blob: 78945b53b0f827fed88da656666ec1dd6fa9aaa9 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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>
OGAWA Hirofumia5425d22006-01-08 01:02:10 -080021#include <linux/mpage.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070022#include <linux/buffer_head.h>
23#include <linux/mount.h>
24#include <linux/vfs.h>
25#include <linux/parser.h>
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -080026#include <linux/uio.h>
Chris Masonae78bf92006-09-29 02:00:03 -070027#include <linux/writeback.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070028#include <asm/unaligned.h>
29
30#ifndef CONFIG_FAT_DEFAULT_IOCHARSET
31/* if user don't select VFAT, this is undefined. */
32#define CONFIG_FAT_DEFAULT_IOCHARSET ""
33#endif
34
35static int fat_default_codepage = CONFIG_FAT_DEFAULT_CODEPAGE;
36static char fat_default_iocharset[] = CONFIG_FAT_DEFAULT_IOCHARSET;
37
38
39static int fat_add_cluster(struct inode *inode)
40{
41 int err, cluster;
42
43 err = fat_alloc_clusters(inode, &cluster, 1);
44 if (err)
45 return err;
46 /* FIXME: this cluster should be added after data of this
47 * cluster is writed */
48 err = fat_chain_add(inode, cluster, 1);
49 if (err)
50 fat_free_clusters(inode, cluster);
51 return err;
52}
53
OGAWA Hirofumi6a1d9802006-09-27 01:50:45 -070054static inline int __fat_get_block(struct inode *inode, sector_t iblock,
55 unsigned long *max_blocks,
56 struct buffer_head *bh_result, int create)
Linus Torvalds1da177e2005-04-16 15:20:36 -070057{
58 struct super_block *sb = inode->i_sb;
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -080059 struct msdos_sb_info *sbi = MSDOS_SB(sb);
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -080060 unsigned long mapped_blocks;
OGAWA Hirofumi6a1d9802006-09-27 01:50:45 -070061 sector_t phys;
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -080062 int err, offset;
Linus Torvalds1da177e2005-04-16 15:20:36 -070063
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -080064 err = fat_bmap(inode, iblock, &phys, &mapped_blocks);
Linus Torvalds1da177e2005-04-16 15:20:36 -070065 if (err)
66 return err;
67 if (phys) {
68 map_bh(bh_result, sb, phys);
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -080069 *max_blocks = min(mapped_blocks, *max_blocks);
Linus Torvalds1da177e2005-04-16 15:20:36 -070070 return 0;
71 }
72 if (!create)
73 return 0;
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -080074
Linus Torvalds1da177e2005-04-16 15:20:36 -070075 if (iblock != MSDOS_I(inode)->mmu_private >> sb->s_blocksize_bits) {
76 fat_fs_panic(sb, "corrupted file size (i_pos %lld, %lld)",
OGAWA Hirofumi6a1d9802006-09-27 01:50:45 -070077 MSDOS_I(inode)->i_pos, MSDOS_I(inode)->mmu_private);
Linus Torvalds1da177e2005-04-16 15:20:36 -070078 return -EIO;
79 }
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -080080
81 offset = (unsigned long)iblock & (sbi->sec_per_clus - 1);
82 if (!offset) {
83 /* TODO: multiple cluster allocation would be desirable. */
Linus Torvalds1da177e2005-04-16 15:20:36 -070084 err = fat_add_cluster(inode);
85 if (err)
86 return err;
87 }
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -080088 /* available blocks on this cluster */
89 mapped_blocks = sbi->sec_per_clus - offset;
90
91 *max_blocks = min(mapped_blocks, *max_blocks);
92 MSDOS_I(inode)->mmu_private += *max_blocks << sb->s_blocksize_bits;
93
94 err = fat_bmap(inode, iblock, &phys, &mapped_blocks);
Linus Torvalds1da177e2005-04-16 15:20:36 -070095 if (err)
96 return err;
OGAWA Hirofumi6a1d9802006-09-27 01:50:45 -070097
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -080098 BUG_ON(!phys);
99 BUG_ON(*max_blocks != mapped_blocks);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700100 set_buffer_new(bh_result);
101 map_bh(bh_result, sb, phys);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700102
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -0800103 return 0;
104}
105
106static int fat_get_block(struct inode *inode, sector_t iblock,
107 struct buffer_head *bh_result, int create)
108{
OGAWA Hirofumi6a1d9802006-09-27 01:50:45 -0700109 struct super_block *sb = inode->i_sb;
110 unsigned long max_blocks = bh_result->b_size >> inode->i_blkbits;
111 int err;
112
113 err = __fat_get_block(inode, iblock, &max_blocks, bh_result, create);
114 if (err)
115 return err;
116 bh_result->b_size = max_blocks << sb->s_blocksize_bits;
117 return 0;
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -0800118}
119
Linus Torvalds1da177e2005-04-16 15:20:36 -0700120static int fat_writepage(struct page *page, struct writeback_control *wbc)
121{
122 return block_write_full_page(page, fat_get_block, wbc);
123}
124
OGAWA Hirofumia5425d22006-01-08 01:02:10 -0800125static int fat_writepages(struct address_space *mapping,
126 struct writeback_control *wbc)
127{
128 return mpage_writepages(mapping, wbc, fat_get_block);
129}
130
Linus Torvalds1da177e2005-04-16 15:20:36 -0700131static int fat_readpage(struct file *file, struct page *page)
132{
OGAWA Hirofumia5425d22006-01-08 01:02:10 -0800133 return mpage_readpage(page, fat_get_block);
134}
135
136static int fat_readpages(struct file *file, struct address_space *mapping,
137 struct list_head *pages, unsigned nr_pages)
138{
139 return mpage_readpages(mapping, pages, nr_pages, fat_get_block);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700140}
141
142static int fat_prepare_write(struct file *file, struct page *page,
143 unsigned from, unsigned to)
144{
145 return cont_prepare_write(page, from, to, fat_get_block,
146 &MSDOS_I(page->mapping->host)->mmu_private);
147}
148
OGAWA Hirofumief402262005-09-16 19:28:13 -0700149static int fat_commit_write(struct file *file, struct page *page,
150 unsigned from, unsigned to)
151{
152 struct inode *inode = page->mapping->host;
153 int err = generic_commit_write(file, page, from, to);
154 if (!err && !(MSDOS_I(inode)->i_attrs & ATTR_ARCH)) {
155 inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC;
156 MSDOS_I(inode)->i_attrs |= ATTR_ARCH;
157 mark_inode_dirty(inode);
158 }
159 return err;
160}
161
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -0800162static ssize_t fat_direct_IO(int rw, struct kiocb *iocb,
163 const struct iovec *iov,
164 loff_t offset, unsigned long nr_segs)
165{
166 struct file *file = iocb->ki_filp;
167 struct inode *inode = file->f_mapping->host;
168
169 if (rw == WRITE) {
170 /*
171 * FIXME: blockdev_direct_IO() doesn't use ->prepare_write(),
172 * so we need to update the ->mmu_private to block boundary.
173 *
174 * But we must fill the remaining area or hole by nul for
175 * updating ->mmu_private.
176 */
177 loff_t size = offset + iov_length(iov, nr_segs);
178 if (MSDOS_I(inode)->mmu_private < size)
179 return -EINVAL;
180 }
181
182 /*
183 * FAT need to use the DIO_LOCKING for avoiding the race
184 * condition of fat_get_block() and ->truncate().
185 */
186 return blockdev_direct_IO(rw, iocb, inode, inode->i_sb->s_bdev, iov,
OGAWA Hirofumi6a1d9802006-09-27 01:50:45 -0700187 offset, nr_segs, fat_get_block, NULL);
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -0800188}
189
Linus Torvalds1da177e2005-04-16 15:20:36 -0700190static sector_t _fat_bmap(struct address_space *mapping, sector_t block)
191{
192 return generic_block_bmap(mapping, block, fat_get_block);
193}
194
Christoph Hellwigf5e54d62006-06-28 04:26:44 -0700195static const struct address_space_operations fat_aops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700196 .readpage = fat_readpage,
OGAWA Hirofumia5425d22006-01-08 01:02:10 -0800197 .readpages = fat_readpages,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700198 .writepage = fat_writepage,
OGAWA Hirofumia5425d22006-01-08 01:02:10 -0800199 .writepages = fat_writepages,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700200 .sync_page = block_sync_page,
201 .prepare_write = fat_prepare_write,
OGAWA Hirofumief402262005-09-16 19:28:13 -0700202 .commit_write = fat_commit_write,
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -0800203 .direct_IO = fat_direct_IO,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700204 .bmap = _fat_bmap
205};
206
207/*
208 * New FAT inode stuff. We do the following:
209 * a) i_ino is constant and has nothing with on-disk location.
210 * b) FAT manages its own cache of directory entries.
211 * c) *This* cache is indexed by on-disk location.
212 * d) inode has an associated directory entry, all right, but
213 * it may be unhashed.
214 * e) currently entries are stored within struct inode. That should
215 * change.
216 * f) we deal with races in the following way:
217 * 1. readdir() and lookup() do FAT-dir-cache lookup.
218 * 2. rename() unhashes the F-d-c entry and rehashes it in
219 * a new place.
220 * 3. unlink() and rmdir() unhash F-d-c entry.
221 * 4. fat_write_inode() checks whether the thing is unhashed.
222 * If it is we silently return. If it isn't we do bread(),
223 * check if the location is still valid and retry if it
224 * isn't. Otherwise we do changes.
225 * 5. Spinlock is used to protect hash/unhash/location check/lookup
226 * 6. fat_clear_inode() unhashes the F-d-c entry.
227 * 7. lookup() and readdir() do igrab() if they find a F-d-c entry
228 * and consider negative result as cache miss.
229 */
230
231static void fat_hash_init(struct super_block *sb)
232{
233 struct msdos_sb_info *sbi = MSDOS_SB(sb);
234 int i;
235
236 spin_lock_init(&sbi->inode_hash_lock);
237 for (i = 0; i < FAT_HASH_SIZE; i++)
238 INIT_HLIST_HEAD(&sbi->inode_hashtable[i]);
239}
240
241static inline unsigned long fat_hash(struct super_block *sb, loff_t i_pos)
242{
243 unsigned long tmp = (unsigned long)i_pos | (unsigned long) sb;
244 tmp = tmp + (tmp >> FAT_HASH_BITS) + (tmp >> FAT_HASH_BITS * 2);
245 return tmp & FAT_HASH_MASK;
246}
247
248void fat_attach(struct inode *inode, loff_t i_pos)
249{
250 struct super_block *sb = inode->i_sb;
251 struct msdos_sb_info *sbi = MSDOS_SB(sb);
252
253 spin_lock(&sbi->inode_hash_lock);
254 MSDOS_I(inode)->i_pos = i_pos;
255 hlist_add_head(&MSDOS_I(inode)->i_fat_hash,
256 sbi->inode_hashtable + fat_hash(sb, i_pos));
257 spin_unlock(&sbi->inode_hash_lock);
258}
259
OGAWA Hirofumi7c709d02006-01-08 01:02:10 -0800260EXPORT_SYMBOL_GPL(fat_attach);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700261
262void fat_detach(struct inode *inode)
263{
264 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
265 spin_lock(&sbi->inode_hash_lock);
266 MSDOS_I(inode)->i_pos = 0;
267 hlist_del_init(&MSDOS_I(inode)->i_fat_hash);
268 spin_unlock(&sbi->inode_hash_lock);
269}
270
OGAWA Hirofumi7c709d02006-01-08 01:02:10 -0800271EXPORT_SYMBOL_GPL(fat_detach);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700272
273struct inode *fat_iget(struct super_block *sb, loff_t i_pos)
274{
275 struct msdos_sb_info *sbi = MSDOS_SB(sb);
276 struct hlist_head *head = sbi->inode_hashtable + fat_hash(sb, i_pos);
277 struct hlist_node *_p;
278 struct msdos_inode_info *i;
279 struct inode *inode = NULL;
280
281 spin_lock(&sbi->inode_hash_lock);
282 hlist_for_each_entry(i, _p, head, i_fat_hash) {
283 BUG_ON(i->vfs_inode.i_sb != sb);
284 if (i->i_pos != i_pos)
285 continue;
286 inode = igrab(&i->vfs_inode);
287 if (inode)
288 break;
289 }
290 spin_unlock(&sbi->inode_hash_lock);
291 return inode;
292}
293
294static int is_exec(unsigned char *extension)
295{
296 unsigned char *exe_extensions = "EXECOMBAT", *walk;
297
298 for (walk = exe_extensions; *walk; walk += 3)
299 if (!strncmp(extension, walk, 3))
300 return 1;
301 return 0;
302}
303
304static int fat_calc_dir_size(struct inode *inode)
305{
306 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
307 int ret, fclus, dclus;
308
309 inode->i_size = 0;
310 if (MSDOS_I(inode)->i_start == 0)
311 return 0;
312
313 ret = fat_get_cluster(inode, FAT_ENT_EOF, &fclus, &dclus);
314 if (ret < 0)
315 return ret;
316 inode->i_size = (fclus + 1) << sbi->cluster_bits;
317
318 return 0;
319}
320
321/* doesn't deal with root inode */
322static int fat_fill_inode(struct inode *inode, struct msdos_dir_entry *de)
323{
324 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
325 int error;
326
327 MSDOS_I(inode)->i_pos = 0;
328 inode->i_uid = sbi->options.fs_uid;
329 inode->i_gid = sbi->options.fs_gid;
330 inode->i_version++;
331 inode->i_generation = get_seconds();
332
333 if ((de->attr & ATTR_DIR) && !IS_FREE(de->name)) {
334 inode->i_generation &= ~1;
335 inode->i_mode = MSDOS_MKMODE(de->attr,
336 S_IRWXUGO & ~sbi->options.fs_dmask) | S_IFDIR;
337 inode->i_op = sbi->dir_ops;
338 inode->i_fop = &fat_dir_operations;
339
340 MSDOS_I(inode)->i_start = le16_to_cpu(de->start);
341 if (sbi->fat_bits == 32)
342 MSDOS_I(inode)->i_start |= (le16_to_cpu(de->starthi) << 16);
343
344 MSDOS_I(inode)->i_logstart = MSDOS_I(inode)->i_start;
345 error = fat_calc_dir_size(inode);
346 if (error < 0)
347 return error;
348 MSDOS_I(inode)->mmu_private = inode->i_size;
349
350 inode->i_nlink = fat_subdirs(inode);
351 } else { /* not a directory */
352 inode->i_generation |= 1;
353 inode->i_mode = MSDOS_MKMODE(de->attr,
354 ((sbi->options.showexec &&
355 !is_exec(de->ext))
356 ? S_IRUGO|S_IWUGO : S_IRWXUGO)
357 & ~sbi->options.fs_fmask) | S_IFREG;
358 MSDOS_I(inode)->i_start = le16_to_cpu(de->start);
359 if (sbi->fat_bits == 32)
360 MSDOS_I(inode)->i_start |= (le16_to_cpu(de->starthi) << 16);
361
362 MSDOS_I(inode)->i_logstart = MSDOS_I(inode)->i_start;
363 inode->i_size = le32_to_cpu(de->size);
364 inode->i_op = &fat_file_inode_operations;
365 inode->i_fop = &fat_file_operations;
366 inode->i_mapping->a_ops = &fat_aops;
367 MSDOS_I(inode)->mmu_private = inode->i_size;
368 }
369 if (de->attr & ATTR_SYS) {
370 if (sbi->options.sys_immutable)
371 inode->i_flags |= S_IMMUTABLE;
372 }
373 MSDOS_I(inode)->i_attrs = de->attr & ATTR_UNUSED;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700374 inode->i_blocks = ((inode->i_size + (sbi->cluster_size - 1))
375 & ~((loff_t)sbi->cluster_size - 1)) >> 9;
Stephane Kardas62a36c42005-09-21 09:55:45 -0700376 inode->i_mtime.tv_sec =
Linus Torvalds1da177e2005-04-16 15:20:36 -0700377 date_dos2unix(le16_to_cpu(de->time), le16_to_cpu(de->date));
Stephane Kardas62a36c42005-09-21 09:55:45 -0700378 inode->i_mtime.tv_nsec = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700379 if (sbi->options.isvfat) {
380 int secs = de->ctime_cs / 100;
381 int csecs = de->ctime_cs % 100;
382 inode->i_ctime.tv_sec =
383 date_dos2unix(le16_to_cpu(de->ctime),
384 le16_to_cpu(de->cdate)) + secs;
385 inode->i_ctime.tv_nsec = csecs * 10000000;
Stephane Kardas62a36c42005-09-21 09:55:45 -0700386 inode->i_atime.tv_sec =
Al Viro31b1f852005-12-24 14:31:04 -0500387 date_dos2unix(0, le16_to_cpu(de->adate));
Stephane Kardas62a36c42005-09-21 09:55:45 -0700388 inode->i_atime.tv_nsec = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700389 } else
Stephane Kardas62a36c42005-09-21 09:55:45 -0700390 inode->i_ctime = inode->i_atime = inode->i_mtime;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700391
392 return 0;
393}
394
395struct inode *fat_build_inode(struct super_block *sb,
396 struct msdos_dir_entry *de, loff_t i_pos)
397{
398 struct inode *inode;
399 int err;
400
401 inode = fat_iget(sb, i_pos);
402 if (inode)
403 goto out;
404 inode = new_inode(sb);
405 if (!inode) {
406 inode = ERR_PTR(-ENOMEM);
407 goto out;
408 }
409 inode->i_ino = iunique(sb, MSDOS_ROOT_INO);
410 inode->i_version = 1;
411 err = fat_fill_inode(inode, de);
412 if (err) {
413 iput(inode);
414 inode = ERR_PTR(err);
415 goto out;
416 }
417 fat_attach(inode, i_pos);
418 insert_inode_hash(inode);
419out:
420 return inode;
421}
422
OGAWA Hirofumi7c709d02006-01-08 01:02:10 -0800423EXPORT_SYMBOL_GPL(fat_build_inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700424
425static void fat_delete_inode(struct inode *inode)
426{
Mark Fashehfef26652005-09-09 13:01:31 -0700427 truncate_inode_pages(&inode->i_data, 0);
428
Linus Torvalds1da177e2005-04-16 15:20:36 -0700429 if (!is_bad_inode(inode)) {
430 inode->i_size = 0;
431 fat_truncate(inode);
432 }
433 clear_inode(inode);
434}
435
436static void fat_clear_inode(struct inode *inode)
437{
438 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
439
440 if (is_bad_inode(inode))
441 return;
442 lock_kernel();
443 spin_lock(&sbi->inode_hash_lock);
444 fat_cache_inval_inode(inode);
445 hlist_del_init(&MSDOS_I(inode)->i_fat_hash);
446 spin_unlock(&sbi->inode_hash_lock);
447 unlock_kernel();
448}
449
OGAWA Hirofumia6bf6b22006-01-08 01:02:08 -0800450static void fat_write_super(struct super_block *sb)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700451{
OGAWA Hirofumia6bf6b22006-01-08 01:02:08 -0800452 sb->s_dirt = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700453
454 if (!(sb->s_flags & MS_RDONLY))
455 fat_clusters_flush(sb);
OGAWA Hirofumia6bf6b22006-01-08 01:02:08 -0800456}
457
458static void fat_put_super(struct super_block *sb)
459{
460 struct msdos_sb_info *sbi = MSDOS_SB(sb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700461
462 if (sbi->nls_disk) {
463 unload_nls(sbi->nls_disk);
464 sbi->nls_disk = NULL;
465 sbi->options.codepage = fat_default_codepage;
466 }
467 if (sbi->nls_io) {
468 unload_nls(sbi->nls_io);
469 sbi->nls_io = NULL;
470 }
471 if (sbi->options.iocharset != fat_default_iocharset) {
472 kfree(sbi->options.iocharset);
473 sbi->options.iocharset = fat_default_iocharset;
474 }
475
476 sb->s_fs_info = NULL;
477 kfree(sbi);
478}
479
480static kmem_cache_t *fat_inode_cachep;
481
482static struct inode *fat_alloc_inode(struct super_block *sb)
483{
484 struct msdos_inode_info *ei;
485 ei = kmem_cache_alloc(fat_inode_cachep, SLAB_KERNEL);
486 if (!ei)
487 return NULL;
488 return &ei->vfs_inode;
489}
490
491static void fat_destroy_inode(struct inode *inode)
492{
493 kmem_cache_free(fat_inode_cachep, MSDOS_I(inode));
494}
495
496static void init_once(void * foo, kmem_cache_t * cachep, unsigned long flags)
497{
498 struct msdos_inode_info *ei = (struct msdos_inode_info *)foo;
499
500 if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) ==
501 SLAB_CTOR_CONSTRUCTOR) {
502 spin_lock_init(&ei->cache_lru_lock);
503 ei->nr_caches = 0;
504 ei->cache_valid_id = FAT_CACHE_VALID + 1;
505 INIT_LIST_HEAD(&ei->cache_lru);
506 INIT_HLIST_NODE(&ei->i_fat_hash);
507 inode_init_once(&ei->vfs_inode);
508 }
509}
510
511static int __init fat_init_inodecache(void)
512{
513 fat_inode_cachep = kmem_cache_create("fat_inode_cache",
514 sizeof(struct msdos_inode_info),
Paul Jacksonfffb60f2006-03-24 03:16:06 -0800515 0, (SLAB_RECLAIM_ACCOUNT|
516 SLAB_MEM_SPREAD),
Linus Torvalds1da177e2005-04-16 15:20:36 -0700517 init_once, NULL);
518 if (fat_inode_cachep == NULL)
519 return -ENOMEM;
520 return 0;
521}
522
523static void __exit fat_destroy_inodecache(void)
524{
Alexey Dobriyan1a1d92c2006-09-27 01:49:40 -0700525 kmem_cache_destroy(fat_inode_cachep);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700526}
527
528static int fat_remount(struct super_block *sb, int *flags, char *data)
529{
530 struct msdos_sb_info *sbi = MSDOS_SB(sb);
531 *flags |= MS_NODIRATIME | (sbi->options.isvfat ? 0 : MS_NOATIME);
532 return 0;
533}
534
David Howells726c3342006-06-23 02:02:58 -0700535static int fat_statfs(struct dentry *dentry, struct kstatfs *buf)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700536{
David Howells726c3342006-06-23 02:02:58 -0700537 struct msdos_sb_info *sbi = MSDOS_SB(dentry->d_sb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700538
539 /* If the count of free cluster is still unknown, counts it here. */
540 if (sbi->free_clusters == -1) {
David Howells726c3342006-06-23 02:02:58 -0700541 int err = fat_count_free_clusters(dentry->d_sb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700542 if (err)
543 return err;
544 }
545
David Howells726c3342006-06-23 02:02:58 -0700546 buf->f_type = dentry->d_sb->s_magic;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700547 buf->f_bsize = sbi->cluster_size;
548 buf->f_blocks = sbi->max_cluster - FAT_START_ENT;
549 buf->f_bfree = sbi->free_clusters;
550 buf->f_bavail = sbi->free_clusters;
551 buf->f_namelen = sbi->options.isvfat ? 260 : 12;
552
553 return 0;
554}
555
556static int fat_write_inode(struct inode *inode, int wait)
557{
558 struct super_block *sb = inode->i_sb;
559 struct msdos_sb_info *sbi = MSDOS_SB(sb);
560 struct buffer_head *bh;
561 struct msdos_dir_entry *raw_entry;
562 loff_t i_pos;
563 int err = 0;
564
565retry:
566 i_pos = MSDOS_I(inode)->i_pos;
567 if (inode->i_ino == MSDOS_ROOT_INO || !i_pos)
568 return 0;
569
570 lock_kernel();
571 bh = sb_bread(sb, i_pos >> sbi->dir_per_block_bits);
572 if (!bh) {
573 printk(KERN_ERR "FAT: unable to read inode block "
574 "for updating (i_pos %lld)\n", i_pos);
575 err = -EIO;
576 goto out;
577 }
578 spin_lock(&sbi->inode_hash_lock);
579 if (i_pos != MSDOS_I(inode)->i_pos) {
580 spin_unlock(&sbi->inode_hash_lock);
581 brelse(bh);
582 unlock_kernel();
583 goto retry;
584 }
585
586 raw_entry = &((struct msdos_dir_entry *) (bh->b_data))
587 [i_pos & (sbi->dir_per_block - 1)];
588 if (S_ISDIR(inode->i_mode))
589 raw_entry->size = 0;
590 else
591 raw_entry->size = cpu_to_le32(inode->i_size);
592 raw_entry->attr = fat_attr(inode);
593 raw_entry->start = cpu_to_le16(MSDOS_I(inode)->i_logstart);
594 raw_entry->starthi = cpu_to_le16(MSDOS_I(inode)->i_logstart >> 16);
595 fat_date_unix2dos(inode->i_mtime.tv_sec, &raw_entry->time, &raw_entry->date);
596 if (sbi->options.isvfat) {
Stephane Kardas62a36c42005-09-21 09:55:45 -0700597 __le16 atime;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700598 fat_date_unix2dos(inode->i_ctime.tv_sec,&raw_entry->ctime,&raw_entry->cdate);
Stephane Kardas62a36c42005-09-21 09:55:45 -0700599 fat_date_unix2dos(inode->i_atime.tv_sec,&atime,&raw_entry->adate);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700600 raw_entry->ctime_cs = (inode->i_ctime.tv_sec & 1) * 100 +
601 inode->i_ctime.tv_nsec / 10000000;
602 }
603 spin_unlock(&sbi->inode_hash_lock);
604 mark_buffer_dirty(bh);
605 if (wait)
606 err = sync_dirty_buffer(bh);
607 brelse(bh);
608out:
609 unlock_kernel();
610 return err;
611}
612
613int fat_sync_inode(struct inode *inode)
614{
615 return fat_write_inode(inode, 1);
616}
617
OGAWA Hirofumi7c709d02006-01-08 01:02:10 -0800618EXPORT_SYMBOL_GPL(fat_sync_inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700619
620static int fat_show_options(struct seq_file *m, struct vfsmount *mnt);
621static struct super_operations fat_sops = {
622 .alloc_inode = fat_alloc_inode,
623 .destroy_inode = fat_destroy_inode,
624 .write_inode = fat_write_inode,
625 .delete_inode = fat_delete_inode,
626 .put_super = fat_put_super,
OGAWA Hirofumia6bf6b22006-01-08 01:02:08 -0800627 .write_super = fat_write_super,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700628 .statfs = fat_statfs,
629 .clear_inode = fat_clear_inode,
630 .remount_fs = fat_remount,
631
632 .read_inode = make_bad_inode,
633
634 .show_options = fat_show_options,
635};
636
637/*
638 * a FAT file handle with fhtype 3 is
639 * 0/ i_ino - for fast, reliable lookup if still in the cache
640 * 1/ i_generation - to see if i_ino is still valid
641 * bit 0 == 0 iff directory
642 * 2/ i_pos(8-39) - if ino has changed, but still in cache
643 * 3/ i_pos(4-7)|i_logstart - to semi-verify inode found at i_pos
644 * 4/ i_pos(0-3)|parent->i_logstart - maybe used to hunt for the file on disc
645 *
646 * Hack for NFSv2: Maximum FAT entry number is 28bits and maximum
647 * i_pos is 40bits (blocknr(32) + dir offset(8)), so two 4bits
648 * of i_logstart is used to store the directory entry offset.
649 */
650
651static struct dentry *
652fat_decode_fh(struct super_block *sb, __u32 *fh, int len, int fhtype,
653 int (*acceptable)(void *context, struct dentry *de),
654 void *context)
655{
656 if (fhtype != 3)
657 return ERR_PTR(-ESTALE);
658 if (len < 5)
659 return ERR_PTR(-ESTALE);
660
661 return sb->s_export_op->find_exported_dentry(sb, fh, NULL, acceptable, context);
662}
663
664static struct dentry *fat_get_dentry(struct super_block *sb, void *inump)
665{
666 struct inode *inode = NULL;
667 struct dentry *result;
668 __u32 *fh = inump;
669
670 inode = iget(sb, fh[0]);
671 if (!inode || is_bad_inode(inode) || inode->i_generation != fh[1]) {
672 if (inode)
673 iput(inode);
674 inode = NULL;
675 }
676 if (!inode) {
677 loff_t i_pos;
678 int i_logstart = fh[3] & 0x0fffffff;
679
680 i_pos = (loff_t)fh[2] << 8;
681 i_pos |= ((fh[3] >> 24) & 0xf0) | (fh[4] >> 28);
682
683 /* try 2 - see if i_pos is in F-d-c
684 * require i_logstart to be the same
685 * Will fail if you truncate and then re-write
686 */
687
688 inode = fat_iget(sb, i_pos);
689 if (inode && MSDOS_I(inode)->i_logstart != i_logstart) {
690 iput(inode);
691 inode = NULL;
692 }
693 }
694 if (!inode) {
695 /* For now, do nothing
696 * What we could do is:
697 * follow the file starting at fh[4], and record
698 * the ".." entry, and the name of the fh[2] entry.
699 * The follow the ".." file finding the next step up.
700 * This way we build a path to the root of
701 * the tree. If this works, we lookup the path and so
702 * get this inode into the cache.
703 * Finally try the fat_iget lookup again
704 * If that fails, then weare totally out of luck
705 * But all that is for another day
706 */
707 }
708 if (!inode)
709 return ERR_PTR(-ESTALE);
710
711
712 /* now to find a dentry.
713 * If possible, get a well-connected one
714 */
715 result = d_alloc_anon(inode);
716 if (result == NULL) {
717 iput(inode);
718 return ERR_PTR(-ENOMEM);
719 }
720 result->d_op = sb->s_root->d_op;
721 return result;
722}
723
724static int
725fat_encode_fh(struct dentry *de, __u32 *fh, int *lenp, int connectable)
726{
727 int len = *lenp;
728 struct inode *inode = de->d_inode;
729 u32 ipos_h, ipos_m, ipos_l;
730
731 if (len < 5)
732 return 255; /* no room */
733
734 ipos_h = MSDOS_I(inode)->i_pos >> 8;
735 ipos_m = (MSDOS_I(inode)->i_pos & 0xf0) << 24;
736 ipos_l = (MSDOS_I(inode)->i_pos & 0x0f) << 28;
737 *lenp = 5;
738 fh[0] = inode->i_ino;
739 fh[1] = inode->i_generation;
740 fh[2] = ipos_h;
741 fh[3] = ipos_m | MSDOS_I(inode)->i_logstart;
742 spin_lock(&de->d_lock);
743 fh[4] = ipos_l | MSDOS_I(de->d_parent->d_inode)->i_logstart;
744 spin_unlock(&de->d_lock);
745 return 3;
746}
747
748static struct dentry *fat_get_parent(struct dentry *child)
749{
750 struct buffer_head *bh;
751 struct msdos_dir_entry *de;
752 loff_t i_pos;
753 struct dentry *parent;
754 struct inode *inode;
755 int err;
756
757 lock_kernel();
758
759 err = fat_get_dotdot_entry(child->d_inode, &bh, &de, &i_pos);
760 if (err) {
761 parent = ERR_PTR(err);
762 goto out;
763 }
764 inode = fat_build_inode(child->d_sb, de, i_pos);
765 brelse(bh);
766 if (IS_ERR(inode)) {
767 parent = ERR_PTR(PTR_ERR(inode));
768 goto out;
769 }
770 parent = d_alloc_anon(inode);
771 if (!parent) {
772 iput(inode);
773 parent = ERR_PTR(-ENOMEM);
774 }
775out:
776 unlock_kernel();
777
778 return parent;
779}
780
781static struct export_operations fat_export_ops = {
782 .decode_fh = fat_decode_fh,
783 .encode_fh = fat_encode_fh,
784 .get_dentry = fat_get_dentry,
785 .get_parent = fat_get_parent,
786};
787
788static int fat_show_options(struct seq_file *m, struct vfsmount *mnt)
789{
790 struct msdos_sb_info *sbi = MSDOS_SB(mnt->mnt_sb);
791 struct fat_mount_options *opts = &sbi->options;
792 int isvfat = opts->isvfat;
793
794 if (opts->fs_uid != 0)
795 seq_printf(m, ",uid=%u", opts->fs_uid);
796 if (opts->fs_gid != 0)
797 seq_printf(m, ",gid=%u", opts->fs_gid);
798 seq_printf(m, ",fmask=%04o", opts->fs_fmask);
799 seq_printf(m, ",dmask=%04o", opts->fs_dmask);
800 if (sbi->nls_disk)
801 seq_printf(m, ",codepage=%s", sbi->nls_disk->charset);
802 if (isvfat) {
803 if (sbi->nls_io)
804 seq_printf(m, ",iocharset=%s", sbi->nls_io->charset);
805
806 switch (opts->shortname) {
807 case VFAT_SFN_DISPLAY_WIN95 | VFAT_SFN_CREATE_WIN95:
808 seq_puts(m, ",shortname=win95");
809 break;
810 case VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WINNT:
811 seq_puts(m, ",shortname=winnt");
812 break;
813 case VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WIN95:
814 seq_puts(m, ",shortname=mixed");
815 break;
816 case VFAT_SFN_DISPLAY_LOWER | VFAT_SFN_CREATE_WIN95:
817 /* seq_puts(m, ",shortname=lower"); */
818 break;
819 default:
820 seq_puts(m, ",shortname=unknown");
821 break;
822 }
823 }
824 if (opts->name_check != 'n')
825 seq_printf(m, ",check=%c", opts->name_check);
826 if (opts->quiet)
827 seq_puts(m, ",quiet");
828 if (opts->showexec)
829 seq_puts(m, ",showexec");
830 if (opts->sys_immutable)
831 seq_puts(m, ",sys_immutable");
832 if (!isvfat) {
833 if (opts->dotsOK)
834 seq_puts(m, ",dotsOK=yes");
835 if (opts->nocase)
836 seq_puts(m, ",nocase");
837 } else {
838 if (opts->utf8)
839 seq_puts(m, ",utf8");
840 if (opts->unicode_xlate)
841 seq_puts(m, ",uni_xlate");
842 if (!opts->numtail)
843 seq_puts(m, ",nonumtail");
844 }
845
846 return 0;
847}
848
849enum {
850 Opt_check_n, Opt_check_r, Opt_check_s, Opt_uid, Opt_gid,
851 Opt_umask, Opt_dmask, Opt_fmask, Opt_codepage, Opt_nocase,
852 Opt_quiet, Opt_showexec, Opt_debug, Opt_immutable,
853 Opt_dots, Opt_nodots,
854 Opt_charset, Opt_shortname_lower, Opt_shortname_win95,
855 Opt_shortname_winnt, Opt_shortname_mixed, Opt_utf8_no, Opt_utf8_yes,
856 Opt_uni_xl_no, Opt_uni_xl_yes, Opt_nonumtail_no, Opt_nonumtail_yes,
Chris Masonae78bf92006-09-29 02:00:03 -0700857 Opt_obsolate, Opt_flush, Opt_err,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700858};
859
860static match_table_t fat_tokens = {
861 {Opt_check_r, "check=relaxed"},
862 {Opt_check_s, "check=strict"},
863 {Opt_check_n, "check=normal"},
864 {Opt_check_r, "check=r"},
865 {Opt_check_s, "check=s"},
866 {Opt_check_n, "check=n"},
867 {Opt_uid, "uid=%u"},
868 {Opt_gid, "gid=%u"},
869 {Opt_umask, "umask=%o"},
870 {Opt_dmask, "dmask=%o"},
871 {Opt_fmask, "fmask=%o"},
872 {Opt_codepage, "codepage=%u"},
873 {Opt_nocase, "nocase"},
874 {Opt_quiet, "quiet"},
875 {Opt_showexec, "showexec"},
876 {Opt_debug, "debug"},
877 {Opt_immutable, "sys_immutable"},
878 {Opt_obsolate, "conv=binary"},
879 {Opt_obsolate, "conv=text"},
880 {Opt_obsolate, "conv=auto"},
881 {Opt_obsolate, "conv=b"},
882 {Opt_obsolate, "conv=t"},
883 {Opt_obsolate, "conv=a"},
884 {Opt_obsolate, "fat=%u"},
885 {Opt_obsolate, "blocksize=%u"},
886 {Opt_obsolate, "cvf_format=%20s"},
887 {Opt_obsolate, "cvf_options=%100s"},
888 {Opt_obsolate, "posix"},
Chris Masonae78bf92006-09-29 02:00:03 -0700889 {Opt_flush, "flush"},
890 {Opt_err, NULL},
Linus Torvalds1da177e2005-04-16 15:20:36 -0700891};
892static match_table_t msdos_tokens = {
893 {Opt_nodots, "nodots"},
894 {Opt_nodots, "dotsOK=no"},
895 {Opt_dots, "dots"},
896 {Opt_dots, "dotsOK=yes"},
897 {Opt_err, NULL}
898};
899static match_table_t vfat_tokens = {
900 {Opt_charset, "iocharset=%s"},
901 {Opt_shortname_lower, "shortname=lower"},
902 {Opt_shortname_win95, "shortname=win95"},
903 {Opt_shortname_winnt, "shortname=winnt"},
904 {Opt_shortname_mixed, "shortname=mixed"},
905 {Opt_utf8_no, "utf8=0"}, /* 0 or no or false */
906 {Opt_utf8_no, "utf8=no"},
907 {Opt_utf8_no, "utf8=false"},
908 {Opt_utf8_yes, "utf8=1"}, /* empty or 1 or yes or true */
909 {Opt_utf8_yes, "utf8=yes"},
910 {Opt_utf8_yes, "utf8=true"},
911 {Opt_utf8_yes, "utf8"},
912 {Opt_uni_xl_no, "uni_xlate=0"}, /* 0 or no or false */
913 {Opt_uni_xl_no, "uni_xlate=no"},
914 {Opt_uni_xl_no, "uni_xlate=false"},
915 {Opt_uni_xl_yes, "uni_xlate=1"}, /* empty or 1 or yes or true */
916 {Opt_uni_xl_yes, "uni_xlate=yes"},
917 {Opt_uni_xl_yes, "uni_xlate=true"},
918 {Opt_uni_xl_yes, "uni_xlate"},
919 {Opt_nonumtail_no, "nonumtail=0"}, /* 0 or no or false */
920 {Opt_nonumtail_no, "nonumtail=no"},
921 {Opt_nonumtail_no, "nonumtail=false"},
922 {Opt_nonumtail_yes, "nonumtail=1"}, /* empty or 1 or yes or true */
923 {Opt_nonumtail_yes, "nonumtail=yes"},
924 {Opt_nonumtail_yes, "nonumtail=true"},
925 {Opt_nonumtail_yes, "nonumtail"},
926 {Opt_err, NULL}
927};
928
Christoph Hellwig41a34a42005-11-08 21:34:57 -0800929static int parse_options(char *options, int is_vfat, int silent, int *debug,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700930 struct fat_mount_options *opts)
931{
932 char *p;
933 substring_t args[MAX_OPT_ARGS];
934 int option;
935 char *iocharset;
936
937 opts->isvfat = is_vfat;
938
939 opts->fs_uid = current->uid;
940 opts->fs_gid = current->gid;
941 opts->fs_fmask = opts->fs_dmask = current->fs->umask;
942 opts->codepage = fat_default_codepage;
943 opts->iocharset = fat_default_iocharset;
944 if (is_vfat)
945 opts->shortname = VFAT_SFN_DISPLAY_LOWER|VFAT_SFN_CREATE_WIN95;
946 else
947 opts->shortname = 0;
948 opts->name_check = 'n';
949 opts->quiet = opts->showexec = opts->sys_immutable = opts->dotsOK = 0;
950 opts->utf8 = opts->unicode_xlate = 0;
951 opts->numtail = 1;
952 opts->nocase = 0;
953 *debug = 0;
954
955 if (!options)
956 return 0;
957
958 while ((p = strsep(&options, ",")) != NULL) {
959 int token;
960 if (!*p)
961 continue;
962
963 token = match_token(p, fat_tokens, args);
964 if (token == Opt_err) {
965 if (is_vfat)
966 token = match_token(p, vfat_tokens, args);
967 else
968 token = match_token(p, msdos_tokens, args);
969 }
970 switch (token) {
971 case Opt_check_s:
972 opts->name_check = 's';
973 break;
974 case Opt_check_r:
975 opts->name_check = 'r';
976 break;
977 case Opt_check_n:
978 opts->name_check = 'n';
979 break;
980 case Opt_nocase:
981 if (!is_vfat)
982 opts->nocase = 1;
983 else {
984 /* for backward compatibility */
985 opts->shortname = VFAT_SFN_DISPLAY_WIN95
986 | VFAT_SFN_CREATE_WIN95;
987 }
988 break;
989 case Opt_quiet:
990 opts->quiet = 1;
991 break;
992 case Opt_showexec:
993 opts->showexec = 1;
994 break;
995 case Opt_debug:
996 *debug = 1;
997 break;
998 case Opt_immutable:
999 opts->sys_immutable = 1;
1000 break;
1001 case Opt_uid:
1002 if (match_int(&args[0], &option))
1003 return 0;
1004 opts->fs_uid = option;
1005 break;
1006 case Opt_gid:
1007 if (match_int(&args[0], &option))
1008 return 0;
1009 opts->fs_gid = option;
1010 break;
1011 case Opt_umask:
1012 if (match_octal(&args[0], &option))
1013 return 0;
1014 opts->fs_fmask = opts->fs_dmask = option;
1015 break;
1016 case Opt_dmask:
1017 if (match_octal(&args[0], &option))
1018 return 0;
1019 opts->fs_dmask = option;
1020 break;
1021 case Opt_fmask:
1022 if (match_octal(&args[0], &option))
1023 return 0;
1024 opts->fs_fmask = option;
1025 break;
1026 case Opt_codepage:
1027 if (match_int(&args[0], &option))
1028 return 0;
1029 opts->codepage = option;
1030 break;
Chris Masonae78bf92006-09-29 02:00:03 -07001031 case Opt_flush:
1032 opts->flush = 1;
1033 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001034
1035 /* msdos specific */
1036 case Opt_dots:
1037 opts->dotsOK = 1;
1038 break;
1039 case Opt_nodots:
1040 opts->dotsOK = 0;
1041 break;
1042
1043 /* vfat specific */
1044 case Opt_charset:
1045 if (opts->iocharset != fat_default_iocharset)
1046 kfree(opts->iocharset);
1047 iocharset = match_strdup(&args[0]);
1048 if (!iocharset)
1049 return -ENOMEM;
1050 opts->iocharset = iocharset;
1051 break;
1052 case Opt_shortname_lower:
1053 opts->shortname = VFAT_SFN_DISPLAY_LOWER
1054 | VFAT_SFN_CREATE_WIN95;
1055 break;
1056 case Opt_shortname_win95:
1057 opts->shortname = VFAT_SFN_DISPLAY_WIN95
1058 | VFAT_SFN_CREATE_WIN95;
1059 break;
1060 case Opt_shortname_winnt:
1061 opts->shortname = VFAT_SFN_DISPLAY_WINNT
1062 | VFAT_SFN_CREATE_WINNT;
1063 break;
1064 case Opt_shortname_mixed:
1065 opts->shortname = VFAT_SFN_DISPLAY_WINNT
1066 | VFAT_SFN_CREATE_WIN95;
1067 break;
1068 case Opt_utf8_no: /* 0 or no or false */
1069 opts->utf8 = 0;
1070 break;
1071 case Opt_utf8_yes: /* empty or 1 or yes or true */
1072 opts->utf8 = 1;
1073 break;
1074 case Opt_uni_xl_no: /* 0 or no or false */
1075 opts->unicode_xlate = 0;
1076 break;
1077 case Opt_uni_xl_yes: /* empty or 1 or yes or true */
1078 opts->unicode_xlate = 1;
1079 break;
1080 case Opt_nonumtail_no: /* 0 or no or false */
1081 opts->numtail = 1; /* negated option */
1082 break;
1083 case Opt_nonumtail_yes: /* empty or 1 or yes or true */
1084 opts->numtail = 0; /* negated option */
1085 break;
1086
1087 /* obsolete mount options */
1088 case Opt_obsolate:
1089 printk(KERN_INFO "FAT: \"%s\" option is obsolete, "
1090 "not supported now\n", p);
1091 break;
1092 /* unknown option */
1093 default:
Christoph Hellwig41a34a42005-11-08 21:34:57 -08001094 if (!silent) {
1095 printk(KERN_ERR
1096 "FAT: Unrecognized mount option \"%s\" "
1097 "or missing value\n", p);
1098 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001099 return -EINVAL;
1100 }
1101 }
Alexey Dobriyan4de151d2006-03-22 00:13:35 +01001102 /* UTF-8 doesn't provide FAT semantics */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001103 if (!strcmp(opts->iocharset, "utf8")) {
1104 printk(KERN_ERR "FAT: utf8 is not a recommended IO charset"
1105 " for FAT filesystems, filesystem will be case sensitive!\n");
1106 }
1107
1108 if (opts->unicode_xlate)
1109 opts->utf8 = 0;
1110
1111 return 0;
1112}
1113
1114static int fat_read_root(struct inode *inode)
1115{
1116 struct super_block *sb = inode->i_sb;
1117 struct msdos_sb_info *sbi = MSDOS_SB(sb);
1118 int error;
1119
1120 MSDOS_I(inode)->i_pos = 0;
1121 inode->i_uid = sbi->options.fs_uid;
1122 inode->i_gid = sbi->options.fs_gid;
1123 inode->i_version++;
1124 inode->i_generation = 0;
1125 inode->i_mode = (S_IRWXUGO & ~sbi->options.fs_dmask) | S_IFDIR;
1126 inode->i_op = sbi->dir_ops;
1127 inode->i_fop = &fat_dir_operations;
1128 if (sbi->fat_bits == 32) {
1129 MSDOS_I(inode)->i_start = sbi->root_cluster;
1130 error = fat_calc_dir_size(inode);
1131 if (error < 0)
1132 return error;
1133 } else {
1134 MSDOS_I(inode)->i_start = 0;
1135 inode->i_size = sbi->dir_entries * sizeof(struct msdos_dir_entry);
1136 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001137 inode->i_blocks = ((inode->i_size + (sbi->cluster_size - 1))
1138 & ~((loff_t)sbi->cluster_size - 1)) >> 9;
1139 MSDOS_I(inode)->i_logstart = 0;
1140 MSDOS_I(inode)->mmu_private = inode->i_size;
1141
1142 MSDOS_I(inode)->i_attrs = ATTR_NONE;
1143 inode->i_mtime.tv_sec = inode->i_atime.tv_sec = inode->i_ctime.tv_sec = 0;
1144 inode->i_mtime.tv_nsec = inode->i_atime.tv_nsec = inode->i_ctime.tv_nsec = 0;
1145 inode->i_nlink = fat_subdirs(inode)+2;
1146
1147 return 0;
1148}
1149
1150/*
1151 * Read the super block of an MS-DOS FS.
1152 */
1153int fat_fill_super(struct super_block *sb, void *data, int silent,
1154 struct inode_operations *fs_dir_inode_ops, int isvfat)
1155{
1156 struct inode *root_inode = NULL;
1157 struct buffer_head *bh;
1158 struct fat_boot_sector *b;
1159 struct msdos_sb_info *sbi;
1160 u16 logical_sector_size;
1161 u32 total_sectors, total_clusters, fat_clusters, rootdir_sectors;
1162 int debug;
1163 unsigned int media;
1164 long error;
1165 char buf[50];
1166
Panagiotis Issarisf8314dc2006-09-27 01:49:37 -07001167 sbi = kzalloc(sizeof(struct msdos_sb_info), GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001168 if (!sbi)
1169 return -ENOMEM;
1170 sb->s_fs_info = sbi;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001171
1172 sb->s_flags |= MS_NODIRATIME;
1173 sb->s_magic = MSDOS_SUPER_MAGIC;
1174 sb->s_op = &fat_sops;
1175 sb->s_export_op = &fat_export_ops;
1176 sbi->dir_ops = fs_dir_inode_ops;
1177
Christoph Hellwig41a34a42005-11-08 21:34:57 -08001178 error = parse_options(data, isvfat, silent, &debug, &sbi->options);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001179 if (error)
1180 goto out_fail;
1181
1182 error = -EIO;
1183 sb_min_blocksize(sb, 512);
1184 bh = sb_bread(sb, 0);
1185 if (bh == NULL) {
1186 printk(KERN_ERR "FAT: unable to read boot sector\n");
1187 goto out_fail;
1188 }
1189
1190 b = (struct fat_boot_sector *) bh->b_data;
1191 if (!b->reserved) {
1192 if (!silent)
1193 printk(KERN_ERR "FAT: bogus number of reserved sectors\n");
1194 brelse(bh);
1195 goto out_invalid;
1196 }
1197 if (!b->fats) {
1198 if (!silent)
1199 printk(KERN_ERR "FAT: bogus number of FAT structure\n");
1200 brelse(bh);
1201 goto out_invalid;
1202 }
1203
1204 /*
1205 * Earlier we checked here that b->secs_track and b->head are nonzero,
1206 * but it turns out valid FAT filesystems can have zero there.
1207 */
1208
1209 media = b->media;
1210 if (!FAT_VALID_MEDIA(media)) {
1211 if (!silent)
1212 printk(KERN_ERR "FAT: invalid media value (0x%02x)\n",
1213 media);
1214 brelse(bh);
1215 goto out_invalid;
1216 }
1217 logical_sector_size =
1218 le16_to_cpu(get_unaligned((__le16 *)&b->sector_size));
1219 if (!logical_sector_size
1220 || (logical_sector_size & (logical_sector_size - 1))
1221 || (logical_sector_size < 512)
1222 || (PAGE_CACHE_SIZE < logical_sector_size)) {
1223 if (!silent)
1224 printk(KERN_ERR "FAT: bogus logical sector size %u\n",
1225 logical_sector_size);
1226 brelse(bh);
1227 goto out_invalid;
1228 }
1229 sbi->sec_per_clus = b->sec_per_clus;
1230 if (!sbi->sec_per_clus
1231 || (sbi->sec_per_clus & (sbi->sec_per_clus - 1))) {
1232 if (!silent)
1233 printk(KERN_ERR "FAT: bogus sectors per cluster %u\n",
1234 sbi->sec_per_clus);
1235 brelse(bh);
1236 goto out_invalid;
1237 }
1238
1239 if (logical_sector_size < sb->s_blocksize) {
1240 printk(KERN_ERR "FAT: logical sector size too small for device"
1241 " (logical sector size = %u)\n", logical_sector_size);
1242 brelse(bh);
1243 goto out_fail;
1244 }
1245 if (logical_sector_size > sb->s_blocksize) {
1246 brelse(bh);
1247
1248 if (!sb_set_blocksize(sb, logical_sector_size)) {
1249 printk(KERN_ERR "FAT: unable to set blocksize %u\n",
1250 logical_sector_size);
1251 goto out_fail;
1252 }
1253 bh = sb_bread(sb, 0);
1254 if (bh == NULL) {
1255 printk(KERN_ERR "FAT: unable to read boot sector"
1256 " (logical sector size = %lu)\n",
1257 sb->s_blocksize);
1258 goto out_fail;
1259 }
1260 b = (struct fat_boot_sector *) bh->b_data;
1261 }
1262
1263 sbi->cluster_size = sb->s_blocksize * sbi->sec_per_clus;
1264 sbi->cluster_bits = ffs(sbi->cluster_size) - 1;
1265 sbi->fats = b->fats;
1266 sbi->fat_bits = 0; /* Don't know yet */
1267 sbi->fat_start = le16_to_cpu(b->reserved);
1268 sbi->fat_length = le16_to_cpu(b->fat_length);
1269 sbi->root_cluster = 0;
1270 sbi->free_clusters = -1; /* Don't know yet */
1271 sbi->prev_free = FAT_START_ENT;
1272
1273 if (!sbi->fat_length && b->fat32_length) {
1274 struct fat_boot_fsinfo *fsinfo;
1275 struct buffer_head *fsinfo_bh;
1276
1277 /* Must be FAT32 */
1278 sbi->fat_bits = 32;
1279 sbi->fat_length = le32_to_cpu(b->fat32_length);
1280 sbi->root_cluster = le32_to_cpu(b->root_cluster);
1281
1282 sb->s_maxbytes = 0xffffffff;
1283
1284 /* MC - if info_sector is 0, don't multiply by 0 */
1285 sbi->fsinfo_sector = le16_to_cpu(b->info_sector);
1286 if (sbi->fsinfo_sector == 0)
1287 sbi->fsinfo_sector = 1;
1288
1289 fsinfo_bh = sb_bread(sb, sbi->fsinfo_sector);
1290 if (fsinfo_bh == NULL) {
1291 printk(KERN_ERR "FAT: bread failed, FSINFO block"
1292 " (sector = %lu)\n", sbi->fsinfo_sector);
1293 brelse(bh);
1294 goto out_fail;
1295 }
1296
1297 fsinfo = (struct fat_boot_fsinfo *)fsinfo_bh->b_data;
1298 if (!IS_FSINFO(fsinfo)) {
1299 printk(KERN_WARNING
1300 "FAT: Did not find valid FSINFO signature.\n"
1301 " Found signature1 0x%08x signature2 0x%08x"
1302 " (sector = %lu)\n",
1303 le32_to_cpu(fsinfo->signature1),
1304 le32_to_cpu(fsinfo->signature2),
1305 sbi->fsinfo_sector);
1306 } else {
1307 sbi->free_clusters = le32_to_cpu(fsinfo->free_clusters);
1308 sbi->prev_free = le32_to_cpu(fsinfo->next_cluster);
1309 }
1310
1311 brelse(fsinfo_bh);
1312 }
1313
1314 sbi->dir_per_block = sb->s_blocksize / sizeof(struct msdos_dir_entry);
1315 sbi->dir_per_block_bits = ffs(sbi->dir_per_block) - 1;
1316
1317 sbi->dir_start = sbi->fat_start + sbi->fats * sbi->fat_length;
1318 sbi->dir_entries =
1319 le16_to_cpu(get_unaligned((__le16 *)&b->dir_entries));
1320 if (sbi->dir_entries & (sbi->dir_per_block - 1)) {
1321 if (!silent)
1322 printk(KERN_ERR "FAT: bogus directroy-entries per block"
1323 " (%u)\n", sbi->dir_entries);
1324 brelse(bh);
1325 goto out_invalid;
1326 }
1327
1328 rootdir_sectors = sbi->dir_entries
1329 * sizeof(struct msdos_dir_entry) / sb->s_blocksize;
1330 sbi->data_start = sbi->dir_start + rootdir_sectors;
1331 total_sectors = le16_to_cpu(get_unaligned((__le16 *)&b->sectors));
1332 if (total_sectors == 0)
1333 total_sectors = le32_to_cpu(b->total_sect);
1334
1335 total_clusters = (total_sectors - sbi->data_start) / sbi->sec_per_clus;
1336
1337 if (sbi->fat_bits != 32)
1338 sbi->fat_bits = (total_clusters > MAX_FAT12) ? 16 : 12;
1339
1340 /* check that FAT table does not overflow */
1341 fat_clusters = sbi->fat_length * sb->s_blocksize * 8 / sbi->fat_bits;
1342 total_clusters = min(total_clusters, fat_clusters - FAT_START_ENT);
1343 if (total_clusters > MAX_FAT(sb)) {
1344 if (!silent)
1345 printk(KERN_ERR "FAT: count of clusters too big (%u)\n",
1346 total_clusters);
1347 brelse(bh);
1348 goto out_invalid;
1349 }
1350
1351 sbi->max_cluster = total_clusters + FAT_START_ENT;
1352 /* check the free_clusters, it's not necessarily correct */
1353 if (sbi->free_clusters != -1 && sbi->free_clusters > total_clusters)
1354 sbi->free_clusters = -1;
1355 /* check the prev_free, it's not necessarily correct */
1356 sbi->prev_free %= sbi->max_cluster;
1357 if (sbi->prev_free < FAT_START_ENT)
1358 sbi->prev_free = FAT_START_ENT;
1359
1360 brelse(bh);
1361
1362 /* set up enough so that it can read an inode */
1363 fat_hash_init(sb);
1364 fat_ent_access_init(sb);
1365
1366 /*
1367 * The low byte of FAT's first entry must have same value with
1368 * media-field. But in real world, too many devices is
1369 * writing wrong value. So, removed that validity check.
1370 *
1371 * if (FAT_FIRST_ENT(sb, media) != first)
1372 */
1373
1374 error = -EINVAL;
1375 sprintf(buf, "cp%d", sbi->options.codepage);
1376 sbi->nls_disk = load_nls(buf);
1377 if (!sbi->nls_disk) {
1378 printk(KERN_ERR "FAT: codepage %s not found\n", buf);
1379 goto out_fail;
1380 }
1381
1382 /* FIXME: utf8 is using iocharset for upper/lower conversion */
1383 if (sbi->options.isvfat) {
1384 sbi->nls_io = load_nls(sbi->options.iocharset);
1385 if (!sbi->nls_io) {
1386 printk(KERN_ERR "FAT: IO charset %s not found\n",
1387 sbi->options.iocharset);
1388 goto out_fail;
1389 }
1390 }
1391
1392 error = -ENOMEM;
1393 root_inode = new_inode(sb);
1394 if (!root_inode)
1395 goto out_fail;
1396 root_inode->i_ino = MSDOS_ROOT_INO;
1397 root_inode->i_version = 1;
1398 error = fat_read_root(root_inode);
1399 if (error < 0)
1400 goto out_fail;
1401 error = -ENOMEM;
1402 insert_inode_hash(root_inode);
1403 sb->s_root = d_alloc_root(root_inode);
1404 if (!sb->s_root) {
1405 printk(KERN_ERR "FAT: get root inode failed\n");
1406 goto out_fail;
1407 }
1408
1409 return 0;
1410
1411out_invalid:
1412 error = -EINVAL;
1413 if (!silent)
1414 printk(KERN_INFO "VFS: Can't find a valid FAT filesystem"
1415 " on dev %s.\n", sb->s_id);
1416
1417out_fail:
1418 if (root_inode)
1419 iput(root_inode);
1420 if (sbi->nls_io)
1421 unload_nls(sbi->nls_io);
1422 if (sbi->nls_disk)
1423 unload_nls(sbi->nls_disk);
1424 if (sbi->options.iocharset != fat_default_iocharset)
1425 kfree(sbi->options.iocharset);
1426 sb->s_fs_info = NULL;
1427 kfree(sbi);
1428 return error;
1429}
1430
OGAWA Hirofumi7c709d02006-01-08 01:02:10 -08001431EXPORT_SYMBOL_GPL(fat_fill_super);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001432
Chris Masonae78bf92006-09-29 02:00:03 -07001433/*
1434 * helper function for fat_flush_inodes. This writes both the inode
1435 * and the file data blocks, waiting for in flight data blocks before
1436 * the start of the call. It does not wait for any io started
1437 * during the call
1438 */
1439static int writeback_inode(struct inode *inode)
1440{
1441
1442 int ret;
1443 struct address_space *mapping = inode->i_mapping;
1444 struct writeback_control wbc = {
1445 .sync_mode = WB_SYNC_NONE,
1446 .nr_to_write = 0,
1447 };
1448 /* if we used WB_SYNC_ALL, sync_inode waits for the io for the
1449 * inode to finish. So WB_SYNC_NONE is sent down to sync_inode
1450 * and filemap_fdatawrite is used for the data blocks
1451 */
1452 ret = sync_inode(inode, &wbc);
1453 if (!ret)
1454 ret = filemap_fdatawrite(mapping);
1455 return ret;
1456}
1457
1458/*
1459 * write data and metadata corresponding to i1 and i2. The io is
1460 * started but we do not wait for any of it to finish.
1461 *
1462 * filemap_flush is used for the block device, so if there is a dirty
1463 * page for a block already in flight, we will not wait and start the
1464 * io over again
1465 */
1466int fat_flush_inodes(struct super_block *sb, struct inode *i1, struct inode *i2)
1467{
1468 int ret = 0;
1469 if (!MSDOS_SB(sb)->options.flush)
1470 return 0;
1471 if (i1)
1472 ret = writeback_inode(i1);
1473 if (!ret && i2)
1474 ret = writeback_inode(i2);
Eric Sesterhenn97e860d2006-10-11 01:21:59 -07001475 if (!ret) {
Chris Masonae78bf92006-09-29 02:00:03 -07001476 struct address_space *mapping = sb->s_bdev->bd_inode->i_mapping;
1477 ret = filemap_flush(mapping);
1478 }
1479 return ret;
1480}
1481EXPORT_SYMBOL_GPL(fat_flush_inodes);
1482
Linus Torvalds1da177e2005-04-16 15:20:36 -07001483static int __init init_fat_fs(void)
1484{
Pekka J Enberg532a39a2005-06-30 02:59:01 -07001485 int err;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001486
Pekka J Enberg532a39a2005-06-30 02:59:01 -07001487 err = fat_cache_init();
1488 if (err)
1489 return err;
1490
1491 err = fat_init_inodecache();
1492 if (err)
1493 goto failed;
1494
1495 return 0;
1496
1497failed:
1498 fat_cache_destroy();
1499 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001500}
1501
1502static void __exit exit_fat_fs(void)
1503{
1504 fat_cache_destroy();
1505 fat_destroy_inodecache();
1506}
1507
1508module_init(init_fat_fs)
1509module_exit(exit_fat_fs)
1510
1511MODULE_LICENSE("GPL");