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fs: push rcu_barrier() from deactivate_locked_super() to filesystems
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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 <linux/crc32.h>
33 #include <linux/slab.h>
34 #include <asm/uaccess.h>
35 #include <linux/seq_file.h>
36
37 #include "jfs_incore.h"
38 #include "jfs_filsys.h"
39 #include "jfs_inode.h"
40 #include "jfs_metapage.h"
41 #include "jfs_superblock.h"
42 #include "jfs_dmap.h"
43 #include "jfs_imap.h"
44 #include "jfs_acl.h"
45 #include "jfs_debug.h"
46
47 MODULE_DESCRIPTION("The Journaled Filesystem (JFS)");
48 MODULE_AUTHOR("Steve Best/Dave Kleikamp/Barry Arndt, IBM");
49 MODULE_LICENSE("GPL");
50
51 static struct kmem_cache * jfs_inode_cachep;
52
53 static const struct super_operations jfs_super_operations;
54 static const struct export_operations jfs_export_operations;
55 static struct file_system_type jfs_fs_type;
56
57 #define MAX_COMMIT_THREADS 64
58 static int commit_threads = 0;
59 module_param(commit_threads, int, 0);
60 MODULE_PARM_DESC(commit_threads, "Number of commit threads");
61
62 static struct task_struct *jfsCommitThread[MAX_COMMIT_THREADS];
63 struct task_struct *jfsIOthread;
64 struct task_struct *jfsSyncThread;
65
66 #ifdef CONFIG_JFS_DEBUG
67 int jfsloglevel = JFS_LOGLEVEL_WARN;
68 module_param(jfsloglevel, int, 0644);
69 MODULE_PARM_DESC(jfsloglevel, "Specify JFS loglevel (0, 1 or 2)");
70 #endif
71
72 static void jfs_handle_error(struct super_block *sb)
73 {
74         struct jfs_sb_info *sbi = JFS_SBI(sb);
75
76         if (sb->s_flags & MS_RDONLY)
77                 return;
78
79         updateSuper(sb, FM_DIRTY);
80
81         if (sbi->flag & JFS_ERR_PANIC)
82                 panic("JFS (device %s): panic forced after error\n",
83                         sb->s_id);
84         else if (sbi->flag & JFS_ERR_REMOUNT_RO) {
85                 jfs_err("ERROR: (device %s): remounting filesystem "
86                         "as read-only\n",
87                         sb->s_id);
88                 sb->s_flags |= MS_RDONLY;
89         }
90
91         /* nothing is done for continue beyond marking the superblock dirty */
92 }
93
94 void jfs_error(struct super_block *sb, const char * function, ...)
95 {
96         static char error_buf[256];
97         va_list args;
98
99         va_start(args, function);
100         vsnprintf(error_buf, sizeof(error_buf), function, args);
101         va_end(args);
102
103         printk(KERN_ERR "ERROR: (device %s): %s\n", sb->s_id, error_buf);
104
105         jfs_handle_error(sb);
106 }
107
108 static struct inode *jfs_alloc_inode(struct super_block *sb)
109 {
110         struct jfs_inode_info *jfs_inode;
111
112         jfs_inode = kmem_cache_alloc(jfs_inode_cachep, GFP_NOFS);
113         if (!jfs_inode)
114                 return NULL;
115         return &jfs_inode->vfs_inode;
116 }
117
118 static void jfs_i_callback(struct rcu_head *head)
119 {
120         struct inode *inode = container_of(head, struct inode, i_rcu);
121         struct jfs_inode_info *ji = JFS_IP(inode);
122         kmem_cache_free(jfs_inode_cachep, ji);
123 }
124
125 static void jfs_destroy_inode(struct inode *inode)
126 {
127         struct jfs_inode_info *ji = JFS_IP(inode);
128
129         BUG_ON(!list_empty(&ji->anon_inode_list));
130
131         spin_lock_irq(&ji->ag_lock);
132         if (ji->active_ag != -1) {
133                 struct bmap *bmap = JFS_SBI(inode->i_sb)->bmap;
134                 atomic_dec(&bmap->db_active[ji->active_ag]);
135                 ji->active_ag = -1;
136         }
137         spin_unlock_irq(&ji->ag_lock);
138         call_rcu(&inode->i_rcu, jfs_i_callback);
139 }
140
141 static int jfs_statfs(struct dentry *dentry, struct kstatfs *buf)
142 {
143         struct jfs_sb_info *sbi = JFS_SBI(dentry->d_sb);
144         s64 maxinodes;
145         struct inomap *imap = JFS_IP(sbi->ipimap)->i_imap;
146
147         jfs_info("In jfs_statfs");
148         buf->f_type = JFS_SUPER_MAGIC;
149         buf->f_bsize = sbi->bsize;
150         buf->f_blocks = sbi->bmap->db_mapsize;
151         buf->f_bfree = sbi->bmap->db_nfree;
152         buf->f_bavail = sbi->bmap->db_nfree;
153         /*
154          * If we really return the number of allocated & free inodes, some
155          * applications will fail because they won't see enough free inodes.
156          * We'll try to calculate some guess as to how may inodes we can
157          * really allocate
158          *
159          * buf->f_files = atomic_read(&imap->im_numinos);
160          * buf->f_ffree = atomic_read(&imap->im_numfree);
161          */
162         maxinodes = min((s64) atomic_read(&imap->im_numinos) +
163                         ((sbi->bmap->db_nfree >> imap->im_l2nbperiext)
164                          << L2INOSPEREXT), (s64) 0xffffffffLL);
165         buf->f_files = maxinodes;
166         buf->f_ffree = maxinodes - (atomic_read(&imap->im_numinos) -
167                                     atomic_read(&imap->im_numfree));
168         buf->f_fsid.val[0] = (u32)crc32_le(0, sbi->uuid, sizeof(sbi->uuid)/2);
169         buf->f_fsid.val[1] = (u32)crc32_le(0, sbi->uuid + sizeof(sbi->uuid)/2,
170                                         sizeof(sbi->uuid)/2);
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
183         dquot_disable(sb, -1, DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);
184
185         rc = jfs_umount(sb);
186         if (rc)
187                 jfs_err("jfs_umount failed with return code %d", rc);
188
189         unload_nls(sbi->nls_tab);
190
191         truncate_inode_pages(sbi->direct_inode->i_mapping, 0);
192         iput(sbi->direct_inode);
193
194         kfree(sbi);
195 }
196
197 enum {
198         Opt_integrity, Opt_nointegrity, Opt_iocharset, Opt_resize,
199         Opt_resize_nosize, Opt_errors, Opt_ignore, Opt_err, Opt_quota,
200         Opt_usrquota, Opt_grpquota, Opt_uid, Opt_gid, Opt_umask
201 };
202
203 static const match_table_t tokens = {
204         {Opt_integrity, "integrity"},
205         {Opt_nointegrity, "nointegrity"},
206         {Opt_iocharset, "iocharset=%s"},
207         {Opt_resize, "resize=%u"},
208         {Opt_resize_nosize, "resize"},
209         {Opt_errors, "errors=%s"},
210         {Opt_ignore, "noquota"},
211         {Opt_ignore, "quota"},
212         {Opt_usrquota, "usrquota"},
213         {Opt_grpquota, "grpquota"},
214         {Opt_uid, "uid=%u"},
215         {Opt_gid, "gid=%u"},
216         {Opt_umask, "umask=%u"},
217         {Opt_err, NULL}
218 };
219
220 static int parse_options(char *options, struct super_block *sb, s64 *newLVSize,
221                          int *flag)
222 {
223         void *nls_map = (void *)-1;     /* -1: no change;  NULL: none */
224         char *p;
225         struct jfs_sb_info *sbi = JFS_SBI(sb);
226
227         *newLVSize = 0;
228
229         if (!options)
230                 return 1;
231
232         while ((p = strsep(&options, ",")) != NULL) {
233                 substring_t args[MAX_OPT_ARGS];
234                 int token;
235                 if (!*p)
236                         continue;
237
238                 token = match_token(p, tokens, args);
239                 switch (token) {
240                 case Opt_integrity:
241                         *flag &= ~JFS_NOINTEGRITY;
242                         break;
243                 case Opt_nointegrity:
244                         *flag |= JFS_NOINTEGRITY;
245                         break;
246                 case Opt_ignore:
247                         /* Silently ignore the quota options */
248                         /* Don't do anything ;-) */
249                         break;
250                 case Opt_iocharset:
251                         if (nls_map && nls_map != (void *) -1)
252                                 unload_nls(nls_map);
253                         if (!strcmp(args[0].from, "none"))
254                                 nls_map = NULL;
255                         else {
256                                 nls_map = load_nls(args[0].from);
257                                 if (!nls_map) {
258                                         printk(KERN_ERR
259                                                "JFS: charset not found\n");
260                                         goto cleanup;
261                                 }
262                         }
263                         break;
264                 case Opt_resize:
265                 {
266                         char *resize = args[0].from;
267                         *newLVSize = simple_strtoull(resize, &resize, 0);
268                         break;
269                 }
270                 case Opt_resize_nosize:
271                 {
272                         *newLVSize = sb->s_bdev->bd_inode->i_size >>
273                                 sb->s_blocksize_bits;
274                         if (*newLVSize == 0)
275                                 printk(KERN_ERR
276                                        "JFS: Cannot determine volume size\n");
277                         break;
278                 }
279                 case Opt_errors:
280                 {
281                         char *errors = args[0].from;
282                         if (!errors || !*errors)
283                                 goto cleanup;
284                         if (!strcmp(errors, "continue")) {
285                                 *flag &= ~JFS_ERR_REMOUNT_RO;
286                                 *flag &= ~JFS_ERR_PANIC;
287                                 *flag |= JFS_ERR_CONTINUE;
288                         } else if (!strcmp(errors, "remount-ro")) {
289                                 *flag &= ~JFS_ERR_CONTINUE;
290                                 *flag &= ~JFS_ERR_PANIC;
291                                 *flag |= JFS_ERR_REMOUNT_RO;
292                         } else if (!strcmp(errors, "panic")) {
293                                 *flag &= ~JFS_ERR_CONTINUE;
294                                 *flag &= ~JFS_ERR_REMOUNT_RO;
295                                 *flag |= JFS_ERR_PANIC;
296                         } else {
297                                 printk(KERN_ERR
298                                        "JFS: %s is an invalid error handler\n",
299                                        errors);
300                                 goto cleanup;
301                         }
302                         break;
303                 }
304
305 #ifdef CONFIG_QUOTA
306                 case Opt_quota:
307                 case Opt_usrquota:
308                         *flag |= JFS_USRQUOTA;
309                         break;
310                 case Opt_grpquota:
311                         *flag |= JFS_GRPQUOTA;
312                         break;
313 #else
314                 case Opt_usrquota:
315                 case Opt_grpquota:
316                 case Opt_quota:
317                         printk(KERN_ERR
318                                "JFS: quota operations not supported\n");
319                         break;
320 #endif
321                 case Opt_uid:
322                 {
323                         char *uid = args[0].from;
324                         sbi->uid = simple_strtoul(uid, &uid, 0);
325                         break;
326                 }
327                 case Opt_gid:
328                 {
329                         char *gid = args[0].from;
330                         sbi->gid = simple_strtoul(gid, &gid, 0);
331                         break;
332                 }
333                 case Opt_umask:
334                 {
335                         char *umask = args[0].from;
336                         sbi->umask = simple_strtoul(umask, &umask, 8);
337                         if (sbi->umask & ~0777) {
338                                 printk(KERN_ERR
339                                        "JFS: Invalid value of umask\n");
340                                 goto cleanup;
341                         }
342                         break;
343                 }
344                 default:
345                         printk("jfs: Unrecognized mount option \"%s\" "
346                                         " or missing value\n", p);
347                         goto cleanup;
348                 }
349         }
350
351         if (nls_map != (void *) -1) {
352                 /* Discard old (if remount) */
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         int ret;
370
371         if (!parse_options(data, sb, &newLVSize, &flag)) {
372                 return -EINVAL;
373         }
374
375         if (newLVSize) {
376                 if (sb->s_flags & MS_RDONLY) {
377                         printk(KERN_ERR
378                   "JFS: resize requires volume to be mounted read-write\n");
379                         return -EROFS;
380                 }
381                 rc = jfs_extendfs(sb, newLVSize, 0);
382                 if (rc)
383                         return rc;
384         }
385
386         if ((sb->s_flags & MS_RDONLY) && !(*flags & MS_RDONLY)) {
387                 /*
388                  * Invalidate any previously read metadata.  fsck may have
389                  * changed the on-disk data since we mounted r/o
390                  */
391                 truncate_inode_pages(JFS_SBI(sb)->direct_inode->i_mapping, 0);
392
393                 JFS_SBI(sb)->flag = flag;
394                 ret = jfs_mount_rw(sb, 1);
395
396                 /* mark the fs r/w for quota activity */
397                 sb->s_flags &= ~MS_RDONLY;
398
399                 dquot_resume(sb, -1);
400                 return ret;
401         }
402         if ((!(sb->s_flags & MS_RDONLY)) && (*flags & MS_RDONLY)) {
403                 rc = dquot_suspend(sb, -1);
404                 if (rc < 0) {
405                         return rc;
406                 }
407                 rc = jfs_umount_rw(sb);
408                 JFS_SBI(sb)->flag = flag;
409                 return rc;
410         }
411         if ((JFS_SBI(sb)->flag & JFS_NOINTEGRITY) != (flag & JFS_NOINTEGRITY))
412                 if (!(sb->s_flags & MS_RDONLY)) {
413                         rc = jfs_umount_rw(sb);
414                         if (rc)
415                                 return rc;
416
417                         JFS_SBI(sb)->flag = flag;
418                         ret = jfs_mount_rw(sb, 1);
419                         return ret;
420                 }
421         JFS_SBI(sb)->flag = flag;
422
423         return 0;
424 }
425
426 static int jfs_fill_super(struct super_block *sb, void *data, int silent)
427 {
428         struct jfs_sb_info *sbi;
429         struct inode *inode;
430         int rc;
431         s64 newLVSize = 0;
432         int flag, ret = -EINVAL;
433
434         jfs_info("In jfs_read_super: s_flags=0x%lx", sb->s_flags);
435
436         if (!new_valid_dev(sb->s_bdev->bd_dev))
437                 return -EOVERFLOW;
438
439         sbi = kzalloc(sizeof (struct jfs_sb_info), GFP_KERNEL);
440         if (!sbi)
441                 return -ENOMEM;
442
443         sb->s_fs_info = sbi;
444         sb->s_max_links = JFS_LINK_MAX;
445         sbi->sb = sb;
446         sbi->uid = sbi->gid = sbi->umask = -1;
447
448         /* initialize the mount flag and determine the default error handler */
449         flag = JFS_ERR_REMOUNT_RO;
450
451         if (!parse_options((char *) data, sb, &newLVSize, &flag))
452                 goto out_kfree;
453         sbi->flag = flag;
454
455 #ifdef CONFIG_JFS_POSIX_ACL
456         sb->s_flags |= MS_POSIXACL;
457 #endif
458
459         if (newLVSize) {
460                 printk(KERN_ERR "resize option for remount only\n");
461                 goto out_kfree;
462         }
463
464         /*
465          * Initialize blocksize to 4K.
466          */
467         sb_set_blocksize(sb, PSIZE);
468
469         /*
470          * Set method vectors.
471          */
472         sb->s_op = &jfs_super_operations;
473         sb->s_export_op = &jfs_export_operations;
474 #ifdef CONFIG_QUOTA
475         sb->dq_op = &dquot_operations;
476         sb->s_qcop = &dquot_quotactl_ops;
477 #endif
478
479         /*
480          * Initialize direct-mapping inode/address-space
481          */
482         inode = new_inode(sb);
483         if (inode == NULL) {
484                 ret = -ENOMEM;
485                 goto out_unload;
486         }
487         inode->i_ino = 0;
488         inode->i_size = sb->s_bdev->bd_inode->i_size;
489         inode->i_mapping->a_ops = &jfs_metapage_aops;
490         insert_inode_hash(inode);
491         mapping_set_gfp_mask(inode->i_mapping, GFP_NOFS);
492
493         sbi->direct_inode = inode;
494
495         rc = jfs_mount(sb);
496         if (rc) {
497                 if (!silent) {
498                         jfs_err("jfs_mount failed w/return code = %d", rc);
499                 }
500                 goto out_mount_failed;
501         }
502         if (sb->s_flags & MS_RDONLY)
503                 sbi->log = NULL;
504         else {
505                 rc = jfs_mount_rw(sb, 0);
506                 if (rc) {
507                         if (!silent) {
508                                 jfs_err("jfs_mount_rw failed, return code = %d",
509                                         rc);
510                         }
511                         goto out_no_rw;
512                 }
513         }
514
515         sb->s_magic = JFS_SUPER_MAGIC;
516
517         if (sbi->mntflag & JFS_OS2)
518                 sb->s_d_op = &jfs_ci_dentry_operations;
519
520         inode = jfs_iget(sb, ROOT_I);
521         if (IS_ERR(inode)) {
522                 ret = PTR_ERR(inode);
523                 goto out_no_rw;
524         }
525         sb->s_root = d_make_root(inode);
526         if (!sb->s_root)
527                 goto out_no_root;
528
529         /* logical blocks are represented by 40 bits in pxd_t, etc. */
530         sb->s_maxbytes = ((u64) sb->s_blocksize) << 40;
531 #if BITS_PER_LONG == 32
532         /*
533          * Page cache is indexed by long.
534          * I would use MAX_LFS_FILESIZE, but it's only half as big
535          */
536         sb->s_maxbytes = min(((u64) PAGE_CACHE_SIZE << 32) - 1, (u64)sb->s_maxbytes);
537 #endif
538         sb->s_time_gran = 1;
539         return 0;
540
541 out_no_root:
542         jfs_err("jfs_read_super: get root dentry failed");
543
544 out_no_rw:
545         rc = jfs_umount(sb);
546         if (rc) {
547                 jfs_err("jfs_umount failed with return code %d", rc);
548         }
549 out_mount_failed:
550         filemap_write_and_wait(sbi->direct_inode->i_mapping);
551         truncate_inode_pages(sbi->direct_inode->i_mapping, 0);
552         make_bad_inode(sbi->direct_inode);
553         iput(sbi->direct_inode);
554         sbi->direct_inode = NULL;
555 out_unload:
556         if (sbi->nls_tab)
557                 unload_nls(sbi->nls_tab);
558 out_kfree:
559         kfree(sbi);
560         return ret;
561 }
562
563 static int jfs_freeze(struct super_block *sb)
564 {
565         struct jfs_sb_info *sbi = JFS_SBI(sb);
566         struct jfs_log *log = sbi->log;
567
568         if (!(sb->s_flags & MS_RDONLY)) {
569                 txQuiesce(sb);
570                 lmLogShutdown(log);
571                 updateSuper(sb, FM_CLEAN);
572         }
573         return 0;
574 }
575
576 static int jfs_unfreeze(struct super_block *sb)
577 {
578         struct jfs_sb_info *sbi = JFS_SBI(sb);
579         struct jfs_log *log = sbi->log;
580         int rc = 0;
581
582         if (!(sb->s_flags & MS_RDONLY)) {
583                 updateSuper(sb, FM_MOUNT);
584                 if ((rc = lmLogInit(log)))
585                         jfs_err("jfs_unlock failed with return code %d", rc);
586                 else
587                         txResume(sb);
588         }
589         return 0;
590 }
591
592 static struct dentry *jfs_do_mount(struct file_system_type *fs_type,
593         int flags, const char *dev_name, void *data)
594 {
595         return mount_bdev(fs_type, flags, dev_name, data, jfs_fill_super);
596 }
597
598 static int jfs_sync_fs(struct super_block *sb, int wait)
599 {
600         struct jfs_log *log = JFS_SBI(sb)->log;
601
602         /* log == NULL indicates read-only mount */
603         if (log) {
604                 /*
605                  * Write quota structures to quota file, sync_blockdev() will
606                  * write them to disk later
607                  */
608                 dquot_writeback_dquots(sb, -1);
609                 jfs_flush_journal(log, wait);
610                 jfs_syncpt(log, 0);
611         }
612
613         return 0;
614 }
615
616 static int jfs_show_options(struct seq_file *seq, struct dentry *root)
617 {
618         struct jfs_sb_info *sbi = JFS_SBI(root->d_sb);
619
620         if (sbi->uid != -1)
621                 seq_printf(seq, ",uid=%d", sbi->uid);
622         if (sbi->gid != -1)
623                 seq_printf(seq, ",gid=%d", sbi->gid);
624         if (sbi->umask != -1)
625                 seq_printf(seq, ",umask=%03o", sbi->umask);
626         if (sbi->flag & JFS_NOINTEGRITY)
627                 seq_puts(seq, ",nointegrity");
628         if (sbi->nls_tab)
629                 seq_printf(seq, ",iocharset=%s", sbi->nls_tab->charset);
630         if (sbi->flag & JFS_ERR_CONTINUE)
631                 seq_printf(seq, ",errors=continue");
632         if (sbi->flag & JFS_ERR_PANIC)
633                 seq_printf(seq, ",errors=panic");
634
635 #ifdef CONFIG_QUOTA
636         if (sbi->flag & JFS_USRQUOTA)
637                 seq_puts(seq, ",usrquota");
638
639         if (sbi->flag & JFS_GRPQUOTA)
640                 seq_puts(seq, ",grpquota");
641 #endif
642
643         return 0;
644 }
645
646 #ifdef CONFIG_QUOTA
647
648 /* Read data from quotafile - avoid pagecache and such because we cannot afford
649  * acquiring the locks... As quota files are never truncated and quota code
650  * itself serializes the operations (and no one else should touch the files)
651  * we don't have to be afraid of races */
652 static ssize_t jfs_quota_read(struct super_block *sb, int type, char *data,
653                               size_t len, loff_t off)
654 {
655         struct inode *inode = sb_dqopt(sb)->files[type];
656         sector_t blk = off >> sb->s_blocksize_bits;
657         int err = 0;
658         int offset = off & (sb->s_blocksize - 1);
659         int tocopy;
660         size_t toread;
661         struct buffer_head tmp_bh;
662         struct buffer_head *bh;
663         loff_t i_size = i_size_read(inode);
664
665         if (off > i_size)
666                 return 0;
667         if (off+len > i_size)
668                 len = i_size-off;
669         toread = len;
670         while (toread > 0) {
671                 tocopy = sb->s_blocksize - offset < toread ?
672                                 sb->s_blocksize - offset : toread;
673
674                 tmp_bh.b_state = 0;
675                 tmp_bh.b_size = 1 << inode->i_blkbits;
676                 err = jfs_get_block(inode, blk, &tmp_bh, 0);
677                 if (err)
678                         return err;
679                 if (!buffer_mapped(&tmp_bh))    /* A hole? */
680                         memset(data, 0, tocopy);
681                 else {
682                         bh = sb_bread(sb, tmp_bh.b_blocknr);
683                         if (!bh)
684                                 return -EIO;
685                         memcpy(data, bh->b_data+offset, tocopy);
686                         brelse(bh);
687                 }
688                 offset = 0;
689                 toread -= tocopy;
690                 data += tocopy;
691                 blk++;
692         }
693         return len;
694 }
695
696 /* Write to quotafile */
697 static ssize_t jfs_quota_write(struct super_block *sb, int type,
698                                const char *data, size_t len, loff_t off)
699 {
700         struct inode *inode = sb_dqopt(sb)->files[type];
701         sector_t blk = off >> sb->s_blocksize_bits;
702         int err = 0;
703         int offset = off & (sb->s_blocksize - 1);
704         int tocopy;
705         size_t towrite = len;
706         struct buffer_head tmp_bh;
707         struct buffer_head *bh;
708
709         mutex_lock(&inode->i_mutex);
710         while (towrite > 0) {
711                 tocopy = sb->s_blocksize - offset < towrite ?
712                                 sb->s_blocksize - offset : towrite;
713
714                 tmp_bh.b_state = 0;
715                 tmp_bh.b_size = 1 << inode->i_blkbits;
716                 err = jfs_get_block(inode, blk, &tmp_bh, 1);
717                 if (err)
718                         goto out;
719                 if (offset || tocopy != sb->s_blocksize)
720                         bh = sb_bread(sb, tmp_bh.b_blocknr);
721                 else
722                         bh = sb_getblk(sb, tmp_bh.b_blocknr);
723                 if (!bh) {
724                         err = -EIO;
725                         goto out;
726                 }
727                 lock_buffer(bh);
728                 memcpy(bh->b_data+offset, data, tocopy);
729                 flush_dcache_page(bh->b_page);
730                 set_buffer_uptodate(bh);
731                 mark_buffer_dirty(bh);
732                 unlock_buffer(bh);
733                 brelse(bh);
734                 offset = 0;
735                 towrite -= tocopy;
736                 data += tocopy;
737                 blk++;
738         }
739 out:
740         if (len == towrite) {
741                 mutex_unlock(&inode->i_mutex);
742                 return err;
743         }
744         if (inode->i_size < off+len-towrite)
745                 i_size_write(inode, off+len-towrite);
746         inode->i_version++;
747         inode->i_mtime = inode->i_ctime = CURRENT_TIME;
748         mark_inode_dirty(inode);
749         mutex_unlock(&inode->i_mutex);
750         return len - towrite;
751 }
752
753 #endif
754
755 static const struct super_operations jfs_super_operations = {
756         .alloc_inode    = jfs_alloc_inode,
757         .destroy_inode  = jfs_destroy_inode,
758         .dirty_inode    = jfs_dirty_inode,
759         .write_inode    = jfs_write_inode,
760         .evict_inode    = jfs_evict_inode,
761         .put_super      = jfs_put_super,
762         .sync_fs        = jfs_sync_fs,
763         .freeze_fs      = jfs_freeze,
764         .unfreeze_fs    = jfs_unfreeze,
765         .statfs         = jfs_statfs,
766         .remount_fs     = jfs_remount,
767         .show_options   = jfs_show_options,
768 #ifdef CONFIG_QUOTA
769         .quota_read     = jfs_quota_read,
770         .quota_write    = jfs_quota_write,
771 #endif
772 };
773
774 static const struct export_operations jfs_export_operations = {
775         .fh_to_dentry   = jfs_fh_to_dentry,
776         .fh_to_parent   = jfs_fh_to_parent,
777         .get_parent     = jfs_get_parent,
778 };
779
780 static struct file_system_type jfs_fs_type = {
781         .owner          = THIS_MODULE,
782         .name           = "jfs",
783         .mount          = jfs_do_mount,
784         .kill_sb        = kill_block_super,
785         .fs_flags       = FS_REQUIRES_DEV,
786 };
787
788 static void init_once(void *foo)
789 {
790         struct jfs_inode_info *jfs_ip = (struct jfs_inode_info *) foo;
791
792         memset(jfs_ip, 0, sizeof(struct jfs_inode_info));
793         INIT_LIST_HEAD(&jfs_ip->anon_inode_list);
794         init_rwsem(&jfs_ip->rdwrlock);
795         mutex_init(&jfs_ip->commit_mutex);
796         init_rwsem(&jfs_ip->xattr_sem);
797         spin_lock_init(&jfs_ip->ag_lock);
798         jfs_ip->active_ag = -1;
799         inode_init_once(&jfs_ip->vfs_inode);
800 }
801
802 static int __init init_jfs_fs(void)
803 {
804         int i;
805         int rc;
806
807         jfs_inode_cachep =
808             kmem_cache_create("jfs_ip", sizeof(struct jfs_inode_info), 0,
809                             SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD,
810                             init_once);
811         if (jfs_inode_cachep == NULL)
812                 return -ENOMEM;
813
814         /*
815          * Metapage initialization
816          */
817         rc = metapage_init();
818         if (rc) {
819                 jfs_err("metapage_init failed w/rc = %d", rc);
820                 goto free_slab;
821         }
822
823         /*
824          * Transaction Manager initialization
825          */
826         rc = txInit();
827         if (rc) {
828                 jfs_err("txInit failed w/rc = %d", rc);
829                 goto free_metapage;
830         }
831
832         /*
833          * I/O completion thread (endio)
834          */
835         jfsIOthread = kthread_run(jfsIOWait, NULL, "jfsIO");
836         if (IS_ERR(jfsIOthread)) {
837                 rc = PTR_ERR(jfsIOthread);
838                 jfs_err("init_jfs_fs: fork failed w/rc = %d", rc);
839                 goto end_txmngr;
840         }
841
842         if (commit_threads < 1)
843                 commit_threads = num_online_cpus();
844         if (commit_threads > MAX_COMMIT_THREADS)
845                 commit_threads = MAX_COMMIT_THREADS;
846
847         for (i = 0; i < commit_threads; i++) {
848                 jfsCommitThread[i] = kthread_run(jfs_lazycommit, NULL, "jfsCommit");
849                 if (IS_ERR(jfsCommitThread[i])) {
850                         rc = PTR_ERR(jfsCommitThread[i]);
851                         jfs_err("init_jfs_fs: fork failed w/rc = %d", rc);
852                         commit_threads = i;
853                         goto kill_committask;
854                 }
855         }
856
857         jfsSyncThread = kthread_run(jfs_sync, NULL, "jfsSync");
858         if (IS_ERR(jfsSyncThread)) {
859                 rc = PTR_ERR(jfsSyncThread);
860                 jfs_err("init_jfs_fs: fork failed w/rc = %d", rc);
861                 goto kill_committask;
862         }
863
864 #ifdef PROC_FS_JFS
865         jfs_proc_init();
866 #endif
867
868         rc = register_filesystem(&jfs_fs_type);
869         if (!rc)
870                 return 0;
871
872 #ifdef PROC_FS_JFS
873         jfs_proc_clean();
874 #endif
875         kthread_stop(jfsSyncThread);
876 kill_committask:
877         for (i = 0; i < commit_threads; i++)
878                 kthread_stop(jfsCommitThread[i]);
879         kthread_stop(jfsIOthread);
880 end_txmngr:
881         txExit();
882 free_metapage:
883         metapage_exit();
884 free_slab:
885         kmem_cache_destroy(jfs_inode_cachep);
886         return rc;
887 }
888
889 static void __exit exit_jfs_fs(void)
890 {
891         int i;
892
893         jfs_info("exit_jfs_fs called");
894
895         txExit();
896         metapage_exit();
897
898         kthread_stop(jfsIOthread);
899         for (i = 0; i < commit_threads; i++)
900                 kthread_stop(jfsCommitThread[i]);
901         kthread_stop(jfsSyncThread);
902 #ifdef PROC_FS_JFS
903         jfs_proc_clean();
904 #endif
905         unregister_filesystem(&jfs_fs_type);
906
907         /*
908          * Make sure all delayed rcu free inodes are flushed before we
909          * destroy cache.
910          */
911         rcu_barrier();
912         kmem_cache_destroy(jfs_inode_cachep);
913 }
914
915 module_init(init_jfs_fs)
916 module_exit(exit_jfs_fs)