blob: a5599052116c48fcf8f5a0b0a64e9c638276a362 [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>
Linus Torvalds1da177e2005-04-16 15:20:36 -070014#include <linux/pagemap.h>
OGAWA Hirofumia5425d22006-01-08 01:02:10 -080015#include <linux/mpage.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070016#include <linux/vfs.h>
Alexander Kuleshov58932ef2015-04-16 12:47:24 -070017#include <linux/seq_file.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070018#include <linux/parser.h>
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -080019#include <linux/uio.h>
Namjae Jeonf5621462012-12-17 16:02:56 -080020#include <linux/blkdev.h>
Tejun Heo66114ca2015-05-22 17:13:32 -040021#include <linux/backing-dev.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070022#include <asm/unaligned.h>
OGAWA Hirofumi9e975da2008-11-06 12:53:46 -080023#include "fat.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -070024
25#ifndef CONFIG_FAT_DEFAULT_IOCHARSET
26/* if user don't select VFAT, this is undefined. */
27#define CONFIG_FAT_DEFAULT_IOCHARSET ""
28#endif
29
Conrad Meyer190a8842014-06-06 14:36:37 -070030#define KB_IN_SECTORS 2
31
32/*
33 * A deserialized copy of the on-disk structure laid out in struct
34 * fat_boot_sector.
35 */
36struct fat_bios_param_block {
37 u16 fat_sector_size;
38 u8 fat_sec_per_clus;
39 u16 fat_reserved;
40 u8 fat_fats;
41 u16 fat_dir_entries;
42 u16 fat_sectors;
43 u16 fat_fat_length;
44 u32 fat_total_sect;
45
46 u8 fat16_state;
47 u32 fat16_vol_id;
48
49 u32 fat32_length;
50 u32 fat32_root_cluster;
51 u16 fat32_info_sector;
52 u8 fat32_state;
53 u32 fat32_vol_id;
54};
55
Linus Torvalds1da177e2005-04-16 15:20:36 -070056static int fat_default_codepage = CONFIG_FAT_DEFAULT_CODEPAGE;
57static char fat_default_iocharset[] = CONFIG_FAT_DEFAULT_IOCHARSET;
58
Conrad Meyer190a8842014-06-06 14:36:37 -070059static struct fat_floppy_defaults {
60 unsigned nr_sectors;
61 unsigned sec_per_clus;
62 unsigned dir_entries;
63 unsigned media;
64 unsigned fat_length;
65} floppy_defaults[] = {
66{
67 .nr_sectors = 160 * KB_IN_SECTORS,
68 .sec_per_clus = 1,
69 .dir_entries = 64,
70 .media = 0xFE,
71 .fat_length = 1,
72},
73{
74 .nr_sectors = 180 * KB_IN_SECTORS,
75 .sec_per_clus = 1,
76 .dir_entries = 64,
77 .media = 0xFC,
78 .fat_length = 2,
79},
80{
81 .nr_sectors = 320 * KB_IN_SECTORS,
82 .sec_per_clus = 2,
83 .dir_entries = 112,
84 .media = 0xFF,
85 .fat_length = 1,
86},
87{
88 .nr_sectors = 360 * KB_IN_SECTORS,
89 .sec_per_clus = 2,
90 .dir_entries = 112,
91 .media = 0xFD,
92 .fat_length = 2,
93},
94};
Linus Torvalds1da177e2005-04-16 15:20:36 -070095
Namjae Jeonb13bb332016-01-20 14:59:41 -080096int fat_add_cluster(struct inode *inode)
Linus Torvalds1da177e2005-04-16 15:20:36 -070097{
98 int err, cluster;
99
100 err = fat_alloc_clusters(inode, &cluster, 1);
101 if (err)
102 return err;
103 /* FIXME: this cluster should be added after data of this
104 * cluster is writed */
105 err = fat_chain_add(inode, cluster, 1);
106 if (err)
107 fat_free_clusters(inode, cluster);
108 return err;
109}
110
OGAWA Hirofumi6a1d9802006-09-27 01:50:45 -0700111static inline int __fat_get_block(struct inode *inode, sector_t iblock,
112 unsigned long *max_blocks,
113 struct buffer_head *bh_result, int create)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700114{
115 struct super_block *sb = inode->i_sb;
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -0800116 struct msdos_sb_info *sbi = MSDOS_SB(sb);
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -0800117 unsigned long mapped_blocks;
Namjae Jeon7e0f2362016-01-20 14:59:43 -0800118 sector_t phys, last_block;
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -0800119 int err, offset;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700120
Namjae Jeon16fab202016-01-20 14:59:46 -0800121 err = fat_bmap(inode, iblock, &phys, &mapped_blocks, create, false);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700122 if (err)
123 return err;
124 if (phys) {
125 map_bh(bh_result, sb, phys);
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -0800126 *max_blocks = min(mapped_blocks, *max_blocks);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700127 return 0;
128 }
129 if (!create)
130 return 0;
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -0800131
Linus Torvalds1da177e2005-04-16 15:20:36 -0700132 if (iblock != MSDOS_I(inode)->mmu_private >> sb->s_blocksize_bits) {
Denis Karpov85c78592009-06-04 02:34:22 +0900133 fat_fs_error(sb, "corrupted file size (i_pos %lld, %lld)",
OGAWA Hirofumi6a1d9802006-09-27 01:50:45 -0700134 MSDOS_I(inode)->i_pos, MSDOS_I(inode)->mmu_private);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700135 return -EIO;
136 }
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -0800137
Namjae Jeon7e0f2362016-01-20 14:59:43 -0800138 last_block = inode->i_blocks >> (sb->s_blocksize_bits - 9);
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -0800139 offset = (unsigned long)iblock & (sbi->sec_per_clus - 1);
Namjae Jeon7e0f2362016-01-20 14:59:43 -0800140 /*
141 * allocate a cluster according to the following.
142 * 1) no more available blocks
143 * 2) not part of fallocate region
144 */
145 if (!offset && !(iblock < last_block)) {
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -0800146 /* TODO: multiple cluster allocation would be desirable. */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700147 err = fat_add_cluster(inode);
148 if (err)
149 return err;
150 }
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -0800151 /* available blocks on this cluster */
152 mapped_blocks = sbi->sec_per_clus - offset;
153
154 *max_blocks = min(mapped_blocks, *max_blocks);
155 MSDOS_I(inode)->mmu_private += *max_blocks << sb->s_blocksize_bits;
156
Namjae Jeon16fab202016-01-20 14:59:46 -0800157 err = fat_bmap(inode, iblock, &phys, &mapped_blocks, create, false);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700158 if (err)
159 return err;
OGAWA Hirofumi6a1d9802006-09-27 01:50:45 -0700160
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -0800161 BUG_ON(!phys);
162 BUG_ON(*max_blocks != mapped_blocks);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700163 set_buffer_new(bh_result);
164 map_bh(bh_result, sb, phys);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700165
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -0800166 return 0;
167}
168
169static int fat_get_block(struct inode *inode, sector_t iblock,
170 struct buffer_head *bh_result, int create)
171{
OGAWA Hirofumi6a1d9802006-09-27 01:50:45 -0700172 struct super_block *sb = inode->i_sb;
173 unsigned long max_blocks = bh_result->b_size >> inode->i_blkbits;
174 int err;
175
176 err = __fat_get_block(inode, iblock, &max_blocks, bh_result, create);
177 if (err)
178 return err;
179 bh_result->b_size = max_blocks << sb->s_blocksize_bits;
180 return 0;
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -0800181}
182
Linus Torvalds1da177e2005-04-16 15:20:36 -0700183static int fat_writepage(struct page *page, struct writeback_control *wbc)
184{
185 return block_write_full_page(page, fat_get_block, wbc);
186}
187
OGAWA Hirofumia5425d22006-01-08 01:02:10 -0800188static int fat_writepages(struct address_space *mapping,
189 struct writeback_control *wbc)
190{
191 return mpage_writepages(mapping, wbc, fat_get_block);
192}
193
Linus Torvalds1da177e2005-04-16 15:20:36 -0700194static int fat_readpage(struct file *file, struct page *page)
195{
OGAWA Hirofumia5425d22006-01-08 01:02:10 -0800196 return mpage_readpage(page, fat_get_block);
197}
198
199static int fat_readpages(struct file *file, struct address_space *mapping,
200 struct list_head *pages, unsigned nr_pages)
201{
202 return mpage_readpages(mapping, pages, nr_pages, fat_get_block);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700203}
204
npiggin@suse.de459f6ed2010-05-27 01:05:38 +1000205static void fat_write_failed(struct address_space *mapping, loff_t to)
206{
207 struct inode *inode = mapping->host;
208
209 if (to > inode->i_size) {
Kirill A. Shutemov7caef262013-09-12 15:13:56 -0700210 truncate_pagecache(inode, inode->i_size);
npiggin@suse.de459f6ed2010-05-27 01:05:38 +1000211 fat_truncate_blocks(inode, inode->i_size);
212 }
213}
214
Nick Piggind7777a22007-10-16 01:25:08 -0700215static int fat_write_begin(struct file *file, struct address_space *mapping,
216 loff_t pos, unsigned len, unsigned flags,
217 struct page **pagep, void **fsdata)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700218{
npiggin@suse.de459f6ed2010-05-27 01:05:38 +1000219 int err;
220
Nick Piggind7777a22007-10-16 01:25:08 -0700221 *pagep = NULL;
Christoph Hellwig282dc172010-06-04 11:29:55 +0200222 err = cont_write_begin(file, mapping, pos, len, flags,
npiggin@suse.de459f6ed2010-05-27 01:05:38 +1000223 pagep, fsdata, fat_get_block,
Nick Piggind7777a22007-10-16 01:25:08 -0700224 &MSDOS_I(mapping->host)->mmu_private);
npiggin@suse.de459f6ed2010-05-27 01:05:38 +1000225 if (err < 0)
226 fat_write_failed(mapping, pos + len);
227 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700228}
229
Nick Piggind7777a22007-10-16 01:25:08 -0700230static int fat_write_end(struct file *file, struct address_space *mapping,
231 loff_t pos, unsigned len, unsigned copied,
232 struct page *pagep, void *fsdata)
OGAWA Hirofumief402262005-09-16 19:28:13 -0700233{
Nick Piggind7777a22007-10-16 01:25:08 -0700234 struct inode *inode = mapping->host;
235 int err;
236 err = generic_write_end(file, mapping, pos, len, copied, pagep, fsdata);
npiggin@suse.de459f6ed2010-05-27 01:05:38 +1000237 if (err < len)
238 fat_write_failed(mapping, pos + len);
Nick Piggind7777a22007-10-16 01:25:08 -0700239 if (!(err < 0) && !(MSDOS_I(inode)->i_attrs & ATTR_ARCH)) {
OGAWA Hirofumief402262005-09-16 19:28:13 -0700240 inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC;
241 MSDOS_I(inode)->i_attrs |= ATTR_ARCH;
242 mark_inode_dirty(inode);
243 }
244 return err;
245}
246
Omar Sandoval22c61862015-03-16 04:33:53 -0700247static ssize_t fat_direct_IO(struct kiocb *iocb, struct iov_iter *iter,
Al Virod8d3d942014-03-04 21:27:34 -0500248 loff_t offset)
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -0800249{
250 struct file *file = iocb->ki_filp;
npiggin@suse.de459f6ed2010-05-27 01:05:38 +1000251 struct address_space *mapping = file->f_mapping;
252 struct inode *inode = mapping->host;
Al Viroa6cbcd42014-03-04 22:38:00 -0500253 size_t count = iov_iter_count(iter);
npiggin@suse.de459f6ed2010-05-27 01:05:38 +1000254 ssize_t ret;
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -0800255
Omar Sandoval6f673762015-03-16 04:33:52 -0700256 if (iov_iter_rw(iter) == WRITE) {
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -0800257 /*
Nick Piggin4e02ed42008-10-29 14:00:55 -0700258 * FIXME: blockdev_direct_IO() doesn't use ->write_begin(),
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -0800259 * so we need to update the ->mmu_private to block boundary.
260 *
261 * But we must fill the remaining area or hole by nul for
262 * updating ->mmu_private.
OGAWA Hirofumi94412a92007-02-20 13:57:55 -0800263 *
264 * Return 0, and fallback to normal buffered write.
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -0800265 */
Al Viroa6cbcd42014-03-04 22:38:00 -0500266 loff_t size = offset + count;
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -0800267 if (MSDOS_I(inode)->mmu_private < size)
OGAWA Hirofumi94412a92007-02-20 13:57:55 -0800268 return 0;
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -0800269 }
270
271 /*
272 * FAT need to use the DIO_LOCKING for avoiding the race
273 * condition of fat_get_block() and ->truncate().
274 */
Omar Sandoval17f8c842015-03-16 04:33:50 -0700275 ret = blockdev_direct_IO(iocb, inode, iter, offset, fat_get_block);
Omar Sandoval6f673762015-03-16 04:33:52 -0700276 if (ret < 0 && iov_iter_rw(iter) == WRITE)
Al Viroa6cbcd42014-03-04 22:38:00 -0500277 fat_write_failed(mapping, offset + count);
npiggin@suse.de459f6ed2010-05-27 01:05:38 +1000278
279 return ret;
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -0800280}
281
Namjae Jeon16fab202016-01-20 14:59:46 -0800282static int fat_get_block_bmap(struct inode *inode, sector_t iblock,
283 struct buffer_head *bh_result, int create)
284{
285 struct super_block *sb = inode->i_sb;
286 unsigned long max_blocks = bh_result->b_size >> inode->i_blkbits;
287 int err;
288 sector_t bmap;
289 unsigned long mapped_blocks;
290
291 BUG_ON(create != 0);
292
293 err = fat_bmap(inode, iblock, &bmap, &mapped_blocks, create, true);
294 if (err)
295 return err;
296
297 if (bmap) {
298 map_bh(bh_result, sb, bmap);
299 max_blocks = min(mapped_blocks, max_blocks);
300 }
301
302 bh_result->b_size = max_blocks << sb->s_blocksize_bits;
303
304 return 0;
305}
306
Linus Torvalds1da177e2005-04-16 15:20:36 -0700307static sector_t _fat_bmap(struct address_space *mapping, sector_t block)
308{
OGAWA Hirofumifa93ca12008-11-06 12:53:56 -0800309 sector_t blocknr;
310
311 /* fat_get_cluster() assumes the requested blocknr isn't truncated. */
Christoph Hellwig58268692011-06-24 14:29:40 -0400312 down_read(&MSDOS_I(mapping->host)->truncate_lock);
Namjae Jeon16fab202016-01-20 14:59:46 -0800313 blocknr = generic_block_bmap(mapping, block, fat_get_block_bmap);
Christoph Hellwig58268692011-06-24 14:29:40 -0400314 up_read(&MSDOS_I(mapping->host)->truncate_lock);
OGAWA Hirofumifa93ca12008-11-06 12:53:56 -0800315
316 return blocknr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700317}
318
Namjae Jeonc0ef0cc2014-12-12 16:57:26 -0800319/*
320 * fat_block_truncate_page() zeroes out a mapping from file offset `from'
321 * up to the end of the block which corresponds to `from'.
322 * This is required during truncate to physically zeroout the tail end
323 * of that block so it doesn't yield old data if the file is later grown.
324 * Also, avoid causing failure from fsx for cases of "data past EOF"
325 */
326int fat_block_truncate_page(struct inode *inode, loff_t from)
327{
328 return block_truncate_page(inode->i_mapping, from, fat_get_block);
329}
330
Christoph Hellwigf5e54d62006-06-28 04:26:44 -0700331static const struct address_space_operations fat_aops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700332 .readpage = fat_readpage,
OGAWA Hirofumia5425d22006-01-08 01:02:10 -0800333 .readpages = fat_readpages,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700334 .writepage = fat_writepage,
OGAWA Hirofumia5425d22006-01-08 01:02:10 -0800335 .writepages = fat_writepages,
Nick Piggind7777a22007-10-16 01:25:08 -0700336 .write_begin = fat_write_begin,
337 .write_end = fat_write_end,
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -0800338 .direct_IO = fat_direct_IO,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700339 .bmap = _fat_bmap
340};
341
342/*
343 * New FAT inode stuff. We do the following:
344 * a) i_ino is constant and has nothing with on-disk location.
345 * b) FAT manages its own cache of directory entries.
346 * c) *This* cache is indexed by on-disk location.
347 * d) inode has an associated directory entry, all right, but
348 * it may be unhashed.
349 * e) currently entries are stored within struct inode. That should
350 * change.
351 * f) we deal with races in the following way:
352 * 1. readdir() and lookup() do FAT-dir-cache lookup.
353 * 2. rename() unhashes the F-d-c entry and rehashes it in
354 * a new place.
355 * 3. unlink() and rmdir() unhash F-d-c entry.
356 * 4. fat_write_inode() checks whether the thing is unhashed.
357 * If it is we silently return. If it isn't we do bread(),
358 * check if the location is still valid and retry if it
359 * isn't. Otherwise we do changes.
360 * 5. Spinlock is used to protect hash/unhash/location check/lookup
Al Virodeee3ce2010-06-05 19:28:32 -0400361 * 6. fat_evict_inode() unhashes the F-d-c entry.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700362 * 7. lookup() and readdir() do igrab() if they find a F-d-c entry
363 * and consider negative result as cache miss.
364 */
365
366static void fat_hash_init(struct super_block *sb)
367{
368 struct msdos_sb_info *sbi = MSDOS_SB(sb);
369 int i;
370
371 spin_lock_init(&sbi->inode_hash_lock);
372 for (i = 0; i < FAT_HASH_SIZE; i++)
373 INIT_HLIST_HEAD(&sbi->inode_hashtable[i]);
374}
375
OGAWA Hirofumid3dfa822008-11-06 12:53:49 -0800376static inline unsigned long fat_hash(loff_t i_pos)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700377{
OGAWA Hirofumid3dfa822008-11-06 12:53:49 -0800378 return hash_32(i_pos, FAT_HASH_BITS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700379}
380
Steven J. Magnani7669e8f2012-10-04 17:14:45 -0700381static void dir_hash_init(struct super_block *sb)
382{
383 struct msdos_sb_info *sbi = MSDOS_SB(sb);
384 int i;
385
386 spin_lock_init(&sbi->dir_hash_lock);
387 for (i = 0; i < FAT_HASH_SIZE; i++)
388 INIT_HLIST_HEAD(&sbi->dir_hashtable[i]);
389}
390
Linus Torvalds1da177e2005-04-16 15:20:36 -0700391void fat_attach(struct inode *inode, loff_t i_pos)
392{
OGAWA Hirofumid3dfa822008-11-06 12:53:49 -0800393 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700394
Steven J. Magnani7669e8f2012-10-04 17:14:45 -0700395 if (inode->i_ino != MSDOS_ROOT_INO) {
396 struct hlist_head *head = sbi->inode_hashtable
397 + fat_hash(i_pos);
398
399 spin_lock(&sbi->inode_hash_lock);
400 MSDOS_I(inode)->i_pos = i_pos;
401 hlist_add_head(&MSDOS_I(inode)->i_fat_hash, head);
402 spin_unlock(&sbi->inode_hash_lock);
403 }
404
405 /* If NFS support is enabled, cache the mapping of start cluster
406 * to directory inode. This is used during reconnection of
407 * dentries to the filesystem root.
408 */
409 if (S_ISDIR(inode->i_mode) && sbi->options.nfs) {
410 struct hlist_head *d_head = sbi->dir_hashtable;
411 d_head += fat_dir_hash(MSDOS_I(inode)->i_logstart);
412
413 spin_lock(&sbi->dir_hash_lock);
414 hlist_add_head(&MSDOS_I(inode)->i_dir_hash, d_head);
415 spin_unlock(&sbi->dir_hash_lock);
416 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700417}
OGAWA Hirofumi7c709d02006-01-08 01:02:10 -0800418EXPORT_SYMBOL_GPL(fat_attach);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700419
420void fat_detach(struct inode *inode)
421{
422 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
423 spin_lock(&sbi->inode_hash_lock);
424 MSDOS_I(inode)->i_pos = 0;
425 hlist_del_init(&MSDOS_I(inode)->i_fat_hash);
426 spin_unlock(&sbi->inode_hash_lock);
Steven J. Magnani7669e8f2012-10-04 17:14:45 -0700427
428 if (S_ISDIR(inode->i_mode) && sbi->options.nfs) {
429 spin_lock(&sbi->dir_hash_lock);
430 hlist_del_init(&MSDOS_I(inode)->i_dir_hash);
431 spin_unlock(&sbi->dir_hash_lock);
432 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700433}
OGAWA Hirofumi7c709d02006-01-08 01:02:10 -0800434EXPORT_SYMBOL_GPL(fat_detach);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700435
436struct inode *fat_iget(struct super_block *sb, loff_t i_pos)
437{
438 struct msdos_sb_info *sbi = MSDOS_SB(sb);
OGAWA Hirofumid3dfa822008-11-06 12:53:49 -0800439 struct hlist_head *head = sbi->inode_hashtable + fat_hash(i_pos);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700440 struct msdos_inode_info *i;
441 struct inode *inode = NULL;
442
443 spin_lock(&sbi->inode_hash_lock);
Sasha Levinb67bfe02013-02-27 17:06:00 -0800444 hlist_for_each_entry(i, head, i_fat_hash) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700445 BUG_ON(i->vfs_inode.i_sb != sb);
446 if (i->i_pos != i_pos)
447 continue;
448 inode = igrab(&i->vfs_inode);
449 if (inode)
450 break;
451 }
452 spin_unlock(&sbi->inode_hash_lock);
453 return inode;
454}
455
456static int is_exec(unsigned char *extension)
457{
Manuel Schöllingef194702014-06-06 14:36:38 -0700458 unsigned char exe_extensions[] = "EXECOMBAT", *walk;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700459
460 for (walk = exe_extensions; *walk; walk += 3)
461 if (!strncmp(extension, walk, 3))
462 return 1;
463 return 0;
464}
465
466static int fat_calc_dir_size(struct inode *inode)
467{
468 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
469 int ret, fclus, dclus;
470
471 inode->i_size = 0;
472 if (MSDOS_I(inode)->i_start == 0)
473 return 0;
474
475 ret = fat_get_cluster(inode, FAT_ENT_EOF, &fclus, &dclus);
476 if (ret < 0)
477 return ret;
478 inode->i_size = (fclus + 1) << sbi->cluster_bits;
479
480 return 0;
481}
482
OGAWA Hirofumia3082d52016-01-20 14:59:38 -0800483static int fat_validate_dir(struct inode *dir)
484{
485 struct super_block *sb = dir->i_sb;
486
487 if (dir->i_nlink < 2) {
488 /* Directory should have "."/".." entries at least. */
489 fat_fs_error(sb, "corrupted directory (invalid entries)");
490 return -EIO;
491 }
492 if (MSDOS_I(dir)->i_start == 0 ||
493 MSDOS_I(dir)->i_start == MSDOS_SB(sb)->root_cluster) {
494 /* Directory should point valid cluster. */
495 fat_fs_error(sb, "corrupted directory (invalid i_start)");
496 return -EIO;
497 }
498 return 0;
499}
500
Linus Torvalds1da177e2005-04-16 15:20:36 -0700501/* doesn't deal with root inode */
Namjae Jeonf1e6fb02013-04-29 16:21:14 -0700502int fat_fill_inode(struct inode *inode, struct msdos_dir_entry *de)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700503{
504 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
505 int error;
506
507 MSDOS_I(inode)->i_pos = 0;
508 inode->i_uid = sbi->options.fs_uid;
509 inode->i_gid = sbi->options.fs_gid;
510 inode->i_version++;
511 inode->i_generation = get_seconds();
512
513 if ((de->attr & ATTR_DIR) && !IS_FREE(de->name)) {
514 inode->i_generation &= ~1;
OGAWA Hirofumi9c0aa1b2008-11-06 12:53:54 -0800515 inode->i_mode = fat_make_mode(sbi, de->attr, S_IRWXUGO);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700516 inode->i_op = sbi->dir_ops;
517 inode->i_fop = &fat_dir_operations;
518
Steven J. Magnania943ed72012-07-30 14:42:13 -0700519 MSDOS_I(inode)->i_start = fat_get_start(sbi, de);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700520 MSDOS_I(inode)->i_logstart = MSDOS_I(inode)->i_start;
521 error = fat_calc_dir_size(inode);
522 if (error < 0)
523 return error;
524 MSDOS_I(inode)->mmu_private = inode->i_size;
525
Miklos Szeredibfe86842011-10-28 14:13:29 +0200526 set_nlink(inode, fat_subdirs(inode));
OGAWA Hirofumia3082d52016-01-20 14:59:38 -0800527
528 error = fat_validate_dir(inode);
529 if (error < 0)
530 return error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700531 } else { /* not a directory */
532 inode->i_generation |= 1;
OGAWA Hirofumi9c0aa1b2008-11-06 12:53:54 -0800533 inode->i_mode = fat_make_mode(sbi, de->attr,
534 ((sbi->options.showexec && !is_exec(de->name + 8))
535 ? S_IRUGO|S_IWUGO : S_IRWXUGO));
Steven J. Magnania943ed72012-07-30 14:42:13 -0700536 MSDOS_I(inode)->i_start = fat_get_start(sbi, de);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700537
538 MSDOS_I(inode)->i_logstart = MSDOS_I(inode)->i_start;
539 inode->i_size = le32_to_cpu(de->size);
540 inode->i_op = &fat_file_inode_operations;
541 inode->i_fop = &fat_file_operations;
542 inode->i_mapping->a_ops = &fat_aops;
543 MSDOS_I(inode)->mmu_private = inode->i_size;
544 }
545 if (de->attr & ATTR_SYS) {
546 if (sbi->options.sys_immutable)
547 inode->i_flags |= S_IMMUTABLE;
548 }
OGAWA Hirofumi9c0aa1b2008-11-06 12:53:54 -0800549 fat_save_attrs(inode, de->attr);
550
Linus Torvalds1da177e2005-04-16 15:20:36 -0700551 inode->i_blocks = ((inode->i_size + (sbi->cluster_size - 1))
552 & ~((loff_t)sbi->cluster_size - 1)) >> 9;
OGAWA Hirofumi7decd1c2008-11-06 12:53:47 -0800553
554 fat_time_fat2unix(sbi, &inode->i_mtime, de->time, de->date, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700555 if (sbi->options.isvfat) {
OGAWA Hirofumi7decd1c2008-11-06 12:53:47 -0800556 fat_time_fat2unix(sbi, &inode->i_ctime, de->ctime,
557 de->cdate, de->ctime_cs);
558 fat_time_fat2unix(sbi, &inode->i_atime, 0, de->adate, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700559 } else
Stephane Kardas62a36c42005-09-21 09:55:45 -0700560 inode->i_ctime = inode->i_atime = inode->i_mtime;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700561
562 return 0;
563}
564
Namjae Jeon8fceb4e2013-04-29 16:21:12 -0700565static inline void fat_lock_build_inode(struct msdos_sb_info *sbi)
566{
567 if (sbi->options.nfs == FAT_NFS_NOSTALE_RO)
568 mutex_lock(&sbi->nfs_build_inode_lock);
569}
570
571static inline void fat_unlock_build_inode(struct msdos_sb_info *sbi)
572{
573 if (sbi->options.nfs == FAT_NFS_NOSTALE_RO)
574 mutex_unlock(&sbi->nfs_build_inode_lock);
575}
576
Linus Torvalds1da177e2005-04-16 15:20:36 -0700577struct inode *fat_build_inode(struct super_block *sb,
578 struct msdos_dir_entry *de, loff_t i_pos)
579{
580 struct inode *inode;
581 int err;
582
Namjae Jeon8fceb4e2013-04-29 16:21:12 -0700583 fat_lock_build_inode(MSDOS_SB(sb));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700584 inode = fat_iget(sb, i_pos);
585 if (inode)
586 goto out;
587 inode = new_inode(sb);
588 if (!inode) {
589 inode = ERR_PTR(-ENOMEM);
590 goto out;
591 }
592 inode->i_ino = iunique(sb, MSDOS_ROOT_INO);
593 inode->i_version = 1;
594 err = fat_fill_inode(inode, de);
595 if (err) {
596 iput(inode);
597 inode = ERR_PTR(err);
598 goto out;
599 }
600 fat_attach(inode, i_pos);
601 insert_inode_hash(inode);
602out:
Namjae Jeon8fceb4e2013-04-29 16:21:12 -0700603 fat_unlock_build_inode(MSDOS_SB(sb));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700604 return inode;
605}
606
OGAWA Hirofumi7c709d02006-01-08 01:02:10 -0800607EXPORT_SYMBOL_GPL(fat_build_inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700608
Namjae Jeonb13bb332016-01-20 14:59:41 -0800609static int __fat_write_inode(struct inode *inode, int wait);
610
611static void fat_free_eofblocks(struct inode *inode)
612{
613 /* Release unwritten fallocated blocks on inode eviction. */
614 if ((inode->i_blocks << 9) >
615 round_up(MSDOS_I(inode)->mmu_private,
616 MSDOS_SB(inode->i_sb)->cluster_size)) {
617 int err;
618
619 fat_truncate_blocks(inode, MSDOS_I(inode)->mmu_private);
620 /* Fallocate results in updating the i_start/iogstart
621 * for the zero byte file. So, make it return to
622 * original state during evict and commit it to avoid
623 * any corruption on the next access to the cluster
624 * chain for the file.
625 */
626 err = __fat_write_inode(inode, inode_needs_sync(inode));
627 if (err) {
628 fat_msg(inode->i_sb, KERN_WARNING, "Failed to "
629 "update on disk inode for unused "
630 "fallocated blocks, inode could be "
631 "corrupted. Please run fsck");
632 }
633
634 }
635}
636
Al Virodeee3ce2010-06-05 19:28:32 -0400637static void fat_evict_inode(struct inode *inode)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700638{
Johannes Weiner91b0abe2014-04-03 14:47:49 -0700639 truncate_inode_pages_final(&inode->i_data);
Al Virodeee3ce2010-06-05 19:28:32 -0400640 if (!inode->i_nlink) {
641 inode->i_size = 0;
642 fat_truncate_blocks(inode, 0);
Namjae Jeonb13bb332016-01-20 14:59:41 -0800643 } else
644 fat_free_eofblocks(inode);
645
Al Virodeee3ce2010-06-05 19:28:32 -0400646 invalidate_inode_buffers(inode);
Jan Karadbd57682012-05-03 14:48:02 +0200647 clear_inode(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700648 fat_cache_inval_inode(inode);
OGAWA Hirofumia993b542008-11-06 12:53:50 -0800649 fat_detach(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700650}
651
Oleksij Rempelb88a10582013-02-27 17:03:09 -0800652static void fat_set_state(struct super_block *sb,
653 unsigned int set, unsigned int force)
654{
655 struct buffer_head *bh;
656 struct fat_boot_sector *b;
Fred Choud6bd4282015-02-17 13:45:36 -0800657 struct msdos_sb_info *sbi = MSDOS_SB(sb);
Oleksij Rempelb88a10582013-02-27 17:03:09 -0800658
659 /* do not change any thing if mounted read only */
660 if ((sb->s_flags & MS_RDONLY) && !force)
661 return;
662
663 /* do not change state if fs was dirty */
664 if (sbi->dirty) {
665 /* warn only on set (mount). */
666 if (set)
667 fat_msg(sb, KERN_WARNING, "Volume was not properly "
668 "unmounted. Some data may be corrupt. "
669 "Please run fsck.");
670 return;
671 }
672
673 bh = sb_bread(sb, 0);
674 if (bh == NULL) {
675 fat_msg(sb, KERN_ERR, "unable to read boot sector "
676 "to mark fs as dirty");
677 return;
678 }
679
680 b = (struct fat_boot_sector *) bh->b_data;
681
682 if (sbi->fat_bits == 32) {
683 if (set)
684 b->fat32.state |= FAT_STATE_DIRTY;
685 else
686 b->fat32.state &= ~FAT_STATE_DIRTY;
687 } else /* fat 16 and 12 */ {
688 if (set)
689 b->fat16.state |= FAT_STATE_DIRTY;
690 else
691 b->fat16.state &= ~FAT_STATE_DIRTY;
692 }
693
694 mark_buffer_dirty(bh);
695 sync_dirty_buffer(bh);
696 brelse(bh);
697}
698
Al Virocac45b02013-10-03 13:16:50 -0400699static void delayed_free(struct rcu_head *p)
700{
701 struct msdos_sb_info *sbi = container_of(p, struct msdos_sb_info, rcu);
702 unload_nls(sbi->nls_disk);
703 unload_nls(sbi->nls_io);
704 if (sbi->options.iocharset != fat_default_iocharset)
705 kfree(sbi->options.iocharset);
706 kfree(sbi);
707}
708
OGAWA Hirofumia6bf6b22006-01-08 01:02:08 -0800709static void fat_put_super(struct super_block *sb)
710{
711 struct msdos_sb_info *sbi = MSDOS_SB(sb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700712
Oleksij Rempelb88a10582013-02-27 17:03:09 -0800713 fat_set_state(sb, 0, 0);
714
Artem Bityutskiy020ac5b2012-05-31 16:26:12 -0700715 iput(sbi->fsinfo_inode);
Al Virob5224122009-06-07 13:44:36 -0400716 iput(sbi->fat_inode);
717
Al Virocac45b02013-10-03 13:16:50 -0400718 call_rcu(&sbi->rcu, delayed_free);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700719}
720
Christoph Lametere18b8902006-12-06 20:33:20 -0800721static struct kmem_cache *fat_inode_cachep;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700722
723static struct inode *fat_alloc_inode(struct super_block *sb)
724{
725 struct msdos_inode_info *ei;
Linus Torvalds8f593422008-05-19 19:53:01 -0700726 ei = kmem_cache_alloc(fat_inode_cachep, GFP_NOFS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700727 if (!ei)
728 return NULL;
Christoph Hellwig58268692011-06-24 14:29:40 -0400729
730 init_rwsem(&ei->truncate_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700731 return &ei->vfs_inode;
732}
733
Nick Pigginfa0d7e3d2011-01-07 17:49:49 +1100734static void fat_i_callback(struct rcu_head *head)
735{
736 struct inode *inode = container_of(head, struct inode, i_rcu);
Nick Pigginfa0d7e3d2011-01-07 17:49:49 +1100737 kmem_cache_free(fat_inode_cachep, MSDOS_I(inode));
738}
739
Linus Torvalds1da177e2005-04-16 15:20:36 -0700740static void fat_destroy_inode(struct inode *inode)
741{
Nick Pigginfa0d7e3d2011-01-07 17:49:49 +1100742 call_rcu(&inode->i_rcu, fat_i_callback);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700743}
744
Alexey Dobriyan51cc5062008-07-25 19:45:34 -0700745static void init_once(void *foo)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700746{
747 struct msdos_inode_info *ei = (struct msdos_inode_info *)foo;
748
Christoph Lametera35afb82007-05-16 22:10:57 -0700749 spin_lock_init(&ei->cache_lru_lock);
750 ei->nr_caches = 0;
751 ei->cache_valid_id = FAT_CACHE_VALID + 1;
752 INIT_LIST_HEAD(&ei->cache_lru);
753 INIT_HLIST_NODE(&ei->i_fat_hash);
Steven J. Magnani7669e8f2012-10-04 17:14:45 -0700754 INIT_HLIST_NODE(&ei->i_dir_hash);
Christoph Lametera35afb82007-05-16 22:10:57 -0700755 inode_init_once(&ei->vfs_inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700756}
757
758static int __init fat_init_inodecache(void)
759{
760 fat_inode_cachep = kmem_cache_create("fat_inode_cache",
761 sizeof(struct msdos_inode_info),
Paul Jacksonfffb60f2006-03-24 03:16:06 -0800762 0, (SLAB_RECLAIM_ACCOUNT|
Vladimir Davydov5d097052016-01-14 15:18:21 -0800763 SLAB_MEM_SPREAD|SLAB_ACCOUNT),
Paul Mundt20c2df82007-07-20 10:11:58 +0900764 init_once);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700765 if (fat_inode_cachep == NULL)
766 return -ENOMEM;
767 return 0;
768}
769
770static void __exit fat_destroy_inodecache(void)
771{
Kirill A. Shutemov8c0a8532012-09-26 11:33:07 +1000772 /*
773 * Make sure all delayed rcu free inodes are flushed before we
774 * destroy cache.
775 */
776 rcu_barrier();
Alexey Dobriyan1a1d92c2006-09-27 01:49:40 -0700777 kmem_cache_destroy(fat_inode_cachep);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700778}
779
780static int fat_remount(struct super_block *sb, int *flags, char *data)
781{
Oleksij Rempelb88a10582013-02-27 17:03:09 -0800782 int new_rdonly;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700783 struct msdos_sb_info *sbi = MSDOS_SB(sb);
784 *flags |= MS_NODIRATIME | (sbi->options.isvfat ? 0 : MS_NOATIME);
Oleksij Rempelb88a10582013-02-27 17:03:09 -0800785
Theodore Ts'o02b99842014-03-13 10:14:33 -0400786 sync_filesystem(sb);
787
Oleksij Rempelb88a10582013-02-27 17:03:09 -0800788 /* make sure we update state on remount. */
789 new_rdonly = *flags & MS_RDONLY;
790 if (new_rdonly != (sb->s_flags & MS_RDONLY)) {
791 if (new_rdonly)
792 fat_set_state(sb, 0, 0);
793 else
794 fat_set_state(sb, 1, 1);
795 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700796 return 0;
797}
798
David Howells726c3342006-06-23 02:02:58 -0700799static int fat_statfs(struct dentry *dentry, struct kstatfs *buf)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700800{
Coly Liaac49b72009-04-02 16:59:35 -0700801 struct super_block *sb = dentry->d_sb;
802 struct msdos_sb_info *sbi = MSDOS_SB(sb);
803 u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700804
805 /* If the count of free cluster is still unknown, counts it here. */
OGAWA Hirofumi606e4232008-04-28 02:16:27 -0700806 if (sbi->free_clusters == -1 || !sbi->free_clus_valid) {
David Howells726c3342006-06-23 02:02:58 -0700807 int err = fat_count_free_clusters(dentry->d_sb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700808 if (err)
809 return err;
810 }
811
David Howells726c3342006-06-23 02:02:58 -0700812 buf->f_type = dentry->d_sb->s_magic;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700813 buf->f_bsize = sbi->cluster_size;
814 buf->f_blocks = sbi->max_cluster - FAT_START_ENT;
815 buf->f_bfree = sbi->free_clusters;
816 buf->f_bavail = sbi->free_clusters;
Coly Liaac49b72009-04-02 16:59:35 -0700817 buf->f_fsid.val[0] = (u32)id;
818 buf->f_fsid.val[1] = (u32)(id >> 32);
OGAWA Hirofumif68e5422011-04-12 21:08:39 +0900819 buf->f_namelen =
820 (sbi->options.isvfat ? FAT_LFN_LEN : 12) * NLS_MAX_CHARSET_SIZE;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700821
822 return 0;
823}
824
Christoph Hellwiga9185b42010-03-05 09:21:37 +0100825static int __fat_write_inode(struct inode *inode, int wait)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700826{
827 struct super_block *sb = inode->i_sb;
828 struct msdos_sb_info *sbi = MSDOS_SB(sb);
829 struct buffer_head *bh;
830 struct msdos_dir_entry *raw_entry;
831 loff_t i_pos;
Namjae Jeone22a4442013-04-29 16:21:10 -0700832 sector_t blocknr;
833 int err, offset;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700834
OGAWA Hirofumi9ca59f42008-11-06 12:53:57 -0800835 if (inode->i_ino == MSDOS_ROOT_INO)
836 return 0;
837
Linus Torvalds1da177e2005-04-16 15:20:36 -0700838retry:
OGAWA Hirofumi9ca59f42008-11-06 12:53:57 -0800839 i_pos = fat_i_pos_read(sbi, inode);
840 if (!i_pos)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700841 return 0;
842
Namjae Jeone22a4442013-04-29 16:21:10 -0700843 fat_get_blknr_offset(sbi, i_pos, &blocknr, &offset);
844 bh = sb_bread(sb, blocknr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700845 if (!bh) {
Alexey Fisher869f58c2011-04-12 21:08:38 +0900846 fat_msg(sb, KERN_ERR, "unable to read inode block "
847 "for updating (i_pos %lld)", i_pos);
Linus Torvalds5f22ca92008-08-20 08:31:19 -0700848 return -EIO;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700849 }
850 spin_lock(&sbi->inode_hash_lock);
851 if (i_pos != MSDOS_I(inode)->i_pos) {
852 spin_unlock(&sbi->inode_hash_lock);
853 brelse(bh);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700854 goto retry;
855 }
856
Namjae Jeone22a4442013-04-29 16:21:10 -0700857 raw_entry = &((struct msdos_dir_entry *) (bh->b_data))[offset];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700858 if (S_ISDIR(inode->i_mode))
859 raw_entry->size = 0;
860 else
861 raw_entry->size = cpu_to_le32(inode->i_size);
OGAWA Hirofumi9c0aa1b2008-11-06 12:53:54 -0800862 raw_entry->attr = fat_make_attrs(inode);
Steven J. Magnania943ed72012-07-30 14:42:13 -0700863 fat_set_start(raw_entry, MSDOS_I(inode)->i_logstart);
OGAWA Hirofumi7decd1c2008-11-06 12:53:47 -0800864 fat_time_unix2fat(sbi, &inode->i_mtime, &raw_entry->time,
865 &raw_entry->date, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700866 if (sbi->options.isvfat) {
Stephane Kardas62a36c42005-09-21 09:55:45 -0700867 __le16 atime;
OGAWA Hirofumi7decd1c2008-11-06 12:53:47 -0800868 fat_time_unix2fat(sbi, &inode->i_ctime, &raw_entry->ctime,
869 &raw_entry->cdate, &raw_entry->ctime_cs);
870 fat_time_unix2fat(sbi, &inode->i_atime, &atime,
871 &raw_entry->adate, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700872 }
873 spin_unlock(&sbi->inode_hash_lock);
874 mark_buffer_dirty(bh);
Linus Torvalds5f22ca92008-08-20 08:31:19 -0700875 err = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700876 if (wait)
877 err = sync_dirty_buffer(bh);
878 brelse(bh);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700879 return err;
880}
881
Christoph Hellwiga9185b42010-03-05 09:21:37 +0100882static int fat_write_inode(struct inode *inode, struct writeback_control *wbc)
883{
Artem Bityutskiy78491182012-05-31 16:26:13 -0700884 int err;
885
886 if (inode->i_ino == MSDOS_FSINFO_INO) {
887 struct super_block *sb = inode->i_sb;
888
Marco Stornellie40b34c2012-10-06 12:40:03 +0200889 mutex_lock(&MSDOS_SB(sb)->s_lock);
Artem Bityutskiy78491182012-05-31 16:26:13 -0700890 err = fat_clusters_flush(sb);
Marco Stornellie40b34c2012-10-06 12:40:03 +0200891 mutex_unlock(&MSDOS_SB(sb)->s_lock);
Artem Bityutskiy78491182012-05-31 16:26:13 -0700892 } else
893 err = __fat_write_inode(inode, wbc->sync_mode == WB_SYNC_ALL);
894
895 return err;
Christoph Hellwiga9185b42010-03-05 09:21:37 +0100896}
897
Linus Torvalds1da177e2005-04-16 15:20:36 -0700898int fat_sync_inode(struct inode *inode)
899{
Christoph Hellwiga9185b42010-03-05 09:21:37 +0100900 return __fat_write_inode(inode, 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700901}
902
OGAWA Hirofumi7c709d02006-01-08 01:02:10 -0800903EXPORT_SYMBOL_GPL(fat_sync_inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700904
Al Viro34c80b12011-12-08 21:32:45 -0500905static int fat_show_options(struct seq_file *m, struct dentry *root);
Josef 'Jeff' Sipekee9b6d62007-02-12 00:55:41 -0800906static const struct super_operations fat_sops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700907 .alloc_inode = fat_alloc_inode,
908 .destroy_inode = fat_destroy_inode,
909 .write_inode = fat_write_inode,
Al Virodeee3ce2010-06-05 19:28:32 -0400910 .evict_inode = fat_evict_inode,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700911 .put_super = fat_put_super,
912 .statfs = fat_statfs,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700913 .remount_fs = fat_remount,
914
Linus Torvalds1da177e2005-04-16 15:20:36 -0700915 .show_options = fat_show_options,
916};
917
Al Viro34c80b12011-12-08 21:32:45 -0500918static int fat_show_options(struct seq_file *m, struct dentry *root)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700919{
Al Viro34c80b12011-12-08 21:32:45 -0500920 struct msdos_sb_info *sbi = MSDOS_SB(root->d_sb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700921 struct fat_mount_options *opts = &sbi->options;
922 int isvfat = opts->isvfat;
923
Eric W. Biederman170782e2012-02-07 16:25:39 -0800924 if (!uid_eq(opts->fs_uid, GLOBAL_ROOT_UID))
925 seq_printf(m, ",uid=%u",
926 from_kuid_munged(&init_user_ns, opts->fs_uid));
927 if (!gid_eq(opts->fs_gid, GLOBAL_ROOT_GID))
928 seq_printf(m, ",gid=%u",
929 from_kgid_munged(&init_user_ns, opts->fs_gid));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700930 seq_printf(m, ",fmask=%04o", opts->fs_fmask);
931 seq_printf(m, ",dmask=%04o", opts->fs_dmask);
OGAWA Hirofumi1ae43f82008-04-28 02:16:26 -0700932 if (opts->allow_utime)
933 seq_printf(m, ",allow_utime=%04o", opts->allow_utime);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700934 if (sbi->nls_disk)
Dave Reisnerc6c20372012-12-17 16:03:01 -0800935 /* strip "cp" prefix from displayed option */
936 seq_printf(m, ",codepage=%s", &sbi->nls_disk->charset[2]);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700937 if (isvfat) {
938 if (sbi->nls_io)
939 seq_printf(m, ",iocharset=%s", sbi->nls_io->charset);
940
941 switch (opts->shortname) {
942 case VFAT_SFN_DISPLAY_WIN95 | VFAT_SFN_CREATE_WIN95:
943 seq_puts(m, ",shortname=win95");
944 break;
945 case VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WINNT:
946 seq_puts(m, ",shortname=winnt");
947 break;
948 case VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WIN95:
949 seq_puts(m, ",shortname=mixed");
950 break;
951 case VFAT_SFN_DISPLAY_LOWER | VFAT_SFN_CREATE_WIN95:
Paul Wise95523472009-08-01 21:30:31 +0900952 seq_puts(m, ",shortname=lower");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700953 break;
954 default:
955 seq_puts(m, ",shortname=unknown");
956 break;
957 }
958 }
959 if (opts->name_check != 'n')
960 seq_printf(m, ",check=%c", opts->name_check);
OGAWA Hirofumi28ec0392007-05-08 00:31:01 -0700961 if (opts->usefree)
962 seq_puts(m, ",usefree");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700963 if (opts->quiet)
964 seq_puts(m, ",quiet");
965 if (opts->showexec)
966 seq_puts(m, ",showexec");
967 if (opts->sys_immutable)
968 seq_puts(m, ",sys_immutable");
969 if (!isvfat) {
970 if (opts->dotsOK)
971 seq_puts(m, ",dotsOK=yes");
972 if (opts->nocase)
973 seq_puts(m, ",nocase");
974 } else {
975 if (opts->utf8)
976 seq_puts(m, ",utf8");
977 if (opts->unicode_xlate)
978 seq_puts(m, ",uni_xlate");
979 if (!opts->numtail)
980 seq_puts(m, ",nonumtail");
OGAWA Hirofumidfc209c2008-11-06 12:53:55 -0800981 if (opts->rodir)
982 seq_puts(m, ",rodir");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700983 }
OGAWA Hirofumidfc209c2008-11-06 12:53:55 -0800984 if (opts->flush)
Miklos Szeredic1fca3b2008-02-08 04:21:42 -0800985 seq_puts(m, ",flush");
Jan Kara58156c82012-12-17 16:02:58 -0800986 if (opts->tz_set) {
987 if (opts->time_offset)
988 seq_printf(m, ",time_offset=%d", opts->time_offset);
989 else
990 seq_puts(m, ",tz=UTC");
991 }
Denis Karpov85c78592009-06-04 02:34:22 +0900992 if (opts->errors == FAT_ERRORS_CONT)
993 seq_puts(m, ",errors=continue");
994 else if (opts->errors == FAT_ERRORS_PANIC)
995 seq_puts(m, ",errors=panic");
996 else
997 seq_puts(m, ",errors=remount-ro");
Namjae Jeon2628b7a2013-04-29 16:21:08 -0700998 if (opts->nfs == FAT_NFS_NOSTALE_RO)
999 seq_puts(m, ",nfs=nostale_ro");
1000 else if (opts->nfs)
1001 seq_puts(m, ",nfs=stale_rw");
Christoph Hellwig681142f2009-11-21 20:28:52 +09001002 if (opts->discard)
1003 seq_puts(m, ",discard");
Conrad Meyer190a8842014-06-06 14:36:37 -07001004 if (opts->dos1xfloppy)
1005 seq_puts(m, ",dos1xfloppy");
Linus Torvalds1da177e2005-04-16 15:20:36 -07001006
1007 return 0;
1008}
1009
1010enum {
1011 Opt_check_n, Opt_check_r, Opt_check_s, Opt_uid, Opt_gid,
OGAWA Hirofumi1ae43f82008-04-28 02:16:26 -07001012 Opt_umask, Opt_dmask, Opt_fmask, Opt_allow_utime, Opt_codepage,
1013 Opt_usefree, Opt_nocase, Opt_quiet, Opt_showexec, Opt_debug,
1014 Opt_immutable, Opt_dots, Opt_nodots,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001015 Opt_charset, Opt_shortname_lower, Opt_shortname_win95,
1016 Opt_shortname_winnt, Opt_shortname_mixed, Opt_utf8_no, Opt_utf8_yes,
1017 Opt_uni_xl_no, Opt_uni_xl_yes, Opt_nonumtail_no, Opt_nonumtail_yes,
Geert Uytterhoevend7a83c02011-10-31 20:50:45 +01001018 Opt_obsolete, Opt_flush, Opt_tz_utc, Opt_rodir, Opt_err_cont,
Jan Kara58156c82012-12-17 16:02:58 -08001019 Opt_err_panic, Opt_err_ro, Opt_discard, Opt_nfs, Opt_time_offset,
Conrad Meyer190a8842014-06-06 14:36:37 -07001020 Opt_nfs_stale_rw, Opt_nfs_nostale_ro, Opt_err, Opt_dos1xfloppy,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001021};
1022
Steven Whitehousea447c092008-10-13 10:46:57 +01001023static const match_table_t fat_tokens = {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001024 {Opt_check_r, "check=relaxed"},
1025 {Opt_check_s, "check=strict"},
1026 {Opt_check_n, "check=normal"},
1027 {Opt_check_r, "check=r"},
1028 {Opt_check_s, "check=s"},
1029 {Opt_check_n, "check=n"},
1030 {Opt_uid, "uid=%u"},
1031 {Opt_gid, "gid=%u"},
1032 {Opt_umask, "umask=%o"},
1033 {Opt_dmask, "dmask=%o"},
1034 {Opt_fmask, "fmask=%o"},
OGAWA Hirofumi1ae43f82008-04-28 02:16:26 -07001035 {Opt_allow_utime, "allow_utime=%o"},
Linus Torvalds1da177e2005-04-16 15:20:36 -07001036 {Opt_codepage, "codepage=%u"},
OGAWA Hirofumi28ec0392007-05-08 00:31:01 -07001037 {Opt_usefree, "usefree"},
Linus Torvalds1da177e2005-04-16 15:20:36 -07001038 {Opt_nocase, "nocase"},
1039 {Opt_quiet, "quiet"},
1040 {Opt_showexec, "showexec"},
1041 {Opt_debug, "debug"},
1042 {Opt_immutable, "sys_immutable"},
Denis Karpov85c78592009-06-04 02:34:22 +09001043 {Opt_flush, "flush"},
1044 {Opt_tz_utc, "tz=UTC"},
Jan Kara58156c82012-12-17 16:02:58 -08001045 {Opt_time_offset, "time_offset=%d"},
Denis Karpov85c78592009-06-04 02:34:22 +09001046 {Opt_err_cont, "errors=continue"},
1047 {Opt_err_panic, "errors=panic"},
1048 {Opt_err_ro, "errors=remount-ro"},
Christoph Hellwig681142f2009-11-21 20:28:52 +09001049 {Opt_discard, "discard"},
Namjae Jeon2628b7a2013-04-29 16:21:08 -07001050 {Opt_nfs_stale_rw, "nfs"},
1051 {Opt_nfs_stale_rw, "nfs=stale_rw"},
1052 {Opt_nfs_nostale_ro, "nfs=nostale_ro"},
Conrad Meyer190a8842014-06-06 14:36:37 -07001053 {Opt_dos1xfloppy, "dos1xfloppy"},
Geert Uytterhoevend7a83c02011-10-31 20:50:45 +01001054 {Opt_obsolete, "conv=binary"},
1055 {Opt_obsolete, "conv=text"},
1056 {Opt_obsolete, "conv=auto"},
1057 {Opt_obsolete, "conv=b"},
1058 {Opt_obsolete, "conv=t"},
1059 {Opt_obsolete, "conv=a"},
1060 {Opt_obsolete, "fat=%u"},
1061 {Opt_obsolete, "blocksize=%u"},
1062 {Opt_obsolete, "cvf_format=%20s"},
1063 {Opt_obsolete, "cvf_options=%100s"},
1064 {Opt_obsolete, "posix"},
Chris Masonae78bf92006-09-29 02:00:03 -07001065 {Opt_err, NULL},
Linus Torvalds1da177e2005-04-16 15:20:36 -07001066};
Steven Whitehousea447c092008-10-13 10:46:57 +01001067static const match_table_t msdos_tokens = {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001068 {Opt_nodots, "nodots"},
1069 {Opt_nodots, "dotsOK=no"},
1070 {Opt_dots, "dots"},
1071 {Opt_dots, "dotsOK=yes"},
1072 {Opt_err, NULL}
1073};
Steven Whitehousea447c092008-10-13 10:46:57 +01001074static const match_table_t vfat_tokens = {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001075 {Opt_charset, "iocharset=%s"},
1076 {Opt_shortname_lower, "shortname=lower"},
1077 {Opt_shortname_win95, "shortname=win95"},
1078 {Opt_shortname_winnt, "shortname=winnt"},
1079 {Opt_shortname_mixed, "shortname=mixed"},
1080 {Opt_utf8_no, "utf8=0"}, /* 0 or no or false */
1081 {Opt_utf8_no, "utf8=no"},
1082 {Opt_utf8_no, "utf8=false"},
1083 {Opt_utf8_yes, "utf8=1"}, /* empty or 1 or yes or true */
1084 {Opt_utf8_yes, "utf8=yes"},
1085 {Opt_utf8_yes, "utf8=true"},
1086 {Opt_utf8_yes, "utf8"},
1087 {Opt_uni_xl_no, "uni_xlate=0"}, /* 0 or no or false */
1088 {Opt_uni_xl_no, "uni_xlate=no"},
1089 {Opt_uni_xl_no, "uni_xlate=false"},
1090 {Opt_uni_xl_yes, "uni_xlate=1"}, /* empty or 1 or yes or true */
1091 {Opt_uni_xl_yes, "uni_xlate=yes"},
1092 {Opt_uni_xl_yes, "uni_xlate=true"},
1093 {Opt_uni_xl_yes, "uni_xlate"},
1094 {Opt_nonumtail_no, "nonumtail=0"}, /* 0 or no or false */
1095 {Opt_nonumtail_no, "nonumtail=no"},
1096 {Opt_nonumtail_no, "nonumtail=false"},
1097 {Opt_nonumtail_yes, "nonumtail=1"}, /* empty or 1 or yes or true */
1098 {Opt_nonumtail_yes, "nonumtail=yes"},
1099 {Opt_nonumtail_yes, "nonumtail=true"},
1100 {Opt_nonumtail_yes, "nonumtail"},
OGAWA Hirofumidfc209c2008-11-06 12:53:55 -08001101 {Opt_rodir, "rodir"},
Linus Torvalds1da177e2005-04-16 15:20:36 -07001102 {Opt_err, NULL}
1103};
1104
Alexey Fisher869f58c2011-04-12 21:08:38 +09001105static int parse_options(struct super_block *sb, char *options, int is_vfat,
1106 int silent, int *debug, struct fat_mount_options *opts)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001107{
1108 char *p;
1109 substring_t args[MAX_OPT_ARGS];
1110 int option;
1111 char *iocharset;
1112
1113 opts->isvfat = is_vfat;
1114
David Howellsf0ce7ee2008-11-14 10:38:52 +11001115 opts->fs_uid = current_uid();
1116 opts->fs_gid = current_gid();
OGAWA Hirofumi3e107602009-06-20 21:50:07 +09001117 opts->fs_fmask = opts->fs_dmask = current_umask();
OGAWA Hirofumi1ae43f82008-04-28 02:16:26 -07001118 opts->allow_utime = -1;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001119 opts->codepage = fat_default_codepage;
1120 opts->iocharset = fat_default_iocharset;
OGAWA Hirofumidfc209c2008-11-06 12:53:55 -08001121 if (is_vfat) {
Paul Wise95523472009-08-01 21:30:31 +09001122 opts->shortname = VFAT_SFN_DISPLAY_WINNT|VFAT_SFN_CREATE_WIN95;
OGAWA Hirofumidfc209c2008-11-06 12:53:55 -08001123 opts->rodir = 0;
1124 } else {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001125 opts->shortname = 0;
OGAWA Hirofumidfc209c2008-11-06 12:53:55 -08001126 opts->rodir = 1;
1127 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001128 opts->name_check = 'n';
1129 opts->quiet = opts->showexec = opts->sys_immutable = opts->dotsOK = 0;
1130 opts->utf8 = opts->unicode_xlate = 0;
1131 opts->numtail = 1;
OGAWA Hirofumi28ec0392007-05-08 00:31:01 -07001132 opts->usefree = opts->nocase = 0;
Jan Kara58156c82012-12-17 16:02:58 -08001133 opts->tz_set = 0;
Steven J. Magnani7669e8f2012-10-04 17:14:45 -07001134 opts->nfs = 0;
Denis Karpov85c78592009-06-04 02:34:22 +09001135 opts->errors = FAT_ERRORS_RO;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001136 *debug = 0;
1137
1138 if (!options)
OGAWA Hirofumi8d44d972008-07-25 01:46:41 -07001139 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001140
1141 while ((p = strsep(&options, ",")) != NULL) {
1142 int token;
1143 if (!*p)
1144 continue;
1145
1146 token = match_token(p, fat_tokens, args);
1147 if (token == Opt_err) {
1148 if (is_vfat)
1149 token = match_token(p, vfat_tokens, args);
1150 else
1151 token = match_token(p, msdos_tokens, args);
1152 }
1153 switch (token) {
1154 case Opt_check_s:
1155 opts->name_check = 's';
1156 break;
1157 case Opt_check_r:
1158 opts->name_check = 'r';
1159 break;
1160 case Opt_check_n:
1161 opts->name_check = 'n';
1162 break;
OGAWA Hirofumi28ec0392007-05-08 00:31:01 -07001163 case Opt_usefree:
1164 opts->usefree = 1;
1165 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001166 case Opt_nocase:
1167 if (!is_vfat)
1168 opts->nocase = 1;
1169 else {
1170 /* for backward compatibility */
1171 opts->shortname = VFAT_SFN_DISPLAY_WIN95
1172 | VFAT_SFN_CREATE_WIN95;
1173 }
1174 break;
1175 case Opt_quiet:
1176 opts->quiet = 1;
1177 break;
1178 case Opt_showexec:
1179 opts->showexec = 1;
1180 break;
1181 case Opt_debug:
1182 *debug = 1;
1183 break;
1184 case Opt_immutable:
1185 opts->sys_immutable = 1;
1186 break;
1187 case Opt_uid:
1188 if (match_int(&args[0], &option))
Jan Kara5b3d5ae2012-12-17 16:02:59 -08001189 return -EINVAL;
Eric W. Biederman170782e2012-02-07 16:25:39 -08001190 opts->fs_uid = make_kuid(current_user_ns(), option);
1191 if (!uid_valid(opts->fs_uid))
Jan Kara5b3d5ae2012-12-17 16:02:59 -08001192 return -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001193 break;
1194 case Opt_gid:
1195 if (match_int(&args[0], &option))
Jan Kara5b3d5ae2012-12-17 16:02:59 -08001196 return -EINVAL;
Eric W. Biederman170782e2012-02-07 16:25:39 -08001197 opts->fs_gid = make_kgid(current_user_ns(), option);
1198 if (!gid_valid(opts->fs_gid))
Jan Kara5b3d5ae2012-12-17 16:02:59 -08001199 return -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001200 break;
1201 case Opt_umask:
1202 if (match_octal(&args[0], &option))
Jan Kara5b3d5ae2012-12-17 16:02:59 -08001203 return -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001204 opts->fs_fmask = opts->fs_dmask = option;
1205 break;
1206 case Opt_dmask:
1207 if (match_octal(&args[0], &option))
Jan Kara5b3d5ae2012-12-17 16:02:59 -08001208 return -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001209 opts->fs_dmask = option;
1210 break;
1211 case Opt_fmask:
1212 if (match_octal(&args[0], &option))
Jan Kara5b3d5ae2012-12-17 16:02:59 -08001213 return -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001214 opts->fs_fmask = option;
1215 break;
OGAWA Hirofumi1ae43f82008-04-28 02:16:26 -07001216 case Opt_allow_utime:
1217 if (match_octal(&args[0], &option))
Jan Kara5b3d5ae2012-12-17 16:02:59 -08001218 return -EINVAL;
OGAWA Hirofumi1ae43f82008-04-28 02:16:26 -07001219 opts->allow_utime = option & (S_IWGRP | S_IWOTH);
1220 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001221 case Opt_codepage:
1222 if (match_int(&args[0], &option))
Jan Kara5b3d5ae2012-12-17 16:02:59 -08001223 return -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001224 opts->codepage = option;
1225 break;
Chris Masonae78bf92006-09-29 02:00:03 -07001226 case Opt_flush:
1227 opts->flush = 1;
1228 break;
Jan Kara58156c82012-12-17 16:02:58 -08001229 case Opt_time_offset:
1230 if (match_int(&args[0], &option))
Jan Kara5b3d5ae2012-12-17 16:02:59 -08001231 return -EINVAL;
Jan Karaa513d862016-01-20 14:59:35 -08001232 /*
1233 * GMT+-12 zones may have DST corrections so at least
1234 * 13 hours difference is needed. Make the limit 24
1235 * just in case someone invents something unusual.
1236 */
1237 if (option < -24 * 60 || option > 24 * 60)
Jan Kara5b3d5ae2012-12-17 16:02:59 -08001238 return -EINVAL;
Jan Kara58156c82012-12-17 16:02:58 -08001239 opts->tz_set = 1;
1240 opts->time_offset = option;
1241 break;
Joe Petersonb271e062008-07-25 01:46:47 -07001242 case Opt_tz_utc:
Jan Kara58156c82012-12-17 16:02:58 -08001243 opts->tz_set = 1;
1244 opts->time_offset = 0;
Joe Petersonb271e062008-07-25 01:46:47 -07001245 break;
Denis Karpov85c78592009-06-04 02:34:22 +09001246 case Opt_err_cont:
1247 opts->errors = FAT_ERRORS_CONT;
1248 break;
1249 case Opt_err_panic:
1250 opts->errors = FAT_ERRORS_PANIC;
1251 break;
1252 case Opt_err_ro:
1253 opts->errors = FAT_ERRORS_RO;
1254 break;
Namjae Jeon2628b7a2013-04-29 16:21:08 -07001255 case Opt_nfs_stale_rw:
1256 opts->nfs = FAT_NFS_STALE_RW;
1257 break;
1258 case Opt_nfs_nostale_ro:
1259 opts->nfs = FAT_NFS_NOSTALE_RO;
1260 break;
Conrad Meyer190a8842014-06-06 14:36:37 -07001261 case Opt_dos1xfloppy:
1262 opts->dos1xfloppy = 1;
1263 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001264
1265 /* msdos specific */
1266 case Opt_dots:
1267 opts->dotsOK = 1;
1268 break;
1269 case Opt_nodots:
1270 opts->dotsOK = 0;
1271 break;
1272
1273 /* vfat specific */
1274 case Opt_charset:
1275 if (opts->iocharset != fat_default_iocharset)
1276 kfree(opts->iocharset);
1277 iocharset = match_strdup(&args[0]);
1278 if (!iocharset)
1279 return -ENOMEM;
1280 opts->iocharset = iocharset;
1281 break;
1282 case Opt_shortname_lower:
1283 opts->shortname = VFAT_SFN_DISPLAY_LOWER
1284 | VFAT_SFN_CREATE_WIN95;
1285 break;
1286 case Opt_shortname_win95:
1287 opts->shortname = VFAT_SFN_DISPLAY_WIN95
1288 | VFAT_SFN_CREATE_WIN95;
1289 break;
1290 case Opt_shortname_winnt:
1291 opts->shortname = VFAT_SFN_DISPLAY_WINNT
1292 | VFAT_SFN_CREATE_WINNT;
1293 break;
1294 case Opt_shortname_mixed:
1295 opts->shortname = VFAT_SFN_DISPLAY_WINNT
1296 | VFAT_SFN_CREATE_WIN95;
1297 break;
1298 case Opt_utf8_no: /* 0 or no or false */
1299 opts->utf8 = 0;
1300 break;
1301 case Opt_utf8_yes: /* empty or 1 or yes or true */
1302 opts->utf8 = 1;
1303 break;
1304 case Opt_uni_xl_no: /* 0 or no or false */
1305 opts->unicode_xlate = 0;
1306 break;
1307 case Opt_uni_xl_yes: /* empty or 1 or yes or true */
1308 opts->unicode_xlate = 1;
1309 break;
1310 case Opt_nonumtail_no: /* 0 or no or false */
1311 opts->numtail = 1; /* negated option */
1312 break;
1313 case Opt_nonumtail_yes: /* empty or 1 or yes or true */
1314 opts->numtail = 0; /* negated option */
1315 break;
OGAWA Hirofumidfc209c2008-11-06 12:53:55 -08001316 case Opt_rodir:
1317 opts->rodir = 1;
1318 break;
Christoph Hellwig681142f2009-11-21 20:28:52 +09001319 case Opt_discard:
1320 opts->discard = 1;
1321 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001322
1323 /* obsolete mount options */
Geert Uytterhoevend7a83c02011-10-31 20:50:45 +01001324 case Opt_obsolete:
Alexey Fisher869f58c2011-04-12 21:08:38 +09001325 fat_msg(sb, KERN_INFO, "\"%s\" option is obsolete, "
1326 "not supported now", p);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001327 break;
1328 /* unknown option */
1329 default:
Christoph Hellwig41a34a42005-11-08 21:34:57 -08001330 if (!silent) {
Alexey Fisher869f58c2011-04-12 21:08:38 +09001331 fat_msg(sb, KERN_ERR,
1332 "Unrecognized mount option \"%s\" "
1333 "or missing value", p);
Christoph Hellwig41a34a42005-11-08 21:34:57 -08001334 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001335 return -EINVAL;
1336 }
1337 }
OGAWA Hirofumi8d44d972008-07-25 01:46:41 -07001338
1339out:
Alexey Dobriyan4de151d2006-03-22 00:13:35 +01001340 /* UTF-8 doesn't provide FAT semantics */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001341 if (!strcmp(opts->iocharset, "utf8")) {
Mihai Moldovan186b5372011-08-17 19:10:08 +09001342 fat_msg(sb, KERN_WARNING, "utf8 is not a recommended IO charset"
OGAWA Hirofumi8d44d972008-07-25 01:46:41 -07001343 " for FAT filesystems, filesystem will be "
Mihai Moldovan186b5372011-08-17 19:10:08 +09001344 "case sensitive!");
Linus Torvalds1da177e2005-04-16 15:20:36 -07001345 }
1346
OGAWA Hirofumi1ae43f82008-04-28 02:16:26 -07001347 /* If user doesn't specify allow_utime, it's initialized from dmask. */
1348 if (opts->allow_utime == (unsigned short)-1)
1349 opts->allow_utime = ~opts->fs_dmask & (S_IWGRP | S_IWOTH);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001350 if (opts->unicode_xlate)
1351 opts->utf8 = 0;
Namjae Jeonea3983a2013-04-29 16:21:11 -07001352 if (opts->nfs == FAT_NFS_NOSTALE_RO) {
Namjae Jeon2628b7a2013-04-29 16:21:08 -07001353 sb->s_flags |= MS_RDONLY;
Namjae Jeonea3983a2013-04-29 16:21:11 -07001354 sb->s_export_op = &fat_export_ops_nostale;
1355 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001356
1357 return 0;
1358}
1359
1360static int fat_read_root(struct inode *inode)
1361{
Alexander Kuleshova40a7d92015-04-16 12:47:21 -07001362 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001363 int error;
1364
Namjae Jeonea3983a2013-04-29 16:21:11 -07001365 MSDOS_I(inode)->i_pos = MSDOS_ROOT_INO;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001366 inode->i_uid = sbi->options.fs_uid;
1367 inode->i_gid = sbi->options.fs_gid;
1368 inode->i_version++;
1369 inode->i_generation = 0;
OGAWA Hirofumi9c0aa1b2008-11-06 12:53:54 -08001370 inode->i_mode = fat_make_mode(sbi, ATTR_DIR, S_IRWXUGO);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001371 inode->i_op = sbi->dir_ops;
1372 inode->i_fop = &fat_dir_operations;
1373 if (sbi->fat_bits == 32) {
1374 MSDOS_I(inode)->i_start = sbi->root_cluster;
1375 error = fat_calc_dir_size(inode);
1376 if (error < 0)
1377 return error;
1378 } else {
1379 MSDOS_I(inode)->i_start = 0;
1380 inode->i_size = sbi->dir_entries * sizeof(struct msdos_dir_entry);
1381 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001382 inode->i_blocks = ((inode->i_size + (sbi->cluster_size - 1))
1383 & ~((loff_t)sbi->cluster_size - 1)) >> 9;
1384 MSDOS_I(inode)->i_logstart = 0;
1385 MSDOS_I(inode)->mmu_private = inode->i_size;
1386
OGAWA Hirofumi9c0aa1b2008-11-06 12:53:54 -08001387 fat_save_attrs(inode, ATTR_DIR);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001388 inode->i_mtime.tv_sec = inode->i_atime.tv_sec = inode->i_ctime.tv_sec = 0;
1389 inode->i_mtime.tv_nsec = inode->i_atime.tv_nsec = inode->i_ctime.tv_nsec = 0;
Miklos Szeredibfe86842011-10-28 14:13:29 +02001390 set_nlink(inode, fat_subdirs(inode)+2);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001391
1392 return 0;
1393}
1394
OGAWA Hirofumi7b92d032013-05-24 15:55:08 -07001395static unsigned long calc_fat_clusters(struct super_block *sb)
1396{
1397 struct msdos_sb_info *sbi = MSDOS_SB(sb);
1398
1399 /* Divide first to avoid overflow */
1400 if (sbi->fat_bits != 12) {
1401 unsigned long ent_per_sec = sb->s_blocksize * 8 / sbi->fat_bits;
1402 return ent_per_sec * sbi->fat_length;
1403 }
1404
1405 return sbi->fat_length * sb->s_blocksize * 8 / sbi->fat_bits;
1406}
1407
Conrad Meyer190a8842014-06-06 14:36:37 -07001408static bool fat_bpb_is_zero(struct fat_boot_sector *b)
1409{
1410 if (get_unaligned_le16(&b->sector_size))
1411 return false;
1412 if (b->sec_per_clus)
1413 return false;
1414 if (b->reserved)
1415 return false;
1416 if (b->fats)
1417 return false;
1418 if (get_unaligned_le16(&b->dir_entries))
1419 return false;
1420 if (get_unaligned_le16(&b->sectors))
1421 return false;
1422 if (b->media)
1423 return false;
1424 if (b->fat_length)
1425 return false;
1426 if (b->secs_track)
1427 return false;
1428 if (b->heads)
1429 return false;
1430 return true;
1431}
1432
1433static int fat_read_bpb(struct super_block *sb, struct fat_boot_sector *b,
1434 int silent, struct fat_bios_param_block *bpb)
1435{
1436 int error = -EINVAL;
1437
1438 /* Read in BPB ... */
1439 memset(bpb, 0, sizeof(*bpb));
1440 bpb->fat_sector_size = get_unaligned_le16(&b->sector_size);
1441 bpb->fat_sec_per_clus = b->sec_per_clus;
1442 bpb->fat_reserved = le16_to_cpu(b->reserved);
1443 bpb->fat_fats = b->fats;
1444 bpb->fat_dir_entries = get_unaligned_le16(&b->dir_entries);
1445 bpb->fat_sectors = get_unaligned_le16(&b->sectors);
1446 bpb->fat_fat_length = le16_to_cpu(b->fat_length);
1447 bpb->fat_total_sect = le32_to_cpu(b->total_sect);
1448
1449 bpb->fat16_state = b->fat16.state;
1450 bpb->fat16_vol_id = get_unaligned_le32(b->fat16.vol_id);
1451
1452 bpb->fat32_length = le32_to_cpu(b->fat32.length);
1453 bpb->fat32_root_cluster = le32_to_cpu(b->fat32.root_cluster);
1454 bpb->fat32_info_sector = le16_to_cpu(b->fat32.info_sector);
1455 bpb->fat32_state = b->fat32.state;
1456 bpb->fat32_vol_id = get_unaligned_le32(b->fat32.vol_id);
1457
1458 /* Validate this looks like a FAT filesystem BPB */
1459 if (!bpb->fat_reserved) {
1460 if (!silent)
1461 fat_msg(sb, KERN_ERR,
1462 "bogus number of reserved sectors");
1463 goto out;
1464 }
1465 if (!bpb->fat_fats) {
1466 if (!silent)
1467 fat_msg(sb, KERN_ERR, "bogus number of FAT structure");
1468 goto out;
1469 }
1470
1471 /*
1472 * Earlier we checked here that b->secs_track and b->head are nonzero,
1473 * but it turns out valid FAT filesystems can have zero there.
1474 */
1475
1476 if (!fat_valid_media(b->media)) {
1477 if (!silent)
1478 fat_msg(sb, KERN_ERR, "invalid media value (0x%02x)",
1479 (unsigned)b->media);
1480 goto out;
1481 }
1482
1483 if (!is_power_of_2(bpb->fat_sector_size)
1484 || (bpb->fat_sector_size < 512)
1485 || (bpb->fat_sector_size > 4096)) {
1486 if (!silent)
1487 fat_msg(sb, KERN_ERR, "bogus logical sector size %u",
1488 (unsigned)bpb->fat_sector_size);
1489 goto out;
1490 }
1491
1492 if (!is_power_of_2(bpb->fat_sec_per_clus)) {
1493 if (!silent)
1494 fat_msg(sb, KERN_ERR, "bogus sectors per cluster %u",
1495 (unsigned)bpb->fat_sec_per_clus);
1496 goto out;
1497 }
1498
1499 error = 0;
1500
1501out:
1502 return error;
1503}
1504
1505static int fat_read_static_bpb(struct super_block *sb,
1506 struct fat_boot_sector *b, int silent,
1507 struct fat_bios_param_block *bpb)
1508{
1509 static const char *notdos1x = "This doesn't look like a DOS 1.x volume";
1510
1511 struct fat_floppy_defaults *fdefaults = NULL;
1512 int error = -EINVAL;
1513 sector_t bd_sects;
1514 unsigned i;
1515
1516 bd_sects = i_size_read(sb->s_bdev->bd_inode) / SECTOR_SIZE;
1517
1518 /* 16-bit DOS 1.x reliably wrote bootstrap short-jmp code */
1519 if (b->ignored[0] != 0xeb || b->ignored[2] != 0x90) {
1520 if (!silent)
1521 fat_msg(sb, KERN_ERR,
1522 "%s; no bootstrapping code", notdos1x);
1523 goto out;
1524 }
1525
1526 /*
1527 * If any value in this region is non-zero, it isn't archaic
1528 * DOS.
1529 */
1530 if (!fat_bpb_is_zero(b)) {
1531 if (!silent)
1532 fat_msg(sb, KERN_ERR,
1533 "%s; DOS 2.x BPB is non-zero", notdos1x);
1534 goto out;
1535 }
1536
1537 for (i = 0; i < ARRAY_SIZE(floppy_defaults); i++) {
1538 if (floppy_defaults[i].nr_sectors == bd_sects) {
1539 fdefaults = &floppy_defaults[i];
1540 break;
1541 }
1542 }
1543
1544 if (fdefaults == NULL) {
1545 if (!silent)
1546 fat_msg(sb, KERN_WARNING,
1547 "This looks like a DOS 1.x volume, but isn't a recognized floppy size (%llu sectors)",
1548 (u64)bd_sects);
1549 goto out;
1550 }
1551
1552 if (!silent)
1553 fat_msg(sb, KERN_INFO,
1554 "This looks like a DOS 1.x volume; assuming default BPB values");
1555
1556 memset(bpb, 0, sizeof(*bpb));
1557 bpb->fat_sector_size = SECTOR_SIZE;
1558 bpb->fat_sec_per_clus = fdefaults->sec_per_clus;
1559 bpb->fat_reserved = 1;
1560 bpb->fat_fats = 2;
1561 bpb->fat_dir_entries = fdefaults->dir_entries;
1562 bpb->fat_sectors = fdefaults->nr_sectors;
1563 bpb->fat_fat_length = fdefaults->fat_length;
1564
1565 error = 0;
1566
1567out:
1568 return error;
1569}
1570
Linus Torvalds1da177e2005-04-16 15:20:36 -07001571/*
1572 * Read the super block of an MS-DOS FS.
1573 */
OGAWA Hirofumi384f5c92011-04-12 21:08:37 +09001574int fat_fill_super(struct super_block *sb, void *data, int silent, int isvfat,
Al Viro3d239852010-12-18 10:44:00 -05001575 void (*setup)(struct super_block *))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001576{
Al Virob5224122009-06-07 13:44:36 -04001577 struct inode *root_inode = NULL, *fat_inode = NULL;
Artem Bityutskiy020ac5b2012-05-31 16:26:12 -07001578 struct inode *fsinfo_inode = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001579 struct buffer_head *bh;
Conrad Meyer190a8842014-06-06 14:36:37 -07001580 struct fat_bios_param_block bpb;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001581 struct msdos_sb_info *sbi;
1582 u16 logical_sector_size;
1583 u32 total_sectors, total_clusters, fat_clusters, rootdir_sectors;
1584 int debug;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001585 long error;
1586 char buf[50];
1587
Linus Torvalds8f593422008-05-19 19:53:01 -07001588 /*
1589 * GFP_KERNEL is ok here, because while we do hold the
1590 * supeblock lock, memory pressure can't call back into
1591 * the filesystem, since we're only just about to mount
1592 * it and have no inodes etc active!
1593 */
Panagiotis Issarisf8314dc2006-09-27 01:49:37 -07001594 sbi = kzalloc(sizeof(struct msdos_sb_info), GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001595 if (!sbi)
1596 return -ENOMEM;
1597 sb->s_fs_info = sbi;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001598
1599 sb->s_flags |= MS_NODIRATIME;
1600 sb->s_magic = MSDOS_SUPER_MAGIC;
1601 sb->s_op = &fat_sops;
1602 sb->s_export_op = &fat_export_ops;
Namjae Jeon8fceb4e2013-04-29 16:21:12 -07001603 mutex_init(&sbi->nfs_build_inode_lock);
OGAWA Hirofumiaaa04b42010-05-24 14:33:12 -07001604 ratelimit_state_init(&sbi->ratelimit, DEFAULT_RATELIMIT_INTERVAL,
1605 DEFAULT_RATELIMIT_BURST);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001606
Alexey Fisher869f58c2011-04-12 21:08:38 +09001607 error = parse_options(sb, data, isvfat, silent, &debug, &sbi->options);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001608 if (error)
1609 goto out_fail;
1610
Al Viro3d239852010-12-18 10:44:00 -05001611 setup(sb); /* flavour-specific stuff that needs options */
1612
Linus Torvalds1da177e2005-04-16 15:20:36 -07001613 error = -EIO;
1614 sb_min_blocksize(sb, 512);
1615 bh = sb_bread(sb, 0);
1616 if (bh == NULL) {
Alexey Fisher869f58c2011-04-12 21:08:38 +09001617 fat_msg(sb, KERN_ERR, "unable to read boot sector");
Linus Torvalds1da177e2005-04-16 15:20:36 -07001618 goto out_fail;
1619 }
1620
Conrad Meyer190a8842014-06-06 14:36:37 -07001621 error = fat_read_bpb(sb, (struct fat_boot_sector *)bh->b_data, silent,
1622 &bpb);
1623 if (error == -EINVAL && sbi->options.dos1xfloppy)
1624 error = fat_read_static_bpb(sb,
1625 (struct fat_boot_sector *)bh->b_data, silent, &bpb);
1626 brelse(bh);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001627
Conrad Meyer190a8842014-06-06 14:36:37 -07001628 if (error == -EINVAL)
1629 goto out_invalid;
1630 else if (error)
1631 goto out_fail;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001632
Conrad Meyer190a8842014-06-06 14:36:37 -07001633 logical_sector_size = bpb.fat_sector_size;
1634 sbi->sec_per_clus = bpb.fat_sec_per_clus;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001635
Conrad Meyer190a8842014-06-06 14:36:37 -07001636 error = -EIO;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001637 if (logical_sector_size < sb->s_blocksize) {
Alexey Fisher869f58c2011-04-12 21:08:38 +09001638 fat_msg(sb, KERN_ERR, "logical sector size too small for device"
1639 " (logical sector size = %u)", logical_sector_size);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001640 goto out_fail;
1641 }
Conrad Meyer190a8842014-06-06 14:36:37 -07001642
Linus Torvalds1da177e2005-04-16 15:20:36 -07001643 if (logical_sector_size > sb->s_blocksize) {
Conrad Meyer190a8842014-06-06 14:36:37 -07001644 struct buffer_head *bh_resize;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001645
1646 if (!sb_set_blocksize(sb, logical_sector_size)) {
Alexey Fisher869f58c2011-04-12 21:08:38 +09001647 fat_msg(sb, KERN_ERR, "unable to set blocksize %u",
Linus Torvalds1da177e2005-04-16 15:20:36 -07001648 logical_sector_size);
1649 goto out_fail;
1650 }
Conrad Meyer190a8842014-06-06 14:36:37 -07001651
1652 /* Verify that the larger boot sector is fully readable */
1653 bh_resize = sb_bread(sb, 0);
1654 if (bh_resize == NULL) {
Alexey Fisher869f58c2011-04-12 21:08:38 +09001655 fat_msg(sb, KERN_ERR, "unable to read boot sector"
1656 " (logical sector size = %lu)",
Linus Torvalds1da177e2005-04-16 15:20:36 -07001657 sb->s_blocksize);
1658 goto out_fail;
1659 }
Conrad Meyer190a8842014-06-06 14:36:37 -07001660 brelse(bh_resize);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001661 }
1662
Marco Stornellie40b34c2012-10-06 12:40:03 +02001663 mutex_init(&sbi->s_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001664 sbi->cluster_size = sb->s_blocksize * sbi->sec_per_clus;
1665 sbi->cluster_bits = ffs(sbi->cluster_size) - 1;
Conrad Meyer190a8842014-06-06 14:36:37 -07001666 sbi->fats = bpb.fat_fats;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001667 sbi->fat_bits = 0; /* Don't know yet */
Conrad Meyer190a8842014-06-06 14:36:37 -07001668 sbi->fat_start = bpb.fat_reserved;
1669 sbi->fat_length = bpb.fat_fat_length;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001670 sbi->root_cluster = 0;
1671 sbi->free_clusters = -1; /* Don't know yet */
OGAWA Hirofumi606e4232008-04-28 02:16:27 -07001672 sbi->free_clus_valid = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001673 sbi->prev_free = FAT_START_ENT;
Namjae Jeon710d4402011-08-17 19:10:09 +09001674 sb->s_maxbytes = 0xffffffff;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001675
Conrad Meyer190a8842014-06-06 14:36:37 -07001676 if (!sbi->fat_length && bpb.fat32_length) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001677 struct fat_boot_fsinfo *fsinfo;
1678 struct buffer_head *fsinfo_bh;
1679
1680 /* Must be FAT32 */
1681 sbi->fat_bits = 32;
Conrad Meyer190a8842014-06-06 14:36:37 -07001682 sbi->fat_length = bpb.fat32_length;
1683 sbi->root_cluster = bpb.fat32_root_cluster;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001684
Linus Torvalds1da177e2005-04-16 15:20:36 -07001685 /* MC - if info_sector is 0, don't multiply by 0 */
Conrad Meyer190a8842014-06-06 14:36:37 -07001686 sbi->fsinfo_sector = bpb.fat32_info_sector;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001687 if (sbi->fsinfo_sector == 0)
1688 sbi->fsinfo_sector = 1;
1689
1690 fsinfo_bh = sb_bread(sb, sbi->fsinfo_sector);
1691 if (fsinfo_bh == NULL) {
Alexey Fisher869f58c2011-04-12 21:08:38 +09001692 fat_msg(sb, KERN_ERR, "bread failed, FSINFO block"
1693 " (sector = %lu)", sbi->fsinfo_sector);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001694 goto out_fail;
1695 }
1696
1697 fsinfo = (struct fat_boot_fsinfo *)fsinfo_bh->b_data;
1698 if (!IS_FSINFO(fsinfo)) {
Alexey Fisher869f58c2011-04-12 21:08:38 +09001699 fat_msg(sb, KERN_WARNING, "Invalid FSINFO signature: "
1700 "0x%08x, 0x%08x (sector = %lu)",
Linus Torvalds1da177e2005-04-16 15:20:36 -07001701 le32_to_cpu(fsinfo->signature1),
1702 le32_to_cpu(fsinfo->signature2),
1703 sbi->fsinfo_sector);
1704 } else {
OGAWA Hirofumi28ec0392007-05-08 00:31:01 -07001705 if (sbi->options.usefree)
OGAWA Hirofumi606e4232008-04-28 02:16:27 -07001706 sbi->free_clus_valid = 1;
1707 sbi->free_clusters = le32_to_cpu(fsinfo->free_clusters);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001708 sbi->prev_free = le32_to_cpu(fsinfo->next_cluster);
1709 }
1710
1711 brelse(fsinfo_bh);
1712 }
1713
Mike Lockwood6e5b93e2013-07-08 16:00:46 -07001714 /* interpret volume ID as a little endian 32 bit integer */
1715 if (sbi->fat_bits == 32)
Conrad Meyer190a8842014-06-06 14:36:37 -07001716 sbi->vol_id = bpb.fat32_vol_id;
Mike Lockwood6e5b93e2013-07-08 16:00:46 -07001717 else /* fat 16 or 12 */
Conrad Meyer190a8842014-06-06 14:36:37 -07001718 sbi->vol_id = bpb.fat16_vol_id;
Mike Lockwood6e5b93e2013-07-08 16:00:46 -07001719
Linus Torvalds1da177e2005-04-16 15:20:36 -07001720 sbi->dir_per_block = sb->s_blocksize / sizeof(struct msdos_dir_entry);
1721 sbi->dir_per_block_bits = ffs(sbi->dir_per_block) - 1;
1722
1723 sbi->dir_start = sbi->fat_start + sbi->fats * sbi->fat_length;
Conrad Meyer190a8842014-06-06 14:36:37 -07001724 sbi->dir_entries = bpb.fat_dir_entries;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001725 if (sbi->dir_entries & (sbi->dir_per_block - 1)) {
1726 if (!silent)
Ravishankar Nc39540c2012-12-20 15:05:46 -08001727 fat_msg(sb, KERN_ERR, "bogus directory-entries per block"
Alexey Fisher869f58c2011-04-12 21:08:38 +09001728 " (%u)", sbi->dir_entries);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001729 goto out_invalid;
1730 }
1731
1732 rootdir_sectors = sbi->dir_entries
1733 * sizeof(struct msdos_dir_entry) / sb->s_blocksize;
1734 sbi->data_start = sbi->dir_start + rootdir_sectors;
Conrad Meyer190a8842014-06-06 14:36:37 -07001735 total_sectors = bpb.fat_sectors;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001736 if (total_sectors == 0)
Conrad Meyer190a8842014-06-06 14:36:37 -07001737 total_sectors = bpb.fat_total_sect;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001738
1739 total_clusters = (total_sectors - sbi->data_start) / sbi->sec_per_clus;
1740
1741 if (sbi->fat_bits != 32)
1742 sbi->fat_bits = (total_clusters > MAX_FAT12) ? 16 : 12;
1743
Oleksij Rempelb88a10582013-02-27 17:03:09 -08001744 /* some OSes set FAT_STATE_DIRTY and clean it on unmount. */
1745 if (sbi->fat_bits == 32)
Conrad Meyer190a8842014-06-06 14:36:37 -07001746 sbi->dirty = bpb.fat32_state & FAT_STATE_DIRTY;
Oleksij Rempelb88a10582013-02-27 17:03:09 -08001747 else /* fat 16 or 12 */
Conrad Meyer190a8842014-06-06 14:36:37 -07001748 sbi->dirty = bpb.fat16_state & FAT_STATE_DIRTY;
Oleksij Rempelb88a10582013-02-27 17:03:09 -08001749
Linus Torvalds1da177e2005-04-16 15:20:36 -07001750 /* check that FAT table does not overflow */
OGAWA Hirofumi7b92d032013-05-24 15:55:08 -07001751 fat_clusters = calc_fat_clusters(sb);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001752 total_clusters = min(total_clusters, fat_clusters - FAT_START_ENT);
1753 if (total_clusters > MAX_FAT(sb)) {
1754 if (!silent)
Alexey Fisher869f58c2011-04-12 21:08:38 +09001755 fat_msg(sb, KERN_ERR, "count of clusters too big (%u)",
Linus Torvalds1da177e2005-04-16 15:20:36 -07001756 total_clusters);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001757 goto out_invalid;
1758 }
1759
1760 sbi->max_cluster = total_clusters + FAT_START_ENT;
1761 /* check the free_clusters, it's not necessarily correct */
1762 if (sbi->free_clusters != -1 && sbi->free_clusters > total_clusters)
1763 sbi->free_clusters = -1;
1764 /* check the prev_free, it's not necessarily correct */
1765 sbi->prev_free %= sbi->max_cluster;
1766 if (sbi->prev_free < FAT_START_ENT)
1767 sbi->prev_free = FAT_START_ENT;
1768
Linus Torvalds1da177e2005-04-16 15:20:36 -07001769 /* set up enough so that it can read an inode */
1770 fat_hash_init(sb);
Steven J. Magnani7669e8f2012-10-04 17:14:45 -07001771 dir_hash_init(sb);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001772 fat_ent_access_init(sb);
1773
1774 /*
1775 * The low byte of FAT's first entry must have same value with
1776 * media-field. But in real world, too many devices is
1777 * writing wrong value. So, removed that validity check.
1778 *
1779 * if (FAT_FIRST_ENT(sb, media) != first)
1780 */
1781
1782 error = -EINVAL;
1783 sprintf(buf, "cp%d", sbi->options.codepage);
1784 sbi->nls_disk = load_nls(buf);
1785 if (!sbi->nls_disk) {
Alexey Fisher869f58c2011-04-12 21:08:38 +09001786 fat_msg(sb, KERN_ERR, "codepage %s not found", buf);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001787 goto out_fail;
1788 }
1789
1790 /* FIXME: utf8 is using iocharset for upper/lower conversion */
1791 if (sbi->options.isvfat) {
1792 sbi->nls_io = load_nls(sbi->options.iocharset);
1793 if (!sbi->nls_io) {
Alexey Fisher869f58c2011-04-12 21:08:38 +09001794 fat_msg(sb, KERN_ERR, "IO charset %s not found",
Linus Torvalds1da177e2005-04-16 15:20:36 -07001795 sbi->options.iocharset);
1796 goto out_fail;
1797 }
1798 }
1799
1800 error = -ENOMEM;
Al Virob5224122009-06-07 13:44:36 -04001801 fat_inode = new_inode(sb);
1802 if (!fat_inode)
1803 goto out_fail;
1804 MSDOS_I(fat_inode)->i_pos = 0;
1805 sbi->fat_inode = fat_inode;
Artem Bityutskiy020ac5b2012-05-31 16:26:12 -07001806
1807 fsinfo_inode = new_inode(sb);
1808 if (!fsinfo_inode)
1809 goto out_fail;
1810 fsinfo_inode->i_ino = MSDOS_FSINFO_INO;
1811 sbi->fsinfo_inode = fsinfo_inode;
1812 insert_inode_hash(fsinfo_inode);
1813
Linus Torvalds1da177e2005-04-16 15:20:36 -07001814 root_inode = new_inode(sb);
1815 if (!root_inode)
1816 goto out_fail;
1817 root_inode->i_ino = MSDOS_ROOT_INO;
1818 root_inode->i_version = 1;
1819 error = fat_read_root(root_inode);
Al Viro1688f862012-02-12 22:06:33 -05001820 if (error < 0) {
1821 iput(root_inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001822 goto out_fail;
Al Viro1688f862012-02-12 22:06:33 -05001823 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001824 error = -ENOMEM;
1825 insert_inode_hash(root_inode);
Steven J. Magnani7669e8f2012-10-04 17:14:45 -07001826 fat_attach(root_inode, 0);
Al Viro1688f862012-02-12 22:06:33 -05001827 sb->s_root = d_make_root(root_inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001828 if (!sb->s_root) {
Alexey Fisher869f58c2011-04-12 21:08:38 +09001829 fat_msg(sb, KERN_ERR, "get root inode failed");
Linus Torvalds1da177e2005-04-16 15:20:36 -07001830 goto out_fail;
1831 }
1832
Namjae Jeonf5621462012-12-17 16:02:56 -08001833 if (sbi->options.discard) {
1834 struct request_queue *q = bdev_get_queue(sb->s_bdev);
1835 if (!blk_queue_discard(q))
1836 fat_msg(sb, KERN_WARNING,
1837 "mounting with \"discard\" option, but "
1838 "the device does not support discard");
1839 }
1840
Oleksij Rempelb88a10582013-02-27 17:03:09 -08001841 fat_set_state(sb, 1, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001842 return 0;
1843
1844out_invalid:
1845 error = -EINVAL;
1846 if (!silent)
Alexey Fisher869f58c2011-04-12 21:08:38 +09001847 fat_msg(sb, KERN_INFO, "Can't find a valid FAT filesystem");
Linus Torvalds1da177e2005-04-16 15:20:36 -07001848
1849out_fail:
Artem Bityutskiy020ac5b2012-05-31 16:26:12 -07001850 if (fsinfo_inode)
1851 iput(fsinfo_inode);
Al Virob5224122009-06-07 13:44:36 -04001852 if (fat_inode)
1853 iput(fat_inode);
OGAWA Hirofumi1bdb6f92010-03-16 05:48:09 +09001854 unload_nls(sbi->nls_io);
1855 unload_nls(sbi->nls_disk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001856 if (sbi->options.iocharset != fat_default_iocharset)
1857 kfree(sbi->options.iocharset);
1858 sb->s_fs_info = NULL;
1859 kfree(sbi);
1860 return error;
1861}
1862
OGAWA Hirofumi7c709d02006-01-08 01:02:10 -08001863EXPORT_SYMBOL_GPL(fat_fill_super);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001864
Chris Masonae78bf92006-09-29 02:00:03 -07001865/*
1866 * helper function for fat_flush_inodes. This writes both the inode
1867 * and the file data blocks, waiting for in flight data blocks before
1868 * the start of the call. It does not wait for any io started
1869 * during the call
1870 */
1871static int writeback_inode(struct inode *inode)
1872{
1873
1874 int ret;
Namjae Jeon14864652012-10-04 17:15:04 -07001875
1876 /* if we used wait=1, sync_inode_metadata waits for the io for the
1877 * inode to finish. So wait=0 is sent down to sync_inode_metadata
Chris Masonae78bf92006-09-29 02:00:03 -07001878 * and filemap_fdatawrite is used for the data blocks
1879 */
Namjae Jeon14864652012-10-04 17:15:04 -07001880 ret = sync_inode_metadata(inode, 0);
Chris Masonae78bf92006-09-29 02:00:03 -07001881 if (!ret)
Namjae Jeon14864652012-10-04 17:15:04 -07001882 ret = filemap_fdatawrite(inode->i_mapping);
Chris Masonae78bf92006-09-29 02:00:03 -07001883 return ret;
1884}
1885
1886/*
1887 * write data and metadata corresponding to i1 and i2. The io is
1888 * started but we do not wait for any of it to finish.
1889 *
1890 * filemap_flush is used for the block device, so if there is a dirty
1891 * page for a block already in flight, we will not wait and start the
1892 * io over again
1893 */
1894int fat_flush_inodes(struct super_block *sb, struct inode *i1, struct inode *i2)
1895{
1896 int ret = 0;
1897 if (!MSDOS_SB(sb)->options.flush)
1898 return 0;
1899 if (i1)
1900 ret = writeback_inode(i1);
1901 if (!ret && i2)
1902 ret = writeback_inode(i2);
Eric Sesterhenn97e860d2006-10-11 01:21:59 -07001903 if (!ret) {
Chris Masonae78bf92006-09-29 02:00:03 -07001904 struct address_space *mapping = sb->s_bdev->bd_inode->i_mapping;
1905 ret = filemap_flush(mapping);
1906 }
1907 return ret;
1908}
1909EXPORT_SYMBOL_GPL(fat_flush_inodes);
1910
Linus Torvalds1da177e2005-04-16 15:20:36 -07001911static int __init init_fat_fs(void)
1912{
Pekka J Enberg532a39a2005-06-30 02:59:01 -07001913 int err;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001914
Pekka J Enberg532a39a2005-06-30 02:59:01 -07001915 err = fat_cache_init();
1916 if (err)
1917 return err;
1918
1919 err = fat_init_inodecache();
1920 if (err)
1921 goto failed;
1922
1923 return 0;
1924
1925failed:
1926 fat_cache_destroy();
1927 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001928}
1929
1930static void __exit exit_fat_fs(void)
1931{
1932 fat_cache_destroy();
1933 fat_destroy_inodecache();
1934}
1935
1936module_init(init_fat_fs)
1937module_exit(exit_fat_fs)
1938
1939MODULE_LICENSE("GPL");