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1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * NILFS module and super block management.
4 *
5 * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation.
6 *
7 * Written by Ryusuke Konishi.
8 */
9/*
10 * linux/fs/ext2/super.c
11 *
12 * Copyright (C) 1992, 1993, 1994, 1995
13 * Remy Card (card@masi.ibp.fr)
14 * Laboratoire MASI - Institut Blaise Pascal
15 * Universite Pierre et Marie Curie (Paris VI)
16 *
17 * from
18 *
19 * linux/fs/minix/inode.c
20 *
21 * Copyright (C) 1991, 1992 Linus Torvalds
22 *
23 * Big-endian to little-endian byte-swapping/bitmaps by
24 * David S. Miller (davem@caip.rutgers.edu), 1995
25 */
26
27#include <linux/module.h>
28#include <linux/string.h>
29#include <linux/slab.h>
30#include <linux/init.h>
31#include <linux/blkdev.h>
32#include <linux/crc32.h>
33#include <linux/vfs.h>
34#include <linux/writeback.h>
35#include <linux/seq_file.h>
36#include <linux/mount.h>
37#include <linux/fs_context.h>
38#include <linux/fs_parser.h>
39#include "nilfs.h"
40#include "export.h"
41#include "mdt.h"
42#include "alloc.h"
43#include "btree.h"
44#include "btnode.h"
45#include "page.h"
46#include "cpfile.h"
47#include "sufile.h" /* nilfs_sufile_resize(), nilfs_sufile_set_alloc_range() */
48#include "ifile.h"
49#include "dat.h"
50#include "segment.h"
51#include "segbuf.h"
52
53MODULE_AUTHOR("NTT Corp.");
54MODULE_DESCRIPTION("A New Implementation of the Log-structured Filesystem "
55 "(NILFS)");
56MODULE_LICENSE("GPL");
57
58static struct kmem_cache *nilfs_inode_cachep;
59struct kmem_cache *nilfs_transaction_cachep;
60struct kmem_cache *nilfs_segbuf_cachep;
61struct kmem_cache *nilfs_btree_path_cache;
62
63static int nilfs_setup_super(struct super_block *sb, int is_mount);
64
65void __nilfs_msg(struct super_block *sb, const char *fmt, ...)
66{
67 struct va_format vaf;
68 va_list args;
69 int level;
70
71 va_start(args, fmt);
72
73 level = printk_get_level(fmt);
74 vaf.fmt = printk_skip_level(fmt);
75 vaf.va = &args;
76
77 if (sb)
78 printk("%c%cNILFS (%s): %pV\n",
79 KERN_SOH_ASCII, level, sb->s_id, &vaf);
80 else
81 printk("%c%cNILFS: %pV\n",
82 KERN_SOH_ASCII, level, &vaf);
83
84 va_end(args);
85}
86
87static void nilfs_set_error(struct super_block *sb)
88{
89 struct the_nilfs *nilfs = sb->s_fs_info;
90 struct nilfs_super_block **sbp;
91
92 down_write(&nilfs->ns_sem);
93 if (!(nilfs->ns_mount_state & NILFS_ERROR_FS)) {
94 nilfs->ns_mount_state |= NILFS_ERROR_FS;
95 sbp = nilfs_prepare_super(sb, 0);
96 if (likely(sbp)) {
97 sbp[0]->s_state |= cpu_to_le16(NILFS_ERROR_FS);
98 if (sbp[1])
99 sbp[1]->s_state |= cpu_to_le16(NILFS_ERROR_FS);
100 nilfs_commit_super(sb, NILFS_SB_COMMIT_ALL);
101 }
102 }
103 up_write(&nilfs->ns_sem);
104}
105
106/**
107 * __nilfs_error() - report failure condition on a filesystem
108 * @sb: super block instance
109 * @function: name of calling function
110 * @fmt: format string for message to be output
111 * @...: optional arguments to @fmt
112 *
113 * __nilfs_error() sets an ERROR_FS flag on the superblock as well as
114 * reporting an error message. This function should be called when
115 * NILFS detects incoherences or defects of meta data on disk.
116 *
117 * This implements the body of nilfs_error() macro. Normally,
118 * nilfs_error() should be used. As for sustainable errors such as a
119 * single-shot I/O error, nilfs_err() should be used instead.
120 *
121 * Callers should not add a trailing newline since this will do it.
122 */
123void __nilfs_error(struct super_block *sb, const char *function,
124 const char *fmt, ...)
125{
126 struct the_nilfs *nilfs = sb->s_fs_info;
127 struct va_format vaf;
128 va_list args;
129
130 va_start(args, fmt);
131
132 vaf.fmt = fmt;
133 vaf.va = &args;
134
135 printk(KERN_CRIT "NILFS error (device %s): %s: %pV\n",
136 sb->s_id, function, &vaf);
137
138 va_end(args);
139
140 if (!sb_rdonly(sb)) {
141 nilfs_set_error(sb);
142
143 if (nilfs_test_opt(nilfs, ERRORS_RO)) {
144 printk(KERN_CRIT "Remounting filesystem read-only\n");
145 sb->s_flags |= SB_RDONLY;
146 }
147 }
148
149 if (nilfs_test_opt(nilfs, ERRORS_PANIC))
150 panic("NILFS (device %s): panic forced after error\n",
151 sb->s_id);
152}
153
154struct inode *nilfs_alloc_inode(struct super_block *sb)
155{
156 struct nilfs_inode_info *ii;
157
158 ii = alloc_inode_sb(sb, nilfs_inode_cachep, GFP_NOFS);
159 if (!ii)
160 return NULL;
161 ii->i_bh = NULL;
162 ii->i_state = 0;
163 ii->i_type = 0;
164 ii->i_cno = 0;
165 ii->i_assoc_inode = NULL;
166 ii->i_bmap = &ii->i_bmap_data;
167 return &ii->vfs_inode;
168}
169
170static void nilfs_free_inode(struct inode *inode)
171{
172 if (nilfs_is_metadata_file_inode(inode))
173 nilfs_mdt_destroy(inode);
174
175 kmem_cache_free(nilfs_inode_cachep, NILFS_I(inode));
176}
177
178static int nilfs_sync_super(struct super_block *sb, int flag)
179{
180 struct the_nilfs *nilfs = sb->s_fs_info;
181 int err;
182
183 retry:
184 set_buffer_dirty(nilfs->ns_sbh[0]);
185 if (nilfs_test_opt(nilfs, BARRIER)) {
186 err = __sync_dirty_buffer(nilfs->ns_sbh[0],
187 REQ_SYNC | REQ_PREFLUSH | REQ_FUA);
188 } else {
189 err = sync_dirty_buffer(nilfs->ns_sbh[0]);
190 }
191
192 if (unlikely(err)) {
193 nilfs_err(sb, "unable to write superblock: err=%d", err);
194 if (err == -EIO && nilfs->ns_sbh[1]) {
195 /*
196 * sbp[0] points to newer log than sbp[1],
197 * so copy sbp[0] to sbp[1] to take over sbp[0].
198 */
199 memcpy(nilfs->ns_sbp[1], nilfs->ns_sbp[0],
200 nilfs->ns_sbsize);
201 nilfs_fall_back_super_block(nilfs);
202 goto retry;
203 }
204 } else {
205 struct nilfs_super_block *sbp = nilfs->ns_sbp[0];
206
207 nilfs->ns_sbwcount++;
208
209 /*
210 * The latest segment becomes trailable from the position
211 * written in superblock.
212 */
213 clear_nilfs_discontinued(nilfs);
214
215 /* update GC protection for recent segments */
216 if (nilfs->ns_sbh[1]) {
217 if (flag == NILFS_SB_COMMIT_ALL) {
218 set_buffer_dirty(nilfs->ns_sbh[1]);
219 if (sync_dirty_buffer(nilfs->ns_sbh[1]) < 0)
220 goto out;
221 }
222 if (le64_to_cpu(nilfs->ns_sbp[1]->s_last_cno) <
223 le64_to_cpu(nilfs->ns_sbp[0]->s_last_cno))
224 sbp = nilfs->ns_sbp[1];
225 }
226
227 spin_lock(&nilfs->ns_last_segment_lock);
228 nilfs->ns_prot_seq = le64_to_cpu(sbp->s_last_seq);
229 spin_unlock(&nilfs->ns_last_segment_lock);
230 }
231 out:
232 return err;
233}
234
235void nilfs_set_log_cursor(struct nilfs_super_block *sbp,
236 struct the_nilfs *nilfs)
237{
238 sector_t nfreeblocks;
239
240 /* nilfs->ns_sem must be locked by the caller. */
241 nilfs_count_free_blocks(nilfs, &nfreeblocks);
242 sbp->s_free_blocks_count = cpu_to_le64(nfreeblocks);
243
244 spin_lock(&nilfs->ns_last_segment_lock);
245 sbp->s_last_seq = cpu_to_le64(nilfs->ns_last_seq);
246 sbp->s_last_pseg = cpu_to_le64(nilfs->ns_last_pseg);
247 sbp->s_last_cno = cpu_to_le64(nilfs->ns_last_cno);
248 spin_unlock(&nilfs->ns_last_segment_lock);
249}
250
251struct nilfs_super_block **nilfs_prepare_super(struct super_block *sb,
252 int flip)
253{
254 struct the_nilfs *nilfs = sb->s_fs_info;
255 struct nilfs_super_block **sbp = nilfs->ns_sbp;
256
257 /* nilfs->ns_sem must be locked by the caller. */
258 if (sbp[0]->s_magic != cpu_to_le16(NILFS_SUPER_MAGIC)) {
259 if (sbp[1] &&
260 sbp[1]->s_magic == cpu_to_le16(NILFS_SUPER_MAGIC)) {
261 memcpy(sbp[0], sbp[1], nilfs->ns_sbsize);
262 } else {
263 nilfs_crit(sb, "superblock broke");
264 return NULL;
265 }
266 } else if (sbp[1] &&
267 sbp[1]->s_magic != cpu_to_le16(NILFS_SUPER_MAGIC)) {
268 memcpy(sbp[1], sbp[0], nilfs->ns_sbsize);
269 }
270
271 if (flip && sbp[1])
272 nilfs_swap_super_block(nilfs);
273
274 return sbp;
275}
276
277int nilfs_commit_super(struct super_block *sb, int flag)
278{
279 struct the_nilfs *nilfs = sb->s_fs_info;
280 struct nilfs_super_block **sbp = nilfs->ns_sbp;
281 time64_t t;
282
283 /* nilfs->ns_sem must be locked by the caller. */
284 t = ktime_get_real_seconds();
285 nilfs->ns_sbwtime = t;
286 sbp[0]->s_wtime = cpu_to_le64(t);
287 sbp[0]->s_sum = 0;
288 sbp[0]->s_sum = cpu_to_le32(crc32_le(nilfs->ns_crc_seed,
289 (unsigned char *)sbp[0],
290 nilfs->ns_sbsize));
291 if (flag == NILFS_SB_COMMIT_ALL && sbp[1]) {
292 sbp[1]->s_wtime = sbp[0]->s_wtime;
293 sbp[1]->s_sum = 0;
294 sbp[1]->s_sum = cpu_to_le32(crc32_le(nilfs->ns_crc_seed,
295 (unsigned char *)sbp[1],
296 nilfs->ns_sbsize));
297 }
298 clear_nilfs_sb_dirty(nilfs);
299 nilfs->ns_flushed_device = 1;
300 /* make sure store to ns_flushed_device cannot be reordered */
301 smp_wmb();
302 return nilfs_sync_super(sb, flag);
303}
304
305/**
306 * nilfs_cleanup_super() - write filesystem state for cleanup
307 * @sb: super block instance to be unmounted or degraded to read-only
308 *
309 * This function restores state flags in the on-disk super block.
310 * This will set "clean" flag (i.e. NILFS_VALID_FS) unless the
311 * filesystem was not clean previously.
312 */
313int nilfs_cleanup_super(struct super_block *sb)
314{
315 struct the_nilfs *nilfs = sb->s_fs_info;
316 struct nilfs_super_block **sbp;
317 int flag = NILFS_SB_COMMIT;
318 int ret = -EIO;
319
320 sbp = nilfs_prepare_super(sb, 0);
321 if (sbp) {
322 sbp[0]->s_state = cpu_to_le16(nilfs->ns_mount_state);
323 nilfs_set_log_cursor(sbp[0], nilfs);
324 if (sbp[1] && sbp[0]->s_last_cno == sbp[1]->s_last_cno) {
325 /*
326 * make the "clean" flag also to the opposite
327 * super block if both super blocks point to
328 * the same checkpoint.
329 */
330 sbp[1]->s_state = sbp[0]->s_state;
331 flag = NILFS_SB_COMMIT_ALL;
332 }
333 ret = nilfs_commit_super(sb, flag);
334 }
335 return ret;
336}
337
338/**
339 * nilfs_move_2nd_super - relocate secondary super block
340 * @sb: super block instance
341 * @sb2off: new offset of the secondary super block (in bytes)
342 */
343static int nilfs_move_2nd_super(struct super_block *sb, loff_t sb2off)
344{
345 struct the_nilfs *nilfs = sb->s_fs_info;
346 struct buffer_head *nsbh;
347 struct nilfs_super_block *nsbp;
348 sector_t blocknr, newblocknr;
349 unsigned long offset;
350 int sb2i; /* array index of the secondary superblock */
351 int ret = 0;
352
353 /* nilfs->ns_sem must be locked by the caller. */
354 if (nilfs->ns_sbh[1] &&
355 nilfs->ns_sbh[1]->b_blocknr > nilfs->ns_first_data_block) {
356 sb2i = 1;
357 blocknr = nilfs->ns_sbh[1]->b_blocknr;
358 } else if (nilfs->ns_sbh[0]->b_blocknr > nilfs->ns_first_data_block) {
359 sb2i = 0;
360 blocknr = nilfs->ns_sbh[0]->b_blocknr;
361 } else {
362 sb2i = -1;
363 blocknr = 0;
364 }
365 if (sb2i >= 0 && (u64)blocknr << nilfs->ns_blocksize_bits == sb2off)
366 goto out; /* super block location is unchanged */
367
368 /* Get new super block buffer */
369 newblocknr = sb2off >> nilfs->ns_blocksize_bits;
370 offset = sb2off & (nilfs->ns_blocksize - 1);
371 nsbh = sb_getblk(sb, newblocknr);
372 if (!nsbh) {
373 nilfs_warn(sb,
374 "unable to move secondary superblock to block %llu",
375 (unsigned long long)newblocknr);
376 ret = -EIO;
377 goto out;
378 }
379 nsbp = (void *)nsbh->b_data + offset;
380
381 lock_buffer(nsbh);
382 if (sb2i >= 0) {
383 /*
384 * The position of the second superblock only changes by 4KiB,
385 * which is larger than the maximum superblock data size
386 * (= 1KiB), so there is no need to use memmove() to allow
387 * overlap between source and destination.
388 */
389 memcpy(nsbp, nilfs->ns_sbp[sb2i], nilfs->ns_sbsize);
390
391 /*
392 * Zero fill after copy to avoid overwriting in case of move
393 * within the same block.
394 */
395 memset(nsbh->b_data, 0, offset);
396 memset((void *)nsbp + nilfs->ns_sbsize, 0,
397 nsbh->b_size - offset - nilfs->ns_sbsize);
398 } else {
399 memset(nsbh->b_data, 0, nsbh->b_size);
400 }
401 set_buffer_uptodate(nsbh);
402 unlock_buffer(nsbh);
403
404 if (sb2i >= 0) {
405 brelse(nilfs->ns_sbh[sb2i]);
406 nilfs->ns_sbh[sb2i] = nsbh;
407 nilfs->ns_sbp[sb2i] = nsbp;
408 } else if (nilfs->ns_sbh[0]->b_blocknr < nilfs->ns_first_data_block) {
409 /* secondary super block will be restored to index 1 */
410 nilfs->ns_sbh[1] = nsbh;
411 nilfs->ns_sbp[1] = nsbp;
412 } else {
413 brelse(nsbh);
414 }
415out:
416 return ret;
417}
418
419/**
420 * nilfs_resize_fs - resize the filesystem
421 * @sb: super block instance
422 * @newsize: new size of the filesystem (in bytes)
423 */
424int nilfs_resize_fs(struct super_block *sb, __u64 newsize)
425{
426 struct the_nilfs *nilfs = sb->s_fs_info;
427 struct nilfs_super_block **sbp;
428 __u64 devsize, newnsegs;
429 loff_t sb2off;
430 int ret;
431
432 ret = -ERANGE;
433 devsize = bdev_nr_bytes(sb->s_bdev);
434 if (newsize > devsize)
435 goto out;
436
437 /*
438 * Prevent underflow in second superblock position calculation.
439 * The exact minimum size check is done in nilfs_sufile_resize().
440 */
441 if (newsize < 4096) {
442 ret = -ENOSPC;
443 goto out;
444 }
445
446 /*
447 * Write lock is required to protect some functions depending
448 * on the number of segments, the number of reserved segments,
449 * and so forth.
450 */
451 down_write(&nilfs->ns_segctor_sem);
452
453 sb2off = NILFS_SB2_OFFSET_BYTES(newsize);
454 newnsegs = sb2off >> nilfs->ns_blocksize_bits;
455 newnsegs = div64_ul(newnsegs, nilfs->ns_blocks_per_segment);
456
457 ret = nilfs_sufile_resize(nilfs->ns_sufile, newnsegs);
458 up_write(&nilfs->ns_segctor_sem);
459 if (ret < 0)
460 goto out;
461
462 ret = nilfs_construct_segment(sb);
463 if (ret < 0)
464 goto out;
465
466 down_write(&nilfs->ns_sem);
467 nilfs_move_2nd_super(sb, sb2off);
468 ret = -EIO;
469 sbp = nilfs_prepare_super(sb, 0);
470 if (likely(sbp)) {
471 nilfs_set_log_cursor(sbp[0], nilfs);
472 /*
473 * Drop NILFS_RESIZE_FS flag for compatibility with
474 * mount-time resize which may be implemented in a
475 * future release.
476 */
477 sbp[0]->s_state = cpu_to_le16(le16_to_cpu(sbp[0]->s_state) &
478 ~NILFS_RESIZE_FS);
479 sbp[0]->s_dev_size = cpu_to_le64(newsize);
480 sbp[0]->s_nsegments = cpu_to_le64(nilfs->ns_nsegments);
481 if (sbp[1])
482 memcpy(sbp[1], sbp[0], nilfs->ns_sbsize);
483 ret = nilfs_commit_super(sb, NILFS_SB_COMMIT_ALL);
484 }
485 up_write(&nilfs->ns_sem);
486
487 /*
488 * Reset the range of allocatable segments last. This order
489 * is important in the case of expansion because the secondary
490 * superblock must be protected from log write until migration
491 * completes.
492 */
493 if (!ret)
494 nilfs_sufile_set_alloc_range(nilfs->ns_sufile, 0, newnsegs - 1);
495out:
496 return ret;
497}
498
499static void nilfs_put_super(struct super_block *sb)
500{
501 struct the_nilfs *nilfs = sb->s_fs_info;
502
503 nilfs_detach_log_writer(sb);
504
505 if (!sb_rdonly(sb)) {
506 down_write(&nilfs->ns_sem);
507 nilfs_cleanup_super(sb);
508 up_write(&nilfs->ns_sem);
509 }
510
511 nilfs_sysfs_delete_device_group(nilfs);
512 iput(nilfs->ns_sufile);
513 iput(nilfs->ns_cpfile);
514 iput(nilfs->ns_dat);
515
516 destroy_nilfs(nilfs);
517 sb->s_fs_info = NULL;
518}
519
520static int nilfs_sync_fs(struct super_block *sb, int wait)
521{
522 struct the_nilfs *nilfs = sb->s_fs_info;
523 struct nilfs_super_block **sbp;
524 int err = 0;
525
526 /* This function is called when super block should be written back */
527 if (wait)
528 err = nilfs_construct_segment(sb);
529
530 down_write(&nilfs->ns_sem);
531 if (nilfs_sb_dirty(nilfs)) {
532 sbp = nilfs_prepare_super(sb, nilfs_sb_will_flip(nilfs));
533 if (likely(sbp)) {
534 nilfs_set_log_cursor(sbp[0], nilfs);
535 nilfs_commit_super(sb, NILFS_SB_COMMIT);
536 }
537 }
538 up_write(&nilfs->ns_sem);
539
540 if (!err)
541 err = nilfs_flush_device(nilfs);
542
543 return err;
544}
545
546int nilfs_attach_checkpoint(struct super_block *sb, __u64 cno, int curr_mnt,
547 struct nilfs_root **rootp)
548{
549 struct the_nilfs *nilfs = sb->s_fs_info;
550 struct nilfs_root *root;
551 int err = -ENOMEM;
552
553 root = nilfs_find_or_create_root(
554 nilfs, curr_mnt ? NILFS_CPTREE_CURRENT_CNO : cno);
555 if (!root)
556 return err;
557
558 if (root->ifile)
559 goto reuse; /* already attached checkpoint */
560
561 down_read(&nilfs->ns_segctor_sem);
562 err = nilfs_ifile_read(sb, root, cno, nilfs->ns_inode_size);
563 up_read(&nilfs->ns_segctor_sem);
564 if (unlikely(err))
565 goto failed;
566
567 reuse:
568 *rootp = root;
569 return 0;
570
571 failed:
572 if (err == -EINVAL)
573 nilfs_err(sb, "Invalid checkpoint (checkpoint number=%llu)",
574 (unsigned long long)cno);
575 nilfs_put_root(root);
576
577 return err;
578}
579
580static int nilfs_freeze(struct super_block *sb)
581{
582 struct the_nilfs *nilfs = sb->s_fs_info;
583 int err;
584
585 if (sb_rdonly(sb))
586 return 0;
587
588 /* Mark super block clean */
589 down_write(&nilfs->ns_sem);
590 err = nilfs_cleanup_super(sb);
591 up_write(&nilfs->ns_sem);
592 return err;
593}
594
595static int nilfs_unfreeze(struct super_block *sb)
596{
597 struct the_nilfs *nilfs = sb->s_fs_info;
598
599 if (sb_rdonly(sb))
600 return 0;
601
602 down_write(&nilfs->ns_sem);
603 nilfs_setup_super(sb, false);
604 up_write(&nilfs->ns_sem);
605 return 0;
606}
607
608static int nilfs_statfs(struct dentry *dentry, struct kstatfs *buf)
609{
610 struct super_block *sb = dentry->d_sb;
611 struct nilfs_root *root = NILFS_I(d_inode(dentry))->i_root;
612 struct the_nilfs *nilfs = root->nilfs;
613 u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
614 unsigned long long blocks;
615 unsigned long overhead;
616 unsigned long nrsvblocks;
617 sector_t nfreeblocks;
618 u64 nmaxinodes, nfreeinodes;
619 int err;
620
621 /*
622 * Compute all of the segment blocks
623 *
624 * The blocks before first segment and after last segment
625 * are excluded.
626 */
627 blocks = nilfs->ns_blocks_per_segment * nilfs->ns_nsegments
628 - nilfs->ns_first_data_block;
629 nrsvblocks = nilfs->ns_nrsvsegs * nilfs->ns_blocks_per_segment;
630
631 /*
632 * Compute the overhead
633 *
634 * When distributing meta data blocks outside segment structure,
635 * We must count them as the overhead.
636 */
637 overhead = 0;
638
639 err = nilfs_count_free_blocks(nilfs, &nfreeblocks);
640 if (unlikely(err))
641 return err;
642
643 err = nilfs_ifile_count_free_inodes(root->ifile,
644 &nmaxinodes, &nfreeinodes);
645 if (unlikely(err)) {
646 nilfs_warn(sb, "failed to count free inodes: err=%d", err);
647 if (err == -ERANGE) {
648 /*
649 * If nilfs_palloc_count_max_entries() returns
650 * -ERANGE error code then we simply treat
651 * curent inodes count as maximum possible and
652 * zero as free inodes value.
653 */
654 nmaxinodes = atomic64_read(&root->inodes_count);
655 nfreeinodes = 0;
656 err = 0;
657 } else
658 return err;
659 }
660
661 buf->f_type = NILFS_SUPER_MAGIC;
662 buf->f_bsize = sb->s_blocksize;
663 buf->f_blocks = blocks - overhead;
664 buf->f_bfree = nfreeblocks;
665 buf->f_bavail = (buf->f_bfree >= nrsvblocks) ?
666 (buf->f_bfree - nrsvblocks) : 0;
667 buf->f_files = nmaxinodes;
668 buf->f_ffree = nfreeinodes;
669 buf->f_namelen = NILFS_NAME_LEN;
670 buf->f_fsid = u64_to_fsid(id);
671
672 return 0;
673}
674
675static int nilfs_show_options(struct seq_file *seq, struct dentry *dentry)
676{
677 struct super_block *sb = dentry->d_sb;
678 struct the_nilfs *nilfs = sb->s_fs_info;
679 struct nilfs_root *root = NILFS_I(d_inode(dentry))->i_root;
680
681 if (!nilfs_test_opt(nilfs, BARRIER))
682 seq_puts(seq, ",nobarrier");
683 if (root->cno != NILFS_CPTREE_CURRENT_CNO)
684 seq_printf(seq, ",cp=%llu", (unsigned long long)root->cno);
685 if (nilfs_test_opt(nilfs, ERRORS_PANIC))
686 seq_puts(seq, ",errors=panic");
687 if (nilfs_test_opt(nilfs, ERRORS_CONT))
688 seq_puts(seq, ",errors=continue");
689 if (nilfs_test_opt(nilfs, STRICT_ORDER))
690 seq_puts(seq, ",order=strict");
691 if (nilfs_test_opt(nilfs, NORECOVERY))
692 seq_puts(seq, ",norecovery");
693 if (nilfs_test_opt(nilfs, DISCARD))
694 seq_puts(seq, ",discard");
695
696 return 0;
697}
698
699static const struct super_operations nilfs_sops = {
700 .alloc_inode = nilfs_alloc_inode,
701 .free_inode = nilfs_free_inode,
702 .dirty_inode = nilfs_dirty_inode,
703 .evict_inode = nilfs_evict_inode,
704 .put_super = nilfs_put_super,
705 .sync_fs = nilfs_sync_fs,
706 .freeze_fs = nilfs_freeze,
707 .unfreeze_fs = nilfs_unfreeze,
708 .statfs = nilfs_statfs,
709 .show_options = nilfs_show_options
710};
711
712enum {
713 Opt_err, Opt_barrier, Opt_snapshot, Opt_order, Opt_norecovery,
714 Opt_discard,
715};
716
717static const struct constant_table nilfs_param_err[] = {
718 {"continue", NILFS_MOUNT_ERRORS_CONT},
719 {"panic", NILFS_MOUNT_ERRORS_PANIC},
720 {"remount-ro", NILFS_MOUNT_ERRORS_RO},
721 {}
722};
723
724static const struct fs_parameter_spec nilfs_param_spec[] = {
725 fsparam_enum ("errors", Opt_err, nilfs_param_err),
726 fsparam_flag_no ("barrier", Opt_barrier),
727 fsparam_u64 ("cp", Opt_snapshot),
728 fsparam_string ("order", Opt_order),
729 fsparam_flag ("norecovery", Opt_norecovery),
730 fsparam_flag_no ("discard", Opt_discard),
731 {}
732};
733
734struct nilfs_fs_context {
735 unsigned long ns_mount_opt;
736 __u64 cno;
737};
738
739static int nilfs_parse_param(struct fs_context *fc, struct fs_parameter *param)
740{
741 struct nilfs_fs_context *nilfs = fc->fs_private;
742 int is_remount = fc->purpose == FS_CONTEXT_FOR_RECONFIGURE;
743 struct fs_parse_result result;
744 int opt;
745
746 opt = fs_parse(fc, nilfs_param_spec, param, &result);
747 if (opt < 0)
748 return opt;
749
750 switch (opt) {
751 case Opt_barrier:
752 if (result.negated)
753 nilfs_clear_opt(nilfs, BARRIER);
754 else
755 nilfs_set_opt(nilfs, BARRIER);
756 break;
757 case Opt_order:
758 if (strcmp(param->string, "relaxed") == 0)
759 /* Ordered data semantics */
760 nilfs_clear_opt(nilfs, STRICT_ORDER);
761 else if (strcmp(param->string, "strict") == 0)
762 /* Strict in-order semantics */
763 nilfs_set_opt(nilfs, STRICT_ORDER);
764 else
765 return -EINVAL;
766 break;
767 case Opt_err:
768 nilfs->ns_mount_opt &= ~NILFS_MOUNT_ERROR_MODE;
769 nilfs->ns_mount_opt |= result.uint_32;
770 break;
771 case Opt_snapshot:
772 if (is_remount) {
773 struct super_block *sb = fc->root->d_sb;
774
775 nilfs_err(sb,
776 "\"%s\" option is invalid for remount",
777 param->key);
778 return -EINVAL;
779 }
780 if (result.uint_64 == 0) {
781 nilfs_err(NULL,
782 "invalid option \"cp=0\": invalid checkpoint number 0");
783 return -EINVAL;
784 }
785 nilfs->cno = result.uint_64;
786 break;
787 case Opt_norecovery:
788 nilfs_set_opt(nilfs, NORECOVERY);
789 break;
790 case Opt_discard:
791 if (result.negated)
792 nilfs_clear_opt(nilfs, DISCARD);
793 else
794 nilfs_set_opt(nilfs, DISCARD);
795 break;
796 default:
797 return -EINVAL;
798 }
799
800 return 0;
801}
802
803static int nilfs_setup_super(struct super_block *sb, int is_mount)
804{
805 struct the_nilfs *nilfs = sb->s_fs_info;
806 struct nilfs_super_block **sbp;
807 int max_mnt_count;
808 int mnt_count;
809
810 /* nilfs->ns_sem must be locked by the caller. */
811 sbp = nilfs_prepare_super(sb, 0);
812 if (!sbp)
813 return -EIO;
814
815 if (!is_mount)
816 goto skip_mount_setup;
817
818 max_mnt_count = le16_to_cpu(sbp[0]->s_max_mnt_count);
819 mnt_count = le16_to_cpu(sbp[0]->s_mnt_count);
820
821 if (nilfs->ns_mount_state & NILFS_ERROR_FS) {
822 nilfs_warn(sb, "mounting fs with errors");
823#if 0
824 } else if (max_mnt_count >= 0 && mnt_count >= max_mnt_count) {
825 nilfs_warn(sb, "maximal mount count reached");
826#endif
827 }
828 if (!max_mnt_count)
829 sbp[0]->s_max_mnt_count = cpu_to_le16(NILFS_DFL_MAX_MNT_COUNT);
830
831 sbp[0]->s_mnt_count = cpu_to_le16(mnt_count + 1);
832 sbp[0]->s_mtime = cpu_to_le64(ktime_get_real_seconds());
833
834skip_mount_setup:
835 sbp[0]->s_state =
836 cpu_to_le16(le16_to_cpu(sbp[0]->s_state) & ~NILFS_VALID_FS);
837 /* synchronize sbp[1] with sbp[0] */
838 if (sbp[1])
839 memcpy(sbp[1], sbp[0], nilfs->ns_sbsize);
840 return nilfs_commit_super(sb, NILFS_SB_COMMIT_ALL);
841}
842
843struct nilfs_super_block *nilfs_read_super_block(struct super_block *sb,
844 u64 pos, int blocksize,
845 struct buffer_head **pbh)
846{
847 unsigned long long sb_index = pos;
848 unsigned long offset;
849
850 offset = do_div(sb_index, blocksize);
851 *pbh = sb_bread(sb, sb_index);
852 if (!*pbh)
853 return NULL;
854 return (struct nilfs_super_block *)((char *)(*pbh)->b_data + offset);
855}
856
857int nilfs_store_magic(struct super_block *sb,
858 struct nilfs_super_block *sbp)
859{
860 struct the_nilfs *nilfs = sb->s_fs_info;
861
862 sb->s_magic = le16_to_cpu(sbp->s_magic);
863
864 /* FS independent flags */
865#ifdef NILFS_ATIME_DISABLE
866 sb->s_flags |= SB_NOATIME;
867#endif
868
869 nilfs->ns_resuid = le16_to_cpu(sbp->s_def_resuid);
870 nilfs->ns_resgid = le16_to_cpu(sbp->s_def_resgid);
871 nilfs->ns_interval = le32_to_cpu(sbp->s_c_interval);
872 nilfs->ns_watermark = le32_to_cpu(sbp->s_c_block_max);
873
874 return 0;
875}
876
877int nilfs_check_feature_compatibility(struct super_block *sb,
878 struct nilfs_super_block *sbp)
879{
880 __u64 features;
881
882 features = le64_to_cpu(sbp->s_feature_incompat) &
883 ~NILFS_FEATURE_INCOMPAT_SUPP;
884 if (features) {
885 nilfs_err(sb,
886 "couldn't mount because of unsupported optional features (%llx)",
887 (unsigned long long)features);
888 return -EINVAL;
889 }
890 features = le64_to_cpu(sbp->s_feature_compat_ro) &
891 ~NILFS_FEATURE_COMPAT_RO_SUPP;
892 if (!sb_rdonly(sb) && features) {
893 nilfs_err(sb,
894 "couldn't mount RDWR because of unsupported optional features (%llx)",
895 (unsigned long long)features);
896 return -EINVAL;
897 }
898 return 0;
899}
900
901static int nilfs_get_root_dentry(struct super_block *sb,
902 struct nilfs_root *root,
903 struct dentry **root_dentry)
904{
905 struct inode *inode;
906 struct dentry *dentry;
907 int ret = 0;
908
909 inode = nilfs_iget(sb, root, NILFS_ROOT_INO);
910 if (IS_ERR(inode)) {
911 ret = PTR_ERR(inode);
912 nilfs_err(sb, "error %d getting root inode", ret);
913 goto out;
914 }
915 if (!S_ISDIR(inode->i_mode) || !inode->i_blocks || !inode->i_size) {
916 iput(inode);
917 nilfs_err(sb, "corrupt root inode");
918 ret = -EINVAL;
919 goto out;
920 }
921
922 if (root->cno == NILFS_CPTREE_CURRENT_CNO) {
923 dentry = d_find_alias(inode);
924 if (!dentry) {
925 dentry = d_make_root(inode);
926 if (!dentry) {
927 ret = -ENOMEM;
928 goto failed_dentry;
929 }
930 } else {
931 iput(inode);
932 }
933 } else {
934 dentry = d_obtain_root(inode);
935 if (IS_ERR(dentry)) {
936 ret = PTR_ERR(dentry);
937 goto failed_dentry;
938 }
939 }
940 *root_dentry = dentry;
941 out:
942 return ret;
943
944 failed_dentry:
945 nilfs_err(sb, "error %d getting root dentry", ret);
946 goto out;
947}
948
949static int nilfs_attach_snapshot(struct super_block *s, __u64 cno,
950 struct dentry **root_dentry)
951{
952 struct the_nilfs *nilfs = s->s_fs_info;
953 struct nilfs_root *root;
954 int ret;
955
956 mutex_lock(&nilfs->ns_snapshot_mount_mutex);
957
958 down_read(&nilfs->ns_segctor_sem);
959 ret = nilfs_cpfile_is_snapshot(nilfs->ns_cpfile, cno);
960 up_read(&nilfs->ns_segctor_sem);
961 if (ret < 0) {
962 ret = (ret == -ENOENT) ? -EINVAL : ret;
963 goto out;
964 } else if (!ret) {
965 nilfs_err(s,
966 "The specified checkpoint is not a snapshot (checkpoint number=%llu)",
967 (unsigned long long)cno);
968 ret = -EINVAL;
969 goto out;
970 }
971
972 ret = nilfs_attach_checkpoint(s, cno, false, &root);
973 if (ret) {
974 nilfs_err(s,
975 "error %d while loading snapshot (checkpoint number=%llu)",
976 ret, (unsigned long long)cno);
977 goto out;
978 }
979 ret = nilfs_get_root_dentry(s, root, root_dentry);
980 nilfs_put_root(root);
981 out:
982 mutex_unlock(&nilfs->ns_snapshot_mount_mutex);
983 return ret;
984}
985
986/**
987 * nilfs_tree_is_busy() - try to shrink dentries of a checkpoint
988 * @root_dentry: root dentry of the tree to be shrunk
989 *
990 * This function returns true if the tree was in-use.
991 */
992static bool nilfs_tree_is_busy(struct dentry *root_dentry)
993{
994 shrink_dcache_parent(root_dentry);
995 return d_count(root_dentry) > 1;
996}
997
998int nilfs_checkpoint_is_mounted(struct super_block *sb, __u64 cno)
999{
1000 struct the_nilfs *nilfs = sb->s_fs_info;
1001 struct nilfs_root *root;
1002 struct inode *inode;
1003 struct dentry *dentry;
1004 int ret;
1005
1006 if (cno > nilfs->ns_cno)
1007 return false;
1008
1009 if (cno >= nilfs_last_cno(nilfs))
1010 return true; /* protect recent checkpoints */
1011
1012 ret = false;
1013 root = nilfs_lookup_root(nilfs, cno);
1014 if (root) {
1015 inode = nilfs_ilookup(sb, root, NILFS_ROOT_INO);
1016 if (inode) {
1017 dentry = d_find_alias(inode);
1018 if (dentry) {
1019 ret = nilfs_tree_is_busy(dentry);
1020 dput(dentry);
1021 }
1022 iput(inode);
1023 }
1024 nilfs_put_root(root);
1025 }
1026 return ret;
1027}
1028
1029/**
1030 * nilfs_fill_super() - initialize a super block instance
1031 * @sb: super_block
1032 * @fc: filesystem context
1033 *
1034 * This function is called exclusively by nilfs->ns_mount_mutex.
1035 * So, the recovery process is protected from other simultaneous mounts.
1036 */
1037static int
1038nilfs_fill_super(struct super_block *sb, struct fs_context *fc)
1039{
1040 struct the_nilfs *nilfs;
1041 struct nilfs_root *fsroot;
1042 struct nilfs_fs_context *ctx = fc->fs_private;
1043 __u64 cno;
1044 int err;
1045
1046 nilfs = alloc_nilfs(sb);
1047 if (!nilfs)
1048 return -ENOMEM;
1049
1050 sb->s_fs_info = nilfs;
1051
1052 err = init_nilfs(nilfs, sb);
1053 if (err)
1054 goto failed_nilfs;
1055
1056 /* Copy in parsed mount options */
1057 nilfs->ns_mount_opt = ctx->ns_mount_opt;
1058
1059 sb->s_op = &nilfs_sops;
1060 sb->s_export_op = &nilfs_export_ops;
1061 sb->s_root = NULL;
1062 sb->s_time_gran = 1;
1063 sb->s_max_links = NILFS_LINK_MAX;
1064
1065 sb->s_bdi = bdi_get(sb->s_bdev->bd_disk->bdi);
1066
1067 err = load_nilfs(nilfs, sb);
1068 if (err)
1069 goto failed_nilfs;
1070
1071 super_set_uuid(sb, nilfs->ns_sbp[0]->s_uuid,
1072 sizeof(nilfs->ns_sbp[0]->s_uuid));
1073 super_set_sysfs_name_bdev(sb);
1074
1075 cno = nilfs_last_cno(nilfs);
1076 err = nilfs_attach_checkpoint(sb, cno, true, &fsroot);
1077 if (err) {
1078 nilfs_err(sb,
1079 "error %d while loading last checkpoint (checkpoint number=%llu)",
1080 err, (unsigned long long)cno);
1081 goto failed_unload;
1082 }
1083
1084 if (!sb_rdonly(sb)) {
1085 err = nilfs_attach_log_writer(sb, fsroot);
1086 if (err)
1087 goto failed_checkpoint;
1088 }
1089
1090 err = nilfs_get_root_dentry(sb, fsroot, &sb->s_root);
1091 if (err)
1092 goto failed_segctor;
1093
1094 nilfs_put_root(fsroot);
1095
1096 if (!sb_rdonly(sb)) {
1097 down_write(&nilfs->ns_sem);
1098 nilfs_setup_super(sb, true);
1099 up_write(&nilfs->ns_sem);
1100 }
1101
1102 return 0;
1103
1104 failed_segctor:
1105 nilfs_detach_log_writer(sb);
1106
1107 failed_checkpoint:
1108 nilfs_put_root(fsroot);
1109
1110 failed_unload:
1111 nilfs_sysfs_delete_device_group(nilfs);
1112 iput(nilfs->ns_sufile);
1113 iput(nilfs->ns_cpfile);
1114 iput(nilfs->ns_dat);
1115
1116 failed_nilfs:
1117 destroy_nilfs(nilfs);
1118 return err;
1119}
1120
1121static int nilfs_reconfigure(struct fs_context *fc)
1122{
1123 struct nilfs_fs_context *ctx = fc->fs_private;
1124 struct super_block *sb = fc->root->d_sb;
1125 struct the_nilfs *nilfs = sb->s_fs_info;
1126 int err;
1127
1128 sync_filesystem(sb);
1129
1130 err = -EINVAL;
1131
1132 if (!nilfs_valid_fs(nilfs)) {
1133 nilfs_warn(sb,
1134 "couldn't remount because the filesystem is in an incomplete recovery state");
1135 goto ignore_opts;
1136 }
1137 if ((bool)(fc->sb_flags & SB_RDONLY) == sb_rdonly(sb))
1138 goto out;
1139 if (fc->sb_flags & SB_RDONLY) {
1140 sb->s_flags |= SB_RDONLY;
1141
1142 /*
1143 * Remounting a valid RW partition RDONLY, so set
1144 * the RDONLY flag and then mark the partition as valid again.
1145 */
1146 down_write(&nilfs->ns_sem);
1147 nilfs_cleanup_super(sb);
1148 up_write(&nilfs->ns_sem);
1149 } else {
1150 __u64 features;
1151 struct nilfs_root *root;
1152
1153 /*
1154 * Mounting a RDONLY partition read-write, so reread and
1155 * store the current valid flag. (It may have been changed
1156 * by fsck since we originally mounted the partition.)
1157 */
1158 down_read(&nilfs->ns_sem);
1159 features = le64_to_cpu(nilfs->ns_sbp[0]->s_feature_compat_ro) &
1160 ~NILFS_FEATURE_COMPAT_RO_SUPP;
1161 up_read(&nilfs->ns_sem);
1162 if (features) {
1163 nilfs_warn(sb,
1164 "couldn't remount RDWR because of unsupported optional features (%llx)",
1165 (unsigned long long)features);
1166 err = -EROFS;
1167 goto ignore_opts;
1168 }
1169
1170 sb->s_flags &= ~SB_RDONLY;
1171
1172 root = NILFS_I(d_inode(sb->s_root))->i_root;
1173 err = nilfs_attach_log_writer(sb, root);
1174 if (err) {
1175 sb->s_flags |= SB_RDONLY;
1176 goto ignore_opts;
1177 }
1178
1179 down_write(&nilfs->ns_sem);
1180 nilfs_setup_super(sb, true);
1181 up_write(&nilfs->ns_sem);
1182 }
1183 out:
1184 sb->s_flags = (sb->s_flags & ~SB_POSIXACL);
1185 /* Copy over parsed remount options */
1186 nilfs->ns_mount_opt = ctx->ns_mount_opt;
1187
1188 return 0;
1189
1190 ignore_opts:
1191 return err;
1192}
1193
1194static int
1195nilfs_get_tree(struct fs_context *fc)
1196{
1197 struct nilfs_fs_context *ctx = fc->fs_private;
1198 struct super_block *s;
1199 dev_t dev;
1200 int err;
1201
1202 if (ctx->cno && !(fc->sb_flags & SB_RDONLY)) {
1203 nilfs_err(NULL,
1204 "invalid option \"cp=%llu\": read-only option is not specified",
1205 ctx->cno);
1206 return -EINVAL;
1207 }
1208
1209 err = lookup_bdev(fc->source, &dev);
1210 if (err)
1211 return err;
1212
1213 s = sget_dev(fc, dev);
1214 if (IS_ERR(s))
1215 return PTR_ERR(s);
1216
1217 if (!s->s_root) {
1218 err = setup_bdev_super(s, fc->sb_flags, fc);
1219 if (!err)
1220 err = nilfs_fill_super(s, fc);
1221 if (err)
1222 goto failed_super;
1223
1224 s->s_flags |= SB_ACTIVE;
1225 } else if (!ctx->cno) {
1226 if (nilfs_tree_is_busy(s->s_root)) {
1227 if ((fc->sb_flags ^ s->s_flags) & SB_RDONLY) {
1228 nilfs_err(s,
1229 "the device already has a %s mount.",
1230 sb_rdonly(s) ? "read-only" : "read/write");
1231 err = -EBUSY;
1232 goto failed_super;
1233 }
1234 } else {
1235 /*
1236 * Try reconfigure to setup mount states if the current
1237 * tree is not mounted and only snapshots use this sb.
1238 *
1239 * Since nilfs_reconfigure() requires fc->root to be
1240 * set, set it first and release it on failure.
1241 */
1242 fc->root = dget(s->s_root);
1243 err = nilfs_reconfigure(fc);
1244 if (err) {
1245 dput(fc->root);
1246 fc->root = NULL; /* prevent double release */
1247 goto failed_super;
1248 }
1249 return 0;
1250 }
1251 }
1252
1253 if (ctx->cno) {
1254 struct dentry *root_dentry;
1255
1256 err = nilfs_attach_snapshot(s, ctx->cno, &root_dentry);
1257 if (err)
1258 goto failed_super;
1259 fc->root = root_dentry;
1260 return 0;
1261 }
1262
1263 fc->root = dget(s->s_root);
1264 return 0;
1265
1266 failed_super:
1267 deactivate_locked_super(s);
1268 return err;
1269}
1270
1271static void nilfs_free_fc(struct fs_context *fc)
1272{
1273 kfree(fc->fs_private);
1274}
1275
1276static const struct fs_context_operations nilfs_context_ops = {
1277 .parse_param = nilfs_parse_param,
1278 .get_tree = nilfs_get_tree,
1279 .reconfigure = nilfs_reconfigure,
1280 .free = nilfs_free_fc,
1281};
1282
1283static int nilfs_init_fs_context(struct fs_context *fc)
1284{
1285 struct nilfs_fs_context *ctx;
1286
1287 ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
1288 if (!ctx)
1289 return -ENOMEM;
1290
1291 ctx->ns_mount_opt = NILFS_MOUNT_ERRORS_RO | NILFS_MOUNT_BARRIER;
1292 fc->fs_private = ctx;
1293 fc->ops = &nilfs_context_ops;
1294
1295 return 0;
1296}
1297
1298struct file_system_type nilfs_fs_type = {
1299 .owner = THIS_MODULE,
1300 .name = "nilfs2",
1301 .kill_sb = kill_block_super,
1302 .fs_flags = FS_REQUIRES_DEV,
1303 .init_fs_context = nilfs_init_fs_context,
1304 .parameters = nilfs_param_spec,
1305};
1306MODULE_ALIAS_FS("nilfs2");
1307
1308static void nilfs_inode_init_once(void *obj)
1309{
1310 struct nilfs_inode_info *ii = obj;
1311
1312 INIT_LIST_HEAD(&ii->i_dirty);
1313#ifdef CONFIG_NILFS_XATTR
1314 init_rwsem(&ii->xattr_sem);
1315#endif
1316 inode_init_once(&ii->vfs_inode);
1317}
1318
1319static void nilfs_segbuf_init_once(void *obj)
1320{
1321 memset(obj, 0, sizeof(struct nilfs_segment_buffer));
1322}
1323
1324static void nilfs_destroy_cachep(void)
1325{
1326 /*
1327 * Make sure all delayed rcu free inodes are flushed before we
1328 * destroy cache.
1329 */
1330 rcu_barrier();
1331
1332 kmem_cache_destroy(nilfs_inode_cachep);
1333 kmem_cache_destroy(nilfs_transaction_cachep);
1334 kmem_cache_destroy(nilfs_segbuf_cachep);
1335 kmem_cache_destroy(nilfs_btree_path_cache);
1336}
1337
1338static int __init nilfs_init_cachep(void)
1339{
1340 nilfs_inode_cachep = kmem_cache_create("nilfs2_inode_cache",
1341 sizeof(struct nilfs_inode_info), 0,
1342 SLAB_RECLAIM_ACCOUNT|SLAB_ACCOUNT,
1343 nilfs_inode_init_once);
1344 if (!nilfs_inode_cachep)
1345 goto fail;
1346
1347 nilfs_transaction_cachep = kmem_cache_create("nilfs2_transaction_cache",
1348 sizeof(struct nilfs_transaction_info), 0,
1349 SLAB_RECLAIM_ACCOUNT, NULL);
1350 if (!nilfs_transaction_cachep)
1351 goto fail;
1352
1353 nilfs_segbuf_cachep = kmem_cache_create("nilfs2_segbuf_cache",
1354 sizeof(struct nilfs_segment_buffer), 0,
1355 SLAB_RECLAIM_ACCOUNT, nilfs_segbuf_init_once);
1356 if (!nilfs_segbuf_cachep)
1357 goto fail;
1358
1359 nilfs_btree_path_cache = kmem_cache_create("nilfs2_btree_path_cache",
1360 sizeof(struct nilfs_btree_path) * NILFS_BTREE_LEVEL_MAX,
1361 0, 0, NULL);
1362 if (!nilfs_btree_path_cache)
1363 goto fail;
1364
1365 return 0;
1366
1367fail:
1368 nilfs_destroy_cachep();
1369 return -ENOMEM;
1370}
1371
1372static int __init init_nilfs_fs(void)
1373{
1374 int err;
1375
1376 err = nilfs_init_cachep();
1377 if (err)
1378 goto fail;
1379
1380 err = nilfs_sysfs_init();
1381 if (err)
1382 goto free_cachep;
1383
1384 err = register_filesystem(&nilfs_fs_type);
1385 if (err)
1386 goto deinit_sysfs_entry;
1387
1388 printk(KERN_INFO "NILFS version 2 loaded\n");
1389 return 0;
1390
1391deinit_sysfs_entry:
1392 nilfs_sysfs_exit();
1393free_cachep:
1394 nilfs_destroy_cachep();
1395fail:
1396 return err;
1397}
1398
1399static void __exit exit_nilfs_fs(void)
1400{
1401 nilfs_destroy_cachep();
1402 nilfs_sysfs_exit();
1403 unregister_filesystem(&nilfs_fs_type);
1404}
1405
1406module_init(init_nilfs_fs)
1407module_exit(exit_nilfs_fs)
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
65MODULE_AUTHOR("NTT Corp.");
66MODULE_DESCRIPTION("A New Implementation of the Log-structured Filesystem "
67 "(NILFS)");
68MODULE_LICENSE("GPL");
69
70static struct kmem_cache *nilfs_inode_cachep;
71struct kmem_cache *nilfs_transaction_cachep;
72struct kmem_cache *nilfs_segbuf_cachep;
73struct kmem_cache *nilfs_btree_path_cache;
74
75static int nilfs_setup_super(struct super_block *sb, int is_mount);
76static int nilfs_remount(struct super_block *sb, int *flags, char *data);
77
78static 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 */
109void 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
140void 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
158struct 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);
170 return &ii->vfs_inode;
171}
172
173static 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
185void nilfs_destroy_inode(struct inode *inode)
186{
187 call_rcu(&inode->i_rcu, nilfs_i_callback);
188}
189
190static 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
248void 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
264struct 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
291int 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 nilfs->ns_flushed_device = 1;
314 /* make sure store to ns_flushed_device cannot be reordered */
315 smp_wmb();
316 return nilfs_sync_super(sb, flag);
317}
318
319/**
320 * nilfs_cleanup_super() - write filesystem state for cleanup
321 * @sb: super block instance to be unmounted or degraded to read-only
322 *
323 * This function restores state flags in the on-disk super block.
324 * This will set "clean" flag (i.e. NILFS_VALID_FS) unless the
325 * filesystem was not clean previously.
326 */
327int nilfs_cleanup_super(struct super_block *sb)
328{
329 struct the_nilfs *nilfs = sb->s_fs_info;
330 struct nilfs_super_block **sbp;
331 int flag = NILFS_SB_COMMIT;
332 int ret = -EIO;
333
334 sbp = nilfs_prepare_super(sb, 0);
335 if (sbp) {
336 sbp[0]->s_state = cpu_to_le16(nilfs->ns_mount_state);
337 nilfs_set_log_cursor(sbp[0], nilfs);
338 if (sbp[1] && sbp[0]->s_last_cno == sbp[1]->s_last_cno) {
339 /*
340 * make the "clean" flag also to the opposite
341 * super block if both super blocks point to
342 * the same checkpoint.
343 */
344 sbp[1]->s_state = sbp[0]->s_state;
345 flag = NILFS_SB_COMMIT_ALL;
346 }
347 ret = nilfs_commit_super(sb, flag);
348 }
349 return ret;
350}
351
352/**
353 * nilfs_move_2nd_super - relocate secondary super block
354 * @sb: super block instance
355 * @sb2off: new offset of the secondary super block (in bytes)
356 */
357static int nilfs_move_2nd_super(struct super_block *sb, loff_t sb2off)
358{
359 struct the_nilfs *nilfs = sb->s_fs_info;
360 struct buffer_head *nsbh;
361 struct nilfs_super_block *nsbp;
362 sector_t blocknr, newblocknr;
363 unsigned long offset;
364 int sb2i; /* array index of the secondary superblock */
365 int ret = 0;
366
367 /* nilfs->ns_sem must be locked by the caller. */
368 if (nilfs->ns_sbh[1] &&
369 nilfs->ns_sbh[1]->b_blocknr > nilfs->ns_first_data_block) {
370 sb2i = 1;
371 blocknr = nilfs->ns_sbh[1]->b_blocknr;
372 } else if (nilfs->ns_sbh[0]->b_blocknr > nilfs->ns_first_data_block) {
373 sb2i = 0;
374 blocknr = nilfs->ns_sbh[0]->b_blocknr;
375 } else {
376 sb2i = -1;
377 blocknr = 0;
378 }
379 if (sb2i >= 0 && (u64)blocknr << nilfs->ns_blocksize_bits == sb2off)
380 goto out; /* super block location is unchanged */
381
382 /* Get new super block buffer */
383 newblocknr = sb2off >> nilfs->ns_blocksize_bits;
384 offset = sb2off & (nilfs->ns_blocksize - 1);
385 nsbh = sb_getblk(sb, newblocknr);
386 if (!nsbh) {
387 printk(KERN_WARNING
388 "NILFS warning: unable to move secondary superblock "
389 "to block %llu\n", (unsigned long long)newblocknr);
390 ret = -EIO;
391 goto out;
392 }
393 nsbp = (void *)nsbh->b_data + offset;
394 memset(nsbp, 0, nilfs->ns_blocksize);
395
396 if (sb2i >= 0) {
397 memcpy(nsbp, nilfs->ns_sbp[sb2i], nilfs->ns_sbsize);
398 brelse(nilfs->ns_sbh[sb2i]);
399 nilfs->ns_sbh[sb2i] = nsbh;
400 nilfs->ns_sbp[sb2i] = nsbp;
401 } else if (nilfs->ns_sbh[0]->b_blocknr < nilfs->ns_first_data_block) {
402 /* secondary super block will be restored to index 1 */
403 nilfs->ns_sbh[1] = nsbh;
404 nilfs->ns_sbp[1] = nsbp;
405 } else {
406 brelse(nsbh);
407 }
408out:
409 return ret;
410}
411
412/**
413 * nilfs_resize_fs - resize the filesystem
414 * @sb: super block instance
415 * @newsize: new size of the filesystem (in bytes)
416 */
417int nilfs_resize_fs(struct super_block *sb, __u64 newsize)
418{
419 struct the_nilfs *nilfs = sb->s_fs_info;
420 struct nilfs_super_block **sbp;
421 __u64 devsize, newnsegs;
422 loff_t sb2off;
423 int ret;
424
425 ret = -ERANGE;
426 devsize = i_size_read(sb->s_bdev->bd_inode);
427 if (newsize > devsize)
428 goto out;
429
430 /*
431 * Write lock is required to protect some functions depending
432 * on the number of segments, the number of reserved segments,
433 * and so forth.
434 */
435 down_write(&nilfs->ns_segctor_sem);
436
437 sb2off = NILFS_SB2_OFFSET_BYTES(newsize);
438 newnsegs = sb2off >> nilfs->ns_blocksize_bits;
439 do_div(newnsegs, nilfs->ns_blocks_per_segment);
440
441 ret = nilfs_sufile_resize(nilfs->ns_sufile, newnsegs);
442 up_write(&nilfs->ns_segctor_sem);
443 if (ret < 0)
444 goto out;
445
446 ret = nilfs_construct_segment(sb);
447 if (ret < 0)
448 goto out;
449
450 down_write(&nilfs->ns_sem);
451 nilfs_move_2nd_super(sb, sb2off);
452 ret = -EIO;
453 sbp = nilfs_prepare_super(sb, 0);
454 if (likely(sbp)) {
455 nilfs_set_log_cursor(sbp[0], nilfs);
456 /*
457 * Drop NILFS_RESIZE_FS flag for compatibility with
458 * mount-time resize which may be implemented in a
459 * future release.
460 */
461 sbp[0]->s_state = cpu_to_le16(le16_to_cpu(sbp[0]->s_state) &
462 ~NILFS_RESIZE_FS);
463 sbp[0]->s_dev_size = cpu_to_le64(newsize);
464 sbp[0]->s_nsegments = cpu_to_le64(nilfs->ns_nsegments);
465 if (sbp[1])
466 memcpy(sbp[1], sbp[0], nilfs->ns_sbsize);
467 ret = nilfs_commit_super(sb, NILFS_SB_COMMIT_ALL);
468 }
469 up_write(&nilfs->ns_sem);
470
471 /*
472 * Reset the range of allocatable segments last. This order
473 * is important in the case of expansion because the secondary
474 * superblock must be protected from log write until migration
475 * completes.
476 */
477 if (!ret)
478 nilfs_sufile_set_alloc_range(nilfs->ns_sufile, 0, newnsegs - 1);
479out:
480 return ret;
481}
482
483static void nilfs_put_super(struct super_block *sb)
484{
485 struct the_nilfs *nilfs = sb->s_fs_info;
486
487 nilfs_detach_log_writer(sb);
488
489 if (!(sb->s_flags & MS_RDONLY)) {
490 down_write(&nilfs->ns_sem);
491 nilfs_cleanup_super(sb);
492 up_write(&nilfs->ns_sem);
493 }
494
495 iput(nilfs->ns_sufile);
496 iput(nilfs->ns_cpfile);
497 iput(nilfs->ns_dat);
498
499 destroy_nilfs(nilfs);
500 sb->s_fs_info = NULL;
501}
502
503static int nilfs_sync_fs(struct super_block *sb, int wait)
504{
505 struct the_nilfs *nilfs = sb->s_fs_info;
506 struct nilfs_super_block **sbp;
507 int err = 0;
508
509 /* This function is called when super block should be written back */
510 if (wait)
511 err = nilfs_construct_segment(sb);
512
513 down_write(&nilfs->ns_sem);
514 if (nilfs_sb_dirty(nilfs)) {
515 sbp = nilfs_prepare_super(sb, nilfs_sb_will_flip(nilfs));
516 if (likely(sbp)) {
517 nilfs_set_log_cursor(sbp[0], nilfs);
518 nilfs_commit_super(sb, NILFS_SB_COMMIT);
519 }
520 }
521 up_write(&nilfs->ns_sem);
522
523 if (!err)
524 err = nilfs_flush_device(nilfs);
525
526 return err;
527}
528
529int nilfs_attach_checkpoint(struct super_block *sb, __u64 cno, int curr_mnt,
530 struct nilfs_root **rootp)
531{
532 struct the_nilfs *nilfs = sb->s_fs_info;
533 struct nilfs_root *root;
534 struct nilfs_checkpoint *raw_cp;
535 struct buffer_head *bh_cp;
536 int err = -ENOMEM;
537
538 root = nilfs_find_or_create_root(
539 nilfs, curr_mnt ? NILFS_CPTREE_CURRENT_CNO : cno);
540 if (!root)
541 return err;
542
543 if (root->ifile)
544 goto reuse; /* already attached checkpoint */
545
546 down_read(&nilfs->ns_segctor_sem);
547 err = nilfs_cpfile_get_checkpoint(nilfs->ns_cpfile, cno, 0, &raw_cp,
548 &bh_cp);
549 up_read(&nilfs->ns_segctor_sem);
550 if (unlikely(err)) {
551 if (err == -ENOENT || err == -EINVAL) {
552 printk(KERN_ERR
553 "NILFS: Invalid checkpoint "
554 "(checkpoint number=%llu)\n",
555 (unsigned long long)cno);
556 err = -EINVAL;
557 }
558 goto failed;
559 }
560
561 err = nilfs_ifile_read(sb, root, nilfs->ns_inode_size,
562 &raw_cp->cp_ifile_inode, &root->ifile);
563 if (err)
564 goto failed_bh;
565
566 atomic64_set(&root->inodes_count,
567 le64_to_cpu(raw_cp->cp_inodes_count));
568 atomic64_set(&root->blocks_count,
569 le64_to_cpu(raw_cp->cp_blocks_count));
570
571 nilfs_cpfile_put_checkpoint(nilfs->ns_cpfile, cno, bh_cp);
572
573 reuse:
574 *rootp = root;
575 return 0;
576
577 failed_bh:
578 nilfs_cpfile_put_checkpoint(nilfs->ns_cpfile, cno, bh_cp);
579 failed:
580 nilfs_put_root(root);
581
582 return err;
583}
584
585static int nilfs_freeze(struct super_block *sb)
586{
587 struct the_nilfs *nilfs = sb->s_fs_info;
588 int err;
589
590 if (sb->s_flags & MS_RDONLY)
591 return 0;
592
593 /* Mark super block clean */
594 down_write(&nilfs->ns_sem);
595 err = nilfs_cleanup_super(sb);
596 up_write(&nilfs->ns_sem);
597 return err;
598}
599
600static int nilfs_unfreeze(struct super_block *sb)
601{
602 struct the_nilfs *nilfs = sb->s_fs_info;
603
604 if (sb->s_flags & MS_RDONLY)
605 return 0;
606
607 down_write(&nilfs->ns_sem);
608 nilfs_setup_super(sb, false);
609 up_write(&nilfs->ns_sem);
610 return 0;
611}
612
613static int nilfs_statfs(struct dentry *dentry, struct kstatfs *buf)
614{
615 struct super_block *sb = dentry->d_sb;
616 struct nilfs_root *root = NILFS_I(d_inode(dentry))->i_root;
617 struct the_nilfs *nilfs = root->nilfs;
618 u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
619 unsigned long long blocks;
620 unsigned long overhead;
621 unsigned long nrsvblocks;
622 sector_t nfreeblocks;
623 u64 nmaxinodes, nfreeinodes;
624 int err;
625
626 /*
627 * Compute all of the segment blocks
628 *
629 * The blocks before first segment and after last segment
630 * are excluded.
631 */
632 blocks = nilfs->ns_blocks_per_segment * nilfs->ns_nsegments
633 - nilfs->ns_first_data_block;
634 nrsvblocks = nilfs->ns_nrsvsegs * nilfs->ns_blocks_per_segment;
635
636 /*
637 * Compute the overhead
638 *
639 * When distributing meta data blocks outside segment structure,
640 * We must count them as the overhead.
641 */
642 overhead = 0;
643
644 err = nilfs_count_free_blocks(nilfs, &nfreeblocks);
645 if (unlikely(err))
646 return err;
647
648 err = nilfs_ifile_count_free_inodes(root->ifile,
649 &nmaxinodes, &nfreeinodes);
650 if (unlikely(err)) {
651 printk(KERN_WARNING
652 "NILFS warning: fail to count free inodes: err %d.\n",
653 err);
654 if (err == -ERANGE) {
655 /*
656 * If nilfs_palloc_count_max_entries() returns
657 * -ERANGE error code then we simply treat
658 * curent inodes count as maximum possible and
659 * zero as free inodes value.
660 */
661 nmaxinodes = atomic64_read(&root->inodes_count);
662 nfreeinodes = 0;
663 err = 0;
664 } else
665 return err;
666 }
667
668 buf->f_type = NILFS_SUPER_MAGIC;
669 buf->f_bsize = sb->s_blocksize;
670 buf->f_blocks = blocks - overhead;
671 buf->f_bfree = nfreeblocks;
672 buf->f_bavail = (buf->f_bfree >= nrsvblocks) ?
673 (buf->f_bfree - nrsvblocks) : 0;
674 buf->f_files = nmaxinodes;
675 buf->f_ffree = nfreeinodes;
676 buf->f_namelen = NILFS_NAME_LEN;
677 buf->f_fsid.val[0] = (u32)id;
678 buf->f_fsid.val[1] = (u32)(id >> 32);
679
680 return 0;
681}
682
683static int nilfs_show_options(struct seq_file *seq, struct dentry *dentry)
684{
685 struct super_block *sb = dentry->d_sb;
686 struct the_nilfs *nilfs = sb->s_fs_info;
687 struct nilfs_root *root = NILFS_I(d_inode(dentry))->i_root;
688
689 if (!nilfs_test_opt(nilfs, BARRIER))
690 seq_puts(seq, ",nobarrier");
691 if (root->cno != NILFS_CPTREE_CURRENT_CNO)
692 seq_printf(seq, ",cp=%llu", (unsigned long long)root->cno);
693 if (nilfs_test_opt(nilfs, ERRORS_PANIC))
694 seq_puts(seq, ",errors=panic");
695 if (nilfs_test_opt(nilfs, ERRORS_CONT))
696 seq_puts(seq, ",errors=continue");
697 if (nilfs_test_opt(nilfs, STRICT_ORDER))
698 seq_puts(seq, ",order=strict");
699 if (nilfs_test_opt(nilfs, NORECOVERY))
700 seq_puts(seq, ",norecovery");
701 if (nilfs_test_opt(nilfs, DISCARD))
702 seq_puts(seq, ",discard");
703
704 return 0;
705}
706
707static const struct super_operations nilfs_sops = {
708 .alloc_inode = nilfs_alloc_inode,
709 .destroy_inode = nilfs_destroy_inode,
710 .dirty_inode = nilfs_dirty_inode,
711 .evict_inode = nilfs_evict_inode,
712 .put_super = nilfs_put_super,
713 .sync_fs = nilfs_sync_fs,
714 .freeze_fs = nilfs_freeze,
715 .unfreeze_fs = nilfs_unfreeze,
716 .statfs = nilfs_statfs,
717 .remount_fs = nilfs_remount,
718 .show_options = nilfs_show_options
719};
720
721enum {
722 Opt_err_cont, Opt_err_panic, Opt_err_ro,
723 Opt_barrier, Opt_nobarrier, Opt_snapshot, Opt_order, Opt_norecovery,
724 Opt_discard, Opt_nodiscard, Opt_err,
725};
726
727static match_table_t tokens = {
728 {Opt_err_cont, "errors=continue"},
729 {Opt_err_panic, "errors=panic"},
730 {Opt_err_ro, "errors=remount-ro"},
731 {Opt_barrier, "barrier"},
732 {Opt_nobarrier, "nobarrier"},
733 {Opt_snapshot, "cp=%u"},
734 {Opt_order, "order=%s"},
735 {Opt_norecovery, "norecovery"},
736 {Opt_discard, "discard"},
737 {Opt_nodiscard, "nodiscard"},
738 {Opt_err, NULL}
739};
740
741static int parse_options(char *options, struct super_block *sb, int is_remount)
742{
743 struct the_nilfs *nilfs = sb->s_fs_info;
744 char *p;
745 substring_t args[MAX_OPT_ARGS];
746
747 if (!options)
748 return 1;
749
750 while ((p = strsep(&options, ",")) != NULL) {
751 int token;
752 if (!*p)
753 continue;
754
755 token = match_token(p, tokens, args);
756 switch (token) {
757 case Opt_barrier:
758 nilfs_set_opt(nilfs, BARRIER);
759 break;
760 case Opt_nobarrier:
761 nilfs_clear_opt(nilfs, BARRIER);
762 break;
763 case Opt_order:
764 if (strcmp(args[0].from, "relaxed") == 0)
765 /* Ordered data semantics */
766 nilfs_clear_opt(nilfs, STRICT_ORDER);
767 else if (strcmp(args[0].from, "strict") == 0)
768 /* Strict in-order semantics */
769 nilfs_set_opt(nilfs, STRICT_ORDER);
770 else
771 return 0;
772 break;
773 case Opt_err_panic:
774 nilfs_write_opt(nilfs, ERROR_MODE, ERRORS_PANIC);
775 break;
776 case Opt_err_ro:
777 nilfs_write_opt(nilfs, ERROR_MODE, ERRORS_RO);
778 break;
779 case Opt_err_cont:
780 nilfs_write_opt(nilfs, ERROR_MODE, ERRORS_CONT);
781 break;
782 case Opt_snapshot:
783 if (is_remount) {
784 printk(KERN_ERR
785 "NILFS: \"%s\" option is invalid "
786 "for remount.\n", p);
787 return 0;
788 }
789 break;
790 case Opt_norecovery:
791 nilfs_set_opt(nilfs, NORECOVERY);
792 break;
793 case Opt_discard:
794 nilfs_set_opt(nilfs, DISCARD);
795 break;
796 case Opt_nodiscard:
797 nilfs_clear_opt(nilfs, DISCARD);
798 break;
799 default:
800 printk(KERN_ERR
801 "NILFS: Unrecognized mount option \"%s\"\n", p);
802 return 0;
803 }
804 }
805 return 1;
806}
807
808static inline void
809nilfs_set_default_options(struct super_block *sb,
810 struct nilfs_super_block *sbp)
811{
812 struct the_nilfs *nilfs = sb->s_fs_info;
813
814 nilfs->ns_mount_opt =
815 NILFS_MOUNT_ERRORS_RO | NILFS_MOUNT_BARRIER;
816}
817
818static int nilfs_setup_super(struct super_block *sb, int is_mount)
819{
820 struct the_nilfs *nilfs = sb->s_fs_info;
821 struct nilfs_super_block **sbp;
822 int max_mnt_count;
823 int mnt_count;
824
825 /* nilfs->ns_sem must be locked by the caller. */
826 sbp = nilfs_prepare_super(sb, 0);
827 if (!sbp)
828 return -EIO;
829
830 if (!is_mount)
831 goto skip_mount_setup;
832
833 max_mnt_count = le16_to_cpu(sbp[0]->s_max_mnt_count);
834 mnt_count = le16_to_cpu(sbp[0]->s_mnt_count);
835
836 if (nilfs->ns_mount_state & NILFS_ERROR_FS) {
837 printk(KERN_WARNING
838 "NILFS warning: mounting fs with errors\n");
839#if 0
840 } else if (max_mnt_count >= 0 && mnt_count >= max_mnt_count) {
841 printk(KERN_WARNING
842 "NILFS warning: maximal mount count reached\n");
843#endif
844 }
845 if (!max_mnt_count)
846 sbp[0]->s_max_mnt_count = cpu_to_le16(NILFS_DFL_MAX_MNT_COUNT);
847
848 sbp[0]->s_mnt_count = cpu_to_le16(mnt_count + 1);
849 sbp[0]->s_mtime = cpu_to_le64(get_seconds());
850
851skip_mount_setup:
852 sbp[0]->s_state =
853 cpu_to_le16(le16_to_cpu(sbp[0]->s_state) & ~NILFS_VALID_FS);
854 /* synchronize sbp[1] with sbp[0] */
855 if (sbp[1])
856 memcpy(sbp[1], sbp[0], nilfs->ns_sbsize);
857 return nilfs_commit_super(sb, NILFS_SB_COMMIT_ALL);
858}
859
860struct nilfs_super_block *nilfs_read_super_block(struct super_block *sb,
861 u64 pos, int blocksize,
862 struct buffer_head **pbh)
863{
864 unsigned long long sb_index = pos;
865 unsigned long offset;
866
867 offset = do_div(sb_index, blocksize);
868 *pbh = sb_bread(sb, sb_index);
869 if (!*pbh)
870 return NULL;
871 return (struct nilfs_super_block *)((char *)(*pbh)->b_data + offset);
872}
873
874int nilfs_store_magic_and_option(struct super_block *sb,
875 struct nilfs_super_block *sbp,
876 char *data)
877{
878 struct the_nilfs *nilfs = sb->s_fs_info;
879
880 sb->s_magic = le16_to_cpu(sbp->s_magic);
881
882 /* FS independent flags */
883#ifdef NILFS_ATIME_DISABLE
884 sb->s_flags |= MS_NOATIME;
885#endif
886
887 nilfs_set_default_options(sb, sbp);
888
889 nilfs->ns_resuid = le16_to_cpu(sbp->s_def_resuid);
890 nilfs->ns_resgid = le16_to_cpu(sbp->s_def_resgid);
891 nilfs->ns_interval = le32_to_cpu(sbp->s_c_interval);
892 nilfs->ns_watermark = le32_to_cpu(sbp->s_c_block_max);
893
894 return !parse_options(data, sb, 0) ? -EINVAL : 0 ;
895}
896
897int nilfs_check_feature_compatibility(struct super_block *sb,
898 struct nilfs_super_block *sbp)
899{
900 __u64 features;
901
902 features = le64_to_cpu(sbp->s_feature_incompat) &
903 ~NILFS_FEATURE_INCOMPAT_SUPP;
904 if (features) {
905 printk(KERN_ERR "NILFS: couldn't mount because of unsupported "
906 "optional features (%llx)\n",
907 (unsigned long long)features);
908 return -EINVAL;
909 }
910 features = le64_to_cpu(sbp->s_feature_compat_ro) &
911 ~NILFS_FEATURE_COMPAT_RO_SUPP;
912 if (!(sb->s_flags & MS_RDONLY) && features) {
913 printk(KERN_ERR "NILFS: couldn't mount RDWR because of "
914 "unsupported optional features (%llx)\n",
915 (unsigned long long)features);
916 return -EINVAL;
917 }
918 return 0;
919}
920
921static int nilfs_get_root_dentry(struct super_block *sb,
922 struct nilfs_root *root,
923 struct dentry **root_dentry)
924{
925 struct inode *inode;
926 struct dentry *dentry;
927 int ret = 0;
928
929 inode = nilfs_iget(sb, root, NILFS_ROOT_INO);
930 if (IS_ERR(inode)) {
931 printk(KERN_ERR "NILFS: get root inode failed\n");
932 ret = PTR_ERR(inode);
933 goto out;
934 }
935 if (!S_ISDIR(inode->i_mode) || !inode->i_blocks || !inode->i_size) {
936 iput(inode);
937 printk(KERN_ERR "NILFS: corrupt root inode.\n");
938 ret = -EINVAL;
939 goto out;
940 }
941
942 if (root->cno == NILFS_CPTREE_CURRENT_CNO) {
943 dentry = d_find_alias(inode);
944 if (!dentry) {
945 dentry = d_make_root(inode);
946 if (!dentry) {
947 ret = -ENOMEM;
948 goto failed_dentry;
949 }
950 } else {
951 iput(inode);
952 }
953 } else {
954 dentry = d_obtain_root(inode);
955 if (IS_ERR(dentry)) {
956 ret = PTR_ERR(dentry);
957 goto failed_dentry;
958 }
959 }
960 *root_dentry = dentry;
961 out:
962 return ret;
963
964 failed_dentry:
965 printk(KERN_ERR "NILFS: get root dentry failed\n");
966 goto out;
967}
968
969static int nilfs_attach_snapshot(struct super_block *s, __u64 cno,
970 struct dentry **root_dentry)
971{
972 struct the_nilfs *nilfs = s->s_fs_info;
973 struct nilfs_root *root;
974 int ret;
975
976 mutex_lock(&nilfs->ns_snapshot_mount_mutex);
977
978 down_read(&nilfs->ns_segctor_sem);
979 ret = nilfs_cpfile_is_snapshot(nilfs->ns_cpfile, cno);
980 up_read(&nilfs->ns_segctor_sem);
981 if (ret < 0) {
982 ret = (ret == -ENOENT) ? -EINVAL : ret;
983 goto out;
984 } else if (!ret) {
985 printk(KERN_ERR "NILFS: The specified checkpoint is "
986 "not a snapshot (checkpoint number=%llu).\n",
987 (unsigned long long)cno);
988 ret = -EINVAL;
989 goto out;
990 }
991
992 ret = nilfs_attach_checkpoint(s, cno, false, &root);
993 if (ret) {
994 printk(KERN_ERR "NILFS: error loading snapshot "
995 "(checkpoint number=%llu).\n",
996 (unsigned long long)cno);
997 goto out;
998 }
999 ret = nilfs_get_root_dentry(s, root, root_dentry);
1000 nilfs_put_root(root);
1001 out:
1002 mutex_unlock(&nilfs->ns_snapshot_mount_mutex);
1003 return ret;
1004}
1005
1006/**
1007 * nilfs_tree_is_busy() - try to shrink dentries of a checkpoint
1008 * @root_dentry: root dentry of the tree to be shrunk
1009 *
1010 * This function returns true if the tree was in-use.
1011 */
1012static bool nilfs_tree_is_busy(struct dentry *root_dentry)
1013{
1014 shrink_dcache_parent(root_dentry);
1015 return d_count(root_dentry) > 1;
1016}
1017
1018int nilfs_checkpoint_is_mounted(struct super_block *sb, __u64 cno)
1019{
1020 struct the_nilfs *nilfs = sb->s_fs_info;
1021 struct nilfs_root *root;
1022 struct inode *inode;
1023 struct dentry *dentry;
1024 int ret;
1025
1026 if (cno > nilfs->ns_cno)
1027 return false;
1028
1029 if (cno >= nilfs_last_cno(nilfs))
1030 return true; /* protect recent checkpoints */
1031
1032 ret = false;
1033 root = nilfs_lookup_root(nilfs, cno);
1034 if (root) {
1035 inode = nilfs_ilookup(sb, root, NILFS_ROOT_INO);
1036 if (inode) {
1037 dentry = d_find_alias(inode);
1038 if (dentry) {
1039 ret = nilfs_tree_is_busy(dentry);
1040 dput(dentry);
1041 }
1042 iput(inode);
1043 }
1044 nilfs_put_root(root);
1045 }
1046 return ret;
1047}
1048
1049/**
1050 * nilfs_fill_super() - initialize a super block instance
1051 * @sb: super_block
1052 * @data: mount options
1053 * @silent: silent mode flag
1054 *
1055 * This function is called exclusively by nilfs->ns_mount_mutex.
1056 * So, the recovery process is protected from other simultaneous mounts.
1057 */
1058static int
1059nilfs_fill_super(struct super_block *sb, void *data, int silent)
1060{
1061 struct the_nilfs *nilfs;
1062 struct nilfs_root *fsroot;
1063 __u64 cno;
1064 int err;
1065
1066 nilfs = alloc_nilfs(sb->s_bdev);
1067 if (!nilfs)
1068 return -ENOMEM;
1069
1070 sb->s_fs_info = nilfs;
1071
1072 err = init_nilfs(nilfs, sb, (char *)data);
1073 if (err)
1074 goto failed_nilfs;
1075
1076 sb->s_op = &nilfs_sops;
1077 sb->s_export_op = &nilfs_export_ops;
1078 sb->s_root = NULL;
1079 sb->s_time_gran = 1;
1080 sb->s_max_links = NILFS_LINK_MAX;
1081
1082 sb->s_bdi = &bdev_get_queue(sb->s_bdev)->backing_dev_info;
1083
1084 err = load_nilfs(nilfs, sb);
1085 if (err)
1086 goto failed_nilfs;
1087
1088 cno = nilfs_last_cno(nilfs);
1089 err = nilfs_attach_checkpoint(sb, cno, true, &fsroot);
1090 if (err) {
1091 printk(KERN_ERR "NILFS: error loading last checkpoint "
1092 "(checkpoint number=%llu).\n", (unsigned long long)cno);
1093 goto failed_unload;
1094 }
1095
1096 if (!(sb->s_flags & MS_RDONLY)) {
1097 err = nilfs_attach_log_writer(sb, fsroot);
1098 if (err)
1099 goto failed_checkpoint;
1100 }
1101
1102 err = nilfs_get_root_dentry(sb, fsroot, &sb->s_root);
1103 if (err)
1104 goto failed_segctor;
1105
1106 nilfs_put_root(fsroot);
1107
1108 if (!(sb->s_flags & MS_RDONLY)) {
1109 down_write(&nilfs->ns_sem);
1110 nilfs_setup_super(sb, true);
1111 up_write(&nilfs->ns_sem);
1112 }
1113
1114 return 0;
1115
1116 failed_segctor:
1117 nilfs_detach_log_writer(sb);
1118
1119 failed_checkpoint:
1120 nilfs_put_root(fsroot);
1121
1122 failed_unload:
1123 iput(nilfs->ns_sufile);
1124 iput(nilfs->ns_cpfile);
1125 iput(nilfs->ns_dat);
1126
1127 failed_nilfs:
1128 destroy_nilfs(nilfs);
1129 return err;
1130}
1131
1132static int nilfs_remount(struct super_block *sb, int *flags, char *data)
1133{
1134 struct the_nilfs *nilfs = sb->s_fs_info;
1135 unsigned long old_sb_flags;
1136 unsigned long old_mount_opt;
1137 int err;
1138
1139 sync_filesystem(sb);
1140 old_sb_flags = sb->s_flags;
1141 old_mount_opt = nilfs->ns_mount_opt;
1142
1143 if (!parse_options(data, sb, 1)) {
1144 err = -EINVAL;
1145 goto restore_opts;
1146 }
1147 sb->s_flags = (sb->s_flags & ~MS_POSIXACL);
1148
1149 err = -EINVAL;
1150
1151 if (!nilfs_valid_fs(nilfs)) {
1152 printk(KERN_WARNING "NILFS (device %s): couldn't "
1153 "remount because the filesystem is in an "
1154 "incomplete recovery state.\n", sb->s_id);
1155 goto restore_opts;
1156 }
1157
1158 if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
1159 goto out;
1160 if (*flags & MS_RDONLY) {
1161 /* Shutting down log writer */
1162 nilfs_detach_log_writer(sb);
1163 sb->s_flags |= MS_RDONLY;
1164
1165 /*
1166 * Remounting a valid RW partition RDONLY, so set
1167 * the RDONLY flag and then mark the partition as valid again.
1168 */
1169 down_write(&nilfs->ns_sem);
1170 nilfs_cleanup_super(sb);
1171 up_write(&nilfs->ns_sem);
1172 } else {
1173 __u64 features;
1174 struct nilfs_root *root;
1175
1176 /*
1177 * Mounting a RDONLY partition read-write, so reread and
1178 * store the current valid flag. (It may have been changed
1179 * by fsck since we originally mounted the partition.)
1180 */
1181 down_read(&nilfs->ns_sem);
1182 features = le64_to_cpu(nilfs->ns_sbp[0]->s_feature_compat_ro) &
1183 ~NILFS_FEATURE_COMPAT_RO_SUPP;
1184 up_read(&nilfs->ns_sem);
1185 if (features) {
1186 printk(KERN_WARNING "NILFS (device %s): couldn't "
1187 "remount RDWR because of unsupported optional "
1188 "features (%llx)\n",
1189 sb->s_id, (unsigned long long)features);
1190 err = -EROFS;
1191 goto restore_opts;
1192 }
1193
1194 sb->s_flags &= ~MS_RDONLY;
1195
1196 root = NILFS_I(d_inode(sb->s_root))->i_root;
1197 err = nilfs_attach_log_writer(sb, root);
1198 if (err)
1199 goto restore_opts;
1200
1201 down_write(&nilfs->ns_sem);
1202 nilfs_setup_super(sb, true);
1203 up_write(&nilfs->ns_sem);
1204 }
1205 out:
1206 return 0;
1207
1208 restore_opts:
1209 sb->s_flags = old_sb_flags;
1210 nilfs->ns_mount_opt = old_mount_opt;
1211 return err;
1212}
1213
1214struct nilfs_super_data {
1215 struct block_device *bdev;
1216 __u64 cno;
1217 int flags;
1218};
1219
1220/**
1221 * nilfs_identify - pre-read mount options needed to identify mount instance
1222 * @data: mount options
1223 * @sd: nilfs_super_data
1224 */
1225static int nilfs_identify(char *data, struct nilfs_super_data *sd)
1226{
1227 char *p, *options = data;
1228 substring_t args[MAX_OPT_ARGS];
1229 int token;
1230 int ret = 0;
1231
1232 do {
1233 p = strsep(&options, ",");
1234 if (p != NULL && *p) {
1235 token = match_token(p, tokens, args);
1236 if (token == Opt_snapshot) {
1237 if (!(sd->flags & MS_RDONLY)) {
1238 ret++;
1239 } else {
1240 sd->cno = simple_strtoull(args[0].from,
1241 NULL, 0);
1242 /*
1243 * No need to see the end pointer;
1244 * match_token() has done syntax
1245 * checking.
1246 */
1247 if (sd->cno == 0)
1248 ret++;
1249 }
1250 }
1251 if (ret)
1252 printk(KERN_ERR
1253 "NILFS: invalid mount option: %s\n", p);
1254 }
1255 if (!options)
1256 break;
1257 BUG_ON(options == data);
1258 *(options - 1) = ',';
1259 } while (!ret);
1260 return ret;
1261}
1262
1263static int nilfs_set_bdev_super(struct super_block *s, void *data)
1264{
1265 s->s_bdev = data;
1266 s->s_dev = s->s_bdev->bd_dev;
1267 return 0;
1268}
1269
1270static int nilfs_test_bdev_super(struct super_block *s, void *data)
1271{
1272 return (void *)s->s_bdev == data;
1273}
1274
1275static struct dentry *
1276nilfs_mount(struct file_system_type *fs_type, int flags,
1277 const char *dev_name, void *data)
1278{
1279 struct nilfs_super_data sd;
1280 struct super_block *s;
1281 fmode_t mode = FMODE_READ | FMODE_EXCL;
1282 struct dentry *root_dentry;
1283 int err, s_new = false;
1284
1285 if (!(flags & MS_RDONLY))
1286 mode |= FMODE_WRITE;
1287
1288 sd.bdev = blkdev_get_by_path(dev_name, mode, fs_type);
1289 if (IS_ERR(sd.bdev))
1290 return ERR_CAST(sd.bdev);
1291
1292 sd.cno = 0;
1293 sd.flags = flags;
1294 if (nilfs_identify((char *)data, &sd)) {
1295 err = -EINVAL;
1296 goto failed;
1297 }
1298
1299 /*
1300 * once the super is inserted into the list by sget, s_umount
1301 * will protect the lockfs code from trying to start a snapshot
1302 * while we are mounting
1303 */
1304 mutex_lock(&sd.bdev->bd_fsfreeze_mutex);
1305 if (sd.bdev->bd_fsfreeze_count > 0) {
1306 mutex_unlock(&sd.bdev->bd_fsfreeze_mutex);
1307 err = -EBUSY;
1308 goto failed;
1309 }
1310 s = sget(fs_type, nilfs_test_bdev_super, nilfs_set_bdev_super, flags,
1311 sd.bdev);
1312 mutex_unlock(&sd.bdev->bd_fsfreeze_mutex);
1313 if (IS_ERR(s)) {
1314 err = PTR_ERR(s);
1315 goto failed;
1316 }
1317
1318 if (!s->s_root) {
1319 s_new = true;
1320
1321 /* New superblock instance created */
1322 s->s_mode = mode;
1323 snprintf(s->s_id, sizeof(s->s_id), "%pg", sd.bdev);
1324 sb_set_blocksize(s, block_size(sd.bdev));
1325
1326 err = nilfs_fill_super(s, data, flags & MS_SILENT ? 1 : 0);
1327 if (err)
1328 goto failed_super;
1329
1330 s->s_flags |= MS_ACTIVE;
1331 } else if (!sd.cno) {
1332 if (nilfs_tree_is_busy(s->s_root)) {
1333 if ((flags ^ s->s_flags) & MS_RDONLY) {
1334 printk(KERN_ERR "NILFS: the device already "
1335 "has a %s mount.\n",
1336 (s->s_flags & MS_RDONLY) ?
1337 "read-only" : "read/write");
1338 err = -EBUSY;
1339 goto failed_super;
1340 }
1341 } else {
1342 /*
1343 * Try remount to setup mount states if the current
1344 * tree is not mounted and only snapshots use this sb.
1345 */
1346 err = nilfs_remount(s, &flags, data);
1347 if (err)
1348 goto failed_super;
1349 }
1350 }
1351
1352 if (sd.cno) {
1353 err = nilfs_attach_snapshot(s, sd.cno, &root_dentry);
1354 if (err)
1355 goto failed_super;
1356 } else {
1357 root_dentry = dget(s->s_root);
1358 }
1359
1360 if (!s_new)
1361 blkdev_put(sd.bdev, mode);
1362
1363 return root_dentry;
1364
1365 failed_super:
1366 deactivate_locked_super(s);
1367
1368 failed:
1369 if (!s_new)
1370 blkdev_put(sd.bdev, mode);
1371 return ERR_PTR(err);
1372}
1373
1374struct file_system_type nilfs_fs_type = {
1375 .owner = THIS_MODULE,
1376 .name = "nilfs2",
1377 .mount = nilfs_mount,
1378 .kill_sb = kill_block_super,
1379 .fs_flags = FS_REQUIRES_DEV,
1380};
1381MODULE_ALIAS_FS("nilfs2");
1382
1383static void nilfs_inode_init_once(void *obj)
1384{
1385 struct nilfs_inode_info *ii = obj;
1386
1387 INIT_LIST_HEAD(&ii->i_dirty);
1388#ifdef CONFIG_NILFS_XATTR
1389 init_rwsem(&ii->xattr_sem);
1390#endif
1391 address_space_init_once(&ii->i_btnode_cache);
1392 ii->i_bmap = &ii->i_bmap_data;
1393 inode_init_once(&ii->vfs_inode);
1394}
1395
1396static void nilfs_segbuf_init_once(void *obj)
1397{
1398 memset(obj, 0, sizeof(struct nilfs_segment_buffer));
1399}
1400
1401static void nilfs_destroy_cachep(void)
1402{
1403 /*
1404 * Make sure all delayed rcu free inodes are flushed before we
1405 * destroy cache.
1406 */
1407 rcu_barrier();
1408
1409 kmem_cache_destroy(nilfs_inode_cachep);
1410 kmem_cache_destroy(nilfs_transaction_cachep);
1411 kmem_cache_destroy(nilfs_segbuf_cachep);
1412 kmem_cache_destroy(nilfs_btree_path_cache);
1413}
1414
1415static int __init nilfs_init_cachep(void)
1416{
1417 nilfs_inode_cachep = kmem_cache_create("nilfs2_inode_cache",
1418 sizeof(struct nilfs_inode_info), 0,
1419 SLAB_RECLAIM_ACCOUNT|SLAB_ACCOUNT,
1420 nilfs_inode_init_once);
1421 if (!nilfs_inode_cachep)
1422 goto fail;
1423
1424 nilfs_transaction_cachep = kmem_cache_create("nilfs2_transaction_cache",
1425 sizeof(struct nilfs_transaction_info), 0,
1426 SLAB_RECLAIM_ACCOUNT, NULL);
1427 if (!nilfs_transaction_cachep)
1428 goto fail;
1429
1430 nilfs_segbuf_cachep = kmem_cache_create("nilfs2_segbuf_cache",
1431 sizeof(struct nilfs_segment_buffer), 0,
1432 SLAB_RECLAIM_ACCOUNT, nilfs_segbuf_init_once);
1433 if (!nilfs_segbuf_cachep)
1434 goto fail;
1435
1436 nilfs_btree_path_cache = kmem_cache_create("nilfs2_btree_path_cache",
1437 sizeof(struct nilfs_btree_path) * NILFS_BTREE_LEVEL_MAX,
1438 0, 0, NULL);
1439 if (!nilfs_btree_path_cache)
1440 goto fail;
1441
1442 return 0;
1443
1444fail:
1445 nilfs_destroy_cachep();
1446 return -ENOMEM;
1447}
1448
1449static int __init init_nilfs_fs(void)
1450{
1451 int err;
1452
1453 err = nilfs_init_cachep();
1454 if (err)
1455 goto fail;
1456
1457 err = nilfs_sysfs_init();
1458 if (err)
1459 goto free_cachep;
1460
1461 err = register_filesystem(&nilfs_fs_type);
1462 if (err)
1463 goto deinit_sysfs_entry;
1464
1465 printk(KERN_INFO "NILFS version 2 loaded\n");
1466 return 0;
1467
1468deinit_sysfs_entry:
1469 nilfs_sysfs_exit();
1470free_cachep:
1471 nilfs_destroy_cachep();
1472fail:
1473 return err;
1474}
1475
1476static void __exit exit_nilfs_fs(void)
1477{
1478 nilfs_destroy_cachep();
1479 nilfs_sysfs_exit();
1480 unregister_filesystem(&nilfs_fs_type);
1481}
1482
1483module_init(init_nilfs_fs)
1484module_exit(exit_nilfs_fs)