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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 "compat.h"
42#include "ctree.h"
43#include "disk-io.h"
44#include "transaction.h"
45#include "btrfs_inode.h"
46#include "ioctl.h"
47#include "print-tree.h"
48#include "xattr.h"
49#include "volumes.h"
50#include "version.h"
51#include "export.h"
52#include "compression.h"
53
54static const struct super_operations btrfs_super_ops;
55
56static void btrfs_put_super(struct super_block *sb)
57{
58 struct btrfs_root *root = btrfs_sb(sb);
59 int ret;
60
61 ret = close_ctree(root);
62 sb->s_fs_info = NULL;
63}
64
65enum {
66 Opt_degraded, Opt_subvol, Opt_device, Opt_nodatasum, Opt_nodatacow,
67 Opt_max_extent, Opt_max_inline, Opt_alloc_start, Opt_nobarrier,
68 Opt_ssd, Opt_nossd, Opt_ssd_spread, Opt_thread_pool, Opt_noacl,
69 Opt_compress, Opt_notreelog, Opt_ratio, Opt_flushoncommit,
70 Opt_discard, Opt_err,
71};
72
73static match_table_t tokens = {
74 {Opt_degraded, "degraded"},
75 {Opt_subvol, "subvol=%s"},
76 {Opt_device, "device=%s"},
77 {Opt_nodatasum, "nodatasum"},
78 {Opt_nodatacow, "nodatacow"},
79 {Opt_nobarrier, "nobarrier"},
80 {Opt_max_extent, "max_extent=%s"},
81 {Opt_max_inline, "max_inline=%s"},
82 {Opt_alloc_start, "alloc_start=%s"},
83 {Opt_thread_pool, "thread_pool=%d"},
84 {Opt_compress, "compress"},
85 {Opt_ssd, "ssd"},
86 {Opt_ssd_spread, "ssd_spread"},
87 {Opt_nossd, "nossd"},
88 {Opt_noacl, "noacl"},
89 {Opt_notreelog, "notreelog"},
90 {Opt_flushoncommit, "flushoncommit"},
91 {Opt_ratio, "metadata_ratio=%d"},
92 {Opt_discard, "discard"},
93 {Opt_err, NULL},
94};
95
96u64 btrfs_parse_size(char *str)
97{
98 u64 res;
99 int mult = 1;
100 char *end;
101 char last;
102
103 res = simple_strtoul(str, &end, 10);
104
105 last = end[0];
106 if (isalpha(last)) {
107 last = tolower(last);
108 switch (last) {
109 case 'g':
110 mult *= 1024;
111 case 'm':
112 mult *= 1024;
113 case 'k':
114 mult *= 1024;
115 }
116 res = res * mult;
117 }
118 return res;
119}
120
121
122
123
124
125int btrfs_parse_options(struct btrfs_root *root, char *options)
126{
127 struct btrfs_fs_info *info = root->fs_info;
128 substring_t args[MAX_OPT_ARGS];
129 char *p, *num;
130 int intarg;
131
132 if (!options)
133 return 0;
134
135
136
137
138
139 options = kstrdup(options, GFP_NOFS);
140 if (!options)
141 return -ENOMEM;
142
143
144 while ((p = strsep(&options, ",")) != NULL) {
145 int token;
146 if (!*p)
147 continue;
148
149 token = match_token(p, tokens, args);
150 switch (token) {
151 case Opt_degraded:
152 printk(KERN_INFO "btrfs: allowing degraded mounts\n");
153 btrfs_set_opt(info->mount_opt, DEGRADED);
154 break;
155 case Opt_subvol:
156 case Opt_device:
157
158
159
160
161 break;
162 case Opt_nodatasum:
163 printk(KERN_INFO "btrfs: setting nodatasum\n");
164 btrfs_set_opt(info->mount_opt, NODATASUM);
165 break;
166 case Opt_nodatacow:
167 printk(KERN_INFO "btrfs: setting nodatacow\n");
168 btrfs_set_opt(info->mount_opt, NODATACOW);
169 btrfs_set_opt(info->mount_opt, NODATASUM);
170 break;
171 case Opt_compress:
172 printk(KERN_INFO "btrfs: use compression\n");
173 btrfs_set_opt(info->mount_opt, COMPRESS);
174 break;
175 case Opt_ssd:
176 printk(KERN_INFO "btrfs: use ssd allocation scheme\n");
177 btrfs_set_opt(info->mount_opt, SSD);
178 break;
179 case Opt_ssd_spread:
180 printk(KERN_INFO "btrfs: use spread ssd "
181 "allocation scheme\n");
182 btrfs_set_opt(info->mount_opt, SSD);
183 btrfs_set_opt(info->mount_opt, SSD_SPREAD);
184 break;
185 case Opt_nossd:
186 printk(KERN_INFO "btrfs: not using ssd allocation "
187 "scheme\n");
188 btrfs_set_opt(info->mount_opt, NOSSD);
189 btrfs_clear_opt(info->mount_opt, SSD);
190 btrfs_clear_opt(info->mount_opt, SSD_SPREAD);
191 break;
192 case Opt_nobarrier:
193 printk(KERN_INFO "btrfs: turning off barriers\n");
194 btrfs_set_opt(info->mount_opt, NOBARRIER);
195 break;
196 case Opt_thread_pool:
197 intarg = 0;
198 match_int(&args[0], &intarg);
199 if (intarg) {
200 info->thread_pool_size = intarg;
201 printk(KERN_INFO "btrfs: thread pool %d\n",
202 info->thread_pool_size);
203 }
204 break;
205 case Opt_max_extent:
206 num = match_strdup(&args[0]);
207 if (num) {
208 info->max_extent = btrfs_parse_size(num);
209 kfree(num);
210
211 info->max_extent = max_t(u64,
212 info->max_extent, root->sectorsize);
213 printk(KERN_INFO "btrfs: max_extent at %llu\n",
214 (unsigned long long)info->max_extent);
215 }
216 break;
217 case Opt_max_inline:
218 num = match_strdup(&args[0]);
219 if (num) {
220 info->max_inline = btrfs_parse_size(num);
221 kfree(num);
222
223 if (info->max_inline) {
224 info->max_inline = max_t(u64,
225 info->max_inline,
226 root->sectorsize);
227 }
228 printk(KERN_INFO "btrfs: max_inline at %llu\n",
229 (unsigned long long)info->max_inline);
230 }
231 break;
232 case Opt_alloc_start:
233 num = match_strdup(&args[0]);
234 if (num) {
235 info->alloc_start = btrfs_parse_size(num);
236 kfree(num);
237 printk(KERN_INFO
238 "btrfs: allocations start at %llu\n",
239 (unsigned long long)info->alloc_start);
240 }
241 break;
242 case Opt_noacl:
243 root->fs_info->sb->s_flags &= ~MS_POSIXACL;
244 break;
245 case Opt_notreelog:
246 printk(KERN_INFO "btrfs: disabling tree log\n");
247 btrfs_set_opt(info->mount_opt, NOTREELOG);
248 break;
249 case Opt_flushoncommit:
250 printk(KERN_INFO "btrfs: turning on flush-on-commit\n");
251 btrfs_set_opt(info->mount_opt, FLUSHONCOMMIT);
252 break;
253 case Opt_ratio:
254 intarg = 0;
255 match_int(&args[0], &intarg);
256 if (intarg) {
257 info->metadata_ratio = intarg;
258 printk(KERN_INFO "btrfs: metadata ratio %d\n",
259 info->metadata_ratio);
260 }
261 break;
262 case Opt_discard:
263 btrfs_set_opt(info->mount_opt, DISCARD);
264 break;
265 default:
266 break;
267 }
268 }
269 kfree(options);
270 return 0;
271}
272
273
274
275
276
277
278
279static int btrfs_parse_early_options(const char *options, fmode_t flags,
280 void *holder, char **subvol_name,
281 struct btrfs_fs_devices **fs_devices)
282{
283 substring_t args[MAX_OPT_ARGS];
284 char *opts, *p;
285 int error = 0;
286
287 if (!options)
288 goto out;
289
290
291
292
293
294 opts = kstrdup(options, GFP_KERNEL);
295 if (!opts)
296 return -ENOMEM;
297
298 while ((p = strsep(&opts, ",")) != NULL) {
299 int token;
300 if (!*p)
301 continue;
302
303 token = match_token(p, tokens, args);
304 switch (token) {
305 case Opt_subvol:
306 *subvol_name = match_strdup(&args[0]);
307 break;
308 case Opt_device:
309 error = btrfs_scan_one_device(match_strdup(&args[0]),
310 flags, holder, fs_devices);
311 if (error)
312 goto out_free_opts;
313 break;
314 default:
315 break;
316 }
317 }
318
319 out_free_opts:
320 kfree(opts);
321 out:
322
323
324
325
326
327 if (!*subvol_name) {
328 *subvol_name = kstrdup(".", GFP_KERNEL);
329 if (!*subvol_name)
330 return -ENOMEM;
331 }
332 return error;
333}
334
335static int btrfs_fill_super(struct super_block *sb,
336 struct btrfs_fs_devices *fs_devices,
337 void *data, int silent)
338{
339 struct inode *inode;
340 struct dentry *root_dentry;
341 struct btrfs_super_block *disk_super;
342 struct btrfs_root *tree_root;
343 struct btrfs_key key;
344 int err;
345
346 sb->s_maxbytes = MAX_LFS_FILESIZE;
347 sb->s_magic = BTRFS_SUPER_MAGIC;
348 sb->s_op = &btrfs_super_ops;
349 sb->s_export_op = &btrfs_export_ops;
350 sb->s_xattr = btrfs_xattr_handlers;
351 sb->s_time_gran = 1;
352#ifdef CONFIG_BTRFS_FS_POSIX_ACL
353 sb->s_flags |= MS_POSIXACL;
354#endif
355
356 tree_root = open_ctree(sb, fs_devices, (char *)data);
357
358 if (IS_ERR(tree_root)) {
359 printk("btrfs: open_ctree failed\n");
360 return PTR_ERR(tree_root);
361 }
362 sb->s_fs_info = tree_root;
363 disk_super = &tree_root->fs_info->super_copy;
364
365 key.objectid = BTRFS_FIRST_FREE_OBJECTID;
366 key.type = BTRFS_INODE_ITEM_KEY;
367 key.offset = 0;
368 inode = btrfs_iget(sb, &key, tree_root->fs_info->fs_root);
369 if (IS_ERR(inode)) {
370 err = PTR_ERR(inode);
371 goto fail_close;
372 }
373
374 root_dentry = d_alloc_root(inode);
375 if (!root_dentry) {
376 iput(inode);
377 err = -ENOMEM;
378 goto fail_close;
379 }
380#if 0
381
382 err = btrfs_sysfs_add_super(tree_root->fs_info);
383 if (err)
384 goto fail_close;
385#endif
386
387 sb->s_root = root_dentry;
388
389 save_mount_options(sb, data);
390 return 0;
391
392fail_close:
393 close_ctree(tree_root);
394 return err;
395}
396
397int btrfs_sync_fs(struct super_block *sb, int wait)
398{
399 struct btrfs_trans_handle *trans;
400 struct btrfs_root *root = btrfs_sb(sb);
401 int ret;
402
403 if (!wait) {
404 filemap_flush(root->fs_info->btree_inode->i_mapping);
405 return 0;
406 }
407
408 btrfs_start_delalloc_inodes(root);
409 btrfs_wait_ordered_extents(root, 0);
410
411 trans = btrfs_start_transaction(root, 1);
412 ret = btrfs_commit_transaction(trans, root);
413 return ret;
414}
415
416static int btrfs_show_options(struct seq_file *seq, struct vfsmount *vfs)
417{
418 struct btrfs_root *root = btrfs_sb(vfs->mnt_sb);
419 struct btrfs_fs_info *info = root->fs_info;
420
421 if (btrfs_test_opt(root, DEGRADED))
422 seq_puts(seq, ",degraded");
423 if (btrfs_test_opt(root, NODATASUM))
424 seq_puts(seq, ",nodatasum");
425 if (btrfs_test_opt(root, NODATACOW))
426 seq_puts(seq, ",nodatacow");
427 if (btrfs_test_opt(root, NOBARRIER))
428 seq_puts(seq, ",nobarrier");
429 if (info->max_extent != (u64)-1)
430 seq_printf(seq, ",max_extent=%llu",
431 (unsigned long long)info->max_extent);
432 if (info->max_inline != 8192 * 1024)
433 seq_printf(seq, ",max_inline=%llu",
434 (unsigned long long)info->max_inline);
435 if (info->alloc_start != 0)
436 seq_printf(seq, ",alloc_start=%llu",
437 (unsigned long long)info->alloc_start);
438 if (info->thread_pool_size != min_t(unsigned long,
439 num_online_cpus() + 2, 8))
440 seq_printf(seq, ",thread_pool=%d", info->thread_pool_size);
441 if (btrfs_test_opt(root, COMPRESS))
442 seq_puts(seq, ",compress");
443 if (btrfs_test_opt(root, NOSSD))
444 seq_puts(seq, ",nossd");
445 if (btrfs_test_opt(root, SSD_SPREAD))
446 seq_puts(seq, ",ssd_spread");
447 else if (btrfs_test_opt(root, SSD))
448 seq_puts(seq, ",ssd");
449 if (btrfs_test_opt(root, NOTREELOG))
450 seq_puts(seq, ",notreelog");
451 if (btrfs_test_opt(root, FLUSHONCOMMIT))
452 seq_puts(seq, ",flushoncommit");
453 if (!(root->fs_info->sb->s_flags & MS_POSIXACL))
454 seq_puts(seq, ",noacl");
455 return 0;
456}
457
458static int btrfs_test_super(struct super_block *s, void *data)
459{
460 struct btrfs_fs_devices *test_fs_devices = data;
461 struct btrfs_root *root = btrfs_sb(s);
462
463 return root->fs_info->fs_devices == test_fs_devices;
464}
465
466
467
468
469
470
471
472static int btrfs_get_sb(struct file_system_type *fs_type, int flags,
473 const char *dev_name, void *data, struct vfsmount *mnt)
474{
475 char *subvol_name = NULL;
476 struct block_device *bdev = NULL;
477 struct super_block *s;
478 struct dentry *root;
479 struct btrfs_fs_devices *fs_devices = NULL;
480 fmode_t mode = FMODE_READ;
481 int error = 0;
482
483 if (!(flags & MS_RDONLY))
484 mode |= FMODE_WRITE;
485
486 error = btrfs_parse_early_options(data, mode, fs_type,
487 &subvol_name, &fs_devices);
488 if (error)
489 return error;
490
491 error = btrfs_scan_one_device(dev_name, mode, fs_type, &fs_devices);
492 if (error)
493 goto error_free_subvol_name;
494
495 error = btrfs_open_devices(fs_devices, mode, fs_type);
496 if (error)
497 goto error_free_subvol_name;
498
499 if (!(flags & MS_RDONLY) && fs_devices->rw_devices == 0) {
500 error = -EACCES;
501 goto error_close_devices;
502 }
503
504 bdev = fs_devices->latest_bdev;
505 s = sget(fs_type, btrfs_test_super, set_anon_super, fs_devices);
506 if (IS_ERR(s))
507 goto error_s;
508
509 if (s->s_root) {
510 if ((flags ^ s->s_flags) & MS_RDONLY) {
511 deactivate_locked_super(s);
512 error = -EBUSY;
513 goto error_close_devices;
514 }
515
516 btrfs_close_devices(fs_devices);
517 } else {
518 char b[BDEVNAME_SIZE];
519
520 s->s_flags = flags;
521 strlcpy(s->s_id, bdevname(bdev, b), sizeof(s->s_id));
522 error = btrfs_fill_super(s, fs_devices, data,
523 flags & MS_SILENT ? 1 : 0);
524 if (error) {
525 deactivate_locked_super(s);
526 goto error_free_subvol_name;
527 }
528
529 btrfs_sb(s)->fs_info->bdev_holder = fs_type;
530 s->s_flags |= MS_ACTIVE;
531 }
532
533 if (!strcmp(subvol_name, "."))
534 root = dget(s->s_root);
535 else {
536 mutex_lock(&s->s_root->d_inode->i_mutex);
537 root = lookup_one_len(subvol_name, s->s_root,
538 strlen(subvol_name));
539 mutex_unlock(&s->s_root->d_inode->i_mutex);
540
541 if (IS_ERR(root)) {
542 deactivate_locked_super(s);
543 error = PTR_ERR(root);
544 goto error_free_subvol_name;
545 }
546 if (!root->d_inode) {
547 dput(root);
548 deactivate_locked_super(s);
549 error = -ENXIO;
550 goto error_free_subvol_name;
551 }
552 }
553
554 mnt->mnt_sb = s;
555 mnt->mnt_root = root;
556
557 kfree(subvol_name);
558 return 0;
559
560error_s:
561 error = PTR_ERR(s);
562error_close_devices:
563 btrfs_close_devices(fs_devices);
564error_free_subvol_name:
565 kfree(subvol_name);
566 return error;
567}
568
569static int btrfs_remount(struct super_block *sb, int *flags, char *data)
570{
571 struct btrfs_root *root = btrfs_sb(sb);
572 int ret;
573
574 ret = btrfs_parse_options(root, data);
575 if (ret)
576 return -EINVAL;
577
578 if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
579 return 0;
580
581 if (*flags & MS_RDONLY) {
582 sb->s_flags |= MS_RDONLY;
583
584 ret = btrfs_commit_super(root);
585 WARN_ON(ret);
586 } else {
587 if (root->fs_info->fs_devices->rw_devices == 0)
588 return -EACCES;
589
590 if (btrfs_super_log_root(&root->fs_info->super_copy) != 0)
591 return -EINVAL;
592
593
594 ret = btrfs_recover_relocation(root);
595 WARN_ON(ret);
596
597 ret = btrfs_cleanup_fs_roots(root->fs_info);
598 WARN_ON(ret);
599
600 sb->s_flags &= ~MS_RDONLY;
601 }
602
603 return 0;
604}
605
606static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf)
607{
608 struct btrfs_root *root = btrfs_sb(dentry->d_sb);
609 struct btrfs_super_block *disk_super = &root->fs_info->super_copy;
610 int bits = dentry->d_sb->s_blocksize_bits;
611 __be32 *fsid = (__be32 *)root->fs_info->fsid;
612
613 buf->f_namelen = BTRFS_NAME_LEN;
614 buf->f_blocks = btrfs_super_total_bytes(disk_super) >> bits;
615 buf->f_bfree = buf->f_blocks -
616 (btrfs_super_bytes_used(disk_super) >> bits);
617 buf->f_bavail = buf->f_bfree;
618 buf->f_bsize = dentry->d_sb->s_blocksize;
619 buf->f_type = BTRFS_SUPER_MAGIC;
620
621
622
623
624 buf->f_fsid.val[0] = be32_to_cpu(fsid[0]) ^ be32_to_cpu(fsid[2]);
625 buf->f_fsid.val[1] = be32_to_cpu(fsid[1]) ^ be32_to_cpu(fsid[3]);
626
627 buf->f_fsid.val[0] ^= BTRFS_I(dentry->d_inode)->root->objectid >> 32;
628 buf->f_fsid.val[1] ^= BTRFS_I(dentry->d_inode)->root->objectid;
629
630 return 0;
631}
632
633static struct file_system_type btrfs_fs_type = {
634 .owner = THIS_MODULE,
635 .name = "btrfs",
636 .get_sb = btrfs_get_sb,
637 .kill_sb = kill_anon_super,
638 .fs_flags = FS_REQUIRES_DEV,
639};
640
641
642
643
644static long btrfs_control_ioctl(struct file *file, unsigned int cmd,
645 unsigned long arg)
646{
647 struct btrfs_ioctl_vol_args *vol;
648 struct btrfs_fs_devices *fs_devices;
649 int ret = -ENOTTY;
650
651 if (!capable(CAP_SYS_ADMIN))
652 return -EPERM;
653
654 vol = memdup_user((void __user *)arg, sizeof(*vol));
655 if (IS_ERR(vol))
656 return PTR_ERR(vol);
657
658 switch (cmd) {
659 case BTRFS_IOC_SCAN_DEV:
660 ret = btrfs_scan_one_device(vol->name, FMODE_READ,
661 &btrfs_fs_type, &fs_devices);
662 break;
663 }
664
665 kfree(vol);
666 return ret;
667}
668
669static int btrfs_freeze(struct super_block *sb)
670{
671 struct btrfs_root *root = btrfs_sb(sb);
672 mutex_lock(&root->fs_info->transaction_kthread_mutex);
673 mutex_lock(&root->fs_info->cleaner_mutex);
674 return 0;
675}
676
677static int btrfs_unfreeze(struct super_block *sb)
678{
679 struct btrfs_root *root = btrfs_sb(sb);
680 mutex_unlock(&root->fs_info->cleaner_mutex);
681 mutex_unlock(&root->fs_info->transaction_kthread_mutex);
682 return 0;
683}
684
685static const struct super_operations btrfs_super_ops = {
686 .drop_inode = btrfs_drop_inode,
687 .delete_inode = btrfs_delete_inode,
688 .put_super = btrfs_put_super,
689 .sync_fs = btrfs_sync_fs,
690 .show_options = btrfs_show_options,
691 .write_inode = btrfs_write_inode,
692 .dirty_inode = btrfs_dirty_inode,
693 .alloc_inode = btrfs_alloc_inode,
694 .destroy_inode = btrfs_destroy_inode,
695 .statfs = btrfs_statfs,
696 .remount_fs = btrfs_remount,
697 .freeze_fs = btrfs_freeze,
698 .unfreeze_fs = btrfs_unfreeze,
699};
700
701static const struct file_operations btrfs_ctl_fops = {
702 .unlocked_ioctl = btrfs_control_ioctl,
703 .compat_ioctl = btrfs_control_ioctl,
704 .owner = THIS_MODULE,
705};
706
707static struct miscdevice btrfs_misc = {
708 .minor = MISC_DYNAMIC_MINOR,
709 .name = "btrfs-control",
710 .fops = &btrfs_ctl_fops
711};
712
713static int btrfs_interface_init(void)
714{
715 return misc_register(&btrfs_misc);
716}
717
718static void btrfs_interface_exit(void)
719{
720 if (misc_deregister(&btrfs_misc) < 0)
721 printk(KERN_INFO "misc_deregister failed for control device");
722}
723
724static int __init init_btrfs_fs(void)
725{
726 int err;
727
728 err = btrfs_init_sysfs();
729 if (err)
730 return err;
731
732 err = btrfs_init_cachep();
733 if (err)
734 goto free_sysfs;
735
736 err = extent_io_init();
737 if (err)
738 goto free_cachep;
739
740 err = extent_map_init();
741 if (err)
742 goto free_extent_io;
743
744 err = btrfs_interface_init();
745 if (err)
746 goto free_extent_map;
747
748 err = register_filesystem(&btrfs_fs_type);
749 if (err)
750 goto unregister_ioctl;
751
752 printk(KERN_INFO "%s loaded\n", BTRFS_BUILD_VERSION);
753 return 0;
754
755unregister_ioctl:
756 btrfs_interface_exit();
757free_extent_map:
758 extent_map_exit();
759free_extent_io:
760 extent_io_exit();
761free_cachep:
762 btrfs_destroy_cachep();
763free_sysfs:
764 btrfs_exit_sysfs();
765 return err;
766}
767
768static void __exit exit_btrfs_fs(void)
769{
770 btrfs_destroy_cachep();
771 extent_map_exit();
772 extent_io_exit();
773 btrfs_interface_exit();
774 unregister_filesystem(&btrfs_fs_type);
775 btrfs_exit_sysfs();
776 btrfs_cleanup_fs_uuids();
777 btrfs_zlib_exit();
778}
779
780module_init(init_btrfs_fs)
781module_exit(exit_btrfs_fs)
782
783MODULE_LICENSE("GPL");
784
