Commit | Line | Data |
---|---|---|
a3ab7155 BC |
1 | /* |
2 | * OMFS (as used by RIO Karma) directory operations. | |
3 | * Copyright (C) 2005 Bob Copeland <me@bobcopeland.com> | |
4 | * Released under GPL v2. | |
5 | */ | |
6 | ||
7 | #include <linux/fs.h> | |
8 | #include <linux/ctype.h> | |
9 | #include <linux/buffer_head.h> | |
10 | #include "omfs.h" | |
11 | ||
12 | static int omfs_hash(const char *name, int namelen, int mod) | |
13 | { | |
14 | int i, hash = 0; | |
15 | for (i = 0; i < namelen; i++) | |
16 | hash ^= tolower(name[i]) << (i % 24); | |
17 | return hash % mod; | |
18 | } | |
19 | ||
20 | /* | |
21 | * Finds the bucket for a given name and reads the containing block; | |
22 | * *ofs is set to the offset of the first list entry. | |
23 | */ | |
24 | static struct buffer_head *omfs_get_bucket(struct inode *dir, | |
25 | const char *name, int namelen, int *ofs) | |
26 | { | |
27 | int nbuckets = (dir->i_size - OMFS_DIR_START)/8; | |
a3ab7155 BC |
28 | int bucket = omfs_hash(name, namelen, nbuckets); |
29 | ||
30 | *ofs = OMFS_DIR_START + bucket * 8; | |
f068272c | 31 | return omfs_bread(dir->i_sb, dir->i_ino); |
a3ab7155 BC |
32 | } |
33 | ||
34 | static struct buffer_head *omfs_scan_list(struct inode *dir, u64 block, | |
35 | const char *name, int namelen, | |
36 | u64 *prev_block) | |
37 | { | |
38 | struct buffer_head *bh; | |
39 | struct omfs_inode *oi; | |
40 | int err = -ENOENT; | |
41 | *prev_block = ~0; | |
42 | ||
43 | while (block != ~0) { | |
f068272c | 44 | bh = omfs_bread(dir->i_sb, block); |
a3ab7155 BC |
45 | if (!bh) { |
46 | err = -EIO; | |
47 | goto err; | |
48 | } | |
49 | ||
50 | oi = (struct omfs_inode *) bh->b_data; | |
51 | if (omfs_is_bad(OMFS_SB(dir->i_sb), &oi->i_head, block)) { | |
52 | brelse(bh); | |
53 | goto err; | |
54 | } | |
55 | ||
56 | if (strncmp(oi->i_name, name, namelen) == 0) | |
57 | return bh; | |
58 | ||
59 | *prev_block = block; | |
60 | block = be64_to_cpu(oi->i_sibling); | |
61 | brelse(bh); | |
62 | } | |
63 | err: | |
64 | return ERR_PTR(err); | |
65 | } | |
66 | ||
67 | static struct buffer_head *omfs_find_entry(struct inode *dir, | |
68 | const char *name, int namelen) | |
69 | { | |
70 | struct buffer_head *bh; | |
71 | int ofs; | |
72 | u64 block, dummy; | |
73 | ||
74 | bh = omfs_get_bucket(dir, name, namelen, &ofs); | |
75 | if (!bh) | |
76 | return ERR_PTR(-EIO); | |
77 | ||
78 | block = be64_to_cpu(*((__be64 *) &bh->b_data[ofs])); | |
79 | brelse(bh); | |
80 | ||
81 | return omfs_scan_list(dir, block, name, namelen, &dummy); | |
82 | } | |
83 | ||
84 | int omfs_make_empty(struct inode *inode, struct super_block *sb) | |
85 | { | |
86 | struct omfs_sb_info *sbi = OMFS_SB(sb); | |
a3ab7155 BC |
87 | struct buffer_head *bh; |
88 | struct omfs_inode *oi; | |
89 | ||
f068272c | 90 | bh = omfs_bread(sb, inode->i_ino); |
a3ab7155 BC |
91 | if (!bh) |
92 | return -ENOMEM; | |
93 | ||
94 | memset(bh->b_data, 0, sizeof(struct omfs_inode)); | |
95 | ||
96 | if (inode->i_mode & S_IFDIR) { | |
97 | memset(&bh->b_data[OMFS_DIR_START], 0xff, | |
98 | sbi->s_sys_blocksize - OMFS_DIR_START); | |
99 | } else | |
100 | omfs_make_empty_table(bh, OMFS_EXTENT_START); | |
101 | ||
102 | oi = (struct omfs_inode *) bh->b_data; | |
103 | oi->i_head.h_self = cpu_to_be64(inode->i_ino); | |
d406f66d | 104 | oi->i_sibling = ~cpu_to_be64(0ULL); |
a3ab7155 BC |
105 | |
106 | mark_buffer_dirty(bh); | |
107 | brelse(bh); | |
108 | return 0; | |
109 | } | |
110 | ||
111 | static int omfs_add_link(struct dentry *dentry, struct inode *inode) | |
112 | { | |
113 | struct inode *dir = dentry->d_parent->d_inode; | |
114 | const char *name = dentry->d_name.name; | |
115 | int namelen = dentry->d_name.len; | |
116 | struct omfs_inode *oi; | |
117 | struct buffer_head *bh; | |
118 | u64 block; | |
119 | __be64 *entry; | |
120 | int ofs; | |
121 | ||
122 | /* just prepend to head of queue in proper bucket */ | |
123 | bh = omfs_get_bucket(dir, name, namelen, &ofs); | |
124 | if (!bh) | |
125 | goto out; | |
126 | ||
127 | entry = (__be64 *) &bh->b_data[ofs]; | |
128 | block = be64_to_cpu(*entry); | |
129 | *entry = cpu_to_be64(inode->i_ino); | |
130 | mark_buffer_dirty(bh); | |
131 | brelse(bh); | |
132 | ||
133 | /* now set the sibling and parent pointers on the new inode */ | |
f068272c | 134 | bh = omfs_bread(dir->i_sb, inode->i_ino); |
a3ab7155 BC |
135 | if (!bh) |
136 | goto out; | |
137 | ||
138 | oi = (struct omfs_inode *) bh->b_data; | |
139 | memcpy(oi->i_name, name, namelen); | |
140 | memset(oi->i_name + namelen, 0, OMFS_NAMELEN - namelen); | |
141 | oi->i_sibling = cpu_to_be64(block); | |
142 | oi->i_parent = cpu_to_be64(dir->i_ino); | |
143 | mark_buffer_dirty(bh); | |
144 | brelse(bh); | |
145 | ||
146 | dir->i_ctime = CURRENT_TIME_SEC; | |
147 | ||
148 | /* mark affected inodes dirty to rebuild checksums */ | |
149 | mark_inode_dirty(dir); | |
150 | mark_inode_dirty(inode); | |
151 | return 0; | |
152 | out: | |
153 | return -ENOMEM; | |
154 | } | |
155 | ||
156 | static int omfs_delete_entry(struct dentry *dentry) | |
157 | { | |
158 | struct inode *dir = dentry->d_parent->d_inode; | |
159 | struct inode *dirty; | |
160 | const char *name = dentry->d_name.name; | |
161 | int namelen = dentry->d_name.len; | |
162 | struct omfs_inode *oi; | |
163 | struct buffer_head *bh, *bh2; | |
164 | __be64 *entry, next; | |
165 | u64 block, prev; | |
166 | int ofs; | |
167 | int err = -ENOMEM; | |
168 | ||
169 | /* delete the proper node in the bucket's linked list */ | |
170 | bh = omfs_get_bucket(dir, name, namelen, &ofs); | |
171 | if (!bh) | |
172 | goto out; | |
173 | ||
174 | entry = (__be64 *) &bh->b_data[ofs]; | |
175 | block = be64_to_cpu(*entry); | |
176 | ||
177 | bh2 = omfs_scan_list(dir, block, name, namelen, &prev); | |
178 | if (IS_ERR(bh2)) { | |
179 | err = PTR_ERR(bh2); | |
180 | goto out_free_bh; | |
181 | } | |
182 | ||
183 | oi = (struct omfs_inode *) bh2->b_data; | |
184 | next = oi->i_sibling; | |
185 | brelse(bh2); | |
186 | ||
187 | if (prev != ~0) { | |
188 | /* found in middle of list, get list ptr */ | |
189 | brelse(bh); | |
f068272c | 190 | bh = omfs_bread(dir->i_sb, prev); |
a3ab7155 BC |
191 | if (!bh) |
192 | goto out; | |
193 | ||
194 | oi = (struct omfs_inode *) bh->b_data; | |
195 | entry = &oi->i_sibling; | |
196 | } | |
197 | ||
198 | *entry = next; | |
199 | mark_buffer_dirty(bh); | |
200 | ||
201 | if (prev != ~0) { | |
202 | dirty = omfs_iget(dir->i_sb, prev); | |
203 | if (!IS_ERR(dirty)) { | |
204 | mark_inode_dirty(dirty); | |
205 | iput(dirty); | |
206 | } | |
207 | } | |
208 | ||
209 | err = 0; | |
210 | out_free_bh: | |
211 | brelse(bh); | |
212 | out: | |
213 | return err; | |
214 | } | |
215 | ||
216 | static int omfs_dir_is_empty(struct inode *inode) | |
217 | { | |
218 | int nbuckets = (inode->i_size - OMFS_DIR_START) / 8; | |
219 | struct buffer_head *bh; | |
220 | u64 *ptr; | |
221 | int i; | |
222 | ||
f068272c | 223 | bh = omfs_bread(inode->i_sb, inode->i_ino); |
a3ab7155 BC |
224 | |
225 | if (!bh) | |
226 | return 0; | |
227 | ||
228 | ptr = (u64 *) &bh->b_data[OMFS_DIR_START]; | |
229 | ||
230 | for (i = 0; i < nbuckets; i++, ptr++) | |
231 | if (*ptr != ~0) | |
232 | break; | |
233 | ||
234 | brelse(bh); | |
235 | return *ptr != ~0; | |
236 | } | |
237 | ||
d932805b | 238 | static int omfs_remove(struct inode *dir, struct dentry *dentry) |
a3ab7155 | 239 | { |
a3ab7155 | 240 | struct inode *inode = dentry->d_inode; |
d932805b AV |
241 | int ret; |
242 | ||
79bf7c73 SW |
243 | |
244 | if (S_ISDIR(inode->i_mode)) { | |
245 | dentry_unhash(dentry); | |
246 | if (!omfs_dir_is_empty(inode)) | |
247 | return -ENOTEMPTY; | |
248 | } | |
a3ab7155 BC |
249 | |
250 | ret = omfs_delete_entry(dentry); | |
251 | if (ret) | |
d932805b AV |
252 | return ret; |
253 | ||
254 | clear_nlink(inode); | |
255 | mark_inode_dirty(inode); | |
a3ab7155 | 256 | mark_inode_dirty(dir); |
d932805b | 257 | return 0; |
a3ab7155 BC |
258 | } |
259 | ||
260 | static int omfs_add_node(struct inode *dir, struct dentry *dentry, int mode) | |
261 | { | |
262 | int err; | |
263 | struct inode *inode = omfs_new_inode(dir, mode); | |
264 | ||
265 | if (IS_ERR(inode)) | |
266 | return PTR_ERR(inode); | |
267 | ||
268 | err = omfs_make_empty(inode, dir->i_sb); | |
269 | if (err) | |
270 | goto out_free_inode; | |
271 | ||
272 | err = omfs_add_link(dentry, inode); | |
273 | if (err) | |
274 | goto out_free_inode; | |
275 | ||
276 | d_instantiate(dentry, inode); | |
277 | return 0; | |
278 | ||
279 | out_free_inode: | |
280 | iput(inode); | |
281 | return err; | |
282 | } | |
283 | ||
284 | static int omfs_mkdir(struct inode *dir, struct dentry *dentry, int mode) | |
285 | { | |
286 | return omfs_add_node(dir, dentry, mode | S_IFDIR); | |
287 | } | |
288 | ||
289 | static int omfs_create(struct inode *dir, struct dentry *dentry, int mode, | |
290 | struct nameidata *nd) | |
291 | { | |
292 | return omfs_add_node(dir, dentry, mode | S_IFREG); | |
293 | } | |
294 | ||
295 | static struct dentry *omfs_lookup(struct inode *dir, struct dentry *dentry, | |
296 | struct nameidata *nd) | |
297 | { | |
298 | struct buffer_head *bh; | |
299 | struct inode *inode = NULL; | |
300 | ||
301 | if (dentry->d_name.len > OMFS_NAMELEN) | |
302 | return ERR_PTR(-ENAMETOOLONG); | |
303 | ||
304 | bh = omfs_find_entry(dir, dentry->d_name.name, dentry->d_name.len); | |
305 | if (!IS_ERR(bh)) { | |
306 | struct omfs_inode *oi = (struct omfs_inode *)bh->b_data; | |
307 | ino_t ino = be64_to_cpu(oi->i_head.h_self); | |
308 | brelse(bh); | |
309 | inode = omfs_iget(dir->i_sb, ino); | |
310 | if (IS_ERR(inode)) | |
311 | return ERR_CAST(inode); | |
312 | } | |
313 | d_add(dentry, inode); | |
314 | return NULL; | |
315 | } | |
316 | ||
317 | /* sanity check block's self pointer */ | |
318 | int omfs_is_bad(struct omfs_sb_info *sbi, struct omfs_header *header, | |
319 | u64 fsblock) | |
320 | { | |
321 | int is_bad; | |
322 | u64 ino = be64_to_cpu(header->h_self); | |
323 | is_bad = ((ino != fsblock) || (ino < sbi->s_root_ino) || | |
324 | (ino > sbi->s_num_blocks)); | |
325 | ||
326 | if (is_bad) | |
327 | printk(KERN_WARNING "omfs: bad hash chain detected\n"); | |
328 | ||
329 | return is_bad; | |
330 | } | |
331 | ||
332 | static int omfs_fill_chain(struct file *filp, void *dirent, filldir_t filldir, | |
333 | u64 fsblock, int hindex) | |
334 | { | |
335 | struct inode *dir = filp->f_dentry->d_inode; | |
336 | struct buffer_head *bh; | |
337 | struct omfs_inode *oi; | |
338 | u64 self; | |
339 | int res = 0; | |
340 | unsigned char d_type; | |
341 | ||
342 | /* follow chain in this bucket */ | |
343 | while (fsblock != ~0) { | |
f068272c | 344 | bh = omfs_bread(dir->i_sb, fsblock); |
a3ab7155 BC |
345 | if (!bh) |
346 | goto out; | |
347 | ||
348 | oi = (struct omfs_inode *) bh->b_data; | |
349 | if (omfs_is_bad(OMFS_SB(dir->i_sb), &oi->i_head, fsblock)) { | |
350 | brelse(bh); | |
351 | goto out; | |
352 | } | |
353 | ||
354 | self = fsblock; | |
355 | fsblock = be64_to_cpu(oi->i_sibling); | |
356 | ||
357 | /* skip visited nodes */ | |
358 | if (hindex) { | |
359 | hindex--; | |
360 | brelse(bh); | |
361 | continue; | |
362 | } | |
363 | ||
364 | d_type = (oi->i_type == OMFS_DIR) ? DT_DIR : DT_REG; | |
365 | ||
366 | res = filldir(dirent, oi->i_name, strnlen(oi->i_name, | |
367 | OMFS_NAMELEN), filp->f_pos, self, d_type); | |
a3ab7155 | 368 | brelse(bh); |
31be83ae AV |
369 | if (res < 0) |
370 | break; | |
371 | filp->f_pos++; | |
a3ab7155 BC |
372 | } |
373 | out: | |
374 | return res; | |
375 | } | |
376 | ||
377 | static int omfs_rename(struct inode *old_dir, struct dentry *old_dentry, | |
378 | struct inode *new_dir, struct dentry *new_dentry) | |
379 | { | |
380 | struct inode *new_inode = new_dentry->d_inode; | |
381 | struct inode *old_inode = old_dentry->d_inode; | |
a3ab7155 BC |
382 | int err; |
383 | ||
a3ab7155 | 384 | if (new_inode) { |
e4eaac06 SW |
385 | if (S_ISDIR(new_inode->i_mode)) |
386 | dentry_unhash(new_dentry); | |
387 | ||
a3ab7155 | 388 | /* overwriting existing file/dir */ |
d932805b | 389 | err = omfs_remove(new_dir, new_dentry); |
a3ab7155 BC |
390 | if (err) |
391 | goto out; | |
392 | } | |
393 | ||
394 | /* since omfs locates files by name, we need to unlink _before_ | |
395 | * adding the new link or we won't find the old one */ | |
cdb26496 AV |
396 | err = omfs_delete_entry(old_dentry); |
397 | if (err) | |
a3ab7155 | 398 | goto out; |
a3ab7155 | 399 | |
cdb26496 | 400 | mark_inode_dirty(old_dir); |
a3ab7155 BC |
401 | err = omfs_add_link(new_dentry, old_inode); |
402 | if (err) | |
403 | goto out; | |
404 | ||
405 | old_inode->i_ctime = CURRENT_TIME_SEC; | |
013e4f4a | 406 | mark_inode_dirty(old_inode); |
a3ab7155 BC |
407 | out: |
408 | return err; | |
409 | } | |
410 | ||
411 | static int omfs_readdir(struct file *filp, void *dirent, filldir_t filldir) | |
412 | { | |
413 | struct inode *dir = filp->f_dentry->d_inode; | |
414 | struct buffer_head *bh; | |
415 | loff_t offset, res; | |
416 | unsigned int hchain, hindex; | |
417 | int nbuckets; | |
418 | u64 fsblock; | |
419 | int ret = -EINVAL; | |
420 | ||
421 | if (filp->f_pos >> 32) | |
422 | goto success; | |
423 | ||
424 | switch ((unsigned long) filp->f_pos) { | |
425 | case 0: | |
426 | if (filldir(dirent, ".", 1, 0, dir->i_ino, DT_DIR) < 0) | |
427 | goto success; | |
428 | filp->f_pos++; | |
429 | /* fall through */ | |
430 | case 1: | |
431 | if (filldir(dirent, "..", 2, 1, | |
432 | parent_ino(filp->f_dentry), DT_DIR) < 0) | |
433 | goto success; | |
434 | filp->f_pos = 1 << 20; | |
435 | /* fall through */ | |
436 | } | |
437 | ||
438 | nbuckets = (dir->i_size - OMFS_DIR_START) / 8; | |
439 | ||
440 | /* high 12 bits store bucket + 1 and low 20 bits store hash index */ | |
441 | hchain = (filp->f_pos >> 20) - 1; | |
442 | hindex = filp->f_pos & 0xfffff; | |
443 | ||
f068272c | 444 | bh = omfs_bread(dir->i_sb, dir->i_ino); |
a3ab7155 BC |
445 | if (!bh) |
446 | goto out; | |
447 | ||
448 | offset = OMFS_DIR_START + hchain * 8; | |
449 | ||
450 | for (; hchain < nbuckets; hchain++, offset += 8) { | |
451 | fsblock = be64_to_cpu(*((__be64 *) &bh->b_data[offset])); | |
452 | ||
453 | res = omfs_fill_chain(filp, dirent, filldir, fsblock, hindex); | |
454 | hindex = 0; | |
455 | if (res < 0) | |
456 | break; | |
457 | ||
458 | filp->f_pos = (hchain+2) << 20; | |
459 | } | |
460 | brelse(bh); | |
461 | success: | |
462 | ret = 0; | |
463 | out: | |
464 | return ret; | |
465 | } | |
466 | ||
6e1d5dcc | 467 | const struct inode_operations omfs_dir_inops = { |
a3ab7155 BC |
468 | .lookup = omfs_lookup, |
469 | .mkdir = omfs_mkdir, | |
470 | .rename = omfs_rename, | |
471 | .create = omfs_create, | |
d932805b AV |
472 | .unlink = omfs_remove, |
473 | .rmdir = omfs_remove, | |
a3ab7155 BC |
474 | }; |
475 | ||
828c0950 | 476 | const struct file_operations omfs_dir_operations = { |
a3ab7155 BC |
477 | .read = generic_read_dir, |
478 | .readdir = omfs_readdir, | |
3222a3e5 | 479 | .llseek = generic_file_llseek, |
a3ab7155 | 480 | }; |