blob: ad6998a92c30d4a90336bcb295743ffb9547ec3f [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>
Linus Torvalds1da177e2005-04-16 15:20:36 -070017#include <linux/seq_file.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070018#include <linux/pagemap.h>
OGAWA Hirofumia5425d22006-01-08 01:02:10 -080019#include <linux/mpage.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070020#include <linux/buffer_head.h>
Christoph Hellwiga5694252007-07-17 04:04:28 -070021#include <linux/exportfs.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070022#include <linux/mount.h>
23#include <linux/vfs.h>
24#include <linux/parser.h>
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -080025#include <linux/uio.h>
Chris Masonae78bf92006-09-29 02:00:03 -070026#include <linux/writeback.h>
Vignesh Babu BMe7d709c2007-05-08 00:24:27 -070027#include <linux/log2.h>
OGAWA Hirofumid3dfa822008-11-06 12:53:49 -080028#include <linux/hash.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070029#include <asm/unaligned.h>
OGAWA Hirofumi9e975da2008-11-06 12:53:46 -080030#include "fat.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -070031
32#ifndef CONFIG_FAT_DEFAULT_IOCHARSET
33/* if user don't select VFAT, this is undefined. */
34#define CONFIG_FAT_DEFAULT_IOCHARSET ""
35#endif
36
37static int fat_default_codepage = CONFIG_FAT_DEFAULT_CODEPAGE;
38static char fat_default_iocharset[] = CONFIG_FAT_DEFAULT_IOCHARSET;
39
40
41static int fat_add_cluster(struct inode *inode)
42{
43 int err, cluster;
44
45 err = fat_alloc_clusters(inode, &cluster, 1);
46 if (err)
47 return err;
48 /* FIXME: this cluster should be added after data of this
49 * cluster is writed */
50 err = fat_chain_add(inode, cluster, 1);
51 if (err)
52 fat_free_clusters(inode, cluster);
53 return err;
54}
55
OGAWA Hirofumi6a1d9802006-09-27 01:50:45 -070056static inline int __fat_get_block(struct inode *inode, sector_t iblock,
57 unsigned long *max_blocks,
58 struct buffer_head *bh_result, int create)
Linus Torvalds1da177e2005-04-16 15:20:36 -070059{
60 struct super_block *sb = inode->i_sb;
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -080061 struct msdos_sb_info *sbi = MSDOS_SB(sb);
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -080062 unsigned long mapped_blocks;
OGAWA Hirofumi6a1d9802006-09-27 01:50:45 -070063 sector_t phys;
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -080064 int err, offset;
Linus Torvalds1da177e2005-04-16 15:20:36 -070065
OGAWA Hirofumi2bdf67e2008-11-06 12:53:57 -080066 err = fat_bmap(inode, iblock, &phys, &mapped_blocks, create);
Linus Torvalds1da177e2005-04-16 15:20:36 -070067 if (err)
68 return err;
69 if (phys) {
70 map_bh(bh_result, sb, phys);
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -080071 *max_blocks = min(mapped_blocks, *max_blocks);
Linus Torvalds1da177e2005-04-16 15:20:36 -070072 return 0;
73 }
74 if (!create)
75 return 0;
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -080076
Linus Torvalds1da177e2005-04-16 15:20:36 -070077 if (iblock != MSDOS_I(inode)->mmu_private >> sb->s_blocksize_bits) {
Denis Karpov85c78592009-06-04 02:34:22 +090078 fat_fs_error(sb, "corrupted file size (i_pos %lld, %lld)",
OGAWA Hirofumi6a1d9802006-09-27 01:50:45 -070079 MSDOS_I(inode)->i_pos, MSDOS_I(inode)->mmu_private);
Linus Torvalds1da177e2005-04-16 15:20:36 -070080 return -EIO;
81 }
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -080082
83 offset = (unsigned long)iblock & (sbi->sec_per_clus - 1);
84 if (!offset) {
85 /* TODO: multiple cluster allocation would be desirable. */
Linus Torvalds1da177e2005-04-16 15:20:36 -070086 err = fat_add_cluster(inode);
87 if (err)
88 return err;
89 }
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -080090 /* available blocks on this cluster */
91 mapped_blocks = sbi->sec_per_clus - offset;
92
93 *max_blocks = min(mapped_blocks, *max_blocks);
94 MSDOS_I(inode)->mmu_private += *max_blocks << sb->s_blocksize_bits;
95
OGAWA Hirofumi2bdf67e2008-11-06 12:53:57 -080096 err = fat_bmap(inode, iblock, &phys, &mapped_blocks, create);
Linus Torvalds1da177e2005-04-16 15:20:36 -070097 if (err)
98 return err;
OGAWA Hirofumi6a1d9802006-09-27 01:50:45 -070099
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -0800100 BUG_ON(!phys);
101 BUG_ON(*max_blocks != mapped_blocks);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700102 set_buffer_new(bh_result);
103 map_bh(bh_result, sb, phys);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700104
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -0800105 return 0;
106}
107
108static int fat_get_block(struct inode *inode, sector_t iblock,
109 struct buffer_head *bh_result, int create)
110{
OGAWA Hirofumi6a1d9802006-09-27 01:50:45 -0700111 struct super_block *sb = inode->i_sb;
112 unsigned long max_blocks = bh_result->b_size >> inode->i_blkbits;
113 int err;
114
115 err = __fat_get_block(inode, iblock, &max_blocks, bh_result, create);
116 if (err)
117 return err;
118 bh_result->b_size = max_blocks << sb->s_blocksize_bits;
119 return 0;
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -0800120}
121
Linus Torvalds1da177e2005-04-16 15:20:36 -0700122static int fat_writepage(struct page *page, struct writeback_control *wbc)
123{
124 return block_write_full_page(page, fat_get_block, wbc);
125}
126
OGAWA Hirofumia5425d22006-01-08 01:02:10 -0800127static int fat_writepages(struct address_space *mapping,
128 struct writeback_control *wbc)
129{
130 return mpage_writepages(mapping, wbc, fat_get_block);
131}
132
Linus Torvalds1da177e2005-04-16 15:20:36 -0700133static int fat_readpage(struct file *file, struct page *page)
134{
OGAWA Hirofumia5425d22006-01-08 01:02:10 -0800135 return mpage_readpage(page, fat_get_block);
136}
137
138static int fat_readpages(struct file *file, struct address_space *mapping,
139 struct list_head *pages, unsigned nr_pages)
140{
141 return mpage_readpages(mapping, pages, nr_pages, fat_get_block);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700142}
143
npiggin@suse.de459f6ed2010-05-27 01:05:38 +1000144static void fat_write_failed(struct address_space *mapping, loff_t to)
145{
146 struct inode *inode = mapping->host;
147
148 if (to > inode->i_size) {
149 truncate_pagecache(inode, to, inode->i_size);
150 fat_truncate_blocks(inode, inode->i_size);
151 }
152}
153
Nick Piggind7777a22007-10-16 01:25:08 -0700154static int fat_write_begin(struct file *file, struct address_space *mapping,
155 loff_t pos, unsigned len, unsigned flags,
156 struct page **pagep, void **fsdata)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700157{
npiggin@suse.de459f6ed2010-05-27 01:05:38 +1000158 int err;
159
Nick Piggind7777a22007-10-16 01:25:08 -0700160 *pagep = NULL;
Christoph Hellwig282dc172010-06-04 11:29:55 +0200161 err = cont_write_begin(file, mapping, pos, len, flags,
npiggin@suse.de459f6ed2010-05-27 01:05:38 +1000162 pagep, fsdata, fat_get_block,
Nick Piggind7777a22007-10-16 01:25:08 -0700163 &MSDOS_I(mapping->host)->mmu_private);
npiggin@suse.de459f6ed2010-05-27 01:05:38 +1000164 if (err < 0)
165 fat_write_failed(mapping, pos + len);
166 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700167}
168
Nick Piggind7777a22007-10-16 01:25:08 -0700169static int fat_write_end(struct file *file, struct address_space *mapping,
170 loff_t pos, unsigned len, unsigned copied,
171 struct page *pagep, void *fsdata)
OGAWA Hirofumief402262005-09-16 19:28:13 -0700172{
Nick Piggind7777a22007-10-16 01:25:08 -0700173 struct inode *inode = mapping->host;
174 int err;
175 err = generic_write_end(file, mapping, pos, len, copied, pagep, fsdata);
npiggin@suse.de459f6ed2010-05-27 01:05:38 +1000176 if (err < len)
177 fat_write_failed(mapping, pos + len);
Nick Piggind7777a22007-10-16 01:25:08 -0700178 if (!(err < 0) && !(MSDOS_I(inode)->i_attrs & ATTR_ARCH)) {
OGAWA Hirofumief402262005-09-16 19:28:13 -0700179 inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC;
180 MSDOS_I(inode)->i_attrs |= ATTR_ARCH;
181 mark_inode_dirty(inode);
182 }
183 return err;
184}
185
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -0800186static ssize_t fat_direct_IO(int rw, struct kiocb *iocb,
187 const struct iovec *iov,
188 loff_t offset, unsigned long nr_segs)
189{
190 struct file *file = iocb->ki_filp;
npiggin@suse.de459f6ed2010-05-27 01:05:38 +1000191 struct address_space *mapping = file->f_mapping;
192 struct inode *inode = mapping->host;
193 ssize_t ret;
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -0800194
195 if (rw == WRITE) {
196 /*
Nick Piggin4e02ed42008-10-29 14:00:55 -0700197 * FIXME: blockdev_direct_IO() doesn't use ->write_begin(),
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -0800198 * so we need to update the ->mmu_private to block boundary.
199 *
200 * But we must fill the remaining area or hole by nul for
201 * updating ->mmu_private.
OGAWA Hirofumi94412a92007-02-20 13:57:55 -0800202 *
203 * Return 0, and fallback to normal buffered write.
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -0800204 */
205 loff_t size = offset + iov_length(iov, nr_segs);
206 if (MSDOS_I(inode)->mmu_private < size)
OGAWA Hirofumi94412a92007-02-20 13:57:55 -0800207 return 0;
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -0800208 }
209
210 /*
211 * FAT need to use the DIO_LOCKING for avoiding the race
212 * condition of fat_get_block() and ->truncate().
213 */
Christoph Hellwigeafdc7d2010-06-04 11:29:53 +0200214 ret = blockdev_direct_IO(rw, iocb, inode, inode->i_sb->s_bdev,
215 iov, offset, nr_segs, fat_get_block, NULL);
npiggin@suse.de459f6ed2010-05-27 01:05:38 +1000216 if (ret < 0 && (rw & WRITE))
217 fat_write_failed(mapping, offset + iov_length(iov, nr_segs));
218
219 return ret;
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -0800220}
221
Linus Torvalds1da177e2005-04-16 15:20:36 -0700222static sector_t _fat_bmap(struct address_space *mapping, sector_t block)
223{
OGAWA Hirofumifa93ca12008-11-06 12:53:56 -0800224 sector_t blocknr;
225
226 /* fat_get_cluster() assumes the requested blocknr isn't truncated. */
OGAWA Hirofumi3a95ea12009-03-12 02:03:23 +0900227 down_read(&mapping->host->i_alloc_sem);
OGAWA Hirofumifa93ca12008-11-06 12:53:56 -0800228 blocknr = generic_block_bmap(mapping, block, fat_get_block);
OGAWA Hirofumi3a95ea12009-03-12 02:03:23 +0900229 up_read(&mapping->host->i_alloc_sem);
OGAWA Hirofumifa93ca12008-11-06 12:53:56 -0800230
231 return blocknr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700232}
233
Christoph Hellwigf5e54d62006-06-28 04:26:44 -0700234static const struct address_space_operations fat_aops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700235 .readpage = fat_readpage,
OGAWA Hirofumia5425d22006-01-08 01:02:10 -0800236 .readpages = fat_readpages,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700237 .writepage = fat_writepage,
OGAWA Hirofumia5425d22006-01-08 01:02:10 -0800238 .writepages = fat_writepages,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700239 .sync_page = block_sync_page,
Nick Piggind7777a22007-10-16 01:25:08 -0700240 .write_begin = fat_write_begin,
241 .write_end = fat_write_end,
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -0800242 .direct_IO = fat_direct_IO,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700243 .bmap = _fat_bmap
244};
245
246/*
247 * New FAT inode stuff. We do the following:
248 * a) i_ino is constant and has nothing with on-disk location.
249 * b) FAT manages its own cache of directory entries.
250 * c) *This* cache is indexed by on-disk location.
251 * d) inode has an associated directory entry, all right, but
252 * it may be unhashed.
253 * e) currently entries are stored within struct inode. That should
254 * change.
255 * f) we deal with races in the following way:
256 * 1. readdir() and lookup() do FAT-dir-cache lookup.
257 * 2. rename() unhashes the F-d-c entry and rehashes it in
258 * a new place.
259 * 3. unlink() and rmdir() unhash F-d-c entry.
260 * 4. fat_write_inode() checks whether the thing is unhashed.
261 * If it is we silently return. If it isn't we do bread(),
262 * check if the location is still valid and retry if it
263 * isn't. Otherwise we do changes.
264 * 5. Spinlock is used to protect hash/unhash/location check/lookup
Al Virodeee3ce2010-06-05 19:28:32 -0400265 * 6. fat_evict_inode() unhashes the F-d-c entry.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700266 * 7. lookup() and readdir() do igrab() if they find a F-d-c entry
267 * and consider negative result as cache miss.
268 */
269
270static void fat_hash_init(struct super_block *sb)
271{
272 struct msdos_sb_info *sbi = MSDOS_SB(sb);
273 int i;
274
275 spin_lock_init(&sbi->inode_hash_lock);
276 for (i = 0; i < FAT_HASH_SIZE; i++)
277 INIT_HLIST_HEAD(&sbi->inode_hashtable[i]);
278}
279
OGAWA Hirofumid3dfa822008-11-06 12:53:49 -0800280static inline unsigned long fat_hash(loff_t i_pos)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700281{
OGAWA Hirofumid3dfa822008-11-06 12:53:49 -0800282 return hash_32(i_pos, FAT_HASH_BITS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700283}
284
285void fat_attach(struct inode *inode, loff_t i_pos)
286{
OGAWA Hirofumid3dfa822008-11-06 12:53:49 -0800287 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
288 struct hlist_head *head = sbi->inode_hashtable + fat_hash(i_pos);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700289
290 spin_lock(&sbi->inode_hash_lock);
291 MSDOS_I(inode)->i_pos = i_pos;
OGAWA Hirofumid3dfa822008-11-06 12:53:49 -0800292 hlist_add_head(&MSDOS_I(inode)->i_fat_hash, head);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700293 spin_unlock(&sbi->inode_hash_lock);
294}
OGAWA Hirofumi7c709d02006-01-08 01:02:10 -0800295EXPORT_SYMBOL_GPL(fat_attach);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700296
297void fat_detach(struct inode *inode)
298{
299 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
300 spin_lock(&sbi->inode_hash_lock);
301 MSDOS_I(inode)->i_pos = 0;
302 hlist_del_init(&MSDOS_I(inode)->i_fat_hash);
303 spin_unlock(&sbi->inode_hash_lock);
304}
OGAWA Hirofumi7c709d02006-01-08 01:02:10 -0800305EXPORT_SYMBOL_GPL(fat_detach);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700306
307struct inode *fat_iget(struct super_block *sb, loff_t i_pos)
308{
309 struct msdos_sb_info *sbi = MSDOS_SB(sb);
OGAWA Hirofumid3dfa822008-11-06 12:53:49 -0800310 struct hlist_head *head = sbi->inode_hashtable + fat_hash(i_pos);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700311 struct hlist_node *_p;
312 struct msdos_inode_info *i;
313 struct inode *inode = NULL;
314
315 spin_lock(&sbi->inode_hash_lock);
316 hlist_for_each_entry(i, _p, head, i_fat_hash) {
317 BUG_ON(i->vfs_inode.i_sb != sb);
318 if (i->i_pos != i_pos)
319 continue;
320 inode = igrab(&i->vfs_inode);
321 if (inode)
322 break;
323 }
324 spin_unlock(&sbi->inode_hash_lock);
325 return inode;
326}
327
328static int is_exec(unsigned char *extension)
329{
330 unsigned char *exe_extensions = "EXECOMBAT", *walk;
331
332 for (walk = exe_extensions; *walk; walk += 3)
333 if (!strncmp(extension, walk, 3))
334 return 1;
335 return 0;
336}
337
338static int fat_calc_dir_size(struct inode *inode)
339{
340 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
341 int ret, fclus, dclus;
342
343 inode->i_size = 0;
344 if (MSDOS_I(inode)->i_start == 0)
345 return 0;
346
347 ret = fat_get_cluster(inode, FAT_ENT_EOF, &fclus, &dclus);
348 if (ret < 0)
349 return ret;
350 inode->i_size = (fclus + 1) << sbi->cluster_bits;
351
352 return 0;
353}
354
355/* doesn't deal with root inode */
356static int fat_fill_inode(struct inode *inode, struct msdos_dir_entry *de)
357{
358 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
359 int error;
360
361 MSDOS_I(inode)->i_pos = 0;
362 inode->i_uid = sbi->options.fs_uid;
363 inode->i_gid = sbi->options.fs_gid;
364 inode->i_version++;
365 inode->i_generation = get_seconds();
366
367 if ((de->attr & ATTR_DIR) && !IS_FREE(de->name)) {
368 inode->i_generation &= ~1;
OGAWA Hirofumi9c0aa1b2008-11-06 12:53:54 -0800369 inode->i_mode = fat_make_mode(sbi, de->attr, S_IRWXUGO);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700370 inode->i_op = sbi->dir_ops;
371 inode->i_fop = &fat_dir_operations;
372
373 MSDOS_I(inode)->i_start = le16_to_cpu(de->start);
374 if (sbi->fat_bits == 32)
375 MSDOS_I(inode)->i_start |= (le16_to_cpu(de->starthi) << 16);
376
377 MSDOS_I(inode)->i_logstart = MSDOS_I(inode)->i_start;
378 error = fat_calc_dir_size(inode);
379 if (error < 0)
380 return error;
381 MSDOS_I(inode)->mmu_private = inode->i_size;
382
383 inode->i_nlink = fat_subdirs(inode);
384 } else { /* not a directory */
385 inode->i_generation |= 1;
OGAWA Hirofumi9c0aa1b2008-11-06 12:53:54 -0800386 inode->i_mode = fat_make_mode(sbi, de->attr,
387 ((sbi->options.showexec && !is_exec(de->name + 8))
388 ? S_IRUGO|S_IWUGO : S_IRWXUGO));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700389 MSDOS_I(inode)->i_start = le16_to_cpu(de->start);
390 if (sbi->fat_bits == 32)
391 MSDOS_I(inode)->i_start |= (le16_to_cpu(de->starthi) << 16);
392
393 MSDOS_I(inode)->i_logstart = MSDOS_I(inode)->i_start;
394 inode->i_size = le32_to_cpu(de->size);
395 inode->i_op = &fat_file_inode_operations;
396 inode->i_fop = &fat_file_operations;
397 inode->i_mapping->a_ops = &fat_aops;
398 MSDOS_I(inode)->mmu_private = inode->i_size;
399 }
400 if (de->attr & ATTR_SYS) {
401 if (sbi->options.sys_immutable)
402 inode->i_flags |= S_IMMUTABLE;
403 }
OGAWA Hirofumi9c0aa1b2008-11-06 12:53:54 -0800404 fat_save_attrs(inode, de->attr);
405
Linus Torvalds1da177e2005-04-16 15:20:36 -0700406 inode->i_blocks = ((inode->i_size + (sbi->cluster_size - 1))
407 & ~((loff_t)sbi->cluster_size - 1)) >> 9;
OGAWA Hirofumi7decd1c2008-11-06 12:53:47 -0800408
409 fat_time_fat2unix(sbi, &inode->i_mtime, de->time, de->date, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700410 if (sbi->options.isvfat) {
OGAWA Hirofumi7decd1c2008-11-06 12:53:47 -0800411 fat_time_fat2unix(sbi, &inode->i_ctime, de->ctime,
412 de->cdate, de->ctime_cs);
413 fat_time_fat2unix(sbi, &inode->i_atime, 0, de->adate, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700414 } else
Stephane Kardas62a36c42005-09-21 09:55:45 -0700415 inode->i_ctime = inode->i_atime = inode->i_mtime;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700416
417 return 0;
418}
419
420struct inode *fat_build_inode(struct super_block *sb,
421 struct msdos_dir_entry *de, loff_t i_pos)
422{
423 struct inode *inode;
424 int err;
425
426 inode = fat_iget(sb, i_pos);
427 if (inode)
428 goto out;
429 inode = new_inode(sb);
430 if (!inode) {
431 inode = ERR_PTR(-ENOMEM);
432 goto out;
433 }
434 inode->i_ino = iunique(sb, MSDOS_ROOT_INO);
435 inode->i_version = 1;
436 err = fat_fill_inode(inode, de);
437 if (err) {
438 iput(inode);
439 inode = ERR_PTR(err);
440 goto out;
441 }
442 fat_attach(inode, i_pos);
443 insert_inode_hash(inode);
444out:
445 return inode;
446}
447
OGAWA Hirofumi7c709d02006-01-08 01:02:10 -0800448EXPORT_SYMBOL_GPL(fat_build_inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700449
Al Virodeee3ce2010-06-05 19:28:32 -0400450static void fat_evict_inode(struct inode *inode)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700451{
Mark Fashehfef26652005-09-09 13:01:31 -0700452 truncate_inode_pages(&inode->i_data, 0);
Al Virodeee3ce2010-06-05 19:28:32 -0400453 if (!inode->i_nlink) {
454 inode->i_size = 0;
455 fat_truncate_blocks(inode, 0);
456 }
457 invalidate_inode_buffers(inode);
458 end_writeback(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700459 fat_cache_inval_inode(inode);
OGAWA Hirofumia993b542008-11-06 12:53:50 -0800460 fat_detach(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700461}
462
OGAWA Hirofumia6bf6b22006-01-08 01:02:08 -0800463static void fat_write_super(struct super_block *sb)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700464{
Christoph Hellwigebc1ac12009-05-11 23:35:03 +0200465 lock_super(sb);
OGAWA Hirofumia6bf6b22006-01-08 01:02:08 -0800466 sb->s_dirt = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700467
468 if (!(sb->s_flags & MS_RDONLY))
469 fat_clusters_flush(sb);
Christoph Hellwigebc1ac12009-05-11 23:35:03 +0200470 unlock_super(sb);
OGAWA Hirofumia6bf6b22006-01-08 01:02:08 -0800471}
472
Christoph Hellwigf83d6d42009-06-08 10:04:35 +0200473static int fat_sync_fs(struct super_block *sb, int wait)
474{
OGAWA Hirofumied248b22009-09-20 01:31:58 +0900475 int err = 0;
Christoph Hellwigf83d6d42009-06-08 10:04:35 +0200476
OGAWA Hirofumied248b22009-09-20 01:31:58 +0900477 if (sb->s_dirt) {
478 lock_super(sb);
479 sb->s_dirt = 0;
480 err = fat_clusters_flush(sb);
481 unlock_super(sb);
482 }
483
484 return err;
Christoph Hellwigf83d6d42009-06-08 10:04:35 +0200485}
486
OGAWA Hirofumia6bf6b22006-01-08 01:02:08 -0800487static void fat_put_super(struct super_block *sb)
488{
489 struct msdos_sb_info *sbi = MSDOS_SB(sb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700490
Christoph Hellwig8c85e122009-04-28 18:00:26 +0200491 if (sb->s_dirt)
492 fat_write_super(sb);
493
Al Virob5224122009-06-07 13:44:36 -0400494 iput(sbi->fat_inode);
495
Thomas Gleixner6d729e42009-08-16 21:05:08 +0000496 unload_nls(sbi->nls_disk);
497 unload_nls(sbi->nls_io);
498
499 if (sbi->options.iocharset != fat_default_iocharset)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700500 kfree(sbi->options.iocharset);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700501
502 sb->s_fs_info = NULL;
503 kfree(sbi);
504}
505
Christoph Lametere18b8902006-12-06 20:33:20 -0800506static struct kmem_cache *fat_inode_cachep;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700507
508static struct inode *fat_alloc_inode(struct super_block *sb)
509{
510 struct msdos_inode_info *ei;
Linus Torvalds8f593422008-05-19 19:53:01 -0700511 ei = kmem_cache_alloc(fat_inode_cachep, GFP_NOFS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700512 if (!ei)
513 return NULL;
514 return &ei->vfs_inode;
515}
516
517static void fat_destroy_inode(struct inode *inode)
518{
519 kmem_cache_free(fat_inode_cachep, MSDOS_I(inode));
520}
521
Alexey Dobriyan51cc5062008-07-25 19:45:34 -0700522static void init_once(void *foo)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700523{
524 struct msdos_inode_info *ei = (struct msdos_inode_info *)foo;
525
Christoph Lametera35afb82007-05-16 22:10:57 -0700526 spin_lock_init(&ei->cache_lru_lock);
527 ei->nr_caches = 0;
528 ei->cache_valid_id = FAT_CACHE_VALID + 1;
529 INIT_LIST_HEAD(&ei->cache_lru);
530 INIT_HLIST_NODE(&ei->i_fat_hash);
531 inode_init_once(&ei->vfs_inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700532}
533
534static int __init fat_init_inodecache(void)
535{
536 fat_inode_cachep = kmem_cache_create("fat_inode_cache",
537 sizeof(struct msdos_inode_info),
Paul Jacksonfffb60f2006-03-24 03:16:06 -0800538 0, (SLAB_RECLAIM_ACCOUNT|
539 SLAB_MEM_SPREAD),
Paul Mundt20c2df82007-07-20 10:11:58 +0900540 init_once);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700541 if (fat_inode_cachep == NULL)
542 return -ENOMEM;
543 return 0;
544}
545
546static void __exit fat_destroy_inodecache(void)
547{
Alexey Dobriyan1a1d92c2006-09-27 01:49:40 -0700548 kmem_cache_destroy(fat_inode_cachep);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700549}
550
551static int fat_remount(struct super_block *sb, int *flags, char *data)
552{
553 struct msdos_sb_info *sbi = MSDOS_SB(sb);
554 *flags |= MS_NODIRATIME | (sbi->options.isvfat ? 0 : MS_NOATIME);
555 return 0;
556}
557
David Howells726c3342006-06-23 02:02:58 -0700558static int fat_statfs(struct dentry *dentry, struct kstatfs *buf)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700559{
Coly Liaac49b72009-04-02 16:59:35 -0700560 struct super_block *sb = dentry->d_sb;
561 struct msdos_sb_info *sbi = MSDOS_SB(sb);
562 u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700563
564 /* If the count of free cluster is still unknown, counts it here. */
OGAWA Hirofumi606e4232008-04-28 02:16:27 -0700565 if (sbi->free_clusters == -1 || !sbi->free_clus_valid) {
David Howells726c3342006-06-23 02:02:58 -0700566 int err = fat_count_free_clusters(dentry->d_sb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700567 if (err)
568 return err;
569 }
570
David Howells726c3342006-06-23 02:02:58 -0700571 buf->f_type = dentry->d_sb->s_magic;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700572 buf->f_bsize = sbi->cluster_size;
573 buf->f_blocks = sbi->max_cluster - FAT_START_ENT;
574 buf->f_bfree = sbi->free_clusters;
575 buf->f_bavail = sbi->free_clusters;
Coly Liaac49b72009-04-02 16:59:35 -0700576 buf->f_fsid.val[0] = (u32)id;
577 buf->f_fsid.val[1] = (u32)(id >> 32);
Kevin Dankwardteeb5b4a2010-02-10 23:43:40 +0900578 buf->f_namelen = sbi->options.isvfat ? FAT_LFN_LEN : 12;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700579
580 return 0;
581}
582
OGAWA Hirofumi9ca59f42008-11-06 12:53:57 -0800583static inline loff_t fat_i_pos_read(struct msdos_sb_info *sbi,
584 struct inode *inode)
585{
586 loff_t i_pos;
587#if BITS_PER_LONG == 32
588 spin_lock(&sbi->inode_hash_lock);
589#endif
590 i_pos = MSDOS_I(inode)->i_pos;
591#if BITS_PER_LONG == 32
592 spin_unlock(&sbi->inode_hash_lock);
593#endif
594 return i_pos;
595}
596
Christoph Hellwiga9185b42010-03-05 09:21:37 +0100597static int __fat_write_inode(struct inode *inode, int wait)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700598{
599 struct super_block *sb = inode->i_sb;
600 struct msdos_sb_info *sbi = MSDOS_SB(sb);
601 struct buffer_head *bh;
602 struct msdos_dir_entry *raw_entry;
603 loff_t i_pos;
Linus Torvalds5f22ca92008-08-20 08:31:19 -0700604 int err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700605
OGAWA Hirofumi9ca59f42008-11-06 12:53:57 -0800606 if (inode->i_ino == MSDOS_ROOT_INO)
607 return 0;
608
Linus Torvalds1da177e2005-04-16 15:20:36 -0700609retry:
OGAWA Hirofumi9ca59f42008-11-06 12:53:57 -0800610 i_pos = fat_i_pos_read(sbi, inode);
611 if (!i_pos)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700612 return 0;
613
Linus Torvalds1da177e2005-04-16 15:20:36 -0700614 bh = sb_bread(sb, i_pos >> sbi->dir_per_block_bits);
615 if (!bh) {
616 printk(KERN_ERR "FAT: unable to read inode block "
617 "for updating (i_pos %lld)\n", i_pos);
Linus Torvalds5f22ca92008-08-20 08:31:19 -0700618 return -EIO;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700619 }
620 spin_lock(&sbi->inode_hash_lock);
621 if (i_pos != MSDOS_I(inode)->i_pos) {
622 spin_unlock(&sbi->inode_hash_lock);
623 brelse(bh);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700624 goto retry;
625 }
626
627 raw_entry = &((struct msdos_dir_entry *) (bh->b_data))
628 [i_pos & (sbi->dir_per_block - 1)];
629 if (S_ISDIR(inode->i_mode))
630 raw_entry->size = 0;
631 else
632 raw_entry->size = cpu_to_le32(inode->i_size);
OGAWA Hirofumi9c0aa1b2008-11-06 12:53:54 -0800633 raw_entry->attr = fat_make_attrs(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700634 raw_entry->start = cpu_to_le16(MSDOS_I(inode)->i_logstart);
635 raw_entry->starthi = cpu_to_le16(MSDOS_I(inode)->i_logstart >> 16);
OGAWA Hirofumi7decd1c2008-11-06 12:53:47 -0800636 fat_time_unix2fat(sbi, &inode->i_mtime, &raw_entry->time,
637 &raw_entry->date, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700638 if (sbi->options.isvfat) {
Stephane Kardas62a36c42005-09-21 09:55:45 -0700639 __le16 atime;
OGAWA Hirofumi7decd1c2008-11-06 12:53:47 -0800640 fat_time_unix2fat(sbi, &inode->i_ctime, &raw_entry->ctime,
641 &raw_entry->cdate, &raw_entry->ctime_cs);
642 fat_time_unix2fat(sbi, &inode->i_atime, &atime,
643 &raw_entry->adate, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700644 }
645 spin_unlock(&sbi->inode_hash_lock);
646 mark_buffer_dirty(bh);
Linus Torvalds5f22ca92008-08-20 08:31:19 -0700647 err = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700648 if (wait)
649 err = sync_dirty_buffer(bh);
650 brelse(bh);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700651 return err;
652}
653
Christoph Hellwiga9185b42010-03-05 09:21:37 +0100654static int fat_write_inode(struct inode *inode, struct writeback_control *wbc)
655{
656 return __fat_write_inode(inode, wbc->sync_mode == WB_SYNC_ALL);
657}
658
Linus Torvalds1da177e2005-04-16 15:20:36 -0700659int fat_sync_inode(struct inode *inode)
660{
Christoph Hellwiga9185b42010-03-05 09:21:37 +0100661 return __fat_write_inode(inode, 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700662}
663
OGAWA Hirofumi7c709d02006-01-08 01:02:10 -0800664EXPORT_SYMBOL_GPL(fat_sync_inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700665
666static int fat_show_options(struct seq_file *m, struct vfsmount *mnt);
Josef 'Jeff' Sipekee9b6d62007-02-12 00:55:41 -0800667static const struct super_operations fat_sops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700668 .alloc_inode = fat_alloc_inode,
669 .destroy_inode = fat_destroy_inode,
670 .write_inode = fat_write_inode,
Al Virodeee3ce2010-06-05 19:28:32 -0400671 .evict_inode = fat_evict_inode,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700672 .put_super = fat_put_super,
OGAWA Hirofumia6bf6b22006-01-08 01:02:08 -0800673 .write_super = fat_write_super,
Christoph Hellwigf83d6d42009-06-08 10:04:35 +0200674 .sync_fs = fat_sync_fs,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700675 .statfs = fat_statfs,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700676 .remount_fs = fat_remount,
677
Linus Torvalds1da177e2005-04-16 15:20:36 -0700678 .show_options = fat_show_options,
679};
680
681/*
682 * a FAT file handle with fhtype 3 is
683 * 0/ i_ino - for fast, reliable lookup if still in the cache
684 * 1/ i_generation - to see if i_ino is still valid
685 * bit 0 == 0 iff directory
686 * 2/ i_pos(8-39) - if ino has changed, but still in cache
687 * 3/ i_pos(4-7)|i_logstart - to semi-verify inode found at i_pos
688 * 4/ i_pos(0-3)|parent->i_logstart - maybe used to hunt for the file on disc
689 *
690 * Hack for NFSv2: Maximum FAT entry number is 28bits and maximum
691 * i_pos is 40bits (blocknr(32) + dir offset(8)), so two 4bits
692 * of i_logstart is used to store the directory entry offset.
693 */
694
Christoph Hellwig1305edad2007-10-21 16:42:11 -0700695static struct dentry *fat_fh_to_dentry(struct super_block *sb,
696 struct fid *fid, int fh_len, int fh_type)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700697{
698 struct inode *inode = NULL;
699 struct dentry *result;
Christoph Hellwig1305edad2007-10-21 16:42:11 -0700700 u32 *fh = fid->raw;
701
702 if (fh_len < 5 || fh_type != 3)
703 return NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700704
David Howells17f95a72008-02-07 00:15:38 -0800705 inode = ilookup(sb, fh[0]);
706 if (!inode || inode->i_generation != fh[1]) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700707 if (inode)
708 iput(inode);
709 inode = NULL;
710 }
711 if (!inode) {
712 loff_t i_pos;
713 int i_logstart = fh[3] & 0x0fffffff;
714
715 i_pos = (loff_t)fh[2] << 8;
716 i_pos |= ((fh[3] >> 24) & 0xf0) | (fh[4] >> 28);
717
718 /* try 2 - see if i_pos is in F-d-c
719 * require i_logstart to be the same
720 * Will fail if you truncate and then re-write
721 */
722
723 inode = fat_iget(sb, i_pos);
724 if (inode && MSDOS_I(inode)->i_logstart != i_logstart) {
725 iput(inode);
726 inode = NULL;
727 }
728 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700729
Christoph Hellwig44003722008-08-11 15:49:04 +0200730 /*
731 * For now, do nothing if the inode is not found.
732 *
733 * What we could do is:
734 *
735 * - follow the file starting at fh[4], and record the ".." entry,
736 * and the name of the fh[2] entry.
737 * - then follow the ".." file finding the next step up.
738 *
739 * This way we build a path to the root of the tree. If this works, we
740 * lookup the path and so get this inode into the cache. Finally try
741 * the fat_iget lookup again. If that fails, then we are totally out
742 * of luck. But all that is for another day
Linus Torvalds1da177e2005-04-16 15:20:36 -0700743 */
Christoph Hellwig44003722008-08-11 15:49:04 +0200744 result = d_obtain_alias(inode);
745 if (!IS_ERR(result))
746 result->d_op = sb->s_root->d_op;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700747 return result;
748}
749
750static int
751fat_encode_fh(struct dentry *de, __u32 *fh, int *lenp, int connectable)
752{
753 int len = *lenp;
754 struct inode *inode = de->d_inode;
755 u32 ipos_h, ipos_m, ipos_l;
756
757 if (len < 5)
758 return 255; /* no room */
759
760 ipos_h = MSDOS_I(inode)->i_pos >> 8;
761 ipos_m = (MSDOS_I(inode)->i_pos & 0xf0) << 24;
762 ipos_l = (MSDOS_I(inode)->i_pos & 0x0f) << 28;
763 *lenp = 5;
764 fh[0] = inode->i_ino;
765 fh[1] = inode->i_generation;
766 fh[2] = ipos_h;
767 fh[3] = ipos_m | MSDOS_I(inode)->i_logstart;
768 spin_lock(&de->d_lock);
769 fh[4] = ipos_l | MSDOS_I(de->d_parent->d_inode)->i_logstart;
770 spin_unlock(&de->d_lock);
771 return 3;
772}
773
774static struct dentry *fat_get_parent(struct dentry *child)
775{
Linus Torvalds8f593422008-05-19 19:53:01 -0700776 struct super_block *sb = child->d_sb;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700777 struct buffer_head *bh;
778 struct msdos_dir_entry *de;
779 loff_t i_pos;
780 struct dentry *parent;
781 struct inode *inode;
782 int err;
783
Linus Torvalds8f593422008-05-19 19:53:01 -0700784 lock_super(sb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700785
786 err = fat_get_dotdot_entry(child->d_inode, &bh, &de, &i_pos);
787 if (err) {
788 parent = ERR_PTR(err);
789 goto out;
790 }
Linus Torvalds8f593422008-05-19 19:53:01 -0700791 inode = fat_build_inode(sb, de, i_pos);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700792 brelse(bh);
Christoph Hellwig44003722008-08-11 15:49:04 +0200793
794 parent = d_obtain_alias(inode);
Christoph Hellwig5a6bb102008-11-12 07:48:01 +0900795 if (!IS_ERR(parent))
796 parent->d_op = sb->s_root->d_op;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700797out:
Linus Torvalds8f593422008-05-19 19:53:01 -0700798 unlock_super(sb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700799
800 return parent;
801}
802
Christoph Hellwig39655162007-10-21 16:42:17 -0700803static const struct export_operations fat_export_ops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700804 .encode_fh = fat_encode_fh,
Christoph Hellwig1305edad2007-10-21 16:42:11 -0700805 .fh_to_dentry = fat_fh_to_dentry,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700806 .get_parent = fat_get_parent,
807};
808
809static int fat_show_options(struct seq_file *m, struct vfsmount *mnt)
810{
811 struct msdos_sb_info *sbi = MSDOS_SB(mnt->mnt_sb);
812 struct fat_mount_options *opts = &sbi->options;
813 int isvfat = opts->isvfat;
814
815 if (opts->fs_uid != 0)
816 seq_printf(m, ",uid=%u", opts->fs_uid);
817 if (opts->fs_gid != 0)
818 seq_printf(m, ",gid=%u", opts->fs_gid);
819 seq_printf(m, ",fmask=%04o", opts->fs_fmask);
820 seq_printf(m, ",dmask=%04o", opts->fs_dmask);
OGAWA Hirofumi1ae43f82008-04-28 02:16:26 -0700821 if (opts->allow_utime)
822 seq_printf(m, ",allow_utime=%04o", opts->allow_utime);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700823 if (sbi->nls_disk)
824 seq_printf(m, ",codepage=%s", sbi->nls_disk->charset);
825 if (isvfat) {
826 if (sbi->nls_io)
827 seq_printf(m, ",iocharset=%s", sbi->nls_io->charset);
828
829 switch (opts->shortname) {
830 case VFAT_SFN_DISPLAY_WIN95 | VFAT_SFN_CREATE_WIN95:
831 seq_puts(m, ",shortname=win95");
832 break;
833 case VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WINNT:
834 seq_puts(m, ",shortname=winnt");
835 break;
836 case VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WIN95:
837 seq_puts(m, ",shortname=mixed");
838 break;
839 case VFAT_SFN_DISPLAY_LOWER | VFAT_SFN_CREATE_WIN95:
Paul Wise95523472009-08-01 21:30:31 +0900840 seq_puts(m, ",shortname=lower");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700841 break;
842 default:
843 seq_puts(m, ",shortname=unknown");
844 break;
845 }
846 }
847 if (opts->name_check != 'n')
848 seq_printf(m, ",check=%c", opts->name_check);
OGAWA Hirofumi28ec0392007-05-08 00:31:01 -0700849 if (opts->usefree)
850 seq_puts(m, ",usefree");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700851 if (opts->quiet)
852 seq_puts(m, ",quiet");
853 if (opts->showexec)
854 seq_puts(m, ",showexec");
855 if (opts->sys_immutable)
856 seq_puts(m, ",sys_immutable");
857 if (!isvfat) {
858 if (opts->dotsOK)
859 seq_puts(m, ",dotsOK=yes");
860 if (opts->nocase)
861 seq_puts(m, ",nocase");
862 } else {
863 if (opts->utf8)
864 seq_puts(m, ",utf8");
865 if (opts->unicode_xlate)
866 seq_puts(m, ",uni_xlate");
867 if (!opts->numtail)
868 seq_puts(m, ",nonumtail");
OGAWA Hirofumidfc209c2008-11-06 12:53:55 -0800869 if (opts->rodir)
870 seq_puts(m, ",rodir");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700871 }
OGAWA Hirofumidfc209c2008-11-06 12:53:55 -0800872 if (opts->flush)
Miklos Szeredic1fca3b2008-02-08 04:21:42 -0800873 seq_puts(m, ",flush");
Joe Petersonb271e062008-07-25 01:46:47 -0700874 if (opts->tz_utc)
875 seq_puts(m, ",tz=UTC");
Denis Karpov85c78592009-06-04 02:34:22 +0900876 if (opts->errors == FAT_ERRORS_CONT)
877 seq_puts(m, ",errors=continue");
878 else if (opts->errors == FAT_ERRORS_PANIC)
879 seq_puts(m, ",errors=panic");
880 else
881 seq_puts(m, ",errors=remount-ro");
Christoph Hellwig681142f2009-11-21 20:28:52 +0900882 if (opts->discard)
883 seq_puts(m, ",discard");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700884
885 return 0;
886}
887
888enum {
889 Opt_check_n, Opt_check_r, Opt_check_s, Opt_uid, Opt_gid,
OGAWA Hirofumi1ae43f82008-04-28 02:16:26 -0700890 Opt_umask, Opt_dmask, Opt_fmask, Opt_allow_utime, Opt_codepage,
891 Opt_usefree, Opt_nocase, Opt_quiet, Opt_showexec, Opt_debug,
892 Opt_immutable, Opt_dots, Opt_nodots,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700893 Opt_charset, Opt_shortname_lower, Opt_shortname_win95,
894 Opt_shortname_winnt, Opt_shortname_mixed, Opt_utf8_no, Opt_utf8_yes,
895 Opt_uni_xl_no, Opt_uni_xl_yes, Opt_nonumtail_no, Opt_nonumtail_yes,
Denis Karpov85c78592009-06-04 02:34:22 +0900896 Opt_obsolate, Opt_flush, Opt_tz_utc, Opt_rodir, Opt_err_cont,
Christoph Hellwig681142f2009-11-21 20:28:52 +0900897 Opt_err_panic, Opt_err_ro, Opt_discard, Opt_err,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700898};
899
Steven Whitehousea447c092008-10-13 10:46:57 +0100900static const match_table_t fat_tokens = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700901 {Opt_check_r, "check=relaxed"},
902 {Opt_check_s, "check=strict"},
903 {Opt_check_n, "check=normal"},
904 {Opt_check_r, "check=r"},
905 {Opt_check_s, "check=s"},
906 {Opt_check_n, "check=n"},
907 {Opt_uid, "uid=%u"},
908 {Opt_gid, "gid=%u"},
909 {Opt_umask, "umask=%o"},
910 {Opt_dmask, "dmask=%o"},
911 {Opt_fmask, "fmask=%o"},
OGAWA Hirofumi1ae43f82008-04-28 02:16:26 -0700912 {Opt_allow_utime, "allow_utime=%o"},
Linus Torvalds1da177e2005-04-16 15:20:36 -0700913 {Opt_codepage, "codepage=%u"},
OGAWA Hirofumi28ec0392007-05-08 00:31:01 -0700914 {Opt_usefree, "usefree"},
Linus Torvalds1da177e2005-04-16 15:20:36 -0700915 {Opt_nocase, "nocase"},
916 {Opt_quiet, "quiet"},
917 {Opt_showexec, "showexec"},
918 {Opt_debug, "debug"},
919 {Opt_immutable, "sys_immutable"},
Denis Karpov85c78592009-06-04 02:34:22 +0900920 {Opt_flush, "flush"},
921 {Opt_tz_utc, "tz=UTC"},
922 {Opt_err_cont, "errors=continue"},
923 {Opt_err_panic, "errors=panic"},
924 {Opt_err_ro, "errors=remount-ro"},
Christoph Hellwig681142f2009-11-21 20:28:52 +0900925 {Opt_discard, "discard"},
Linus Torvalds1da177e2005-04-16 15:20:36 -0700926 {Opt_obsolate, "conv=binary"},
927 {Opt_obsolate, "conv=text"},
928 {Opt_obsolate, "conv=auto"},
929 {Opt_obsolate, "conv=b"},
930 {Opt_obsolate, "conv=t"},
931 {Opt_obsolate, "conv=a"},
932 {Opt_obsolate, "fat=%u"},
933 {Opt_obsolate, "blocksize=%u"},
934 {Opt_obsolate, "cvf_format=%20s"},
935 {Opt_obsolate, "cvf_options=%100s"},
936 {Opt_obsolate, "posix"},
Chris Masonae78bf92006-09-29 02:00:03 -0700937 {Opt_err, NULL},
Linus Torvalds1da177e2005-04-16 15:20:36 -0700938};
Steven Whitehousea447c092008-10-13 10:46:57 +0100939static const match_table_t msdos_tokens = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700940 {Opt_nodots, "nodots"},
941 {Opt_nodots, "dotsOK=no"},
942 {Opt_dots, "dots"},
943 {Opt_dots, "dotsOK=yes"},
944 {Opt_err, NULL}
945};
Steven Whitehousea447c092008-10-13 10:46:57 +0100946static const match_table_t vfat_tokens = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700947 {Opt_charset, "iocharset=%s"},
948 {Opt_shortname_lower, "shortname=lower"},
949 {Opt_shortname_win95, "shortname=win95"},
950 {Opt_shortname_winnt, "shortname=winnt"},
951 {Opt_shortname_mixed, "shortname=mixed"},
952 {Opt_utf8_no, "utf8=0"}, /* 0 or no or false */
953 {Opt_utf8_no, "utf8=no"},
954 {Opt_utf8_no, "utf8=false"},
955 {Opt_utf8_yes, "utf8=1"}, /* empty or 1 or yes or true */
956 {Opt_utf8_yes, "utf8=yes"},
957 {Opt_utf8_yes, "utf8=true"},
958 {Opt_utf8_yes, "utf8"},
959 {Opt_uni_xl_no, "uni_xlate=0"}, /* 0 or no or false */
960 {Opt_uni_xl_no, "uni_xlate=no"},
961 {Opt_uni_xl_no, "uni_xlate=false"},
962 {Opt_uni_xl_yes, "uni_xlate=1"}, /* empty or 1 or yes or true */
963 {Opt_uni_xl_yes, "uni_xlate=yes"},
964 {Opt_uni_xl_yes, "uni_xlate=true"},
965 {Opt_uni_xl_yes, "uni_xlate"},
966 {Opt_nonumtail_no, "nonumtail=0"}, /* 0 or no or false */
967 {Opt_nonumtail_no, "nonumtail=no"},
968 {Opt_nonumtail_no, "nonumtail=false"},
969 {Opt_nonumtail_yes, "nonumtail=1"}, /* empty or 1 or yes or true */
970 {Opt_nonumtail_yes, "nonumtail=yes"},
971 {Opt_nonumtail_yes, "nonumtail=true"},
972 {Opt_nonumtail_yes, "nonumtail"},
OGAWA Hirofumidfc209c2008-11-06 12:53:55 -0800973 {Opt_rodir, "rodir"},
Linus Torvalds1da177e2005-04-16 15:20:36 -0700974 {Opt_err, NULL}
975};
976
Christoph Hellwig41a34a42005-11-08 21:34:57 -0800977static int parse_options(char *options, int is_vfat, int silent, int *debug,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700978 struct fat_mount_options *opts)
979{
980 char *p;
981 substring_t args[MAX_OPT_ARGS];
982 int option;
983 char *iocharset;
984
985 opts->isvfat = is_vfat;
986
David Howellsf0ce7ee2008-11-14 10:38:52 +1100987 opts->fs_uid = current_uid();
988 opts->fs_gid = current_gid();
OGAWA Hirofumi3e107602009-06-20 21:50:07 +0900989 opts->fs_fmask = opts->fs_dmask = current_umask();
OGAWA Hirofumi1ae43f82008-04-28 02:16:26 -0700990 opts->allow_utime = -1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700991 opts->codepage = fat_default_codepage;
992 opts->iocharset = fat_default_iocharset;
OGAWA Hirofumidfc209c2008-11-06 12:53:55 -0800993 if (is_vfat) {
Paul Wise95523472009-08-01 21:30:31 +0900994 opts->shortname = VFAT_SFN_DISPLAY_WINNT|VFAT_SFN_CREATE_WIN95;
OGAWA Hirofumidfc209c2008-11-06 12:53:55 -0800995 opts->rodir = 0;
996 } else {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700997 opts->shortname = 0;
OGAWA Hirofumidfc209c2008-11-06 12:53:55 -0800998 opts->rodir = 1;
999 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001000 opts->name_check = 'n';
1001 opts->quiet = opts->showexec = opts->sys_immutable = opts->dotsOK = 0;
1002 opts->utf8 = opts->unicode_xlate = 0;
1003 opts->numtail = 1;
OGAWA Hirofumi28ec0392007-05-08 00:31:01 -07001004 opts->usefree = opts->nocase = 0;
Joe Petersonb271e062008-07-25 01:46:47 -07001005 opts->tz_utc = 0;
Denis Karpov85c78592009-06-04 02:34:22 +09001006 opts->errors = FAT_ERRORS_RO;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001007 *debug = 0;
1008
1009 if (!options)
OGAWA Hirofumi8d44d972008-07-25 01:46:41 -07001010 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001011
1012 while ((p = strsep(&options, ",")) != NULL) {
1013 int token;
1014 if (!*p)
1015 continue;
1016
1017 token = match_token(p, fat_tokens, args);
1018 if (token == Opt_err) {
1019 if (is_vfat)
1020 token = match_token(p, vfat_tokens, args);
1021 else
1022 token = match_token(p, msdos_tokens, args);
1023 }
1024 switch (token) {
1025 case Opt_check_s:
1026 opts->name_check = 's';
1027 break;
1028 case Opt_check_r:
1029 opts->name_check = 'r';
1030 break;
1031 case Opt_check_n:
1032 opts->name_check = 'n';
1033 break;
OGAWA Hirofumi28ec0392007-05-08 00:31:01 -07001034 case Opt_usefree:
1035 opts->usefree = 1;
1036 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001037 case Opt_nocase:
1038 if (!is_vfat)
1039 opts->nocase = 1;
1040 else {
1041 /* for backward compatibility */
1042 opts->shortname = VFAT_SFN_DISPLAY_WIN95
1043 | VFAT_SFN_CREATE_WIN95;
1044 }
1045 break;
1046 case Opt_quiet:
1047 opts->quiet = 1;
1048 break;
1049 case Opt_showexec:
1050 opts->showexec = 1;
1051 break;
1052 case Opt_debug:
1053 *debug = 1;
1054 break;
1055 case Opt_immutable:
1056 opts->sys_immutable = 1;
1057 break;
1058 case Opt_uid:
1059 if (match_int(&args[0], &option))
1060 return 0;
1061 opts->fs_uid = option;
1062 break;
1063 case Opt_gid:
1064 if (match_int(&args[0], &option))
1065 return 0;
1066 opts->fs_gid = option;
1067 break;
1068 case Opt_umask:
1069 if (match_octal(&args[0], &option))
1070 return 0;
1071 opts->fs_fmask = opts->fs_dmask = option;
1072 break;
1073 case Opt_dmask:
1074 if (match_octal(&args[0], &option))
1075 return 0;
1076 opts->fs_dmask = option;
1077 break;
1078 case Opt_fmask:
1079 if (match_octal(&args[0], &option))
1080 return 0;
1081 opts->fs_fmask = option;
1082 break;
OGAWA Hirofumi1ae43f82008-04-28 02:16:26 -07001083 case Opt_allow_utime:
1084 if (match_octal(&args[0], &option))
1085 return 0;
1086 opts->allow_utime = option & (S_IWGRP | S_IWOTH);
1087 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001088 case Opt_codepage:
1089 if (match_int(&args[0], &option))
1090 return 0;
1091 opts->codepage = option;
1092 break;
Chris Masonae78bf92006-09-29 02:00:03 -07001093 case Opt_flush:
1094 opts->flush = 1;
1095 break;
Joe Petersonb271e062008-07-25 01:46:47 -07001096 case Opt_tz_utc:
1097 opts->tz_utc = 1;
1098 break;
Denis Karpov85c78592009-06-04 02:34:22 +09001099 case Opt_err_cont:
1100 opts->errors = FAT_ERRORS_CONT;
1101 break;
1102 case Opt_err_panic:
1103 opts->errors = FAT_ERRORS_PANIC;
1104 break;
1105 case Opt_err_ro:
1106 opts->errors = FAT_ERRORS_RO;
1107 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001108
1109 /* msdos specific */
1110 case Opt_dots:
1111 opts->dotsOK = 1;
1112 break;
1113 case Opt_nodots:
1114 opts->dotsOK = 0;
1115 break;
1116
1117 /* vfat specific */
1118 case Opt_charset:
1119 if (opts->iocharset != fat_default_iocharset)
1120 kfree(opts->iocharset);
1121 iocharset = match_strdup(&args[0]);
1122 if (!iocharset)
1123 return -ENOMEM;
1124 opts->iocharset = iocharset;
1125 break;
1126 case Opt_shortname_lower:
1127 opts->shortname = VFAT_SFN_DISPLAY_LOWER
1128 | VFAT_SFN_CREATE_WIN95;
1129 break;
1130 case Opt_shortname_win95:
1131 opts->shortname = VFAT_SFN_DISPLAY_WIN95
1132 | VFAT_SFN_CREATE_WIN95;
1133 break;
1134 case Opt_shortname_winnt:
1135 opts->shortname = VFAT_SFN_DISPLAY_WINNT
1136 | VFAT_SFN_CREATE_WINNT;
1137 break;
1138 case Opt_shortname_mixed:
1139 opts->shortname = VFAT_SFN_DISPLAY_WINNT
1140 | VFAT_SFN_CREATE_WIN95;
1141 break;
1142 case Opt_utf8_no: /* 0 or no or false */
1143 opts->utf8 = 0;
1144 break;
1145 case Opt_utf8_yes: /* empty or 1 or yes or true */
1146 opts->utf8 = 1;
1147 break;
1148 case Opt_uni_xl_no: /* 0 or no or false */
1149 opts->unicode_xlate = 0;
1150 break;
1151 case Opt_uni_xl_yes: /* empty or 1 or yes or true */
1152 opts->unicode_xlate = 1;
1153 break;
1154 case Opt_nonumtail_no: /* 0 or no or false */
1155 opts->numtail = 1; /* negated option */
1156 break;
1157 case Opt_nonumtail_yes: /* empty or 1 or yes or true */
1158 opts->numtail = 0; /* negated option */
1159 break;
OGAWA Hirofumidfc209c2008-11-06 12:53:55 -08001160 case Opt_rodir:
1161 opts->rodir = 1;
1162 break;
Christoph Hellwig681142f2009-11-21 20:28:52 +09001163 case Opt_discard:
1164 opts->discard = 1;
1165 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001166
1167 /* obsolete mount options */
1168 case Opt_obsolate:
1169 printk(KERN_INFO "FAT: \"%s\" option is obsolete, "
1170 "not supported now\n", p);
1171 break;
1172 /* unknown option */
1173 default:
Christoph Hellwig41a34a42005-11-08 21:34:57 -08001174 if (!silent) {
1175 printk(KERN_ERR
1176 "FAT: Unrecognized mount option \"%s\" "
1177 "or missing value\n", p);
1178 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001179 return -EINVAL;
1180 }
1181 }
OGAWA Hirofumi8d44d972008-07-25 01:46:41 -07001182
1183out:
Alexey Dobriyan4de151d2006-03-22 00:13:35 +01001184 /* UTF-8 doesn't provide FAT semantics */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001185 if (!strcmp(opts->iocharset, "utf8")) {
1186 printk(KERN_ERR "FAT: utf8 is not a recommended IO charset"
OGAWA Hirofumi8d44d972008-07-25 01:46:41 -07001187 " for FAT filesystems, filesystem will be "
1188 "case sensitive!\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -07001189 }
1190
OGAWA Hirofumi1ae43f82008-04-28 02:16:26 -07001191 /* If user doesn't specify allow_utime, it's initialized from dmask. */
1192 if (opts->allow_utime == (unsigned short)-1)
1193 opts->allow_utime = ~opts->fs_dmask & (S_IWGRP | S_IWOTH);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001194 if (opts->unicode_xlate)
1195 opts->utf8 = 0;
1196
1197 return 0;
1198}
1199
1200static int fat_read_root(struct inode *inode)
1201{
1202 struct super_block *sb = inode->i_sb;
1203 struct msdos_sb_info *sbi = MSDOS_SB(sb);
1204 int error;
1205
1206 MSDOS_I(inode)->i_pos = 0;
1207 inode->i_uid = sbi->options.fs_uid;
1208 inode->i_gid = sbi->options.fs_gid;
1209 inode->i_version++;
1210 inode->i_generation = 0;
OGAWA Hirofumi9c0aa1b2008-11-06 12:53:54 -08001211 inode->i_mode = fat_make_mode(sbi, ATTR_DIR, S_IRWXUGO);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001212 inode->i_op = sbi->dir_ops;
1213 inode->i_fop = &fat_dir_operations;
1214 if (sbi->fat_bits == 32) {
1215 MSDOS_I(inode)->i_start = sbi->root_cluster;
1216 error = fat_calc_dir_size(inode);
1217 if (error < 0)
1218 return error;
1219 } else {
1220 MSDOS_I(inode)->i_start = 0;
1221 inode->i_size = sbi->dir_entries * sizeof(struct msdos_dir_entry);
1222 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001223 inode->i_blocks = ((inode->i_size + (sbi->cluster_size - 1))
1224 & ~((loff_t)sbi->cluster_size - 1)) >> 9;
1225 MSDOS_I(inode)->i_logstart = 0;
1226 MSDOS_I(inode)->mmu_private = inode->i_size;
1227
OGAWA Hirofumi9c0aa1b2008-11-06 12:53:54 -08001228 fat_save_attrs(inode, ATTR_DIR);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001229 inode->i_mtime.tv_sec = inode->i_atime.tv_sec = inode->i_ctime.tv_sec = 0;
1230 inode->i_mtime.tv_nsec = inode->i_atime.tv_nsec = inode->i_ctime.tv_nsec = 0;
1231 inode->i_nlink = fat_subdirs(inode)+2;
1232
1233 return 0;
1234}
1235
1236/*
1237 * Read the super block of an MS-DOS FS.
1238 */
1239int fat_fill_super(struct super_block *sb, void *data, int silent,
Arjan van de Ven754661f2007-02-12 00:55:38 -08001240 const struct inode_operations *fs_dir_inode_ops, int isvfat)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001241{
Al Virob5224122009-06-07 13:44:36 -04001242 struct inode *root_inode = NULL, *fat_inode = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001243 struct buffer_head *bh;
1244 struct fat_boot_sector *b;
1245 struct msdos_sb_info *sbi;
1246 u16 logical_sector_size;
1247 u32 total_sectors, total_clusters, fat_clusters, rootdir_sectors;
1248 int debug;
1249 unsigned int media;
1250 long error;
1251 char buf[50];
1252
Linus Torvalds8f593422008-05-19 19:53:01 -07001253 /*
1254 * GFP_KERNEL is ok here, because while we do hold the
1255 * supeblock lock, memory pressure can't call back into
1256 * the filesystem, since we're only just about to mount
1257 * it and have no inodes etc active!
1258 */
Panagiotis Issarisf8314dc2006-09-27 01:49:37 -07001259 sbi = kzalloc(sizeof(struct msdos_sb_info), GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001260 if (!sbi)
1261 return -ENOMEM;
1262 sb->s_fs_info = sbi;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001263
1264 sb->s_flags |= MS_NODIRATIME;
1265 sb->s_magic = MSDOS_SUPER_MAGIC;
1266 sb->s_op = &fat_sops;
1267 sb->s_export_op = &fat_export_ops;
1268 sbi->dir_ops = fs_dir_inode_ops;
OGAWA Hirofumiaaa04b42010-05-24 14:33:12 -07001269 ratelimit_state_init(&sbi->ratelimit, DEFAULT_RATELIMIT_INTERVAL,
1270 DEFAULT_RATELIMIT_BURST);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001271
Christoph Hellwig41a34a42005-11-08 21:34:57 -08001272 error = parse_options(data, isvfat, silent, &debug, &sbi->options);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001273 if (error)
1274 goto out_fail;
1275
1276 error = -EIO;
1277 sb_min_blocksize(sb, 512);
1278 bh = sb_bread(sb, 0);
1279 if (bh == NULL) {
1280 printk(KERN_ERR "FAT: unable to read boot sector\n");
1281 goto out_fail;
1282 }
1283
1284 b = (struct fat_boot_sector *) bh->b_data;
1285 if (!b->reserved) {
1286 if (!silent)
1287 printk(KERN_ERR "FAT: bogus number of reserved sectors\n");
1288 brelse(bh);
1289 goto out_invalid;
1290 }
1291 if (!b->fats) {
1292 if (!silent)
1293 printk(KERN_ERR "FAT: bogus number of FAT structure\n");
1294 brelse(bh);
1295 goto out_invalid;
1296 }
1297
1298 /*
1299 * Earlier we checked here that b->secs_track and b->head are nonzero,
1300 * but it turns out valid FAT filesystems can have zero there.
1301 */
1302
1303 media = b->media;
Andrew Morton73f20e52008-04-28 02:16:30 -07001304 if (!fat_valid_media(media)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001305 if (!silent)
1306 printk(KERN_ERR "FAT: invalid media value (0x%02x)\n",
1307 media);
1308 brelse(bh);
1309 goto out_invalid;
1310 }
Harvey Harrison803f4452008-04-29 01:03:43 -07001311 logical_sector_size = get_unaligned_le16(&b->sector_size);
Vignesh Babu BMe7d709c2007-05-08 00:24:27 -07001312 if (!is_power_of_2(logical_sector_size)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001313 || (logical_sector_size < 512)
Olof Johansson9f354852008-04-28 02:16:32 -07001314 || (logical_sector_size > 4096)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001315 if (!silent)
1316 printk(KERN_ERR "FAT: bogus logical sector size %u\n",
1317 logical_sector_size);
1318 brelse(bh);
1319 goto out_invalid;
1320 }
1321 sbi->sec_per_clus = b->sec_per_clus;
Vignesh Babu BMe7d709c2007-05-08 00:24:27 -07001322 if (!is_power_of_2(sbi->sec_per_clus)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001323 if (!silent)
1324 printk(KERN_ERR "FAT: bogus sectors per cluster %u\n",
1325 sbi->sec_per_clus);
1326 brelse(bh);
1327 goto out_invalid;
1328 }
1329
1330 if (logical_sector_size < sb->s_blocksize) {
1331 printk(KERN_ERR "FAT: logical sector size too small for device"
1332 " (logical sector size = %u)\n", logical_sector_size);
1333 brelse(bh);
1334 goto out_fail;
1335 }
1336 if (logical_sector_size > sb->s_blocksize) {
1337 brelse(bh);
1338
1339 if (!sb_set_blocksize(sb, logical_sector_size)) {
1340 printk(KERN_ERR "FAT: unable to set blocksize %u\n",
1341 logical_sector_size);
1342 goto out_fail;
1343 }
1344 bh = sb_bread(sb, 0);
1345 if (bh == NULL) {
1346 printk(KERN_ERR "FAT: unable to read boot sector"
1347 " (logical sector size = %lu)\n",
1348 sb->s_blocksize);
1349 goto out_fail;
1350 }
1351 b = (struct fat_boot_sector *) bh->b_data;
1352 }
1353
1354 sbi->cluster_size = sb->s_blocksize * sbi->sec_per_clus;
1355 sbi->cluster_bits = ffs(sbi->cluster_size) - 1;
1356 sbi->fats = b->fats;
1357 sbi->fat_bits = 0; /* Don't know yet */
1358 sbi->fat_start = le16_to_cpu(b->reserved);
1359 sbi->fat_length = le16_to_cpu(b->fat_length);
1360 sbi->root_cluster = 0;
1361 sbi->free_clusters = -1; /* Don't know yet */
OGAWA Hirofumi606e4232008-04-28 02:16:27 -07001362 sbi->free_clus_valid = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001363 sbi->prev_free = FAT_START_ENT;
1364
1365 if (!sbi->fat_length && b->fat32_length) {
1366 struct fat_boot_fsinfo *fsinfo;
1367 struct buffer_head *fsinfo_bh;
1368
1369 /* Must be FAT32 */
1370 sbi->fat_bits = 32;
1371 sbi->fat_length = le32_to_cpu(b->fat32_length);
1372 sbi->root_cluster = le32_to_cpu(b->root_cluster);
1373
1374 sb->s_maxbytes = 0xffffffff;
1375
1376 /* MC - if info_sector is 0, don't multiply by 0 */
1377 sbi->fsinfo_sector = le16_to_cpu(b->info_sector);
1378 if (sbi->fsinfo_sector == 0)
1379 sbi->fsinfo_sector = 1;
1380
1381 fsinfo_bh = sb_bread(sb, sbi->fsinfo_sector);
1382 if (fsinfo_bh == NULL) {
1383 printk(KERN_ERR "FAT: bread failed, FSINFO block"
1384 " (sector = %lu)\n", sbi->fsinfo_sector);
1385 brelse(bh);
1386 goto out_fail;
1387 }
1388
1389 fsinfo = (struct fat_boot_fsinfo *)fsinfo_bh->b_data;
1390 if (!IS_FSINFO(fsinfo)) {
Vegard Nossumb4cf9c32008-02-06 01:36:36 -08001391 printk(KERN_WARNING "FAT: Invalid FSINFO signature: "
1392 "0x%08x, 0x%08x (sector = %lu)\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -07001393 le32_to_cpu(fsinfo->signature1),
1394 le32_to_cpu(fsinfo->signature2),
1395 sbi->fsinfo_sector);
1396 } else {
OGAWA Hirofumi28ec0392007-05-08 00:31:01 -07001397 if (sbi->options.usefree)
OGAWA Hirofumi606e4232008-04-28 02:16:27 -07001398 sbi->free_clus_valid = 1;
1399 sbi->free_clusters = le32_to_cpu(fsinfo->free_clusters);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001400 sbi->prev_free = le32_to_cpu(fsinfo->next_cluster);
1401 }
1402
1403 brelse(fsinfo_bh);
1404 }
1405
1406 sbi->dir_per_block = sb->s_blocksize / sizeof(struct msdos_dir_entry);
1407 sbi->dir_per_block_bits = ffs(sbi->dir_per_block) - 1;
1408
1409 sbi->dir_start = sbi->fat_start + sbi->fats * sbi->fat_length;
Harvey Harrison803f4452008-04-29 01:03:43 -07001410 sbi->dir_entries = get_unaligned_le16(&b->dir_entries);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001411 if (sbi->dir_entries & (sbi->dir_per_block - 1)) {
1412 if (!silent)
1413 printk(KERN_ERR "FAT: bogus directroy-entries per block"
1414 " (%u)\n", sbi->dir_entries);
1415 brelse(bh);
1416 goto out_invalid;
1417 }
1418
1419 rootdir_sectors = sbi->dir_entries
1420 * sizeof(struct msdos_dir_entry) / sb->s_blocksize;
1421 sbi->data_start = sbi->dir_start + rootdir_sectors;
Harvey Harrison803f4452008-04-29 01:03:43 -07001422 total_sectors = get_unaligned_le16(&b->sectors);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001423 if (total_sectors == 0)
1424 total_sectors = le32_to_cpu(b->total_sect);
1425
1426 total_clusters = (total_sectors - sbi->data_start) / sbi->sec_per_clus;
1427
1428 if (sbi->fat_bits != 32)
1429 sbi->fat_bits = (total_clusters > MAX_FAT12) ? 16 : 12;
1430
1431 /* check that FAT table does not overflow */
1432 fat_clusters = sbi->fat_length * sb->s_blocksize * 8 / sbi->fat_bits;
1433 total_clusters = min(total_clusters, fat_clusters - FAT_START_ENT);
1434 if (total_clusters > MAX_FAT(sb)) {
1435 if (!silent)
1436 printk(KERN_ERR "FAT: count of clusters too big (%u)\n",
1437 total_clusters);
1438 brelse(bh);
1439 goto out_invalid;
1440 }
1441
1442 sbi->max_cluster = total_clusters + FAT_START_ENT;
1443 /* check the free_clusters, it's not necessarily correct */
1444 if (sbi->free_clusters != -1 && sbi->free_clusters > total_clusters)
1445 sbi->free_clusters = -1;
1446 /* check the prev_free, it's not necessarily correct */
1447 sbi->prev_free %= sbi->max_cluster;
1448 if (sbi->prev_free < FAT_START_ENT)
1449 sbi->prev_free = FAT_START_ENT;
1450
1451 brelse(bh);
1452
1453 /* set up enough so that it can read an inode */
1454 fat_hash_init(sb);
1455 fat_ent_access_init(sb);
1456
1457 /*
1458 * The low byte of FAT's first entry must have same value with
1459 * media-field. But in real world, too many devices is
1460 * writing wrong value. So, removed that validity check.
1461 *
1462 * if (FAT_FIRST_ENT(sb, media) != first)
1463 */
1464
1465 error = -EINVAL;
1466 sprintf(buf, "cp%d", sbi->options.codepage);
1467 sbi->nls_disk = load_nls(buf);
1468 if (!sbi->nls_disk) {
1469 printk(KERN_ERR "FAT: codepage %s not found\n", buf);
1470 goto out_fail;
1471 }
1472
1473 /* FIXME: utf8 is using iocharset for upper/lower conversion */
1474 if (sbi->options.isvfat) {
1475 sbi->nls_io = load_nls(sbi->options.iocharset);
1476 if (!sbi->nls_io) {
1477 printk(KERN_ERR "FAT: IO charset %s not found\n",
1478 sbi->options.iocharset);
1479 goto out_fail;
1480 }
1481 }
1482
1483 error = -ENOMEM;
Al Virob5224122009-06-07 13:44:36 -04001484 fat_inode = new_inode(sb);
1485 if (!fat_inode)
1486 goto out_fail;
1487 MSDOS_I(fat_inode)->i_pos = 0;
1488 sbi->fat_inode = fat_inode;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001489 root_inode = new_inode(sb);
1490 if (!root_inode)
1491 goto out_fail;
1492 root_inode->i_ino = MSDOS_ROOT_INO;
1493 root_inode->i_version = 1;
1494 error = fat_read_root(root_inode);
1495 if (error < 0)
1496 goto out_fail;
1497 error = -ENOMEM;
1498 insert_inode_hash(root_inode);
1499 sb->s_root = d_alloc_root(root_inode);
1500 if (!sb->s_root) {
1501 printk(KERN_ERR "FAT: get root inode failed\n");
1502 goto out_fail;
1503 }
1504
1505 return 0;
1506
1507out_invalid:
1508 error = -EINVAL;
1509 if (!silent)
1510 printk(KERN_INFO "VFS: Can't find a valid FAT filesystem"
1511 " on dev %s.\n", sb->s_id);
1512
1513out_fail:
Al Virob5224122009-06-07 13:44:36 -04001514 if (fat_inode)
1515 iput(fat_inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001516 if (root_inode)
1517 iput(root_inode);
OGAWA Hirofumi1bdb6f92010-03-16 05:48:09 +09001518 unload_nls(sbi->nls_io);
1519 unload_nls(sbi->nls_disk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001520 if (sbi->options.iocharset != fat_default_iocharset)
1521 kfree(sbi->options.iocharset);
1522 sb->s_fs_info = NULL;
1523 kfree(sbi);
1524 return error;
1525}
1526
OGAWA Hirofumi7c709d02006-01-08 01:02:10 -08001527EXPORT_SYMBOL_GPL(fat_fill_super);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001528
Chris Masonae78bf92006-09-29 02:00:03 -07001529/*
1530 * helper function for fat_flush_inodes. This writes both the inode
1531 * and the file data blocks, waiting for in flight data blocks before
1532 * the start of the call. It does not wait for any io started
1533 * during the call
1534 */
1535static int writeback_inode(struct inode *inode)
1536{
1537
1538 int ret;
1539 struct address_space *mapping = inode->i_mapping;
1540 struct writeback_control wbc = {
1541 .sync_mode = WB_SYNC_NONE,
1542 .nr_to_write = 0,
1543 };
1544 /* if we used WB_SYNC_ALL, sync_inode waits for the io for the
1545 * inode to finish. So WB_SYNC_NONE is sent down to sync_inode
1546 * and filemap_fdatawrite is used for the data blocks
1547 */
1548 ret = sync_inode(inode, &wbc);
1549 if (!ret)
1550 ret = filemap_fdatawrite(mapping);
1551 return ret;
1552}
1553
1554/*
1555 * write data and metadata corresponding to i1 and i2. The io is
1556 * started but we do not wait for any of it to finish.
1557 *
1558 * filemap_flush is used for the block device, so if there is a dirty
1559 * page for a block already in flight, we will not wait and start the
1560 * io over again
1561 */
1562int fat_flush_inodes(struct super_block *sb, struct inode *i1, struct inode *i2)
1563{
1564 int ret = 0;
1565 if (!MSDOS_SB(sb)->options.flush)
1566 return 0;
1567 if (i1)
1568 ret = writeback_inode(i1);
1569 if (!ret && i2)
1570 ret = writeback_inode(i2);
Eric Sesterhenn97e860d2006-10-11 01:21:59 -07001571 if (!ret) {
Chris Masonae78bf92006-09-29 02:00:03 -07001572 struct address_space *mapping = sb->s_bdev->bd_inode->i_mapping;
1573 ret = filemap_flush(mapping);
1574 }
1575 return ret;
1576}
1577EXPORT_SYMBOL_GPL(fat_flush_inodes);
1578
Linus Torvalds1da177e2005-04-16 15:20:36 -07001579static int __init init_fat_fs(void)
1580{
Pekka J Enberg532a39a2005-06-30 02:59:01 -07001581 int err;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001582
Pekka J Enberg532a39a2005-06-30 02:59:01 -07001583 err = fat_cache_init();
1584 if (err)
1585 return err;
1586
1587 err = fat_init_inodecache();
1588 if (err)
1589 goto failed;
1590
1591 return 0;
1592
1593failed:
1594 fat_cache_destroy();
1595 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001596}
1597
1598static void __exit exit_fat_fs(void)
1599{
1600 fat_cache_destroy();
1601 fat_destroy_inodecache();
1602}
1603
1604module_init(init_fat_fs)
1605module_exit(exit_fat_fs)
1606
1607MODULE_LICENSE("GPL");