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Linux 3.12.28
[linux/fpc-iii.git] / fs / nilfs2 / super.c
blob7ac2a122ca1dd1ce042005600d1396990d0ec3a4
1 /*
2 * super.c - NILFS module and super block management.
3 *
4 * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation.
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
19 *
20 * Written by Ryusuke Konishi <ryusuke@osrg.net>
21 */
22 /*
23 * linux/fs/ext2/super.c
24 *
25 * Copyright (C) 1992, 1993, 1994, 1995
26 * Remy Card (card@masi.ibp.fr)
27 * Laboratoire MASI - Institut Blaise Pascal
28 * Universite Pierre et Marie Curie (Paris VI)
29 *
30 * from
31 *
32 * linux/fs/minix/inode.c
33 *
34 * Copyright (C) 1991, 1992 Linus Torvalds
35 *
36 * Big-endian to little-endian byte-swapping/bitmaps by
37 * David S. Miller (davem@caip.rutgers.edu), 1995
38 */
39
40 #include <linux/module.h>
41 #include <linux/string.h>
42 #include <linux/slab.h>
43 #include <linux/init.h>
44 #include <linux/blkdev.h>
45 #include <linux/parser.h>
46 #include <linux/crc32.h>
47 #include <linux/vfs.h>
48 #include <linux/writeback.h>
49 #include <linux/seq_file.h>
50 #include <linux/mount.h>
51 #include "nilfs.h"
52 #include "export.h"
53 #include "mdt.h"
54 #include "alloc.h"
55 #include "btree.h"
56 #include "btnode.h"
57 #include "page.h"
58 #include "cpfile.h"
59 #include "sufile.h" /* nilfs_sufile_resize(), nilfs_sufile_set_alloc_range() */
60 #include "ifile.h"
61 #include "dat.h"
62 #include "segment.h"
63 #include "segbuf.h"
64
65 MODULE_AUTHOR("NTT Corp.");
66 MODULE_DESCRIPTION("A New Implementation of the Log-structured Filesystem "
67 "(NILFS)");
68 MODULE_LICENSE("GPL");
69
70 static struct kmem_cache *nilfs_inode_cachep;
71 struct kmem_cache *nilfs_transaction_cachep;
72 struct kmem_cache *nilfs_segbuf_cachep;
73 struct kmem_cache *nilfs_btree_path_cache;
74
75 static int nilfs_setup_super(struct super_block *sb, int is_mount);
76 static int nilfs_remount(struct super_block *sb, int *flags, char *data);
77
78 static void nilfs_set_error(struct super_block *sb)
79 {
80 struct the_nilfs *nilfs = sb->s_fs_info;
81 struct nilfs_super_block **sbp;
82
83 down_write(&nilfs->ns_sem);
84 if (!(nilfs->ns_mount_state & NILFS_ERROR_FS)) {
85 nilfs->ns_mount_state |= NILFS_ERROR_FS;
86 sbp = nilfs_prepare_super(sb, 0);
87 if (likely(sbp)) {
88 sbp[0]->s_state |= cpu_to_le16(NILFS_ERROR_FS);
89 if (sbp[1])
90 sbp[1]->s_state |= cpu_to_le16(NILFS_ERROR_FS);
91 nilfs_commit_super(sb, NILFS_SB_COMMIT_ALL);
92 }
93 }
94 up_write(&nilfs->ns_sem);
95 }
96
97 /**
98 * nilfs_error() - report failure condition on a filesystem
99 *
100 * nilfs_error() sets an ERROR_FS flag on the superblock as well as
101 * reporting an error message. It should be called when NILFS detects
102 * incoherences or defects of meta data on disk. As for sustainable
103 * errors such as a single-shot I/O error, nilfs_warning() or the printk()
104 * function should be used instead.
105 *
106 * The segment constructor must not call this function because it can
107 * kill itself.
108 */
109 void nilfs_error(struct super_block *sb, const char *function,
110 const char *fmt, ...)
111 {
112 struct the_nilfs *nilfs = sb->s_fs_info;
113 struct va_format vaf;
114 va_list args;
115
116 va_start(args, fmt);
117
118 vaf.fmt = fmt;
119 vaf.va = &args;
120
121 printk(KERN_CRIT "NILFS error (device %s): %s: %pV\n",
122 sb->s_id, function, &vaf);
123
124 va_end(args);
125
126 if (!(sb->s_flags & MS_RDONLY)) {
127 nilfs_set_error(sb);
128
129 if (nilfs_test_opt(nilfs, ERRORS_RO)) {
130 printk(KERN_CRIT "Remounting filesystem read-only\n");
131 sb->s_flags |= MS_RDONLY;
132 }
133 }
134
135 if (nilfs_test_opt(nilfs, ERRORS_PANIC))
136 panic("NILFS (device %s): panic forced after error\n",
137 sb->s_id);
138 }
139
140 void nilfs_warning(struct super_block *sb, const char *function,
141 const char *fmt, ...)
142 {
143 struct va_format vaf;
144 va_list args;
145
146 va_start(args, fmt);
147
148 vaf.fmt = fmt;
149 vaf.va = &args;
150
151 printk(KERN_WARNING "NILFS warning (device %s): %s: %pV\n",
152 sb->s_id, function, &vaf);
153
154 va_end(args);
155 }
156
157
158 struct inode *nilfs_alloc_inode(struct super_block *sb)
159 {
160 struct nilfs_inode_info *ii;
161
162 ii = kmem_cache_alloc(nilfs_inode_cachep, GFP_NOFS);
163 if (!ii)
164 return NULL;
165 ii->i_bh = NULL;
166 ii->i_state = 0;
167 ii->i_cno = 0;
168 ii->vfs_inode.i_version = 1;
169 nilfs_mapping_init(&ii->i_btnode_cache, &ii->vfs_inode, sb->s_bdi);
170 return &ii->vfs_inode;
171 }
172
173 static void nilfs_i_callback(struct rcu_head *head)
174 {
175 struct inode *inode = container_of(head, struct inode, i_rcu);
176 struct nilfs_mdt_info *mdi = NILFS_MDT(inode);
177
178 if (mdi) {
179 kfree(mdi->mi_bgl); /* kfree(NULL) is safe */
180 kfree(mdi);
181 }
182 kmem_cache_free(nilfs_inode_cachep, NILFS_I(inode));
183 }
184
185 void nilfs_destroy_inode(struct inode *inode)
186 {
187 call_rcu(&inode->i_rcu, nilfs_i_callback);
188 }
189
190 static int nilfs_sync_super(struct super_block *sb, int flag)
191 {
192 struct the_nilfs *nilfs = sb->s_fs_info;
193 int err;
194
195 retry:
196 set_buffer_dirty(nilfs->ns_sbh[0]);
197 if (nilfs_test_opt(nilfs, BARRIER)) {
198 err = __sync_dirty_buffer(nilfs->ns_sbh[0],
199 WRITE_SYNC | WRITE_FLUSH_FUA);
200 } else {
201 err = sync_dirty_buffer(nilfs->ns_sbh[0]);
202 }
203
204 if (unlikely(err)) {
205 printk(KERN_ERR
206 "NILFS: unable to write superblock (err=%d)\n", err);
207 if (err == -EIO && nilfs->ns_sbh[1]) {
208 /*
209 * sbp[0] points to newer log than sbp[1],
210 * so copy sbp[0] to sbp[1] to take over sbp[0].
211 */
212 memcpy(nilfs->ns_sbp[1], nilfs->ns_sbp[0],
213 nilfs->ns_sbsize);
214 nilfs_fall_back_super_block(nilfs);
215 goto retry;
216 }
217 } else {
218 struct nilfs_super_block *sbp = nilfs->ns_sbp[0];
219
220 nilfs->ns_sbwcount++;
221
222 /*
223 * The latest segment becomes trailable from the position
224 * written in superblock.
225 */
226 clear_nilfs_discontinued(nilfs);
227
228 /* update GC protection for recent segments */
229 if (nilfs->ns_sbh[1]) {
230 if (flag == NILFS_SB_COMMIT_ALL) {
231 set_buffer_dirty(nilfs->ns_sbh[1]);
232 if (sync_dirty_buffer(nilfs->ns_sbh[1]) < 0)
233 goto out;
234 }
235 if (le64_to_cpu(nilfs->ns_sbp[1]->s_last_cno) <
236 le64_to_cpu(nilfs->ns_sbp[0]->s_last_cno))
237 sbp = nilfs->ns_sbp[1];
238 }
239
240 spin_lock(&nilfs->ns_last_segment_lock);
241 nilfs->ns_prot_seq = le64_to_cpu(sbp->s_last_seq);
242 spin_unlock(&nilfs->ns_last_segment_lock);
243 }
244 out:
245 return err;
246 }
247
248 void nilfs_set_log_cursor(struct nilfs_super_block *sbp,
249 struct the_nilfs *nilfs)
250 {
251 sector_t nfreeblocks;
252
253 /* nilfs->ns_sem must be locked by the caller. */
254 nilfs_count_free_blocks(nilfs, &nfreeblocks);
255 sbp->s_free_blocks_count = cpu_to_le64(nfreeblocks);
256
257 spin_lock(&nilfs->ns_last_segment_lock);
258 sbp->s_last_seq = cpu_to_le64(nilfs->ns_last_seq);
259 sbp->s_last_pseg = cpu_to_le64(nilfs->ns_last_pseg);
260 sbp->s_last_cno = cpu_to_le64(nilfs->ns_last_cno);
261 spin_unlock(&nilfs->ns_last_segment_lock);
262 }
263
264 struct nilfs_super_block **nilfs_prepare_super(struct super_block *sb,
265 int flip)
266 {
267 struct the_nilfs *nilfs = sb->s_fs_info;
268 struct nilfs_super_block **sbp = nilfs->ns_sbp;
269
270 /* nilfs->ns_sem must be locked by the caller. */
271 if (sbp[0]->s_magic != cpu_to_le16(NILFS_SUPER_MAGIC)) {
272 if (sbp[1] &&
273 sbp[1]->s_magic == cpu_to_le16(NILFS_SUPER_MAGIC)) {
274 memcpy(sbp[0], sbp[1], nilfs->ns_sbsize);
275 } else {
276 printk(KERN_CRIT "NILFS: superblock broke on dev %s\n",
277 sb->s_id);
278 return NULL;
279 }
280 } else if (sbp[1] &&
281 sbp[1]->s_magic != cpu_to_le16(NILFS_SUPER_MAGIC)) {
282 memcpy(sbp[1], sbp[0], nilfs->ns_sbsize);
283 }
284
285 if (flip && sbp[1])
286 nilfs_swap_super_block(nilfs);
287
288 return sbp;
289 }
290
291 int nilfs_commit_super(struct super_block *sb, int flag)
292 {
293 struct the_nilfs *nilfs = sb->s_fs_info;
294 struct nilfs_super_block **sbp = nilfs->ns_sbp;
295 time_t t;
296
297 /* nilfs->ns_sem must be locked by the caller. */
298 t = get_seconds();
299 nilfs->ns_sbwtime = t;
300 sbp[0]->s_wtime = cpu_to_le64(t);
301 sbp[0]->s_sum = 0;
302 sbp[0]->s_sum = cpu_to_le32(crc32_le(nilfs->ns_crc_seed,
303 (unsigned char *)sbp[0],
304 nilfs->ns_sbsize));
305 if (flag == NILFS_SB_COMMIT_ALL && sbp[1]) {
306 sbp[1]->s_wtime = sbp[0]->s_wtime;
307 sbp[1]->s_sum = 0;
308 sbp[1]->s_sum = cpu_to_le32(crc32_le(nilfs->ns_crc_seed,
309 (unsigned char *)sbp[1],
310 nilfs->ns_sbsize));
311 }
312 clear_nilfs_sb_dirty(nilfs);
313 return nilfs_sync_super(sb, flag);
314 }
315
316 /**
317 * nilfs_cleanup_super() - write filesystem state for cleanup
318 * @sb: super block instance to be unmounted or degraded to read-only
319 *
320 * This function restores state flags in the on-disk super block.
321 * This will set "clean" flag (i.e. NILFS_VALID_FS) unless the
322 * filesystem was not clean previously.
323 */
324 int nilfs_cleanup_super(struct super_block *sb)
325 {
326 struct the_nilfs *nilfs = sb->s_fs_info;
327 struct nilfs_super_block **sbp;
328 int flag = NILFS_SB_COMMIT;
329 int ret = -EIO;
330
331 sbp = nilfs_prepare_super(sb, 0);
332 if (sbp) {
333 sbp[0]->s_state = cpu_to_le16(nilfs->ns_mount_state);
334 nilfs_set_log_cursor(sbp[0], nilfs);
335 if (sbp[1] && sbp[0]->s_last_cno == sbp[1]->s_last_cno) {
336 /*
337 * make the "clean" flag also to the opposite
338 * super block if both super blocks point to
339 * the same checkpoint.
340 */
341 sbp[1]->s_state = sbp[0]->s_state;
342 flag = NILFS_SB_COMMIT_ALL;
343 }
344 ret = nilfs_commit_super(sb, flag);
345 }
346 return ret;
347 }
348
349 /**
350 * nilfs_move_2nd_super - relocate secondary super block
351 * @sb: super block instance
352 * @sb2off: new offset of the secondary super block (in bytes)
353 */
354 static int nilfs_move_2nd_super(struct super_block *sb, loff_t sb2off)
355 {
356 struct the_nilfs *nilfs = sb->s_fs_info;
357 struct buffer_head *nsbh;
358 struct nilfs_super_block *nsbp;
359 sector_t blocknr, newblocknr;
360 unsigned long offset;
361 int sb2i = -1; /* array index of the secondary superblock */
362 int ret = 0;
363
364 /* nilfs->ns_sem must be locked by the caller. */
365 if (nilfs->ns_sbh[1] &&
366 nilfs->ns_sbh[1]->b_blocknr > nilfs->ns_first_data_block) {
367 sb2i = 1;
368 blocknr = nilfs->ns_sbh[1]->b_blocknr;
369 } else if (nilfs->ns_sbh[0]->b_blocknr > nilfs->ns_first_data_block) {
370 sb2i = 0;
371 blocknr = nilfs->ns_sbh[0]->b_blocknr;
372 }
373 if (sb2i >= 0 && (u64)blocknr << nilfs->ns_blocksize_bits == sb2off)
374 goto out; /* super block location is unchanged */
375
376 /* Get new super block buffer */
377 newblocknr = sb2off >> nilfs->ns_blocksize_bits;
378 offset = sb2off & (nilfs->ns_blocksize - 1);
379 nsbh = sb_getblk(sb, newblocknr);
380 if (!nsbh) {
381 printk(KERN_WARNING
382 "NILFS warning: unable to move secondary superblock "
383 "to block %llu\n", (unsigned long long)newblocknr);
384 ret = -EIO;
385 goto out;
386 }
387 nsbp = (void *)nsbh->b_data + offset;
388 memset(nsbp, 0, nilfs->ns_blocksize);
389
390 if (sb2i >= 0) {
391 memcpy(nsbp, nilfs->ns_sbp[sb2i], nilfs->ns_sbsize);
392 brelse(nilfs->ns_sbh[sb2i]);
393 nilfs->ns_sbh[sb2i] = nsbh;
394 nilfs->ns_sbp[sb2i] = nsbp;
395 } else if (nilfs->ns_sbh[0]->b_blocknr < nilfs->ns_first_data_block) {
396 /* secondary super block will be restored to index 1 */
397 nilfs->ns_sbh[1] = nsbh;
398 nilfs->ns_sbp[1] = nsbp;
399 } else {
400 brelse(nsbh);
401 }
402 out:
403 return ret;
404 }
405
406 /**
407 * nilfs_resize_fs - resize the filesystem
408 * @sb: super block instance
409 * @newsize: new size of the filesystem (in bytes)
410 */
411 int nilfs_resize_fs(struct super_block *sb, __u64 newsize)
412 {
413 struct the_nilfs *nilfs = sb->s_fs_info;
414 struct nilfs_super_block **sbp;
415 __u64 devsize, newnsegs;
416 loff_t sb2off;
417 int ret;
418
419 ret = -ERANGE;
420 devsize = i_size_read(sb->s_bdev->bd_inode);
421 if (newsize > devsize)
422 goto out;
423
424 /*
425 * Write lock is required to protect some functions depending
426 * on the number of segments, the number of reserved segments,
427 * and so forth.
428 */
429 down_write(&nilfs->ns_segctor_sem);
430
431 sb2off = NILFS_SB2_OFFSET_BYTES(newsize);
432 newnsegs = sb2off >> nilfs->ns_blocksize_bits;
433 do_div(newnsegs, nilfs->ns_blocks_per_segment);
434
435 ret = nilfs_sufile_resize(nilfs->ns_sufile, newnsegs);
436 up_write(&nilfs->ns_segctor_sem);
437 if (ret < 0)
438 goto out;
439
440 ret = nilfs_construct_segment(sb);
441 if (ret < 0)
442 goto out;
443
444 down_write(&nilfs->ns_sem);
445 nilfs_move_2nd_super(sb, sb2off);
446 ret = -EIO;
447 sbp = nilfs_prepare_super(sb, 0);
448 if (likely(sbp)) {
449 nilfs_set_log_cursor(sbp[0], nilfs);
450 /*
451 * Drop NILFS_RESIZE_FS flag for compatibility with
452 * mount-time resize which may be implemented in a
453 * future release.
454 */
455 sbp[0]->s_state = cpu_to_le16(le16_to_cpu(sbp[0]->s_state) &
456 ~NILFS_RESIZE_FS);
457 sbp[0]->s_dev_size = cpu_to_le64(newsize);
458 sbp[0]->s_nsegments = cpu_to_le64(nilfs->ns_nsegments);
459 if (sbp[1])
460 memcpy(sbp[1], sbp[0], nilfs->ns_sbsize);
461 ret = nilfs_commit_super(sb, NILFS_SB_COMMIT_ALL);
462 }
463 up_write(&nilfs->ns_sem);
464
465 /*
466 * Reset the range of allocatable segments last. This order
467 * is important in the case of expansion because the secondary
468 * superblock must be protected from log write until migration
469 * completes.
470 */
471 if (!ret)
472 nilfs_sufile_set_alloc_range(nilfs->ns_sufile, 0, newnsegs - 1);
473 out:
474 return ret;
475 }
476
477 static void nilfs_put_super(struct super_block *sb)
478 {
479 struct the_nilfs *nilfs = sb->s_fs_info;
480
481 nilfs_detach_log_writer(sb);
482
483 if (!(sb->s_flags & MS_RDONLY)) {
484 down_write(&nilfs->ns_sem);
485 nilfs_cleanup_super(sb);
486 up_write(&nilfs->ns_sem);
487 }
488
489 iput(nilfs->ns_sufile);
490 iput(nilfs->ns_cpfile);
491 iput(nilfs->ns_dat);
492
493 destroy_nilfs(nilfs);
494 sb->s_fs_info = NULL;
495 }
496
497 static int nilfs_sync_fs(struct super_block *sb, int wait)
498 {
499 struct the_nilfs *nilfs = sb->s_fs_info;
500 struct nilfs_super_block **sbp;
501 int err = 0;
502
503 /* This function is called when super block should be written back */
504 if (wait)
505 err = nilfs_construct_segment(sb);
506
507 down_write(&nilfs->ns_sem);
508 if (nilfs_sb_dirty(nilfs)) {
509 sbp = nilfs_prepare_super(sb, nilfs_sb_will_flip(nilfs));
510 if (likely(sbp)) {
511 nilfs_set_log_cursor(sbp[0], nilfs);
512 nilfs_commit_super(sb, NILFS_SB_COMMIT);
513 }
514 }
515 up_write(&nilfs->ns_sem);
516
517 return err;
518 }
519
520 int nilfs_attach_checkpoint(struct super_block *sb, __u64 cno, int curr_mnt,
521 struct nilfs_root **rootp)
522 {
523 struct the_nilfs *nilfs = sb->s_fs_info;
524 struct nilfs_root *root;
525 struct nilfs_checkpoint *raw_cp;
526 struct buffer_head *bh_cp;
527 int err = -ENOMEM;
528
529 root = nilfs_find_or_create_root(
530 nilfs, curr_mnt ? NILFS_CPTREE_CURRENT_CNO : cno);
531 if (!root)
532 return err;
533
534 if (root->ifile)
535 goto reuse; /* already attached checkpoint */
536
537 down_read(&nilfs->ns_segctor_sem);
538 err = nilfs_cpfile_get_checkpoint(nilfs->ns_cpfile, cno, 0, &raw_cp,
539 &bh_cp);
540 up_read(&nilfs->ns_segctor_sem);
541 if (unlikely(err)) {
542 if (err == -ENOENT || err == -EINVAL) {
543 printk(KERN_ERR
544 "NILFS: Invalid checkpoint "
545 "(checkpoint number=%llu)\n",
546 (unsigned long long)cno);
547 err = -EINVAL;
548 }
549 goto failed;
550 }
551
552 err = nilfs_ifile_read(sb, root, nilfs->ns_inode_size,
553 &raw_cp->cp_ifile_inode, &root->ifile);
554 if (err)
555 goto failed_bh;
556
557 atomic64_set(&root->inodes_count,
558 le64_to_cpu(raw_cp->cp_inodes_count));
559 atomic64_set(&root->blocks_count,
560 le64_to_cpu(raw_cp->cp_blocks_count));
561
562 nilfs_cpfile_put_checkpoint(nilfs->ns_cpfile, cno, bh_cp);
563
564 reuse:
565 *rootp = root;
566 return 0;
567
568 failed_bh:
569 nilfs_cpfile_put_checkpoint(nilfs->ns_cpfile, cno, bh_cp);
570 failed:
571 nilfs_put_root(root);
572
573 return err;
574 }
575
576 static int nilfs_freeze(struct super_block *sb)
577 {
578 struct the_nilfs *nilfs = sb->s_fs_info;
579 int err;
580
581 if (sb->s_flags & MS_RDONLY)
582 return 0;
583
584 /* Mark super block clean */
585 down_write(&nilfs->ns_sem);
586 err = nilfs_cleanup_super(sb);
587 up_write(&nilfs->ns_sem);
588 return err;
589 }
590
591 static int nilfs_unfreeze(struct super_block *sb)
592 {
593 struct the_nilfs *nilfs = sb->s_fs_info;
594
595 if (sb->s_flags & MS_RDONLY)
596 return 0;
597
598 down_write(&nilfs->ns_sem);
599 nilfs_setup_super(sb, false);
600 up_write(&nilfs->ns_sem);
601 return 0;
602 }
603
604 static int nilfs_statfs(struct dentry *dentry, struct kstatfs *buf)
605 {
606 struct super_block *sb = dentry->d_sb;
607 struct nilfs_root *root = NILFS_I(dentry->d_inode)->i_root;
608 struct the_nilfs *nilfs = root->nilfs;
609 u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
610 unsigned long long blocks;
611 unsigned long overhead;
612 unsigned long nrsvblocks;
613 sector_t nfreeblocks;
614 u64 nmaxinodes, nfreeinodes;
615 int err;
616
617 /*
618 * Compute all of the segment blocks
619 *
620 * The blocks before first segment and after last segment
621 * are excluded.
622 */
623 blocks = nilfs->ns_blocks_per_segment * nilfs->ns_nsegments
624 - nilfs->ns_first_data_block;
625 nrsvblocks = nilfs->ns_nrsvsegs * nilfs->ns_blocks_per_segment;
626
627 /*
628 * Compute the overhead
629 *
630 * When distributing meta data blocks outside segment structure,
631 * We must count them as the overhead.
632 */
633 overhead = 0;
634
635 err = nilfs_count_free_blocks(nilfs, &nfreeblocks);
636 if (unlikely(err))
637 return err;
638
639 err = nilfs_ifile_count_free_inodes(root->ifile,
640 &nmaxinodes, &nfreeinodes);
641 if (unlikely(err)) {
642 printk(KERN_WARNING
643 "NILFS warning: fail to count free inodes: err %d.\n",
644 err);
645 if (err == -ERANGE) {
646 /*
647 * If nilfs_palloc_count_max_entries() returns
648 * -ERANGE error code then we simply treat
649 * curent inodes count as maximum possible and
650 * zero as free inodes value.
651 */
652 nmaxinodes = atomic64_read(&root->inodes_count);
653 nfreeinodes = 0;
654 err = 0;
655 } else
656 return err;
657 }
658
659 buf->f_type = NILFS_SUPER_MAGIC;
660 buf->f_bsize = sb->s_blocksize;
661 buf->f_blocks = blocks - overhead;
662 buf->f_bfree = nfreeblocks;
663 buf->f_bavail = (buf->f_bfree >= nrsvblocks) ?
664 (buf->f_bfree - nrsvblocks) : 0;
665 buf->f_files = nmaxinodes;
666 buf->f_ffree = nfreeinodes;
667 buf->f_namelen = NILFS_NAME_LEN;
668 buf->f_fsid.val[0] = (u32)id;
669 buf->f_fsid.val[1] = (u32)(id >> 32);
670
671 return 0;
672 }
673
674 static int nilfs_show_options(struct seq_file *seq, struct dentry *dentry)
675 {
676 struct super_block *sb = dentry->d_sb;
677 struct the_nilfs *nilfs = sb->s_fs_info;
678 struct nilfs_root *root = NILFS_I(dentry->d_inode)->i_root;
679
680 if (!nilfs_test_opt(nilfs, BARRIER))
681 seq_puts(seq, ",nobarrier");
682 if (root->cno != NILFS_CPTREE_CURRENT_CNO)
683 seq_printf(seq, ",cp=%llu", (unsigned long long)root->cno);
684 if (nilfs_test_opt(nilfs, ERRORS_PANIC))
685 seq_puts(seq, ",errors=panic");
686 if (nilfs_test_opt(nilfs, ERRORS_CONT))
687 seq_puts(seq, ",errors=continue");
688 if (nilfs_test_opt(nilfs, STRICT_ORDER))
689 seq_puts(seq, ",order=strict");
690 if (nilfs_test_opt(nilfs, NORECOVERY))
691 seq_puts(seq, ",norecovery");
692 if (nilfs_test_opt(nilfs, DISCARD))
693 seq_puts(seq, ",discard");
694
695 return 0;
696 }
697
698 static const struct super_operations nilfs_sops = {
699 .alloc_inode = nilfs_alloc_inode,
700 .destroy_inode = nilfs_destroy_inode,
701 .dirty_inode = nilfs_dirty_inode,
702 .evict_inode = nilfs_evict_inode,
703 .put_super = nilfs_put_super,
704 .sync_fs = nilfs_sync_fs,
705 .freeze_fs = nilfs_freeze,
706 .unfreeze_fs = nilfs_unfreeze,
707 .statfs = nilfs_statfs,
708 .remount_fs = nilfs_remount,
709 .show_options = nilfs_show_options
710 };
711
712 enum {
713 Opt_err_cont, Opt_err_panic, Opt_err_ro,
714 Opt_barrier, Opt_nobarrier, Opt_snapshot, Opt_order, Opt_norecovery,
715 Opt_discard, Opt_nodiscard, Opt_err,
716 };
717
718 static match_table_t tokens = {
719 {Opt_err_cont, "errors=continue"},
720 {Opt_err_panic, "errors=panic"},
721 {Opt_err_ro, "errors=remount-ro"},
722 {Opt_barrier, "barrier"},
723 {Opt_nobarrier, "nobarrier"},
724 {Opt_snapshot, "cp=%u"},
725 {Opt_order, "order=%s"},
726 {Opt_norecovery, "norecovery"},
727 {Opt_discard, "discard"},
728 {Opt_nodiscard, "nodiscard"},
729 {Opt_err, NULL}
730 };
731
732 static int parse_options(char *options, struct super_block *sb, int is_remount)
733 {
734 struct the_nilfs *nilfs = sb->s_fs_info;
735 char *p;
736 substring_t args[MAX_OPT_ARGS];
737
738 if (!options)
739 return 1;
740
741 while ((p = strsep(&options, ",")) != NULL) {
742 int token;
743 if (!*p)
744 continue;
745
746 token = match_token(p, tokens, args);
747 switch (token) {
748 case Opt_barrier:
749 nilfs_set_opt(nilfs, BARRIER);
750 break;
751 case Opt_nobarrier:
752 nilfs_clear_opt(nilfs, BARRIER);
753 break;
754 case Opt_order:
755 if (strcmp(args[0].from, "relaxed") == 0)
756 /* Ordered data semantics */
757 nilfs_clear_opt(nilfs, STRICT_ORDER);
758 else if (strcmp(args[0].from, "strict") == 0)
759 /* Strict in-order semantics */
760 nilfs_set_opt(nilfs, STRICT_ORDER);
761 else
762 return 0;
763 break;
764 case Opt_err_panic:
765 nilfs_write_opt(nilfs, ERROR_MODE, ERRORS_PANIC);
766 break;
767 case Opt_err_ro:
768 nilfs_write_opt(nilfs, ERROR_MODE, ERRORS_RO);
769 break;
770 case Opt_err_cont:
771 nilfs_write_opt(nilfs, ERROR_MODE, ERRORS_CONT);
772 break;
773 case Opt_snapshot:
774 if (is_remount) {
775 printk(KERN_ERR
776 "NILFS: \"%s\" option is invalid "
777 "for remount.\n", p);
778 return 0;
779 }
780 break;
781 case Opt_norecovery:
782 nilfs_set_opt(nilfs, NORECOVERY);
783 break;
784 case Opt_discard:
785 nilfs_set_opt(nilfs, DISCARD);
786 break;
787 case Opt_nodiscard:
788 nilfs_clear_opt(nilfs, DISCARD);
789 break;
790 default:
791 printk(KERN_ERR
792 "NILFS: Unrecognized mount option \"%s\"\n", p);
793 return 0;
794 }
795 }
796 return 1;
797 }
798
799 static inline void
800 nilfs_set_default_options(struct super_block *sb,
801 struct nilfs_super_block *sbp)
802 {
803 struct the_nilfs *nilfs = sb->s_fs_info;
804
805 nilfs->ns_mount_opt =
806 NILFS_MOUNT_ERRORS_RO | NILFS_MOUNT_BARRIER;
807 }
808
809 static int nilfs_setup_super(struct super_block *sb, int is_mount)
810 {
811 struct the_nilfs *nilfs = sb->s_fs_info;
812 struct nilfs_super_block **sbp;
813 int max_mnt_count;
814 int mnt_count;
815
816 /* nilfs->ns_sem must be locked by the caller. */
817 sbp = nilfs_prepare_super(sb, 0);
818 if (!sbp)
819 return -EIO;
820
821 if (!is_mount)
822 goto skip_mount_setup;
823
824 max_mnt_count = le16_to_cpu(sbp[0]->s_max_mnt_count);
825 mnt_count = le16_to_cpu(sbp[0]->s_mnt_count);
826
827 if (nilfs->ns_mount_state & NILFS_ERROR_FS) {
828 printk(KERN_WARNING
829 "NILFS warning: mounting fs with errors\n");
830 #if 0
831 } else if (max_mnt_count >= 0 && mnt_count >= max_mnt_count) {
832 printk(KERN_WARNING
833 "NILFS warning: maximal mount count reached\n");
834 #endif
835 }
836 if (!max_mnt_count)
837 sbp[0]->s_max_mnt_count = cpu_to_le16(NILFS_DFL_MAX_MNT_COUNT);
838
839 sbp[0]->s_mnt_count = cpu_to_le16(mnt_count + 1);
840 sbp[0]->s_mtime = cpu_to_le64(get_seconds());
841
842 skip_mount_setup:
843 sbp[0]->s_state =
844 cpu_to_le16(le16_to_cpu(sbp[0]->s_state) & ~NILFS_VALID_FS);
845 /* synchronize sbp[1] with sbp[0] */
846 if (sbp[1])
847 memcpy(sbp[1], sbp[0], nilfs->ns_sbsize);
848 return nilfs_commit_super(sb, NILFS_SB_COMMIT_ALL);
849 }
850
851 struct nilfs_super_block *nilfs_read_super_block(struct super_block *sb,
852 u64 pos, int blocksize,
853 struct buffer_head **pbh)
854 {
855 unsigned long long sb_index = pos;
856 unsigned long offset;
857
858 offset = do_div(sb_index, blocksize);
859 *pbh = sb_bread(sb, sb_index);
860 if (!*pbh)
861 return NULL;
862 return (struct nilfs_super_block *)((char *)(*pbh)->b_data + offset);
863 }
864
865 int nilfs_store_magic_and_option(struct super_block *sb,
866 struct nilfs_super_block *sbp,
867 char *data)
868 {
869 struct the_nilfs *nilfs = sb->s_fs_info;
870
871 sb->s_magic = le16_to_cpu(sbp->s_magic);
872
873 /* FS independent flags */
874 #ifdef NILFS_ATIME_DISABLE
875 sb->s_flags |= MS_NOATIME;
876 #endif
877
878 nilfs_set_default_options(sb, sbp);
879
880 nilfs->ns_resuid = le16_to_cpu(sbp->s_def_resuid);
881 nilfs->ns_resgid = le16_to_cpu(sbp->s_def_resgid);
882 nilfs->ns_interval = le32_to_cpu(sbp->s_c_interval);
883 nilfs->ns_watermark = le32_to_cpu(sbp->s_c_block_max);
884
885 return !parse_options(data, sb, 0) ? -EINVAL : 0 ;
886 }
887
888 int nilfs_check_feature_compatibility(struct super_block *sb,
889 struct nilfs_super_block *sbp)
890 {
891 __u64 features;
892
893 features = le64_to_cpu(sbp->s_feature_incompat) &
894 ~NILFS_FEATURE_INCOMPAT_SUPP;
895 if (features) {
896 printk(KERN_ERR "NILFS: couldn't mount because of unsupported "
897 "optional features (%llx)\n",
898 (unsigned long long)features);
899 return -EINVAL;
900 }
901 features = le64_to_cpu(sbp->s_feature_compat_ro) &
902 ~NILFS_FEATURE_COMPAT_RO_SUPP;
903 if (!(sb->s_flags & MS_RDONLY) && features) {
904 printk(KERN_ERR "NILFS: couldn't mount RDWR because of "
905 "unsupported optional features (%llx)\n",
906 (unsigned long long)features);
907 return -EINVAL;
908 }
909 return 0;
910 }
911
912 static int nilfs_get_root_dentry(struct super_block *sb,
913 struct nilfs_root *root,
914 struct dentry **root_dentry)
915 {
916 struct inode *inode;
917 struct dentry *dentry;
918 int ret = 0;
919
920 inode = nilfs_iget(sb, root, NILFS_ROOT_INO);
921 if (IS_ERR(inode)) {
922 printk(KERN_ERR "NILFS: get root inode failed\n");
923 ret = PTR_ERR(inode);
924 goto out;
925 }
926 if (!S_ISDIR(inode->i_mode) || !inode->i_blocks || !inode->i_size) {
927 iput(inode);
928 printk(KERN_ERR "NILFS: corrupt root inode.\n");
929 ret = -EINVAL;
930 goto out;
931 }
932
933 if (root->cno == NILFS_CPTREE_CURRENT_CNO) {
934 dentry = d_find_alias(inode);
935 if (!dentry) {
936 dentry = d_make_root(inode);
937 if (!dentry) {
938 ret = -ENOMEM;
939 goto failed_dentry;
940 }
941 } else {
942 iput(inode);
943 }
944 } else {
945 dentry = d_obtain_alias(inode);
946 if (IS_ERR(dentry)) {
947 ret = PTR_ERR(dentry);
948 goto failed_dentry;
949 }
950 }
951 *root_dentry = dentry;
952 out:
953 return ret;
954
955 failed_dentry:
956 printk(KERN_ERR "NILFS: get root dentry failed\n");
957 goto out;
958 }
959
960 static int nilfs_attach_snapshot(struct super_block *s, __u64 cno,
961 struct dentry **root_dentry)
962 {
963 struct the_nilfs *nilfs = s->s_fs_info;
964 struct nilfs_root *root;
965 int ret;
966
967 mutex_lock(&nilfs->ns_snapshot_mount_mutex);
968
969 down_read(&nilfs->ns_segctor_sem);
970 ret = nilfs_cpfile_is_snapshot(nilfs->ns_cpfile, cno);
971 up_read(&nilfs->ns_segctor_sem);
972 if (ret < 0) {
973 ret = (ret == -ENOENT) ? -EINVAL : ret;
974 goto out;
975 } else if (!ret) {
976 printk(KERN_ERR "NILFS: The specified checkpoint is "
977 "not a snapshot (checkpoint number=%llu).\n",
978 (unsigned long long)cno);
979 ret = -EINVAL;
980 goto out;
981 }
982
983 ret = nilfs_attach_checkpoint(s, cno, false, &root);
984 if (ret) {
985 printk(KERN_ERR "NILFS: error loading snapshot "
986 "(checkpoint number=%llu).\n",
987 (unsigned long long)cno);
988 goto out;
989 }
990 ret = nilfs_get_root_dentry(s, root, root_dentry);
991 nilfs_put_root(root);
992 out:
993 mutex_unlock(&nilfs->ns_snapshot_mount_mutex);
994 return ret;
995 }
996
997 /**
998 * nilfs_tree_is_busy() - try to shrink dentries of a checkpoint
999 * @root_dentry: root dentry of the tree to be shrunk
1000 *
1001 * This function returns true if the tree was in-use.
1002 */
1003 static bool nilfs_tree_is_busy(struct dentry *root_dentry)
1004 {
1005 shrink_dcache_parent(root_dentry);
1006 return d_count(root_dentry) > 1;
1007 }
1008
1009 int nilfs_checkpoint_is_mounted(struct super_block *sb, __u64 cno)
1010 {
1011 struct the_nilfs *nilfs = sb->s_fs_info;
1012 struct nilfs_root *root;
1013 struct inode *inode;
1014 struct dentry *dentry;
1015 int ret;
1016
1017 if (cno < 0 || cno > nilfs->ns_cno)
1018 return false;
1019
1020 if (cno >= nilfs_last_cno(nilfs))
1021 return true; /* protect recent checkpoints */
1022
1023 ret = false;
1024 root = nilfs_lookup_root(nilfs, cno);
1025 if (root) {
1026 inode = nilfs_ilookup(sb, root, NILFS_ROOT_INO);
1027 if (inode) {
1028 dentry = d_find_alias(inode);
1029 if (dentry) {
1030 ret = nilfs_tree_is_busy(dentry);
1031 dput(dentry);
1032 }
1033 iput(inode);
1034 }
1035 nilfs_put_root(root);
1036 }
1037 return ret;
1038 }
1039
1040 /**
1041 * nilfs_fill_super() - initialize a super block instance
1042 * @sb: super_block
1043 * @data: mount options
1044 * @silent: silent mode flag
1045 *
1046 * This function is called exclusively by nilfs->ns_mount_mutex.
1047 * So, the recovery process is protected from other simultaneous mounts.
1048 */
1049 static int
1050 nilfs_fill_super(struct super_block *sb, void *data, int silent)
1051 {
1052 struct the_nilfs *nilfs;
1053 struct nilfs_root *fsroot;
1054 struct backing_dev_info *bdi;
1055 __u64 cno;
1056 int err;
1057
1058 nilfs = alloc_nilfs(sb->s_bdev);
1059 if (!nilfs)
1060 return -ENOMEM;
1061
1062 sb->s_fs_info = nilfs;
1063
1064 err = init_nilfs(nilfs, sb, (char *)data);
1065 if (err)
1066 goto failed_nilfs;
1067
1068 sb->s_op = &nilfs_sops;
1069 sb->s_export_op = &nilfs_export_ops;
1070 sb->s_root = NULL;
1071 sb->s_time_gran = 1;
1072 sb->s_max_links = NILFS_LINK_MAX;
1073
1074 bdi = sb->s_bdev->bd_inode->i_mapping->backing_dev_info;
1075 sb->s_bdi = bdi ? : &default_backing_dev_info;
1076
1077 err = load_nilfs(nilfs, sb);
1078 if (err)
1079 goto failed_nilfs;
1080
1081 cno = nilfs_last_cno(nilfs);
1082 err = nilfs_attach_checkpoint(sb, cno, true, &fsroot);
1083 if (err) {
1084 printk(KERN_ERR "NILFS: error loading last checkpoint "
1085 "(checkpoint number=%llu).\n", (unsigned long long)cno);
1086 goto failed_unload;
1087 }
1088
1089 if (!(sb->s_flags & MS_RDONLY)) {
1090 err = nilfs_attach_log_writer(sb, fsroot);
1091 if (err)
1092 goto failed_checkpoint;
1093 }
1094
1095 err = nilfs_get_root_dentry(sb, fsroot, &sb->s_root);
1096 if (err)
1097 goto failed_segctor;
1098
1099 nilfs_put_root(fsroot);
1100
1101 if (!(sb->s_flags & MS_RDONLY)) {
1102 down_write(&nilfs->ns_sem);
1103 nilfs_setup_super(sb, true);
1104 up_write(&nilfs->ns_sem);
1105 }
1106
1107 return 0;
1108
1109 failed_segctor:
1110 nilfs_detach_log_writer(sb);
1111
1112 failed_checkpoint:
1113 nilfs_put_root(fsroot);
1114
1115 failed_unload:
1116 iput(nilfs->ns_sufile);
1117 iput(nilfs->ns_cpfile);
1118 iput(nilfs->ns_dat);
1119
1120 failed_nilfs:
1121 destroy_nilfs(nilfs);
1122 return err;
1123 }
1124
1125 static int nilfs_remount(struct super_block *sb, int *flags, char *data)
1126 {
1127 struct the_nilfs *nilfs = sb->s_fs_info;
1128 unsigned long old_sb_flags;
1129 unsigned long old_mount_opt;
1130 int err;
1131
1132 old_sb_flags = sb->s_flags;
1133 old_mount_opt = nilfs->ns_mount_opt;
1134
1135 if (!parse_options(data, sb, 1)) {
1136 err = -EINVAL;
1137 goto restore_opts;
1138 }
1139 sb->s_flags = (sb->s_flags & ~MS_POSIXACL);
1140
1141 err = -EINVAL;
1142
1143 if (!nilfs_valid_fs(nilfs)) {
1144 printk(KERN_WARNING "NILFS (device %s): couldn't "
1145 "remount because the filesystem is in an "
1146 "incomplete recovery state.\n", sb->s_id);
1147 goto restore_opts;
1148 }
1149
1150 if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
1151 goto out;
1152 if (*flags & MS_RDONLY) {
1153 /* Shutting down log writer */
1154 nilfs_detach_log_writer(sb);
1155 sb->s_flags |= MS_RDONLY;
1156
1157 /*
1158 * Remounting a valid RW partition RDONLY, so set
1159 * the RDONLY flag and then mark the partition as valid again.
1160 */
1161 down_write(&nilfs->ns_sem);
1162 nilfs_cleanup_super(sb);
1163 up_write(&nilfs->ns_sem);
1164 } else {
1165 __u64 features;
1166 struct nilfs_root *root;
1167
1168 /*
1169 * Mounting a RDONLY partition read-write, so reread and
1170 * store the current valid flag. (It may have been changed
1171 * by fsck since we originally mounted the partition.)
1172 */
1173 down_read(&nilfs->ns_sem);
1174 features = le64_to_cpu(nilfs->ns_sbp[0]->s_feature_compat_ro) &
1175 ~NILFS_FEATURE_COMPAT_RO_SUPP;
1176 up_read(&nilfs->ns_sem);
1177 if (features) {
1178 printk(KERN_WARNING "NILFS (device %s): couldn't "
1179 "remount RDWR because of unsupported optional "
1180 "features (%llx)\n",
1181 sb->s_id, (unsigned long long)features);
1182 err = -EROFS;
1183 goto restore_opts;
1184 }
1185
1186 sb->s_flags &= ~MS_RDONLY;
1187
1188 root = NILFS_I(sb->s_root->d_inode)->i_root;
1189 err = nilfs_attach_log_writer(sb, root);
1190 if (err)
1191 goto restore_opts;
1192
1193 down_write(&nilfs->ns_sem);
1194 nilfs_setup_super(sb, true);
1195 up_write(&nilfs->ns_sem);
1196 }
1197 out:
1198 return 0;
1199
1200 restore_opts:
1201 sb->s_flags = old_sb_flags;
1202 nilfs->ns_mount_opt = old_mount_opt;
1203 return err;
1204 }
1205
1206 struct nilfs_super_data {
1207 struct block_device *bdev;
1208 __u64 cno;
1209 int flags;
1210 };
1211
1212 /**
1213 * nilfs_identify - pre-read mount options needed to identify mount instance
1214 * @data: mount options
1215 * @sd: nilfs_super_data
1216 */
1217 static int nilfs_identify(char *data, struct nilfs_super_data *sd)
1218 {
1219 char *p, *options = data;
1220 substring_t args[MAX_OPT_ARGS];
1221 int token;
1222 int ret = 0;
1223
1224 do {
1225 p = strsep(&options, ",");
1226 if (p != NULL && *p) {
1227 token = match_token(p, tokens, args);
1228 if (token == Opt_snapshot) {
1229 if (!(sd->flags & MS_RDONLY)) {
1230 ret++;
1231 } else {
1232 sd->cno = simple_strtoull(args[0].from,
1233 NULL, 0);
1234 /*
1235 * No need to see the end pointer;
1236 * match_token() has done syntax
1237 * checking.
1238 */
1239 if (sd->cno == 0)
1240 ret++;
1241 }
1242 }
1243 if (ret)
1244 printk(KERN_ERR
1245 "NILFS: invalid mount option: %s\n", p);
1246 }
1247 if (!options)
1248 break;
1249 BUG_ON(options == data);
1250 *(options - 1) = ',';
1251 } while (!ret);
1252 return ret;
1253 }
1254
1255 static int nilfs_set_bdev_super(struct super_block *s, void *data)
1256 {
1257 s->s_bdev = data;
1258 s->s_dev = s->s_bdev->bd_dev;
1259 return 0;
1260 }
1261
1262 static int nilfs_test_bdev_super(struct super_block *s, void *data)
1263 {
1264 return (void *)s->s_bdev == data;
1265 }
1266
1267 static struct dentry *
1268 nilfs_mount(struct file_system_type *fs_type, int flags,
1269 const char *dev_name, void *data)
1270 {
1271 struct nilfs_super_data sd;
1272 struct super_block *s;
1273 fmode_t mode = FMODE_READ | FMODE_EXCL;
1274 struct dentry *root_dentry;
1275 int err, s_new = false;
1276
1277 if (!(flags & MS_RDONLY))
1278 mode |= FMODE_WRITE;
1279
1280 sd.bdev = blkdev_get_by_path(dev_name, mode, fs_type);
1281 if (IS_ERR(sd.bdev))
1282 return ERR_CAST(sd.bdev);
1283
1284 sd.cno = 0;
1285 sd.flags = flags;
1286 if (nilfs_identify((char *)data, &sd)) {
1287 err = -EINVAL;
1288 goto failed;
1289 }
1290
1291 /*
1292 * once the super is inserted into the list by sget, s_umount
1293 * will protect the lockfs code from trying to start a snapshot
1294 * while we are mounting
1295 */
1296 mutex_lock(&sd.bdev->bd_fsfreeze_mutex);
1297 if (sd.bdev->bd_fsfreeze_count > 0) {
1298 mutex_unlock(&sd.bdev->bd_fsfreeze_mutex);
1299 err = -EBUSY;
1300 goto failed;
1301 }
1302 s = sget(fs_type, nilfs_test_bdev_super, nilfs_set_bdev_super, flags,
1303 sd.bdev);
1304 mutex_unlock(&sd.bdev->bd_fsfreeze_mutex);
1305 if (IS_ERR(s)) {
1306 err = PTR_ERR(s);
1307 goto failed;
1308 }
1309
1310 if (!s->s_root) {
1311 char b[BDEVNAME_SIZE];
1312
1313 s_new = true;
1314
1315 /* New superblock instance created */
1316 s->s_mode = mode;
1317 strlcpy(s->s_id, bdevname(sd.bdev, b), sizeof(s->s_id));
1318 sb_set_blocksize(s, block_size(sd.bdev));
1319
1320 err = nilfs_fill_super(s, data, flags & MS_SILENT ? 1 : 0);
1321 if (err)
1322 goto failed_super;
1323
1324 s->s_flags |= MS_ACTIVE;
1325 } else if (!sd.cno) {
1326 if (nilfs_tree_is_busy(s->s_root)) {
1327 if ((flags ^ s->s_flags) & MS_RDONLY) {
1328 printk(KERN_ERR "NILFS: the device already "
1329 "has a %s mount.\n",
1330 (s->s_flags & MS_RDONLY) ?
1331 "read-only" : "read/write");
1332 err = -EBUSY;
1333 goto failed_super;
1334 }
1335 } else {
1336 /*
1337 * Try remount to setup mount states if the current
1338 * tree is not mounted and only snapshots use this sb.
1339 */
1340 err = nilfs_remount(s, &flags, data);
1341 if (err)
1342 goto failed_super;
1343 }
1344 }
1345
1346 if (sd.cno) {
1347 err = nilfs_attach_snapshot(s, sd.cno, &root_dentry);
1348 if (err)
1349 goto failed_super;
1350 } else {
1351 root_dentry = dget(s->s_root);
1352 }
1353
1354 if (!s_new)
1355 blkdev_put(sd.bdev, mode);
1356
1357 return root_dentry;
1358
1359 failed_super:
1360 deactivate_locked_super(s);
1361
1362 failed:
1363 if (!s_new)
1364 blkdev_put(sd.bdev, mode);
1365 return ERR_PTR(err);
1366 }
1367
1368 struct file_system_type nilfs_fs_type = {
1369 .owner = THIS_MODULE,
1370 .name = "nilfs2",
1371 .mount = nilfs_mount,
1372 .kill_sb = kill_block_super,
1373 .fs_flags = FS_REQUIRES_DEV,
1374 };
1375 MODULE_ALIAS_FS("nilfs2");
1376
1377 static void nilfs_inode_init_once(void *obj)
1378 {
1379 struct nilfs_inode_info *ii = obj;
1380
1381 INIT_LIST_HEAD(&ii->i_dirty);
1382 #ifdef CONFIG_NILFS_XATTR
1383 init_rwsem(&ii->xattr_sem);
1384 #endif
1385 address_space_init_once(&ii->i_btnode_cache);
1386 ii->i_bmap = &ii->i_bmap_data;
1387 inode_init_once(&ii->vfs_inode);
1388 }
1389
1390 static void nilfs_segbuf_init_once(void *obj)
1391 {
1392 memset(obj, 0, sizeof(struct nilfs_segment_buffer));
1393 }
1394
1395 static void nilfs_destroy_cachep(void)
1396 {
1397 /*
1398 * Make sure all delayed rcu free inodes are flushed before we
1399 * destroy cache.
1400 */
1401 rcu_barrier();
1402
1403 if (nilfs_inode_cachep)
1404 kmem_cache_destroy(nilfs_inode_cachep);
1405 if (nilfs_transaction_cachep)
1406 kmem_cache_destroy(nilfs_transaction_cachep);
1407 if (nilfs_segbuf_cachep)
1408 kmem_cache_destroy(nilfs_segbuf_cachep);
1409 if (nilfs_btree_path_cache)
1410 kmem_cache_destroy(nilfs_btree_path_cache);
1411 }
1412
1413 static int __init nilfs_init_cachep(void)
1414 {
1415 nilfs_inode_cachep = kmem_cache_create("nilfs2_inode_cache",
1416 sizeof(struct nilfs_inode_info), 0,
1417 SLAB_RECLAIM_ACCOUNT, nilfs_inode_init_once);
1418 if (!nilfs_inode_cachep)
1419 goto fail;
1420
1421 nilfs_transaction_cachep = kmem_cache_create("nilfs2_transaction_cache",
1422 sizeof(struct nilfs_transaction_info), 0,
1423 SLAB_RECLAIM_ACCOUNT, NULL);
1424 if (!nilfs_transaction_cachep)
1425 goto fail;
1426
1427 nilfs_segbuf_cachep = kmem_cache_create("nilfs2_segbuf_cache",
1428 sizeof(struct nilfs_segment_buffer), 0,
1429 SLAB_RECLAIM_ACCOUNT, nilfs_segbuf_init_once);
1430 if (!nilfs_segbuf_cachep)
1431 goto fail;
1432
1433 nilfs_btree_path_cache = kmem_cache_create("nilfs2_btree_path_cache",
1434 sizeof(struct nilfs_btree_path) * NILFS_BTREE_LEVEL_MAX,
1435 0, 0, NULL);
1436 if (!nilfs_btree_path_cache)
1437 goto fail;
1438
1439 return 0;
1440
1441 fail:
1442 nilfs_destroy_cachep();
1443 return -ENOMEM;
1444 }
1445
1446 static int __init init_nilfs_fs(void)
1447 {
1448 int err;
1449
1450 err = nilfs_init_cachep();
1451 if (err)
1452 goto fail;
1453
1454 err = register_filesystem(&nilfs_fs_type);
1455 if (err)
1456 goto free_cachep;
1457
1458 printk(KERN_INFO "NILFS version 2 loaded\n");
1459 return 0;
1460
1461 free_cachep:
1462 nilfs_destroy_cachep();
1463 fail:
1464 return err;
1465 }
1466
1467 static void __exit exit_nilfs_fs(void)
1468 {
1469 nilfs_destroy_cachep();
1470 unregister_filesystem(&nilfs_fs_type);
1471 }
1472
1473 module_init(init_nilfs_fs)
1474 module_exit(exit_nilfs_fs)
Linux with added FPC-III support