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const: mark remaining super_operations const
[linux-2.6-block.git] / fs / nilfs2 / super.c
CommitLineData
783f6184
RK		 1/*
2 * super.c - NILFS module and super block management.
3 *
4 * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation.
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
19 *
20 * Written by Ryusuke Konishi <ryusuke@osrg.net>
21 */
22/*
23 * linux/fs/ext2/super.c
24 *
25 * Copyright (C) 1992, 1993, 1994, 1995
26 * Remy Card (card@masi.ibp.fr)
27 * Laboratoire MASI - Institut Blaise Pascal
28 * Universite Pierre et Marie Curie (Paris VI)
29 *
30 * from
31 *
32 * linux/fs/minix/inode.c
33 *
34 * Copyright (C) 1991, 1992 Linus Torvalds
35 *
36 * Big-endian to little-endian byte-swapping/bitmaps by
37 * David S. Miller (davem@caip.rutgers.edu), 1995
38 */
39
40#include <linux/module.h>
41#include <linux/string.h>
42#include <linux/slab.h>
43#include <linux/init.h>
44#include <linux/blkdev.h>
45#include <linux/parser.h>
46#include <linux/random.h>
47#include <linux/crc32.h>
48#include <linux/smp_lock.h>
49#include <linux/vfs.h>
50#include <linux/writeback.h>
51#include <linux/kobject.h>
52#include <linux/exportfs.h>
b58a285b
JS		 53#include <linux/seq_file.h>
54#include <linux/mount.h>
783f6184
RK		 55#include "nilfs.h"
56#include "mdt.h"
57#include "alloc.h"
58#include "page.h"
59#include "cpfile.h"
60#include "ifile.h"
61#include "dat.h"
62#include "segment.h"
63#include "segbuf.h"
64
65MODULE_AUTHOR("NTT Corp.");
66MODULE_DESCRIPTION("A New Implementation of the Log-structured Filesystem "
67 "(NILFS)");
783f6184
RK		 68MODULE_LICENSE("GPL");
69
70static int nilfs_remount(struct super_block *sb, int *flags, char *data);
783f6184
RK		 71
72/**
73 * nilfs_error() - report failure condition on a filesystem
74 *
75 * nilfs_error() sets an ERROR_FS flag on the superblock as well as
76 * reporting an error message. It should be called when NILFS detects
77 * incoherences or defects of meta data on disk. As for sustainable
78 * errors such as a single-shot I/O error, nilfs_warning() or the printk()
79 * function should be used instead.
80 *
81 * The segment constructor must not call this function because it can
82 * kill itself.
83 */
84void nilfs_error(struct super_block *sb, const char *function,
85 const char *fmt, ...)
86{
87 struct nilfs_sb_info *sbi = NILFS_SB(sb);
88 va_list args;
89
90 va_start(args, fmt);
91 printk(KERN_CRIT "NILFS error (device %s): %s: ", sb->s_id, function);
92 vprintk(fmt, args);
93 printk("\n");
94 va_end(args);
95
96 if (!(sb->s_flags & MS_RDONLY)) {
97 struct the_nilfs *nilfs = sbi->s_nilfs;
98
99 if (!nilfs_test_opt(sbi, ERRORS_CONT))
100 nilfs_detach_segment_constructor(sbi);
101
102 down_write(&nilfs->ns_sem);
103 if (!(nilfs->ns_mount_state & NILFS_ERROR_FS)) {
104 nilfs->ns_mount_state |= NILFS_ERROR_FS;
e339ad31
RK		 105 nilfs->ns_sbp[0]->s_state |=
106 cpu_to_le16(NILFS_ERROR_FS);
107 nilfs_commit_super(sbi, 1);
783f6184
RK		 108 }
109 up_write(&nilfs->ns_sem);
110
111 if (nilfs_test_opt(sbi, ERRORS_RO)) {
112 printk(KERN_CRIT "Remounting filesystem read-only\n");
113 sb->s_flags |= MS_RDONLY;
114 }
115 }
116
117 if (nilfs_test_opt(sbi, ERRORS_PANIC))
118 panic("NILFS (device %s): panic forced after error\n",
119 sb->s_id);
120}
121
122void nilfs_warning(struct super_block *sb, const char *function,
123 const char *fmt, ...)
124{
125 va_list args;
126
127 va_start(args, fmt);
128 printk(KERN_WARNING "NILFS warning (device %s): %s: ",
129 sb->s_id, function);
130 vprintk(fmt, args);
131 printk("\n");
132 va_end(args);
133}
134
135static struct kmem_cache *nilfs_inode_cachep;
136
a53b4751 137struct inode *nilfs_alloc_inode_common(struct the_nilfs *nilfs)
783f6184
RK		 138{
139 struct nilfs_inode_info *ii;
140
141 ii = kmem_cache_alloc(nilfs_inode_cachep, GFP_NOFS);
142 if (!ii)
143 return NULL;
144 ii->i_bh = NULL;
145 ii->i_state = 0;
146 ii->vfs_inode.i_version = 1;
a53b4751 147 nilfs_btnode_cache_init(&ii->i_btnode_cache, nilfs->ns_bdi);
783f6184
RK		 148 return &ii->vfs_inode;
149}
150
a53b4751
RK		 151struct inode *nilfs_alloc_inode(struct super_block *sb)
152{
153 return nilfs_alloc_inode_common(NILFS_SB(sb)->s_nilfs);
154}
155
783f6184
RK		 156void nilfs_destroy_inode(struct inode *inode)
157{
158 kmem_cache_free(nilfs_inode_cachep, NILFS_I(inode));
159}
160
161static void init_once(void *obj)
162{
163 struct nilfs_inode_info *ii = obj;
164
165 INIT_LIST_HEAD(&ii->i_dirty);
166#ifdef CONFIG_NILFS_XATTR
167 init_rwsem(&ii->xattr_sem);
168#endif
169 nilfs_btnode_cache_init_once(&ii->i_btnode_cache);
170 ii->i_bmap = (struct nilfs_bmap *)&ii->i_bmap_union;
171 inode_init_once(&ii->vfs_inode);
172}
173
174static int nilfs_init_inode_cache(void)
175{
176 nilfs_inode_cachep = kmem_cache_create("nilfs2_inode_cache",
177 sizeof(struct nilfs_inode_info),
178 0, SLAB_RECLAIM_ACCOUNT,
179 init_once);
180
181 return (nilfs_inode_cachep == NULL) ? -ENOMEM : 0;
182}
183
184static inline void nilfs_destroy_inode_cache(void)
185{
186 kmem_cache_destroy(nilfs_inode_cachep);
187}
188
189static void nilfs_clear_inode(struct inode *inode)
190{
191 struct nilfs_inode_info *ii = NILFS_I(inode);
783f6184 192
783f6184
RK		 193 /*
194 * Free resources allocated in nilfs_read_inode(), here.
195 */
a2e7d2df 196 BUG_ON(!list_empty(&ii->i_dirty));
783f6184
RK		 197 brelse(ii->i_bh);
198 ii->i_bh = NULL;
783f6184
RK		 199
200 if (test_bit(NILFS_I_BMAP, &ii->i_state))
201 nilfs_bmap_clear(ii->i_bmap);
202
203 nilfs_btnode_cache_clear(&ii->i_btnode_cache);
783f6184
RK		 204}
205
e339ad31 206static int nilfs_sync_super(struct nilfs_sb_info *sbi, int dupsb)
783f6184
RK		 207{
208 struct the_nilfs *nilfs = sbi->s_nilfs;
209 int err;
210 int barrier_done = 0;
211
212 if (nilfs_test_opt(sbi, BARRIER)) {
e339ad31 213 set_buffer_ordered(nilfs->ns_sbh[0]);
783f6184
RK		 214 barrier_done = 1;
215 }
216 retry:
e339ad31
RK		 217 set_buffer_dirty(nilfs->ns_sbh[0]);
218 err = sync_dirty_buffer(nilfs->ns_sbh[0]);
783f6184
RK		 219 if (err == -EOPNOTSUPP && barrier_done) {
220 nilfs_warning(sbi->s_super, __func__,
221 "barrier-based sync failed. "
222 "disabling barriers\n");
223 nilfs_clear_opt(sbi, BARRIER);
224 barrier_done = 0;
e339ad31 225 clear_buffer_ordered(nilfs->ns_sbh[0]);
783f6184
RK		 226 goto retry;
227 }
e339ad31 228 if (unlikely(err)) {
783f6184
RK		 229 printk(KERN_ERR
230 "NILFS: unable to write superblock (err=%d)\n", err);
e339ad31
RK		 231 if (err == -EIO && nilfs->ns_sbh[1]) {
232 nilfs_fall_back_super_block(nilfs);
233 goto retry;
234 }
235 } else {
236 struct nilfs_super_block *sbp = nilfs->ns_sbp[0];
237
238 /*
239 * The latest segment becomes trailable from the position
240 * written in superblock.
241 */
783f6184 242 clear_nilfs_discontinued(nilfs);
e339ad31
RK		 243
244 /* update GC protection for recent segments */
245 if (nilfs->ns_sbh[1]) {
246 sbp = NULL;
247 if (dupsb) {
248 set_buffer_dirty(nilfs->ns_sbh[1]);
249 if (!sync_dirty_buffer(nilfs->ns_sbh[1]))
250 sbp = nilfs->ns_sbp[1];
251 }
252 }
253 if (sbp) {
254 spin_lock(&nilfs->ns_last_segment_lock);
255 nilfs->ns_prot_seq = le64_to_cpu(sbp->s_last_seq);
256 spin_unlock(&nilfs->ns_last_segment_lock);
257 }
783f6184
RK		 258 }
259
260 return err;
261}
262
e339ad31 263int nilfs_commit_super(struct nilfs_sb_info *sbi, int dupsb)
783f6184
RK		 264{
265 struct the_nilfs *nilfs = sbi->s_nilfs;
e339ad31 266 struct nilfs_super_block **sbp = nilfs->ns_sbp;
783f6184 267 sector_t nfreeblocks;
e339ad31 268 time_t t;
783f6184
RK		 269 int err;
270
271 /* nilfs->sem must be locked by the caller. */
e339ad31
RK		 272 if (sbp[0]->s_magic != NILFS_SUPER_MAGIC) {
273 if (sbp[1] && sbp[1]->s_magic == NILFS_SUPER_MAGIC)
274 nilfs_swap_super_block(nilfs);
275 else {
276 printk(KERN_CRIT "NILFS: superblock broke on dev %s\n",
277 sbi->s_super->s_id);
278 return -EIO;
279 }
280 }
783f6184
RK		 281 err = nilfs_count_free_blocks(nilfs, &nfreeblocks);
282 if (unlikely(err)) {
283 printk(KERN_ERR "NILFS: failed to count free blocks\n");
284 return err;
285 }
e339ad31
RK		 286 spin_lock(&nilfs->ns_last_segment_lock);
287 sbp[0]->s_last_seq = cpu_to_le64(nilfs->ns_last_seq);
288 sbp[0]->s_last_pseg = cpu_to_le64(nilfs->ns_last_pseg);
289 sbp[0]->s_last_cno = cpu_to_le64(nilfs->ns_last_cno);
290 spin_unlock(&nilfs->ns_last_segment_lock);
291
292 t = get_seconds();
293 nilfs->ns_sbwtime[0] = t;
294 sbp[0]->s_free_blocks_count = cpu_to_le64(nfreeblocks);
295 sbp[0]->s_wtime = cpu_to_le64(t);
296 sbp[0]->s_sum = 0;
297 sbp[0]->s_sum = cpu_to_le32(crc32_le(nilfs->ns_crc_seed,
298 (unsigned char *)sbp[0],
299 nilfs->ns_sbsize));
300 if (dupsb && sbp[1]) {
301 memcpy(sbp[1], sbp[0], nilfs->ns_sbsize);
302 nilfs->ns_sbwtime[1] = t;
303 }
783f6184 304 sbi->s_super->s_dirt = 0;
e339ad31 305 return nilfs_sync_super(sbi, dupsb);
783f6184
RK		 306}
307
308static void nilfs_put_super(struct super_block *sb)
309{
310 struct nilfs_sb_info *sbi = NILFS_SB(sb);
311 struct the_nilfs *nilfs = sbi->s_nilfs;
312
6cfd0148
CH		 313 lock_kernel();
314
783f6184
RK		 315 nilfs_detach_segment_constructor(sbi);
316
317 if (!(sb->s_flags & MS_RDONLY)) {
318 down_write(&nilfs->ns_sem);
e339ad31
RK		 319 nilfs->ns_sbp[0]->s_state = cpu_to_le16(nilfs->ns_mount_state);
320 nilfs_commit_super(sbi, 1);
783f6184
RK		 321 up_write(&nilfs->ns_sem);
322 }
e59399d0 323 down_write(&nilfs->ns_super_sem);
3f82ff55
RK		 324 if (nilfs->ns_current == sbi)
325 nilfs->ns_current = NULL;
e59399d0 326 up_write(&nilfs->ns_super_sem);
783f6184
RK		 327
328 nilfs_detach_checkpoint(sbi);
329 put_nilfs(sbi->s_nilfs);
330 sbi->s_super = NULL;
331 sb->s_fs_info = NULL;
6dd47406 332 nilfs_put_sbinfo(sbi);
6cfd0148
CH		 333
334 unlock_kernel();
783f6184
RK		 335}
336
783f6184
RK		 337static int nilfs_sync_fs(struct super_block *sb, int wait)
338{
6233caa9
JS		 339 struct nilfs_sb_info *sbi = NILFS_SB(sb);
340 struct the_nilfs *nilfs = sbi->s_nilfs;
783f6184
RK		 341 int err = 0;
342
343 /* This function is called when super block should be written back */
344 if (wait)
345 err = nilfs_construct_segment(sb);
6233caa9
JS		 346
347 down_write(&nilfs->ns_sem);
348 if (sb->s_dirt)
349 nilfs_commit_super(sbi, 1);
350 up_write(&nilfs->ns_sem);
351
783f6184
RK		 352 return err;
353}
354
355int nilfs_attach_checkpoint(struct nilfs_sb_info *sbi, __u64 cno)
356{
357 struct the_nilfs *nilfs = sbi->s_nilfs;
358 struct nilfs_checkpoint *raw_cp;
359 struct buffer_head *bh_cp;
360 int err;
361
e59399d0 362 down_write(&nilfs->ns_super_sem);
783f6184 363 list_add(&sbi->s_list, &nilfs->ns_supers);
e59399d0 364 up_write(&nilfs->ns_super_sem);
783f6184 365
7a102b09 366 sbi->s_ifile = nilfs_mdt_new(nilfs, sbi->s_super, NILFS_IFILE_INO);
783f6184
RK		 367 if (!sbi->s_ifile)
368 return -ENOMEM;
369
370 err = nilfs_palloc_init_blockgroup(sbi->s_ifile, nilfs->ns_inode_size);
371 if (unlikely(err))
372 goto failed;
373
1154ecbd 374 down_read(&nilfs->ns_segctor_sem);
783f6184
RK		 375 err = nilfs_cpfile_get_checkpoint(nilfs->ns_cpfile, cno, 0, &raw_cp,
376 &bh_cp);
1154ecbd 377 up_read(&nilfs->ns_segctor_sem);
783f6184
RK		 378 if (unlikely(err)) {
379 if (err == -ENOENT || err == -EINVAL) {
380 printk(KERN_ERR
381 "NILFS: Invalid checkpoint "
382 "(checkpoint number=%llu)\n",
383 (unsigned long long)cno);
384 err = -EINVAL;
385 }
386 goto failed;
387 }
388 err = nilfs_read_inode_common(sbi->s_ifile, &raw_cp->cp_ifile_inode);
389 if (unlikely(err))
390 goto failed_bh;
391 atomic_set(&sbi->s_inodes_count, le64_to_cpu(raw_cp->cp_inodes_count));
392 atomic_set(&sbi->s_blocks_count, le64_to_cpu(raw_cp->cp_blocks_count));
393
394 nilfs_cpfile_put_checkpoint(nilfs->ns_cpfile, cno, bh_cp);
395 return 0;
396
397 failed_bh:
398 nilfs_cpfile_put_checkpoint(nilfs->ns_cpfile, cno, bh_cp);
399 failed:
400 nilfs_mdt_destroy(sbi->s_ifile);
401 sbi->s_ifile = NULL;
402
e59399d0 403 down_write(&nilfs->ns_super_sem);
783f6184 404 list_del_init(&sbi->s_list);
e59399d0 405 up_write(&nilfs->ns_super_sem);
783f6184
RK		 406
407 return err;
408}
409
410void nilfs_detach_checkpoint(struct nilfs_sb_info *sbi)
411{
412 struct the_nilfs *nilfs = sbi->s_nilfs;
413
414 nilfs_mdt_clear(sbi->s_ifile);
415 nilfs_mdt_destroy(sbi->s_ifile);
416 sbi->s_ifile = NULL;
e59399d0 417 down_write(&nilfs->ns_super_sem);
783f6184 418 list_del_init(&sbi->s_list);
e59399d0 419 up_write(&nilfs->ns_super_sem);
783f6184
RK		 420}
421
422static int nilfs_mark_recovery_complete(struct nilfs_sb_info *sbi)
423{
424 struct the_nilfs *nilfs = sbi->s_nilfs;
425 int err = 0;
426
427 down_write(&nilfs->ns_sem);
428 if (!(nilfs->ns_mount_state & NILFS_VALID_FS)) {
429 nilfs->ns_mount_state |= NILFS_VALID_FS;
e339ad31 430 err = nilfs_commit_super(sbi, 1);
783f6184
RK		 431 if (likely(!err))
432 printk(KERN_INFO "NILFS: recovery complete.\n");
433 }
434 up_write(&nilfs->ns_sem);
435 return err;
436}
437
438static int nilfs_statfs(struct dentry *dentry, struct kstatfs *buf)
439{
440 struct super_block *sb = dentry->d_sb;
441 struct nilfs_sb_info *sbi = NILFS_SB(sb);
c306af23
RK		 442 struct the_nilfs *nilfs = sbi->s_nilfs;
443 u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
783f6184
RK		 444 unsigned long long blocks;
445 unsigned long overhead;
446 unsigned long nrsvblocks;
447 sector_t nfreeblocks;
783f6184
RK		 448 int err;
449
450 /*
451 * Compute all of the segment blocks
452 *
453 * The blocks before first segment and after last segment
454 * are excluded.
455 */
456 blocks = nilfs->ns_blocks_per_segment * nilfs->ns_nsegments
457 - nilfs->ns_first_data_block;
458 nrsvblocks = nilfs->ns_nrsvsegs * nilfs->ns_blocks_per_segment;
459
460 /*
461 * Compute the overhead
462 *
463 * When distributing meta data blocks outside semgent structure,
464 * We must count them as the overhead.
465 */
466 overhead = 0;
467
468 err = nilfs_count_free_blocks(nilfs, &nfreeblocks);
469 if (unlikely(err))
470 return err;
471
472 buf->f_type = NILFS_SUPER_MAGIC;
473 buf->f_bsize = sb->s_blocksize;
474 buf->f_blocks = blocks - overhead;
475 buf->f_bfree = nfreeblocks;
476 buf->f_bavail = (buf->f_bfree >= nrsvblocks) ?
477 (buf->f_bfree - nrsvblocks) : 0;
478 buf->f_files = atomic_read(&sbi->s_inodes_count);
479 buf->f_ffree = 0; /* nilfs_count_free_inodes(sb); */
480 buf->f_namelen = NILFS_NAME_LEN;
c306af23
RK		 481 buf->f_fsid.val[0] = (u32)id;
482 buf->f_fsid.val[1] = (u32)(id >> 32);
483
783f6184
RK		 484 return 0;
485}
486
b58a285b
JS		 487static int nilfs_show_options(struct seq_file *seq, struct vfsmount *vfs)
488{
489 struct super_block *sb = vfs->mnt_sb;
490 struct nilfs_sb_info *sbi = NILFS_SB(sb);
491
492 if (!nilfs_test_opt(sbi, BARRIER))
493 seq_printf(seq, ",barrier=off");
494 if (nilfs_test_opt(sbi, SNAPSHOT))
495 seq_printf(seq, ",cp=%llu",
496 (unsigned long long int)sbi->s_snapshot_cno);
497 if (nilfs_test_opt(sbi, ERRORS_RO))
498 seq_printf(seq, ",errors=remount-ro");
499 if (nilfs_test_opt(sbi, ERRORS_PANIC))
500 seq_printf(seq, ",errors=panic");
501 if (nilfs_test_opt(sbi, STRICT_ORDER))
502 seq_printf(seq, ",order=strict");
503
504 return 0;
505}
506
b87221de 507static const struct super_operations nilfs_sops = {
783f6184
RK		 508 .alloc_inode = nilfs_alloc_inode,
509 .destroy_inode = nilfs_destroy_inode,
510 .dirty_inode = nilfs_dirty_inode,
511 /* .write_inode = nilfs_write_inode, */
512 /* .put_inode = nilfs_put_inode, */
513 /* .drop_inode = nilfs_drop_inode, */
514 .delete_inode = nilfs_delete_inode,
515 .put_super = nilfs_put_super,
1dfa2710 516 /* .write_super = nilfs_write_super, */
783f6184
RK		 517 .sync_fs = nilfs_sync_fs,
518 /* .write_super_lockfs */
519 /* .unlockfs */
520 .statfs = nilfs_statfs,
521 .remount_fs = nilfs_remount,
522 .clear_inode = nilfs_clear_inode,
523 /* .umount_begin */
b58a285b 524 .show_options = nilfs_show_options
783f6184
RK		 525};
526
527static struct inode *
528nilfs_nfs_get_inode(struct super_block *sb, u64 ino, u32 generation)
529{
530 struct inode *inode;
531
532 if (ino < NILFS_FIRST_INO(sb) && ino != NILFS_ROOT_INO &&
533 ino != NILFS_SKETCH_INO)
534 return ERR_PTR(-ESTALE);
535
536 inode = nilfs_iget(sb, ino);
537 if (IS_ERR(inode))
538 return ERR_CAST(inode);
539 if (generation && inode->i_generation != generation) {
540 iput(inode);
541 return ERR_PTR(-ESTALE);
542 }
543
544 return inode;
545}
546
547static struct dentry *
548nilfs_fh_to_dentry(struct super_block *sb, struct fid *fid, int fh_len,
549 int fh_type)
550{
551 return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
552 nilfs_nfs_get_inode);
553}
554
555static struct dentry *
556nilfs_fh_to_parent(struct super_block *sb, struct fid *fid, int fh_len,
557 int fh_type)
558{
559 return generic_fh_to_parent(sb, fid, fh_len, fh_type,
560 nilfs_nfs_get_inode);
561}
562
563static struct export_operations nilfs_export_ops = {
564 .fh_to_dentry = nilfs_fh_to_dentry,
565 .fh_to_parent = nilfs_fh_to_parent,
566 .get_parent = nilfs_get_parent,
567};
568
569enum {
570 Opt_err_cont, Opt_err_panic, Opt_err_ro,
571 Opt_barrier, Opt_snapshot, Opt_order,
572 Opt_err,
573};
574
575static match_table_t tokens = {
576 {Opt_err_cont, "errors=continue"},
577 {Opt_err_panic, "errors=panic"},
578 {Opt_err_ro, "errors=remount-ro"},
579 {Opt_barrier, "barrier=%s"},
580 {Opt_snapshot, "cp=%u"},
581 {Opt_order, "order=%s"},
582 {Opt_err, NULL}
583};
584
585static int match_bool(substring_t *s, int *result)
586{
587 int len = s->to - s->from;
588
589 if (strncmp(s->from, "on", len) == 0)
590 *result = 1;
591 else if (strncmp(s->from, "off", len) == 0)
592 *result = 0;
593 else
594 return 1;
595 return 0;
596}
597
598static int parse_options(char *options, struct super_block *sb)
599{
600 struct nilfs_sb_info *sbi = NILFS_SB(sb);
601 char *p;
602 substring_t args[MAX_OPT_ARGS];
603 int option;
604
605 if (!options)
606 return 1;
607
608 while ((p = strsep(&options, ",")) != NULL) {
609 int token;
610 if (!*p)
611 continue;
612
613 token = match_token(p, tokens, args);
614 switch (token) {
615 case Opt_barrier:
616 if (match_bool(&args[0], &option))
617 return 0;
618 if (option)
619 nilfs_set_opt(sbi, BARRIER);
620 else
621 nilfs_clear_opt(sbi, BARRIER);
622 break;
623 case Opt_order:
624 if (strcmp(args[0].from, "relaxed") == 0)
625 /* Ordered data semantics */
626 nilfs_clear_opt(sbi, STRICT_ORDER);
627 else if (strcmp(args[0].from, "strict") == 0)
628 /* Strict in-order semantics */
629 nilfs_set_opt(sbi, STRICT_ORDER);
630 else
631 return 0;
632 break;
633 case Opt_err_panic:
634 nilfs_write_opt(sbi, ERROR_MODE, ERRORS_PANIC);
635 break;
636 case Opt_err_ro:
637 nilfs_write_opt(sbi, ERROR_MODE, ERRORS_RO);
638 break;
639 case Opt_err_cont:
640 nilfs_write_opt(sbi, ERROR_MODE, ERRORS_CONT);
641 break;
642 case Opt_snapshot:
643 if (match_int(&args[0], &option) || option <= 0)
644 return 0;
645 if (!(sb->s_flags & MS_RDONLY))
646 return 0;
647 sbi->s_snapshot_cno = option;
648 nilfs_set_opt(sbi, SNAPSHOT);
649 break;
650 default:
651 printk(KERN_ERR
652 "NILFS: Unrecognized mount option \"%s\"\n", p);
653 return 0;
654 }
655 }
656 return 1;
657}
658
659static inline void
660nilfs_set_default_options(struct nilfs_sb_info *sbi,
661 struct nilfs_super_block *sbp)
662{
663 sbi->s_mount_opt =
664 NILFS_MOUNT_ERRORS_CONT | NILFS_MOUNT_BARRIER;
665}
666
667static int nilfs_setup_super(struct nilfs_sb_info *sbi)
668{
669 struct the_nilfs *nilfs = sbi->s_nilfs;
e339ad31 670 struct nilfs_super_block *sbp = nilfs->ns_sbp[0];
783f6184
RK		 671 int max_mnt_count = le16_to_cpu(sbp->s_max_mnt_count);
672 int mnt_count = le16_to_cpu(sbp->s_mnt_count);
673
674 /* nilfs->sem must be locked by the caller. */
675 if (!(nilfs->ns_mount_state & NILFS_VALID_FS)) {
676 printk(KERN_WARNING "NILFS warning: mounting unchecked fs\n");
677 } else if (nilfs->ns_mount_state & NILFS_ERROR_FS) {
678 printk(KERN_WARNING
679 "NILFS warning: mounting fs with errors\n");
680#if 0
681 } else if (max_mnt_count >= 0 && mnt_count >= max_mnt_count) {
682 printk(KERN_WARNING
683 "NILFS warning: maximal mount count reached\n");
684#endif
685 }
686 if (!max_mnt_count)
687 sbp->s_max_mnt_count = cpu_to_le16(NILFS_DFL_MAX_MNT_COUNT);
688
689 sbp->s_mnt_count = cpu_to_le16(mnt_count + 1);
690 sbp->s_state = cpu_to_le16(le16_to_cpu(sbp->s_state) & ~NILFS_VALID_FS);
691 sbp->s_mtime = cpu_to_le64(get_seconds());
e339ad31 692 return nilfs_commit_super(sbi, 1);
783f6184
RK		 693}
694
e339ad31
RK		 695struct nilfs_super_block *nilfs_read_super_block(struct super_block *sb,
696 u64 pos, int blocksize,
697 struct buffer_head **pbh)
783f6184 698{
e339ad31
RK		 699 unsigned long long sb_index = pos;
700 unsigned long offset;
783f6184 701
e339ad31 702 offset = do_div(sb_index, blocksize);
783f6184 703 *pbh = sb_bread(sb, sb_index);
e339ad31 704 if (!*pbh)
783f6184 705 return NULL;
783f6184
RK		 706 return (struct nilfs_super_block *)((char *)(*pbh)->b_data + offset);
707}
708
783f6184
RK		 709int nilfs_store_magic_and_option(struct super_block *sb,
710 struct nilfs_super_block *sbp,
711 char *data)
712{
713 struct nilfs_sb_info *sbi = NILFS_SB(sb);
714
783f6184
RK		 715 sb->s_magic = le16_to_cpu(sbp->s_magic);
716
717 /* FS independent flags */
718#ifdef NILFS_ATIME_DISABLE
719 sb->s_flags |= MS_NOATIME;
720#endif
721
783f6184
RK		 722 nilfs_set_default_options(sbi, sbp);
723
724 sbi->s_resuid = le16_to_cpu(sbp->s_def_resuid);
725 sbi->s_resgid = le16_to_cpu(sbp->s_def_resgid);
726 sbi->s_interval = le32_to_cpu(sbp->s_c_interval);
727 sbi->s_watermark = le32_to_cpu(sbp->s_c_block_max);
728
e339ad31 729 return !parse_options(data, sb) ? -EINVAL : 0 ;
783f6184
RK		 730}
731
732/**
733 * nilfs_fill_super() - initialize a super block instance
734 * @sb: super_block
735 * @data: mount options
736 * @silent: silent mode flag
737 * @nilfs: the_nilfs struct
738 *
aa7dfb89 739 * This function is called exclusively by nilfs->ns_mount_mutex.
783f6184
RK		 740 * So, the recovery process is protected from other simultaneous mounts.
741 */
742static int
743nilfs_fill_super(struct super_block *sb, void *data, int silent,
744 struct the_nilfs *nilfs)
745{
746 struct nilfs_sb_info *sbi;
747 struct inode *root;
748 __u64 cno;
749 int err;
750
751 sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
752 if (!sbi)
753 return -ENOMEM;
754
755 sb->s_fs_info = sbi;
756
757 get_nilfs(nilfs);
758 sbi->s_nilfs = nilfs;
759 sbi->s_super = sb;
6dd47406 760 atomic_set(&sbi->s_count, 1);
783f6184
RK		 761
762 err = init_nilfs(nilfs, sbi, (char *)data);
763 if (err)
764 goto failed_sbi;
765
766 spin_lock_init(&sbi->s_inode_lock);
767 INIT_LIST_HEAD(&sbi->s_dirty_files);
768 INIT_LIST_HEAD(&sbi->s_list);
769
770 /*
771 * Following initialization is overlapped because
772 * nilfs_sb_info structure has been cleared at the beginning.
773 * But we reserve them to keep our interest and make ready
774 * for the future change.
775 */
776 get_random_bytes(&sbi->s_next_generation,
777 sizeof(sbi->s_next_generation));
778 spin_lock_init(&sbi->s_next_gen_lock);
779
780 sb->s_op = &nilfs_sops;
781 sb->s_export_op = &nilfs_export_ops;
782 sb->s_root = NULL;
61239230 783 sb->s_time_gran = 1;
783f6184
RK		 784
785 if (!nilfs_loaded(nilfs)) {
786 err = load_nilfs(nilfs, sbi);
787 if (err)
788 goto failed_sbi;
789 }
790 cno = nilfs_last_cno(nilfs);
791
792 if (sb->s_flags & MS_RDONLY) {
793 if (nilfs_test_opt(sbi, SNAPSHOT)) {
43be0ec0 794 down_read(&nilfs->ns_segctor_sem);
1f5abe7e
RK		 795 err = nilfs_cpfile_is_snapshot(nilfs->ns_cpfile,
796 sbi->s_snapshot_cno);
43be0ec0
ZY		 797 up_read(&nilfs->ns_segctor_sem);
798 if (err < 0) {
799 if (err == -ENOENT)
800 err = -EINVAL;
1f5abe7e 801 goto failed_sbi;
43be0ec0 802 }
1f5abe7e 803 if (!err) {
783f6184
RK		 804 printk(KERN_ERR
805 "NILFS: The specified checkpoint is "
806 "not a snapshot "
807 "(checkpoint number=%llu).\n",
808 (unsigned long long)sbi->s_snapshot_cno);
809 err = -EINVAL;
810 goto failed_sbi;
811 }
812 cno = sbi->s_snapshot_cno;
813 } else
814 /* Read-only mount */
815 sbi->s_snapshot_cno = cno;
816 }
817
818 err = nilfs_attach_checkpoint(sbi, cno);
819 if (err) {
820 printk(KERN_ERR "NILFS: error loading a checkpoint"
821 " (checkpoint number=%llu).\n", (unsigned long long)cno);
822 goto failed_sbi;
823 }
824
825 if (!(sb->s_flags & MS_RDONLY)) {
cece5520 826 err = nilfs_attach_segment_constructor(sbi);
783f6184
RK		 827 if (err)
828 goto failed_checkpoint;
829 }
830
831 root = nilfs_iget(sb, NILFS_ROOT_INO);
832 if (IS_ERR(root)) {
833 printk(KERN_ERR "NILFS: get root inode failed\n");
834 err = PTR_ERR(root);
835 goto failed_segctor;
836 }
837 if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
838 iput(root);
839 printk(KERN_ERR "NILFS: corrupt root inode.\n");
840 err = -EINVAL;
841 goto failed_segctor;
842 }
843 sb->s_root = d_alloc_root(root);
844 if (!sb->s_root) {
845 iput(root);
846 printk(KERN_ERR "NILFS: get root dentry failed\n");
847 err = -ENOMEM;
848 goto failed_segctor;
849 }
850
851 if (!(sb->s_flags & MS_RDONLY)) {
852 down_write(&nilfs->ns_sem);
853 nilfs_setup_super(sbi);
854 up_write(&nilfs->ns_sem);
855 }
856
857 err = nilfs_mark_recovery_complete(sbi);
858 if (unlikely(err)) {
859 printk(KERN_ERR "NILFS: recovery failed.\n");
860 goto failed_root;
861 }
862
e59399d0 863 down_write(&nilfs->ns_super_sem);
3f82ff55
RK		 864 if (!nilfs_test_opt(sbi, SNAPSHOT))
865 nilfs->ns_current = sbi;
e59399d0 866 up_write(&nilfs->ns_super_sem);
3f82ff55 867
783f6184
RK		 868 return 0;
869
870 failed_root:
871 dput(sb->s_root);
872 sb->s_root = NULL;
873
874 failed_segctor:
875 nilfs_detach_segment_constructor(sbi);
876
877 failed_checkpoint:
878 nilfs_detach_checkpoint(sbi);
879
880 failed_sbi:
881 put_nilfs(nilfs);
882 sb->s_fs_info = NULL;
6dd47406 883 nilfs_put_sbinfo(sbi);
783f6184
RK		 884 return err;
885}
886
887static int nilfs_remount(struct super_block *sb, int *flags, char *data)
888{
889 struct nilfs_sb_info *sbi = NILFS_SB(sb);
890 struct nilfs_super_block *sbp;
891 struct the_nilfs *nilfs = sbi->s_nilfs;
892 unsigned long old_sb_flags;
893 struct nilfs_mount_options old_opts;
894 int err;
895
337eb00a
AIB		 896 lock_kernel();
897
e59399d0 898 down_write(&nilfs->ns_super_sem);
783f6184
RK		 899 old_sb_flags = sb->s_flags;
900 old_opts.mount_opt = sbi->s_mount_opt;
901 old_opts.snapshot_cno = sbi->s_snapshot_cno;
902
903 if (!parse_options(data, sb)) {
904 err = -EINVAL;
905 goto restore_opts;
906 }
907 sb->s_flags = (sb->s_flags & ~MS_POSIXACL);
908
909 if ((*flags & MS_RDONLY) &&
910 sbi->s_snapshot_cno != old_opts.snapshot_cno) {
911 printk(KERN_WARNING "NILFS (device %s): couldn't "
912 "remount to a different snapshot. \n",
913 sb->s_id);
914 err = -EINVAL;
915 goto restore_opts;
916 }
917
918 if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
919 goto out;
920 if (*flags & MS_RDONLY) {
921 /* Shutting down the segment constructor */
922 nilfs_detach_segment_constructor(sbi);
923 sb->s_flags |= MS_RDONLY;
924
925 sbi->s_snapshot_cno = nilfs_last_cno(nilfs);
926 /* nilfs_set_opt(sbi, SNAPSHOT); */
927
928 /*
929 * Remounting a valid RW partition RDONLY, so set
930 * the RDONLY flag and then mark the partition as valid again.
931 */
932 down_write(&nilfs->ns_sem);
e339ad31 933 sbp = nilfs->ns_sbp[0];
783f6184
RK		 934 if (!(sbp->s_state & le16_to_cpu(NILFS_VALID_FS)) &&
935 (nilfs->ns_mount_state & NILFS_VALID_FS))
936 sbp->s_state = cpu_to_le16(nilfs->ns_mount_state);
937 sbp->s_mtime = cpu_to_le64(get_seconds());
e339ad31 938 nilfs_commit_super(sbi, 1);
783f6184
RK		 939 up_write(&nilfs->ns_sem);
940 } else {
941 /*
942 * Mounting a RDONLY partition read-write, so reread and
943 * store the current valid flag. (It may have been changed
944 * by fsck since we originally mounted the partition.)
945 */
3f82ff55 946 if (nilfs->ns_current && nilfs->ns_current != sbi) {
783f6184 947 printk(KERN_WARNING "NILFS (device %s): couldn't "
3f82ff55 948 "remount because an RW-mount exists.\n",
783f6184
RK		 949 sb->s_id);
950 err = -EBUSY;
e59399d0 951 goto restore_opts;
783f6184
RK		 952 }
953 if (sbi->s_snapshot_cno != nilfs_last_cno(nilfs)) {
954 printk(KERN_WARNING "NILFS (device %s): couldn't "
955 "remount because the current RO-mount is not "
956 "the latest one.\n",
957 sb->s_id);
958 err = -EINVAL;
e59399d0 959 goto restore_opts;
783f6184
RK		 960 }
961 sb->s_flags &= ~MS_RDONLY;
962 nilfs_clear_opt(sbi, SNAPSHOT);
963 sbi->s_snapshot_cno = 0;
964
cece5520 965 err = nilfs_attach_segment_constructor(sbi);
783f6184 966 if (err)
e59399d0 967 goto restore_opts;
783f6184
RK		 968
969 down_write(&nilfs->ns_sem);
970 nilfs_setup_super(sbi);
971 up_write(&nilfs->ns_sem);
972
e59399d0 973 nilfs->ns_current = sbi;
783f6184
RK		 974 }
975 out:
e59399d0 976 up_write(&nilfs->ns_super_sem);
337eb00a 977 unlock_kernel();
783f6184
RK		 978 return 0;
979
783f6184
RK		 980 restore_opts:
981 sb->s_flags = old_sb_flags;
982 sbi->s_mount_opt = old_opts.mount_opt;
983 sbi->s_snapshot_cno = old_opts.snapshot_cno;
e59399d0 984 up_write(&nilfs->ns_super_sem);
337eb00a 985 unlock_kernel();
783f6184
RK		 986 return err;
987}
988
989struct nilfs_super_data {
990 struct block_device *bdev;
6dd47406 991 struct nilfs_sb_info *sbi;
783f6184
RK		 992 __u64 cno;
993 int flags;
994};
995
996/**
997 * nilfs_identify - pre-read mount options needed to identify mount instance
998 * @data: mount options
999 * @sd: nilfs_super_data
1000 */
1001static int nilfs_identify(char *data, struct nilfs_super_data *sd)
1002{
1003 char *p, *options = data;
1004 substring_t args[MAX_OPT_ARGS];
1005 int option, token;
1006 int ret = 0;
1007
1008 do {
1009 p = strsep(&options, ",");
1010 if (p != NULL && *p) {
1011 token = match_token(p, tokens, args);
1012 if (token == Opt_snapshot) {
1013 if (!(sd->flags & MS_RDONLY))
1014 ret++;
1015 else {
1016 ret = match_int(&args[0], &option);
1017 if (!ret) {
1018 if (option > 0)
1019 sd->cno = option;
1020 else
1021 ret++;
1022 }
1023 }
1024 }
1025 if (ret)
1026 printk(KERN_ERR
1027 "NILFS: invalid mount option: %s\n", p);
1028 }
1029 if (!options)
1030 break;
1031 BUG_ON(options == data);
1032 *(options - 1) = ',';
1033 } while (!ret);
1034 return ret;
1035}
1036
1037static int nilfs_set_bdev_super(struct super_block *s, void *data)
1038{
1039 struct nilfs_super_data *sd = data;
1040
1041 s->s_bdev = sd->bdev;
1042 s->s_dev = s->s_bdev->bd_dev;
1043 return 0;
1044}
1045
1046static int nilfs_test_bdev_super(struct super_block *s, void *data)
783f6184
RK		 1047{
1048 struct nilfs_super_data *sd = data;
6dd47406
RK		 1049
1050 return sd->sbi && s->s_fs_info == (void *)sd->sbi;
783f6184
RK		 1051}
1052
1053static int
1054nilfs_get_sb(struct file_system_type *fs_type, int flags,
1055 const char *dev_name, void *data, struct vfsmount *mnt)
1056{
1057 struct nilfs_super_data sd;
33c8e57c
RK		 1058 struct super_block *s;
1059 struct the_nilfs *nilfs;
783f6184
RK		 1060 int err, need_to_close = 1;
1061
1062 sd.bdev = open_bdev_exclusive(dev_name, flags, fs_type);
1063 if (IS_ERR(sd.bdev))
1064 return PTR_ERR(sd.bdev);
1065
1066 /*
1067 * To get mount instance using sget() vfs-routine, NILFS needs
1068 * much more information than normal filesystems to identify mount
1069 * instance. For snapshot mounts, not only a mount type (ro-mount
1070 * or rw-mount) but also a checkpoint number is required.
783f6184
RK		 1071 */
1072 sd.cno = 0;
1073 sd.flags = flags;
1074 if (nilfs_identify((char *)data, &sd)) {
1075 err = -EINVAL;
1076 goto failed;
1077 }
1078
33c8e57c
RK		 1079 nilfs = find_or_create_nilfs(sd.bdev);
1080 if (!nilfs) {
1081 err = -ENOMEM;
1082 goto failed;
1083 }
1084
aa7dfb89 1085 mutex_lock(&nilfs->ns_mount_mutex);
3f82ff55
RK		 1086
1087 if (!sd.cno) {
1088 /*
1089 * Check if an exclusive mount exists or not.
1090 * Snapshot mounts coexist with a current mount
1091 * (i.e. rw-mount or ro-mount), whereas rw-mount and
1092 * ro-mount are mutually exclusive.
1093 */
e59399d0 1094 down_read(&nilfs->ns_super_sem);
3f82ff55
RK		 1095 if (nilfs->ns_current &&
1096 ((nilfs->ns_current->s_super->s_flags ^ flags)
1097 & MS_RDONLY)) {
e59399d0 1098 up_read(&nilfs->ns_super_sem);
3f82ff55
RK		 1099 err = -EBUSY;
1100 goto failed_unlock;
1101 }
e59399d0 1102 up_read(&nilfs->ns_super_sem);
783f6184
RK		 1103 }
1104
1105 /*
6dd47406 1106 * Find existing nilfs_sb_info struct
783f6184 1107 */
6dd47406
RK		 1108 sd.sbi = nilfs_find_sbinfo(nilfs, !(flags & MS_RDONLY), sd.cno);
1109
6dd47406
RK		 1110 /*
1111 * Get super block instance holding the nilfs_sb_info struct.
1112 * A new instance is allocated if no existing mount is present or
1113 * existing instance has been unmounted.
1114 */
33c8e57c 1115 s = sget(fs_type, nilfs_test_bdev_super, nilfs_set_bdev_super, &sd);
6dd47406
RK		 1116 if (sd.sbi)
1117 nilfs_put_sbinfo(sd.sbi);
1118
33c8e57c
RK		 1119 if (IS_ERR(s)) {
1120 err = PTR_ERR(s);
1121 goto failed_unlock;
783f6184
RK		 1122 }
1123
1124 if (!s->s_root) {
1125 char b[BDEVNAME_SIZE];
1126
33c8e57c 1127 /* New superblock instance created */
783f6184
RK		 1128 s->s_flags = flags;
1129 strlcpy(s->s_id, bdevname(sd.bdev, b), sizeof(s->s_id));
1130 sb_set_blocksize(s, block_size(sd.bdev));
1131
1132 err = nilfs_fill_super(s, data, flags & MS_VERBOSE, nilfs);
1133 if (err)
1134 goto cancel_new;
1135
1136 s->s_flags |= MS_ACTIVE;
1137 need_to_close = 0;
783f6184
RK		 1138 }
1139
aa7dfb89 1140 mutex_unlock(&nilfs->ns_mount_mutex);
783f6184
RK		 1141 put_nilfs(nilfs);
1142 if (need_to_close)
1143 close_bdev_exclusive(sd.bdev, flags);
1144 simple_set_mnt(mnt, s);
1145 return 0;
1146
783f6184 1147 failed_unlock:
aa7dfb89 1148 mutex_unlock(&nilfs->ns_mount_mutex);
33c8e57c 1149 put_nilfs(nilfs);
783f6184
RK		 1150 failed:
1151 close_bdev_exclusive(sd.bdev, flags);
1152
1153 return err;
1154
1155 cancel_new:
1156 /* Abandoning the newly allocated superblock */
aa7dfb89 1157 mutex_unlock(&nilfs->ns_mount_mutex);
33c8e57c 1158 put_nilfs(nilfs);
783f6184
RK		 1159 up_write(&s->s_umount);
1160 deactivate_super(s);
1161 /*
1162 * deactivate_super() invokes close_bdev_exclusive().
1163 * We must finish all post-cleaning before this call;
aa7dfb89 1164 * put_nilfs() needs the block device.
783f6184
RK		 1165 */
1166 return err;
1167}
1168
783f6184
RK		 1169struct file_system_type nilfs_fs_type = {
1170 .owner = THIS_MODULE,
1171 .name = "nilfs2",
1172 .get_sb = nilfs_get_sb,
1173 .kill_sb = kill_block_super,
1174 .fs_flags = FS_REQUIRES_DEV,
1175};
1176
1177static int __init init_nilfs_fs(void)
1178{
1179 int err;
1180
1181 err = nilfs_init_inode_cache();
1182 if (err)
1183 goto failed;
1184
1185 err = nilfs_init_transaction_cache();
1186 if (err)
1187 goto failed_inode_cache;
1188
1189 err = nilfs_init_segbuf_cache();
1190 if (err)
1191 goto failed_transaction_cache;
1192
1193 err = nilfs_btree_path_cache_init();
1194 if (err)
1195 goto failed_segbuf_cache;
1196
1197 err = register_filesystem(&nilfs_fs_type);
1198 if (err)
1199 goto failed_btree_path_cache;
1200
1201 return 0;
1202
1203 failed_btree_path_cache:
1204 nilfs_btree_path_cache_destroy();
1205
1206 failed_segbuf_cache:
1207 nilfs_destroy_segbuf_cache();
1208
1209 failed_transaction_cache:
1210 nilfs_destroy_transaction_cache();
1211
1212 failed_inode_cache:
1213 nilfs_destroy_inode_cache();
1214
1215 failed:
1216 return err;
1217}
1218
1219static void __exit exit_nilfs_fs(void)
1220{
1221 nilfs_destroy_segbuf_cache();
1222 nilfs_destroy_transaction_cache();
1223 nilfs_destroy_inode_cache();
1224 nilfs_btree_path_cache_destroy();
1225 unregister_filesystem(&nilfs_fs_type);
1226}
1227
1228module_init(init_nilfs_fs)
1229module_exit(exit_nilfs_fs)
Linux 6.x block layer and io_uring tree(s)