This source file includes following definitions.
- msdos_put_inode
- msdos_put_super
- parse_options
- msdos_read_super
- msdos_statfs
- msdos_bmap
- msdos_read_inode
- msdos_write_inode
- msdos_notify_change
1
2
3
4
5
6
7 #include <linux/msdos_fs.h>
8 #include <linux/kernel.h>
9 #include <linux/sched.h>
10 #include <linux/errno.h>
11 #include <linux/string.h>
12 #include <linux/ctype.h>
13 #include <linux/stat.h>
14 #include <linux/locks.h>
15
16 #include <asm/segment.h>
17
18
19 void msdos_put_inode(struct inode *inode)
20 {
21 struct inode *depend;
22 struct super_block *sb;
23
24 if (inode->i_nlink) {
25 if (MSDOS_I(inode)->i_busy) cache_inval_inode(inode);
26 return;
27 }
28 inode->i_size = 0;
29 msdos_truncate(inode);
30 depend = MSDOS_I(inode)->i_depend;
31 sb = inode->i_sb;
32 clear_inode(inode);
33 if (depend) {
34 if (MSDOS_I(depend)->i_old != inode) {
35 printk("Invalid link (0x%X): expected 0x%X, got 0x%X\n",
36 (int) depend,(int) inode,(int) MSDOS_I(depend)->
37 i_old);
38 fs_panic(sb,"...");
39 return;
40 }
41 MSDOS_I(depend)->i_old = NULL;
42 iput(depend);
43 }
44 }
45
46
47 void msdos_put_super(struct super_block *sb)
48 {
49 cache_inval_dev(sb->s_dev);
50 lock_super(sb);
51 sb->s_dev = 0;
52 unlock_super(sb);
53 return;
54 }
55
56
57 static struct super_operations msdos_sops = {
58 msdos_read_inode,
59 msdos_notify_change,
60 msdos_write_inode,
61 msdos_put_inode,
62 msdos_put_super,
63 NULL,
64 msdos_statfs
65 };
66
67
68 static int parse_options(char *options,char *check,char *conversion,uid_t *uid,
69 gid_t *gid,int *umask,int *debug,int *fat,int *quiet)
70 {
71 char *this,*value;
72
73 *check = 'n';
74 *conversion = 'b';
75 *uid = current->uid;
76 *gid = current->gid;
77 *umask = current->umask;
78 *debug = *fat = *quiet = 0;
79 if (!options) return 1;
80 for (this = strtok(options,","); this; this = strtok(NULL,",")) {
81 if ((value = strchr(this,'=')) != NULL)
82 *value++ = 0;
83 if (!strcmp(this,"check") && value) {
84 if (value[0] && !value[1] && strchr("rns",*value))
85 *check = *value;
86 else if (!strcmp(value,"relaxed")) *check = 'r';
87 else if (!strcmp(value,"normal")) *check = 'n';
88 else if (!strcmp(value,"strict")) *check = 's';
89 else return 0;
90 }
91 else if (!strcmp(this,"conv") && value) {
92 if (value[0] && !value[1] && strchr("bta",*value))
93 *conversion = *value;
94 else if (!strcmp(value,"binary")) *conversion = 'b';
95 else if (!strcmp(value,"text")) *conversion = 't';
96 else if (!strcmp(value,"auto")) *conversion = 'a';
97 else return 0;
98 }
99 else if (!strcmp(this,"uid")) {
100 if (!value || !*value)
101 return 0;
102 *uid = simple_strtoul(value,&value,0);
103 if (*value)
104 return 0;
105 }
106 else if (!strcmp(this,"gid")) {
107 if (!value || !*value)
108 return 0;
109 *gid = simple_strtoul(value,&value,0);
110 if (*value)
111 return 0;
112 }
113 else if (!strcmp(this,"umask")) {
114 if (!value || !*value)
115 return 0;
116 *umask = simple_strtoul(value,&value,8);
117 if (*value)
118 return 0;
119 }
120 else if (!strcmp(this,"debug")) {
121 if (value) return 0;
122 *debug = 1;
123 }
124 else if (!strcmp(this,"fat")) {
125 if (!value || !*value)
126 return 0;
127 *fat = simple_strtoul(value,&value,0);
128 if (*value || (*fat != 12 && *fat != 16))
129 return 0;
130 }
131 else if (!strcmp(this,"quiet")) {
132 if (value) return 0;
133 *quiet = 1;
134 }
135 else return 0;
136 }
137 return 1;
138 }
139
140
141
142
143 struct super_block *msdos_read_super(struct super_block *s,void *data,
144 int silent)
145 {
146 struct buffer_head *bh;
147 struct msdos_boot_sector *b;
148 int data_sectors,logical_sector_size,sector_mult;
149 int debug,error,fat,quiet;
150 char check,conversion;
151 uid_t uid;
152 gid_t gid;
153 int umask;
154
155 if (!parse_options((char *) data,&check,&conversion,&uid,&gid,&umask,
156 &debug,&fat,&quiet)) {
157 s->s_dev = 0;
158 return NULL;
159 }
160 cache_init();
161 lock_super(s);
162 bh = bread(s->s_dev, 0, BLOCK_SIZE);
163 unlock_super(s);
164 if (bh == NULL) {
165 s->s_dev = 0;
166 printk("MSDOS bread failed\n");
167 return NULL;
168 }
169 b = (struct msdos_boot_sector *) bh->b_data;
170 s->s_blocksize = 1024;
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187 #define ROUND_TO_MULTIPLE(n,m) ((n) && (m) ? (n)+(m)-1-((n)-1)%(m) : 0)
188
189
190 logical_sector_size = CF_LE_W(*(unsigned short *) &b->sector_size);
191 sector_mult = logical_sector_size >> SECTOR_BITS;
192 MSDOS_SB(s)->cluster_size = b->cluster_size*sector_mult;
193 MSDOS_SB(s)->fats = b->fats;
194 MSDOS_SB(s)->fat_start = CF_LE_W(b->reserved)*sector_mult;
195 MSDOS_SB(s)->fat_length = CF_LE_W(b->fat_length)*sector_mult;
196 MSDOS_SB(s)->dir_start = (CF_LE_W(b->reserved)+b->fats*CF_LE_W(
197 b->fat_length))*sector_mult;
198 MSDOS_SB(s)->dir_entries = CF_LE_W(*((unsigned short *) &b->dir_entries
199 ));
200 MSDOS_SB(s)->data_start = MSDOS_SB(s)->dir_start+ROUND_TO_MULTIPLE((
201 MSDOS_SB(s)->dir_entries << MSDOS_DIR_BITS) >> SECTOR_BITS,
202 sector_mult);
203 data_sectors = (CF_LE_W(*((unsigned short *) &b->sectors)) ?
204 CF_LE_W(*((unsigned short *) &b->sectors)) :
205 CF_LE_L(b->total_sect))*sector_mult-MSDOS_SB(s)->data_start;
206 error = !b->cluster_size || !sector_mult;
207 if (!error) {
208 MSDOS_SB(s)->clusters = b->cluster_size ? data_sectors/
209 b->cluster_size/sector_mult : 0;
210 MSDOS_SB(s)->fat_bits = fat ? fat : MSDOS_SB(s)->clusters >
211 MSDOS_FAT12 ? 16 : 12;
212 error = !MSDOS_SB(s)->fats || (MSDOS_SB(s)->dir_entries &
213 (MSDOS_DPS-1)) || MSDOS_SB(s)->clusters+2 > MSDOS_SB(s)->
214 fat_length*SECTOR_SIZE*8/MSDOS_SB(s)->fat_bits ||
215 (logical_sector_size & (SECTOR_SIZE-1)) || !b->secs_track ||
216 !b->heads;
217 }
218 brelse(bh);
219 if (error || debug) {
220 printk("[MS-DOS FS Rel. 12,FAT %d,check=%c,conv=%c,"
221 "uid=%d,gid=%d,umask=%03o%s]\n",MSDOS_SB(s)->fat_bits,check,
222 conversion,uid,gid,umask,MSDOS_CAN_BMAP(MSDOS_SB(s)) ?
223 ",bmap" : "");
224 printk("[me=0x%x,cs=%d,#f=%d,fs=%d,fl=%d,ds=%d,de=%d,data=%d,"
225 "se=%d,ts=%d,ls=%d]\n",b->media,MSDOS_SB(s)->cluster_size,
226 MSDOS_SB(s)->fats,MSDOS_SB(s)->fat_start,MSDOS_SB(s)->
227 fat_length,MSDOS_SB(s)->dir_start,MSDOS_SB(s)->dir_entries,
228 MSDOS_SB(s)->data_start,CF_LE_W(*(unsigned short *) &b->
229 sectors),b->total_sect,logical_sector_size);
230 }
231 if (error) {
232 if (!silent)
233 printk("VFS: Can't find a valid MSDOS filesystem on dev 0x%04x.\n",
234 s->s_dev);
235 s->s_dev = 0;
236 return NULL;
237 }
238 s->s_magic = MSDOS_SUPER_MAGIC;
239 MSDOS_SB(s)->name_check = check;
240 MSDOS_SB(s)->conversion = conversion;
241
242 s->s_op = &msdos_sops;
243 MSDOS_SB(s)->fs_uid = uid;
244 MSDOS_SB(s)->fs_gid = gid;
245 MSDOS_SB(s)->fs_umask = umask;
246 MSDOS_SB(s)->quiet = quiet;
247 MSDOS_SB(s)->free_clusters = -1;
248 MSDOS_SB(s)->fat_wait = NULL;
249 MSDOS_SB(s)->fat_lock = 0;
250 MSDOS_SB(s)->prev_free = 0;
251 if (!(s->s_mounted = iget(s,MSDOS_ROOT_INO))) {
252 s->s_dev = 0;
253 printk("get root inode failed\n");
254 return NULL;
255 }
256 return s;
257 }
258
259
260 void msdos_statfs(struct super_block *sb,struct statfs *buf)
261 {
262 int free,this;
263
264 put_fs_long(sb->s_magic,&buf->f_type);
265 put_fs_long(MSDOS_SB(sb)->cluster_size*SECTOR_SIZE,&buf->f_bsize);
266 put_fs_long(MSDOS_SB(sb)->clusters,&buf->f_blocks);
267 lock_fat(sb);
268 if (MSDOS_SB(sb)->free_clusters != -1)
269 free = MSDOS_SB(sb)->free_clusters;
270 else {
271 free = 0;
272 for (this = 2; this < MSDOS_SB(sb)->clusters+2; this++)
273 if (!fat_access(sb,this,-1)) free++;
274 MSDOS_SB(sb)->free_clusters = free;
275 }
276 unlock_fat(sb);
277 put_fs_long(free,&buf->f_bfree);
278 put_fs_long(free,&buf->f_bavail);
279 put_fs_long(0,&buf->f_files);
280 put_fs_long(0,&buf->f_ffree);
281 put_fs_long(12,&buf->f_namelen);
282 }
283
284
285 int msdos_bmap(struct inode *inode,int block)
286 {
287 struct msdos_sb_info *sb;
288 int cluster,offset;
289
290 sb = MSDOS_SB(inode->i_sb);
291 if ((sb->cluster_size & 1) || (sb->data_start & 1)) return 0;
292 if (inode->i_ino == MSDOS_ROOT_INO) {
293 if (sb->dir_start & 1) return 0;
294 return (sb->dir_start >> 1)+block;
295 }
296 cluster = (block*2)/sb->cluster_size;
297 offset = (block*2) % sb->cluster_size;
298 if (!(cluster = get_cluster(inode,cluster))) return 0;
299 return ((cluster-2)*sb->cluster_size+sb->data_start+offset) >> 1;
300 }
301
302
303 void msdos_read_inode(struct inode *inode)
304 {
305 struct buffer_head *bh;
306 struct msdos_dir_entry *raw_entry;
307 int this;
308
309
310 MSDOS_I(inode)->i_busy = 0;
311 MSDOS_I(inode)->i_depend = MSDOS_I(inode)->i_old = NULL;
312 MSDOS_I(inode)->i_binary = 1;
313 inode->i_uid = MSDOS_SB(inode->i_sb)->fs_uid;
314 inode->i_gid = MSDOS_SB(inode->i_sb)->fs_gid;
315 if (inode->i_ino == MSDOS_ROOT_INO) {
316 inode->i_mode = (0777 & ~MSDOS_SB(inode->i_sb)->fs_umask) |
317 S_IFDIR;
318 inode->i_op = &msdos_dir_inode_operations;
319 inode->i_nlink = msdos_subdirs(inode)+2;
320
321 inode->i_size = MSDOS_SB(inode->i_sb)->dir_entries*
322 sizeof(struct msdos_dir_entry);
323 inode->i_blksize = MSDOS_SB(inode->i_sb)->cluster_size*
324 SECTOR_SIZE;
325 inode->i_blocks = (inode->i_size+inode->i_blksize-1)/
326 inode->i_blksize*MSDOS_SB(inode->i_sb)->cluster_size;
327 MSDOS_I(inode)->i_start = 0;
328 MSDOS_I(inode)->i_attrs = 0;
329 inode->i_mtime = inode->i_atime = inode->i_ctime = 0;
330 return;
331 }
332 if (!(bh = bread(inode->i_dev,inode->i_ino >> MSDOS_DPB_BITS,
333 BLOCK_SIZE))) {
334 printk("dev = 0x%04X, ino = %d\n",inode->i_dev,inode->i_ino);
335 panic("msdos_read_inode: unable to read i-node block");
336 }
337 raw_entry = &((struct msdos_dir_entry *) (bh->b_data))
338 [inode->i_ino & (MSDOS_DPB-1)];
339 if ((raw_entry->attr & ATTR_DIR) && !IS_FREE(raw_entry->name)) {
340 inode->i_mode = MSDOS_MKMODE(raw_entry->attr,0777 &
341 ~MSDOS_SB(inode->i_sb)->fs_umask) | S_IFDIR;
342 inode->i_op = &msdos_dir_inode_operations;
343 MSDOS_I(inode)->i_start = CF_LE_W(raw_entry->start);
344 inode->i_nlink = msdos_subdirs(inode);
345
346 #ifdef DEBUG
347 if (!inode->i_nlink) {
348 printk("directory %d: i_nlink == 0\n",inode->i_ino);
349 inode->i_nlink = 1;
350 }
351 #endif
352 inode->i_size = 0;
353 if ((this = CF_LE_W(raw_entry->start)) != 0)
354 while (this != -1) {
355 inode->i_size += SECTOR_SIZE*MSDOS_SB(inode->
356 i_sb)->cluster_size;
357 if (!(this = fat_access(inode->i_sb,this,-1)))
358 printk("Directory %d: bad FAT\n",
359 inode->i_ino);
360 }
361 }
362 else {
363 inode->i_mode = MSDOS_MKMODE(raw_entry->attr,(IS_NOEXEC(inode)
364 ? 0666 : 0777) & ~MSDOS_SB(inode->i_sb)->fs_umask) |
365 S_IFREG;
366 inode->i_op = MSDOS_CAN_BMAP(MSDOS_SB(inode->i_sb)) ?
367 &msdos_file_inode_operations :
368 &msdos_file_inode_operations_no_bmap;
369 MSDOS_I(inode)->i_start = CF_LE_W(raw_entry->start);
370 inode->i_nlink = 1;
371 inode->i_size = CF_LE_L(raw_entry->size);
372 }
373 MSDOS_I(inode)->i_binary = is_binary(MSDOS_SB(inode->i_sb)->conversion,
374 raw_entry->ext);
375 MSDOS_I(inode)->i_attrs = raw_entry->attr & ATTR_UNUSED;
376
377 inode->i_blksize = MSDOS_SB(inode->i_sb)->cluster_size*SECTOR_SIZE;
378 inode->i_blocks = (inode->i_size+inode->i_blksize-1)/
379 inode->i_blksize*MSDOS_SB(inode->i_sb)->cluster_size;
380 inode->i_mtime = inode->i_atime = inode->i_ctime =
381 date_dos2unix(CF_LE_W(raw_entry->time),CF_LE_W(raw_entry->date));
382 brelse(bh);
383 }
384
385
386 void msdos_write_inode(struct inode *inode)
387 {
388 struct buffer_head *bh;
389 struct msdos_dir_entry *raw_entry;
390
391 inode->i_dirt = 0;
392 if (inode->i_ino == MSDOS_ROOT_INO || !inode->i_nlink) return;
393 if (!(bh = bread(inode->i_dev,inode->i_ino >> MSDOS_DPB_BITS,
394 BLOCK_SIZE))) {
395 printk("dev = 0x%04X, ino = %d\n",inode->i_dev,inode->i_ino);
396 panic("msdos_write_inode: unable to read i-node block");
397 }
398 raw_entry = &((struct msdos_dir_entry *) (bh->b_data))
399 [inode->i_ino & (MSDOS_DPB-1)];
400 if (S_ISDIR(inode->i_mode)) {
401 raw_entry->attr = ATTR_DIR;
402 raw_entry->size = 0;
403 }
404 else {
405 raw_entry->attr = ATTR_NONE;
406 raw_entry->size = CT_LE_L(inode->i_size);
407 }
408 raw_entry->attr |= MSDOS_MKATTR(inode->i_mode) |
409 MSDOS_I(inode)->i_attrs;
410 raw_entry->start = CT_LE_L(MSDOS_I(inode)->i_start);
411 date_unix2dos(inode->i_mtime,&raw_entry->time,&raw_entry->date);
412 raw_entry->time = CT_LE_W(raw_entry->time);
413 raw_entry->date = CT_LE_W(raw_entry->date);
414 bh->b_dirt = 1;
415 brelse(bh);
416 }
417
418
419 int msdos_notify_change(int flags,struct inode *inode)
420 {
421 int error;
422
423 error = 0;
424 if ((flags & NOTIFY_UIDGID) && (inode->i_uid != MSDOS_SB(inode->i_sb)->
425 fs_uid || inode->i_gid != MSDOS_SB(inode->i_sb)->fs_gid)) {
426 inode->i_uid = MSDOS_SB(inode->i_sb)->fs_uid;
427 inode->i_gid = MSDOS_SB(inode->i_sb)->fs_gid;
428 error = -EPERM;
429 }
430 if (!(flags & NOTIFY_MODE))
431 return MSDOS_SB(inode->i_sb)->quiet ? 0 : error;
432 if (inode->i_mode & ~MSDOS_VALID_MODE) {
433 inode->i_mode &= MSDOS_VALID_MODE;
434 error = -EPERM;
435 }
436 if (IS_NOEXEC(inode) && !S_ISDIR(inode->i_mode))
437 inode->i_mode &= S_IFMT | 0666;
438 else inode->i_mode |= 0111;
439 inode->i_mode = ((inode->i_mode & S_IFMT) | ((((inode->i_mode & S_IRWXU
440 & ~MSDOS_SB(inode->i_sb)->fs_umask) | S_IRUSR) >> 6)*0111)) &
441 ~MSDOS_SB(inode->i_sb)->fs_umask;
442 return MSDOS_SB(inode->i_sb)->quiet ? 0 : error;
443 }
![[first]](../icons/first.png){kind=icon}
![[previous]](../icons/n_left.png){kind=icon}
![[next]](../icons/n_right.png){kind=icon}
![[last]](../icons/last.png){kind=icon}
![[top]](../icons/n_top.png){kind=icon}
![[bottom]](../icons/bottom.png){kind=icon}
![[index]](../icons/index.png){kind=icon}
![[help]](../icons/help.png){kind=icon}
*/
![[next]](../icons/right.png)
![[first]](../icons/n_first.png)
![[top]](../icons/top.png)
![[previous]](../icons/left.png)
![[last]](../icons/n_last.png)
![[bottom]](../icons/n_bottom.png){kind=icon}