blob: 76b7961ab6632e5d955a9139eaa4b0652e11ff8c [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>
Linus Torvalds1da177e2005-04-16 15:20:36 -070019#include <linux/pagemap.h>
OGAWA Hirofumia5425d22006-01-08 01:02:10 -080020#include <linux/mpage.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070021#include <linux/buffer_head.h>
Christoph Hellwiga5694252007-07-17 04:04:28 -070022#include <linux/exportfs.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070023#include <linux/mount.h>
24#include <linux/vfs.h>
25#include <linux/parser.h>
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -080026#include <linux/uio.h>
Chris Masonae78bf92006-09-29 02:00:03 -070027#include <linux/writeback.h>
Vignesh Babu BMe7d709c2007-05-08 00:24:27 -070028#include <linux/log2.h>
OGAWA Hirofumid3dfa822008-11-06 12:53:49 -080029#include <linux/hash.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070030#include <asm/unaligned.h>
OGAWA Hirofumi9e975da2008-11-06 12:53:46 -080031#include "fat.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -070032
33#ifndef CONFIG_FAT_DEFAULT_IOCHARSET
34/* if user don't select VFAT, this is undefined. */
35#define CONFIG_FAT_DEFAULT_IOCHARSET ""
36#endif
37
38static int fat_default_codepage = CONFIG_FAT_DEFAULT_CODEPAGE;
39static char fat_default_iocharset[] = CONFIG_FAT_DEFAULT_IOCHARSET;
40
41
42static int fat_add_cluster(struct inode *inode)
43{
44 int err, cluster;
45
46 err = fat_alloc_clusters(inode, &cluster, 1);
47 if (err)
48 return err;
49 /* FIXME: this cluster should be added after data of this
50 * cluster is writed */
51 err = fat_chain_add(inode, cluster, 1);
52 if (err)
53 fat_free_clusters(inode, cluster);
54 return err;
55}
56
OGAWA Hirofumi6a1d9802006-09-27 01:50:45 -070057static inline int __fat_get_block(struct inode *inode, sector_t iblock,
58 unsigned long *max_blocks,
59 struct buffer_head *bh_result, int create)
Linus Torvalds1da177e2005-04-16 15:20:36 -070060{
61 struct super_block *sb = inode->i_sb;
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -080062 struct msdos_sb_info *sbi = MSDOS_SB(sb);
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -080063 unsigned long mapped_blocks;
OGAWA Hirofumi6a1d9802006-09-27 01:50:45 -070064 sector_t phys;
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -080065 int err, offset;
Linus Torvalds1da177e2005-04-16 15:20:36 -070066
OGAWA Hirofumi2bdf67e2008-11-06 12:53:57 -080067 err = fat_bmap(inode, iblock, &phys, &mapped_blocks, create);
Linus Torvalds1da177e2005-04-16 15:20:36 -070068 if (err)
69 return err;
70 if (phys) {
71 map_bh(bh_result, sb, phys);
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -080072 *max_blocks = min(mapped_blocks, *max_blocks);
Linus Torvalds1da177e2005-04-16 15:20:36 -070073 return 0;
74 }
75 if (!create)
76 return 0;
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -080077
Linus Torvalds1da177e2005-04-16 15:20:36 -070078 if (iblock != MSDOS_I(inode)->mmu_private >> sb->s_blocksize_bits) {
Denis Karpov85c78592009-06-04 02:34:22 +090079 fat_fs_error(sb, "corrupted file size (i_pos %lld, %lld)",
OGAWA Hirofumi6a1d9802006-09-27 01:50:45 -070080 MSDOS_I(inode)->i_pos, MSDOS_I(inode)->mmu_private);
Linus Torvalds1da177e2005-04-16 15:20:36 -070081 return -EIO;
82 }
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -080083
84 offset = (unsigned long)iblock & (sbi->sec_per_clus - 1);
85 if (!offset) {
86 /* TODO: multiple cluster allocation would be desirable. */
Linus Torvalds1da177e2005-04-16 15:20:36 -070087 err = fat_add_cluster(inode);
88 if (err)
89 return err;
90 }
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -080091 /* available blocks on this cluster */
92 mapped_blocks = sbi->sec_per_clus - offset;
93
94 *max_blocks = min(mapped_blocks, *max_blocks);
95 MSDOS_I(inode)->mmu_private += *max_blocks << sb->s_blocksize_bits;
96
OGAWA Hirofumi2bdf67e2008-11-06 12:53:57 -080097 err = fat_bmap(inode, iblock, &phys, &mapped_blocks, create);
Linus Torvalds1da177e2005-04-16 15:20:36 -070098 if (err)
99 return err;
OGAWA Hirofumi6a1d9802006-09-27 01:50:45 -0700100
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -0800101 BUG_ON(!phys);
102 BUG_ON(*max_blocks != mapped_blocks);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700103 set_buffer_new(bh_result);
104 map_bh(bh_result, sb, phys);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700105
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -0800106 return 0;
107}
108
109static int fat_get_block(struct inode *inode, sector_t iblock,
110 struct buffer_head *bh_result, int create)
111{
OGAWA Hirofumi6a1d9802006-09-27 01:50:45 -0700112 struct super_block *sb = inode->i_sb;
113 unsigned long max_blocks = bh_result->b_size >> inode->i_blkbits;
114 int err;
115
116 err = __fat_get_block(inode, iblock, &max_blocks, bh_result, create);
117 if (err)
118 return err;
119 bh_result->b_size = max_blocks << sb->s_blocksize_bits;
120 return 0;
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -0800121}
122
Linus Torvalds1da177e2005-04-16 15:20:36 -0700123static int fat_writepage(struct page *page, struct writeback_control *wbc)
124{
125 return block_write_full_page(page, fat_get_block, wbc);
126}
127
OGAWA Hirofumia5425d22006-01-08 01:02:10 -0800128static int fat_writepages(struct address_space *mapping,
129 struct writeback_control *wbc)
130{
131 return mpage_writepages(mapping, wbc, fat_get_block);
132}
133
Linus Torvalds1da177e2005-04-16 15:20:36 -0700134static int fat_readpage(struct file *file, struct page *page)
135{
OGAWA Hirofumia5425d22006-01-08 01:02:10 -0800136 return mpage_readpage(page, fat_get_block);
137}
138
139static int fat_readpages(struct file *file, struct address_space *mapping,
140 struct list_head *pages, unsigned nr_pages)
141{
142 return mpage_readpages(mapping, pages, nr_pages, fat_get_block);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700143}
144
Nick Piggind7777a22007-10-16 01:25:08 -0700145static int fat_write_begin(struct file *file, struct address_space *mapping,
146 loff_t pos, unsigned len, unsigned flags,
147 struct page **pagep, void **fsdata)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700148{
Nick Piggind7777a22007-10-16 01:25:08 -0700149 *pagep = NULL;
150 return cont_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
151 fat_get_block,
152 &MSDOS_I(mapping->host)->mmu_private);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700153}
154
Nick Piggind7777a22007-10-16 01:25:08 -0700155static int fat_write_end(struct file *file, struct address_space *mapping,
156 loff_t pos, unsigned len, unsigned copied,
157 struct page *pagep, void *fsdata)
OGAWA Hirofumief402262005-09-16 19:28:13 -0700158{
Nick Piggind7777a22007-10-16 01:25:08 -0700159 struct inode *inode = mapping->host;
160 int err;
161 err = generic_write_end(file, mapping, pos, len, copied, pagep, fsdata);
162 if (!(err < 0) && !(MSDOS_I(inode)->i_attrs & ATTR_ARCH)) {
OGAWA Hirofumief402262005-09-16 19:28:13 -0700163 inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC;
164 MSDOS_I(inode)->i_attrs |= ATTR_ARCH;
165 mark_inode_dirty(inode);
166 }
167 return err;
168}
169
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -0800170static ssize_t fat_direct_IO(int rw, struct kiocb *iocb,
171 const struct iovec *iov,
172 loff_t offset, unsigned long nr_segs)
173{
174 struct file *file = iocb->ki_filp;
175 struct inode *inode = file->f_mapping->host;
176
177 if (rw == WRITE) {
178 /*
Nick Piggin4e02ed42008-10-29 14:00:55 -0700179 * FIXME: blockdev_direct_IO() doesn't use ->write_begin(),
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -0800180 * so we need to update the ->mmu_private to block boundary.
181 *
182 * But we must fill the remaining area or hole by nul for
183 * updating ->mmu_private.
OGAWA Hirofumi94412a92007-02-20 13:57:55 -0800184 *
185 * Return 0, and fallback to normal buffered write.
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -0800186 */
187 loff_t size = offset + iov_length(iov, nr_segs);
188 if (MSDOS_I(inode)->mmu_private < size)
OGAWA Hirofumi94412a92007-02-20 13:57:55 -0800189 return 0;
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -0800190 }
191
192 /*
193 * FAT need to use the DIO_LOCKING for avoiding the race
194 * condition of fat_get_block() and ->truncate().
195 */
196 return blockdev_direct_IO(rw, iocb, inode, inode->i_sb->s_bdev, iov,
OGAWA Hirofumi6a1d9802006-09-27 01:50:45 -0700197 offset, nr_segs, fat_get_block, NULL);
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -0800198}
199
Linus Torvalds1da177e2005-04-16 15:20:36 -0700200static sector_t _fat_bmap(struct address_space *mapping, sector_t block)
201{
OGAWA Hirofumifa93ca12008-11-06 12:53:56 -0800202 sector_t blocknr;
203
204 /* fat_get_cluster() assumes the requested blocknr isn't truncated. */
OGAWA Hirofumi3a95ea12009-03-12 02:03:23 +0900205 down_read(&mapping->host->i_alloc_sem);
OGAWA Hirofumifa93ca12008-11-06 12:53:56 -0800206 blocknr = generic_block_bmap(mapping, block, fat_get_block);
OGAWA Hirofumi3a95ea12009-03-12 02:03:23 +0900207 up_read(&mapping->host->i_alloc_sem);
OGAWA Hirofumifa93ca12008-11-06 12:53:56 -0800208
209 return blocknr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700210}
211
Christoph Hellwigf5e54d62006-06-28 04:26:44 -0700212static const struct address_space_operations fat_aops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700213 .readpage = fat_readpage,
OGAWA Hirofumia5425d22006-01-08 01:02:10 -0800214 .readpages = fat_readpages,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700215 .writepage = fat_writepage,
OGAWA Hirofumia5425d22006-01-08 01:02:10 -0800216 .writepages = fat_writepages,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700217 .sync_page = block_sync_page,
Nick Piggind7777a22007-10-16 01:25:08 -0700218 .write_begin = fat_write_begin,
219 .write_end = fat_write_end,
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -0800220 .direct_IO = fat_direct_IO,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700221 .bmap = _fat_bmap
222};
223
224/*
225 * New FAT inode stuff. We do the following:
226 * a) i_ino is constant and has nothing with on-disk location.
227 * b) FAT manages its own cache of directory entries.
228 * c) *This* cache is indexed by on-disk location.
229 * d) inode has an associated directory entry, all right, but
230 * it may be unhashed.
231 * e) currently entries are stored within struct inode. That should
232 * change.
233 * f) we deal with races in the following way:
234 * 1. readdir() and lookup() do FAT-dir-cache lookup.
235 * 2. rename() unhashes the F-d-c entry and rehashes it in
236 * a new place.
237 * 3. unlink() and rmdir() unhash F-d-c entry.
238 * 4. fat_write_inode() checks whether the thing is unhashed.
239 * If it is we silently return. If it isn't we do bread(),
240 * check if the location is still valid and retry if it
241 * isn't. Otherwise we do changes.
242 * 5. Spinlock is used to protect hash/unhash/location check/lookup
243 * 6. fat_clear_inode() unhashes the F-d-c entry.
244 * 7. lookup() and readdir() do igrab() if they find a F-d-c entry
245 * and consider negative result as cache miss.
246 */
247
248static void fat_hash_init(struct super_block *sb)
249{
250 struct msdos_sb_info *sbi = MSDOS_SB(sb);
251 int i;
252
253 spin_lock_init(&sbi->inode_hash_lock);
254 for (i = 0; i < FAT_HASH_SIZE; i++)
255 INIT_HLIST_HEAD(&sbi->inode_hashtable[i]);
256}
257
OGAWA Hirofumid3dfa822008-11-06 12:53:49 -0800258static inline unsigned long fat_hash(loff_t i_pos)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700259{
OGAWA Hirofumid3dfa822008-11-06 12:53:49 -0800260 return hash_32(i_pos, FAT_HASH_BITS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700261}
262
263void fat_attach(struct inode *inode, loff_t i_pos)
264{
OGAWA Hirofumid3dfa822008-11-06 12:53:49 -0800265 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
266 struct hlist_head *head = sbi->inode_hashtable + fat_hash(i_pos);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700267
268 spin_lock(&sbi->inode_hash_lock);
269 MSDOS_I(inode)->i_pos = i_pos;
OGAWA Hirofumid3dfa822008-11-06 12:53:49 -0800270 hlist_add_head(&MSDOS_I(inode)->i_fat_hash, head);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700271 spin_unlock(&sbi->inode_hash_lock);
272}
OGAWA Hirofumi7c709d02006-01-08 01:02:10 -0800273EXPORT_SYMBOL_GPL(fat_attach);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700274
275void fat_detach(struct inode *inode)
276{
277 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
278 spin_lock(&sbi->inode_hash_lock);
279 MSDOS_I(inode)->i_pos = 0;
280 hlist_del_init(&MSDOS_I(inode)->i_fat_hash);
281 spin_unlock(&sbi->inode_hash_lock);
282}
OGAWA Hirofumi7c709d02006-01-08 01:02:10 -0800283EXPORT_SYMBOL_GPL(fat_detach);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700284
285struct inode *fat_iget(struct super_block *sb, loff_t i_pos)
286{
287 struct msdos_sb_info *sbi = MSDOS_SB(sb);
OGAWA Hirofumid3dfa822008-11-06 12:53:49 -0800288 struct hlist_head *head = sbi->inode_hashtable + fat_hash(i_pos);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700289 struct hlist_node *_p;
290 struct msdos_inode_info *i;
291 struct inode *inode = NULL;
292
293 spin_lock(&sbi->inode_hash_lock);
294 hlist_for_each_entry(i, _p, head, i_fat_hash) {
295 BUG_ON(i->vfs_inode.i_sb != sb);
296 if (i->i_pos != i_pos)
297 continue;
298 inode = igrab(&i->vfs_inode);
299 if (inode)
300 break;
301 }
302 spin_unlock(&sbi->inode_hash_lock);
303 return inode;
304}
305
306static int is_exec(unsigned char *extension)
307{
308 unsigned char *exe_extensions = "EXECOMBAT", *walk;
309
310 for (walk = exe_extensions; *walk; walk += 3)
311 if (!strncmp(extension, walk, 3))
312 return 1;
313 return 0;
314}
315
316static int fat_calc_dir_size(struct inode *inode)
317{
318 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
319 int ret, fclus, dclus;
320
321 inode->i_size = 0;
322 if (MSDOS_I(inode)->i_start == 0)
323 return 0;
324
325 ret = fat_get_cluster(inode, FAT_ENT_EOF, &fclus, &dclus);
326 if (ret < 0)
327 return ret;
328 inode->i_size = (fclus + 1) << sbi->cluster_bits;
329
330 return 0;
331}
332
333/* doesn't deal with root inode */
334static int fat_fill_inode(struct inode *inode, struct msdos_dir_entry *de)
335{
336 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
337 int error;
338
339 MSDOS_I(inode)->i_pos = 0;
340 inode->i_uid = sbi->options.fs_uid;
341 inode->i_gid = sbi->options.fs_gid;
342 inode->i_version++;
343 inode->i_generation = get_seconds();
344
345 if ((de->attr & ATTR_DIR) && !IS_FREE(de->name)) {
346 inode->i_generation &= ~1;
OGAWA Hirofumi9c0aa1b2008-11-06 12:53:54 -0800347 inode->i_mode = fat_make_mode(sbi, de->attr, S_IRWXUGO);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700348 inode->i_op = sbi->dir_ops;
349 inode->i_fop = &fat_dir_operations;
350
351 MSDOS_I(inode)->i_start = le16_to_cpu(de->start);
352 if (sbi->fat_bits == 32)
353 MSDOS_I(inode)->i_start |= (le16_to_cpu(de->starthi) << 16);
354
355 MSDOS_I(inode)->i_logstart = MSDOS_I(inode)->i_start;
356 error = fat_calc_dir_size(inode);
357 if (error < 0)
358 return error;
359 MSDOS_I(inode)->mmu_private = inode->i_size;
360
361 inode->i_nlink = fat_subdirs(inode);
362 } else { /* not a directory */
363 inode->i_generation |= 1;
OGAWA Hirofumi9c0aa1b2008-11-06 12:53:54 -0800364 inode->i_mode = fat_make_mode(sbi, de->attr,
365 ((sbi->options.showexec && !is_exec(de->name + 8))
366 ? S_IRUGO|S_IWUGO : S_IRWXUGO));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700367 MSDOS_I(inode)->i_start = le16_to_cpu(de->start);
368 if (sbi->fat_bits == 32)
369 MSDOS_I(inode)->i_start |= (le16_to_cpu(de->starthi) << 16);
370
371 MSDOS_I(inode)->i_logstart = MSDOS_I(inode)->i_start;
372 inode->i_size = le32_to_cpu(de->size);
373 inode->i_op = &fat_file_inode_operations;
374 inode->i_fop = &fat_file_operations;
375 inode->i_mapping->a_ops = &fat_aops;
376 MSDOS_I(inode)->mmu_private = inode->i_size;
377 }
378 if (de->attr & ATTR_SYS) {
379 if (sbi->options.sys_immutable)
380 inode->i_flags |= S_IMMUTABLE;
381 }
OGAWA Hirofumi9c0aa1b2008-11-06 12:53:54 -0800382 fat_save_attrs(inode, de->attr);
383
Linus Torvalds1da177e2005-04-16 15:20:36 -0700384 inode->i_blocks = ((inode->i_size + (sbi->cluster_size - 1))
385 & ~((loff_t)sbi->cluster_size - 1)) >> 9;
OGAWA Hirofumi7decd1c2008-11-06 12:53:47 -0800386
387 fat_time_fat2unix(sbi, &inode->i_mtime, de->time, de->date, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700388 if (sbi->options.isvfat) {
OGAWA Hirofumi7decd1c2008-11-06 12:53:47 -0800389 fat_time_fat2unix(sbi, &inode->i_ctime, de->ctime,
390 de->cdate, de->ctime_cs);
391 fat_time_fat2unix(sbi, &inode->i_atime, 0, de->adate, 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);
OGAWA Hirofumi3754a542008-04-28 02:16:24 -0700431 inode->i_size = 0;
432 fat_truncate(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700433 clear_inode(inode);
434}
435
436static void fat_clear_inode(struct inode *inode)
437{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700438 fat_cache_inval_inode(inode);
OGAWA Hirofumia993b542008-11-06 12:53:50 -0800439 fat_detach(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700440}
441
OGAWA Hirofumia6bf6b22006-01-08 01:02:08 -0800442static void fat_write_super(struct super_block *sb)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700443{
Christoph Hellwigebc1ac12009-05-11 23:35:03 +0200444 lock_super(sb);
OGAWA Hirofumia6bf6b22006-01-08 01:02:08 -0800445 sb->s_dirt = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700446
447 if (!(sb->s_flags & MS_RDONLY))
448 fat_clusters_flush(sb);
Christoph Hellwigebc1ac12009-05-11 23:35:03 +0200449 unlock_super(sb);
OGAWA Hirofumia6bf6b22006-01-08 01:02:08 -0800450}
451
Christoph Hellwigf83d6d42009-06-08 10:04:35 +0200452static int fat_sync_fs(struct super_block *sb, int wait)
453{
OGAWA Hirofumied248b22009-09-20 01:31:58 +0900454 int err = 0;
Christoph Hellwigf83d6d42009-06-08 10:04:35 +0200455
OGAWA Hirofumied248b22009-09-20 01:31:58 +0900456 if (sb->s_dirt) {
457 lock_super(sb);
458 sb->s_dirt = 0;
459 err = fat_clusters_flush(sb);
460 unlock_super(sb);
461 }
462
463 return err;
Christoph Hellwigf83d6d42009-06-08 10:04:35 +0200464}
465
OGAWA Hirofumia6bf6b22006-01-08 01:02:08 -0800466static 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
Christoph Hellwig6cfd0142009-05-05 15:40:36 +0200470 lock_kernel();
471
Christoph Hellwig8c85e122009-04-28 18:00:26 +0200472 if (sb->s_dirt)
473 fat_write_super(sb);
474
Al Virob5224122009-06-07 13:44:36 -0400475 iput(sbi->fat_inode);
476
Thomas Gleixner6d729e42009-08-16 21:05:08 +0000477 unload_nls(sbi->nls_disk);
478 unload_nls(sbi->nls_io);
479
480 if (sbi->options.iocharset != fat_default_iocharset)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700481 kfree(sbi->options.iocharset);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700482
483 sb->s_fs_info = NULL;
484 kfree(sbi);
Christoph Hellwig6cfd0142009-05-05 15:40:36 +0200485
486 unlock_kernel();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700487}
488
Christoph Lametere18b8902006-12-06 20:33:20 -0800489static struct kmem_cache *fat_inode_cachep;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700490
491static struct inode *fat_alloc_inode(struct super_block *sb)
492{
493 struct msdos_inode_info *ei;
Linus Torvalds8f593422008-05-19 19:53:01 -0700494 ei = kmem_cache_alloc(fat_inode_cachep, GFP_NOFS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700495 if (!ei)
496 return NULL;
497 return &ei->vfs_inode;
498}
499
500static void fat_destroy_inode(struct inode *inode)
501{
502 kmem_cache_free(fat_inode_cachep, MSDOS_I(inode));
503}
504
Alexey Dobriyan51cc5062008-07-25 19:45:34 -0700505static void init_once(void *foo)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700506{
507 struct msdos_inode_info *ei = (struct msdos_inode_info *)foo;
508
Christoph Lametera35afb82007-05-16 22:10:57 -0700509 spin_lock_init(&ei->cache_lru_lock);
510 ei->nr_caches = 0;
511 ei->cache_valid_id = FAT_CACHE_VALID + 1;
512 INIT_LIST_HEAD(&ei->cache_lru);
513 INIT_HLIST_NODE(&ei->i_fat_hash);
514 inode_init_once(&ei->vfs_inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700515}
516
517static int __init fat_init_inodecache(void)
518{
519 fat_inode_cachep = kmem_cache_create("fat_inode_cache",
520 sizeof(struct msdos_inode_info),
Paul Jacksonfffb60f2006-03-24 03:16:06 -0800521 0, (SLAB_RECLAIM_ACCOUNT|
522 SLAB_MEM_SPREAD),
Paul Mundt20c2df82007-07-20 10:11:58 +0900523 init_once);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700524 if (fat_inode_cachep == NULL)
525 return -ENOMEM;
526 return 0;
527}
528
529static void __exit fat_destroy_inodecache(void)
530{
Alexey Dobriyan1a1d92c2006-09-27 01:49:40 -0700531 kmem_cache_destroy(fat_inode_cachep);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700532}
533
534static int fat_remount(struct super_block *sb, int *flags, char *data)
535{
536 struct msdos_sb_info *sbi = MSDOS_SB(sb);
537 *flags |= MS_NODIRATIME | (sbi->options.isvfat ? 0 : MS_NOATIME);
538 return 0;
539}
540
David Howells726c3342006-06-23 02:02:58 -0700541static int fat_statfs(struct dentry *dentry, struct kstatfs *buf)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700542{
Coly Liaac49b72009-04-02 16:59:35 -0700543 struct super_block *sb = dentry->d_sb;
544 struct msdos_sb_info *sbi = MSDOS_SB(sb);
545 u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700546
547 /* If the count of free cluster is still unknown, counts it here. */
OGAWA Hirofumi606e4232008-04-28 02:16:27 -0700548 if (sbi->free_clusters == -1 || !sbi->free_clus_valid) {
David Howells726c3342006-06-23 02:02:58 -0700549 int err = fat_count_free_clusters(dentry->d_sb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700550 if (err)
551 return err;
552 }
553
David Howells726c3342006-06-23 02:02:58 -0700554 buf->f_type = dentry->d_sb->s_magic;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700555 buf->f_bsize = sbi->cluster_size;
556 buf->f_blocks = sbi->max_cluster - FAT_START_ENT;
557 buf->f_bfree = sbi->free_clusters;
558 buf->f_bavail = sbi->free_clusters;
Coly Liaac49b72009-04-02 16:59:35 -0700559 buf->f_fsid.val[0] = (u32)id;
560 buf->f_fsid.val[1] = (u32)(id >> 32);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700561 buf->f_namelen = sbi->options.isvfat ? 260 : 12;
562
563 return 0;
564}
565
OGAWA Hirofumi9ca59f42008-11-06 12:53:57 -0800566static inline loff_t fat_i_pos_read(struct msdos_sb_info *sbi,
567 struct inode *inode)
568{
569 loff_t i_pos;
570#if BITS_PER_LONG == 32
571 spin_lock(&sbi->inode_hash_lock);
572#endif
573 i_pos = MSDOS_I(inode)->i_pos;
574#if BITS_PER_LONG == 32
575 spin_unlock(&sbi->inode_hash_lock);
576#endif
577 return i_pos;
578}
579
Linus Torvalds1da177e2005-04-16 15:20:36 -0700580static int fat_write_inode(struct inode *inode, int wait)
581{
582 struct super_block *sb = inode->i_sb;
583 struct msdos_sb_info *sbi = MSDOS_SB(sb);
584 struct buffer_head *bh;
585 struct msdos_dir_entry *raw_entry;
586 loff_t i_pos;
Linus Torvalds5f22ca92008-08-20 08:31:19 -0700587 int err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700588
OGAWA Hirofumi9ca59f42008-11-06 12:53:57 -0800589 if (inode->i_ino == MSDOS_ROOT_INO)
590 return 0;
591
Linus Torvalds1da177e2005-04-16 15:20:36 -0700592retry:
OGAWA Hirofumi9ca59f42008-11-06 12:53:57 -0800593 i_pos = fat_i_pos_read(sbi, inode);
594 if (!i_pos)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700595 return 0;
596
Linus Torvalds1da177e2005-04-16 15:20:36 -0700597 bh = sb_bread(sb, i_pos >> sbi->dir_per_block_bits);
598 if (!bh) {
599 printk(KERN_ERR "FAT: unable to read inode block "
600 "for updating (i_pos %lld)\n", i_pos);
Linus Torvalds5f22ca92008-08-20 08:31:19 -0700601 return -EIO;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700602 }
603 spin_lock(&sbi->inode_hash_lock);
604 if (i_pos != MSDOS_I(inode)->i_pos) {
605 spin_unlock(&sbi->inode_hash_lock);
606 brelse(bh);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700607 goto retry;
608 }
609
610 raw_entry = &((struct msdos_dir_entry *) (bh->b_data))
611 [i_pos & (sbi->dir_per_block - 1)];
612 if (S_ISDIR(inode->i_mode))
613 raw_entry->size = 0;
614 else
615 raw_entry->size = cpu_to_le32(inode->i_size);
OGAWA Hirofumi9c0aa1b2008-11-06 12:53:54 -0800616 raw_entry->attr = fat_make_attrs(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700617 raw_entry->start = cpu_to_le16(MSDOS_I(inode)->i_logstart);
618 raw_entry->starthi = cpu_to_le16(MSDOS_I(inode)->i_logstart >> 16);
OGAWA Hirofumi7decd1c2008-11-06 12:53:47 -0800619 fat_time_unix2fat(sbi, &inode->i_mtime, &raw_entry->time,
620 &raw_entry->date, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700621 if (sbi->options.isvfat) {
Stephane Kardas62a36c42005-09-21 09:55:45 -0700622 __le16 atime;
OGAWA Hirofumi7decd1c2008-11-06 12:53:47 -0800623 fat_time_unix2fat(sbi, &inode->i_ctime, &raw_entry->ctime,
624 &raw_entry->cdate, &raw_entry->ctime_cs);
625 fat_time_unix2fat(sbi, &inode->i_atime, &atime,
626 &raw_entry->adate, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700627 }
628 spin_unlock(&sbi->inode_hash_lock);
629 mark_buffer_dirty(bh);
Linus Torvalds5f22ca92008-08-20 08:31:19 -0700630 err = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700631 if (wait)
632 err = sync_dirty_buffer(bh);
633 brelse(bh);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700634 return err;
635}
636
637int fat_sync_inode(struct inode *inode)
638{
639 return fat_write_inode(inode, 1);
640}
641
OGAWA Hirofumi7c709d02006-01-08 01:02:10 -0800642EXPORT_SYMBOL_GPL(fat_sync_inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700643
644static int fat_show_options(struct seq_file *m, struct vfsmount *mnt);
Josef 'Jeff' Sipekee9b6d62007-02-12 00:55:41 -0800645static const struct super_operations fat_sops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700646 .alloc_inode = fat_alloc_inode,
647 .destroy_inode = fat_destroy_inode,
648 .write_inode = fat_write_inode,
649 .delete_inode = fat_delete_inode,
650 .put_super = fat_put_super,
OGAWA Hirofumia6bf6b22006-01-08 01:02:08 -0800651 .write_super = fat_write_super,
Christoph Hellwigf83d6d42009-06-08 10:04:35 +0200652 .sync_fs = fat_sync_fs,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700653 .statfs = fat_statfs,
654 .clear_inode = fat_clear_inode,
655 .remount_fs = fat_remount,
656
Linus Torvalds1da177e2005-04-16 15:20:36 -0700657 .show_options = fat_show_options,
658};
659
660/*
661 * a FAT file handle with fhtype 3 is
662 * 0/ i_ino - for fast, reliable lookup if still in the cache
663 * 1/ i_generation - to see if i_ino is still valid
664 * bit 0 == 0 iff directory
665 * 2/ i_pos(8-39) - if ino has changed, but still in cache
666 * 3/ i_pos(4-7)|i_logstart - to semi-verify inode found at i_pos
667 * 4/ i_pos(0-3)|parent->i_logstart - maybe used to hunt for the file on disc
668 *
669 * Hack for NFSv2: Maximum FAT entry number is 28bits and maximum
670 * i_pos is 40bits (blocknr(32) + dir offset(8)), so two 4bits
671 * of i_logstart is used to store the directory entry offset.
672 */
673
Christoph Hellwig1305edad2007-10-21 16:42:11 -0700674static struct dentry *fat_fh_to_dentry(struct super_block *sb,
675 struct fid *fid, int fh_len, int fh_type)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700676{
677 struct inode *inode = NULL;
678 struct dentry *result;
Christoph Hellwig1305edad2007-10-21 16:42:11 -0700679 u32 *fh = fid->raw;
680
681 if (fh_len < 5 || fh_type != 3)
682 return NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700683
David Howells17f95a72008-02-07 00:15:38 -0800684 inode = ilookup(sb, fh[0]);
685 if (!inode || inode->i_generation != fh[1]) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700686 if (inode)
687 iput(inode);
688 inode = NULL;
689 }
690 if (!inode) {
691 loff_t i_pos;
692 int i_logstart = fh[3] & 0x0fffffff;
693
694 i_pos = (loff_t)fh[2] << 8;
695 i_pos |= ((fh[3] >> 24) & 0xf0) | (fh[4] >> 28);
696
697 /* try 2 - see if i_pos is in F-d-c
698 * require i_logstart to be the same
699 * Will fail if you truncate and then re-write
700 */
701
702 inode = fat_iget(sb, i_pos);
703 if (inode && MSDOS_I(inode)->i_logstart != i_logstart) {
704 iput(inode);
705 inode = NULL;
706 }
707 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700708
Christoph Hellwig44003722008-08-11 15:49:04 +0200709 /*
710 * For now, do nothing if the inode is not found.
711 *
712 * What we could do is:
713 *
714 * - follow the file starting at fh[4], and record the ".." entry,
715 * and the name of the fh[2] entry.
716 * - then follow the ".." file finding the next step up.
717 *
718 * This way we build a path to the root of the tree. If this works, we
719 * lookup the path and so get this inode into the cache. Finally try
720 * the fat_iget lookup again. If that fails, then we are totally out
721 * of luck. But all that is for another day
Linus Torvalds1da177e2005-04-16 15:20:36 -0700722 */
Christoph Hellwig44003722008-08-11 15:49:04 +0200723 result = d_obtain_alias(inode);
724 if (!IS_ERR(result))
725 result->d_op = sb->s_root->d_op;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700726 return result;
727}
728
729static int
730fat_encode_fh(struct dentry *de, __u32 *fh, int *lenp, int connectable)
731{
732 int len = *lenp;
733 struct inode *inode = de->d_inode;
734 u32 ipos_h, ipos_m, ipos_l;
735
736 if (len < 5)
737 return 255; /* no room */
738
739 ipos_h = MSDOS_I(inode)->i_pos >> 8;
740 ipos_m = (MSDOS_I(inode)->i_pos & 0xf0) << 24;
741 ipos_l = (MSDOS_I(inode)->i_pos & 0x0f) << 28;
742 *lenp = 5;
743 fh[0] = inode->i_ino;
744 fh[1] = inode->i_generation;
745 fh[2] = ipos_h;
746 fh[3] = ipos_m | MSDOS_I(inode)->i_logstart;
747 spin_lock(&de->d_lock);
748 fh[4] = ipos_l | MSDOS_I(de->d_parent->d_inode)->i_logstart;
749 spin_unlock(&de->d_lock);
750 return 3;
751}
752
753static struct dentry *fat_get_parent(struct dentry *child)
754{
Linus Torvalds8f593422008-05-19 19:53:01 -0700755 struct super_block *sb = child->d_sb;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700756 struct buffer_head *bh;
757 struct msdos_dir_entry *de;
758 loff_t i_pos;
759 struct dentry *parent;
760 struct inode *inode;
761 int err;
762
Linus Torvalds8f593422008-05-19 19:53:01 -0700763 lock_super(sb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700764
765 err = fat_get_dotdot_entry(child->d_inode, &bh, &de, &i_pos);
766 if (err) {
767 parent = ERR_PTR(err);
768 goto out;
769 }
Linus Torvalds8f593422008-05-19 19:53:01 -0700770 inode = fat_build_inode(sb, de, i_pos);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700771 brelse(bh);
Christoph Hellwig44003722008-08-11 15:49:04 +0200772
773 parent = d_obtain_alias(inode);
Christoph Hellwig5a6bb102008-11-12 07:48:01 +0900774 if (!IS_ERR(parent))
775 parent->d_op = sb->s_root->d_op;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700776out:
Linus Torvalds8f593422008-05-19 19:53:01 -0700777 unlock_super(sb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700778
779 return parent;
780}
781
Christoph Hellwig39655162007-10-21 16:42:17 -0700782static const struct export_operations fat_export_ops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700783 .encode_fh = fat_encode_fh,
Christoph Hellwig1305edad2007-10-21 16:42:11 -0700784 .fh_to_dentry = fat_fh_to_dentry,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700785 .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);
OGAWA Hirofumi1ae43f82008-04-28 02:16:26 -0700800 if (opts->allow_utime)
801 seq_printf(m, ",allow_utime=%04o", opts->allow_utime);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700802 if (sbi->nls_disk)
803 seq_printf(m, ",codepage=%s", sbi->nls_disk->charset);
804 if (isvfat) {
805 if (sbi->nls_io)
806 seq_printf(m, ",iocharset=%s", sbi->nls_io->charset);
807
808 switch (opts->shortname) {
809 case VFAT_SFN_DISPLAY_WIN95 | VFAT_SFN_CREATE_WIN95:
810 seq_puts(m, ",shortname=win95");
811 break;
812 case VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WINNT:
813 seq_puts(m, ",shortname=winnt");
814 break;
815 case VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WIN95:
816 seq_puts(m, ",shortname=mixed");
817 break;
818 case VFAT_SFN_DISPLAY_LOWER | VFAT_SFN_CREATE_WIN95:
Paul Wise95523472009-08-01 21:30:31 +0900819 seq_puts(m, ",shortname=lower");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700820 break;
821 default:
822 seq_puts(m, ",shortname=unknown");
823 break;
824 }
825 }
826 if (opts->name_check != 'n')
827 seq_printf(m, ",check=%c", opts->name_check);
OGAWA Hirofumi28ec0392007-05-08 00:31:01 -0700828 if (opts->usefree)
829 seq_puts(m, ",usefree");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700830 if (opts->quiet)
831 seq_puts(m, ",quiet");
832 if (opts->showexec)
833 seq_puts(m, ",showexec");
834 if (opts->sys_immutable)
835 seq_puts(m, ",sys_immutable");
836 if (!isvfat) {
837 if (opts->dotsOK)
838 seq_puts(m, ",dotsOK=yes");
839 if (opts->nocase)
840 seq_puts(m, ",nocase");
841 } else {
842 if (opts->utf8)
843 seq_puts(m, ",utf8");
844 if (opts->unicode_xlate)
845 seq_puts(m, ",uni_xlate");
846 if (!opts->numtail)
847 seq_puts(m, ",nonumtail");
OGAWA Hirofumidfc209c2008-11-06 12:53:55 -0800848 if (opts->rodir)
849 seq_puts(m, ",rodir");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700850 }
OGAWA Hirofumidfc209c2008-11-06 12:53:55 -0800851 if (opts->flush)
Miklos Szeredic1fca3b2008-02-08 04:21:42 -0800852 seq_puts(m, ",flush");
Joe Petersonb271e062008-07-25 01:46:47 -0700853 if (opts->tz_utc)
854 seq_puts(m, ",tz=UTC");
Denis Karpov85c78592009-06-04 02:34:22 +0900855 if (opts->errors == FAT_ERRORS_CONT)
856 seq_puts(m, ",errors=continue");
857 else if (opts->errors == FAT_ERRORS_PANIC)
858 seq_puts(m, ",errors=panic");
859 else
860 seq_puts(m, ",errors=remount-ro");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700861
862 return 0;
863}
864
865enum {
866 Opt_check_n, Opt_check_r, Opt_check_s, Opt_uid, Opt_gid,
OGAWA Hirofumi1ae43f82008-04-28 02:16:26 -0700867 Opt_umask, Opt_dmask, Opt_fmask, Opt_allow_utime, Opt_codepage,
868 Opt_usefree, Opt_nocase, Opt_quiet, Opt_showexec, Opt_debug,
869 Opt_immutable, Opt_dots, Opt_nodots,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700870 Opt_charset, Opt_shortname_lower, Opt_shortname_win95,
871 Opt_shortname_winnt, Opt_shortname_mixed, Opt_utf8_no, Opt_utf8_yes,
872 Opt_uni_xl_no, Opt_uni_xl_yes, Opt_nonumtail_no, Opt_nonumtail_yes,
Denis Karpov85c78592009-06-04 02:34:22 +0900873 Opt_obsolate, Opt_flush, Opt_tz_utc, Opt_rodir, Opt_err_cont,
874 Opt_err_panic, Opt_err_ro, Opt_err,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700875};
876
Steven Whitehousea447c092008-10-13 10:46:57 +0100877static const match_table_t fat_tokens = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700878 {Opt_check_r, "check=relaxed"},
879 {Opt_check_s, "check=strict"},
880 {Opt_check_n, "check=normal"},
881 {Opt_check_r, "check=r"},
882 {Opt_check_s, "check=s"},
883 {Opt_check_n, "check=n"},
884 {Opt_uid, "uid=%u"},
885 {Opt_gid, "gid=%u"},
886 {Opt_umask, "umask=%o"},
887 {Opt_dmask, "dmask=%o"},
888 {Opt_fmask, "fmask=%o"},
OGAWA Hirofumi1ae43f82008-04-28 02:16:26 -0700889 {Opt_allow_utime, "allow_utime=%o"},
Linus Torvalds1da177e2005-04-16 15:20:36 -0700890 {Opt_codepage, "codepage=%u"},
OGAWA Hirofumi28ec0392007-05-08 00:31:01 -0700891 {Opt_usefree, "usefree"},
Linus Torvalds1da177e2005-04-16 15:20:36 -0700892 {Opt_nocase, "nocase"},
893 {Opt_quiet, "quiet"},
894 {Opt_showexec, "showexec"},
895 {Opt_debug, "debug"},
896 {Opt_immutable, "sys_immutable"},
Denis Karpov85c78592009-06-04 02:34:22 +0900897 {Opt_flush, "flush"},
898 {Opt_tz_utc, "tz=UTC"},
899 {Opt_err_cont, "errors=continue"},
900 {Opt_err_panic, "errors=panic"},
901 {Opt_err_ro, "errors=remount-ro"},
Linus Torvalds1da177e2005-04-16 15:20:36 -0700902 {Opt_obsolate, "conv=binary"},
903 {Opt_obsolate, "conv=text"},
904 {Opt_obsolate, "conv=auto"},
905 {Opt_obsolate, "conv=b"},
906 {Opt_obsolate, "conv=t"},
907 {Opt_obsolate, "conv=a"},
908 {Opt_obsolate, "fat=%u"},
909 {Opt_obsolate, "blocksize=%u"},
910 {Opt_obsolate, "cvf_format=%20s"},
911 {Opt_obsolate, "cvf_options=%100s"},
912 {Opt_obsolate, "posix"},
Chris Masonae78bf92006-09-29 02:00:03 -0700913 {Opt_err, NULL},
Linus Torvalds1da177e2005-04-16 15:20:36 -0700914};
Steven Whitehousea447c092008-10-13 10:46:57 +0100915static const match_table_t msdos_tokens = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700916 {Opt_nodots, "nodots"},
917 {Opt_nodots, "dotsOK=no"},
918 {Opt_dots, "dots"},
919 {Opt_dots, "dotsOK=yes"},
920 {Opt_err, NULL}
921};
Steven Whitehousea447c092008-10-13 10:46:57 +0100922static const match_table_t vfat_tokens = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700923 {Opt_charset, "iocharset=%s"},
924 {Opt_shortname_lower, "shortname=lower"},
925 {Opt_shortname_win95, "shortname=win95"},
926 {Opt_shortname_winnt, "shortname=winnt"},
927 {Opt_shortname_mixed, "shortname=mixed"},
928 {Opt_utf8_no, "utf8=0"}, /* 0 or no or false */
929 {Opt_utf8_no, "utf8=no"},
930 {Opt_utf8_no, "utf8=false"},
931 {Opt_utf8_yes, "utf8=1"}, /* empty or 1 or yes or true */
932 {Opt_utf8_yes, "utf8=yes"},
933 {Opt_utf8_yes, "utf8=true"},
934 {Opt_utf8_yes, "utf8"},
935 {Opt_uni_xl_no, "uni_xlate=0"}, /* 0 or no or false */
936 {Opt_uni_xl_no, "uni_xlate=no"},
937 {Opt_uni_xl_no, "uni_xlate=false"},
938 {Opt_uni_xl_yes, "uni_xlate=1"}, /* empty or 1 or yes or true */
939 {Opt_uni_xl_yes, "uni_xlate=yes"},
940 {Opt_uni_xl_yes, "uni_xlate=true"},
941 {Opt_uni_xl_yes, "uni_xlate"},
942 {Opt_nonumtail_no, "nonumtail=0"}, /* 0 or no or false */
943 {Opt_nonumtail_no, "nonumtail=no"},
944 {Opt_nonumtail_no, "nonumtail=false"},
945 {Opt_nonumtail_yes, "nonumtail=1"}, /* empty or 1 or yes or true */
946 {Opt_nonumtail_yes, "nonumtail=yes"},
947 {Opt_nonumtail_yes, "nonumtail=true"},
948 {Opt_nonumtail_yes, "nonumtail"},
OGAWA Hirofumidfc209c2008-11-06 12:53:55 -0800949 {Opt_rodir, "rodir"},
Linus Torvalds1da177e2005-04-16 15:20:36 -0700950 {Opt_err, NULL}
951};
952
Christoph Hellwig41a34a42005-11-08 21:34:57 -0800953static int parse_options(char *options, int is_vfat, int silent, int *debug,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700954 struct fat_mount_options *opts)
955{
956 char *p;
957 substring_t args[MAX_OPT_ARGS];
958 int option;
959 char *iocharset;
960
961 opts->isvfat = is_vfat;
962
David Howellsf0ce7ee2008-11-14 10:38:52 +1100963 opts->fs_uid = current_uid();
964 opts->fs_gid = current_gid();
OGAWA Hirofumi3e107602009-06-20 21:50:07 +0900965 opts->fs_fmask = opts->fs_dmask = current_umask();
OGAWA Hirofumi1ae43f82008-04-28 02:16:26 -0700966 opts->allow_utime = -1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700967 opts->codepage = fat_default_codepage;
968 opts->iocharset = fat_default_iocharset;
OGAWA Hirofumidfc209c2008-11-06 12:53:55 -0800969 if (is_vfat) {
Paul Wise95523472009-08-01 21:30:31 +0900970 opts->shortname = VFAT_SFN_DISPLAY_WINNT|VFAT_SFN_CREATE_WIN95;
OGAWA Hirofumidfc209c2008-11-06 12:53:55 -0800971 opts->rodir = 0;
972 } else {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700973 opts->shortname = 0;
OGAWA Hirofumidfc209c2008-11-06 12:53:55 -0800974 opts->rodir = 1;
975 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700976 opts->name_check = 'n';
977 opts->quiet = opts->showexec = opts->sys_immutable = opts->dotsOK = 0;
978 opts->utf8 = opts->unicode_xlate = 0;
979 opts->numtail = 1;
OGAWA Hirofumi28ec0392007-05-08 00:31:01 -0700980 opts->usefree = opts->nocase = 0;
Joe Petersonb271e062008-07-25 01:46:47 -0700981 opts->tz_utc = 0;
Denis Karpov85c78592009-06-04 02:34:22 +0900982 opts->errors = FAT_ERRORS_RO;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700983 *debug = 0;
984
985 if (!options)
OGAWA Hirofumi8d44d972008-07-25 01:46:41 -0700986 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700987
988 while ((p = strsep(&options, ",")) != NULL) {
989 int token;
990 if (!*p)
991 continue;
992
993 token = match_token(p, fat_tokens, args);
994 if (token == Opt_err) {
995 if (is_vfat)
996 token = match_token(p, vfat_tokens, args);
997 else
998 token = match_token(p, msdos_tokens, args);
999 }
1000 switch (token) {
1001 case Opt_check_s:
1002 opts->name_check = 's';
1003 break;
1004 case Opt_check_r:
1005 opts->name_check = 'r';
1006 break;
1007 case Opt_check_n:
1008 opts->name_check = 'n';
1009 break;
OGAWA Hirofumi28ec0392007-05-08 00:31:01 -07001010 case Opt_usefree:
1011 opts->usefree = 1;
1012 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001013 case Opt_nocase:
1014 if (!is_vfat)
1015 opts->nocase = 1;
1016 else {
1017 /* for backward compatibility */
1018 opts->shortname = VFAT_SFN_DISPLAY_WIN95
1019 | VFAT_SFN_CREATE_WIN95;
1020 }
1021 break;
1022 case Opt_quiet:
1023 opts->quiet = 1;
1024 break;
1025 case Opt_showexec:
1026 opts->showexec = 1;
1027 break;
1028 case Opt_debug:
1029 *debug = 1;
1030 break;
1031 case Opt_immutable:
1032 opts->sys_immutable = 1;
1033 break;
1034 case Opt_uid:
1035 if (match_int(&args[0], &option))
1036 return 0;
1037 opts->fs_uid = option;
1038 break;
1039 case Opt_gid:
1040 if (match_int(&args[0], &option))
1041 return 0;
1042 opts->fs_gid = option;
1043 break;
1044 case Opt_umask:
1045 if (match_octal(&args[0], &option))
1046 return 0;
1047 opts->fs_fmask = opts->fs_dmask = option;
1048 break;
1049 case Opt_dmask:
1050 if (match_octal(&args[0], &option))
1051 return 0;
1052 opts->fs_dmask = option;
1053 break;
1054 case Opt_fmask:
1055 if (match_octal(&args[0], &option))
1056 return 0;
1057 opts->fs_fmask = option;
1058 break;
OGAWA Hirofumi1ae43f82008-04-28 02:16:26 -07001059 case Opt_allow_utime:
1060 if (match_octal(&args[0], &option))
1061 return 0;
1062 opts->allow_utime = option & (S_IWGRP | S_IWOTH);
1063 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001064 case Opt_codepage:
1065 if (match_int(&args[0], &option))
1066 return 0;
1067 opts->codepage = option;
1068 break;
Chris Masonae78bf92006-09-29 02:00:03 -07001069 case Opt_flush:
1070 opts->flush = 1;
1071 break;
Joe Petersonb271e062008-07-25 01:46:47 -07001072 case Opt_tz_utc:
1073 opts->tz_utc = 1;
1074 break;
Denis Karpov85c78592009-06-04 02:34:22 +09001075 case Opt_err_cont:
1076 opts->errors = FAT_ERRORS_CONT;
1077 break;
1078 case Opt_err_panic:
1079 opts->errors = FAT_ERRORS_PANIC;
1080 break;
1081 case Opt_err_ro:
1082 opts->errors = FAT_ERRORS_RO;
1083 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001084
1085 /* msdos specific */
1086 case Opt_dots:
1087 opts->dotsOK = 1;
1088 break;
1089 case Opt_nodots:
1090 opts->dotsOK = 0;
1091 break;
1092
1093 /* vfat specific */
1094 case Opt_charset:
1095 if (opts->iocharset != fat_default_iocharset)
1096 kfree(opts->iocharset);
1097 iocharset = match_strdup(&args[0]);
1098 if (!iocharset)
1099 return -ENOMEM;
1100 opts->iocharset = iocharset;
1101 break;
1102 case Opt_shortname_lower:
1103 opts->shortname = VFAT_SFN_DISPLAY_LOWER
1104 | VFAT_SFN_CREATE_WIN95;
1105 break;
1106 case Opt_shortname_win95:
1107 opts->shortname = VFAT_SFN_DISPLAY_WIN95
1108 | VFAT_SFN_CREATE_WIN95;
1109 break;
1110 case Opt_shortname_winnt:
1111 opts->shortname = VFAT_SFN_DISPLAY_WINNT
1112 | VFAT_SFN_CREATE_WINNT;
1113 break;
1114 case Opt_shortname_mixed:
1115 opts->shortname = VFAT_SFN_DISPLAY_WINNT
1116 | VFAT_SFN_CREATE_WIN95;
1117 break;
1118 case Opt_utf8_no: /* 0 or no or false */
1119 opts->utf8 = 0;
1120 break;
1121 case Opt_utf8_yes: /* empty or 1 or yes or true */
1122 opts->utf8 = 1;
1123 break;
1124 case Opt_uni_xl_no: /* 0 or no or false */
1125 opts->unicode_xlate = 0;
1126 break;
1127 case Opt_uni_xl_yes: /* empty or 1 or yes or true */
1128 opts->unicode_xlate = 1;
1129 break;
1130 case Opt_nonumtail_no: /* 0 or no or false */
1131 opts->numtail = 1; /* negated option */
1132 break;
1133 case Opt_nonumtail_yes: /* empty or 1 or yes or true */
1134 opts->numtail = 0; /* negated option */
1135 break;
OGAWA Hirofumidfc209c2008-11-06 12:53:55 -08001136 case Opt_rodir:
1137 opts->rodir = 1;
1138 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001139
1140 /* obsolete mount options */
1141 case Opt_obsolate:
1142 printk(KERN_INFO "FAT: \"%s\" option is obsolete, "
1143 "not supported now\n", p);
1144 break;
1145 /* unknown option */
1146 default:
Christoph Hellwig41a34a42005-11-08 21:34:57 -08001147 if (!silent) {
1148 printk(KERN_ERR
1149 "FAT: Unrecognized mount option \"%s\" "
1150 "or missing value\n", p);
1151 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001152 return -EINVAL;
1153 }
1154 }
OGAWA Hirofumi8d44d972008-07-25 01:46:41 -07001155
1156out:
Alexey Dobriyan4de151d2006-03-22 00:13:35 +01001157 /* UTF-8 doesn't provide FAT semantics */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001158 if (!strcmp(opts->iocharset, "utf8")) {
1159 printk(KERN_ERR "FAT: utf8 is not a recommended IO charset"
OGAWA Hirofumi8d44d972008-07-25 01:46:41 -07001160 " for FAT filesystems, filesystem will be "
1161 "case sensitive!\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -07001162 }
1163
OGAWA Hirofumi1ae43f82008-04-28 02:16:26 -07001164 /* If user doesn't specify allow_utime, it's initialized from dmask. */
1165 if (opts->allow_utime == (unsigned short)-1)
1166 opts->allow_utime = ~opts->fs_dmask & (S_IWGRP | S_IWOTH);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001167 if (opts->unicode_xlate)
1168 opts->utf8 = 0;
1169
1170 return 0;
1171}
1172
1173static int fat_read_root(struct inode *inode)
1174{
1175 struct super_block *sb = inode->i_sb;
1176 struct msdos_sb_info *sbi = MSDOS_SB(sb);
1177 int error;
1178
1179 MSDOS_I(inode)->i_pos = 0;
1180 inode->i_uid = sbi->options.fs_uid;
1181 inode->i_gid = sbi->options.fs_gid;
1182 inode->i_version++;
1183 inode->i_generation = 0;
OGAWA Hirofumi9c0aa1b2008-11-06 12:53:54 -08001184 inode->i_mode = fat_make_mode(sbi, ATTR_DIR, S_IRWXUGO);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001185 inode->i_op = sbi->dir_ops;
1186 inode->i_fop = &fat_dir_operations;
1187 if (sbi->fat_bits == 32) {
1188 MSDOS_I(inode)->i_start = sbi->root_cluster;
1189 error = fat_calc_dir_size(inode);
1190 if (error < 0)
1191 return error;
1192 } else {
1193 MSDOS_I(inode)->i_start = 0;
1194 inode->i_size = sbi->dir_entries * sizeof(struct msdos_dir_entry);
1195 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001196 inode->i_blocks = ((inode->i_size + (sbi->cluster_size - 1))
1197 & ~((loff_t)sbi->cluster_size - 1)) >> 9;
1198 MSDOS_I(inode)->i_logstart = 0;
1199 MSDOS_I(inode)->mmu_private = inode->i_size;
1200
OGAWA Hirofumi9c0aa1b2008-11-06 12:53:54 -08001201 fat_save_attrs(inode, ATTR_DIR);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001202 inode->i_mtime.tv_sec = inode->i_atime.tv_sec = inode->i_ctime.tv_sec = 0;
1203 inode->i_mtime.tv_nsec = inode->i_atime.tv_nsec = inode->i_ctime.tv_nsec = 0;
1204 inode->i_nlink = fat_subdirs(inode)+2;
1205
1206 return 0;
1207}
1208
1209/*
1210 * Read the super block of an MS-DOS FS.
1211 */
1212int fat_fill_super(struct super_block *sb, void *data, int silent,
Arjan van de Ven754661f2007-02-12 00:55:38 -08001213 const struct inode_operations *fs_dir_inode_ops, int isvfat)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001214{
Al Virob5224122009-06-07 13:44:36 -04001215 struct inode *root_inode = NULL, *fat_inode = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001216 struct buffer_head *bh;
1217 struct fat_boot_sector *b;
1218 struct msdos_sb_info *sbi;
1219 u16 logical_sector_size;
1220 u32 total_sectors, total_clusters, fat_clusters, rootdir_sectors;
1221 int debug;
1222 unsigned int media;
1223 long error;
1224 char buf[50];
1225
Linus Torvalds8f593422008-05-19 19:53:01 -07001226 /*
1227 * GFP_KERNEL is ok here, because while we do hold the
1228 * supeblock lock, memory pressure can't call back into
1229 * the filesystem, since we're only just about to mount
1230 * it and have no inodes etc active!
1231 */
Panagiotis Issarisf8314dc2006-09-27 01:49:37 -07001232 sbi = kzalloc(sizeof(struct msdos_sb_info), GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001233 if (!sbi)
1234 return -ENOMEM;
1235 sb->s_fs_info = sbi;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001236
1237 sb->s_flags |= MS_NODIRATIME;
1238 sb->s_magic = MSDOS_SUPER_MAGIC;
1239 sb->s_op = &fat_sops;
1240 sb->s_export_op = &fat_export_ops;
1241 sbi->dir_ops = fs_dir_inode_ops;
1242
Christoph Hellwig41a34a42005-11-08 21:34:57 -08001243 error = parse_options(data, isvfat, silent, &debug, &sbi->options);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001244 if (error)
1245 goto out_fail;
1246
1247 error = -EIO;
1248 sb_min_blocksize(sb, 512);
1249 bh = sb_bread(sb, 0);
1250 if (bh == NULL) {
1251 printk(KERN_ERR "FAT: unable to read boot sector\n");
1252 goto out_fail;
1253 }
1254
1255 b = (struct fat_boot_sector *) bh->b_data;
1256 if (!b->reserved) {
1257 if (!silent)
1258 printk(KERN_ERR "FAT: bogus number of reserved sectors\n");
1259 brelse(bh);
1260 goto out_invalid;
1261 }
1262 if (!b->fats) {
1263 if (!silent)
1264 printk(KERN_ERR "FAT: bogus number of FAT structure\n");
1265 brelse(bh);
1266 goto out_invalid;
1267 }
1268
1269 /*
1270 * Earlier we checked here that b->secs_track and b->head are nonzero,
1271 * but it turns out valid FAT filesystems can have zero there.
1272 */
1273
1274 media = b->media;
Andrew Morton73f20e52008-04-28 02:16:30 -07001275 if (!fat_valid_media(media)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001276 if (!silent)
1277 printk(KERN_ERR "FAT: invalid media value (0x%02x)\n",
1278 media);
1279 brelse(bh);
1280 goto out_invalid;
1281 }
Harvey Harrison803f4452008-04-29 01:03:43 -07001282 logical_sector_size = get_unaligned_le16(&b->sector_size);
Vignesh Babu BMe7d709c2007-05-08 00:24:27 -07001283 if (!is_power_of_2(logical_sector_size)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001284 || (logical_sector_size < 512)
Olof Johansson9f354852008-04-28 02:16:32 -07001285 || (logical_sector_size > 4096)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001286 if (!silent)
1287 printk(KERN_ERR "FAT: bogus logical sector size %u\n",
1288 logical_sector_size);
1289 brelse(bh);
1290 goto out_invalid;
1291 }
1292 sbi->sec_per_clus = b->sec_per_clus;
Vignesh Babu BMe7d709c2007-05-08 00:24:27 -07001293 if (!is_power_of_2(sbi->sec_per_clus)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001294 if (!silent)
1295 printk(KERN_ERR "FAT: bogus sectors per cluster %u\n",
1296 sbi->sec_per_clus);
1297 brelse(bh);
1298 goto out_invalid;
1299 }
1300
1301 if (logical_sector_size < sb->s_blocksize) {
1302 printk(KERN_ERR "FAT: logical sector size too small for device"
1303 " (logical sector size = %u)\n", logical_sector_size);
1304 brelse(bh);
1305 goto out_fail;
1306 }
1307 if (logical_sector_size > sb->s_blocksize) {
1308 brelse(bh);
1309
1310 if (!sb_set_blocksize(sb, logical_sector_size)) {
1311 printk(KERN_ERR "FAT: unable to set blocksize %u\n",
1312 logical_sector_size);
1313 goto out_fail;
1314 }
1315 bh = sb_bread(sb, 0);
1316 if (bh == NULL) {
1317 printk(KERN_ERR "FAT: unable to read boot sector"
1318 " (logical sector size = %lu)\n",
1319 sb->s_blocksize);
1320 goto out_fail;
1321 }
1322 b = (struct fat_boot_sector *) bh->b_data;
1323 }
1324
1325 sbi->cluster_size = sb->s_blocksize * sbi->sec_per_clus;
1326 sbi->cluster_bits = ffs(sbi->cluster_size) - 1;
1327 sbi->fats = b->fats;
1328 sbi->fat_bits = 0; /* Don't know yet */
1329 sbi->fat_start = le16_to_cpu(b->reserved);
1330 sbi->fat_length = le16_to_cpu(b->fat_length);
1331 sbi->root_cluster = 0;
1332 sbi->free_clusters = -1; /* Don't know yet */
OGAWA Hirofumi606e4232008-04-28 02:16:27 -07001333 sbi->free_clus_valid = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001334 sbi->prev_free = FAT_START_ENT;
1335
1336 if (!sbi->fat_length && b->fat32_length) {
1337 struct fat_boot_fsinfo *fsinfo;
1338 struct buffer_head *fsinfo_bh;
1339
1340 /* Must be FAT32 */
1341 sbi->fat_bits = 32;
1342 sbi->fat_length = le32_to_cpu(b->fat32_length);
1343 sbi->root_cluster = le32_to_cpu(b->root_cluster);
1344
1345 sb->s_maxbytes = 0xffffffff;
1346
1347 /* MC - if info_sector is 0, don't multiply by 0 */
1348 sbi->fsinfo_sector = le16_to_cpu(b->info_sector);
1349 if (sbi->fsinfo_sector == 0)
1350 sbi->fsinfo_sector = 1;
1351
1352 fsinfo_bh = sb_bread(sb, sbi->fsinfo_sector);
1353 if (fsinfo_bh == NULL) {
1354 printk(KERN_ERR "FAT: bread failed, FSINFO block"
1355 " (sector = %lu)\n", sbi->fsinfo_sector);
1356 brelse(bh);
1357 goto out_fail;
1358 }
1359
1360 fsinfo = (struct fat_boot_fsinfo *)fsinfo_bh->b_data;
1361 if (!IS_FSINFO(fsinfo)) {
Vegard Nossumb4cf9c32008-02-06 01:36:36 -08001362 printk(KERN_WARNING "FAT: Invalid FSINFO signature: "
1363 "0x%08x, 0x%08x (sector = %lu)\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -07001364 le32_to_cpu(fsinfo->signature1),
1365 le32_to_cpu(fsinfo->signature2),
1366 sbi->fsinfo_sector);
1367 } else {
OGAWA Hirofumi28ec0392007-05-08 00:31:01 -07001368 if (sbi->options.usefree)
OGAWA Hirofumi606e4232008-04-28 02:16:27 -07001369 sbi->free_clus_valid = 1;
1370 sbi->free_clusters = le32_to_cpu(fsinfo->free_clusters);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001371 sbi->prev_free = le32_to_cpu(fsinfo->next_cluster);
1372 }
1373
1374 brelse(fsinfo_bh);
1375 }
1376
1377 sbi->dir_per_block = sb->s_blocksize / sizeof(struct msdos_dir_entry);
1378 sbi->dir_per_block_bits = ffs(sbi->dir_per_block) - 1;
1379
1380 sbi->dir_start = sbi->fat_start + sbi->fats * sbi->fat_length;
Harvey Harrison803f4452008-04-29 01:03:43 -07001381 sbi->dir_entries = get_unaligned_le16(&b->dir_entries);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001382 if (sbi->dir_entries & (sbi->dir_per_block - 1)) {
1383 if (!silent)
1384 printk(KERN_ERR "FAT: bogus directroy-entries per block"
1385 " (%u)\n", sbi->dir_entries);
1386 brelse(bh);
1387 goto out_invalid;
1388 }
1389
1390 rootdir_sectors = sbi->dir_entries
1391 * sizeof(struct msdos_dir_entry) / sb->s_blocksize;
1392 sbi->data_start = sbi->dir_start + rootdir_sectors;
Harvey Harrison803f4452008-04-29 01:03:43 -07001393 total_sectors = get_unaligned_le16(&b->sectors);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001394 if (total_sectors == 0)
1395 total_sectors = le32_to_cpu(b->total_sect);
1396
1397 total_clusters = (total_sectors - sbi->data_start) / sbi->sec_per_clus;
1398
1399 if (sbi->fat_bits != 32)
1400 sbi->fat_bits = (total_clusters > MAX_FAT12) ? 16 : 12;
1401
1402 /* check that FAT table does not overflow */
1403 fat_clusters = sbi->fat_length * sb->s_blocksize * 8 / sbi->fat_bits;
1404 total_clusters = min(total_clusters, fat_clusters - FAT_START_ENT);
1405 if (total_clusters > MAX_FAT(sb)) {
1406 if (!silent)
1407 printk(KERN_ERR "FAT: count of clusters too big (%u)\n",
1408 total_clusters);
1409 brelse(bh);
1410 goto out_invalid;
1411 }
1412
1413 sbi->max_cluster = total_clusters + FAT_START_ENT;
1414 /* check the free_clusters, it's not necessarily correct */
1415 if (sbi->free_clusters != -1 && sbi->free_clusters > total_clusters)
1416 sbi->free_clusters = -1;
1417 /* check the prev_free, it's not necessarily correct */
1418 sbi->prev_free %= sbi->max_cluster;
1419 if (sbi->prev_free < FAT_START_ENT)
1420 sbi->prev_free = FAT_START_ENT;
1421
1422 brelse(bh);
1423
1424 /* set up enough so that it can read an inode */
1425 fat_hash_init(sb);
1426 fat_ent_access_init(sb);
1427
1428 /*
1429 * The low byte of FAT's first entry must have same value with
1430 * media-field. But in real world, too many devices is
1431 * writing wrong value. So, removed that validity check.
1432 *
1433 * if (FAT_FIRST_ENT(sb, media) != first)
1434 */
1435
1436 error = -EINVAL;
1437 sprintf(buf, "cp%d", sbi->options.codepage);
1438 sbi->nls_disk = load_nls(buf);
1439 if (!sbi->nls_disk) {
1440 printk(KERN_ERR "FAT: codepage %s not found\n", buf);
1441 goto out_fail;
1442 }
1443
1444 /* FIXME: utf8 is using iocharset for upper/lower conversion */
1445 if (sbi->options.isvfat) {
1446 sbi->nls_io = load_nls(sbi->options.iocharset);
1447 if (!sbi->nls_io) {
1448 printk(KERN_ERR "FAT: IO charset %s not found\n",
1449 sbi->options.iocharset);
1450 goto out_fail;
1451 }
1452 }
1453
1454 error = -ENOMEM;
Al Virob5224122009-06-07 13:44:36 -04001455 fat_inode = new_inode(sb);
1456 if (!fat_inode)
1457 goto out_fail;
1458 MSDOS_I(fat_inode)->i_pos = 0;
1459 sbi->fat_inode = fat_inode;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001460 root_inode = new_inode(sb);
1461 if (!root_inode)
1462 goto out_fail;
1463 root_inode->i_ino = MSDOS_ROOT_INO;
1464 root_inode->i_version = 1;
1465 error = fat_read_root(root_inode);
1466 if (error < 0)
1467 goto out_fail;
1468 error = -ENOMEM;
1469 insert_inode_hash(root_inode);
1470 sb->s_root = d_alloc_root(root_inode);
1471 if (!sb->s_root) {
1472 printk(KERN_ERR "FAT: get root inode failed\n");
1473 goto out_fail;
1474 }
1475
1476 return 0;
1477
1478out_invalid:
1479 error = -EINVAL;
1480 if (!silent)
1481 printk(KERN_INFO "VFS: Can't find a valid FAT filesystem"
1482 " on dev %s.\n", sb->s_id);
1483
1484out_fail:
Al Virob5224122009-06-07 13:44:36 -04001485 if (fat_inode)
1486 iput(fat_inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001487 if (root_inode)
1488 iput(root_inode);
1489 if (sbi->nls_io)
1490 unload_nls(sbi->nls_io);
1491 if (sbi->nls_disk)
1492 unload_nls(sbi->nls_disk);
1493 if (sbi->options.iocharset != fat_default_iocharset)
1494 kfree(sbi->options.iocharset);
1495 sb->s_fs_info = NULL;
1496 kfree(sbi);
1497 return error;
1498}
1499
OGAWA Hirofumi7c709d02006-01-08 01:02:10 -08001500EXPORT_SYMBOL_GPL(fat_fill_super);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001501
Chris Masonae78bf92006-09-29 02:00:03 -07001502/*
1503 * helper function for fat_flush_inodes. This writes both the inode
1504 * and the file data blocks, waiting for in flight data blocks before
1505 * the start of the call. It does not wait for any io started
1506 * during the call
1507 */
1508static int writeback_inode(struct inode *inode)
1509{
1510
1511 int ret;
1512 struct address_space *mapping = inode->i_mapping;
1513 struct writeback_control wbc = {
1514 .sync_mode = WB_SYNC_NONE,
1515 .nr_to_write = 0,
1516 };
1517 /* if we used WB_SYNC_ALL, sync_inode waits for the io for the
1518 * inode to finish. So WB_SYNC_NONE is sent down to sync_inode
1519 * and filemap_fdatawrite is used for the data blocks
1520 */
1521 ret = sync_inode(inode, &wbc);
1522 if (!ret)
1523 ret = filemap_fdatawrite(mapping);
1524 return ret;
1525}
1526
1527/*
1528 * write data and metadata corresponding to i1 and i2. The io is
1529 * started but we do not wait for any of it to finish.
1530 *
1531 * filemap_flush is used for the block device, so if there is a dirty
1532 * page for a block already in flight, we will not wait and start the
1533 * io over again
1534 */
1535int fat_flush_inodes(struct super_block *sb, struct inode *i1, struct inode *i2)
1536{
1537 int ret = 0;
1538 if (!MSDOS_SB(sb)->options.flush)
1539 return 0;
1540 if (i1)
1541 ret = writeback_inode(i1);
1542 if (!ret && i2)
1543 ret = writeback_inode(i2);
Eric Sesterhenn97e860d2006-10-11 01:21:59 -07001544 if (!ret) {
Chris Masonae78bf92006-09-29 02:00:03 -07001545 struct address_space *mapping = sb->s_bdev->bd_inode->i_mapping;
1546 ret = filemap_flush(mapping);
1547 }
1548 return ret;
1549}
1550EXPORT_SYMBOL_GPL(fat_flush_inodes);
1551
Linus Torvalds1da177e2005-04-16 15:20:36 -07001552static int __init init_fat_fs(void)
1553{
Pekka J Enberg532a39a2005-06-30 02:59:01 -07001554 int err;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001555
Pekka J Enberg532a39a2005-06-30 02:59:01 -07001556 err = fat_cache_init();
1557 if (err)
1558 return err;
1559
1560 err = fat_init_inodecache();
1561 if (err)
1562 goto failed;
1563
1564 return 0;
1565
1566failed:
1567 fat_cache_destroy();
1568 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001569}
1570
1571static void __exit exit_fat_fs(void)
1572{
1573 fat_cache_destroy();
1574 fat_destroy_inodecache();
1575}
1576
1577module_init(init_fat_fs)
1578module_exit(exit_fat_fs)
1579
1580MODULE_LICENSE("GPL");