blob: 4baa5f2053680944dcc480a95da6bbea7f384c62 [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>
Christoph Hellwiga5694252007-07-17 04:04:28 -070023#include <linux/exportfs.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070024#include <linux/mount.h>
25#include <linux/vfs.h>
26#include <linux/parser.h>
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -080027#include <linux/uio.h>
Chris Masonae78bf92006-09-29 02:00:03 -070028#include <linux/writeback.h>
Vignesh Babu BMe7d709c2007-05-08 00:24:27 -070029#include <linux/log2.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070030#include <asm/unaligned.h>
31
32#ifndef CONFIG_FAT_DEFAULT_IOCHARSET
33/* if user don't select VFAT, this is undefined. */
34#define CONFIG_FAT_DEFAULT_IOCHARSET ""
35#endif
36
37static int fat_default_codepage = CONFIG_FAT_DEFAULT_CODEPAGE;
38static char fat_default_iocharset[] = CONFIG_FAT_DEFAULT_IOCHARSET;
39
40
41static int fat_add_cluster(struct inode *inode)
42{
43 int err, cluster;
44
45 err = fat_alloc_clusters(inode, &cluster, 1);
46 if (err)
47 return err;
48 /* FIXME: this cluster should be added after data of this
49 * cluster is writed */
50 err = fat_chain_add(inode, cluster, 1);
51 if (err)
52 fat_free_clusters(inode, cluster);
53 return err;
54}
55
OGAWA Hirofumi6a1d9802006-09-27 01:50:45 -070056static inline int __fat_get_block(struct inode *inode, sector_t iblock,
57 unsigned long *max_blocks,
58 struct buffer_head *bh_result, int create)
Linus Torvalds1da177e2005-04-16 15:20:36 -070059{
60 struct super_block *sb = inode->i_sb;
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -080061 struct msdos_sb_info *sbi = MSDOS_SB(sb);
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -080062 unsigned long mapped_blocks;
OGAWA Hirofumi6a1d9802006-09-27 01:50:45 -070063 sector_t phys;
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -080064 int err, offset;
Linus Torvalds1da177e2005-04-16 15:20:36 -070065
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -080066 err = fat_bmap(inode, iblock, &phys, &mapped_blocks);
Linus Torvalds1da177e2005-04-16 15:20:36 -070067 if (err)
68 return err;
69 if (phys) {
70 map_bh(bh_result, sb, phys);
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -080071 *max_blocks = min(mapped_blocks, *max_blocks);
Linus Torvalds1da177e2005-04-16 15:20:36 -070072 return 0;
73 }
74 if (!create)
75 return 0;
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -080076
Linus Torvalds1da177e2005-04-16 15:20:36 -070077 if (iblock != MSDOS_I(inode)->mmu_private >> sb->s_blocksize_bits) {
78 fat_fs_panic(sb, "corrupted file size (i_pos %lld, %lld)",
OGAWA Hirofumi6a1d9802006-09-27 01:50:45 -070079 MSDOS_I(inode)->i_pos, MSDOS_I(inode)->mmu_private);
Linus Torvalds1da177e2005-04-16 15:20:36 -070080 return -EIO;
81 }
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -080082
83 offset = (unsigned long)iblock & (sbi->sec_per_clus - 1);
84 if (!offset) {
85 /* TODO: multiple cluster allocation would be desirable. */
Linus Torvalds1da177e2005-04-16 15:20:36 -070086 err = fat_add_cluster(inode);
87 if (err)
88 return err;
89 }
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -080090 /* available blocks on this cluster */
91 mapped_blocks = sbi->sec_per_clus - offset;
92
93 *max_blocks = min(mapped_blocks, *max_blocks);
94 MSDOS_I(inode)->mmu_private += *max_blocks << sb->s_blocksize_bits;
95
96 err = fat_bmap(inode, iblock, &phys, &mapped_blocks);
Linus Torvalds1da177e2005-04-16 15:20:36 -070097 if (err)
98 return err;
OGAWA Hirofumi6a1d9802006-09-27 01:50:45 -070099
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -0800100 BUG_ON(!phys);
101 BUG_ON(*max_blocks != mapped_blocks);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700102 set_buffer_new(bh_result);
103 map_bh(bh_result, sb, phys);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700104
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -0800105 return 0;
106}
107
108static int fat_get_block(struct inode *inode, sector_t iblock,
109 struct buffer_head *bh_result, int create)
110{
OGAWA Hirofumi6a1d9802006-09-27 01:50:45 -0700111 struct super_block *sb = inode->i_sb;
112 unsigned long max_blocks = bh_result->b_size >> inode->i_blkbits;
113 int err;
114
115 err = __fat_get_block(inode, iblock, &max_blocks, bh_result, create);
116 if (err)
117 return err;
118 bh_result->b_size = max_blocks << sb->s_blocksize_bits;
119 return 0;
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -0800120}
121
Linus Torvalds1da177e2005-04-16 15:20:36 -0700122static int fat_writepage(struct page *page, struct writeback_control *wbc)
123{
124 return block_write_full_page(page, fat_get_block, wbc);
125}
126
OGAWA Hirofumia5425d22006-01-08 01:02:10 -0800127static int fat_writepages(struct address_space *mapping,
128 struct writeback_control *wbc)
129{
130 return mpage_writepages(mapping, wbc, fat_get_block);
131}
132
Linus Torvalds1da177e2005-04-16 15:20:36 -0700133static int fat_readpage(struct file *file, struct page *page)
134{
OGAWA Hirofumia5425d22006-01-08 01:02:10 -0800135 return mpage_readpage(page, fat_get_block);
136}
137
138static int fat_readpages(struct file *file, struct address_space *mapping,
139 struct list_head *pages, unsigned nr_pages)
140{
141 return mpage_readpages(mapping, pages, nr_pages, fat_get_block);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700142}
143
144static int fat_prepare_write(struct file *file, struct page *page,
145 unsigned from, unsigned to)
146{
147 return cont_prepare_write(page, from, to, fat_get_block,
148 &MSDOS_I(page->mapping->host)->mmu_private);
149}
150
OGAWA Hirofumief402262005-09-16 19:28:13 -0700151static int fat_commit_write(struct file *file, struct page *page,
152 unsigned from, unsigned to)
153{
154 struct inode *inode = page->mapping->host;
155 int err = generic_commit_write(file, page, from, to);
156 if (!err && !(MSDOS_I(inode)->i_attrs & ATTR_ARCH)) {
157 inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC;
158 MSDOS_I(inode)->i_attrs |= ATTR_ARCH;
159 mark_inode_dirty(inode);
160 }
161 return err;
162}
163
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -0800164static ssize_t fat_direct_IO(int rw, struct kiocb *iocb,
165 const struct iovec *iov,
166 loff_t offset, unsigned long nr_segs)
167{
168 struct file *file = iocb->ki_filp;
169 struct inode *inode = file->f_mapping->host;
170
171 if (rw == WRITE) {
172 /*
173 * FIXME: blockdev_direct_IO() doesn't use ->prepare_write(),
174 * so we need to update the ->mmu_private to block boundary.
175 *
176 * But we must fill the remaining area or hole by nul for
177 * updating ->mmu_private.
OGAWA Hirofumi94412a92007-02-20 13:57:55 -0800178 *
179 * Return 0, and fallback to normal buffered write.
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -0800180 */
181 loff_t size = offset + iov_length(iov, nr_segs);
182 if (MSDOS_I(inode)->mmu_private < size)
OGAWA Hirofumi94412a92007-02-20 13:57:55 -0800183 return 0;
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -0800184 }
185
186 /*
187 * FAT need to use the DIO_LOCKING for avoiding the race
188 * condition of fat_get_block() and ->truncate().
189 */
190 return blockdev_direct_IO(rw, iocb, inode, inode->i_sb->s_bdev, iov,
OGAWA Hirofumi6a1d9802006-09-27 01:50:45 -0700191 offset, nr_segs, fat_get_block, NULL);
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -0800192}
193
Linus Torvalds1da177e2005-04-16 15:20:36 -0700194static sector_t _fat_bmap(struct address_space *mapping, sector_t block)
195{
196 return generic_block_bmap(mapping, block, fat_get_block);
197}
198
Christoph Hellwigf5e54d62006-06-28 04:26:44 -0700199static const struct address_space_operations fat_aops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700200 .readpage = fat_readpage,
OGAWA Hirofumia5425d22006-01-08 01:02:10 -0800201 .readpages = fat_readpages,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700202 .writepage = fat_writepage,
OGAWA Hirofumia5425d22006-01-08 01:02:10 -0800203 .writepages = fat_writepages,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700204 .sync_page = block_sync_page,
205 .prepare_write = fat_prepare_write,
OGAWA Hirofumief402262005-09-16 19:28:13 -0700206 .commit_write = fat_commit_write,
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -0800207 .direct_IO = fat_direct_IO,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700208 .bmap = _fat_bmap
209};
210
211/*
212 * New FAT inode stuff. We do the following:
213 * a) i_ino is constant and has nothing with on-disk location.
214 * b) FAT manages its own cache of directory entries.
215 * c) *This* cache is indexed by on-disk location.
216 * d) inode has an associated directory entry, all right, but
217 * it may be unhashed.
218 * e) currently entries are stored within struct inode. That should
219 * change.
220 * f) we deal with races in the following way:
221 * 1. readdir() and lookup() do FAT-dir-cache lookup.
222 * 2. rename() unhashes the F-d-c entry and rehashes it in
223 * a new place.
224 * 3. unlink() and rmdir() unhash F-d-c entry.
225 * 4. fat_write_inode() checks whether the thing is unhashed.
226 * If it is we silently return. If it isn't we do bread(),
227 * check if the location is still valid and retry if it
228 * isn't. Otherwise we do changes.
229 * 5. Spinlock is used to protect hash/unhash/location check/lookup
230 * 6. fat_clear_inode() unhashes the F-d-c entry.
231 * 7. lookup() and readdir() do igrab() if they find a F-d-c entry
232 * and consider negative result as cache miss.
233 */
234
235static void fat_hash_init(struct super_block *sb)
236{
237 struct msdos_sb_info *sbi = MSDOS_SB(sb);
238 int i;
239
240 spin_lock_init(&sbi->inode_hash_lock);
241 for (i = 0; i < FAT_HASH_SIZE; i++)
242 INIT_HLIST_HEAD(&sbi->inode_hashtable[i]);
243}
244
245static inline unsigned long fat_hash(struct super_block *sb, loff_t i_pos)
246{
247 unsigned long tmp = (unsigned long)i_pos | (unsigned long) sb;
248 tmp = tmp + (tmp >> FAT_HASH_BITS) + (tmp >> FAT_HASH_BITS * 2);
249 return tmp & FAT_HASH_MASK;
250}
251
252void fat_attach(struct inode *inode, loff_t i_pos)
253{
254 struct super_block *sb = inode->i_sb;
255 struct msdos_sb_info *sbi = MSDOS_SB(sb);
256
257 spin_lock(&sbi->inode_hash_lock);
258 MSDOS_I(inode)->i_pos = i_pos;
259 hlist_add_head(&MSDOS_I(inode)->i_fat_hash,
260 sbi->inode_hashtable + fat_hash(sb, i_pos));
261 spin_unlock(&sbi->inode_hash_lock);
262}
263
OGAWA Hirofumi7c709d02006-01-08 01:02:10 -0800264EXPORT_SYMBOL_GPL(fat_attach);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700265
266void fat_detach(struct inode *inode)
267{
268 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
269 spin_lock(&sbi->inode_hash_lock);
270 MSDOS_I(inode)->i_pos = 0;
271 hlist_del_init(&MSDOS_I(inode)->i_fat_hash);
272 spin_unlock(&sbi->inode_hash_lock);
273}
274
OGAWA Hirofumi7c709d02006-01-08 01:02:10 -0800275EXPORT_SYMBOL_GPL(fat_detach);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700276
277struct inode *fat_iget(struct super_block *sb, loff_t i_pos)
278{
279 struct msdos_sb_info *sbi = MSDOS_SB(sb);
280 struct hlist_head *head = sbi->inode_hashtable + fat_hash(sb, i_pos);
281 struct hlist_node *_p;
282 struct msdos_inode_info *i;
283 struct inode *inode = NULL;
284
285 spin_lock(&sbi->inode_hash_lock);
286 hlist_for_each_entry(i, _p, head, i_fat_hash) {
287 BUG_ON(i->vfs_inode.i_sb != sb);
288 if (i->i_pos != i_pos)
289 continue;
290 inode = igrab(&i->vfs_inode);
291 if (inode)
292 break;
293 }
294 spin_unlock(&sbi->inode_hash_lock);
295 return inode;
296}
297
298static int is_exec(unsigned char *extension)
299{
300 unsigned char *exe_extensions = "EXECOMBAT", *walk;
301
302 for (walk = exe_extensions; *walk; walk += 3)
303 if (!strncmp(extension, walk, 3))
304 return 1;
305 return 0;
306}
307
308static int fat_calc_dir_size(struct inode *inode)
309{
310 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
311 int ret, fclus, dclus;
312
313 inode->i_size = 0;
314 if (MSDOS_I(inode)->i_start == 0)
315 return 0;
316
317 ret = fat_get_cluster(inode, FAT_ENT_EOF, &fclus, &dclus);
318 if (ret < 0)
319 return ret;
320 inode->i_size = (fclus + 1) << sbi->cluster_bits;
321
322 return 0;
323}
324
325/* doesn't deal with root inode */
326static int fat_fill_inode(struct inode *inode, struct msdos_dir_entry *de)
327{
328 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
329 int error;
330
331 MSDOS_I(inode)->i_pos = 0;
332 inode->i_uid = sbi->options.fs_uid;
333 inode->i_gid = sbi->options.fs_gid;
334 inode->i_version++;
335 inode->i_generation = get_seconds();
336
337 if ((de->attr & ATTR_DIR) && !IS_FREE(de->name)) {
338 inode->i_generation &= ~1;
339 inode->i_mode = MSDOS_MKMODE(de->attr,
340 S_IRWXUGO & ~sbi->options.fs_dmask) | S_IFDIR;
341 inode->i_op = sbi->dir_ops;
342 inode->i_fop = &fat_dir_operations;
343
344 MSDOS_I(inode)->i_start = le16_to_cpu(de->start);
345 if (sbi->fat_bits == 32)
346 MSDOS_I(inode)->i_start |= (le16_to_cpu(de->starthi) << 16);
347
348 MSDOS_I(inode)->i_logstart = MSDOS_I(inode)->i_start;
349 error = fat_calc_dir_size(inode);
350 if (error < 0)
351 return error;
352 MSDOS_I(inode)->mmu_private = inode->i_size;
353
354 inode->i_nlink = fat_subdirs(inode);
355 } else { /* not a directory */
356 inode->i_generation |= 1;
357 inode->i_mode = MSDOS_MKMODE(de->attr,
OGAWA Hirofumi9aacd592007-07-15 23:39:56 -0700358 ((sbi->options.showexec && !is_exec(de->name + 8))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700359 ? 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 Lametera35afb82007-05-16 22:10:57 -0700503 spin_lock_init(&ei->cache_lru_lock);
504 ei->nr_caches = 0;
505 ei->cache_valid_id = FAT_CACHE_VALID + 1;
506 INIT_LIST_HEAD(&ei->cache_lru);
507 INIT_HLIST_NODE(&ei->i_fat_hash);
508 inode_init_once(&ei->vfs_inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700509}
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),
Paul Mundt20c2df82007-07-20 10:11:58 +0900517 init_once);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700518 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);
Josef 'Jeff' Sipekee9b6d62007-02-12 00:55:41 -0800621static const struct super_operations fat_sops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700622 .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);
OGAWA Hirofumi28ec0392007-05-08 00:31:01 -0700826 if (opts->usefree)
827 seq_puts(m, ",usefree");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700828 if (opts->quiet)
829 seq_puts(m, ",quiet");
830 if (opts->showexec)
831 seq_puts(m, ",showexec");
832 if (opts->sys_immutable)
833 seq_puts(m, ",sys_immutable");
834 if (!isvfat) {
835 if (opts->dotsOK)
836 seq_puts(m, ",dotsOK=yes");
837 if (opts->nocase)
838 seq_puts(m, ",nocase");
839 } else {
840 if (opts->utf8)
841 seq_puts(m, ",utf8");
842 if (opts->unicode_xlate)
843 seq_puts(m, ",uni_xlate");
844 if (!opts->numtail)
845 seq_puts(m, ",nonumtail");
846 }
847
848 return 0;
849}
850
851enum {
852 Opt_check_n, Opt_check_r, Opt_check_s, Opt_uid, Opt_gid,
OGAWA Hirofumi28ec0392007-05-08 00:31:01 -0700853 Opt_umask, Opt_dmask, Opt_fmask, Opt_codepage, Opt_usefree, Opt_nocase,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700854 Opt_quiet, Opt_showexec, Opt_debug, Opt_immutable,
855 Opt_dots, Opt_nodots,
856 Opt_charset, Opt_shortname_lower, Opt_shortname_win95,
857 Opt_shortname_winnt, Opt_shortname_mixed, Opt_utf8_no, Opt_utf8_yes,
858 Opt_uni_xl_no, Opt_uni_xl_yes, Opt_nonumtail_no, Opt_nonumtail_yes,
Chris Masonae78bf92006-09-29 02:00:03 -0700859 Opt_obsolate, Opt_flush, Opt_err,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700860};
861
862static match_table_t fat_tokens = {
863 {Opt_check_r, "check=relaxed"},
864 {Opt_check_s, "check=strict"},
865 {Opt_check_n, "check=normal"},
866 {Opt_check_r, "check=r"},
867 {Opt_check_s, "check=s"},
868 {Opt_check_n, "check=n"},
869 {Opt_uid, "uid=%u"},
870 {Opt_gid, "gid=%u"},
871 {Opt_umask, "umask=%o"},
872 {Opt_dmask, "dmask=%o"},
873 {Opt_fmask, "fmask=%o"},
874 {Opt_codepage, "codepage=%u"},
OGAWA Hirofumi28ec0392007-05-08 00:31:01 -0700875 {Opt_usefree, "usefree"},
Linus Torvalds1da177e2005-04-16 15:20:36 -0700876 {Opt_nocase, "nocase"},
877 {Opt_quiet, "quiet"},
878 {Opt_showexec, "showexec"},
879 {Opt_debug, "debug"},
880 {Opt_immutable, "sys_immutable"},
881 {Opt_obsolate, "conv=binary"},
882 {Opt_obsolate, "conv=text"},
883 {Opt_obsolate, "conv=auto"},
884 {Opt_obsolate, "conv=b"},
885 {Opt_obsolate, "conv=t"},
886 {Opt_obsolate, "conv=a"},
887 {Opt_obsolate, "fat=%u"},
888 {Opt_obsolate, "blocksize=%u"},
889 {Opt_obsolate, "cvf_format=%20s"},
890 {Opt_obsolate, "cvf_options=%100s"},
891 {Opt_obsolate, "posix"},
Chris Masonae78bf92006-09-29 02:00:03 -0700892 {Opt_flush, "flush"},
893 {Opt_err, NULL},
Linus Torvalds1da177e2005-04-16 15:20:36 -0700894};
895static match_table_t msdos_tokens = {
896 {Opt_nodots, "nodots"},
897 {Opt_nodots, "dotsOK=no"},
898 {Opt_dots, "dots"},
899 {Opt_dots, "dotsOK=yes"},
900 {Opt_err, NULL}
901};
902static match_table_t vfat_tokens = {
903 {Opt_charset, "iocharset=%s"},
904 {Opt_shortname_lower, "shortname=lower"},
905 {Opt_shortname_win95, "shortname=win95"},
906 {Opt_shortname_winnt, "shortname=winnt"},
907 {Opt_shortname_mixed, "shortname=mixed"},
908 {Opt_utf8_no, "utf8=0"}, /* 0 or no or false */
909 {Opt_utf8_no, "utf8=no"},
910 {Opt_utf8_no, "utf8=false"},
911 {Opt_utf8_yes, "utf8=1"}, /* empty or 1 or yes or true */
912 {Opt_utf8_yes, "utf8=yes"},
913 {Opt_utf8_yes, "utf8=true"},
914 {Opt_utf8_yes, "utf8"},
915 {Opt_uni_xl_no, "uni_xlate=0"}, /* 0 or no or false */
916 {Opt_uni_xl_no, "uni_xlate=no"},
917 {Opt_uni_xl_no, "uni_xlate=false"},
918 {Opt_uni_xl_yes, "uni_xlate=1"}, /* empty or 1 or yes or true */
919 {Opt_uni_xl_yes, "uni_xlate=yes"},
920 {Opt_uni_xl_yes, "uni_xlate=true"},
921 {Opt_uni_xl_yes, "uni_xlate"},
922 {Opt_nonumtail_no, "nonumtail=0"}, /* 0 or no or false */
923 {Opt_nonumtail_no, "nonumtail=no"},
924 {Opt_nonumtail_no, "nonumtail=false"},
925 {Opt_nonumtail_yes, "nonumtail=1"}, /* empty or 1 or yes or true */
926 {Opt_nonumtail_yes, "nonumtail=yes"},
927 {Opt_nonumtail_yes, "nonumtail=true"},
928 {Opt_nonumtail_yes, "nonumtail"},
929 {Opt_err, NULL}
930};
931
Christoph Hellwig41a34a42005-11-08 21:34:57 -0800932static int parse_options(char *options, int is_vfat, int silent, int *debug,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700933 struct fat_mount_options *opts)
934{
935 char *p;
936 substring_t args[MAX_OPT_ARGS];
937 int option;
938 char *iocharset;
939
940 opts->isvfat = is_vfat;
941
942 opts->fs_uid = current->uid;
943 opts->fs_gid = current->gid;
944 opts->fs_fmask = opts->fs_dmask = current->fs->umask;
945 opts->codepage = fat_default_codepage;
946 opts->iocharset = fat_default_iocharset;
947 if (is_vfat)
948 opts->shortname = VFAT_SFN_DISPLAY_LOWER|VFAT_SFN_CREATE_WIN95;
949 else
950 opts->shortname = 0;
951 opts->name_check = 'n';
952 opts->quiet = opts->showexec = opts->sys_immutable = opts->dotsOK = 0;
953 opts->utf8 = opts->unicode_xlate = 0;
954 opts->numtail = 1;
OGAWA Hirofumi28ec0392007-05-08 00:31:01 -0700955 opts->usefree = opts->nocase = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700956 *debug = 0;
957
958 if (!options)
959 return 0;
960
961 while ((p = strsep(&options, ",")) != NULL) {
962 int token;
963 if (!*p)
964 continue;
965
966 token = match_token(p, fat_tokens, args);
967 if (token == Opt_err) {
968 if (is_vfat)
969 token = match_token(p, vfat_tokens, args);
970 else
971 token = match_token(p, msdos_tokens, args);
972 }
973 switch (token) {
974 case Opt_check_s:
975 opts->name_check = 's';
976 break;
977 case Opt_check_r:
978 opts->name_check = 'r';
979 break;
980 case Opt_check_n:
981 opts->name_check = 'n';
982 break;
OGAWA Hirofumi28ec0392007-05-08 00:31:01 -0700983 case Opt_usefree:
984 opts->usefree = 1;
985 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700986 case Opt_nocase:
987 if (!is_vfat)
988 opts->nocase = 1;
989 else {
990 /* for backward compatibility */
991 opts->shortname = VFAT_SFN_DISPLAY_WIN95
992 | VFAT_SFN_CREATE_WIN95;
993 }
994 break;
995 case Opt_quiet:
996 opts->quiet = 1;
997 break;
998 case Opt_showexec:
999 opts->showexec = 1;
1000 break;
1001 case Opt_debug:
1002 *debug = 1;
1003 break;
1004 case Opt_immutable:
1005 opts->sys_immutable = 1;
1006 break;
1007 case Opt_uid:
1008 if (match_int(&args[0], &option))
1009 return 0;
1010 opts->fs_uid = option;
1011 break;
1012 case Opt_gid:
1013 if (match_int(&args[0], &option))
1014 return 0;
1015 opts->fs_gid = option;
1016 break;
1017 case Opt_umask:
1018 if (match_octal(&args[0], &option))
1019 return 0;
1020 opts->fs_fmask = opts->fs_dmask = option;
1021 break;
1022 case Opt_dmask:
1023 if (match_octal(&args[0], &option))
1024 return 0;
1025 opts->fs_dmask = option;
1026 break;
1027 case Opt_fmask:
1028 if (match_octal(&args[0], &option))
1029 return 0;
1030 opts->fs_fmask = option;
1031 break;
1032 case Opt_codepage:
1033 if (match_int(&args[0], &option))
1034 return 0;
1035 opts->codepage = option;
1036 break;
Chris Masonae78bf92006-09-29 02:00:03 -07001037 case Opt_flush:
1038 opts->flush = 1;
1039 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001040
1041 /* msdos specific */
1042 case Opt_dots:
1043 opts->dotsOK = 1;
1044 break;
1045 case Opt_nodots:
1046 opts->dotsOK = 0;
1047 break;
1048
1049 /* vfat specific */
1050 case Opt_charset:
1051 if (opts->iocharset != fat_default_iocharset)
1052 kfree(opts->iocharset);
1053 iocharset = match_strdup(&args[0]);
1054 if (!iocharset)
1055 return -ENOMEM;
1056 opts->iocharset = iocharset;
1057 break;
1058 case Opt_shortname_lower:
1059 opts->shortname = VFAT_SFN_DISPLAY_LOWER
1060 | VFAT_SFN_CREATE_WIN95;
1061 break;
1062 case Opt_shortname_win95:
1063 opts->shortname = VFAT_SFN_DISPLAY_WIN95
1064 | VFAT_SFN_CREATE_WIN95;
1065 break;
1066 case Opt_shortname_winnt:
1067 opts->shortname = VFAT_SFN_DISPLAY_WINNT
1068 | VFAT_SFN_CREATE_WINNT;
1069 break;
1070 case Opt_shortname_mixed:
1071 opts->shortname = VFAT_SFN_DISPLAY_WINNT
1072 | VFAT_SFN_CREATE_WIN95;
1073 break;
1074 case Opt_utf8_no: /* 0 or no or false */
1075 opts->utf8 = 0;
1076 break;
1077 case Opt_utf8_yes: /* empty or 1 or yes or true */
1078 opts->utf8 = 1;
1079 break;
1080 case Opt_uni_xl_no: /* 0 or no or false */
1081 opts->unicode_xlate = 0;
1082 break;
1083 case Opt_uni_xl_yes: /* empty or 1 or yes or true */
1084 opts->unicode_xlate = 1;
1085 break;
1086 case Opt_nonumtail_no: /* 0 or no or false */
1087 opts->numtail = 1; /* negated option */
1088 break;
1089 case Opt_nonumtail_yes: /* empty or 1 or yes or true */
1090 opts->numtail = 0; /* negated option */
1091 break;
1092
1093 /* obsolete mount options */
1094 case Opt_obsolate:
1095 printk(KERN_INFO "FAT: \"%s\" option is obsolete, "
1096 "not supported now\n", p);
1097 break;
1098 /* unknown option */
1099 default:
Christoph Hellwig41a34a42005-11-08 21:34:57 -08001100 if (!silent) {
1101 printk(KERN_ERR
1102 "FAT: Unrecognized mount option \"%s\" "
1103 "or missing value\n", p);
1104 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001105 return -EINVAL;
1106 }
1107 }
Alexey Dobriyan4de151d2006-03-22 00:13:35 +01001108 /* UTF-8 doesn't provide FAT semantics */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001109 if (!strcmp(opts->iocharset, "utf8")) {
1110 printk(KERN_ERR "FAT: utf8 is not a recommended IO charset"
1111 " for FAT filesystems, filesystem will be case sensitive!\n");
1112 }
1113
1114 if (opts->unicode_xlate)
1115 opts->utf8 = 0;
1116
1117 return 0;
1118}
1119
1120static int fat_read_root(struct inode *inode)
1121{
1122 struct super_block *sb = inode->i_sb;
1123 struct msdos_sb_info *sbi = MSDOS_SB(sb);
1124 int error;
1125
1126 MSDOS_I(inode)->i_pos = 0;
1127 inode->i_uid = sbi->options.fs_uid;
1128 inode->i_gid = sbi->options.fs_gid;
1129 inode->i_version++;
1130 inode->i_generation = 0;
1131 inode->i_mode = (S_IRWXUGO & ~sbi->options.fs_dmask) | S_IFDIR;
1132 inode->i_op = sbi->dir_ops;
1133 inode->i_fop = &fat_dir_operations;
1134 if (sbi->fat_bits == 32) {
1135 MSDOS_I(inode)->i_start = sbi->root_cluster;
1136 error = fat_calc_dir_size(inode);
1137 if (error < 0)
1138 return error;
1139 } else {
1140 MSDOS_I(inode)->i_start = 0;
1141 inode->i_size = sbi->dir_entries * sizeof(struct msdos_dir_entry);
1142 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001143 inode->i_blocks = ((inode->i_size + (sbi->cluster_size - 1))
1144 & ~((loff_t)sbi->cluster_size - 1)) >> 9;
1145 MSDOS_I(inode)->i_logstart = 0;
1146 MSDOS_I(inode)->mmu_private = inode->i_size;
1147
1148 MSDOS_I(inode)->i_attrs = ATTR_NONE;
1149 inode->i_mtime.tv_sec = inode->i_atime.tv_sec = inode->i_ctime.tv_sec = 0;
1150 inode->i_mtime.tv_nsec = inode->i_atime.tv_nsec = inode->i_ctime.tv_nsec = 0;
1151 inode->i_nlink = fat_subdirs(inode)+2;
1152
1153 return 0;
1154}
1155
1156/*
1157 * Read the super block of an MS-DOS FS.
1158 */
1159int fat_fill_super(struct super_block *sb, void *data, int silent,
Arjan van de Ven754661f2007-02-12 00:55:38 -08001160 const struct inode_operations *fs_dir_inode_ops, int isvfat)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001161{
1162 struct inode *root_inode = NULL;
1163 struct buffer_head *bh;
1164 struct fat_boot_sector *b;
1165 struct msdos_sb_info *sbi;
1166 u16 logical_sector_size;
1167 u32 total_sectors, total_clusters, fat_clusters, rootdir_sectors;
1168 int debug;
1169 unsigned int media;
1170 long error;
1171 char buf[50];
1172
Panagiotis Issarisf8314dc2006-09-27 01:49:37 -07001173 sbi = kzalloc(sizeof(struct msdos_sb_info), GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001174 if (!sbi)
1175 return -ENOMEM;
1176 sb->s_fs_info = sbi;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001177
1178 sb->s_flags |= MS_NODIRATIME;
1179 sb->s_magic = MSDOS_SUPER_MAGIC;
1180 sb->s_op = &fat_sops;
1181 sb->s_export_op = &fat_export_ops;
1182 sbi->dir_ops = fs_dir_inode_ops;
1183
Christoph Hellwig41a34a42005-11-08 21:34:57 -08001184 error = parse_options(data, isvfat, silent, &debug, &sbi->options);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001185 if (error)
1186 goto out_fail;
1187
1188 error = -EIO;
1189 sb_min_blocksize(sb, 512);
1190 bh = sb_bread(sb, 0);
1191 if (bh == NULL) {
1192 printk(KERN_ERR "FAT: unable to read boot sector\n");
1193 goto out_fail;
1194 }
1195
1196 b = (struct fat_boot_sector *) bh->b_data;
1197 if (!b->reserved) {
1198 if (!silent)
1199 printk(KERN_ERR "FAT: bogus number of reserved sectors\n");
1200 brelse(bh);
1201 goto out_invalid;
1202 }
1203 if (!b->fats) {
1204 if (!silent)
1205 printk(KERN_ERR "FAT: bogus number of FAT structure\n");
1206 brelse(bh);
1207 goto out_invalid;
1208 }
1209
1210 /*
1211 * Earlier we checked here that b->secs_track and b->head are nonzero,
1212 * but it turns out valid FAT filesystems can have zero there.
1213 */
1214
1215 media = b->media;
1216 if (!FAT_VALID_MEDIA(media)) {
1217 if (!silent)
1218 printk(KERN_ERR "FAT: invalid media value (0x%02x)\n",
1219 media);
1220 brelse(bh);
1221 goto out_invalid;
1222 }
1223 logical_sector_size =
1224 le16_to_cpu(get_unaligned((__le16 *)&b->sector_size));
Vignesh Babu BMe7d709c2007-05-08 00:24:27 -07001225 if (!is_power_of_2(logical_sector_size)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001226 || (logical_sector_size < 512)
1227 || (PAGE_CACHE_SIZE < logical_sector_size)) {
1228 if (!silent)
1229 printk(KERN_ERR "FAT: bogus logical sector size %u\n",
1230 logical_sector_size);
1231 brelse(bh);
1232 goto out_invalid;
1233 }
1234 sbi->sec_per_clus = b->sec_per_clus;
Vignesh Babu BMe7d709c2007-05-08 00:24:27 -07001235 if (!is_power_of_2(sbi->sec_per_clus)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001236 if (!silent)
1237 printk(KERN_ERR "FAT: bogus sectors per cluster %u\n",
1238 sbi->sec_per_clus);
1239 brelse(bh);
1240 goto out_invalid;
1241 }
1242
1243 if (logical_sector_size < sb->s_blocksize) {
1244 printk(KERN_ERR "FAT: logical sector size too small for device"
1245 " (logical sector size = %u)\n", logical_sector_size);
1246 brelse(bh);
1247 goto out_fail;
1248 }
1249 if (logical_sector_size > sb->s_blocksize) {
1250 brelse(bh);
1251
1252 if (!sb_set_blocksize(sb, logical_sector_size)) {
1253 printk(KERN_ERR "FAT: unable to set blocksize %u\n",
1254 logical_sector_size);
1255 goto out_fail;
1256 }
1257 bh = sb_bread(sb, 0);
1258 if (bh == NULL) {
1259 printk(KERN_ERR "FAT: unable to read boot sector"
1260 " (logical sector size = %lu)\n",
1261 sb->s_blocksize);
1262 goto out_fail;
1263 }
1264 b = (struct fat_boot_sector *) bh->b_data;
1265 }
1266
1267 sbi->cluster_size = sb->s_blocksize * sbi->sec_per_clus;
1268 sbi->cluster_bits = ffs(sbi->cluster_size) - 1;
1269 sbi->fats = b->fats;
1270 sbi->fat_bits = 0; /* Don't know yet */
1271 sbi->fat_start = le16_to_cpu(b->reserved);
1272 sbi->fat_length = le16_to_cpu(b->fat_length);
1273 sbi->root_cluster = 0;
1274 sbi->free_clusters = -1; /* Don't know yet */
1275 sbi->prev_free = FAT_START_ENT;
1276
1277 if (!sbi->fat_length && b->fat32_length) {
1278 struct fat_boot_fsinfo *fsinfo;
1279 struct buffer_head *fsinfo_bh;
1280
1281 /* Must be FAT32 */
1282 sbi->fat_bits = 32;
1283 sbi->fat_length = le32_to_cpu(b->fat32_length);
1284 sbi->root_cluster = le32_to_cpu(b->root_cluster);
1285
1286 sb->s_maxbytes = 0xffffffff;
1287
1288 /* MC - if info_sector is 0, don't multiply by 0 */
1289 sbi->fsinfo_sector = le16_to_cpu(b->info_sector);
1290 if (sbi->fsinfo_sector == 0)
1291 sbi->fsinfo_sector = 1;
1292
1293 fsinfo_bh = sb_bread(sb, sbi->fsinfo_sector);
1294 if (fsinfo_bh == NULL) {
1295 printk(KERN_ERR "FAT: bread failed, FSINFO block"
1296 " (sector = %lu)\n", sbi->fsinfo_sector);
1297 brelse(bh);
1298 goto out_fail;
1299 }
1300
1301 fsinfo = (struct fat_boot_fsinfo *)fsinfo_bh->b_data;
1302 if (!IS_FSINFO(fsinfo)) {
1303 printk(KERN_WARNING
1304 "FAT: Did not find valid FSINFO signature.\n"
1305 " Found signature1 0x%08x signature2 0x%08x"
1306 " (sector = %lu)\n",
1307 le32_to_cpu(fsinfo->signature1),
1308 le32_to_cpu(fsinfo->signature2),
1309 sbi->fsinfo_sector);
1310 } else {
OGAWA Hirofumi28ec0392007-05-08 00:31:01 -07001311 if (sbi->options.usefree)
1312 sbi->free_clusters =
1313 le32_to_cpu(fsinfo->free_clusters);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001314 sbi->prev_free = le32_to_cpu(fsinfo->next_cluster);
1315 }
1316
1317 brelse(fsinfo_bh);
1318 }
1319
1320 sbi->dir_per_block = sb->s_blocksize / sizeof(struct msdos_dir_entry);
1321 sbi->dir_per_block_bits = ffs(sbi->dir_per_block) - 1;
1322
1323 sbi->dir_start = sbi->fat_start + sbi->fats * sbi->fat_length;
1324 sbi->dir_entries =
1325 le16_to_cpu(get_unaligned((__le16 *)&b->dir_entries));
1326 if (sbi->dir_entries & (sbi->dir_per_block - 1)) {
1327 if (!silent)
1328 printk(KERN_ERR "FAT: bogus directroy-entries per block"
1329 " (%u)\n", sbi->dir_entries);
1330 brelse(bh);
1331 goto out_invalid;
1332 }
1333
1334 rootdir_sectors = sbi->dir_entries
1335 * sizeof(struct msdos_dir_entry) / sb->s_blocksize;
1336 sbi->data_start = sbi->dir_start + rootdir_sectors;
1337 total_sectors = le16_to_cpu(get_unaligned((__le16 *)&b->sectors));
1338 if (total_sectors == 0)
1339 total_sectors = le32_to_cpu(b->total_sect);
1340
1341 total_clusters = (total_sectors - sbi->data_start) / sbi->sec_per_clus;
1342
1343 if (sbi->fat_bits != 32)
1344 sbi->fat_bits = (total_clusters > MAX_FAT12) ? 16 : 12;
1345
1346 /* check that FAT table does not overflow */
1347 fat_clusters = sbi->fat_length * sb->s_blocksize * 8 / sbi->fat_bits;
1348 total_clusters = min(total_clusters, fat_clusters - FAT_START_ENT);
1349 if (total_clusters > MAX_FAT(sb)) {
1350 if (!silent)
1351 printk(KERN_ERR "FAT: count of clusters too big (%u)\n",
1352 total_clusters);
1353 brelse(bh);
1354 goto out_invalid;
1355 }
1356
1357 sbi->max_cluster = total_clusters + FAT_START_ENT;
1358 /* check the free_clusters, it's not necessarily correct */
1359 if (sbi->free_clusters != -1 && sbi->free_clusters > total_clusters)
1360 sbi->free_clusters = -1;
1361 /* check the prev_free, it's not necessarily correct */
1362 sbi->prev_free %= sbi->max_cluster;
1363 if (sbi->prev_free < FAT_START_ENT)
1364 sbi->prev_free = FAT_START_ENT;
1365
1366 brelse(bh);
1367
1368 /* set up enough so that it can read an inode */
1369 fat_hash_init(sb);
1370 fat_ent_access_init(sb);
1371
1372 /*
1373 * The low byte of FAT's first entry must have same value with
1374 * media-field. But in real world, too many devices is
1375 * writing wrong value. So, removed that validity check.
1376 *
1377 * if (FAT_FIRST_ENT(sb, media) != first)
1378 */
1379
1380 error = -EINVAL;
1381 sprintf(buf, "cp%d", sbi->options.codepage);
1382 sbi->nls_disk = load_nls(buf);
1383 if (!sbi->nls_disk) {
1384 printk(KERN_ERR "FAT: codepage %s not found\n", buf);
1385 goto out_fail;
1386 }
1387
1388 /* FIXME: utf8 is using iocharset for upper/lower conversion */
1389 if (sbi->options.isvfat) {
1390 sbi->nls_io = load_nls(sbi->options.iocharset);
1391 if (!sbi->nls_io) {
1392 printk(KERN_ERR "FAT: IO charset %s not found\n",
1393 sbi->options.iocharset);
1394 goto out_fail;
1395 }
1396 }
1397
1398 error = -ENOMEM;
1399 root_inode = new_inode(sb);
1400 if (!root_inode)
1401 goto out_fail;
1402 root_inode->i_ino = MSDOS_ROOT_INO;
1403 root_inode->i_version = 1;
1404 error = fat_read_root(root_inode);
1405 if (error < 0)
1406 goto out_fail;
1407 error = -ENOMEM;
1408 insert_inode_hash(root_inode);
1409 sb->s_root = d_alloc_root(root_inode);
1410 if (!sb->s_root) {
1411 printk(KERN_ERR "FAT: get root inode failed\n");
1412 goto out_fail;
1413 }
1414
1415 return 0;
1416
1417out_invalid:
1418 error = -EINVAL;
1419 if (!silent)
1420 printk(KERN_INFO "VFS: Can't find a valid FAT filesystem"
1421 " on dev %s.\n", sb->s_id);
1422
1423out_fail:
1424 if (root_inode)
1425 iput(root_inode);
1426 if (sbi->nls_io)
1427 unload_nls(sbi->nls_io);
1428 if (sbi->nls_disk)
1429 unload_nls(sbi->nls_disk);
1430 if (sbi->options.iocharset != fat_default_iocharset)
1431 kfree(sbi->options.iocharset);
1432 sb->s_fs_info = NULL;
1433 kfree(sbi);
1434 return error;
1435}
1436
OGAWA Hirofumi7c709d02006-01-08 01:02:10 -08001437EXPORT_SYMBOL_GPL(fat_fill_super);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001438
Chris Masonae78bf92006-09-29 02:00:03 -07001439/*
1440 * helper function for fat_flush_inodes. This writes both the inode
1441 * and the file data blocks, waiting for in flight data blocks before
1442 * the start of the call. It does not wait for any io started
1443 * during the call
1444 */
1445static int writeback_inode(struct inode *inode)
1446{
1447
1448 int ret;
1449 struct address_space *mapping = inode->i_mapping;
1450 struct writeback_control wbc = {
1451 .sync_mode = WB_SYNC_NONE,
1452 .nr_to_write = 0,
1453 };
1454 /* if we used WB_SYNC_ALL, sync_inode waits for the io for the
1455 * inode to finish. So WB_SYNC_NONE is sent down to sync_inode
1456 * and filemap_fdatawrite is used for the data blocks
1457 */
1458 ret = sync_inode(inode, &wbc);
1459 if (!ret)
1460 ret = filemap_fdatawrite(mapping);
1461 return ret;
1462}
1463
1464/*
1465 * write data and metadata corresponding to i1 and i2. The io is
1466 * started but we do not wait for any of it to finish.
1467 *
1468 * filemap_flush is used for the block device, so if there is a dirty
1469 * page for a block already in flight, we will not wait and start the
1470 * io over again
1471 */
1472int fat_flush_inodes(struct super_block *sb, struct inode *i1, struct inode *i2)
1473{
1474 int ret = 0;
1475 if (!MSDOS_SB(sb)->options.flush)
1476 return 0;
1477 if (i1)
1478 ret = writeback_inode(i1);
1479 if (!ret && i2)
1480 ret = writeback_inode(i2);
Eric Sesterhenn97e860d2006-10-11 01:21:59 -07001481 if (!ret) {
Chris Masonae78bf92006-09-29 02:00:03 -07001482 struct address_space *mapping = sb->s_bdev->bd_inode->i_mapping;
1483 ret = filemap_flush(mapping);
1484 }
1485 return ret;
1486}
1487EXPORT_SYMBOL_GPL(fat_flush_inodes);
1488
Linus Torvalds1da177e2005-04-16 15:20:36 -07001489static int __init init_fat_fs(void)
1490{
Pekka J Enberg532a39a2005-06-30 02:59:01 -07001491 int err;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001492
Pekka J Enberg532a39a2005-06-30 02:59:01 -07001493 err = fat_cache_init();
1494 if (err)
1495 return err;
1496
1497 err = fat_init_inodecache();
1498 if (err)
1499 goto failed;
1500
1501 return 0;
1502
1503failed:
1504 fat_cache_destroy();
1505 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001506}
1507
1508static void __exit exit_fat_fs(void)
1509{
1510 fat_cache_destroy();
1511 fat_destroy_inodecache();
1512}
1513
1514module_init(init_fat_fs)
1515module_exit(exit_fat_fs)
1516
1517MODULE_LICENSE("GPL");