blob: 2c55e8dce7932cfaa2b8b7b026633267a6c82b0f [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>
Vignesh Babu BMe7d709c2007-05-08 00:24:27 -070028#include <linux/log2.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070029#include <asm/unaligned.h>
30
31#ifndef CONFIG_FAT_DEFAULT_IOCHARSET
32/* if user don't select VFAT, this is undefined. */
33#define CONFIG_FAT_DEFAULT_IOCHARSET ""
34#endif
35
36static int fat_default_codepage = CONFIG_FAT_DEFAULT_CODEPAGE;
37static char fat_default_iocharset[] = CONFIG_FAT_DEFAULT_IOCHARSET;
38
39
40static int fat_add_cluster(struct inode *inode)
41{
42 int err, cluster;
43
44 err = fat_alloc_clusters(inode, &cluster, 1);
45 if (err)
46 return err;
47 /* FIXME: this cluster should be added after data of this
48 * cluster is writed */
49 err = fat_chain_add(inode, cluster, 1);
50 if (err)
51 fat_free_clusters(inode, cluster);
52 return err;
53}
54
OGAWA Hirofumi6a1d9802006-09-27 01:50:45 -070055static inline int __fat_get_block(struct inode *inode, sector_t iblock,
56 unsigned long *max_blocks,
57 struct buffer_head *bh_result, int create)
Linus Torvalds1da177e2005-04-16 15:20:36 -070058{
59 struct super_block *sb = inode->i_sb;
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -080060 struct msdos_sb_info *sbi = MSDOS_SB(sb);
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -080061 unsigned long mapped_blocks;
OGAWA Hirofumi6a1d9802006-09-27 01:50:45 -070062 sector_t phys;
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -080063 int err, offset;
Linus Torvalds1da177e2005-04-16 15:20:36 -070064
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -080065 err = fat_bmap(inode, iblock, &phys, &mapped_blocks);
Linus Torvalds1da177e2005-04-16 15:20:36 -070066 if (err)
67 return err;
68 if (phys) {
69 map_bh(bh_result, sb, phys);
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -080070 *max_blocks = min(mapped_blocks, *max_blocks);
Linus Torvalds1da177e2005-04-16 15:20:36 -070071 return 0;
72 }
73 if (!create)
74 return 0;
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -080075
Linus Torvalds1da177e2005-04-16 15:20:36 -070076 if (iblock != MSDOS_I(inode)->mmu_private >> sb->s_blocksize_bits) {
77 fat_fs_panic(sb, "corrupted file size (i_pos %lld, %lld)",
OGAWA Hirofumi6a1d9802006-09-27 01:50:45 -070078 MSDOS_I(inode)->i_pos, MSDOS_I(inode)->mmu_private);
Linus Torvalds1da177e2005-04-16 15:20:36 -070079 return -EIO;
80 }
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -080081
82 offset = (unsigned long)iblock & (sbi->sec_per_clus - 1);
83 if (!offset) {
84 /* TODO: multiple cluster allocation would be desirable. */
Linus Torvalds1da177e2005-04-16 15:20:36 -070085 err = fat_add_cluster(inode);
86 if (err)
87 return err;
88 }
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -080089 /* available blocks on this cluster */
90 mapped_blocks = sbi->sec_per_clus - offset;
91
92 *max_blocks = min(mapped_blocks, *max_blocks);
93 MSDOS_I(inode)->mmu_private += *max_blocks << sb->s_blocksize_bits;
94
95 err = fat_bmap(inode, iblock, &phys, &mapped_blocks);
Linus Torvalds1da177e2005-04-16 15:20:36 -070096 if (err)
97 return err;
OGAWA Hirofumi6a1d9802006-09-27 01:50:45 -070098
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -080099 BUG_ON(!phys);
100 BUG_ON(*max_blocks != mapped_blocks);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700101 set_buffer_new(bh_result);
102 map_bh(bh_result, sb, phys);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700103
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -0800104 return 0;
105}
106
107static int fat_get_block(struct inode *inode, sector_t iblock,
108 struct buffer_head *bh_result, int create)
109{
OGAWA Hirofumi6a1d9802006-09-27 01:50:45 -0700110 struct super_block *sb = inode->i_sb;
111 unsigned long max_blocks = bh_result->b_size >> inode->i_blkbits;
112 int err;
113
114 err = __fat_get_block(inode, iblock, &max_blocks, bh_result, create);
115 if (err)
116 return err;
117 bh_result->b_size = max_blocks << sb->s_blocksize_bits;
118 return 0;
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -0800119}
120
Linus Torvalds1da177e2005-04-16 15:20:36 -0700121static int fat_writepage(struct page *page, struct writeback_control *wbc)
122{
123 return block_write_full_page(page, fat_get_block, wbc);
124}
125
OGAWA Hirofumia5425d22006-01-08 01:02:10 -0800126static int fat_writepages(struct address_space *mapping,
127 struct writeback_control *wbc)
128{
129 return mpage_writepages(mapping, wbc, fat_get_block);
130}
131
Linus Torvalds1da177e2005-04-16 15:20:36 -0700132static int fat_readpage(struct file *file, struct page *page)
133{
OGAWA Hirofumia5425d22006-01-08 01:02:10 -0800134 return mpage_readpage(page, fat_get_block);
135}
136
137static int fat_readpages(struct file *file, struct address_space *mapping,
138 struct list_head *pages, unsigned nr_pages)
139{
140 return mpage_readpages(mapping, pages, nr_pages, fat_get_block);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700141}
142
143static int fat_prepare_write(struct file *file, struct page *page,
144 unsigned from, unsigned to)
145{
146 return cont_prepare_write(page, from, to, fat_get_block,
147 &MSDOS_I(page->mapping->host)->mmu_private);
148}
149
OGAWA Hirofumief402262005-09-16 19:28:13 -0700150static int fat_commit_write(struct file *file, struct page *page,
151 unsigned from, unsigned to)
152{
153 struct inode *inode = page->mapping->host;
154 int err = generic_commit_write(file, page, from, to);
155 if (!err && !(MSDOS_I(inode)->i_attrs & ATTR_ARCH)) {
156 inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC;
157 MSDOS_I(inode)->i_attrs |= ATTR_ARCH;
158 mark_inode_dirty(inode);
159 }
160 return err;
161}
162
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -0800163static ssize_t fat_direct_IO(int rw, struct kiocb *iocb,
164 const struct iovec *iov,
165 loff_t offset, unsigned long nr_segs)
166{
167 struct file *file = iocb->ki_filp;
168 struct inode *inode = file->f_mapping->host;
169
170 if (rw == WRITE) {
171 /*
172 * FIXME: blockdev_direct_IO() doesn't use ->prepare_write(),
173 * so we need to update the ->mmu_private to block boundary.
174 *
175 * But we must fill the remaining area or hole by nul for
176 * updating ->mmu_private.
OGAWA Hirofumi94412a92007-02-20 13:57:55 -0800177 *
178 * Return 0, and fallback to normal buffered write.
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -0800179 */
180 loff_t size = offset + iov_length(iov, nr_segs);
181 if (MSDOS_I(inode)->mmu_private < size)
OGAWA Hirofumi94412a92007-02-20 13:57:55 -0800182 return 0;
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -0800183 }
184
185 /*
186 * FAT need to use the DIO_LOCKING for avoiding the race
187 * condition of fat_get_block() and ->truncate().
188 */
189 return blockdev_direct_IO(rw, iocb, inode, inode->i_sb->s_bdev, iov,
OGAWA Hirofumi6a1d9802006-09-27 01:50:45 -0700190 offset, nr_segs, fat_get_block, NULL);
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -0800191}
192
Linus Torvalds1da177e2005-04-16 15:20:36 -0700193static sector_t _fat_bmap(struct address_space *mapping, sector_t block)
194{
195 return generic_block_bmap(mapping, block, fat_get_block);
196}
197
Christoph Hellwigf5e54d62006-06-28 04:26:44 -0700198static const struct address_space_operations fat_aops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700199 .readpage = fat_readpage,
OGAWA Hirofumia5425d22006-01-08 01:02:10 -0800200 .readpages = fat_readpages,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700201 .writepage = fat_writepage,
OGAWA Hirofumia5425d22006-01-08 01:02:10 -0800202 .writepages = fat_writepages,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700203 .sync_page = block_sync_page,
204 .prepare_write = fat_prepare_write,
OGAWA Hirofumief402262005-09-16 19:28:13 -0700205 .commit_write = fat_commit_write,
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -0800206 .direct_IO = fat_direct_IO,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700207 .bmap = _fat_bmap
208};
209
210/*
211 * New FAT inode stuff. We do the following:
212 * a) i_ino is constant and has nothing with on-disk location.
213 * b) FAT manages its own cache of directory entries.
214 * c) *This* cache is indexed by on-disk location.
215 * d) inode has an associated directory entry, all right, but
216 * it may be unhashed.
217 * e) currently entries are stored within struct inode. That should
218 * change.
219 * f) we deal with races in the following way:
220 * 1. readdir() and lookup() do FAT-dir-cache lookup.
221 * 2. rename() unhashes the F-d-c entry and rehashes it in
222 * a new place.
223 * 3. unlink() and rmdir() unhash F-d-c entry.
224 * 4. fat_write_inode() checks whether the thing is unhashed.
225 * If it is we silently return. If it isn't we do bread(),
226 * check if the location is still valid and retry if it
227 * isn't. Otherwise we do changes.
228 * 5. Spinlock is used to protect hash/unhash/location check/lookup
229 * 6. fat_clear_inode() unhashes the F-d-c entry.
230 * 7. lookup() and readdir() do igrab() if they find a F-d-c entry
231 * and consider negative result as cache miss.
232 */
233
234static void fat_hash_init(struct super_block *sb)
235{
236 struct msdos_sb_info *sbi = MSDOS_SB(sb);
237 int i;
238
239 spin_lock_init(&sbi->inode_hash_lock);
240 for (i = 0; i < FAT_HASH_SIZE; i++)
241 INIT_HLIST_HEAD(&sbi->inode_hashtable[i]);
242}
243
244static inline unsigned long fat_hash(struct super_block *sb, loff_t i_pos)
245{
246 unsigned long tmp = (unsigned long)i_pos | (unsigned long) sb;
247 tmp = tmp + (tmp >> FAT_HASH_BITS) + (tmp >> FAT_HASH_BITS * 2);
248 return tmp & FAT_HASH_MASK;
249}
250
251void fat_attach(struct inode *inode, loff_t i_pos)
252{
253 struct super_block *sb = inode->i_sb;
254 struct msdos_sb_info *sbi = MSDOS_SB(sb);
255
256 spin_lock(&sbi->inode_hash_lock);
257 MSDOS_I(inode)->i_pos = i_pos;
258 hlist_add_head(&MSDOS_I(inode)->i_fat_hash,
259 sbi->inode_hashtable + fat_hash(sb, i_pos));
260 spin_unlock(&sbi->inode_hash_lock);
261}
262
OGAWA Hirofumi7c709d02006-01-08 01:02:10 -0800263EXPORT_SYMBOL_GPL(fat_attach);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700264
265void fat_detach(struct inode *inode)
266{
267 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
268 spin_lock(&sbi->inode_hash_lock);
269 MSDOS_I(inode)->i_pos = 0;
270 hlist_del_init(&MSDOS_I(inode)->i_fat_hash);
271 spin_unlock(&sbi->inode_hash_lock);
272}
273
OGAWA Hirofumi7c709d02006-01-08 01:02:10 -0800274EXPORT_SYMBOL_GPL(fat_detach);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700275
276struct inode *fat_iget(struct super_block *sb, loff_t i_pos)
277{
278 struct msdos_sb_info *sbi = MSDOS_SB(sb);
279 struct hlist_head *head = sbi->inode_hashtable + fat_hash(sb, i_pos);
280 struct hlist_node *_p;
281 struct msdos_inode_info *i;
282 struct inode *inode = NULL;
283
284 spin_lock(&sbi->inode_hash_lock);
285 hlist_for_each_entry(i, _p, head, i_fat_hash) {
286 BUG_ON(i->vfs_inode.i_sb != sb);
287 if (i->i_pos != i_pos)
288 continue;
289 inode = igrab(&i->vfs_inode);
290 if (inode)
291 break;
292 }
293 spin_unlock(&sbi->inode_hash_lock);
294 return inode;
295}
296
297static int is_exec(unsigned char *extension)
298{
299 unsigned char *exe_extensions = "EXECOMBAT", *walk;
300
301 for (walk = exe_extensions; *walk; walk += 3)
302 if (!strncmp(extension, walk, 3))
303 return 1;
304 return 0;
305}
306
307static int fat_calc_dir_size(struct inode *inode)
308{
309 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
310 int ret, fclus, dclus;
311
312 inode->i_size = 0;
313 if (MSDOS_I(inode)->i_start == 0)
314 return 0;
315
316 ret = fat_get_cluster(inode, FAT_ENT_EOF, &fclus, &dclus);
317 if (ret < 0)
318 return ret;
319 inode->i_size = (fclus + 1) << sbi->cluster_bits;
320
321 return 0;
322}
323
324/* doesn't deal with root inode */
325static int fat_fill_inode(struct inode *inode, struct msdos_dir_entry *de)
326{
327 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
328 int error;
329
330 MSDOS_I(inode)->i_pos = 0;
331 inode->i_uid = sbi->options.fs_uid;
332 inode->i_gid = sbi->options.fs_gid;
333 inode->i_version++;
334 inode->i_generation = get_seconds();
335
336 if ((de->attr & ATTR_DIR) && !IS_FREE(de->name)) {
337 inode->i_generation &= ~1;
338 inode->i_mode = MSDOS_MKMODE(de->attr,
339 S_IRWXUGO & ~sbi->options.fs_dmask) | S_IFDIR;
340 inode->i_op = sbi->dir_ops;
341 inode->i_fop = &fat_dir_operations;
342
343 MSDOS_I(inode)->i_start = le16_to_cpu(de->start);
344 if (sbi->fat_bits == 32)
345 MSDOS_I(inode)->i_start |= (le16_to_cpu(de->starthi) << 16);
346
347 MSDOS_I(inode)->i_logstart = MSDOS_I(inode)->i_start;
348 error = fat_calc_dir_size(inode);
349 if (error < 0)
350 return error;
351 MSDOS_I(inode)->mmu_private = inode->i_size;
352
353 inode->i_nlink = fat_subdirs(inode);
354 } else { /* not a directory */
355 inode->i_generation |= 1;
356 inode->i_mode = MSDOS_MKMODE(de->attr,
357 ((sbi->options.showexec &&
358 !is_exec(de->ext))
359 ? S_IRUGO|S_IWUGO : S_IRWXUGO)
360 & ~sbi->options.fs_fmask) | S_IFREG;
361 MSDOS_I(inode)->i_start = le16_to_cpu(de->start);
362 if (sbi->fat_bits == 32)
363 MSDOS_I(inode)->i_start |= (le16_to_cpu(de->starthi) << 16);
364
365 MSDOS_I(inode)->i_logstart = MSDOS_I(inode)->i_start;
366 inode->i_size = le32_to_cpu(de->size);
367 inode->i_op = &fat_file_inode_operations;
368 inode->i_fop = &fat_file_operations;
369 inode->i_mapping->a_ops = &fat_aops;
370 MSDOS_I(inode)->mmu_private = inode->i_size;
371 }
372 if (de->attr & ATTR_SYS) {
373 if (sbi->options.sys_immutable)
374 inode->i_flags |= S_IMMUTABLE;
375 }
376 MSDOS_I(inode)->i_attrs = de->attr & ATTR_UNUSED;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700377 inode->i_blocks = ((inode->i_size + (sbi->cluster_size - 1))
378 & ~((loff_t)sbi->cluster_size - 1)) >> 9;
Stephane Kardas62a36c42005-09-21 09:55:45 -0700379 inode->i_mtime.tv_sec =
Linus Torvalds1da177e2005-04-16 15:20:36 -0700380 date_dos2unix(le16_to_cpu(de->time), le16_to_cpu(de->date));
Stephane Kardas62a36c42005-09-21 09:55:45 -0700381 inode->i_mtime.tv_nsec = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700382 if (sbi->options.isvfat) {
383 int secs = de->ctime_cs / 100;
384 int csecs = de->ctime_cs % 100;
385 inode->i_ctime.tv_sec =
386 date_dos2unix(le16_to_cpu(de->ctime),
387 le16_to_cpu(de->cdate)) + secs;
388 inode->i_ctime.tv_nsec = csecs * 10000000;
Stephane Kardas62a36c42005-09-21 09:55:45 -0700389 inode->i_atime.tv_sec =
Al Viro31b1f852005-12-24 14:31:04 -0500390 date_dos2unix(0, le16_to_cpu(de->adate));
Stephane Kardas62a36c42005-09-21 09:55:45 -0700391 inode->i_atime.tv_nsec = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700392 } else
Stephane Kardas62a36c42005-09-21 09:55:45 -0700393 inode->i_ctime = inode->i_atime = inode->i_mtime;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700394
395 return 0;
396}
397
398struct inode *fat_build_inode(struct super_block *sb,
399 struct msdos_dir_entry *de, loff_t i_pos)
400{
401 struct inode *inode;
402 int err;
403
404 inode = fat_iget(sb, i_pos);
405 if (inode)
406 goto out;
407 inode = new_inode(sb);
408 if (!inode) {
409 inode = ERR_PTR(-ENOMEM);
410 goto out;
411 }
412 inode->i_ino = iunique(sb, MSDOS_ROOT_INO);
413 inode->i_version = 1;
414 err = fat_fill_inode(inode, de);
415 if (err) {
416 iput(inode);
417 inode = ERR_PTR(err);
418 goto out;
419 }
420 fat_attach(inode, i_pos);
421 insert_inode_hash(inode);
422out:
423 return inode;
424}
425
OGAWA Hirofumi7c709d02006-01-08 01:02:10 -0800426EXPORT_SYMBOL_GPL(fat_build_inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700427
428static void fat_delete_inode(struct inode *inode)
429{
Mark Fashehfef26652005-09-09 13:01:31 -0700430 truncate_inode_pages(&inode->i_data, 0);
431
Linus Torvalds1da177e2005-04-16 15:20:36 -0700432 if (!is_bad_inode(inode)) {
433 inode->i_size = 0;
434 fat_truncate(inode);
435 }
436 clear_inode(inode);
437}
438
439static void fat_clear_inode(struct inode *inode)
440{
441 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
442
443 if (is_bad_inode(inode))
444 return;
445 lock_kernel();
446 spin_lock(&sbi->inode_hash_lock);
447 fat_cache_inval_inode(inode);
448 hlist_del_init(&MSDOS_I(inode)->i_fat_hash);
449 spin_unlock(&sbi->inode_hash_lock);
450 unlock_kernel();
451}
452
OGAWA Hirofumia6bf6b22006-01-08 01:02:08 -0800453static void fat_write_super(struct super_block *sb)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700454{
OGAWA Hirofumia6bf6b22006-01-08 01:02:08 -0800455 sb->s_dirt = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700456
457 if (!(sb->s_flags & MS_RDONLY))
458 fat_clusters_flush(sb);
OGAWA Hirofumia6bf6b22006-01-08 01:02:08 -0800459}
460
461static void fat_put_super(struct super_block *sb)
462{
463 struct msdos_sb_info *sbi = MSDOS_SB(sb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700464
465 if (sbi->nls_disk) {
466 unload_nls(sbi->nls_disk);
467 sbi->nls_disk = NULL;
468 sbi->options.codepage = fat_default_codepage;
469 }
470 if (sbi->nls_io) {
471 unload_nls(sbi->nls_io);
472 sbi->nls_io = NULL;
473 }
474 if (sbi->options.iocharset != fat_default_iocharset) {
475 kfree(sbi->options.iocharset);
476 sbi->options.iocharset = fat_default_iocharset;
477 }
478
479 sb->s_fs_info = NULL;
480 kfree(sbi);
481}
482
Christoph Lametere18b8902006-12-06 20:33:20 -0800483static struct kmem_cache *fat_inode_cachep;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700484
485static struct inode *fat_alloc_inode(struct super_block *sb)
486{
487 struct msdos_inode_info *ei;
Christoph Lametere94b1762006-12-06 20:33:17 -0800488 ei = kmem_cache_alloc(fat_inode_cachep, GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700489 if (!ei)
490 return NULL;
491 return &ei->vfs_inode;
492}
493
494static void fat_destroy_inode(struct inode *inode)
495{
496 kmem_cache_free(fat_inode_cachep, MSDOS_I(inode));
497}
498
Christoph Lametere18b8902006-12-06 20:33:20 -0800499static void init_once(void * foo, struct kmem_cache * cachep, unsigned long flags)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700500{
501 struct msdos_inode_info *ei = (struct msdos_inode_info *)foo;
502
Christoph Lameter50953fe2007-05-06 14:50:16 -0700503 if (flags & SLAB_CTOR_CONSTRUCTOR) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700504 spin_lock_init(&ei->cache_lru_lock);
505 ei->nr_caches = 0;
506 ei->cache_valid_id = FAT_CACHE_VALID + 1;
507 INIT_LIST_HEAD(&ei->cache_lru);
508 INIT_HLIST_NODE(&ei->i_fat_hash);
509 inode_init_once(&ei->vfs_inode);
510 }
511}
512
513static int __init fat_init_inodecache(void)
514{
515 fat_inode_cachep = kmem_cache_create("fat_inode_cache",
516 sizeof(struct msdos_inode_info),
Paul Jacksonfffb60f2006-03-24 03:16:06 -0800517 0, (SLAB_RECLAIM_ACCOUNT|
518 SLAB_MEM_SPREAD),
Linus Torvalds1da177e2005-04-16 15:20:36 -0700519 init_once, NULL);
520 if (fat_inode_cachep == NULL)
521 return -ENOMEM;
522 return 0;
523}
524
525static void __exit fat_destroy_inodecache(void)
526{
Alexey Dobriyan1a1d92c2006-09-27 01:49:40 -0700527 kmem_cache_destroy(fat_inode_cachep);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700528}
529
530static int fat_remount(struct super_block *sb, int *flags, char *data)
531{
532 struct msdos_sb_info *sbi = MSDOS_SB(sb);
533 *flags |= MS_NODIRATIME | (sbi->options.isvfat ? 0 : MS_NOATIME);
534 return 0;
535}
536
David Howells726c3342006-06-23 02:02:58 -0700537static int fat_statfs(struct dentry *dentry, struct kstatfs *buf)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700538{
David Howells726c3342006-06-23 02:02:58 -0700539 struct msdos_sb_info *sbi = MSDOS_SB(dentry->d_sb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700540
541 /* If the count of free cluster is still unknown, counts it here. */
542 if (sbi->free_clusters == -1) {
David Howells726c3342006-06-23 02:02:58 -0700543 int err = fat_count_free_clusters(dentry->d_sb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700544 if (err)
545 return err;
546 }
547
David Howells726c3342006-06-23 02:02:58 -0700548 buf->f_type = dentry->d_sb->s_magic;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700549 buf->f_bsize = sbi->cluster_size;
550 buf->f_blocks = sbi->max_cluster - FAT_START_ENT;
551 buf->f_bfree = sbi->free_clusters;
552 buf->f_bavail = sbi->free_clusters;
553 buf->f_namelen = sbi->options.isvfat ? 260 : 12;
554
555 return 0;
556}
557
558static int fat_write_inode(struct inode *inode, int wait)
559{
560 struct super_block *sb = inode->i_sb;
561 struct msdos_sb_info *sbi = MSDOS_SB(sb);
562 struct buffer_head *bh;
563 struct msdos_dir_entry *raw_entry;
564 loff_t i_pos;
565 int err = 0;
566
567retry:
568 i_pos = MSDOS_I(inode)->i_pos;
569 if (inode->i_ino == MSDOS_ROOT_INO || !i_pos)
570 return 0;
571
572 lock_kernel();
573 bh = sb_bread(sb, i_pos >> sbi->dir_per_block_bits);
574 if (!bh) {
575 printk(KERN_ERR "FAT: unable to read inode block "
576 "for updating (i_pos %lld)\n", i_pos);
577 err = -EIO;
578 goto out;
579 }
580 spin_lock(&sbi->inode_hash_lock);
581 if (i_pos != MSDOS_I(inode)->i_pos) {
582 spin_unlock(&sbi->inode_hash_lock);
583 brelse(bh);
584 unlock_kernel();
585 goto retry;
586 }
587
588 raw_entry = &((struct msdos_dir_entry *) (bh->b_data))
589 [i_pos & (sbi->dir_per_block - 1)];
590 if (S_ISDIR(inode->i_mode))
591 raw_entry->size = 0;
592 else
593 raw_entry->size = cpu_to_le32(inode->i_size);
594 raw_entry->attr = fat_attr(inode);
595 raw_entry->start = cpu_to_le16(MSDOS_I(inode)->i_logstart);
596 raw_entry->starthi = cpu_to_le16(MSDOS_I(inode)->i_logstart >> 16);
597 fat_date_unix2dos(inode->i_mtime.tv_sec, &raw_entry->time, &raw_entry->date);
598 if (sbi->options.isvfat) {
Stephane Kardas62a36c42005-09-21 09:55:45 -0700599 __le16 atime;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700600 fat_date_unix2dos(inode->i_ctime.tv_sec,&raw_entry->ctime,&raw_entry->cdate);
Stephane Kardas62a36c42005-09-21 09:55:45 -0700601 fat_date_unix2dos(inode->i_atime.tv_sec,&atime,&raw_entry->adate);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700602 raw_entry->ctime_cs = (inode->i_ctime.tv_sec & 1) * 100 +
603 inode->i_ctime.tv_nsec / 10000000;
604 }
605 spin_unlock(&sbi->inode_hash_lock);
606 mark_buffer_dirty(bh);
607 if (wait)
608 err = sync_dirty_buffer(bh);
609 brelse(bh);
610out:
611 unlock_kernel();
612 return err;
613}
614
615int fat_sync_inode(struct inode *inode)
616{
617 return fat_write_inode(inode, 1);
618}
619
OGAWA Hirofumi7c709d02006-01-08 01:02:10 -0800620EXPORT_SYMBOL_GPL(fat_sync_inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700621
622static int fat_show_options(struct seq_file *m, struct vfsmount *mnt);
Josef 'Jeff' Sipekee9b6d62007-02-12 00:55:41 -0800623static const struct super_operations fat_sops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700624 .alloc_inode = fat_alloc_inode,
625 .destroy_inode = fat_destroy_inode,
626 .write_inode = fat_write_inode,
627 .delete_inode = fat_delete_inode,
628 .put_super = fat_put_super,
OGAWA Hirofumia6bf6b22006-01-08 01:02:08 -0800629 .write_super = fat_write_super,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700630 .statfs = fat_statfs,
631 .clear_inode = fat_clear_inode,
632 .remount_fs = fat_remount,
633
634 .read_inode = make_bad_inode,
635
636 .show_options = fat_show_options,
637};
638
639/*
640 * a FAT file handle with fhtype 3 is
641 * 0/ i_ino - for fast, reliable lookup if still in the cache
642 * 1/ i_generation - to see if i_ino is still valid
643 * bit 0 == 0 iff directory
644 * 2/ i_pos(8-39) - if ino has changed, but still in cache
645 * 3/ i_pos(4-7)|i_logstart - to semi-verify inode found at i_pos
646 * 4/ i_pos(0-3)|parent->i_logstart - maybe used to hunt for the file on disc
647 *
648 * Hack for NFSv2: Maximum FAT entry number is 28bits and maximum
649 * i_pos is 40bits (blocknr(32) + dir offset(8)), so two 4bits
650 * of i_logstart is used to store the directory entry offset.
651 */
652
653static struct dentry *
654fat_decode_fh(struct super_block *sb, __u32 *fh, int len, int fhtype,
655 int (*acceptable)(void *context, struct dentry *de),
656 void *context)
657{
658 if (fhtype != 3)
659 return ERR_PTR(-ESTALE);
660 if (len < 5)
661 return ERR_PTR(-ESTALE);
662
663 return sb->s_export_op->find_exported_dentry(sb, fh, NULL, acceptable, context);
664}
665
666static struct dentry *fat_get_dentry(struct super_block *sb, void *inump)
667{
668 struct inode *inode = NULL;
669 struct dentry *result;
670 __u32 *fh = inump;
671
672 inode = iget(sb, fh[0]);
673 if (!inode || is_bad_inode(inode) || inode->i_generation != fh[1]) {
674 if (inode)
675 iput(inode);
676 inode = NULL;
677 }
678 if (!inode) {
679 loff_t i_pos;
680 int i_logstart = fh[3] & 0x0fffffff;
681
682 i_pos = (loff_t)fh[2] << 8;
683 i_pos |= ((fh[3] >> 24) & 0xf0) | (fh[4] >> 28);
684
685 /* try 2 - see if i_pos is in F-d-c
686 * require i_logstart to be the same
687 * Will fail if you truncate and then re-write
688 */
689
690 inode = fat_iget(sb, i_pos);
691 if (inode && MSDOS_I(inode)->i_logstart != i_logstart) {
692 iput(inode);
693 inode = NULL;
694 }
695 }
696 if (!inode) {
697 /* For now, do nothing
698 * What we could do is:
699 * follow the file starting at fh[4], and record
700 * the ".." entry, and the name of the fh[2] entry.
701 * The follow the ".." file finding the next step up.
702 * This way we build a path to the root of
703 * the tree. If this works, we lookup the path and so
704 * get this inode into the cache.
705 * Finally try the fat_iget lookup again
706 * If that fails, then weare totally out of luck
707 * But all that is for another day
708 */
709 }
710 if (!inode)
711 return ERR_PTR(-ESTALE);
712
713
714 /* now to find a dentry.
715 * If possible, get a well-connected one
716 */
717 result = d_alloc_anon(inode);
718 if (result == NULL) {
719 iput(inode);
720 return ERR_PTR(-ENOMEM);
721 }
722 result->d_op = sb->s_root->d_op;
723 return result;
724}
725
726static int
727fat_encode_fh(struct dentry *de, __u32 *fh, int *lenp, int connectable)
728{
729 int len = *lenp;
730 struct inode *inode = de->d_inode;
731 u32 ipos_h, ipos_m, ipos_l;
732
733 if (len < 5)
734 return 255; /* no room */
735
736 ipos_h = MSDOS_I(inode)->i_pos >> 8;
737 ipos_m = (MSDOS_I(inode)->i_pos & 0xf0) << 24;
738 ipos_l = (MSDOS_I(inode)->i_pos & 0x0f) << 28;
739 *lenp = 5;
740 fh[0] = inode->i_ino;
741 fh[1] = inode->i_generation;
742 fh[2] = ipos_h;
743 fh[3] = ipos_m | MSDOS_I(inode)->i_logstart;
744 spin_lock(&de->d_lock);
745 fh[4] = ipos_l | MSDOS_I(de->d_parent->d_inode)->i_logstart;
746 spin_unlock(&de->d_lock);
747 return 3;
748}
749
750static struct dentry *fat_get_parent(struct dentry *child)
751{
752 struct buffer_head *bh;
753 struct msdos_dir_entry *de;
754 loff_t i_pos;
755 struct dentry *parent;
756 struct inode *inode;
757 int err;
758
759 lock_kernel();
760
761 err = fat_get_dotdot_entry(child->d_inode, &bh, &de, &i_pos);
762 if (err) {
763 parent = ERR_PTR(err);
764 goto out;
765 }
766 inode = fat_build_inode(child->d_sb, de, i_pos);
767 brelse(bh);
768 if (IS_ERR(inode)) {
769 parent = ERR_PTR(PTR_ERR(inode));
770 goto out;
771 }
772 parent = d_alloc_anon(inode);
773 if (!parent) {
774 iput(inode);
775 parent = ERR_PTR(-ENOMEM);
776 }
777out:
778 unlock_kernel();
779
780 return parent;
781}
782
783static struct export_operations fat_export_ops = {
784 .decode_fh = fat_decode_fh,
785 .encode_fh = fat_encode_fh,
786 .get_dentry = fat_get_dentry,
787 .get_parent = fat_get_parent,
788};
789
790static int fat_show_options(struct seq_file *m, struct vfsmount *mnt)
791{
792 struct msdos_sb_info *sbi = MSDOS_SB(mnt->mnt_sb);
793 struct fat_mount_options *opts = &sbi->options;
794 int isvfat = opts->isvfat;
795
796 if (opts->fs_uid != 0)
797 seq_printf(m, ",uid=%u", opts->fs_uid);
798 if (opts->fs_gid != 0)
799 seq_printf(m, ",gid=%u", opts->fs_gid);
800 seq_printf(m, ",fmask=%04o", opts->fs_fmask);
801 seq_printf(m, ",dmask=%04o", opts->fs_dmask);
802 if (sbi->nls_disk)
803 seq_printf(m, ",codepage=%s", sbi->nls_disk->charset);
804 if (isvfat) {
805 if (sbi->nls_io)
806 seq_printf(m, ",iocharset=%s", sbi->nls_io->charset);
807
808 switch (opts->shortname) {
809 case VFAT_SFN_DISPLAY_WIN95 | VFAT_SFN_CREATE_WIN95:
810 seq_puts(m, ",shortname=win95");
811 break;
812 case VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WINNT:
813 seq_puts(m, ",shortname=winnt");
814 break;
815 case VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WIN95:
816 seq_puts(m, ",shortname=mixed");
817 break;
818 case VFAT_SFN_DISPLAY_LOWER | VFAT_SFN_CREATE_WIN95:
819 /* seq_puts(m, ",shortname=lower"); */
820 break;
821 default:
822 seq_puts(m, ",shortname=unknown");
823 break;
824 }
825 }
826 if (opts->name_check != 'n')
827 seq_printf(m, ",check=%c", opts->name_check);
OGAWA Hirofumi28ec0392007-05-08 00:31:01 -0700828 if (opts->usefree)
829 seq_puts(m, ",usefree");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700830 if (opts->quiet)
831 seq_puts(m, ",quiet");
832 if (opts->showexec)
833 seq_puts(m, ",showexec");
834 if (opts->sys_immutable)
835 seq_puts(m, ",sys_immutable");
836 if (!isvfat) {
837 if (opts->dotsOK)
838 seq_puts(m, ",dotsOK=yes");
839 if (opts->nocase)
840 seq_puts(m, ",nocase");
841 } else {
842 if (opts->utf8)
843 seq_puts(m, ",utf8");
844 if (opts->unicode_xlate)
845 seq_puts(m, ",uni_xlate");
846 if (!opts->numtail)
847 seq_puts(m, ",nonumtail");
848 }
849
850 return 0;
851}
852
853enum {
854 Opt_check_n, Opt_check_r, Opt_check_s, Opt_uid, Opt_gid,
OGAWA Hirofumi28ec0392007-05-08 00:31:01 -0700855 Opt_umask, Opt_dmask, Opt_fmask, Opt_codepage, Opt_usefree, Opt_nocase,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700856 Opt_quiet, Opt_showexec, Opt_debug, Opt_immutable,
857 Opt_dots, Opt_nodots,
858 Opt_charset, Opt_shortname_lower, Opt_shortname_win95,
859 Opt_shortname_winnt, Opt_shortname_mixed, Opt_utf8_no, Opt_utf8_yes,
860 Opt_uni_xl_no, Opt_uni_xl_yes, Opt_nonumtail_no, Opt_nonumtail_yes,
Chris Masonae78bf92006-09-29 02:00:03 -0700861 Opt_obsolate, Opt_flush, Opt_err,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700862};
863
864static match_table_t fat_tokens = {
865 {Opt_check_r, "check=relaxed"},
866 {Opt_check_s, "check=strict"},
867 {Opt_check_n, "check=normal"},
868 {Opt_check_r, "check=r"},
869 {Opt_check_s, "check=s"},
870 {Opt_check_n, "check=n"},
871 {Opt_uid, "uid=%u"},
872 {Opt_gid, "gid=%u"},
873 {Opt_umask, "umask=%o"},
874 {Opt_dmask, "dmask=%o"},
875 {Opt_fmask, "fmask=%o"},
876 {Opt_codepage, "codepage=%u"},
OGAWA Hirofumi28ec0392007-05-08 00:31:01 -0700877 {Opt_usefree, "usefree"},
Linus Torvalds1da177e2005-04-16 15:20:36 -0700878 {Opt_nocase, "nocase"},
879 {Opt_quiet, "quiet"},
880 {Opt_showexec, "showexec"},
881 {Opt_debug, "debug"},
882 {Opt_immutable, "sys_immutable"},
883 {Opt_obsolate, "conv=binary"},
884 {Opt_obsolate, "conv=text"},
885 {Opt_obsolate, "conv=auto"},
886 {Opt_obsolate, "conv=b"},
887 {Opt_obsolate, "conv=t"},
888 {Opt_obsolate, "conv=a"},
889 {Opt_obsolate, "fat=%u"},
890 {Opt_obsolate, "blocksize=%u"},
891 {Opt_obsolate, "cvf_format=%20s"},
892 {Opt_obsolate, "cvf_options=%100s"},
893 {Opt_obsolate, "posix"},
Chris Masonae78bf92006-09-29 02:00:03 -0700894 {Opt_flush, "flush"},
895 {Opt_err, NULL},
Linus Torvalds1da177e2005-04-16 15:20:36 -0700896};
897static match_table_t msdos_tokens = {
898 {Opt_nodots, "nodots"},
899 {Opt_nodots, "dotsOK=no"},
900 {Opt_dots, "dots"},
901 {Opt_dots, "dotsOK=yes"},
902 {Opt_err, NULL}
903};
904static match_table_t vfat_tokens = {
905 {Opt_charset, "iocharset=%s"},
906 {Opt_shortname_lower, "shortname=lower"},
907 {Opt_shortname_win95, "shortname=win95"},
908 {Opt_shortname_winnt, "shortname=winnt"},
909 {Opt_shortname_mixed, "shortname=mixed"},
910 {Opt_utf8_no, "utf8=0"}, /* 0 or no or false */
911 {Opt_utf8_no, "utf8=no"},
912 {Opt_utf8_no, "utf8=false"},
913 {Opt_utf8_yes, "utf8=1"}, /* empty or 1 or yes or true */
914 {Opt_utf8_yes, "utf8=yes"},
915 {Opt_utf8_yes, "utf8=true"},
916 {Opt_utf8_yes, "utf8"},
917 {Opt_uni_xl_no, "uni_xlate=0"}, /* 0 or no or false */
918 {Opt_uni_xl_no, "uni_xlate=no"},
919 {Opt_uni_xl_no, "uni_xlate=false"},
920 {Opt_uni_xl_yes, "uni_xlate=1"}, /* empty or 1 or yes or true */
921 {Opt_uni_xl_yes, "uni_xlate=yes"},
922 {Opt_uni_xl_yes, "uni_xlate=true"},
923 {Opt_uni_xl_yes, "uni_xlate"},
924 {Opt_nonumtail_no, "nonumtail=0"}, /* 0 or no or false */
925 {Opt_nonumtail_no, "nonumtail=no"},
926 {Opt_nonumtail_no, "nonumtail=false"},
927 {Opt_nonumtail_yes, "nonumtail=1"}, /* empty or 1 or yes or true */
928 {Opt_nonumtail_yes, "nonumtail=yes"},
929 {Opt_nonumtail_yes, "nonumtail=true"},
930 {Opt_nonumtail_yes, "nonumtail"},
931 {Opt_err, NULL}
932};
933
Christoph Hellwig41a34a42005-11-08 21:34:57 -0800934static int parse_options(char *options, int is_vfat, int silent, int *debug,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700935 struct fat_mount_options *opts)
936{
937 char *p;
938 substring_t args[MAX_OPT_ARGS];
939 int option;
940 char *iocharset;
941
942 opts->isvfat = is_vfat;
943
944 opts->fs_uid = current->uid;
945 opts->fs_gid = current->gid;
946 opts->fs_fmask = opts->fs_dmask = current->fs->umask;
947 opts->codepage = fat_default_codepage;
948 opts->iocharset = fat_default_iocharset;
949 if (is_vfat)
950 opts->shortname = VFAT_SFN_DISPLAY_LOWER|VFAT_SFN_CREATE_WIN95;
951 else
952 opts->shortname = 0;
953 opts->name_check = 'n';
954 opts->quiet = opts->showexec = opts->sys_immutable = opts->dotsOK = 0;
955 opts->utf8 = opts->unicode_xlate = 0;
956 opts->numtail = 1;
OGAWA Hirofumi28ec0392007-05-08 00:31:01 -0700957 opts->usefree = opts->nocase = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700958 *debug = 0;
959
960 if (!options)
961 return 0;
962
963 while ((p = strsep(&options, ",")) != NULL) {
964 int token;
965 if (!*p)
966 continue;
967
968 token = match_token(p, fat_tokens, args);
969 if (token == Opt_err) {
970 if (is_vfat)
971 token = match_token(p, vfat_tokens, args);
972 else
973 token = match_token(p, msdos_tokens, args);
974 }
975 switch (token) {
976 case Opt_check_s:
977 opts->name_check = 's';
978 break;
979 case Opt_check_r:
980 opts->name_check = 'r';
981 break;
982 case Opt_check_n:
983 opts->name_check = 'n';
984 break;
OGAWA Hirofumi28ec0392007-05-08 00:31:01 -0700985 case Opt_usefree:
986 opts->usefree = 1;
987 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700988 case Opt_nocase:
989 if (!is_vfat)
990 opts->nocase = 1;
991 else {
992 /* for backward compatibility */
993 opts->shortname = VFAT_SFN_DISPLAY_WIN95
994 | VFAT_SFN_CREATE_WIN95;
995 }
996 break;
997 case Opt_quiet:
998 opts->quiet = 1;
999 break;
1000 case Opt_showexec:
1001 opts->showexec = 1;
1002 break;
1003 case Opt_debug:
1004 *debug = 1;
1005 break;
1006 case Opt_immutable:
1007 opts->sys_immutable = 1;
1008 break;
1009 case Opt_uid:
1010 if (match_int(&args[0], &option))
1011 return 0;
1012 opts->fs_uid = option;
1013 break;
1014 case Opt_gid:
1015 if (match_int(&args[0], &option))
1016 return 0;
1017 opts->fs_gid = option;
1018 break;
1019 case Opt_umask:
1020 if (match_octal(&args[0], &option))
1021 return 0;
1022 opts->fs_fmask = opts->fs_dmask = option;
1023 break;
1024 case Opt_dmask:
1025 if (match_octal(&args[0], &option))
1026 return 0;
1027 opts->fs_dmask = option;
1028 break;
1029 case Opt_fmask:
1030 if (match_octal(&args[0], &option))
1031 return 0;
1032 opts->fs_fmask = option;
1033 break;
1034 case Opt_codepage:
1035 if (match_int(&args[0], &option))
1036 return 0;
1037 opts->codepage = option;
1038 break;
Chris Masonae78bf92006-09-29 02:00:03 -07001039 case Opt_flush:
1040 opts->flush = 1;
1041 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001042
1043 /* msdos specific */
1044 case Opt_dots:
1045 opts->dotsOK = 1;
1046 break;
1047 case Opt_nodots:
1048 opts->dotsOK = 0;
1049 break;
1050
1051 /* vfat specific */
1052 case Opt_charset:
1053 if (opts->iocharset != fat_default_iocharset)
1054 kfree(opts->iocharset);
1055 iocharset = match_strdup(&args[0]);
1056 if (!iocharset)
1057 return -ENOMEM;
1058 opts->iocharset = iocharset;
1059 break;
1060 case Opt_shortname_lower:
1061 opts->shortname = VFAT_SFN_DISPLAY_LOWER
1062 | VFAT_SFN_CREATE_WIN95;
1063 break;
1064 case Opt_shortname_win95:
1065 opts->shortname = VFAT_SFN_DISPLAY_WIN95
1066 | VFAT_SFN_CREATE_WIN95;
1067 break;
1068 case Opt_shortname_winnt:
1069 opts->shortname = VFAT_SFN_DISPLAY_WINNT
1070 | VFAT_SFN_CREATE_WINNT;
1071 break;
1072 case Opt_shortname_mixed:
1073 opts->shortname = VFAT_SFN_DISPLAY_WINNT
1074 | VFAT_SFN_CREATE_WIN95;
1075 break;
1076 case Opt_utf8_no: /* 0 or no or false */
1077 opts->utf8 = 0;
1078 break;
1079 case Opt_utf8_yes: /* empty or 1 or yes or true */
1080 opts->utf8 = 1;
1081 break;
1082 case Opt_uni_xl_no: /* 0 or no or false */
1083 opts->unicode_xlate = 0;
1084 break;
1085 case Opt_uni_xl_yes: /* empty or 1 or yes or true */
1086 opts->unicode_xlate = 1;
1087 break;
1088 case Opt_nonumtail_no: /* 0 or no or false */
1089 opts->numtail = 1; /* negated option */
1090 break;
1091 case Opt_nonumtail_yes: /* empty or 1 or yes or true */
1092 opts->numtail = 0; /* negated option */
1093 break;
1094
1095 /* obsolete mount options */
1096 case Opt_obsolate:
1097 printk(KERN_INFO "FAT: \"%s\" option is obsolete, "
1098 "not supported now\n", p);
1099 break;
1100 /* unknown option */
1101 default:
Christoph Hellwig41a34a42005-11-08 21:34:57 -08001102 if (!silent) {
1103 printk(KERN_ERR
1104 "FAT: Unrecognized mount option \"%s\" "
1105 "or missing value\n", p);
1106 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001107 return -EINVAL;
1108 }
1109 }
Alexey Dobriyan4de151d2006-03-22 00:13:35 +01001110 /* UTF-8 doesn't provide FAT semantics */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001111 if (!strcmp(opts->iocharset, "utf8")) {
1112 printk(KERN_ERR "FAT: utf8 is not a recommended IO charset"
1113 " for FAT filesystems, filesystem will be case sensitive!\n");
1114 }
1115
1116 if (opts->unicode_xlate)
1117 opts->utf8 = 0;
1118
1119 return 0;
1120}
1121
1122static int fat_read_root(struct inode *inode)
1123{
1124 struct super_block *sb = inode->i_sb;
1125 struct msdos_sb_info *sbi = MSDOS_SB(sb);
1126 int error;
1127
1128 MSDOS_I(inode)->i_pos = 0;
1129 inode->i_uid = sbi->options.fs_uid;
1130 inode->i_gid = sbi->options.fs_gid;
1131 inode->i_version++;
1132 inode->i_generation = 0;
1133 inode->i_mode = (S_IRWXUGO & ~sbi->options.fs_dmask) | S_IFDIR;
1134 inode->i_op = sbi->dir_ops;
1135 inode->i_fop = &fat_dir_operations;
1136 if (sbi->fat_bits == 32) {
1137 MSDOS_I(inode)->i_start = sbi->root_cluster;
1138 error = fat_calc_dir_size(inode);
1139 if (error < 0)
1140 return error;
1141 } else {
1142 MSDOS_I(inode)->i_start = 0;
1143 inode->i_size = sbi->dir_entries * sizeof(struct msdos_dir_entry);
1144 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001145 inode->i_blocks = ((inode->i_size + (sbi->cluster_size - 1))
1146 & ~((loff_t)sbi->cluster_size - 1)) >> 9;
1147 MSDOS_I(inode)->i_logstart = 0;
1148 MSDOS_I(inode)->mmu_private = inode->i_size;
1149
1150 MSDOS_I(inode)->i_attrs = ATTR_NONE;
1151 inode->i_mtime.tv_sec = inode->i_atime.tv_sec = inode->i_ctime.tv_sec = 0;
1152 inode->i_mtime.tv_nsec = inode->i_atime.tv_nsec = inode->i_ctime.tv_nsec = 0;
1153 inode->i_nlink = fat_subdirs(inode)+2;
1154
1155 return 0;
1156}
1157
1158/*
1159 * Read the super block of an MS-DOS FS.
1160 */
1161int fat_fill_super(struct super_block *sb, void *data, int silent,
Arjan van de Ven754661f2007-02-12 00:55:38 -08001162 const struct inode_operations *fs_dir_inode_ops, int isvfat)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001163{
1164 struct inode *root_inode = NULL;
1165 struct buffer_head *bh;
1166 struct fat_boot_sector *b;
1167 struct msdos_sb_info *sbi;
1168 u16 logical_sector_size;
1169 u32 total_sectors, total_clusters, fat_clusters, rootdir_sectors;
1170 int debug;
1171 unsigned int media;
1172 long error;
1173 char buf[50];
1174
Panagiotis Issarisf8314dc2006-09-27 01:49:37 -07001175 sbi = kzalloc(sizeof(struct msdos_sb_info), GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001176 if (!sbi)
1177 return -ENOMEM;
1178 sb->s_fs_info = sbi;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001179
1180 sb->s_flags |= MS_NODIRATIME;
1181 sb->s_magic = MSDOS_SUPER_MAGIC;
1182 sb->s_op = &fat_sops;
1183 sb->s_export_op = &fat_export_ops;
1184 sbi->dir_ops = fs_dir_inode_ops;
1185
Christoph Hellwig41a34a42005-11-08 21:34:57 -08001186 error = parse_options(data, isvfat, silent, &debug, &sbi->options);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001187 if (error)
1188 goto out_fail;
1189
1190 error = -EIO;
1191 sb_min_blocksize(sb, 512);
1192 bh = sb_bread(sb, 0);
1193 if (bh == NULL) {
1194 printk(KERN_ERR "FAT: unable to read boot sector\n");
1195 goto out_fail;
1196 }
1197
1198 b = (struct fat_boot_sector *) bh->b_data;
1199 if (!b->reserved) {
1200 if (!silent)
1201 printk(KERN_ERR "FAT: bogus number of reserved sectors\n");
1202 brelse(bh);
1203 goto out_invalid;
1204 }
1205 if (!b->fats) {
1206 if (!silent)
1207 printk(KERN_ERR "FAT: bogus number of FAT structure\n");
1208 brelse(bh);
1209 goto out_invalid;
1210 }
1211
1212 /*
1213 * Earlier we checked here that b->secs_track and b->head are nonzero,
1214 * but it turns out valid FAT filesystems can have zero there.
1215 */
1216
1217 media = b->media;
1218 if (!FAT_VALID_MEDIA(media)) {
1219 if (!silent)
1220 printk(KERN_ERR "FAT: invalid media value (0x%02x)\n",
1221 media);
1222 brelse(bh);
1223 goto out_invalid;
1224 }
1225 logical_sector_size =
1226 le16_to_cpu(get_unaligned((__le16 *)&b->sector_size));
Vignesh Babu BMe7d709c2007-05-08 00:24:27 -07001227 if (!is_power_of_2(logical_sector_size)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001228 || (logical_sector_size < 512)
1229 || (PAGE_CACHE_SIZE < logical_sector_size)) {
1230 if (!silent)
1231 printk(KERN_ERR "FAT: bogus logical sector size %u\n",
1232 logical_sector_size);
1233 brelse(bh);
1234 goto out_invalid;
1235 }
1236 sbi->sec_per_clus = b->sec_per_clus;
Vignesh Babu BMe7d709c2007-05-08 00:24:27 -07001237 if (!is_power_of_2(sbi->sec_per_clus)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001238 if (!silent)
1239 printk(KERN_ERR "FAT: bogus sectors per cluster %u\n",
1240 sbi->sec_per_clus);
1241 brelse(bh);
1242 goto out_invalid;
1243 }
1244
1245 if (logical_sector_size < sb->s_blocksize) {
1246 printk(KERN_ERR "FAT: logical sector size too small for device"
1247 " (logical sector size = %u)\n", logical_sector_size);
1248 brelse(bh);
1249 goto out_fail;
1250 }
1251 if (logical_sector_size > sb->s_blocksize) {
1252 brelse(bh);
1253
1254 if (!sb_set_blocksize(sb, logical_sector_size)) {
1255 printk(KERN_ERR "FAT: unable to set blocksize %u\n",
1256 logical_sector_size);
1257 goto out_fail;
1258 }
1259 bh = sb_bread(sb, 0);
1260 if (bh == NULL) {
1261 printk(KERN_ERR "FAT: unable to read boot sector"
1262 " (logical sector size = %lu)\n",
1263 sb->s_blocksize);
1264 goto out_fail;
1265 }
1266 b = (struct fat_boot_sector *) bh->b_data;
1267 }
1268
1269 sbi->cluster_size = sb->s_blocksize * sbi->sec_per_clus;
1270 sbi->cluster_bits = ffs(sbi->cluster_size) - 1;
1271 sbi->fats = b->fats;
1272 sbi->fat_bits = 0; /* Don't know yet */
1273 sbi->fat_start = le16_to_cpu(b->reserved);
1274 sbi->fat_length = le16_to_cpu(b->fat_length);
1275 sbi->root_cluster = 0;
1276 sbi->free_clusters = -1; /* Don't know yet */
1277 sbi->prev_free = FAT_START_ENT;
1278
1279 if (!sbi->fat_length && b->fat32_length) {
1280 struct fat_boot_fsinfo *fsinfo;
1281 struct buffer_head *fsinfo_bh;
1282
1283 /* Must be FAT32 */
1284 sbi->fat_bits = 32;
1285 sbi->fat_length = le32_to_cpu(b->fat32_length);
1286 sbi->root_cluster = le32_to_cpu(b->root_cluster);
1287
1288 sb->s_maxbytes = 0xffffffff;
1289
1290 /* MC - if info_sector is 0, don't multiply by 0 */
1291 sbi->fsinfo_sector = le16_to_cpu(b->info_sector);
1292 if (sbi->fsinfo_sector == 0)
1293 sbi->fsinfo_sector = 1;
1294
1295 fsinfo_bh = sb_bread(sb, sbi->fsinfo_sector);
1296 if (fsinfo_bh == NULL) {
1297 printk(KERN_ERR "FAT: bread failed, FSINFO block"
1298 " (sector = %lu)\n", sbi->fsinfo_sector);
1299 brelse(bh);
1300 goto out_fail;
1301 }
1302
1303 fsinfo = (struct fat_boot_fsinfo *)fsinfo_bh->b_data;
1304 if (!IS_FSINFO(fsinfo)) {
1305 printk(KERN_WARNING
1306 "FAT: Did not find valid FSINFO signature.\n"
1307 " Found signature1 0x%08x signature2 0x%08x"
1308 " (sector = %lu)\n",
1309 le32_to_cpu(fsinfo->signature1),
1310 le32_to_cpu(fsinfo->signature2),
1311 sbi->fsinfo_sector);
1312 } else {
OGAWA Hirofumi28ec0392007-05-08 00:31:01 -07001313 if (sbi->options.usefree)
1314 sbi->free_clusters =
1315 le32_to_cpu(fsinfo->free_clusters);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001316 sbi->prev_free = le32_to_cpu(fsinfo->next_cluster);
1317 }
1318
1319 brelse(fsinfo_bh);
1320 }
1321
1322 sbi->dir_per_block = sb->s_blocksize / sizeof(struct msdos_dir_entry);
1323 sbi->dir_per_block_bits = ffs(sbi->dir_per_block) - 1;
1324
1325 sbi->dir_start = sbi->fat_start + sbi->fats * sbi->fat_length;
1326 sbi->dir_entries =
1327 le16_to_cpu(get_unaligned((__le16 *)&b->dir_entries));
1328 if (sbi->dir_entries & (sbi->dir_per_block - 1)) {
1329 if (!silent)
1330 printk(KERN_ERR "FAT: bogus directroy-entries per block"
1331 " (%u)\n", sbi->dir_entries);
1332 brelse(bh);
1333 goto out_invalid;
1334 }
1335
1336 rootdir_sectors = sbi->dir_entries
1337 * sizeof(struct msdos_dir_entry) / sb->s_blocksize;
1338 sbi->data_start = sbi->dir_start + rootdir_sectors;
1339 total_sectors = le16_to_cpu(get_unaligned((__le16 *)&b->sectors));
1340 if (total_sectors == 0)
1341 total_sectors = le32_to_cpu(b->total_sect);
1342
1343 total_clusters = (total_sectors - sbi->data_start) / sbi->sec_per_clus;
1344
1345 if (sbi->fat_bits != 32)
1346 sbi->fat_bits = (total_clusters > MAX_FAT12) ? 16 : 12;
1347
1348 /* check that FAT table does not overflow */
1349 fat_clusters = sbi->fat_length * sb->s_blocksize * 8 / sbi->fat_bits;
1350 total_clusters = min(total_clusters, fat_clusters - FAT_START_ENT);
1351 if (total_clusters > MAX_FAT(sb)) {
1352 if (!silent)
1353 printk(KERN_ERR "FAT: count of clusters too big (%u)\n",
1354 total_clusters);
1355 brelse(bh);
1356 goto out_invalid;
1357 }
1358
1359 sbi->max_cluster = total_clusters + FAT_START_ENT;
1360 /* check the free_clusters, it's not necessarily correct */
1361 if (sbi->free_clusters != -1 && sbi->free_clusters > total_clusters)
1362 sbi->free_clusters = -1;
1363 /* check the prev_free, it's not necessarily correct */
1364 sbi->prev_free %= sbi->max_cluster;
1365 if (sbi->prev_free < FAT_START_ENT)
1366 sbi->prev_free = FAT_START_ENT;
1367
1368 brelse(bh);
1369
1370 /* set up enough so that it can read an inode */
1371 fat_hash_init(sb);
1372 fat_ent_access_init(sb);
1373
1374 /*
1375 * The low byte of FAT's first entry must have same value with
1376 * media-field. But in real world, too many devices is
1377 * writing wrong value. So, removed that validity check.
1378 *
1379 * if (FAT_FIRST_ENT(sb, media) != first)
1380 */
1381
1382 error = -EINVAL;
1383 sprintf(buf, "cp%d", sbi->options.codepage);
1384 sbi->nls_disk = load_nls(buf);
1385 if (!sbi->nls_disk) {
1386 printk(KERN_ERR "FAT: codepage %s not found\n", buf);
1387 goto out_fail;
1388 }
1389
1390 /* FIXME: utf8 is using iocharset for upper/lower conversion */
1391 if (sbi->options.isvfat) {
1392 sbi->nls_io = load_nls(sbi->options.iocharset);
1393 if (!sbi->nls_io) {
1394 printk(KERN_ERR "FAT: IO charset %s not found\n",
1395 sbi->options.iocharset);
1396 goto out_fail;
1397 }
1398 }
1399
1400 error = -ENOMEM;
1401 root_inode = new_inode(sb);
1402 if (!root_inode)
1403 goto out_fail;
1404 root_inode->i_ino = MSDOS_ROOT_INO;
1405 root_inode->i_version = 1;
1406 error = fat_read_root(root_inode);
1407 if (error < 0)
1408 goto out_fail;
1409 error = -ENOMEM;
1410 insert_inode_hash(root_inode);
1411 sb->s_root = d_alloc_root(root_inode);
1412 if (!sb->s_root) {
1413 printk(KERN_ERR "FAT: get root inode failed\n");
1414 goto out_fail;
1415 }
1416
1417 return 0;
1418
1419out_invalid:
1420 error = -EINVAL;
1421 if (!silent)
1422 printk(KERN_INFO "VFS: Can't find a valid FAT filesystem"
1423 " on dev %s.\n", sb->s_id);
1424
1425out_fail:
1426 if (root_inode)
1427 iput(root_inode);
1428 if (sbi->nls_io)
1429 unload_nls(sbi->nls_io);
1430 if (sbi->nls_disk)
1431 unload_nls(sbi->nls_disk);
1432 if (sbi->options.iocharset != fat_default_iocharset)
1433 kfree(sbi->options.iocharset);
1434 sb->s_fs_info = NULL;
1435 kfree(sbi);
1436 return error;
1437}
1438
OGAWA Hirofumi7c709d02006-01-08 01:02:10 -08001439EXPORT_SYMBOL_GPL(fat_fill_super);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001440
Chris Masonae78bf92006-09-29 02:00:03 -07001441/*
1442 * helper function for fat_flush_inodes. This writes both the inode
1443 * and the file data blocks, waiting for in flight data blocks before
1444 * the start of the call. It does not wait for any io started
1445 * during the call
1446 */
1447static int writeback_inode(struct inode *inode)
1448{
1449
1450 int ret;
1451 struct address_space *mapping = inode->i_mapping;
1452 struct writeback_control wbc = {
1453 .sync_mode = WB_SYNC_NONE,
1454 .nr_to_write = 0,
1455 };
1456 /* if we used WB_SYNC_ALL, sync_inode waits for the io for the
1457 * inode to finish. So WB_SYNC_NONE is sent down to sync_inode
1458 * and filemap_fdatawrite is used for the data blocks
1459 */
1460 ret = sync_inode(inode, &wbc);
1461 if (!ret)
1462 ret = filemap_fdatawrite(mapping);
1463 return ret;
1464}
1465
1466/*
1467 * write data and metadata corresponding to i1 and i2. The io is
1468 * started but we do not wait for any of it to finish.
1469 *
1470 * filemap_flush is used for the block device, so if there is a dirty
1471 * page for a block already in flight, we will not wait and start the
1472 * io over again
1473 */
1474int fat_flush_inodes(struct super_block *sb, struct inode *i1, struct inode *i2)
1475{
1476 int ret = 0;
1477 if (!MSDOS_SB(sb)->options.flush)
1478 return 0;
1479 if (i1)
1480 ret = writeback_inode(i1);
1481 if (!ret && i2)
1482 ret = writeback_inode(i2);
Eric Sesterhenn97e860d2006-10-11 01:21:59 -07001483 if (!ret) {
Chris Masonae78bf92006-09-29 02:00:03 -07001484 struct address_space *mapping = sb->s_bdev->bd_inode->i_mapping;
1485 ret = filemap_flush(mapping);
1486 }
1487 return ret;
1488}
1489EXPORT_SYMBOL_GPL(fat_flush_inodes);
1490
Linus Torvalds1da177e2005-04-16 15:20:36 -07001491static int __init init_fat_fs(void)
1492{
Pekka J Enberg532a39a2005-06-30 02:59:01 -07001493 int err;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001494
Pekka J Enberg532a39a2005-06-30 02:59:01 -07001495 err = fat_cache_init();
1496 if (err)
1497 return err;
1498
1499 err = fat_init_inodecache();
1500 if (err)
1501 goto failed;
1502
1503 return 0;
1504
1505failed:
1506 fat_cache_destroy();
1507 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001508}
1509
1510static void __exit exit_fat_fs(void)
1511{
1512 fat_cache_destroy();
1513 fat_destroy_inodecache();
1514}
1515
1516module_init(init_fat_fs)
1517module_exit(exit_fat_fs)
1518
1519MODULE_LICENSE("GPL");