xref: /openbmc/linux/fs/jfs/super.c (revision 257ba15cedf1288f0c96118d7e63947231d27278)
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 <asm/uaccess.h>
34 #include <linux/seq_file.h>
35 #include <linux/smp_lock.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_destroy_inode(struct inode *inode)
119 {
120 	struct jfs_inode_info *ji = JFS_IP(inode);
121 
122 	BUG_ON(!list_empty(&ji->anon_inode_list));
123 
124 	spin_lock_irq(&ji->ag_lock);
125 	if (ji->active_ag != -1) {
126 		struct bmap *bmap = JFS_SBI(inode->i_sb)->bmap;
127 		atomic_dec(&bmap->db_active[ji->active_ag]);
128 		ji->active_ag = -1;
129 	}
130 	spin_unlock_irq(&ji->ag_lock);
131 	kmem_cache_free(jfs_inode_cachep, ji);
132 }
133 
134 static void jfs_clear_inode(struct inode *inode)
135 {
136 	vfs_dq_drop(inode);
137 }
138 
139 static int jfs_statfs(struct dentry *dentry, struct kstatfs *buf)
140 {
141 	struct jfs_sb_info *sbi = JFS_SBI(dentry->d_sb);
142 	s64 maxinodes;
143 	struct inomap *imap = JFS_IP(sbi->ipimap)->i_imap;
144 
145 	jfs_info("In jfs_statfs");
146 	buf->f_type = JFS_SUPER_MAGIC;
147 	buf->f_bsize = sbi->bsize;
148 	buf->f_blocks = sbi->bmap->db_mapsize;
149 	buf->f_bfree = sbi->bmap->db_nfree;
150 	buf->f_bavail = sbi->bmap->db_nfree;
151 	/*
152 	 * If we really return the number of allocated & free inodes, some
153 	 * applications will fail because they won't see enough free inodes.
154 	 * We'll try to calculate some guess as to how may inodes we can
155 	 * really allocate
156 	 *
157 	 * buf->f_files = atomic_read(&imap->im_numinos);
158 	 * buf->f_ffree = atomic_read(&imap->im_numfree);
159 	 */
160 	maxinodes = min((s64) atomic_read(&imap->im_numinos) +
161 			((sbi->bmap->db_nfree >> imap->im_l2nbperiext)
162 			 << L2INOSPEREXT), (s64) 0xffffffffLL);
163 	buf->f_files = maxinodes;
164 	buf->f_ffree = maxinodes - (atomic_read(&imap->im_numinos) -
165 				    atomic_read(&imap->im_numfree));
166 	buf->f_fsid.val[0] = (u32)crc32_le(0, sbi->uuid, sizeof(sbi->uuid)/2);
167 	buf->f_fsid.val[1] = (u32)crc32_le(0, sbi->uuid + sizeof(sbi->uuid)/2,
168 					sizeof(sbi->uuid)/2);
169 
170 	buf->f_namelen = JFS_NAME_MAX;
171 	return 0;
172 }
173 
174 static void jfs_put_super(struct super_block *sb)
175 {
176 	struct jfs_sb_info *sbi = JFS_SBI(sb);
177 	int rc;
178 
179 	jfs_info("In jfs_put_super");
180 
181 	lock_kernel();
182 
183 	rc = jfs_umount(sb);
184 	if (rc)
185 		jfs_err("jfs_umount failed with return code %d", rc);
186 
187 	unload_nls(sbi->nls_tab);
188 
189 	truncate_inode_pages(sbi->direct_inode->i_mapping, 0);
190 	iput(sbi->direct_inode);
191 
192 	kfree(sbi);
193 
194 	unlock_kernel();
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 	lock_kernel();
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 			unlock_kernel();
380 			return -EROFS;
381 		}
382 		rc = jfs_extendfs(sb, newLVSize, 0);
383 		if (rc) {
384 			unlock_kernel();
385 			return rc;
386 		}
387 	}
388 
389 	if ((sb->s_flags & MS_RDONLY) && !(*flags & MS_RDONLY)) {
390 		/*
391 		 * Invalidate any previously read metadata.  fsck may have
392 		 * changed the on-disk data since we mounted r/o
393 		 */
394 		truncate_inode_pages(JFS_SBI(sb)->direct_inode->i_mapping, 0);
395 
396 		JFS_SBI(sb)->flag = flag;
397 		ret = jfs_mount_rw(sb, 1);
398 		unlock_kernel();
399 		return ret;
400 	}
401 	if ((!(sb->s_flags & MS_RDONLY)) && (*flags & MS_RDONLY)) {
402 		rc = jfs_umount_rw(sb);
403 		JFS_SBI(sb)->flag = flag;
404 		unlock_kernel();
405 		return rc;
406 	}
407 	if ((JFS_SBI(sb)->flag & JFS_NOINTEGRITY) != (flag & JFS_NOINTEGRITY))
408 		if (!(sb->s_flags & MS_RDONLY)) {
409 			rc = jfs_umount_rw(sb);
410 			if (rc) {
411 				unlock_kernel();
412 				return rc;
413 			}
414 			JFS_SBI(sb)->flag = flag;
415 			ret = jfs_mount_rw(sb, 1);
416 			unlock_kernel();
417 			return ret;
418 		}
419 	JFS_SBI(sb)->flag = flag;
420 
421 	unlock_kernel();
422 	return 0;
423 }
424 
425 static int jfs_fill_super(struct super_block *sb, void *data, int silent)
426 {
427 	struct jfs_sb_info *sbi;
428 	struct inode *inode;
429 	int rc;
430 	s64 newLVSize = 0;
431 	int flag, ret = -EINVAL;
432 
433 	jfs_info("In jfs_read_super: s_flags=0x%lx", sb->s_flags);
434 
435 	if (!new_valid_dev(sb->s_bdev->bd_dev))
436 		return -EOVERFLOW;
437 
438 	sbi = kzalloc(sizeof (struct jfs_sb_info), GFP_KERNEL);
439 	if (!sbi)
440 		return -ENOMEM;
441 	sb->s_fs_info = sbi;
442 	sbi->sb = sb;
443 	sbi->uid = sbi->gid = sbi->umask = -1;
444 
445 	/* initialize the mount flag and determine the default error handler */
446 	flag = JFS_ERR_REMOUNT_RO;
447 
448 	if (!parse_options((char *) data, sb, &newLVSize, &flag)) {
449 		kfree(sbi);
450 		return -EINVAL;
451 	}
452 	sbi->flag = flag;
453 
454 #ifdef CONFIG_JFS_POSIX_ACL
455 	sb->s_flags |= MS_POSIXACL;
456 #endif
457 
458 	if (newLVSize) {
459 		printk(KERN_ERR "resize option for remount only\n");
460 		return -EINVAL;
461 	}
462 
463 	/*
464 	 * Initialize blocksize to 4K.
465 	 */
466 	sb_set_blocksize(sb, PSIZE);
467 
468 	/*
469 	 * Set method vectors.
470 	 */
471 	sb->s_op = &jfs_super_operations;
472 	sb->s_export_op = &jfs_export_operations;
473 
474 	/*
475 	 * Initialize direct-mapping inode/address-space
476 	 */
477 	inode = new_inode(sb);
478 	if (inode == NULL) {
479 		ret = -ENOMEM;
480 		goto out_kfree;
481 	}
482 	inode->i_ino = 0;
483 	inode->i_nlink = 1;
484 	inode->i_size = sb->s_bdev->bd_inode->i_size;
485 	inode->i_mapping->a_ops = &jfs_metapage_aops;
486 	insert_inode_hash(inode);
487 	mapping_set_gfp_mask(inode->i_mapping, GFP_NOFS);
488 
489 	sbi->direct_inode = inode;
490 
491 	rc = jfs_mount(sb);
492 	if (rc) {
493 		if (!silent) {
494 			jfs_err("jfs_mount failed w/return code = %d", rc);
495 		}
496 		goto out_mount_failed;
497 	}
498 	if (sb->s_flags & MS_RDONLY)
499 		sbi->log = NULL;
500 	else {
501 		rc = jfs_mount_rw(sb, 0);
502 		if (rc) {
503 			if (!silent) {
504 				jfs_err("jfs_mount_rw failed, return code = %d",
505 					rc);
506 			}
507 			goto out_no_rw;
508 		}
509 	}
510 
511 	sb->s_magic = JFS_SUPER_MAGIC;
512 
513 	inode = jfs_iget(sb, ROOT_I);
514 	if (IS_ERR(inode)) {
515 		ret = PTR_ERR(inode);
516 		goto out_no_rw;
517 	}
518 	sb->s_root = d_alloc_root(inode);
519 	if (!sb->s_root)
520 		goto out_no_root;
521 
522 	if (sbi->mntflag & JFS_OS2)
523 		sb->s_root->d_op = &jfs_ci_dentry_operations;
524 
525 	/* logical blocks are represented by 40 bits in pxd_t, etc. */
526 	sb->s_maxbytes = ((u64) sb->s_blocksize) << 40;
527 #if BITS_PER_LONG == 32
528 	/*
529 	 * Page cache is indexed by long.
530 	 * I would use MAX_LFS_FILESIZE, but it's only half as big
531 	 */
532 	sb->s_maxbytes = min(((u64) PAGE_CACHE_SIZE << 32) - 1, (u64)sb->s_maxbytes);
533 #endif
534 	sb->s_time_gran = 1;
535 	return 0;
536 
537 out_no_root:
538 	jfs_err("jfs_read_super: get root dentry failed");
539 	iput(inode);
540 
541 out_no_rw:
542 	rc = jfs_umount(sb);
543 	if (rc) {
544 		jfs_err("jfs_umount failed with return code %d", rc);
545 	}
546 out_mount_failed:
547 	filemap_write_and_wait(sbi->direct_inode->i_mapping);
548 	truncate_inode_pages(sbi->direct_inode->i_mapping, 0);
549 	make_bad_inode(sbi->direct_inode);
550 	iput(sbi->direct_inode);
551 	sbi->direct_inode = NULL;
552 out_kfree:
553 	if (sbi->nls_tab)
554 		unload_nls(sbi->nls_tab);
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