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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 * Written by Ryusuke Konishi.
17 */
18/*
19 * linux/fs/ext2/super.c
20 *
21 * Copyright (C) 1992, 1993, 1994, 1995
22 * Remy Card (card@masi.ibp.fr)
23 * Laboratoire MASI - Institut Blaise Pascal
24 * Universite Pierre et Marie Curie (Paris VI)
25 *
26 * from
27 *
28 * linux/fs/minix/inode.c
29 *
30 * Copyright (C) 1991, 1992 Linus Torvalds
31 *
32 * Big-endian to little-endian byte-swapping/bitmaps by
33 * David S. Miller (davem@caip.rutgers.edu), 1995
34 */
35
36#include <linux/module.h>
37#include <linux/string.h>
38#include <linux/slab.h>
39#include <linux/init.h>
40#include <linux/blkdev.h>
41#include <linux/parser.h>
42#include <linux/crc32.h>
43#include <linux/vfs.h>
44#include <linux/writeback.h>
45#include <linux/seq_file.h>
46#include <linux/mount.h>
47#include "nilfs.h"
48#include "export.h"
49#include "mdt.h"
50#include "alloc.h"
51#include "btree.h"
52#include "btnode.h"
53#include "page.h"
54#include "cpfile.h"
55#include "sufile.h" /* nilfs_sufile_resize(), nilfs_sufile_set_alloc_range() */
56#include "ifile.h"
57#include "dat.h"
58#include "segment.h"
59#include "segbuf.h"
60
61MODULE_AUTHOR("NTT Corp.");
62MODULE_DESCRIPTION("A New Implementation of the Log-structured Filesystem "
63 "(NILFS)");
64MODULE_LICENSE("GPL");
65
66static struct kmem_cache *nilfs_inode_cachep;
67struct kmem_cache *nilfs_transaction_cachep;
68struct kmem_cache *nilfs_segbuf_cachep;
69struct kmem_cache *nilfs_btree_path_cache;
70
71static int nilfs_setup_super(struct super_block *sb, int is_mount);
72static int nilfs_remount(struct super_block *sb, int *flags, char *data);
73
74void __nilfs_msg(struct super_block *sb, const char *level, const char *fmt,
75 ...)
76{
77 struct va_format vaf;
78 va_list args;
79
80 va_start(args, fmt);
81 vaf.fmt = fmt;
82 vaf.va = &args;
83 if (sb)
84 printk("%sNILFS (%s): %pV\n", level, sb->s_id, &vaf);
85 else
86 printk("%sNILFS: %pV\n", level, &vaf);
87 va_end(args);
88}
89
90static void nilfs_set_error(struct super_block *sb)
91{
92 struct the_nilfs *nilfs = sb->s_fs_info;
93 struct nilfs_super_block **sbp;
94
95 down_write(&nilfs->ns_sem);
96 if (!(nilfs->ns_mount_state & NILFS_ERROR_FS)) {
97 nilfs->ns_mount_state |= NILFS_ERROR_FS;
98 sbp = nilfs_prepare_super(sb, 0);
99 if (likely(sbp)) {
100 sbp[0]->s_state |= cpu_to_le16(NILFS_ERROR_FS);
101 if (sbp[1])
102 sbp[1]->s_state |= cpu_to_le16(NILFS_ERROR_FS);
103 nilfs_commit_super(sb, NILFS_SB_COMMIT_ALL);
104 }
105 }
106 up_write(&nilfs->ns_sem);
107}
108
109/**
110 * __nilfs_error() - report failure condition on a filesystem
111 *
112 * __nilfs_error() sets an ERROR_FS flag on the superblock as well as
113 * reporting an error message. This function should be called when
114 * NILFS detects incoherences or defects of meta data on disk.
115 *
116 * This implements the body of nilfs_error() macro. Normally,
117 * nilfs_error() should be used. As for sustainable errors such as a
118 * single-shot I/O error, nilfs_msg() should be used instead.
119 *
120 * Callers should not add a trailing newline since this will do it.
121 */
122void __nilfs_error(struct super_block *sb, const char *function,
123 const char *fmt, ...)
124{
125 struct the_nilfs *nilfs = sb->s_fs_info;
126 struct va_format vaf;
127 va_list args;
128
129 va_start(args, fmt);
130
131 vaf.fmt = fmt;
132 vaf.va = &args;
133
134 printk(KERN_CRIT "NILFS error (device %s): %s: %pV\n",
135 sb->s_id, function, &vaf);
136
137 va_end(args);
138
139 if (!sb_rdonly(sb)) {
140 nilfs_set_error(sb);
141
142 if (nilfs_test_opt(nilfs, ERRORS_RO)) {
143 printk(KERN_CRIT "Remounting filesystem read-only\n");
144 sb->s_flags |= SB_RDONLY;
145 }
146 }
147
148 if (nilfs_test_opt(nilfs, ERRORS_PANIC))
149 panic("NILFS (device %s): panic forced after error\n",
150 sb->s_id);
151}
152
153struct inode *nilfs_alloc_inode(struct super_block *sb)
154{
155 struct nilfs_inode_info *ii;
156
157 ii = kmem_cache_alloc(nilfs_inode_cachep, GFP_NOFS);
158 if (!ii)
159 return NULL;
160 ii->i_bh = NULL;
161 ii->i_state = 0;
162 ii->i_cno = 0;
163 nilfs_mapping_init(&ii->i_btnode_cache, &ii->vfs_inode);
164 return &ii->vfs_inode;
165}
166
167static void nilfs_i_callback(struct rcu_head *head)
168{
169 struct inode *inode = container_of(head, struct inode, i_rcu);
170
171 if (nilfs_is_metadata_file_inode(inode))
172 nilfs_mdt_destroy(inode);
173
174 kmem_cache_free(nilfs_inode_cachep, NILFS_I(inode));
175}
176
177void nilfs_destroy_inode(struct inode *inode)
178{
179 call_rcu(&inode->i_rcu, nilfs_i_callback);
180}
181
182static int nilfs_sync_super(struct super_block *sb, int flag)
183{
184 struct the_nilfs *nilfs = sb->s_fs_info;
185 int err;
186
187 retry:
188 set_buffer_dirty(nilfs->ns_sbh[0]);
189 if (nilfs_test_opt(nilfs, BARRIER)) {
190 err = __sync_dirty_buffer(nilfs->ns_sbh[0],
191 REQ_SYNC | REQ_PREFLUSH | REQ_FUA);
192 } else {
193 err = sync_dirty_buffer(nilfs->ns_sbh[0]);
194 }
195
196 if (unlikely(err)) {
197 nilfs_msg(sb, KERN_ERR, "unable to write superblock: err=%d",
198 err);
199 if (err == -EIO && nilfs->ns_sbh[1]) {
200 /*
201 * sbp[0] points to newer log than sbp[1],
202 * so copy sbp[0] to sbp[1] to take over sbp[0].
203 */
204 memcpy(nilfs->ns_sbp[1], nilfs->ns_sbp[0],
205 nilfs->ns_sbsize);
206 nilfs_fall_back_super_block(nilfs);
207 goto retry;
208 }
209 } else {
210 struct nilfs_super_block *sbp = nilfs->ns_sbp[0];
211
212 nilfs->ns_sbwcount++;
213
214 /*
215 * The latest segment becomes trailable from the position
216 * written in superblock.
217 */
218 clear_nilfs_discontinued(nilfs);
219
220 /* update GC protection for recent segments */
221 if (nilfs->ns_sbh[1]) {
222 if (flag == NILFS_SB_COMMIT_ALL) {
223 set_buffer_dirty(nilfs->ns_sbh[1]);
224 if (sync_dirty_buffer(nilfs->ns_sbh[1]) < 0)
225 goto out;
226 }
227 if (le64_to_cpu(nilfs->ns_sbp[1]->s_last_cno) <
228 le64_to_cpu(nilfs->ns_sbp[0]->s_last_cno))
229 sbp = nilfs->ns_sbp[1];
230 }
231
232 spin_lock(&nilfs->ns_last_segment_lock);
233 nilfs->ns_prot_seq = le64_to_cpu(sbp->s_last_seq);
234 spin_unlock(&nilfs->ns_last_segment_lock);
235 }
236 out:
237 return err;
238}
239
240void nilfs_set_log_cursor(struct nilfs_super_block *sbp,
241 struct the_nilfs *nilfs)
242{
243 sector_t nfreeblocks;
244
245 /* nilfs->ns_sem must be locked by the caller. */
246 nilfs_count_free_blocks(nilfs, &nfreeblocks);
247 sbp->s_free_blocks_count = cpu_to_le64(nfreeblocks);
248
249 spin_lock(&nilfs->ns_last_segment_lock);
250 sbp->s_last_seq = cpu_to_le64(nilfs->ns_last_seq);
251 sbp->s_last_pseg = cpu_to_le64(nilfs->ns_last_pseg);
252 sbp->s_last_cno = cpu_to_le64(nilfs->ns_last_cno);
253 spin_unlock(&nilfs->ns_last_segment_lock);
254}
255
256struct nilfs_super_block **nilfs_prepare_super(struct super_block *sb,
257 int flip)
258{
259 struct the_nilfs *nilfs = sb->s_fs_info;
260 struct nilfs_super_block **sbp = nilfs->ns_sbp;
261
262 /* nilfs->ns_sem must be locked by the caller. */
263 if (sbp[0]->s_magic != cpu_to_le16(NILFS_SUPER_MAGIC)) {
264 if (sbp[1] &&
265 sbp[1]->s_magic == cpu_to_le16(NILFS_SUPER_MAGIC)) {
266 memcpy(sbp[0], sbp[1], nilfs->ns_sbsize);
267 } else {
268 nilfs_msg(sb, KERN_CRIT, "superblock broke");
269 return NULL;
270 }
271 } else if (sbp[1] &&
272 sbp[1]->s_magic != cpu_to_le16(NILFS_SUPER_MAGIC)) {
273 memcpy(sbp[1], sbp[0], nilfs->ns_sbsize);
274 }
275
276 if (flip && sbp[1])
277 nilfs_swap_super_block(nilfs);
278
279 return sbp;
280}
281
282int nilfs_commit_super(struct super_block *sb, int flag)
283{
284 struct the_nilfs *nilfs = sb->s_fs_info;
285 struct nilfs_super_block **sbp = nilfs->ns_sbp;
286 time64_t t;
287
288 /* nilfs->ns_sem must be locked by the caller. */
289 t = ktime_get_real_seconds();
290 nilfs->ns_sbwtime = t;
291 sbp[0]->s_wtime = cpu_to_le64(t);
292 sbp[0]->s_sum = 0;
293 sbp[0]->s_sum = cpu_to_le32(crc32_le(nilfs->ns_crc_seed,
294 (unsigned char *)sbp[0],
295 nilfs->ns_sbsize));
296 if (flag == NILFS_SB_COMMIT_ALL && sbp[1]) {
297 sbp[1]->s_wtime = sbp[0]->s_wtime;
298 sbp[1]->s_sum = 0;
299 sbp[1]->s_sum = cpu_to_le32(crc32_le(nilfs->ns_crc_seed,
300 (unsigned char *)sbp[1],
301 nilfs->ns_sbsize));
302 }
303 clear_nilfs_sb_dirty(nilfs);
304 nilfs->ns_flushed_device = 1;
305 /* make sure store to ns_flushed_device cannot be reordered */
306 smp_wmb();
307 return nilfs_sync_super(sb, flag);
308}
309
310/**
311 * nilfs_cleanup_super() - write filesystem state for cleanup
312 * @sb: super block instance to be unmounted or degraded to read-only
313 *
314 * This function restores state flags in the on-disk super block.
315 * This will set "clean" flag (i.e. NILFS_VALID_FS) unless the
316 * filesystem was not clean previously.
317 */
318int nilfs_cleanup_super(struct super_block *sb)
319{
320 struct the_nilfs *nilfs = sb->s_fs_info;
321 struct nilfs_super_block **sbp;
322 int flag = NILFS_SB_COMMIT;
323 int ret = -EIO;
324
325 sbp = nilfs_prepare_super(sb, 0);
326 if (sbp) {
327 sbp[0]->s_state = cpu_to_le16(nilfs->ns_mount_state);
328 nilfs_set_log_cursor(sbp[0], nilfs);
329 if (sbp[1] && sbp[0]->s_last_cno == sbp[1]->s_last_cno) {
330 /*
331 * make the "clean" flag also to the opposite
332 * super block if both super blocks point to
333 * the same checkpoint.
334 */
335 sbp[1]->s_state = sbp[0]->s_state;
336 flag = NILFS_SB_COMMIT_ALL;
337 }
338 ret = nilfs_commit_super(sb, flag);
339 }
340 return ret;
341}
342
343/**
344 * nilfs_move_2nd_super - relocate secondary super block
345 * @sb: super block instance
346 * @sb2off: new offset of the secondary super block (in bytes)
347 */
348static int nilfs_move_2nd_super(struct super_block *sb, loff_t sb2off)
349{
350 struct the_nilfs *nilfs = sb->s_fs_info;
351 struct buffer_head *nsbh;
352 struct nilfs_super_block *nsbp;
353 sector_t blocknr, newblocknr;
354 unsigned long offset;
355 int sb2i; /* array index of the secondary superblock */
356 int ret = 0;
357
358 /* nilfs->ns_sem must be locked by the caller. */
359 if (nilfs->ns_sbh[1] &&
360 nilfs->ns_sbh[1]->b_blocknr > nilfs->ns_first_data_block) {
361 sb2i = 1;
362 blocknr = nilfs->ns_sbh[1]->b_blocknr;
363 } else if (nilfs->ns_sbh[0]->b_blocknr > nilfs->ns_first_data_block) {
364 sb2i = 0;
365 blocknr = nilfs->ns_sbh[0]->b_blocknr;
366 } else {
367 sb2i = -1;
368 blocknr = 0;
369 }
370 if (sb2i >= 0 && (u64)blocknr << nilfs->ns_blocksize_bits == sb2off)
371 goto out; /* super block location is unchanged */
372
373 /* Get new super block buffer */
374 newblocknr = sb2off >> nilfs->ns_blocksize_bits;
375 offset = sb2off & (nilfs->ns_blocksize - 1);
376 nsbh = sb_getblk(sb, newblocknr);
377 if (!nsbh) {
378 nilfs_msg(sb, KERN_WARNING,
379 "unable to move secondary superblock to block %llu",
380 (unsigned long long)newblocknr);
381 ret = -EIO;
382 goto out;
383 }
384 nsbp = (void *)nsbh->b_data + offset;
385 memset(nsbp, 0, nilfs->ns_blocksize);
386
387 if (sb2i >= 0) {
388 memcpy(nsbp, nilfs->ns_sbp[sb2i], nilfs->ns_sbsize);
389 brelse(nilfs->ns_sbh[sb2i]);
390 nilfs->ns_sbh[sb2i] = nsbh;
391 nilfs->ns_sbp[sb2i] = nsbp;
392 } else if (nilfs->ns_sbh[0]->b_blocknr < nilfs->ns_first_data_block) {
393 /* secondary super block will be restored to index 1 */
394 nilfs->ns_sbh[1] = nsbh;
395 nilfs->ns_sbp[1] = nsbp;
396 } else {
397 brelse(nsbh);
398 }
399out:
400 return ret;
401}
402
403/**
404 * nilfs_resize_fs - resize the filesystem
405 * @sb: super block instance
406 * @newsize: new size of the filesystem (in bytes)
407 */
408int nilfs_resize_fs(struct super_block *sb, __u64 newsize)
409{
410 struct the_nilfs *nilfs = sb->s_fs_info;
411 struct nilfs_super_block **sbp;
412 __u64 devsize, newnsegs;
413 loff_t sb2off;
414 int ret;
415
416 ret = -ERANGE;
417 devsize = i_size_read(sb->s_bdev->bd_inode);
418 if (newsize > devsize)
419 goto out;
420
421 /*
422 * Write lock is required to protect some functions depending
423 * on the number of segments, the number of reserved segments,
424 * and so forth.
425 */
426 down_write(&nilfs->ns_segctor_sem);
427
428 sb2off = NILFS_SB2_OFFSET_BYTES(newsize);
429 newnsegs = sb2off >> nilfs->ns_blocksize_bits;
430 do_div(newnsegs, nilfs->ns_blocks_per_segment);
431
432 ret = nilfs_sufile_resize(nilfs->ns_sufile, newnsegs);
433 up_write(&nilfs->ns_segctor_sem);
434 if (ret < 0)
435 goto out;
436
437 ret = nilfs_construct_segment(sb);
438 if (ret < 0)
439 goto out;
440
441 down_write(&nilfs->ns_sem);
442 nilfs_move_2nd_super(sb, sb2off);
443 ret = -EIO;
444 sbp = nilfs_prepare_super(sb, 0);
445 if (likely(sbp)) {
446 nilfs_set_log_cursor(sbp[0], nilfs);
447 /*
448 * Drop NILFS_RESIZE_FS flag for compatibility with
449 * mount-time resize which may be implemented in a
450 * future release.
451 */
452 sbp[0]->s_state = cpu_to_le16(le16_to_cpu(sbp[0]->s_state) &
453 ~NILFS_RESIZE_FS);
454 sbp[0]->s_dev_size = cpu_to_le64(newsize);
455 sbp[0]->s_nsegments = cpu_to_le64(nilfs->ns_nsegments);
456 if (sbp[1])
457 memcpy(sbp[1], sbp[0], nilfs->ns_sbsize);
458 ret = nilfs_commit_super(sb, NILFS_SB_COMMIT_ALL);
459 }
460 up_write(&nilfs->ns_sem);
461
462 /*
463 * Reset the range of allocatable segments last. This order
464 * is important in the case of expansion because the secondary
465 * superblock must be protected from log write until migration
466 * completes.
467 */
468 if (!ret)
469 nilfs_sufile_set_alloc_range(nilfs->ns_sufile, 0, newnsegs - 1);
470out:
471 return ret;
472}
473
474static void nilfs_put_super(struct super_block *sb)
475{
476 struct the_nilfs *nilfs = sb->s_fs_info;
477
478 nilfs_detach_log_writer(sb);
479
480 if (!sb_rdonly(sb)) {
481 down_write(&nilfs->ns_sem);
482 nilfs_cleanup_super(sb);
483 up_write(&nilfs->ns_sem);
484 }
485
486 iput(nilfs->ns_sufile);
487 iput(nilfs->ns_cpfile);
488 iput(nilfs->ns_dat);
489
490 destroy_nilfs(nilfs);
491 sb->s_fs_info = NULL;
492}
493
494static int nilfs_sync_fs(struct super_block *sb, int wait)
495{
496 struct the_nilfs *nilfs = sb->s_fs_info;
497 struct nilfs_super_block **sbp;
498 int err = 0;
499
500 /* This function is called when super block should be written back */
501 if (wait)
502 err = nilfs_construct_segment(sb);
503
504 down_write(&nilfs->ns_sem);
505 if (nilfs_sb_dirty(nilfs)) {
506 sbp = nilfs_prepare_super(sb, nilfs_sb_will_flip(nilfs));
507 if (likely(sbp)) {
508 nilfs_set_log_cursor(sbp[0], nilfs);
509 nilfs_commit_super(sb, NILFS_SB_COMMIT);
510 }
511 }
512 up_write(&nilfs->ns_sem);
513
514 if (!err)
515 err = nilfs_flush_device(nilfs);
516
517 return err;
518}
519
520int nilfs_attach_checkpoint(struct super_block *sb, __u64 cno, int curr_mnt,
521 struct nilfs_root **rootp)
522{
523 struct the_nilfs *nilfs = sb->s_fs_info;
524 struct nilfs_root *root;
525 struct nilfs_checkpoint *raw_cp;
526 struct buffer_head *bh_cp;
527 int err = -ENOMEM;
528
529 root = nilfs_find_or_create_root(
530 nilfs, curr_mnt ? NILFS_CPTREE_CURRENT_CNO : cno);
531 if (!root)
532 return err;
533
534 if (root->ifile)
535 goto reuse; /* already attached checkpoint */
536
537 down_read(&nilfs->ns_segctor_sem);
538 err = nilfs_cpfile_get_checkpoint(nilfs->ns_cpfile, cno, 0, &raw_cp,
539 &bh_cp);
540 up_read(&nilfs->ns_segctor_sem);
541 if (unlikely(err)) {
542 if (err == -ENOENT || err == -EINVAL) {
543 nilfs_msg(sb, KERN_ERR,
544 "Invalid checkpoint (checkpoint number=%llu)",
545 (unsigned long long)cno);
546 err = -EINVAL;
547 }
548 goto failed;
549 }
550
551 err = nilfs_ifile_read(sb, root, nilfs->ns_inode_size,
552 &raw_cp->cp_ifile_inode, &root->ifile);
553 if (err)
554 goto failed_bh;
555
556 atomic64_set(&root->inodes_count,
557 le64_to_cpu(raw_cp->cp_inodes_count));
558 atomic64_set(&root->blocks_count,
559 le64_to_cpu(raw_cp->cp_blocks_count));
560
561 nilfs_cpfile_put_checkpoint(nilfs->ns_cpfile, cno, bh_cp);
562
563 reuse:
564 *rootp = root;
565 return 0;
566
567 failed_bh:
568 nilfs_cpfile_put_checkpoint(nilfs->ns_cpfile, cno, bh_cp);
569 failed:
570 nilfs_put_root(root);
571
572 return err;
573}
574
575static int nilfs_freeze(struct super_block *sb)
576{
577 struct the_nilfs *nilfs = sb->s_fs_info;
578 int err;
579
580 if (sb_rdonly(sb))
581 return 0;
582
583 /* Mark super block clean */
584 down_write(&nilfs->ns_sem);
585 err = nilfs_cleanup_super(sb);
586 up_write(&nilfs->ns_sem);
587 return err;
588}
589
590static int nilfs_unfreeze(struct super_block *sb)
591{
592 struct the_nilfs *nilfs = sb->s_fs_info;
593
594 if (sb_rdonly(sb))
595 return 0;
596
597 down_write(&nilfs->ns_sem);
598 nilfs_setup_super(sb, false);
599 up_write(&nilfs->ns_sem);
600 return 0;
601}
602
603static int nilfs_statfs(struct dentry *dentry, struct kstatfs *buf)
604{
605 struct super_block *sb = dentry->d_sb;
606 struct nilfs_root *root = NILFS_I(d_inode(dentry))->i_root;
607 struct the_nilfs *nilfs = root->nilfs;
608 u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
609 unsigned long long blocks;
610 unsigned long overhead;
611 unsigned long nrsvblocks;
612 sector_t nfreeblocks;
613 u64 nmaxinodes, nfreeinodes;
614 int err;
615
616 /*
617 * Compute all of the segment blocks
618 *
619 * The blocks before first segment and after last segment
620 * are excluded.
621 */
622 blocks = nilfs->ns_blocks_per_segment * nilfs->ns_nsegments
623 - nilfs->ns_first_data_block;
624 nrsvblocks = nilfs->ns_nrsvsegs * nilfs->ns_blocks_per_segment;
625
626 /*
627 * Compute the overhead
628 *
629 * When distributing meta data blocks outside segment structure,
630 * We must count them as the overhead.
631 */
632 overhead = 0;
633
634 err = nilfs_count_free_blocks(nilfs, &nfreeblocks);
635 if (unlikely(err))
636 return err;
637
638 err = nilfs_ifile_count_free_inodes(root->ifile,
639 &nmaxinodes, &nfreeinodes);
640 if (unlikely(err)) {
641 nilfs_msg(sb, KERN_WARNING,
642 "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(&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.val[0] = (u32)id;
667 buf->f_fsid.val[1] = (u32)(id >> 32);
668
669 return 0;
670}
671
672static int nilfs_show_options(struct seq_file *seq, struct dentry *dentry)
673{
674 struct super_block *sb = dentry->d_sb;
675 struct the_nilfs *nilfs = sb->s_fs_info;
676 struct nilfs_root *root = NILFS_I(d_inode(dentry))->i_root;
677
678 if (!nilfs_test_opt(nilfs, BARRIER))
679 seq_puts(seq, ",nobarrier");
680 if (root->cno != NILFS_CPTREE_CURRENT_CNO)
681 seq_printf(seq, ",cp=%llu", (unsigned long long)root->cno);
682 if (nilfs_test_opt(nilfs, ERRORS_PANIC))
683 seq_puts(seq, ",errors=panic");
684 if (nilfs_test_opt(nilfs, ERRORS_CONT))
685 seq_puts(seq, ",errors=continue");
686 if (nilfs_test_opt(nilfs, STRICT_ORDER))
687 seq_puts(seq, ",order=strict");
688 if (nilfs_test_opt(nilfs, NORECOVERY))
689 seq_puts(seq, ",norecovery");
690 if (nilfs_test_opt(nilfs, DISCARD))
691 seq_puts(seq, ",discard");
692
693 return 0;
694}
695
696static const struct super_operations nilfs_sops = {
697 .alloc_inode = nilfs_alloc_inode,
698 .destroy_inode = nilfs_destroy_inode,
699 .dirty_inode = nilfs_dirty_inode,
700 .evict_inode = nilfs_evict_inode,
701 .put_super = nilfs_put_super,
702 .sync_fs = nilfs_sync_fs,
703 .freeze_fs = nilfs_freeze,
704 .unfreeze_fs = nilfs_unfreeze,
705 .statfs = nilfs_statfs,
706 .remount_fs = nilfs_remount,
707 .show_options = nilfs_show_options
708};
709
710enum {
711 Opt_err_cont, Opt_err_panic, Opt_err_ro,
712 Opt_barrier, Opt_nobarrier, Opt_snapshot, Opt_order, Opt_norecovery,
713 Opt_discard, Opt_nodiscard, Opt_err,
714};
715
716static match_table_t tokens = {
717 {Opt_err_cont, "errors=continue"},
718 {Opt_err_panic, "errors=panic"},
719 {Opt_err_ro, "errors=remount-ro"},
720 {Opt_barrier, "barrier"},
721 {Opt_nobarrier, "nobarrier"},
722 {Opt_snapshot, "cp=%u"},
723 {Opt_order, "order=%s"},
724 {Opt_norecovery, "norecovery"},
725 {Opt_discard, "discard"},
726 {Opt_nodiscard, "nodiscard"},
727 {Opt_err, NULL}
728};
729
730static int parse_options(char *options, struct super_block *sb, int is_remount)
731{
732 struct the_nilfs *nilfs = sb->s_fs_info;
733 char *p;
734 substring_t args[MAX_OPT_ARGS];
735
736 if (!options)
737 return 1;
738
739 while ((p = strsep(&options, ",")) != NULL) {
740 int token;
741
742 if (!*p)
743 continue;
744
745 token = match_token(p, tokens, args);
746 switch (token) {
747 case Opt_barrier:
748 nilfs_set_opt(nilfs, BARRIER);
749 break;
750 case Opt_nobarrier:
751 nilfs_clear_opt(nilfs, BARRIER);
752 break;
753 case Opt_order:
754 if (strcmp(args[0].from, "relaxed") == 0)
755 /* Ordered data semantics */
756 nilfs_clear_opt(nilfs, STRICT_ORDER);
757 else if (strcmp(args[0].from, "strict") == 0)
758 /* Strict in-order semantics */
759 nilfs_set_opt(nilfs, STRICT_ORDER);
760 else
761 return 0;
762 break;
763 case Opt_err_panic:
764 nilfs_write_opt(nilfs, ERROR_MODE, ERRORS_PANIC);
765 break;
766 case Opt_err_ro:
767 nilfs_write_opt(nilfs, ERROR_MODE, ERRORS_RO);
768 break;
769 case Opt_err_cont:
770 nilfs_write_opt(nilfs, ERROR_MODE, ERRORS_CONT);
771 break;
772 case Opt_snapshot:
773 if (is_remount) {
774 nilfs_msg(sb, KERN_ERR,
775 "\"%s\" option is invalid for remount",
776 p);
777 return 0;
778 }
779 break;
780 case Opt_norecovery:
781 nilfs_set_opt(nilfs, NORECOVERY);
782 break;
783 case Opt_discard:
784 nilfs_set_opt(nilfs, DISCARD);
785 break;
786 case Opt_nodiscard:
787 nilfs_clear_opt(nilfs, DISCARD);
788 break;
789 default:
790 nilfs_msg(sb, KERN_ERR,
791 "unrecognized mount option \"%s\"", p);
792 return 0;
793 }
794 }
795 return 1;
796}
797
798static inline void
799nilfs_set_default_options(struct super_block *sb,
800 struct nilfs_super_block *sbp)
801{
802 struct the_nilfs *nilfs = sb->s_fs_info;
803
804 nilfs->ns_mount_opt =
805 NILFS_MOUNT_ERRORS_RO | NILFS_MOUNT_BARRIER;
806}
807
808static int nilfs_setup_super(struct super_block *sb, int is_mount)
809{
810 struct the_nilfs *nilfs = sb->s_fs_info;
811 struct nilfs_super_block **sbp;
812 int max_mnt_count;
813 int mnt_count;
814
815 /* nilfs->ns_sem must be locked by the caller. */
816 sbp = nilfs_prepare_super(sb, 0);
817 if (!sbp)
818 return -EIO;
819
820 if (!is_mount)
821 goto skip_mount_setup;
822
823 max_mnt_count = le16_to_cpu(sbp[0]->s_max_mnt_count);
824 mnt_count = le16_to_cpu(sbp[0]->s_mnt_count);
825
826 if (nilfs->ns_mount_state & NILFS_ERROR_FS) {
827 nilfs_msg(sb, KERN_WARNING, "mounting fs with errors");
828#if 0
829 } else if (max_mnt_count >= 0 && mnt_count >= max_mnt_count) {
830 nilfs_msg(sb, KERN_WARNING, "maximal mount count reached");
831#endif
832 }
833 if (!max_mnt_count)
834 sbp[0]->s_max_mnt_count = cpu_to_le16(NILFS_DFL_MAX_MNT_COUNT);
835
836 sbp[0]->s_mnt_count = cpu_to_le16(mnt_count + 1);
837 sbp[0]->s_mtime = cpu_to_le64(get_seconds());
838
839skip_mount_setup:
840 sbp[0]->s_state =
841 cpu_to_le16(le16_to_cpu(sbp[0]->s_state) & ~NILFS_VALID_FS);
842 /* synchronize sbp[1] with sbp[0] */
843 if (sbp[1])
844 memcpy(sbp[1], sbp[0], nilfs->ns_sbsize);
845 return nilfs_commit_super(sb, NILFS_SB_COMMIT_ALL);
846}
847
848struct nilfs_super_block *nilfs_read_super_block(struct super_block *sb,
849 u64 pos, int blocksize,
850 struct buffer_head **pbh)
851{
852 unsigned long long sb_index = pos;
853 unsigned long offset;
854
855 offset = do_div(sb_index, blocksize);
856 *pbh = sb_bread(sb, sb_index);
857 if (!*pbh)
858 return NULL;
859 return (struct nilfs_super_block *)((char *)(*pbh)->b_data + offset);
860}
861
862int nilfs_store_magic_and_option(struct super_block *sb,
863 struct nilfs_super_block *sbp,
864 char *data)
865{
866 struct the_nilfs *nilfs = sb->s_fs_info;
867
868 sb->s_magic = le16_to_cpu(sbp->s_magic);
869
870 /* FS independent flags */
871#ifdef NILFS_ATIME_DISABLE
872 sb->s_flags |= SB_NOATIME;
873#endif
874
875 nilfs_set_default_options(sb, sbp);
876
877 nilfs->ns_resuid = le16_to_cpu(sbp->s_def_resuid);
878 nilfs->ns_resgid = le16_to_cpu(sbp->s_def_resgid);
879 nilfs->ns_interval = le32_to_cpu(sbp->s_c_interval);
880 nilfs->ns_watermark = le32_to_cpu(sbp->s_c_block_max);
881
882 return !parse_options(data, sb, 0) ? -EINVAL : 0;
883}
884
885int nilfs_check_feature_compatibility(struct super_block *sb,
886 struct nilfs_super_block *sbp)
887{
888 __u64 features;
889
890 features = le64_to_cpu(sbp->s_feature_incompat) &
891 ~NILFS_FEATURE_INCOMPAT_SUPP;
892 if (features) {
893 nilfs_msg(sb, KERN_ERR,
894 "couldn't mount because of unsupported optional features (%llx)",
895 (unsigned long long)features);
896 return -EINVAL;
897 }
898 features = le64_to_cpu(sbp->s_feature_compat_ro) &
899 ~NILFS_FEATURE_COMPAT_RO_SUPP;
900 if (!sb_rdonly(sb) && features) {
901 nilfs_msg(sb, KERN_ERR,
902 "couldn't mount RDWR because of unsupported optional features (%llx)",
903 (unsigned long long)features);
904 return -EINVAL;
905 }
906 return 0;
907}
908
909static int nilfs_get_root_dentry(struct super_block *sb,
910 struct nilfs_root *root,
911 struct dentry **root_dentry)
912{
913 struct inode *inode;
914 struct dentry *dentry;
915 int ret = 0;
916
917 inode = nilfs_iget(sb, root, NILFS_ROOT_INO);
918 if (IS_ERR(inode)) {
919 ret = PTR_ERR(inode);
920 nilfs_msg(sb, KERN_ERR, "error %d getting root inode", ret);
921 goto out;
922 }
923 if (!S_ISDIR(inode->i_mode) || !inode->i_blocks || !inode->i_size) {
924 iput(inode);
925 nilfs_msg(sb, KERN_ERR, "corrupt root inode");
926 ret = -EINVAL;
927 goto out;
928 }
929
930 if (root->cno == NILFS_CPTREE_CURRENT_CNO) {
931 dentry = d_find_alias(inode);
932 if (!dentry) {
933 dentry = d_make_root(inode);
934 if (!dentry) {
935 ret = -ENOMEM;
936 goto failed_dentry;
937 }
938 } else {
939 iput(inode);
940 }
941 } else {
942 dentry = d_obtain_root(inode);
943 if (IS_ERR(dentry)) {
944 ret = PTR_ERR(dentry);
945 goto failed_dentry;
946 }
947 }
948 *root_dentry = dentry;
949 out:
950 return ret;
951
952 failed_dentry:
953 nilfs_msg(sb, KERN_ERR, "error %d getting root dentry", ret);
954 goto out;
955}
956
957static int nilfs_attach_snapshot(struct super_block *s, __u64 cno,
958 struct dentry **root_dentry)
959{
960 struct the_nilfs *nilfs = s->s_fs_info;
961 struct nilfs_root *root;
962 int ret;
963
964 mutex_lock(&nilfs->ns_snapshot_mount_mutex);
965
966 down_read(&nilfs->ns_segctor_sem);
967 ret = nilfs_cpfile_is_snapshot(nilfs->ns_cpfile, cno);
968 up_read(&nilfs->ns_segctor_sem);
969 if (ret < 0) {
970 ret = (ret == -ENOENT) ? -EINVAL : ret;
971 goto out;
972 } else if (!ret) {
973 nilfs_msg(s, KERN_ERR,
974 "The specified checkpoint is not a snapshot (checkpoint number=%llu)",
975 (unsigned long long)cno);
976 ret = -EINVAL;
977 goto out;
978 }
979
980 ret = nilfs_attach_checkpoint(s, cno, false, &root);
981 if (ret) {
982 nilfs_msg(s, KERN_ERR,
983 "error %d while loading snapshot (checkpoint number=%llu)",
984 ret, (unsigned long long)cno);
985 goto out;
986 }
987 ret = nilfs_get_root_dentry(s, root, root_dentry);
988 nilfs_put_root(root);
989 out:
990 mutex_unlock(&nilfs->ns_snapshot_mount_mutex);
991 return ret;
992}
993
994/**
995 * nilfs_tree_is_busy() - try to shrink dentries of a checkpoint
996 * @root_dentry: root dentry of the tree to be shrunk
997 *
998 * This function returns true if the tree was in-use.
999 */
1000static bool nilfs_tree_is_busy(struct dentry *root_dentry)
1001{
1002 shrink_dcache_parent(root_dentry);
1003 return d_count(root_dentry) > 1;
1004}
1005
1006int nilfs_checkpoint_is_mounted(struct super_block *sb, __u64 cno)
1007{
1008 struct the_nilfs *nilfs = sb->s_fs_info;
1009 struct nilfs_root *root;
1010 struct inode *inode;
1011 struct dentry *dentry;
1012 int ret;
1013
1014 if (cno > nilfs->ns_cno)
1015 return false;
1016
1017 if (cno >= nilfs_last_cno(nilfs))
1018 return true; /* protect recent checkpoints */
1019
1020 ret = false;
1021 root = nilfs_lookup_root(nilfs, cno);
1022 if (root) {
1023 inode = nilfs_ilookup(sb, root, NILFS_ROOT_INO);
1024 if (inode) {
1025 dentry = d_find_alias(inode);
1026 if (dentry) {
1027 ret = nilfs_tree_is_busy(dentry);
1028 dput(dentry);
1029 }
1030 iput(inode);
1031 }
1032 nilfs_put_root(root);
1033 }
1034 return ret;
1035}
1036
1037/**
1038 * nilfs_fill_super() - initialize a super block instance
1039 * @sb: super_block
1040 * @data: mount options
1041 * @silent: silent mode flag
1042 *
1043 * This function is called exclusively by nilfs->ns_mount_mutex.
1044 * So, the recovery process is protected from other simultaneous mounts.
1045 */
1046static int
1047nilfs_fill_super(struct super_block *sb, void *data, int silent)
1048{
1049 struct the_nilfs *nilfs;
1050 struct nilfs_root *fsroot;
1051 __u64 cno;
1052 int err;
1053
1054 nilfs = alloc_nilfs(sb);
1055 if (!nilfs)
1056 return -ENOMEM;
1057
1058 sb->s_fs_info = nilfs;
1059
1060 err = init_nilfs(nilfs, sb, (char *)data);
1061 if (err)
1062 goto failed_nilfs;
1063
1064 sb->s_op = &nilfs_sops;
1065 sb->s_export_op = &nilfs_export_ops;
1066 sb->s_root = NULL;
1067 sb->s_time_gran = 1;
1068 sb->s_max_links = NILFS_LINK_MAX;
1069
1070 sb->s_bdi = bdi_get(sb->s_bdev->bd_bdi);
1071
1072 err = load_nilfs(nilfs, sb);
1073 if (err)
1074 goto failed_nilfs;
1075
1076 cno = nilfs_last_cno(nilfs);
1077 err = nilfs_attach_checkpoint(sb, cno, true, &fsroot);
1078 if (err) {
1079 nilfs_msg(sb, KERN_ERR,
1080 "error %d while loading last checkpoint (checkpoint number=%llu)",
1081 err, (unsigned long long)cno);
1082 goto failed_unload;
1083 }
1084
1085 if (!sb_rdonly(sb)) {
1086 err = nilfs_attach_log_writer(sb, fsroot);
1087 if (err)
1088 goto failed_checkpoint;
1089 }
1090
1091 err = nilfs_get_root_dentry(sb, fsroot, &sb->s_root);
1092 if (err)
1093 goto failed_segctor;
1094
1095 nilfs_put_root(fsroot);
1096
1097 if (!sb_rdonly(sb)) {
1098 down_write(&nilfs->ns_sem);
1099 nilfs_setup_super(sb, true);
1100 up_write(&nilfs->ns_sem);
1101 }
1102
1103 return 0;
1104
1105 failed_segctor:
1106 nilfs_detach_log_writer(sb);
1107
1108 failed_checkpoint:
1109 nilfs_put_root(fsroot);
1110
1111 failed_unload:
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_remount(struct super_block *sb, int *flags, char *data)
1122{
1123 struct the_nilfs *nilfs = sb->s_fs_info;
1124 unsigned long old_sb_flags;
1125 unsigned long old_mount_opt;
1126 int err;
1127
1128 sync_filesystem(sb);
1129 old_sb_flags = sb->s_flags;
1130 old_mount_opt = nilfs->ns_mount_opt;
1131
1132 if (!parse_options(data, sb, 1)) {
1133 err = -EINVAL;
1134 goto restore_opts;
1135 }
1136 sb->s_flags = (sb->s_flags & ~SB_POSIXACL);
1137
1138 err = -EINVAL;
1139
1140 if (!nilfs_valid_fs(nilfs)) {
1141 nilfs_msg(sb, KERN_WARNING,
1142 "couldn't remount because the filesystem is in an incomplete recovery state");
1143 goto restore_opts;
1144 }
1145
1146 if ((bool)(*flags & SB_RDONLY) == sb_rdonly(sb))
1147 goto out;
1148 if (*flags & SB_RDONLY) {
1149 /* Shutting down log writer */
1150 nilfs_detach_log_writer(sb);
1151 sb->s_flags |= SB_RDONLY;
1152
1153 /*
1154 * Remounting a valid RW partition RDONLY, so set
1155 * the RDONLY flag and then mark the partition as valid again.
1156 */
1157 down_write(&nilfs->ns_sem);
1158 nilfs_cleanup_super(sb);
1159 up_write(&nilfs->ns_sem);
1160 } else {
1161 __u64 features;
1162 struct nilfs_root *root;
1163
1164 /*
1165 * Mounting a RDONLY partition read-write, so reread and
1166 * store the current valid flag. (It may have been changed
1167 * by fsck since we originally mounted the partition.)
1168 */
1169 down_read(&nilfs->ns_sem);
1170 features = le64_to_cpu(nilfs->ns_sbp[0]->s_feature_compat_ro) &
1171 ~NILFS_FEATURE_COMPAT_RO_SUPP;
1172 up_read(&nilfs->ns_sem);
1173 if (features) {
1174 nilfs_msg(sb, KERN_WARNING,
1175 "couldn't remount RDWR because of unsupported optional features (%llx)",
1176 (unsigned long long)features);
1177 err = -EROFS;
1178 goto restore_opts;
1179 }
1180
1181 sb->s_flags &= ~SB_RDONLY;
1182
1183 root = NILFS_I(d_inode(sb->s_root))->i_root;
1184 err = nilfs_attach_log_writer(sb, root);
1185 if (err)
1186 goto restore_opts;
1187
1188 down_write(&nilfs->ns_sem);
1189 nilfs_setup_super(sb, true);
1190 up_write(&nilfs->ns_sem);
1191 }
1192 out:
1193 return 0;
1194
1195 restore_opts:
1196 sb->s_flags = old_sb_flags;
1197 nilfs->ns_mount_opt = old_mount_opt;
1198 return err;
1199}
1200
1201struct nilfs_super_data {
1202 struct block_device *bdev;
1203 __u64 cno;
1204 int flags;
1205};
1206
1207static int nilfs_parse_snapshot_option(const char *option,
1208 const substring_t *arg,
1209 struct nilfs_super_data *sd)
1210{
1211 unsigned long long val;
1212 const char *msg = NULL;
1213 int err;
1214
1215 if (!(sd->flags & SB_RDONLY)) {
1216 msg = "read-only option is not specified";
1217 goto parse_error;
1218 }
1219
1220 err = kstrtoull(arg->from, 0, &val);
1221 if (err) {
1222 if (err == -ERANGE)
1223 msg = "too large checkpoint number";
1224 else
1225 msg = "malformed argument";
1226 goto parse_error;
1227 } else if (val == 0) {
1228 msg = "invalid checkpoint number 0";
1229 goto parse_error;
1230 }
1231 sd->cno = val;
1232 return 0;
1233
1234parse_error:
1235 nilfs_msg(NULL, KERN_ERR, "invalid option \"%s\": %s", option, msg);
1236 return 1;
1237}
1238
1239/**
1240 * nilfs_identify - pre-read mount options needed to identify mount instance
1241 * @data: mount options
1242 * @sd: nilfs_super_data
1243 */
1244static int nilfs_identify(char *data, struct nilfs_super_data *sd)
1245{
1246 char *p, *options = data;
1247 substring_t args[MAX_OPT_ARGS];
1248 int token;
1249 int ret = 0;
1250
1251 do {
1252 p = strsep(&options, ",");
1253 if (p != NULL && *p) {
1254 token = match_token(p, tokens, args);
1255 if (token == Opt_snapshot)
1256 ret = nilfs_parse_snapshot_option(p, &args[0],
1257 sd);
1258 }
1259 if (!options)
1260 break;
1261 BUG_ON(options == data);
1262 *(options - 1) = ',';
1263 } while (!ret);
1264 return ret;
1265}
1266
1267static int nilfs_set_bdev_super(struct super_block *s, void *data)
1268{
1269 s->s_bdev = data;
1270 s->s_dev = s->s_bdev->bd_dev;
1271 return 0;
1272}
1273
1274static int nilfs_test_bdev_super(struct super_block *s, void *data)
1275{
1276 return (void *)s->s_bdev == data;
1277}
1278
1279static struct dentry *
1280nilfs_mount(struct file_system_type *fs_type, int flags,
1281 const char *dev_name, void *data)
1282{
1283 struct nilfs_super_data sd;
1284 struct super_block *s;
1285 fmode_t mode = FMODE_READ | FMODE_EXCL;
1286 struct dentry *root_dentry;
1287 int err, s_new = false;
1288
1289 if (!(flags & SB_RDONLY))
1290 mode |= FMODE_WRITE;
1291
1292 sd.bdev = blkdev_get_by_path(dev_name, mode, fs_type);
1293 if (IS_ERR(sd.bdev))
1294 return ERR_CAST(sd.bdev);
1295
1296 sd.cno = 0;
1297 sd.flags = flags;
1298 if (nilfs_identify((char *)data, &sd)) {
1299 err = -EINVAL;
1300 goto failed;
1301 }
1302
1303 /*
1304 * once the super is inserted into the list by sget, s_umount
1305 * will protect the lockfs code from trying to start a snapshot
1306 * while we are mounting
1307 */
1308 mutex_lock(&sd.bdev->bd_fsfreeze_mutex);
1309 if (sd.bdev->bd_fsfreeze_count > 0) {
1310 mutex_unlock(&sd.bdev->bd_fsfreeze_mutex);
1311 err = -EBUSY;
1312 goto failed;
1313 }
1314 s = sget(fs_type, nilfs_test_bdev_super, nilfs_set_bdev_super, flags,
1315 sd.bdev);
1316 mutex_unlock(&sd.bdev->bd_fsfreeze_mutex);
1317 if (IS_ERR(s)) {
1318 err = PTR_ERR(s);
1319 goto failed;
1320 }
1321
1322 if (!s->s_root) {
1323 s_new = true;
1324
1325 /* New superblock instance created */
1326 s->s_mode = mode;
1327 snprintf(s->s_id, sizeof(s->s_id), "%pg", sd.bdev);
1328 sb_set_blocksize(s, block_size(sd.bdev));
1329
1330 err = nilfs_fill_super(s, data, flags & SB_SILENT ? 1 : 0);
1331 if (err)
1332 goto failed_super;
1333
1334 s->s_flags |= SB_ACTIVE;
1335 } else if (!sd.cno) {
1336 if (nilfs_tree_is_busy(s->s_root)) {
1337 if ((flags ^ s->s_flags) & SB_RDONLY) {
1338 nilfs_msg(s, KERN_ERR,
1339 "the device already has a %s mount.",
1340 sb_rdonly(s) ? "read-only" : "read/write");
1341 err = -EBUSY;
1342 goto failed_super;
1343 }
1344 } else {
1345 /*
1346 * Try remount to setup mount states if the current
1347 * tree is not mounted and only snapshots use this sb.
1348 */
1349 err = nilfs_remount(s, &flags, data);
1350 if (err)
1351 goto failed_super;
1352 }
1353 }
1354
1355 if (sd.cno) {
1356 err = nilfs_attach_snapshot(s, sd.cno, &root_dentry);
1357 if (err)
1358 goto failed_super;
1359 } else {
1360 root_dentry = dget(s->s_root);
1361 }
1362
1363 if (!s_new)
1364 blkdev_put(sd.bdev, mode);
1365
1366 return root_dentry;
1367
1368 failed_super:
1369 deactivate_locked_super(s);
1370
1371 failed:
1372 if (!s_new)
1373 blkdev_put(sd.bdev, mode);
1374 return ERR_PTR(err);
1375}
1376
1377struct file_system_type nilfs_fs_type = {
1378 .owner = THIS_MODULE,
1379 .name = "nilfs2",
1380 .mount = nilfs_mount,
1381 .kill_sb = kill_block_super,
1382 .fs_flags = FS_REQUIRES_DEV,
1383};
1384MODULE_ALIAS_FS("nilfs2");
1385
1386static void nilfs_inode_init_once(void *obj)
1387{
1388 struct nilfs_inode_info *ii = obj;
1389
1390 INIT_LIST_HEAD(&ii->i_dirty);
1391#ifdef CONFIG_NILFS_XATTR
1392 init_rwsem(&ii->xattr_sem);
1393#endif
1394 address_space_init_once(&ii->i_btnode_cache);
1395 ii->i_bmap = &ii->i_bmap_data;
1396 inode_init_once(&ii->vfs_inode);
1397}
1398
1399static void nilfs_segbuf_init_once(void *obj)
1400{
1401 memset(obj, 0, sizeof(struct nilfs_segment_buffer));
1402}
1403
1404static void nilfs_destroy_cachep(void)
1405{
1406 /*
1407 * Make sure all delayed rcu free inodes are flushed before we
1408 * destroy cache.
1409 */
1410 rcu_barrier();
1411
1412 kmem_cache_destroy(nilfs_inode_cachep);
1413 kmem_cache_destroy(nilfs_transaction_cachep);
1414 kmem_cache_destroy(nilfs_segbuf_cachep);
1415 kmem_cache_destroy(nilfs_btree_path_cache);
1416}
1417
1418static int __init nilfs_init_cachep(void)
1419{
1420 nilfs_inode_cachep = kmem_cache_create("nilfs2_inode_cache",
1421 sizeof(struct nilfs_inode_info), 0,
1422 SLAB_RECLAIM_ACCOUNT|SLAB_ACCOUNT,
1423 nilfs_inode_init_once);
1424 if (!nilfs_inode_cachep)
1425 goto fail;
1426
1427 nilfs_transaction_cachep = kmem_cache_create("nilfs2_transaction_cache",
1428 sizeof(struct nilfs_transaction_info), 0,
1429 SLAB_RECLAIM_ACCOUNT, NULL);
1430 if (!nilfs_transaction_cachep)
1431 goto fail;
1432
1433 nilfs_segbuf_cachep = kmem_cache_create("nilfs2_segbuf_cache",
1434 sizeof(struct nilfs_segment_buffer), 0,
1435 SLAB_RECLAIM_ACCOUNT, nilfs_segbuf_init_once);
1436 if (!nilfs_segbuf_cachep)
1437 goto fail;
1438
1439 nilfs_btree_path_cache = kmem_cache_create("nilfs2_btree_path_cache",
1440 sizeof(struct nilfs_btree_path) * NILFS_BTREE_LEVEL_MAX,
1441 0, 0, NULL);
1442 if (!nilfs_btree_path_cache)
1443 goto fail;
1444
1445 return 0;
1446
1447fail:
1448 nilfs_destroy_cachep();
1449 return -ENOMEM;
1450}
1451
1452static int __init init_nilfs_fs(void)
1453{
1454 int err;
1455
1456 err = nilfs_init_cachep();
1457 if (err)
1458 goto fail;
1459
1460 err = nilfs_sysfs_init();
1461 if (err)
1462 goto free_cachep;
1463
1464 err = register_filesystem(&nilfs_fs_type);
1465 if (err)
1466 goto deinit_sysfs_entry;
1467
1468 printk(KERN_INFO "NILFS version 2 loaded\n");
1469 return 0;
1470
1471deinit_sysfs_entry:
1472 nilfs_sysfs_exit();
1473free_cachep:
1474 nilfs_destroy_cachep();
1475fail:
1476 return err;
1477}
1478
1479static void __exit exit_nilfs_fs(void)
1480{
1481 nilfs_destroy_cachep();
1482 nilfs_sysfs_exit();
1483 unregister_filesystem(&nilfs_fs_type);
1484}
1485
1486module_init(init_nilfs_fs)
1487module_exit(exit_nilfs_fs)
1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * super.c - 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 "nilfs.h"
39#include "export.h"
40#include "mdt.h"
41#include "alloc.h"
42#include "btree.h"
43#include "btnode.h"
44#include "page.h"
45#include "cpfile.h"
46#include "sufile.h" /* nilfs_sufile_resize(), nilfs_sufile_set_alloc_range() */
47#include "ifile.h"
48#include "dat.h"
49#include "segment.h"
50#include "segbuf.h"
51
52MODULE_AUTHOR("NTT Corp.");
53MODULE_DESCRIPTION("A New Implementation of the Log-structured Filesystem "
54 "(NILFS)");
55MODULE_LICENSE("GPL");
56
57static struct kmem_cache *nilfs_inode_cachep;
58struct kmem_cache *nilfs_transaction_cachep;
59struct kmem_cache *nilfs_segbuf_cachep;
60struct kmem_cache *nilfs_btree_path_cache;
61
62static int nilfs_setup_super(struct super_block *sb, int is_mount);
63static int nilfs_remount(struct super_block *sb, int *flags, char *data);
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 *
109 * __nilfs_error() sets an ERROR_FS flag on the superblock as well as
110 * reporting an error message. This function should be called when
111 * NILFS detects incoherences or defects of meta data on disk.
112 *
113 * This implements the body of nilfs_error() macro. Normally,
114 * nilfs_error() should be used. As for sustainable errors such as a
115 * single-shot I/O error, nilfs_err() should be used instead.
116 *
117 * Callers should not add a trailing newline since this will do it.
118 */
119void __nilfs_error(struct super_block *sb, const char *function,
120 const char *fmt, ...)
121{
122 struct the_nilfs *nilfs = sb->s_fs_info;
123 struct va_format vaf;
124 va_list args;
125
126 va_start(args, fmt);
127
128 vaf.fmt = fmt;
129 vaf.va = &args;
130
131 printk(KERN_CRIT "NILFS error (device %s): %s: %pV\n",
132 sb->s_id, function, &vaf);
133
134 va_end(args);
135
136 if (!sb_rdonly(sb)) {
137 nilfs_set_error(sb);
138
139 if (nilfs_test_opt(nilfs, ERRORS_RO)) {
140 printk(KERN_CRIT "Remounting filesystem read-only\n");
141 sb->s_flags |= SB_RDONLY;
142 }
143 }
144
145 if (nilfs_test_opt(nilfs, ERRORS_PANIC))
146 panic("NILFS (device %s): panic forced after error\n",
147 sb->s_id);
148}
149
150struct inode *nilfs_alloc_inode(struct super_block *sb)
151{
152 struct nilfs_inode_info *ii;
153
154 ii = kmem_cache_alloc(nilfs_inode_cachep, GFP_NOFS);
155 if (!ii)
156 return NULL;
157 ii->i_bh = NULL;
158 ii->i_state = 0;
159 ii->i_cno = 0;
160 nilfs_mapping_init(&ii->i_btnode_cache, &ii->vfs_inode);
161 return &ii->vfs_inode;
162}
163
164static void nilfs_free_inode(struct inode *inode)
165{
166 if (nilfs_is_metadata_file_inode(inode))
167 nilfs_mdt_destroy(inode);
168
169 kmem_cache_free(nilfs_inode_cachep, NILFS_I(inode));
170}
171
172static int nilfs_sync_super(struct super_block *sb, int flag)
173{
174 struct the_nilfs *nilfs = sb->s_fs_info;
175 int err;
176
177 retry:
178 set_buffer_dirty(nilfs->ns_sbh[0]);
179 if (nilfs_test_opt(nilfs, BARRIER)) {
180 err = __sync_dirty_buffer(nilfs->ns_sbh[0],
181 REQ_SYNC | REQ_PREFLUSH | REQ_FUA);
182 } else {
183 err = sync_dirty_buffer(nilfs->ns_sbh[0]);
184 }
185
186 if (unlikely(err)) {
187 nilfs_err(sb, "unable to write superblock: err=%d", err);
188 if (err == -EIO && nilfs->ns_sbh[1]) {
189 /*
190 * sbp[0] points to newer log than sbp[1],
191 * so copy sbp[0] to sbp[1] to take over sbp[0].
192 */
193 memcpy(nilfs->ns_sbp[1], nilfs->ns_sbp[0],
194 nilfs->ns_sbsize);
195 nilfs_fall_back_super_block(nilfs);
196 goto retry;
197 }
198 } else {
199 struct nilfs_super_block *sbp = nilfs->ns_sbp[0];
200
201 nilfs->ns_sbwcount++;
202
203 /*
204 * The latest segment becomes trailable from the position
205 * written in superblock.
206 */
207 clear_nilfs_discontinued(nilfs);
208
209 /* update GC protection for recent segments */
210 if (nilfs->ns_sbh[1]) {
211 if (flag == NILFS_SB_COMMIT_ALL) {
212 set_buffer_dirty(nilfs->ns_sbh[1]);
213 if (sync_dirty_buffer(nilfs->ns_sbh[1]) < 0)
214 goto out;
215 }
216 if (le64_to_cpu(nilfs->ns_sbp[1]->s_last_cno) <
217 le64_to_cpu(nilfs->ns_sbp[0]->s_last_cno))
218 sbp = nilfs->ns_sbp[1];
219 }
220
221 spin_lock(&nilfs->ns_last_segment_lock);
222 nilfs->ns_prot_seq = le64_to_cpu(sbp->s_last_seq);
223 spin_unlock(&nilfs->ns_last_segment_lock);
224 }
225 out:
226 return err;
227}
228
229void nilfs_set_log_cursor(struct nilfs_super_block *sbp,
230 struct the_nilfs *nilfs)
231{
232 sector_t nfreeblocks;
233
234 /* nilfs->ns_sem must be locked by the caller. */
235 nilfs_count_free_blocks(nilfs, &nfreeblocks);
236 sbp->s_free_blocks_count = cpu_to_le64(nfreeblocks);
237
238 spin_lock(&nilfs->ns_last_segment_lock);
239 sbp->s_last_seq = cpu_to_le64(nilfs->ns_last_seq);
240 sbp->s_last_pseg = cpu_to_le64(nilfs->ns_last_pseg);
241 sbp->s_last_cno = cpu_to_le64(nilfs->ns_last_cno);
242 spin_unlock(&nilfs->ns_last_segment_lock);
243}
244
245struct nilfs_super_block **nilfs_prepare_super(struct super_block *sb,
246 int flip)
247{
248 struct the_nilfs *nilfs = sb->s_fs_info;
249 struct nilfs_super_block **sbp = nilfs->ns_sbp;
250
251 /* nilfs->ns_sem must be locked by the caller. */
252 if (sbp[0]->s_magic != cpu_to_le16(NILFS_SUPER_MAGIC)) {
253 if (sbp[1] &&
254 sbp[1]->s_magic == cpu_to_le16(NILFS_SUPER_MAGIC)) {
255 memcpy(sbp[0], sbp[1], nilfs->ns_sbsize);
256 } else {
257 nilfs_crit(sb, "superblock broke");
258 return NULL;
259 }
260 } else if (sbp[1] &&
261 sbp[1]->s_magic != cpu_to_le16(NILFS_SUPER_MAGIC)) {
262 memcpy(sbp[1], sbp[0], nilfs->ns_sbsize);
263 }
264
265 if (flip && sbp[1])
266 nilfs_swap_super_block(nilfs);
267
268 return sbp;
269}
270
271int nilfs_commit_super(struct super_block *sb, int flag)
272{
273 struct the_nilfs *nilfs = sb->s_fs_info;
274 struct nilfs_super_block **sbp = nilfs->ns_sbp;
275 time64_t t;
276
277 /* nilfs->ns_sem must be locked by the caller. */
278 t = ktime_get_real_seconds();
279 nilfs->ns_sbwtime = t;
280 sbp[0]->s_wtime = cpu_to_le64(t);
281 sbp[0]->s_sum = 0;
282 sbp[0]->s_sum = cpu_to_le32(crc32_le(nilfs->ns_crc_seed,
283 (unsigned char *)sbp[0],
284 nilfs->ns_sbsize));
285 if (flag == NILFS_SB_COMMIT_ALL && sbp[1]) {
286 sbp[1]->s_wtime = sbp[0]->s_wtime;
287 sbp[1]->s_sum = 0;
288 sbp[1]->s_sum = cpu_to_le32(crc32_le(nilfs->ns_crc_seed,
289 (unsigned char *)sbp[1],
290 nilfs->ns_sbsize));
291 }
292 clear_nilfs_sb_dirty(nilfs);
293 nilfs->ns_flushed_device = 1;
294 /* make sure store to ns_flushed_device cannot be reordered */
295 smp_wmb();
296 return nilfs_sync_super(sb, flag);
297}
298
299/**
300 * nilfs_cleanup_super() - write filesystem state for cleanup
301 * @sb: super block instance to be unmounted or degraded to read-only
302 *
303 * This function restores state flags in the on-disk super block.
304 * This will set "clean" flag (i.e. NILFS_VALID_FS) unless the
305 * filesystem was not clean previously.
306 */
307int nilfs_cleanup_super(struct super_block *sb)
308{
309 struct the_nilfs *nilfs = sb->s_fs_info;
310 struct nilfs_super_block **sbp;
311 int flag = NILFS_SB_COMMIT;
312 int ret = -EIO;
313
314 sbp = nilfs_prepare_super(sb, 0);
315 if (sbp) {
316 sbp[0]->s_state = cpu_to_le16(nilfs->ns_mount_state);
317 nilfs_set_log_cursor(sbp[0], nilfs);
318 if (sbp[1] && sbp[0]->s_last_cno == sbp[1]->s_last_cno) {
319 /*
320 * make the "clean" flag also to the opposite
321 * super block if both super blocks point to
322 * the same checkpoint.
323 */
324 sbp[1]->s_state = sbp[0]->s_state;
325 flag = NILFS_SB_COMMIT_ALL;
326 }
327 ret = nilfs_commit_super(sb, flag);
328 }
329 return ret;
330}
331
332/**
333 * nilfs_move_2nd_super - relocate secondary super block
334 * @sb: super block instance
335 * @sb2off: new offset of the secondary super block (in bytes)
336 */
337static int nilfs_move_2nd_super(struct super_block *sb, loff_t sb2off)
338{
339 struct the_nilfs *nilfs = sb->s_fs_info;
340 struct buffer_head *nsbh;
341 struct nilfs_super_block *nsbp;
342 sector_t blocknr, newblocknr;
343 unsigned long offset;
344 int sb2i; /* array index of the secondary superblock */
345 int ret = 0;
346
347 /* nilfs->ns_sem must be locked by the caller. */
348 if (nilfs->ns_sbh[1] &&
349 nilfs->ns_sbh[1]->b_blocknr > nilfs->ns_first_data_block) {
350 sb2i = 1;
351 blocknr = nilfs->ns_sbh[1]->b_blocknr;
352 } else if (nilfs->ns_sbh[0]->b_blocknr > nilfs->ns_first_data_block) {
353 sb2i = 0;
354 blocknr = nilfs->ns_sbh[0]->b_blocknr;
355 } else {
356 sb2i = -1;
357 blocknr = 0;
358 }
359 if (sb2i >= 0 && (u64)blocknr << nilfs->ns_blocksize_bits == sb2off)
360 goto out; /* super block location is unchanged */
361
362 /* Get new super block buffer */
363 newblocknr = sb2off >> nilfs->ns_blocksize_bits;
364 offset = sb2off & (nilfs->ns_blocksize - 1);
365 nsbh = sb_getblk(sb, newblocknr);
366 if (!nsbh) {
367 nilfs_warn(sb,
368 "unable to move secondary superblock to block %llu",
369 (unsigned long long)newblocknr);
370 ret = -EIO;
371 goto out;
372 }
373 nsbp = (void *)nsbh->b_data + offset;
374 memset(nsbp, 0, nilfs->ns_blocksize);
375
376 if (sb2i >= 0) {
377 memcpy(nsbp, nilfs->ns_sbp[sb2i], nilfs->ns_sbsize);
378 brelse(nilfs->ns_sbh[sb2i]);
379 nilfs->ns_sbh[sb2i] = nsbh;
380 nilfs->ns_sbp[sb2i] = nsbp;
381 } else if (nilfs->ns_sbh[0]->b_blocknr < nilfs->ns_first_data_block) {
382 /* secondary super block will be restored to index 1 */
383 nilfs->ns_sbh[1] = nsbh;
384 nilfs->ns_sbp[1] = nsbp;
385 } else {
386 brelse(nsbh);
387 }
388out:
389 return ret;
390}
391
392/**
393 * nilfs_resize_fs - resize the filesystem
394 * @sb: super block instance
395 * @newsize: new size of the filesystem (in bytes)
396 */
397int nilfs_resize_fs(struct super_block *sb, __u64 newsize)
398{
399 struct the_nilfs *nilfs = sb->s_fs_info;
400 struct nilfs_super_block **sbp;
401 __u64 devsize, newnsegs;
402 loff_t sb2off;
403 int ret;
404
405 ret = -ERANGE;
406 devsize = i_size_read(sb->s_bdev->bd_inode);
407 if (newsize > devsize)
408 goto out;
409
410 /*
411 * Write lock is required to protect some functions depending
412 * on the number of segments, the number of reserved segments,
413 * and so forth.
414 */
415 down_write(&nilfs->ns_segctor_sem);
416
417 sb2off = NILFS_SB2_OFFSET_BYTES(newsize);
418 newnsegs = sb2off >> nilfs->ns_blocksize_bits;
419 do_div(newnsegs, nilfs->ns_blocks_per_segment);
420
421 ret = nilfs_sufile_resize(nilfs->ns_sufile, newnsegs);
422 up_write(&nilfs->ns_segctor_sem);
423 if (ret < 0)
424 goto out;
425
426 ret = nilfs_construct_segment(sb);
427 if (ret < 0)
428 goto out;
429
430 down_write(&nilfs->ns_sem);
431 nilfs_move_2nd_super(sb, sb2off);
432 ret = -EIO;
433 sbp = nilfs_prepare_super(sb, 0);
434 if (likely(sbp)) {
435 nilfs_set_log_cursor(sbp[0], nilfs);
436 /*
437 * Drop NILFS_RESIZE_FS flag for compatibility with
438 * mount-time resize which may be implemented in a
439 * future release.
440 */
441 sbp[0]->s_state = cpu_to_le16(le16_to_cpu(sbp[0]->s_state) &
442 ~NILFS_RESIZE_FS);
443 sbp[0]->s_dev_size = cpu_to_le64(newsize);
444 sbp[0]->s_nsegments = cpu_to_le64(nilfs->ns_nsegments);
445 if (sbp[1])
446 memcpy(sbp[1], sbp[0], nilfs->ns_sbsize);
447 ret = nilfs_commit_super(sb, NILFS_SB_COMMIT_ALL);
448 }
449 up_write(&nilfs->ns_sem);
450
451 /*
452 * Reset the range of allocatable segments last. This order
453 * is important in the case of expansion because the secondary
454 * superblock must be protected from log write until migration
455 * completes.
456 */
457 if (!ret)
458 nilfs_sufile_set_alloc_range(nilfs->ns_sufile, 0, newnsegs - 1);
459out:
460 return ret;
461}
462
463static void nilfs_put_super(struct super_block *sb)
464{
465 struct the_nilfs *nilfs = sb->s_fs_info;
466
467 nilfs_detach_log_writer(sb);
468
469 if (!sb_rdonly(sb)) {
470 down_write(&nilfs->ns_sem);
471 nilfs_cleanup_super(sb);
472 up_write(&nilfs->ns_sem);
473 }
474
475 iput(nilfs->ns_sufile);
476 iput(nilfs->ns_cpfile);
477 iput(nilfs->ns_dat);
478
479 destroy_nilfs(nilfs);
480 sb->s_fs_info = NULL;
481}
482
483static int nilfs_sync_fs(struct super_block *sb, int wait)
484{
485 struct the_nilfs *nilfs = sb->s_fs_info;
486 struct nilfs_super_block **sbp;
487 int err = 0;
488
489 /* This function is called when super block should be written back */
490 if (wait)
491 err = nilfs_construct_segment(sb);
492
493 down_write(&nilfs->ns_sem);
494 if (nilfs_sb_dirty(nilfs)) {
495 sbp = nilfs_prepare_super(sb, nilfs_sb_will_flip(nilfs));
496 if (likely(sbp)) {
497 nilfs_set_log_cursor(sbp[0], nilfs);
498 nilfs_commit_super(sb, NILFS_SB_COMMIT);
499 }
500 }
501 up_write(&nilfs->ns_sem);
502
503 if (!err)
504 err = nilfs_flush_device(nilfs);
505
506 return err;
507}
508
509int nilfs_attach_checkpoint(struct super_block *sb, __u64 cno, int curr_mnt,
510 struct nilfs_root **rootp)
511{
512 struct the_nilfs *nilfs = sb->s_fs_info;
513 struct nilfs_root *root;
514 struct nilfs_checkpoint *raw_cp;
515 struct buffer_head *bh_cp;
516 int err = -ENOMEM;
517
518 root = nilfs_find_or_create_root(
519 nilfs, curr_mnt ? NILFS_CPTREE_CURRENT_CNO : cno);
520 if (!root)
521 return err;
522
523 if (root->ifile)
524 goto reuse; /* already attached checkpoint */
525
526 down_read(&nilfs->ns_segctor_sem);
527 err = nilfs_cpfile_get_checkpoint(nilfs->ns_cpfile, cno, 0, &raw_cp,
528 &bh_cp);
529 up_read(&nilfs->ns_segctor_sem);
530 if (unlikely(err)) {
531 if (err == -ENOENT || err == -EINVAL) {
532 nilfs_err(sb,
533 "Invalid checkpoint (checkpoint number=%llu)",
534 (unsigned long long)cno);
535 err = -EINVAL;
536 }
537 goto failed;
538 }
539
540 err = nilfs_ifile_read(sb, root, nilfs->ns_inode_size,
541 &raw_cp->cp_ifile_inode, &root->ifile);
542 if (err)
543 goto failed_bh;
544
545 atomic64_set(&root->inodes_count,
546 le64_to_cpu(raw_cp->cp_inodes_count));
547 atomic64_set(&root->blocks_count,
548 le64_to_cpu(raw_cp->cp_blocks_count));
549
550 nilfs_cpfile_put_checkpoint(nilfs->ns_cpfile, cno, bh_cp);
551
552 reuse:
553 *rootp = root;
554 return 0;
555
556 failed_bh:
557 nilfs_cpfile_put_checkpoint(nilfs->ns_cpfile, cno, bh_cp);
558 failed:
559 nilfs_put_root(root);
560
561 return err;
562}
563
564static int nilfs_freeze(struct super_block *sb)
565{
566 struct the_nilfs *nilfs = sb->s_fs_info;
567 int err;
568
569 if (sb_rdonly(sb))
570 return 0;
571
572 /* Mark super block clean */
573 down_write(&nilfs->ns_sem);
574 err = nilfs_cleanup_super(sb);
575 up_write(&nilfs->ns_sem);
576 return err;
577}
578
579static int nilfs_unfreeze(struct super_block *sb)
580{
581 struct the_nilfs *nilfs = sb->s_fs_info;
582
583 if (sb_rdonly(sb))
584 return 0;
585
586 down_write(&nilfs->ns_sem);
587 nilfs_setup_super(sb, false);
588 up_write(&nilfs->ns_sem);
589 return 0;
590}
591
592static int nilfs_statfs(struct dentry *dentry, struct kstatfs *buf)
593{
594 struct super_block *sb = dentry->d_sb;
595 struct nilfs_root *root = NILFS_I(d_inode(dentry))->i_root;
596 struct the_nilfs *nilfs = root->nilfs;
597 u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
598 unsigned long long blocks;
599 unsigned long overhead;
600 unsigned long nrsvblocks;
601 sector_t nfreeblocks;
602 u64 nmaxinodes, nfreeinodes;
603 int err;
604
605 /*
606 * Compute all of the segment blocks
607 *
608 * The blocks before first segment and after last segment
609 * are excluded.
610 */
611 blocks = nilfs->ns_blocks_per_segment * nilfs->ns_nsegments
612 - nilfs->ns_first_data_block;
613 nrsvblocks = nilfs->ns_nrsvsegs * nilfs->ns_blocks_per_segment;
614
615 /*
616 * Compute the overhead
617 *
618 * When distributing meta data blocks outside segment structure,
619 * We must count them as the overhead.
620 */
621 overhead = 0;
622
623 err = nilfs_count_free_blocks(nilfs, &nfreeblocks);
624 if (unlikely(err))
625 return err;
626
627 err = nilfs_ifile_count_free_inodes(root->ifile,
628 &nmaxinodes, &nfreeinodes);
629 if (unlikely(err)) {
630 nilfs_warn(sb, "failed to count free inodes: err=%d", err);
631 if (err == -ERANGE) {
632 /*
633 * If nilfs_palloc_count_max_entries() returns
634 * -ERANGE error code then we simply treat
635 * curent inodes count as maximum possible and
636 * zero as free inodes value.
637 */
638 nmaxinodes = atomic64_read(&root->inodes_count);
639 nfreeinodes = 0;
640 err = 0;
641 } else
642 return err;
643 }
644
645 buf->f_type = NILFS_SUPER_MAGIC;
646 buf->f_bsize = sb->s_blocksize;
647 buf->f_blocks = blocks - overhead;
648 buf->f_bfree = nfreeblocks;
649 buf->f_bavail = (buf->f_bfree >= nrsvblocks) ?
650 (buf->f_bfree - nrsvblocks) : 0;
651 buf->f_files = nmaxinodes;
652 buf->f_ffree = nfreeinodes;
653 buf->f_namelen = NILFS_NAME_LEN;
654 buf->f_fsid.val[0] = (u32)id;
655 buf->f_fsid.val[1] = (u32)(id >> 32);
656
657 return 0;
658}
659
660static int nilfs_show_options(struct seq_file *seq, struct dentry *dentry)
661{
662 struct super_block *sb = dentry->d_sb;
663 struct the_nilfs *nilfs = sb->s_fs_info;
664 struct nilfs_root *root = NILFS_I(d_inode(dentry))->i_root;
665
666 if (!nilfs_test_opt(nilfs, BARRIER))
667 seq_puts(seq, ",nobarrier");
668 if (root->cno != NILFS_CPTREE_CURRENT_CNO)
669 seq_printf(seq, ",cp=%llu", (unsigned long long)root->cno);
670 if (nilfs_test_opt(nilfs, ERRORS_PANIC))
671 seq_puts(seq, ",errors=panic");
672 if (nilfs_test_opt(nilfs, ERRORS_CONT))
673 seq_puts(seq, ",errors=continue");
674 if (nilfs_test_opt(nilfs, STRICT_ORDER))
675 seq_puts(seq, ",order=strict");
676 if (nilfs_test_opt(nilfs, NORECOVERY))
677 seq_puts(seq, ",norecovery");
678 if (nilfs_test_opt(nilfs, DISCARD))
679 seq_puts(seq, ",discard");
680
681 return 0;
682}
683
684static const struct super_operations nilfs_sops = {
685 .alloc_inode = nilfs_alloc_inode,
686 .free_inode = nilfs_free_inode,
687 .dirty_inode = nilfs_dirty_inode,
688 .evict_inode = nilfs_evict_inode,
689 .put_super = nilfs_put_super,
690 .sync_fs = nilfs_sync_fs,
691 .freeze_fs = nilfs_freeze,
692 .unfreeze_fs = nilfs_unfreeze,
693 .statfs = nilfs_statfs,
694 .remount_fs = nilfs_remount,
695 .show_options = nilfs_show_options
696};
697
698enum {
699 Opt_err_cont, Opt_err_panic, Opt_err_ro,
700 Opt_barrier, Opt_nobarrier, Opt_snapshot, Opt_order, Opt_norecovery,
701 Opt_discard, Opt_nodiscard, Opt_err,
702};
703
704static match_table_t tokens = {
705 {Opt_err_cont, "errors=continue"},
706 {Opt_err_panic, "errors=panic"},
707 {Opt_err_ro, "errors=remount-ro"},
708 {Opt_barrier, "barrier"},
709 {Opt_nobarrier, "nobarrier"},
710 {Opt_snapshot, "cp=%u"},
711 {Opt_order, "order=%s"},
712 {Opt_norecovery, "norecovery"},
713 {Opt_discard, "discard"},
714 {Opt_nodiscard, "nodiscard"},
715 {Opt_err, NULL}
716};
717
718static int parse_options(char *options, struct super_block *sb, int is_remount)
719{
720 struct the_nilfs *nilfs = sb->s_fs_info;
721 char *p;
722 substring_t args[MAX_OPT_ARGS];
723
724 if (!options)
725 return 1;
726
727 while ((p = strsep(&options, ",")) != NULL) {
728 int token;
729
730 if (!*p)
731 continue;
732
733 token = match_token(p, tokens, args);
734 switch (token) {
735 case Opt_barrier:
736 nilfs_set_opt(nilfs, BARRIER);
737 break;
738 case Opt_nobarrier:
739 nilfs_clear_opt(nilfs, BARRIER);
740 break;
741 case Opt_order:
742 if (strcmp(args[0].from, "relaxed") == 0)
743 /* Ordered data semantics */
744 nilfs_clear_opt(nilfs, STRICT_ORDER);
745 else if (strcmp(args[0].from, "strict") == 0)
746 /* Strict in-order semantics */
747 nilfs_set_opt(nilfs, STRICT_ORDER);
748 else
749 return 0;
750 break;
751 case Opt_err_panic:
752 nilfs_write_opt(nilfs, ERROR_MODE, ERRORS_PANIC);
753 break;
754 case Opt_err_ro:
755 nilfs_write_opt(nilfs, ERROR_MODE, ERRORS_RO);
756 break;
757 case Opt_err_cont:
758 nilfs_write_opt(nilfs, ERROR_MODE, ERRORS_CONT);
759 break;
760 case Opt_snapshot:
761 if (is_remount) {
762 nilfs_err(sb,
763 "\"%s\" option is invalid for remount",
764 p);
765 return 0;
766 }
767 break;
768 case Opt_norecovery:
769 nilfs_set_opt(nilfs, NORECOVERY);
770 break;
771 case Opt_discard:
772 nilfs_set_opt(nilfs, DISCARD);
773 break;
774 case Opt_nodiscard:
775 nilfs_clear_opt(nilfs, DISCARD);
776 break;
777 default:
778 nilfs_err(sb, "unrecognized mount option \"%s\"", p);
779 return 0;
780 }
781 }
782 return 1;
783}
784
785static inline void
786nilfs_set_default_options(struct super_block *sb,
787 struct nilfs_super_block *sbp)
788{
789 struct the_nilfs *nilfs = sb->s_fs_info;
790
791 nilfs->ns_mount_opt =
792 NILFS_MOUNT_ERRORS_RO | NILFS_MOUNT_BARRIER;
793}
794
795static int nilfs_setup_super(struct super_block *sb, int is_mount)
796{
797 struct the_nilfs *nilfs = sb->s_fs_info;
798 struct nilfs_super_block **sbp;
799 int max_mnt_count;
800 int mnt_count;
801
802 /* nilfs->ns_sem must be locked by the caller. */
803 sbp = nilfs_prepare_super(sb, 0);
804 if (!sbp)
805 return -EIO;
806
807 if (!is_mount)
808 goto skip_mount_setup;
809
810 max_mnt_count = le16_to_cpu(sbp[0]->s_max_mnt_count);
811 mnt_count = le16_to_cpu(sbp[0]->s_mnt_count);
812
813 if (nilfs->ns_mount_state & NILFS_ERROR_FS) {
814 nilfs_warn(sb, "mounting fs with errors");
815#if 0
816 } else if (max_mnt_count >= 0 && mnt_count >= max_mnt_count) {
817 nilfs_warn(sb, "maximal mount count reached");
818#endif
819 }
820 if (!max_mnt_count)
821 sbp[0]->s_max_mnt_count = cpu_to_le16(NILFS_DFL_MAX_MNT_COUNT);
822
823 sbp[0]->s_mnt_count = cpu_to_le16(mnt_count + 1);
824 sbp[0]->s_mtime = cpu_to_le64(ktime_get_real_seconds());
825
826skip_mount_setup:
827 sbp[0]->s_state =
828 cpu_to_le16(le16_to_cpu(sbp[0]->s_state) & ~NILFS_VALID_FS);
829 /* synchronize sbp[1] with sbp[0] */
830 if (sbp[1])
831 memcpy(sbp[1], sbp[0], nilfs->ns_sbsize);
832 return nilfs_commit_super(sb, NILFS_SB_COMMIT_ALL);
833}
834
835struct nilfs_super_block *nilfs_read_super_block(struct super_block *sb,
836 u64 pos, int blocksize,
837 struct buffer_head **pbh)
838{
839 unsigned long long sb_index = pos;
840 unsigned long offset;
841
842 offset = do_div(sb_index, blocksize);
843 *pbh = sb_bread(sb, sb_index);
844 if (!*pbh)
845 return NULL;
846 return (struct nilfs_super_block *)((char *)(*pbh)->b_data + offset);
847}
848
849int nilfs_store_magic_and_option(struct super_block *sb,
850 struct nilfs_super_block *sbp,
851 char *data)
852{
853 struct the_nilfs *nilfs = sb->s_fs_info;
854
855 sb->s_magic = le16_to_cpu(sbp->s_magic);
856
857 /* FS independent flags */
858#ifdef NILFS_ATIME_DISABLE
859 sb->s_flags |= SB_NOATIME;
860#endif
861
862 nilfs_set_default_options(sb, sbp);
863
864 nilfs->ns_resuid = le16_to_cpu(sbp->s_def_resuid);
865 nilfs->ns_resgid = le16_to_cpu(sbp->s_def_resgid);
866 nilfs->ns_interval = le32_to_cpu(sbp->s_c_interval);
867 nilfs->ns_watermark = le32_to_cpu(sbp->s_c_block_max);
868
869 return !parse_options(data, sb, 0) ? -EINVAL : 0;
870}
871
872int nilfs_check_feature_compatibility(struct super_block *sb,
873 struct nilfs_super_block *sbp)
874{
875 __u64 features;
876
877 features = le64_to_cpu(sbp->s_feature_incompat) &
878 ~NILFS_FEATURE_INCOMPAT_SUPP;
879 if (features) {
880 nilfs_err(sb,
881 "couldn't mount because of unsupported optional features (%llx)",
882 (unsigned long long)features);
883 return -EINVAL;
884 }
885 features = le64_to_cpu(sbp->s_feature_compat_ro) &
886 ~NILFS_FEATURE_COMPAT_RO_SUPP;
887 if (!sb_rdonly(sb) && features) {
888 nilfs_err(sb,
889 "couldn't mount RDWR because of unsupported optional features (%llx)",
890 (unsigned long long)features);
891 return -EINVAL;
892 }
893 return 0;
894}
895
896static int nilfs_get_root_dentry(struct super_block *sb,
897 struct nilfs_root *root,
898 struct dentry **root_dentry)
899{
900 struct inode *inode;
901 struct dentry *dentry;
902 int ret = 0;
903
904 inode = nilfs_iget(sb, root, NILFS_ROOT_INO);
905 if (IS_ERR(inode)) {
906 ret = PTR_ERR(inode);
907 nilfs_err(sb, "error %d getting root inode", ret);
908 goto out;
909 }
910 if (!S_ISDIR(inode->i_mode) || !inode->i_blocks || !inode->i_size) {
911 iput(inode);
912 nilfs_err(sb, "corrupt root inode");
913 ret = -EINVAL;
914 goto out;
915 }
916
917 if (root->cno == NILFS_CPTREE_CURRENT_CNO) {
918 dentry = d_find_alias(inode);
919 if (!dentry) {
920 dentry = d_make_root(inode);
921 if (!dentry) {
922 ret = -ENOMEM;
923 goto failed_dentry;
924 }
925 } else {
926 iput(inode);
927 }
928 } else {
929 dentry = d_obtain_root(inode);
930 if (IS_ERR(dentry)) {
931 ret = PTR_ERR(dentry);
932 goto failed_dentry;
933 }
934 }
935 *root_dentry = dentry;
936 out:
937 return ret;
938
939 failed_dentry:
940 nilfs_err(sb, "error %d getting root dentry", ret);
941 goto out;
942}
943
944static int nilfs_attach_snapshot(struct super_block *s, __u64 cno,
945 struct dentry **root_dentry)
946{
947 struct the_nilfs *nilfs = s->s_fs_info;
948 struct nilfs_root *root;
949 int ret;
950
951 mutex_lock(&nilfs->ns_snapshot_mount_mutex);
952
953 down_read(&nilfs->ns_segctor_sem);
954 ret = nilfs_cpfile_is_snapshot(nilfs->ns_cpfile, cno);
955 up_read(&nilfs->ns_segctor_sem);
956 if (ret < 0) {
957 ret = (ret == -ENOENT) ? -EINVAL : ret;
958 goto out;
959 } else if (!ret) {
960 nilfs_err(s,
961 "The specified checkpoint is not a snapshot (checkpoint number=%llu)",
962 (unsigned long long)cno);
963 ret = -EINVAL;
964 goto out;
965 }
966
967 ret = nilfs_attach_checkpoint(s, cno, false, &root);
968 if (ret) {
969 nilfs_err(s,
970 "error %d while loading snapshot (checkpoint number=%llu)",
971 ret, (unsigned long long)cno);
972 goto out;
973 }
974 ret = nilfs_get_root_dentry(s, root, root_dentry);
975 nilfs_put_root(root);
976 out:
977 mutex_unlock(&nilfs->ns_snapshot_mount_mutex);
978 return ret;
979}
980
981/**
982 * nilfs_tree_is_busy() - try to shrink dentries of a checkpoint
983 * @root_dentry: root dentry of the tree to be shrunk
984 *
985 * This function returns true if the tree was in-use.
986 */
987static bool nilfs_tree_is_busy(struct dentry *root_dentry)
988{
989 shrink_dcache_parent(root_dentry);
990 return d_count(root_dentry) > 1;
991}
992
993int nilfs_checkpoint_is_mounted(struct super_block *sb, __u64 cno)
994{
995 struct the_nilfs *nilfs = sb->s_fs_info;
996 struct nilfs_root *root;
997 struct inode *inode;
998 struct dentry *dentry;
999 int ret;
1000
1001 if (cno > nilfs->ns_cno)
1002 return false;
1003
1004 if (cno >= nilfs_last_cno(nilfs))
1005 return true; /* protect recent checkpoints */
1006
1007 ret = false;
1008 root = nilfs_lookup_root(nilfs, cno);
1009 if (root) {
1010 inode = nilfs_ilookup(sb, root, NILFS_ROOT_INO);
1011 if (inode) {
1012 dentry = d_find_alias(inode);
1013 if (dentry) {
1014 ret = nilfs_tree_is_busy(dentry);
1015 dput(dentry);
1016 }
1017 iput(inode);
1018 }
1019 nilfs_put_root(root);
1020 }
1021 return ret;
1022}
1023
1024/**
1025 * nilfs_fill_super() - initialize a super block instance
1026 * @sb: super_block
1027 * @data: mount options
1028 * @silent: silent mode flag
1029 *
1030 * This function is called exclusively by nilfs->ns_mount_mutex.
1031 * So, the recovery process is protected from other simultaneous mounts.
1032 */
1033static int
1034nilfs_fill_super(struct super_block *sb, void *data, int silent)
1035{
1036 struct the_nilfs *nilfs;
1037 struct nilfs_root *fsroot;
1038 __u64 cno;
1039 int err;
1040
1041 nilfs = alloc_nilfs(sb);
1042 if (!nilfs)
1043 return -ENOMEM;
1044
1045 sb->s_fs_info = nilfs;
1046
1047 err = init_nilfs(nilfs, sb, (char *)data);
1048 if (err)
1049 goto failed_nilfs;
1050
1051 sb->s_op = &nilfs_sops;
1052 sb->s_export_op = &nilfs_export_ops;
1053 sb->s_root = NULL;
1054 sb->s_time_gran = 1;
1055 sb->s_max_links = NILFS_LINK_MAX;
1056
1057 sb->s_bdi = bdi_get(sb->s_bdev->bd_bdi);
1058
1059 err = load_nilfs(nilfs, sb);
1060 if (err)
1061 goto failed_nilfs;
1062
1063 cno = nilfs_last_cno(nilfs);
1064 err = nilfs_attach_checkpoint(sb, cno, true, &fsroot);
1065 if (err) {
1066 nilfs_err(sb,
1067 "error %d while loading last checkpoint (checkpoint number=%llu)",
1068 err, (unsigned long long)cno);
1069 goto failed_unload;
1070 }
1071
1072 if (!sb_rdonly(sb)) {
1073 err = nilfs_attach_log_writer(sb, fsroot);
1074 if (err)
1075 goto failed_checkpoint;
1076 }
1077
1078 err = nilfs_get_root_dentry(sb, fsroot, &sb->s_root);
1079 if (err)
1080 goto failed_segctor;
1081
1082 nilfs_put_root(fsroot);
1083
1084 if (!sb_rdonly(sb)) {
1085 down_write(&nilfs->ns_sem);
1086 nilfs_setup_super(sb, true);
1087 up_write(&nilfs->ns_sem);
1088 }
1089
1090 return 0;
1091
1092 failed_segctor:
1093 nilfs_detach_log_writer(sb);
1094
1095 failed_checkpoint:
1096 nilfs_put_root(fsroot);
1097
1098 failed_unload:
1099 iput(nilfs->ns_sufile);
1100 iput(nilfs->ns_cpfile);
1101 iput(nilfs->ns_dat);
1102
1103 failed_nilfs:
1104 destroy_nilfs(nilfs);
1105 return err;
1106}
1107
1108static int nilfs_remount(struct super_block *sb, int *flags, char *data)
1109{
1110 struct the_nilfs *nilfs = sb->s_fs_info;
1111 unsigned long old_sb_flags;
1112 unsigned long old_mount_opt;
1113 int err;
1114
1115 sync_filesystem(sb);
1116 old_sb_flags = sb->s_flags;
1117 old_mount_opt = nilfs->ns_mount_opt;
1118
1119 if (!parse_options(data, sb, 1)) {
1120 err = -EINVAL;
1121 goto restore_opts;
1122 }
1123 sb->s_flags = (sb->s_flags & ~SB_POSIXACL);
1124
1125 err = -EINVAL;
1126
1127 if (!nilfs_valid_fs(nilfs)) {
1128 nilfs_warn(sb,
1129 "couldn't remount because the filesystem is in an incomplete recovery state");
1130 goto restore_opts;
1131 }
1132
1133 if ((bool)(*flags & SB_RDONLY) == sb_rdonly(sb))
1134 goto out;
1135 if (*flags & SB_RDONLY) {
1136 /* Shutting down log writer */
1137 nilfs_detach_log_writer(sb);
1138 sb->s_flags |= SB_RDONLY;
1139
1140 /*
1141 * Remounting a valid RW partition RDONLY, so set
1142 * the RDONLY flag and then mark the partition as valid again.
1143 */
1144 down_write(&nilfs->ns_sem);
1145 nilfs_cleanup_super(sb);
1146 up_write(&nilfs->ns_sem);
1147 } else {
1148 __u64 features;
1149 struct nilfs_root *root;
1150
1151 /*
1152 * Mounting a RDONLY partition read-write, so reread and
1153 * store the current valid flag. (It may have been changed
1154 * by fsck since we originally mounted the partition.)
1155 */
1156 down_read(&nilfs->ns_sem);
1157 features = le64_to_cpu(nilfs->ns_sbp[0]->s_feature_compat_ro) &
1158 ~NILFS_FEATURE_COMPAT_RO_SUPP;
1159 up_read(&nilfs->ns_sem);
1160 if (features) {
1161 nilfs_warn(sb,
1162 "couldn't remount RDWR because of unsupported optional features (%llx)",
1163 (unsigned long long)features);
1164 err = -EROFS;
1165 goto restore_opts;
1166 }
1167
1168 sb->s_flags &= ~SB_RDONLY;
1169
1170 root = NILFS_I(d_inode(sb->s_root))->i_root;
1171 err = nilfs_attach_log_writer(sb, root);
1172 if (err)
1173 goto restore_opts;
1174
1175 down_write(&nilfs->ns_sem);
1176 nilfs_setup_super(sb, true);
1177 up_write(&nilfs->ns_sem);
1178 }
1179 out:
1180 return 0;
1181
1182 restore_opts:
1183 sb->s_flags = old_sb_flags;
1184 nilfs->ns_mount_opt = old_mount_opt;
1185 return err;
1186}
1187
1188struct nilfs_super_data {
1189 struct block_device *bdev;
1190 __u64 cno;
1191 int flags;
1192};
1193
1194static int nilfs_parse_snapshot_option(const char *option,
1195 const substring_t *arg,
1196 struct nilfs_super_data *sd)
1197{
1198 unsigned long long val;
1199 const char *msg = NULL;
1200 int err;
1201
1202 if (!(sd->flags & SB_RDONLY)) {
1203 msg = "read-only option is not specified";
1204 goto parse_error;
1205 }
1206
1207 err = kstrtoull(arg->from, 0, &val);
1208 if (err) {
1209 if (err == -ERANGE)
1210 msg = "too large checkpoint number";
1211 else
1212 msg = "malformed argument";
1213 goto parse_error;
1214 } else if (val == 0) {
1215 msg = "invalid checkpoint number 0";
1216 goto parse_error;
1217 }
1218 sd->cno = val;
1219 return 0;
1220
1221parse_error:
1222 nilfs_err(NULL, "invalid option \"%s\": %s", option, msg);
1223 return 1;
1224}
1225
1226/**
1227 * nilfs_identify - pre-read mount options needed to identify mount instance
1228 * @data: mount options
1229 * @sd: nilfs_super_data
1230 */
1231static int nilfs_identify(char *data, struct nilfs_super_data *sd)
1232{
1233 char *p, *options = data;
1234 substring_t args[MAX_OPT_ARGS];
1235 int token;
1236 int ret = 0;
1237
1238 do {
1239 p = strsep(&options, ",");
1240 if (p != NULL && *p) {
1241 token = match_token(p, tokens, args);
1242 if (token == Opt_snapshot)
1243 ret = nilfs_parse_snapshot_option(p, &args[0],
1244 sd);
1245 }
1246 if (!options)
1247 break;
1248 BUG_ON(options == data);
1249 *(options - 1) = ',';
1250 } while (!ret);
1251 return ret;
1252}
1253
1254static int nilfs_set_bdev_super(struct super_block *s, void *data)
1255{
1256 s->s_bdev = data;
1257 s->s_dev = s->s_bdev->bd_dev;
1258 return 0;
1259}
1260
1261static int nilfs_test_bdev_super(struct super_block *s, void *data)
1262{
1263 return (void *)s->s_bdev == data;
1264}
1265
1266static struct dentry *
1267nilfs_mount(struct file_system_type *fs_type, int flags,
1268 const char *dev_name, void *data)
1269{
1270 struct nilfs_super_data sd;
1271 struct super_block *s;
1272 fmode_t mode = FMODE_READ | FMODE_EXCL;
1273 struct dentry *root_dentry;
1274 int err, s_new = false;
1275
1276 if (!(flags & SB_RDONLY))
1277 mode |= FMODE_WRITE;
1278
1279 sd.bdev = blkdev_get_by_path(dev_name, mode, fs_type);
1280 if (IS_ERR(sd.bdev))
1281 return ERR_CAST(sd.bdev);
1282
1283 sd.cno = 0;
1284 sd.flags = flags;
1285 if (nilfs_identify((char *)data, &sd)) {
1286 err = -EINVAL;
1287 goto failed;
1288 }
1289
1290 /*
1291 * once the super is inserted into the list by sget, s_umount
1292 * will protect the lockfs code from trying to start a snapshot
1293 * while we are mounting
1294 */
1295 mutex_lock(&sd.bdev->bd_fsfreeze_mutex);
1296 if (sd.bdev->bd_fsfreeze_count > 0) {
1297 mutex_unlock(&sd.bdev->bd_fsfreeze_mutex);
1298 err = -EBUSY;
1299 goto failed;
1300 }
1301 s = sget(fs_type, nilfs_test_bdev_super, nilfs_set_bdev_super, flags,
1302 sd.bdev);
1303 mutex_unlock(&sd.bdev->bd_fsfreeze_mutex);
1304 if (IS_ERR(s)) {
1305 err = PTR_ERR(s);
1306 goto failed;
1307 }
1308
1309 if (!s->s_root) {
1310 s_new = true;
1311
1312 /* New superblock instance created */
1313 s->s_mode = mode;
1314 snprintf(s->s_id, sizeof(s->s_id), "%pg", sd.bdev);
1315 sb_set_blocksize(s, block_size(sd.bdev));
1316
1317 err = nilfs_fill_super(s, data, flags & SB_SILENT ? 1 : 0);
1318 if (err)
1319 goto failed_super;
1320
1321 s->s_flags |= SB_ACTIVE;
1322 } else if (!sd.cno) {
1323 if (nilfs_tree_is_busy(s->s_root)) {
1324 if ((flags ^ s->s_flags) & SB_RDONLY) {
1325 nilfs_err(s,
1326 "the device already has a %s mount.",
1327 sb_rdonly(s) ? "read-only" : "read/write");
1328 err = -EBUSY;
1329 goto failed_super;
1330 }
1331 } else {
1332 /*
1333 * Try remount to setup mount states if the current
1334 * tree is not mounted and only snapshots use this sb.
1335 */
1336 err = nilfs_remount(s, &flags, data);
1337 if (err)
1338 goto failed_super;
1339 }
1340 }
1341
1342 if (sd.cno) {
1343 err = nilfs_attach_snapshot(s, sd.cno, &root_dentry);
1344 if (err)
1345 goto failed_super;
1346 } else {
1347 root_dentry = dget(s->s_root);
1348 }
1349
1350 if (!s_new)
1351 blkdev_put(sd.bdev, mode);
1352
1353 return root_dentry;
1354
1355 failed_super:
1356 deactivate_locked_super(s);
1357
1358 failed:
1359 if (!s_new)
1360 blkdev_put(sd.bdev, mode);
1361 return ERR_PTR(err);
1362}
1363
1364struct file_system_type nilfs_fs_type = {
1365 .owner = THIS_MODULE,
1366 .name = "nilfs2",
1367 .mount = nilfs_mount,
1368 .kill_sb = kill_block_super,
1369 .fs_flags = FS_REQUIRES_DEV,
1370};
1371MODULE_ALIAS_FS("nilfs2");
1372
1373static void nilfs_inode_init_once(void *obj)
1374{
1375 struct nilfs_inode_info *ii = obj;
1376
1377 INIT_LIST_HEAD(&ii->i_dirty);
1378#ifdef CONFIG_NILFS_XATTR
1379 init_rwsem(&ii->xattr_sem);
1380#endif
1381 address_space_init_once(&ii->i_btnode_cache);
1382 ii->i_bmap = &ii->i_bmap_data;
1383 inode_init_once(&ii->vfs_inode);
1384}
1385
1386static void nilfs_segbuf_init_once(void *obj)
1387{
1388 memset(obj, 0, sizeof(struct nilfs_segment_buffer));
1389}
1390
1391static void nilfs_destroy_cachep(void)
1392{
1393 /*
1394 * Make sure all delayed rcu free inodes are flushed before we
1395 * destroy cache.
1396 */
1397 rcu_barrier();
1398
1399 kmem_cache_destroy(nilfs_inode_cachep);
1400 kmem_cache_destroy(nilfs_transaction_cachep);
1401 kmem_cache_destroy(nilfs_segbuf_cachep);
1402 kmem_cache_destroy(nilfs_btree_path_cache);
1403}
1404
1405static int __init nilfs_init_cachep(void)
1406{
1407 nilfs_inode_cachep = kmem_cache_create("nilfs2_inode_cache",
1408 sizeof(struct nilfs_inode_info), 0,
1409 SLAB_RECLAIM_ACCOUNT|SLAB_ACCOUNT,
1410 nilfs_inode_init_once);
1411 if (!nilfs_inode_cachep)
1412 goto fail;
1413
1414 nilfs_transaction_cachep = kmem_cache_create("nilfs2_transaction_cache",
1415 sizeof(struct nilfs_transaction_info), 0,
1416 SLAB_RECLAIM_ACCOUNT, NULL);
1417 if (!nilfs_transaction_cachep)
1418 goto fail;
1419
1420 nilfs_segbuf_cachep = kmem_cache_create("nilfs2_segbuf_cache",
1421 sizeof(struct nilfs_segment_buffer), 0,
1422 SLAB_RECLAIM_ACCOUNT, nilfs_segbuf_init_once);
1423 if (!nilfs_segbuf_cachep)
1424 goto fail;
1425
1426 nilfs_btree_path_cache = kmem_cache_create("nilfs2_btree_path_cache",
1427 sizeof(struct nilfs_btree_path) * NILFS_BTREE_LEVEL_MAX,
1428 0, 0, NULL);
1429 if (!nilfs_btree_path_cache)
1430 goto fail;
1431
1432 return 0;
1433
1434fail:
1435 nilfs_destroy_cachep();
1436 return -ENOMEM;
1437}
1438
1439static int __init init_nilfs_fs(void)
1440{
1441 int err;
1442
1443 err = nilfs_init_cachep();
1444 if (err)
1445 goto fail;
1446
1447 err = nilfs_sysfs_init();
1448 if (err)
1449 goto free_cachep;
1450
1451 err = register_filesystem(&nilfs_fs_type);
1452 if (err)
1453 goto deinit_sysfs_entry;
1454
1455 printk(KERN_INFO "NILFS version 2 loaded\n");
1456 return 0;
1457
1458deinit_sysfs_entry:
1459 nilfs_sysfs_exit();
1460free_cachep:
1461 nilfs_destroy_cachep();
1462fail:
1463 return err;
1464}
1465
1466static void __exit exit_nilfs_fs(void)
1467{
1468 nilfs_destroy_cachep();
1469 nilfs_sysfs_exit();
1470 unregister_filesystem(&nilfs_fs_type);
1471}
1472
1473module_init(init_nilfs_fs)
1474module_exit(exit_nilfs_fs)