Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * fs/bfs/dir.c | |
3 | * BFS directory operations. | |
4 | * Copyright (C) 1999,2000 Tigran Aivazian <tigran@veritas.com> | |
fac92bec | 5 | * Made endianness-clean by Andrew Stribblehill <ads@wompom.org> 2005 |
1da177e4 LT |
6 | */ |
7 | ||
8 | #include <linux/time.h> | |
9 | #include <linux/string.h> | |
10 | #include <linux/fs.h> | |
11 | #include <linux/smp_lock.h> | |
12 | #include <linux/buffer_head.h> | |
13 | #include <linux/sched.h> | |
14 | #include "bfs.h" | |
15 | ||
16 | #undef DEBUG | |
17 | ||
18 | #ifdef DEBUG | |
19 | #define dprintf(x...) printf(x) | |
20 | #else | |
21 | #define dprintf(x...) | |
22 | #endif | |
23 | ||
fac92bec | 24 | static int bfs_add_entry(struct inode * dir, const unsigned char * name, int namelen, int ino); |
1da177e4 | 25 | static struct buffer_head * bfs_find_entry(struct inode * dir, |
fac92bec | 26 | const unsigned char * name, int namelen, struct bfs_dirent ** res_dir); |
1da177e4 LT |
27 | |
28 | static int bfs_readdir(struct file * f, void * dirent, filldir_t filldir) | |
29 | { | |
30 | struct inode * dir = f->f_dentry->d_inode; | |
31 | struct buffer_head * bh; | |
32 | struct bfs_dirent * de; | |
33 | unsigned int offset; | |
34 | int block; | |
35 | ||
36 | lock_kernel(); | |
37 | ||
38 | if (f->f_pos & (BFS_DIRENT_SIZE-1)) { | |
39 | printf("Bad f_pos=%08lx for %s:%08lx\n", (unsigned long)f->f_pos, | |
40 | dir->i_sb->s_id, dir->i_ino); | |
41 | unlock_kernel(); | |
42 | return -EBADF; | |
43 | } | |
44 | ||
45 | while (f->f_pos < dir->i_size) { | |
46 | offset = f->f_pos & (BFS_BSIZE-1); | |
47 | block = BFS_I(dir)->i_sblock + (f->f_pos >> BFS_BSIZE_BITS); | |
48 | bh = sb_bread(dir->i_sb, block); | |
49 | if (!bh) { | |
50 | f->f_pos += BFS_BSIZE - offset; | |
51 | continue; | |
52 | } | |
53 | do { | |
54 | de = (struct bfs_dirent *)(bh->b_data + offset); | |
55 | if (de->ino) { | |
56 | int size = strnlen(de->name, BFS_NAMELEN); | |
fac92bec | 57 | if (filldir(dirent, de->name, size, f->f_pos, le16_to_cpu(de->ino), DT_UNKNOWN) < 0) { |
1da177e4 LT |
58 | brelse(bh); |
59 | unlock_kernel(); | |
60 | return 0; | |
61 | } | |
62 | } | |
63 | offset += BFS_DIRENT_SIZE; | |
64 | f->f_pos += BFS_DIRENT_SIZE; | |
65 | } while (offset < BFS_BSIZE && f->f_pos < dir->i_size); | |
66 | brelse(bh); | |
67 | } | |
68 | ||
69 | unlock_kernel(); | |
70 | return 0; | |
71 | } | |
72 | ||
73 | struct file_operations bfs_dir_operations = { | |
74 | .read = generic_read_dir, | |
75 | .readdir = bfs_readdir, | |
76 | .fsync = file_fsync, | |
77 | }; | |
78 | ||
79 | extern void dump_imap(const char *, struct super_block *); | |
80 | ||
81 | static int bfs_create(struct inode * dir, struct dentry * dentry, int mode, | |
82 | struct nameidata *nd) | |
83 | { | |
84 | int err; | |
85 | struct inode * inode; | |
86 | struct super_block * s = dir->i_sb; | |
87 | struct bfs_sb_info * info = BFS_SB(s); | |
88 | unsigned long ino; | |
89 | ||
90 | inode = new_inode(s); | |
91 | if (!inode) | |
92 | return -ENOSPC; | |
93 | lock_kernel(); | |
94 | ino = find_first_zero_bit(info->si_imap, info->si_lasti); | |
95 | if (ino > info->si_lasti) { | |
96 | unlock_kernel(); | |
97 | iput(inode); | |
98 | return -ENOSPC; | |
99 | } | |
100 | set_bit(ino, info->si_imap); | |
101 | info->si_freei--; | |
102 | inode->i_uid = current->fsuid; | |
103 | inode->i_gid = (dir->i_mode & S_ISGID) ? dir->i_gid : current->fsgid; | |
104 | inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME_SEC; | |
105 | inode->i_blocks = inode->i_blksize = 0; | |
106 | inode->i_op = &bfs_file_inops; | |
107 | inode->i_fop = &bfs_file_operations; | |
108 | inode->i_mapping->a_ops = &bfs_aops; | |
109 | inode->i_mode = mode; | |
110 | inode->i_ino = ino; | |
ce0fe7e7 | 111 | BFS_I(inode)->i_dsk_ino = ino; |
1da177e4 LT |
112 | BFS_I(inode)->i_sblock = 0; |
113 | BFS_I(inode)->i_eblock = 0; | |
114 | insert_inode_hash(inode); | |
115 | mark_inode_dirty(inode); | |
116 | dump_imap("create",s); | |
117 | ||
118 | err = bfs_add_entry(dir, dentry->d_name.name, dentry->d_name.len, inode->i_ino); | |
119 | if (err) { | |
120 | inode->i_nlink--; | |
121 | mark_inode_dirty(inode); | |
122 | iput(inode); | |
123 | unlock_kernel(); | |
124 | return err; | |
125 | } | |
126 | unlock_kernel(); | |
127 | d_instantiate(dentry, inode); | |
128 | return 0; | |
129 | } | |
130 | ||
131 | static struct dentry * bfs_lookup(struct inode * dir, struct dentry * dentry, struct nameidata *nd) | |
132 | { | |
133 | struct inode * inode = NULL; | |
134 | struct buffer_head * bh; | |
135 | struct bfs_dirent * de; | |
136 | ||
137 | if (dentry->d_name.len > BFS_NAMELEN) | |
138 | return ERR_PTR(-ENAMETOOLONG); | |
139 | ||
140 | lock_kernel(); | |
141 | bh = bfs_find_entry(dir, dentry->d_name.name, dentry->d_name.len, &de); | |
142 | if (bh) { | |
fac92bec | 143 | unsigned long ino = (unsigned long)le16_to_cpu(de->ino); |
1da177e4 LT |
144 | brelse(bh); |
145 | inode = iget(dir->i_sb, ino); | |
146 | if (!inode) { | |
147 | unlock_kernel(); | |
148 | return ERR_PTR(-EACCES); | |
149 | } | |
150 | } | |
151 | unlock_kernel(); | |
152 | d_add(dentry, inode); | |
153 | return NULL; | |
154 | } | |
155 | ||
156 | static int bfs_link(struct dentry * old, struct inode * dir, struct dentry * new) | |
157 | { | |
158 | struct inode * inode = old->d_inode; | |
159 | int err; | |
160 | ||
161 | lock_kernel(); | |
162 | err = bfs_add_entry(dir, new->d_name.name, new->d_name.len, inode->i_ino); | |
163 | if (err) { | |
164 | unlock_kernel(); | |
165 | return err; | |
166 | } | |
167 | inode->i_nlink++; | |
168 | inode->i_ctime = CURRENT_TIME_SEC; | |
169 | mark_inode_dirty(inode); | |
170 | atomic_inc(&inode->i_count); | |
171 | d_instantiate(new, inode); | |
172 | unlock_kernel(); | |
173 | return 0; | |
174 | } | |
175 | ||
176 | ||
177 | static int bfs_unlink(struct inode * dir, struct dentry * dentry) | |
178 | { | |
179 | int error = -ENOENT; | |
180 | struct inode * inode; | |
181 | struct buffer_head * bh; | |
182 | struct bfs_dirent * de; | |
183 | ||
184 | inode = dentry->d_inode; | |
185 | lock_kernel(); | |
186 | bh = bfs_find_entry(dir, dentry->d_name.name, dentry->d_name.len, &de); | |
fac92bec | 187 | if (!bh || le16_to_cpu(de->ino) != inode->i_ino) |
1da177e4 LT |
188 | goto out_brelse; |
189 | ||
190 | if (!inode->i_nlink) { | |
191 | printf("unlinking non-existent file %s:%lu (nlink=%d)\n", inode->i_sb->s_id, | |
192 | inode->i_ino, inode->i_nlink); | |
193 | inode->i_nlink = 1; | |
194 | } | |
195 | de->ino = 0; | |
196 | mark_buffer_dirty(bh); | |
197 | dir->i_ctime = dir->i_mtime = CURRENT_TIME_SEC; | |
198 | mark_inode_dirty(dir); | |
199 | inode->i_nlink--; | |
200 | inode->i_ctime = dir->i_ctime; | |
201 | mark_inode_dirty(inode); | |
202 | error = 0; | |
203 | ||
204 | out_brelse: | |
205 | brelse(bh); | |
206 | unlock_kernel(); | |
207 | return error; | |
208 | } | |
209 | ||
210 | static int bfs_rename(struct inode * old_dir, struct dentry * old_dentry, | |
211 | struct inode * new_dir, struct dentry * new_dentry) | |
212 | { | |
213 | struct inode * old_inode, * new_inode; | |
214 | struct buffer_head * old_bh, * new_bh; | |
215 | struct bfs_dirent * old_de, * new_de; | |
216 | int error = -ENOENT; | |
217 | ||
218 | old_bh = new_bh = NULL; | |
219 | old_inode = old_dentry->d_inode; | |
220 | if (S_ISDIR(old_inode->i_mode)) | |
221 | return -EINVAL; | |
222 | ||
223 | lock_kernel(); | |
224 | old_bh = bfs_find_entry(old_dir, | |
225 | old_dentry->d_name.name, | |
226 | old_dentry->d_name.len, &old_de); | |
227 | ||
fac92bec | 228 | if (!old_bh || le16_to_cpu(old_de->ino) != old_inode->i_ino) |
1da177e4 LT |
229 | goto end_rename; |
230 | ||
231 | error = -EPERM; | |
232 | new_inode = new_dentry->d_inode; | |
233 | new_bh = bfs_find_entry(new_dir, | |
234 | new_dentry->d_name.name, | |
235 | new_dentry->d_name.len, &new_de); | |
236 | ||
237 | if (new_bh && !new_inode) { | |
238 | brelse(new_bh); | |
239 | new_bh = NULL; | |
240 | } | |
241 | if (!new_bh) { | |
242 | error = bfs_add_entry(new_dir, | |
243 | new_dentry->d_name.name, | |
244 | new_dentry->d_name.len, old_inode->i_ino); | |
245 | if (error) | |
246 | goto end_rename; | |
247 | } | |
248 | old_de->ino = 0; | |
249 | old_dir->i_ctime = old_dir->i_mtime = CURRENT_TIME_SEC; | |
250 | mark_inode_dirty(old_dir); | |
251 | if (new_inode) { | |
252 | new_inode->i_nlink--; | |
253 | new_inode->i_ctime = CURRENT_TIME_SEC; | |
254 | mark_inode_dirty(new_inode); | |
255 | } | |
256 | mark_buffer_dirty(old_bh); | |
257 | error = 0; | |
258 | ||
259 | end_rename: | |
260 | unlock_kernel(); | |
261 | brelse(old_bh); | |
262 | brelse(new_bh); | |
263 | return error; | |
264 | } | |
265 | ||
266 | struct inode_operations bfs_dir_inops = { | |
267 | .create = bfs_create, | |
268 | .lookup = bfs_lookup, | |
269 | .link = bfs_link, | |
270 | .unlink = bfs_unlink, | |
271 | .rename = bfs_rename, | |
272 | }; | |
273 | ||
fac92bec | 274 | static int bfs_add_entry(struct inode * dir, const unsigned char * name, int namelen, int ino) |
1da177e4 LT |
275 | { |
276 | struct buffer_head * bh; | |
277 | struct bfs_dirent * de; | |
278 | int block, sblock, eblock, off, eoff; | |
279 | int i; | |
280 | ||
281 | dprintf("name=%s, namelen=%d\n", name, namelen); | |
282 | ||
283 | if (!namelen) | |
284 | return -ENOENT; | |
285 | if (namelen > BFS_NAMELEN) | |
286 | return -ENAMETOOLONG; | |
287 | ||
288 | sblock = BFS_I(dir)->i_sblock; | |
289 | eblock = BFS_I(dir)->i_eblock; | |
290 | eoff = dir->i_size % BFS_BSIZE; | |
291 | for (block=sblock; block<=eblock; block++) { | |
292 | bh = sb_bread(dir->i_sb, block); | |
293 | if(!bh) | |
294 | return -ENOSPC; | |
295 | for (off=0; off<BFS_BSIZE; off+=BFS_DIRENT_SIZE) { | |
296 | de = (struct bfs_dirent *)(bh->b_data + off); | |
297 | if (block==eblock && off>=eoff) { | |
298 | /* Do not read/interpret the garbage in the end of eblock. */ | |
299 | de->ino = 0; | |
300 | } | |
301 | if (!de->ino) { | |
302 | if ((block-sblock)*BFS_BSIZE + off >= dir->i_size) { | |
303 | dir->i_size += BFS_DIRENT_SIZE; | |
304 | dir->i_ctime = CURRENT_TIME_SEC; | |
305 | } | |
306 | dir->i_mtime = CURRENT_TIME_SEC; | |
307 | mark_inode_dirty(dir); | |
fac92bec | 308 | de->ino = cpu_to_le16((u16)ino); |
1da177e4 LT |
309 | for (i=0; i<BFS_NAMELEN; i++) |
310 | de->name[i] = (i < namelen) ? name[i] : 0; | |
311 | mark_buffer_dirty(bh); | |
312 | brelse(bh); | |
313 | return 0; | |
314 | } | |
315 | } | |
316 | brelse(bh); | |
317 | } | |
318 | return -ENOSPC; | |
319 | } | |
320 | ||
fac92bec | 321 | static inline int bfs_namecmp(int len, const unsigned char * name, const char * buffer) |
1da177e4 LT |
322 | { |
323 | if (len < BFS_NAMELEN && buffer[len]) | |
324 | return 0; | |
325 | return !memcmp(name, buffer, len); | |
326 | } | |
327 | ||
328 | static struct buffer_head * bfs_find_entry(struct inode * dir, | |
fac92bec | 329 | const unsigned char * name, int namelen, struct bfs_dirent ** res_dir) |
1da177e4 LT |
330 | { |
331 | unsigned long block, offset; | |
332 | struct buffer_head * bh; | |
333 | struct bfs_dirent * de; | |
334 | ||
335 | *res_dir = NULL; | |
336 | if (namelen > BFS_NAMELEN) | |
337 | return NULL; | |
338 | bh = NULL; | |
339 | block = offset = 0; | |
340 | while (block * BFS_BSIZE + offset < dir->i_size) { | |
341 | if (!bh) { | |
342 | bh = sb_bread(dir->i_sb, BFS_I(dir)->i_sblock + block); | |
343 | if (!bh) { | |
344 | block++; | |
345 | continue; | |
346 | } | |
347 | } | |
348 | de = (struct bfs_dirent *)(bh->b_data + offset); | |
349 | offset += BFS_DIRENT_SIZE; | |
fac92bec | 350 | if (le16_to_cpu(de->ino) && bfs_namecmp(namelen, name, de->name)) { |
1da177e4 LT |
351 | *res_dir = de; |
352 | return bh; | |
353 | } | |
354 | if (offset < bh->b_size) | |
355 | continue; | |
356 | brelse(bh); | |
357 | bh = NULL; | |
358 | offset = 0; | |
359 | block++; | |
360 | } | |
361 | brelse(bh); | |
362 | return NULL; | |
363 | } |