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[PATCH] oprofile: ppro: need to enable/disable all the counters
[deliverable/linux.git] / fs / fat / inode.c
CommitLineData
1da177e4
LT		 1/*
2 * linux/fs/fat/inode.c
3 *
4 * Written 1992,1993 by Werner Almesberger
5 * VFAT extensions by Gordon Chaffee, merged with msdos fs by Henrik Storner
6 * Rewritten for the constant inumbers support by Al Viro
7 *
8 * Fixes:
9 *
10 * Max Cohan: Fixed invalid FSINFO offset when info_sector is 0
11 */
12
13#include <linux/module.h>
14#include <linux/init.h>
15#include <linux/time.h>
16#include <linux/slab.h>
17#include <linux/smp_lock.h>
18#include <linux/seq_file.h>
19#include <linux/msdos_fs.h>
20#include <linux/pagemap.h>
a5425d29 21#include <linux/mpage.h>
1da177e4
LT		 22#include <linux/buffer_head.h>
23#include <linux/mount.h>
24#include <linux/vfs.h>
25#include <linux/parser.h>
e5174baa 26#include <linux/uio.h>
1da177e4
LT		 27#include <asm/unaligned.h>
28
29#ifndef CONFIG_FAT_DEFAULT_IOCHARSET
30/* if user don't select VFAT, this is undefined. */
31#define CONFIG_FAT_DEFAULT_IOCHARSET ""
32#endif
33
34static int fat_default_codepage = CONFIG_FAT_DEFAULT_CODEPAGE;
35static char fat_default_iocharset[] = CONFIG_FAT_DEFAULT_IOCHARSET;
36
37
38static int fat_add_cluster(struct inode *inode)
39{
40 int err, cluster;
41
42 err = fat_alloc_clusters(inode, &cluster, 1);
43 if (err)
44 return err;
45 /* FIXME: this cluster should be added after data of this
46 * cluster is writed */
47 err = fat_chain_add(inode, cluster, 1);
48 if (err)
49 fat_free_clusters(inode, cluster);
50 return err;
51}
52
6a1d9805
OH		 53static inline int __fat_get_block(struct inode *inode, sector_t iblock,
54 unsigned long *max_blocks,
55 struct buffer_head *bh_result, int create)
1da177e4
LT		 56{
57 struct super_block *sb = inode->i_sb;
e5174baa 58 struct msdos_sb_info *sbi = MSDOS_SB(sb);
e5174baa 59 unsigned long mapped_blocks;
6a1d9805 60 sector_t phys;
e5174baa 61 int err, offset;
1da177e4 62
e5174baa 63 err = fat_bmap(inode, iblock, &phys, &mapped_blocks);
1da177e4
LT		 64 if (err)
65 return err;
66 if (phys) {
67 map_bh(bh_result, sb, phys);
e5174baa 68 *max_blocks = min(mapped_blocks, *max_blocks);
1da177e4
LT		 69 return 0;
70 }
71 if (!create)
72 return 0;
e5174baa 73
1da177e4
LT		 74 if (iblock != MSDOS_I(inode)->mmu_private >> sb->s_blocksize_bits) {
75 fat_fs_panic(sb, "corrupted file size (i_pos %lld, %lld)",
6a1d9805 76 MSDOS_I(inode)->i_pos, MSDOS_I(inode)->mmu_private);
1da177e4
LT		 77 return -EIO;
78 }
e5174baa
OH		 79
80 offset = (unsigned long)iblock & (sbi->sec_per_clus - 1);
81 if (!offset) {
82 /* TODO: multiple cluster allocation would be desirable. */
1da177e4
LT		 83 err = fat_add_cluster(inode);
84 if (err)
85 return err;
86 }
e5174baa
OH		 87 /* available blocks on this cluster */
88 mapped_blocks = sbi->sec_per_clus - offset;
89
90 *max_blocks = min(mapped_blocks, *max_blocks);
91 MSDOS_I(inode)->mmu_private += *max_blocks << sb->s_blocksize_bits;
92
93 err = fat_bmap(inode, iblock, &phys, &mapped_blocks);
1da177e4
LT		 94 if (err)
95 return err;
6a1d9805 96
e5174baa
OH		 97 BUG_ON(!phys);
98 BUG_ON(*max_blocks != mapped_blocks);
1da177e4
LT		 99 set_buffer_new(bh_result);
100 map_bh(bh_result, sb, phys);
6a1d9805 101
1da177e4
LT		 102 return 0;
103}
104
6a1d9805
OH		 105static int fat_get_block(struct inode *inode, sector_t iblock,
106 struct buffer_head *bh_result, int create)
e5174baa
OH		 107{
108 struct super_block *sb = inode->i_sb;
1d8fa7a2 109 unsigned long max_blocks = bh_result->b_size >> inode->i_blkbits;
6a1d9805 110 int err;
e5174baa 111
6a1d9805 112 err = __fat_get_block(inode, iblock, &max_blocks, bh_result, create);
e5174baa
OH		 113 if (err)
114 return err;
115 bh_result->b_size = max_blocks << sb->s_blocksize_bits;
116 return 0;
117}
118
1da177e4
LT		 119static int fat_writepage(struct page *page, struct writeback_control *wbc)
120{
121 return block_write_full_page(page, fat_get_block, wbc);
122}
123
a5425d29
OH		 124static int fat_writepages(struct address_space *mapping,
125 struct writeback_control *wbc)
126{
127 return mpage_writepages(mapping, wbc, fat_get_block);
128}
129
1da177e4
LT		 130static int fat_readpage(struct file *file, struct page *page)
131{
a5425d29
OH		 132 return mpage_readpage(page, fat_get_block);
133}
134
135static int fat_readpages(struct file *file, struct address_space *mapping,
136 struct list_head *pages, unsigned nr_pages)
137{
138 return mpage_readpages(mapping, pages, nr_pages, fat_get_block);
1da177e4
LT		 139}
140
141static int fat_prepare_write(struct file *file, struct page *page,
142 unsigned from, unsigned to)
143{
144 return cont_prepare_write(page, from, to, fat_get_block,
145 &MSDOS_I(page->mapping->host)->mmu_private);
146}
147
ef402268
OH		 148static int fat_commit_write(struct file *file, struct page *page,
149 unsigned from, unsigned to)
150{
151 struct inode *inode = page->mapping->host;
152 int err = generic_commit_write(file, page, from, to);
153 if (!err && !(MSDOS_I(inode)->i_attrs & ATTR_ARCH)) {
154 inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC;
155 MSDOS_I(inode)->i_attrs |= ATTR_ARCH;
156 mark_inode_dirty(inode);
157 }
158 return err;
159}
160
e5174baa
OH		 161static ssize_t fat_direct_IO(int rw, struct kiocb *iocb,
162 const struct iovec *iov,
163 loff_t offset, unsigned long nr_segs)
164{
165 struct file *file = iocb->ki_filp;
166 struct inode *inode = file->f_mapping->host;
167
168 if (rw == WRITE) {
169 /*
170 * FIXME: blockdev_direct_IO() doesn't use ->prepare_write(),
171 * so we need to update the ->mmu_private to block boundary.
172 *
173 * But we must fill the remaining area or hole by nul for
174 * updating ->mmu_private.
175 */
176 loff_t size = offset + iov_length(iov, nr_segs);
177 if (MSDOS_I(inode)->mmu_private < size)
178 return -EINVAL;
179 }
180
181 /*
182 * FAT need to use the DIO_LOCKING for avoiding the race
183 * condition of fat_get_block() and ->truncate().
184 */
185 return blockdev_direct_IO(rw, iocb, inode, inode->i_sb->s_bdev, iov,
6a1d9805 186 offset, nr_segs, fat_get_block, NULL);
e5174baa
OH		 187}
188
1da177e4
LT		 189static sector_t _fat_bmap(struct address_space *mapping, sector_t block)
190{
191 return generic_block_bmap(mapping, block, fat_get_block);
192}
193
f5e54d6e 194static const struct address_space_operations fat_aops = {
1da177e4 195 .readpage = fat_readpage,
a5425d29 196 .readpages = fat_readpages,
1da177e4 197 .writepage = fat_writepage,
a5425d29 198 .writepages = fat_writepages,
1da177e4
LT		 199 .sync_page = block_sync_page,
200 .prepare_write = fat_prepare_write,
ef402268 201 .commit_write = fat_commit_write,
e5174baa 202 .direct_IO = fat_direct_IO,
1da177e4
LT		 203 .bmap = _fat_bmap
204};
205
206/*
207 * New FAT inode stuff. We do the following:
208 * a) i_ino is constant and has nothing with on-disk location.
209 * b) FAT manages its own cache of directory entries.
210 * c) *This* cache is indexed by on-disk location.
211 * d) inode has an associated directory entry, all right, but
212 * it may be unhashed.
213 * e) currently entries are stored within struct inode. That should
214 * change.
215 * f) we deal with races in the following way:
216 * 1. readdir() and lookup() do FAT-dir-cache lookup.
217 * 2. rename() unhashes the F-d-c entry and rehashes it in
218 * a new place.
219 * 3. unlink() and rmdir() unhash F-d-c entry.
220 * 4. fat_write_inode() checks whether the thing is unhashed.
221 * If it is we silently return. If it isn't we do bread(),
222 * check if the location is still valid and retry if it
223 * isn't. Otherwise we do changes.
224 * 5. Spinlock is used to protect hash/unhash/location check/lookup
225 * 6. fat_clear_inode() unhashes the F-d-c entry.
226 * 7. lookup() and readdir() do igrab() if they find a F-d-c entry
227 * and consider negative result as cache miss.
228 */
229
230static void fat_hash_init(struct super_block *sb)
231{
232 struct msdos_sb_info *sbi = MSDOS_SB(sb);
233 int i;
234
235 spin_lock_init(&sbi->inode_hash_lock);
236 for (i = 0; i < FAT_HASH_SIZE; i++)
237 INIT_HLIST_HEAD(&sbi->inode_hashtable[i]);
238}
239
240static inline unsigned long fat_hash(struct super_block *sb, loff_t i_pos)
241{
242 unsigned long tmp = (unsigned long)i_pos | (unsigned long) sb;
243 tmp = tmp + (tmp >> FAT_HASH_BITS) + (tmp >> FAT_HASH_BITS * 2);
244 return tmp & FAT_HASH_MASK;
245}
246
247void fat_attach(struct inode *inode, loff_t i_pos)
248{
249 struct super_block *sb = inode->i_sb;
250 struct msdos_sb_info *sbi = MSDOS_SB(sb);
251
252 spin_lock(&sbi->inode_hash_lock);
253 MSDOS_I(inode)->i_pos = i_pos;
254 hlist_add_head(&MSDOS_I(inode)->i_fat_hash,
255 sbi->inode_hashtable + fat_hash(sb, i_pos));
256 spin_unlock(&sbi->inode_hash_lock);
257}
258
7c709d00 259EXPORT_SYMBOL_GPL(fat_attach);
1da177e4
LT		 260
261void fat_detach(struct inode *inode)
262{
263 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
264 spin_lock(&sbi->inode_hash_lock);
265 MSDOS_I(inode)->i_pos = 0;
266 hlist_del_init(&MSDOS_I(inode)->i_fat_hash);
267 spin_unlock(&sbi->inode_hash_lock);
268}
269
7c709d00 270EXPORT_SYMBOL_GPL(fat_detach);
1da177e4
LT		 271
272struct inode *fat_iget(struct super_block *sb, loff_t i_pos)
273{
274 struct msdos_sb_info *sbi = MSDOS_SB(sb);
275 struct hlist_head *head = sbi->inode_hashtable + fat_hash(sb, i_pos);
276 struct hlist_node *_p;
277 struct msdos_inode_info *i;
278 struct inode *inode = NULL;
279
280 spin_lock(&sbi->inode_hash_lock);
281 hlist_for_each_entry(i, _p, head, i_fat_hash) {
282 BUG_ON(i->vfs_inode.i_sb != sb);
283 if (i->i_pos != i_pos)
284 continue;
285 inode = igrab(&i->vfs_inode);
286 if (inode)
287 break;
288 }
289 spin_unlock(&sbi->inode_hash_lock);
290 return inode;
291}
292
293static int is_exec(unsigned char *extension)
294{
295 unsigned char *exe_extensions = "EXECOMBAT", *walk;
296
297 for (walk = exe_extensions; *walk; walk += 3)
298 if (!strncmp(extension, walk, 3))
299 return 1;
300 return 0;
301}
302
303static int fat_calc_dir_size(struct inode *inode)
304{
305 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
306 int ret, fclus, dclus;
307
308 inode->i_size = 0;
309 if (MSDOS_I(inode)->i_start == 0)
310 return 0;
311
312 ret = fat_get_cluster(inode, FAT_ENT_EOF, &fclus, &dclus);
313 if (ret < 0)
314 return ret;
315 inode->i_size = (fclus + 1) << sbi->cluster_bits;
316
317 return 0;
318}
319
320/* doesn't deal with root inode */
321static int fat_fill_inode(struct inode *inode, struct msdos_dir_entry *de)
322{
323 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
324 int error;
325
326 MSDOS_I(inode)->i_pos = 0;
327 inode->i_uid = sbi->options.fs_uid;
328 inode->i_gid = sbi->options.fs_gid;
329 inode->i_version++;
330 inode->i_generation = get_seconds();
331
332 if ((de->attr & ATTR_DIR) && !IS_FREE(de->name)) {
333 inode->i_generation &= ~1;
334 inode->i_mode = MSDOS_MKMODE(de->attr,
335 S_IRWXUGO & ~sbi->options.fs_dmask) | S_IFDIR;
336 inode->i_op = sbi->dir_ops;
337 inode->i_fop = &fat_dir_operations;
338
339 MSDOS_I(inode)->i_start = le16_to_cpu(de->start);
340 if (sbi->fat_bits == 32)
341 MSDOS_I(inode)->i_start |= (le16_to_cpu(de->starthi) << 16);
342
343 MSDOS_I(inode)->i_logstart = MSDOS_I(inode)->i_start;
344 error = fat_calc_dir_size(inode);
345 if (error < 0)
346 return error;
347 MSDOS_I(inode)->mmu_private = inode->i_size;
348
349 inode->i_nlink = fat_subdirs(inode);
350 } else { /* not a directory */
351 inode->i_generation |= 1;
352 inode->i_mode = MSDOS_MKMODE(de->attr,
353 ((sbi->options.showexec &&
354 !is_exec(de->ext))
355 ? S_IRUGO|S_IWUGO : S_IRWXUGO)
356 & ~sbi->options.fs_fmask) | S_IFREG;
357 MSDOS_I(inode)->i_start = le16_to_cpu(de->start);
358 if (sbi->fat_bits == 32)
359 MSDOS_I(inode)->i_start |= (le16_to_cpu(de->starthi) << 16);
360
361 MSDOS_I(inode)->i_logstart = MSDOS_I(inode)->i_start;
362 inode->i_size = le32_to_cpu(de->size);
363 inode->i_op = &fat_file_inode_operations;
364 inode->i_fop = &fat_file_operations;
365 inode->i_mapping->a_ops = &fat_aops;
366 MSDOS_I(inode)->mmu_private = inode->i_size;
367 }
368 if (de->attr & ATTR_SYS) {
369 if (sbi->options.sys_immutable)
370 inode->i_flags |= S_IMMUTABLE;
371 }
372 MSDOS_I(inode)->i_attrs = de->attr & ATTR_UNUSED;
1da177e4
LT		 373 inode->i_blocks = ((inode->i_size + (sbi->cluster_size - 1))
374 & ~((loff_t)sbi->cluster_size - 1)) >> 9;
62a36c43 375 inode->i_mtime.tv_sec =
1da177e4 376 date_dos2unix(le16_to_cpu(de->time), le16_to_cpu(de->date));
62a36c43 377 inode->i_mtime.tv_nsec = 0;
1da177e4
LT		 378 if (sbi->options.isvfat) {
379 int secs = de->ctime_cs / 100;
380 int csecs = de->ctime_cs % 100;
381 inode->i_ctime.tv_sec =
382 date_dos2unix(le16_to_cpu(de->ctime),
383 le16_to_cpu(de->cdate)) + secs;
384 inode->i_ctime.tv_nsec = csecs * 10000000;
62a36c43
SK		 385 inode->i_atime.tv_sec =
386 date_dos2unix(le16_to_cpu(0), le16_to_cpu(de->adate));
387 inode->i_atime.tv_nsec = 0;
1da177e4 388 } else
62a36c43 389 inode->i_ctime = inode->i_atime = inode->i_mtime;
1da177e4
LT		 390
391 return 0;
392}
393
394struct inode *fat_build_inode(struct super_block *sb,
395 struct msdos_dir_entry *de, loff_t i_pos)
396{
397 struct inode *inode;
398 int err;
399
400 inode = fat_iget(sb, i_pos);
401 if (inode)
402 goto out;
403 inode = new_inode(sb);
404 if (!inode) {
405 inode = ERR_PTR(-ENOMEM);
406 goto out;
407 }
408 inode->i_ino = iunique(sb, MSDOS_ROOT_INO);
409 inode->i_version = 1;
410 err = fat_fill_inode(inode, de);
411 if (err) {
412 iput(inode);
413 inode = ERR_PTR(err);
414 goto out;
415 }
416 fat_attach(inode, i_pos);
417 insert_inode_hash(inode);
418out:
419 return inode;
420}
421
7c709d00 422EXPORT_SYMBOL_GPL(fat_build_inode);
1da177e4
LT		 423
424static void fat_delete_inode(struct inode *inode)
425{
fef26658
MF		 426 truncate_inode_pages(&inode->i_data, 0);
427
1da177e4
LT		 428 if (!is_bad_inode(inode)) {
429 inode->i_size = 0;
430 fat_truncate(inode);
431 }
432 clear_inode(inode);
433}
434
435static void fat_clear_inode(struct inode *inode)
436{
437 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
438
439 if (is_bad_inode(inode))
440 return;
441 lock_kernel();
442 spin_lock(&sbi->inode_hash_lock);
443 fat_cache_inval_inode(inode);
444 hlist_del_init(&MSDOS_I(inode)->i_fat_hash);
445 spin_unlock(&sbi->inode_hash_lock);
446 unlock_kernel();
447}
448
a6bf6b21 449static void fat_write_super(struct super_block *sb)
1da177e4 450{
a6bf6b21 451 sb->s_dirt = 0;
1da177e4
LT		 452
453 if (!(sb->s_flags & MS_RDONLY))
454 fat_clusters_flush(sb);
a6bf6b21
OH		 455}
456
457static void fat_put_super(struct super_block *sb)
458{
459 struct msdos_sb_info *sbi = MSDOS_SB(sb);
1da177e4
LT		 460
461 if (sbi->nls_disk) {
462 unload_nls(sbi->nls_disk);
463 sbi->nls_disk = NULL;
464 sbi->options.codepage = fat_default_codepage;
465 }
466 if (sbi->nls_io) {
467 unload_nls(sbi->nls_io);
468 sbi->nls_io = NULL;
469 }
470 if (sbi->options.iocharset != fat_default_iocharset) {
471 kfree(sbi->options.iocharset);
472 sbi->options.iocharset = fat_default_iocharset;
473 }
474
475 sb->s_fs_info = NULL;
476 kfree(sbi);
477}
478
479static kmem_cache_t *fat_inode_cachep;
480
481static struct inode *fat_alloc_inode(struct super_block *sb)
482{
483 struct msdos_inode_info *ei;
484 ei = kmem_cache_alloc(fat_inode_cachep, SLAB_KERNEL);
485 if (!ei)
486 return NULL;
487 return &ei->vfs_inode;
488}
489
490static void fat_destroy_inode(struct inode *inode)
491{
492 kmem_cache_free(fat_inode_cachep, MSDOS_I(inode));
493}
494
495static void init_once(void * foo, kmem_cache_t * cachep, unsigned long flags)
496{
497 struct msdos_inode_info *ei = (struct msdos_inode_info *)foo;
498
499 if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) ==
500 SLAB_CTOR_CONSTRUCTOR) {
501 spin_lock_init(&ei->cache_lru_lock);
502 ei->nr_caches = 0;
503 ei->cache_valid_id = FAT_CACHE_VALID + 1;
504 INIT_LIST_HEAD(&ei->cache_lru);
505 INIT_HLIST_NODE(&ei->i_fat_hash);
506 inode_init_once(&ei->vfs_inode);
507 }
508}
509
510static int __init fat_init_inodecache(void)
511{
512 fat_inode_cachep = kmem_cache_create("fat_inode_cache",
513 sizeof(struct msdos_inode_info),
fffb60f9
PJ		 514 0, (SLAB_RECLAIM_ACCOUNT|
515 SLAB_MEM_SPREAD),
1da177e4
LT		 516 init_once, NULL);
517 if (fat_inode_cachep == NULL)
518 return -ENOMEM;
519 return 0;
520}
521
522static void __exit fat_destroy_inodecache(void)
523{
1a1d92c1 524 kmem_cache_destroy(fat_inode_cachep);
1da177e4
LT		 525}
526
527static int fat_remount(struct super_block *sb, int *flags, char *data)
528{
529 struct msdos_sb_info *sbi = MSDOS_SB(sb);
530 *flags |= MS_NODIRATIME | (sbi->options.isvfat ? 0 : MS_NOATIME);
531 return 0;
532}
533
726c3342 534static int fat_statfs(struct dentry *dentry, struct kstatfs *buf)
1da177e4 535{
726c3342 536 struct msdos_sb_info *sbi = MSDOS_SB(dentry->d_sb);
1da177e4
LT		 537
538 /* If the count of free cluster is still unknown, counts it here. */
539 if (sbi->free_clusters == -1) {
726c3342 540 int err = fat_count_free_clusters(dentry->d_sb);
1da177e4
LT		 541 if (err)
542 return err;
543 }
544
726c3342 545 buf->f_type = dentry->d_sb->s_magic;
1da177e4
LT		 546 buf->f_bsize = sbi->cluster_size;
547 buf->f_blocks = sbi->max_cluster - FAT_START_ENT;
548 buf->f_bfree = sbi->free_clusters;
549 buf->f_bavail = sbi->free_clusters;
550 buf->f_namelen = sbi->options.isvfat ? 260 : 12;
551
552 return 0;
553}
554
555static int fat_write_inode(struct inode *inode, int wait)
556{
557 struct super_block *sb = inode->i_sb;
558 struct msdos_sb_info *sbi = MSDOS_SB(sb);
559 struct buffer_head *bh;
560 struct msdos_dir_entry *raw_entry;
561 loff_t i_pos;
562 int err = 0;
563
564retry:
565 i_pos = MSDOS_I(inode)->i_pos;
566 if (inode->i_ino == MSDOS_ROOT_INO || !i_pos)
567 return 0;
568
569 lock_kernel();
570 bh = sb_bread(sb, i_pos >> sbi->dir_per_block_bits);
571 if (!bh) {
572 printk(KERN_ERR "FAT: unable to read inode block "
573 "for updating (i_pos %lld)\n", i_pos);
574 err = -EIO;
575 goto out;
576 }
577 spin_lock(&sbi->inode_hash_lock);
578 if (i_pos != MSDOS_I(inode)->i_pos) {
579 spin_unlock(&sbi->inode_hash_lock);
580 brelse(bh);
581 unlock_kernel();
582 goto retry;
583 }
584
585 raw_entry = &((struct msdos_dir_entry *) (bh->b_data))
586 [i_pos & (sbi->dir_per_block - 1)];
587 if (S_ISDIR(inode->i_mode))
588 raw_entry->size = 0;
589 else
590 raw_entry->size = cpu_to_le32(inode->i_size);
591 raw_entry->attr = fat_attr(inode);
592 raw_entry->start = cpu_to_le16(MSDOS_I(inode)->i_logstart);
593 raw_entry->starthi = cpu_to_le16(MSDOS_I(inode)->i_logstart >> 16);
594 fat_date_unix2dos(inode->i_mtime.tv_sec, &raw_entry->time, &raw_entry->date);
595 if (sbi->options.isvfat) {
62a36c43 596 __le16 atime;
1da177e4 597 fat_date_unix2dos(inode->i_ctime.tv_sec,&raw_entry->ctime,&raw_entry->cdate);
62a36c43 598 fat_date_unix2dos(inode->i_atime.tv_sec,&atime,&raw_entry->adate);
1da177e4
LT		 599 raw_entry->ctime_cs = (inode->i_ctime.tv_sec & 1) * 100 +
600 inode->i_ctime.tv_nsec / 10000000;
601 }
602 spin_unlock(&sbi->inode_hash_lock);
603 mark_buffer_dirty(bh);
604 if (wait)
605 err = sync_dirty_buffer(bh);
606 brelse(bh);
607out:
608 unlock_kernel();
609 return err;
610}
611
612int fat_sync_inode(struct inode *inode)
613{
614 return fat_write_inode(inode, 1);
615}
616
7c709d00 617EXPORT_SYMBOL_GPL(fat_sync_inode);
1da177e4
LT		 618
619static int fat_show_options(struct seq_file *m, struct vfsmount *mnt);
620static struct super_operations fat_sops = {
621 .alloc_inode = fat_alloc_inode,
622 .destroy_inode = fat_destroy_inode,
623 .write_inode = fat_write_inode,
624 .delete_inode = fat_delete_inode,
625 .put_super = fat_put_super,
a6bf6b21 626 .write_super = fat_write_super,
1da177e4
LT		 627 .statfs = fat_statfs,
628 .clear_inode = fat_clear_inode,
629 .remount_fs = fat_remount,
630
631 .read_inode = make_bad_inode,
632
633 .show_options = fat_show_options,
634};
635
636/*
637 * a FAT file handle with fhtype 3 is
638 * 0/ i_ino - for fast, reliable lookup if still in the cache
639 * 1/ i_generation - to see if i_ino is still valid
640 * bit 0 == 0 iff directory
641 * 2/ i_pos(8-39) - if ino has changed, but still in cache
642 * 3/ i_pos(4-7)|i_logstart - to semi-verify inode found at i_pos
643 * 4/ i_pos(0-3)|parent->i_logstart - maybe used to hunt for the file on disc
644 *
645 * Hack for NFSv2: Maximum FAT entry number is 28bits and maximum
646 * i_pos is 40bits (blocknr(32) + dir offset(8)), so two 4bits
647 * of i_logstart is used to store the directory entry offset.
648 */
649
650static struct dentry *
651fat_decode_fh(struct super_block *sb, __u32 *fh, int len, int fhtype,
652 int (*acceptable)(void *context, struct dentry *de),
653 void *context)
654{
655 if (fhtype != 3)
656 return ERR_PTR(-ESTALE);
657 if (len < 5)
658 return ERR_PTR(-ESTALE);
659
660 return sb->s_export_op->find_exported_dentry(sb, fh, NULL, acceptable, context);
661}
662
663static struct dentry *fat_get_dentry(struct super_block *sb, void *inump)
664{
665 struct inode *inode = NULL;
666 struct dentry *result;
667 __u32 *fh = inump;
668
669 inode = iget(sb, fh[0]);
670 if (!inode || is_bad_inode(inode) || inode->i_generation != fh[1]) {
671 if (inode)
672 iput(inode);
673 inode = NULL;
674 }
675 if (!inode) {
676 loff_t i_pos;
677 int i_logstart = fh[3] & 0x0fffffff;
678
679 i_pos = (loff_t)fh[2] << 8;
680 i_pos |= ((fh[3] >> 24) & 0xf0) | (fh[4] >> 28);
681
682 /* try 2 - see if i_pos is in F-d-c
683 * require i_logstart to be the same
684 * Will fail if you truncate and then re-write
685 */
686
687 inode = fat_iget(sb, i_pos);
688 if (inode && MSDOS_I(inode)->i_logstart != i_logstart) {
689 iput(inode);
690 inode = NULL;
691 }
692 }
693 if (!inode) {
694 /* For now, do nothing
695 * What we could do is:
696 * follow the file starting at fh[4], and record
697 * the ".." entry, and the name of the fh[2] entry.
698 * The follow the ".." file finding the next step up.
699 * This way we build a path to the root of
700 * the tree. If this works, we lookup the path and so
701 * get this inode into the cache.
702 * Finally try the fat_iget lookup again
703 * If that fails, then weare totally out of luck
704 * But all that is for another day
705 */
706 }
707 if (!inode)
708 return ERR_PTR(-ESTALE);
709
710
711 /* now to find a dentry.
712 * If possible, get a well-connected one
713 */
714 result = d_alloc_anon(inode);
715 if (result == NULL) {
716 iput(inode);
717 return ERR_PTR(-ENOMEM);
718 }
719 result->d_op = sb->s_root->d_op;
720 return result;
721}
722
723static int
724fat_encode_fh(struct dentry *de, __u32 *fh, int *lenp, int connectable)
725{
726 int len = *lenp;
727 struct inode *inode = de->d_inode;
728 u32 ipos_h, ipos_m, ipos_l;
729
730 if (len < 5)
731 return 255; /* no room */
732
733 ipos_h = MSDOS_I(inode)->i_pos >> 8;
734 ipos_m = (MSDOS_I(inode)->i_pos & 0xf0) << 24;
735 ipos_l = (MSDOS_I(inode)->i_pos & 0x0f) << 28;
736 *lenp = 5;
737 fh[0] = inode->i_ino;
738 fh[1] = inode->i_generation;
739 fh[2] = ipos_h;
740 fh[3] = ipos_m | MSDOS_I(inode)->i_logstart;
741 spin_lock(&de->d_lock);
742 fh[4] = ipos_l | MSDOS_I(de->d_parent->d_inode)->i_logstart;
743 spin_unlock(&de->d_lock);
744 return 3;
745}
746
747static struct dentry *fat_get_parent(struct dentry *child)
748{
749 struct buffer_head *bh;
750 struct msdos_dir_entry *de;
751 loff_t i_pos;
752 struct dentry *parent;
753 struct inode *inode;
754 int err;
755
756 lock_kernel();
757
758 err = fat_get_dotdot_entry(child->d_inode, &bh, &de, &i_pos);
759 if (err) {
760 parent = ERR_PTR(err);
761 goto out;
762 }
763 inode = fat_build_inode(child->d_sb, de, i_pos);
764 brelse(bh);
765 if (IS_ERR(inode)) {
766 parent = ERR_PTR(PTR_ERR(inode));
767 goto out;
768 }
769 parent = d_alloc_anon(inode);
770 if (!parent) {
771 iput(inode);
772 parent = ERR_PTR(-ENOMEM);
773 }
774out:
775 unlock_kernel();
776
777 return parent;
778}
779
780static struct export_operations fat_export_ops = {
781 .decode_fh = fat_decode_fh,
782 .encode_fh = fat_encode_fh,
783 .get_dentry = fat_get_dentry,
784 .get_parent = fat_get_parent,
785};
786
787static int fat_show_options(struct seq_file *m, struct vfsmount *mnt)
788{
789 struct msdos_sb_info *sbi = MSDOS_SB(mnt->mnt_sb);
790 struct fat_mount_options *opts = &sbi->options;
791 int isvfat = opts->isvfat;
792
793 if (opts->fs_uid != 0)
794 seq_printf(m, ",uid=%u", opts->fs_uid);
795 if (opts->fs_gid != 0)
796 seq_printf(m, ",gid=%u", opts->fs_gid);
797 seq_printf(m, ",fmask=%04o", opts->fs_fmask);
798 seq_printf(m, ",dmask=%04o", opts->fs_dmask);
799 if (sbi->nls_disk)
800 seq_printf(m, ",codepage=%s", sbi->nls_disk->charset);
801 if (isvfat) {
802 if (sbi->nls_io)
803 seq_printf(m, ",iocharset=%s", sbi->nls_io->charset);
804
805 switch (opts->shortname) {
806 case VFAT_SFN_DISPLAY_WIN95 | VFAT_SFN_CREATE_WIN95:
807 seq_puts(m, ",shortname=win95");
808 break;
809 case VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WINNT:
810 seq_puts(m, ",shortname=winnt");
811 break;
812 case VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WIN95:
813 seq_puts(m, ",shortname=mixed");
814 break;
815 case VFAT_SFN_DISPLAY_LOWER | VFAT_SFN_CREATE_WIN95:
816 /* seq_puts(m, ",shortname=lower"); */
817 break;
818 default:
819 seq_puts(m, ",shortname=unknown");
820 break;
821 }
822 }
823 if (opts->name_check != 'n')
824 seq_printf(m, ",check=%c", opts->name_check);
825 if (opts->quiet)
826 seq_puts(m, ",quiet");
827 if (opts->showexec)
828 seq_puts(m, ",showexec");
829 if (opts->sys_immutable)
830 seq_puts(m, ",sys_immutable");
831 if (!isvfat) {
832 if (opts->dotsOK)
833 seq_puts(m, ",dotsOK=yes");
834 if (opts->nocase)
835 seq_puts(m, ",nocase");
836 } else {
837 if (opts->utf8)
838 seq_puts(m, ",utf8");
839 if (opts->unicode_xlate)
840 seq_puts(m, ",uni_xlate");
841 if (!opts->numtail)
842 seq_puts(m, ",nonumtail");
843 }
844
845 return 0;
846}
847
848enum {
849 Opt_check_n, Opt_check_r, Opt_check_s, Opt_uid, Opt_gid,
850 Opt_umask, Opt_dmask, Opt_fmask, Opt_codepage, Opt_nocase,
851 Opt_quiet, Opt_showexec, Opt_debug, Opt_immutable,
852 Opt_dots, Opt_nodots,
853 Opt_charset, Opt_shortname_lower, Opt_shortname_win95,
854 Opt_shortname_winnt, Opt_shortname_mixed, Opt_utf8_no, Opt_utf8_yes,
855 Opt_uni_xl_no, Opt_uni_xl_yes, Opt_nonumtail_no, Opt_nonumtail_yes,
856 Opt_obsolate, Opt_err,
857};
858
859static match_table_t fat_tokens = {
860 {Opt_check_r, "check=relaxed"},
861 {Opt_check_s, "check=strict"},
862 {Opt_check_n, "check=normal"},
863 {Opt_check_r, "check=r"},
864 {Opt_check_s, "check=s"},
865 {Opt_check_n, "check=n"},
866 {Opt_uid, "uid=%u"},
867 {Opt_gid, "gid=%u"},
868 {Opt_umask, "umask=%o"},
869 {Opt_dmask, "dmask=%o"},
870 {Opt_fmask, "fmask=%o"},
871 {Opt_codepage, "codepage=%u"},
872 {Opt_nocase, "nocase"},
873 {Opt_quiet, "quiet"},
874 {Opt_showexec, "showexec"},
875 {Opt_debug, "debug"},
876 {Opt_immutable, "sys_immutable"},
877 {Opt_obsolate, "conv=binary"},
878 {Opt_obsolate, "conv=text"},
879 {Opt_obsolate, "conv=auto"},
880 {Opt_obsolate, "conv=b"},
881 {Opt_obsolate, "conv=t"},
882 {Opt_obsolate, "conv=a"},
883 {Opt_obsolate, "fat=%u"},
884 {Opt_obsolate, "blocksize=%u"},
885 {Opt_obsolate, "cvf_format=%20s"},
886 {Opt_obsolate, "cvf_options=%100s"},
887 {Opt_obsolate, "posix"},
888 {Opt_err, NULL}
889};
890static match_table_t msdos_tokens = {
891 {Opt_nodots, "nodots"},
892 {Opt_nodots, "dotsOK=no"},
893 {Opt_dots, "dots"},
894 {Opt_dots, "dotsOK=yes"},
895 {Opt_err, NULL}
896};
897static match_table_t vfat_tokens = {
898 {Opt_charset, "iocharset=%s"},
899 {Opt_shortname_lower, "shortname=lower"},
900 {Opt_shortname_win95, "shortname=win95"},
901 {Opt_shortname_winnt, "shortname=winnt"},
902 {Opt_shortname_mixed, "shortname=mixed"},
903 {Opt_utf8_no, "utf8=0"}, /* 0 or no or false */
904 {Opt_utf8_no, "utf8=no"},
905 {Opt_utf8_no, "utf8=false"},
906 {Opt_utf8_yes, "utf8=1"}, /* empty or 1 or yes or true */
907 {Opt_utf8_yes, "utf8=yes"},
908 {Opt_utf8_yes, "utf8=true"},
909 {Opt_utf8_yes, "utf8"},
910 {Opt_uni_xl_no, "uni_xlate=0"}, /* 0 or no or false */
911 {Opt_uni_xl_no, "uni_xlate=no"},
912 {Opt_uni_xl_no, "uni_xlate=false"},
913 {Opt_uni_xl_yes, "uni_xlate=1"}, /* empty or 1 or yes or true */
914 {Opt_uni_xl_yes, "uni_xlate=yes"},
915 {Opt_uni_xl_yes, "uni_xlate=true"},
916 {Opt_uni_xl_yes, "uni_xlate"},
917 {Opt_nonumtail_no, "nonumtail=0"}, /* 0 or no or false */
918 {Opt_nonumtail_no, "nonumtail=no"},
919 {Opt_nonumtail_no, "nonumtail=false"},
920 {Opt_nonumtail_yes, "nonumtail=1"}, /* empty or 1 or yes or true */
921 {Opt_nonumtail_yes, "nonumtail=yes"},
922 {Opt_nonumtail_yes, "nonumtail=true"},
923 {Opt_nonumtail_yes, "nonumtail"},
924 {Opt_err, NULL}
925};
926
41a34a4f 927static int parse_options(char *options, int is_vfat, int silent, int *debug,
1da177e4
LT		 928 struct fat_mount_options *opts)
929{
930 char *p;
931 substring_t args[MAX_OPT_ARGS];
932 int option;
933 char *iocharset;
934
935 opts->isvfat = is_vfat;
936
937 opts->fs_uid = current->uid;
938 opts->fs_gid = current->gid;
939 opts->fs_fmask = opts->fs_dmask = current->fs->umask;
940 opts->codepage = fat_default_codepage;
941 opts->iocharset = fat_default_iocharset;
942 if (is_vfat)
943 opts->shortname = VFAT_SFN_DISPLAY_LOWER|VFAT_SFN_CREATE_WIN95;
944 else
945 opts->shortname = 0;
946 opts->name_check = 'n';
947 opts->quiet = opts->showexec = opts->sys_immutable = opts->dotsOK = 0;
948 opts->utf8 = opts->unicode_xlate = 0;
949 opts->numtail = 1;
950 opts->nocase = 0;
951 *debug = 0;
952
953 if (!options)
954 return 0;
955
956 while ((p = strsep(&options, ",")) != NULL) {
957 int token;
958 if (!*p)
959 continue;
960
961 token = match_token(p, fat_tokens, args);
962 if (token == Opt_err) {
963 if (is_vfat)
964 token = match_token(p, vfat_tokens, args);
965 else
966 token = match_token(p, msdos_tokens, args);
967 }
968 switch (token) {
969 case Opt_check_s:
970 opts->name_check = 's';
971 break;
972 case Opt_check_r:
973 opts->name_check = 'r';
974 break;
975 case Opt_check_n:
976 opts->name_check = 'n';
977 break;
978 case Opt_nocase:
979 if (!is_vfat)
980 opts->nocase = 1;
981 else {
982 /* for backward compatibility */
983 opts->shortname = VFAT_SFN_DISPLAY_WIN95
984 | VFAT_SFN_CREATE_WIN95;
985 }
986 break;
987 case Opt_quiet:
988 opts->quiet = 1;
989 break;
990 case Opt_showexec:
991 opts->showexec = 1;
992 break;
993 case Opt_debug:
994 *debug = 1;
995 break;
996 case Opt_immutable:
997 opts->sys_immutable = 1;
998 break;
999 case Opt_uid:
1000 if (match_int(&args[0], &option))
1001 return 0;
1002 opts->fs_uid = option;
1003 break;
1004 case Opt_gid:
1005 if (match_int(&args[0], &option))
1006 return 0;
1007 opts->fs_gid = option;
1008 break;
1009 case Opt_umask:
1010 if (match_octal(&args[0], &option))
1011 return 0;
1012 opts->fs_fmask = opts->fs_dmask = option;
1013 break;
1014 case Opt_dmask:
1015 if (match_octal(&args[0], &option))
1016 return 0;
1017 opts->fs_dmask = option;
1018 break;
1019 case Opt_fmask:
1020 if (match_octal(&args[0], &option))
1021 return 0;
1022 opts->fs_fmask = option;
1023 break;
1024 case Opt_codepage:
1025 if (match_int(&args[0], &option))
1026 return 0;
1027 opts->codepage = option;
1028 break;
1029
1030 /* msdos specific */
1031 case Opt_dots:
1032 opts->dotsOK = 1;
1033 break;
1034 case Opt_nodots:
1035 opts->dotsOK = 0;
1036 break;
1037
1038 /* vfat specific */
1039 case Opt_charset:
1040 if (opts->iocharset != fat_default_iocharset)
1041 kfree(opts->iocharset);
1042 iocharset = match_strdup(&args[0]);
1043 if (!iocharset)
1044 return -ENOMEM;
1045 opts->iocharset = iocharset;
1046 break;
1047 case Opt_shortname_lower:
1048 opts->shortname = VFAT_SFN_DISPLAY_LOWER
1049 | VFAT_SFN_CREATE_WIN95;
1050 break;
1051 case Opt_shortname_win95:
1052 opts->shortname = VFAT_SFN_DISPLAY_WIN95
1053 | VFAT_SFN_CREATE_WIN95;
1054 break;
1055 case Opt_shortname_winnt:
1056 opts->shortname = VFAT_SFN_DISPLAY_WINNT
1057 | VFAT_SFN_CREATE_WINNT;
1058 break;
1059 case Opt_shortname_mixed:
1060 opts->shortname = VFAT_SFN_DISPLAY_WINNT
1061 | VFAT_SFN_CREATE_WIN95;
1062 break;
1063 case Opt_utf8_no: /* 0 or no or false */
1064 opts->utf8 = 0;
1065 break;
1066 case Opt_utf8_yes: /* empty or 1 or yes or true */
1067 opts->utf8 = 1;
1068 break;
1069 case Opt_uni_xl_no: /* 0 or no or false */
1070 opts->unicode_xlate = 0;
1071 break;
1072 case Opt_uni_xl_yes: /* empty or 1 or yes or true */
1073 opts->unicode_xlate = 1;
1074 break;
1075 case Opt_nonumtail_no: /* 0 or no or false */
1076 opts->numtail = 1; /* negated option */
1077 break;
1078 case Opt_nonumtail_yes: /* empty or 1 or yes or true */
1079 opts->numtail = 0; /* negated option */
1080 break;
1081
1082 /* obsolete mount options */
1083 case Opt_obsolate:
1084 printk(KERN_INFO "FAT: \"%s\" option is obsolete, "
1085 "not supported now\n", p);
1086 break;
1087 /* unknown option */
1088 default:
41a34a4f
CH		 1089 if (!silent) {
1090 printk(KERN_ERR
1091 "FAT: Unrecognized mount option \"%s\" "
1092 "or missing value\n", p);
1093 }
1da177e4
LT		 1094 return -EINVAL;
1095 }
1096 }
4de151d8 1097 /* UTF-8 doesn't provide FAT semantics */
1da177e4
LT		 1098 if (!strcmp(opts->iocharset, "utf8")) {
1099 printk(KERN_ERR "FAT: utf8 is not a recommended IO charset"
1100 " for FAT filesystems, filesystem will be case sensitive!\n");
1101 }
1102
1103 if (opts->unicode_xlate)
1104 opts->utf8 = 0;
1105
1106 return 0;
1107}
1108
1109static int fat_read_root(struct inode *inode)
1110{
1111 struct super_block *sb = inode->i_sb;
1112 struct msdos_sb_info *sbi = MSDOS_SB(sb);
1113 int error;
1114
1115 MSDOS_I(inode)->i_pos = 0;
1116 inode->i_uid = sbi->options.fs_uid;
1117 inode->i_gid = sbi->options.fs_gid;
1118 inode->i_version++;
1119 inode->i_generation = 0;
1120 inode->i_mode = (S_IRWXUGO & ~sbi->options.fs_dmask) | S_IFDIR;
1121 inode->i_op = sbi->dir_ops;
1122 inode->i_fop = &fat_dir_operations;
1123 if (sbi->fat_bits == 32) {
1124 MSDOS_I(inode)->i_start = sbi->root_cluster;
1125 error = fat_calc_dir_size(inode);
1126 if (error < 0)
1127 return error;
1128 } else {
1129 MSDOS_I(inode)->i_start = 0;
1130 inode->i_size = sbi->dir_entries * sizeof(struct msdos_dir_entry);
1131 }
1da177e4
LT		 1132 inode->i_blocks = ((inode->i_size + (sbi->cluster_size - 1))
1133 & ~((loff_t)sbi->cluster_size - 1)) >> 9;
1134 MSDOS_I(inode)->i_logstart = 0;
1135 MSDOS_I(inode)->mmu_private = inode->i_size;
1136
1137 MSDOS_I(inode)->i_attrs = ATTR_NONE;
1138 inode->i_mtime.tv_sec = inode->i_atime.tv_sec = inode->i_ctime.tv_sec = 0;
1139 inode->i_mtime.tv_nsec = inode->i_atime.tv_nsec = inode->i_ctime.tv_nsec = 0;
1140 inode->i_nlink = fat_subdirs(inode)+2;
1141
1142 return 0;
1143}
1144
1145/*
1146 * Read the super block of an MS-DOS FS.
1147 */
1148int fat_fill_super(struct super_block *sb, void *data, int silent,
1149 struct inode_operations *fs_dir_inode_ops, int isvfat)
1150{
1151 struct inode *root_inode = NULL;
1152 struct buffer_head *bh;
1153 struct fat_boot_sector *b;
1154 struct msdos_sb_info *sbi;
1155 u16 logical_sector_size;
1156 u32 total_sectors, total_clusters, fat_clusters, rootdir_sectors;
1157 int debug;
1158 unsigned int media;
1159 long error;
1160 char buf[50];
1161
f8314dc6 1162 sbi = kzalloc(sizeof(struct msdos_sb_info), GFP_KERNEL);
1da177e4
LT		 1163 if (!sbi)
1164 return -ENOMEM;
1165 sb->s_fs_info = sbi;
1da177e4
LT		 1166
1167 sb->s_flags |= MS_NODIRATIME;
1168 sb->s_magic = MSDOS_SUPER_MAGIC;
1169 sb->s_op = &fat_sops;
1170 sb->s_export_op = &fat_export_ops;
1171 sbi->dir_ops = fs_dir_inode_ops;
1172
41a34a4f 1173 error = parse_options(data, isvfat, silent, &debug, &sbi->options);
1da177e4
LT		 1174 if (error)
1175 goto out_fail;
1176
1177 error = -EIO;
1178 sb_min_blocksize(sb, 512);
1179 bh = sb_bread(sb, 0);
1180 if (bh == NULL) {
1181 printk(KERN_ERR "FAT: unable to read boot sector\n");
1182 goto out_fail;
1183 }
1184
1185 b = (struct fat_boot_sector *) bh->b_data;
1186 if (!b->reserved) {
1187 if (!silent)
1188 printk(KERN_ERR "FAT: bogus number of reserved sectors\n");
1189 brelse(bh);
1190 goto out_invalid;
1191 }
1192 if (!b->fats) {
1193 if (!silent)
1194 printk(KERN_ERR "FAT: bogus number of FAT structure\n");
1195 brelse(bh);
1196 goto out_invalid;
1197 }
1198
1199 /*
1200 * Earlier we checked here that b->secs_track and b->head are nonzero,
1201 * but it turns out valid FAT filesystems can have zero there.
1202 */
1203
1204 media = b->media;
1205 if (!FAT_VALID_MEDIA(media)) {
1206 if (!silent)
1207 printk(KERN_ERR "FAT: invalid media value (0x%02x)\n",
1208 media);
1209 brelse(bh);
1210 goto out_invalid;
1211 }
1212 logical_sector_size =
1213 le16_to_cpu(get_unaligned((__le16 *)&b->sector_size));
1214 if (!logical_sector_size
1215 || (logical_sector_size & (logical_sector_size - 1))
1216 || (logical_sector_size < 512)
1217 || (PAGE_CACHE_SIZE < logical_sector_size)) {
1218 if (!silent)
1219 printk(KERN_ERR "FAT: bogus logical sector size %u\n",
1220 logical_sector_size);
1221 brelse(bh);
1222 goto out_invalid;
1223 }
1224 sbi->sec_per_clus = b->sec_per_clus;
1225 if (!sbi->sec_per_clus
1226 || (sbi->sec_per_clus & (sbi->sec_per_clus - 1))) {
1227 if (!silent)
1228 printk(KERN_ERR "FAT: bogus sectors per cluster %u\n",
1229 sbi->sec_per_clus);
1230 brelse(bh);
1231 goto out_invalid;
1232 }
1233
1234 if (logical_sector_size < sb->s_blocksize) {
1235 printk(KERN_ERR "FAT: logical sector size too small for device"
1236 " (logical sector size = %u)\n", logical_sector_size);
1237 brelse(bh);
1238 goto out_fail;
1239 }
1240 if (logical_sector_size > sb->s_blocksize) {
1241 brelse(bh);
1242
1243 if (!sb_set_blocksize(sb, logical_sector_size)) {
1244 printk(KERN_ERR "FAT: unable to set blocksize %u\n",
1245 logical_sector_size);
1246 goto out_fail;
1247 }
1248 bh = sb_bread(sb, 0);
1249 if (bh == NULL) {
1250 printk(KERN_ERR "FAT: unable to read boot sector"
1251 " (logical sector size = %lu)\n",
1252 sb->s_blocksize);
1253 goto out_fail;
1254 }
1255 b = (struct fat_boot_sector *) bh->b_data;
1256 }
1257
1258 sbi->cluster_size = sb->s_blocksize * sbi->sec_per_clus;
1259 sbi->cluster_bits = ffs(sbi->cluster_size) - 1;
1260 sbi->fats = b->fats;
1261 sbi->fat_bits = 0; /* Don't know yet */
1262 sbi->fat_start = le16_to_cpu(b->reserved);
1263 sbi->fat_length = le16_to_cpu(b->fat_length);
1264 sbi->root_cluster = 0;
1265 sbi->free_clusters = -1; /* Don't know yet */
1266 sbi->prev_free = FAT_START_ENT;
1267
1268 if (!sbi->fat_length && b->fat32_length) {
1269 struct fat_boot_fsinfo *fsinfo;
1270 struct buffer_head *fsinfo_bh;
1271
1272 /* Must be FAT32 */
1273 sbi->fat_bits = 32;
1274 sbi->fat_length = le32_to_cpu(b->fat32_length);
1275 sbi->root_cluster = le32_to_cpu(b->root_cluster);
1276
1277 sb->s_maxbytes = 0xffffffff;
1278
1279 /* MC - if info_sector is 0, don't multiply by 0 */
1280 sbi->fsinfo_sector = le16_to_cpu(b->info_sector);
1281 if (sbi->fsinfo_sector == 0)
1282 sbi->fsinfo_sector = 1;
1283
1284 fsinfo_bh = sb_bread(sb, sbi->fsinfo_sector);
1285 if (fsinfo_bh == NULL) {
1286 printk(KERN_ERR "FAT: bread failed, FSINFO block"
1287 " (sector = %lu)\n", sbi->fsinfo_sector);
1288 brelse(bh);
1289 goto out_fail;
1290 }
1291
1292 fsinfo = (struct fat_boot_fsinfo *)fsinfo_bh->b_data;
1293 if (!IS_FSINFO(fsinfo)) {
1294 printk(KERN_WARNING
1295 "FAT: Did not find valid FSINFO signature.\n"
1296 " Found signature1 0x%08x signature2 0x%08x"
1297 " (sector = %lu)\n",
1298 le32_to_cpu(fsinfo->signature1),
1299 le32_to_cpu(fsinfo->signature2),
1300 sbi->fsinfo_sector);
1301 } else {
1302 sbi->free_clusters = le32_to_cpu(fsinfo->free_clusters);
1303 sbi->prev_free = le32_to_cpu(fsinfo->next_cluster);
1304 }
1305
1306 brelse(fsinfo_bh);
1307 }
1308
1309 sbi->dir_per_block = sb->s_blocksize / sizeof(struct msdos_dir_entry);
1310 sbi->dir_per_block_bits = ffs(sbi->dir_per_block) - 1;
1311
1312 sbi->dir_start = sbi->fat_start + sbi->fats * sbi->fat_length;
1313 sbi->dir_entries =
1314 le16_to_cpu(get_unaligned((__le16 *)&b->dir_entries));
1315 if (sbi->dir_entries & (sbi->dir_per_block - 1)) {
1316 if (!silent)
1317 printk(KERN_ERR "FAT: bogus directroy-entries per block"
1318 " (%u)\n", sbi->dir_entries);
1319 brelse(bh);
1320 goto out_invalid;
1321 }
1322
1323 rootdir_sectors = sbi->dir_entries
1324 * sizeof(struct msdos_dir_entry) / sb->s_blocksize;
1325 sbi->data_start = sbi->dir_start + rootdir_sectors;
1326 total_sectors = le16_to_cpu(get_unaligned((__le16 *)&b->sectors));
1327 if (total_sectors == 0)
1328 total_sectors = le32_to_cpu(b->total_sect);
1329
1330 total_clusters = (total_sectors - sbi->data_start) / sbi->sec_per_clus;
1331
1332 if (sbi->fat_bits != 32)
1333 sbi->fat_bits = (total_clusters > MAX_FAT12) ? 16 : 12;
1334
1335 /* check that FAT table does not overflow */
1336 fat_clusters = sbi->fat_length * sb->s_blocksize * 8 / sbi->fat_bits;
1337 total_clusters = min(total_clusters, fat_clusters - FAT_START_ENT);
1338 if (total_clusters > MAX_FAT(sb)) {
1339 if (!silent)
1340 printk(KERN_ERR "FAT: count of clusters too big (%u)\n",
1341 total_clusters);
1342 brelse(bh);
1343 goto out_invalid;
1344 }
1345
1346 sbi->max_cluster = total_clusters + FAT_START_ENT;
1347 /* check the free_clusters, it's not necessarily correct */
1348 if (sbi->free_clusters != -1 && sbi->free_clusters > total_clusters)
1349 sbi->free_clusters = -1;
1350 /* check the prev_free, it's not necessarily correct */
1351 sbi->prev_free %= sbi->max_cluster;
1352 if (sbi->prev_free < FAT_START_ENT)
1353 sbi->prev_free = FAT_START_ENT;
1354
1355 brelse(bh);
1356
1357 /* set up enough so that it can read an inode */
1358 fat_hash_init(sb);
1359 fat_ent_access_init(sb);
1360
1361 /*
1362 * The low byte of FAT's first entry must have same value with
1363 * media-field. But in real world, too many devices is
1364 * writing wrong value. So, removed that validity check.
1365 *
1366 * if (FAT_FIRST_ENT(sb, media) != first)
1367 */
1368
1369 error = -EINVAL;
1370 sprintf(buf, "cp%d", sbi->options.codepage);
1371 sbi->nls_disk = load_nls(buf);
1372 if (!sbi->nls_disk) {
1373 printk(KERN_ERR "FAT: codepage %s not found\n", buf);
1374 goto out_fail;
1375 }
1376
1377 /* FIXME: utf8 is using iocharset for upper/lower conversion */
1378 if (sbi->options.isvfat) {
1379 sbi->nls_io = load_nls(sbi->options.iocharset);
1380 if (!sbi->nls_io) {
1381 printk(KERN_ERR "FAT: IO charset %s not found\n",
1382 sbi->options.iocharset);
1383 goto out_fail;
1384 }
1385 }
1386
1387 error = -ENOMEM;
1388 root_inode = new_inode(sb);
1389 if (!root_inode)
1390 goto out_fail;
1391 root_inode->i_ino = MSDOS_ROOT_INO;
1392 root_inode->i_version = 1;
1393 error = fat_read_root(root_inode);
1394 if (error < 0)
1395 goto out_fail;
1396 error = -ENOMEM;
1397 insert_inode_hash(root_inode);
1398 sb->s_root = d_alloc_root(root_inode);
1399 if (!sb->s_root) {
1400 printk(KERN_ERR "FAT: get root inode failed\n");
1401 goto out_fail;
1402 }
1403
1404 return 0;
1405
1406out_invalid:
1407 error = -EINVAL;
1408 if (!silent)
1409 printk(KERN_INFO "VFS: Can't find a valid FAT filesystem"
1410 " on dev %s.\n", sb->s_id);
1411
1412out_fail:
1413 if (root_inode)
1414 iput(root_inode);
1415 if (sbi->nls_io)
1416 unload_nls(sbi->nls_io);
1417 if (sbi->nls_disk)
1418 unload_nls(sbi->nls_disk);
1419 if (sbi->options.iocharset != fat_default_iocharset)
1420 kfree(sbi->options.iocharset);
1421 sb->s_fs_info = NULL;
1422 kfree(sbi);
1423 return error;
1424}
1425
7c709d00 1426EXPORT_SYMBOL_GPL(fat_fill_super);
1da177e4 1427
1da177e4
LT		 1428static int __init init_fat_fs(void)
1429{
532a39a3 1430 int err;
1da177e4 1431
532a39a3
PE		 1432 err = fat_cache_init();
1433 if (err)
1434 return err;
1435
1436 err = fat_init_inodecache();
1437 if (err)
1438 goto failed;
1439
1440 return 0;
1441
1442failed:
1443 fat_cache_destroy();
1444 return err;
1da177e4
LT		 1445}
1446
1447static void __exit exit_fat_fs(void)
1448{
1449 fat_cache_destroy();
1450 fat_destroy_inodecache();
1451}
1452
1453module_init(init_fat_fs)
1454module_exit(exit_fat_fs)
1455
1456MODULE_LICENSE("GPL");
Linux kernel - Deliverables
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