blob: cb8d8391ac0bb67c815e45b90127f89a3f6368f5 [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,
Nick Piggind7777a22007-10-16 01:25:08 -0700239 .write_begin = fat_write_begin,
240 .write_end = fat_write_end,
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -0800241 .direct_IO = fat_direct_IO,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700242 .bmap = _fat_bmap
243};
244
245/*
246 * New FAT inode stuff. We do the following:
247 * a) i_ino is constant and has nothing with on-disk location.
248 * b) FAT manages its own cache of directory entries.
249 * c) *This* cache is indexed by on-disk location.
250 * d) inode has an associated directory entry, all right, but
251 * it may be unhashed.
252 * e) currently entries are stored within struct inode. That should
253 * change.
254 * f) we deal with races in the following way:
255 * 1. readdir() and lookup() do FAT-dir-cache lookup.
256 * 2. rename() unhashes the F-d-c entry and rehashes it in
257 * a new place.
258 * 3. unlink() and rmdir() unhash F-d-c entry.
259 * 4. fat_write_inode() checks whether the thing is unhashed.
260 * If it is we silently return. If it isn't we do bread(),
261 * check if the location is still valid and retry if it
262 * isn't. Otherwise we do changes.
263 * 5. Spinlock is used to protect hash/unhash/location check/lookup
Al Virodeee3ce2010-06-05 19:28:32 -0400264 * 6. fat_evict_inode() unhashes the F-d-c entry.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700265 * 7. lookup() and readdir() do igrab() if they find a F-d-c entry
266 * and consider negative result as cache miss.
267 */
268
269static void fat_hash_init(struct super_block *sb)
270{
271 struct msdos_sb_info *sbi = MSDOS_SB(sb);
272 int i;
273
274 spin_lock_init(&sbi->inode_hash_lock);
275 for (i = 0; i < FAT_HASH_SIZE; i++)
276 INIT_HLIST_HEAD(&sbi->inode_hashtable[i]);
277}
278
OGAWA Hirofumid3dfa822008-11-06 12:53:49 -0800279static inline unsigned long fat_hash(loff_t i_pos)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700280{
OGAWA Hirofumid3dfa822008-11-06 12:53:49 -0800281 return hash_32(i_pos, FAT_HASH_BITS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700282}
283
284void fat_attach(struct inode *inode, loff_t i_pos)
285{
OGAWA Hirofumid3dfa822008-11-06 12:53:49 -0800286 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
287 struct hlist_head *head = sbi->inode_hashtable + fat_hash(i_pos);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700288
289 spin_lock(&sbi->inode_hash_lock);
290 MSDOS_I(inode)->i_pos = i_pos;
OGAWA Hirofumid3dfa822008-11-06 12:53:49 -0800291 hlist_add_head(&MSDOS_I(inode)->i_fat_hash, head);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700292 spin_unlock(&sbi->inode_hash_lock);
293}
OGAWA Hirofumi7c709d02006-01-08 01:02:10 -0800294EXPORT_SYMBOL_GPL(fat_attach);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700295
296void fat_detach(struct inode *inode)
297{
298 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
299 spin_lock(&sbi->inode_hash_lock);
300 MSDOS_I(inode)->i_pos = 0;
301 hlist_del_init(&MSDOS_I(inode)->i_fat_hash);
302 spin_unlock(&sbi->inode_hash_lock);
303}
OGAWA Hirofumi7c709d02006-01-08 01:02:10 -0800304EXPORT_SYMBOL_GPL(fat_detach);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700305
306struct inode *fat_iget(struct super_block *sb, loff_t i_pos)
307{
308 struct msdos_sb_info *sbi = MSDOS_SB(sb);
OGAWA Hirofumid3dfa822008-11-06 12:53:49 -0800309 struct hlist_head *head = sbi->inode_hashtable + fat_hash(i_pos);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700310 struct hlist_node *_p;
311 struct msdos_inode_info *i;
312 struct inode *inode = NULL;
313
314 spin_lock(&sbi->inode_hash_lock);
315 hlist_for_each_entry(i, _p, head, i_fat_hash) {
316 BUG_ON(i->vfs_inode.i_sb != sb);
317 if (i->i_pos != i_pos)
318 continue;
319 inode = igrab(&i->vfs_inode);
320 if (inode)
321 break;
322 }
323 spin_unlock(&sbi->inode_hash_lock);
324 return inode;
325}
326
327static int is_exec(unsigned char *extension)
328{
329 unsigned char *exe_extensions = "EXECOMBAT", *walk;
330
331 for (walk = exe_extensions; *walk; walk += 3)
332 if (!strncmp(extension, walk, 3))
333 return 1;
334 return 0;
335}
336
337static int fat_calc_dir_size(struct inode *inode)
338{
339 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
340 int ret, fclus, dclus;
341
342 inode->i_size = 0;
343 if (MSDOS_I(inode)->i_start == 0)
344 return 0;
345
346 ret = fat_get_cluster(inode, FAT_ENT_EOF, &fclus, &dclus);
347 if (ret < 0)
348 return ret;
349 inode->i_size = (fclus + 1) << sbi->cluster_bits;
350
351 return 0;
352}
353
354/* doesn't deal with root inode */
355static int fat_fill_inode(struct inode *inode, struct msdos_dir_entry *de)
356{
357 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
358 int error;
359
360 MSDOS_I(inode)->i_pos = 0;
361 inode->i_uid = sbi->options.fs_uid;
362 inode->i_gid = sbi->options.fs_gid;
363 inode->i_version++;
364 inode->i_generation = get_seconds();
365
366 if ((de->attr & ATTR_DIR) && !IS_FREE(de->name)) {
367 inode->i_generation &= ~1;
OGAWA Hirofumi9c0aa1b2008-11-06 12:53:54 -0800368 inode->i_mode = fat_make_mode(sbi, de->attr, S_IRWXUGO);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700369 inode->i_op = sbi->dir_ops;
370 inode->i_fop = &fat_dir_operations;
371
372 MSDOS_I(inode)->i_start = le16_to_cpu(de->start);
373 if (sbi->fat_bits == 32)
374 MSDOS_I(inode)->i_start |= (le16_to_cpu(de->starthi) << 16);
375
376 MSDOS_I(inode)->i_logstart = MSDOS_I(inode)->i_start;
377 error = fat_calc_dir_size(inode);
378 if (error < 0)
379 return error;
380 MSDOS_I(inode)->mmu_private = inode->i_size;
381
382 inode->i_nlink = fat_subdirs(inode);
383 } else { /* not a directory */
384 inode->i_generation |= 1;
OGAWA Hirofumi9c0aa1b2008-11-06 12:53:54 -0800385 inode->i_mode = fat_make_mode(sbi, de->attr,
386 ((sbi->options.showexec && !is_exec(de->name + 8))
387 ? S_IRUGO|S_IWUGO : S_IRWXUGO));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700388 MSDOS_I(inode)->i_start = le16_to_cpu(de->start);
389 if (sbi->fat_bits == 32)
390 MSDOS_I(inode)->i_start |= (le16_to_cpu(de->starthi) << 16);
391
392 MSDOS_I(inode)->i_logstart = MSDOS_I(inode)->i_start;
393 inode->i_size = le32_to_cpu(de->size);
394 inode->i_op = &fat_file_inode_operations;
395 inode->i_fop = &fat_file_operations;
396 inode->i_mapping->a_ops = &fat_aops;
397 MSDOS_I(inode)->mmu_private = inode->i_size;
398 }
399 if (de->attr & ATTR_SYS) {
400 if (sbi->options.sys_immutable)
401 inode->i_flags |= S_IMMUTABLE;
402 }
OGAWA Hirofumi9c0aa1b2008-11-06 12:53:54 -0800403 fat_save_attrs(inode, de->attr);
404
Linus Torvalds1da177e2005-04-16 15:20:36 -0700405 inode->i_blocks = ((inode->i_size + (sbi->cluster_size - 1))
406 & ~((loff_t)sbi->cluster_size - 1)) >> 9;
OGAWA Hirofumi7decd1c2008-11-06 12:53:47 -0800407
408 fat_time_fat2unix(sbi, &inode->i_mtime, de->time, de->date, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700409 if (sbi->options.isvfat) {
OGAWA Hirofumi7decd1c2008-11-06 12:53:47 -0800410 fat_time_fat2unix(sbi, &inode->i_ctime, de->ctime,
411 de->cdate, de->ctime_cs);
412 fat_time_fat2unix(sbi, &inode->i_atime, 0, de->adate, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700413 } else
Stephane Kardas62a36c42005-09-21 09:55:45 -0700414 inode->i_ctime = inode->i_atime = inode->i_mtime;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700415
416 return 0;
417}
418
419struct inode *fat_build_inode(struct super_block *sb,
420 struct msdos_dir_entry *de, loff_t i_pos)
421{
422 struct inode *inode;
423 int err;
424
425 inode = fat_iget(sb, i_pos);
426 if (inode)
427 goto out;
428 inode = new_inode(sb);
429 if (!inode) {
430 inode = ERR_PTR(-ENOMEM);
431 goto out;
432 }
433 inode->i_ino = iunique(sb, MSDOS_ROOT_INO);
434 inode->i_version = 1;
435 err = fat_fill_inode(inode, de);
436 if (err) {
437 iput(inode);
438 inode = ERR_PTR(err);
439 goto out;
440 }
441 fat_attach(inode, i_pos);
442 insert_inode_hash(inode);
443out:
444 return inode;
445}
446
OGAWA Hirofumi7c709d02006-01-08 01:02:10 -0800447EXPORT_SYMBOL_GPL(fat_build_inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700448
Al Virodeee3ce2010-06-05 19:28:32 -0400449static void fat_evict_inode(struct inode *inode)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700450{
Mark Fashehfef26652005-09-09 13:01:31 -0700451 truncate_inode_pages(&inode->i_data, 0);
Al Virodeee3ce2010-06-05 19:28:32 -0400452 if (!inode->i_nlink) {
453 inode->i_size = 0;
454 fat_truncate_blocks(inode, 0);
455 }
456 invalidate_inode_buffers(inode);
457 end_writeback(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700458 fat_cache_inval_inode(inode);
OGAWA Hirofumia993b542008-11-06 12:53:50 -0800459 fat_detach(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700460}
461
OGAWA Hirofumia6bf6b22006-01-08 01:02:08 -0800462static void fat_write_super(struct super_block *sb)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700463{
Christoph Hellwigebc1ac12009-05-11 23:35:03 +0200464 lock_super(sb);
OGAWA Hirofumia6bf6b22006-01-08 01:02:08 -0800465 sb->s_dirt = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700466
467 if (!(sb->s_flags & MS_RDONLY))
468 fat_clusters_flush(sb);
Christoph Hellwigebc1ac12009-05-11 23:35:03 +0200469 unlock_super(sb);
OGAWA Hirofumia6bf6b22006-01-08 01:02:08 -0800470}
471
Christoph Hellwigf83d6d42009-06-08 10:04:35 +0200472static int fat_sync_fs(struct super_block *sb, int wait)
473{
OGAWA Hirofumied248b22009-09-20 01:31:58 +0900474 int err = 0;
Christoph Hellwigf83d6d42009-06-08 10:04:35 +0200475
OGAWA Hirofumied248b22009-09-20 01:31:58 +0900476 if (sb->s_dirt) {
477 lock_super(sb);
478 sb->s_dirt = 0;
479 err = fat_clusters_flush(sb);
480 unlock_super(sb);
481 }
482
483 return err;
Christoph Hellwigf83d6d42009-06-08 10:04:35 +0200484}
485
OGAWA Hirofumia6bf6b22006-01-08 01:02:08 -0800486static void fat_put_super(struct super_block *sb)
487{
488 struct msdos_sb_info *sbi = MSDOS_SB(sb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700489
Christoph Hellwig8c85e122009-04-28 18:00:26 +0200490 if (sb->s_dirt)
491 fat_write_super(sb);
492
Al Virob5224122009-06-07 13:44:36 -0400493 iput(sbi->fat_inode);
494
Thomas Gleixner6d729e42009-08-16 21:05:08 +0000495 unload_nls(sbi->nls_disk);
496 unload_nls(sbi->nls_io);
497
498 if (sbi->options.iocharset != fat_default_iocharset)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700499 kfree(sbi->options.iocharset);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700500
501 sb->s_fs_info = NULL;
502 kfree(sbi);
503}
504
Christoph Lametere18b8902006-12-06 20:33:20 -0800505static struct kmem_cache *fat_inode_cachep;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700506
507static struct inode *fat_alloc_inode(struct super_block *sb)
508{
509 struct msdos_inode_info *ei;
Linus Torvalds8f593422008-05-19 19:53:01 -0700510 ei = kmem_cache_alloc(fat_inode_cachep, GFP_NOFS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700511 if (!ei)
512 return NULL;
513 return &ei->vfs_inode;
514}
515
Nick Pigginfa0d7e3d2011-01-07 17:49:49 +1100516static void fat_i_callback(struct rcu_head *head)
517{
518 struct inode *inode = container_of(head, struct inode, i_rcu);
519 INIT_LIST_HEAD(&inode->i_dentry);
520 kmem_cache_free(fat_inode_cachep, MSDOS_I(inode));
521}
522
Linus Torvalds1da177e2005-04-16 15:20:36 -0700523static void fat_destroy_inode(struct inode *inode)
524{
Nick Pigginfa0d7e3d2011-01-07 17:49:49 +1100525 call_rcu(&inode->i_rcu, fat_i_callback);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700526}
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 Liaac49b752009-04-02 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 Liaac49b752009-04-02 16:59:35 -0700582 buf->f_fsid.val[0] = (u32)id;
583 buf->f_fsid.val[1] = (u32)(id >> 32);
OGAWA Hirofumif68e5422011-04-12 21:08:39 +0900584 buf->f_namelen =
585 (sbi->options.isvfat ? FAT_LFN_LEN : 12) * NLS_MAX_CHARSET_SIZE;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700586
587 return 0;
588}
589
OGAWA Hirofumi9ca59f42008-11-06 12:53:57 -0800590static inline loff_t fat_i_pos_read(struct msdos_sb_info *sbi,
591 struct inode *inode)
592{
593 loff_t i_pos;
594#if BITS_PER_LONG == 32
595 spin_lock(&sbi->inode_hash_lock);
596#endif
597 i_pos = MSDOS_I(inode)->i_pos;
598#if BITS_PER_LONG == 32
599 spin_unlock(&sbi->inode_hash_lock);
600#endif
601 return i_pos;
602}
603
Christoph Hellwiga9185b42010-03-05 09:21:37 +0100604static int __fat_write_inode(struct inode *inode, int wait)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700605{
606 struct super_block *sb = inode->i_sb;
607 struct msdos_sb_info *sbi = MSDOS_SB(sb);
608 struct buffer_head *bh;
609 struct msdos_dir_entry *raw_entry;
610 loff_t i_pos;
Linus Torvalds5f22ca92008-08-20 08:31:19 -0700611 int err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700612
OGAWA Hirofumi9ca59f42008-11-06 12:53:57 -0800613 if (inode->i_ino == MSDOS_ROOT_INO)
614 return 0;
615
Linus Torvalds1da177e2005-04-16 15:20:36 -0700616retry:
OGAWA Hirofumi9ca59f42008-11-06 12:53:57 -0800617 i_pos = fat_i_pos_read(sbi, inode);
618 if (!i_pos)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700619 return 0;
620
Linus Torvalds1da177e2005-04-16 15:20:36 -0700621 bh = sb_bread(sb, i_pos >> sbi->dir_per_block_bits);
622 if (!bh) {
Alexey Fisher869f58c2011-04-12 21:08:38 +0900623 fat_msg(sb, KERN_ERR, "unable to read inode block "
624 "for updating (i_pos %lld)", i_pos);
Linus Torvalds5f22ca92008-08-20 08:31:19 -0700625 return -EIO;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700626 }
627 spin_lock(&sbi->inode_hash_lock);
628 if (i_pos != MSDOS_I(inode)->i_pos) {
629 spin_unlock(&sbi->inode_hash_lock);
630 brelse(bh);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700631 goto retry;
632 }
633
634 raw_entry = &((struct msdos_dir_entry *) (bh->b_data))
635 [i_pos & (sbi->dir_per_block - 1)];
636 if (S_ISDIR(inode->i_mode))
637 raw_entry->size = 0;
638 else
639 raw_entry->size = cpu_to_le32(inode->i_size);
OGAWA Hirofumi9c0aa1b2008-11-06 12:53:54 -0800640 raw_entry->attr = fat_make_attrs(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700641 raw_entry->start = cpu_to_le16(MSDOS_I(inode)->i_logstart);
642 raw_entry->starthi = cpu_to_le16(MSDOS_I(inode)->i_logstart >> 16);
OGAWA Hirofumi7decd1c2008-11-06 12:53:47 -0800643 fat_time_unix2fat(sbi, &inode->i_mtime, &raw_entry->time,
644 &raw_entry->date, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700645 if (sbi->options.isvfat) {
Stephane Kardas62a36c42005-09-21 09:55:45 -0700646 __le16 atime;
OGAWA Hirofumi7decd1c2008-11-06 12:53:47 -0800647 fat_time_unix2fat(sbi, &inode->i_ctime, &raw_entry->ctime,
648 &raw_entry->cdate, &raw_entry->ctime_cs);
649 fat_time_unix2fat(sbi, &inode->i_atime, &atime,
650 &raw_entry->adate, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700651 }
652 spin_unlock(&sbi->inode_hash_lock);
653 mark_buffer_dirty(bh);
Linus Torvalds5f22ca92008-08-20 08:31:19 -0700654 err = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700655 if (wait)
656 err = sync_dirty_buffer(bh);
657 brelse(bh);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700658 return err;
659}
660
Christoph Hellwiga9185b42010-03-05 09:21:37 +0100661static int fat_write_inode(struct inode *inode, struct writeback_control *wbc)
662{
663 return __fat_write_inode(inode, wbc->sync_mode == WB_SYNC_ALL);
664}
665
Linus Torvalds1da177e2005-04-16 15:20:36 -0700666int fat_sync_inode(struct inode *inode)
667{
Christoph Hellwiga9185b42010-03-05 09:21:37 +0100668 return __fat_write_inode(inode, 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700669}
670
OGAWA Hirofumi7c709d02006-01-08 01:02:10 -0800671EXPORT_SYMBOL_GPL(fat_sync_inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700672
673static int fat_show_options(struct seq_file *m, struct vfsmount *mnt);
Josef 'Jeff' Sipekee9b6d62007-02-12 00:55:41 -0800674static const struct super_operations fat_sops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700675 .alloc_inode = fat_alloc_inode,
676 .destroy_inode = fat_destroy_inode,
677 .write_inode = fat_write_inode,
Al Virodeee3ce2010-06-05 19:28:32 -0400678 .evict_inode = fat_evict_inode,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700679 .put_super = fat_put_super,
OGAWA Hirofumia6bf6b22006-01-08 01:02:08 -0800680 .write_super = fat_write_super,
Christoph Hellwigf83d6d42009-06-08 10:04:35 +0200681 .sync_fs = fat_sync_fs,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700682 .statfs = fat_statfs,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700683 .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;
Christoph Hellwig1305edad2007-10-21 16:42:11 -0700706 u32 *fh = fid->raw;
707
708 if (fh_len < 5 || fh_type != 3)
709 return NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700710
David Howells17f95a72008-02-07 00:15:38 -0800711 inode = ilookup(sb, fh[0]);
712 if (!inode || inode->i_generation != fh[1]) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700713 if (inode)
714 iput(inode);
715 inode = NULL;
716 }
717 if (!inode) {
718 loff_t i_pos;
719 int i_logstart = fh[3] & 0x0fffffff;
720
721 i_pos = (loff_t)fh[2] << 8;
722 i_pos |= ((fh[3] >> 24) & 0xf0) | (fh[4] >> 28);
723
724 /* try 2 - see if i_pos is in F-d-c
725 * require i_logstart to be the same
726 * Will fail if you truncate and then re-write
727 */
728
729 inode = fat_iget(sb, i_pos);
730 if (inode && MSDOS_I(inode)->i_logstart != i_logstart) {
731 iput(inode);
732 inode = NULL;
733 }
734 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700735
Christoph Hellwig44003722008-08-11 15:49:04 +0200736 /*
737 * For now, do nothing if the inode is not found.
738 *
739 * What we could do is:
740 *
741 * - follow the file starting at fh[4], and record the ".." entry,
742 * and the name of the fh[2] entry.
743 * - then follow the ".." file finding the next step up.
744 *
745 * This way we build a path to the root of the tree. If this works, we
746 * lookup the path and so get this inode into the cache. Finally try
747 * the fat_iget lookup again. If that fails, then we are totally out
748 * of luck. But all that is for another day
Linus Torvalds1da177e2005-04-16 15:20:36 -0700749 */
Al Viro3d239852010-12-18 10:44:00 -0500750 return d_obtain_alias(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700751}
752
753static int
754fat_encode_fh(struct dentry *de, __u32 *fh, int *lenp, int connectable)
755{
756 int len = *lenp;
757 struct inode *inode = de->d_inode;
758 u32 ipos_h, ipos_m, ipos_l;
759
Aneesh Kumar K.V5fe0c232011-01-29 18:43:25 +0530760 if (len < 5) {
761 *lenp = 5;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700762 return 255; /* no room */
Aneesh Kumar K.V5fe0c232011-01-29 18:43:25 +0530763 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700764
765 ipos_h = MSDOS_I(inode)->i_pos >> 8;
766 ipos_m = (MSDOS_I(inode)->i_pos & 0xf0) << 24;
767 ipos_l = (MSDOS_I(inode)->i_pos & 0x0f) << 28;
768 *lenp = 5;
769 fh[0] = inode->i_ino;
770 fh[1] = inode->i_generation;
771 fh[2] = ipos_h;
772 fh[3] = ipos_m | MSDOS_I(inode)->i_logstart;
773 spin_lock(&de->d_lock);
774 fh[4] = ipos_l | MSDOS_I(de->d_parent->d_inode)->i_logstart;
775 spin_unlock(&de->d_lock);
776 return 3;
777}
778
779static struct dentry *fat_get_parent(struct dentry *child)
780{
Linus Torvalds8f593422008-05-19 19:53:01 -0700781 struct super_block *sb = child->d_sb;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700782 struct buffer_head *bh;
783 struct msdos_dir_entry *de;
784 loff_t i_pos;
785 struct dentry *parent;
786 struct inode *inode;
787 int err;
788
Linus Torvalds8f593422008-05-19 19:53:01 -0700789 lock_super(sb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700790
791 err = fat_get_dotdot_entry(child->d_inode, &bh, &de, &i_pos);
792 if (err) {
793 parent = ERR_PTR(err);
794 goto out;
795 }
Linus Torvalds8f593422008-05-19 19:53:01 -0700796 inode = fat_build_inode(sb, de, i_pos);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700797 brelse(bh);
Christoph Hellwig44003722008-08-11 15:49:04 +0200798
799 parent = d_obtain_alias(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700800out:
Linus Torvalds8f593422008-05-19 19:53:01 -0700801 unlock_super(sb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700802
803 return parent;
804}
805
Christoph Hellwig39655162007-10-21 16:42:17 -0700806static const struct export_operations fat_export_ops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700807 .encode_fh = fat_encode_fh,
Christoph Hellwig1305edad2007-10-21 16:42:11 -0700808 .fh_to_dentry = fat_fh_to_dentry,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700809 .get_parent = fat_get_parent,
810};
811
812static int fat_show_options(struct seq_file *m, struct vfsmount *mnt)
813{
814 struct msdos_sb_info *sbi = MSDOS_SB(mnt->mnt_sb);
815 struct fat_mount_options *opts = &sbi->options;
816 int isvfat = opts->isvfat;
817
818 if (opts->fs_uid != 0)
819 seq_printf(m, ",uid=%u", opts->fs_uid);
820 if (opts->fs_gid != 0)
821 seq_printf(m, ",gid=%u", opts->fs_gid);
822 seq_printf(m, ",fmask=%04o", opts->fs_fmask);
823 seq_printf(m, ",dmask=%04o", opts->fs_dmask);
OGAWA Hirofumi1ae43f82008-04-28 02:16:26 -0700824 if (opts->allow_utime)
825 seq_printf(m, ",allow_utime=%04o", opts->allow_utime);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700826 if (sbi->nls_disk)
827 seq_printf(m, ",codepage=%s", sbi->nls_disk->charset);
828 if (isvfat) {
829 if (sbi->nls_io)
830 seq_printf(m, ",iocharset=%s", sbi->nls_io->charset);
831
832 switch (opts->shortname) {
833 case VFAT_SFN_DISPLAY_WIN95 | VFAT_SFN_CREATE_WIN95:
834 seq_puts(m, ",shortname=win95");
835 break;
836 case VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WINNT:
837 seq_puts(m, ",shortname=winnt");
838 break;
839 case VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WIN95:
840 seq_puts(m, ",shortname=mixed");
841 break;
842 case VFAT_SFN_DISPLAY_LOWER | VFAT_SFN_CREATE_WIN95:
Paul Wise95523472009-08-01 21:30:31 +0900843 seq_puts(m, ",shortname=lower");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700844 break;
845 default:
846 seq_puts(m, ",shortname=unknown");
847 break;
848 }
849 }
850 if (opts->name_check != 'n')
851 seq_printf(m, ",check=%c", opts->name_check);
OGAWA Hirofumi28ec0392007-05-08 00:31:01 -0700852 if (opts->usefree)
853 seq_puts(m, ",usefree");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700854 if (opts->quiet)
855 seq_puts(m, ",quiet");
856 if (opts->showexec)
857 seq_puts(m, ",showexec");
858 if (opts->sys_immutable)
859 seq_puts(m, ",sys_immutable");
860 if (!isvfat) {
861 if (opts->dotsOK)
862 seq_puts(m, ",dotsOK=yes");
863 if (opts->nocase)
864 seq_puts(m, ",nocase");
865 } else {
866 if (opts->utf8)
867 seq_puts(m, ",utf8");
868 if (opts->unicode_xlate)
869 seq_puts(m, ",uni_xlate");
870 if (!opts->numtail)
871 seq_puts(m, ",nonumtail");
OGAWA Hirofumidfc209c2008-11-06 12:53:55 -0800872 if (opts->rodir)
873 seq_puts(m, ",rodir");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700874 }
OGAWA Hirofumidfc209c2008-11-06 12:53:55 -0800875 if (opts->flush)
Miklos Szeredic1fca3b2008-02-08 04:21:42 -0800876 seq_puts(m, ",flush");
Joe Petersonb271e062008-07-25 01:46:47 -0700877 if (opts->tz_utc)
878 seq_puts(m, ",tz=UTC");
Denis Karpov85c78592009-06-04 02:34:22 +0900879 if (opts->errors == FAT_ERRORS_CONT)
880 seq_puts(m, ",errors=continue");
881 else if (opts->errors == FAT_ERRORS_PANIC)
882 seq_puts(m, ",errors=panic");
883 else
884 seq_puts(m, ",errors=remount-ro");
Christoph Hellwig681142f2009-11-21 20:28:52 +0900885 if (opts->discard)
886 seq_puts(m, ",discard");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700887
888 return 0;
889}
890
891enum {
892 Opt_check_n, Opt_check_r, Opt_check_s, Opt_uid, Opt_gid,
OGAWA Hirofumi1ae43f82008-04-28 02:16:26 -0700893 Opt_umask, Opt_dmask, Opt_fmask, Opt_allow_utime, Opt_codepage,
894 Opt_usefree, Opt_nocase, Opt_quiet, Opt_showexec, Opt_debug,
895 Opt_immutable, Opt_dots, Opt_nodots,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700896 Opt_charset, Opt_shortname_lower, Opt_shortname_win95,
897 Opt_shortname_winnt, Opt_shortname_mixed, Opt_utf8_no, Opt_utf8_yes,
898 Opt_uni_xl_no, Opt_uni_xl_yes, Opt_nonumtail_no, Opt_nonumtail_yes,
Denis Karpov85c78592009-06-04 02:34:22 +0900899 Opt_obsolate, Opt_flush, Opt_tz_utc, Opt_rodir, Opt_err_cont,
Christoph Hellwig681142f2009-11-21 20:28:52 +0900900 Opt_err_panic, Opt_err_ro, Opt_discard, Opt_err,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700901};
902
Steven Whitehousea447c092008-10-13 10:46:57 +0100903static const match_table_t fat_tokens = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700904 {Opt_check_r, "check=relaxed"},
905 {Opt_check_s, "check=strict"},
906 {Opt_check_n, "check=normal"},
907 {Opt_check_r, "check=r"},
908 {Opt_check_s, "check=s"},
909 {Opt_check_n, "check=n"},
910 {Opt_uid, "uid=%u"},
911 {Opt_gid, "gid=%u"},
912 {Opt_umask, "umask=%o"},
913 {Opt_dmask, "dmask=%o"},
914 {Opt_fmask, "fmask=%o"},
OGAWA Hirofumi1ae43f82008-04-28 02:16:26 -0700915 {Opt_allow_utime, "allow_utime=%o"},
Linus Torvalds1da177e2005-04-16 15:20:36 -0700916 {Opt_codepage, "codepage=%u"},
OGAWA Hirofumi28ec0392007-05-08 00:31:01 -0700917 {Opt_usefree, "usefree"},
Linus Torvalds1da177e2005-04-16 15:20:36 -0700918 {Opt_nocase, "nocase"},
919 {Opt_quiet, "quiet"},
920 {Opt_showexec, "showexec"},
921 {Opt_debug, "debug"},
922 {Opt_immutable, "sys_immutable"},
Denis Karpov85c78592009-06-04 02:34:22 +0900923 {Opt_flush, "flush"},
924 {Opt_tz_utc, "tz=UTC"},
925 {Opt_err_cont, "errors=continue"},
926 {Opt_err_panic, "errors=panic"},
927 {Opt_err_ro, "errors=remount-ro"},
Christoph Hellwig681142f2009-11-21 20:28:52 +0900928 {Opt_discard, "discard"},
Linus Torvalds1da177e2005-04-16 15:20:36 -0700929 {Opt_obsolate, "conv=binary"},
930 {Opt_obsolate, "conv=text"},
931 {Opt_obsolate, "conv=auto"},
932 {Opt_obsolate, "conv=b"},
933 {Opt_obsolate, "conv=t"},
934 {Opt_obsolate, "conv=a"},
935 {Opt_obsolate, "fat=%u"},
936 {Opt_obsolate, "blocksize=%u"},
937 {Opt_obsolate, "cvf_format=%20s"},
938 {Opt_obsolate, "cvf_options=%100s"},
939 {Opt_obsolate, "posix"},
Chris Masonae78bf92006-09-29 02:00:03 -0700940 {Opt_err, NULL},
Linus Torvalds1da177e2005-04-16 15:20:36 -0700941};
Steven Whitehousea447c092008-10-13 10:46:57 +0100942static const match_table_t msdos_tokens = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700943 {Opt_nodots, "nodots"},
944 {Opt_nodots, "dotsOK=no"},
945 {Opt_dots, "dots"},
946 {Opt_dots, "dotsOK=yes"},
947 {Opt_err, NULL}
948};
Steven Whitehousea447c092008-10-13 10:46:57 +0100949static const match_table_t vfat_tokens = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700950 {Opt_charset, "iocharset=%s"},
951 {Opt_shortname_lower, "shortname=lower"},
952 {Opt_shortname_win95, "shortname=win95"},
953 {Opt_shortname_winnt, "shortname=winnt"},
954 {Opt_shortname_mixed, "shortname=mixed"},
955 {Opt_utf8_no, "utf8=0"}, /* 0 or no or false */
956 {Opt_utf8_no, "utf8=no"},
957 {Opt_utf8_no, "utf8=false"},
958 {Opt_utf8_yes, "utf8=1"}, /* empty or 1 or yes or true */
959 {Opt_utf8_yes, "utf8=yes"},
960 {Opt_utf8_yes, "utf8=true"},
961 {Opt_utf8_yes, "utf8"},
962 {Opt_uni_xl_no, "uni_xlate=0"}, /* 0 or no or false */
963 {Opt_uni_xl_no, "uni_xlate=no"},
964 {Opt_uni_xl_no, "uni_xlate=false"},
965 {Opt_uni_xl_yes, "uni_xlate=1"}, /* empty or 1 or yes or true */
966 {Opt_uni_xl_yes, "uni_xlate=yes"},
967 {Opt_uni_xl_yes, "uni_xlate=true"},
968 {Opt_uni_xl_yes, "uni_xlate"},
969 {Opt_nonumtail_no, "nonumtail=0"}, /* 0 or no or false */
970 {Opt_nonumtail_no, "nonumtail=no"},
971 {Opt_nonumtail_no, "nonumtail=false"},
972 {Opt_nonumtail_yes, "nonumtail=1"}, /* empty or 1 or yes or true */
973 {Opt_nonumtail_yes, "nonumtail=yes"},
974 {Opt_nonumtail_yes, "nonumtail=true"},
975 {Opt_nonumtail_yes, "nonumtail"},
OGAWA Hirofumidfc209c2008-11-06 12:53:55 -0800976 {Opt_rodir, "rodir"},
Linus Torvalds1da177e2005-04-16 15:20:36 -0700977 {Opt_err, NULL}
978};
979
Alexey Fisher869f58c2011-04-12 21:08:38 +0900980static int parse_options(struct super_block *sb, char *options, int is_vfat,
981 int silent, int *debug, struct fat_mount_options *opts)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700982{
983 char *p;
984 substring_t args[MAX_OPT_ARGS];
985 int option;
986 char *iocharset;
987
988 opts->isvfat = is_vfat;
989
David Howellsf0ce7ee2008-11-14 10:38:52 +1100990 opts->fs_uid = current_uid();
991 opts->fs_gid = current_gid();
OGAWA Hirofumi3e107602009-06-20 21:50:07 +0900992 opts->fs_fmask = opts->fs_dmask = current_umask();
OGAWA Hirofumi1ae43f82008-04-28 02:16:26 -0700993 opts->allow_utime = -1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700994 opts->codepage = fat_default_codepage;
995 opts->iocharset = fat_default_iocharset;
OGAWA Hirofumidfc209c2008-11-06 12:53:55 -0800996 if (is_vfat) {
Paul Wise95523472009-08-01 21:30:31 +0900997 opts->shortname = VFAT_SFN_DISPLAY_WINNT|VFAT_SFN_CREATE_WIN95;
OGAWA Hirofumidfc209c2008-11-06 12:53:55 -0800998 opts->rodir = 0;
999 } else {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001000 opts->shortname = 0;
OGAWA Hirofumidfc209c2008-11-06 12:53:55 -08001001 opts->rodir = 1;
1002 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001003 opts->name_check = 'n';
1004 opts->quiet = opts->showexec = opts->sys_immutable = opts->dotsOK = 0;
1005 opts->utf8 = opts->unicode_xlate = 0;
1006 opts->numtail = 1;
OGAWA Hirofumi28ec0392007-05-08 00:31:01 -07001007 opts->usefree = opts->nocase = 0;
Joe Petersonb271e062008-07-25 01:46:47 -07001008 opts->tz_utc = 0;
Denis Karpov85c78592009-06-04 02:34:22 +09001009 opts->errors = FAT_ERRORS_RO;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001010 *debug = 0;
1011
1012 if (!options)
OGAWA Hirofumi8d44d972008-07-25 01:46:41 -07001013 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001014
1015 while ((p = strsep(&options, ",")) != NULL) {
1016 int token;
1017 if (!*p)
1018 continue;
1019
1020 token = match_token(p, fat_tokens, args);
1021 if (token == Opt_err) {
1022 if (is_vfat)
1023 token = match_token(p, vfat_tokens, args);
1024 else
1025 token = match_token(p, msdos_tokens, args);
1026 }
1027 switch (token) {
1028 case Opt_check_s:
1029 opts->name_check = 's';
1030 break;
1031 case Opt_check_r:
1032 opts->name_check = 'r';
1033 break;
1034 case Opt_check_n:
1035 opts->name_check = 'n';
1036 break;
OGAWA Hirofumi28ec0392007-05-08 00:31:01 -07001037 case Opt_usefree:
1038 opts->usefree = 1;
1039 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001040 case Opt_nocase:
1041 if (!is_vfat)
1042 opts->nocase = 1;
1043 else {
1044 /* for backward compatibility */
1045 opts->shortname = VFAT_SFN_DISPLAY_WIN95
1046 | VFAT_SFN_CREATE_WIN95;
1047 }
1048 break;
1049 case Opt_quiet:
1050 opts->quiet = 1;
1051 break;
1052 case Opt_showexec:
1053 opts->showexec = 1;
1054 break;
1055 case Opt_debug:
1056 *debug = 1;
1057 break;
1058 case Opt_immutable:
1059 opts->sys_immutable = 1;
1060 break;
1061 case Opt_uid:
1062 if (match_int(&args[0], &option))
1063 return 0;
1064 opts->fs_uid = option;
1065 break;
1066 case Opt_gid:
1067 if (match_int(&args[0], &option))
1068 return 0;
1069 opts->fs_gid = option;
1070 break;
1071 case Opt_umask:
1072 if (match_octal(&args[0], &option))
1073 return 0;
1074 opts->fs_fmask = opts->fs_dmask = option;
1075 break;
1076 case Opt_dmask:
1077 if (match_octal(&args[0], &option))
1078 return 0;
1079 opts->fs_dmask = option;
1080 break;
1081 case Opt_fmask:
1082 if (match_octal(&args[0], &option))
1083 return 0;
1084 opts->fs_fmask = option;
1085 break;
OGAWA Hirofumi1ae43f82008-04-28 02:16:26 -07001086 case Opt_allow_utime:
1087 if (match_octal(&args[0], &option))
1088 return 0;
1089 opts->allow_utime = option & (S_IWGRP | S_IWOTH);
1090 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001091 case Opt_codepage:
1092 if (match_int(&args[0], &option))
1093 return 0;
1094 opts->codepage = option;
1095 break;
Chris Masonae78bf92006-09-29 02:00:03 -07001096 case Opt_flush:
1097 opts->flush = 1;
1098 break;
Joe Petersonb271e062008-07-25 01:46:47 -07001099 case Opt_tz_utc:
1100 opts->tz_utc = 1;
1101 break;
Denis Karpov85c78592009-06-04 02:34:22 +09001102 case Opt_err_cont:
1103 opts->errors = FAT_ERRORS_CONT;
1104 break;
1105 case Opt_err_panic:
1106 opts->errors = FAT_ERRORS_PANIC;
1107 break;
1108 case Opt_err_ro:
1109 opts->errors = FAT_ERRORS_RO;
1110 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001111
1112 /* msdos specific */
1113 case Opt_dots:
1114 opts->dotsOK = 1;
1115 break;
1116 case Opt_nodots:
1117 opts->dotsOK = 0;
1118 break;
1119
1120 /* vfat specific */
1121 case Opt_charset:
1122 if (opts->iocharset != fat_default_iocharset)
1123 kfree(opts->iocharset);
1124 iocharset = match_strdup(&args[0]);
1125 if (!iocharset)
1126 return -ENOMEM;
1127 opts->iocharset = iocharset;
1128 break;
1129 case Opt_shortname_lower:
1130 opts->shortname = VFAT_SFN_DISPLAY_LOWER
1131 | VFAT_SFN_CREATE_WIN95;
1132 break;
1133 case Opt_shortname_win95:
1134 opts->shortname = VFAT_SFN_DISPLAY_WIN95
1135 | VFAT_SFN_CREATE_WIN95;
1136 break;
1137 case Opt_shortname_winnt:
1138 opts->shortname = VFAT_SFN_DISPLAY_WINNT
1139 | VFAT_SFN_CREATE_WINNT;
1140 break;
1141 case Opt_shortname_mixed:
1142 opts->shortname = VFAT_SFN_DISPLAY_WINNT
1143 | VFAT_SFN_CREATE_WIN95;
1144 break;
1145 case Opt_utf8_no: /* 0 or no or false */
1146 opts->utf8 = 0;
1147 break;
1148 case Opt_utf8_yes: /* empty or 1 or yes or true */
1149 opts->utf8 = 1;
1150 break;
1151 case Opt_uni_xl_no: /* 0 or no or false */
1152 opts->unicode_xlate = 0;
1153 break;
1154 case Opt_uni_xl_yes: /* empty or 1 or yes or true */
1155 opts->unicode_xlate = 1;
1156 break;
1157 case Opt_nonumtail_no: /* 0 or no or false */
1158 opts->numtail = 1; /* negated option */
1159 break;
1160 case Opt_nonumtail_yes: /* empty or 1 or yes or true */
1161 opts->numtail = 0; /* negated option */
1162 break;
OGAWA Hirofumidfc209c2008-11-06 12:53:55 -08001163 case Opt_rodir:
1164 opts->rodir = 1;
1165 break;
Christoph Hellwig681142f2009-11-21 20:28:52 +09001166 case Opt_discard:
1167 opts->discard = 1;
1168 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001169
1170 /* obsolete mount options */
1171 case Opt_obsolate:
Alexey Fisher869f58c2011-04-12 21:08:38 +09001172 fat_msg(sb, KERN_INFO, "\"%s\" option is obsolete, "
1173 "not supported now", p);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001174 break;
1175 /* unknown option */
1176 default:
Christoph Hellwig41a34a42005-11-08 21:34:57 -08001177 if (!silent) {
Alexey Fisher869f58c2011-04-12 21:08:38 +09001178 fat_msg(sb, KERN_ERR,
1179 "Unrecognized mount option \"%s\" "
1180 "or missing value", p);
Christoph Hellwig41a34a42005-11-08 21:34:57 -08001181 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001182 return -EINVAL;
1183 }
1184 }
OGAWA Hirofumi8d44d972008-07-25 01:46:41 -07001185
1186out:
Alexey Dobriyan4de151d2006-03-22 00:13:35 +01001187 /* UTF-8 doesn't provide FAT semantics */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001188 if (!strcmp(opts->iocharset, "utf8")) {
Alexey Fisher869f58c2011-04-12 21:08:38 +09001189 fat_msg(sb, KERN_ERR, "utf8 is not a recommended IO charset"
OGAWA Hirofumi8d44d972008-07-25 01:46:41 -07001190 " for FAT filesystems, filesystem will be "
1191 "case sensitive!\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -07001192 }
1193
OGAWA Hirofumi1ae43f82008-04-28 02:16:26 -07001194 /* If user doesn't specify allow_utime, it's initialized from dmask. */
1195 if (opts->allow_utime == (unsigned short)-1)
1196 opts->allow_utime = ~opts->fs_dmask & (S_IWGRP | S_IWOTH);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001197 if (opts->unicode_xlate)
1198 opts->utf8 = 0;
1199
1200 return 0;
1201}
1202
1203static int fat_read_root(struct inode *inode)
1204{
1205 struct super_block *sb = inode->i_sb;
1206 struct msdos_sb_info *sbi = MSDOS_SB(sb);
1207 int error;
1208
1209 MSDOS_I(inode)->i_pos = 0;
1210 inode->i_uid = sbi->options.fs_uid;
1211 inode->i_gid = sbi->options.fs_gid;
1212 inode->i_version++;
1213 inode->i_generation = 0;
OGAWA Hirofumi9c0aa1b2008-11-06 12:53:54 -08001214 inode->i_mode = fat_make_mode(sbi, ATTR_DIR, S_IRWXUGO);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001215 inode->i_op = sbi->dir_ops;
1216 inode->i_fop = &fat_dir_operations;
1217 if (sbi->fat_bits == 32) {
1218 MSDOS_I(inode)->i_start = sbi->root_cluster;
1219 error = fat_calc_dir_size(inode);
1220 if (error < 0)
1221 return error;
1222 } else {
1223 MSDOS_I(inode)->i_start = 0;
1224 inode->i_size = sbi->dir_entries * sizeof(struct msdos_dir_entry);
1225 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001226 inode->i_blocks = ((inode->i_size + (sbi->cluster_size - 1))
1227 & ~((loff_t)sbi->cluster_size - 1)) >> 9;
1228 MSDOS_I(inode)->i_logstart = 0;
1229 MSDOS_I(inode)->mmu_private = inode->i_size;
1230
OGAWA Hirofumi9c0aa1b2008-11-06 12:53:54 -08001231 fat_save_attrs(inode, ATTR_DIR);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001232 inode->i_mtime.tv_sec = inode->i_atime.tv_sec = inode->i_ctime.tv_sec = 0;
1233 inode->i_mtime.tv_nsec = inode->i_atime.tv_nsec = inode->i_ctime.tv_nsec = 0;
1234 inode->i_nlink = fat_subdirs(inode)+2;
1235
1236 return 0;
1237}
1238
1239/*
1240 * Read the super block of an MS-DOS FS.
1241 */
OGAWA Hirofumi384f5c92011-04-12 21:08:37 +09001242int fat_fill_super(struct super_block *sb, void *data, int silent, int isvfat,
Al Viro3d239852010-12-18 10:44:00 -05001243 void (*setup)(struct super_block *))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001244{
Al Virob5224122009-06-07 13:44:36 -04001245 struct inode *root_inode = NULL, *fat_inode = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001246 struct buffer_head *bh;
1247 struct fat_boot_sector *b;
1248 struct msdos_sb_info *sbi;
1249 u16 logical_sector_size;
1250 u32 total_sectors, total_clusters, fat_clusters, rootdir_sectors;
1251 int debug;
1252 unsigned int media;
1253 long error;
1254 char buf[50];
1255
Linus Torvalds8f593422008-05-19 19:53:01 -07001256 /*
1257 * GFP_KERNEL is ok here, because while we do hold the
1258 * supeblock lock, memory pressure can't call back into
1259 * the filesystem, since we're only just about to mount
1260 * it and have no inodes etc active!
1261 */
Panagiotis Issarisf8314dc2006-09-27 01:49:37 -07001262 sbi = kzalloc(sizeof(struct msdos_sb_info), GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001263 if (!sbi)
1264 return -ENOMEM;
1265 sb->s_fs_info = sbi;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001266
1267 sb->s_flags |= MS_NODIRATIME;
1268 sb->s_magic = MSDOS_SUPER_MAGIC;
1269 sb->s_op = &fat_sops;
1270 sb->s_export_op = &fat_export_ops;
OGAWA Hirofumiaaa04b42010-05-24 14:33:12 -07001271 ratelimit_state_init(&sbi->ratelimit, DEFAULT_RATELIMIT_INTERVAL,
1272 DEFAULT_RATELIMIT_BURST);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001273
Alexey Fisher869f58c2011-04-12 21:08:38 +09001274 error = parse_options(sb, data, isvfat, silent, &debug, &sbi->options);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001275 if (error)
1276 goto out_fail;
1277
Al Viro3d239852010-12-18 10:44:00 -05001278 setup(sb); /* flavour-specific stuff that needs options */
1279
Linus Torvalds1da177e2005-04-16 15:20:36 -07001280 error = -EIO;
1281 sb_min_blocksize(sb, 512);
1282 bh = sb_bread(sb, 0);
1283 if (bh == NULL) {
Alexey Fisher869f58c2011-04-12 21:08:38 +09001284 fat_msg(sb, KERN_ERR, "unable to read boot sector");
Linus Torvalds1da177e2005-04-16 15:20:36 -07001285 goto out_fail;
1286 }
1287
1288 b = (struct fat_boot_sector *) bh->b_data;
1289 if (!b->reserved) {
1290 if (!silent)
Alexey Fisher869f58c2011-04-12 21:08:38 +09001291 fat_msg(sb, KERN_ERR, "bogus number of reserved sectors");
Linus Torvalds1da177e2005-04-16 15:20:36 -07001292 brelse(bh);
1293 goto out_invalid;
1294 }
1295 if (!b->fats) {
1296 if (!silent)
Alexey Fisher869f58c2011-04-12 21:08:38 +09001297 fat_msg(sb, KERN_ERR, "bogus number of FAT structure");
Linus Torvalds1da177e2005-04-16 15:20:36 -07001298 brelse(bh);
1299 goto out_invalid;
1300 }
1301
1302 /*
1303 * Earlier we checked here that b->secs_track and b->head are nonzero,
1304 * but it turns out valid FAT filesystems can have zero there.
1305 */
1306
1307 media = b->media;
Andrew Morton73f20e52008-04-28 02:16:30 -07001308 if (!fat_valid_media(media)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001309 if (!silent)
Alexey Fisher869f58c2011-04-12 21:08:38 +09001310 fat_msg(sb, KERN_ERR, "invalid media value (0x%02x)",
Linus Torvalds1da177e2005-04-16 15:20:36 -07001311 media);
1312 brelse(bh);
1313 goto out_invalid;
1314 }
Harvey Harrison803f4452008-04-29 01:03:43 -07001315 logical_sector_size = get_unaligned_le16(&b->sector_size);
Vignesh Babu BMe7d709c2007-05-08 00:24:27 -07001316 if (!is_power_of_2(logical_sector_size)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001317 || (logical_sector_size < 512)
Olof Johansson9f354852008-04-28 02:16:32 -07001318 || (logical_sector_size > 4096)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001319 if (!silent)
Alexey Fisher869f58c2011-04-12 21:08:38 +09001320 fat_msg(sb, KERN_ERR, "bogus logical sector size %u",
Linus Torvalds1da177e2005-04-16 15:20:36 -07001321 logical_sector_size);
1322 brelse(bh);
1323 goto out_invalid;
1324 }
1325 sbi->sec_per_clus = b->sec_per_clus;
Vignesh Babu BMe7d709c2007-05-08 00:24:27 -07001326 if (!is_power_of_2(sbi->sec_per_clus)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001327 if (!silent)
Alexey Fisher869f58c2011-04-12 21:08:38 +09001328 fat_msg(sb, KERN_ERR, "bogus sectors per cluster %u",
Linus Torvalds1da177e2005-04-16 15:20:36 -07001329 sbi->sec_per_clus);
1330 brelse(bh);
1331 goto out_invalid;
1332 }
1333
1334 if (logical_sector_size < sb->s_blocksize) {
Alexey Fisher869f58c2011-04-12 21:08:38 +09001335 fat_msg(sb, KERN_ERR, "logical sector size too small for device"
1336 " (logical sector size = %u)", logical_sector_size);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001337 brelse(bh);
1338 goto out_fail;
1339 }
1340 if (logical_sector_size > sb->s_blocksize) {
1341 brelse(bh);
1342
1343 if (!sb_set_blocksize(sb, logical_sector_size)) {
Alexey Fisher869f58c2011-04-12 21:08:38 +09001344 fat_msg(sb, KERN_ERR, "unable to set blocksize %u",
Linus Torvalds1da177e2005-04-16 15:20:36 -07001345 logical_sector_size);
1346 goto out_fail;
1347 }
1348 bh = sb_bread(sb, 0);
1349 if (bh == NULL) {
Alexey Fisher869f58c2011-04-12 21:08:38 +09001350 fat_msg(sb, KERN_ERR, "unable to read boot sector"
1351 " (logical sector size = %lu)",
Linus Torvalds1da177e2005-04-16 15:20:36 -07001352 sb->s_blocksize);
1353 goto out_fail;
1354 }
1355 b = (struct fat_boot_sector *) bh->b_data;
1356 }
1357
1358 sbi->cluster_size = sb->s_blocksize * sbi->sec_per_clus;
1359 sbi->cluster_bits = ffs(sbi->cluster_size) - 1;
1360 sbi->fats = b->fats;
1361 sbi->fat_bits = 0; /* Don't know yet */
1362 sbi->fat_start = le16_to_cpu(b->reserved);
1363 sbi->fat_length = le16_to_cpu(b->fat_length);
1364 sbi->root_cluster = 0;
1365 sbi->free_clusters = -1; /* Don't know yet */
OGAWA Hirofumi606e4232008-04-28 02:16:27 -07001366 sbi->free_clus_valid = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001367 sbi->prev_free = FAT_START_ENT;
1368
1369 if (!sbi->fat_length && b->fat32_length) {
1370 struct fat_boot_fsinfo *fsinfo;
1371 struct buffer_head *fsinfo_bh;
1372
1373 /* Must be FAT32 */
1374 sbi->fat_bits = 32;
1375 sbi->fat_length = le32_to_cpu(b->fat32_length);
1376 sbi->root_cluster = le32_to_cpu(b->root_cluster);
1377
1378 sb->s_maxbytes = 0xffffffff;
1379
1380 /* MC - if info_sector is 0, don't multiply by 0 */
1381 sbi->fsinfo_sector = le16_to_cpu(b->info_sector);
1382 if (sbi->fsinfo_sector == 0)
1383 sbi->fsinfo_sector = 1;
1384
1385 fsinfo_bh = sb_bread(sb, sbi->fsinfo_sector);
1386 if (fsinfo_bh == NULL) {
Alexey Fisher869f58c2011-04-12 21:08:38 +09001387 fat_msg(sb, KERN_ERR, "bread failed, FSINFO block"
1388 " (sector = %lu)", sbi->fsinfo_sector);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001389 brelse(bh);
1390 goto out_fail;
1391 }
1392
1393 fsinfo = (struct fat_boot_fsinfo *)fsinfo_bh->b_data;
1394 if (!IS_FSINFO(fsinfo)) {
Alexey Fisher869f58c2011-04-12 21:08:38 +09001395 fat_msg(sb, KERN_WARNING, "Invalid FSINFO signature: "
1396 "0x%08x, 0x%08x (sector = %lu)",
Linus Torvalds1da177e2005-04-16 15:20:36 -07001397 le32_to_cpu(fsinfo->signature1),
1398 le32_to_cpu(fsinfo->signature2),
1399 sbi->fsinfo_sector);
1400 } else {
OGAWA Hirofumi28ec0392007-05-08 00:31:01 -07001401 if (sbi->options.usefree)
OGAWA Hirofumi606e4232008-04-28 02:16:27 -07001402 sbi->free_clus_valid = 1;
1403 sbi->free_clusters = le32_to_cpu(fsinfo->free_clusters);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001404 sbi->prev_free = le32_to_cpu(fsinfo->next_cluster);
1405 }
1406
1407 brelse(fsinfo_bh);
1408 }
1409
1410 sbi->dir_per_block = sb->s_blocksize / sizeof(struct msdos_dir_entry);
1411 sbi->dir_per_block_bits = ffs(sbi->dir_per_block) - 1;
1412
1413 sbi->dir_start = sbi->fat_start + sbi->fats * sbi->fat_length;
Harvey Harrison803f4452008-04-29 01:03:43 -07001414 sbi->dir_entries = get_unaligned_le16(&b->dir_entries);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001415 if (sbi->dir_entries & (sbi->dir_per_block - 1)) {
1416 if (!silent)
Alexey Fisher869f58c2011-04-12 21:08:38 +09001417 fat_msg(sb, KERN_ERR, "bogus directroy-entries per block"
1418 " (%u)", sbi->dir_entries);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001419 brelse(bh);
1420 goto out_invalid;
1421 }
1422
1423 rootdir_sectors = sbi->dir_entries
1424 * sizeof(struct msdos_dir_entry) / sb->s_blocksize;
1425 sbi->data_start = sbi->dir_start + rootdir_sectors;
Harvey Harrison803f4452008-04-29 01:03:43 -07001426 total_sectors = get_unaligned_le16(&b->sectors);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001427 if (total_sectors == 0)
1428 total_sectors = le32_to_cpu(b->total_sect);
1429
1430 total_clusters = (total_sectors - sbi->data_start) / sbi->sec_per_clus;
1431
1432 if (sbi->fat_bits != 32)
1433 sbi->fat_bits = (total_clusters > MAX_FAT12) ? 16 : 12;
1434
1435 /* check that FAT table does not overflow */
1436 fat_clusters = sbi->fat_length * sb->s_blocksize * 8 / sbi->fat_bits;
1437 total_clusters = min(total_clusters, fat_clusters - FAT_START_ENT);
1438 if (total_clusters > MAX_FAT(sb)) {
1439 if (!silent)
Alexey Fisher869f58c2011-04-12 21:08:38 +09001440 fat_msg(sb, KERN_ERR, "count of clusters too big (%u)",
Linus Torvalds1da177e2005-04-16 15:20:36 -07001441 total_clusters);
1442 brelse(bh);
1443 goto out_invalid;
1444 }
1445
1446 sbi->max_cluster = total_clusters + FAT_START_ENT;
1447 /* check the free_clusters, it's not necessarily correct */
1448 if (sbi->free_clusters != -1 && sbi->free_clusters > total_clusters)
1449 sbi->free_clusters = -1;
1450 /* check the prev_free, it's not necessarily correct */
1451 sbi->prev_free %= sbi->max_cluster;
1452 if (sbi->prev_free < FAT_START_ENT)
1453 sbi->prev_free = FAT_START_ENT;
1454
1455 brelse(bh);
1456
1457 /* set up enough so that it can read an inode */
1458 fat_hash_init(sb);
1459 fat_ent_access_init(sb);
1460
1461 /*
1462 * The low byte of FAT's first entry must have same value with
1463 * media-field. But in real world, too many devices is
1464 * writing wrong value. So, removed that validity check.
1465 *
1466 * if (FAT_FIRST_ENT(sb, media) != first)
1467 */
1468
1469 error = -EINVAL;
1470 sprintf(buf, "cp%d", sbi->options.codepage);
1471 sbi->nls_disk = load_nls(buf);
1472 if (!sbi->nls_disk) {
Alexey Fisher869f58c2011-04-12 21:08:38 +09001473 fat_msg(sb, KERN_ERR, "codepage %s not found", buf);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001474 goto out_fail;
1475 }
1476
1477 /* FIXME: utf8 is using iocharset for upper/lower conversion */
1478 if (sbi->options.isvfat) {
1479 sbi->nls_io = load_nls(sbi->options.iocharset);
1480 if (!sbi->nls_io) {
Alexey Fisher869f58c2011-04-12 21:08:38 +09001481 fat_msg(sb, KERN_ERR, "IO charset %s not found",
Linus Torvalds1da177e2005-04-16 15:20:36 -07001482 sbi->options.iocharset);
1483 goto out_fail;
1484 }
1485 }
1486
1487 error = -ENOMEM;
Al Virob5224122009-06-07 13:44:36 -04001488 fat_inode = new_inode(sb);
1489 if (!fat_inode)
1490 goto out_fail;
1491 MSDOS_I(fat_inode)->i_pos = 0;
1492 sbi->fat_inode = fat_inode;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001493 root_inode = new_inode(sb);
1494 if (!root_inode)
1495 goto out_fail;
1496 root_inode->i_ino = MSDOS_ROOT_INO;
1497 root_inode->i_version = 1;
1498 error = fat_read_root(root_inode);
1499 if (error < 0)
1500 goto out_fail;
1501 error = -ENOMEM;
1502 insert_inode_hash(root_inode);
1503 sb->s_root = d_alloc_root(root_inode);
1504 if (!sb->s_root) {
Alexey Fisher869f58c2011-04-12 21:08:38 +09001505 fat_msg(sb, KERN_ERR, "get root inode failed");
Linus Torvalds1da177e2005-04-16 15:20:36 -07001506 goto out_fail;
1507 }
1508
1509 return 0;
1510
1511out_invalid:
1512 error = -EINVAL;
1513 if (!silent)
Alexey Fisher869f58c2011-04-12 21:08:38 +09001514 fat_msg(sb, KERN_INFO, "Can't find a valid FAT filesystem");
Linus Torvalds1da177e2005-04-16 15:20:36 -07001515
1516out_fail:
Al Virob5224122009-06-07 13:44:36 -04001517 if (fat_inode)
1518 iput(fat_inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001519 if (root_inode)
1520 iput(root_inode);
OGAWA Hirofumi1bdb6f92010-03-16 05:48:09 +09001521 unload_nls(sbi->nls_io);
1522 unload_nls(sbi->nls_disk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001523 if (sbi->options.iocharset != fat_default_iocharset)
1524 kfree(sbi->options.iocharset);
1525 sb->s_fs_info = NULL;
1526 kfree(sbi);
1527 return error;
1528}
1529
OGAWA Hirofumi7c709d02006-01-08 01:02:10 -08001530EXPORT_SYMBOL_GPL(fat_fill_super);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001531
Chris Masonae78bf92006-09-29 02:00:03 -07001532/*
1533 * helper function for fat_flush_inodes. This writes both the inode
1534 * and the file data blocks, waiting for in flight data blocks before
1535 * the start of the call. It does not wait for any io started
1536 * during the call
1537 */
1538static int writeback_inode(struct inode *inode)
1539{
1540
1541 int ret;
1542 struct address_space *mapping = inode->i_mapping;
1543 struct writeback_control wbc = {
1544 .sync_mode = WB_SYNC_NONE,
1545 .nr_to_write = 0,
1546 };
1547 /* if we used WB_SYNC_ALL, sync_inode waits for the io for the
1548 * inode to finish. So WB_SYNC_NONE is sent down to sync_inode
1549 * and filemap_fdatawrite is used for the data blocks
1550 */
1551 ret = sync_inode(inode, &wbc);
1552 if (!ret)
1553 ret = filemap_fdatawrite(mapping);
1554 return ret;
1555}
1556
1557/*
1558 * write data and metadata corresponding to i1 and i2. The io is
1559 * started but we do not wait for any of it to finish.
1560 *
1561 * filemap_flush is used for the block device, so if there is a dirty
1562 * page for a block already in flight, we will not wait and start the
1563 * io over again
1564 */
1565int fat_flush_inodes(struct super_block *sb, struct inode *i1, struct inode *i2)
1566{
1567 int ret = 0;
1568 if (!MSDOS_SB(sb)->options.flush)
1569 return 0;
1570 if (i1)
1571 ret = writeback_inode(i1);
1572 if (!ret && i2)
1573 ret = writeback_inode(i2);
Eric Sesterhenn97e860d2006-10-11 01:21:59 -07001574 if (!ret) {
Chris Masonae78bf92006-09-29 02:00:03 -07001575 struct address_space *mapping = sb->s_bdev->bd_inode->i_mapping;
1576 ret = filemap_flush(mapping);
1577 }
1578 return ret;
1579}
1580EXPORT_SYMBOL_GPL(fat_flush_inodes);
1581
Linus Torvalds1da177e2005-04-16 15:20:36 -07001582static int __init init_fat_fs(void)
1583{
Pekka J Enberg532a39a2005-06-30 02:59:01 -07001584 int err;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001585
Pekka J Enberg532a39a2005-06-30 02:59:01 -07001586 err = fat_cache_init();
1587 if (err)
1588 return err;
1589
1590 err = fat_init_inodecache();
1591 if (err)
1592 goto failed;
1593
1594 return 0;
1595
1596failed:
1597 fat_cache_destroy();
1598 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001599}
1600
1601static void __exit exit_fat_fs(void)
1602{
1603 fat_cache_destroy();
1604 fat_destroy_inodecache();
1605}
1606
1607module_init(init_fat_fs)
1608module_exit(exit_fat_fs)
1609
1610MODULE_LICENSE("GPL");