xref: /linux/fs/jfs/super.c (revision 9f6d3c4b76314c40c866a935d78c80fd284768bd)
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 #include <linux/smp_lock.h>
37 
38 #include "jfs_incore.h"
39 #include "jfs_filsys.h"
40 #include "jfs_inode.h"
41 #include "jfs_metapage.h"
42 #include "jfs_superblock.h"
43 #include "jfs_dmap.h"
44 #include "jfs_imap.h"
45 #include "jfs_acl.h"
46 #include "jfs_debug.h"
47 
48 MODULE_DESCRIPTION("The Journaled Filesystem (JFS)");
49 MODULE_AUTHOR("Steve Best/Dave Kleikamp/Barry Arndt, IBM");
50 MODULE_LICENSE("GPL");
51 
52 static struct kmem_cache * jfs_inode_cachep;
53 
54 static const struct super_operations jfs_super_operations;
55 static const struct export_operations jfs_export_operations;
56 static struct file_system_type jfs_fs_type;
57 
58 #define MAX_COMMIT_THREADS 64
59 static int commit_threads = 0;
60 module_param(commit_threads, int, 0);
61 MODULE_PARM_DESC(commit_threads, "Number of commit threads");
62 
63 static struct task_struct *jfsCommitThread[MAX_COMMIT_THREADS];
64 struct task_struct *jfsIOthread;
65 struct task_struct *jfsSyncThread;
66 
67 #ifdef CONFIG_JFS_DEBUG
68 int jfsloglevel = JFS_LOGLEVEL_WARN;
69 module_param(jfsloglevel, int, 0644);
70 MODULE_PARM_DESC(jfsloglevel, "Specify JFS loglevel (0, 1 or 2)");
71 #endif
72 
73 static void jfs_handle_error(struct super_block *sb)
74 {
75 	struct jfs_sb_info *sbi = JFS_SBI(sb);
76 
77 	if (sb->s_flags & MS_RDONLY)
78 		return;
79 
80 	updateSuper(sb, FM_DIRTY);
81 
82 	if (sbi->flag & JFS_ERR_PANIC)
83 		panic("JFS (device %s): panic forced after error\n",
84 			sb->s_id);
85 	else if (sbi->flag & JFS_ERR_REMOUNT_RO) {
86 		jfs_err("ERROR: (device %s): remounting filesystem "
87 			"as read-only\n",
88 			sb->s_id);
89 		sb->s_flags |= MS_RDONLY;
90 	}
91 
92 	/* nothing is done for continue beyond marking the superblock dirty */
93 }
94 
95 void jfs_error(struct super_block *sb, const char * function, ...)
96 {
97 	static char error_buf[256];
98 	va_list args;
99 
100 	va_start(args, function);
101 	vsnprintf(error_buf, sizeof(error_buf), function, args);
102 	va_end(args);
103 
104 	printk(KERN_ERR "ERROR: (device %s): %s\n", sb->s_id, error_buf);
105 
106 	jfs_handle_error(sb);
107 }
108 
109 static struct inode *jfs_alloc_inode(struct super_block *sb)
110 {
111 	struct jfs_inode_info *jfs_inode;
112 
113 	jfs_inode = kmem_cache_alloc(jfs_inode_cachep, GFP_NOFS);
114 	if (!jfs_inode)
115 		return NULL;
116 	return &jfs_inode->vfs_inode;
117 }
118 
119 static void jfs_destroy_inode(struct inode *inode)
120 {
121 	struct jfs_inode_info *ji = JFS_IP(inode);
122 
123 	BUG_ON(!list_empty(&ji->anon_inode_list));
124 
125 	spin_lock_irq(&ji->ag_lock);
126 	if (ji->active_ag != -1) {
127 		struct bmap *bmap = JFS_SBI(inode->i_sb)->bmap;
128 		atomic_dec(&bmap->db_active[ji->active_ag]);
129 		ji->active_ag = -1;
130 	}
131 	spin_unlock_irq(&ji->ag_lock);
132 	kmem_cache_free(jfs_inode_cachep, ji);
133 }
134 
135 static void jfs_clear_inode(struct inode *inode)
136 {
137 	dquot_drop(inode);
138 }
139 
140 static int jfs_statfs(struct dentry *dentry, struct kstatfs *buf)
141 {
142 	struct jfs_sb_info *sbi = JFS_SBI(dentry->d_sb);
143 	s64 maxinodes;
144 	struct inomap *imap = JFS_IP(sbi->ipimap)->i_imap;
145 
146 	jfs_info("In jfs_statfs");
147 	buf->f_type = JFS_SUPER_MAGIC;
148 	buf->f_bsize = sbi->bsize;
149 	buf->f_blocks = sbi->bmap->db_mapsize;
150 	buf->f_bfree = sbi->bmap->db_nfree;
151 	buf->f_bavail = sbi->bmap->db_nfree;
152 	/*
153 	 * If we really return the number of allocated & free inodes, some
154 	 * applications will fail because they won't see enough free inodes.
155 	 * We'll try to calculate some guess as to how may inodes we can
156 	 * really allocate
157 	 *
158 	 * buf->f_files = atomic_read(&imap->im_numinos);
159 	 * buf->f_ffree = atomic_read(&imap->im_numfree);
160 	 */
161 	maxinodes = min((s64) atomic_read(&imap->im_numinos) +
162 			((sbi->bmap->db_nfree >> imap->im_l2nbperiext)
163 			 << L2INOSPEREXT), (s64) 0xffffffffLL);
164 	buf->f_files = maxinodes;
165 	buf->f_ffree = maxinodes - (atomic_read(&imap->im_numinos) -
166 				    atomic_read(&imap->im_numfree));
167 	buf->f_fsid.val[0] = (u32)crc32_le(0, sbi->uuid, sizeof(sbi->uuid)/2);
168 	buf->f_fsid.val[1] = (u32)crc32_le(0, sbi->uuid + sizeof(sbi->uuid)/2,
169 					sizeof(sbi->uuid)/2);
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 
182 	lock_kernel();
183 
184 	rc = jfs_umount(sb);
185 	if (rc)
186 		jfs_err("jfs_umount failed with return code %d", rc);
187 
188 	unload_nls(sbi->nls_tab);
189 
190 	truncate_inode_pages(sbi->direct_inode->i_mapping, 0);
191 	iput(sbi->direct_inode);
192 
193 	kfree(sbi);
194 
195 	unlock_kernel();
196 }
197 
198 enum {
199 	Opt_integrity, Opt_nointegrity, Opt_iocharset, Opt_resize,
200 	Opt_resize_nosize, Opt_errors, Opt_ignore, Opt_err, Opt_quota,
201 	Opt_usrquota, Opt_grpquota, Opt_uid, Opt_gid, Opt_umask
202 };
203 
204 static const match_table_t tokens = {
205 	{Opt_integrity, "integrity"},
206 	{Opt_nointegrity, "nointegrity"},
207 	{Opt_iocharset, "iocharset=%s"},
208 	{Opt_resize, "resize=%u"},
209 	{Opt_resize_nosize, "resize"},
210 	{Opt_errors, "errors=%s"},
211 	{Opt_ignore, "noquota"},
212 	{Opt_ignore, "quota"},
213 	{Opt_usrquota, "usrquota"},
214 	{Opt_grpquota, "grpquota"},
215 	{Opt_uid, "uid=%u"},
216 	{Opt_gid, "gid=%u"},
217 	{Opt_umask, "umask=%u"},
218 	{Opt_err, NULL}
219 };
220 
221 static int parse_options(char *options, struct super_block *sb, s64 *newLVSize,
222 			 int *flag)
223 {
224 	void *nls_map = (void *)-1;	/* -1: no change;  NULL: none */
225 	char *p;
226 	struct jfs_sb_info *sbi = JFS_SBI(sb);
227 
228 	*newLVSize = 0;
229 
230 	if (!options)
231 		return 1;
232 
233 	while ((p = strsep(&options, ",")) != NULL) {
234 		substring_t args[MAX_OPT_ARGS];
235 		int token;
236 		if (!*p)
237 			continue;
238 
239 		token = match_token(p, tokens, args);
240 		switch (token) {
241 		case Opt_integrity:
242 			*flag &= ~JFS_NOINTEGRITY;
243 			break;
244 		case Opt_nointegrity:
245 			*flag |= JFS_NOINTEGRITY;
246 			break;
247 		case Opt_ignore:
248 			/* Silently ignore the quota options */
249 			/* Don't do anything ;-) */
250 			break;
251 		case Opt_iocharset:
252 			if (nls_map && nls_map != (void *) -1)
253 				unload_nls(nls_map);
254 			if (!strcmp(args[0].from, "none"))
255 				nls_map = NULL;
256 			else {
257 				nls_map = load_nls(args[0].from);
258 				if (!nls_map) {
259 					printk(KERN_ERR
260 					       "JFS: charset not found\n");
261 					goto cleanup;
262 				}
263 			}
264 			break;
265 		case Opt_resize:
266 		{
267 			char *resize = args[0].from;
268 			*newLVSize = simple_strtoull(resize, &resize, 0);
269 			break;
270 		}
271 		case Opt_resize_nosize:
272 		{
273 			*newLVSize = sb->s_bdev->bd_inode->i_size >>
274 				sb->s_blocksize_bits;
275 			if (*newLVSize == 0)
276 				printk(KERN_ERR
277 				       "JFS: Cannot determine volume size\n");
278 			break;
279 		}
280 		case Opt_errors:
281 		{
282 			char *errors = args[0].from;
283 			if (!errors || !*errors)
284 				goto cleanup;
285 			if (!strcmp(errors, "continue")) {
286 				*flag &= ~JFS_ERR_REMOUNT_RO;
287 				*flag &= ~JFS_ERR_PANIC;
288 				*flag |= JFS_ERR_CONTINUE;
289 			} else if (!strcmp(errors, "remount-ro")) {
290 				*flag &= ~JFS_ERR_CONTINUE;
291 				*flag &= ~JFS_ERR_PANIC;
292 				*flag |= JFS_ERR_REMOUNT_RO;
293 			} else if (!strcmp(errors, "panic")) {
294 				*flag &= ~JFS_ERR_CONTINUE;
295 				*flag &= ~JFS_ERR_REMOUNT_RO;
296 				*flag |= JFS_ERR_PANIC;
297 			} else {
298 				printk(KERN_ERR
299 				       "JFS: %s is an invalid error handler\n",
300 				       errors);
301 				goto cleanup;
302 			}
303 			break;
304 		}
305 
306 #ifdef CONFIG_QUOTA
307 		case Opt_quota:
308 		case Opt_usrquota:
309 			*flag |= JFS_USRQUOTA;
310 			break;
311 		case Opt_grpquota:
312 			*flag |= JFS_GRPQUOTA;
313 			break;
314 #else
315 		case Opt_usrquota:
316 		case Opt_grpquota:
317 		case Opt_quota:
318 			printk(KERN_ERR
319 			       "JFS: quota operations not supported\n");
320 			break;
321 #endif
322 		case Opt_uid:
323 		{
324 			char *uid = args[0].from;
325 			sbi->uid = simple_strtoul(uid, &uid, 0);
326 			break;
327 		}
328 		case Opt_gid:
329 		{
330 			char *gid = args[0].from;
331 			sbi->gid = simple_strtoul(gid, &gid, 0);
332 			break;
333 		}
334 		case Opt_umask:
335 		{
336 			char *umask = args[0].from;
337 			sbi->umask = simple_strtoul(umask, &umask, 8);
338 			if (sbi->umask & ~0777) {
339 				printk(KERN_ERR
340 				       "JFS: Invalid value of umask\n");
341 				goto cleanup;
342 			}
343 			break;
344 		}
345 		default:
346 			printk("jfs: Unrecognized mount option \"%s\" "
347 					" or missing value\n", p);
348 			goto cleanup;
349 		}
350 	}
351 
352 	if (nls_map != (void *) -1) {
353 		/* Discard old (if remount) */
354 		unload_nls(sbi->nls_tab);
355 		sbi->nls_tab = nls_map;
356 	}
357 	return 1;
358 
359 cleanup:
360 	if (nls_map && nls_map != (void *) -1)
361 		unload_nls(nls_map);
362 	return 0;
363 }
364 
365 static int jfs_remount(struct super_block *sb, int *flags, char *data)
366 {
367 	s64 newLVSize = 0;
368 	int rc = 0;
369 	int flag = JFS_SBI(sb)->flag;
370 	int ret;
371 
372 	if (!parse_options(data, sb, &newLVSize, &flag)) {
373 		return -EINVAL;
374 	}
375 	lock_kernel();
376 	if (newLVSize) {
377 		if (sb->s_flags & MS_RDONLY) {
378 			printk(KERN_ERR
379 		  "JFS: resize requires volume to be mounted read-write\n");
380 			unlock_kernel();
381 			return -EROFS;
382 		}
383 		rc = jfs_extendfs(sb, newLVSize, 0);
384 		if (rc) {
385 			unlock_kernel();
386 			return rc;
387 		}
388 	}
389 
390 	if ((sb->s_flags & MS_RDONLY) && !(*flags & MS_RDONLY)) {
391 		/*
392 		 * Invalidate any previously read metadata.  fsck may have
393 		 * changed the on-disk data since we mounted r/o
394 		 */
395 		truncate_inode_pages(JFS_SBI(sb)->direct_inode->i_mapping, 0);
396 
397 		JFS_SBI(sb)->flag = flag;
398 		ret = jfs_mount_rw(sb, 1);
399 		unlock_kernel();
400 		return ret;
401 	}
402 	if ((!(sb->s_flags & MS_RDONLY)) && (*flags & MS_RDONLY)) {
403 		rc = jfs_umount_rw(sb);
404 		JFS_SBI(sb)->flag = flag;
405 		unlock_kernel();
406 		return rc;
407 	}
408 	if ((JFS_SBI(sb)->flag & JFS_NOINTEGRITY) != (flag & JFS_NOINTEGRITY))
409 		if (!(sb->s_flags & MS_RDONLY)) {
410 			rc = jfs_umount_rw(sb);
411 			if (rc) {
412 				unlock_kernel();
413 				return rc;
414 			}
415 			JFS_SBI(sb)->flag = flag;
416 			ret = jfs_mount_rw(sb, 1);
417 			unlock_kernel();
418 			return ret;
419 		}
420 	JFS_SBI(sb)->flag = flag;
421 
422 	unlock_kernel();
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 	sb->s_fs_info = sbi;
443 	sbi->sb = sb;
444 	sbi->uid = sbi->gid = sbi->umask = -1;
445 
446 	/* initialize the mount flag and determine the default error handler */
447 	flag = JFS_ERR_REMOUNT_RO;
448 
449 	if (!parse_options((char *) data, sb, &newLVSize, &flag))
450 		goto out_kfree;
451 	sbi->flag = flag;
452 
453 #ifdef CONFIG_JFS_POSIX_ACL
454 	sb->s_flags |= MS_POSIXACL;
455 #endif
456 
457 	if (newLVSize) {
458 		printk(KERN_ERR "resize option for remount only\n");
459 		goto out_kfree;
460 	}
461 
462 	/*
463 	 * Initialize blocksize to 4K.
464 	 */
465 	sb_set_blocksize(sb, PSIZE);
466 
467 	/*
468 	 * Set method vectors.
469 	 */
470 	sb->s_op = &jfs_super_operations;
471 	sb->s_export_op = &jfs_export_operations;
472 
473 	/*
474 	 * Initialize direct-mapping inode/address-space
475 	 */
476 	inode = new_inode(sb);
477 	if (inode == NULL) {
478 		ret = -ENOMEM;
479 		goto out_unload;
480 	}
481 	inode->i_ino = 0;
482 	inode->i_nlink = 1;
483 	inode->i_size = sb->s_bdev->bd_inode->i_size;
484 	inode->i_mapping->a_ops = &jfs_metapage_aops;
485 	insert_inode_hash(inode);
486 	mapping_set_gfp_mask(inode->i_mapping, GFP_NOFS);
487 
488 	sbi->direct_inode = inode;
489 
490 	rc = jfs_mount(sb);
491 	if (rc) {
492 		if (!silent) {
493 			jfs_err("jfs_mount failed w/return code = %d", rc);
494 		}
495 		goto out_mount_failed;
496 	}
497 	if (sb->s_flags & MS_RDONLY)
498 		sbi->log = NULL;
499 	else {
500 		rc = jfs_mount_rw(sb, 0);
501 		if (rc) {
502 			if (!silent) {
503 				jfs_err("jfs_mount_rw failed, return code = %d",
504 					rc);
505 			}
506 			goto out_no_rw;
507 		}
508 	}
509 
510 	sb->s_magic = JFS_SUPER_MAGIC;
511 
512 	inode = jfs_iget(sb, ROOT_I);
513 	if (IS_ERR(inode)) {
514 		ret = PTR_ERR(inode);
515 		goto out_no_rw;
516 	}
517 	sb->s_root = d_alloc_root(inode);
518 	if (!sb->s_root)
519 		goto out_no_root;
520 
521 	if (sbi->mntflag & JFS_OS2)
522 		sb->s_root->d_op = &jfs_ci_dentry_operations;
523 
524 	/* logical blocks are represented by 40 bits in pxd_t, etc. */
525 	sb->s_maxbytes = ((u64) sb->s_blocksize) << 40;
526 #if BITS_PER_LONG == 32
527 	/*
528 	 * Page cache is indexed by long.
529 	 * I would use MAX_LFS_FILESIZE, but it's only half as big
530 	 */
531 	sb->s_maxbytes = min(((u64) PAGE_CACHE_SIZE << 32) - 1, (u64)sb->s_maxbytes);
532 #endif
533 	sb->s_time_gran = 1;
534 	return 0;
535 
536 out_no_root:
537 	jfs_err("jfs_read_super: get root dentry failed");
538 	iput(inode);
539 
540 out_no_rw:
541 	rc = jfs_umount(sb);
542 	if (rc) {
543 		jfs_err("jfs_umount failed with return code %d", rc);
544 	}
545 out_mount_failed:
546 	filemap_write_and_wait(sbi->direct_inode->i_mapping);
547 	truncate_inode_pages(sbi->direct_inode->i_mapping, 0);
548 	make_bad_inode(sbi->direct_inode);
549 	iput(sbi->direct_inode);
550 	sbi->direct_inode = NULL;
551 out_unload:
552 	if (sbi->nls_tab)
553 		unload_nls(sbi->nls_tab);
554 out_kfree:
555 	kfree(sbi);
556 	return ret;
557 }
558 
559 static int jfs_freeze(struct super_block *sb)
560 {
561 	struct jfs_sb_info *sbi = JFS_SBI(sb);
562 	struct jfs_log *log = sbi->log;
563 
564 	if (!(sb->s_flags & MS_RDONLY)) {
565 		txQuiesce(sb);
566 		lmLogShutdown(log);
567 		updateSuper(sb, FM_CLEAN);
568 	}
569 	return 0;
570 }
571 
572 static int jfs_unfreeze(struct super_block *sb)
573 {
574 	struct jfs_sb_info *sbi = JFS_SBI(sb);
575 	struct jfs_log *log = sbi->log;
576 	int rc = 0;
577 
578 	if (!(sb->s_flags & MS_RDONLY)) {
579 		updateSuper(sb, FM_MOUNT);
580 		if ((rc = lmLogInit(log)))
581 			jfs_err("jfs_unlock failed with return code %d", rc);
582 		else
583 			txResume(sb);
584 	}
585 	return 0;
586 }
587 
588 static int jfs_get_sb(struct file_system_type *fs_type,
589 	int flags, const char *dev_name, void *data, struct vfsmount *mnt)
590 {
591 	return get_sb_bdev(fs_type, flags, dev_name, data, jfs_fill_super,
592 			   mnt);
593 }
594 
595 static int jfs_sync_fs(struct super_block *sb, int wait)
596 {
597 	struct jfs_log *log = JFS_SBI(sb)->log;
598 
599 	/* log == NULL indicates read-only mount */
600 	if (log) {
601 		jfs_flush_journal(log, wait);
602 		jfs_syncpt(log, 0);
603 	}
604 
605 	return 0;
606 }
607 
608 static int jfs_show_options(struct seq_file *seq, struct vfsmount *vfs)
609 {
610 	struct jfs_sb_info *sbi = JFS_SBI(vfs->mnt_sb);
611 
612 	if (sbi->uid != -1)
613 		seq_printf(seq, ",uid=%d", sbi->uid);
614 	if (sbi->gid != -1)
615 		seq_printf(seq, ",gid=%d", sbi->gid);
616 	if (sbi->umask != -1)
617 		seq_printf(seq, ",umask=%03o", sbi->umask);
618 	if (sbi->flag & JFS_NOINTEGRITY)
619 		seq_puts(seq, ",nointegrity");
620 	if (sbi->nls_tab)
621 		seq_printf(seq, ",iocharset=%s", sbi->nls_tab->charset);
622 	if (sbi->flag & JFS_ERR_CONTINUE)
623 		seq_printf(seq, ",errors=continue");
624 	if (sbi->flag & JFS_ERR_PANIC)
625 		seq_printf(seq, ",errors=panic");
626 
627 #ifdef CONFIG_QUOTA
628 	if (sbi->flag & JFS_USRQUOTA)
629 		seq_puts(seq, ",usrquota");
630 
631 	if (sbi->flag & JFS_GRPQUOTA)
632 		seq_puts(seq, ",grpquota");
633 #endif
634 
635 	return 0;
636 }
637 
638 #ifdef CONFIG_QUOTA
639 
640 /* Read data from quotafile - avoid pagecache and such because we cannot afford
641  * acquiring the locks... As quota files are never truncated and quota code
642  * itself serializes the operations (and noone else should touch the files)
643  * we don't have to be afraid of races */
644 static ssize_t jfs_quota_read(struct super_block *sb, int type, char *data,
645 			      size_t len, loff_t off)
646 {
647 	struct inode *inode = sb_dqopt(sb)->files[type];
648 	sector_t blk = off >> sb->s_blocksize_bits;
649 	int err = 0;
650 	int offset = off & (sb->s_blocksize - 1);
651 	int tocopy;
652 	size_t toread;
653 	struct buffer_head tmp_bh;
654 	struct buffer_head *bh;
655 	loff_t i_size = i_size_read(inode);
656 
657 	if (off > i_size)
658 		return 0;
659 	if (off+len > i_size)
660 		len = i_size-off;
661 	toread = len;
662 	while (toread > 0) {
663 		tocopy = sb->s_blocksize - offset < toread ?
664 				sb->s_blocksize - offset : toread;
665 
666 		tmp_bh.b_state = 0;
667 		tmp_bh.b_size = 1 << inode->i_blkbits;
668 		err = jfs_get_block(inode, blk, &tmp_bh, 0);
669 		if (err)
670 			return err;
671 		if (!buffer_mapped(&tmp_bh))	/* A hole? */
672 			memset(data, 0, tocopy);
673 		else {
674 			bh = sb_bread(sb, tmp_bh.b_blocknr);
675 			if (!bh)
676 				return -EIO;
677 			memcpy(data, bh->b_data+offset, tocopy);
678 			brelse(bh);
679 		}
680 		offset = 0;
681 		toread -= tocopy;
682 		data += tocopy;
683 		blk++;
684 	}
685 	return len;
686 }
687 
688 /* Write to quotafile */
689 static ssize_t jfs_quota_write(struct super_block *sb, int type,
690 			       const char *data, size_t len, loff_t off)
691 {
692 	struct inode *inode = sb_dqopt(sb)->files[type];
693 	sector_t blk = off >> sb->s_blocksize_bits;
694 	int err = 0;
695 	int offset = off & (sb->s_blocksize - 1);
696 	int tocopy;
697 	size_t towrite = len;
698 	struct buffer_head tmp_bh;
699 	struct buffer_head *bh;
700 
701 	mutex_lock(&inode->i_mutex);
702 	while (towrite > 0) {
703 		tocopy = sb->s_blocksize - offset < towrite ?
704 				sb->s_blocksize - offset : towrite;
705 
706 		tmp_bh.b_state = 0;
707 		tmp_bh.b_size = 1 << inode->i_blkbits;
708 		err = jfs_get_block(inode, blk, &tmp_bh, 1);
709 		if (err)
710 			goto out;
711 		if (offset || tocopy != sb->s_blocksize)
712 			bh = sb_bread(sb, tmp_bh.b_blocknr);
713 		else
714 			bh = sb_getblk(sb, tmp_bh.b_blocknr);
715 		if (!bh) {
716 			err = -EIO;
717 			goto out;
718 		}
719 		lock_buffer(bh);
720 		memcpy(bh->b_data+offset, data, tocopy);
721 		flush_dcache_page(bh->b_page);
722 		set_buffer_uptodate(bh);
723 		mark_buffer_dirty(bh);
724 		unlock_buffer(bh);
725 		brelse(bh);
726 		offset = 0;
727 		towrite -= tocopy;
728 		data += tocopy;
729 		blk++;
730 	}
731 out:
732 	if (len == towrite) {
733 		mutex_unlock(&inode->i_mutex);
734 		return err;
735 	}
736 	if (inode->i_size < off+len-towrite)
737 		i_size_write(inode, off+len-towrite);
738 	inode->i_version++;
739 	inode->i_mtime = inode->i_ctime = CURRENT_TIME;
740 	mark_inode_dirty(inode);
741 	mutex_unlock(&inode->i_mutex);
742 	return len - towrite;
743 }
744 
745 #endif
746 
747 static const struct super_operations jfs_super_operations = {
748 	.alloc_inode	= jfs_alloc_inode,
749 	.destroy_inode	= jfs_destroy_inode,
750 	.dirty_inode	= jfs_dirty_inode,
751 	.write_inode	= jfs_write_inode,
752 	.delete_inode	= jfs_delete_inode,
753 	.clear_inode	= jfs_clear_inode,
754 	.put_super	= jfs_put_super,
755 	.sync_fs	= jfs_sync_fs,
756 	.freeze_fs	= jfs_freeze,
757 	.unfreeze_fs	= jfs_unfreeze,
758 	.statfs		= jfs_statfs,
759 	.remount_fs	= jfs_remount,
760 	.show_options	= jfs_show_options,
761 #ifdef CONFIG_QUOTA
762 	.quota_read	= jfs_quota_read,
763 	.quota_write	= jfs_quota_write,
764 #endif
765 };
766 
767 static const struct export_operations jfs_export_operations = {
768 	.fh_to_dentry	= jfs_fh_to_dentry,
769 	.fh_to_parent	= jfs_fh_to_parent,
770 	.get_parent	= jfs_get_parent,
771 };
772 
773 static struct file_system_type jfs_fs_type = {
774 	.owner		= THIS_MODULE,
775 	.name		= "jfs",
776 	.get_sb		= jfs_get_sb,
777 	.kill_sb	= kill_block_super,
778 	.fs_flags	= FS_REQUIRES_DEV,
779 };
780 
781 static void init_once(void *foo)
782 {
783 	struct jfs_inode_info *jfs_ip = (struct jfs_inode_info *) foo;
784 
785 	memset(jfs_ip, 0, sizeof(struct jfs_inode_info));
786 	INIT_LIST_HEAD(&jfs_ip->anon_inode_list);
787 	init_rwsem(&jfs_ip->rdwrlock);
788 	mutex_init(&jfs_ip->commit_mutex);
789 	init_rwsem(&jfs_ip->xattr_sem);
790 	spin_lock_init(&jfs_ip->ag_lock);
791 	jfs_ip->active_ag = -1;
792 	inode_init_once(&jfs_ip->vfs_inode);
793 }
794 
795 static int __init init_jfs_fs(void)
796 {
797 	int i;
798 	int rc;
799 
800 	jfs_inode_cachep =
801 	    kmem_cache_create("jfs_ip", sizeof(struct jfs_inode_info), 0,
802 			    SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD,
803 			    init_once);
804 	if (jfs_inode_cachep == NULL)
805 		return -ENOMEM;
806 
807 	/*
808 	 * Metapage initialization
809 	 */
810 	rc = metapage_init();
811 	if (rc) {
812 		jfs_err("metapage_init failed w/rc = %d", rc);
813 		goto free_slab;
814 	}
815 
816 	/*
817 	 * Transaction Manager initialization
818 	 */
819 	rc = txInit();
820 	if (rc) {
821 		jfs_err("txInit failed w/rc = %d", rc);
822 		goto free_metapage;
823 	}
824 
825 	/*
826 	 * I/O completion thread (endio)
827 	 */
828 	jfsIOthread = kthread_run(jfsIOWait, NULL, "jfsIO");
829 	if (IS_ERR(jfsIOthread)) {
830 		rc = PTR_ERR(jfsIOthread);
831 		jfs_err("init_jfs_fs: fork failed w/rc = %d", rc);
832 		goto end_txmngr;
833 	}
834 
835 	if (commit_threads < 1)
836 		commit_threads = num_online_cpus();
837 	if (commit_threads > MAX_COMMIT_THREADS)
838 		commit_threads = MAX_COMMIT_THREADS;
839 
840 	for (i = 0; i < commit_threads; i++) {
841 		jfsCommitThread[i] = kthread_run(jfs_lazycommit, NULL, "jfsCommit");
842 		if (IS_ERR(jfsCommitThread[i])) {
843 			rc = PTR_ERR(jfsCommitThread[i]);
844 			jfs_err("init_jfs_fs: fork failed w/rc = %d", rc);
845 			commit_threads = i;
846 			goto kill_committask;
847 		}
848 	}
849 
850 	jfsSyncThread = kthread_run(jfs_sync, NULL, "jfsSync");
851 	if (IS_ERR(jfsSyncThread)) {
852 		rc = PTR_ERR(jfsSyncThread);
853 		jfs_err("init_jfs_fs: fork failed w/rc = %d", rc);
854 		goto kill_committask;
855 	}
856 
857 #ifdef PROC_FS_JFS
858 	jfs_proc_init();
859 #endif
860 
861 	return register_filesystem(&jfs_fs_type);
862 
863 kill_committask:
864 	for (i = 0; i < commit_threads; i++)
865 		kthread_stop(jfsCommitThread[i]);
866 	kthread_stop(jfsIOthread);
867 end_txmngr:
868 	txExit();
869 free_metapage:
870 	metapage_exit();
871 free_slab:
872 	kmem_cache_destroy(jfs_inode_cachep);
873 	return rc;
874 }
875 
876 static void __exit exit_jfs_fs(void)
877 {
878 	int i;
879 
880 	jfs_info("exit_jfs_fs called");
881 
882 	txExit();
883 	metapage_exit();
884 
885 	kthread_stop(jfsIOthread);
886 	for (i = 0; i < commit_threads; i++)
887 		kthread_stop(jfsCommitThread[i]);
888 	kthread_stop(jfsSyncThread);
889 #ifdef PROC_FS_JFS
890 	jfs_proc_clean();
891 #endif
892 	unregister_filesystem(&jfs_fs_type);
893 	kmem_cache_destroy(jfs_inode_cachep);
894 }
895 
896 module_init(init_jfs_fs)
897 module_exit(exit_jfs_fs)
898