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
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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 void msdos_put_inode(struct inode *inode)
19 {
20 struct inode *depend;
21
22 if (inode->i_nlink)
23 return;
24 inode->i_size = 0;
25 msdos_truncate(inode);
26 depend = MSDOS_I(inode)->i_depend;
27 clear_inode(inode);
28 if (depend) {
29 if (MSDOS_I(depend)->i_old != inode) {
30 printk("Invalid link (0x%X): expected 0x%X, got "
31 "0x%X\n",(int) depend,(int) inode,(int)
32 MSDOS_I(depend)->i_old);
33 panic("That's fatal");
34 }
35 MSDOS_I(depend)->i_old = NULL;
36 iput(depend);
37 }
38 }
39
40
41 void msdos_put_super(struct super_block *sb)
42 {
43 cache_inval_dev(sb->s_dev);
44 lock_super(sb);
45 sb->s_dev = 0;
46 unlock_super(sb);
47 return;
48 }
49
50
51 static struct super_operations msdos_sops = {
52 msdos_read_inode,
53 NULL,
54 msdos_write_inode,
55 msdos_put_inode,
56 msdos_put_super,
57 NULL,
58 msdos_statfs
59 };
60
61
62 static int parse_options(char *options,char *check,char *conversion,uid_t *uid, gid_t *gid, int *umask)
63 {
64 char *this,*value;
65
66 *check = 'n';
67 *conversion = 'b';
68 *uid = current->uid;
69 *gid = current->gid;
70 *umask = current->umask;
71 if (!options) return 1;
72 for (this = strtok(options,","); this; this = strtok(NULL,",")) {
73 if ((value = strchr(this,'=')) != NULL)
74 *value++ = 0;
75 if (!strcmp(this,"check") && value) {
76 if (value[0] && !value[1] && strchr("rns",*value))
77 *check = *value;
78 else if (!strcmp(value,"relaxed")) *check = 'r';
79 else if (!strcmp(value,"normal")) *check = 'n';
80 else if (!strcmp(value,"strict")) *check = 's';
81 else return 0;
82 }
83 else if (!strcmp(this,"conv") && value) {
84 if (value[0] && !value[1] && strchr("bta",*value))
85 *conversion = *value;
86 else if (!strcmp(value,"binary")) *conversion = 'b';
87 else if (!strcmp(value,"text")) *conversion = 't';
88 else if (!strcmp(value,"auto")) *conversion = 'a';
89 else return 0;
90 }
91 else if (!strcmp(this,"uid")) {
92 if (!value || !*value)
93 return 0;
94 *uid = simple_strtoul(value,&value,0);
95 if (*value)
96 return 0;
97 }
98 else if (!strcmp(this,"gid")) {
99 if (!value || !*value)
100 return 0;
101 *gid = simple_strtoul(value,&value,0);
102 if (*value)
103 return 0;
104 }
105 else if (!strcmp(this,"umask")) {
106 if (!value || !*value)
107 return 0;
108 *umask = simple_strtoul(value,&value,8);
109 if (*value)
110 return 0;
111 }
112 else return 0;
113 }
114 return 1;
115 }
116
117
118
119
120 struct super_block *msdos_read_super(struct super_block *s,void *data)
121 {
122 struct buffer_head *bh;
123 struct msdos_boot_sector *b;
124 int data_sectors;
125 char check,conversion;
126 uid_t uid;
127 gid_t gid;
128 int umask;
129
130 if (!parse_options((char *) data,&check,&conversion,&uid,&gid,&umask)) {
131 s->s_dev = 0;
132 return NULL;
133 }
134 cache_init();
135 lock_super(s);
136 bh = bread(s->s_dev, 0, BLOCK_SIZE);
137 unlock_super(s);
138 if (bh == NULL) {
139 s->s_dev = 0;
140 printk("MSDOS bread failed\n");
141 return NULL;
142 }
143 b = (struct msdos_boot_sector *) bh->b_data;
144 s->s_blocksize = 1024;
145 MSDOS_SB(s)->cluster_size = b->cluster_size;
146 MSDOS_SB(s)->fats = b->fats;
147 MSDOS_SB(s)->fat_start = b->reserved;
148 MSDOS_SB(s)->fat_length = b->fat_length;
149 MSDOS_SB(s)->dir_start = b->reserved+b->fats*b->fat_length;
150 MSDOS_SB(s)->dir_entries = *((unsigned short *) &b->dir_entries);
151 MSDOS_SB(s)->data_start = MSDOS_SB(s)->dir_start+((MSDOS_SB(s)->
152 dir_entries << 5) >> 9);
153 data_sectors = (*((unsigned short *) &b->sectors) ? *((unsigned short *)
154 &b->sectors) : b->total_sect)-MSDOS_SB(s)->data_start;
155 MSDOS_SB(s)->clusters = b->cluster_size ? data_sectors/b->cluster_size :
156 0;
157 MSDOS_SB(s)->fat_bits = MSDOS_SB(s)->clusters > MSDOS_FAT12 ? 16 : 12;
158 brelse(bh);
159 printk("[MS-DOS FS Rel. alpha.8, FAT %d, check=%c, conv=%c, uid=%d, gid=%d, umask=%03o]\n",
160 MSDOS_SB(s)->fat_bits,check,conversion,uid,gid,umask);
161 printk("[me=0x%x,cs=%d,#f=%d,fs=%d,fl=%d,ds=%d,de=%d,data=%d,se=%d,ts=%d]\n",
162 b->media,MSDOS_SB(s)->cluster_size,MSDOS_SB(s)->fats,MSDOS_SB(s)->fat_start,
163 MSDOS_SB(s)->fat_length,MSDOS_SB(s)->dir_start,MSDOS_SB(s)->dir_entries,
164 MSDOS_SB(s)->data_start,*(unsigned short *) &b->sectors,b->total_sect);
165 if (!MSDOS_SB(s)->fats || (MSDOS_SB(s)->dir_entries & (MSDOS_DPS-1))
166 || !b->cluster_size || MSDOS_SB(s)->clusters+2 > MSDOS_SB(s)->
167 fat_length*SECTOR_SIZE*8/MSDOS_SB(s)->fat_bits) {
168 s->s_dev = 0;
169 printk("Unsupported FS parameters\n");
170 return NULL;
171 }
172 s->s_magic = MSDOS_SUPER_MAGIC;
173 MSDOS_SB(s)->name_check = check;
174 MSDOS_SB(s)->conversion = conversion;
175
176 s->s_op = &msdos_sops;
177 MSDOS_SB(s)->fs_uid = uid;
178 MSDOS_SB(s)->fs_gid = gid;
179 MSDOS_SB(s)->fs_umask = umask;
180 MSDOS_SB(s)->free_clusters = -1;
181 MSDOS_SB(s)->fat_wait = NULL;
182 MSDOS_SB(s)->fat_lock = 0;
183 if (!(s->s_mounted = iget(s,MSDOS_ROOT_INO))) {
184 s->s_dev = 0;
185 printk("get root inode failed\n");
186 return NULL;
187 }
188 return s;
189 }
190
191
192 void msdos_statfs(struct super_block *sb,struct statfs *buf)
193 {
194 int free,this;
195
196 put_fs_long(sb->s_magic,&buf->f_type);
197 put_fs_long(MSDOS_SB(sb)->cluster_size*SECTOR_SIZE,&buf->f_bsize);
198 put_fs_long(MSDOS_SB(sb)->clusters,&buf->f_blocks);
199 lock_fat(sb);
200 if (MSDOS_SB(sb)->free_clusters != -1)
201 free = MSDOS_SB(sb)->free_clusters;
202 else {
203 free = 0;
204 for (this = 2; this < MSDOS_SB(sb)->clusters+2; this++)
205 if (!fat_access(sb,this,-1)) free++;
206 MSDOS_SB(sb)->free_clusters = free;
207 }
208 unlock_fat(sb);
209 put_fs_long(free,&buf->f_bfree);
210 put_fs_long(free,&buf->f_bavail);
211 put_fs_long(0,&buf->f_files);
212 put_fs_long(0,&buf->f_ffree);
213 }
214
215
216 int msdos_bmap(struct inode *inode,int block)
217 {
218 struct msdos_sb_info *sb;
219 int cluster,offset;
220
221 sb = MSDOS_SB(inode->i_sb);
222 if ((sb->cluster_size & 1) || (sb->data_start & 1)) return 0;
223 if (inode->i_ino == MSDOS_ROOT_INO) {
224 if (sb->dir_start & 1) return 0;
225 return (sb->dir_start >> 1)+block;
226 }
227 cluster = (block*2)/sb->cluster_size;
228 offset = (block*2) % sb->cluster_size;
229 if (!(cluster = get_cluster(inode,cluster))) return 0;
230 return ((cluster-2)*sb->cluster_size+sb->data_start+offset) >> 1;
231 }
232
233
234 void msdos_read_inode(struct inode *inode)
235 {
236 struct buffer_head *bh;
237 struct msdos_dir_entry *raw_entry;
238 int this;
239
240
241 MSDOS_I(inode)->i_busy = 0;
242 MSDOS_I(inode)->i_depend = MSDOS_I(inode)->i_old = NULL;
243 MSDOS_I(inode)->i_binary = 1;
244 inode->i_uid = MSDOS_SB(inode->i_sb)->fs_uid;
245 inode->i_gid = MSDOS_SB(inode->i_sb)->fs_gid;
246 if (inode->i_ino == MSDOS_ROOT_INO) {
247 inode->i_mode = (0777 & ~MSDOS_SB(inode->i_sb)->fs_umask) |
248 S_IFDIR;
249 inode->i_op = &msdos_dir_inode_operations;
250 inode->i_nlink = msdos_subdirs(inode)+2;
251
252 inode->i_size = MSDOS_SB(inode->i_sb)->dir_entries*
253 sizeof(struct msdos_dir_entry);
254 inode->i_blksize = MSDOS_SB(inode->i_sb)->cluster_size*
255 SECTOR_SIZE;
256 inode->i_blocks = (inode->i_size+inode->i_blksize-1)/
257 inode->i_blksize*MSDOS_SB(inode->i_sb)->cluster_size;
258 MSDOS_I(inode)->i_start = 0;
259 MSDOS_I(inode)->i_attrs = 0;
260 inode->i_mtime = inode->i_atime = inode->i_ctime = 0;
261 return;
262 }
263 if (!(bh = bread(inode->i_dev,inode->i_ino >> MSDOS_DPB_BITS, BLOCK_SIZE)))
264 panic("unable to read i-node block");
265 raw_entry = &((struct msdos_dir_entry *) (bh->b_data))
266 [inode->i_ino & (MSDOS_DPB-1)];
267 if ((raw_entry->attr & ATTR_DIR) && *raw_entry->name && *(unsigned char *)
268 raw_entry->name != DELETED_FLAG) {
269 inode->i_mode = MSDOS_MKMODE(raw_entry->attr,0777 &
270 ~MSDOS_SB(inode->i_sb)->fs_umask) | S_IFDIR;
271 inode->i_op = &msdos_dir_inode_operations;
272 MSDOS_I(inode)->i_start = raw_entry->start;
273 inode->i_nlink = msdos_subdirs(inode);
274
275 #ifdef DEBUG
276 if (!inode->i_nlink) {
277 printk("directory %d: i_nlink == 0\n",inode->i_ino);
278 inode->i_nlink = 1;
279 }
280 #endif
281 inode->i_size = 0;
282 if ((this = raw_entry->start) != 0)
283 while (this != -1) {
284 inode->i_size += SECTOR_SIZE*MSDOS_SB(inode->
285 i_sb)->cluster_size;
286 if (!(this = fat_access(inode->i_sb,this,-1)))
287 printk("Directory %d: bad FAT\n",
288 inode->i_ino);
289 }
290 }
291 else {
292 inode->i_mode = MSDOS_MKMODE(raw_entry->attr,0666 &
293 ~MSDOS_SB(inode->i_sb)->fs_umask) | S_IFREG;
294 inode->i_op = MSDOS_CAN_BMAP(MSDOS_SB(inode->i_sb)) ?
295 &msdos_file_inode_operations :
296 &msdos_file_inode_operations_no_bmap;
297 MSDOS_I(inode)->i_start = raw_entry->start;
298 inode->i_nlink = 1;
299 inode->i_size = raw_entry->size;
300 }
301 MSDOS_I(inode)->i_binary = is_binary(MSDOS_SB(inode->i_sb)->conversion,
302 raw_entry->ext);
303 MSDOS_I(inode)->i_attrs = raw_entry->attr & ATTR_UNUSED;
304
305 inode->i_blksize = MSDOS_SB(inode->i_sb)->cluster_size*SECTOR_SIZE;
306 inode->i_blocks = (inode->i_size+inode->i_blksize-1)/
307 inode->i_blksize*MSDOS_SB(inode->i_sb)->cluster_size;
308 inode->i_mtime = inode->i_atime = inode->i_ctime =
309 date_dos2unix(raw_entry->time,raw_entry->date);
310 brelse(bh);
311 }
312
313
314 void msdos_write_inode(struct inode *inode)
315 {
316 struct buffer_head *bh;
317 struct msdos_dir_entry *raw_entry;
318
319 inode->i_dirt = 0;
320 if (inode->i_ino == MSDOS_ROOT_INO || !inode->i_nlink) return;
321 if (!(bh = bread(inode->i_dev,inode->i_ino >> MSDOS_DPB_BITS, BLOCK_SIZE)))
322 panic("unable to read i-node block");
323 raw_entry = &((struct msdos_dir_entry *) (bh->b_data))
324 [inode->i_ino & (MSDOS_DPB-1)];
325 if (S_ISDIR(inode->i_mode)) {
326 raw_entry->attr = ATTR_DIR;
327 raw_entry->size = 0;
328 }
329 else {
330 raw_entry->attr = ATTR_NONE;
331 raw_entry->size = inode->i_size;
332 }
333 raw_entry->attr |= MSDOS_MKATTR(inode->i_mode) |
334 MSDOS_I(inode)->i_attrs;
335 raw_entry->start = MSDOS_I(inode)->i_start;
336 date_unix2dos(inode->i_mtime,&raw_entry->time,&raw_entry->date);
337 bh->b_dirt = 1;
338 brelse(bh);
339 }
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