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

source code of linux/fs/nilfs2/super.c