blob: 085269e07fb3a86f9849b54d5403f68de5bed844 [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
Nick Piggind7777a22007-10-16 01:25:08 -0700144static int fat_write_begin(struct file *file, struct address_space *mapping,
145 loff_t pos, unsigned len, unsigned flags,
146 struct page **pagep, void **fsdata)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700147{
Nick Piggind7777a22007-10-16 01:25:08 -0700148 *pagep = NULL;
149 return cont_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
150 fat_get_block,
151 &MSDOS_I(mapping->host)->mmu_private);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700152}
153
Nick Piggind7777a22007-10-16 01:25:08 -0700154static int fat_write_end(struct file *file, struct address_space *mapping,
155 loff_t pos, unsigned len, unsigned copied,
156 struct page *pagep, void *fsdata)
OGAWA Hirofumief402262005-09-16 19:28:13 -0700157{
Nick Piggind7777a22007-10-16 01:25:08 -0700158 struct inode *inode = mapping->host;
159 int err;
160 err = generic_write_end(file, mapping, pos, len, copied, pagep, fsdata);
161 if (!(err < 0) && !(MSDOS_I(inode)->i_attrs & ATTR_ARCH)) {
OGAWA Hirofumief402262005-09-16 19:28:13 -0700162 inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC;
163 MSDOS_I(inode)->i_attrs |= ATTR_ARCH;
164 mark_inode_dirty(inode);
165 }
166 return err;
167}
168
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -0800169static ssize_t fat_direct_IO(int rw, struct kiocb *iocb,
170 const struct iovec *iov,
171 loff_t offset, unsigned long nr_segs)
172{
173 struct file *file = iocb->ki_filp;
174 struct inode *inode = file->f_mapping->host;
175
176 if (rw == WRITE) {
177 /*
178 * FIXME: blockdev_direct_IO() doesn't use ->prepare_write(),
179 * so we need to update the ->mmu_private to block boundary.
180 *
181 * But we must fill the remaining area or hole by nul for
182 * updating ->mmu_private.
OGAWA Hirofumi94412a92007-02-20 13:57:55 -0800183 *
184 * Return 0, and fallback to normal buffered write.
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -0800185 */
186 loff_t size = offset + iov_length(iov, nr_segs);
187 if (MSDOS_I(inode)->mmu_private < size)
OGAWA Hirofumi94412a92007-02-20 13:57:55 -0800188 return 0;
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -0800189 }
190
191 /*
192 * FAT need to use the DIO_LOCKING for avoiding the race
193 * condition of fat_get_block() and ->truncate().
194 */
195 return blockdev_direct_IO(rw, iocb, inode, inode->i_sb->s_bdev, iov,
OGAWA Hirofumi6a1d9802006-09-27 01:50:45 -0700196 offset, nr_segs, fat_get_block, NULL);
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -0800197}
198
Linus Torvalds1da177e2005-04-16 15:20:36 -0700199static sector_t _fat_bmap(struct address_space *mapping, sector_t block)
200{
201 return generic_block_bmap(mapping, block, fat_get_block);
202}
203
Christoph Hellwigf5e54d62006-06-28 04:26:44 -0700204static const struct address_space_operations fat_aops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700205 .readpage = fat_readpage,
OGAWA Hirofumia5425d22006-01-08 01:02:10 -0800206 .readpages = fat_readpages,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700207 .writepage = fat_writepage,
OGAWA Hirofumia5425d22006-01-08 01:02:10 -0800208 .writepages = fat_writepages,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700209 .sync_page = block_sync_page,
Nick Piggind7777a22007-10-16 01:25:08 -0700210 .write_begin = fat_write_begin,
211 .write_end = fat_write_end,
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -0800212 .direct_IO = fat_direct_IO,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700213 .bmap = _fat_bmap
214};
215
216/*
217 * New FAT inode stuff. We do the following:
218 * a) i_ino is constant and has nothing with on-disk location.
219 * b) FAT manages its own cache of directory entries.
220 * c) *This* cache is indexed by on-disk location.
221 * d) inode has an associated directory entry, all right, but
222 * it may be unhashed.
223 * e) currently entries are stored within struct inode. That should
224 * change.
225 * f) we deal with races in the following way:
226 * 1. readdir() and lookup() do FAT-dir-cache lookup.
227 * 2. rename() unhashes the F-d-c entry and rehashes it in
228 * a new place.
229 * 3. unlink() and rmdir() unhash F-d-c entry.
230 * 4. fat_write_inode() checks whether the thing is unhashed.
231 * If it is we silently return. If it isn't we do bread(),
232 * check if the location is still valid and retry if it
233 * isn't. Otherwise we do changes.
234 * 5. Spinlock is used to protect hash/unhash/location check/lookup
235 * 6. fat_clear_inode() unhashes the F-d-c entry.
236 * 7. lookup() and readdir() do igrab() if they find a F-d-c entry
237 * and consider negative result as cache miss.
238 */
239
240static void fat_hash_init(struct super_block *sb)
241{
242 struct msdos_sb_info *sbi = MSDOS_SB(sb);
243 int i;
244
245 spin_lock_init(&sbi->inode_hash_lock);
246 for (i = 0; i < FAT_HASH_SIZE; i++)
247 INIT_HLIST_HEAD(&sbi->inode_hashtable[i]);
248}
249
250static inline unsigned long fat_hash(struct super_block *sb, loff_t i_pos)
251{
252 unsigned long tmp = (unsigned long)i_pos | (unsigned long) sb;
253 tmp = tmp + (tmp >> FAT_HASH_BITS) + (tmp >> FAT_HASH_BITS * 2);
254 return tmp & FAT_HASH_MASK;
255}
256
257void fat_attach(struct inode *inode, loff_t i_pos)
258{
259 struct super_block *sb = inode->i_sb;
260 struct msdos_sb_info *sbi = MSDOS_SB(sb);
261
262 spin_lock(&sbi->inode_hash_lock);
263 MSDOS_I(inode)->i_pos = i_pos;
264 hlist_add_head(&MSDOS_I(inode)->i_fat_hash,
265 sbi->inode_hashtable + fat_hash(sb, i_pos));
266 spin_unlock(&sbi->inode_hash_lock);
267}
268
OGAWA Hirofumi7c709d02006-01-08 01:02:10 -0800269EXPORT_SYMBOL_GPL(fat_attach);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700270
271void fat_detach(struct inode *inode)
272{
273 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
274 spin_lock(&sbi->inode_hash_lock);
275 MSDOS_I(inode)->i_pos = 0;
276 hlist_del_init(&MSDOS_I(inode)->i_fat_hash);
277 spin_unlock(&sbi->inode_hash_lock);
278}
279
OGAWA Hirofumi7c709d02006-01-08 01:02:10 -0800280EXPORT_SYMBOL_GPL(fat_detach);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700281
282struct inode *fat_iget(struct super_block *sb, loff_t i_pos)
283{
284 struct msdos_sb_info *sbi = MSDOS_SB(sb);
285 struct hlist_head *head = sbi->inode_hashtable + fat_hash(sb, i_pos);
286 struct hlist_node *_p;
287 struct msdos_inode_info *i;
288 struct inode *inode = NULL;
289
290 spin_lock(&sbi->inode_hash_lock);
291 hlist_for_each_entry(i, _p, head, i_fat_hash) {
292 BUG_ON(i->vfs_inode.i_sb != sb);
293 if (i->i_pos != i_pos)
294 continue;
295 inode = igrab(&i->vfs_inode);
296 if (inode)
297 break;
298 }
299 spin_unlock(&sbi->inode_hash_lock);
300 return inode;
301}
302
303static int is_exec(unsigned char *extension)
304{
305 unsigned char *exe_extensions = "EXECOMBAT", *walk;
306
307 for (walk = exe_extensions; *walk; walk += 3)
308 if (!strncmp(extension, walk, 3))
309 return 1;
310 return 0;
311}
312
313static int fat_calc_dir_size(struct inode *inode)
314{
315 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
316 int ret, fclus, dclus;
317
318 inode->i_size = 0;
319 if (MSDOS_I(inode)->i_start == 0)
320 return 0;
321
322 ret = fat_get_cluster(inode, FAT_ENT_EOF, &fclus, &dclus);
323 if (ret < 0)
324 return ret;
325 inode->i_size = (fclus + 1) << sbi->cluster_bits;
326
327 return 0;
328}
329
330/* doesn't deal with root inode */
331static int fat_fill_inode(struct inode *inode, struct msdos_dir_entry *de)
332{
333 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
334 int error;
335
336 MSDOS_I(inode)->i_pos = 0;
337 inode->i_uid = sbi->options.fs_uid;
338 inode->i_gid = sbi->options.fs_gid;
339 inode->i_version++;
340 inode->i_generation = get_seconds();
341
342 if ((de->attr & ATTR_DIR) && !IS_FREE(de->name)) {
343 inode->i_generation &= ~1;
344 inode->i_mode = MSDOS_MKMODE(de->attr,
345 S_IRWXUGO & ~sbi->options.fs_dmask) | S_IFDIR;
346 inode->i_op = sbi->dir_ops;
347 inode->i_fop = &fat_dir_operations;
348
349 MSDOS_I(inode)->i_start = le16_to_cpu(de->start);
350 if (sbi->fat_bits == 32)
351 MSDOS_I(inode)->i_start |= (le16_to_cpu(de->starthi) << 16);
352
353 MSDOS_I(inode)->i_logstart = MSDOS_I(inode)->i_start;
354 error = fat_calc_dir_size(inode);
355 if (error < 0)
356 return error;
357 MSDOS_I(inode)->mmu_private = inode->i_size;
358
359 inode->i_nlink = fat_subdirs(inode);
360 } else { /* not a directory */
361 inode->i_generation |= 1;
362 inode->i_mode = MSDOS_MKMODE(de->attr,
OGAWA Hirofumi9aacd592007-07-15 23:39:56 -0700363 ((sbi->options.showexec && !is_exec(de->name + 8))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700364 ? S_IRUGO|S_IWUGO : S_IRWXUGO)
365 & ~sbi->options.fs_fmask) | S_IFREG;
366 MSDOS_I(inode)->i_start = le16_to_cpu(de->start);
367 if (sbi->fat_bits == 32)
368 MSDOS_I(inode)->i_start |= (le16_to_cpu(de->starthi) << 16);
369
370 MSDOS_I(inode)->i_logstart = MSDOS_I(inode)->i_start;
371 inode->i_size = le32_to_cpu(de->size);
372 inode->i_op = &fat_file_inode_operations;
373 inode->i_fop = &fat_file_operations;
374 inode->i_mapping->a_ops = &fat_aops;
375 MSDOS_I(inode)->mmu_private = inode->i_size;
376 }
377 if (de->attr & ATTR_SYS) {
378 if (sbi->options.sys_immutable)
379 inode->i_flags |= S_IMMUTABLE;
380 }
381 MSDOS_I(inode)->i_attrs = de->attr & ATTR_UNUSED;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700382 inode->i_blocks = ((inode->i_size + (sbi->cluster_size - 1))
383 & ~((loff_t)sbi->cluster_size - 1)) >> 9;
Stephane Kardas62a36c42005-09-21 09:55:45 -0700384 inode->i_mtime.tv_sec =
Linus Torvalds1da177e2005-04-16 15:20:36 -0700385 date_dos2unix(le16_to_cpu(de->time), le16_to_cpu(de->date));
Stephane Kardas62a36c42005-09-21 09:55:45 -0700386 inode->i_mtime.tv_nsec = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700387 if (sbi->options.isvfat) {
388 int secs = de->ctime_cs / 100;
389 int csecs = de->ctime_cs % 100;
390 inode->i_ctime.tv_sec =
391 date_dos2unix(le16_to_cpu(de->ctime),
392 le16_to_cpu(de->cdate)) + secs;
393 inode->i_ctime.tv_nsec = csecs * 10000000;
Stephane Kardas62a36c42005-09-21 09:55:45 -0700394 inode->i_atime.tv_sec =
Al Viro31b1f852005-12-24 14:31:04 -0500395 date_dos2unix(0, le16_to_cpu(de->adate));
Stephane Kardas62a36c42005-09-21 09:55:45 -0700396 inode->i_atime.tv_nsec = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700397 } else
Stephane Kardas62a36c42005-09-21 09:55:45 -0700398 inode->i_ctime = inode->i_atime = inode->i_mtime;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700399
400 return 0;
401}
402
403struct inode *fat_build_inode(struct super_block *sb,
404 struct msdos_dir_entry *de, loff_t i_pos)
405{
406 struct inode *inode;
407 int err;
408
409 inode = fat_iget(sb, i_pos);
410 if (inode)
411 goto out;
412 inode = new_inode(sb);
413 if (!inode) {
414 inode = ERR_PTR(-ENOMEM);
415 goto out;
416 }
417 inode->i_ino = iunique(sb, MSDOS_ROOT_INO);
418 inode->i_version = 1;
419 err = fat_fill_inode(inode, de);
420 if (err) {
421 iput(inode);
422 inode = ERR_PTR(err);
423 goto out;
424 }
425 fat_attach(inode, i_pos);
426 insert_inode_hash(inode);
427out:
428 return inode;
429}
430
OGAWA Hirofumi7c709d02006-01-08 01:02:10 -0800431EXPORT_SYMBOL_GPL(fat_build_inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700432
433static void fat_delete_inode(struct inode *inode)
434{
Mark Fashehfef26652005-09-09 13:01:31 -0700435 truncate_inode_pages(&inode->i_data, 0);
436
Linus Torvalds1da177e2005-04-16 15:20:36 -0700437 if (!is_bad_inode(inode)) {
438 inode->i_size = 0;
439 fat_truncate(inode);
440 }
441 clear_inode(inode);
442}
443
444static void fat_clear_inode(struct inode *inode)
445{
446 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
447
448 if (is_bad_inode(inode))
449 return;
450 lock_kernel();
451 spin_lock(&sbi->inode_hash_lock);
452 fat_cache_inval_inode(inode);
453 hlist_del_init(&MSDOS_I(inode)->i_fat_hash);
454 spin_unlock(&sbi->inode_hash_lock);
455 unlock_kernel();
456}
457
OGAWA Hirofumia6bf6b22006-01-08 01:02:08 -0800458static void fat_write_super(struct super_block *sb)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700459{
OGAWA Hirofumia6bf6b22006-01-08 01:02:08 -0800460 sb->s_dirt = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700461
462 if (!(sb->s_flags & MS_RDONLY))
463 fat_clusters_flush(sb);
OGAWA Hirofumia6bf6b22006-01-08 01:02:08 -0800464}
465
466static void fat_put_super(struct super_block *sb)
467{
468 struct msdos_sb_info *sbi = MSDOS_SB(sb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700469
470 if (sbi->nls_disk) {
471 unload_nls(sbi->nls_disk);
472 sbi->nls_disk = NULL;
473 sbi->options.codepage = fat_default_codepage;
474 }
475 if (sbi->nls_io) {
476 unload_nls(sbi->nls_io);
477 sbi->nls_io = NULL;
478 }
479 if (sbi->options.iocharset != fat_default_iocharset) {
480 kfree(sbi->options.iocharset);
481 sbi->options.iocharset = fat_default_iocharset;
482 }
483
484 sb->s_fs_info = NULL;
485 kfree(sbi);
486}
487
Christoph Lametere18b8902006-12-06 20:33:20 -0800488static struct kmem_cache *fat_inode_cachep;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700489
490static struct inode *fat_alloc_inode(struct super_block *sb)
491{
492 struct msdos_inode_info *ei;
Christoph Lametere94b1762006-12-06 20:33:17 -0800493 ei = kmem_cache_alloc(fat_inode_cachep, GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700494 if (!ei)
495 return NULL;
496 return &ei->vfs_inode;
497}
498
499static void fat_destroy_inode(struct inode *inode)
500{
501 kmem_cache_free(fat_inode_cachep, MSDOS_I(inode));
502}
503
Christoph Lameter4ba9b9d2007-10-16 23:25:51 -0700504static void init_once(struct kmem_cache *cachep, void *foo)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700505{
506 struct msdos_inode_info *ei = (struct msdos_inode_info *)foo;
507
Christoph Lametera35afb82007-05-16 22:10:57 -0700508 spin_lock_init(&ei->cache_lru_lock);
509 ei->nr_caches = 0;
510 ei->cache_valid_id = FAT_CACHE_VALID + 1;
511 INIT_LIST_HEAD(&ei->cache_lru);
512 INIT_HLIST_NODE(&ei->i_fat_hash);
513 inode_init_once(&ei->vfs_inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700514}
515
516static int __init fat_init_inodecache(void)
517{
518 fat_inode_cachep = kmem_cache_create("fat_inode_cache",
519 sizeof(struct msdos_inode_info),
Paul Jacksonfffb60f2006-03-24 03:16:06 -0800520 0, (SLAB_RECLAIM_ACCOUNT|
521 SLAB_MEM_SPREAD),
Paul Mundt20c2df82007-07-20 10:11:58 +0900522 init_once);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700523 if (fat_inode_cachep == NULL)
524 return -ENOMEM;
525 return 0;
526}
527
528static void __exit fat_destroy_inodecache(void)
529{
Alexey Dobriyan1a1d92c2006-09-27 01:49:40 -0700530 kmem_cache_destroy(fat_inode_cachep);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700531}
532
533static int fat_remount(struct super_block *sb, int *flags, char *data)
534{
535 struct msdos_sb_info *sbi = MSDOS_SB(sb);
536 *flags |= MS_NODIRATIME | (sbi->options.isvfat ? 0 : MS_NOATIME);
537 return 0;
538}
539
David Howells726c3342006-06-23 02:02:58 -0700540static int fat_statfs(struct dentry *dentry, struct kstatfs *buf)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700541{
David Howells726c3342006-06-23 02:02:58 -0700542 struct msdos_sb_info *sbi = MSDOS_SB(dentry->d_sb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700543
544 /* If the count of free cluster is still unknown, counts it here. */
545 if (sbi->free_clusters == -1) {
David Howells726c3342006-06-23 02:02:58 -0700546 int err = fat_count_free_clusters(dentry->d_sb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700547 if (err)
548 return err;
549 }
550
David Howells726c3342006-06-23 02:02:58 -0700551 buf->f_type = dentry->d_sb->s_magic;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700552 buf->f_bsize = sbi->cluster_size;
553 buf->f_blocks = sbi->max_cluster - FAT_START_ENT;
554 buf->f_bfree = sbi->free_clusters;
555 buf->f_bavail = sbi->free_clusters;
556 buf->f_namelen = sbi->options.isvfat ? 260 : 12;
557
558 return 0;
559}
560
561static int fat_write_inode(struct inode *inode, int wait)
562{
563 struct super_block *sb = inode->i_sb;
564 struct msdos_sb_info *sbi = MSDOS_SB(sb);
565 struct buffer_head *bh;
566 struct msdos_dir_entry *raw_entry;
567 loff_t i_pos;
568 int err = 0;
569
570retry:
571 i_pos = MSDOS_I(inode)->i_pos;
572 if (inode->i_ino == MSDOS_ROOT_INO || !i_pos)
573 return 0;
574
575 lock_kernel();
576 bh = sb_bread(sb, i_pos >> sbi->dir_per_block_bits);
577 if (!bh) {
578 printk(KERN_ERR "FAT: unable to read inode block "
579 "for updating (i_pos %lld)\n", i_pos);
580 err = -EIO;
581 goto out;
582 }
583 spin_lock(&sbi->inode_hash_lock);
584 if (i_pos != MSDOS_I(inode)->i_pos) {
585 spin_unlock(&sbi->inode_hash_lock);
586 brelse(bh);
587 unlock_kernel();
588 goto retry;
589 }
590
591 raw_entry = &((struct msdos_dir_entry *) (bh->b_data))
592 [i_pos & (sbi->dir_per_block - 1)];
593 if (S_ISDIR(inode->i_mode))
594 raw_entry->size = 0;
595 else
596 raw_entry->size = cpu_to_le32(inode->i_size);
597 raw_entry->attr = fat_attr(inode);
598 raw_entry->start = cpu_to_le16(MSDOS_I(inode)->i_logstart);
599 raw_entry->starthi = cpu_to_le16(MSDOS_I(inode)->i_logstart >> 16);
600 fat_date_unix2dos(inode->i_mtime.tv_sec, &raw_entry->time, &raw_entry->date);
601 if (sbi->options.isvfat) {
Stephane Kardas62a36c42005-09-21 09:55:45 -0700602 __le16 atime;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700603 fat_date_unix2dos(inode->i_ctime.tv_sec,&raw_entry->ctime,&raw_entry->cdate);
Stephane Kardas62a36c42005-09-21 09:55:45 -0700604 fat_date_unix2dos(inode->i_atime.tv_sec,&atime,&raw_entry->adate);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700605 raw_entry->ctime_cs = (inode->i_ctime.tv_sec & 1) * 100 +
606 inode->i_ctime.tv_nsec / 10000000;
607 }
608 spin_unlock(&sbi->inode_hash_lock);
609 mark_buffer_dirty(bh);
610 if (wait)
611 err = sync_dirty_buffer(bh);
612 brelse(bh);
613out:
614 unlock_kernel();
615 return err;
616}
617
618int fat_sync_inode(struct inode *inode)
619{
620 return fat_write_inode(inode, 1);
621}
622
OGAWA Hirofumi7c709d02006-01-08 01:02:10 -0800623EXPORT_SYMBOL_GPL(fat_sync_inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700624
625static int fat_show_options(struct seq_file *m, struct vfsmount *mnt);
Josef 'Jeff' Sipekee9b6d62007-02-12 00:55:41 -0800626static const struct super_operations fat_sops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700627 .alloc_inode = fat_alloc_inode,
628 .destroy_inode = fat_destroy_inode,
629 .write_inode = fat_write_inode,
630 .delete_inode = fat_delete_inode,
631 .put_super = fat_put_super,
OGAWA Hirofumia6bf6b22006-01-08 01:02:08 -0800632 .write_super = fat_write_super,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700633 .statfs = fat_statfs,
634 .clear_inode = fat_clear_inode,
635 .remount_fs = fat_remount,
636
Linus Torvalds1da177e2005-04-16 15:20:36 -0700637 .show_options = fat_show_options,
638};
639
640/*
641 * a FAT file handle with fhtype 3 is
642 * 0/ i_ino - for fast, reliable lookup if still in the cache
643 * 1/ i_generation - to see if i_ino is still valid
644 * bit 0 == 0 iff directory
645 * 2/ i_pos(8-39) - if ino has changed, but still in cache
646 * 3/ i_pos(4-7)|i_logstart - to semi-verify inode found at i_pos
647 * 4/ i_pos(0-3)|parent->i_logstart - maybe used to hunt for the file on disc
648 *
649 * Hack for NFSv2: Maximum FAT entry number is 28bits and maximum
650 * i_pos is 40bits (blocknr(32) + dir offset(8)), so two 4bits
651 * of i_logstart is used to store the directory entry offset.
652 */
653
Christoph Hellwig1305edad2007-10-21 16:42:11 -0700654static struct dentry *fat_fh_to_dentry(struct super_block *sb,
655 struct fid *fid, int fh_len, int fh_type)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700656{
657 struct inode *inode = NULL;
658 struct dentry *result;
Christoph Hellwig1305edad2007-10-21 16:42:11 -0700659 u32 *fh = fid->raw;
660
661 if (fh_len < 5 || fh_type != 3)
662 return NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700663
David Howells17f95a72008-02-07 00:15:38 -0800664 inode = ilookup(sb, fh[0]);
665 if (!inode || inode->i_generation != fh[1]) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700666 if (inode)
667 iput(inode);
668 inode = NULL;
669 }
670 if (!inode) {
671 loff_t i_pos;
672 int i_logstart = fh[3] & 0x0fffffff;
673
674 i_pos = (loff_t)fh[2] << 8;
675 i_pos |= ((fh[3] >> 24) & 0xf0) | (fh[4] >> 28);
676
677 /* try 2 - see if i_pos is in F-d-c
678 * require i_logstart to be the same
679 * Will fail if you truncate and then re-write
680 */
681
682 inode = fat_iget(sb, i_pos);
683 if (inode && MSDOS_I(inode)->i_logstart != i_logstart) {
684 iput(inode);
685 inode = NULL;
686 }
687 }
688 if (!inode) {
689 /* For now, do nothing
690 * What we could do is:
691 * follow the file starting at fh[4], and record
692 * the ".." entry, and the name of the fh[2] entry.
693 * The follow the ".." file finding the next step up.
694 * This way we build a path to the root of
695 * the tree. If this works, we lookup the path and so
696 * get this inode into the cache.
697 * Finally try the fat_iget lookup again
698 * If that fails, then weare totally out of luck
699 * But all that is for another day
700 */
701 }
702 if (!inode)
703 return ERR_PTR(-ESTALE);
704
705
706 /* now to find a dentry.
707 * If possible, get a well-connected one
708 */
709 result = d_alloc_anon(inode);
710 if (result == NULL) {
711 iput(inode);
712 return ERR_PTR(-ENOMEM);
713 }
714 result->d_op = sb->s_root->d_op;
715 return result;
716}
717
718static int
719fat_encode_fh(struct dentry *de, __u32 *fh, int *lenp, int connectable)
720{
721 int len = *lenp;
722 struct inode *inode = de->d_inode;
723 u32 ipos_h, ipos_m, ipos_l;
724
725 if (len < 5)
726 return 255; /* no room */
727
728 ipos_h = MSDOS_I(inode)->i_pos >> 8;
729 ipos_m = (MSDOS_I(inode)->i_pos & 0xf0) << 24;
730 ipos_l = (MSDOS_I(inode)->i_pos & 0x0f) << 28;
731 *lenp = 5;
732 fh[0] = inode->i_ino;
733 fh[1] = inode->i_generation;
734 fh[2] = ipos_h;
735 fh[3] = ipos_m | MSDOS_I(inode)->i_logstart;
736 spin_lock(&de->d_lock);
737 fh[4] = ipos_l | MSDOS_I(de->d_parent->d_inode)->i_logstart;
738 spin_unlock(&de->d_lock);
739 return 3;
740}
741
742static struct dentry *fat_get_parent(struct dentry *child)
743{
744 struct buffer_head *bh;
745 struct msdos_dir_entry *de;
746 loff_t i_pos;
747 struct dentry *parent;
748 struct inode *inode;
749 int err;
750
751 lock_kernel();
752
753 err = fat_get_dotdot_entry(child->d_inode, &bh, &de, &i_pos);
754 if (err) {
755 parent = ERR_PTR(err);
756 goto out;
757 }
758 inode = fat_build_inode(child->d_sb, de, i_pos);
759 brelse(bh);
760 if (IS_ERR(inode)) {
David Howellse231c2e2008-02-07 00:15:26 -0800761 parent = ERR_CAST(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700762 goto out;
763 }
764 parent = d_alloc_anon(inode);
765 if (!parent) {
766 iput(inode);
767 parent = ERR_PTR(-ENOMEM);
768 }
769out:
770 unlock_kernel();
771
772 return parent;
773}
774
Christoph Hellwig39655162007-10-21 16:42:17 -0700775static const struct export_operations fat_export_ops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700776 .encode_fh = fat_encode_fh,
Christoph Hellwig1305edad2007-10-21 16:42:11 -0700777 .fh_to_dentry = fat_fh_to_dentry,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700778 .get_parent = fat_get_parent,
779};
780
781static int fat_show_options(struct seq_file *m, struct vfsmount *mnt)
782{
783 struct msdos_sb_info *sbi = MSDOS_SB(mnt->mnt_sb);
784 struct fat_mount_options *opts = &sbi->options;
785 int isvfat = opts->isvfat;
786
787 if (opts->fs_uid != 0)
788 seq_printf(m, ",uid=%u", opts->fs_uid);
789 if (opts->fs_gid != 0)
790 seq_printf(m, ",gid=%u", opts->fs_gid);
791 seq_printf(m, ",fmask=%04o", opts->fs_fmask);
792 seq_printf(m, ",dmask=%04o", opts->fs_dmask);
793 if (sbi->nls_disk)
794 seq_printf(m, ",codepage=%s", sbi->nls_disk->charset);
795 if (isvfat) {
796 if (sbi->nls_io)
797 seq_printf(m, ",iocharset=%s", sbi->nls_io->charset);
798
799 switch (opts->shortname) {
800 case VFAT_SFN_DISPLAY_WIN95 | VFAT_SFN_CREATE_WIN95:
801 seq_puts(m, ",shortname=win95");
802 break;
803 case VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WINNT:
804 seq_puts(m, ",shortname=winnt");
805 break;
806 case VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WIN95:
807 seq_puts(m, ",shortname=mixed");
808 break;
809 case VFAT_SFN_DISPLAY_LOWER | VFAT_SFN_CREATE_WIN95:
810 /* seq_puts(m, ",shortname=lower"); */
811 break;
812 default:
813 seq_puts(m, ",shortname=unknown");
814 break;
815 }
816 }
817 if (opts->name_check != 'n')
818 seq_printf(m, ",check=%c", opts->name_check);
OGAWA Hirofumi28ec0392007-05-08 00:31:01 -0700819 if (opts->usefree)
820 seq_puts(m, ",usefree");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700821 if (opts->quiet)
822 seq_puts(m, ",quiet");
823 if (opts->showexec)
824 seq_puts(m, ",showexec");
825 if (opts->sys_immutable)
826 seq_puts(m, ",sys_immutable");
827 if (!isvfat) {
828 if (opts->dotsOK)
829 seq_puts(m, ",dotsOK=yes");
830 if (opts->nocase)
831 seq_puts(m, ",nocase");
832 } else {
833 if (opts->utf8)
834 seq_puts(m, ",utf8");
835 if (opts->unicode_xlate)
836 seq_puts(m, ",uni_xlate");
837 if (!opts->numtail)
838 seq_puts(m, ",nonumtail");
839 }
840
841 return 0;
842}
843
844enum {
845 Opt_check_n, Opt_check_r, Opt_check_s, Opt_uid, Opt_gid,
OGAWA Hirofumi28ec0392007-05-08 00:31:01 -0700846 Opt_umask, Opt_dmask, Opt_fmask, Opt_codepage, Opt_usefree, Opt_nocase,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700847 Opt_quiet, Opt_showexec, Opt_debug, Opt_immutable,
848 Opt_dots, Opt_nodots,
849 Opt_charset, Opt_shortname_lower, Opt_shortname_win95,
850 Opt_shortname_winnt, Opt_shortname_mixed, Opt_utf8_no, Opt_utf8_yes,
851 Opt_uni_xl_no, Opt_uni_xl_yes, Opt_nonumtail_no, Opt_nonumtail_yes,
Chris Masonae78bf92006-09-29 02:00:03 -0700852 Opt_obsolate, Opt_flush, Opt_err,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700853};
854
855static match_table_t fat_tokens = {
856 {Opt_check_r, "check=relaxed"},
857 {Opt_check_s, "check=strict"},
858 {Opt_check_n, "check=normal"},
859 {Opt_check_r, "check=r"},
860 {Opt_check_s, "check=s"},
861 {Opt_check_n, "check=n"},
862 {Opt_uid, "uid=%u"},
863 {Opt_gid, "gid=%u"},
864 {Opt_umask, "umask=%o"},
865 {Opt_dmask, "dmask=%o"},
866 {Opt_fmask, "fmask=%o"},
867 {Opt_codepage, "codepage=%u"},
OGAWA Hirofumi28ec0392007-05-08 00:31:01 -0700868 {Opt_usefree, "usefree"},
Linus Torvalds1da177e2005-04-16 15:20:36 -0700869 {Opt_nocase, "nocase"},
870 {Opt_quiet, "quiet"},
871 {Opt_showexec, "showexec"},
872 {Opt_debug, "debug"},
873 {Opt_immutable, "sys_immutable"},
874 {Opt_obsolate, "conv=binary"},
875 {Opt_obsolate, "conv=text"},
876 {Opt_obsolate, "conv=auto"},
877 {Opt_obsolate, "conv=b"},
878 {Opt_obsolate, "conv=t"},
879 {Opt_obsolate, "conv=a"},
880 {Opt_obsolate, "fat=%u"},
881 {Opt_obsolate, "blocksize=%u"},
882 {Opt_obsolate, "cvf_format=%20s"},
883 {Opt_obsolate, "cvf_options=%100s"},
884 {Opt_obsolate, "posix"},
Chris Masonae78bf92006-09-29 02:00:03 -0700885 {Opt_flush, "flush"},
886 {Opt_err, NULL},
Linus Torvalds1da177e2005-04-16 15:20:36 -0700887};
888static match_table_t msdos_tokens = {
889 {Opt_nodots, "nodots"},
890 {Opt_nodots, "dotsOK=no"},
891 {Opt_dots, "dots"},
892 {Opt_dots, "dotsOK=yes"},
893 {Opt_err, NULL}
894};
895static match_table_t vfat_tokens = {
896 {Opt_charset, "iocharset=%s"},
897 {Opt_shortname_lower, "shortname=lower"},
898 {Opt_shortname_win95, "shortname=win95"},
899 {Opt_shortname_winnt, "shortname=winnt"},
900 {Opt_shortname_mixed, "shortname=mixed"},
901 {Opt_utf8_no, "utf8=0"}, /* 0 or no or false */
902 {Opt_utf8_no, "utf8=no"},
903 {Opt_utf8_no, "utf8=false"},
904 {Opt_utf8_yes, "utf8=1"}, /* empty or 1 or yes or true */
905 {Opt_utf8_yes, "utf8=yes"},
906 {Opt_utf8_yes, "utf8=true"},
907 {Opt_utf8_yes, "utf8"},
908 {Opt_uni_xl_no, "uni_xlate=0"}, /* 0 or no or false */
909 {Opt_uni_xl_no, "uni_xlate=no"},
910 {Opt_uni_xl_no, "uni_xlate=false"},
911 {Opt_uni_xl_yes, "uni_xlate=1"}, /* empty or 1 or yes or true */
912 {Opt_uni_xl_yes, "uni_xlate=yes"},
913 {Opt_uni_xl_yes, "uni_xlate=true"},
914 {Opt_uni_xl_yes, "uni_xlate"},
915 {Opt_nonumtail_no, "nonumtail=0"}, /* 0 or no or false */
916 {Opt_nonumtail_no, "nonumtail=no"},
917 {Opt_nonumtail_no, "nonumtail=false"},
918 {Opt_nonumtail_yes, "nonumtail=1"}, /* empty or 1 or yes or true */
919 {Opt_nonumtail_yes, "nonumtail=yes"},
920 {Opt_nonumtail_yes, "nonumtail=true"},
921 {Opt_nonumtail_yes, "nonumtail"},
922 {Opt_err, NULL}
923};
924
Christoph Hellwig41a34a42005-11-08 21:34:57 -0800925static int parse_options(char *options, int is_vfat, int silent, int *debug,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700926 struct fat_mount_options *opts)
927{
928 char *p;
929 substring_t args[MAX_OPT_ARGS];
930 int option;
931 char *iocharset;
932
933 opts->isvfat = is_vfat;
934
935 opts->fs_uid = current->uid;
936 opts->fs_gid = current->gid;
937 opts->fs_fmask = opts->fs_dmask = current->fs->umask;
938 opts->codepage = fat_default_codepage;
939 opts->iocharset = fat_default_iocharset;
940 if (is_vfat)
941 opts->shortname = VFAT_SFN_DISPLAY_LOWER|VFAT_SFN_CREATE_WIN95;
942 else
943 opts->shortname = 0;
944 opts->name_check = 'n';
945 opts->quiet = opts->showexec = opts->sys_immutable = opts->dotsOK = 0;
946 opts->utf8 = opts->unicode_xlate = 0;
947 opts->numtail = 1;
OGAWA Hirofumi28ec0392007-05-08 00:31:01 -0700948 opts->usefree = opts->nocase = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700949 *debug = 0;
950
951 if (!options)
952 return 0;
953
954 while ((p = strsep(&options, ",")) != NULL) {
955 int token;
956 if (!*p)
957 continue;
958
959 token = match_token(p, fat_tokens, args);
960 if (token == Opt_err) {
961 if (is_vfat)
962 token = match_token(p, vfat_tokens, args);
963 else
964 token = match_token(p, msdos_tokens, args);
965 }
966 switch (token) {
967 case Opt_check_s:
968 opts->name_check = 's';
969 break;
970 case Opt_check_r:
971 opts->name_check = 'r';
972 break;
973 case Opt_check_n:
974 opts->name_check = 'n';
975 break;
OGAWA Hirofumi28ec0392007-05-08 00:31:01 -0700976 case Opt_usefree:
977 opts->usefree = 1;
978 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700979 case Opt_nocase:
980 if (!is_vfat)
981 opts->nocase = 1;
982 else {
983 /* for backward compatibility */
984 opts->shortname = VFAT_SFN_DISPLAY_WIN95
985 | VFAT_SFN_CREATE_WIN95;
986 }
987 break;
988 case Opt_quiet:
989 opts->quiet = 1;
990 break;
991 case Opt_showexec:
992 opts->showexec = 1;
993 break;
994 case Opt_debug:
995 *debug = 1;
996 break;
997 case Opt_immutable:
998 opts->sys_immutable = 1;
999 break;
1000 case Opt_uid:
1001 if (match_int(&args[0], &option))
1002 return 0;
1003 opts->fs_uid = option;
1004 break;
1005 case Opt_gid:
1006 if (match_int(&args[0], &option))
1007 return 0;
1008 opts->fs_gid = option;
1009 break;
1010 case Opt_umask:
1011 if (match_octal(&args[0], &option))
1012 return 0;
1013 opts->fs_fmask = opts->fs_dmask = option;
1014 break;
1015 case Opt_dmask:
1016 if (match_octal(&args[0], &option))
1017 return 0;
1018 opts->fs_dmask = option;
1019 break;
1020 case Opt_fmask:
1021 if (match_octal(&args[0], &option))
1022 return 0;
1023 opts->fs_fmask = option;
1024 break;
1025 case Opt_codepage:
1026 if (match_int(&args[0], &option))
1027 return 0;
1028 opts->codepage = option;
1029 break;
Chris Masonae78bf92006-09-29 02:00:03 -07001030 case Opt_flush:
1031 opts->flush = 1;
1032 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001033
1034 /* msdos specific */
1035 case Opt_dots:
1036 opts->dotsOK = 1;
1037 break;
1038 case Opt_nodots:
1039 opts->dotsOK = 0;
1040 break;
1041
1042 /* vfat specific */
1043 case Opt_charset:
1044 if (opts->iocharset != fat_default_iocharset)
1045 kfree(opts->iocharset);
1046 iocharset = match_strdup(&args[0]);
1047 if (!iocharset)
1048 return -ENOMEM;
1049 opts->iocharset = iocharset;
1050 break;
1051 case Opt_shortname_lower:
1052 opts->shortname = VFAT_SFN_DISPLAY_LOWER
1053 | VFAT_SFN_CREATE_WIN95;
1054 break;
1055 case Opt_shortname_win95:
1056 opts->shortname = VFAT_SFN_DISPLAY_WIN95
1057 | VFAT_SFN_CREATE_WIN95;
1058 break;
1059 case Opt_shortname_winnt:
1060 opts->shortname = VFAT_SFN_DISPLAY_WINNT
1061 | VFAT_SFN_CREATE_WINNT;
1062 break;
1063 case Opt_shortname_mixed:
1064 opts->shortname = VFAT_SFN_DISPLAY_WINNT
1065 | VFAT_SFN_CREATE_WIN95;
1066 break;
1067 case Opt_utf8_no: /* 0 or no or false */
1068 opts->utf8 = 0;
1069 break;
1070 case Opt_utf8_yes: /* empty or 1 or yes or true */
1071 opts->utf8 = 1;
1072 break;
1073 case Opt_uni_xl_no: /* 0 or no or false */
1074 opts->unicode_xlate = 0;
1075 break;
1076 case Opt_uni_xl_yes: /* empty or 1 or yes or true */
1077 opts->unicode_xlate = 1;
1078 break;
1079 case Opt_nonumtail_no: /* 0 or no or false */
1080 opts->numtail = 1; /* negated option */
1081 break;
1082 case Opt_nonumtail_yes: /* empty or 1 or yes or true */
1083 opts->numtail = 0; /* negated option */
1084 break;
1085
1086 /* obsolete mount options */
1087 case Opt_obsolate:
1088 printk(KERN_INFO "FAT: \"%s\" option is obsolete, "
1089 "not supported now\n", p);
1090 break;
1091 /* unknown option */
1092 default:
Christoph Hellwig41a34a42005-11-08 21:34:57 -08001093 if (!silent) {
1094 printk(KERN_ERR
1095 "FAT: Unrecognized mount option \"%s\" "
1096 "or missing value\n", p);
1097 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001098 return -EINVAL;
1099 }
1100 }
Alexey Dobriyan4de151d2006-03-22 00:13:35 +01001101 /* UTF-8 doesn't provide FAT semantics */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001102 if (!strcmp(opts->iocharset, "utf8")) {
1103 printk(KERN_ERR "FAT: utf8 is not a recommended IO charset"
1104 " for FAT filesystems, filesystem will be case sensitive!\n");
1105 }
1106
1107 if (opts->unicode_xlate)
1108 opts->utf8 = 0;
1109
1110 return 0;
1111}
1112
1113static int fat_read_root(struct inode *inode)
1114{
1115 struct super_block *sb = inode->i_sb;
1116 struct msdos_sb_info *sbi = MSDOS_SB(sb);
1117 int error;
1118
1119 MSDOS_I(inode)->i_pos = 0;
1120 inode->i_uid = sbi->options.fs_uid;
1121 inode->i_gid = sbi->options.fs_gid;
1122 inode->i_version++;
1123 inode->i_generation = 0;
1124 inode->i_mode = (S_IRWXUGO & ~sbi->options.fs_dmask) | S_IFDIR;
1125 inode->i_op = sbi->dir_ops;
1126 inode->i_fop = &fat_dir_operations;
1127 if (sbi->fat_bits == 32) {
1128 MSDOS_I(inode)->i_start = sbi->root_cluster;
1129 error = fat_calc_dir_size(inode);
1130 if (error < 0)
1131 return error;
1132 } else {
1133 MSDOS_I(inode)->i_start = 0;
1134 inode->i_size = sbi->dir_entries * sizeof(struct msdos_dir_entry);
1135 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001136 inode->i_blocks = ((inode->i_size + (sbi->cluster_size - 1))
1137 & ~((loff_t)sbi->cluster_size - 1)) >> 9;
1138 MSDOS_I(inode)->i_logstart = 0;
1139 MSDOS_I(inode)->mmu_private = inode->i_size;
1140
1141 MSDOS_I(inode)->i_attrs = ATTR_NONE;
1142 inode->i_mtime.tv_sec = inode->i_atime.tv_sec = inode->i_ctime.tv_sec = 0;
1143 inode->i_mtime.tv_nsec = inode->i_atime.tv_nsec = inode->i_ctime.tv_nsec = 0;
1144 inode->i_nlink = fat_subdirs(inode)+2;
1145
1146 return 0;
1147}
1148
1149/*
1150 * Read the super block of an MS-DOS FS.
1151 */
1152int fat_fill_super(struct super_block *sb, void *data, int silent,
Arjan van de Ven754661f2007-02-12 00:55:38 -08001153 const struct inode_operations *fs_dir_inode_ops, int isvfat)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001154{
1155 struct inode *root_inode = NULL;
1156 struct buffer_head *bh;
1157 struct fat_boot_sector *b;
1158 struct msdos_sb_info *sbi;
1159 u16 logical_sector_size;
1160 u32 total_sectors, total_clusters, fat_clusters, rootdir_sectors;
1161 int debug;
1162 unsigned int media;
1163 long error;
1164 char buf[50];
1165
Panagiotis Issarisf8314dc2006-09-27 01:49:37 -07001166 sbi = kzalloc(sizeof(struct msdos_sb_info), GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001167 if (!sbi)
1168 return -ENOMEM;
1169 sb->s_fs_info = sbi;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001170
1171 sb->s_flags |= MS_NODIRATIME;
1172 sb->s_magic = MSDOS_SUPER_MAGIC;
1173 sb->s_op = &fat_sops;
1174 sb->s_export_op = &fat_export_ops;
1175 sbi->dir_ops = fs_dir_inode_ops;
1176
Christoph Hellwig41a34a42005-11-08 21:34:57 -08001177 error = parse_options(data, isvfat, silent, &debug, &sbi->options);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001178 if (error)
1179 goto out_fail;
1180
1181 error = -EIO;
1182 sb_min_blocksize(sb, 512);
1183 bh = sb_bread(sb, 0);
1184 if (bh == NULL) {
1185 printk(KERN_ERR "FAT: unable to read boot sector\n");
1186 goto out_fail;
1187 }
1188
1189 b = (struct fat_boot_sector *) bh->b_data;
1190 if (!b->reserved) {
1191 if (!silent)
1192 printk(KERN_ERR "FAT: bogus number of reserved sectors\n");
1193 brelse(bh);
1194 goto out_invalid;
1195 }
1196 if (!b->fats) {
1197 if (!silent)
1198 printk(KERN_ERR "FAT: bogus number of FAT structure\n");
1199 brelse(bh);
1200 goto out_invalid;
1201 }
1202
1203 /*
1204 * Earlier we checked here that b->secs_track and b->head are nonzero,
1205 * but it turns out valid FAT filesystems can have zero there.
1206 */
1207
1208 media = b->media;
1209 if (!FAT_VALID_MEDIA(media)) {
1210 if (!silent)
1211 printk(KERN_ERR "FAT: invalid media value (0x%02x)\n",
1212 media);
1213 brelse(bh);
1214 goto out_invalid;
1215 }
1216 logical_sector_size =
1217 le16_to_cpu(get_unaligned((__le16 *)&b->sector_size));
Vignesh Babu BMe7d709c2007-05-08 00:24:27 -07001218 if (!is_power_of_2(logical_sector_size)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001219 || (logical_sector_size < 512)
1220 || (PAGE_CACHE_SIZE < logical_sector_size)) {
1221 if (!silent)
1222 printk(KERN_ERR "FAT: bogus logical sector size %u\n",
1223 logical_sector_size);
1224 brelse(bh);
1225 goto out_invalid;
1226 }
1227 sbi->sec_per_clus = b->sec_per_clus;
Vignesh Babu BMe7d709c2007-05-08 00:24:27 -07001228 if (!is_power_of_2(sbi->sec_per_clus)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001229 if (!silent)
1230 printk(KERN_ERR "FAT: bogus sectors per cluster %u\n",
1231 sbi->sec_per_clus);
1232 brelse(bh);
1233 goto out_invalid;
1234 }
1235
1236 if (logical_sector_size < sb->s_blocksize) {
1237 printk(KERN_ERR "FAT: logical sector size too small for device"
1238 " (logical sector size = %u)\n", logical_sector_size);
1239 brelse(bh);
1240 goto out_fail;
1241 }
1242 if (logical_sector_size > sb->s_blocksize) {
1243 brelse(bh);
1244
1245 if (!sb_set_blocksize(sb, logical_sector_size)) {
1246 printk(KERN_ERR "FAT: unable to set blocksize %u\n",
1247 logical_sector_size);
1248 goto out_fail;
1249 }
1250 bh = sb_bread(sb, 0);
1251 if (bh == NULL) {
1252 printk(KERN_ERR "FAT: unable to read boot sector"
1253 " (logical sector size = %lu)\n",
1254 sb->s_blocksize);
1255 goto out_fail;
1256 }
1257 b = (struct fat_boot_sector *) bh->b_data;
1258 }
1259
1260 sbi->cluster_size = sb->s_blocksize * sbi->sec_per_clus;
1261 sbi->cluster_bits = ffs(sbi->cluster_size) - 1;
1262 sbi->fats = b->fats;
1263 sbi->fat_bits = 0; /* Don't know yet */
1264 sbi->fat_start = le16_to_cpu(b->reserved);
1265 sbi->fat_length = le16_to_cpu(b->fat_length);
1266 sbi->root_cluster = 0;
1267 sbi->free_clusters = -1; /* Don't know yet */
1268 sbi->prev_free = FAT_START_ENT;
1269
1270 if (!sbi->fat_length && b->fat32_length) {
1271 struct fat_boot_fsinfo *fsinfo;
1272 struct buffer_head *fsinfo_bh;
1273
1274 /* Must be FAT32 */
1275 sbi->fat_bits = 32;
1276 sbi->fat_length = le32_to_cpu(b->fat32_length);
1277 sbi->root_cluster = le32_to_cpu(b->root_cluster);
1278
1279 sb->s_maxbytes = 0xffffffff;
1280
1281 /* MC - if info_sector is 0, don't multiply by 0 */
1282 sbi->fsinfo_sector = le16_to_cpu(b->info_sector);
1283 if (sbi->fsinfo_sector == 0)
1284 sbi->fsinfo_sector = 1;
1285
1286 fsinfo_bh = sb_bread(sb, sbi->fsinfo_sector);
1287 if (fsinfo_bh == NULL) {
1288 printk(KERN_ERR "FAT: bread failed, FSINFO block"
1289 " (sector = %lu)\n", sbi->fsinfo_sector);
1290 brelse(bh);
1291 goto out_fail;
1292 }
1293
1294 fsinfo = (struct fat_boot_fsinfo *)fsinfo_bh->b_data;
1295 if (!IS_FSINFO(fsinfo)) {
Vegard Nossumb4cf9c32008-02-06 01:36:36 -08001296 printk(KERN_WARNING "FAT: Invalid FSINFO signature: "
1297 "0x%08x, 0x%08x (sector = %lu)\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -07001298 le32_to_cpu(fsinfo->signature1),
1299 le32_to_cpu(fsinfo->signature2),
1300 sbi->fsinfo_sector);
1301 } else {
OGAWA Hirofumi28ec0392007-05-08 00:31:01 -07001302 if (sbi->options.usefree)
1303 sbi->free_clusters =
1304 le32_to_cpu(fsinfo->free_clusters);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001305 sbi->prev_free = le32_to_cpu(fsinfo->next_cluster);
1306 }
1307
1308 brelse(fsinfo_bh);
1309 }
1310
1311 sbi->dir_per_block = sb->s_blocksize / sizeof(struct msdos_dir_entry);
1312 sbi->dir_per_block_bits = ffs(sbi->dir_per_block) - 1;
1313
1314 sbi->dir_start = sbi->fat_start + sbi->fats * sbi->fat_length;
1315 sbi->dir_entries =
1316 le16_to_cpu(get_unaligned((__le16 *)&b->dir_entries));
1317 if (sbi->dir_entries & (sbi->dir_per_block - 1)) {
1318 if (!silent)
1319 printk(KERN_ERR "FAT: bogus directroy-entries per block"
1320 " (%u)\n", sbi->dir_entries);
1321 brelse(bh);
1322 goto out_invalid;
1323 }
1324
1325 rootdir_sectors = sbi->dir_entries
1326 * sizeof(struct msdos_dir_entry) / sb->s_blocksize;
1327 sbi->data_start = sbi->dir_start + rootdir_sectors;
1328 total_sectors = le16_to_cpu(get_unaligned((__le16 *)&b->sectors));
1329 if (total_sectors == 0)
1330 total_sectors = le32_to_cpu(b->total_sect);
1331
1332 total_clusters = (total_sectors - sbi->data_start) / sbi->sec_per_clus;
1333
1334 if (sbi->fat_bits != 32)
1335 sbi->fat_bits = (total_clusters > MAX_FAT12) ? 16 : 12;
1336
1337 /* check that FAT table does not overflow */
1338 fat_clusters = sbi->fat_length * sb->s_blocksize * 8 / sbi->fat_bits;
1339 total_clusters = min(total_clusters, fat_clusters - FAT_START_ENT);
1340 if (total_clusters > MAX_FAT(sb)) {
1341 if (!silent)
1342 printk(KERN_ERR "FAT: count of clusters too big (%u)\n",
1343 total_clusters);
1344 brelse(bh);
1345 goto out_invalid;
1346 }
1347
1348 sbi->max_cluster = total_clusters + FAT_START_ENT;
1349 /* check the free_clusters, it's not necessarily correct */
1350 if (sbi->free_clusters != -1 && sbi->free_clusters > total_clusters)
1351 sbi->free_clusters = -1;
1352 /* check the prev_free, it's not necessarily correct */
1353 sbi->prev_free %= sbi->max_cluster;
1354 if (sbi->prev_free < FAT_START_ENT)
1355 sbi->prev_free = FAT_START_ENT;
1356
1357 brelse(bh);
1358
1359 /* set up enough so that it can read an inode */
1360 fat_hash_init(sb);
1361 fat_ent_access_init(sb);
1362
1363 /*
1364 * The low byte of FAT's first entry must have same value with
1365 * media-field. But in real world, too many devices is
1366 * writing wrong value. So, removed that validity check.
1367 *
1368 * if (FAT_FIRST_ENT(sb, media) != first)
1369 */
1370
1371 error = -EINVAL;
1372 sprintf(buf, "cp%d", sbi->options.codepage);
1373 sbi->nls_disk = load_nls(buf);
1374 if (!sbi->nls_disk) {
1375 printk(KERN_ERR "FAT: codepage %s not found\n", buf);
1376 goto out_fail;
1377 }
1378
1379 /* FIXME: utf8 is using iocharset for upper/lower conversion */
1380 if (sbi->options.isvfat) {
1381 sbi->nls_io = load_nls(sbi->options.iocharset);
1382 if (!sbi->nls_io) {
1383 printk(KERN_ERR "FAT: IO charset %s not found\n",
1384 sbi->options.iocharset);
1385 goto out_fail;
1386 }
1387 }
1388
1389 error = -ENOMEM;
1390 root_inode = new_inode(sb);
1391 if (!root_inode)
1392 goto out_fail;
1393 root_inode->i_ino = MSDOS_ROOT_INO;
1394 root_inode->i_version = 1;
1395 error = fat_read_root(root_inode);
1396 if (error < 0)
1397 goto out_fail;
1398 error = -ENOMEM;
1399 insert_inode_hash(root_inode);
1400 sb->s_root = d_alloc_root(root_inode);
1401 if (!sb->s_root) {
1402 printk(KERN_ERR "FAT: get root inode failed\n");
1403 goto out_fail;
1404 }
1405
1406 return 0;
1407
1408out_invalid:
1409 error = -EINVAL;
1410 if (!silent)
1411 printk(KERN_INFO "VFS: Can't find a valid FAT filesystem"
1412 " on dev %s.\n", sb->s_id);
1413
1414out_fail:
1415 if (root_inode)
1416 iput(root_inode);
1417 if (sbi->nls_io)
1418 unload_nls(sbi->nls_io);
1419 if (sbi->nls_disk)
1420 unload_nls(sbi->nls_disk);
1421 if (sbi->options.iocharset != fat_default_iocharset)
1422 kfree(sbi->options.iocharset);
1423 sb->s_fs_info = NULL;
1424 kfree(sbi);
1425 return error;
1426}
1427
OGAWA Hirofumi7c709d02006-01-08 01:02:10 -08001428EXPORT_SYMBOL_GPL(fat_fill_super);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001429
Chris Masonae78bf92006-09-29 02:00:03 -07001430/*
1431 * helper function for fat_flush_inodes. This writes both the inode
1432 * and the file data blocks, waiting for in flight data blocks before
1433 * the start of the call. It does not wait for any io started
1434 * during the call
1435 */
1436static int writeback_inode(struct inode *inode)
1437{
1438
1439 int ret;
1440 struct address_space *mapping = inode->i_mapping;
1441 struct writeback_control wbc = {
1442 .sync_mode = WB_SYNC_NONE,
1443 .nr_to_write = 0,
1444 };
1445 /* if we used WB_SYNC_ALL, sync_inode waits for the io for the
1446 * inode to finish. So WB_SYNC_NONE is sent down to sync_inode
1447 * and filemap_fdatawrite is used for the data blocks
1448 */
1449 ret = sync_inode(inode, &wbc);
1450 if (!ret)
1451 ret = filemap_fdatawrite(mapping);
1452 return ret;
1453}
1454
1455/*
1456 * write data and metadata corresponding to i1 and i2. The io is
1457 * started but we do not wait for any of it to finish.
1458 *
1459 * filemap_flush is used for the block device, so if there is a dirty
1460 * page for a block already in flight, we will not wait and start the
1461 * io over again
1462 */
1463int fat_flush_inodes(struct super_block *sb, struct inode *i1, struct inode *i2)
1464{
1465 int ret = 0;
1466 if (!MSDOS_SB(sb)->options.flush)
1467 return 0;
1468 if (i1)
1469 ret = writeback_inode(i1);
1470 if (!ret && i2)
1471 ret = writeback_inode(i2);
Eric Sesterhenn97e860d2006-10-11 01:21:59 -07001472 if (!ret) {
Chris Masonae78bf92006-09-29 02:00:03 -07001473 struct address_space *mapping = sb->s_bdev->bd_inode->i_mapping;
1474 ret = filemap_flush(mapping);
1475 }
1476 return ret;
1477}
1478EXPORT_SYMBOL_GPL(fat_flush_inodes);
1479
Linus Torvalds1da177e2005-04-16 15:20:36 -07001480static int __init init_fat_fs(void)
1481{
Pekka J Enberg532a39a2005-06-30 02:59:01 -07001482 int err;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001483
Pekka J Enberg532a39a2005-06-30 02:59:01 -07001484 err = fat_cache_init();
1485 if (err)
1486 return err;
1487
1488 err = fat_init_inodecache();
1489 if (err)
1490 goto failed;
1491
1492 return 0;
1493
1494failed:
1495 fat_cache_destroy();
1496 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001497}
1498
1499static void __exit exit_fat_fs(void)
1500{
1501 fat_cache_destroy();
1502 fat_destroy_inodecache();
1503}
1504
1505module_init(init_fat_fs)
1506module_exit(exit_fat_fs)
1507
1508MODULE_LICENSE("GPL");