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 memset(inode,0,sizeof(struct 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 msdos_write_inode,
54 msdos_put_inode,
55 msdos_put_super,
56 NULL,
57 msdos_statfs
58 };
59
60
61 static int parse_options(char *options,char *check,char *conversion,uid_t *uid, gid_t *gid, int *umask)
62 {
63 char *this,*value;
64
65 *check = 'n';
66 *conversion = 'b';
67 *uid = current->uid;
68 *gid = current->gid;
69 *umask = current->umask;
70 if (!options) return 1;
71 for (this = strtok(options,","); this; this = strtok(NULL,",")) {
72 if (value = strchr(this,'=')) *value++ = 0;
73 if (!strcmp(this,"check") && value) {
74 if (value[0] && !value[1] && strchr("rns",*value))
75 *check = *value;
76 else if (!strcmp(value,"relaxed")) *check = 'r';
77 else if (!strcmp(value,"normal")) *check = 'n';
78 else if (!strcmp(value,"strict")) *check = 's';
79 else return 0;
80 }
81 else if (!strcmp(this,"conv") && value) {
82 if (value[0] && !value[1] && strchr("bta",*value))
83 *conversion = *value;
84 else if (!strcmp(value,"binary")) *conversion = 'b';
85 else if (!strcmp(value,"text")) *conversion = 't';
86 else if (!strcmp(value,"auto")) *conversion = 'a';
87 else return 0;
88 }
89 else if (!strcmp(this,"uid")) {
90 if (!value || !*value)
91 return 0;
92 *uid = simple_strtoul(value,&value,0);
93 if (*value)
94 return 0;
95 }
96 else if (!strcmp(this,"gid")) {
97 if (!value || !*value)
98 return 0;
99 *gid = simple_strtoul(value,&value,0);
100 if (*value)
101 return 0;
102 }
103 else if (!strcmp(this,"umask")) {
104 if (!value || !*value)
105 return 0;
106 *umask = simple_strtoul(value,&value,8);
107 if (*value)
108 return 0;
109 }
110 else return 0;
111 }
112 return 1;
113 }
114
115
116
117
118 struct super_block *msdos_read_super(struct super_block *s,void *data)
119 {
120 struct buffer_head *bh;
121 struct msdos_boot_sector *b;
122 int data_sectors;
123 char check,conversion;
124 uid_t uid;
125 gid_t gid;
126 int umask;
127
128 if (!parse_options((char *) data,&check,&conversion,&uid,&gid,&umask)) {
129 s->s_dev = 0;
130 return NULL;
131 }
132 cache_init();
133 lock_super(s);
134 bh = bread(s->s_dev, 0, BLOCK_SIZE);
135 unlock_super(s);
136 if (bh == NULL) {
137 s->s_dev = 0;
138 printk("MSDOS bread failed\n");
139 return NULL;
140 }
141 b = (struct msdos_boot_sector *) bh->b_data;
142 s->s_blocksize = 1024;
143 MSDOS_SB(s)->cluster_size = b->cluster_size;
144 MSDOS_SB(s)->fats = b->fats;
145 MSDOS_SB(s)->fat_start = b->reserved;
146 MSDOS_SB(s)->fat_length = b->fat_length;
147 MSDOS_SB(s)->dir_start = b->reserved+b->fats*b->fat_length;
148 MSDOS_SB(s)->dir_entries = *((unsigned short *) &b->dir_entries);
149 MSDOS_SB(s)->data_start = MSDOS_SB(s)->dir_start+((MSDOS_SB(s)->
150 dir_entries << 5) >> 9);
151 data_sectors = (*((unsigned short *) &b->sectors) ? *((unsigned short *)
152 &b->sectors) : b->total_sect)-MSDOS_SB(s)->data_start;
153 MSDOS_SB(s)->clusters = b->cluster_size ? data_sectors/b->cluster_size :
154 0;
155 MSDOS_SB(s)->fat_bits = MSDOS_SB(s)->clusters > MSDOS_FAT12 ? 16 : 12;
156 brelse(bh);
157 printk("[MS-DOS FS Rel. alpha.8, FAT %d, check=%c, conv=%c, uid=%d, gid=%d, umask=%03o]\n",
158 MSDOS_SB(s)->fat_bits,check,conversion,uid,gid,umask);
159 printk("[me=0x%x,cs=%d,#f=%d,fs=%d,fl=%d,ds=%d,de=%d,data=%d,se=%d,ts=%d]\n",
160 b->media,MSDOS_SB(s)->cluster_size,MSDOS_SB(s)->fats,MSDOS_SB(s)->fat_start,
161 MSDOS_SB(s)->fat_length,MSDOS_SB(s)->dir_start,MSDOS_SB(s)->dir_entries,
162 MSDOS_SB(s)->data_start,*(unsigned short *) &b->sectors,b->total_sect);
163 if (!MSDOS_SB(s)->fats || (MSDOS_SB(s)->dir_entries & (MSDOS_DPS-1))
164 || !b->cluster_size || MSDOS_SB(s)->clusters+2 > MSDOS_SB(s)->
165 fat_length*SECTOR_SIZE*8/MSDOS_SB(s)->fat_bits) {
166 s->s_dev = 0;
167 printk("Unsupported FS parameters\n");
168 return NULL;
169 }
170 if (!MSDOS_CAN_BMAP(MSDOS_SB(s))) printk("No bmap support\n");
171 s->s_magic = MSDOS_SUPER_MAGIC;
172 MSDOS_SB(s)->name_check = check;
173 MSDOS_SB(s)->conversion = conversion;
174
175 s->s_op = &msdos_sops;
176 MSDOS_SB(s)->fs_uid = uid;
177 MSDOS_SB(s)->fs_gid = gid;
178 MSDOS_SB(s)->fs_umask = umask;
179 MSDOS_SB(s)->free_clusters = -1;
180 MSDOS_SB(s)->fat_wait = NULL;
181 MSDOS_SB(s)->fat_lock = 0;
182 if (!(s->s_mounted = iget(s,MSDOS_ROOT_INO))) {
183 s->s_dev = 0;
184 printk("get root inode failed\n");
185 return NULL;
186 }
187 return s;
188 }
189
190
191 void msdos_statfs(struct super_block *sb,struct statfs *buf)
192 {
193 int free,this;
194
195 put_fs_long(sb->s_magic,&buf->f_type);
196 put_fs_long(MSDOS_SB(sb)->cluster_size*SECTOR_SIZE,&buf->f_bsize);
197 put_fs_long(MSDOS_SB(sb)->clusters,&buf->f_blocks);
198 lock_fat(sb);
199 if (MSDOS_SB(sb)->free_clusters != -1)
200 free = MSDOS_SB(sb)->free_clusters;
201 else {
202 free = 0;
203 for (this = 2; this < MSDOS_SB(sb)->clusters+2; this++)
204 if (!fat_access(sb,this,-1)) free++;
205 MSDOS_SB(sb)->free_clusters = free;
206 }
207 unlock_fat(sb);
208 put_fs_long(free,&buf->f_bfree);
209 put_fs_long(free,&buf->f_bavail);
210 put_fs_long(0,&buf->f_files);
211 put_fs_long(0,&buf->f_ffree);
212 }
213
214
215 int msdos_bmap(struct inode *inode,int block)
216 {
217 struct msdos_sb_info *sb;
218 int cluster,offset;
219
220 sb = MSDOS_SB(inode->i_sb);
221 if ((sb->cluster_size & 1) || (sb->data_start & 1)) return 0;
222 if (inode->i_ino == MSDOS_ROOT_INO) {
223 if (sb->dir_start & 1) return 0;
224 return (sb->dir_start >> 1)+block;
225 }
226 cluster = (block*2)/sb->cluster_size;
227 offset = (block*2) % sb->cluster_size;
228 if (!(cluster = get_cluster(inode,cluster))) return 0;
229 return ((cluster-2)*sb->cluster_size+sb->data_start+offset) >> 1;
230 }
231
232
233 void msdos_read_inode(struct inode *inode)
234 {
235 struct buffer_head *bh;
236 struct msdos_dir_entry *raw_entry;
237 int this;
238
239
240 MSDOS_I(inode)->i_busy = 0;
241 MSDOS_I(inode)->i_depend = MSDOS_I(inode)->i_old = NULL;
242 MSDOS_I(inode)->i_binary = 1;
243 inode->i_uid = MSDOS_SB(inode->i_sb)->fs_uid;
244 inode->i_gid = MSDOS_SB(inode->i_sb)->fs_gid;
245 if (inode->i_ino == MSDOS_ROOT_INO) {
246 inode->i_mode = (0777 & ~MSDOS_SB(inode->i_sb)->fs_umask) |
247 S_IFDIR;
248 inode->i_op = &msdos_dir_inode_operations;
249 inode->i_nlink = msdos_subdirs(inode)+2;
250
251 inode->i_size = MSDOS_SB(inode->i_sb)->dir_entries*
252 sizeof(struct msdos_dir_entry);
253 inode->i_blksize = MSDOS_SB(inode->i_sb)->cluster_size*
254 SECTOR_SIZE;
255 inode->i_blocks = (inode->i_size+inode->i_blksize-1)/
256 inode->i_blksize;
257 MSDOS_I(inode)->i_start = 0;
258 MSDOS_I(inode)->i_attrs = 0;
259 inode->i_mtime = inode->i_atime = inode->i_ctime = 0;
260 return;
261 }
262 if (!(bh = bread(inode->i_dev,inode->i_ino >> MSDOS_DPB_BITS, BLOCK_SIZE)))
263 panic("unable to read i-node block");
264 raw_entry = &((struct msdos_dir_entry *) (bh->b_data))
265 [inode->i_ino & (MSDOS_DPB-1)];
266 if ((raw_entry->attr & ATTR_DIR) && *raw_entry->name && *(unsigned char *)
267 raw_entry->name != DELETED_FLAG) {
268 inode->i_mode = MSDOS_MKMODE(raw_entry->attr,0777 &
269 ~MSDOS_SB(inode->i_sb)->fs_umask) | S_IFDIR;
270 inode->i_op = &msdos_dir_inode_operations;
271 MSDOS_I(inode)->i_start = raw_entry->start;
272 inode->i_nlink = msdos_subdirs(inode);
273
274 #ifdef DEBUG
275 if (!inode->i_nlink) {
276 printk("directory %d: i_nlink == 0\n",inode->i_ino);
277 inode->i_nlink = 1;
278 }
279 #endif
280 inode->i_size = 0;
281 if (this = raw_entry->start)
282 while (this != -1) {
283 inode->i_size += SECTOR_SIZE*MSDOS_SB(inode->
284 i_sb)->cluster_size;
285 if (!(this = fat_access(inode->i_sb,this,-1)))
286 printk("Directory %d: bad FAT\n",
287 inode->i_ino);
288 }
289 }
290 else {
291 inode->i_mode = MSDOS_MKMODE(raw_entry->attr,0666 &
292 ~MSDOS_SB(inode->i_sb)->fs_umask) | S_IFREG;
293 inode->i_op = MSDOS_CAN_BMAP(MSDOS_SB(inode->i_sb)) ?
294 &msdos_file_inode_operations :
295 &msdos_file_inode_operations_no_bmap;
296 MSDOS_I(inode)->i_start = raw_entry->start;
297 inode->i_nlink = 1;
298 inode->i_size = raw_entry->size;
299 }
300 MSDOS_I(inode)->i_binary = is_binary(MSDOS_SB(inode->i_sb)->conversion,
301 raw_entry->ext);
302 MSDOS_I(inode)->i_attrs = raw_entry->attr & ATTR_UNUSED;
303
304 inode->i_blksize = MSDOS_SB(inode->i_sb)->cluster_size*SECTOR_SIZE;
305 inode->i_blocks = (inode->i_size+inode->i_blksize-1)/
306 inode->i_blksize;
307 inode->i_mtime = inode->i_atime = inode->i_ctime =
308 date_dos2unix(raw_entry->time,raw_entry->date);
309 brelse(bh);
310 }
311
312
313 void msdos_write_inode(struct inode *inode)
314 {
315 struct buffer_head *bh;
316 struct msdos_dir_entry *raw_entry;
317
318 inode->i_dirt = 0;
319 if (inode->i_ino == MSDOS_ROOT_INO || !inode->i_nlink) return;
320 if (!(bh = bread(inode->i_dev,inode->i_ino >> MSDOS_DPB_BITS, BLOCK_SIZE)))
321 panic("unable to read i-node block");
322 raw_entry = &((struct msdos_dir_entry *) (bh->b_data))
323 [inode->i_ino & (MSDOS_DPB-1)];
324 if (S_ISDIR(inode->i_mode)) {
325 raw_entry->attr = ATTR_DIR;
326 raw_entry->size = 0;
327 }
328 else {
329 raw_entry->attr = ATTR_NONE;
330 raw_entry->size = inode->i_size;
331 }
332 raw_entry->attr |= MSDOS_MKATTR(inode->i_mode) |
333 MSDOS_I(inode)->i_attrs;
334 raw_entry->start = MSDOS_I(inode)->i_start;
335 date_unix2dos(inode->i_mtime,&raw_entry->time,&raw_entry->date);
336 bh->b_dirt = 1;
337 brelse(bh);
338 }
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