blob: 6989b03e97ab57517e35abb2f56011775d4af990 [file] [log] [blame]
Ryusuke Konishi783f6182009-04-06 19:01:35 -07001/*
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>
53#include "nilfs.h"
54#include "mdt.h"
55#include "alloc.h"
56#include "page.h"
57#include "cpfile.h"
58#include "ifile.h"
59#include "dat.h"
60#include "segment.h"
61#include "segbuf.h"
62
63MODULE_AUTHOR("NTT Corp.");
64MODULE_DESCRIPTION("A New Implementation of the Log-structured Filesystem "
65 "(NILFS)");
Ryusuke Konishi783f6182009-04-06 19:01:35 -070066MODULE_LICENSE("GPL");
67
68static int nilfs_remount(struct super_block *sb, int *flags, char *data);
69static int test_exclusive_mount(struct file_system_type *fs_type,
70 struct block_device *bdev, int flags);
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;
Ryusuke Konishie339ad32009-04-06 19:01:59 -0700105 nilfs->ns_sbp[0]->s_state |=
106 cpu_to_le16(NILFS_ERROR_FS);
107 nilfs_commit_super(sbi, 1);
Ryusuke Konishi783f6182009-04-06 19:01:35 -0700108 }
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
137struct inode *nilfs_alloc_inode(struct super_block *sb)
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;
147 nilfs_btnode_cache_init(&ii->i_btnode_cache);
148 return &ii->vfs_inode;
149}
150
151void nilfs_destroy_inode(struct inode *inode)
152{
153 kmem_cache_free(nilfs_inode_cachep, NILFS_I(inode));
154}
155
156static void init_once(void *obj)
157{
158 struct nilfs_inode_info *ii = obj;
159
160 INIT_LIST_HEAD(&ii->i_dirty);
161#ifdef CONFIG_NILFS_XATTR
162 init_rwsem(&ii->xattr_sem);
163#endif
164 nilfs_btnode_cache_init_once(&ii->i_btnode_cache);
165 ii->i_bmap = (struct nilfs_bmap *)&ii->i_bmap_union;
166 inode_init_once(&ii->vfs_inode);
167}
168
169static int nilfs_init_inode_cache(void)
170{
171 nilfs_inode_cachep = kmem_cache_create("nilfs2_inode_cache",
172 sizeof(struct nilfs_inode_info),
173 0, SLAB_RECLAIM_ACCOUNT,
174 init_once);
175
176 return (nilfs_inode_cachep == NULL) ? -ENOMEM : 0;
177}
178
179static inline void nilfs_destroy_inode_cache(void)
180{
181 kmem_cache_destroy(nilfs_inode_cachep);
182}
183
184static void nilfs_clear_inode(struct inode *inode)
185{
186 struct nilfs_inode_info *ii = NILFS_I(inode);
Ryusuke Konishi783f6182009-04-06 19:01:35 -0700187
188#ifdef CONFIG_NILFS_POSIX_ACL
189 if (ii->i_acl && ii->i_acl != NILFS_ACL_NOT_CACHED) {
190 posix_acl_release(ii->i_acl);
191 ii->i_acl = NILFS_ACL_NOT_CACHED;
192 }
193 if (ii->i_default_acl && ii->i_default_acl != NILFS_ACL_NOT_CACHED) {
194 posix_acl_release(ii->i_default_acl);
195 ii->i_default_acl = NILFS_ACL_NOT_CACHED;
196 }
197#endif
198 /*
199 * Free resources allocated in nilfs_read_inode(), here.
200 */
Ryusuke Konishia2e7d2d2009-04-06 19:01:44 -0700201 BUG_ON(!list_empty(&ii->i_dirty));
Ryusuke Konishi783f6182009-04-06 19:01:35 -0700202 brelse(ii->i_bh);
203 ii->i_bh = NULL;
Ryusuke Konishi783f6182009-04-06 19:01:35 -0700204
205 if (test_bit(NILFS_I_BMAP, &ii->i_state))
206 nilfs_bmap_clear(ii->i_bmap);
207
208 nilfs_btnode_cache_clear(&ii->i_btnode_cache);
Ryusuke Konishi783f6182009-04-06 19:01:35 -0700209}
210
Ryusuke Konishie339ad32009-04-06 19:01:59 -0700211static int nilfs_sync_super(struct nilfs_sb_info *sbi, int dupsb)
Ryusuke Konishi783f6182009-04-06 19:01:35 -0700212{
213 struct the_nilfs *nilfs = sbi->s_nilfs;
214 int err;
215 int barrier_done = 0;
216
217 if (nilfs_test_opt(sbi, BARRIER)) {
Ryusuke Konishie339ad32009-04-06 19:01:59 -0700218 set_buffer_ordered(nilfs->ns_sbh[0]);
Ryusuke Konishi783f6182009-04-06 19:01:35 -0700219 barrier_done = 1;
220 }
221 retry:
Ryusuke Konishie339ad32009-04-06 19:01:59 -0700222 set_buffer_dirty(nilfs->ns_sbh[0]);
223 err = sync_dirty_buffer(nilfs->ns_sbh[0]);
Ryusuke Konishi783f6182009-04-06 19:01:35 -0700224 if (err == -EOPNOTSUPP && barrier_done) {
225 nilfs_warning(sbi->s_super, __func__,
226 "barrier-based sync failed. "
227 "disabling barriers\n");
228 nilfs_clear_opt(sbi, BARRIER);
229 barrier_done = 0;
Ryusuke Konishie339ad32009-04-06 19:01:59 -0700230 clear_buffer_ordered(nilfs->ns_sbh[0]);
Ryusuke Konishi783f6182009-04-06 19:01:35 -0700231 goto retry;
232 }
Ryusuke Konishie339ad32009-04-06 19:01:59 -0700233 if (unlikely(err)) {
Ryusuke Konishi783f6182009-04-06 19:01:35 -0700234 printk(KERN_ERR
235 "NILFS: unable to write superblock (err=%d)\n", err);
Ryusuke Konishie339ad32009-04-06 19:01:59 -0700236 if (err == -EIO && nilfs->ns_sbh[1]) {
237 nilfs_fall_back_super_block(nilfs);
238 goto retry;
239 }
240 } else {
241 struct nilfs_super_block *sbp = nilfs->ns_sbp[0];
242
243 /*
244 * The latest segment becomes trailable from the position
245 * written in superblock.
246 */
Ryusuke Konishi783f6182009-04-06 19:01:35 -0700247 clear_nilfs_discontinued(nilfs);
Ryusuke Konishie339ad32009-04-06 19:01:59 -0700248
249 /* update GC protection for recent segments */
250 if (nilfs->ns_sbh[1]) {
251 sbp = NULL;
252 if (dupsb) {
253 set_buffer_dirty(nilfs->ns_sbh[1]);
254 if (!sync_dirty_buffer(nilfs->ns_sbh[1]))
255 sbp = nilfs->ns_sbp[1];
256 }
257 }
258 if (sbp) {
259 spin_lock(&nilfs->ns_last_segment_lock);
260 nilfs->ns_prot_seq = le64_to_cpu(sbp->s_last_seq);
261 spin_unlock(&nilfs->ns_last_segment_lock);
262 }
Ryusuke Konishi783f6182009-04-06 19:01:35 -0700263 }
264
265 return err;
266}
267
Ryusuke Konishie339ad32009-04-06 19:01:59 -0700268int nilfs_commit_super(struct nilfs_sb_info *sbi, int dupsb)
Ryusuke Konishi783f6182009-04-06 19:01:35 -0700269{
270 struct the_nilfs *nilfs = sbi->s_nilfs;
Ryusuke Konishie339ad32009-04-06 19:01:59 -0700271 struct nilfs_super_block **sbp = nilfs->ns_sbp;
Ryusuke Konishi783f6182009-04-06 19:01:35 -0700272 sector_t nfreeblocks;
Ryusuke Konishie339ad32009-04-06 19:01:59 -0700273 time_t t;
Ryusuke Konishi783f6182009-04-06 19:01:35 -0700274 int err;
275
276 /* nilfs->sem must be locked by the caller. */
Ryusuke Konishie339ad32009-04-06 19:01:59 -0700277 if (sbp[0]->s_magic != NILFS_SUPER_MAGIC) {
278 if (sbp[1] && sbp[1]->s_magic == NILFS_SUPER_MAGIC)
279 nilfs_swap_super_block(nilfs);
280 else {
281 printk(KERN_CRIT "NILFS: superblock broke on dev %s\n",
282 sbi->s_super->s_id);
283 return -EIO;
284 }
285 }
Ryusuke Konishi783f6182009-04-06 19:01:35 -0700286 err = nilfs_count_free_blocks(nilfs, &nfreeblocks);
287 if (unlikely(err)) {
288 printk(KERN_ERR "NILFS: failed to count free blocks\n");
289 return err;
290 }
Ryusuke Konishie339ad32009-04-06 19:01:59 -0700291 spin_lock(&nilfs->ns_last_segment_lock);
292 sbp[0]->s_last_seq = cpu_to_le64(nilfs->ns_last_seq);
293 sbp[0]->s_last_pseg = cpu_to_le64(nilfs->ns_last_pseg);
294 sbp[0]->s_last_cno = cpu_to_le64(nilfs->ns_last_cno);
295 spin_unlock(&nilfs->ns_last_segment_lock);
296
297 t = get_seconds();
298 nilfs->ns_sbwtime[0] = t;
299 sbp[0]->s_free_blocks_count = cpu_to_le64(nfreeblocks);
300 sbp[0]->s_wtime = cpu_to_le64(t);
301 sbp[0]->s_sum = 0;
302 sbp[0]->s_sum = cpu_to_le32(crc32_le(nilfs->ns_crc_seed,
303 (unsigned char *)sbp[0],
304 nilfs->ns_sbsize));
305 if (dupsb && sbp[1]) {
306 memcpy(sbp[1], sbp[0], nilfs->ns_sbsize);
307 nilfs->ns_sbwtime[1] = t;
308 }
Ryusuke Konishi783f6182009-04-06 19:01:35 -0700309 sbi->s_super->s_dirt = 0;
Ryusuke Konishie339ad32009-04-06 19:01:59 -0700310 return nilfs_sync_super(sbi, dupsb);
Ryusuke Konishi783f6182009-04-06 19:01:35 -0700311}
312
313static void nilfs_put_super(struct super_block *sb)
314{
315 struct nilfs_sb_info *sbi = NILFS_SB(sb);
316 struct the_nilfs *nilfs = sbi->s_nilfs;
317
318 nilfs_detach_segment_constructor(sbi);
319
320 if (!(sb->s_flags & MS_RDONLY)) {
321 down_write(&nilfs->ns_sem);
Ryusuke Konishie339ad32009-04-06 19:01:59 -0700322 nilfs->ns_sbp[0]->s_state = cpu_to_le16(nilfs->ns_mount_state);
323 nilfs_commit_super(sbi, 1);
Ryusuke Konishi783f6182009-04-06 19:01:35 -0700324 up_write(&nilfs->ns_sem);
325 }
326
327 nilfs_detach_checkpoint(sbi);
328 put_nilfs(sbi->s_nilfs);
329 sbi->s_super = NULL;
330 sb->s_fs_info = NULL;
331 kfree(sbi);
332}
333
334/**
335 * nilfs_write_super - write super block(s) of NILFS
336 * @sb: super_block
337 *
338 * nilfs_write_super() gets a fs-dependent lock, writes super block(s), and
339 * clears s_dirt. This function is called in the section protected by
340 * lock_super().
341 *
342 * The s_dirt flag is managed by each filesystem and we protect it by ns_sem
343 * of the struct the_nilfs. Lock order must be as follows:
344 *
345 * 1. lock_super()
346 * 2. down_write(&nilfs->ns_sem)
347 *
348 * Inside NILFS, locking ns_sem is enough to protect s_dirt and the buffer
Ryusuke Konishie339ad32009-04-06 19:01:59 -0700349 * of the super block (nilfs->ns_sbp[]).
Ryusuke Konishi783f6182009-04-06 19:01:35 -0700350 *
351 * In most cases, VFS functions call lock_super() before calling these
352 * methods. So we must be careful not to bring on deadlocks when using
353 * lock_super(); see generic_shutdown_super(), write_super(), and so on.
354 *
355 * Note that order of lock_kernel() and lock_super() depends on contexts
356 * of VFS. We should also note that lock_kernel() can be used in its
357 * protective section and only the outermost one has an effect.
358 */
359static void nilfs_write_super(struct super_block *sb)
360{
361 struct nilfs_sb_info *sbi = NILFS_SB(sb);
362 struct the_nilfs *nilfs = sbi->s_nilfs;
363
364 down_write(&nilfs->ns_sem);
Ryusuke Konishie339ad32009-04-06 19:01:59 -0700365 if (!(sb->s_flags & MS_RDONLY)) {
366 struct nilfs_super_block **sbp = nilfs->ns_sbp;
367 u64 t = get_seconds();
368 int dupsb;
369
370 if (!nilfs_discontinued(nilfs) && t >= nilfs->ns_sbwtime[0] &&
371 t < nilfs->ns_sbwtime[0] + NILFS_SB_FREQ) {
372 up_write(&nilfs->ns_sem);
373 return;
374 }
375 dupsb = sbp[1] && t > nilfs->ns_sbwtime[1] + NILFS_ALTSB_FREQ;
376 nilfs_commit_super(sbi, dupsb);
377 }
Ryusuke Konishi783f6182009-04-06 19:01:35 -0700378 sb->s_dirt = 0;
379 up_write(&nilfs->ns_sem);
380}
381
382static int nilfs_sync_fs(struct super_block *sb, int wait)
383{
384 int err = 0;
385
386 /* This function is called when super block should be written back */
387 if (wait)
388 err = nilfs_construct_segment(sb);
389 return err;
390}
391
392int nilfs_attach_checkpoint(struct nilfs_sb_info *sbi, __u64 cno)
393{
394 struct the_nilfs *nilfs = sbi->s_nilfs;
395 struct nilfs_checkpoint *raw_cp;
396 struct buffer_head *bh_cp;
397 int err;
398
399 down_write(&nilfs->ns_sem);
400 list_add(&sbi->s_list, &nilfs->ns_supers);
401 up_write(&nilfs->ns_sem);
402
403 sbi->s_ifile = nilfs_mdt_new(
404 nilfs, sbi->s_super, NILFS_IFILE_INO, NILFS_IFILE_GFP);
405 if (!sbi->s_ifile)
406 return -ENOMEM;
407
408 err = nilfs_palloc_init_blockgroup(sbi->s_ifile, nilfs->ns_inode_size);
409 if (unlikely(err))
410 goto failed;
411
412 err = nilfs_cpfile_get_checkpoint(nilfs->ns_cpfile, cno, 0, &raw_cp,
413 &bh_cp);
414 if (unlikely(err)) {
415 if (err == -ENOENT || err == -EINVAL) {
416 printk(KERN_ERR
417 "NILFS: Invalid checkpoint "
418 "(checkpoint number=%llu)\n",
419 (unsigned long long)cno);
420 err = -EINVAL;
421 }
422 goto failed;
423 }
424 err = nilfs_read_inode_common(sbi->s_ifile, &raw_cp->cp_ifile_inode);
425 if (unlikely(err))
426 goto failed_bh;
427 atomic_set(&sbi->s_inodes_count, le64_to_cpu(raw_cp->cp_inodes_count));
428 atomic_set(&sbi->s_blocks_count, le64_to_cpu(raw_cp->cp_blocks_count));
429
430 nilfs_cpfile_put_checkpoint(nilfs->ns_cpfile, cno, bh_cp);
431 return 0;
432
433 failed_bh:
434 nilfs_cpfile_put_checkpoint(nilfs->ns_cpfile, cno, bh_cp);
435 failed:
436 nilfs_mdt_destroy(sbi->s_ifile);
437 sbi->s_ifile = NULL;
438
439 down_write(&nilfs->ns_sem);
440 list_del_init(&sbi->s_list);
441 up_write(&nilfs->ns_sem);
442
443 return err;
444}
445
446void nilfs_detach_checkpoint(struct nilfs_sb_info *sbi)
447{
448 struct the_nilfs *nilfs = sbi->s_nilfs;
449
450 nilfs_mdt_clear(sbi->s_ifile);
451 nilfs_mdt_destroy(sbi->s_ifile);
452 sbi->s_ifile = NULL;
453 down_write(&nilfs->ns_sem);
454 list_del_init(&sbi->s_list);
455 up_write(&nilfs->ns_sem);
456}
457
458static int nilfs_mark_recovery_complete(struct nilfs_sb_info *sbi)
459{
460 struct the_nilfs *nilfs = sbi->s_nilfs;
461 int err = 0;
462
463 down_write(&nilfs->ns_sem);
464 if (!(nilfs->ns_mount_state & NILFS_VALID_FS)) {
465 nilfs->ns_mount_state |= NILFS_VALID_FS;
Ryusuke Konishie339ad32009-04-06 19:01:59 -0700466 err = nilfs_commit_super(sbi, 1);
Ryusuke Konishi783f6182009-04-06 19:01:35 -0700467 if (likely(!err))
468 printk(KERN_INFO "NILFS: recovery complete.\n");
469 }
470 up_write(&nilfs->ns_sem);
471 return err;
472}
473
474static int nilfs_statfs(struct dentry *dentry, struct kstatfs *buf)
475{
476 struct super_block *sb = dentry->d_sb;
477 struct nilfs_sb_info *sbi = NILFS_SB(sb);
Ryusuke Konishic306af22009-03-26 10:16:57 +0900478 struct the_nilfs *nilfs = sbi->s_nilfs;
479 u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
Ryusuke Konishi783f6182009-04-06 19:01:35 -0700480 unsigned long long blocks;
481 unsigned long overhead;
482 unsigned long nrsvblocks;
483 sector_t nfreeblocks;
Ryusuke Konishi783f6182009-04-06 19:01:35 -0700484 int err;
485
486 /*
487 * Compute all of the segment blocks
488 *
489 * The blocks before first segment and after last segment
490 * are excluded.
491 */
492 blocks = nilfs->ns_blocks_per_segment * nilfs->ns_nsegments
493 - nilfs->ns_first_data_block;
494 nrsvblocks = nilfs->ns_nrsvsegs * nilfs->ns_blocks_per_segment;
495
496 /*
497 * Compute the overhead
498 *
499 * When distributing meta data blocks outside semgent structure,
500 * We must count them as the overhead.
501 */
502 overhead = 0;
503
504 err = nilfs_count_free_blocks(nilfs, &nfreeblocks);
505 if (unlikely(err))
506 return err;
507
508 buf->f_type = NILFS_SUPER_MAGIC;
509 buf->f_bsize = sb->s_blocksize;
510 buf->f_blocks = blocks - overhead;
511 buf->f_bfree = nfreeblocks;
512 buf->f_bavail = (buf->f_bfree >= nrsvblocks) ?
513 (buf->f_bfree - nrsvblocks) : 0;
514 buf->f_files = atomic_read(&sbi->s_inodes_count);
515 buf->f_ffree = 0; /* nilfs_count_free_inodes(sb); */
516 buf->f_namelen = NILFS_NAME_LEN;
Ryusuke Konishic306af22009-03-26 10:16:57 +0900517 buf->f_fsid.val[0] = (u32)id;
518 buf->f_fsid.val[1] = (u32)(id >> 32);
519
Ryusuke Konishi783f6182009-04-06 19:01:35 -0700520 return 0;
521}
522
523static struct super_operations nilfs_sops = {
524 .alloc_inode = nilfs_alloc_inode,
525 .destroy_inode = nilfs_destroy_inode,
526 .dirty_inode = nilfs_dirty_inode,
527 /* .write_inode = nilfs_write_inode, */
528 /* .put_inode = nilfs_put_inode, */
529 /* .drop_inode = nilfs_drop_inode, */
530 .delete_inode = nilfs_delete_inode,
531 .put_super = nilfs_put_super,
532 .write_super = nilfs_write_super,
533 .sync_fs = nilfs_sync_fs,
534 /* .write_super_lockfs */
535 /* .unlockfs */
536 .statfs = nilfs_statfs,
537 .remount_fs = nilfs_remount,
538 .clear_inode = nilfs_clear_inode,
539 /* .umount_begin */
540 /* .show_options */
541};
542
543static struct inode *
544nilfs_nfs_get_inode(struct super_block *sb, u64 ino, u32 generation)
545{
546 struct inode *inode;
547
548 if (ino < NILFS_FIRST_INO(sb) && ino != NILFS_ROOT_INO &&
549 ino != NILFS_SKETCH_INO)
550 return ERR_PTR(-ESTALE);
551
552 inode = nilfs_iget(sb, ino);
553 if (IS_ERR(inode))
554 return ERR_CAST(inode);
555 if (generation && inode->i_generation != generation) {
556 iput(inode);
557 return ERR_PTR(-ESTALE);
558 }
559
560 return inode;
561}
562
563static struct dentry *
564nilfs_fh_to_dentry(struct super_block *sb, struct fid *fid, int fh_len,
565 int fh_type)
566{
567 return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
568 nilfs_nfs_get_inode);
569}
570
571static struct dentry *
572nilfs_fh_to_parent(struct super_block *sb, struct fid *fid, int fh_len,
573 int fh_type)
574{
575 return generic_fh_to_parent(sb, fid, fh_len, fh_type,
576 nilfs_nfs_get_inode);
577}
578
579static struct export_operations nilfs_export_ops = {
580 .fh_to_dentry = nilfs_fh_to_dentry,
581 .fh_to_parent = nilfs_fh_to_parent,
582 .get_parent = nilfs_get_parent,
583};
584
585enum {
586 Opt_err_cont, Opt_err_panic, Opt_err_ro,
587 Opt_barrier, Opt_snapshot, Opt_order,
588 Opt_err,
589};
590
591static match_table_t tokens = {
592 {Opt_err_cont, "errors=continue"},
593 {Opt_err_panic, "errors=panic"},
594 {Opt_err_ro, "errors=remount-ro"},
595 {Opt_barrier, "barrier=%s"},
596 {Opt_snapshot, "cp=%u"},
597 {Opt_order, "order=%s"},
598 {Opt_err, NULL}
599};
600
601static int match_bool(substring_t *s, int *result)
602{
603 int len = s->to - s->from;
604
605 if (strncmp(s->from, "on", len) == 0)
606 *result = 1;
607 else if (strncmp(s->from, "off", len) == 0)
608 *result = 0;
609 else
610 return 1;
611 return 0;
612}
613
614static int parse_options(char *options, struct super_block *sb)
615{
616 struct nilfs_sb_info *sbi = NILFS_SB(sb);
617 char *p;
618 substring_t args[MAX_OPT_ARGS];
619 int option;
620
621 if (!options)
622 return 1;
623
624 while ((p = strsep(&options, ",")) != NULL) {
625 int token;
626 if (!*p)
627 continue;
628
629 token = match_token(p, tokens, args);
630 switch (token) {
631 case Opt_barrier:
632 if (match_bool(&args[0], &option))
633 return 0;
634 if (option)
635 nilfs_set_opt(sbi, BARRIER);
636 else
637 nilfs_clear_opt(sbi, BARRIER);
638 break;
639 case Opt_order:
640 if (strcmp(args[0].from, "relaxed") == 0)
641 /* Ordered data semantics */
642 nilfs_clear_opt(sbi, STRICT_ORDER);
643 else if (strcmp(args[0].from, "strict") == 0)
644 /* Strict in-order semantics */
645 nilfs_set_opt(sbi, STRICT_ORDER);
646 else
647 return 0;
648 break;
649 case Opt_err_panic:
650 nilfs_write_opt(sbi, ERROR_MODE, ERRORS_PANIC);
651 break;
652 case Opt_err_ro:
653 nilfs_write_opt(sbi, ERROR_MODE, ERRORS_RO);
654 break;
655 case Opt_err_cont:
656 nilfs_write_opt(sbi, ERROR_MODE, ERRORS_CONT);
657 break;
658 case Opt_snapshot:
659 if (match_int(&args[0], &option) || option <= 0)
660 return 0;
661 if (!(sb->s_flags & MS_RDONLY))
662 return 0;
663 sbi->s_snapshot_cno = option;
664 nilfs_set_opt(sbi, SNAPSHOT);
665 break;
666 default:
667 printk(KERN_ERR
668 "NILFS: Unrecognized mount option \"%s\"\n", p);
669 return 0;
670 }
671 }
672 return 1;
673}
674
675static inline void
676nilfs_set_default_options(struct nilfs_sb_info *sbi,
677 struct nilfs_super_block *sbp)
678{
679 sbi->s_mount_opt =
680 NILFS_MOUNT_ERRORS_CONT | NILFS_MOUNT_BARRIER;
681}
682
683static int nilfs_setup_super(struct nilfs_sb_info *sbi)
684{
685 struct the_nilfs *nilfs = sbi->s_nilfs;
Ryusuke Konishie339ad32009-04-06 19:01:59 -0700686 struct nilfs_super_block *sbp = nilfs->ns_sbp[0];
Ryusuke Konishi783f6182009-04-06 19:01:35 -0700687 int max_mnt_count = le16_to_cpu(sbp->s_max_mnt_count);
688 int mnt_count = le16_to_cpu(sbp->s_mnt_count);
689
690 /* nilfs->sem must be locked by the caller. */
691 if (!(nilfs->ns_mount_state & NILFS_VALID_FS)) {
692 printk(KERN_WARNING "NILFS warning: mounting unchecked fs\n");
693 } else if (nilfs->ns_mount_state & NILFS_ERROR_FS) {
694 printk(KERN_WARNING
695 "NILFS warning: mounting fs with errors\n");
696#if 0
697 } else if (max_mnt_count >= 0 && mnt_count >= max_mnt_count) {
698 printk(KERN_WARNING
699 "NILFS warning: maximal mount count reached\n");
700#endif
701 }
702 if (!max_mnt_count)
703 sbp->s_max_mnt_count = cpu_to_le16(NILFS_DFL_MAX_MNT_COUNT);
704
705 sbp->s_mnt_count = cpu_to_le16(mnt_count + 1);
706 sbp->s_state = cpu_to_le16(le16_to_cpu(sbp->s_state) & ~NILFS_VALID_FS);
707 sbp->s_mtime = cpu_to_le64(get_seconds());
Ryusuke Konishie339ad32009-04-06 19:01:59 -0700708 return nilfs_commit_super(sbi, 1);
Ryusuke Konishi783f6182009-04-06 19:01:35 -0700709}
710
Ryusuke Konishie339ad32009-04-06 19:01:59 -0700711struct nilfs_super_block *nilfs_read_super_block(struct super_block *sb,
712 u64 pos, int blocksize,
713 struct buffer_head **pbh)
Ryusuke Konishi783f6182009-04-06 19:01:35 -0700714{
Ryusuke Konishie339ad32009-04-06 19:01:59 -0700715 unsigned long long sb_index = pos;
716 unsigned long offset;
Ryusuke Konishi783f6182009-04-06 19:01:35 -0700717
Ryusuke Konishie339ad32009-04-06 19:01:59 -0700718 offset = do_div(sb_index, blocksize);
Ryusuke Konishi783f6182009-04-06 19:01:35 -0700719 *pbh = sb_bread(sb, sb_index);
Ryusuke Konishie339ad32009-04-06 19:01:59 -0700720 if (!*pbh)
Ryusuke Konishi783f6182009-04-06 19:01:35 -0700721 return NULL;
Ryusuke Konishi783f6182009-04-06 19:01:35 -0700722 return (struct nilfs_super_block *)((char *)(*pbh)->b_data + offset);
723}
724
Ryusuke Konishi783f6182009-04-06 19:01:35 -0700725int nilfs_store_magic_and_option(struct super_block *sb,
726 struct nilfs_super_block *sbp,
727 char *data)
728{
729 struct nilfs_sb_info *sbi = NILFS_SB(sb);
730
Ryusuke Konishi783f6182009-04-06 19:01:35 -0700731 sb->s_magic = le16_to_cpu(sbp->s_magic);
732
733 /* FS independent flags */
734#ifdef NILFS_ATIME_DISABLE
735 sb->s_flags |= MS_NOATIME;
736#endif
737
Ryusuke Konishi783f6182009-04-06 19:01:35 -0700738 nilfs_set_default_options(sbi, sbp);
739
740 sbi->s_resuid = le16_to_cpu(sbp->s_def_resuid);
741 sbi->s_resgid = le16_to_cpu(sbp->s_def_resgid);
742 sbi->s_interval = le32_to_cpu(sbp->s_c_interval);
743 sbi->s_watermark = le32_to_cpu(sbp->s_c_block_max);
744
Ryusuke Konishie339ad32009-04-06 19:01:59 -0700745 return !parse_options(data, sb) ? -EINVAL : 0 ;
Ryusuke Konishi783f6182009-04-06 19:01:35 -0700746}
747
748/**
749 * nilfs_fill_super() - initialize a super block instance
750 * @sb: super_block
751 * @data: mount options
752 * @silent: silent mode flag
753 * @nilfs: the_nilfs struct
754 *
755 * This function is called exclusively by bd_mount_mutex.
756 * So, the recovery process is protected from other simultaneous mounts.
757 */
758static int
759nilfs_fill_super(struct super_block *sb, void *data, int silent,
760 struct the_nilfs *nilfs)
761{
762 struct nilfs_sb_info *sbi;
763 struct inode *root;
764 __u64 cno;
765 int err;
766
767 sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
768 if (!sbi)
769 return -ENOMEM;
770
771 sb->s_fs_info = sbi;
772
773 get_nilfs(nilfs);
774 sbi->s_nilfs = nilfs;
775 sbi->s_super = sb;
776
777 err = init_nilfs(nilfs, sbi, (char *)data);
778 if (err)
779 goto failed_sbi;
780
781 spin_lock_init(&sbi->s_inode_lock);
782 INIT_LIST_HEAD(&sbi->s_dirty_files);
783 INIT_LIST_HEAD(&sbi->s_list);
784
785 /*
786 * Following initialization is overlapped because
787 * nilfs_sb_info structure has been cleared at the beginning.
788 * But we reserve them to keep our interest and make ready
789 * for the future change.
790 */
791 get_random_bytes(&sbi->s_next_generation,
792 sizeof(sbi->s_next_generation));
793 spin_lock_init(&sbi->s_next_gen_lock);
794
795 sb->s_op = &nilfs_sops;
796 sb->s_export_op = &nilfs_export_ops;
797 sb->s_root = NULL;
Ryusuke Konishi61239232009-04-06 19:02:00 -0700798 sb->s_time_gran = 1;
Ryusuke Konishi783f6182009-04-06 19:01:35 -0700799
800 if (!nilfs_loaded(nilfs)) {
801 err = load_nilfs(nilfs, sbi);
802 if (err)
803 goto failed_sbi;
804 }
805 cno = nilfs_last_cno(nilfs);
806
807 if (sb->s_flags & MS_RDONLY) {
808 if (nilfs_test_opt(sbi, SNAPSHOT)) {
Ryusuke Konishi1f5abe72009-04-06 19:01:55 -0700809 err = nilfs_cpfile_is_snapshot(nilfs->ns_cpfile,
810 sbi->s_snapshot_cno);
811 if (err < 0)
812 goto failed_sbi;
813 if (!err) {
Ryusuke Konishi783f6182009-04-06 19:01:35 -0700814 printk(KERN_ERR
815 "NILFS: The specified checkpoint is "
816 "not a snapshot "
817 "(checkpoint number=%llu).\n",
818 (unsigned long long)sbi->s_snapshot_cno);
819 err = -EINVAL;
820 goto failed_sbi;
821 }
822 cno = sbi->s_snapshot_cno;
823 } else
824 /* Read-only mount */
825 sbi->s_snapshot_cno = cno;
826 }
827
828 err = nilfs_attach_checkpoint(sbi, cno);
829 if (err) {
830 printk(KERN_ERR "NILFS: error loading a checkpoint"
831 " (checkpoint number=%llu).\n", (unsigned long long)cno);
832 goto failed_sbi;
833 }
834
835 if (!(sb->s_flags & MS_RDONLY)) {
Ryusuke Konishicece5522009-04-06 19:01:58 -0700836 err = nilfs_attach_segment_constructor(sbi);
Ryusuke Konishi783f6182009-04-06 19:01:35 -0700837 if (err)
838 goto failed_checkpoint;
839 }
840
841 root = nilfs_iget(sb, NILFS_ROOT_INO);
842 if (IS_ERR(root)) {
843 printk(KERN_ERR "NILFS: get root inode failed\n");
844 err = PTR_ERR(root);
845 goto failed_segctor;
846 }
847 if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
848 iput(root);
849 printk(KERN_ERR "NILFS: corrupt root inode.\n");
850 err = -EINVAL;
851 goto failed_segctor;
852 }
853 sb->s_root = d_alloc_root(root);
854 if (!sb->s_root) {
855 iput(root);
856 printk(KERN_ERR "NILFS: get root dentry failed\n");
857 err = -ENOMEM;
858 goto failed_segctor;
859 }
860
861 if (!(sb->s_flags & MS_RDONLY)) {
862 down_write(&nilfs->ns_sem);
863 nilfs_setup_super(sbi);
864 up_write(&nilfs->ns_sem);
865 }
866
867 err = nilfs_mark_recovery_complete(sbi);
868 if (unlikely(err)) {
869 printk(KERN_ERR "NILFS: recovery failed.\n");
870 goto failed_root;
871 }
872
873 return 0;
874
875 failed_root:
876 dput(sb->s_root);
877 sb->s_root = NULL;
878
879 failed_segctor:
880 nilfs_detach_segment_constructor(sbi);
881
882 failed_checkpoint:
883 nilfs_detach_checkpoint(sbi);
884
885 failed_sbi:
886 put_nilfs(nilfs);
887 sb->s_fs_info = NULL;
888 kfree(sbi);
889 return err;
890}
891
892static int nilfs_remount(struct super_block *sb, int *flags, char *data)
893{
894 struct nilfs_sb_info *sbi = NILFS_SB(sb);
895 struct nilfs_super_block *sbp;
896 struct the_nilfs *nilfs = sbi->s_nilfs;
897 unsigned long old_sb_flags;
898 struct nilfs_mount_options old_opts;
899 int err;
900
901 old_sb_flags = sb->s_flags;
902 old_opts.mount_opt = sbi->s_mount_opt;
903 old_opts.snapshot_cno = sbi->s_snapshot_cno;
904
905 if (!parse_options(data, sb)) {
906 err = -EINVAL;
907 goto restore_opts;
908 }
909 sb->s_flags = (sb->s_flags & ~MS_POSIXACL);
910
911 if ((*flags & MS_RDONLY) &&
912 sbi->s_snapshot_cno != old_opts.snapshot_cno) {
913 printk(KERN_WARNING "NILFS (device %s): couldn't "
914 "remount to a different snapshot. \n",
915 sb->s_id);
916 err = -EINVAL;
917 goto restore_opts;
918 }
919
920 if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
921 goto out;
922 if (*flags & MS_RDONLY) {
923 /* Shutting down the segment constructor */
924 nilfs_detach_segment_constructor(sbi);
925 sb->s_flags |= MS_RDONLY;
926
927 sbi->s_snapshot_cno = nilfs_last_cno(nilfs);
928 /* nilfs_set_opt(sbi, SNAPSHOT); */
929
930 /*
931 * Remounting a valid RW partition RDONLY, so set
932 * the RDONLY flag and then mark the partition as valid again.
933 */
934 down_write(&nilfs->ns_sem);
Ryusuke Konishie339ad32009-04-06 19:01:59 -0700935 sbp = nilfs->ns_sbp[0];
Ryusuke Konishi783f6182009-04-06 19:01:35 -0700936 if (!(sbp->s_state & le16_to_cpu(NILFS_VALID_FS)) &&
937 (nilfs->ns_mount_state & NILFS_VALID_FS))
938 sbp->s_state = cpu_to_le16(nilfs->ns_mount_state);
939 sbp->s_mtime = cpu_to_le64(get_seconds());
Ryusuke Konishie339ad32009-04-06 19:01:59 -0700940 nilfs_commit_super(sbi, 1);
Ryusuke Konishi783f6182009-04-06 19:01:35 -0700941 up_write(&nilfs->ns_sem);
942 } else {
943 /*
944 * Mounting a RDONLY partition read-write, so reread and
945 * store the current valid flag. (It may have been changed
946 * by fsck since we originally mounted the partition.)
947 */
948 down(&sb->s_bdev->bd_mount_sem);
949 /* Check existing RW-mount */
950 if (test_exclusive_mount(sb->s_type, sb->s_bdev, 0)) {
951 printk(KERN_WARNING "NILFS (device %s): couldn't "
952 "remount because a RW-mount exists.\n",
953 sb->s_id);
954 err = -EBUSY;
955 goto rw_remount_failed;
956 }
957 if (sbi->s_snapshot_cno != nilfs_last_cno(nilfs)) {
958 printk(KERN_WARNING "NILFS (device %s): couldn't "
959 "remount because the current RO-mount is not "
960 "the latest one.\n",
961 sb->s_id);
962 err = -EINVAL;
963 goto rw_remount_failed;
964 }
965 sb->s_flags &= ~MS_RDONLY;
966 nilfs_clear_opt(sbi, SNAPSHOT);
967 sbi->s_snapshot_cno = 0;
968
Ryusuke Konishicece5522009-04-06 19:01:58 -0700969 err = nilfs_attach_segment_constructor(sbi);
Ryusuke Konishi783f6182009-04-06 19:01:35 -0700970 if (err)
971 goto rw_remount_failed;
972
973 down_write(&nilfs->ns_sem);
974 nilfs_setup_super(sbi);
975 up_write(&nilfs->ns_sem);
976
977 up(&sb->s_bdev->bd_mount_sem);
978 }
979 out:
980 return 0;
981
982 rw_remount_failed:
983 up(&sb->s_bdev->bd_mount_sem);
984 restore_opts:
985 sb->s_flags = old_sb_flags;
986 sbi->s_mount_opt = old_opts.mount_opt;
987 sbi->s_snapshot_cno = old_opts.snapshot_cno;
988 return err;
989}
990
991struct nilfs_super_data {
992 struct block_device *bdev;
993 __u64 cno;
994 int flags;
995};
996
997/**
998 * nilfs_identify - pre-read mount options needed to identify mount instance
999 * @data: mount options
1000 * @sd: nilfs_super_data
1001 */
1002static int nilfs_identify(char *data, struct nilfs_super_data *sd)
1003{
1004 char *p, *options = data;
1005 substring_t args[MAX_OPT_ARGS];
1006 int option, token;
1007 int ret = 0;
1008
1009 do {
1010 p = strsep(&options, ",");
1011 if (p != NULL && *p) {
1012 token = match_token(p, tokens, args);
1013 if (token == Opt_snapshot) {
1014 if (!(sd->flags & MS_RDONLY))
1015 ret++;
1016 else {
1017 ret = match_int(&args[0], &option);
1018 if (!ret) {
1019 if (option > 0)
1020 sd->cno = option;
1021 else
1022 ret++;
1023 }
1024 }
1025 }
1026 if (ret)
1027 printk(KERN_ERR
1028 "NILFS: invalid mount option: %s\n", p);
1029 }
1030 if (!options)
1031 break;
1032 BUG_ON(options == data);
1033 *(options - 1) = ',';
1034 } while (!ret);
1035 return ret;
1036}
1037
1038static int nilfs_set_bdev_super(struct super_block *s, void *data)
1039{
1040 struct nilfs_super_data *sd = data;
1041
1042 s->s_bdev = sd->bdev;
1043 s->s_dev = s->s_bdev->bd_dev;
1044 return 0;
1045}
1046
1047static int nilfs_test_bdev_super(struct super_block *s, void *data)
1048{
1049 struct nilfs_super_data *sd = data;
1050
1051 return s->s_bdev == sd->bdev;
1052}
1053
1054static int nilfs_test_bdev_super2(struct super_block *s, void *data)
1055{
1056 struct nilfs_super_data *sd = data;
1057 int ret;
1058
1059 if (s->s_bdev != sd->bdev)
1060 return 0;
1061
1062 if (!((s->s_flags | sd->flags) & MS_RDONLY))
1063 return 1; /* Reuse an old R/W-mode super_block */
1064
1065 if (s->s_flags & sd->flags & MS_RDONLY) {
1066 if (down_read_trylock(&s->s_umount)) {
1067 ret = s->s_root &&
1068 (sd->cno == NILFS_SB(s)->s_snapshot_cno);
1069 up_read(&s->s_umount);
1070 /*
1071 * This path is locked with sb_lock by sget().
1072 * So, drop_super() causes deadlock.
1073 */
1074 return ret;
1075 }
1076 }
1077 return 0;
1078}
1079
1080static int
1081nilfs_get_sb(struct file_system_type *fs_type, int flags,
1082 const char *dev_name, void *data, struct vfsmount *mnt)
1083{
1084 struct nilfs_super_data sd;
1085 struct super_block *s, *s2;
1086 struct the_nilfs *nilfs = NULL;
1087 int err, need_to_close = 1;
1088
1089 sd.bdev = open_bdev_exclusive(dev_name, flags, fs_type);
1090 if (IS_ERR(sd.bdev))
1091 return PTR_ERR(sd.bdev);
1092
1093 /*
1094 * To get mount instance using sget() vfs-routine, NILFS needs
1095 * much more information than normal filesystems to identify mount
1096 * instance. For snapshot mounts, not only a mount type (ro-mount
1097 * or rw-mount) but also a checkpoint number is required.
1098 * The results are passed in sget() using nilfs_super_data.
1099 */
1100 sd.cno = 0;
1101 sd.flags = flags;
1102 if (nilfs_identify((char *)data, &sd)) {
1103 err = -EINVAL;
1104 goto failed;
1105 }
1106
1107 /*
1108 * once the super is inserted into the list by sget, s_umount
1109 * will protect the lockfs code from trying to start a snapshot
1110 * while we are mounting
1111 */
1112 down(&sd.bdev->bd_mount_sem);
1113 if (!sd.cno &&
1114 (err = test_exclusive_mount(fs_type, sd.bdev, flags ^ MS_RDONLY))) {
1115 err = (err < 0) ? : -EBUSY;
1116 goto failed_unlock;
1117 }
1118
1119 /*
1120 * Phase-1: search any existent instance and get the_nilfs
1121 */
1122 s = sget(fs_type, nilfs_test_bdev_super, nilfs_set_bdev_super, &sd);
1123 if (IS_ERR(s))
1124 goto error_s;
1125
1126 if (!s->s_root) {
1127 err = -ENOMEM;
1128 nilfs = alloc_nilfs(sd.bdev);
1129 if (!nilfs)
1130 goto cancel_new;
1131 } else {
1132 struct nilfs_sb_info *sbi = NILFS_SB(s);
1133
Ryusuke Konishi783f6182009-04-06 19:01:35 -07001134 /*
1135 * s_umount protects super_block from unmount process;
1136 * It covers pointers of nilfs_sb_info and the_nilfs.
1137 */
1138 nilfs = sbi->s_nilfs;
1139 get_nilfs(nilfs);
1140 up_write(&s->s_umount);
1141
1142 /*
1143 * Phase-2: search specified snapshot or R/W mode super_block
1144 */
1145 if (!sd.cno)
1146 /* trying to get the latest checkpoint. */
1147 sd.cno = nilfs_last_cno(nilfs);
1148
1149 s2 = sget(fs_type, nilfs_test_bdev_super2,
1150 nilfs_set_bdev_super, &sd);
1151 deactivate_super(s);
1152 /*
1153 * Although deactivate_super() invokes close_bdev_exclusive() at
1154 * kill_block_super(). Here, s is an existent mount; we need
1155 * one more close_bdev_exclusive() call.
1156 */
1157 s = s2;
1158 if (IS_ERR(s))
1159 goto error_s;
1160 }
1161
1162 if (!s->s_root) {
1163 char b[BDEVNAME_SIZE];
1164
1165 s->s_flags = flags;
1166 strlcpy(s->s_id, bdevname(sd.bdev, b), sizeof(s->s_id));
1167 sb_set_blocksize(s, block_size(sd.bdev));
1168
1169 err = nilfs_fill_super(s, data, flags & MS_VERBOSE, nilfs);
1170 if (err)
1171 goto cancel_new;
1172
1173 s->s_flags |= MS_ACTIVE;
1174 need_to_close = 0;
1175 } else if (!(s->s_flags & MS_RDONLY)) {
1176 err = -EBUSY;
1177 }
1178
1179 up(&sd.bdev->bd_mount_sem);
1180 put_nilfs(nilfs);
1181 if (need_to_close)
1182 close_bdev_exclusive(sd.bdev, flags);
1183 simple_set_mnt(mnt, s);
1184 return 0;
1185
1186 error_s:
1187 up(&sd.bdev->bd_mount_sem);
1188 if (nilfs)
1189 put_nilfs(nilfs);
1190 close_bdev_exclusive(sd.bdev, flags);
1191 return PTR_ERR(s);
1192
1193 failed_unlock:
1194 up(&sd.bdev->bd_mount_sem);
1195 failed:
1196 close_bdev_exclusive(sd.bdev, flags);
1197
1198 return err;
1199
1200 cancel_new:
1201 /* Abandoning the newly allocated superblock */
1202 up(&sd.bdev->bd_mount_sem);
1203 if (nilfs)
1204 put_nilfs(nilfs);
1205 up_write(&s->s_umount);
1206 deactivate_super(s);
1207 /*
1208 * deactivate_super() invokes close_bdev_exclusive().
1209 * We must finish all post-cleaning before this call;
1210 * put_nilfs() and unlocking bd_mount_sem need the block device.
1211 */
1212 return err;
1213}
1214
1215static int nilfs_test_bdev_super3(struct super_block *s, void *data)
1216{
1217 struct nilfs_super_data *sd = data;
1218 int ret;
1219
1220 if (s->s_bdev != sd->bdev)
1221 return 0;
1222 if (down_read_trylock(&s->s_umount)) {
1223 ret = (s->s_flags & MS_RDONLY) && s->s_root &&
1224 nilfs_test_opt(NILFS_SB(s), SNAPSHOT);
1225 up_read(&s->s_umount);
1226 if (ret)
1227 return 0; /* ignore snapshot mounts */
1228 }
1229 return !((sd->flags ^ s->s_flags) & MS_RDONLY);
1230}
1231
1232static int __false_bdev_super(struct super_block *s, void *data)
1233{
1234#if 0 /* XXX: workaround for lock debug. This is not good idea */
1235 up_write(&s->s_umount);
1236#endif
1237 return -EFAULT;
1238}
1239
1240/**
1241 * test_exclusive_mount - check whether an exclusive RW/RO mount exists or not.
1242 * fs_type: filesystem type
1243 * bdev: block device
1244 * flag: 0 (check rw-mount) or MS_RDONLY (check ro-mount)
1245 * res: pointer to an integer to store result
1246 *
1247 * This function must be called within a section protected by bd_mount_mutex.
1248 */
1249static int test_exclusive_mount(struct file_system_type *fs_type,
1250 struct block_device *bdev, int flags)
1251{
1252 struct super_block *s;
1253 struct nilfs_super_data sd = { .flags = flags, .bdev = bdev };
1254
1255 s = sget(fs_type, nilfs_test_bdev_super3, __false_bdev_super, &sd);
1256 if (IS_ERR(s)) {
1257 if (PTR_ERR(s) != -EFAULT)
1258 return PTR_ERR(s);
1259 return 0; /* Not found */
1260 }
1261 up_write(&s->s_umount);
1262 deactivate_super(s);
1263 return 1; /* Found */
1264}
1265
1266struct file_system_type nilfs_fs_type = {
1267 .owner = THIS_MODULE,
1268 .name = "nilfs2",
1269 .get_sb = nilfs_get_sb,
1270 .kill_sb = kill_block_super,
1271 .fs_flags = FS_REQUIRES_DEV,
1272};
1273
1274static int __init init_nilfs_fs(void)
1275{
1276 int err;
1277
1278 err = nilfs_init_inode_cache();
1279 if (err)
1280 goto failed;
1281
1282 err = nilfs_init_transaction_cache();
1283 if (err)
1284 goto failed_inode_cache;
1285
1286 err = nilfs_init_segbuf_cache();
1287 if (err)
1288 goto failed_transaction_cache;
1289
1290 err = nilfs_btree_path_cache_init();
1291 if (err)
1292 goto failed_segbuf_cache;
1293
1294 err = register_filesystem(&nilfs_fs_type);
1295 if (err)
1296 goto failed_btree_path_cache;
1297
1298 return 0;
1299
1300 failed_btree_path_cache:
1301 nilfs_btree_path_cache_destroy();
1302
1303 failed_segbuf_cache:
1304 nilfs_destroy_segbuf_cache();
1305
1306 failed_transaction_cache:
1307 nilfs_destroy_transaction_cache();
1308
1309 failed_inode_cache:
1310 nilfs_destroy_inode_cache();
1311
1312 failed:
1313 return err;
1314}
1315
1316static void __exit exit_nilfs_fs(void)
1317{
1318 nilfs_destroy_segbuf_cache();
1319 nilfs_destroy_transaction_cache();
1320 nilfs_destroy_inode_cache();
1321 nilfs_btree_path_cache_destroy();
1322 unregister_filesystem(&nilfs_fs_type);
1323}
1324
1325module_init(init_nilfs_fs)
1326module_exit(exit_nilfs_fs)