filesystem freeze: add error handling of write_super_lockfs/unlockfs
[linux-3.10.git] / fs / jfs / super.c
1 /*
2  *   Copyright (C) International Business Machines Corp., 2000-2004
3  *   Portions Copyright (C) Christoph Hellwig, 2001-2002
4  *
5  *   This program is free software;  you can redistribute it and/or modify
6  *   it under the terms of the GNU General Public License as published by
7  *   the Free Software Foundation; either version 2 of the License, or
8  *   (at your option) any later version.
9  *
10  *   This program is distributed in the hope that it will be useful,
11  *   but WITHOUT ANY WARRANTY;  without even the implied warranty of
12  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
13  *   the GNU General Public License for more details.
14  *
15  *   You should have received a copy of the GNU General Public License
16  *   along with this program;  if not, write to the Free Software
17  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
18  */
19
20 #include <linux/fs.h>
21 #include <linux/module.h>
22 #include <linux/parser.h>
23 #include <linux/completion.h>
24 #include <linux/vfs.h>
25 #include <linux/quotaops.h>
26 #include <linux/mount.h>
27 #include <linux/moduleparam.h>
28 #include <linux/kthread.h>
29 #include <linux/posix_acl.h>
30 #include <linux/buffer_head.h>
31 #include <linux/exportfs.h>
32 #include <asm/uaccess.h>
33 #include <linux/seq_file.h>
34
35 #include "jfs_incore.h"
36 #include "jfs_filsys.h"
37 #include "jfs_inode.h"
38 #include "jfs_metapage.h"
39 #include "jfs_superblock.h"
40 #include "jfs_dmap.h"
41 #include "jfs_imap.h"
42 #include "jfs_acl.h"
43 #include "jfs_debug.h"
44
45 MODULE_DESCRIPTION("The Journaled Filesystem (JFS)");
46 MODULE_AUTHOR("Steve Best/Dave Kleikamp/Barry Arndt, IBM");
47 MODULE_LICENSE("GPL");
48
49 static struct kmem_cache * jfs_inode_cachep;
50
51 static const struct super_operations jfs_super_operations;
52 static const struct export_operations jfs_export_operations;
53 static struct file_system_type jfs_fs_type;
54
55 #define MAX_COMMIT_THREADS 64
56 static int commit_threads = 0;
57 module_param(commit_threads, int, 0);
58 MODULE_PARM_DESC(commit_threads, "Number of commit threads");
59
60 static struct task_struct *jfsCommitThread[MAX_COMMIT_THREADS];
61 struct task_struct *jfsIOthread;
62 struct task_struct *jfsSyncThread;
63
64 #ifdef CONFIG_JFS_DEBUG
65 int jfsloglevel = JFS_LOGLEVEL_WARN;
66 module_param(jfsloglevel, int, 0644);
67 MODULE_PARM_DESC(jfsloglevel, "Specify JFS loglevel (0, 1 or 2)");
68 #endif
69
70 static void jfs_handle_error(struct super_block *sb)
71 {
72         struct jfs_sb_info *sbi = JFS_SBI(sb);
73
74         if (sb->s_flags & MS_RDONLY)
75                 return;
76
77         updateSuper(sb, FM_DIRTY);
78
79         if (sbi->flag & JFS_ERR_PANIC)
80                 panic("JFS (device %s): panic forced after error\n",
81                         sb->s_id);
82         else if (sbi->flag & JFS_ERR_REMOUNT_RO) {
83                 jfs_err("ERROR: (device %s): remounting filesystem "
84                         "as read-only\n",
85                         sb->s_id);
86                 sb->s_flags |= MS_RDONLY;
87         }
88
89         /* nothing is done for continue beyond marking the superblock dirty */
90 }
91
92 void jfs_error(struct super_block *sb, const char * function, ...)
93 {
94         static char error_buf[256];
95         va_list args;
96
97         va_start(args, function);
98         vsnprintf(error_buf, sizeof(error_buf), function, args);
99         va_end(args);
100
101         printk(KERN_ERR "ERROR: (device %s): %s\n", sb->s_id, error_buf);
102
103         jfs_handle_error(sb);
104 }
105
106 static struct inode *jfs_alloc_inode(struct super_block *sb)
107 {
108         struct jfs_inode_info *jfs_inode;
109
110         jfs_inode = kmem_cache_alloc(jfs_inode_cachep, GFP_NOFS);
111         if (!jfs_inode)
112                 return NULL;
113         return &jfs_inode->vfs_inode;
114 }
115
116 static void jfs_destroy_inode(struct inode *inode)
117 {
118         struct jfs_inode_info *ji = JFS_IP(inode);
119
120         BUG_ON(!list_empty(&ji->anon_inode_list));
121
122         spin_lock_irq(&ji->ag_lock);
123         if (ji->active_ag != -1) {
124                 struct bmap *bmap = JFS_SBI(inode->i_sb)->bmap;
125                 atomic_dec(&bmap->db_active[ji->active_ag]);
126                 ji->active_ag = -1;
127         }
128         spin_unlock_irq(&ji->ag_lock);
129
130 #ifdef CONFIG_JFS_POSIX_ACL
131         if (ji->i_acl != JFS_ACL_NOT_CACHED) {
132                 posix_acl_release(ji->i_acl);
133                 ji->i_acl = JFS_ACL_NOT_CACHED;
134         }
135         if (ji->i_default_acl != JFS_ACL_NOT_CACHED) {
136                 posix_acl_release(ji->i_default_acl);
137                 ji->i_default_acl = JFS_ACL_NOT_CACHED;
138         }
139 #endif
140
141         kmem_cache_free(jfs_inode_cachep, ji);
142 }
143
144 static int jfs_statfs(struct dentry *dentry, struct kstatfs *buf)
145 {
146         struct jfs_sb_info *sbi = JFS_SBI(dentry->d_sb);
147         s64 maxinodes;
148         struct inomap *imap = JFS_IP(sbi->ipimap)->i_imap;
149
150         jfs_info("In jfs_statfs");
151         buf->f_type = JFS_SUPER_MAGIC;
152         buf->f_bsize = sbi->bsize;
153         buf->f_blocks = sbi->bmap->db_mapsize;
154         buf->f_bfree = sbi->bmap->db_nfree;
155         buf->f_bavail = sbi->bmap->db_nfree;
156         /*
157          * If we really return the number of allocated & free inodes, some
158          * applications will fail because they won't see enough free inodes.
159          * We'll try to calculate some guess as to how may inodes we can
160          * really allocate
161          *
162          * buf->f_files = atomic_read(&imap->im_numinos);
163          * buf->f_ffree = atomic_read(&imap->im_numfree);
164          */
165         maxinodes = min((s64) atomic_read(&imap->im_numinos) +
166                         ((sbi->bmap->db_nfree >> imap->im_l2nbperiext)
167                          << L2INOSPEREXT), (s64) 0xffffffffLL);
168         buf->f_files = maxinodes;
169         buf->f_ffree = maxinodes - (atomic_read(&imap->im_numinos) -
170                                     atomic_read(&imap->im_numfree));
171
172         buf->f_namelen = JFS_NAME_MAX;
173         return 0;
174 }
175
176 static void jfs_put_super(struct super_block *sb)
177 {
178         struct jfs_sb_info *sbi = JFS_SBI(sb);
179         int rc;
180
181         jfs_info("In jfs_put_super");
182         rc = jfs_umount(sb);
183         if (rc)
184                 jfs_err("jfs_umount failed with return code %d", rc);
185         if (sbi->nls_tab)
186                 unload_nls(sbi->nls_tab);
187         sbi->nls_tab = NULL;
188
189         truncate_inode_pages(sbi->direct_inode->i_mapping, 0);
190         iput(sbi->direct_inode);
191         sbi->direct_inode = NULL;
192
193         kfree(sbi);
194 }
195
196 enum {
197         Opt_integrity, Opt_nointegrity, Opt_iocharset, Opt_resize,
198         Opt_resize_nosize, Opt_errors, Opt_ignore, Opt_err, Opt_quota,
199         Opt_usrquota, Opt_grpquota, Opt_uid, Opt_gid, Opt_umask
200 };
201
202 static const match_table_t tokens = {
203         {Opt_integrity, "integrity"},
204         {Opt_nointegrity, "nointegrity"},
205         {Opt_iocharset, "iocharset=%s"},
206         {Opt_resize, "resize=%u"},
207         {Opt_resize_nosize, "resize"},
208         {Opt_errors, "errors=%s"},
209         {Opt_ignore, "noquota"},
210         {Opt_ignore, "quota"},
211         {Opt_usrquota, "usrquota"},
212         {Opt_grpquota, "grpquota"},
213         {Opt_uid, "uid=%u"},
214         {Opt_gid, "gid=%u"},
215         {Opt_umask, "umask=%u"},
216         {Opt_err, NULL}
217 };
218
219 static int parse_options(char *options, struct super_block *sb, s64 *newLVSize,
220                          int *flag)
221 {
222         void *nls_map = (void *)-1;     /* -1: no change;  NULL: none */
223         char *p;
224         struct jfs_sb_info *sbi = JFS_SBI(sb);
225
226         *newLVSize = 0;
227
228         if (!options)
229                 return 1;
230
231         while ((p = strsep(&options, ",")) != NULL) {
232                 substring_t args[MAX_OPT_ARGS];
233                 int token;
234                 if (!*p)
235                         continue;
236
237                 token = match_token(p, tokens, args);
238                 switch (token) {
239                 case Opt_integrity:
240                         *flag &= ~JFS_NOINTEGRITY;
241                         break;
242                 case Opt_nointegrity:
243                         *flag |= JFS_NOINTEGRITY;
244                         break;
245                 case Opt_ignore:
246                         /* Silently ignore the quota options */
247                         /* Don't do anything ;-) */
248                         break;
249                 case Opt_iocharset:
250                         if (nls_map && nls_map != (void *) -1)
251                                 unload_nls(nls_map);
252                         if (!strcmp(args[0].from, "none"))
253                                 nls_map = NULL;
254                         else {
255                                 nls_map = load_nls(args[0].from);
256                                 if (!nls_map) {
257                                         printk(KERN_ERR
258                                                "JFS: charset not found\n");
259                                         goto cleanup;
260                                 }
261                         }
262                         break;
263                 case Opt_resize:
264                 {
265                         char *resize = args[0].from;
266                         *newLVSize = simple_strtoull(resize, &resize, 0);
267                         break;
268                 }
269                 case Opt_resize_nosize:
270                 {
271                         *newLVSize = sb->s_bdev->bd_inode->i_size >>
272                                 sb->s_blocksize_bits;
273                         if (*newLVSize == 0)
274                                 printk(KERN_ERR
275                                        "JFS: Cannot determine volume size\n");
276                         break;
277                 }
278                 case Opt_errors:
279                 {
280                         char *errors = args[0].from;
281                         if (!errors || !*errors)
282                                 goto cleanup;
283                         if (!strcmp(errors, "continue")) {
284                                 *flag &= ~JFS_ERR_REMOUNT_RO;
285                                 *flag &= ~JFS_ERR_PANIC;
286                                 *flag |= JFS_ERR_CONTINUE;
287                         } else if (!strcmp(errors, "remount-ro")) {
288                                 *flag &= ~JFS_ERR_CONTINUE;
289                                 *flag &= ~JFS_ERR_PANIC;
290                                 *flag |= JFS_ERR_REMOUNT_RO;
291                         } else if (!strcmp(errors, "panic")) {
292                                 *flag &= ~JFS_ERR_CONTINUE;
293                                 *flag &= ~JFS_ERR_REMOUNT_RO;
294                                 *flag |= JFS_ERR_PANIC;
295                         } else {
296                                 printk(KERN_ERR
297                                        "JFS: %s is an invalid error handler\n",
298                                        errors);
299                                 goto cleanup;
300                         }
301                         break;
302                 }
303
304 #ifdef CONFIG_QUOTA
305                 case Opt_quota:
306                 case Opt_usrquota:
307                         *flag |= JFS_USRQUOTA;
308                         break;
309                 case Opt_grpquota:
310                         *flag |= JFS_GRPQUOTA;
311                         break;
312 #else
313                 case Opt_usrquota:
314                 case Opt_grpquota:
315                 case Opt_quota:
316                         printk(KERN_ERR
317                                "JFS: quota operations not supported\n");
318                         break;
319 #endif
320                 case Opt_uid:
321                 {
322                         char *uid = args[0].from;
323                         sbi->uid = simple_strtoul(uid, &uid, 0);
324                         break;
325                 }
326                 case Opt_gid:
327                 {
328                         char *gid = args[0].from;
329                         sbi->gid = simple_strtoul(gid, &gid, 0);
330                         break;
331                 }
332                 case Opt_umask:
333                 {
334                         char *umask = args[0].from;
335                         sbi->umask = simple_strtoul(umask, &umask, 8);
336                         if (sbi->umask & ~0777) {
337                                 printk(KERN_ERR
338                                        "JFS: Invalid value of umask\n");
339                                 goto cleanup;
340                         }
341                         break;
342                 }
343                 default:
344                         printk("jfs: Unrecognized mount option \"%s\" "
345                                         " or missing value\n", p);
346                         goto cleanup;
347                 }
348         }
349
350         if (nls_map != (void *) -1) {
351                 /* Discard old (if remount) */
352                 if (sbi->nls_tab)
353                         unload_nls(sbi->nls_tab);
354                 sbi->nls_tab = nls_map;
355         }
356         return 1;
357
358 cleanup:
359         if (nls_map && nls_map != (void *) -1)
360                 unload_nls(nls_map);
361         return 0;
362 }
363
364 static int jfs_remount(struct super_block *sb, int *flags, char *data)
365 {
366         s64 newLVSize = 0;
367         int rc = 0;
368         int flag = JFS_SBI(sb)->flag;
369
370         if (!parse_options(data, sb, &newLVSize, &flag)) {
371                 return -EINVAL;
372         }
373         if (newLVSize) {
374                 if (sb->s_flags & MS_RDONLY) {
375                         printk(KERN_ERR
376                   "JFS: resize requires volume to be mounted read-write\n");
377                         return -EROFS;
378                 }
379                 rc = jfs_extendfs(sb, newLVSize, 0);
380                 if (rc)
381                         return rc;
382         }
383
384         if ((sb->s_flags & MS_RDONLY) && !(*flags & MS_RDONLY)) {
385                 /*
386                  * Invalidate any previously read metadata.  fsck may have
387                  * changed the on-disk data since we mounted r/o
388                  */
389                 truncate_inode_pages(JFS_SBI(sb)->direct_inode->i_mapping, 0);
390
391                 JFS_SBI(sb)->flag = flag;
392                 return jfs_mount_rw(sb, 1);
393         }
394         if ((!(sb->s_flags & MS_RDONLY)) && (*flags & MS_RDONLY)) {
395                 rc = jfs_umount_rw(sb);
396                 JFS_SBI(sb)->flag = flag;
397                 return rc;
398         }
399         if ((JFS_SBI(sb)->flag & JFS_NOINTEGRITY) != (flag & JFS_NOINTEGRITY))
400                 if (!(sb->s_flags & MS_RDONLY)) {
401                         rc = jfs_umount_rw(sb);
402                         if (rc)
403                                 return rc;
404                         JFS_SBI(sb)->flag = flag;
405                         return jfs_mount_rw(sb, 1);
406                 }
407         JFS_SBI(sb)->flag = flag;
408
409         return 0;
410 }
411
412 static int jfs_fill_super(struct super_block *sb, void *data, int silent)
413 {
414         struct jfs_sb_info *sbi;
415         struct inode *inode;
416         int rc;
417         s64 newLVSize = 0;
418         int flag, ret = -EINVAL;
419
420         jfs_info("In jfs_read_super: s_flags=0x%lx", sb->s_flags);
421
422         if (!new_valid_dev(sb->s_bdev->bd_dev))
423                 return -EOVERFLOW;
424
425         sbi = kzalloc(sizeof (struct jfs_sb_info), GFP_KERNEL);
426         if (!sbi)
427                 return -ENOMEM;
428         sb->s_fs_info = sbi;
429         sbi->sb = sb;
430         sbi->uid = sbi->gid = sbi->umask = -1;
431
432         /* initialize the mount flag and determine the default error handler */
433         flag = JFS_ERR_REMOUNT_RO;
434
435         if (!parse_options((char *) data, sb, &newLVSize, &flag)) {
436                 kfree(sbi);
437                 return -EINVAL;
438         }
439         sbi->flag = flag;
440
441 #ifdef CONFIG_JFS_POSIX_ACL
442         sb->s_flags |= MS_POSIXACL;
443 #endif
444
445         if (newLVSize) {
446                 printk(KERN_ERR "resize option for remount only\n");
447                 return -EINVAL;
448         }
449
450         /*
451          * Initialize blocksize to 4K.
452          */
453         sb_set_blocksize(sb, PSIZE);
454
455         /*
456          * Set method vectors.
457          */
458         sb->s_op = &jfs_super_operations;
459         sb->s_export_op = &jfs_export_operations;
460
461         /*
462          * Initialize direct-mapping inode/address-space
463          */
464         inode = new_inode(sb);
465         if (inode == NULL) {
466                 ret = -ENOMEM;
467                 goto out_kfree;
468         }
469         inode->i_ino = 0;
470         inode->i_nlink = 1;
471         inode->i_size = sb->s_bdev->bd_inode->i_size;
472         inode->i_mapping->a_ops = &jfs_metapage_aops;
473         insert_inode_hash(inode);
474         mapping_set_gfp_mask(inode->i_mapping, GFP_NOFS);
475
476         sbi->direct_inode = inode;
477
478         rc = jfs_mount(sb);
479         if (rc) {
480                 if (!silent) {
481                         jfs_err("jfs_mount failed w/return code = %d", rc);
482                 }
483                 goto out_mount_failed;
484         }
485         if (sb->s_flags & MS_RDONLY)
486                 sbi->log = NULL;
487         else {
488                 rc = jfs_mount_rw(sb, 0);
489                 if (rc) {
490                         if (!silent) {
491                                 jfs_err("jfs_mount_rw failed, return code = %d",
492                                         rc);
493                         }
494                         goto out_no_rw;
495                 }
496         }
497
498         sb->s_magic = JFS_SUPER_MAGIC;
499
500         inode = jfs_iget(sb, ROOT_I);
501         if (IS_ERR(inode)) {
502                 ret = PTR_ERR(inode);
503                 goto out_no_rw;
504         }
505         sb->s_root = d_alloc_root(inode);
506         if (!sb->s_root)
507                 goto out_no_root;
508
509         if (sbi->mntflag & JFS_OS2)
510                 sb->s_root->d_op = &jfs_ci_dentry_operations;
511
512         /* logical blocks are represented by 40 bits in pxd_t, etc. */
513         sb->s_maxbytes = ((u64) sb->s_blocksize) << 40;
514 #if BITS_PER_LONG == 32
515         /*
516          * Page cache is indexed by long.
517          * I would use MAX_LFS_FILESIZE, but it's only half as big
518          */
519         sb->s_maxbytes = min(((u64) PAGE_CACHE_SIZE << 32) - 1, sb->s_maxbytes);
520 #endif
521         sb->s_time_gran = 1;
522         return 0;
523
524 out_no_root:
525         jfs_err("jfs_read_super: get root dentry failed");
526         iput(inode);
527
528 out_no_rw:
529         rc = jfs_umount(sb);
530         if (rc) {
531                 jfs_err("jfs_umount failed with return code %d", rc);
532         }
533 out_mount_failed:
534         filemap_write_and_wait(sbi->direct_inode->i_mapping);
535         truncate_inode_pages(sbi->direct_inode->i_mapping, 0);
536         make_bad_inode(sbi->direct_inode);
537         iput(sbi->direct_inode);
538         sbi->direct_inode = NULL;
539 out_kfree:
540         if (sbi->nls_tab)
541                 unload_nls(sbi->nls_tab);
542         kfree(sbi);
543         return ret;
544 }
545
546 static int jfs_freeze(struct super_block *sb)
547 {
548         struct jfs_sb_info *sbi = JFS_SBI(sb);
549         struct jfs_log *log = sbi->log;
550
551         if (!(sb->s_flags & MS_RDONLY)) {
552                 txQuiesce(sb);
553                 lmLogShutdown(log);
554                 updateSuper(sb, FM_CLEAN);
555         }
556         return 0;
557 }
558
559 static int jfs_unfreeze(struct super_block *sb)
560 {
561         struct jfs_sb_info *sbi = JFS_SBI(sb);
562         struct jfs_log *log = sbi->log;
563         int rc = 0;
564
565         if (!(sb->s_flags & MS_RDONLY)) {
566                 updateSuper(sb, FM_MOUNT);
567                 if ((rc = lmLogInit(log)))
568                         jfs_err("jfs_unlock failed with return code %d", rc);
569                 else
570                         txResume(sb);
571         }
572         return 0;
573 }
574
575 static int jfs_get_sb(struct file_system_type *fs_type,
576         int flags, const char *dev_name, void *data, struct vfsmount *mnt)
577 {
578         return get_sb_bdev(fs_type, flags, dev_name, data, jfs_fill_super,
579                            mnt);
580 }
581
582 static int jfs_sync_fs(struct super_block *sb, int wait)
583 {
584         struct jfs_log *log = JFS_SBI(sb)->log;
585
586         /* log == NULL indicates read-only mount */
587         if (log) {
588                 jfs_flush_journal(log, wait);
589                 jfs_syncpt(log, 0);
590         }
591
592         return 0;
593 }
594
595 static int jfs_show_options(struct seq_file *seq, struct vfsmount *vfs)
596 {
597         struct jfs_sb_info *sbi = JFS_SBI(vfs->mnt_sb);
598
599         if (sbi->uid != -1)
600                 seq_printf(seq, ",uid=%d", sbi->uid);
601         if (sbi->gid != -1)
602                 seq_printf(seq, ",gid=%d", sbi->gid);
603         if (sbi->umask != -1)
604                 seq_printf(seq, ",umask=%03o", sbi->umask);
605         if (sbi->flag & JFS_NOINTEGRITY)
606                 seq_puts(seq, ",nointegrity");
607         if (sbi->nls_tab)
608                 seq_printf(seq, ",iocharset=%s", sbi->nls_tab->charset);
609         if (sbi->flag & JFS_ERR_CONTINUE)
610                 seq_printf(seq, ",errors=continue");
611         if (sbi->flag & JFS_ERR_PANIC)
612                 seq_printf(seq, ",errors=panic");
613
614 #ifdef CONFIG_QUOTA
615         if (sbi->flag & JFS_USRQUOTA)
616                 seq_puts(seq, ",usrquota");
617
618         if (sbi->flag & JFS_GRPQUOTA)
619                 seq_puts(seq, ",grpquota");
620 #endif
621
622         return 0;
623 }
624
625 #ifdef CONFIG_QUOTA
626
627 /* Read data from quotafile - avoid pagecache and such because we cannot afford
628  * acquiring the locks... As quota files are never truncated and quota code
629  * itself serializes the operations (and noone else should touch the files)
630  * we don't have to be afraid of races */
631 static ssize_t jfs_quota_read(struct super_block *sb, int type, char *data,
632                               size_t len, loff_t off)
633 {
634         struct inode *inode = sb_dqopt(sb)->files[type];
635         sector_t blk = off >> sb->s_blocksize_bits;
636         int err = 0;
637         int offset = off & (sb->s_blocksize - 1);
638         int tocopy;
639         size_t toread;
640         struct buffer_head tmp_bh;
641         struct buffer_head *bh;
642         loff_t i_size = i_size_read(inode);
643
644         if (off > i_size)
645                 return 0;
646         if (off+len > i_size)
647                 len = i_size-off;
648         toread = len;
649         while (toread > 0) {
650                 tocopy = sb->s_blocksize - offset < toread ?
651                                 sb->s_blocksize - offset : toread;
652
653                 tmp_bh.b_state = 0;
654                 tmp_bh.b_size = 1 << inode->i_blkbits;
655                 err = jfs_get_block(inode, blk, &tmp_bh, 0);
656                 if (err)
657                         return err;
658                 if (!buffer_mapped(&tmp_bh))    /* A hole? */
659                         memset(data, 0, tocopy);
660                 else {
661                         bh = sb_bread(sb, tmp_bh.b_blocknr);
662                         if (!bh)
663                                 return -EIO;
664                         memcpy(data, bh->b_data+offset, tocopy);
665                         brelse(bh);
666                 }
667                 offset = 0;
668                 toread -= tocopy;
669                 data += tocopy;
670                 blk++;
671         }
672         return len;
673 }
674
675 /* Write to quotafile */
676 static ssize_t jfs_quota_write(struct super_block *sb, int type,
677                                const char *data, size_t len, loff_t off)
678 {
679         struct inode *inode = sb_dqopt(sb)->files[type];
680         sector_t blk = off >> sb->s_blocksize_bits;
681         int err = 0;
682         int offset = off & (sb->s_blocksize - 1);
683         int tocopy;
684         size_t towrite = len;
685         struct buffer_head tmp_bh;
686         struct buffer_head *bh;
687
688         mutex_lock(&inode->i_mutex);
689         while (towrite > 0) {
690                 tocopy = sb->s_blocksize - offset < towrite ?
691                                 sb->s_blocksize - offset : towrite;
692
693                 tmp_bh.b_state = 0;
694                 tmp_bh.b_size = 1 << inode->i_blkbits;
695                 err = jfs_get_block(inode, blk, &tmp_bh, 1);
696                 if (err)
697                         goto out;
698                 if (offset || tocopy != sb->s_blocksize)
699                         bh = sb_bread(sb, tmp_bh.b_blocknr);
700                 else
701                         bh = sb_getblk(sb, tmp_bh.b_blocknr);
702                 if (!bh) {
703                         err = -EIO;
704                         goto out;
705                 }
706                 lock_buffer(bh);
707                 memcpy(bh->b_data+offset, data, tocopy);
708                 flush_dcache_page(bh->b_page);
709                 set_buffer_uptodate(bh);
710                 mark_buffer_dirty(bh);
711                 unlock_buffer(bh);
712                 brelse(bh);
713                 offset = 0;
714                 towrite -= tocopy;
715                 data += tocopy;
716                 blk++;
717         }
718 out:
719         if (len == towrite)
720                 return err;
721         if (inode->i_size < off+len-towrite)
722                 i_size_write(inode, off+len-towrite);
723         inode->i_version++;
724         inode->i_mtime = inode->i_ctime = CURRENT_TIME;
725         mark_inode_dirty(inode);
726         mutex_unlock(&inode->i_mutex);
727         return len - towrite;
728 }
729
730 #endif
731
732 static const struct super_operations jfs_super_operations = {
733         .alloc_inode    = jfs_alloc_inode,
734         .destroy_inode  = jfs_destroy_inode,
735         .dirty_inode    = jfs_dirty_inode,
736         .write_inode    = jfs_write_inode,
737         .delete_inode   = jfs_delete_inode,
738         .put_super      = jfs_put_super,
739         .sync_fs        = jfs_sync_fs,
740         .freeze_fs      = jfs_freeze,
741         .unfreeze_fs    = jfs_unfreeze,
742         .statfs         = jfs_statfs,
743         .remount_fs     = jfs_remount,
744         .show_options   = jfs_show_options,
745 #ifdef CONFIG_QUOTA
746         .quota_read     = jfs_quota_read,
747         .quota_write    = jfs_quota_write,
748 #endif
749 };
750
751 static const struct export_operations jfs_export_operations = {
752         .fh_to_dentry   = jfs_fh_to_dentry,
753         .fh_to_parent   = jfs_fh_to_parent,
754         .get_parent     = jfs_get_parent,
755 };
756
757 static struct file_system_type jfs_fs_type = {
758         .owner          = THIS_MODULE,
759         .name           = "jfs",
760         .get_sb         = jfs_get_sb,
761         .kill_sb        = kill_block_super,
762         .fs_flags       = FS_REQUIRES_DEV,
763 };
764
765 static void init_once(void *foo)
766 {
767         struct jfs_inode_info *jfs_ip = (struct jfs_inode_info *) foo;
768
769         memset(jfs_ip, 0, sizeof(struct jfs_inode_info));
770         INIT_LIST_HEAD(&jfs_ip->anon_inode_list);
771         init_rwsem(&jfs_ip->rdwrlock);
772         mutex_init(&jfs_ip->commit_mutex);
773         init_rwsem(&jfs_ip->xattr_sem);
774         spin_lock_init(&jfs_ip->ag_lock);
775         jfs_ip->active_ag = -1;
776 #ifdef CONFIG_JFS_POSIX_ACL
777         jfs_ip->i_acl = JFS_ACL_NOT_CACHED;
778         jfs_ip->i_default_acl = JFS_ACL_NOT_CACHED;
779 #endif
780         inode_init_once(&jfs_ip->vfs_inode);
781 }
782
783 static int __init init_jfs_fs(void)
784 {
785         int i;
786         int rc;
787
788         jfs_inode_cachep =
789             kmem_cache_create("jfs_ip", sizeof(struct jfs_inode_info), 0,
790                             SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD,
791                             init_once);
792         if (jfs_inode_cachep == NULL)
793                 return -ENOMEM;
794
795         /*
796          * Metapage initialization
797          */
798         rc = metapage_init();
799         if (rc) {
800                 jfs_err("metapage_init failed w/rc = %d", rc);
801                 goto free_slab;
802         }
803
804         /*
805          * Transaction Manager initialization
806          */
807         rc = txInit();
808         if (rc) {
809                 jfs_err("txInit failed w/rc = %d", rc);
810                 goto free_metapage;
811         }
812
813         /*
814          * I/O completion thread (endio)
815          */
816         jfsIOthread = kthread_run(jfsIOWait, NULL, "jfsIO");
817         if (IS_ERR(jfsIOthread)) {
818                 rc = PTR_ERR(jfsIOthread);
819                 jfs_err("init_jfs_fs: fork failed w/rc = %d", rc);
820                 goto end_txmngr;
821         }
822
823         if (commit_threads < 1)
824                 commit_threads = num_online_cpus();
825         if (commit_threads > MAX_COMMIT_THREADS)
826                 commit_threads = MAX_COMMIT_THREADS;
827
828         for (i = 0; i < commit_threads; i++) {
829                 jfsCommitThread[i] = kthread_run(jfs_lazycommit, NULL, "jfsCommit");
830                 if (IS_ERR(jfsCommitThread[i])) {
831                         rc = PTR_ERR(jfsCommitThread[i]);
832                         jfs_err("init_jfs_fs: fork failed w/rc = %d", rc);
833                         commit_threads = i;
834                         goto kill_committask;
835                 }
836         }
837
838         jfsSyncThread = kthread_run(jfs_sync, NULL, "jfsSync");
839         if (IS_ERR(jfsSyncThread)) {
840                 rc = PTR_ERR(jfsSyncThread);
841                 jfs_err("init_jfs_fs: fork failed w/rc = %d", rc);
842                 goto kill_committask;
843         }
844
845 #ifdef PROC_FS_JFS
846         jfs_proc_init();
847 #endif
848
849         return register_filesystem(&jfs_fs_type);
850
851 kill_committask:
852         for (i = 0; i < commit_threads; i++)
853                 kthread_stop(jfsCommitThread[i]);
854         kthread_stop(jfsIOthread);
855 end_txmngr:
856         txExit();
857 free_metapage:
858         metapage_exit();
859 free_slab:
860         kmem_cache_destroy(jfs_inode_cachep);
861         return rc;
862 }
863
864 static void __exit exit_jfs_fs(void)
865 {
866         int i;
867
868         jfs_info("exit_jfs_fs called");
869
870         txExit();
871         metapage_exit();
872
873         kthread_stop(jfsIOthread);
874         for (i = 0; i < commit_threads; i++)
875                 kthread_stop(jfsCommitThread[i]);
876         kthread_stop(jfsSyncThread);
877 #ifdef PROC_FS_JFS
878         jfs_proc_clean();
879 #endif
880         unregister_filesystem(&jfs_fs_type);
881         kmem_cache_destroy(jfs_inode_cachep);
882 }
883
884 module_init(init_jfs_fs)
885 module_exit(exit_jfs_fs)