blob: 7bf45aee56d7631a0e6873744724f2fe382eeef5 [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
npiggin@suse.de459f6ed2010-05-27 01:05:38 +1000145static void fat_write_failed(struct address_space *mapping, loff_t to)
146{
147 struct inode *inode = mapping->host;
148
149 if (to > inode->i_size) {
150 truncate_pagecache(inode, to, inode->i_size);
151 fat_truncate_blocks(inode, inode->i_size);
152 }
153}
154
Nick Piggind7777a22007-10-16 01:25:08 -0700155static int fat_write_begin(struct file *file, struct address_space *mapping,
156 loff_t pos, unsigned len, unsigned flags,
157 struct page **pagep, void **fsdata)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700158{
npiggin@suse.de459f6ed2010-05-27 01:05:38 +1000159 int err;
160
Nick Piggind7777a22007-10-16 01:25:08 -0700161 *pagep = NULL;
npiggin@suse.de459f6ed2010-05-27 01:05:38 +1000162 err = cont_write_begin_newtrunc(file, mapping, pos, len, flags,
163 pagep, fsdata, fat_get_block,
Nick Piggind7777a22007-10-16 01:25:08 -0700164 &MSDOS_I(mapping->host)->mmu_private);
npiggin@suse.de459f6ed2010-05-27 01:05:38 +1000165 if (err < 0)
166 fat_write_failed(mapping, pos + len);
167 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700168}
169
Nick Piggind7777a22007-10-16 01:25:08 -0700170static int fat_write_end(struct file *file, struct address_space *mapping,
171 loff_t pos, unsigned len, unsigned copied,
172 struct page *pagep, void *fsdata)
OGAWA Hirofumief402262005-09-16 19:28:13 -0700173{
Nick Piggind7777a22007-10-16 01:25:08 -0700174 struct inode *inode = mapping->host;
175 int err;
176 err = generic_write_end(file, mapping, pos, len, copied, pagep, fsdata);
npiggin@suse.de459f6ed2010-05-27 01:05:38 +1000177 if (err < len)
178 fat_write_failed(mapping, pos + len);
Nick Piggind7777a22007-10-16 01:25:08 -0700179 if (!(err < 0) && !(MSDOS_I(inode)->i_attrs & ATTR_ARCH)) {
OGAWA Hirofumief402262005-09-16 19:28:13 -0700180 inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC;
181 MSDOS_I(inode)->i_attrs |= ATTR_ARCH;
182 mark_inode_dirty(inode);
183 }
184 return err;
185}
186
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -0800187static ssize_t fat_direct_IO(int rw, struct kiocb *iocb,
188 const struct iovec *iov,
189 loff_t offset, unsigned long nr_segs)
190{
191 struct file *file = iocb->ki_filp;
npiggin@suse.de459f6ed2010-05-27 01:05:38 +1000192 struct address_space *mapping = file->f_mapping;
193 struct inode *inode = mapping->host;
194 ssize_t ret;
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -0800195
196 if (rw == WRITE) {
197 /*
Nick Piggin4e02ed42008-10-29 14:00:55 -0700198 * FIXME: blockdev_direct_IO() doesn't use ->write_begin(),
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -0800199 * so we need to update the ->mmu_private to block boundary.
200 *
201 * But we must fill the remaining area or hole by nul for
202 * updating ->mmu_private.
OGAWA Hirofumi94412a92007-02-20 13:57:55 -0800203 *
204 * Return 0, and fallback to normal buffered write.
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -0800205 */
206 loff_t size = offset + iov_length(iov, nr_segs);
207 if (MSDOS_I(inode)->mmu_private < size)
OGAWA Hirofumi94412a92007-02-20 13:57:55 -0800208 return 0;
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -0800209 }
210
211 /*
212 * FAT need to use the DIO_LOCKING for avoiding the race
213 * condition of fat_get_block() and ->truncate().
214 */
npiggin@suse.de459f6ed2010-05-27 01:05:38 +1000215 ret = blockdev_direct_IO_newtrunc(rw, iocb, inode, inode->i_sb->s_bdev,
216 iov, offset, nr_segs, fat_get_block, NULL);
217 if (ret < 0 && (rw & WRITE))
218 fat_write_failed(mapping, offset + iov_length(iov, nr_segs));
219
220 return ret;
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -0800221}
222
Linus Torvalds1da177e2005-04-16 15:20:36 -0700223static sector_t _fat_bmap(struct address_space *mapping, sector_t block)
224{
OGAWA Hirofumifa93ca12008-11-06 12:53:56 -0800225 sector_t blocknr;
226
227 /* fat_get_cluster() assumes the requested blocknr isn't truncated. */
OGAWA Hirofumi3a95ea12009-03-12 02:03:23 +0900228 down_read(&mapping->host->i_alloc_sem);
OGAWA Hirofumifa93ca12008-11-06 12:53:56 -0800229 blocknr = generic_block_bmap(mapping, block, fat_get_block);
OGAWA Hirofumi3a95ea12009-03-12 02:03:23 +0900230 up_read(&mapping->host->i_alloc_sem);
OGAWA Hirofumifa93ca12008-11-06 12:53:56 -0800231
232 return blocknr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700233}
234
Christoph Hellwigf5e54d62006-06-28 04:26:44 -0700235static const struct address_space_operations fat_aops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700236 .readpage = fat_readpage,
OGAWA Hirofumia5425d22006-01-08 01:02:10 -0800237 .readpages = fat_readpages,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700238 .writepage = fat_writepage,
OGAWA Hirofumia5425d22006-01-08 01:02:10 -0800239 .writepages = fat_writepages,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700240 .sync_page = block_sync_page,
Nick Piggind7777a22007-10-16 01:25:08 -0700241 .write_begin = fat_write_begin,
242 .write_end = fat_write_end,
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -0800243 .direct_IO = fat_direct_IO,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700244 .bmap = _fat_bmap
245};
246
247/*
248 * New FAT inode stuff. We do the following:
249 * a) i_ino is constant and has nothing with on-disk location.
250 * b) FAT manages its own cache of directory entries.
251 * c) *This* cache is indexed by on-disk location.
252 * d) inode has an associated directory entry, all right, but
253 * it may be unhashed.
254 * e) currently entries are stored within struct inode. That should
255 * change.
256 * f) we deal with races in the following way:
257 * 1. readdir() and lookup() do FAT-dir-cache lookup.
258 * 2. rename() unhashes the F-d-c entry and rehashes it in
259 * a new place.
260 * 3. unlink() and rmdir() unhash F-d-c entry.
261 * 4. fat_write_inode() checks whether the thing is unhashed.
262 * If it is we silently return. If it isn't we do bread(),
263 * check if the location is still valid and retry if it
264 * isn't. Otherwise we do changes.
265 * 5. Spinlock is used to protect hash/unhash/location check/lookup
266 * 6. fat_clear_inode() unhashes the F-d-c entry.
267 * 7. lookup() and readdir() do igrab() if they find a F-d-c entry
268 * and consider negative result as cache miss.
269 */
270
271static void fat_hash_init(struct super_block *sb)
272{
273 struct msdos_sb_info *sbi = MSDOS_SB(sb);
274 int i;
275
276 spin_lock_init(&sbi->inode_hash_lock);
277 for (i = 0; i < FAT_HASH_SIZE; i++)
278 INIT_HLIST_HEAD(&sbi->inode_hashtable[i]);
279}
280
OGAWA Hirofumid3dfa822008-11-06 12:53:49 -0800281static inline unsigned long fat_hash(loff_t i_pos)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700282{
OGAWA Hirofumid3dfa822008-11-06 12:53:49 -0800283 return hash_32(i_pos, FAT_HASH_BITS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700284}
285
286void fat_attach(struct inode *inode, loff_t i_pos)
287{
OGAWA Hirofumid3dfa822008-11-06 12:53:49 -0800288 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
289 struct hlist_head *head = sbi->inode_hashtable + fat_hash(i_pos);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700290
291 spin_lock(&sbi->inode_hash_lock);
292 MSDOS_I(inode)->i_pos = i_pos;
OGAWA Hirofumid3dfa822008-11-06 12:53:49 -0800293 hlist_add_head(&MSDOS_I(inode)->i_fat_hash, head);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700294 spin_unlock(&sbi->inode_hash_lock);
295}
OGAWA Hirofumi7c709d02006-01-08 01:02:10 -0800296EXPORT_SYMBOL_GPL(fat_attach);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700297
298void fat_detach(struct inode *inode)
299{
300 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
301 spin_lock(&sbi->inode_hash_lock);
302 MSDOS_I(inode)->i_pos = 0;
303 hlist_del_init(&MSDOS_I(inode)->i_fat_hash);
304 spin_unlock(&sbi->inode_hash_lock);
305}
OGAWA Hirofumi7c709d02006-01-08 01:02:10 -0800306EXPORT_SYMBOL_GPL(fat_detach);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700307
308struct inode *fat_iget(struct super_block *sb, loff_t i_pos)
309{
310 struct msdos_sb_info *sbi = MSDOS_SB(sb);
OGAWA Hirofumid3dfa822008-11-06 12:53:49 -0800311 struct hlist_head *head = sbi->inode_hashtable + fat_hash(i_pos);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700312 struct hlist_node *_p;
313 struct msdos_inode_info *i;
314 struct inode *inode = NULL;
315
316 spin_lock(&sbi->inode_hash_lock);
317 hlist_for_each_entry(i, _p, head, i_fat_hash) {
318 BUG_ON(i->vfs_inode.i_sb != sb);
319 if (i->i_pos != i_pos)
320 continue;
321 inode = igrab(&i->vfs_inode);
322 if (inode)
323 break;
324 }
325 spin_unlock(&sbi->inode_hash_lock);
326 return inode;
327}
328
329static int is_exec(unsigned char *extension)
330{
331 unsigned char *exe_extensions = "EXECOMBAT", *walk;
332
333 for (walk = exe_extensions; *walk; walk += 3)
334 if (!strncmp(extension, walk, 3))
335 return 1;
336 return 0;
337}
338
339static int fat_calc_dir_size(struct inode *inode)
340{
341 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
342 int ret, fclus, dclus;
343
344 inode->i_size = 0;
345 if (MSDOS_I(inode)->i_start == 0)
346 return 0;
347
348 ret = fat_get_cluster(inode, FAT_ENT_EOF, &fclus, &dclus);
349 if (ret < 0)
350 return ret;
351 inode->i_size = (fclus + 1) << sbi->cluster_bits;
352
353 return 0;
354}
355
356/* doesn't deal with root inode */
357static int fat_fill_inode(struct inode *inode, struct msdos_dir_entry *de)
358{
359 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
360 int error;
361
362 MSDOS_I(inode)->i_pos = 0;
363 inode->i_uid = sbi->options.fs_uid;
364 inode->i_gid = sbi->options.fs_gid;
365 inode->i_version++;
366 inode->i_generation = get_seconds();
367
368 if ((de->attr & ATTR_DIR) && !IS_FREE(de->name)) {
369 inode->i_generation &= ~1;
OGAWA Hirofumi9c0aa1b2008-11-06 12:53:54 -0800370 inode->i_mode = fat_make_mode(sbi, de->attr, S_IRWXUGO);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700371 inode->i_op = sbi->dir_ops;
372 inode->i_fop = &fat_dir_operations;
373
374 MSDOS_I(inode)->i_start = le16_to_cpu(de->start);
375 if (sbi->fat_bits == 32)
376 MSDOS_I(inode)->i_start |= (le16_to_cpu(de->starthi) << 16);
377
378 MSDOS_I(inode)->i_logstart = MSDOS_I(inode)->i_start;
379 error = fat_calc_dir_size(inode);
380 if (error < 0)
381 return error;
382 MSDOS_I(inode)->mmu_private = inode->i_size;
383
384 inode->i_nlink = fat_subdirs(inode);
385 } else { /* not a directory */
386 inode->i_generation |= 1;
OGAWA Hirofumi9c0aa1b2008-11-06 12:53:54 -0800387 inode->i_mode = fat_make_mode(sbi, de->attr,
388 ((sbi->options.showexec && !is_exec(de->name + 8))
389 ? S_IRUGO|S_IWUGO : S_IRWXUGO));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700390 MSDOS_I(inode)->i_start = le16_to_cpu(de->start);
391 if (sbi->fat_bits == 32)
392 MSDOS_I(inode)->i_start |= (le16_to_cpu(de->starthi) << 16);
393
394 MSDOS_I(inode)->i_logstart = MSDOS_I(inode)->i_start;
395 inode->i_size = le32_to_cpu(de->size);
396 inode->i_op = &fat_file_inode_operations;
397 inode->i_fop = &fat_file_operations;
398 inode->i_mapping->a_ops = &fat_aops;
399 MSDOS_I(inode)->mmu_private = inode->i_size;
400 }
401 if (de->attr & ATTR_SYS) {
402 if (sbi->options.sys_immutable)
403 inode->i_flags |= S_IMMUTABLE;
404 }
OGAWA Hirofumi9c0aa1b2008-11-06 12:53:54 -0800405 fat_save_attrs(inode, de->attr);
406
Linus Torvalds1da177e2005-04-16 15:20:36 -0700407 inode->i_blocks = ((inode->i_size + (sbi->cluster_size - 1))
408 & ~((loff_t)sbi->cluster_size - 1)) >> 9;
OGAWA Hirofumi7decd1c2008-11-06 12:53:47 -0800409
410 fat_time_fat2unix(sbi, &inode->i_mtime, de->time, de->date, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700411 if (sbi->options.isvfat) {
OGAWA Hirofumi7decd1c2008-11-06 12:53:47 -0800412 fat_time_fat2unix(sbi, &inode->i_ctime, de->ctime,
413 de->cdate, de->ctime_cs);
414 fat_time_fat2unix(sbi, &inode->i_atime, 0, de->adate, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700415 } else
Stephane Kardas62a36c42005-09-21 09:55:45 -0700416 inode->i_ctime = inode->i_atime = inode->i_mtime;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700417
418 return 0;
419}
420
421struct inode *fat_build_inode(struct super_block *sb,
422 struct msdos_dir_entry *de, loff_t i_pos)
423{
424 struct inode *inode;
425 int err;
426
427 inode = fat_iget(sb, i_pos);
428 if (inode)
429 goto out;
430 inode = new_inode(sb);
431 if (!inode) {
432 inode = ERR_PTR(-ENOMEM);
433 goto out;
434 }
435 inode->i_ino = iunique(sb, MSDOS_ROOT_INO);
436 inode->i_version = 1;
437 err = fat_fill_inode(inode, de);
438 if (err) {
439 iput(inode);
440 inode = ERR_PTR(err);
441 goto out;
442 }
443 fat_attach(inode, i_pos);
444 insert_inode_hash(inode);
445out:
446 return inode;
447}
448
OGAWA Hirofumi7c709d02006-01-08 01:02:10 -0800449EXPORT_SYMBOL_GPL(fat_build_inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700450
451static void fat_delete_inode(struct inode *inode)
452{
Mark Fashehfef26652005-09-09 13:01:31 -0700453 truncate_inode_pages(&inode->i_data, 0);
OGAWA Hirofumi3754a542008-04-28 02:16:24 -0700454 inode->i_size = 0;
npiggin@suse.de459f6ed2010-05-27 01:05:38 +1000455 fat_truncate_blocks(inode, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700456 clear_inode(inode);
457}
458
459static void fat_clear_inode(struct inode *inode)
460{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700461 fat_cache_inval_inode(inode);
OGAWA Hirofumia993b542008-11-06 12:53:50 -0800462 fat_detach(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700463}
464
OGAWA Hirofumia6bf6b22006-01-08 01:02:08 -0800465static void fat_write_super(struct super_block *sb)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700466{
Christoph Hellwigebc1ac12009-05-11 23:35:03 +0200467 lock_super(sb);
OGAWA Hirofumia6bf6b22006-01-08 01:02:08 -0800468 sb->s_dirt = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700469
470 if (!(sb->s_flags & MS_RDONLY))
471 fat_clusters_flush(sb);
Christoph Hellwigebc1ac12009-05-11 23:35:03 +0200472 unlock_super(sb);
OGAWA Hirofumia6bf6b22006-01-08 01:02:08 -0800473}
474
Christoph Hellwigf83d6d42009-06-08 10:04:35 +0200475static int fat_sync_fs(struct super_block *sb, int wait)
476{
OGAWA Hirofumied248b22009-09-20 01:31:58 +0900477 int err = 0;
Christoph Hellwigf83d6d42009-06-08 10:04:35 +0200478
OGAWA Hirofumied248b22009-09-20 01:31:58 +0900479 if (sb->s_dirt) {
480 lock_super(sb);
481 sb->s_dirt = 0;
482 err = fat_clusters_flush(sb);
483 unlock_super(sb);
484 }
485
486 return err;
Christoph Hellwigf83d6d42009-06-08 10:04:35 +0200487}
488
OGAWA Hirofumia6bf6b22006-01-08 01:02:08 -0800489static void fat_put_super(struct super_block *sb)
490{
491 struct msdos_sb_info *sbi = MSDOS_SB(sb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700492
Christoph Hellwig6cfd0142009-05-05 15:40:36 +0200493 lock_kernel();
494
Christoph Hellwig8c85e122009-04-28 18:00:26 +0200495 if (sb->s_dirt)
496 fat_write_super(sb);
497
Al Virob5224122009-06-07 13:44:36 -0400498 iput(sbi->fat_inode);
499
Thomas Gleixner6d729e42009-08-16 21:05:08 +0000500 unload_nls(sbi->nls_disk);
501 unload_nls(sbi->nls_io);
502
503 if (sbi->options.iocharset != fat_default_iocharset)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700504 kfree(sbi->options.iocharset);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700505
506 sb->s_fs_info = NULL;
507 kfree(sbi);
Christoph Hellwig6cfd0142009-05-05 15:40:36 +0200508
509 unlock_kernel();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700510}
511
Christoph Lametere18b8902006-12-06 20:33:20 -0800512static struct kmem_cache *fat_inode_cachep;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700513
514static struct inode *fat_alloc_inode(struct super_block *sb)
515{
516 struct msdos_inode_info *ei;
Linus Torvalds8f593422008-05-19 19:53:01 -0700517 ei = kmem_cache_alloc(fat_inode_cachep, GFP_NOFS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700518 if (!ei)
519 return NULL;
520 return &ei->vfs_inode;
521}
522
523static void fat_destroy_inode(struct inode *inode)
524{
525 kmem_cache_free(fat_inode_cachep, MSDOS_I(inode));
526}
527
Alexey Dobriyan51cc5062008-07-25 19:45:34 -0700528static void init_once(void *foo)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700529{
530 struct msdos_inode_info *ei = (struct msdos_inode_info *)foo;
531
Christoph Lametera35afb82007-05-16 22:10:57 -0700532 spin_lock_init(&ei->cache_lru_lock);
533 ei->nr_caches = 0;
534 ei->cache_valid_id = FAT_CACHE_VALID + 1;
535 INIT_LIST_HEAD(&ei->cache_lru);
536 INIT_HLIST_NODE(&ei->i_fat_hash);
537 inode_init_once(&ei->vfs_inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700538}
539
540static int __init fat_init_inodecache(void)
541{
542 fat_inode_cachep = kmem_cache_create("fat_inode_cache",
543 sizeof(struct msdos_inode_info),
Paul Jacksonfffb60f2006-03-24 03:16:06 -0800544 0, (SLAB_RECLAIM_ACCOUNT|
545 SLAB_MEM_SPREAD),
Paul Mundt20c2df82007-07-20 10:11:58 +0900546 init_once);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700547 if (fat_inode_cachep == NULL)
548 return -ENOMEM;
549 return 0;
550}
551
552static void __exit fat_destroy_inodecache(void)
553{
Alexey Dobriyan1a1d92c2006-09-27 01:49:40 -0700554 kmem_cache_destroy(fat_inode_cachep);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700555}
556
557static int fat_remount(struct super_block *sb, int *flags, char *data)
558{
559 struct msdos_sb_info *sbi = MSDOS_SB(sb);
560 *flags |= MS_NODIRATIME | (sbi->options.isvfat ? 0 : MS_NOATIME);
561 return 0;
562}
563
David Howells726c3342006-06-23 02:02:58 -0700564static int fat_statfs(struct dentry *dentry, struct kstatfs *buf)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700565{
Coly Liaac49b72009-04-02 16:59:35 -0700566 struct super_block *sb = dentry->d_sb;
567 struct msdos_sb_info *sbi = MSDOS_SB(sb);
568 u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700569
570 /* If the count of free cluster is still unknown, counts it here. */
OGAWA Hirofumi606e4232008-04-28 02:16:27 -0700571 if (sbi->free_clusters == -1 || !sbi->free_clus_valid) {
David Howells726c3342006-06-23 02:02:58 -0700572 int err = fat_count_free_clusters(dentry->d_sb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700573 if (err)
574 return err;
575 }
576
David Howells726c3342006-06-23 02:02:58 -0700577 buf->f_type = dentry->d_sb->s_magic;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700578 buf->f_bsize = sbi->cluster_size;
579 buf->f_blocks = sbi->max_cluster - FAT_START_ENT;
580 buf->f_bfree = sbi->free_clusters;
581 buf->f_bavail = sbi->free_clusters;
Coly Liaac49b72009-04-02 16:59:35 -0700582 buf->f_fsid.val[0] = (u32)id;
583 buf->f_fsid.val[1] = (u32)(id >> 32);
Kevin Dankwardteeb5b4a2010-02-10 23:43:40 +0900584 buf->f_namelen = sbi->options.isvfat ? FAT_LFN_LEN : 12;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700585
586 return 0;
587}
588
OGAWA Hirofumi9ca59f42008-11-06 12:53:57 -0800589static inline loff_t fat_i_pos_read(struct msdos_sb_info *sbi,
590 struct inode *inode)
591{
592 loff_t i_pos;
593#if BITS_PER_LONG == 32
594 spin_lock(&sbi->inode_hash_lock);
595#endif
596 i_pos = MSDOS_I(inode)->i_pos;
597#if BITS_PER_LONG == 32
598 spin_unlock(&sbi->inode_hash_lock);
599#endif
600 return i_pos;
601}
602
Christoph Hellwiga9185b42010-03-05 09:21:37 +0100603static int __fat_write_inode(struct inode *inode, int wait)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700604{
605 struct super_block *sb = inode->i_sb;
606 struct msdos_sb_info *sbi = MSDOS_SB(sb);
607 struct buffer_head *bh;
608 struct msdos_dir_entry *raw_entry;
609 loff_t i_pos;
Linus Torvalds5f22ca92008-08-20 08:31:19 -0700610 int err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700611
OGAWA Hirofumi9ca59f42008-11-06 12:53:57 -0800612 if (inode->i_ino == MSDOS_ROOT_INO)
613 return 0;
614
Linus Torvalds1da177e2005-04-16 15:20:36 -0700615retry:
OGAWA Hirofumi9ca59f42008-11-06 12:53:57 -0800616 i_pos = fat_i_pos_read(sbi, inode);
617 if (!i_pos)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700618 return 0;
619
Linus Torvalds1da177e2005-04-16 15:20:36 -0700620 bh = sb_bread(sb, i_pos >> sbi->dir_per_block_bits);
621 if (!bh) {
622 printk(KERN_ERR "FAT: unable to read inode block "
623 "for updating (i_pos %lld)\n", i_pos);
Linus Torvalds5f22ca92008-08-20 08:31:19 -0700624 return -EIO;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700625 }
626 spin_lock(&sbi->inode_hash_lock);
627 if (i_pos != MSDOS_I(inode)->i_pos) {
628 spin_unlock(&sbi->inode_hash_lock);
629 brelse(bh);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700630 goto retry;
631 }
632
633 raw_entry = &((struct msdos_dir_entry *) (bh->b_data))
634 [i_pos & (sbi->dir_per_block - 1)];
635 if (S_ISDIR(inode->i_mode))
636 raw_entry->size = 0;
637 else
638 raw_entry->size = cpu_to_le32(inode->i_size);
OGAWA Hirofumi9c0aa1b2008-11-06 12:53:54 -0800639 raw_entry->attr = fat_make_attrs(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700640 raw_entry->start = cpu_to_le16(MSDOS_I(inode)->i_logstart);
641 raw_entry->starthi = cpu_to_le16(MSDOS_I(inode)->i_logstart >> 16);
OGAWA Hirofumi7decd1c2008-11-06 12:53:47 -0800642 fat_time_unix2fat(sbi, &inode->i_mtime, &raw_entry->time,
643 &raw_entry->date, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700644 if (sbi->options.isvfat) {
Stephane Kardas62a36c42005-09-21 09:55:45 -0700645 __le16 atime;
OGAWA Hirofumi7decd1c2008-11-06 12:53:47 -0800646 fat_time_unix2fat(sbi, &inode->i_ctime, &raw_entry->ctime,
647 &raw_entry->cdate, &raw_entry->ctime_cs);
648 fat_time_unix2fat(sbi, &inode->i_atime, &atime,
649 &raw_entry->adate, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700650 }
651 spin_unlock(&sbi->inode_hash_lock);
652 mark_buffer_dirty(bh);
Linus Torvalds5f22ca92008-08-20 08:31:19 -0700653 err = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700654 if (wait)
655 err = sync_dirty_buffer(bh);
656 brelse(bh);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700657 return err;
658}
659
Christoph Hellwiga9185b42010-03-05 09:21:37 +0100660static int fat_write_inode(struct inode *inode, struct writeback_control *wbc)
661{
662 return __fat_write_inode(inode, wbc->sync_mode == WB_SYNC_ALL);
663}
664
Linus Torvalds1da177e2005-04-16 15:20:36 -0700665int fat_sync_inode(struct inode *inode)
666{
Christoph Hellwiga9185b42010-03-05 09:21:37 +0100667 return __fat_write_inode(inode, 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700668}
669
OGAWA Hirofumi7c709d02006-01-08 01:02:10 -0800670EXPORT_SYMBOL_GPL(fat_sync_inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700671
672static int fat_show_options(struct seq_file *m, struct vfsmount *mnt);
Josef 'Jeff' Sipekee9b6d62007-02-12 00:55:41 -0800673static const struct super_operations fat_sops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700674 .alloc_inode = fat_alloc_inode,
675 .destroy_inode = fat_destroy_inode,
676 .write_inode = fat_write_inode,
677 .delete_inode = fat_delete_inode,
678 .put_super = fat_put_super,
OGAWA Hirofumia6bf6b22006-01-08 01:02:08 -0800679 .write_super = fat_write_super,
Christoph Hellwigf83d6d42009-06-08 10:04:35 +0200680 .sync_fs = fat_sync_fs,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700681 .statfs = fat_statfs,
682 .clear_inode = fat_clear_inode,
683 .remount_fs = fat_remount,
684
Linus Torvalds1da177e2005-04-16 15:20:36 -0700685 .show_options = fat_show_options,
686};
687
688/*
689 * a FAT file handle with fhtype 3 is
690 * 0/ i_ino - for fast, reliable lookup if still in the cache
691 * 1/ i_generation - to see if i_ino is still valid
692 * bit 0 == 0 iff directory
693 * 2/ i_pos(8-39) - if ino has changed, but still in cache
694 * 3/ i_pos(4-7)|i_logstart - to semi-verify inode found at i_pos
695 * 4/ i_pos(0-3)|parent->i_logstart - maybe used to hunt for the file on disc
696 *
697 * Hack for NFSv2: Maximum FAT entry number is 28bits and maximum
698 * i_pos is 40bits (blocknr(32) + dir offset(8)), so two 4bits
699 * of i_logstart is used to store the directory entry offset.
700 */
701
Christoph Hellwig1305edad2007-10-21 16:42:11 -0700702static struct dentry *fat_fh_to_dentry(struct super_block *sb,
703 struct fid *fid, int fh_len, int fh_type)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700704{
705 struct inode *inode = NULL;
706 struct dentry *result;
Christoph Hellwig1305edad2007-10-21 16:42:11 -0700707 u32 *fh = fid->raw;
708
709 if (fh_len < 5 || fh_type != 3)
710 return NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700711
David Howells17f95a72008-02-07 00:15:38 -0800712 inode = ilookup(sb, fh[0]);
713 if (!inode || inode->i_generation != fh[1]) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700714 if (inode)
715 iput(inode);
716 inode = NULL;
717 }
718 if (!inode) {
719 loff_t i_pos;
720 int i_logstart = fh[3] & 0x0fffffff;
721
722 i_pos = (loff_t)fh[2] << 8;
723 i_pos |= ((fh[3] >> 24) & 0xf0) | (fh[4] >> 28);
724
725 /* try 2 - see if i_pos is in F-d-c
726 * require i_logstart to be the same
727 * Will fail if you truncate and then re-write
728 */
729
730 inode = fat_iget(sb, i_pos);
731 if (inode && MSDOS_I(inode)->i_logstart != i_logstart) {
732 iput(inode);
733 inode = NULL;
734 }
735 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700736
Christoph Hellwig44003722008-08-11 15:49:04 +0200737 /*
738 * For now, do nothing if the inode is not found.
739 *
740 * What we could do is:
741 *
742 * - follow the file starting at fh[4], and record the ".." entry,
743 * and the name of the fh[2] entry.
744 * - then follow the ".." file finding the next step up.
745 *
746 * This way we build a path to the root of the tree. If this works, we
747 * lookup the path and so get this inode into the cache. Finally try
748 * the fat_iget lookup again. If that fails, then we are totally out
749 * of luck. But all that is for another day
Linus Torvalds1da177e2005-04-16 15:20:36 -0700750 */
Christoph Hellwig44003722008-08-11 15:49:04 +0200751 result = d_obtain_alias(inode);
752 if (!IS_ERR(result))
753 result->d_op = sb->s_root->d_op;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700754 return result;
755}
756
757static int
758fat_encode_fh(struct dentry *de, __u32 *fh, int *lenp, int connectable)
759{
760 int len = *lenp;
761 struct inode *inode = de->d_inode;
762 u32 ipos_h, ipos_m, ipos_l;
763
764 if (len < 5)
765 return 255; /* no room */
766
767 ipos_h = MSDOS_I(inode)->i_pos >> 8;
768 ipos_m = (MSDOS_I(inode)->i_pos & 0xf0) << 24;
769 ipos_l = (MSDOS_I(inode)->i_pos & 0x0f) << 28;
770 *lenp = 5;
771 fh[0] = inode->i_ino;
772 fh[1] = inode->i_generation;
773 fh[2] = ipos_h;
774 fh[3] = ipos_m | MSDOS_I(inode)->i_logstart;
775 spin_lock(&de->d_lock);
776 fh[4] = ipos_l | MSDOS_I(de->d_parent->d_inode)->i_logstart;
777 spin_unlock(&de->d_lock);
778 return 3;
779}
780
781static struct dentry *fat_get_parent(struct dentry *child)
782{
Linus Torvalds8f593422008-05-19 19:53:01 -0700783 struct super_block *sb = child->d_sb;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700784 struct buffer_head *bh;
785 struct msdos_dir_entry *de;
786 loff_t i_pos;
787 struct dentry *parent;
788 struct inode *inode;
789 int err;
790
Linus Torvalds8f593422008-05-19 19:53:01 -0700791 lock_super(sb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700792
793 err = fat_get_dotdot_entry(child->d_inode, &bh, &de, &i_pos);
794 if (err) {
795 parent = ERR_PTR(err);
796 goto out;
797 }
Linus Torvalds8f593422008-05-19 19:53:01 -0700798 inode = fat_build_inode(sb, de, i_pos);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700799 brelse(bh);
Christoph Hellwig44003722008-08-11 15:49:04 +0200800
801 parent = d_obtain_alias(inode);
Christoph Hellwig5a6bb102008-11-12 07:48:01 +0900802 if (!IS_ERR(parent))
803 parent->d_op = sb->s_root->d_op;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700804out:
Linus Torvalds8f593422008-05-19 19:53:01 -0700805 unlock_super(sb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700806
807 return parent;
808}
809
Christoph Hellwig39655162007-10-21 16:42:17 -0700810static const struct export_operations fat_export_ops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700811 .encode_fh = fat_encode_fh,
Christoph Hellwig1305edad2007-10-21 16:42:11 -0700812 .fh_to_dentry = fat_fh_to_dentry,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700813 .get_parent = fat_get_parent,
814};
815
816static int fat_show_options(struct seq_file *m, struct vfsmount *mnt)
817{
818 struct msdos_sb_info *sbi = MSDOS_SB(mnt->mnt_sb);
819 struct fat_mount_options *opts = &sbi->options;
820 int isvfat = opts->isvfat;
821
822 if (opts->fs_uid != 0)
823 seq_printf(m, ",uid=%u", opts->fs_uid);
824 if (opts->fs_gid != 0)
825 seq_printf(m, ",gid=%u", opts->fs_gid);
826 seq_printf(m, ",fmask=%04o", opts->fs_fmask);
827 seq_printf(m, ",dmask=%04o", opts->fs_dmask);
OGAWA Hirofumi1ae43f82008-04-28 02:16:26 -0700828 if (opts->allow_utime)
829 seq_printf(m, ",allow_utime=%04o", opts->allow_utime);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700830 if (sbi->nls_disk)
831 seq_printf(m, ",codepage=%s", sbi->nls_disk->charset);
832 if (isvfat) {
833 if (sbi->nls_io)
834 seq_printf(m, ",iocharset=%s", sbi->nls_io->charset);
835
836 switch (opts->shortname) {
837 case VFAT_SFN_DISPLAY_WIN95 | VFAT_SFN_CREATE_WIN95:
838 seq_puts(m, ",shortname=win95");
839 break;
840 case VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WINNT:
841 seq_puts(m, ",shortname=winnt");
842 break;
843 case VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WIN95:
844 seq_puts(m, ",shortname=mixed");
845 break;
846 case VFAT_SFN_DISPLAY_LOWER | VFAT_SFN_CREATE_WIN95:
Paul Wise95523472009-08-01 21:30:31 +0900847 seq_puts(m, ",shortname=lower");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700848 break;
849 default:
850 seq_puts(m, ",shortname=unknown");
851 break;
852 }
853 }
854 if (opts->name_check != 'n')
855 seq_printf(m, ",check=%c", opts->name_check);
OGAWA Hirofumi28ec0392007-05-08 00:31:01 -0700856 if (opts->usefree)
857 seq_puts(m, ",usefree");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700858 if (opts->quiet)
859 seq_puts(m, ",quiet");
860 if (opts->showexec)
861 seq_puts(m, ",showexec");
862 if (opts->sys_immutable)
863 seq_puts(m, ",sys_immutable");
864 if (!isvfat) {
865 if (opts->dotsOK)
866 seq_puts(m, ",dotsOK=yes");
867 if (opts->nocase)
868 seq_puts(m, ",nocase");
869 } else {
870 if (opts->utf8)
871 seq_puts(m, ",utf8");
872 if (opts->unicode_xlate)
873 seq_puts(m, ",uni_xlate");
874 if (!opts->numtail)
875 seq_puts(m, ",nonumtail");
OGAWA Hirofumidfc209c2008-11-06 12:53:55 -0800876 if (opts->rodir)
877 seq_puts(m, ",rodir");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700878 }
OGAWA Hirofumidfc209c2008-11-06 12:53:55 -0800879 if (opts->flush)
Miklos Szeredic1fca3b2008-02-08 04:21:42 -0800880 seq_puts(m, ",flush");
Joe Petersonb271e062008-07-25 01:46:47 -0700881 if (opts->tz_utc)
882 seq_puts(m, ",tz=UTC");
Denis Karpov85c78592009-06-04 02:34:22 +0900883 if (opts->errors == FAT_ERRORS_CONT)
884 seq_puts(m, ",errors=continue");
885 else if (opts->errors == FAT_ERRORS_PANIC)
886 seq_puts(m, ",errors=panic");
887 else
888 seq_puts(m, ",errors=remount-ro");
Christoph Hellwig681142f2009-11-21 20:28:52 +0900889 if (opts->discard)
890 seq_puts(m, ",discard");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700891
892 return 0;
893}
894
895enum {
896 Opt_check_n, Opt_check_r, Opt_check_s, Opt_uid, Opt_gid,
OGAWA Hirofumi1ae43f82008-04-28 02:16:26 -0700897 Opt_umask, Opt_dmask, Opt_fmask, Opt_allow_utime, Opt_codepage,
898 Opt_usefree, Opt_nocase, Opt_quiet, Opt_showexec, Opt_debug,
899 Opt_immutable, Opt_dots, Opt_nodots,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700900 Opt_charset, Opt_shortname_lower, Opt_shortname_win95,
901 Opt_shortname_winnt, Opt_shortname_mixed, Opt_utf8_no, Opt_utf8_yes,
902 Opt_uni_xl_no, Opt_uni_xl_yes, Opt_nonumtail_no, Opt_nonumtail_yes,
Denis Karpov85c78592009-06-04 02:34:22 +0900903 Opt_obsolate, Opt_flush, Opt_tz_utc, Opt_rodir, Opt_err_cont,
Christoph Hellwig681142f2009-11-21 20:28:52 +0900904 Opt_err_panic, Opt_err_ro, Opt_discard, Opt_err,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700905};
906
Steven Whitehousea447c092008-10-13 10:46:57 +0100907static const match_table_t fat_tokens = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700908 {Opt_check_r, "check=relaxed"},
909 {Opt_check_s, "check=strict"},
910 {Opt_check_n, "check=normal"},
911 {Opt_check_r, "check=r"},
912 {Opt_check_s, "check=s"},
913 {Opt_check_n, "check=n"},
914 {Opt_uid, "uid=%u"},
915 {Opt_gid, "gid=%u"},
916 {Opt_umask, "umask=%o"},
917 {Opt_dmask, "dmask=%o"},
918 {Opt_fmask, "fmask=%o"},
OGAWA Hirofumi1ae43f82008-04-28 02:16:26 -0700919 {Opt_allow_utime, "allow_utime=%o"},
Linus Torvalds1da177e2005-04-16 15:20:36 -0700920 {Opt_codepage, "codepage=%u"},
OGAWA Hirofumi28ec0392007-05-08 00:31:01 -0700921 {Opt_usefree, "usefree"},
Linus Torvalds1da177e2005-04-16 15:20:36 -0700922 {Opt_nocase, "nocase"},
923 {Opt_quiet, "quiet"},
924 {Opt_showexec, "showexec"},
925 {Opt_debug, "debug"},
926 {Opt_immutable, "sys_immutable"},
Denis Karpov85c78592009-06-04 02:34:22 +0900927 {Opt_flush, "flush"},
928 {Opt_tz_utc, "tz=UTC"},
929 {Opt_err_cont, "errors=continue"},
930 {Opt_err_panic, "errors=panic"},
931 {Opt_err_ro, "errors=remount-ro"},
Christoph Hellwig681142f2009-11-21 20:28:52 +0900932 {Opt_discard, "discard"},
Linus Torvalds1da177e2005-04-16 15:20:36 -0700933 {Opt_obsolate, "conv=binary"},
934 {Opt_obsolate, "conv=text"},
935 {Opt_obsolate, "conv=auto"},
936 {Opt_obsolate, "conv=b"},
937 {Opt_obsolate, "conv=t"},
938 {Opt_obsolate, "conv=a"},
939 {Opt_obsolate, "fat=%u"},
940 {Opt_obsolate, "blocksize=%u"},
941 {Opt_obsolate, "cvf_format=%20s"},
942 {Opt_obsolate, "cvf_options=%100s"},
943 {Opt_obsolate, "posix"},
Chris Masonae78bf92006-09-29 02:00:03 -0700944 {Opt_err, NULL},
Linus Torvalds1da177e2005-04-16 15:20:36 -0700945};
Steven Whitehousea447c092008-10-13 10:46:57 +0100946static const match_table_t msdos_tokens = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700947 {Opt_nodots, "nodots"},
948 {Opt_nodots, "dotsOK=no"},
949 {Opt_dots, "dots"},
950 {Opt_dots, "dotsOK=yes"},
951 {Opt_err, NULL}
952};
Steven Whitehousea447c092008-10-13 10:46:57 +0100953static const match_table_t vfat_tokens = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700954 {Opt_charset, "iocharset=%s"},
955 {Opt_shortname_lower, "shortname=lower"},
956 {Opt_shortname_win95, "shortname=win95"},
957 {Opt_shortname_winnt, "shortname=winnt"},
958 {Opt_shortname_mixed, "shortname=mixed"},
959 {Opt_utf8_no, "utf8=0"}, /* 0 or no or false */
960 {Opt_utf8_no, "utf8=no"},
961 {Opt_utf8_no, "utf8=false"},
962 {Opt_utf8_yes, "utf8=1"}, /* empty or 1 or yes or true */
963 {Opt_utf8_yes, "utf8=yes"},
964 {Opt_utf8_yes, "utf8=true"},
965 {Opt_utf8_yes, "utf8"},
966 {Opt_uni_xl_no, "uni_xlate=0"}, /* 0 or no or false */
967 {Opt_uni_xl_no, "uni_xlate=no"},
968 {Opt_uni_xl_no, "uni_xlate=false"},
969 {Opt_uni_xl_yes, "uni_xlate=1"}, /* empty or 1 or yes or true */
970 {Opt_uni_xl_yes, "uni_xlate=yes"},
971 {Opt_uni_xl_yes, "uni_xlate=true"},
972 {Opt_uni_xl_yes, "uni_xlate"},
973 {Opt_nonumtail_no, "nonumtail=0"}, /* 0 or no or false */
974 {Opt_nonumtail_no, "nonumtail=no"},
975 {Opt_nonumtail_no, "nonumtail=false"},
976 {Opt_nonumtail_yes, "nonumtail=1"}, /* empty or 1 or yes or true */
977 {Opt_nonumtail_yes, "nonumtail=yes"},
978 {Opt_nonumtail_yes, "nonumtail=true"},
979 {Opt_nonumtail_yes, "nonumtail"},
OGAWA Hirofumidfc209c2008-11-06 12:53:55 -0800980 {Opt_rodir, "rodir"},
Linus Torvalds1da177e2005-04-16 15:20:36 -0700981 {Opt_err, NULL}
982};
983
Christoph Hellwig41a34a42005-11-08 21:34:57 -0800984static int parse_options(char *options, int is_vfat, int silent, int *debug,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700985 struct fat_mount_options *opts)
986{
987 char *p;
988 substring_t args[MAX_OPT_ARGS];
989 int option;
990 char *iocharset;
991
992 opts->isvfat = is_vfat;
993
David Howellsf0ce7ee2008-11-14 10:38:52 +1100994 opts->fs_uid = current_uid();
995 opts->fs_gid = current_gid();
OGAWA Hirofumi3e107602009-06-20 21:50:07 +0900996 opts->fs_fmask = opts->fs_dmask = current_umask();
OGAWA Hirofumi1ae43f82008-04-28 02:16:26 -0700997 opts->allow_utime = -1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700998 opts->codepage = fat_default_codepage;
999 opts->iocharset = fat_default_iocharset;
OGAWA Hirofumidfc209c2008-11-06 12:53:55 -08001000 if (is_vfat) {
Paul Wise95523472009-08-01 21:30:31 +09001001 opts->shortname = VFAT_SFN_DISPLAY_WINNT|VFAT_SFN_CREATE_WIN95;
OGAWA Hirofumidfc209c2008-11-06 12:53:55 -08001002 opts->rodir = 0;
1003 } else {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001004 opts->shortname = 0;
OGAWA Hirofumidfc209c2008-11-06 12:53:55 -08001005 opts->rodir = 1;
1006 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001007 opts->name_check = 'n';
1008 opts->quiet = opts->showexec = opts->sys_immutable = opts->dotsOK = 0;
1009 opts->utf8 = opts->unicode_xlate = 0;
1010 opts->numtail = 1;
OGAWA Hirofumi28ec0392007-05-08 00:31:01 -07001011 opts->usefree = opts->nocase = 0;
Joe Petersonb271e062008-07-25 01:46:47 -07001012 opts->tz_utc = 0;
Denis Karpov85c78592009-06-04 02:34:22 +09001013 opts->errors = FAT_ERRORS_RO;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001014 *debug = 0;
1015
1016 if (!options)
OGAWA Hirofumi8d44d972008-07-25 01:46:41 -07001017 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001018
1019 while ((p = strsep(&options, ",")) != NULL) {
1020 int token;
1021 if (!*p)
1022 continue;
1023
1024 token = match_token(p, fat_tokens, args);
1025 if (token == Opt_err) {
1026 if (is_vfat)
1027 token = match_token(p, vfat_tokens, args);
1028 else
1029 token = match_token(p, msdos_tokens, args);
1030 }
1031 switch (token) {
1032 case Opt_check_s:
1033 opts->name_check = 's';
1034 break;
1035 case Opt_check_r:
1036 opts->name_check = 'r';
1037 break;
1038 case Opt_check_n:
1039 opts->name_check = 'n';
1040 break;
OGAWA Hirofumi28ec0392007-05-08 00:31:01 -07001041 case Opt_usefree:
1042 opts->usefree = 1;
1043 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001044 case Opt_nocase:
1045 if (!is_vfat)
1046 opts->nocase = 1;
1047 else {
1048 /* for backward compatibility */
1049 opts->shortname = VFAT_SFN_DISPLAY_WIN95
1050 | VFAT_SFN_CREATE_WIN95;
1051 }
1052 break;
1053 case Opt_quiet:
1054 opts->quiet = 1;
1055 break;
1056 case Opt_showexec:
1057 opts->showexec = 1;
1058 break;
1059 case Opt_debug:
1060 *debug = 1;
1061 break;
1062 case Opt_immutable:
1063 opts->sys_immutable = 1;
1064 break;
1065 case Opt_uid:
1066 if (match_int(&args[0], &option))
1067 return 0;
1068 opts->fs_uid = option;
1069 break;
1070 case Opt_gid:
1071 if (match_int(&args[0], &option))
1072 return 0;
1073 opts->fs_gid = option;
1074 break;
1075 case Opt_umask:
1076 if (match_octal(&args[0], &option))
1077 return 0;
1078 opts->fs_fmask = opts->fs_dmask = option;
1079 break;
1080 case Opt_dmask:
1081 if (match_octal(&args[0], &option))
1082 return 0;
1083 opts->fs_dmask = option;
1084 break;
1085 case Opt_fmask:
1086 if (match_octal(&args[0], &option))
1087 return 0;
1088 opts->fs_fmask = option;
1089 break;
OGAWA Hirofumi1ae43f82008-04-28 02:16:26 -07001090 case Opt_allow_utime:
1091 if (match_octal(&args[0], &option))
1092 return 0;
1093 opts->allow_utime = option & (S_IWGRP | S_IWOTH);
1094 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001095 case Opt_codepage:
1096 if (match_int(&args[0], &option))
1097 return 0;
1098 opts->codepage = option;
1099 break;
Chris Masonae78bf92006-09-29 02:00:03 -07001100 case Opt_flush:
1101 opts->flush = 1;
1102 break;
Joe Petersonb271e062008-07-25 01:46:47 -07001103 case Opt_tz_utc:
1104 opts->tz_utc = 1;
1105 break;
Denis Karpov85c78592009-06-04 02:34:22 +09001106 case Opt_err_cont:
1107 opts->errors = FAT_ERRORS_CONT;
1108 break;
1109 case Opt_err_panic:
1110 opts->errors = FAT_ERRORS_PANIC;
1111 break;
1112 case Opt_err_ro:
1113 opts->errors = FAT_ERRORS_RO;
1114 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001115
1116 /* msdos specific */
1117 case Opt_dots:
1118 opts->dotsOK = 1;
1119 break;
1120 case Opt_nodots:
1121 opts->dotsOK = 0;
1122 break;
1123
1124 /* vfat specific */
1125 case Opt_charset:
1126 if (opts->iocharset != fat_default_iocharset)
1127 kfree(opts->iocharset);
1128 iocharset = match_strdup(&args[0]);
1129 if (!iocharset)
1130 return -ENOMEM;
1131 opts->iocharset = iocharset;
1132 break;
1133 case Opt_shortname_lower:
1134 opts->shortname = VFAT_SFN_DISPLAY_LOWER
1135 | VFAT_SFN_CREATE_WIN95;
1136 break;
1137 case Opt_shortname_win95:
1138 opts->shortname = VFAT_SFN_DISPLAY_WIN95
1139 | VFAT_SFN_CREATE_WIN95;
1140 break;
1141 case Opt_shortname_winnt:
1142 opts->shortname = VFAT_SFN_DISPLAY_WINNT
1143 | VFAT_SFN_CREATE_WINNT;
1144 break;
1145 case Opt_shortname_mixed:
1146 opts->shortname = VFAT_SFN_DISPLAY_WINNT
1147 | VFAT_SFN_CREATE_WIN95;
1148 break;
1149 case Opt_utf8_no: /* 0 or no or false */
1150 opts->utf8 = 0;
1151 break;
1152 case Opt_utf8_yes: /* empty or 1 or yes or true */
1153 opts->utf8 = 1;
1154 break;
1155 case Opt_uni_xl_no: /* 0 or no or false */
1156 opts->unicode_xlate = 0;
1157 break;
1158 case Opt_uni_xl_yes: /* empty or 1 or yes or true */
1159 opts->unicode_xlate = 1;
1160 break;
1161 case Opt_nonumtail_no: /* 0 or no or false */
1162 opts->numtail = 1; /* negated option */
1163 break;
1164 case Opt_nonumtail_yes: /* empty or 1 or yes or true */
1165 opts->numtail = 0; /* negated option */
1166 break;
OGAWA Hirofumidfc209c2008-11-06 12:53:55 -08001167 case Opt_rodir:
1168 opts->rodir = 1;
1169 break;
Christoph Hellwig681142f2009-11-21 20:28:52 +09001170 case Opt_discard:
1171 opts->discard = 1;
1172 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001173
1174 /* obsolete mount options */
1175 case Opt_obsolate:
1176 printk(KERN_INFO "FAT: \"%s\" option is obsolete, "
1177 "not supported now\n", p);
1178 break;
1179 /* unknown option */
1180 default:
Christoph Hellwig41a34a42005-11-08 21:34:57 -08001181 if (!silent) {
1182 printk(KERN_ERR
1183 "FAT: Unrecognized mount option \"%s\" "
1184 "or missing value\n", p);
1185 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001186 return -EINVAL;
1187 }
1188 }
OGAWA Hirofumi8d44d972008-07-25 01:46:41 -07001189
1190out:
Alexey Dobriyan4de151d2006-03-22 00:13:35 +01001191 /* UTF-8 doesn't provide FAT semantics */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001192 if (!strcmp(opts->iocharset, "utf8")) {
1193 printk(KERN_ERR "FAT: utf8 is not a recommended IO charset"
OGAWA Hirofumi8d44d972008-07-25 01:46:41 -07001194 " for FAT filesystems, filesystem will be "
1195 "case sensitive!\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -07001196 }
1197
OGAWA Hirofumi1ae43f82008-04-28 02:16:26 -07001198 /* If user doesn't specify allow_utime, it's initialized from dmask. */
1199 if (opts->allow_utime == (unsigned short)-1)
1200 opts->allow_utime = ~opts->fs_dmask & (S_IWGRP | S_IWOTH);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001201 if (opts->unicode_xlate)
1202 opts->utf8 = 0;
1203
1204 return 0;
1205}
1206
1207static int fat_read_root(struct inode *inode)
1208{
1209 struct super_block *sb = inode->i_sb;
1210 struct msdos_sb_info *sbi = MSDOS_SB(sb);
1211 int error;
1212
1213 MSDOS_I(inode)->i_pos = 0;
1214 inode->i_uid = sbi->options.fs_uid;
1215 inode->i_gid = sbi->options.fs_gid;
1216 inode->i_version++;
1217 inode->i_generation = 0;
OGAWA Hirofumi9c0aa1b2008-11-06 12:53:54 -08001218 inode->i_mode = fat_make_mode(sbi, ATTR_DIR, S_IRWXUGO);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001219 inode->i_op = sbi->dir_ops;
1220 inode->i_fop = &fat_dir_operations;
1221 if (sbi->fat_bits == 32) {
1222 MSDOS_I(inode)->i_start = sbi->root_cluster;
1223 error = fat_calc_dir_size(inode);
1224 if (error < 0)
1225 return error;
1226 } else {
1227 MSDOS_I(inode)->i_start = 0;
1228 inode->i_size = sbi->dir_entries * sizeof(struct msdos_dir_entry);
1229 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001230 inode->i_blocks = ((inode->i_size + (sbi->cluster_size - 1))
1231 & ~((loff_t)sbi->cluster_size - 1)) >> 9;
1232 MSDOS_I(inode)->i_logstart = 0;
1233 MSDOS_I(inode)->mmu_private = inode->i_size;
1234
OGAWA Hirofumi9c0aa1b2008-11-06 12:53:54 -08001235 fat_save_attrs(inode, ATTR_DIR);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001236 inode->i_mtime.tv_sec = inode->i_atime.tv_sec = inode->i_ctime.tv_sec = 0;
1237 inode->i_mtime.tv_nsec = inode->i_atime.tv_nsec = inode->i_ctime.tv_nsec = 0;
1238 inode->i_nlink = fat_subdirs(inode)+2;
1239
1240 return 0;
1241}
1242
1243/*
1244 * Read the super block of an MS-DOS FS.
1245 */
1246int fat_fill_super(struct super_block *sb, void *data, int silent,
Arjan van de Ven754661f2007-02-12 00:55:38 -08001247 const struct inode_operations *fs_dir_inode_ops, int isvfat)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001248{
Al Virob5224122009-06-07 13:44:36 -04001249 struct inode *root_inode = NULL, *fat_inode = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001250 struct buffer_head *bh;
1251 struct fat_boot_sector *b;
1252 struct msdos_sb_info *sbi;
1253 u16 logical_sector_size;
1254 u32 total_sectors, total_clusters, fat_clusters, rootdir_sectors;
1255 int debug;
1256 unsigned int media;
1257 long error;
1258 char buf[50];
1259
Linus Torvalds8f593422008-05-19 19:53:01 -07001260 /*
1261 * GFP_KERNEL is ok here, because while we do hold the
1262 * supeblock lock, memory pressure can't call back into
1263 * the filesystem, since we're only just about to mount
1264 * it and have no inodes etc active!
1265 */
Panagiotis Issarisf8314dc2006-09-27 01:49:37 -07001266 sbi = kzalloc(sizeof(struct msdos_sb_info), GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001267 if (!sbi)
1268 return -ENOMEM;
1269 sb->s_fs_info = sbi;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001270
1271 sb->s_flags |= MS_NODIRATIME;
1272 sb->s_magic = MSDOS_SUPER_MAGIC;
1273 sb->s_op = &fat_sops;
1274 sb->s_export_op = &fat_export_ops;
1275 sbi->dir_ops = fs_dir_inode_ops;
OGAWA Hirofumiaaa04b42010-05-24 14:33:12 -07001276 ratelimit_state_init(&sbi->ratelimit, DEFAULT_RATELIMIT_INTERVAL,
1277 DEFAULT_RATELIMIT_BURST);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001278
Christoph Hellwig41a34a42005-11-08 21:34:57 -08001279 error = parse_options(data, isvfat, silent, &debug, &sbi->options);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001280 if (error)
1281 goto out_fail;
1282
1283 error = -EIO;
1284 sb_min_blocksize(sb, 512);
1285 bh = sb_bread(sb, 0);
1286 if (bh == NULL) {
1287 printk(KERN_ERR "FAT: unable to read boot sector\n");
1288 goto out_fail;
1289 }
1290
1291 b = (struct fat_boot_sector *) bh->b_data;
1292 if (!b->reserved) {
1293 if (!silent)
1294 printk(KERN_ERR "FAT: bogus number of reserved sectors\n");
1295 brelse(bh);
1296 goto out_invalid;
1297 }
1298 if (!b->fats) {
1299 if (!silent)
1300 printk(KERN_ERR "FAT: bogus number of FAT structure\n");
1301 brelse(bh);
1302 goto out_invalid;
1303 }
1304
1305 /*
1306 * Earlier we checked here that b->secs_track and b->head are nonzero,
1307 * but it turns out valid FAT filesystems can have zero there.
1308 */
1309
1310 media = b->media;
Andrew Morton73f20e52008-04-28 02:16:30 -07001311 if (!fat_valid_media(media)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001312 if (!silent)
1313 printk(KERN_ERR "FAT: invalid media value (0x%02x)\n",
1314 media);
1315 brelse(bh);
1316 goto out_invalid;
1317 }
Harvey Harrison803f4452008-04-29 01:03:43 -07001318 logical_sector_size = get_unaligned_le16(&b->sector_size);
Vignesh Babu BMe7d709c2007-05-08 00:24:27 -07001319 if (!is_power_of_2(logical_sector_size)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001320 || (logical_sector_size < 512)
Olof Johansson9f354852008-04-28 02:16:32 -07001321 || (logical_sector_size > 4096)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001322 if (!silent)
1323 printk(KERN_ERR "FAT: bogus logical sector size %u\n",
1324 logical_sector_size);
1325 brelse(bh);
1326 goto out_invalid;
1327 }
1328 sbi->sec_per_clus = b->sec_per_clus;
Vignesh Babu BMe7d709c2007-05-08 00:24:27 -07001329 if (!is_power_of_2(sbi->sec_per_clus)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001330 if (!silent)
1331 printk(KERN_ERR "FAT: bogus sectors per cluster %u\n",
1332 sbi->sec_per_clus);
1333 brelse(bh);
1334 goto out_invalid;
1335 }
1336
1337 if (logical_sector_size < sb->s_blocksize) {
1338 printk(KERN_ERR "FAT: logical sector size too small for device"
1339 " (logical sector size = %u)\n", logical_sector_size);
1340 brelse(bh);
1341 goto out_fail;
1342 }
1343 if (logical_sector_size > sb->s_blocksize) {
1344 brelse(bh);
1345
1346 if (!sb_set_blocksize(sb, logical_sector_size)) {
1347 printk(KERN_ERR "FAT: unable to set blocksize %u\n",
1348 logical_sector_size);
1349 goto out_fail;
1350 }
1351 bh = sb_bread(sb, 0);
1352 if (bh == NULL) {
1353 printk(KERN_ERR "FAT: unable to read boot sector"
1354 " (logical sector size = %lu)\n",
1355 sb->s_blocksize);
1356 goto out_fail;
1357 }
1358 b = (struct fat_boot_sector *) bh->b_data;
1359 }
1360
1361 sbi->cluster_size = sb->s_blocksize * sbi->sec_per_clus;
1362 sbi->cluster_bits = ffs(sbi->cluster_size) - 1;
1363 sbi->fats = b->fats;
1364 sbi->fat_bits = 0; /* Don't know yet */
1365 sbi->fat_start = le16_to_cpu(b->reserved);
1366 sbi->fat_length = le16_to_cpu(b->fat_length);
1367 sbi->root_cluster = 0;
1368 sbi->free_clusters = -1; /* Don't know yet */
OGAWA Hirofumi606e4232008-04-28 02:16:27 -07001369 sbi->free_clus_valid = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001370 sbi->prev_free = FAT_START_ENT;
1371
1372 if (!sbi->fat_length && b->fat32_length) {
1373 struct fat_boot_fsinfo *fsinfo;
1374 struct buffer_head *fsinfo_bh;
1375
1376 /* Must be FAT32 */
1377 sbi->fat_bits = 32;
1378 sbi->fat_length = le32_to_cpu(b->fat32_length);
1379 sbi->root_cluster = le32_to_cpu(b->root_cluster);
1380
1381 sb->s_maxbytes = 0xffffffff;
1382
1383 /* MC - if info_sector is 0, don't multiply by 0 */
1384 sbi->fsinfo_sector = le16_to_cpu(b->info_sector);
1385 if (sbi->fsinfo_sector == 0)
1386 sbi->fsinfo_sector = 1;
1387
1388 fsinfo_bh = sb_bread(sb, sbi->fsinfo_sector);
1389 if (fsinfo_bh == NULL) {
1390 printk(KERN_ERR "FAT: bread failed, FSINFO block"
1391 " (sector = %lu)\n", sbi->fsinfo_sector);
1392 brelse(bh);
1393 goto out_fail;
1394 }
1395
1396 fsinfo = (struct fat_boot_fsinfo *)fsinfo_bh->b_data;
1397 if (!IS_FSINFO(fsinfo)) {
Vegard Nossumb4cf9c32008-02-06 01:36:36 -08001398 printk(KERN_WARNING "FAT: Invalid FSINFO signature: "
1399 "0x%08x, 0x%08x (sector = %lu)\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -07001400 le32_to_cpu(fsinfo->signature1),
1401 le32_to_cpu(fsinfo->signature2),
1402 sbi->fsinfo_sector);
1403 } else {
OGAWA Hirofumi28ec0392007-05-08 00:31:01 -07001404 if (sbi->options.usefree)
OGAWA Hirofumi606e4232008-04-28 02:16:27 -07001405 sbi->free_clus_valid = 1;
1406 sbi->free_clusters = le32_to_cpu(fsinfo->free_clusters);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001407 sbi->prev_free = le32_to_cpu(fsinfo->next_cluster);
1408 }
1409
1410 brelse(fsinfo_bh);
1411 }
1412
1413 sbi->dir_per_block = sb->s_blocksize / sizeof(struct msdos_dir_entry);
1414 sbi->dir_per_block_bits = ffs(sbi->dir_per_block) - 1;
1415
1416 sbi->dir_start = sbi->fat_start + sbi->fats * sbi->fat_length;
Harvey Harrison803f4452008-04-29 01:03:43 -07001417 sbi->dir_entries = get_unaligned_le16(&b->dir_entries);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001418 if (sbi->dir_entries & (sbi->dir_per_block - 1)) {
1419 if (!silent)
1420 printk(KERN_ERR "FAT: bogus directroy-entries per block"
1421 " (%u)\n", sbi->dir_entries);
1422 brelse(bh);
1423 goto out_invalid;
1424 }
1425
1426 rootdir_sectors = sbi->dir_entries
1427 * sizeof(struct msdos_dir_entry) / sb->s_blocksize;
1428 sbi->data_start = sbi->dir_start + rootdir_sectors;
Harvey Harrison803f4452008-04-29 01:03:43 -07001429 total_sectors = get_unaligned_le16(&b->sectors);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001430 if (total_sectors == 0)
1431 total_sectors = le32_to_cpu(b->total_sect);
1432
1433 total_clusters = (total_sectors - sbi->data_start) / sbi->sec_per_clus;
1434
1435 if (sbi->fat_bits != 32)
1436 sbi->fat_bits = (total_clusters > MAX_FAT12) ? 16 : 12;
1437
1438 /* check that FAT table does not overflow */
1439 fat_clusters = sbi->fat_length * sb->s_blocksize * 8 / sbi->fat_bits;
1440 total_clusters = min(total_clusters, fat_clusters - FAT_START_ENT);
1441 if (total_clusters > MAX_FAT(sb)) {
1442 if (!silent)
1443 printk(KERN_ERR "FAT: count of clusters too big (%u)\n",
1444 total_clusters);
1445 brelse(bh);
1446 goto out_invalid;
1447 }
1448
1449 sbi->max_cluster = total_clusters + FAT_START_ENT;
1450 /* check the free_clusters, it's not necessarily correct */
1451 if (sbi->free_clusters != -1 && sbi->free_clusters > total_clusters)
1452 sbi->free_clusters = -1;
1453 /* check the prev_free, it's not necessarily correct */
1454 sbi->prev_free %= sbi->max_cluster;
1455 if (sbi->prev_free < FAT_START_ENT)
1456 sbi->prev_free = FAT_START_ENT;
1457
1458 brelse(bh);
1459
1460 /* set up enough so that it can read an inode */
1461 fat_hash_init(sb);
1462 fat_ent_access_init(sb);
1463
1464 /*
1465 * The low byte of FAT's first entry must have same value with
1466 * media-field. But in real world, too many devices is
1467 * writing wrong value. So, removed that validity check.
1468 *
1469 * if (FAT_FIRST_ENT(sb, media) != first)
1470 */
1471
1472 error = -EINVAL;
1473 sprintf(buf, "cp%d", sbi->options.codepage);
1474 sbi->nls_disk = load_nls(buf);
1475 if (!sbi->nls_disk) {
1476 printk(KERN_ERR "FAT: codepage %s not found\n", buf);
1477 goto out_fail;
1478 }
1479
1480 /* FIXME: utf8 is using iocharset for upper/lower conversion */
1481 if (sbi->options.isvfat) {
1482 sbi->nls_io = load_nls(sbi->options.iocharset);
1483 if (!sbi->nls_io) {
1484 printk(KERN_ERR "FAT: IO charset %s not found\n",
1485 sbi->options.iocharset);
1486 goto out_fail;
1487 }
1488 }
1489
1490 error = -ENOMEM;
Al Virob5224122009-06-07 13:44:36 -04001491 fat_inode = new_inode(sb);
1492 if (!fat_inode)
1493 goto out_fail;
1494 MSDOS_I(fat_inode)->i_pos = 0;
1495 sbi->fat_inode = fat_inode;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001496 root_inode = new_inode(sb);
1497 if (!root_inode)
1498 goto out_fail;
1499 root_inode->i_ino = MSDOS_ROOT_INO;
1500 root_inode->i_version = 1;
1501 error = fat_read_root(root_inode);
1502 if (error < 0)
1503 goto out_fail;
1504 error = -ENOMEM;
1505 insert_inode_hash(root_inode);
1506 sb->s_root = d_alloc_root(root_inode);
1507 if (!sb->s_root) {
1508 printk(KERN_ERR "FAT: get root inode failed\n");
1509 goto out_fail;
1510 }
1511
1512 return 0;
1513
1514out_invalid:
1515 error = -EINVAL;
1516 if (!silent)
1517 printk(KERN_INFO "VFS: Can't find a valid FAT filesystem"
1518 " on dev %s.\n", sb->s_id);
1519
1520out_fail:
Al Virob5224122009-06-07 13:44:36 -04001521 if (fat_inode)
1522 iput(fat_inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001523 if (root_inode)
1524 iput(root_inode);
OGAWA Hirofumi1bdb6f92010-03-16 05:48:09 +09001525 unload_nls(sbi->nls_io);
1526 unload_nls(sbi->nls_disk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001527 if (sbi->options.iocharset != fat_default_iocharset)
1528 kfree(sbi->options.iocharset);
1529 sb->s_fs_info = NULL;
1530 kfree(sbi);
1531 return error;
1532}
1533
OGAWA Hirofumi7c709d02006-01-08 01:02:10 -08001534EXPORT_SYMBOL_GPL(fat_fill_super);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001535
Chris Masonae78bf92006-09-29 02:00:03 -07001536/*
1537 * helper function for fat_flush_inodes. This writes both the inode
1538 * and the file data blocks, waiting for in flight data blocks before
1539 * the start of the call. It does not wait for any io started
1540 * during the call
1541 */
1542static int writeback_inode(struct inode *inode)
1543{
1544
1545 int ret;
1546 struct address_space *mapping = inode->i_mapping;
1547 struct writeback_control wbc = {
1548 .sync_mode = WB_SYNC_NONE,
1549 .nr_to_write = 0,
1550 };
1551 /* if we used WB_SYNC_ALL, sync_inode waits for the io for the
1552 * inode to finish. So WB_SYNC_NONE is sent down to sync_inode
1553 * and filemap_fdatawrite is used for the data blocks
1554 */
1555 ret = sync_inode(inode, &wbc);
1556 if (!ret)
1557 ret = filemap_fdatawrite(mapping);
1558 return ret;
1559}
1560
1561/*
1562 * write data and metadata corresponding to i1 and i2. The io is
1563 * started but we do not wait for any of it to finish.
1564 *
1565 * filemap_flush is used for the block device, so if there is a dirty
1566 * page for a block already in flight, we will not wait and start the
1567 * io over again
1568 */
1569int fat_flush_inodes(struct super_block *sb, struct inode *i1, struct inode *i2)
1570{
1571 int ret = 0;
1572 if (!MSDOS_SB(sb)->options.flush)
1573 return 0;
1574 if (i1)
1575 ret = writeback_inode(i1);
1576 if (!ret && i2)
1577 ret = writeback_inode(i2);
Eric Sesterhenn97e860d2006-10-11 01:21:59 -07001578 if (!ret) {
Chris Masonae78bf92006-09-29 02:00:03 -07001579 struct address_space *mapping = sb->s_bdev->bd_inode->i_mapping;
1580 ret = filemap_flush(mapping);
1581 }
1582 return ret;
1583}
1584EXPORT_SYMBOL_GPL(fat_flush_inodes);
1585
Linus Torvalds1da177e2005-04-16 15:20:36 -07001586static int __init init_fat_fs(void)
1587{
Pekka J Enberg532a39a2005-06-30 02:59:01 -07001588 int err;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001589
Pekka J Enberg532a39a2005-06-30 02:59:01 -07001590 err = fat_cache_init();
1591 if (err)
1592 return err;
1593
1594 err = fat_init_inodecache();
1595 if (err)
1596 goto failed;
1597
1598 return 0;
1599
1600failed:
1601 fat_cache_destroy();
1602 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001603}
1604
1605static void __exit exit_fat_fs(void)
1606{
1607 fat_cache_destroy();
1608 fat_destroy_inodecache();
1609}
1610
1611module_init(init_fat_fs)
1612module_exit(exit_fat_fs)
1613
1614MODULE_LICENSE("GPL");