blob: d0b95c95079bbdc085a9746226427ceb3805bc45 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * linux/fs/fat/dir.c
3 *
4 * directory handling functions for fat-based filesystems
5 *
6 * Written 1992,1993 by Werner Almesberger
7 *
8 * Hidden files 1995 by Albert Cahalan <albert@ccs.neu.edu> <adc@coe.neu.edu>
9 *
10 * VFAT extensions by Gordon Chaffee <chaffee@plateau.cs.berkeley.edu>
11 * Merged with msdos fs by Henrik Storner <storner@osiris.ping.dk>
12 * Rewritten for constant inumbers. Plugged buffer overrun in readdir(). AV
13 * Short name translation 1999, 2001 by Wolfram Pienkoss <wp@bszh.de>
14 */
15
Linus Torvalds1da177e2005-04-16 15:20:36 -070016#include <linux/slab.h>
David Howells188f83d2006-08-31 12:50:04 +020017#include <linux/compat.h>
Cruz Julian Bishopf08b4982012-10-04 17:14:57 -070018#include <linux/uaccess.h>
OGAWA Hirofumi9e975da2008-11-06 12:53:46 -080019#include "fat.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -070020
Alan Stern74675a52009-04-30 10:08:18 -040021/*
22 * Maximum buffer size of short name.
23 * [(MSDOS_NAME + '.') * max one char + nul]
24 * For msdos style, ['.' (hidden) + MSDOS_NAME + '.' + nul]
25 */
26#define FAT_MAX_SHORT_SIZE ((MSDOS_NAME + 1) * NLS_MAX_CHARSET_SIZE + 1)
27/*
28 * Maximum buffer size of unicode chars from slots.
29 * [(max longname slots * 13 (size in a slot) + nul) * sizeof(wchar_t)]
30 */
31#define FAT_MAX_UNI_CHARS ((MSDOS_SLOTS - 1) * 13 + 1)
32#define FAT_MAX_UNI_SIZE (FAT_MAX_UNI_CHARS * sizeof(wchar_t))
33
Steven J. Magnanideb82742012-07-30 14:42:16 -070034static inline unsigned char fat_tolower(unsigned char c)
35{
36 return ((c >= 'A') && (c <= 'Z')) ? c+32 : c;
37}
38
Linus Torvalds1da177e2005-04-16 15:20:36 -070039static inline loff_t fat_make_i_pos(struct super_block *sb,
40 struct buffer_head *bh,
41 struct msdos_dir_entry *de)
42{
43 return ((loff_t)bh->b_blocknr << MSDOS_SB(sb)->dir_per_block_bits)
44 | (de - (struct msdos_dir_entry *)bh->b_data);
45}
46
Karsten Wiesef3ef6f62005-09-06 15:17:12 -070047static inline void fat_dir_readahead(struct inode *dir, sector_t iblock,
48 sector_t phys)
49{
50 struct super_block *sb = dir->i_sb;
51 struct msdos_sb_info *sbi = MSDOS_SB(sb);
52 struct buffer_head *bh;
53 int sec;
54
55 /* This is not a first sector of cluster, or sec_per_clus == 1 */
56 if ((iblock & (sbi->sec_per_clus - 1)) || sbi->sec_per_clus == 1)
57 return;
58 /* root dir of FAT12/FAT16 */
59 if ((sbi->fat_bits != 32) && (dir->i_ino == MSDOS_ROOT_INO))
60 return;
61
OGAWA Hirofumi83b7c992006-01-08 01:02:09 -080062 bh = sb_find_get_block(sb, phys);
63 if (bh == NULL || !buffer_uptodate(bh)) {
Karsten Wiesef3ef6f62005-09-06 15:17:12 -070064 for (sec = 0; sec < sbi->sec_per_clus; sec++)
65 sb_breadahead(sb, phys + sec);
66 }
67 brelse(bh);
68}
69
Linus Torvalds1da177e2005-04-16 15:20:36 -070070/* Returns the inode number of the directory entry at offset pos. If bh is
71 non-NULL, it is brelse'd before. Pos is incremented. The buffer header is
72 returned in bh.
73 AV. Most often we do it item-by-item. Makes sense to optimize.
74 AV. OK, there we go: if both bh and de are non-NULL we assume that we just
75 AV. want the next entry (took one explicit de=NULL in vfat/namei.c).
76 AV. It's done in fat_get_entry() (inlined), here the slow case lives.
77 AV. Additionally, when we return -1 (i.e. reached the end of directory)
78 AV. we make bh NULL.
79 */
80static int fat__get_entry(struct inode *dir, loff_t *pos,
81 struct buffer_head **bh, struct msdos_dir_entry **de)
82{
83 struct super_block *sb = dir->i_sb;
84 sector_t phys, iblock;
OGAWA Hirofumie5174ba2006-01-08 01:02:11 -080085 unsigned long mapped_blocks;
86 int err, offset;
Linus Torvalds1da177e2005-04-16 15:20:36 -070087
88next:
89 if (*bh)
90 brelse(*bh);
91
92 *bh = NULL;
93 iblock = *pos >> sb->s_blocksize_bits;
Namjae Jeon16fab202016-01-20 14:59:46 -080094 err = fat_bmap(dir, iblock, &phys, &mapped_blocks, 0, false);
Linus Torvalds1da177e2005-04-16 15:20:36 -070095 if (err || !phys)
96 return -1; /* beyond EOF or error */
97
Karsten Wiesef3ef6f62005-09-06 15:17:12 -070098 fat_dir_readahead(dir, iblock, phys);
99
Linus Torvalds1da177e2005-04-16 15:20:36 -0700100 *bh = sb_bread(sb, phys);
101 if (*bh == NULL) {
Namjae Jeonf0aac612012-05-31 16:26:14 -0700102 fat_msg_ratelimit(sb, KERN_ERR,
103 "Directory bread(block %llu) failed", (llu)phys);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700104 /* skip this block */
105 *pos = (iblock + 1) << sb->s_blocksize_bits;
106 goto next;
107 }
108
109 offset = *pos & (sb->s_blocksize - 1);
110 *pos += sizeof(struct msdos_dir_entry);
111 *de = (struct msdos_dir_entry *)((*bh)->b_data + offset);
112
113 return 0;
114}
115
116static inline int fat_get_entry(struct inode *dir, loff_t *pos,
117 struct buffer_head **bh,
118 struct msdos_dir_entry **de)
119{
120 /* Fast stuff first */
121 if (*bh && *de &&
Cruz Julian Bishopf08b4982012-10-04 17:14:57 -0700122 (*de - (struct msdos_dir_entry *)(*bh)->b_data) <
123 MSDOS_SB(dir->i_sb)->dir_per_block - 1) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700124 *pos += sizeof(struct msdos_dir_entry);
125 (*de)++;
126 return 0;
127 }
128 return fat__get_entry(dir, pos, bh, de);
129}
130
131/*
Alexey Dobriyan4de151d2006-03-22 00:13:35 +0100132 * Convert Unicode 16 to UTF-8, translated Unicode, or ASCII.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700133 * If uni_xlate is enabled and we can't get a 1:1 conversion, use a
134 * colon as an escape character since it is normally invalid on the vfat
135 * filesystem. The following four characters are the hexadecimal digits
136 * of Unicode value. This lets us do a full dump and restore of Unicode
137 * filenames. We could get into some trouble with long Unicode names,
138 * but ignore that right now.
139 * Ahem... Stack smashing in ring 0 isn't fun. Fixed.
140 */
Alexey Fisher869f58c2011-04-12 21:08:38 +0900141static int uni16_to_x8(struct super_block *sb, unsigned char *ascii,
142 const wchar_t *uni, int len, struct nls_table *nls)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700143{
Alexey Fisher869f58c2011-04-12 21:08:38 +0900144 int uni_xlate = MSDOS_SB(sb)->options.unicode_xlate;
OGAWA Hirofumid6886112008-07-25 01:46:43 -0700145 const wchar_t *ip;
146 wchar_t ec;
Andy Shevchenko3ed3dec2010-03-16 05:48:08 +0900147 unsigned char *op;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700148 int charlen;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700149
150 ip = uni;
151 op = ascii;
152
Keith Mokf22032b2008-04-28 02:16:29 -0700153 while (*ip && ((len - NLS_MAX_CHARSET_SIZE) > 0)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700154 ec = *ip++;
Cruz Julian Bishopf08b4982012-10-04 17:14:57 -0700155 charlen = nls->uni2char(ec, op, NLS_MAX_CHARSET_SIZE);
156 if (charlen > 0) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700157 op += charlen;
Keith Mokf22032b2008-04-28 02:16:29 -0700158 len -= charlen;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700159 } else {
160 if (uni_xlate == 1) {
Andy Shevchenko3ed3dec2010-03-16 05:48:08 +0900161 *op++ = ':';
Andy Shevchenko0a90e0f2011-10-31 17:12:57 -0700162 op = hex_byte_pack(op, ec >> 8);
163 op = hex_byte_pack(op, ec);
Keith Mokf22032b2008-04-28 02:16:29 -0700164 len -= 5;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700165 } else {
166 *op++ = '?';
Keith Mokf22032b2008-04-28 02:16:29 -0700167 len--;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700168 }
169 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700170 }
Keith Mokf22032b2008-04-28 02:16:29 -0700171
172 if (unlikely(*ip)) {
Cruz Julian Bishopf08b4982012-10-04 17:14:57 -0700173 fat_msg(sb, KERN_WARNING,
174 "filename was truncated while converting.");
Keith Mokf22032b2008-04-28 02:16:29 -0700175 }
176
Linus Torvalds1da177e2005-04-16 15:20:36 -0700177 *op = 0;
Cruz Julian Bishopf08b4982012-10-04 17:14:57 -0700178 return op - ascii;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700179}
180
Alexey Fisher869f58c2011-04-12 21:08:38 +0900181static inline int fat_uni_to_x8(struct super_block *sb, const wchar_t *uni,
OGAWA Hirofumid6886112008-07-25 01:46:43 -0700182 unsigned char *buf, int size)
183{
Alexey Fisher869f58c2011-04-12 21:08:38 +0900184 struct msdos_sb_info *sbi = MSDOS_SB(sb);
OGAWA Hirofumid6886112008-07-25 01:46:43 -0700185 if (sbi->options.utf8)
Alan Stern74675a52009-04-30 10:08:18 -0400186 return utf16s_to_utf8s(uni, FAT_MAX_UNI_CHARS,
187 UTF16_HOST_ENDIAN, buf, size);
OGAWA Hirofumid6886112008-07-25 01:46:43 -0700188 else
Alexey Fisher869f58c2011-04-12 21:08:38 +0900189 return uni16_to_x8(sb, buf, uni, size, sbi->nls_io);
OGAWA Hirofumid6886112008-07-25 01:46:43 -0700190}
191
Linus Torvalds1da177e2005-04-16 15:20:36 -0700192static inline int
193fat_short2uni(struct nls_table *t, unsigned char *c, int clen, wchar_t *uni)
194{
195 int charlen;
196
197 charlen = t->char2uni(c, clen, uni);
198 if (charlen < 0) {
199 *uni = 0x003f; /* a question mark */
200 charlen = 1;
201 }
202 return charlen;
203}
204
205static inline int
Cruz Julian Bishopf08b4982012-10-04 17:14:57 -0700206fat_short2lower_uni(struct nls_table *t, unsigned char *c,
207 int clen, wchar_t *uni)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700208{
209 int charlen;
210 wchar_t wc;
211
212 charlen = t->char2uni(c, clen, &wc);
213 if (charlen < 0) {
214 *uni = 0x003f; /* a question mark */
215 charlen = 1;
216 } else if (charlen <= 1) {
217 unsigned char nc = t->charset2lower[*c];
218
219 if (!nc)
220 nc = *c;
221
Cruz Julian Bishopf08b4982012-10-04 17:14:57 -0700222 charlen = t->char2uni(&nc, 1, uni);
223 if (charlen < 0) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700224 *uni = 0x003f; /* a question mark */
225 charlen = 1;
226 }
227 } else
228 *uni = wc;
229
230 return charlen;
231}
232
233static inline int
234fat_shortname2uni(struct nls_table *nls, unsigned char *buf, int buf_size,
235 wchar_t *uni_buf, unsigned short opt, int lower)
236{
237 int len = 0;
238
239 if (opt & VFAT_SFN_DISPLAY_LOWER)
240 len = fat_short2lower_uni(nls, buf, buf_size, uni_buf);
241 else if (opt & VFAT_SFN_DISPLAY_WIN95)
242 len = fat_short2uni(nls, buf, buf_size, uni_buf);
243 else if (opt & VFAT_SFN_DISPLAY_WINNT) {
244 if (lower)
245 len = fat_short2lower_uni(nls, buf, buf_size, uni_buf);
246 else
247 len = fat_short2uni(nls, buf, buf_size, uni_buf);
248 } else
249 len = fat_short2uni(nls, buf, buf_size, uni_buf);
250
251 return len;
252}
253
OGAWA Hirofumid6886112008-07-25 01:46:43 -0700254static inline int fat_name_match(struct msdos_sb_info *sbi,
255 const unsigned char *a, int a_len,
256 const unsigned char *b, int b_len)
257{
258 if (a_len != b_len)
259 return 0;
260
261 if (sbi->options.name_check != 's')
262 return !nls_strnicmp(sbi->nls_io, a, b, a_len);
263 else
264 return !memcmp(a, b, a_len);
265}
266
Pekka Enbergad2c1602005-10-30 15:03:50 -0800267enum { PARSE_INVALID = 1, PARSE_NOT_LONGNAME, PARSE_EOF, };
268
269/**
270 * fat_parse_long - Parse extended directory entry.
271 *
272 * This function returns zero on success, negative value on error, or one of
273 * the following:
274 *
275 * %PARSE_INVALID - Directory entry is invalid.
276 * %PARSE_NOT_LONGNAME - Directory entry does not contain longname.
277 * %PARSE_EOF - Directory has no more entries.
278 */
279static int fat_parse_long(struct inode *dir, loff_t *pos,
280 struct buffer_head **bh, struct msdos_dir_entry **de,
281 wchar_t **unicode, unsigned char *nr_slots)
282{
283 struct msdos_dir_slot *ds;
284 unsigned char id, slot, slots, alias_checksum;
285
286 if (!*unicode) {
OGAWA Hirofumic7a6c4e2008-04-28 02:16:29 -0700287 *unicode = __getname();
Pekka Enbergad2c1602005-10-30 15:03:50 -0800288 if (!*unicode) {
289 brelse(*bh);
290 return -ENOMEM;
291 }
292 }
293parse_long:
294 slots = 0;
295 ds = (struct msdos_dir_slot *)*de;
296 id = ds->id;
297 if (!(id & 0x40))
298 return PARSE_INVALID;
299 slots = id & ~0x40;
300 if (slots > 20 || !slots) /* ceil(256 * 2 / 26) */
301 return PARSE_INVALID;
302 *nr_slots = slots;
303 alias_checksum = ds->alias_checksum;
304
305 slot = slots;
306 while (1) {
307 int offset;
308
309 slot--;
310 offset = slot * 13;
311 fat16_towchar(*unicode + offset, ds->name0_4, 5);
312 fat16_towchar(*unicode + offset + 5, ds->name5_10, 6);
313 fat16_towchar(*unicode + offset + 11, ds->name11_12, 2);
314
315 if (ds->id & 0x40)
316 (*unicode)[offset + 13] = 0;
317 if (fat_get_entry(dir, pos, bh, de) < 0)
318 return PARSE_EOF;
319 if (slot == 0)
320 break;
321 ds = (struct msdos_dir_slot *)*de;
322 if (ds->attr != ATTR_EXT)
323 return PARSE_NOT_LONGNAME;
324 if ((ds->id & ~0x40) != slot)
325 goto parse_long;
326 if (ds->alias_checksum != alias_checksum)
327 goto parse_long;
328 }
329 if ((*de)->name[0] == DELETED_FLAG)
330 return PARSE_INVALID;
331 if ((*de)->attr == ATTR_EXT)
332 goto parse_long;
333 if (IS_FREE((*de)->name) || ((*de)->attr & ATTR_VOLUME))
334 return PARSE_INVALID;
335 if (fat_checksum((*de)->name) != alias_checksum)
336 *nr_slots = 0;
337
338 return 0;
339}
340
Steven J. Magnanideb82742012-07-30 14:42:16 -0700341/**
342 * fat_parse_short - Parse MS-DOS (short) directory entry.
343 * @sb: superblock
344 * @de: directory entry to parse
345 * @name: FAT_MAX_SHORT_SIZE array in which to place extracted name
346 * @dot_hidden: Nonzero == prepend '.' to names with ATTR_HIDDEN
347 *
348 * Returns the number of characters extracted into 'name'.
349 */
350static int fat_parse_short(struct super_block *sb,
351 const struct msdos_dir_entry *de,
352 unsigned char *name, int dot_hidden)
353{
354 const struct msdos_sb_info *sbi = MSDOS_SB(sb);
355 int isvfat = sbi->options.isvfat;
356 int nocase = sbi->options.nocase;
357 unsigned short opt_shortname = sbi->options.shortname;
358 struct nls_table *nls_disk = sbi->nls_disk;
359 wchar_t uni_name[14];
360 unsigned char c, work[MSDOS_NAME];
361 unsigned char *ptname = name;
362 int chi, chl, i, j, k;
363 int dotoffset = 0;
364 int name_len = 0, uni_len = 0;
365
366 if (!isvfat && dot_hidden && (de->attr & ATTR_HIDDEN)) {
367 *ptname++ = '.';
368 dotoffset = 1;
369 }
370
371 memcpy(work, de->name, sizeof(work));
372 /* see namei.c, msdos_format_name */
373 if (work[0] == 0x05)
374 work[0] = 0xE5;
375
376 /* Filename */
377 for (i = 0, j = 0; i < 8;) {
378 c = work[i];
379 if (!c)
380 break;
381 chl = fat_shortname2uni(nls_disk, &work[i], 8 - i,
382 &uni_name[j++], opt_shortname,
383 de->lcase & CASE_LOWER_BASE);
384 if (chl <= 1) {
385 if (!isvfat)
386 ptname[i] = nocase ? c : fat_tolower(c);
387 i++;
388 if (c != ' ') {
389 name_len = i;
390 uni_len = j;
391 }
392 } else {
393 uni_len = j;
394 if (isvfat)
395 i += min(chl, 8-i);
396 else {
397 for (chi = 0; chi < chl && i < 8; chi++, i++)
398 ptname[i] = work[i];
399 }
400 if (chl)
401 name_len = i;
402 }
403 }
404
405 i = name_len;
406 j = uni_len;
407 fat_short2uni(nls_disk, ".", 1, &uni_name[j++]);
408 if (!isvfat)
409 ptname[i] = '.';
410 i++;
411
412 /* Extension */
413 for (k = 8; k < MSDOS_NAME;) {
414 c = work[k];
415 if (!c)
416 break;
417 chl = fat_shortname2uni(nls_disk, &work[k], MSDOS_NAME - k,
418 &uni_name[j++], opt_shortname,
419 de->lcase & CASE_LOWER_EXT);
420 if (chl <= 1) {
421 k++;
422 if (!isvfat)
423 ptname[i] = nocase ? c : fat_tolower(c);
424 i++;
425 if (c != ' ') {
426 name_len = i;
427 uni_len = j;
428 }
429 } else {
430 uni_len = j;
431 if (isvfat) {
432 int offset = min(chl, MSDOS_NAME-k);
433 k += offset;
434 i += offset;
435 } else {
436 for (chi = 0; chi < chl && k < MSDOS_NAME;
437 chi++, i++, k++) {
438 ptname[i] = work[k];
439 }
440 }
441 if (chl)
442 name_len = i;
443 }
444 }
445
446 if (name_len > 0) {
447 name_len += dotoffset;
448
449 if (sbi->options.isvfat) {
450 uni_name[uni_len] = 0x0000;
451 name_len = fat_uni_to_x8(sb, uni_name, name,
452 FAT_MAX_SHORT_SIZE);
453 }
454 }
455
456 return name_len;
457}
458
Linus Torvalds1da177e2005-04-16 15:20:36 -0700459/*
Ravishankar Nc39540c2012-12-20 15:05:46 -0800460 * Return values: negative -> error/not found, 0 -> found.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700461 */
462int fat_search_long(struct inode *inode, const unsigned char *name,
463 int name_len, struct fat_slot_info *sinfo)
464{
465 struct super_block *sb = inode->i_sb;
466 struct msdos_sb_info *sbi = MSDOS_SB(sb);
467 struct buffer_head *bh = NULL;
468 struct msdos_dir_entry *de;
Keith Mokf22032b2008-04-28 02:16:29 -0700469 unsigned char nr_slots;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700470 wchar_t *unicode = NULL;
OGAWA Hirofumi98a15162008-07-25 01:46:44 -0700471 unsigned char bufname[FAT_MAX_SHORT_SIZE];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700472 loff_t cpos = 0;
Steven J. Magnanideb82742012-07-30 14:42:16 -0700473 int err, len;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700474
475 err = -ENOENT;
OGAWA Hirofumid6886112008-07-25 01:46:43 -0700476 while (1) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700477 if (fat_get_entry(inode, &cpos, &bh, &de) == -1)
OGAWA Hirofumid6886112008-07-25 01:46:43 -0700478 goto end_of_dir;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700479parse_record:
480 nr_slots = 0;
481 if (de->name[0] == DELETED_FLAG)
482 continue;
483 if (de->attr != ATTR_EXT && (de->attr & ATTR_VOLUME))
484 continue;
485 if (de->attr != ATTR_EXT && IS_FREE(de->name))
486 continue;
487 if (de->attr == ATTR_EXT) {
Pekka Enbergad2c1602005-10-30 15:03:50 -0800488 int status = fat_parse_long(inode, &cpos, &bh, &de,
489 &unicode, &nr_slots);
Darren Jenkins52e9d9f2008-11-06 12:53:48 -0800490 if (status < 0) {
491 err = status;
492 goto end_of_dir;
493 } else if (status == PARSE_INVALID)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700494 continue;
Pekka Enbergad2c1602005-10-30 15:03:50 -0800495 else if (status == PARSE_NOT_LONGNAME)
496 goto parse_record;
497 else if (status == PARSE_EOF)
OGAWA Hirofumid6886112008-07-25 01:46:43 -0700498 goto end_of_dir;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700499 }
500
Steven J. Magnanideb82742012-07-30 14:42:16 -0700501 /* Never prepend '.' to hidden files here.
502 * That is done only for msdos mounts (and only when
503 * 'dotsOK=yes'); if we are executing here, it is in the
504 * context of a vfat mount.
505 */
506 len = fat_parse_short(sb, de, bufname, 0);
507 if (len == 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700508 continue;
509
OGAWA Hirofumid6886112008-07-25 01:46:43 -0700510 /* Compare shortname */
OGAWA Hirofumid6886112008-07-25 01:46:43 -0700511 if (fat_name_match(sbi, name, name_len, bufname, len))
512 goto found;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700513
514 if (nr_slots) {
OGAWA Hirofumi98a15162008-07-25 01:46:44 -0700515 void *longname = unicode + FAT_MAX_UNI_CHARS;
516 int size = PATH_MAX - FAT_MAX_UNI_SIZE;
517
OGAWA Hirofumid6886112008-07-25 01:46:43 -0700518 /* Compare longname */
Alexey Fisher869f58c2011-04-12 21:08:38 +0900519 len = fat_uni_to_x8(sb, unicode, longname, size);
OGAWA Hirofumi98a15162008-07-25 01:46:44 -0700520 if (fat_name_match(sbi, name, name_len, longname, len))
OGAWA Hirofumid6886112008-07-25 01:46:43 -0700521 goto found;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700522 }
523 }
524
OGAWA Hirofumid6886112008-07-25 01:46:43 -0700525found:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700526 nr_slots++; /* include the de */
527 sinfo->slot_off = cpos - nr_slots * sizeof(*de);
528 sinfo->nr_slots = nr_slots;
529 sinfo->de = de;
530 sinfo->bh = bh;
531 sinfo->i_pos = fat_make_i_pos(sb, sinfo->bh, sinfo->de);
532 err = 0;
OGAWA Hirofumid6886112008-07-25 01:46:43 -0700533end_of_dir:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700534 if (unicode)
OGAWA Hirofumic7a6c4e2008-04-28 02:16:29 -0700535 __putname(unicode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700536
537 return err;
538}
OGAWA Hirofumi7c709d02006-01-08 01:02:10 -0800539EXPORT_SYMBOL_GPL(fat_search_long);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700540
541struct fat_ioctl_filldir_callback {
Al Viro2c6a2472013-05-22 18:37:16 -0400542 struct dir_context ctx;
OGAWA Hirofumic483bab2007-05-08 00:31:28 -0700543 void __user *dirent;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700544 int result;
545 /* for dir ioctl */
546 const char *longname;
547 int long_len;
548 const char *shortname;
549 int short_len;
550};
551
Al Viro2c6a2472013-05-22 18:37:16 -0400552static int __fat_readdir(struct inode *inode, struct file *file,
553 struct dir_context *ctx, int short_only,
554 struct fat_ioctl_filldir_callback *both)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700555{
556 struct super_block *sb = inode->i_sb;
557 struct msdos_sb_info *sbi = MSDOS_SB(sb);
558 struct buffer_head *bh;
559 struct msdos_dir_entry *de;
OGAWA Hirofumid6886112008-07-25 01:46:43 -0700560 unsigned char nr_slots;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700561 wchar_t *unicode = NULL;
Steven J. Magnanideb82742012-07-30 14:42:16 -0700562 unsigned char bufname[FAT_MAX_SHORT_SIZE];
OGAWA Hirofumid6886112008-07-25 01:46:43 -0700563 int isvfat = sbi->options.isvfat;
OGAWA Hirofumidcd8c53f2008-07-25 01:46:44 -0700564 const char *fill_name = NULL;
Al Viro2c6a2472013-05-22 18:37:16 -0400565 int fake_offset = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700566 loff_t cpos;
Steven J. Magnanideb82742012-07-30 14:42:16 -0700567 int short_len = 0, fill_len = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700568 int ret = 0;
569
Marco Stornellie40b34c2012-10-06 12:40:03 +0200570 mutex_lock(&sbi->s_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700571
Al Viro2c6a2472013-05-22 18:37:16 -0400572 cpos = ctx->pos;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700573 /* Fake . and .. for the root directory. */
574 if (inode->i_ino == MSDOS_ROOT_INO) {
Al Viro2c6a2472013-05-22 18:37:16 -0400575 if (!dir_emit_dots(file, ctx))
576 goto out;
577 if (ctx->pos == 2) {
578 fake_offset = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700579 cpos = 0;
580 }
581 }
OGAWA Hirofumid6886112008-07-25 01:46:43 -0700582 if (cpos & (sizeof(struct msdos_dir_entry) - 1)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700583 ret = -ENOENT;
584 goto out;
585 }
586
587 bh = NULL;
OGAWA Hirofumid6886112008-07-25 01:46:43 -0700588get_new:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700589 if (fat_get_entry(inode, &cpos, &bh, &de) == -1)
OGAWA Hirofumid6886112008-07-25 01:46:43 -0700590 goto end_of_dir;
Pekka Enbergad2c1602005-10-30 15:03:50 -0800591parse_record:
OGAWA Hirofumid6886112008-07-25 01:46:43 -0700592 nr_slots = 0;
OGAWA Hirofumidcd8c53f2008-07-25 01:46:44 -0700593 /*
594 * Check for long filename entry, but if short_only, we don't
595 * need to parse long filename.
596 */
597 if (isvfat && !short_only) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700598 if (de->name[0] == DELETED_FLAG)
OGAWA Hirofumid6886112008-07-25 01:46:43 -0700599 goto record_end;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700600 if (de->attr != ATTR_EXT && (de->attr & ATTR_VOLUME))
OGAWA Hirofumid6886112008-07-25 01:46:43 -0700601 goto record_end;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700602 if (de->attr != ATTR_EXT && IS_FREE(de->name))
OGAWA Hirofumid6886112008-07-25 01:46:43 -0700603 goto record_end;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700604 } else {
605 if ((de->attr & ATTR_VOLUME) || IS_FREE(de->name))
OGAWA Hirofumid6886112008-07-25 01:46:43 -0700606 goto record_end;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700607 }
608
609 if (isvfat && de->attr == ATTR_EXT) {
Pekka Enbergad2c1602005-10-30 15:03:50 -0800610 int status = fat_parse_long(inode, &cpos, &bh, &de,
OGAWA Hirofumid6886112008-07-25 01:46:43 -0700611 &unicode, &nr_slots);
Pekka Enbergad2c1602005-10-30 15:03:50 -0800612 if (status < 0) {
OGAWA Hirofumi928a4772015-11-20 15:57:15 -0800613 bh = NULL;
Pekka Enbergad2c1602005-10-30 15:03:50 -0800614 ret = status;
OGAWA Hirofumi928a4772015-11-20 15:57:15 -0800615 goto end_of_dir;
Pekka Enbergad2c1602005-10-30 15:03:50 -0800616 } else if (status == PARSE_INVALID)
OGAWA Hirofumid6886112008-07-25 01:46:43 -0700617 goto record_end;
Pekka Enbergad2c1602005-10-30 15:03:50 -0800618 else if (status == PARSE_NOT_LONGNAME)
619 goto parse_record;
620 else if (status == PARSE_EOF)
OGAWA Hirofumid6886112008-07-25 01:46:43 -0700621 goto end_of_dir;
OGAWA Hirofumidcd8c53f2008-07-25 01:46:44 -0700622
623 if (nr_slots) {
624 void *longname = unicode + FAT_MAX_UNI_CHARS;
625 int size = PATH_MAX - FAT_MAX_UNI_SIZE;
Alexey Fisher869f58c2011-04-12 21:08:38 +0900626 int len = fat_uni_to_x8(sb, unicode, longname, size);
OGAWA Hirofumidcd8c53f2008-07-25 01:46:44 -0700627
628 fill_name = longname;
629 fill_len = len;
630 /* !both && !short_only, so we don't need shortname. */
631 if (!both)
632 goto start_filldir;
Al Viro2c6a2472013-05-22 18:37:16 -0400633
634 short_len = fat_parse_short(sb, de, bufname,
635 sbi->options.dotsOK);
636 if (short_len == 0)
637 goto record_end;
638 /* hack for fat_ioctl_filldir() */
639 both->longname = fill_name;
640 both->long_len = fill_len;
641 both->shortname = bufname;
642 both->short_len = short_len;
643 fill_name = NULL;
644 fill_len = 0;
645 goto start_filldir;
OGAWA Hirofumidcd8c53f2008-07-25 01:46:44 -0700646 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700647 }
648
Steven J. Magnanideb82742012-07-30 14:42:16 -0700649 short_len = fat_parse_short(sb, de, bufname, sbi->options.dotsOK);
650 if (short_len == 0)
OGAWA Hirofumid6886112008-07-25 01:46:43 -0700651 goto record_end;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700652
Al Viro2c6a2472013-05-22 18:37:16 -0400653 fill_name = bufname;
654 fill_len = short_len;
OGAWA Hirofumidcd8c53f2008-07-25 01:46:44 -0700655
656start_filldir:
OGAWA Hirofumi928a4772015-11-20 15:57:15 -0800657 ctx->pos = cpos - (nr_slots + 1) * sizeof(struct msdos_dir_entry);
658 if (fake_offset && ctx->pos < 2)
659 ctx->pos = 2;
Al Viro2c6a2472013-05-22 18:37:16 -0400660
661 if (!memcmp(de->name, MSDOS_DOT, MSDOS_NAME)) {
662 if (!dir_emit_dot(file, ctx))
663 goto fill_failed;
664 } else if (!memcmp(de->name, MSDOS_DOTDOT, MSDOS_NAME)) {
665 if (!dir_emit_dotdot(file, ctx))
666 goto fill_failed;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700667 } else {
Al Viro2c6a2472013-05-22 18:37:16 -0400668 unsigned long inum;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700669 loff_t i_pos = fat_make_i_pos(sb, bh, de);
670 struct inode *tmp = fat_iget(sb, i_pos);
671 if (tmp) {
672 inum = tmp->i_ino;
673 iput(tmp);
674 } else
675 inum = iunique(sb, MSDOS_ROOT_INO);
Al Viro2c6a2472013-05-22 18:37:16 -0400676 if (!dir_emit(ctx, fill_name, fill_len, inum,
677 (de->attr & ATTR_DIR) ? DT_DIR : DT_REG))
678 goto fill_failed;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700679 }
680
OGAWA Hirofumid6886112008-07-25 01:46:43 -0700681record_end:
Al Viro2c6a2472013-05-22 18:37:16 -0400682 fake_offset = 0;
683 ctx->pos = cpos;
OGAWA Hirofumid6886112008-07-25 01:46:43 -0700684 goto get_new;
OGAWA Hirofumi928a4772015-11-20 15:57:15 -0800685
OGAWA Hirofumid6886112008-07-25 01:46:43 -0700686end_of_dir:
OGAWA Hirofumi928a4772015-11-20 15:57:15 -0800687 if (fake_offset && cpos < 2)
688 ctx->pos = 2;
689 else
690 ctx->pos = cpos;
OGAWA Hirofumid6886112008-07-25 01:46:43 -0700691fill_failed:
Karsten Wiesef3ef6f62005-09-06 15:17:12 -0700692 brelse(bh);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700693 if (unicode)
OGAWA Hirofumic7a6c4e2008-04-28 02:16:29 -0700694 __putname(unicode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700695out:
Marco Stornellie40b34c2012-10-06 12:40:03 +0200696 mutex_unlock(&sbi->s_lock);
OGAWA Hirofumi928a4772015-11-20 15:57:15 -0800697
Linus Torvalds1da177e2005-04-16 15:20:36 -0700698 return ret;
699}
700
Al Viro2c6a2472013-05-22 18:37:16 -0400701static int fat_readdir(struct file *file, struct dir_context *ctx)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700702{
Al Viro2c6a2472013-05-22 18:37:16 -0400703 return __fat_readdir(file_inode(file), file, ctx, 0, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700704}
705
OGAWA Hirofumic483bab2007-05-08 00:31:28 -0700706#define FAT_IOCTL_FILLDIR_FUNC(func, dirent_type) \
Miklos Szerediac7576f2014-10-30 17:37:34 +0100707static int func(struct dir_context *ctx, const char *name, int name_len, \
OGAWA Hirofumic483bab2007-05-08 00:31:28 -0700708 loff_t offset, u64 ino, unsigned int d_type) \
709{ \
Miklos Szerediac7576f2014-10-30 17:37:34 +0100710 struct fat_ioctl_filldir_callback *buf = \
711 container_of(ctx, struct fat_ioctl_filldir_callback, ctx); \
OGAWA Hirofumic483bab2007-05-08 00:31:28 -0700712 struct dirent_type __user *d1 = buf->dirent; \
713 struct dirent_type __user *d2 = d1 + 1; \
714 \
715 if (buf->result) \
716 return -EINVAL; \
717 buf->result++; \
718 \
719 if (name != NULL) { \
720 /* dirent has only short name */ \
721 if (name_len >= sizeof(d1->d_name)) \
722 name_len = sizeof(d1->d_name) - 1; \
723 \
724 if (put_user(0, d2->d_name) || \
725 put_user(0, &d2->d_reclen) || \
726 copy_to_user(d1->d_name, name, name_len) || \
727 put_user(0, d1->d_name + name_len) || \
728 put_user(name_len, &d1->d_reclen)) \
729 goto efault; \
730 } else { \
731 /* dirent has short and long name */ \
732 const char *longname = buf->longname; \
733 int long_len = buf->long_len; \
734 const char *shortname = buf->shortname; \
735 int short_len = buf->short_len; \
736 \
737 if (long_len >= sizeof(d1->d_name)) \
738 long_len = sizeof(d1->d_name) - 1; \
739 if (short_len >= sizeof(d1->d_name)) \
740 short_len = sizeof(d1->d_name) - 1; \
741 \
742 if (copy_to_user(d2->d_name, longname, long_len) || \
743 put_user(0, d2->d_name + long_len) || \
744 put_user(long_len, &d2->d_reclen) || \
745 put_user(ino, &d2->d_ino) || \
746 put_user(offset, &d2->d_off) || \
747 copy_to_user(d1->d_name, shortname, short_len) || \
748 put_user(0, d1->d_name + short_len) || \
749 put_user(short_len, &d1->d_reclen)) \
750 goto efault; \
751 } \
752 return 0; \
753efault: \
754 buf->result = -EFAULT; \
755 return -EFAULT; \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700756}
757
Adrian Bunk531f7102008-07-25 01:46:43 -0700758FAT_IOCTL_FILLDIR_FUNC(fat_ioctl_filldir, __fat_dirent)
OGAWA Hirofumic483bab2007-05-08 00:31:28 -0700759
Al Viro2c6a2472013-05-22 18:37:16 -0400760static int fat_ioctl_readdir(struct inode *inode, struct file *file,
OGAWA Hirofumic483bab2007-05-08 00:31:28 -0700761 void __user *dirent, filldir_t filldir,
762 int short_only, int both)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700763{
Al Viro2c6a2472013-05-22 18:37:16 -0400764 struct fat_ioctl_filldir_callback buf = {
765 .ctx.actor = filldir,
766 .dirent = dirent
767 };
OGAWA Hirofumic483bab2007-05-08 00:31:28 -0700768 int ret;
769
770 buf.dirent = dirent;
771 buf.result = 0;
Al Viro59551022016-01-22 15:40:57 -0500772 inode_lock(inode);
Al Viro2c6a2472013-05-22 18:37:16 -0400773 buf.ctx.pos = file->f_pos;
OGAWA Hirofumic483bab2007-05-08 00:31:28 -0700774 ret = -ENOENT;
775 if (!IS_DEADDIR(inode)) {
Al Viro2c6a2472013-05-22 18:37:16 -0400776 ret = __fat_readdir(inode, file, &buf.ctx,
777 short_only, both ? &buf : NULL);
778 file->f_pos = buf.ctx.pos;
OGAWA Hirofumic483bab2007-05-08 00:31:28 -0700779 }
Al Viro59551022016-01-22 15:40:57 -0500780 inode_unlock(inode);
OGAWA Hirofumic483bab2007-05-08 00:31:28 -0700781 if (ret >= 0)
782 ret = buf.result;
783 return ret;
784}
785
Arnd Bergmann7845bc3e2010-05-17 08:13:47 +0900786static long fat_dir_ioctl(struct file *filp, unsigned int cmd,
787 unsigned long arg)
OGAWA Hirofumic483bab2007-05-08 00:31:28 -0700788{
Al Viro496ad9a2013-01-23 17:07:38 -0500789 struct inode *inode = file_inode(filp);
Adrian Bunk531f7102008-07-25 01:46:43 -0700790 struct __fat_dirent __user *d1 = (struct __fat_dirent __user *)arg;
OGAWA Hirofumic483bab2007-05-08 00:31:28 -0700791 int short_only, both;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700792
793 switch (cmd) {
794 case VFAT_IOCTL_READDIR_SHORT:
795 short_only = 1;
796 both = 0;
797 break;
798 case VFAT_IOCTL_READDIR_BOTH:
799 short_only = 0;
800 both = 1;
801 break;
802 default:
Arnd Bergmann7845bc3e2010-05-17 08:13:47 +0900803 return fat_generic_ioctl(filp, cmd, arg);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700804 }
805
Adrian Bunk531f7102008-07-25 01:46:43 -0700806 if (!access_ok(VERIFY_WRITE, d1, sizeof(struct __fat_dirent[2])))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700807 return -EFAULT;
808 /*
809 * Yes, we don't need this put_user() absolutely. However old
810 * code didn't return the right value. So, app use this value,
811 * in order to check whether it is EOF.
812 */
813 if (put_user(0, &d1->d_reclen))
814 return -EFAULT;
815
OGAWA Hirofumic483bab2007-05-08 00:31:28 -0700816 return fat_ioctl_readdir(inode, filp, d1, fat_ioctl_filldir,
817 short_only, both);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700818}
819
David Howells188f83d2006-08-31 12:50:04 +0200820#ifdef CONFIG_COMPAT
821#define VFAT_IOCTL_READDIR_BOTH32 _IOR('r', 1, struct compat_dirent[2])
822#define VFAT_IOCTL_READDIR_SHORT32 _IOR('r', 2, struct compat_dirent[2])
823
OGAWA Hirofumic483bab2007-05-08 00:31:28 -0700824FAT_IOCTL_FILLDIR_FUNC(fat_compat_ioctl_filldir, compat_dirent)
David Howells188f83d2006-08-31 12:50:04 +0200825
OGAWA Hirofumic483bab2007-05-08 00:31:28 -0700826static long fat_compat_dir_ioctl(struct file *filp, unsigned cmd,
David Howells188f83d2006-08-31 12:50:04 +0200827 unsigned long arg)
828{
Al Viro496ad9a2013-01-23 17:07:38 -0500829 struct inode *inode = file_inode(filp);
OGAWA Hirofumic483bab2007-05-08 00:31:28 -0700830 struct compat_dirent __user *d1 = compat_ptr(arg);
831 int short_only, both;
David Howells188f83d2006-08-31 12:50:04 +0200832
833 switch (cmd) {
David Howells188f83d2006-08-31 12:50:04 +0200834 case VFAT_IOCTL_READDIR_SHORT32:
OGAWA Hirofumic483bab2007-05-08 00:31:28 -0700835 short_only = 1;
836 both = 0;
837 break;
838 case VFAT_IOCTL_READDIR_BOTH32:
839 short_only = 0;
840 both = 1;
David Howells188f83d2006-08-31 12:50:04 +0200841 break;
842 default:
Arnd Bergmann7845bc3e2010-05-17 08:13:47 +0900843 return fat_generic_ioctl(filp, cmd, (unsigned long)arg);
David Howells188f83d2006-08-31 12:50:04 +0200844 }
845
OGAWA Hirofumic483bab2007-05-08 00:31:28 -0700846 if (!access_ok(VERIFY_WRITE, d1, sizeof(struct compat_dirent[2])))
847 return -EFAULT;
848 /*
849 * Yes, we don't need this put_user() absolutely. However old
850 * code didn't return the right value. So, app use this value,
851 * in order to check whether it is EOF.
852 */
853 if (put_user(0, &d1->d_reclen))
854 return -EFAULT;
855
856 return fat_ioctl_readdir(inode, filp, d1, fat_compat_ioctl_filldir,
857 short_only, both);
David Howells188f83d2006-08-31 12:50:04 +0200858}
859#endif /* CONFIG_COMPAT */
860
Arjan van de Ven4b6f5d22006-03-28 01:56:42 -0800861const struct file_operations fat_dir_operations = {
OGAWA Hirofumi53472bc2008-11-06 12:53:47 -0800862 .llseek = generic_file_llseek,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700863 .read = generic_read_dir,
Al Viro2c6a2472013-05-22 18:37:16 -0400864 .iterate = fat_readdir,
Arnd Bergmann7845bc3e2010-05-17 08:13:47 +0900865 .unlocked_ioctl = fat_dir_ioctl,
David Howells188f83d2006-08-31 12:50:04 +0200866#ifdef CONFIG_COMPAT
867 .compat_ioctl = fat_compat_dir_ioctl,
868#endif
Al Virob5224122009-06-07 13:44:36 -0400869 .fsync = fat_file_fsync,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700870};
871
872static int fat_get_short_entry(struct inode *dir, loff_t *pos,
873 struct buffer_head **bh,
874 struct msdos_dir_entry **de)
875{
876 while (fat_get_entry(dir, pos, bh, de) >= 0) {
877 /* free entry or long name entry or volume label */
878 if (!IS_FREE((*de)->name) && !((*de)->attr & ATTR_VOLUME))
879 return 0;
880 }
881 return -ENOENT;
882}
883
884/*
Steven J. Magnani7669e8f2012-10-04 17:14:45 -0700885 * The ".." entry can not provide the "struct fat_slot_info" information
886 * for inode, nor a usable i_pos. So, this function provides some information
887 * only.
888 *
889 * Since this function walks through the on-disk inodes within a directory,
890 * callers are responsible for taking any locks necessary to prevent the
891 * directory from changing.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700892 */
893int fat_get_dotdot_entry(struct inode *dir, struct buffer_head **bh,
Steven J. Magnani7669e8f2012-10-04 17:14:45 -0700894 struct msdos_dir_entry **de)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700895{
Steven J. Magnani7669e8f2012-10-04 17:14:45 -0700896 loff_t offset = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700897
Steven J. Magnani7669e8f2012-10-04 17:14:45 -0700898 *de = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700899 while (fat_get_short_entry(dir, &offset, bh, de) >= 0) {
Steven J. Magnani7669e8f2012-10-04 17:14:45 -0700900 if (!strncmp((*de)->name, MSDOS_DOTDOT, MSDOS_NAME))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700901 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700902 }
903 return -ENOENT;
904}
OGAWA Hirofumi7c709d02006-01-08 01:02:10 -0800905EXPORT_SYMBOL_GPL(fat_get_dotdot_entry);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700906
907/* See if directory is empty */
908int fat_dir_empty(struct inode *dir)
909{
910 struct buffer_head *bh;
911 struct msdos_dir_entry *de;
912 loff_t cpos;
913 int result = 0;
914
915 bh = NULL;
916 cpos = 0;
917 while (fat_get_short_entry(dir, &cpos, &bh, &de) >= 0) {
918 if (strncmp(de->name, MSDOS_DOT , MSDOS_NAME) &&
919 strncmp(de->name, MSDOS_DOTDOT, MSDOS_NAME)) {
920 result = -ENOTEMPTY;
921 break;
922 }
923 }
924 brelse(bh);
925 return result;
926}
OGAWA Hirofumi7c709d02006-01-08 01:02:10 -0800927EXPORT_SYMBOL_GPL(fat_dir_empty);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700928
929/*
930 * fat_subdirs counts the number of sub-directories of dir. It can be run
931 * on directories being created.
932 */
933int fat_subdirs(struct inode *dir)
934{
935 struct buffer_head *bh;
936 struct msdos_dir_entry *de;
937 loff_t cpos;
938 int count = 0;
939
940 bh = NULL;
941 cpos = 0;
942 while (fat_get_short_entry(dir, &cpos, &bh, &de) >= 0) {
943 if (de->attr & ATTR_DIR)
944 count++;
945 }
946 brelse(bh);
947 return count;
948}
949
950/*
951 * Scans a directory for a given file (name points to its formatted name).
952 * Returns an error code or zero.
953 */
954int fat_scan(struct inode *dir, const unsigned char *name,
955 struct fat_slot_info *sinfo)
956{
957 struct super_block *sb = dir->i_sb;
958
959 sinfo->slot_off = 0;
960 sinfo->bh = NULL;
961 while (fat_get_short_entry(dir, &sinfo->slot_off, &sinfo->bh,
962 &sinfo->de) >= 0) {
963 if (!strncmp(sinfo->de->name, name, MSDOS_NAME)) {
964 sinfo->slot_off -= sizeof(*sinfo->de);
965 sinfo->nr_slots = 1;
966 sinfo->i_pos = fat_make_i_pos(sb, sinfo->bh, sinfo->de);
967 return 0;
968 }
969 }
970 return -ENOENT;
971}
OGAWA Hirofumi7c709d02006-01-08 01:02:10 -0800972EXPORT_SYMBOL_GPL(fat_scan);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700973
Namjae Jeonf1e6fb02013-04-29 16:21:14 -0700974/*
975 * Scans a directory for a given logstart.
976 * Returns an error code or zero.
977 */
978int fat_scan_logstart(struct inode *dir, int i_logstart,
979 struct fat_slot_info *sinfo)
980{
981 struct super_block *sb = dir->i_sb;
982
983 sinfo->slot_off = 0;
984 sinfo->bh = NULL;
985 while (fat_get_short_entry(dir, &sinfo->slot_off, &sinfo->bh,
986 &sinfo->de) >= 0) {
987 if (fat_get_start(MSDOS_SB(sb), sinfo->de) == i_logstart) {
988 sinfo->slot_off -= sizeof(*sinfo->de);
989 sinfo->nr_slots = 1;
990 sinfo->i_pos = fat_make_i_pos(sb, sinfo->bh, sinfo->de);
991 return 0;
992 }
993 }
994 return -ENOENT;
995}
996
Linus Torvalds1da177e2005-04-16 15:20:36 -0700997static int __fat_remove_entries(struct inode *dir, loff_t pos, int nr_slots)
998{
999 struct super_block *sb = dir->i_sb;
1000 struct buffer_head *bh;
1001 struct msdos_dir_entry *de, *endp;
1002 int err = 0, orig_slots;
1003
1004 while (nr_slots) {
1005 bh = NULL;
1006 if (fat_get_entry(dir, &pos, &bh, &de) < 0) {
1007 err = -EIO;
1008 break;
1009 }
1010
1011 orig_slots = nr_slots;
1012 endp = (struct msdos_dir_entry *)(bh->b_data + sb->s_blocksize);
1013 while (nr_slots && de < endp) {
1014 de->name[0] = DELETED_FLAG;
1015 de++;
1016 nr_slots--;
1017 }
Al Virob5224122009-06-07 13:44:36 -04001018 mark_buffer_dirty_inode(bh, dir);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001019 if (IS_DIRSYNC(dir))
1020 err = sync_dirty_buffer(bh);
1021 brelse(bh);
1022 if (err)
1023 break;
1024
1025 /* pos is *next* de's position, so this does `- sizeof(de)' */
1026 pos += ((orig_slots - nr_slots) * sizeof(*de)) - sizeof(*de);
1027 }
1028
1029 return err;
1030}
1031
1032int fat_remove_entries(struct inode *dir, struct fat_slot_info *sinfo)
1033{
Alexey Fisher869f58c2011-04-12 21:08:38 +09001034 struct super_block *sb = dir->i_sb;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001035 struct msdos_dir_entry *de;
1036 struct buffer_head *bh;
1037 int err = 0, nr_slots;
1038
1039 /*
1040 * First stage: Remove the shortname. By this, the directory
1041 * entry is removed.
1042 */
1043 nr_slots = sinfo->nr_slots;
1044 de = sinfo->de;
1045 sinfo->de = NULL;
1046 bh = sinfo->bh;
1047 sinfo->bh = NULL;
1048 while (nr_slots && de >= (struct msdos_dir_entry *)bh->b_data) {
1049 de->name[0] = DELETED_FLAG;
1050 de--;
1051 nr_slots--;
1052 }
Al Virob5224122009-06-07 13:44:36 -04001053 mark_buffer_dirty_inode(bh, dir);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001054 if (IS_DIRSYNC(dir))
1055 err = sync_dirty_buffer(bh);
1056 brelse(bh);
1057 if (err)
1058 return err;
1059 dir->i_version++;
1060
1061 if (nr_slots) {
1062 /*
1063 * Second stage: remove the remaining longname slots.
1064 * (This directory entry is already removed, and so return
1065 * the success)
1066 */
1067 err = __fat_remove_entries(dir, sinfo->slot_off, nr_slots);
1068 if (err) {
Alexey Fisher869f58c2011-04-12 21:08:38 +09001069 fat_msg(sb, KERN_WARNING,
1070 "Couldn't remove the long name slots");
Linus Torvalds1da177e2005-04-16 15:20:36 -07001071 }
1072 }
1073
1074 dir->i_mtime = dir->i_atime = CURRENT_TIME_SEC;
1075 if (IS_DIRSYNC(dir))
1076 (void)fat_sync_inode(dir);
1077 else
1078 mark_inode_dirty(dir);
1079
1080 return 0;
1081}
OGAWA Hirofumi7c709d02006-01-08 01:02:10 -08001082EXPORT_SYMBOL_GPL(fat_remove_entries);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001083
1084static int fat_zeroed_cluster(struct inode *dir, sector_t blknr, int nr_used,
1085 struct buffer_head **bhs, int nr_bhs)
1086{
1087 struct super_block *sb = dir->i_sb;
1088 sector_t last_blknr = blknr + MSDOS_SB(sb)->sec_per_clus;
1089 int err, i, n;
1090
1091 /* Zeroing the unused blocks on this cluster */
1092 blknr += nr_used;
1093 n = nr_used;
1094 while (blknr < last_blknr) {
1095 bhs[n] = sb_getblk(sb, blknr);
1096 if (!bhs[n]) {
1097 err = -ENOMEM;
1098 goto error;
1099 }
1100 memset(bhs[n]->b_data, 0, sb->s_blocksize);
1101 set_buffer_uptodate(bhs[n]);
Al Virob5224122009-06-07 13:44:36 -04001102 mark_buffer_dirty_inode(bhs[n], dir);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001103
1104 n++;
1105 blknr++;
1106 if (n == nr_bhs) {
1107 if (IS_DIRSYNC(dir)) {
1108 err = fat_sync_bhs(bhs, n);
1109 if (err)
1110 goto error;
1111 }
1112 for (i = 0; i < n; i++)
1113 brelse(bhs[i]);
1114 n = 0;
1115 }
1116 }
1117 if (IS_DIRSYNC(dir)) {
1118 err = fat_sync_bhs(bhs, n);
1119 if (err)
1120 goto error;
1121 }
1122 for (i = 0; i < n; i++)
1123 brelse(bhs[i]);
1124
1125 return 0;
1126
1127error:
1128 for (i = 0; i < n; i++)
1129 bforget(bhs[i]);
1130 return err;
1131}
1132
1133int fat_alloc_new_dir(struct inode *dir, struct timespec *ts)
1134{
1135 struct super_block *sb = dir->i_sb;
1136 struct msdos_sb_info *sbi = MSDOS_SB(sb);
1137 struct buffer_head *bhs[MAX_BUF_PER_PAGE];
1138 struct msdos_dir_entry *de;
1139 sector_t blknr;
1140 __le16 date, time;
OGAWA Hirofumi7decd1c2008-11-06 12:53:47 -08001141 u8 time_cs;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001142 int err, cluster;
1143
1144 err = fat_alloc_clusters(dir, &cluster, 1);
1145 if (err)
1146 goto error;
1147
1148 blknr = fat_clus_to_blknr(sbi, cluster);
1149 bhs[0] = sb_getblk(sb, blknr);
1150 if (!bhs[0]) {
1151 err = -ENOMEM;
1152 goto error_free;
1153 }
1154
OGAWA Hirofumi7decd1c2008-11-06 12:53:47 -08001155 fat_time_unix2fat(sbi, ts, &time, &date, &time_cs);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001156
1157 de = (struct msdos_dir_entry *)bhs[0]->b_data;
1158 /* filling the new directory slots ("." and ".." entries) */
1159 memcpy(de[0].name, MSDOS_DOT, MSDOS_NAME);
1160 memcpy(de[1].name, MSDOS_DOTDOT, MSDOS_NAME);
1161 de->attr = de[1].attr = ATTR_DIR;
1162 de[0].lcase = de[1].lcase = 0;
1163 de[0].time = de[1].time = time;
1164 de[0].date = de[1].date = date;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001165 if (sbi->options.isvfat) {
1166 /* extra timestamps */
1167 de[0].ctime = de[1].ctime = time;
OGAWA Hirofumi7decd1c2008-11-06 12:53:47 -08001168 de[0].ctime_cs = de[1].ctime_cs = time_cs;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001169 de[0].adate = de[0].cdate = de[1].adate = de[1].cdate = date;
1170 } else {
1171 de[0].ctime = de[1].ctime = 0;
OGAWA Hirofumi7decd1c2008-11-06 12:53:47 -08001172 de[0].ctime_cs = de[1].ctime_cs = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001173 de[0].adate = de[0].cdate = de[1].adate = de[1].cdate = 0;
1174 }
Namjae Jeon4b637092012-10-04 17:14:41 -07001175 fat_set_start(&de[0], cluster);
1176 fat_set_start(&de[1], MSDOS_I(dir)->i_logstart);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001177 de[0].size = de[1].size = 0;
1178 memset(de + 2, 0, sb->s_blocksize - 2 * sizeof(*de));
1179 set_buffer_uptodate(bhs[0]);
Al Virob5224122009-06-07 13:44:36 -04001180 mark_buffer_dirty_inode(bhs[0], dir);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001181
1182 err = fat_zeroed_cluster(dir, blknr, 1, bhs, MAX_BUF_PER_PAGE);
1183 if (err)
1184 goto error_free;
1185
1186 return cluster;
1187
1188error_free:
1189 fat_free_clusters(dir, cluster);
1190error:
1191 return err;
1192}
OGAWA Hirofumi7c709d02006-01-08 01:02:10 -08001193EXPORT_SYMBOL_GPL(fat_alloc_new_dir);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001194
1195static int fat_add_new_entries(struct inode *dir, void *slots, int nr_slots,
1196 int *nr_cluster, struct msdos_dir_entry **de,
1197 struct buffer_head **bh, loff_t *i_pos)
1198{
1199 struct super_block *sb = dir->i_sb;
1200 struct msdos_sb_info *sbi = MSDOS_SB(sb);
1201 struct buffer_head *bhs[MAX_BUF_PER_PAGE];
1202 sector_t blknr, start_blknr, last_blknr;
1203 unsigned long size, copy;
1204 int err, i, n, offset, cluster[2];
1205
1206 /*
1207 * The minimum cluster size is 512bytes, and maximum entry
1208 * size is 32*slots (672bytes). So, iff the cluster size is
1209 * 512bytes, we may need two clusters.
1210 */
1211 size = nr_slots * sizeof(struct msdos_dir_entry);
1212 *nr_cluster = (size + (sbi->cluster_size - 1)) >> sbi->cluster_bits;
1213 BUG_ON(*nr_cluster > 2);
1214
1215 err = fat_alloc_clusters(dir, cluster, *nr_cluster);
1216 if (err)
1217 goto error;
1218
1219 /*
1220 * First stage: Fill the directory entry. NOTE: This cluster
1221 * is not referenced from any inode yet, so updates order is
1222 * not important.
1223 */
1224 i = n = copy = 0;
1225 do {
1226 start_blknr = blknr = fat_clus_to_blknr(sbi, cluster[i]);
1227 last_blknr = start_blknr + sbi->sec_per_clus;
1228 while (blknr < last_blknr) {
1229 bhs[n] = sb_getblk(sb, blknr);
1230 if (!bhs[n]) {
1231 err = -ENOMEM;
1232 goto error_nomem;
1233 }
1234
1235 /* fill the directory entry */
1236 copy = min(size, sb->s_blocksize);
1237 memcpy(bhs[n]->b_data, slots, copy);
1238 slots += copy;
1239 size -= copy;
1240 set_buffer_uptodate(bhs[n]);
Al Virob5224122009-06-07 13:44:36 -04001241 mark_buffer_dirty_inode(bhs[n], dir);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001242 if (!size)
1243 break;
1244 n++;
1245 blknr++;
1246 }
1247 } while (++i < *nr_cluster);
1248
1249 memset(bhs[n]->b_data + copy, 0, sb->s_blocksize - copy);
1250 offset = copy - sizeof(struct msdos_dir_entry);
1251 get_bh(bhs[n]);
1252 *bh = bhs[n];
1253 *de = (struct msdos_dir_entry *)((*bh)->b_data + offset);
1254 *i_pos = fat_make_i_pos(sb, *bh, *de);
1255
1256 /* Second stage: clear the rest of cluster, and write outs */
1257 err = fat_zeroed_cluster(dir, start_blknr, ++n, bhs, MAX_BUF_PER_PAGE);
1258 if (err)
1259 goto error_free;
1260
1261 return cluster[0];
1262
1263error_free:
1264 brelse(*bh);
1265 *bh = NULL;
1266 n = 0;
1267error_nomem:
1268 for (i = 0; i < n; i++)
1269 bforget(bhs[i]);
1270 fat_free_clusters(dir, cluster[0]);
1271error:
1272 return err;
1273}
1274
1275int fat_add_entries(struct inode *dir, void *slots, int nr_slots,
1276 struct fat_slot_info *sinfo)
1277{
1278 struct super_block *sb = dir->i_sb;
1279 struct msdos_sb_info *sbi = MSDOS_SB(sb);
1280 struct buffer_head *bh, *prev, *bhs[3]; /* 32*slots (672bytes) */
Jonas Aberg8c320c02011-08-17 19:10:06 +09001281 struct msdos_dir_entry *uninitialized_var(de);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001282 int err, free_slots, i, nr_bhs;
1283 loff_t pos, i_pos;
1284
1285 sinfo->nr_slots = nr_slots;
1286
Ravishankar Nc39540c2012-12-20 15:05:46 -08001287 /* First stage: search free directory entries */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001288 free_slots = nr_bhs = 0;
1289 bh = prev = NULL;
1290 pos = 0;
1291 err = -ENOSPC;
1292 while (fat_get_entry(dir, &pos, &bh, &de) > -1) {
1293 /* check the maximum size of directory */
1294 if (pos >= FAT_MAX_DIR_SIZE)
1295 goto error;
1296
1297 if (IS_FREE(de->name)) {
1298 if (prev != bh) {
1299 get_bh(bh);
1300 bhs[nr_bhs] = prev = bh;
1301 nr_bhs++;
1302 }
1303 free_slots++;
1304 if (free_slots == nr_slots)
1305 goto found;
1306 } else {
1307 for (i = 0; i < nr_bhs; i++)
1308 brelse(bhs[i]);
1309 prev = NULL;
1310 free_slots = nr_bhs = 0;
1311 }
1312 }
1313 if (dir->i_ino == MSDOS_ROOT_INO) {
1314 if (sbi->fat_bits != 32)
1315 goto error;
1316 } else if (MSDOS_I(dir)->i_start == 0) {
Alexey Fisher869f58c2011-04-12 21:08:38 +09001317 fat_msg(sb, KERN_ERR, "Corrupted directory (i_pos %lld)",
Linus Torvalds1da177e2005-04-16 15:20:36 -07001318 MSDOS_I(dir)->i_pos);
1319 err = -EIO;
1320 goto error;
1321 }
1322
1323found:
1324 err = 0;
1325 pos -= free_slots * sizeof(*de);
1326 nr_slots -= free_slots;
1327 if (free_slots) {
1328 /*
1329 * Second stage: filling the free entries with new entries.
1330 * NOTE: If this slots has shortname, first, we write
1331 * the long name slots, then write the short name.
1332 */
1333 int size = free_slots * sizeof(*de);
1334 int offset = pos & (sb->s_blocksize - 1);
1335 int long_bhs = nr_bhs - (nr_slots == 0);
1336
1337 /* Fill the long name slots. */
1338 for (i = 0; i < long_bhs; i++) {
1339 int copy = min_t(int, sb->s_blocksize - offset, size);
1340 memcpy(bhs[i]->b_data + offset, slots, copy);
Al Virob5224122009-06-07 13:44:36 -04001341 mark_buffer_dirty_inode(bhs[i], dir);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001342 offset = 0;
1343 slots += copy;
1344 size -= copy;
1345 }
1346 if (long_bhs && IS_DIRSYNC(dir))
1347 err = fat_sync_bhs(bhs, long_bhs);
1348 if (!err && i < nr_bhs) {
1349 /* Fill the short name slot. */
1350 int copy = min_t(int, sb->s_blocksize - offset, size);
1351 memcpy(bhs[i]->b_data + offset, slots, copy);
Al Virob5224122009-06-07 13:44:36 -04001352 mark_buffer_dirty_inode(bhs[i], dir);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001353 if (IS_DIRSYNC(dir))
1354 err = sync_dirty_buffer(bhs[i]);
1355 }
1356 for (i = 0; i < nr_bhs; i++)
1357 brelse(bhs[i]);
1358 if (err)
1359 goto error_remove;
1360 }
1361
1362 if (nr_slots) {
1363 int cluster, nr_cluster;
1364
1365 /*
1366 * Third stage: allocate the cluster for new entries.
1367 * And initialize the cluster with new entries, then
1368 * add the cluster to dir.
1369 */
1370 cluster = fat_add_new_entries(dir, slots, nr_slots, &nr_cluster,
1371 &de, &bh, &i_pos);
1372 if (cluster < 0) {
1373 err = cluster;
1374 goto error_remove;
1375 }
1376 err = fat_chain_add(dir, cluster, nr_cluster);
1377 if (err) {
1378 fat_free_clusters(dir, cluster);
1379 goto error_remove;
1380 }
1381 if (dir->i_size & (sbi->cluster_size - 1)) {
Denis Karpov85c78592009-06-04 02:34:22 +09001382 fat_fs_error(sb, "Odd directory size");
Linus Torvalds1da177e2005-04-16 15:20:36 -07001383 dir->i_size = (dir->i_size + sbi->cluster_size - 1)
1384 & ~((loff_t)sbi->cluster_size - 1);
1385 }
1386 dir->i_size += nr_cluster << sbi->cluster_bits;
1387 MSDOS_I(dir)->mmu_private += nr_cluster << sbi->cluster_bits;
1388 }
1389 sinfo->slot_off = pos;
1390 sinfo->de = de;
1391 sinfo->bh = bh;
1392 sinfo->i_pos = fat_make_i_pos(sb, sinfo->bh, sinfo->de);
1393
1394 return 0;
1395
1396error:
1397 brelse(bh);
1398 for (i = 0; i < nr_bhs; i++)
1399 brelse(bhs[i]);
1400 return err;
1401
1402error_remove:
1403 brelse(bh);
1404 if (free_slots)
1405 __fat_remove_entries(dir, pos, free_slots);
1406 return err;
1407}
OGAWA Hirofumi7c709d02006-01-08 01:02:10 -08001408EXPORT_SYMBOL_GPL(fat_add_entries);