1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
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 <linux/btrfs.h>
45#include "compat.h"
46#include "delayed-inode.h"
47#include "ctree.h"
48#include "disk-io.h"
49#include "transaction.h"
50#include "btrfs_inode.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#include "dev-replace.h"
59#include "free-space-cache.h"
60
61#define CREATE_TRACE_POINTS
62#include <trace/events/btrfs.h>
63
64static const struct super_operations btrfs_super_ops;
65static struct file_system_type btrfs_fs_type;
66
67static const char *btrfs_decode_error(int errno)
68{
69 char *errstr = "unknown";
70
71 switch (errno) {
72 case -EIO:
73 errstr = "IO failure";
74 break;
75 case -ENOMEM:
76 errstr = "Out of memory";
77 break;
78 case -EROFS:
79 errstr = "Readonly filesystem";
80 break;
81 case -EEXIST:
82 errstr = "Object already exists";
83 break;
84 case -ENOSPC:
85 errstr = "No space left";
86 break;
87 case -ENOENT:
88 errstr = "No such entry";
89 break;
90 }
91
92 return errstr;
93}
94
95static void save_error_info(struct btrfs_fs_info *fs_info)
96{
97
98
99
100
101 set_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state);
102}
103
104
105static void btrfs_handle_error(struct btrfs_fs_info *fs_info)
106{
107 struct super_block *sb = fs_info->sb;
108
109 if (sb->s_flags & MS_RDONLY)
110 return;
111
112 if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state)) {
113 sb->s_flags |= MS_RDONLY;
114 btrfs_info(fs_info, "forced readonly");
115
116
117
118
119
120
121
122
123
124
125 }
126}
127
128#ifdef CONFIG_PRINTK
129
130
131
132
133void __btrfs_std_error(struct btrfs_fs_info *fs_info, const char *function,
134 unsigned int line, int errno, const char *fmt, ...)
135{
136 struct super_block *sb = fs_info->sb;
137 const char *errstr;
138
139
140
141
142
143 if (errno == -EROFS && (sb->s_flags & MS_RDONLY))
144 return;
145
146 errstr = btrfs_decode_error(errno);
147 if (fmt) {
148 struct va_format vaf;
149 va_list args;
150
151 va_start(args, fmt);
152 vaf.fmt = fmt;
153 vaf.va = &args;
154
155 printk(KERN_CRIT "BTRFS error (device %s) in %s:%d: errno=%d %s (%pV)\n",
156 sb->s_id, function, line, errno, errstr, &vaf);
157 va_end(args);
158 } else {
159 printk(KERN_CRIT "BTRFS error (device %s) in %s:%d: errno=%d %s\n",
160 sb->s_id, function, line, errno, errstr);
161 }
162
163
164 save_error_info(fs_info);
165 if (sb->s_flags & MS_BORN)
166 btrfs_handle_error(fs_info);
167}
168
169static const char * const logtypes[] = {
170 "emergency",
171 "alert",
172 "critical",
173 "error",
174 "warning",
175 "notice",
176 "info",
177 "debug",
178};
179
180void btrfs_printk(const struct btrfs_fs_info *fs_info, const char *fmt, ...)
181{
182 struct super_block *sb = fs_info->sb;
183 char lvl[4];
184 struct va_format vaf;
185 va_list args;
186 const char *type = logtypes[4];
187 int kern_level;
188
189 va_start(args, fmt);
190
191 kern_level = printk_get_level(fmt);
192 if (kern_level) {
193 size_t size = printk_skip_level(fmt) - fmt;
194 memcpy(lvl, fmt, size);
195 lvl[size] = '\0';
196 fmt += size;
197 type = logtypes[kern_level - '0'];
198 } else
199 *lvl = '\0';
200
201 vaf.fmt = fmt;
202 vaf.va = &args;
203
204 printk("%sBTRFS %s (device %s): %pV\n", lvl, type, sb->s_id, &vaf);
205
206 va_end(args);
207}
208
209#else
210
211void __btrfs_std_error(struct btrfs_fs_info *fs_info, const char *function,
212 unsigned int line, int errno, const char *fmt, ...)
213{
214 struct super_block *sb = fs_info->sb;
215
216
217
218
219
220 if (errno == -EROFS && (sb->s_flags & MS_RDONLY))
221 return;
222
223
224 if (sb->s_flags & MS_BORN) {
225 save_error_info(fs_info);
226 btrfs_handle_error(fs_info);
227 }
228}
229#endif
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244void __btrfs_abort_transaction(struct btrfs_trans_handle *trans,
245 struct btrfs_root *root, const char *function,
246 unsigned int line, int errno)
247{
248
249
250
251 if (!test_and_set_bit(BTRFS_FS_STATE_TRANS_ABORTED,
252 &root->fs_info->fs_state)) {
253 WARN(1, KERN_DEBUG "btrfs: Transaction aborted (error %d)\n",
254 errno);
255 }
256 trans->aborted = errno;
257
258
259 if (!trans->blocks_used) {
260 const char *errstr;
261
262 errstr = btrfs_decode_error(errno);
263 btrfs_warn(root->fs_info,
264 "%s:%d: Aborting unused transaction(%s).",
265 function, line, errstr);
266 return;
267 }
268 ACCESS_ONCE(trans->transaction->aborted) = errno;
269 __btrfs_std_error(root->fs_info, function, line, errno, NULL);
270}
271
272
273
274
275void __btrfs_panic(struct btrfs_fs_info *fs_info, const char *function,
276 unsigned int line, int errno, const char *fmt, ...)
277{
278 char *s_id = "<unknown>";
279 const char *errstr;
280 struct va_format vaf = { .fmt = fmt };
281 va_list args;
282
283 if (fs_info)
284 s_id = fs_info->sb->s_id;
285
286 va_start(args, fmt);
287 vaf.va = &args;
288
289 errstr = btrfs_decode_error(errno);
290 if (fs_info && (fs_info->mount_opt & BTRFS_MOUNT_PANIC_ON_FATAL_ERROR))
291 panic(KERN_CRIT "BTRFS panic (device %s) in %s:%d: %pV (errno=%d %s)\n",
292 s_id, function, line, &vaf, errno, errstr);
293
294 printk(KERN_CRIT "BTRFS panic (device %s) in %s:%d: %pV (errno=%d %s)\n",
295 s_id, function, line, &vaf, errno, errstr);
296 va_end(args);
297
298}
299
300static void btrfs_put_super(struct super_block *sb)
301{
302 (void)close_ctree(btrfs_sb(sb)->tree_root);
303
304
305
306
307
308
309}
310
311enum {
312 Opt_degraded, Opt_subvol, Opt_subvolid, Opt_device, Opt_nodatasum,
313 Opt_nodatacow, Opt_max_inline, Opt_alloc_start, Opt_nobarrier, Opt_ssd,
314 Opt_nossd, Opt_ssd_spread, Opt_thread_pool, Opt_noacl, Opt_compress,
315 Opt_compress_type, Opt_compress_force, Opt_compress_force_type,
316 Opt_notreelog, Opt_ratio, Opt_flushoncommit, Opt_discard,
317 Opt_space_cache, Opt_clear_cache, Opt_user_subvol_rm_allowed,
318 Opt_enospc_debug, Opt_subvolrootid, Opt_defrag, Opt_inode_cache,
319 Opt_no_space_cache, Opt_recovery, Opt_skip_balance,
320 Opt_check_integrity, Opt_check_integrity_including_extent_data,
321 Opt_check_integrity_print_mask, Opt_fatal_errors,
322 Opt_err,
323};
324
325static match_table_t tokens = {
326 {Opt_degraded, "degraded"},
327 {Opt_subvol, "subvol=%s"},
328 {Opt_subvolid, "subvolid=%d"},
329 {Opt_device, "device=%s"},
330 {Opt_nodatasum, "nodatasum"},
331 {Opt_nodatacow, "nodatacow"},
332 {Opt_nobarrier, "nobarrier"},
333 {Opt_max_inline, "max_inline=%s"},
334 {Opt_alloc_start, "alloc_start=%s"},
335 {Opt_thread_pool, "thread_pool=%d"},
336 {Opt_compress, "compress"},
337 {Opt_compress_type, "compress=%s"},
338 {Opt_compress_force, "compress-force"},
339 {Opt_compress_force_type, "compress-force=%s"},
340 {Opt_ssd, "ssd"},
341 {Opt_ssd_spread, "ssd_spread"},
342 {Opt_nossd, "nossd"},
343 {Opt_noacl, "noacl"},
344 {Opt_notreelog, "notreelog"},
345 {Opt_flushoncommit, "flushoncommit"},
346 {Opt_ratio, "metadata_ratio=%d"},
347 {Opt_discard, "discard"},
348 {Opt_space_cache, "space_cache"},
349 {Opt_clear_cache, "clear_cache"},
350 {Opt_user_subvol_rm_allowed, "user_subvol_rm_allowed"},
351 {Opt_enospc_debug, "enospc_debug"},
352 {Opt_subvolrootid, "subvolrootid=%d"},
353 {Opt_defrag, "autodefrag"},
354 {Opt_inode_cache, "inode_cache"},
355 {Opt_no_space_cache, "nospace_cache"},
356 {Opt_recovery, "recovery"},
357 {Opt_skip_balance, "skip_balance"},
358 {Opt_check_integrity, "check_int"},
359 {Opt_check_integrity_including_extent_data, "check_int_data"},
360 {Opt_check_integrity_print_mask, "check_int_print_mask=%d"},
361 {Opt_fatal_errors, "fatal_errors=%s"},
362 {Opt_err, NULL},
363};
364
365
366
367
368
369
370int btrfs_parse_options(struct btrfs_root *root, char *options)
371{
372 struct btrfs_fs_info *info = root->fs_info;
373 substring_t args[MAX_OPT_ARGS];
374 char *p, *num, *orig = NULL;
375 u64 cache_gen;
376 int intarg;
377 int ret = 0;
378 char *compress_type;
379 bool compress_force = false;
380
381 cache_gen = btrfs_super_cache_generation(root->fs_info->super_copy);
382 if (cache_gen)
383 btrfs_set_opt(info->mount_opt, SPACE_CACHE);
384
385 if (!options)
386 goto out;
387
388
389
390
391
392 options = kstrdup(options, GFP_NOFS);
393 if (!options)
394 return -ENOMEM;
395
396 orig = options;
397
398 while ((p = strsep(&options, ",")) != NULL) {
399 int token;
400 if (!*p)
401 continue;
402
403 token = match_token(p, tokens, args);
404 switch (token) {
405 case Opt_degraded:
406 printk(KERN_INFO "btrfs: allowing degraded mounts\n");
407 btrfs_set_opt(info->mount_opt, DEGRADED);
408 break;
409 case Opt_subvol:
410 case Opt_subvolid:
411 case Opt_subvolrootid:
412 case Opt_device:
413
414
415
416
417 break;
418 case Opt_nodatasum:
419 printk(KERN_INFO "btrfs: setting nodatasum\n");
420 btrfs_set_opt(info->mount_opt, NODATASUM);
421 break;
422 case Opt_nodatacow:
423 if (!btrfs_test_opt(root, COMPRESS) ||
424 !btrfs_test_opt(root, FORCE_COMPRESS)) {
425 printk(KERN_INFO "btrfs: setting nodatacow, compression disabled\n");
426 } else {
427 printk(KERN_INFO "btrfs: setting nodatacow\n");
428 }
429 info->compress_type = BTRFS_COMPRESS_NONE;
430 btrfs_clear_opt(info->mount_opt, COMPRESS);
431 btrfs_clear_opt(info->mount_opt, FORCE_COMPRESS);
432 btrfs_set_opt(info->mount_opt, NODATACOW);
433 btrfs_set_opt(info->mount_opt, NODATASUM);
434 break;
435 case Opt_compress_force:
436 case Opt_compress_force_type:
437 compress_force = true;
438
439 case Opt_compress:
440 case Opt_compress_type:
441 if (token == Opt_compress ||
442 token == Opt_compress_force ||
443 strcmp(args[0].from, "zlib") == 0) {
444 compress_type = "zlib";
445 info->compress_type = BTRFS_COMPRESS_ZLIB;
446 btrfs_set_opt(info->mount_opt, COMPRESS);
447 btrfs_clear_opt(info->mount_opt, NODATACOW);
448 btrfs_clear_opt(info->mount_opt, NODATASUM);
449 } else if (strcmp(args[0].from, "lzo") == 0) {
450 compress_type = "lzo";
451 info->compress_type = BTRFS_COMPRESS_LZO;
452 btrfs_set_opt(info->mount_opt, COMPRESS);
453 btrfs_clear_opt(info->mount_opt, NODATACOW);
454 btrfs_clear_opt(info->mount_opt, NODATASUM);
455 btrfs_set_fs_incompat(info, COMPRESS_LZO);
456 } else if (strncmp(args[0].from, "no", 2) == 0) {
457 compress_type = "no";
458 info->compress_type = BTRFS_COMPRESS_NONE;
459 btrfs_clear_opt(info->mount_opt, COMPRESS);
460 btrfs_clear_opt(info->mount_opt, FORCE_COMPRESS);
461 compress_force = false;
462 } else {
463 ret = -EINVAL;
464 goto out;
465 }
466
467 if (compress_force) {
468 btrfs_set_opt(info->mount_opt, FORCE_COMPRESS);
469 pr_info("btrfs: force %s compression\n",
470 compress_type);
471 } else
472 pr_info("btrfs: use %s compression\n",
473 compress_type);
474 break;
475 case Opt_ssd:
476 printk(KERN_INFO "btrfs: use ssd allocation scheme\n");
477 btrfs_set_opt(info->mount_opt, SSD);
478 break;
479 case Opt_ssd_spread:
480 printk(KERN_INFO "btrfs: use spread ssd "
481 "allocation scheme\n");
482 btrfs_set_opt(info->mount_opt, SSD);
483 btrfs_set_opt(info->mount_opt, SSD_SPREAD);
484 break;
485 case Opt_nossd:
486 printk(KERN_INFO "btrfs: not using ssd allocation "
487 "scheme\n");
488 btrfs_set_opt(info->mount_opt, NOSSD);
489 btrfs_clear_opt(info->mount_opt, SSD);
490 btrfs_clear_opt(info->mount_opt, SSD_SPREAD);
491 break;
492 case Opt_nobarrier:
493 printk(KERN_INFO "btrfs: turning off barriers\n");
494 btrfs_set_opt(info->mount_opt, NOBARRIER);
495 break;
496 case Opt_thread_pool:
497 intarg = 0;
498 match_int(&args[0], &intarg);
499 if (intarg)
500 info->thread_pool_size = intarg;
501 break;
502 case Opt_max_inline:
503 num = match_strdup(&args[0]);
504 if (num) {
505 info->max_inline = memparse(num, NULL);
506 kfree(num);
507
508 if (info->max_inline) {
509 info->max_inline = max_t(u64,
510 info->max_inline,
511 root->sectorsize);
512 }
513 printk(KERN_INFO "btrfs: max_inline at %llu\n",
514 (unsigned long long)info->max_inline);
515 }
516 break;
517 case Opt_alloc_start:
518 num = match_strdup(&args[0]);
519 if (num) {
520 mutex_lock(&info->chunk_mutex);
521 info->alloc_start = memparse(num, NULL);
522 mutex_unlock(&info->chunk_mutex);
523 kfree(num);
524 printk(KERN_INFO
525 "btrfs: allocations start at %llu\n",
526 (unsigned long long)info->alloc_start);
527 }
528 break;
529 case Opt_noacl:
530 root->fs_info->sb->s_flags &= ~MS_POSIXACL;
531 break;
532 case Opt_notreelog:
533 printk(KERN_INFO "btrfs: disabling tree log\n");
534 btrfs_set_opt(info->mount_opt, NOTREELOG);
535 break;
536 case Opt_flushoncommit:
537 printk(KERN_INFO "btrfs: turning on flush-on-commit\n");
538 btrfs_set_opt(info->mount_opt, FLUSHONCOMMIT);
539 break;
540 case Opt_ratio:
541 intarg = 0;
542 match_int(&args[0], &intarg);
543 if (intarg) {
544 info->metadata_ratio = intarg;
545 printk(KERN_INFO "btrfs: metadata ratio %d\n",
546 info->metadata_ratio);
547 }
548 break;
549 case Opt_discard:
550 btrfs_set_opt(info->mount_opt, DISCARD);
551 break;
552 case Opt_space_cache:
553 btrfs_set_opt(info->mount_opt, SPACE_CACHE);
554 break;
555 case Opt_no_space_cache:
556 printk(KERN_INFO "btrfs: disabling disk space caching\n");
557 btrfs_clear_opt(info->mount_opt, SPACE_CACHE);
558 break;
559 case Opt_inode_cache:
560 printk(KERN_INFO "btrfs: enabling inode map caching\n");
561 btrfs_set_opt(info->mount_opt, INODE_MAP_CACHE);
562 break;
563 case Opt_clear_cache:
564 printk(KERN_INFO "btrfs: force clearing of disk cache\n");
565 btrfs_set_opt(info->mount_opt, CLEAR_CACHE);
566 break;
567 case Opt_user_subvol_rm_allowed:
568 btrfs_set_opt(info->mount_opt, USER_SUBVOL_RM_ALLOWED);
569 break;
570 case Opt_enospc_debug:
571 btrfs_set_opt(info->mount_opt, ENOSPC_DEBUG);
572 break;
573 case Opt_defrag:
574 printk(KERN_INFO "btrfs: enabling auto defrag\n");
575 btrfs_set_opt(info->mount_opt, AUTO_DEFRAG);
576 break;
577 case Opt_recovery:
578 printk(KERN_INFO "btrfs: enabling auto recovery\n");
579 btrfs_set_opt(info->mount_opt, RECOVERY);
580 break;
581 case Opt_skip_balance:
582 btrfs_set_opt(info->mount_opt, SKIP_BALANCE);
583 break;
584#ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
585 case Opt_check_integrity_including_extent_data:
586 printk(KERN_INFO "btrfs: enabling check integrity"
587 " including extent data\n");
588 btrfs_set_opt(info->mount_opt,
589 CHECK_INTEGRITY_INCLUDING_EXTENT_DATA);
590 btrfs_set_opt(info->mount_opt, CHECK_INTEGRITY);
591 break;
592 case Opt_check_integrity:
593 printk(KERN_INFO "btrfs: enabling check integrity\n");
594 btrfs_set_opt(info->mount_opt, CHECK_INTEGRITY);
595 break;
596 case Opt_check_integrity_print_mask:
597 intarg = 0;
598 match_int(&args[0], &intarg);
599 if (intarg) {
600 info->check_integrity_print_mask = intarg;
601 printk(KERN_INFO "btrfs:"
602 " check_integrity_print_mask 0x%x\n",
603 info->check_integrity_print_mask);
604 }
605 break;
606#else
607 case Opt_check_integrity_including_extent_data:
608 case Opt_check_integrity:
609 case Opt_check_integrity_print_mask:
610 printk(KERN_ERR "btrfs: support for check_integrity*"
611 " not compiled in!\n");
612 ret = -EINVAL;
613 goto out;
614#endif
615 case Opt_fatal_errors:
616 if (strcmp(args[0].from, "panic") == 0)
617 btrfs_set_opt(info->mount_opt,
618 PANIC_ON_FATAL_ERROR);
619 else if (strcmp(args[0].from, "bug") == 0)
620 btrfs_clear_opt(info->mount_opt,
621 PANIC_ON_FATAL_ERROR);
622 else {
623 ret = -EINVAL;
624 goto out;
625 }
626 break;
627 case Opt_err:
628 printk(KERN_INFO "btrfs: unrecognized mount option "
629 "'%s'\n", p);
630 ret = -EINVAL;
631 goto out;
632 default:
633 break;
634 }
635 }
636out:
637 if (!ret && btrfs_test_opt(root, SPACE_CACHE))
638 printk(KERN_INFO "btrfs: disk space caching is enabled\n");
639 kfree(orig);
640 return ret;
641}
642
643
644
645
646
647
648
649static int btrfs_parse_early_options(const char *options, fmode_t flags,
650 void *holder, char **subvol_name, u64 *subvol_objectid,
651 struct btrfs_fs_devices **fs_devices)
652{
653 substring_t args[MAX_OPT_ARGS];
654 char *device_name, *opts, *orig, *p;
655 int error = 0;
656 int intarg;
657
658 if (!options)
659 return 0;
660
661
662
663
664
665 opts = kstrdup(options, GFP_KERNEL);
666 if (!opts)
667 return -ENOMEM;
668 orig = opts;
669
670 while ((p = strsep(&opts, ",")) != NULL) {
671 int token;
672 if (!*p)
673 continue;
674
675 token = match_token(p, tokens, args);
676 switch (token) {
677 case Opt_subvol:
678 kfree(*subvol_name);
679 *subvol_name = match_strdup(&args[0]);
680 break;
681 case Opt_subvolid:
682 intarg = 0;
683 error = match_int(&args[0], &intarg);
684 if (!error) {
685
686 if (!intarg)
687 *subvol_objectid =
688 BTRFS_FS_TREE_OBJECTID;
689 else
690 *subvol_objectid = intarg;
691 }
692 break;
693 case Opt_subvolrootid:
694 printk(KERN_WARNING
695 "btrfs: 'subvolrootid' mount option is deprecated and has no effect\n");
696 break;
697 case Opt_device:
698 device_name = match_strdup(&args[0]);
699 if (!device_name) {
700 error = -ENOMEM;
701 goto out;
702 }
703 error = btrfs_scan_one_device(device_name,
704 flags, holder, fs_devices);
705 kfree(device_name);
706 if (error)
707 goto out;
708 break;
709 default:
710 break;
711 }
712 }
713
714out:
715 kfree(orig);
716 return error;
717}
718
719static struct dentry *get_default_root(struct super_block *sb,
720 u64 subvol_objectid)
721{
722 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
723 struct btrfs_root *root = fs_info->tree_root;
724 struct btrfs_root *new_root;
725 struct btrfs_dir_item *di;
726 struct btrfs_path *path;
727 struct btrfs_key location;
728 struct inode *inode;
729 u64 dir_id;
730 int new = 0;
731
732
733
734
735
736 if (subvol_objectid) {
737 location.objectid = subvol_objectid;
738 location.type = BTRFS_ROOT_ITEM_KEY;
739 location.offset = (u64)-1;
740 goto find_root;
741 }
742
743 path = btrfs_alloc_path();
744 if (!path)
745 return ERR_PTR(-ENOMEM);
746 path->leave_spinning = 1;
747
748
749
750
751
752
753 dir_id = btrfs_super_root_dir(fs_info->super_copy);
754 di = btrfs_lookup_dir_item(NULL, root, path, dir_id, "default", 7, 0);
755 if (IS_ERR(di)) {
756 btrfs_free_path(path);
757 return ERR_CAST(di);
758 }
759 if (!di) {
760
761
762
763
764
765 btrfs_free_path(path);
766 dir_id = BTRFS_FIRST_FREE_OBJECTID;
767 new_root = fs_info->fs_root;
768 goto setup_root;
769 }
770
771 btrfs_dir_item_key_to_cpu(path->nodes[0], di, &location);
772 btrfs_free_path(path);
773
774find_root:
775 new_root = btrfs_read_fs_root_no_name(fs_info, &location);
776 if (IS_ERR(new_root))
777 return ERR_CAST(new_root);
778
779 if (btrfs_root_refs(&new_root->root_item) == 0)
780 return ERR_PTR(-ENOENT);
781
782 dir_id = btrfs_root_dirid(&new_root->root_item);
783setup_root:
784 location.objectid = dir_id;
785 location.type = BTRFS_INODE_ITEM_KEY;
786 location.offset = 0;
787
788 inode = btrfs_iget(sb, &location, new_root, &new);
789 if (IS_ERR(inode))
790 return ERR_CAST(inode);
791
792
793
794
795
796
797 if (!new && sb->s_root->d_inode == inode) {
798 iput(inode);
799 return dget(sb->s_root);
800 }
801
802 return d_obtain_alias(inode);
803}
804
805static int btrfs_fill_super(struct super_block *sb,
806 struct btrfs_fs_devices *fs_devices,
807 void *data, int silent)
808{
809 struct inode *inode;
810 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
811 struct btrfs_key key;
812 int err;
813
814 sb->s_maxbytes = MAX_LFS_FILESIZE;
815 sb->s_magic = BTRFS_SUPER_MAGIC;
816 sb->s_op = &btrfs_super_ops;
817 sb->s_d_op = &btrfs_dentry_operations;
818 sb->s_export_op = &btrfs_export_ops;
819 sb->s_xattr = btrfs_xattr_handlers;
820 sb->s_time_gran = 1;
821#ifdef CONFIG_BTRFS_FS_POSIX_ACL
822 sb->s_flags |= MS_POSIXACL;
823#endif
824 sb->s_flags |= MS_I_VERSION;
825 err = open_ctree(sb, fs_devices, (char *)data);
826 if (err) {
827 printk("btrfs: open_ctree failed\n");
828 return err;
829 }
830
831 key.objectid = BTRFS_FIRST_FREE_OBJECTID;
832 key.type = BTRFS_INODE_ITEM_KEY;
833 key.offset = 0;
834 inode = btrfs_iget(sb, &key, fs_info->fs_root, NULL);
835 if (IS_ERR(inode)) {
836 err = PTR_ERR(inode);
837 goto fail_close;
838 }
839
840 sb->s_root = d_make_root(inode);
841 if (!sb->s_root) {
842 err = -ENOMEM;
843 goto fail_close;
844 }
845
846 save_mount_options(sb, data);
847 cleancache_init_fs(sb);
848 sb->s_flags |= MS_ACTIVE;
849 return 0;
850
851fail_close:
852 close_ctree(fs_info->tree_root);
853 return err;
854}
855
856int btrfs_sync_fs(struct super_block *sb, int wait)
857{
858 struct btrfs_trans_handle *trans;
859 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
860 struct btrfs_root *root = fs_info->tree_root;
861
862 trace_btrfs_sync_fs(wait);
863
864 if (!wait) {
865 filemap_flush(fs_info->btree_inode->i_mapping);
866 return 0;
867 }
868
869 btrfs_wait_ordered_extents(root, 1);
870
871 trans = btrfs_attach_transaction_barrier(root);
872 if (IS_ERR(trans)) {
873
874 if (PTR_ERR(trans) == -ENOENT)
875 return 0;
876 return PTR_ERR(trans);
877 }
878 return btrfs_commit_transaction(trans, root);
879}
880
881static int btrfs_show_options(struct seq_file *seq, struct dentry *dentry)
882{
883 struct btrfs_fs_info *info = btrfs_sb(dentry->d_sb);
884 struct btrfs_root *root = info->tree_root;
885 char *compress_type;
886
887 if (btrfs_test_opt(root, DEGRADED))
888 seq_puts(seq, ",degraded");
889 if (btrfs_test_opt(root, NODATASUM))
890 seq_puts(seq, ",nodatasum");
891 if (btrfs_test_opt(root, NODATACOW))
892 seq_puts(seq, ",nodatacow");
893 if (btrfs_test_opt(root, NOBARRIER))
894 seq_puts(seq, ",nobarrier");
895 if (info->max_inline != 8192 * 1024)
896 seq_printf(seq, ",max_inline=%llu",
897 (unsigned long long)info->max_inline);
898 if (info->alloc_start != 0)
899 seq_printf(seq, ",alloc_start=%llu",
900 (unsigned long long)info->alloc_start);
901 if (info->thread_pool_size != min_t(unsigned long,
902 num_online_cpus() + 2, 8))
903 seq_printf(seq, ",thread_pool=%d", info->thread_pool_size);
904 if (btrfs_test_opt(root, COMPRESS)) {
905 if (info->compress_type == BTRFS_COMPRESS_ZLIB)
906 compress_type = "zlib";
907 else
908 compress_type = "lzo";
909 if (btrfs_test_opt(root, FORCE_COMPRESS))
910 seq_printf(seq, ",compress-force=%s", compress_type);
911 else
912 seq_printf(seq, ",compress=%s", compress_type);
913 }
914 if (btrfs_test_opt(root, NOSSD))
915 seq_puts(seq, ",nossd");
916 if (btrfs_test_opt(root, SSD_SPREAD))
917 seq_puts(seq, ",ssd_spread");
918 else if (btrfs_test_opt(root, SSD))
919 seq_puts(seq, ",ssd");
920 if (btrfs_test_opt(root, NOTREELOG))
921 seq_puts(seq, ",notreelog");
922 if (btrfs_test_opt(root, FLUSHONCOMMIT))
923 seq_puts(seq, ",flushoncommit");
924 if (btrfs_test_opt(root, DISCARD))
925 seq_puts(seq, ",discard");
926 if (!(root->fs_info->sb->s_flags & MS_POSIXACL))
927 seq_puts(seq, ",noacl");
928 if (btrfs_test_opt(root, SPACE_CACHE))
929 seq_puts(seq, ",space_cache");
930 else
931 seq_puts(seq, ",nospace_cache");
932 if (btrfs_test_opt(root, CLEAR_CACHE))
933 seq_puts(seq, ",clear_cache");
934 if (btrfs_test_opt(root, USER_SUBVOL_RM_ALLOWED))
935 seq_puts(seq, ",user_subvol_rm_allowed");
936 if (btrfs_test_opt(root, ENOSPC_DEBUG))
937 seq_puts(seq, ",enospc_debug");
938 if (btrfs_test_opt(root, AUTO_DEFRAG))
939 seq_puts(seq, ",autodefrag");
940 if (btrfs_test_opt(root, INODE_MAP_CACHE))
941 seq_puts(seq, ",inode_cache");
942 if (btrfs_test_opt(root, SKIP_BALANCE))
943 seq_puts(seq, ",skip_balance");
944 if (btrfs_test_opt(root, PANIC_ON_FATAL_ERROR))
945 seq_puts(seq, ",fatal_errors=panic");
946 return 0;
947}
948
949static int btrfs_test_super(struct super_block *s, void *data)
950{
951 struct btrfs_fs_info *p = data;
952 struct btrfs_fs_info *fs_info = btrfs_sb(s);
953
954 return fs_info->fs_devices == p->fs_devices;
955}
956
957static int btrfs_set_super(struct super_block *s, void *data)
958{
959 int err = set_anon_super(s, data);
960 if (!err)
961 s->s_fs_info = data;
962 return err;
963}
964
965
966
967
968static inline int is_subvolume_inode(struct inode *inode)
969{
970 if (inode && inode->i_ino == BTRFS_FIRST_FREE_OBJECTID)
971 return 1;
972 return 0;
973}
974
975
976
977
978
979
980static char *setup_root_args(char *args)
981{
982 unsigned len = strlen(args) + 2 + 1;
983 char *src, *dst, *buf;
984
985
986
987
988
989
990
991
992
993 src = strstr(args, "subvol=");
994
995 if (!src)
996 return NULL;
997
998 buf = dst = kmalloc(len, GFP_NOFS);
999 if (!buf)
1000 return NULL;
1001
1002
1003
1004
1005
1006 if (src != args) {
1007 *src++ = '\0';
1008 strcpy(buf, args);
1009 dst += strlen(args);
1010 }
1011
1012 strcpy(dst, "subvolid=0");
1013 dst += strlen("subvolid=0");
1014
1015
1016
1017
1018
1019 src = strchr(src, ',');
1020 if (src)
1021 strcpy(dst, src);
1022
1023 return buf;
1024}
1025
1026static struct dentry *mount_subvol(const char *subvol_name, int flags,
1027 const char *device_name, char *data)
1028{
1029 struct dentry *root;
1030 struct vfsmount *mnt;
1031 char *newargs;
1032
1033 newargs = setup_root_args(data);
1034 if (!newargs)
1035 return ERR_PTR(-ENOMEM);
1036 mnt = vfs_kern_mount(&btrfs_fs_type, flags, device_name,
1037 newargs);
1038 kfree(newargs);
1039 if (IS_ERR(mnt))
1040 return ERR_CAST(mnt);
1041
1042 root = mount_subtree(mnt, subvol_name);
1043
1044 if (!IS_ERR(root) && !is_subvolume_inode(root->d_inode)) {
1045 struct super_block *s = root->d_sb;
1046 dput(root);
1047 root = ERR_PTR(-EINVAL);
1048 deactivate_locked_super(s);
1049 printk(KERN_ERR "btrfs: '%s' is not a valid subvolume\n",
1050 subvol_name);
1051 }
1052
1053 return root;
1054}
1055
1056
1057
1058
1059
1060
1061
1062static struct dentry *btrfs_mount(struct file_system_type *fs_type, int flags,
1063 const char *device_name, void *data)
1064{
1065 struct block_device *bdev = NULL;
1066 struct super_block *s;
1067 struct dentry *root;
1068 struct btrfs_fs_devices *fs_devices = NULL;
1069 struct btrfs_fs_info *fs_info = NULL;
1070 fmode_t mode = FMODE_READ;
1071 char *subvol_name = NULL;
1072 u64 subvol_objectid = 0;
1073 int error = 0;
1074
1075 if (!(flags & MS_RDONLY))
1076 mode |= FMODE_WRITE;
1077
1078 error = btrfs_parse_early_options(data, mode, fs_type,
1079 &subvol_name, &subvol_objectid,
1080 &fs_devices);
1081 if (error) {
1082 kfree(subvol_name);
1083 return ERR_PTR(error);
1084 }
1085
1086 if (subvol_name) {
1087 root = mount_subvol(subvol_name, flags, device_name, data);
1088 kfree(subvol_name);
1089 return root;
1090 }
1091
1092 error = btrfs_scan_one_device(device_name, mode, fs_type, &fs_devices);
1093 if (error)
1094 return ERR_PTR(error);
1095
1096
1097
1098
1099
1100
1101
1102 fs_info = kzalloc(sizeof(struct btrfs_fs_info), GFP_NOFS);
1103 if (!fs_info)
1104 return ERR_PTR(-ENOMEM);
1105
1106 fs_info->fs_devices = fs_devices;
1107
1108 fs_info->super_copy = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_NOFS);
1109 fs_info->super_for_commit = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_NOFS);
1110 if (!fs_info->super_copy || !fs_info->super_for_commit) {
1111 error = -ENOMEM;
1112 goto error_fs_info;
1113 }
1114
1115 error = btrfs_open_devices(fs_devices, mode, fs_type);
1116 if (error)
1117 goto error_fs_info;
1118
1119 if (!(flags & MS_RDONLY) && fs_devices->rw_devices == 0) {
1120 error = -EACCES;
1121 goto error_close_devices;
1122 }
1123
1124 bdev = fs_devices->latest_bdev;
1125 s = sget(fs_type, btrfs_test_super, btrfs_set_super, flags | MS_NOSEC,
1126 fs_info);
1127 if (IS_ERR(s)) {
1128 error = PTR_ERR(s);
1129 goto error_close_devices;
1130 }
1131
1132 if (s->s_root) {
1133 btrfs_close_devices(fs_devices);
1134 free_fs_info(fs_info);
1135 if ((flags ^ s->s_flags) & MS_RDONLY)
1136 error = -EBUSY;
1137 } else {
1138 char b[BDEVNAME_SIZE];
1139
1140 strlcpy(s->s_id, bdevname(bdev, b), sizeof(s->s_id));
1141 btrfs_sb(s)->bdev_holder = fs_type;
1142 error = btrfs_fill_super(s, fs_devices, data,
1143 flags & MS_SILENT ? 1 : 0);
1144 }
1145
1146 root = !error ? get_default_root(s, subvol_objectid) : ERR_PTR(error);
1147 if (IS_ERR(root))
1148 deactivate_locked_super(s);
1149
1150 return root;
1151
1152error_close_devices:
1153 btrfs_close_devices(fs_devices);
1154error_fs_info:
1155 free_fs_info(fs_info);
1156 return ERR_PTR(error);
1157}
1158
1159static void btrfs_set_max_workers(struct btrfs_workers *workers, int new_limit)
1160{
1161 spin_lock_irq(&workers->lock);
1162 workers->max_workers = new_limit;
1163 spin_unlock_irq(&workers->lock);
1164}
1165
1166static void btrfs_resize_thread_pool(struct btrfs_fs_info *fs_info,
1167 int new_pool_size, int old_pool_size)
1168{
1169 if (new_pool_size == old_pool_size)
1170 return;
1171
1172 fs_info->thread_pool_size = new_pool_size;
1173
1174 printk(KERN_INFO "btrfs: resize thread pool %d -> %d\n",
1175 old_pool_size, new_pool_size);
1176
1177 btrfs_set_max_workers(&fs_info->generic_worker, new_pool_size);
1178 btrfs_set_max_workers(&fs_info->workers, new_pool_size);
1179 btrfs_set_max_workers(&fs_info->delalloc_workers, new_pool_size);
1180 btrfs_set_max_workers(&fs_info->submit_workers, new_pool_size);
1181 btrfs_set_max_workers(&fs_info->caching_workers, new_pool_size);
1182 btrfs_set_max_workers(&fs_info->fixup_workers, new_pool_size);
1183 btrfs_set_max_workers(&fs_info->endio_workers, new_pool_size);
1184 btrfs_set_max_workers(&fs_info->endio_meta_workers, new_pool_size);
1185 btrfs_set_max_workers(&fs_info->endio_meta_write_workers, new_pool_size);
1186 btrfs_set_max_workers(&fs_info->endio_write_workers, new_pool_size);
1187 btrfs_set_max_workers(&fs_info->endio_freespace_worker, new_pool_size);
1188 btrfs_set_max_workers(&fs_info->delayed_workers, new_pool_size);
1189 btrfs_set_max_workers(&fs_info->readahead_workers, new_pool_size);
1190 btrfs_set_max_workers(&fs_info->scrub_wr_completion_workers,
1191 new_pool_size);
1192}
1193
1194static inline void btrfs_remount_prepare(struct btrfs_fs_info *fs_info)
1195{
1196 set_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state);
1197}
1198
1199static inline void btrfs_remount_begin(struct btrfs_fs_info *fs_info,
1200 unsigned long old_opts, int flags)
1201{
1202 if (btrfs_raw_test_opt(old_opts, AUTO_DEFRAG) &&
1203 (!btrfs_raw_test_opt(fs_info->mount_opt, AUTO_DEFRAG) ||
1204 (flags & MS_RDONLY))) {
1205
1206 wait_event(fs_info->transaction_wait,
1207 (atomic_read(&fs_info->defrag_running) == 0));
1208 if (flags & MS_RDONLY)
1209 sync_filesystem(fs_info->sb);
1210 }
1211}
1212
1213static inline void btrfs_remount_cleanup(struct btrfs_fs_info *fs_info,
1214 unsigned long old_opts)
1215{
1216
1217
1218
1219
1220 if (btrfs_raw_test_opt(old_opts, AUTO_DEFRAG) &&
1221 (!btrfs_raw_test_opt(fs_info->mount_opt, AUTO_DEFRAG) ||
1222 (fs_info->sb->s_flags & MS_RDONLY))) {
1223 btrfs_cleanup_defrag_inodes(fs_info);
1224 }
1225
1226 clear_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state);
1227}
1228
1229static int btrfs_remount(struct super_block *sb, int *flags, char *data)
1230{
1231 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
1232 struct btrfs_root *root = fs_info->tree_root;
1233 unsigned old_flags = sb->s_flags;
1234 unsigned long old_opts = fs_info->mount_opt;
1235 unsigned long old_compress_type = fs_info->compress_type;
1236 u64 old_max_inline = fs_info->max_inline;
1237 u64 old_alloc_start = fs_info->alloc_start;
1238 int old_thread_pool_size = fs_info->thread_pool_size;
1239 unsigned int old_metadata_ratio = fs_info->metadata_ratio;
1240 int ret;
1241
1242 btrfs_remount_prepare(fs_info);
1243
1244 ret = btrfs_parse_options(root, data);
1245 if (ret) {
1246 ret = -EINVAL;
1247 goto restore;
1248 }
1249
1250 btrfs_remount_begin(fs_info, old_opts, *flags);
1251 btrfs_resize_thread_pool(fs_info,
1252 fs_info->thread_pool_size, old_thread_pool_size);
1253
1254 if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
1255 goto out;
1256
1257 if (*flags & MS_RDONLY) {
1258
1259
1260
1261
1262 sb->s_flags |= MS_RDONLY;
1263
1264 btrfs_dev_replace_suspend_for_unmount(fs_info);
1265 btrfs_scrub_cancel(fs_info);
1266 btrfs_pause_balance(fs_info);
1267
1268 ret = btrfs_commit_super(root);
1269 if (ret)
1270 goto restore;
1271 } else {
1272 if (fs_info->fs_devices->rw_devices == 0) {
1273 ret = -EACCES;
1274 goto restore;
1275 }
1276
1277 if (fs_info->fs_devices->missing_devices >
1278 fs_info->num_tolerated_disk_barrier_failures &&
1279 !(*flags & MS_RDONLY)) {
1280 printk(KERN_WARNING
1281 "Btrfs: too many missing devices, writeable remount is not allowed\n");
1282 ret = -EACCES;
1283 goto restore;
1284 }
1285
1286 if (btrfs_super_log_root(fs_info->super_copy) != 0) {
1287 ret = -EINVAL;
1288 goto restore;
1289 }
1290
1291 ret = btrfs_cleanup_fs_roots(fs_info);
1292 if (ret)
1293 goto restore;
1294
1295
1296 ret = btrfs_recover_relocation(root);
1297 if (ret)
1298 goto restore;
1299
1300 ret = btrfs_resume_balance_async(fs_info);
1301 if (ret)
1302 goto restore;
1303
1304 ret = btrfs_resume_dev_replace_async(fs_info);
1305 if (ret) {
1306 pr_warn("btrfs: failed to resume dev_replace\n");
1307 goto restore;
1308 }
1309 sb->s_flags &= ~MS_RDONLY;
1310 }
1311out:
1312 btrfs_remount_cleanup(fs_info, old_opts);
1313 return 0;
1314
1315restore:
1316
1317 if (sb->s_flags & MS_RDONLY)
1318 old_flags |= MS_RDONLY;
1319 sb->s_flags = old_flags;
1320 fs_info->mount_opt = old_opts;
1321 fs_info->compress_type = old_compress_type;
1322 fs_info->max_inline = old_max_inline;
1323 mutex_lock(&fs_info->chunk_mutex);
1324 fs_info->alloc_start = old_alloc_start;
1325 mutex_unlock(&fs_info->chunk_mutex);
1326 btrfs_resize_thread_pool(fs_info,
1327 old_thread_pool_size, fs_info->thread_pool_size);
1328 fs_info->metadata_ratio = old_metadata_ratio;
1329 btrfs_remount_cleanup(fs_info, old_opts);
1330 return ret;
1331}
1332
1333
1334static int btrfs_cmp_device_free_bytes(const void *dev_info1,
1335 const void *dev_info2)
1336{
1337 if (((struct btrfs_device_info *)dev_info1)->max_avail >
1338 ((struct btrfs_device_info *)dev_info2)->max_avail)
1339 return -1;
1340 else if (((struct btrfs_device_info *)dev_info1)->max_avail <
1341 ((struct btrfs_device_info *)dev_info2)->max_avail)
1342 return 1;
1343 else
1344 return 0;
1345}
1346
1347
1348
1349
1350
1351static inline void btrfs_descending_sort_devices(
1352 struct btrfs_device_info *devices,
1353 size_t nr_devices)
1354{
1355 sort(devices, nr_devices, sizeof(struct btrfs_device_info),
1356 btrfs_cmp_device_free_bytes, NULL);
1357}
1358
1359
1360
1361
1362
1363static int btrfs_calc_avail_data_space(struct btrfs_root *root, u64 *free_bytes)
1364{
1365 struct btrfs_fs_info *fs_info = root->fs_info;
1366 struct btrfs_device_info *devices_info;
1367 struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
1368 struct btrfs_device *device;
1369 u64 skip_space;
1370 u64 type;
1371 u64 avail_space;
1372 u64 used_space;
1373 u64 min_stripe_size;
1374 int min_stripes = 1, num_stripes = 1;
1375 int i = 0, nr_devices;
1376 int ret;
1377
1378 nr_devices = fs_info->fs_devices->open_devices;
1379 BUG_ON(!nr_devices);
1380
1381 devices_info = kmalloc(sizeof(*devices_info) * nr_devices,
1382 GFP_NOFS);
1383 if (!devices_info)
1384 return -ENOMEM;
1385
1386
1387 type = btrfs_get_alloc_profile(root, 1);
1388 if (type & BTRFS_BLOCK_GROUP_RAID0) {
1389 min_stripes = 2;
1390 num_stripes = nr_devices;
1391 } else if (type & BTRFS_BLOCK_GROUP_RAID1) {
1392 min_stripes = 2;
1393 num_stripes = 2;
1394 } else if (type & BTRFS_BLOCK_GROUP_RAID10) {
1395 min_stripes = 4;
1396 num_stripes = 4;
1397 }
1398
1399 if (type & BTRFS_BLOCK_GROUP_DUP)
1400 min_stripe_size = 2 * BTRFS_STRIPE_LEN;
1401 else
1402 min_stripe_size = BTRFS_STRIPE_LEN;
1403
1404 list_for_each_entry(device, &fs_devices->devices, dev_list) {
1405 if (!device->in_fs_metadata || !device->bdev ||
1406 device->is_tgtdev_for_dev_replace)
1407 continue;
1408
1409 avail_space = device->total_bytes - device->bytes_used;
1410
1411
1412 do_div(avail_space, BTRFS_STRIPE_LEN);
1413 avail_space *= BTRFS_STRIPE_LEN;
1414
1415
1416
1417
1418
1419
1420 skip_space = 1024 * 1024;
1421
1422
1423 if (fs_info->alloc_start + BTRFS_STRIPE_LEN <=
1424 device->total_bytes)
1425 skip_space = max(fs_info->alloc_start, skip_space);
1426
1427
1428
1429
1430
1431
1432 ret = btrfs_account_dev_extents_size(device, 0, skip_space - 1,
1433 &used_space);
1434 if (ret) {
1435 kfree(devices_info);
1436 return ret;
1437 }
1438
1439
1440 skip_space -= used_space;
1441
1442
1443
1444
1445
1446 if (avail_space && avail_space >= skip_space)
1447 avail_space -= skip_space;
1448 else
1449 avail_space = 0;
1450
1451 if (avail_space < min_stripe_size)
1452 continue;
1453
1454 devices_info[i].dev = device;
1455 devices_info[i].max_avail = avail_space;
1456
1457 i++;
1458 }
1459
1460 nr_devices = i;
1461
1462 btrfs_descending_sort_devices(devices_info, nr_devices);
1463
1464 i = nr_devices - 1;
1465 avail_space = 0;
1466 while (nr_devices >= min_stripes) {
1467 if (num_stripes > nr_devices)
1468 num_stripes = nr_devices;
1469
1470 if (devices_info[i].max_avail >= min_stripe_size) {
1471 int j;
1472 u64 alloc_size;
1473
1474 avail_space += devices_info[i].max_avail * num_stripes;
1475 alloc_size = devices_info[i].max_avail;
1476 for (j = i + 1 - num_stripes; j <= i; j++)
1477 devices_info[j].max_avail -= alloc_size;
1478 }
1479 i--;
1480 nr_devices--;
1481 }
1482
1483 kfree(devices_info);
1484 *free_bytes = avail_space;
1485 return 0;
1486}
1487
1488static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf)
1489{
1490 struct btrfs_fs_info *fs_info = btrfs_sb(dentry->d_sb);
1491 struct btrfs_super_block *disk_super = fs_info->super_copy;
1492 struct list_head *head = &fs_info->space_info;
1493 struct btrfs_space_info *found;
1494 u64 total_used = 0;
1495 u64 total_free_data = 0;
1496 int bits = dentry->d_sb->s_blocksize_bits;
1497 __be32 *fsid = (__be32 *)fs_info->fsid;
1498 int ret;
1499
1500
1501 mutex_lock(&fs_info->chunk_mutex);
1502 rcu_read_lock();
1503 list_for_each_entry_rcu(found, head, list) {
1504 if (found->flags & BTRFS_BLOCK_GROUP_DATA) {
1505 total_free_data += found->disk_total - found->disk_used;
1506 total_free_data -=
1507 btrfs_account_ro_block_groups_free_space(found);
1508 }
1509
1510 total_used += found->disk_used;
1511 }
1512 rcu_read_unlock();
1513
1514 buf->f_namelen = BTRFS_NAME_LEN;
1515 buf->f_blocks = btrfs_super_total_bytes(disk_super) >> bits;
1516 buf->f_bfree = buf->f_blocks - (total_used >> bits);
1517 buf->f_bsize = dentry->d_sb->s_blocksize;
1518 buf->f_type = BTRFS_SUPER_MAGIC;
1519 buf->f_bavail = total_free_data;
1520 ret = btrfs_calc_avail_data_space(fs_info->tree_root, &total_free_data);
1521 if (ret) {
1522 mutex_unlock(&fs_info->chunk_mutex);
1523 return ret;
1524 }
1525 buf->f_bavail += total_free_data;
1526 buf->f_bavail = buf->f_bavail >> bits;
1527 mutex_unlock(&fs_info->chunk_mutex);
1528
1529
1530
1531
1532 buf->f_fsid.val[0] = be32_to_cpu(fsid[0]) ^ be32_to_cpu(fsid[2]);
1533 buf->f_fsid.val[1] = be32_to_cpu(fsid[1]) ^ be32_to_cpu(fsid[3]);
1534
1535 buf->f_fsid.val[0] ^= BTRFS_I(dentry->d_inode)->root->objectid >> 32;
1536 buf->f_fsid.val[1] ^= BTRFS_I(dentry->d_inode)->root->objectid;
1537
1538 return 0;
1539}
1540
1541static void btrfs_kill_super(struct super_block *sb)
1542{
1543 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
1544 kill_anon_super(sb);
1545 free_fs_info(fs_info);
1546}
1547
1548static struct file_system_type btrfs_fs_type = {
1549 .owner = THIS_MODULE,
1550 .name = "btrfs",
1551 .mount = btrfs_mount,
1552 .kill_sb = btrfs_kill_super,
1553 .fs_flags = FS_REQUIRES_DEV,
1554};
1555MODULE_ALIAS_FS("btrfs");
1556
1557
1558
1559
1560static long btrfs_control_ioctl(struct file *file, unsigned int cmd,
1561 unsigned long arg)
1562{
1563 struct btrfs_ioctl_vol_args *vol;
1564 struct btrfs_fs_devices *fs_devices;
1565 int ret = -ENOTTY;
1566
1567 if (!capable(CAP_SYS_ADMIN))
1568 return -EPERM;
1569
1570 vol = memdup_user((void __user *)arg, sizeof(*vol));
1571 if (IS_ERR(vol))
1572 return PTR_ERR(vol);
1573
1574 switch (cmd) {
1575 case BTRFS_IOC_SCAN_DEV:
1576 ret = btrfs_scan_one_device(vol->name, FMODE_READ,
1577 &btrfs_fs_type, &fs_devices);
1578 break;
1579 case BTRFS_IOC_DEVICES_READY:
1580 ret = btrfs_scan_one_device(vol->name, FMODE_READ,
1581 &btrfs_fs_type, &fs_devices);
1582 if (ret)
1583 break;
1584 ret = !(fs_devices->num_devices == fs_devices->total_devices);
1585 break;
1586 }
1587
1588 kfree(vol);
1589 return ret;
1590}
1591
1592static int btrfs_freeze(struct super_block *sb)
1593{
1594 struct btrfs_trans_handle *trans;
1595 struct btrfs_root *root = btrfs_sb(sb)->tree_root;
1596
1597 trans = btrfs_attach_transaction_barrier(root);
1598 if (IS_ERR(trans)) {
1599
1600 if (PTR_ERR(trans) == -ENOENT)
1601 return 0;
1602 return PTR_ERR(trans);
1603 }
1604 return btrfs_commit_transaction(trans, root);
1605}
1606
1607static int btrfs_unfreeze(struct super_block *sb)
1608{
1609 return 0;
1610}
1611
1612static int btrfs_show_devname(struct seq_file *m, struct dentry *root)
1613{
1614 struct btrfs_fs_info *fs_info = btrfs_sb(root->d_sb);
1615 struct btrfs_fs_devices *cur_devices;
1616 struct btrfs_device *dev, *first_dev = NULL;
1617 struct list_head *head;
1618 struct rcu_string *name;
1619
1620 mutex_lock(&fs_info->fs_devices->device_list_mutex);
1621 cur_devices = fs_info->fs_devices;
1622 while (cur_devices) {
1623 head = &cur_devices->devices;
1624 list_for_each_entry(dev, head, dev_list) {
1625 if (dev->missing)
1626 continue;
1627 if (!first_dev || dev->devid < first_dev->devid)
1628 first_dev = dev;
1629 }
1630 cur_devices = cur_devices->seed;
1631 }
1632
1633 if (first_dev) {
1634 rcu_read_lock();
1635 name = rcu_dereference(first_dev->name);
1636 seq_escape(m, name->str, " \t\n\\");
1637 rcu_read_unlock();
1638 } else {
1639 WARN_ON(1);
1640 }
1641 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
1642 return 0;
1643}
1644
1645static const struct super_operations btrfs_super_ops = {
1646 .drop_inode = btrfs_drop_inode,
1647 .evict_inode = btrfs_evict_inode,
1648 .put_super = btrfs_put_super,
1649 .sync_fs = btrfs_sync_fs,
1650 .show_options = btrfs_show_options,
1651 .show_devname = btrfs_show_devname,
1652 .write_inode = btrfs_write_inode,
1653 .alloc_inode = btrfs_alloc_inode,
1654 .destroy_inode = btrfs_destroy_inode,
1655 .statfs = btrfs_statfs,
1656 .remount_fs = btrfs_remount,
1657 .freeze_fs = btrfs_freeze,
1658 .unfreeze_fs = btrfs_unfreeze,
1659};
1660
1661static const struct file_operations btrfs_ctl_fops = {
1662 .unlocked_ioctl = btrfs_control_ioctl,
1663 .compat_ioctl = btrfs_control_ioctl,
1664 .owner = THIS_MODULE,
1665 .llseek = noop_llseek,
1666};
1667
1668static struct miscdevice btrfs_misc = {
1669 .minor = BTRFS_MINOR,
1670 .name = "btrfs-control",
1671 .fops = &btrfs_ctl_fops
1672};
1673
1674MODULE_ALIAS_MISCDEV(BTRFS_MINOR);
1675MODULE_ALIAS("devname:btrfs-control");
1676
1677static int btrfs_interface_init(void)
1678{
1679 return misc_register(&btrfs_misc);
1680}
1681
1682static void btrfs_interface_exit(void)
1683{
1684 if (misc_deregister(&btrfs_misc) < 0)
1685 printk(KERN_INFO "btrfs: misc_deregister failed for control device\n");
1686}
1687
1688static int __init init_btrfs_fs(void)
1689{
1690 int err;
1691
1692 err = btrfs_init_sysfs();
1693 if (err)
1694 return err;
1695
1696 btrfs_init_compress();
1697
1698 err = btrfs_init_cachep();
1699 if (err)
1700 goto free_compress;
1701
1702 err = extent_io_init();
1703 if (err)
1704 goto free_cachep;
1705
1706 err = extent_map_init();
1707 if (err)
1708 goto free_extent_io;
1709
1710 err = ordered_data_init();
1711 if (err)
1712 goto free_extent_map;
1713
1714 err = btrfs_delayed_inode_init();
1715 if (err)
1716 goto free_ordered_data;
1717
1718 err = btrfs_auto_defrag_init();
1719 if (err)
1720 goto free_delayed_inode;
1721
1722 err = btrfs_delayed_ref_init();
1723 if (err)
1724 goto free_auto_defrag;
1725
1726 err = btrfs_interface_init();
1727 if (err)
1728 goto free_delayed_ref;
1729
1730 err = register_filesystem(&btrfs_fs_type);
1731 if (err)
1732 goto unregister_ioctl;
1733
1734 btrfs_init_lockdep();
1735
1736#ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
1737 btrfs_test_free_space_cache();
1738#endif
1739
1740 printk(KERN_INFO "%s loaded\n", BTRFS_BUILD_VERSION);
1741 return 0;
1742
1743unregister_ioctl:
1744 btrfs_interface_exit();
1745free_delayed_ref:
1746 btrfs_delayed_ref_exit();
1747free_auto_defrag:
1748 btrfs_auto_defrag_exit();
1749free_delayed_inode:
1750 btrfs_delayed_inode_exit();
1751free_ordered_data:
1752 ordered_data_exit();
1753free_extent_map:
1754 extent_map_exit();
1755free_extent_io:
1756 extent_io_exit();
1757free_cachep:
1758 btrfs_destroy_cachep();
1759free_compress:
1760 btrfs_exit_compress();
1761 btrfs_exit_sysfs();
1762 return err;
1763}
1764
1765static void __exit exit_btrfs_fs(void)
1766{
1767 btrfs_destroy_cachep();
1768 btrfs_delayed_ref_exit();
1769 btrfs_auto_defrag_exit();
1770 btrfs_delayed_inode_exit();
1771 ordered_data_exit();
1772 extent_map_exit();
1773 extent_io_exit();
1774 btrfs_interface_exit();
1775 unregister_filesystem(&btrfs_fs_type);
1776 btrfs_exit_sysfs();
1777 btrfs_cleanup_fs_uuids();
1778 btrfs_exit_compress();
1779}
1780
1781module_init(init_btrfs_fs)
1782module_exit(exit_btrfs_fs)
1783
1784MODULE_LICENSE("GPL");
1785