 ret = -EINVAL;
1178 goto restore;
1179 }
1180
1181 ret = btrfs_cleanup_fs_roots(fs_info);
1182 if (ret)
1183 goto restore;
1184
1185 /* recover relocation */
1186 ret = btrfs_recover_relocation(root);
1187 if (ret)
1188 goto restore;
1189
1190 ret = btrfs_resume_balance_async(fs_info);
1191 if (ret)
1192 goto restore;
1193
1194 sb->s_flags &= ~MS_RDONLY;
1195 }
1196
1197 return 0;
1198
1199restore:
1200 /* We've hit an error - don't reset MS_RDONLY */
1201 if (sb->s_flags & MS_RDONLY)
1202 old_flags |= MS_RDONLY;
1203 sb->s_flags = old_flags;
1204 fs_info->mount_opt = old_opts;
1205 fs_info->compress_type = old_compress_type;
1206 fs_info->max_inline = old_max_inline;
1207 fs_info->alloc_start = old_alloc_start;
1208 btrfs_resize_thread_pool(fs_info,
1209 old_thread_pool_size, fs_info->thread_pool_size);
1210 fs_info->metadata_ratio = old_metadata_ratio;
1211 return ret;
1212}
1213
1214/* Used to sort the devices by max_avail(descending sort) */
1215static int btrfs_cmp_device_free_bytes(const void *dev_info1,
1216 const void *dev_info2)
1217{
1218 if (((struct btrfs_device_info *)dev_info1)->max_avail >
1219 ((struct btrfs_device_info *)dev_info2)->max_avail)
1220 return -1;
1221 else if (((struct btrfs_device_info *)dev_info1)->max_avail <
1222 ((struct btrfs_device_info *)dev_info2)->max_avail)
1223 return 1;
1224 else
1225 return 0;
1226}
1227
1228/*
1229 * sort the devices by max_avail, in which max free extent size of each device
1230 * is stored.(Descending Sort)
1231 */
1232static inline void btrfs_descending_sort_devices(
1233 struct btrfs_device_info *devices,
1234 size_t nr_devices)
1235{
1236 sort(devices, nr_devices, sizeof(struct btrfs_device_info),
1237 btrfs_cmp_device_free_bytes, NULL);
1238}
1239
1240/*
1241 * The helper to calc the free space on the devices that can be used to store
1242 * file data.
1243 */
1244static int btrfs_calc_avail_data_space(struct btrfs_root *root, u64 *free_bytes)
1245{
1246 struct btrfs_fs_info *fs_info = root->fs_info;
1247 struct btrfs_device_info *devices_info;
1248 struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
1249 struct btrfs_device *device;
1250 u64 skip_space;
1251 u64 type;
1252 u64 avail_space;
1253 u64 used_space;
1254 u64 min_stripe_size;
1255 int min_stripes = 1, num_stripes = 1;
1256 int i = 0, nr_devices;
1257 int ret;
1258
1259 nr_devices = fs_info->fs_devices->open_devices;
1260 BUG_ON(!nr_devices);
1261
1262 devices_info = kmalloc(sizeof(*devices_info) * nr_devices,
1263 GFP_NOFS);
1264 if (!devices_info)
1265 return -ENOMEM;
1266
1267 /* calc min stripe number for data space alloction */
1268 type = btrfs_get_alloc_profile(root, 1);
1269 if (type & BTRFS_BLOCK_GROUP_RAID0) {
1270 min_stripes = 2;
1271 num_stripes = nr_devices;
1272 } else if (type & BTRFS_BLOCK_GROUP_RAID1) {
1273 min_stripes = 2;
1274 num_stripes = 2;
1275 } else if (type & BTRFS_BLOCK_GROUP_RAID10) {
1276 min_stripes = 4;
1277 num_stripes = 4;
1278 }
1279
1280 if (type & BTRFS_BLOCK_GROUP_DUP)
1281 min_stripe_size = 2 * BTRFS_STRIPE_LEN;
1282 else
1283 min_stripe_size = BTRFS_STRIPE_LEN;
1284
1285 list_for_each_entry(device, &fs_devices->devices, dev_list) {
1286 if (!device->in_fs_metadata || !device->bdev)
1287 continue;
1288
1289 avail_space = device->total_bytes - device->bytes_used;
1290
1291 /* align with stripe_len */
1292 do_div(avail_space, BTRFS_STRIPE_LEN);
1293 avail_space *= BTRFS_STRIPE_LEN;
1294
1295 /*
1296 * In order to avoid overwritting the superblock on the drive,
1297 * btrfs starts at an offset of at least 1MB when doing chunk
1298 * allocation.
1299 */
1300 skip_space = 1024 * 1024;
1301
1302 /* user can set the offset in fs_info->alloc_start. */
1303 if (fs_info->alloc_start + BTRFS_STRIPE_LEN <=
1304 device->total_bytes)
1305 skip_space = max(fs_info->alloc_start, skip_space);
1306
1307 /*
1308 * btrfs can not use the free space in [0, skip_space - 1],
1309 * we must subtract it from the total. In order to implement
1310 * it, we account the used space in this range first.
1311 */
1312 ret = btrfs_account_dev_extents_size(device, 0, skip_space - 1,
1313 &used_space);
1314 if (ret) {
1315 kfree(devices_info);
1316 return ret;
1317 }
1318
1319 /* calc the free space in [0, skip_space - 1] */
1320 skip_space -= used_space;
1321
1322 /*
1323 * we can use the free space in [0, skip_space - 1], subtract
1324 * it from the total.
1325 */
1326 if (avail_space && avail_space >= skip_space)
1327 avail_space -= skip_space;
1328 else
1329 avail_space = 0;
1330
1331 if (avail_space < min_stripe_size)
1332 continue;
1333
1334 devices_info[i].dev = device;
1335 devices_info[i].max_avail = avail_space;
1336
1337 i++;
1338 }
1339
1340 nr_devices = i;
1341
1342 btrfs_descending_sort_devices(devices_info, nr_devices);
1343
1344 i = nr_devices - 1;
1345 avail_space = 0;
1346 while (nr_devices >= min_stripes) {
1347 if (num_stripes > nr_devices)
1348 num_stripes = nr_devices;
1349
1350 if (devices_info[i].max_avail >= min_stripe_size) {
1351 int j;
1352 u64 alloc_size;
1353
1354 avail_space += devices_info[i].max_avail * num_stripes;
1355 alloc_size = devices_info[i].max_avail;
1356 for (j = i + 1 - num_stripes; j <= i; j++)
1357 devices_info[j].max_avail -= alloc_size;
1358 }
1359 i--;
1360 nr_devices--;
1361 }
1362
1363 kfree(devices_info);
1364 *free_bytes = avail_space;
1365 return 0;
1366}
1367
1368static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf)
1369{
1370 struct btrfs_fs_info *fs_info = btrfs_sb(dentry->d_sb);
1371 struct btrfs_super_block *disk_super = fs_info->super_copy;
1372 struct list_head *head = &fs_info->space_info;
1373 struct btrfs_space_info *found;
1374 u64 total_used = 0;
1375 u64 total_free_data = 0;
1376 int bits = dentry->d_sb->s_blocksize_bits;
1377 __be32 *fsid = (__be32 *)fs_info->fsid;
1378 int ret;
1379
1380 /* holding chunk_muext to avoid allocating new chunks */
1381 mutex_lock(&fs_info->chunk_mutex);
1382 rcu_read_lock();
1383 list_for_each_entry_rcu(found, head, list) {
1384 if (found->flags & BTRFS_BLOCK_GROUP_DATA) {
1385 total_free_data += found->disk_total - found->disk_used;
1386 total_free_data -=
1387 btrfs_account_ro_block_groups_free_space(found);
1388 }
1389
1390 total_used += found->disk_used;
1391 }
1392 rcu_read_unlock();
1393
1394 buf->f_namelen = BTRFS_NAME_LEN;
1395 buf->f_blocks = btrfs_super_total_bytes(disk_super) >> bits;
1396 buf->f_bfree = buf->f_blocks - (total_used >> bits);
1397 buf->f_bsize = dentry->d_sb->s_blocksize;
1398 buf->f_type = BTRFS_SUPER_MAGIC;
1399 buf->f_bavail = total_free_data;
1400 ret = btrfs_calc_avail_data_space(fs_info->tree_root, &total_free_data);
1401 if (ret) {
1402 mutex_unlock(&fs_info->chunk_mutex);
1403 return ret;
1404 }
1405 buf->f_bavail += total_free_data;
1406 buf->f_bavail = buf->f_bavail >> bits;
1407 mutex_unlock(&fs_info->chunk_mutex);
1408
1409 /* We treat it as constant endianness (it doesn't matter _which_)
1410 because we want the fsid to come out the same whether mounted
1411 on a big-endian or little-endian host */
1412 buf->f_fsid.val[0] = be32_to_cpu(fsid[0]) ^ be32_to_cpu(fsid[2]);
1413 buf->f_fsid.val[1] = be32_to_cpu(fsid[1]) ^ be32_to_cpu(fsid[3]);
1414 /* Mask in the root object ID too, to disambiguate subvols */
1415 buf->f_fsid.val[0] ^= BTRFS_I(dentry->d_inode)->root->objectid >> 32;
1416 buf->f_fsid.val[1] ^= BTRFS_I(dentry->d_inode)->root->objectid;
1417
1418 return 0;
1419}
1420
1421static void btrfs_kill_super(struct super_block *sb)
1422{
1423 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
1424 kill_anon_super(sb);
1425 free_fs_info(fs_info);
1426}
1427
1428static struct file_system_type btrfs_fs_type = {
1429 .owner = THIS_MODULE,
1430 .name = "btrfs",
1431 .mount = btrfs_mount,
1432 .kill_sb = btrfs_kill_super,
1433 .fs_flags = FS_REQUIRES_DEV,
1434};
1435
1436/*
1437 * used by btrfsctl to scan devices when no FS is mounted
1438 */
1439static long btrfs_control_ioctl(struct file *file, unsigned int cmd,
1440 unsigned long arg)
1441{
1442 struct btrfs_ioctl_vol_args *vol;
1443 struct btrfs_fs_devices *fs_devices;
1444 int ret = -ENOTTY;
1445
1446 if (!capable(CAP_SYS_ADMIN))
1447 return -EPERM;
1448
1449 vol = memdup_user((void __user *)arg, sizeof(*vol));
1450 if (IS_ERR(vol))
1451 return PTR_ERR(vol);
1452
1453 switch (cmd) {
1454 case BTRFS_IOC_SCAN_DEV:
1455 ret = btrfs_scan_one_device(vol->name, FMODE_READ,
1456 &btrfs_fs_type, &fs_devices);
1457 break;
1458 }
1459
1460 kfree(vol);
1461 return ret;
1462}
1463
1464static int btrfs_freeze(struct super_block *sb)
1465{
1466 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
1467 mutex_lock(&fs_info->transaction_kthread_mutex);
1468 mutex_lock(&fs_info->cleaner_mutex);
1469 return 0;
1470}
1471
1472static int btrfs_unfreeze(struct super_block *sb)
1473{
1474 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
1475 mutex_unlock(&fs_info->cleaner_mutex);
1476 mutex_unlock(&fs_info->transaction_kthread_mutex);
1477 return 0;
1478}
1479
1480static void btrfs_fs_dirty_inode(struct inode *inode, int flags)
1481{
1482 int ret;
1483
1484 ret = btrfs_dirty_inode(inode);
1485 if (ret)
1486 printk_ratelimited(KERN_ERR "btrfs: fail to dirty inode %Lu "
1487 "error %d\n", btrfs_ino(inode), ret);
1488}
1489
1490static int btrfs_show_devname(struct seq_file *m, struct dentry *root)
1491{
1492 struct btrfs_fs_info *fs_info = btrfs_sb(root->d_sb);
1493 struct btrfs_fs_devices *cur_devices;
1494 struct btrfs_device *dev, *first_dev = NULL;
1495 struct list_head *head;
1496 struct rcu_string *name;
1497
1498 mutex_lock(&fs_info->fs_devices->device_list_mutex);
1499 cur_devices = fs_info->fs_devices;
1500 while (cur_devices) {
1501 head = &cur_devices->devices;
1502 list_for_each_entry(dev, head, dev_list) {
1503 if (!first_dev || dev->devid < first_dev->devid)
1504 first_dev = dev;
1505 }
1506 cur_devices = cur_devices->seed;
1507 }
1508
1509 if (first_dev) {
1510 rcu_read_lock();
1511 name = rcu_dereference(first_dev->name);
1512 seq_escape(m, name->str, " \t\n\\");
1513 rcu_read_unlock();
1514 } else {
1515 WARN_ON(1);
1516 }
1517 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
1518 return 0;
1519}
1520
1521static const struct super_operations btrfs_super_ops = {
1522 .drop_inode = btrfs_drop_inode,
1523 .evict_inode = btrfs_evict_inode,
1524 .put_super = btrfs_put_super,
1525 .sync_fs = btrfs_sync_fs,
1526 .show_options = btrfs_show_options,
1527 .show_devname = btrfs_show_devname,
1528 .write_inode = btrfs_write_inode,
1529 .dirty_inode = btrfs_fs_dirty_inode,
1530 .alloc_inode = btrfs_alloc_inode,
1531 .destroy_inode = btrfs_destroy_inode,
1532 .statfs = btrfs_statfs,
1533 .remount_fs = btrfs_remount,
1534 .freeze_fs = btrfs_freeze,
1535 .unfreeze_fs = btrfs_unfreeze,
1536};
1537
1538static const struct file_operations btrfs_ctl_fops = {
1539 .unlocked_ioctl = btrfs_control_ioctl,
1540 .compat_ioctl = btrfs_control_ioctl,
1541 .owner = THIS_MODULE,
1542 .llseek = noop_llseek,
1543};
1544
1545static struct miscdevice btrfs_misc = {
1546 .minor = BTRFS_MINOR,
1547 .name = "btrfs-control",
1548 .fops = &btrfs_ctl_fops
1549};
1550
1551MODULE_ALIAS_MISCDEV(BTRFS_MINOR);
1552MODULE_ALIAS("devname:btrfs-control");
1553
1554static int btrfs_interface_init(void)
1555{
1556 return misc_register(&btrfs_misc);
1557}
1558
1559static void btrfs_interface_exit(void)
1560{
1561 if (misc_deregister(&btrfs_misc) < 0)
1562 printk(KERN_INFO "misc_deregister failed for control device");
1563}
1564
1565static int __init init_btrfs_fs(void)
1566{
1567 int err;
1568
1569 err = btrfs_init_sysfs();
1570 if (err)
1571 return err;
1572
1573 btrfs_init_compress();
1574
1575 err = btrfs_init_cachep();
1576 if (err)
1577 goto free_compress;
1578
1579 err = extent_io_init();
1580 if (err)
1581 goto free_cachep;
1582
1583 err = extent_map_init();
1584 if (err)
1585 goto free_extent_io;
1586
1587 err = btrfs_delayed_inode_init();
1588 if (err)
1589 goto free_extent_map;
1590
1591 err = btrfs_interface_init();
1592 if (err)
1593 goto free_delayed_inode;
1594
1595 err = register_filesystem(&btrfs_fs_type);
1596 if (err)
1597 goto unregister_ioctl;
1598
1599 btrfs_init_lockdep();
1600
1601 printk(KERN_INFO "%s loaded\n", BTRFS_BUILD_VERSION);
1602 return 0;
1603
1604unregister_ioctl:
1605 btrfs_interface_exit();
1606free_delayed_inode:
1607 btrfs_delayed_inode_exit();
1608free_extent_map:
1609 extent_map_exit();
1610free_extent_io:
1611 extent_io_exit();
1612free_cachep:
1613 btrfs_destroy_cachep();
1614free_compress:
1615 btrfs_exit_compress();
1616 btrfs_exit_sysfs();
1617 return err;
1618}
1619
1620static void __exit exit_btrfs_fs(void)
1621{
1622 btrfs_destroy_cachep();
1623 btrfs_delayed_inode_exit();
1624 extent_map_exit();
1625 extent_io_exit();
1626 btrfs_interface_exit();
1627 unregister_filesystem(&btrfs_fs_type);
1628 btrfs_exit_sysfs();
1629 btrfs_cleanup_fs_uuids();
1630 btrfs_exit_compress();
1631}
1632
1633module_init(init_btrfs_fs)
1634module_exit(exit_btrfs_fs)
1635
1636MODULE_LICENSE("GPL");