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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 "export.h"
55#include "compression.h"
56#include "rcu-string.h"
57#include "dev-replace.h"
58#include "free-space-cache.h"
59
60#define CREATE_TRACE_POINTS
61#include <trace/events/btrfs.h>
62
63static const struct super_operations btrfs_super_ops;
64static struct file_system_type btrfs_fs_type;
65
66static const char *btrfs_decode_error(int errno)
67{
68 char *errstr = "unknown";
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 case -ENOSPC:
84 errstr = "No space left";
85 break;
86 case -ENOENT:
87 errstr = "No such entry";
88 break;
89 }
90
91 return errstr;
92}
93
94static void save_error_info(struct btrfs_fs_info *fs_info)
95{
96
97
98
99
100 set_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state);
101}
102
103
104static void btrfs_handle_error(struct btrfs_fs_info *fs_info)
105{
106 struct super_block *sb = fs_info->sb;
107
108 if (sb->s_flags & MS_RDONLY)
109 return;
110
111 if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state)) {
112 sb->s_flags |= MS_RDONLY;
113 btrfs_info(fs_info, "forced readonly");
114
115
116
117
118
119
120
121
122
123
124 }
125}
126
127#ifdef CONFIG_PRINTK
128
129
130
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 const char *errstr;
137
138
139
140
141
142 if (errno == -EROFS && (sb->s_flags & MS_RDONLY))
143 return;
144
145 errstr = btrfs_decode_error(errno);
146 if (fmt) {
147 struct va_format vaf;
148 va_list args;
149
150 va_start(args, fmt);
151 vaf.fmt = fmt;
152 vaf.va = &args;
153
154 printk(KERN_CRIT "BTRFS error (device %s) in %s:%d: errno=%d %s (%pV)\n",
155 sb->s_id, function, line, errno, errstr, &vaf);
156 va_end(args);
157 } else {
158 printk(KERN_CRIT "BTRFS error (device %s) in %s:%d: errno=%d %s\n",
159 sb->s_id, function, line, errno, errstr);
160 }
161
162
163 save_error_info(fs_info);
164 if (sb->s_flags & MS_BORN)
165 btrfs_handle_error(fs_info);
166}
167
168static const char * const logtypes[] = {
169 "emergency",
170 "alert",
171 "critical",
172 "error",
173 "warning",
174 "notice",
175 "info",
176 "debug",
177};
178
179void btrfs_printk(const struct btrfs_fs_info *fs_info, const char *fmt, ...)
180{
181 struct super_block *sb = fs_info->sb;
182 char lvl[4];
183 struct va_format vaf;
184 va_list args;
185 const char *type = logtypes[4];
186 int kern_level;
187
188 va_start(args, fmt);
189
190 kern_level = printk_get_level(fmt);
191 if (kern_level) {
192 size_t size = printk_skip_level(fmt) - fmt;
193 memcpy(lvl, fmt, size);
194 lvl[size] = '\0';
195 fmt += size;
196 type = logtypes[kern_level - '0'];
197 } else
198 *lvl = '\0';
199
200 vaf.fmt = fmt;
201 vaf.va = &args;
202
203 printk("%sBTRFS %s (device %s): %pV\n", lvl, type, sb->s_id, &vaf);
204
205 va_end(args);
206}
207
208#else
209
210void __btrfs_std_error(struct btrfs_fs_info *fs_info, const char *function,
211 unsigned int line, int errno, const char *fmt, ...)
212{
213 struct super_block *sb = fs_info->sb;
214
215
216
217
218
219 if (errno == -EROFS && (sb->s_flags & MS_RDONLY))
220 return;
221
222
223 if (sb->s_flags & MS_BORN) {
224 save_error_info(fs_info);
225 btrfs_handle_error(fs_info);
226 }
227}
228#endif
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243void __btrfs_abort_transaction(struct btrfs_trans_handle *trans,
244 struct btrfs_root *root, const char *function,
245 unsigned int line, int errno)
246{
247
248
249
250 if (!test_and_set_bit(BTRFS_FS_STATE_TRANS_ABORTED,
251 &root->fs_info->fs_state)) {
252 WARN(1, KERN_DEBUG "btrfs: Transaction aborted (error %d)\n",
253 errno);
254 }
255 trans->aborted = errno;
256
257
258 if (!trans->blocks_used) {
259 const char *errstr;
260
261 errstr = btrfs_decode_error(errno);
262 btrfs_warn(root->fs_info,
263 "%s:%d: Aborting unused transaction(%s).",
264 function, line, errstr);
265 return;
266 }
267 ACCESS_ONCE(trans->transaction->aborted) = errno;
268
269 wake_up(&root->fs_info->transaction_wait);
270 wake_up(&root->fs_info->transaction_blocked_wait);
271 __btrfs_std_error(root->fs_info, function, line, errno, NULL);
272}
273
274
275
276
277void __btrfs_panic(struct btrfs_fs_info *fs_info, const char *function,
278 unsigned int line, int errno, const char *fmt, ...)
279{
280 char *s_id = "<unknown>";
281 const char *errstr;
282 struct va_format vaf = { .fmt = fmt };
283 va_list args;
284
285 if (fs_info)
286 s_id = fs_info->sb->s_id;
287
288 va_start(args, fmt);
289 vaf.va = &args;
290
291 errstr = btrfs_decode_error(errno);
292 if (fs_info && (fs_info->mount_opt & BTRFS_MOUNT_PANIC_ON_FATAL_ERROR))
293 panic(KERN_CRIT "BTRFS panic (device %s) in %s:%d: %pV (errno=%d %s)\n",
294 s_id, function, line, &vaf, errno, errstr);
295
296 printk(KERN_CRIT "BTRFS panic (device %s) in %s:%d: %pV (errno=%d %s)\n",
297 s_id, function, line, &vaf, errno, errstr);
298 va_end(args);
299
300}
301
302static void btrfs_put_super(struct super_block *sb)
303{
304 (void)close_ctree(btrfs_sb(sb)->tree_root);
305
306
307
308
309
310
311}
312
313enum {
314 Opt_degraded, Opt_subvol, Opt_subvolid, Opt_device, Opt_nodatasum,
315 Opt_nodatacow, Opt_max_inline, Opt_alloc_start, Opt_nobarrier, Opt_ssd,
316 Opt_nossd, Opt_ssd_spread, Opt_thread_pool, Opt_noacl, Opt_compress,
317 Opt_compress_type, Opt_compress_force, Opt_compress_force_type,
318 Opt_notreelog, Opt_ratio, Opt_flushoncommit, Opt_discard,
319 Opt_space_cache, Opt_clear_cache, Opt_user_subvol_rm_allowed,
320 Opt_enospc_debug, Opt_subvolrootid, Opt_defrag, Opt_inode_cache,
321 Opt_no_space_cache, Opt_recovery, Opt_skip_balance,
322 Opt_check_integrity, Opt_check_integrity_including_extent_data,
323 Opt_check_integrity_print_mask, Opt_fatal_errors,
324 Opt_err,
325};
326
327static match_table_t tokens = {
328 {Opt_degraded, "degraded"},
329 {Opt_subvol, "subvol=%s"},
330 {Opt_subvolid, "subvolid=%d"},
331 {Opt_device, "device=%s"},
332 {Opt_nodatasum, "nodatasum"},
333 {Opt_nodatacow, "nodatacow"},
334 {Opt_nobarrier, "nobarrier"},
335 {Opt_max_inline, "max_inline=%s"},
336 {Opt_alloc_start, "alloc_start=%s"},
337 {Opt_thread_pool, "thread_pool=%d"},
338 {Opt_compress, "compress"},
339 {Opt_compress_type, "compress=%s"},
340 {Opt_compress_force, "compress-force"},
341 {Opt_compress_force_type, "compress-force=%s"},
342 {Opt_ssd, "ssd"},
343 {Opt_ssd_spread, "ssd_spread"},
344 {Opt_nossd, "nossd"},
345 {Opt_noacl, "noacl"},
346 {Opt_notreelog, "notreelog"},
347 {Opt_flushoncommit, "flushoncommit"},
348 {Opt_ratio, "metadata_ratio=%d"},
349 {Opt_discard, "discard"},
350 {Opt_space_cache, "space_cache"},
351 {Opt_clear_cache, "clear_cache"},
352 {Opt_user_subvol_rm_allowed, "user_subvol_rm_allowed"},
353 {Opt_enospc_debug, "enospc_debug"},
354 {Opt_subvolrootid, "subvolrootid=%d"},
355 {Opt_defrag, "autodefrag"},
356 {Opt_inode_cache, "inode_cache"},
357 {Opt_no_space_cache, "nospace_cache"},
358 {Opt_recovery, "recovery"},
359 {Opt_skip_balance, "skip_balance"},
360 {Opt_check_integrity, "check_int"},
361 {Opt_check_integrity_including_extent_data, "check_int_data"},
362 {Opt_check_integrity_print_mask, "check_int_print_mask=%d"},
363 {Opt_fatal_errors, "fatal_errors=%s"},
364 {Opt_err, NULL},
365};
366
367
368
369
370
371
372int btrfs_parse_options(struct btrfs_root *root, char *options)
373{
374 struct btrfs_fs_info *info = root->fs_info;
375 substring_t args[MAX_OPT_ARGS];
376 char *p, *num, *orig = NULL;
377 u64 cache_gen;
378 int intarg;
379 int ret = 0;
380 char *compress_type;
381 bool compress_force = false;
382
383 cache_gen = btrfs_super_cache_generation(root->fs_info->super_copy);
384 if (cache_gen)
385 btrfs_set_opt(info->mount_opt, SPACE_CACHE);
386
387 if (!options)
388 goto out;
389
390
391
392
393
394 options = kstrdup(options, GFP_NOFS);
395 if (!options)
396 return -ENOMEM;
397
398 orig = options;
399
400 while ((p = strsep(&options, ",")) != NULL) {
401 int token;
402 if (!*p)
403 continue;
404
405 token = match_token(p, tokens, args);
406 switch (token) {
407 case Opt_degraded:
408 printk(KERN_INFO "btrfs: allowing degraded mounts\n");
409 btrfs_set_opt(info->mount_opt, DEGRADED);
410 break;
411 case Opt_subvol:
412 case Opt_subvolid:
413 case Opt_subvolrootid:
414 case Opt_device:
415
416
417
418
419 break;
420 case Opt_nodatasum:
421 printk(KERN_INFO "btrfs: setting nodatasum\n");
422 btrfs_set_opt(info->mount_opt, NODATASUM);
423 break;
424 case Opt_nodatacow:
425 if (!btrfs_test_opt(root, COMPRESS) ||
426 !btrfs_test_opt(root, FORCE_COMPRESS)) {
427 printk(KERN_INFO "btrfs: setting nodatacow, compression disabled\n");
428 } else {
429 printk(KERN_INFO "btrfs: setting nodatacow\n");
430 }
431 info->compress_type = BTRFS_COMPRESS_NONE;
432 btrfs_clear_opt(info->mount_opt, COMPRESS);
433 btrfs_clear_opt(info->mount_opt, FORCE_COMPRESS);
434 btrfs_set_opt(info->mount_opt, NODATACOW);
435 btrfs_set_opt(info->mount_opt, NODATASUM);
436 break;
437 case Opt_compress_force:
438 case Opt_compress_force_type:
439 compress_force = true;
440
441 case Opt_compress:
442 case Opt_compress_type:
443 if (token == Opt_compress ||
444 token == Opt_compress_force ||
445 strcmp(args[0].from, "zlib") == 0) {
446 compress_type = "zlib";
447 info->compress_type = BTRFS_COMPRESS_ZLIB;
448 btrfs_set_opt(info->mount_opt, COMPRESS);
449 btrfs_clear_opt(info->mount_opt, NODATACOW);
450 btrfs_clear_opt(info->mount_opt, NODATASUM);
451 } else if (strcmp(args[0].from, "lzo") == 0) {
452 compress_type = "lzo";
453 info->compress_type = BTRFS_COMPRESS_LZO;
454 btrfs_set_opt(info->mount_opt, COMPRESS);
455 btrfs_clear_opt(info->mount_opt, NODATACOW);
456 btrfs_clear_opt(info->mount_opt, NODATASUM);
457 btrfs_set_fs_incompat(info, COMPRESS_LZO);
458 } else if (strncmp(args[0].from, "no", 2) == 0) {
459 compress_type = "no";
460 info->compress_type = BTRFS_COMPRESS_NONE;
461 btrfs_clear_opt(info->mount_opt, COMPRESS);
462 btrfs_clear_opt(info->mount_opt, FORCE_COMPRESS);
463 compress_force = false;
464 } else {
465 ret = -EINVAL;
466 goto out;
467 }
468
469 if (compress_force) {
470 btrfs_set_opt(info->mount_opt, FORCE_COMPRESS);
471 pr_info("btrfs: force %s compression\n",
472 compress_type);
473 } else
474 pr_info("btrfs: use %s compression\n",
475 compress_type);
476 break;
477 case Opt_ssd:
478 printk(KERN_INFO "btrfs: use ssd allocation scheme\n");
479 btrfs_set_opt(info->mount_opt, SSD);
480 break;
481 case Opt_ssd_spread:
482 printk(KERN_INFO "btrfs: use spread ssd "
483 "allocation scheme\n");
484 btrfs_set_opt(info->mount_opt, SSD);
485 btrfs_set_opt(info->mount_opt, SSD_SPREAD);
486 break;
487 case Opt_nossd:
488 printk(KERN_INFO "btrfs: not using ssd allocation "
489 "scheme\n");
490 btrfs_set_opt(info->mount_opt, NOSSD);
491 btrfs_clear_opt(info->mount_opt, SSD);
492 btrfs_clear_opt(info->mount_opt, SSD_SPREAD);
493 break;
494 case Opt_nobarrier:
495 printk(KERN_INFO "btrfs: turning off barriers\n");
496 btrfs_set_opt(info->mount_opt, NOBARRIER);
497 break;
498 case Opt_thread_pool:
499 intarg = 0;
500 match_int(&args[0], &intarg);
501 if (intarg)
502 info->thread_pool_size = intarg;
503 break;
504 case Opt_max_inline:
505 num = match_strdup(&args[0]);
506 if (num) {
507 info->max_inline = memparse(num, NULL);
508 kfree(num);
509
510 if (info->max_inline) {
511 info->max_inline = max_t(u64,
512 info->max_inline,
513 root->sectorsize);
514 }
515 printk(KERN_INFO "btrfs: max_inline at %llu\n",
516 (unsigned long long)info->max_inline);
517 }
518 break;
519 case Opt_alloc_start:
520 num = match_strdup(&args[0]);
521 if (num) {
522 mutex_lock(&info->chunk_mutex);
523 info->alloc_start = memparse(num, NULL);
524 mutex_unlock(&info->chunk_mutex);
525 kfree(num);
526 printk(KERN_INFO
527 "btrfs: allocations start at %llu\n",
528 (unsigned long long)info->alloc_start);
529 }
530 break;
531 case Opt_noacl:
532 root->fs_info->sb->s_flags &= ~MS_POSIXACL;
533 break;
534 case Opt_notreelog:
535 printk(KERN_INFO "btrfs: disabling tree log\n");
536 btrfs_set_opt(info->mount_opt, NOTREELOG);
537 break;
538 case Opt_flushoncommit:
539 printk(KERN_INFO "btrfs: turning on flush-on-commit\n");
540 btrfs_set_opt(info->mount_opt, FLUSHONCOMMIT);
541 break;
542 case Opt_ratio:
543 intarg = 0;
544 match_int(&args[0], &intarg);
545 if (intarg) {
546 info->metadata_ratio = intarg;
547 printk(KERN_INFO "btrfs: metadata ratio %d\n",
548 info->metadata_ratio);
549 }
550 break;
551 case Opt_discard:
552 btrfs_set_opt(info->mount_opt, DISCARD);
553 break;
554 case Opt_space_cache:
555 btrfs_set_opt(info->mount_opt, SPACE_CACHE);
556 break;
557 case Opt_no_space_cache:
558 printk(KERN_INFO "btrfs: disabling disk space caching\n");
559 btrfs_clear_opt(info->mount_opt, SPACE_CACHE);
560 break;
561 case Opt_inode_cache:
562 printk(KERN_INFO "btrfs: enabling inode map caching\n");
563 btrfs_set_opt(info->mount_opt, INODE_MAP_CACHE);
564 break;
565 case Opt_clear_cache:
566 printk(KERN_INFO "btrfs: force clearing of disk cache\n");
567 btrfs_set_opt(info->mount_opt, CLEAR_CACHE);
568 break;
569 case Opt_user_subvol_rm_allowed:
570 btrfs_set_opt(info->mount_opt, USER_SUBVOL_RM_ALLOWED);
571 break;
572 case Opt_enospc_debug:
573 btrfs_set_opt(info->mount_opt, ENOSPC_DEBUG);
574 break;
575 case Opt_defrag:
576 printk(KERN_INFO "btrfs: enabling auto defrag\n");
577 btrfs_set_opt(info->mount_opt, AUTO_DEFRAG);
578 break;
579 case Opt_recovery:
580 printk(KERN_INFO "btrfs: enabling auto recovery\n");
581 btrfs_set_opt(info->mount_opt, RECOVERY);
582 break;
583 case Opt_skip_balance:
584 btrfs_set_opt(info->mount_opt, SKIP_BALANCE);
585 break;
586#ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
587 case Opt_check_integrity_including_extent_data:
588 printk(KERN_INFO "btrfs: enabling check integrity"
589 " including extent data\n");
590 btrfs_set_opt(info->mount_opt,
591 CHECK_INTEGRITY_INCLUDING_EXTENT_DATA);
592 btrfs_set_opt(info->mount_opt, CHECK_INTEGRITY);
593 break;
594 case Opt_check_integrity:
595 printk(KERN_INFO "btrfs: enabling check integrity\n");
596 btrfs_set_opt(info->mount_opt, CHECK_INTEGRITY);
597 break;
598 case Opt_check_integrity_print_mask:
599 intarg = 0;
600 match_int(&args[0], &intarg);
601 if (intarg) {
602 info->check_integrity_print_mask = intarg;
603 printk(KERN_INFO "btrfs:"
604 " check_integrity_print_mask 0x%x\n",
605 info->check_integrity_print_mask);
606 }
607 break;
608#else
609 case Opt_check_integrity_including_extent_data:
610 case Opt_check_integrity:
611 case Opt_check_integrity_print_mask:
612 printk(KERN_ERR "btrfs: support for check_integrity*"
613 " not compiled in!\n");
614 ret = -EINVAL;
615 goto out;
616#endif
617 case Opt_fatal_errors:
618 if (strcmp(args[0].from, "panic") == 0)
619 btrfs_set_opt(info->mount_opt,
620 PANIC_ON_FATAL_ERROR);
621 else if (strcmp(args[0].from, "bug") == 0)
622 btrfs_clear_opt(info->mount_opt,
623 PANIC_ON_FATAL_ERROR);
624 else {
625 ret = -EINVAL;
626 goto out;
627 }
628 break;
629 case Opt_err:
630 printk(KERN_INFO "btrfs: unrecognized mount option "
631 "'%s'\n", p);
632 ret = -EINVAL;
633 goto out;
634 default:
635 break;
636 }
637 }
638out:
639 if (!ret && btrfs_test_opt(root, SPACE_CACHE))
640 printk(KERN_INFO "btrfs: disk space caching is enabled\n");
641 kfree(orig);
642 return ret;
643}
644
645
646
647
648
649
650
651static int btrfs_parse_early_options(const char *options, fmode_t flags,
652 void *holder, char **subvol_name, u64 *subvol_objectid,
653 struct btrfs_fs_devices **fs_devices)
654{
655 substring_t args[MAX_OPT_ARGS];
656 char *device_name, *opts, *orig, *p;
657 int error = 0;
658 int intarg;
659
660 if (!options)
661 return 0;
662
663
664
665
666
667 opts = kstrdup(options, GFP_KERNEL);
668 if (!opts)
669 return -ENOMEM;
670 orig = opts;
671
672 while ((p = strsep(&opts, ",")) != NULL) {
673 int token;
674 if (!*p)
675 continue;
676
677 token = match_token(p, tokens, args);
678 switch (token) {
679 case Opt_subvol:
680 kfree(*subvol_name);
681 *subvol_name = match_strdup(&args[0]);
682 break;
683 case Opt_subvolid:
684 intarg = 0;
685 error = match_int(&args[0], &intarg);
686 if (!error) {
687
688 if (!intarg)
689 *subvol_objectid =
690 BTRFS_FS_TREE_OBJECTID;
691 else
692 *subvol_objectid = intarg;
693 }
694 break;
695 case Opt_subvolrootid:
696 printk(KERN_WARNING
697 "btrfs: 'subvolrootid' mount option is deprecated and has no effect\n");
698 break;
699 case Opt_device:
700 device_name = match_strdup(&args[0]);
701 if (!device_name) {
702 error = -ENOMEM;
703 goto out;
704 }
705 error = btrfs_scan_one_device(device_name,
706 flags, holder, fs_devices);
707 kfree(device_name);
708 if (error)
709 goto out;
710 break;
711 default:
712 break;
713 }
714 }
715
716out:
717 kfree(orig);
718 return error;
719}
720
721static struct dentry *get_default_root(struct super_block *sb,
722 u64 subvol_objectid)
723{
724 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
725 struct btrfs_root *root = fs_info->tree_root;
726 struct btrfs_root *new_root;
727 struct btrfs_dir_item *di;
728 struct btrfs_path *path;
729 struct btrfs_key location;
730 struct inode *inode;
731 u64 dir_id;
732 int new = 0;
733
734
735
736
737
738 if (subvol_objectid) {
739 location.objectid = subvol_objectid;
740 location.type = BTRFS_ROOT_ITEM_KEY;
741 location.offset = (u64)-1;
742 goto find_root;
743 }
744
745 path = btrfs_alloc_path();
746 if (!path)
747 return ERR_PTR(-ENOMEM);
748 path->leave_spinning = 1;
749
750
751
752
753
754
755 dir_id = btrfs_super_root_dir(fs_info->super_copy);
756 di = btrfs_lookup_dir_item(NULL, root, path, dir_id, "default", 7, 0);
757 if (IS_ERR(di)) {
758 btrfs_free_path(path);
759 return ERR_CAST(di);
760 }
761 if (!di) {
762
763
764
765
766
767 btrfs_free_path(path);
768 dir_id = BTRFS_FIRST_FREE_OBJECTID;
769 new_root = fs_info->fs_root;
770 goto setup_root;
771 }
772
773 btrfs_dir_item_key_to_cpu(path->nodes[0], di, &location);
774 btrfs_free_path(path);
775
776find_root:
777 new_root = btrfs_read_fs_root_no_name(fs_info, &location);
778 if (IS_ERR(new_root))
779 return ERR_CAST(new_root);
780
781 dir_id = btrfs_root_dirid(&new_root->root_item);
782setup_root:
783 location.objectid = dir_id;
784 location.type = BTRFS_INODE_ITEM_KEY;
785 location.offset = 0;
786
787 inode = btrfs_iget(sb, &location, new_root, &new);
788 if (IS_ERR(inode))
789 return ERR_CAST(inode);
790
791
792
793
794
795
796 if (!new && sb->s_root->d_inode == inode) {
797 iput(inode);
798 return dget(sb->s_root);
799 }
800
801 return d_obtain_alias(inode);
802}
803
804static int btrfs_fill_super(struct super_block *sb,
805 struct btrfs_fs_devices *fs_devices,
806 void *data, int silent)
807{
808 struct inode *inode;
809 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
810 struct btrfs_key key;
811 int err;
812
813 sb->s_maxbytes = MAX_LFS_FILESIZE;
814 sb->s_magic = BTRFS_SUPER_MAGIC;
815 sb->s_op = &btrfs_super_ops;
816 sb->s_d_op = &btrfs_dentry_operations;
817 sb->s_export_op = &btrfs_export_ops;
818 sb->s_xattr = btrfs_xattr_handlers;
819 sb->s_time_gran = 1;
820#ifdef CONFIG_BTRFS_FS_POSIX_ACL
821 sb->s_flags |= MS_POSIXACL;
822#endif
823 sb->s_flags |= MS_I_VERSION;
824 err = open_ctree(sb, fs_devices, (char *)data);
825 if (err) {
826 printk("btrfs: open_ctree failed\n");
827 return err;
828 }
829
830 key.objectid = BTRFS_FIRST_FREE_OBJECTID;
831 key.type = BTRFS_INODE_ITEM_KEY;
832 key.offset = 0;
833 inode = btrfs_iget(sb, &key, fs_info->fs_root, NULL);
834 if (IS_ERR(inode)) {
835 err = PTR_ERR(inode);
836 goto fail_close;
837 }
838
839 sb->s_root = d_make_root(inode);
840 if (!sb->s_root) {
841 err = -ENOMEM;
842 goto fail_close;
843 }
844
845 save_mount_options(sb, data);
846 cleancache_init_fs(sb);
847 sb->s_flags |= MS_ACTIVE;
848 return 0;
849
850fail_close:
851 close_ctree(fs_info->tree_root);
852 return err;
853}
854
855int btrfs_sync_fs(struct super_block *sb, int wait)
856{
857 struct btrfs_trans_handle *trans;
858 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
859 struct btrfs_root *root = fs_info->tree_root;
860
861 trace_btrfs_sync_fs(wait);
862
863 if (!wait) {
864 filemap_flush(fs_info->btree_inode->i_mapping);
865 return 0;
866 }
867
868 btrfs_wait_all_ordered_extents(fs_info, 1);
869
870 trans = btrfs_attach_transaction_barrier(root);
871 if (IS_ERR(trans)) {
872
873 if (PTR_ERR(trans) == -ENOENT)
874 return 0;
875 return PTR_ERR(trans);
876 }
877 return btrfs_commit_transaction(trans, root);
878}
879
880static int btrfs_show_options(struct seq_file *seq, struct dentry *dentry)
881{
882 struct btrfs_fs_info *info = btrfs_sb(dentry->d_sb);
883 struct btrfs_root *root = info->tree_root;
884 char *compress_type;
885
886 if (btrfs_test_opt(root, DEGRADED))
887 seq_puts(seq, ",degraded");
888 if (btrfs_test_opt(root, NODATASUM))
889 seq_puts(seq, ",nodatasum");
890 if (btrfs_test_opt(root, NODATACOW))
891 seq_puts(seq, ",nodatacow");
892 if (btrfs_test_opt(root, NOBARRIER))
893 seq_puts(seq, ",nobarrier");
894 if (info->max_inline != 8192 * 1024)
895 seq_printf(seq, ",max_inline=%llu",
896 (unsigned long long)info->max_inline);
897 if (info->alloc_start != 0)
898 seq_printf(seq, ",alloc_start=%llu",
899 (unsigned long long)info->alloc_start);
900 if (info->thread_pool_size != min_t(unsigned long,
901 num_online_cpus() + 2, 8))
902 seq_printf(seq, ",thread_pool=%d", info->thread_pool_size);
903 if (btrfs_test_opt(root, COMPRESS)) {
904 if (info->compress_type == BTRFS_COMPRESS_ZLIB)
905 compress_type = "zlib";
906 else
907 compress_type = "lzo";
908 if (btrfs_test_opt(root, FORCE_COMPRESS))
909 seq_printf(seq, ",compress-force=%s", compress_type);
910 else
911 seq_printf(seq, ",compress=%s", compress_type);
912 }
913 if (btrfs_test_opt(root, NOSSD))
914 seq_puts(seq, ",nossd");
915 if (btrfs_test_opt(root, SSD_SPREAD))
916 seq_puts(seq, ",ssd_spread");
917 else if (btrfs_test_opt(root, SSD))
918 seq_puts(seq, ",ssd");
919 if (btrfs_test_opt(root, NOTREELOG))
920 seq_puts(seq, ",notreelog");
921 if (btrfs_test_opt(root, FLUSHONCOMMIT))
922 seq_puts(seq, ",flushoncommit");
923 if (btrfs_test_opt(root, DISCARD))
924 seq_puts(seq, ",discard");
925 if (!(root->fs_info->sb->s_flags & MS_POSIXACL))
926 seq_puts(seq, ",noacl");
927 if (btrfs_test_opt(root, SPACE_CACHE))
928 seq_puts(seq, ",space_cache");
929 else
930 seq_puts(seq, ",nospace_cache");
931 if (btrfs_test_opt(root, CLEAR_CACHE))
932 seq_puts(seq, ",clear_cache");
933 if (btrfs_test_opt(root, USER_SUBVOL_RM_ALLOWED))
934 seq_puts(seq, ",user_subvol_rm_allowed");
935 if (btrfs_test_opt(root, ENOSPC_DEBUG))
936 seq_puts(seq, ",enospc_debug");
937 if (btrfs_test_opt(root, AUTO_DEFRAG))
938 seq_puts(seq, ",autodefrag");
939 if (btrfs_test_opt(root, INODE_MAP_CACHE))
940 seq_puts(seq, ",inode_cache");
941 if (btrfs_test_opt(root, SKIP_BALANCE))
942 seq_puts(seq, ",skip_balance");
943 if (btrfs_test_opt(root, PANIC_ON_FATAL_ERROR))
944 seq_puts(seq, ",fatal_errors=panic");
945 return 0;
946}
947
948static int btrfs_test_super(struct super_block *s, void *data)
949{
950 struct btrfs_fs_info *p = data;
951 struct btrfs_fs_info *fs_info = btrfs_sb(s);
952
953 return fs_info->fs_devices == p->fs_devices;
954}
955
956static int btrfs_set_super(struct super_block *s, void *data)
957{
958 int err = set_anon_super(s, data);
959 if (!err)
960 s->s_fs_info = data;
961 return err;
962}
963
964
965
966
967static inline int is_subvolume_inode(struct inode *inode)
968{
969 if (inode && inode->i_ino == BTRFS_FIRST_FREE_OBJECTID)
970 return 1;
971 return 0;
972}
973
974
975
976
977
978
979static char *setup_root_args(char *args)
980{
981 unsigned len = strlen(args) + 2 + 1;
982 char *src, *dst, *buf;
983
984
985
986
987
988
989
990
991
992 src = strstr(args, "subvol=");
993
994 if (!src)
995 return NULL;
996
997 buf = dst = kmalloc(len, GFP_NOFS);
998 if (!buf)
999 return NULL;
1000
1001
1002
1003
1004
1005 if (src != args) {
1006 *src++ = '\0';
1007 strcpy(buf, args);
1008 dst += strlen(args);
1009 }
1010
1011 strcpy(dst, "subvolid=0");
1012 dst += strlen("subvolid=0");
1013
1014
1015
1016
1017
1018 src = strchr(src, ',');
1019 if (src)
1020 strcpy(dst, src);
1021
1022 return buf;
1023}
1024
1025static struct dentry *mount_subvol(const char *subvol_name, int flags,
1026 const char *device_name, char *data)
1027{
1028 struct dentry *root;
1029 struct vfsmount *mnt;
1030 char *newargs;
1031
1032 newargs = setup_root_args(data);
1033 if (!newargs)
1034 return ERR_PTR(-ENOMEM);
1035 mnt = vfs_kern_mount(&btrfs_fs_type, flags, device_name,
1036 newargs);
1037 kfree(newargs);
1038 if (IS_ERR(mnt))
1039 return ERR_CAST(mnt);
1040
1041 root = mount_subtree(mnt, subvol_name);
1042
1043 if (!IS_ERR(root) && !is_subvolume_inode(root->d_inode)) {
1044 struct super_block *s = root->d_sb;
1045 dput(root);
1046 root = ERR_PTR(-EINVAL);
1047 deactivate_locked_super(s);
1048 printk(KERN_ERR "btrfs: '%s' is not a valid subvolume\n",
1049 subvol_name);
1050 }
1051
1052 return root;
1053}
1054
1055
1056
1057
1058
1059
1060
1061static struct dentry *btrfs_mount(struct file_system_type *fs_type, int flags,
1062 const char *device_name, void *data)
1063{
1064 struct block_device *bdev = NULL;
1065 struct super_block *s;
1066 struct dentry *root;
1067 struct btrfs_fs_devices *fs_devices = NULL;
1068 struct btrfs_fs_info *fs_info = NULL;
1069 fmode_t mode = FMODE_READ;
1070 char *subvol_name = NULL;
1071 u64 subvol_objectid = 0;
1072 int error = 0;
1073
1074 if (!(flags & MS_RDONLY))
1075 mode |= FMODE_WRITE;
1076
1077 error = btrfs_parse_early_options(data, mode, fs_type,
1078 &subvol_name, &subvol_objectid,
1079 &fs_devices);
1080 if (error) {
1081 kfree(subvol_name);
1082 return ERR_PTR(error);
1083 }
1084
1085 if (subvol_name) {
1086 root = mount_subvol(subvol_name, flags, device_name, data);
1087 kfree(subvol_name);
1088 return root;
1089 }
1090
1091 error = btrfs_scan_one_device(device_name, mode, fs_type, &fs_devices);
1092 if (error)
1093 return ERR_PTR(error);
1094
1095
1096
1097
1098
1099
1100
1101 fs_info = kzalloc(sizeof(struct btrfs_fs_info), GFP_NOFS);
1102 if (!fs_info)
1103 return ERR_PTR(-ENOMEM);
1104
1105 fs_info->fs_devices = fs_devices;
1106
1107 fs_info->super_copy = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_NOFS);
1108 fs_info->super_for_commit = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_NOFS);
1109 if (!fs_info->super_copy || !fs_info->super_for_commit) {
1110 error = -ENOMEM;
1111 goto error_fs_info;
1112 }
1113
1114 error = btrfs_open_devices(fs_devices, mode, fs_type);
1115 if (error)
1116 goto error_fs_info;
1117
1118 if (!(flags & MS_RDONLY) && fs_devices->rw_devices == 0) {
1119 error = -EACCES;
1120 goto error_close_devices;
1121 }
1122
1123 bdev = fs_devices->latest_bdev;
1124 s = sget(fs_type, btrfs_test_super, btrfs_set_super, flags | MS_NOSEC,
1125 fs_info);
1126 if (IS_ERR(s)) {
1127 error = PTR_ERR(s);
1128 goto error_close_devices;
1129 }
1130
1131 if (s->s_root) {
1132 btrfs_close_devices(fs_devices);
1133 free_fs_info(fs_info);
1134 if ((flags ^ s->s_flags) & MS_RDONLY)
1135 error = -EBUSY;
1136 } else {
1137 char b[BDEVNAME_SIZE];
1138
1139 strlcpy(s->s_id, bdevname(bdev, b), sizeof(s->s_id));
1140 btrfs_sb(s)->bdev_holder = fs_type;
1141 error = btrfs_fill_super(s, fs_devices, data,
1142 flags & MS_SILENT ? 1 : 0);
1143 }
1144
1145 root = !error ? get_default_root(s, subvol_objectid) : ERR_PTR(error);
1146 if (IS_ERR(root))
1147 deactivate_locked_super(s);
1148
1149 return root;
1150
1151error_close_devices:
1152 btrfs_close_devices(fs_devices);
1153error_fs_info:
1154 free_fs_info(fs_info);
1155 return ERR_PTR(error);
1156}
1157
1158static void btrfs_set_max_workers(struct btrfs_workers *workers, int new_limit)
1159{
1160 spin_lock_irq(&workers->lock);
1161 workers->max_workers = new_limit;
1162 spin_unlock_irq(&workers->lock);
1163}
1164
1165static void btrfs_resize_thread_pool(struct btrfs_fs_info *fs_info,
1166 int new_pool_size, int old_pool_size)
1167{
1168 if (new_pool_size == old_pool_size)
1169 return;
1170
1171 fs_info->thread_pool_size = new_pool_size;
1172
1173 printk(KERN_INFO "btrfs: resize thread pool %d -> %d\n",
1174 old_pool_size, new_pool_size);
1175
1176 btrfs_set_max_workers(&fs_info->generic_worker, new_pool_size);
1177 btrfs_set_max_workers(&fs_info->workers, new_pool_size);
1178 btrfs_set_max_workers(&fs_info->delalloc_workers, new_pool_size);
1179 btrfs_set_max_workers(&fs_info->submit_workers, new_pool_size);
1180 btrfs_set_max_workers(&fs_info->caching_workers, new_pool_size);
1181 btrfs_set_max_workers(&fs_info->fixup_workers, new_pool_size);
1182 btrfs_set_max_workers(&fs_info->endio_workers, new_pool_size);
1183 btrfs_set_max_workers(&fs_info->endio_meta_workers, new_pool_size);
1184 btrfs_set_max_workers(&fs_info->endio_meta_write_workers, new_pool_size);
1185 btrfs_set_max_workers(&fs_info->endio_write_workers, new_pool_size);
1186 btrfs_set_max_workers(&fs_info->endio_freespace_worker, new_pool_size);
1187 btrfs_set_max_workers(&fs_info->delayed_workers, new_pool_size);
1188 btrfs_set_max_workers(&fs_info->readahead_workers, new_pool_size);
1189 btrfs_set_max_workers(&fs_info->scrub_wr_completion_workers,
1190 new_pool_size);
1191}
1192
1193static inline void btrfs_remount_prepare(struct btrfs_fs_info *fs_info)
1194{
1195 set_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state);
1196}
1197
1198static inline void btrfs_remount_begin(struct btrfs_fs_info *fs_info,
1199 unsigned long old_opts, int flags)
1200{
1201 if (btrfs_raw_test_opt(old_opts, AUTO_DEFRAG) &&
1202 (!btrfs_raw_test_opt(fs_info->mount_opt, AUTO_DEFRAG) ||
1203 (flags & MS_RDONLY))) {
1204
1205 wait_event(fs_info->transaction_wait,
1206 (atomic_read(&fs_info->defrag_running) == 0));
1207 if (flags & MS_RDONLY)
1208 sync_filesystem(fs_info->sb);
1209 }
1210}
1211
1212static inline void btrfs_remount_cleanup(struct btrfs_fs_info *fs_info,
1213 unsigned long old_opts)
1214{
1215
1216
1217
1218
1219 if (btrfs_raw_test_opt(old_opts, AUTO_DEFRAG) &&
1220 (!btrfs_raw_test_opt(fs_info->mount_opt, AUTO_DEFRAG) ||
1221 (fs_info->sb->s_flags & MS_RDONLY))) {
1222 btrfs_cleanup_defrag_inodes(fs_info);
1223 }
1224
1225 clear_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state);
1226}
1227
1228static int btrfs_remount(struct super_block *sb, int *flags, char *data)
1229{
1230 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
1231 struct btrfs_root *root = fs_info->tree_root;
1232 unsigned old_flags = sb->s_flags;
1233 unsigned long old_opts = fs_info->mount_opt;
1234 unsigned long old_compress_type = fs_info->compress_type;
1235 u64 old_max_inline = fs_info->max_inline;
1236 u64 old_alloc_start = fs_info->alloc_start;
1237 int old_thread_pool_size = fs_info->thread_pool_size;
1238 unsigned int old_metadata_ratio = fs_info->metadata_ratio;
1239 int ret;
1240
1241 btrfs_remount_prepare(fs_info);
1242
1243 ret = btrfs_parse_options(root, data);
1244 if (ret) {
1245 ret = -EINVAL;
1246 goto restore;
1247 }
1248
1249 btrfs_remount_begin(fs_info, old_opts, *flags);
1250 btrfs_resize_thread_pool(fs_info,
1251 fs_info->thread_pool_size, old_thread_pool_size);
1252
1253 if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
1254 goto out;
1255
1256 if (*flags & MS_RDONLY) {
1257
1258
1259
1260
1261 sb->s_flags |= MS_RDONLY;
1262
1263 btrfs_dev_replace_suspend_for_unmount(fs_info);
1264 btrfs_scrub_cancel(fs_info);
1265 btrfs_pause_balance(fs_info);
1266
1267 ret = btrfs_commit_super(root);
1268 if (ret)
1269 goto restore;
1270 } else {
1271 if (fs_info->fs_devices->rw_devices == 0) {
1272 ret = -EACCES;
1273 goto restore;
1274 }
1275
1276 if (fs_info->fs_devices->missing_devices >
1277 fs_info->num_tolerated_disk_barrier_failures &&
1278 !(*flags & MS_RDONLY)) {
1279 printk(KERN_WARNING
1280 "Btrfs: too many missing devices, writeable remount is not allowed\n");
1281 ret = -EACCES;
1282 goto restore;
1283 }
1284
1285 if (btrfs_super_log_root(fs_info->super_copy) != 0) {
1286 ret = -EINVAL;
1287 goto restore;
1288 }
1289
1290 ret = btrfs_cleanup_fs_roots(fs_info);
1291 if (ret)
1292 goto restore;
1293
1294
1295 ret = btrfs_recover_relocation(root);
1296 if (ret)
1297 goto restore;
1298
1299 ret = btrfs_resume_balance_async(fs_info);
1300 if (ret)
1301 goto restore;
1302
1303 ret = btrfs_resume_dev_replace_async(fs_info);
1304 if (ret) {
1305 pr_warn("btrfs: failed to resume dev_replace\n");
1306 goto restore;
1307 }
1308 sb->s_flags &= ~MS_RDONLY;
1309 }
1310out:
1311 btrfs_remount_cleanup(fs_info, old_opts);
1312 return 0;
1313
1314restore:
1315
1316 if (sb->s_flags & MS_RDONLY)
1317 old_flags |= MS_RDONLY;
1318 sb->s_flags = old_flags;
1319 fs_info->mount_opt = old_opts;
1320 fs_info->compress_type = old_compress_type;
1321 fs_info->max_inline = old_max_inline;
1322 mutex_lock(&fs_info->chunk_mutex);
1323 fs_info->alloc_start = old_alloc_start;
1324 mutex_unlock(&fs_info->chunk_mutex);
1325 btrfs_resize_thread_pool(fs_info,
1326 old_thread_pool_size, fs_info->thread_pool_size);
1327 fs_info->metadata_ratio = old_metadata_ratio;
1328 btrfs_remount_cleanup(fs_info, old_opts);
1329 return ret;
1330}
1331
1332
1333static int btrfs_cmp_device_free_bytes(const void *dev_info1,
1334 const void *dev_info2)
1335{
1336 if (((struct btrfs_device_info *)dev_info1)->max_avail >
1337 ((struct btrfs_device_info *)dev_info2)->max_avail)
1338 return -1;
1339 else if (((struct btrfs_device_info *)dev_info1)->max_avail <
1340 ((struct btrfs_device_info *)dev_info2)->max_avail)
1341 return 1;
1342 else
1343 return 0;
1344}
1345
1346
1347
1348
1349
1350static inline void btrfs_descending_sort_devices(
1351 struct btrfs_device_info *devices,
1352 size_t nr_devices)
1353{
1354 sort(devices, nr_devices, sizeof(struct btrfs_device_info),
1355 btrfs_cmp_device_free_bytes, NULL);
1356}
1357
1358
1359
1360
1361
1362static int btrfs_calc_avail_data_space(struct btrfs_root *root, u64 *free_bytes)
1363{
1364 struct btrfs_fs_info *fs_info = root->fs_info;
1365 struct btrfs_device_info *devices_info;
1366 struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
1367 struct btrfs_device *device;
1368 u64 skip_space;
1369 u64 type;
1370 u64 avail_space;
1371 u64 used_space;
1372 u64 min_stripe_size;
1373 int min_stripes = 1, num_stripes = 1;
1374 int i = 0, nr_devices;
1375 int ret;
1376
1377 nr_devices = fs_info->fs_devices->open_devices;
1378 BUG_ON(!nr_devices);
1379
1380 devices_info = kmalloc(sizeof(*devices_info) * nr_devices,
1381 GFP_NOFS);
1382 if (!devices_info)
1383 return -ENOMEM;
1384
1385
1386 type = btrfs_get_alloc_profile(root, 1);
1387 if (type & BTRFS_BLOCK_GROUP_RAID0) {
1388 min_stripes = 2;
1389 num_stripes = nr_devices;
1390 } else if (type & BTRFS_BLOCK_GROUP_RAID1) {
1391 min_stripes = 2;
1392 num_stripes = 2;
1393 } else if (type & BTRFS_BLOCK_GROUP_RAID10) {
1394 min_stripes = 4;
1395 num_stripes = 4;
1396 }
1397
1398 if (type & BTRFS_BLOCK_GROUP_DUP)
1399 min_stripe_size = 2 * BTRFS_STRIPE_LEN;
1400 else
1401 min_stripe_size = BTRFS_STRIPE_LEN;
1402
1403 list_for_each_entry(device, &fs_devices->devices, dev_list) {
1404 if (!device->in_fs_metadata || !device->bdev ||
1405 device->is_tgtdev_for_dev_replace)
1406 continue;
1407
1408 avail_space = device->total_bytes - device->bytes_used;
1409
1410
1411 do_div(avail_space, BTRFS_STRIPE_LEN);
1412 avail_space *= BTRFS_STRIPE_LEN;
1413
1414
1415
1416
1417
1418
1419 skip_space = 1024 * 1024;
1420
1421
1422 if (fs_info->alloc_start + BTRFS_STRIPE_LEN <=
1423 device->total_bytes)
1424 skip_space = max(fs_info->alloc_start, skip_space);
1425
1426
1427
1428
1429
1430
1431 ret = btrfs_account_dev_extents_size(device, 0, skip_space - 1,
1432 &used_space);
1433 if (ret) {
1434 kfree(devices_info);
1435 return ret;
1436 }
1437
1438
1439 skip_space -= used_space;
1440
1441
1442
1443
1444
1445 if (avail_space && avail_space >= skip_space)
1446 avail_space -= skip_space;
1447 else
1448 avail_space = 0;
1449
1450 if (avail_space < min_stripe_size)
1451 continue;
1452
1453 devices_info[i].dev = device;
1454 devices_info[i].max_avail = avail_space;
1455
1456 i++;
1457 }
1458
1459 nr_devices = i;
1460
1461 btrfs_descending_sort_devices(devices_info, nr_devices);
1462
1463 i = nr_devices - 1;
1464 avail_space = 0;
1465 while (nr_devices >= min_stripes) {
1466 if (num_stripes > nr_devices)
1467 num_stripes = nr_devices;
1468
1469 if (devices_info[i].max_avail >= min_stripe_size) {
1470 int j;
1471 u64 alloc_size;
1472
1473 avail_space += devices_info[i].max_avail * num_stripes;
1474 alloc_size = devices_info[i].max_avail;
1475 for (j = i + 1 - num_stripes; j <= i; j++)
1476 devices_info[j].max_avail -= alloc_size;
1477 }
1478 i--;
1479 nr_devices--;
1480 }
1481
1482 kfree(devices_info);
1483 *free_bytes = avail_space;
1484 return 0;
1485}
1486
1487static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf)
1488{
1489 struct btrfs_fs_info *fs_info = btrfs_sb(dentry->d_sb);
1490 struct btrfs_super_block *disk_super = fs_info->super_copy;
1491 struct list_head *head = &fs_info->space_info;
1492 struct btrfs_space_info *found;
1493 u64 total_used = 0;
1494 u64 total_free_data = 0;
1495 int bits = dentry->d_sb->s_blocksize_bits;
1496 __be32 *fsid = (__be32 *)fs_info->fsid;
1497 int ret;
1498
1499
1500 mutex_lock(&fs_info->chunk_mutex);
1501 rcu_read_lock();
1502 list_for_each_entry_rcu(found, head, list) {
1503 if (found->flags & BTRFS_BLOCK_GROUP_DATA) {
1504 total_free_data += found->disk_total - found->disk_used;
1505 total_free_data -=
1506 btrfs_account_ro_block_groups_free_space(found);
1507 }
1508
1509 total_used += found->disk_used;
1510 }
1511 rcu_read_unlock();
1512
1513 buf->f_namelen = BTRFS_NAME_LEN;
1514 buf->f_blocks = btrfs_super_total_bytes(disk_super) >> bits;
1515 buf->f_bfree = buf->f_blocks - (total_used >> bits);
1516 buf->f_bsize = dentry->d_sb->s_blocksize;
1517 buf->f_type = BTRFS_SUPER_MAGIC;
1518 buf->f_bavail = total_free_data;
1519 ret = btrfs_calc_avail_data_space(fs_info->tree_root, &total_free_data);
1520 if (ret) {
1521 mutex_unlock(&fs_info->chunk_mutex);
1522 return ret;
1523 }
1524 buf->f_bavail += total_free_data;
1525 buf->f_bavail = buf->f_bavail >> bits;
1526 mutex_unlock(&fs_info->chunk_mutex);
1527
1528
1529
1530
1531 buf->f_fsid.val[0] = be32_to_cpu(fsid[0]) ^ be32_to_cpu(fsid[2]);
1532 buf->f_fsid.val[1] = be32_to_cpu(fsid[1]) ^ be32_to_cpu(fsid[3]);
1533
1534 buf->f_fsid.val[0] ^= BTRFS_I(dentry->d_inode)->root->objectid >> 32;
1535 buf->f_fsid.val[1] ^= BTRFS_I(dentry->d_inode)->root->objectid;
1536
1537 return 0;
1538}
1539
1540static void btrfs_kill_super(struct super_block *sb)
1541{
1542 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
1543 kill_anon_super(sb);
1544 free_fs_info(fs_info);
1545}
1546
1547static struct file_system_type btrfs_fs_type = {
1548 .owner = THIS_MODULE,
1549 .name = "btrfs",
1550 .mount = btrfs_mount,
1551 .kill_sb = btrfs_kill_super,
1552 .fs_flags = FS_REQUIRES_DEV,
1553};
1554MODULE_ALIAS_FS("btrfs");
1555
1556
1557
1558
1559static long btrfs_control_ioctl(struct file *file, unsigned int cmd,
1560 unsigned long arg)
1561{
1562 struct btrfs_ioctl_vol_args *vol;
1563 struct btrfs_fs_devices *fs_devices;
1564 int ret = -ENOTTY;
1565
1566 if (!capable(CAP_SYS_ADMIN))
1567 return -EPERM;
1568
1569 vol = memdup_user((void __user *)arg, sizeof(*vol));
1570 if (IS_ERR(vol))
1571 return PTR_ERR(vol);
1572
1573 switch (cmd) {
1574 case BTRFS_IOC_SCAN_DEV:
1575 ret = btrfs_scan_one_device(vol->name, FMODE_READ,
1576 &btrfs_fs_type, &fs_devices);
1577 break;
1578 case BTRFS_IOC_DEVICES_READY:
1579 ret = btrfs_scan_one_device(vol->name, FMODE_READ,
1580 &btrfs_fs_type, &fs_devices);
1581 if (ret)
1582 break;
1583 ret = !(fs_devices->num_devices == fs_devices->total_devices);
1584 break;
1585 }
1586
1587 kfree(vol);
1588 return ret;
1589}
1590
1591static int btrfs_freeze(struct super_block *sb)
1592{
1593 struct btrfs_trans_handle *trans;
1594 struct btrfs_root *root = btrfs_sb(sb)->tree_root;
1595
1596 trans = btrfs_attach_transaction_barrier(root);
1597 if (IS_ERR(trans)) {
1598
1599 if (PTR_ERR(trans) == -ENOENT)
1600 return 0;
1601 return PTR_ERR(trans);
1602 }
1603 return btrfs_commit_transaction(trans, root);
1604}
1605
1606static int btrfs_unfreeze(struct super_block *sb)
1607{
1608 return 0;
1609}
1610
1611static int btrfs_show_devname(struct seq_file *m, struct dentry *root)
1612{
1613 struct btrfs_fs_info *fs_info = btrfs_sb(root->d_sb);
1614 struct btrfs_fs_devices *cur_devices;
1615 struct btrfs_device *dev, *first_dev = NULL;
1616 struct list_head *head;
1617 struct rcu_string *name;
1618
1619 mutex_lock(&fs_info->fs_devices->device_list_mutex);
1620 cur_devices = fs_info->fs_devices;
1621 while (cur_devices) {
1622 head = &cur_devices->devices;
1623 list_for_each_entry(dev, head, dev_list) {
1624 if (dev->missing)
1625 continue;
1626 if (!first_dev || dev->devid < first_dev->devid)
1627 first_dev = dev;
1628 }
1629 cur_devices = cur_devices->seed;
1630 }
1631
1632 if (first_dev) {
1633 rcu_read_lock();
1634 name = rcu_dereference(first_dev->name);
1635 seq_escape(m, name->str, " \t\n\\");
1636 rcu_read_unlock();
1637 } else {
1638 WARN_ON(1);
1639 }
1640 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
1641 return 0;
1642}
1643
1644static const struct super_operations btrfs_super_ops = {
1645 .drop_inode = btrfs_drop_inode,
1646 .evict_inode = btrfs_evict_inode,
1647 .put_super = btrfs_put_super,
1648 .sync_fs = btrfs_sync_fs,
1649 .show_options = btrfs_show_options,
1650 .show_devname = btrfs_show_devname,
1651 .write_inode = btrfs_write_inode,
1652 .alloc_inode = btrfs_alloc_inode,
1653 .destroy_inode = btrfs_destroy_inode,
1654 .statfs = btrfs_statfs,
1655 .remount_fs = btrfs_remount,
1656 .freeze_fs = btrfs_freeze,
1657 .unfreeze_fs = btrfs_unfreeze,
1658};
1659
1660static const struct file_operations btrfs_ctl_fops = {
1661 .unlocked_ioctl = btrfs_control_ioctl,
1662 .compat_ioctl = btrfs_control_ioctl,
1663 .owner = THIS_MODULE,
1664 .llseek = noop_llseek,
1665};
1666
1667static struct miscdevice btrfs_misc = {
1668 .minor = BTRFS_MINOR,
1669 .name = "btrfs-control",
1670 .fops = &btrfs_ctl_fops
1671};
1672
1673MODULE_ALIAS_MISCDEV(BTRFS_MINOR);
1674MODULE_ALIAS("devname:btrfs-control");
1675
1676static int btrfs_interface_init(void)
1677{
1678 return misc_register(&btrfs_misc);
1679}
1680
1681static void btrfs_interface_exit(void)
1682{
1683 if (misc_deregister(&btrfs_misc) < 0)
1684 printk(KERN_INFO "btrfs: misc_deregister failed for control device\n");
1685}
1686
1687static void btrfs_print_info(void)
1688{
1689 printk(KERN_INFO "Btrfs loaded"
1690#ifdef CONFIG_BTRFS_DEBUG
1691 ", debug=on"
1692#endif
1693#ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
1694 ", integrity-checker=on"
1695#endif
1696 "\n");
1697}
1698
1699static int __init init_btrfs_fs(void)
1700{
1701 int err;
1702
1703 err = btrfs_init_sysfs();
1704 if (err)
1705 return err;
1706
1707 btrfs_init_compress();
1708
1709 err = btrfs_init_cachep();
1710 if (err)
1711 goto free_compress;
1712
1713 err = extent_io_init();
1714 if (err)
1715 goto free_cachep;
1716
1717 err = extent_map_init();
1718 if (err)
1719 goto free_extent_io;
1720
1721 err = ordered_data_init();
1722 if (err)
1723 goto free_extent_map;
1724
1725 err = btrfs_delayed_inode_init();
1726 if (err)
1727 goto free_ordered_data;
1728
1729 err = btrfs_auto_defrag_init();
1730 if (err)
1731 goto free_delayed_inode;
1732
1733 err = btrfs_delayed_ref_init();
1734 if (err)
1735 goto free_auto_defrag;
1736
1737 err = btrfs_interface_init();
1738 if (err)
1739 goto free_delayed_ref;
1740
1741 err = register_filesystem(&btrfs_fs_type);
1742 if (err)
1743 goto unregister_ioctl;
1744
1745 btrfs_init_lockdep();
1746
1747 btrfs_print_info();
1748 btrfs_test_free_space_cache();
1749
1750 return 0;
1751
1752unregister_ioctl:
1753 btrfs_interface_exit();
1754free_delayed_ref:
1755 btrfs_delayed_ref_exit();
1756free_auto_defrag:
1757 btrfs_auto_defrag_exit();
1758free_delayed_inode:
1759 btrfs_delayed_inode_exit();
1760free_ordered_data:
1761 ordered_data_exit();
1762free_extent_map:
1763 extent_map_exit();
1764free_extent_io:
1765 extent_io_exit();
1766free_cachep:
1767 btrfs_destroy_cachep();
1768free_compress:
1769 btrfs_exit_compress();
1770 btrfs_exit_sysfs();
1771 return err;
1772}
1773
1774static void __exit exit_btrfs_fs(void)
1775{
1776 btrfs_destroy_cachep();
1777 btrfs_delayed_ref_exit();
1778 btrfs_auto_defrag_exit();
1779 btrfs_delayed_inode_exit();
1780 ordered_data_exit();
1781 extent_map_exit();
1782 extent_io_exit();
1783 btrfs_interface_exit();
1784 unregister_filesystem(&btrfs_fs_type);
1785 btrfs_exit_sysfs();
1786 btrfs_cleanup_fs_uuids();
1787 btrfs_exit_compress();
1788}
1789
1790module_init(init_btrfs_fs)
1791module_exit(exit_btrfs_fs)
1792
1793MODULE_LICENSE("GPL");
1794