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