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Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * fs/bfs/dir.c | |
3 | * BFS directory operations. | |
4 | * Copyright (C) 1999,2000 Tigran Aivazian <tigran@veritas.com> | |
5 | */ | |
6 | ||
7 | #include <linux/time.h> | |
8 | #include <linux/string.h> | |
9 | #include <linux/fs.h> | |
10 | #include <linux/smp_lock.h> | |
11 | #include <linux/buffer_head.h> | |
12 | #include <linux/sched.h> | |
13 | #include "bfs.h" | |
14 | ||
15 | #undef DEBUG | |
16 | ||
17 | #ifdef DEBUG | |
18 | #define dprintf(x...) printf(x) | |
19 | #else | |
20 | #define dprintf(x...) | |
21 | #endif | |
22 | ||
23 | static int bfs_add_entry(struct inode * dir, const char * name, int namelen, int ino); | |
24 | static struct buffer_head * bfs_find_entry(struct inode * dir, | |
25 | const char * name, int namelen, struct bfs_dirent ** res_dir); | |
26 | ||
27 | static int bfs_readdir(struct file * f, void * dirent, filldir_t filldir) | |
28 | { | |
29 | struct inode * dir = f->f_dentry->d_inode; | |
30 | struct buffer_head * bh; | |
31 | struct bfs_dirent * de; | |
32 | unsigned int offset; | |
33 | int block; | |
34 | ||
35 | lock_kernel(); | |
36 | ||
37 | if (f->f_pos & (BFS_DIRENT_SIZE-1)) { | |
38 | printf("Bad f_pos=%08lx for %s:%08lx\n", (unsigned long)f->f_pos, | |
39 | dir->i_sb->s_id, dir->i_ino); | |
40 | unlock_kernel(); | |
41 | return -EBADF; | |
42 | } | |
43 | ||
44 | while (f->f_pos < dir->i_size) { | |
45 | offset = f->f_pos & (BFS_BSIZE-1); | |
46 | block = BFS_I(dir)->i_sblock + (f->f_pos >> BFS_BSIZE_BITS); | |
47 | bh = sb_bread(dir->i_sb, block); | |
48 | if (!bh) { | |
49 | f->f_pos += BFS_BSIZE - offset; | |
50 | continue; | |
51 | } | |
52 | do { | |
53 | de = (struct bfs_dirent *)(bh->b_data + offset); | |
54 | if (de->ino) { | |
55 | int size = strnlen(de->name, BFS_NAMELEN); | |
56 | if (filldir(dirent, de->name, size, f->f_pos, de->ino, DT_UNKNOWN) < 0) { | |
57 | brelse(bh); | |
58 | unlock_kernel(); | |
59 | return 0; | |
60 | } | |
61 | } | |
62 | offset += BFS_DIRENT_SIZE; | |
63 | f->f_pos += BFS_DIRENT_SIZE; | |
64 | } while (offset < BFS_BSIZE && f->f_pos < dir->i_size); | |
65 | brelse(bh); | |
66 | } | |
67 | ||
68 | unlock_kernel(); | |
69 | return 0; | |
70 | } | |
71 | ||
72 | struct file_operations bfs_dir_operations = { | |
73 | .read = generic_read_dir, | |
74 | .readdir = bfs_readdir, | |
75 | .fsync = file_fsync, | |
76 | }; | |
77 | ||
78 | extern void dump_imap(const char *, struct super_block *); | |
79 | ||
80 | static int bfs_create(struct inode * dir, struct dentry * dentry, int mode, | |
81 | struct nameidata *nd) | |
82 | { | |
83 | int err; | |
84 | struct inode * inode; | |
85 | struct super_block * s = dir->i_sb; | |
86 | struct bfs_sb_info * info = BFS_SB(s); | |
87 | unsigned long ino; | |
88 | ||
89 | inode = new_inode(s); | |
90 | if (!inode) | |
91 | return -ENOSPC; | |
92 | lock_kernel(); | |
93 | ino = find_first_zero_bit(info->si_imap, info->si_lasti); | |
94 | if (ino > info->si_lasti) { | |
95 | unlock_kernel(); | |
96 | iput(inode); | |
97 | return -ENOSPC; | |
98 | } | |
99 | set_bit(ino, info->si_imap); | |
100 | info->si_freei--; | |
101 | inode->i_uid = current->fsuid; | |
102 | inode->i_gid = (dir->i_mode & S_ISGID) ? dir->i_gid : current->fsgid; | |
103 | inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME_SEC; | |
104 | inode->i_blocks = inode->i_blksize = 0; | |
105 | inode->i_op = &bfs_file_inops; | |
106 | inode->i_fop = &bfs_file_operations; | |
107 | inode->i_mapping->a_ops = &bfs_aops; | |
108 | inode->i_mode = mode; | |
109 | inode->i_ino = ino; | |
110 | BFS_I(inode)->i_dsk_ino = ino; | |
111 | BFS_I(inode)->i_sblock = 0; | |
112 | BFS_I(inode)->i_eblock = 0; | |
113 | insert_inode_hash(inode); | |
114 | mark_inode_dirty(inode); | |
115 | dump_imap("create",s); | |
116 | ||
117 | err = bfs_add_entry(dir, dentry->d_name.name, dentry->d_name.len, inode->i_ino); | |
118 | if (err) { | |
119 | inode->i_nlink--; | |
120 | mark_inode_dirty(inode); | |
121 | iput(inode); | |
122 | unlock_kernel(); | |
123 | return err; | |
124 | } | |
125 | unlock_kernel(); | |
126 | d_instantiate(dentry, inode); | |
127 | return 0; | |
128 | } | |
129 | ||
130 | static struct dentry * bfs_lookup(struct inode * dir, struct dentry * dentry, struct nameidata *nd) | |
131 | { | |
132 | struct inode * inode = NULL; | |
133 | struct buffer_head * bh; | |
134 | struct bfs_dirent * de; | |
135 | ||
136 | if (dentry->d_name.len > BFS_NAMELEN) | |
137 | return ERR_PTR(-ENAMETOOLONG); | |
138 | ||
139 | lock_kernel(); | |
140 | bh = bfs_find_entry(dir, dentry->d_name.name, dentry->d_name.len, &de); | |
141 | if (bh) { | |
142 | unsigned long ino = le32_to_cpu(de->ino); | |
143 | brelse(bh); | |
144 | inode = iget(dir->i_sb, ino); | |
145 | if (!inode) { | |
146 | unlock_kernel(); | |
147 | return ERR_PTR(-EACCES); | |
148 | } | |
149 | } | |
150 | unlock_kernel(); | |
151 | d_add(dentry, inode); | |
152 | return NULL; | |
153 | } | |
154 | ||
155 | static int bfs_link(struct dentry * old, struct inode * dir, struct dentry * new) | |
156 | { | |
157 | struct inode * inode = old->d_inode; | |
158 | int err; | |
159 | ||
160 | lock_kernel(); | |
161 | err = bfs_add_entry(dir, new->d_name.name, new->d_name.len, inode->i_ino); | |
162 | if (err) { | |
163 | unlock_kernel(); | |
164 | return err; | |
165 | } | |
166 | inode->i_nlink++; | |
167 | inode->i_ctime = CURRENT_TIME_SEC; | |
168 | mark_inode_dirty(inode); | |
169 | atomic_inc(&inode->i_count); | |
170 | d_instantiate(new, inode); | |
171 | unlock_kernel(); | |
172 | return 0; | |
173 | } | |
174 | ||
175 | ||
176 | static int bfs_unlink(struct inode * dir, struct dentry * dentry) | |
177 | { | |
178 | int error = -ENOENT; | |
179 | struct inode * inode; | |
180 | struct buffer_head * bh; | |
181 | struct bfs_dirent * de; | |
182 | ||
183 | inode = dentry->d_inode; | |
184 | lock_kernel(); | |
185 | bh = bfs_find_entry(dir, dentry->d_name.name, dentry->d_name.len, &de); | |
186 | if (!bh || de->ino != inode->i_ino) | |
187 | goto out_brelse; | |
188 | ||
189 | if (!inode->i_nlink) { | |
190 | printf("unlinking non-existent file %s:%lu (nlink=%d)\n", inode->i_sb->s_id, | |
191 | inode->i_ino, inode->i_nlink); | |
192 | inode->i_nlink = 1; | |
193 | } | |
194 | de->ino = 0; | |
195 | mark_buffer_dirty(bh); | |
196 | dir->i_ctime = dir->i_mtime = CURRENT_TIME_SEC; | |
197 | mark_inode_dirty(dir); | |
198 | inode->i_nlink--; | |
199 | inode->i_ctime = dir->i_ctime; | |
200 | mark_inode_dirty(inode); | |
201 | error = 0; | |
202 | ||
203 | out_brelse: | |
204 | brelse(bh); | |
205 | unlock_kernel(); | |
206 | return error; | |
207 | } | |
208 | ||
209 | static int bfs_rename(struct inode * old_dir, struct dentry * old_dentry, | |
210 | struct inode * new_dir, struct dentry * new_dentry) | |
211 | { | |
212 | struct inode * old_inode, * new_inode; | |
213 | struct buffer_head * old_bh, * new_bh; | |
214 | struct bfs_dirent * old_de, * new_de; | |
215 | int error = -ENOENT; | |
216 | ||
217 | old_bh = new_bh = NULL; | |
218 | old_inode = old_dentry->d_inode; | |
219 | if (S_ISDIR(old_inode->i_mode)) | |
220 | return -EINVAL; | |
221 | ||
222 | lock_kernel(); | |
223 | old_bh = bfs_find_entry(old_dir, | |
224 | old_dentry->d_name.name, | |
225 | old_dentry->d_name.len, &old_de); | |
226 | ||
227 | if (!old_bh || old_de->ino != old_inode->i_ino) | |
228 | goto end_rename; | |
229 | ||
230 | error = -EPERM; | |
231 | new_inode = new_dentry->d_inode; | |
232 | new_bh = bfs_find_entry(new_dir, | |
233 | new_dentry->d_name.name, | |
234 | new_dentry->d_name.len, &new_de); | |
235 | ||
236 | if (new_bh && !new_inode) { | |
237 | brelse(new_bh); | |
238 | new_bh = NULL; | |
239 | } | |
240 | if (!new_bh) { | |
241 | error = bfs_add_entry(new_dir, | |
242 | new_dentry->d_name.name, | |
243 | new_dentry->d_name.len, old_inode->i_ino); | |
244 | if (error) | |
245 | goto end_rename; | |
246 | } | |
247 | old_de->ino = 0; | |
248 | old_dir->i_ctime = old_dir->i_mtime = CURRENT_TIME_SEC; | |
249 | mark_inode_dirty(old_dir); | |
250 | if (new_inode) { | |
251 | new_inode->i_nlink--; | |
252 | new_inode->i_ctime = CURRENT_TIME_SEC; | |
253 | mark_inode_dirty(new_inode); | |
254 | } | |
255 | mark_buffer_dirty(old_bh); | |
256 | error = 0; | |
257 | ||
258 | end_rename: | |
259 | unlock_kernel(); | |
260 | brelse(old_bh); | |
261 | brelse(new_bh); | |
262 | return error; | |
263 | } | |
264 | ||
265 | struct inode_operations bfs_dir_inops = { | |
266 | .create = bfs_create, | |
267 | .lookup = bfs_lookup, | |
268 | .link = bfs_link, | |
269 | .unlink = bfs_unlink, | |
270 | .rename = bfs_rename, | |
271 | }; | |
272 | ||
273 | static int bfs_add_entry(struct inode * dir, const char * name, int namelen, int ino) | |
274 | { | |
275 | struct buffer_head * bh; | |
276 | struct bfs_dirent * de; | |
277 | int block, sblock, eblock, off, eoff; | |
278 | int i; | |
279 | ||
280 | dprintf("name=%s, namelen=%d\n", name, namelen); | |
281 | ||
282 | if (!namelen) | |
283 | return -ENOENT; | |
284 | if (namelen > BFS_NAMELEN) | |
285 | return -ENAMETOOLONG; | |
286 | ||
287 | sblock = BFS_I(dir)->i_sblock; | |
288 | eblock = BFS_I(dir)->i_eblock; | |
289 | eoff = dir->i_size % BFS_BSIZE; | |
290 | for (block=sblock; block<=eblock; block++) { | |
291 | bh = sb_bread(dir->i_sb, block); | |
292 | if(!bh) | |
293 | return -ENOSPC; | |
294 | for (off=0; off<BFS_BSIZE; off+=BFS_DIRENT_SIZE) { | |
295 | de = (struct bfs_dirent *)(bh->b_data + off); | |
296 | if (block==eblock && off>=eoff) { | |
297 | /* Do not read/interpret the garbage in the end of eblock. */ | |
298 | de->ino = 0; | |
299 | } | |
300 | if (!de->ino) { | |
301 | if ((block-sblock)*BFS_BSIZE + off >= dir->i_size) { | |
302 | dir->i_size += BFS_DIRENT_SIZE; | |
303 | dir->i_ctime = CURRENT_TIME_SEC; | |
304 | } | |
305 | dir->i_mtime = CURRENT_TIME_SEC; | |
306 | mark_inode_dirty(dir); | |
307 | de->ino = ino; | |
308 | for (i=0; i<BFS_NAMELEN; i++) | |
309 | de->name[i] = (i < namelen) ? name[i] : 0; | |
310 | mark_buffer_dirty(bh); | |
311 | brelse(bh); | |
312 | return 0; | |
313 | } | |
314 | } | |
315 | brelse(bh); | |
316 | } | |
317 | return -ENOSPC; | |
318 | } | |
319 | ||
320 | static inline int bfs_namecmp(int len, const char * name, const char * buffer) | |
321 | { | |
322 | if (len < BFS_NAMELEN && buffer[len]) | |
323 | return 0; | |
324 | return !memcmp(name, buffer, len); | |
325 | } | |
326 | ||
327 | static struct buffer_head * bfs_find_entry(struct inode * dir, | |
328 | const char * name, int namelen, struct bfs_dirent ** res_dir) | |
329 | { | |
330 | unsigned long block, offset; | |
331 | struct buffer_head * bh; | |
332 | struct bfs_dirent * de; | |
333 | ||
334 | *res_dir = NULL; | |
335 | if (namelen > BFS_NAMELEN) | |
336 | return NULL; | |
337 | bh = NULL; | |
338 | block = offset = 0; | |
339 | while (block * BFS_BSIZE + offset < dir->i_size) { | |
340 | if (!bh) { | |
341 | bh = sb_bread(dir->i_sb, BFS_I(dir)->i_sblock + block); | |
342 | if (!bh) { | |
343 | block++; | |
344 | continue; | |
345 | } | |
346 | } | |
347 | de = (struct bfs_dirent *)(bh->b_data + offset); | |
348 | offset += BFS_DIRENT_SIZE; | |
349 | if (de->ino && bfs_namecmp(namelen, name, de->name)) { | |
350 | *res_dir = de; | |
351 | return bh; | |
352 | } | |
353 | if (offset < bh->b_size) | |
354 | continue; | |
355 | brelse(bh); | |
356 | bh = NULL; | |
357 | offset = 0; | |
358 | block++; | |
359 | } | |
360 | brelse(bh); | |
361 | return NULL; | |
362 | } |