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