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clk: mxs: imx28: decrease the frequency of ref_io1 for SSP2 and SSP3
[deliverable/linux.git] / fs / btrfs / super.c
1 /*
2 * Copyright (C) 2007 Oracle. All rights reserved.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
17 */
18
19 #include <linux/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
58 #define CREATE_TRACE_POINTS
59 #include <trace/events/btrfs.h>
60
61 static const struct super_operations btrfs_super_ops;
62 static struct file_system_type btrfs_fs_type;
63
64 static const char *btrfs_decode_error(struct btrfs_fs_info *fs_info, int errno,
65 char nbuf[16])
66 {
67 char *errstr = NULL;
68
69 switch (errno) {
70 case -EIO:
71 errstr = "IO failure";
72 break;
73 case -ENOMEM:
74 errstr = "Out of memory";
75 break;
76 case -EROFS:
77 errstr = "Readonly filesystem";
78 break;
79 case -EEXIST:
80 errstr = "Object already exists";
81 break;
82 default:
83 if (nbuf) {
84 if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
85 errstr = nbuf;
86 }
87 break;
88 }
89
90 return errstr;
91 }
92
93 static void __save_error_info(struct btrfs_fs_info *fs_info)
94 {
95 /*
96 * today we only save the error info into ram. Long term we'll
97 * also send it down to the disk
98 */
99 fs_info->fs_state = BTRFS_SUPER_FLAG_ERROR;
100 }
101
102 /* NOTE:
103 * We move write_super stuff at umount in order to avoid deadlock
104 * for umount hold all lock.
105 */
106 static void save_error_info(struct btrfs_fs_info *fs_info)
107 {
108 __save_error_info(fs_info);
109 }
110
111 /* btrfs handle error by forcing the filesystem readonly */
112 static void btrfs_handle_error(struct btrfs_fs_info *fs_info)
113 {
114 struct super_block *sb = fs_info->sb;
115
116 if (sb->s_flags & MS_RDONLY)
117 return;
118
119 if (fs_info->fs_state & BTRFS_SUPER_FLAG_ERROR) {
120 sb->s_flags |= MS_RDONLY;
121 printk(KERN_INFO "btrfs is forced readonly\n");
122 __btrfs_scrub_cancel(fs_info);
123 // WARN_ON(1);
124 }
125 }
126
127 /*
128 * __btrfs_std_error decodes expected errors from the caller and
129 * invokes the approciate error response.
130 */
131 void __btrfs_std_error(struct btrfs_fs_info *fs_info, const char *function,
132 unsigned int line, int errno, const char *fmt, ...)
133 {
134 struct super_block *sb = fs_info->sb;
135 char nbuf[16];
136 const char *errstr;
137 va_list args;
138 va_start(args, fmt);
139
140 /*
141 * Special case: if the error is EROFS, and we're already
142 * under MS_RDONLY, then it is safe here.
143 */
144 if (errno == -EROFS && (sb->s_flags & MS_RDONLY))
145 return;
146
147 errstr = btrfs_decode_error(fs_info, errno, nbuf);
148 if (fmt) {
149 struct va_format vaf = {
150 .fmt = fmt,
151 .va = &args,
152 };
153
154 printk(KERN_CRIT "BTRFS error (device %s) in %s:%d: %s (%pV)\n",
155 sb->s_id, function, line, errstr, &vaf);
156 } else {
157 printk(KERN_CRIT "BTRFS error (device %s) in %s:%d: %s\n",
158 sb->s_id, function, line, errstr);
159 }
160
161 /* Don't go through full error handling during mount */
162 if (sb->s_flags & MS_BORN) {
163 save_error_info(fs_info);
164 btrfs_handle_error(fs_info);
165 }
166 va_end(args);
167 }
168
169 const char *logtypes[] = {
170 "emergency",
171 "alert",
172 "critical",
173 "error",
174 "warning",
175 "notice",
176 "info",
177 "debug",
178 };
179
180 void btrfs_printk(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
188 va_start(args, fmt);
189
190 if (fmt[0] == '<' && isdigit(fmt[1]) && fmt[2] == '>') {
191 memcpy(lvl, fmt, 3);
192 lvl[3] = '\0';
193 fmt += 3;
194 type = logtypes[fmt[1] - '0'];
195 } else
196 *lvl = '\0';
197
198 vaf.fmt = fmt;
199 vaf.va = &args;
200 printk("%sBTRFS %s (device %s): %pV", lvl, type, sb->s_id, &vaf);
201 }
202
203 /*
204 * We only mark the transaction aborted and then set the file system read-only.
205 * This will prevent new transactions from starting or trying to join this
206 * one.
207 *
208 * This means that error recovery at the call site is limited to freeing
209 * any local memory allocations and passing the error code up without
210 * further cleanup. The transaction should complete as it normally would
211 * in the call path but will return -EIO.
212 *
213 * We'll complete the cleanup in btrfs_end_transaction and
214 * btrfs_commit_transaction.
215 */
216 void __btrfs_abort_transaction(struct btrfs_trans_handle *trans,
217 struct btrfs_root *root, const char *function,
218 unsigned int line, int errno)
219 {
220 WARN_ONCE(1, KERN_DEBUG "btrfs: Transaction aborted");
221 trans->aborted = errno;
222 /* Nothing used. The other threads that have joined this
223 * transaction may be able to continue. */
224 if (!trans->blocks_used) {
225 btrfs_printk(root->fs_info, "Aborting unused transaction.\n");
226 return;
227 }
228 trans->transaction->aborted = errno;
229 __btrfs_std_error(root->fs_info, function, line, errno, NULL);
230 }
231 /*
232 * __btrfs_panic decodes unexpected, fatal errors from the caller,
233 * issues an alert, and either panics or BUGs, depending on mount options.
234 */
235 void __btrfs_panic(struct btrfs_fs_info *fs_info, const char *function,
236 unsigned int line, int errno, const char *fmt, ...)
237 {
238 char nbuf[16];
239 char *s_id = "<unknown>";
240 const char *errstr;
241 struct va_format vaf = { .fmt = fmt };
242 va_list args;
243
244 if (fs_info)
245 s_id = fs_info->sb->s_id;
246
247 va_start(args, fmt);
248 vaf.va = &args;
249
250 errstr = btrfs_decode_error(fs_info, errno, nbuf);
251 if (fs_info->mount_opt & BTRFS_MOUNT_PANIC_ON_FATAL_ERROR)
252 panic(KERN_CRIT "BTRFS panic (device %s) in %s:%d: %pV (%s)\n",
253 s_id, function, line, &vaf, errstr);
254
255 printk(KERN_CRIT "BTRFS panic (device %s) in %s:%d: %pV (%s)\n",
256 s_id, function, line, &vaf, errstr);
257 va_end(args);
258 /* Caller calls BUG() */
259 }
260
261 static void btrfs_put_super(struct super_block *sb)
262 {
263 (void)close_ctree(btrfs_sb(sb)->tree_root);
264 /* FIXME: need to fix VFS to return error? */
265 /* AV: return it _where_? ->put_super() can be triggered by any number
266 * of async events, up to and including delivery of SIGKILL to the
267 * last process that kept it busy. Or segfault in the aforementioned
268 * process... Whom would you report that to?
269 */
270 }
271
272 enum {
273 Opt_degraded, Opt_subvol, Opt_subvolid, Opt_device, Opt_nodatasum,
274 Opt_nodatacow, Opt_max_inline, Opt_alloc_start, Opt_nobarrier, Opt_ssd,
275 Opt_nossd, Opt_ssd_spread, Opt_thread_pool, Opt_noacl, Opt_compress,
276 Opt_compress_type, Opt_compress_force, Opt_compress_force_type,
277 Opt_notreelog, Opt_ratio, Opt_flushoncommit, Opt_discard,
278 Opt_space_cache, Opt_clear_cache, Opt_user_subvol_rm_allowed,
279 Opt_enospc_debug, Opt_subvolrootid, Opt_defrag, Opt_inode_cache,
280 Opt_no_space_cache, Opt_recovery, Opt_skip_balance,
281 Opt_check_integrity, Opt_check_integrity_including_extent_data,
282 Opt_check_integrity_print_mask, Opt_fatal_errors,
283 Opt_err,
284 };
285
286 static match_table_t tokens = {
287 {Opt_degraded, "degraded"},
288 {Opt_subvol, "subvol=%s"},
289 {Opt_subvolid, "subvolid=%d"},
290 {Opt_device, "device=%s"},
291 {Opt_nodatasum, "nodatasum"},
292 {Opt_nodatacow, "nodatacow"},
293 {Opt_nobarrier, "nobarrier"},
294 {Opt_max_inline, "max_inline=%s"},
295 {Opt_alloc_start, "alloc_start=%s"},
296 {Opt_thread_pool, "thread_pool=%d"},
297 {Opt_compress, "compress"},
298 {Opt_compress_type, "compress=%s"},
299 {Opt_compress_force, "compress-force"},
300 {Opt_compress_force_type, "compress-force=%s"},
301 {Opt_ssd, "ssd"},
302 {Opt_ssd_spread, "ssd_spread"},
303 {Opt_nossd, "nossd"},
304 {Opt_noacl, "noacl"},
305 {Opt_notreelog, "notreelog"},
306 {Opt_flushoncommit, "flushoncommit"},
307 {Opt_ratio, "metadata_ratio=%d"},
308 {Opt_discard, "discard"},
309 {Opt_space_cache, "space_cache"},
310 {Opt_clear_cache, "clear_cache"},
311 {Opt_user_subvol_rm_allowed, "user_subvol_rm_allowed"},
312 {Opt_enospc_debug, "enospc_debug"},
313 {Opt_subvolrootid, "subvolrootid=%d"},
314 {Opt_defrag, "autodefrag"},
315 {Opt_inode_cache, "inode_cache"},
316 {Opt_no_space_cache, "nospace_cache"},
317 {Opt_recovery, "recovery"},
318 {Opt_skip_balance, "skip_balance"},
319 {Opt_check_integrity, "check_int"},
320 {Opt_check_integrity_including_extent_data, "check_int_data"},
321 {Opt_check_integrity_print_mask, "check_int_print_mask=%d"},
322 {Opt_fatal_errors, "fatal_errors=%s"},
323 {Opt_err, NULL},
324 };
325
326 /*
327 * Regular mount options parser. Everything that is needed only when
328 * reading in a new superblock is parsed here.
329 * XXX JDM: This needs to be cleaned up for remount.
330 */
331 int btrfs_parse_options(struct btrfs_root *root, char *options)
332 {
333 struct btrfs_fs_info *info = root->fs_info;
334 substring_t args[MAX_OPT_ARGS];
335 char *p, *num, *orig = NULL;
336 u64 cache_gen;
337 int intarg;
338 int ret = 0;
339 char *compress_type;
340 bool compress_force = false;
341
342 cache_gen = btrfs_super_cache_generation(root->fs_info->super_copy);
343 if (cache_gen)
344 btrfs_set_opt(info->mount_opt, SPACE_CACHE);
345
346 if (!options)
347 goto out;
348
349 /*
350 * strsep changes the string, duplicate it because parse_options
351 * gets called twice
352 */
353 options = kstrdup(options, GFP_NOFS);
354 if (!options)
355 return -ENOMEM;
356
357 orig = options;
358
359 while ((p = strsep(&options, ",")) != NULL) {
360 int token;
361 if (!*p)
362 continue;
363
364 token = match_token(p, tokens, args);
365 switch (token) {
366 case Opt_degraded:
367 printk(KERN_INFO "btrfs: allowing degraded mounts\n");
368 btrfs_set_opt(info->mount_opt, DEGRADED);
369 break;
370 case Opt_subvol:
371 case Opt_subvolid:
372 case Opt_subvolrootid:
373 case Opt_device:
374 /*
375 * These are parsed by btrfs_parse_early_options
376 * and can be happily ignored here.
377 */
378 break;
379 case Opt_nodatasum:
380 printk(KERN_INFO "btrfs: setting nodatasum\n");
381 btrfs_set_opt(info->mount_opt, NODATASUM);
382 break;
383 case Opt_nodatacow:
384 printk(KERN_INFO "btrfs: setting nodatacow\n");
385 btrfs_set_opt(info->mount_opt, NODATACOW);
386 btrfs_set_opt(info->mount_opt, NODATASUM);
387 break;
388 case Opt_compress_force:
389 case Opt_compress_force_type:
390 compress_force = true;
391 case Opt_compress:
392 case Opt_compress_type:
393 if (token == Opt_compress ||
394 token == Opt_compress_force ||
395 strcmp(args[0].from, "zlib") == 0) {
396 compress_type = "zlib";
397 info->compress_type = BTRFS_COMPRESS_ZLIB;
398 } else if (strcmp(args[0].from, "lzo") == 0) {
399 compress_type = "lzo";
400 info->compress_type = BTRFS_COMPRESS_LZO;
401 } else {
402 ret = -EINVAL;
403 goto out;
404 }
405
406 btrfs_set_opt(info->mount_opt, COMPRESS);
407 if (compress_force) {
408 btrfs_set_opt(info->mount_opt, FORCE_COMPRESS);
409 pr_info("btrfs: force %s compression\n",
410 compress_type);
411 } else
412 pr_info("btrfs: use %s compression\n",
413 compress_type);
414 break;
415 case Opt_ssd:
416 printk(KERN_INFO "btrfs: use ssd allocation scheme\n");
417 btrfs_set_opt(info->mount_opt, SSD);
418 break;
419 case Opt_ssd_spread:
420 printk(KERN_INFO "btrfs: use spread ssd "
421 "allocation scheme\n");
422 btrfs_set_opt(info->mount_opt, SSD);
423 btrfs_set_opt(info->mount_opt, SSD_SPREAD);
424 break;
425 case Opt_nossd:
426 printk(KERN_INFO "btrfs: not using ssd allocation "
427 "scheme\n");
428 btrfs_set_opt(info->mount_opt, NOSSD);
429 btrfs_clear_opt(info->mount_opt, SSD);
430 btrfs_clear_opt(info->mount_opt, SSD_SPREAD);
431 break;
432 case Opt_nobarrier:
433 printk(KERN_INFO "btrfs: turning off barriers\n");
434 btrfs_set_opt(info->mount_opt, NOBARRIER);
435 break;
436 case Opt_thread_pool:
437 intarg = 0;
438 match_int(&args[0], &intarg);
439 if (intarg)
440 info->thread_pool_size = intarg;
441 break;
442 case Opt_max_inline:
443 num = match_strdup(&args[0]);
444 if (num) {
445 info->max_inline = memparse(num, NULL);
446 kfree(num);
447
448 if (info->max_inline) {
449 info->max_inline = max_t(u64,
450 info->max_inline,
451 root->sectorsize);
452 }
453 printk(KERN_INFO "btrfs: max_inline at %llu\n",
454 (unsigned long long)info->max_inline);
455 }
456 break;
457 case Opt_alloc_start:
458 num = match_strdup(&args[0]);
459 if (num) {
460 info->alloc_start = memparse(num, NULL);
461 kfree(num);
462 printk(KERN_INFO
463 "btrfs: allocations start at %llu\n",
464 (unsigned long long)info->alloc_start);
465 }
466 break;
467 case Opt_noacl:
468 root->fs_info->sb->s_flags &= ~MS_POSIXACL;
469 break;
470 case Opt_notreelog:
471 printk(KERN_INFO "btrfs: disabling tree log\n");
472 btrfs_set_opt(info->mount_opt, NOTREELOG);
473 break;
474 case Opt_flushoncommit:
475 printk(KERN_INFO "btrfs: turning on flush-on-commit\n");
476 btrfs_set_opt(info->mount_opt, FLUSHONCOMMIT);
477 break;
478 case Opt_ratio:
479 intarg = 0;
480 match_int(&args[0], &intarg);
481 if (intarg) {
482 info->metadata_ratio = intarg;
483 printk(KERN_INFO "btrfs: metadata ratio %d\n",
484 info->metadata_ratio);
485 }
486 break;
487 case Opt_discard:
488 btrfs_set_opt(info->mount_opt, DISCARD);
489 break;
490 case Opt_space_cache:
491 btrfs_set_opt(info->mount_opt, SPACE_CACHE);
492 break;
493 case Opt_no_space_cache:
494 printk(KERN_INFO "btrfs: disabling disk space caching\n");
495 btrfs_clear_opt(info->mount_opt, SPACE_CACHE);
496 break;
497 case Opt_inode_cache:
498 printk(KERN_INFO "btrfs: enabling inode map caching\n");
499 btrfs_set_opt(info->mount_opt, INODE_MAP_CACHE);
500 break;
501 case Opt_clear_cache:
502 printk(KERN_INFO "btrfs: force clearing of disk cache\n");
503 btrfs_set_opt(info->mount_opt, CLEAR_CACHE);
504 break;
505 case Opt_user_subvol_rm_allowed:
506 btrfs_set_opt(info->mount_opt, USER_SUBVOL_RM_ALLOWED);
507 break;
508 case Opt_enospc_debug:
509 btrfs_set_opt(info->mount_opt, ENOSPC_DEBUG);
510 break;
511 case Opt_defrag:
512 printk(KERN_INFO "btrfs: enabling auto defrag");
513 btrfs_set_opt(info->mount_opt, AUTO_DEFRAG);
514 break;
515 case Opt_recovery:
516 printk(KERN_INFO "btrfs: enabling auto recovery");
517 btrfs_set_opt(info->mount_opt, RECOVERY);
518 break;
519 case Opt_skip_balance:
520 btrfs_set_opt(info->mount_opt, SKIP_BALANCE);
521 break;
522 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
523 case Opt_check_integrity_including_extent_data:
524 printk(KERN_INFO "btrfs: enabling check integrity"
525 " including extent data\n");
526 btrfs_set_opt(info->mount_opt,
527 CHECK_INTEGRITY_INCLUDING_EXTENT_DATA);
528 btrfs_set_opt(info->mount_opt, CHECK_INTEGRITY);
529 break;
530 case Opt_check_integrity:
531 printk(KERN_INFO "btrfs: enabling check integrity\n");
532 btrfs_set_opt(info->mount_opt, CHECK_INTEGRITY);
533 break;
534 case Opt_check_integrity_print_mask:
535 intarg = 0;
536 match_int(&args[0], &intarg);
537 if (intarg) {
538 info->check_integrity_print_mask = intarg;
539 printk(KERN_INFO "btrfs:"
540 " check_integrity_print_mask 0x%x\n",
541 info->check_integrity_print_mask);
542 }
543 break;
544 #else
545 case Opt_check_integrity_including_extent_data:
546 case Opt_check_integrity:
547 case Opt_check_integrity_print_mask:
548 printk(KERN_ERR "btrfs: support for check_integrity*"
549 " not compiled in!\n");
550 ret = -EINVAL;
551 goto out;
552 #endif
553 case Opt_fatal_errors:
554 if (strcmp(args[0].from, "panic") == 0)
555 btrfs_set_opt(info->mount_opt,
556 PANIC_ON_FATAL_ERROR);
557 else if (strcmp(args[0].from, "bug") == 0)
558 btrfs_clear_opt(info->mount_opt,
559 PANIC_ON_FATAL_ERROR);
560 else {
561 ret = -EINVAL;
562 goto out;
563 }
564 break;
565 case Opt_err:
566 printk(KERN_INFO "btrfs: unrecognized mount option "
567 "'%s'\n", p);
568 ret = -EINVAL;
569 goto out;
570 default:
571 break;
572 }
573 }
574 out:
575 if (!ret && btrfs_test_opt(root, SPACE_CACHE))
576 printk(KERN_INFO "btrfs: disk space caching is enabled\n");
577 kfree(orig);
578 return ret;
579 }
580
581 /*
582 * Parse mount options that are required early in the mount process.
583 *
584 * All other options will be parsed on much later in the mount process and
585 * only when we need to allocate a new super block.
586 */
587 static int btrfs_parse_early_options(const char *options, fmode_t flags,
588 void *holder, char **subvol_name, u64 *subvol_objectid,
589 u64 *subvol_rootid, struct btrfs_fs_devices **fs_devices)
590 {
591 substring_t args[MAX_OPT_ARGS];
592 char *device_name, *opts, *orig, *p;
593 int error = 0;
594 int intarg;
595
596 if (!options)
597 return 0;
598
599 /*
600 * strsep changes the string, duplicate it because parse_options
601 * gets called twice
602 */
603 opts = kstrdup(options, GFP_KERNEL);
604 if (!opts)
605 return -ENOMEM;
606 orig = opts;
607
608 while ((p = strsep(&opts, ",")) != NULL) {
609 int token;
610 if (!*p)
611 continue;
612
613 token = match_token(p, tokens, args);
614 switch (token) {
615 case Opt_subvol:
616 kfree(*subvol_name);
617 *subvol_name = match_strdup(&args[0]);
618 break;
619 case Opt_subvolid:
620 intarg = 0;
621 error = match_int(&args[0], &intarg);
622 if (!error) {
623 /* we want the original fs_tree */
624 if (!intarg)
625 *subvol_objectid =
626 BTRFS_FS_TREE_OBJECTID;
627 else
628 *subvol_objectid = intarg;
629 }
630 break;
631 case Opt_subvolrootid:
632 intarg = 0;
633 error = match_int(&args[0], &intarg);
634 if (!error) {
635 /* we want the original fs_tree */
636 if (!intarg)
637 *subvol_rootid =
638 BTRFS_FS_TREE_OBJECTID;
639 else
640 *subvol_rootid = intarg;
641 }
642 break;
643 case Opt_device:
644 device_name = match_strdup(&args[0]);
645 if (!device_name) {
646 error = -ENOMEM;
647 goto out;
648 }
649 error = btrfs_scan_one_device(device_name,
650 flags, holder, fs_devices);
651 kfree(device_name);
652 if (error)
653 goto out;
654 break;
655 default:
656 break;
657 }
658 }
659
660 out:
661 kfree(orig);
662 return error;
663 }
664
665 static struct dentry *get_default_root(struct super_block *sb,
666 u64 subvol_objectid)
667 {
668 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
669 struct btrfs_root *root = fs_info->tree_root;
670 struct btrfs_root *new_root;
671 struct btrfs_dir_item *di;
672 struct btrfs_path *path;
673 struct btrfs_key location;
674 struct inode *inode;
675 u64 dir_id;
676 int new = 0;
677
678 /*
679 * We have a specific subvol we want to mount, just setup location and
680 * go look up the root.
681 */
682 if (subvol_objectid) {
683 location.objectid = subvol_objectid;
684 location.type = BTRFS_ROOT_ITEM_KEY;
685 location.offset = (u64)-1;
686 goto find_root;
687 }
688
689 path = btrfs_alloc_path();
690 if (!path)
691 return ERR_PTR(-ENOMEM);
692 path->leave_spinning = 1;
693
694 /*
695 * Find the "default" dir item which points to the root item that we
696 * will mount by default if we haven't been given a specific subvolume
697 * to mount.
698 */
699 dir_id = btrfs_super_root_dir(fs_info->super_copy);
700 di = btrfs_lookup_dir_item(NULL, root, path, dir_id, "default", 7, 0);
701 if (IS_ERR(di)) {
702 btrfs_free_path(path);
703 return ERR_CAST(di);
704 }
705 if (!di) {
706 /*
707 * Ok the default dir item isn't there. This is weird since
708 * it's always been there, but don't freak out, just try and
709 * mount to root most subvolume.
710 */
711 btrfs_free_path(path);
712 dir_id = BTRFS_FIRST_FREE_OBJECTID;
713 new_root = fs_info->fs_root;
714 goto setup_root;
715 }
716
717 btrfs_dir_item_key_to_cpu(path->nodes[0], di, &location);
718 btrfs_free_path(path);
719
720 find_root:
721 new_root = btrfs_read_fs_root_no_name(fs_info, &location);
722 if (IS_ERR(new_root))
723 return ERR_CAST(new_root);
724
725 if (btrfs_root_refs(&new_root->root_item) == 0)
726 return ERR_PTR(-ENOENT);
727
728 dir_id = btrfs_root_dirid(&new_root->root_item);
729 setup_root:
730 location.objectid = dir_id;
731 location.type = BTRFS_INODE_ITEM_KEY;
732 location.offset = 0;
733
734 inode = btrfs_iget(sb, &location, new_root, &new);
735 if (IS_ERR(inode))
736 return ERR_CAST(inode);
737
738 /*
739 * If we're just mounting the root most subvol put the inode and return
740 * a reference to the dentry. We will have already gotten a reference
741 * to the inode in btrfs_fill_super so we're good to go.
742 */
743 if (!new && sb->s_root->d_inode == inode) {
744 iput(inode);
745 return dget(sb->s_root);
746 }
747
748 return d_obtain_alias(inode);
749 }
750
751 static int btrfs_fill_super(struct super_block *sb,
752 struct btrfs_fs_devices *fs_devices,
753 void *data, int silent)
754 {
755 struct inode *inode;
756 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
757 struct btrfs_key key;
758 int err;
759
760 sb->s_maxbytes = MAX_LFS_FILESIZE;
761 sb->s_magic = BTRFS_SUPER_MAGIC;
762 sb->s_op = &btrfs_super_ops;
763 sb->s_d_op = &btrfs_dentry_operations;
764 sb->s_export_op = &btrfs_export_ops;
765 sb->s_xattr = btrfs_xattr_handlers;
766 sb->s_time_gran = 1;
767 #ifdef CONFIG_BTRFS_FS_POSIX_ACL
768 sb->s_flags |= MS_POSIXACL;
769 #endif
770 sb->s_flags |= MS_I_VERSION;
771 err = open_ctree(sb, fs_devices, (char *)data);
772 if (err) {
773 printk("btrfs: open_ctree failed\n");
774 return err;
775 }
776
777 key.objectid = BTRFS_FIRST_FREE_OBJECTID;
778 key.type = BTRFS_INODE_ITEM_KEY;
779 key.offset = 0;
780 inode = btrfs_iget(sb, &key, fs_info->fs_root, NULL);
781 if (IS_ERR(inode)) {
782 err = PTR_ERR(inode);
783 goto fail_close;
784 }
785
786 sb->s_root = d_make_root(inode);
787 if (!sb->s_root) {
788 err = -ENOMEM;
789 goto fail_close;
790 }
791
792 save_mount_options(sb, data);
793 cleancache_init_fs(sb);
794 sb->s_flags |= MS_ACTIVE;
795 return 0;
796
797 fail_close:
798 close_ctree(fs_info->tree_root);
799 return err;
800 }
801
802 int btrfs_sync_fs(struct super_block *sb, int wait)
803 {
804 struct btrfs_trans_handle *trans;
805 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
806 struct btrfs_root *root = fs_info->tree_root;
807 int ret;
808
809 trace_btrfs_sync_fs(wait);
810
811 if (!wait) {
812 filemap_flush(fs_info->btree_inode->i_mapping);
813 return 0;
814 }
815
816 btrfs_wait_ordered_extents(root, 0, 0);
817
818 trans = btrfs_start_transaction(root, 0);
819 if (IS_ERR(trans))
820 return PTR_ERR(trans);
821 ret = btrfs_commit_transaction(trans, root);
822 return ret;
823 }
824
825 static int btrfs_show_options(struct seq_file *seq, struct dentry *dentry)
826 {
827 struct btrfs_fs_info *info = btrfs_sb(dentry->d_sb);
828 struct btrfs_root *root = info->tree_root;
829 char *compress_type;
830
831 if (btrfs_test_opt(root, DEGRADED))
832 seq_puts(seq, ",degraded");
833 if (btrfs_test_opt(root, NODATASUM))
834 seq_puts(seq, ",nodatasum");
835 if (btrfs_test_opt(root, NODATACOW))
836 seq_puts(seq, ",nodatacow");
837 if (btrfs_test_opt(root, NOBARRIER))
838 seq_puts(seq, ",nobarrier");
839 if (info->max_inline != 8192 * 1024)
840 seq_printf(seq, ",max_inline=%llu",
841 (unsigned long long)info->max_inline);
842 if (info->alloc_start != 0)
843 seq_printf(seq, ",alloc_start=%llu",
844 (unsigned long long)info->alloc_start);
845 if (info->thread_pool_size != min_t(unsigned long,
846 num_online_cpus() + 2, 8))
847 seq_printf(seq, ",thread_pool=%d", info->thread_pool_size);
848 if (btrfs_test_opt(root, COMPRESS)) {
849 if (info->compress_type == BTRFS_COMPRESS_ZLIB)
850 compress_type = "zlib";
851 else
852 compress_type = "lzo";
853 if (btrfs_test_opt(root, FORCE_COMPRESS))
854 seq_printf(seq, ",compress-force=%s", compress_type);
855 else
856 seq_printf(seq, ",compress=%s", compress_type);
857 }
858 if (btrfs_test_opt(root, NOSSD))
859 seq_puts(seq, ",nossd");
860 if (btrfs_test_opt(root, SSD_SPREAD))
861 seq_puts(seq, ",ssd_spread");
862 else if (btrfs_test_opt(root, SSD))
863 seq_puts(seq, ",ssd");
864 if (btrfs_test_opt(root, NOTREELOG))
865 seq_puts(seq, ",notreelog");
866 if (btrfs_test_opt(root, FLUSHONCOMMIT))
867 seq_puts(seq, ",flushoncommit");
868 if (btrfs_test_opt(root, DISCARD))
869 seq_puts(seq, ",discard");
870 if (!(root->fs_info->sb->s_flags & MS_POSIXACL))
871 seq_puts(seq, ",noacl");
872 if (btrfs_test_opt(root, SPACE_CACHE))
873 seq_puts(seq, ",space_cache");
874 else
875 seq_puts(seq, ",nospace_cache");
876 if (btrfs_test_opt(root, CLEAR_CACHE))
877 seq_puts(seq, ",clear_cache");
878 if (btrfs_test_opt(root, USER_SUBVOL_RM_ALLOWED))
879 seq_puts(seq, ",user_subvol_rm_allowed");
880 if (btrfs_test_opt(root, ENOSPC_DEBUG))
881 seq_puts(seq, ",enospc_debug");
882 if (btrfs_test_opt(root, AUTO_DEFRAG))
883 seq_puts(seq, ",autodefrag");
884 if (btrfs_test_opt(root, INODE_MAP_CACHE))
885 seq_puts(seq, ",inode_cache");
886 if (btrfs_test_opt(root, SKIP_BALANCE))
887 seq_puts(seq, ",skip_balance");
888 if (btrfs_test_opt(root, PANIC_ON_FATAL_ERROR))
889 seq_puts(seq, ",fatal_errors=panic");
890 return 0;
891 }
892
893 static int btrfs_test_super(struct super_block *s, void *data)
894 {
895 struct btrfs_fs_info *p = data;
896 struct btrfs_fs_info *fs_info = btrfs_sb(s);
897
898 return fs_info->fs_devices == p->fs_devices;
899 }
900
901 static int btrfs_set_super(struct super_block *s, void *data)
902 {
903 int err = set_anon_super(s, data);
904 if (!err)
905 s->s_fs_info = data;
906 return err;
907 }
908
909 /*
910 * subvolumes are identified by ino 256
911 */
912 static inline int is_subvolume_inode(struct inode *inode)
913 {
914 if (inode && inode->i_ino == BTRFS_FIRST_FREE_OBJECTID)
915 return 1;
916 return 0;
917 }
918
919 /*
920 * This will strip out the subvol=%s argument for an argument string and add
921 * subvolid=0 to make sure we get the actual tree root for path walking to the
922 * subvol we want.
923 */
924 static char *setup_root_args(char *args)
925 {
926 unsigned len = strlen(args) + 2 + 1;
927 char *src, *dst, *buf;
928
929 /*
930 * We need the same args as before, but with this substitution:
931 * s!subvol=[^,]+!subvolid=0!
932 *
933 * Since the replacement string is up to 2 bytes longer than the
934 * original, allocate strlen(args) + 2 + 1 bytes.
935 */
936
937 src = strstr(args, "subvol=");
938 /* This shouldn't happen, but just in case.. */
939 if (!src)
940 return NULL;
941
942 buf = dst = kmalloc(len, GFP_NOFS);
943 if (!buf)
944 return NULL;
945
946 /*
947 * If the subvol= arg is not at the start of the string,
948 * copy whatever precedes it into buf.
949 */
950 if (src != args) {
951 *src++ = '\0';
952 strcpy(buf, args);
953 dst += strlen(args);
954 }
955
956 strcpy(dst, "subvolid=0");
957 dst += strlen("subvolid=0");
958
959 /*
960 * If there is a "," after the original subvol=... string,
961 * copy that suffix into our buffer. Otherwise, we're done.
962 */
963 src = strchr(src, ',');
964 if (src)
965 strcpy(dst, src);
966
967 return buf;
968 }
969
970 static struct dentry *mount_subvol(const char *subvol_name, int flags,
971 const char *device_name, char *data)
972 {
973 struct dentry *root;
974 struct vfsmount *mnt;
975 char *newargs;
976
977 newargs = setup_root_args(data);
978 if (!newargs)
979 return ERR_PTR(-ENOMEM);
980 mnt = vfs_kern_mount(&btrfs_fs_type, flags, device_name,
981 newargs);
982 kfree(newargs);
983 if (IS_ERR(mnt))
984 return ERR_CAST(mnt);
985
986 root = mount_subtree(mnt, subvol_name);
987
988 if (!IS_ERR(root) && !is_subvolume_inode(root->d_inode)) {
989 struct super_block *s = root->d_sb;
990 dput(root);
991 root = ERR_PTR(-EINVAL);
992 deactivate_locked_super(s);
993 printk(KERN_ERR "btrfs: '%s' is not a valid subvolume\n",
994 subvol_name);
995 }
996
997 return root;
998 }
999
1000 /*
1001 * Find a superblock for the given device / mount point.
1002 *
1003 * Note: This is based on get_sb_bdev from fs/super.c with a few additions
1004 * for multiple device setup. Make sure to keep it in sync.
1005 */
1006 static struct dentry *btrfs_mount(struct file_system_type *fs_type, int flags,
1007 const char *device_name, void *data)
1008 {
1009 struct block_device *bdev = NULL;
1010 struct super_block *s;
1011 struct dentry *root;
1012 struct btrfs_fs_devices *fs_devices = NULL;
1013 struct btrfs_fs_info *fs_info = NULL;
1014 fmode_t mode = FMODE_READ;
1015 char *subvol_name = NULL;
1016 u64 subvol_objectid = 0;
1017 u64 subvol_rootid = 0;
1018 int error = 0;
1019
1020 if (!(flags & MS_RDONLY))
1021 mode |= FMODE_WRITE;
1022
1023 error = btrfs_parse_early_options(data, mode, fs_type,
1024 &subvol_name, &subvol_objectid,
1025 &subvol_rootid, &fs_devices);
1026 if (error) {
1027 kfree(subvol_name);
1028 return ERR_PTR(error);
1029 }
1030
1031 if (subvol_name) {
1032 root = mount_subvol(subvol_name, flags, device_name, data);
1033 kfree(subvol_name);
1034 return root;
1035 }
1036
1037 error = btrfs_scan_one_device(device_name, mode, fs_type, &fs_devices);
1038 if (error)
1039 return ERR_PTR(error);
1040
1041 /*
1042 * Setup a dummy root and fs_info for test/set super. This is because
1043 * we don't actually fill this stuff out until open_ctree, but we need
1044 * it for searching for existing supers, so this lets us do that and
1045 * then open_ctree will properly initialize everything later.
1046 */
1047 fs_info = kzalloc(sizeof(struct btrfs_fs_info), GFP_NOFS);
1048 if (!fs_info)
1049 return ERR_PTR(-ENOMEM);
1050
1051 fs_info->fs_devices = fs_devices;
1052
1053 fs_info->super_copy = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_NOFS);
1054 fs_info->super_for_commit = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_NOFS);
1055 if (!fs_info->super_copy || !fs_info->super_for_commit) {
1056 error = -ENOMEM;
1057 goto error_fs_info;
1058 }
1059
1060 error = btrfs_open_devices(fs_devices, mode, fs_type);
1061 if (error)
1062 goto error_fs_info;
1063
1064 if (!(flags & MS_RDONLY) && fs_devices->rw_devices == 0) {
1065 error = -EACCES;
1066 goto error_close_devices;
1067 }
1068
1069 bdev = fs_devices->latest_bdev;
1070 s = sget(fs_type, btrfs_test_super, btrfs_set_super, fs_info);
1071 if (IS_ERR(s)) {
1072 error = PTR_ERR(s);
1073 goto error_close_devices;
1074 }
1075
1076 if (s->s_root) {
1077 btrfs_close_devices(fs_devices);
1078 free_fs_info(fs_info);
1079 if ((flags ^ s->s_flags) & MS_RDONLY)
1080 error = -EBUSY;
1081 } else {
1082 char b[BDEVNAME_SIZE];
1083
1084 s->s_flags = flags | MS_NOSEC;
1085 strlcpy(s->s_id, bdevname(bdev, b), sizeof(s->s_id));
1086 btrfs_sb(s)->bdev_holder = fs_type;
1087 error = btrfs_fill_super(s, fs_devices, data,
1088 flags & MS_SILENT ? 1 : 0);
1089 }
1090
1091 root = !error ? get_default_root(s, subvol_objectid) : ERR_PTR(error);
1092 if (IS_ERR(root))
1093 deactivate_locked_super(s);
1094
1095 return root;
1096
1097 error_close_devices:
1098 btrfs_close_devices(fs_devices);
1099 error_fs_info:
1100 free_fs_info(fs_info);
1101 return ERR_PTR(error);
1102 }
1103
1104 static void btrfs_set_max_workers(struct btrfs_workers *workers, int new_limit)
1105 {
1106 spin_lock_irq(&workers->lock);
1107 workers->max_workers = new_limit;
1108 spin_unlock_irq(&workers->lock);
1109 }
1110
1111 static void btrfs_resize_thread_pool(struct btrfs_fs_info *fs_info,
1112 int new_pool_size, int old_pool_size)
1113 {
1114 if (new_pool_size == old_pool_size)
1115 return;
1116
1117 fs_info->thread_pool_size = new_pool_size;
1118
1119 printk(KERN_INFO "btrfs: resize thread pool %d -> %d\n",
1120 old_pool_size, new_pool_size);
1121
1122 btrfs_set_max_workers(&fs_info->generic_worker, new_pool_size);
1123 btrfs_set_max_workers(&fs_info->workers, new_pool_size);
1124 btrfs_set_max_workers(&fs_info->delalloc_workers, new_pool_size);
1125 btrfs_set_max_workers(&fs_info->submit_workers, new_pool_size);
1126 btrfs_set_max_workers(&fs_info->caching_workers, new_pool_size);
1127 btrfs_set_max_workers(&fs_info->fixup_workers, new_pool_size);
1128 btrfs_set_max_workers(&fs_info->endio_workers, new_pool_size);
1129 btrfs_set_max_workers(&fs_info->endio_meta_workers, new_pool_size);
1130 btrfs_set_max_workers(&fs_info->endio_meta_write_workers, new_pool_size);
1131 btrfs_set_max_workers(&fs_info->endio_write_workers, new_pool_size);
1132 btrfs_set_max_workers(&fs_info->endio_freespace_worker, new_pool_size);
1133 btrfs_set_max_workers(&fs_info->delayed_workers, new_pool_size);
1134 btrfs_set_max_workers(&fs_info->readahead_workers, new_pool_size);
1135 btrfs_set_max_workers(&fs_info->scrub_workers, new_pool_size);
1136 }
1137
1138 static int btrfs_remount(struct super_block *sb, int *flags, char *data)
1139 {
1140 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
1141 struct btrfs_root *root = fs_info->tree_root;
1142 unsigned old_flags = sb->s_flags;
1143 unsigned long old_opts = fs_info->mount_opt;
1144 unsigned long old_compress_type = fs_info->compress_type;
1145 u64 old_max_inline = fs_info->max_inline;
1146 u64 old_alloc_start = fs_info->alloc_start;
1147 int old_thread_pool_size = fs_info->thread_pool_size;
1148 unsigned int old_metadata_ratio = fs_info->metadata_ratio;
1149 int ret;
1150
1151 ret = btrfs_parse_options(root, data);
1152 if (ret) {
1153 ret = -EINVAL;
1154 goto restore;
1155 }
1156
1157 btrfs_resize_thread_pool(fs_info,
1158 fs_info->thread_pool_size, old_thread_pool_size);
1159
1160 if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
1161 return 0;
1162
1163 if (*flags & MS_RDONLY) {
1164 sb->s_flags |= MS_RDONLY;
1165
1166 ret = btrfs_commit_super(root);
1167 if (ret)
1168 goto restore;
1169 } else {
1170 if (fs_info->fs_devices->rw_devices == 0) {
1171 ret = -EACCES;
1172 goto restore;
1173 }
1174
1175 if (btrfs_super_log_root(fs_info->super_copy) != 0) {
1176 ret = -EINVAL;
1177 goto restore;
1178 }
1179
1180 ret = btrfs_cleanup_fs_roots(fs_info);
1181 if (ret)
1182 goto restore;
1183
1184 /* recover relocation */
1185 ret = btrfs_recover_relocation(root);
1186 if (ret)
1187 goto restore;
1188
1189 sb->s_flags &= ~MS_RDONLY;
1190 }
1191
1192 return 0;
1193
1194 restore:
1195 /* We've hit an error - don't reset MS_RDONLY */
1196 if (sb->s_flags & MS_RDONLY)
1197 old_flags |= MS_RDONLY;
1198 sb->s_flags = old_flags;
1199 fs_info->mount_opt = old_opts;
1200 fs_info->compress_type = old_compress_type;
1201 fs_info->max_inline = old_max_inline;
1202 fs_info->alloc_start = old_alloc_start;
1203 btrfs_resize_thread_pool(fs_info,
1204 old_thread_pool_size, fs_info->thread_pool_size);
1205 fs_info->metadata_ratio = old_metadata_ratio;
1206 return ret;
1207 }
1208
1209 /* Used to sort the devices by max_avail(descending sort) */
1210 static int btrfs_cmp_device_free_bytes(const void *dev_info1,
1211 const void *dev_info2)
1212 {
1213 if (((struct btrfs_device_info *)dev_info1)->max_avail >
1214 ((struct btrfs_device_info *)dev_info2)->max_avail)
1215 return -1;
1216 else if (((struct btrfs_device_info *)dev_info1)->max_avail <
1217 ((struct btrfs_device_info *)dev_info2)->max_avail)
1218 return 1;
1219 else
1220 return 0;
1221 }
1222
1223 /*
1224 * sort the devices by max_avail, in which max free extent size of each device
1225 * is stored.(Descending Sort)
1226 */
1227 static inline void btrfs_descending_sort_devices(
1228 struct btrfs_device_info *devices,
1229 size_t nr_devices)
1230 {
1231 sort(devices, nr_devices, sizeof(struct btrfs_device_info),
1232 btrfs_cmp_device_free_bytes, NULL);
1233 }
1234
1235 /*
1236 * The helper to calc the free space on the devices that can be used to store
1237 * file data.
1238 */
1239 static int btrfs_calc_avail_data_space(struct btrfs_root *root, u64 *free_bytes)
1240 {
1241 struct btrfs_fs_info *fs_info = root->fs_info;
1242 struct btrfs_device_info *devices_info;
1243 struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
1244 struct btrfs_device *device;
1245 u64 skip_space;
1246 u64 type;
1247 u64 avail_space;
1248 u64 used_space;
1249 u64 min_stripe_size;
1250 int min_stripes = 1, num_stripes = 1;
1251 int i = 0, nr_devices;
1252 int ret;
1253
1254 nr_devices = fs_info->fs_devices->open_devices;
1255 BUG_ON(!nr_devices);
1256
1257 devices_info = kmalloc(sizeof(*devices_info) * nr_devices,
1258 GFP_NOFS);
1259 if (!devices_info)
1260 return -ENOMEM;
1261
1262 /* calc min stripe number for data space alloction */
1263 type = btrfs_get_alloc_profile(root, 1);
1264 if (type & BTRFS_BLOCK_GROUP_RAID0) {
1265 min_stripes = 2;
1266 num_stripes = nr_devices;
1267 } else if (type & BTRFS_BLOCK_GROUP_RAID1) {
1268 min_stripes = 2;
1269 num_stripes = 2;
1270 } else if (type & BTRFS_BLOCK_GROUP_RAID10) {
1271 min_stripes = 4;
1272 num_stripes = 4;
1273 }
1274
1275 if (type & BTRFS_BLOCK_GROUP_DUP)
1276 min_stripe_size = 2 * BTRFS_STRIPE_LEN;
1277 else
1278 min_stripe_size = BTRFS_STRIPE_LEN;
1279
1280 list_for_each_entry(device, &fs_devices->devices, dev_list) {
1281 if (!device->in_fs_metadata || !device->bdev)
1282 continue;
1283
1284 avail_space = device->total_bytes - device->bytes_used;
1285
1286 /* align with stripe_len */
1287 do_div(avail_space, BTRFS_STRIPE_LEN);
1288 avail_space *= BTRFS_STRIPE_LEN;
1289
1290 /*
1291 * In order to avoid overwritting the superblock on the drive,
1292 * btrfs starts at an offset of at least 1MB when doing chunk
1293 * allocation.
1294 */
1295 skip_space = 1024 * 1024;
1296
1297 /* user can set the offset in fs_info->alloc_start. */
1298 if (fs_info->alloc_start + BTRFS_STRIPE_LEN <=
1299 device->total_bytes)
1300 skip_space = max(fs_info->alloc_start, skip_space);
1301
1302 /*
1303 * btrfs can not use the free space in [0, skip_space - 1],
1304 * we must subtract it from the total. In order to implement
1305 * it, we account the used space in this range first.
1306 */
1307 ret = btrfs_account_dev_extents_size(device, 0, skip_space - 1,
1308 &used_space);
1309 if (ret) {
1310 kfree(devices_info);
1311 return ret;
1312 }
1313
1314 /* calc the free space in [0, skip_space - 1] */
1315 skip_space -= used_space;
1316
1317 /*
1318 * we can use the free space in [0, skip_space - 1], subtract
1319 * it from the total.
1320 */
1321 if (avail_space && avail_space >= skip_space)
1322 avail_space -= skip_space;
1323 else
1324 avail_space = 0;
1325
1326 if (avail_space < min_stripe_size)
1327 continue;
1328
1329 devices_info[i].dev = device;
1330 devices_info[i].max_avail = avail_space;
1331
1332 i++;
1333 }
1334
1335 nr_devices = i;
1336
1337 btrfs_descending_sort_devices(devices_info, nr_devices);
1338
1339 i = nr_devices - 1;
1340 avail_space = 0;
1341 while (nr_devices >= min_stripes) {
1342 if (num_stripes > nr_devices)
1343 num_stripes = nr_devices;
1344
1345 if (devices_info[i].max_avail >= min_stripe_size) {
1346 int j;
1347 u64 alloc_size;
1348
1349 avail_space += devices_info[i].max_avail * num_stripes;
1350 alloc_size = devices_info[i].max_avail;
1351 for (j = i + 1 - num_stripes; j <= i; j++)
1352 devices_info[j].max_avail -= alloc_size;
1353 }
1354 i--;
1355 nr_devices--;
1356 }
1357
1358 kfree(devices_info);
1359 *free_bytes = avail_space;
1360 return 0;
1361 }
1362
1363 static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf)
1364 {
1365 struct btrfs_fs_info *fs_info = btrfs_sb(dentry->d_sb);
1366 struct btrfs_super_block *disk_super = fs_info->super_copy;
1367 struct list_head *head = &fs_info->space_info;
1368 struct btrfs_space_info *found;
1369 u64 total_used = 0;
1370 u64 total_free_data = 0;
1371 int bits = dentry->d_sb->s_blocksize_bits;
1372 __be32 *fsid = (__be32 *)fs_info->fsid;
1373 int ret;
1374
1375 /* holding chunk_muext to avoid allocating new chunks */
1376 mutex_lock(&fs_info->chunk_mutex);
1377 rcu_read_lock();
1378 list_for_each_entry_rcu(found, head, list) {
1379 if (found->flags & BTRFS_BLOCK_GROUP_DATA) {
1380 total_free_data += found->disk_total - found->disk_used;
1381 total_free_data -=
1382 btrfs_account_ro_block_groups_free_space(found);
1383 }
1384
1385 total_used += found->disk_used;
1386 }
1387 rcu_read_unlock();
1388
1389 buf->f_namelen = BTRFS_NAME_LEN;
1390 buf->f_blocks = btrfs_super_total_bytes(disk_super) >> bits;
1391 buf->f_bfree = buf->f_blocks - (total_used >> bits);
1392 buf->f_bsize = dentry->d_sb->s_blocksize;
1393 buf->f_type = BTRFS_SUPER_MAGIC;
1394 buf->f_bavail = total_free_data;
1395 ret = btrfs_calc_avail_data_space(fs_info->tree_root, &total_free_data);
1396 if (ret) {
1397 mutex_unlock(&fs_info->chunk_mutex);
1398 return ret;
1399 }
1400 buf->f_bavail += total_free_data;
1401 buf->f_bavail = buf->f_bavail >> bits;
1402 mutex_unlock(&fs_info->chunk_mutex);
1403
1404 /* We treat it as constant endianness (it doesn't matter _which_)
1405 because we want the fsid to come out the same whether mounted
1406 on a big-endian or little-endian host */
1407 buf->f_fsid.val[0] = be32_to_cpu(fsid[0]) ^ be32_to_cpu(fsid[2]);
1408 buf->f_fsid.val[1] = be32_to_cpu(fsid[1]) ^ be32_to_cpu(fsid[3]);
1409 /* Mask in the root object ID too, to disambiguate subvols */
1410 buf->f_fsid.val[0] ^= BTRFS_I(dentry->d_inode)->root->objectid >> 32;
1411 buf->f_fsid.val[1] ^= BTRFS_I(dentry->d_inode)->root->objectid;
1412
1413 return 0;
1414 }
1415
1416 static void btrfs_kill_super(struct super_block *sb)
1417 {
1418 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
1419 kill_anon_super(sb);
1420 free_fs_info(fs_info);
1421 }
1422
1423 static struct file_system_type btrfs_fs_type = {
1424 .owner = THIS_MODULE,
1425 .name = "btrfs",
1426 .mount = btrfs_mount,
1427 .kill_sb = btrfs_kill_super,
1428 .fs_flags = FS_REQUIRES_DEV,
1429 };
1430
1431 /*
1432 * used by btrfsctl to scan devices when no FS is mounted
1433 */
1434 static long btrfs_control_ioctl(struct file *file, unsigned int cmd,
1435 unsigned long arg)
1436 {
1437 struct btrfs_ioctl_vol_args *vol;
1438 struct btrfs_fs_devices *fs_devices;
1439 int ret = -ENOTTY;
1440
1441 if (!capable(CAP_SYS_ADMIN))
1442 return -EPERM;
1443
1444 vol = memdup_user((void __user *)arg, sizeof(*vol));
1445 if (IS_ERR(vol))
1446 return PTR_ERR(vol);
1447
1448 switch (cmd) {
1449 case BTRFS_IOC_SCAN_DEV:
1450 ret = btrfs_scan_one_device(vol->name, FMODE_READ,
1451 &btrfs_fs_type, &fs_devices);
1452 break;
1453 }
1454
1455 kfree(vol);
1456 return ret;
1457 }
1458
1459 static int btrfs_freeze(struct super_block *sb)
1460 {
1461 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
1462 mutex_lock(&fs_info->transaction_kthread_mutex);
1463 mutex_lock(&fs_info->cleaner_mutex);
1464 return 0;
1465 }
1466
1467 static int btrfs_unfreeze(struct super_block *sb)
1468 {
1469 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
1470 mutex_unlock(&fs_info->cleaner_mutex);
1471 mutex_unlock(&fs_info->transaction_kthread_mutex);
1472 return 0;
1473 }
1474
1475 static void btrfs_fs_dirty_inode(struct inode *inode, int flags)
1476 {
1477 int ret;
1478
1479 ret = btrfs_dirty_inode(inode);
1480 if (ret)
1481 printk_ratelimited(KERN_ERR "btrfs: fail to dirty inode %Lu "
1482 "error %d\n", btrfs_ino(inode), ret);
1483 }
1484
1485 static const struct super_operations btrfs_super_ops = {
1486 .drop_inode = btrfs_drop_inode,
1487 .evict_inode = btrfs_evict_inode,
1488 .put_super = btrfs_put_super,
1489 .sync_fs = btrfs_sync_fs,
1490 .show_options = btrfs_show_options,
1491 .write_inode = btrfs_write_inode,
1492 .dirty_inode = btrfs_fs_dirty_inode,
1493 .alloc_inode = btrfs_alloc_inode,
1494 .destroy_inode = btrfs_destroy_inode,
1495 .statfs = btrfs_statfs,
1496 .remount_fs = btrfs_remount,
1497 .freeze_fs = btrfs_freeze,
1498 .unfreeze_fs = btrfs_unfreeze,
1499 };
1500
1501 static const struct file_operations btrfs_ctl_fops = {
1502 .unlocked_ioctl = btrfs_control_ioctl,
1503 .compat_ioctl = btrfs_control_ioctl,
1504 .owner = THIS_MODULE,
1505 .llseek = noop_llseek,
1506 };
1507
1508 static struct miscdevice btrfs_misc = {
1509 .minor = BTRFS_MINOR,
1510 .name = "btrfs-control",
1511 .fops = &btrfs_ctl_fops
1512 };
1513
1514 MODULE_ALIAS_MISCDEV(BTRFS_MINOR);
1515 MODULE_ALIAS("devname:btrfs-control");
1516
1517 static int btrfs_interface_init(void)
1518 {
1519 return misc_register(&btrfs_misc);
1520 }
1521
1522 static void btrfs_interface_exit(void)
1523 {
1524 if (misc_deregister(&btrfs_misc) < 0)
1525 printk(KERN_INFO "misc_deregister failed for control device");
1526 }
1527
1528 static int __init init_btrfs_fs(void)
1529 {
1530 int err;
1531
1532 err = btrfs_init_sysfs();
1533 if (err)
1534 return err;
1535
1536 btrfs_init_compress();
1537
1538 err = btrfs_init_cachep();
1539 if (err)
1540 goto free_compress;
1541
1542 err = extent_io_init();
1543 if (err)
1544 goto free_cachep;
1545
1546 err = extent_map_init();
1547 if (err)
1548 goto free_extent_io;
1549
1550 err = btrfs_delayed_inode_init();
1551 if (err)
1552 goto free_extent_map;
1553
1554 err = btrfs_interface_init();
1555 if (err)
1556 goto free_delayed_inode;
1557
1558 err = register_filesystem(&btrfs_fs_type);
1559 if (err)
1560 goto unregister_ioctl;
1561
1562 btrfs_init_lockdep();
1563
1564 printk(KERN_INFO "%s loaded\n", BTRFS_BUILD_VERSION);
1565 return 0;
1566
1567 unregister_ioctl:
1568 btrfs_interface_exit();
1569 free_delayed_inode:
1570 btrfs_delayed_inode_exit();
1571 free_extent_map:
1572 extent_map_exit();
1573 free_extent_io:
1574 extent_io_exit();
1575 free_cachep:
1576 btrfs_destroy_cachep();
1577 free_compress:
1578 btrfs_exit_compress();
1579 btrfs_exit_sysfs();
1580 return err;
1581 }
1582
1583 static void __exit exit_btrfs_fs(void)
1584 {
1585 btrfs_destroy_cachep();
1586 btrfs_delayed_inode_exit();
1587 extent_map_exit();
1588 extent_io_exit();
1589 btrfs_interface_exit();
1590 unregister_filesystem(&btrfs_fs_type);
1591 btrfs_exit_sysfs();
1592 btrfs_cleanup_fs_uuids();
1593 btrfs_exit_compress();
1594 }
1595
1596 module_init(init_btrfs_fs)
1597 module_exit(exit_btrfs_fs)
1598
1599 MODULE_LICENSE("GPL");
Linux kernel - Deliverables
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