Commit | Line | Data |
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5db53f3e JE |
1 | /* |
2 | * fs/logfs/dir.c - directory-related code | |
3 | * | |
4 | * As should be obvious for Linux kernel code, license is GPLv2 | |
5 | * | |
6 | * Copyright (c) 2005-2008 Joern Engel <joern@logfs.org> | |
7 | */ | |
8 | #include "logfs.h" | |
5a0e3ad6 | 9 | #include <linux/slab.h> |
5db53f3e JE |
10 | |
11 | /* | |
12 | * Atomic dir operations | |
13 | * | |
14 | * Directory operations are by default not atomic. Dentries and Inodes are | |
a8cd4561 | 15 | * created/removed/altered in separate operations. Therefore we need to do |
5db53f3e JE |
16 | * a small amount of journaling. |
17 | * | |
18 | * Create, link, mkdir, mknod and symlink all share the same function to do | |
19 | * the work: __logfs_create. This function works in two atomic steps: | |
20 | * 1. allocate inode (remember in journal) | |
21 | * 2. allocate dentry (clear journal) | |
22 | * | |
23 | * As we can only get interrupted between the two, when the inode we just | |
24 | * created is simply stored in the anchor. On next mount, if we were | |
25 | * interrupted, we delete the inode. From a users point of view the | |
26 | * operation never happened. | |
27 | * | |
28 | * Unlink and rmdir also share the same function: unlink. Again, this | |
29 | * function works in two atomic steps | |
30 | * 1. remove dentry (remember inode in journal) | |
31 | * 2. unlink inode (clear journal) | |
32 | * | |
33 | * And again, on the next mount, if we were interrupted, we delete the inode. | |
34 | * From a users point of view the operation succeeded. | |
35 | * | |
36 | * Rename is the real pain to deal with, harder than all the other methods | |
37 | * combined. Depending on the circumstances we can run into three cases. | |
38 | * A "target rename" where the target dentry already existed, a "local | |
39 | * rename" where both parent directories are identical or a "cross-directory | |
40 | * rename" in the remaining case. | |
41 | * | |
42 | * Local rename is atomic, as the old dentry is simply rewritten with a new | |
43 | * name. | |
44 | * | |
45 | * Cross-directory rename works in two steps, similar to __logfs_create and | |
46 | * logfs_unlink: | |
47 | * 1. Write new dentry (remember old dentry in journal) | |
48 | * 2. Remove old dentry (clear journal) | |
49 | * | |
50 | * Here we remember a dentry instead of an inode. On next mount, if we were | |
51 | * interrupted, we delete the dentry. From a users point of view, the | |
52 | * operation succeeded. | |
53 | * | |
54 | * Target rename works in three atomic steps: | |
55 | * 1. Attach old inode to new dentry (remember old dentry and new inode) | |
56 | * 2. Remove old dentry (still remember the new inode) | |
57 | * 3. Remove victim inode | |
58 | * | |
59 | * Here we remember both an inode an a dentry. If we get interrupted | |
60 | * between steps 1 and 2, we delete both the dentry and the inode. If | |
61 | * we get interrupted between steps 2 and 3, we delete just the inode. | |
62 | * In either case, the remaining objects are deleted on next mount. From | |
63 | * a users point of view, the operation succeeded. | |
64 | */ | |
65 | ||
66 | static int write_dir(struct inode *dir, struct logfs_disk_dentry *dd, | |
67 | loff_t pos) | |
68 | { | |
69 | return logfs_inode_write(dir, dd, sizeof(*dd), pos, WF_LOCK, NULL); | |
70 | } | |
71 | ||
72 | static int write_inode(struct inode *inode) | |
73 | { | |
74 | return __logfs_write_inode(inode, WF_LOCK); | |
75 | } | |
76 | ||
77 | static s64 dir_seek_data(struct inode *inode, s64 pos) | |
78 | { | |
79 | s64 new_pos = logfs_seek_data(inode, pos); | |
80 | ||
81 | return max(pos, new_pos - 1); | |
82 | } | |
83 | ||
84 | static int beyond_eof(struct inode *inode, loff_t bix) | |
85 | { | |
86 | loff_t pos = bix << inode->i_sb->s_blocksize_bits; | |
87 | return pos >= i_size_read(inode); | |
88 | } | |
89 | ||
90 | /* | |
91 | * Prime value was chosen to be roughly 256 + 26. r5 hash uses 11, | |
92 | * so short names (len <= 9) don't even occupy the complete 32bit name | |
93 | * space. A prime >256 ensures short names quickly spread the 32bit | |
94 | * name space. Add about 26 for the estimated amount of information | |
25985edc | 95 | * of each character and pick a prime nearby, preferably a bit-sparse |
5db53f3e JE |
96 | * one. |
97 | */ | |
98 | static u32 hash_32(const char *s, int len, u32 seed) | |
99 | { | |
100 | u32 hash = seed; | |
101 | int i; | |
102 | ||
103 | for (i = 0; i < len; i++) | |
104 | hash = hash * 293 + s[i]; | |
105 | return hash; | |
106 | } | |
107 | ||
108 | /* | |
109 | * We have to satisfy several conflicting requirements here. Small | |
110 | * directories should stay fairly compact and not require too many | |
111 | * indirect blocks. The number of possible locations for a given hash | |
112 | * should be small to make lookup() fast. And we should try hard not | |
113 | * to overflow the 32bit name space or nfs and 32bit host systems will | |
114 | * be unhappy. | |
115 | * | |
116 | * So we use the following scheme. First we reduce the hash to 0..15 | |
117 | * and try a direct block. If that is occupied we reduce the hash to | |
118 | * 16..255 and try an indirect block. Same for 2x and 3x indirect | |
119 | * blocks. Lastly we reduce the hash to 0x800_0000 .. 0xffff_ffff, | |
120 | * but use buckets containing eight entries instead of a single one. | |
121 | * | |
122 | * Using 16 entries should allow for a reasonable amount of hash | |
123 | * collisions, so the 32bit name space can be packed fairly tight | |
124 | * before overflowing. Oh and currently we don't overflow but return | |
125 | * and error. | |
126 | * | |
127 | * How likely are collisions? Doing the appropriate math is beyond me | |
128 | * and the Bronstein textbook. But running a test program to brute | |
129 | * force collisions for a couple of days showed that on average the | |
130 | * first collision occurs after 598M entries, with 290M being the | |
131 | * smallest result. Obviously 21 entries could already cause a | |
132 | * collision if all entries are carefully chosen. | |
133 | */ | |
134 | static pgoff_t hash_index(u32 hash, int round) | |
135 | { | |
30835cd0 JE |
136 | u32 i0_blocks = I0_BLOCKS; |
137 | u32 i1_blocks = I1_BLOCKS; | |
138 | u32 i2_blocks = I2_BLOCKS; | |
139 | u32 i3_blocks = I3_BLOCKS; | |
140 | ||
5db53f3e JE |
141 | switch (round) { |
142 | case 0: | |
30835cd0 | 143 | return hash % i0_blocks; |
5db53f3e | 144 | case 1: |
30835cd0 | 145 | return i0_blocks + hash % (i1_blocks - i0_blocks); |
5db53f3e | 146 | case 2: |
30835cd0 | 147 | return i1_blocks + hash % (i2_blocks - i1_blocks); |
5db53f3e | 148 | case 3: |
30835cd0 | 149 | return i2_blocks + hash % (i3_blocks - i2_blocks); |
5db53f3e | 150 | case 4 ... 19: |
30835cd0 | 151 | return i3_blocks + 16 * (hash % (((1<<31) - i3_blocks) / 16)) |
5db53f3e JE |
152 | + round - 4; |
153 | } | |
154 | BUG(); | |
155 | } | |
156 | ||
157 | static struct page *logfs_get_dd_page(struct inode *dir, struct dentry *dentry) | |
158 | { | |
159 | struct qstr *name = &dentry->d_name; | |
160 | struct page *page; | |
161 | struct logfs_disk_dentry *dd; | |
162 | u32 hash = hash_32(name->name, name->len, 0); | |
163 | pgoff_t index; | |
164 | int round; | |
165 | ||
166 | if (name->len > LOGFS_MAX_NAMELEN) | |
167 | return ERR_PTR(-ENAMETOOLONG); | |
168 | ||
169 | for (round = 0; round < 20; round++) { | |
170 | index = hash_index(hash, round); | |
171 | ||
172 | if (beyond_eof(dir, index)) | |
173 | return NULL; | |
174 | if (!logfs_exist_block(dir, index)) | |
175 | continue; | |
176 | page = read_cache_page(dir->i_mapping, index, | |
177 | (filler_t *)logfs_readpage, NULL); | |
178 | if (IS_ERR(page)) | |
179 | return page; | |
180 | dd = kmap_atomic(page, KM_USER0); | |
181 | BUG_ON(dd->namelen == 0); | |
182 | ||
183 | if (name->len != be16_to_cpu(dd->namelen) || | |
184 | memcmp(name->name, dd->name, name->len)) { | |
185 | kunmap_atomic(dd, KM_USER0); | |
186 | page_cache_release(page); | |
187 | continue; | |
188 | } | |
189 | ||
190 | kunmap_atomic(dd, KM_USER0); | |
191 | return page; | |
192 | } | |
193 | return NULL; | |
194 | } | |
195 | ||
196 | static int logfs_remove_inode(struct inode *inode) | |
197 | { | |
198 | int ret; | |
199 | ||
200 | inode->i_nlink--; | |
201 | ret = write_inode(inode); | |
202 | LOGFS_BUG_ON(ret, inode->i_sb); | |
203 | return ret; | |
204 | } | |
205 | ||
206 | static void abort_transaction(struct inode *inode, struct logfs_transaction *ta) | |
207 | { | |
208 | if (logfs_inode(inode)->li_block) | |
209 | logfs_inode(inode)->li_block->ta = NULL; | |
210 | kfree(ta); | |
211 | } | |
212 | ||
213 | static int logfs_unlink(struct inode *dir, struct dentry *dentry) | |
214 | { | |
215 | struct logfs_super *super = logfs_super(dir->i_sb); | |
216 | struct inode *inode = dentry->d_inode; | |
217 | struct logfs_transaction *ta; | |
218 | struct page *page; | |
219 | pgoff_t index; | |
220 | int ret; | |
221 | ||
222 | ta = kzalloc(sizeof(*ta), GFP_KERNEL); | |
223 | if (!ta) | |
224 | return -ENOMEM; | |
225 | ||
226 | ta->state = UNLINK_1; | |
227 | ta->ino = inode->i_ino; | |
228 | ||
229 | inode->i_ctime = dir->i_ctime = dir->i_mtime = CURRENT_TIME; | |
230 | ||
231 | page = logfs_get_dd_page(dir, dentry); | |
ddfd1f04 JE |
232 | if (!page) { |
233 | kfree(ta); | |
5db53f3e | 234 | return -ENOENT; |
ddfd1f04 JE |
235 | } |
236 | if (IS_ERR(page)) { | |
237 | kfree(ta); | |
5db53f3e | 238 | return PTR_ERR(page); |
ddfd1f04 | 239 | } |
5db53f3e JE |
240 | index = page->index; |
241 | page_cache_release(page); | |
242 | ||
243 | mutex_lock(&super->s_dirop_mutex); | |
244 | logfs_add_transaction(dir, ta); | |
245 | ||
246 | ret = logfs_delete(dir, index, NULL); | |
247 | if (!ret) | |
248 | ret = write_inode(dir); | |
249 | ||
250 | if (ret) { | |
251 | abort_transaction(dir, ta); | |
252 | printk(KERN_ERR"LOGFS: unable to delete inode\n"); | |
253 | goto out; | |
254 | } | |
255 | ||
256 | ta->state = UNLINK_2; | |
257 | logfs_add_transaction(inode, ta); | |
258 | ret = logfs_remove_inode(inode); | |
259 | out: | |
260 | mutex_unlock(&super->s_dirop_mutex); | |
261 | return ret; | |
262 | } | |
263 | ||
264 | static inline int logfs_empty_dir(struct inode *dir) | |
265 | { | |
266 | u64 data; | |
267 | ||
268 | data = logfs_seek_data(dir, 0) << dir->i_sb->s_blocksize_bits; | |
269 | return data >= i_size_read(dir); | |
270 | } | |
271 | ||
272 | static int logfs_rmdir(struct inode *dir, struct dentry *dentry) | |
273 | { | |
274 | struct inode *inode = dentry->d_inode; | |
275 | ||
79bf7c73 SW |
276 | dentry_unhash(dentry); |
277 | ||
5db53f3e JE |
278 | if (!logfs_empty_dir(inode)) |
279 | return -ENOTEMPTY; | |
280 | ||
281 | return logfs_unlink(dir, dentry); | |
282 | } | |
283 | ||
284 | /* FIXME: readdir currently has it's own dir_walk code. I don't see a good | |
285 | * way to combine the two copies */ | |
286 | #define IMPLICIT_NODES 2 | |
287 | static int __logfs_readdir(struct file *file, void *buf, filldir_t filldir) | |
288 | { | |
289 | struct inode *dir = file->f_dentry->d_inode; | |
290 | loff_t pos = file->f_pos - IMPLICIT_NODES; | |
291 | struct page *page; | |
292 | struct logfs_disk_dentry *dd; | |
293 | int full; | |
294 | ||
295 | BUG_ON(pos < 0); | |
296 | for (;; pos++) { | |
297 | if (beyond_eof(dir, pos)) | |
298 | break; | |
299 | if (!logfs_exist_block(dir, pos)) { | |
300 | /* deleted dentry */ | |
301 | pos = dir_seek_data(dir, pos); | |
302 | continue; | |
303 | } | |
304 | page = read_cache_page(dir->i_mapping, pos, | |
305 | (filler_t *)logfs_readpage, NULL); | |
306 | if (IS_ERR(page)) | |
307 | return PTR_ERR(page); | |
e3260688 | 308 | dd = kmap(page); |
5db53f3e JE |
309 | BUG_ON(dd->namelen == 0); |
310 | ||
311 | full = filldir(buf, (char *)dd->name, be16_to_cpu(dd->namelen), | |
312 | pos, be64_to_cpu(dd->ino), dd->type); | |
e3260688 | 313 | kunmap(page); |
5db53f3e JE |
314 | page_cache_release(page); |
315 | if (full) | |
316 | break; | |
317 | } | |
318 | ||
319 | file->f_pos = pos + IMPLICIT_NODES; | |
320 | return 0; | |
321 | } | |
322 | ||
323 | static int logfs_readdir(struct file *file, void *buf, filldir_t filldir) | |
324 | { | |
325 | struct inode *inode = file->f_dentry->d_inode; | |
326 | ino_t pino = parent_ino(file->f_dentry); | |
327 | int err; | |
328 | ||
329 | if (file->f_pos < 0) | |
330 | return -EINVAL; | |
331 | ||
332 | if (file->f_pos == 0) { | |
333 | if (filldir(buf, ".", 1, 1, inode->i_ino, DT_DIR) < 0) | |
334 | return 0; | |
335 | file->f_pos++; | |
336 | } | |
337 | if (file->f_pos == 1) { | |
338 | if (filldir(buf, "..", 2, 2, pino, DT_DIR) < 0) | |
339 | return 0; | |
340 | file->f_pos++; | |
341 | } | |
342 | ||
343 | err = __logfs_readdir(file, buf, filldir); | |
344 | return err; | |
345 | } | |
346 | ||
347 | static void logfs_set_name(struct logfs_disk_dentry *dd, struct qstr *name) | |
348 | { | |
349 | dd->namelen = cpu_to_be16(name->len); | |
350 | memcpy(dd->name, name->name, name->len); | |
351 | } | |
352 | ||
353 | static struct dentry *logfs_lookup(struct inode *dir, struct dentry *dentry, | |
354 | struct nameidata *nd) | |
355 | { | |
356 | struct page *page; | |
357 | struct logfs_disk_dentry *dd; | |
358 | pgoff_t index; | |
359 | u64 ino = 0; | |
360 | struct inode *inode; | |
361 | ||
362 | page = logfs_get_dd_page(dir, dentry); | |
363 | if (IS_ERR(page)) | |
364 | return ERR_CAST(page); | |
365 | if (!page) { | |
366 | d_add(dentry, NULL); | |
367 | return NULL; | |
368 | } | |
369 | index = page->index; | |
370 | dd = kmap_atomic(page, KM_USER0); | |
371 | ino = be64_to_cpu(dd->ino); | |
372 | kunmap_atomic(dd, KM_USER0); | |
373 | page_cache_release(page); | |
374 | ||
375 | inode = logfs_iget(dir->i_sb, ino); | |
376 | if (IS_ERR(inode)) { | |
377 | printk(KERN_ERR"LogFS: Cannot read inode #%llx for dentry (%lx, %lx)n", | |
378 | ino, dir->i_ino, index); | |
379 | return ERR_CAST(inode); | |
380 | } | |
381 | return d_splice_alias(inode, dentry); | |
382 | } | |
383 | ||
384 | static void grow_dir(struct inode *dir, loff_t index) | |
385 | { | |
386 | index = (index + 1) << dir->i_sb->s_blocksize_bits; | |
387 | if (i_size_read(dir) < index) | |
388 | i_size_write(dir, index); | |
389 | } | |
390 | ||
391 | static int logfs_write_dir(struct inode *dir, struct dentry *dentry, | |
392 | struct inode *inode) | |
393 | { | |
394 | struct page *page; | |
395 | struct logfs_disk_dentry *dd; | |
396 | u32 hash = hash_32(dentry->d_name.name, dentry->d_name.len, 0); | |
397 | pgoff_t index; | |
398 | int round, err; | |
399 | ||
400 | for (round = 0; round < 20; round++) { | |
401 | index = hash_index(hash, round); | |
402 | ||
403 | if (logfs_exist_block(dir, index)) | |
404 | continue; | |
405 | page = find_or_create_page(dir->i_mapping, index, GFP_KERNEL); | |
406 | if (!page) | |
407 | return -ENOMEM; | |
408 | ||
409 | dd = kmap_atomic(page, KM_USER0); | |
410 | memset(dd, 0, sizeof(*dd)); | |
411 | dd->ino = cpu_to_be64(inode->i_ino); | |
412 | dd->type = logfs_type(inode); | |
413 | logfs_set_name(dd, &dentry->d_name); | |
414 | kunmap_atomic(dd, KM_USER0); | |
415 | ||
416 | err = logfs_write_buf(dir, page, WF_LOCK); | |
417 | unlock_page(page); | |
418 | page_cache_release(page); | |
419 | if (!err) | |
420 | grow_dir(dir, index); | |
421 | return err; | |
422 | } | |
423 | /* FIXME: Is there a better return value? In most cases neither | |
424 | * the filesystem nor the directory are full. But we have had | |
425 | * too many collisions for this particular hash and no fallback. | |
426 | */ | |
427 | return -ENOSPC; | |
428 | } | |
429 | ||
430 | static int __logfs_create(struct inode *dir, struct dentry *dentry, | |
431 | struct inode *inode, const char *dest, long destlen) | |
432 | { | |
433 | struct logfs_super *super = logfs_super(dir->i_sb); | |
434 | struct logfs_inode *li = logfs_inode(inode); | |
435 | struct logfs_transaction *ta; | |
436 | int ret; | |
437 | ||
438 | ta = kzalloc(sizeof(*ta), GFP_KERNEL); | |
25624958 AV |
439 | if (!ta) { |
440 | inode->i_nlink--; | |
441 | iput(inode); | |
5db53f3e | 442 | return -ENOMEM; |
25624958 | 443 | } |
5db53f3e JE |
444 | |
445 | ta->state = CREATE_1; | |
446 | ta->ino = inode->i_ino; | |
447 | mutex_lock(&super->s_dirop_mutex); | |
448 | logfs_add_transaction(inode, ta); | |
449 | ||
450 | if (dest) { | |
451 | /* symlink */ | |
452 | ret = logfs_inode_write(inode, dest, destlen, 0, WF_LOCK, NULL); | |
453 | if (!ret) | |
454 | ret = write_inode(inode); | |
455 | } else { | |
456 | /* creat/mkdir/mknod */ | |
457 | ret = write_inode(inode); | |
458 | } | |
459 | if (ret) { | |
460 | abort_transaction(inode, ta); | |
461 | li->li_flags |= LOGFS_IF_STILLBORN; | |
462 | /* FIXME: truncate symlink */ | |
463 | inode->i_nlink--; | |
464 | iput(inode); | |
465 | goto out; | |
466 | } | |
467 | ||
468 | ta->state = CREATE_2; | |
469 | logfs_add_transaction(dir, ta); | |
470 | ret = logfs_write_dir(dir, dentry, inode); | |
471 | /* sync directory */ | |
472 | if (!ret) | |
473 | ret = write_inode(dir); | |
474 | ||
475 | if (ret) { | |
476 | logfs_del_transaction(dir, ta); | |
477 | ta->state = CREATE_2; | |
478 | logfs_add_transaction(inode, ta); | |
479 | logfs_remove_inode(inode); | |
480 | iput(inode); | |
481 | goto out; | |
482 | } | |
483 | d_instantiate(dentry, inode); | |
484 | out: | |
485 | mutex_unlock(&super->s_dirop_mutex); | |
486 | return ret; | |
487 | } | |
488 | ||
489 | static int logfs_mkdir(struct inode *dir, struct dentry *dentry, int mode) | |
490 | { | |
491 | struct inode *inode; | |
492 | ||
493 | /* | |
494 | * FIXME: why do we have to fill in S_IFDIR, while the mode is | |
495 | * correct for mknod, creat, etc.? Smells like the vfs *should* | |
496 | * do it for us but for some reason fails to do so. | |
497 | */ | |
498 | inode = logfs_new_inode(dir, S_IFDIR | mode); | |
499 | if (IS_ERR(inode)) | |
500 | return PTR_ERR(inode); | |
501 | ||
502 | inode->i_op = &logfs_dir_iops; | |
503 | inode->i_fop = &logfs_dir_fops; | |
504 | ||
505 | return __logfs_create(dir, dentry, inode, NULL, 0); | |
506 | } | |
507 | ||
508 | static int logfs_create(struct inode *dir, struct dentry *dentry, int mode, | |
509 | struct nameidata *nd) | |
510 | { | |
511 | struct inode *inode; | |
512 | ||
513 | inode = logfs_new_inode(dir, mode); | |
514 | if (IS_ERR(inode)) | |
515 | return PTR_ERR(inode); | |
516 | ||
517 | inode->i_op = &logfs_reg_iops; | |
518 | inode->i_fop = &logfs_reg_fops; | |
519 | inode->i_mapping->a_ops = &logfs_reg_aops; | |
520 | ||
521 | return __logfs_create(dir, dentry, inode, NULL, 0); | |
522 | } | |
523 | ||
524 | static int logfs_mknod(struct inode *dir, struct dentry *dentry, int mode, | |
525 | dev_t rdev) | |
526 | { | |
527 | struct inode *inode; | |
528 | ||
529 | if (dentry->d_name.len > LOGFS_MAX_NAMELEN) | |
530 | return -ENAMETOOLONG; | |
531 | ||
532 | inode = logfs_new_inode(dir, mode); | |
533 | if (IS_ERR(inode)) | |
534 | return PTR_ERR(inode); | |
535 | ||
536 | init_special_inode(inode, mode, rdev); | |
537 | ||
538 | return __logfs_create(dir, dentry, inode, NULL, 0); | |
539 | } | |
540 | ||
541 | static int logfs_symlink(struct inode *dir, struct dentry *dentry, | |
542 | const char *target) | |
543 | { | |
544 | struct inode *inode; | |
545 | size_t destlen = strlen(target) + 1; | |
546 | ||
547 | if (destlen > dir->i_sb->s_blocksize) | |
548 | return -ENAMETOOLONG; | |
549 | ||
550 | inode = logfs_new_inode(dir, S_IFLNK | 0777); | |
551 | if (IS_ERR(inode)) | |
552 | return PTR_ERR(inode); | |
553 | ||
554 | inode->i_op = &logfs_symlink_iops; | |
555 | inode->i_mapping->a_ops = &logfs_reg_aops; | |
556 | ||
557 | return __logfs_create(dir, dentry, inode, target, destlen); | |
558 | } | |
559 | ||
b74c79e9 | 560 | static int logfs_permission(struct inode *inode, int mask, unsigned int flags) |
5db53f3e | 561 | { |
b74c79e9 NP |
562 | if (flags & IPERM_FLAG_RCU) |
563 | return -ECHILD; | |
564 | return generic_permission(inode, mask, flags, NULL); | |
5db53f3e JE |
565 | } |
566 | ||
567 | static int logfs_link(struct dentry *old_dentry, struct inode *dir, | |
568 | struct dentry *dentry) | |
569 | { | |
570 | struct inode *inode = old_dentry->d_inode; | |
571 | ||
572 | if (inode->i_nlink >= LOGFS_LINK_MAX) | |
573 | return -EMLINK; | |
574 | ||
575 | inode->i_ctime = dir->i_ctime = dir->i_mtime = CURRENT_TIME; | |
7de9c6ee | 576 | ihold(inode); |
5db53f3e JE |
577 | inode->i_nlink++; |
578 | mark_inode_dirty_sync(inode); | |
579 | ||
580 | return __logfs_create(dir, dentry, inode, NULL, 0); | |
581 | } | |
582 | ||
583 | static int logfs_get_dd(struct inode *dir, struct dentry *dentry, | |
584 | struct logfs_disk_dentry *dd, loff_t *pos) | |
585 | { | |
586 | struct page *page; | |
587 | void *map; | |
588 | ||
589 | page = logfs_get_dd_page(dir, dentry); | |
590 | if (IS_ERR(page)) | |
591 | return PTR_ERR(page); | |
592 | *pos = page->index; | |
593 | map = kmap_atomic(page, KM_USER0); | |
594 | memcpy(dd, map, sizeof(*dd)); | |
595 | kunmap_atomic(map, KM_USER0); | |
596 | page_cache_release(page); | |
597 | return 0; | |
598 | } | |
599 | ||
600 | static int logfs_delete_dd(struct inode *dir, loff_t pos) | |
601 | { | |
602 | /* | |
603 | * Getting called with pos somewhere beyond eof is either a goofup | |
604 | * within this file or means someone maliciously edited the | |
605 | * (crc-protected) journal. | |
606 | */ | |
607 | BUG_ON(beyond_eof(dir, pos)); | |
608 | dir->i_ctime = dir->i_mtime = CURRENT_TIME; | |
609 | log_dir(" Delete dentry (%lx, %llx)\n", dir->i_ino, pos); | |
610 | return logfs_delete(dir, pos, NULL); | |
611 | } | |
612 | ||
613 | /* | |
614 | * Cross-directory rename, target does not exist. Just a little nasty. | |
615 | * Create a new dentry in the target dir, then remove the old dentry, | |
616 | * all the while taking care to remember our operation in the journal. | |
617 | */ | |
618 | static int logfs_rename_cross(struct inode *old_dir, struct dentry *old_dentry, | |
619 | struct inode *new_dir, struct dentry *new_dentry) | |
620 | { | |
621 | struct logfs_super *super = logfs_super(old_dir->i_sb); | |
622 | struct logfs_disk_dentry dd; | |
623 | struct logfs_transaction *ta; | |
624 | loff_t pos; | |
625 | int err; | |
626 | ||
627 | /* 1. locate source dd */ | |
628 | err = logfs_get_dd(old_dir, old_dentry, &dd, &pos); | |
629 | if (err) | |
630 | return err; | |
631 | ||
632 | ta = kzalloc(sizeof(*ta), GFP_KERNEL); | |
633 | if (!ta) | |
634 | return -ENOMEM; | |
635 | ||
636 | ta->state = CROSS_RENAME_1; | |
637 | ta->dir = old_dir->i_ino; | |
638 | ta->pos = pos; | |
639 | ||
640 | /* 2. write target dd */ | |
641 | mutex_lock(&super->s_dirop_mutex); | |
642 | logfs_add_transaction(new_dir, ta); | |
643 | err = logfs_write_dir(new_dir, new_dentry, old_dentry->d_inode); | |
644 | if (!err) | |
645 | err = write_inode(new_dir); | |
646 | ||
647 | if (err) { | |
648 | super->s_rename_dir = 0; | |
649 | super->s_rename_pos = 0; | |
650 | abort_transaction(new_dir, ta); | |
651 | goto out; | |
652 | } | |
653 | ||
654 | /* 3. remove source dd */ | |
655 | ta->state = CROSS_RENAME_2; | |
656 | logfs_add_transaction(old_dir, ta); | |
657 | err = logfs_delete_dd(old_dir, pos); | |
658 | if (!err) | |
659 | err = write_inode(old_dir); | |
660 | LOGFS_BUG_ON(err, old_dir->i_sb); | |
661 | out: | |
662 | mutex_unlock(&super->s_dirop_mutex); | |
663 | return err; | |
664 | } | |
665 | ||
666 | static int logfs_replace_inode(struct inode *dir, struct dentry *dentry, | |
667 | struct logfs_disk_dentry *dd, struct inode *inode) | |
668 | { | |
669 | loff_t pos; | |
670 | int err; | |
671 | ||
672 | err = logfs_get_dd(dir, dentry, dd, &pos); | |
673 | if (err) | |
674 | return err; | |
675 | dd->ino = cpu_to_be64(inode->i_ino); | |
676 | dd->type = logfs_type(inode); | |
677 | ||
678 | err = write_dir(dir, dd, pos); | |
679 | if (err) | |
680 | return err; | |
681 | log_dir("Replace dentry (%lx, %llx) %s -> %llx\n", dir->i_ino, pos, | |
682 | dd->name, be64_to_cpu(dd->ino)); | |
683 | return write_inode(dir); | |
684 | } | |
685 | ||
686 | /* Target dentry exists - the worst case. We need to attach the source | |
687 | * inode to the target dentry, then remove the orphaned target inode and | |
688 | * source dentry. | |
689 | */ | |
690 | static int logfs_rename_target(struct inode *old_dir, struct dentry *old_dentry, | |
691 | struct inode *new_dir, struct dentry *new_dentry) | |
692 | { | |
693 | struct logfs_super *super = logfs_super(old_dir->i_sb); | |
694 | struct inode *old_inode = old_dentry->d_inode; | |
695 | struct inode *new_inode = new_dentry->d_inode; | |
696 | int isdir = S_ISDIR(old_inode->i_mode); | |
697 | struct logfs_disk_dentry dd; | |
698 | struct logfs_transaction *ta; | |
699 | loff_t pos; | |
700 | int err; | |
701 | ||
702 | BUG_ON(isdir != S_ISDIR(new_inode->i_mode)); | |
703 | if (isdir) { | |
704 | if (!logfs_empty_dir(new_inode)) | |
705 | return -ENOTEMPTY; | |
706 | } | |
707 | ||
708 | /* 1. locate source dd */ | |
709 | err = logfs_get_dd(old_dir, old_dentry, &dd, &pos); | |
710 | if (err) | |
711 | return err; | |
712 | ||
713 | ta = kzalloc(sizeof(*ta), GFP_KERNEL); | |
714 | if (!ta) | |
715 | return -ENOMEM; | |
716 | ||
717 | ta->state = TARGET_RENAME_1; | |
718 | ta->dir = old_dir->i_ino; | |
719 | ta->pos = pos; | |
720 | ta->ino = new_inode->i_ino; | |
721 | ||
722 | /* 2. attach source inode to target dd */ | |
723 | mutex_lock(&super->s_dirop_mutex); | |
724 | logfs_add_transaction(new_dir, ta); | |
725 | err = logfs_replace_inode(new_dir, new_dentry, &dd, old_inode); | |
726 | if (err) { | |
727 | super->s_rename_dir = 0; | |
728 | super->s_rename_pos = 0; | |
729 | super->s_victim_ino = 0; | |
730 | abort_transaction(new_dir, ta); | |
731 | goto out; | |
732 | } | |
733 | ||
734 | /* 3. remove source dd */ | |
735 | ta->state = TARGET_RENAME_2; | |
736 | logfs_add_transaction(old_dir, ta); | |
737 | err = logfs_delete_dd(old_dir, pos); | |
738 | if (!err) | |
739 | err = write_inode(old_dir); | |
740 | LOGFS_BUG_ON(err, old_dir->i_sb); | |
741 | ||
742 | /* 4. remove target inode */ | |
743 | ta->state = TARGET_RENAME_3; | |
744 | logfs_add_transaction(new_inode, ta); | |
745 | err = logfs_remove_inode(new_inode); | |
746 | ||
747 | out: | |
748 | mutex_unlock(&super->s_dirop_mutex); | |
749 | return err; | |
750 | } | |
751 | ||
752 | static int logfs_rename(struct inode *old_dir, struct dentry *old_dentry, | |
753 | struct inode *new_dir, struct dentry *new_dentry) | |
754 | { | |
755 | if (new_dentry->d_inode) | |
756 | return logfs_rename_target(old_dir, old_dentry, | |
757 | new_dir, new_dentry); | |
758 | return logfs_rename_cross(old_dir, old_dentry, new_dir, new_dentry); | |
759 | } | |
760 | ||
761 | /* No locking done here, as this is called before .get_sb() returns. */ | |
762 | int logfs_replay_journal(struct super_block *sb) | |
763 | { | |
764 | struct logfs_super *super = logfs_super(sb); | |
765 | struct inode *inode; | |
766 | u64 ino, pos; | |
767 | int err; | |
768 | ||
769 | if (super->s_victim_ino) { | |
770 | /* delete victim inode */ | |
771 | ino = super->s_victim_ino; | |
772 | printk(KERN_INFO"LogFS: delete unmapped inode #%llx\n", ino); | |
773 | inode = logfs_iget(sb, ino); | |
774 | if (IS_ERR(inode)) | |
775 | goto fail; | |
776 | ||
777 | LOGFS_BUG_ON(i_size_read(inode) > 0, sb); | |
778 | super->s_victim_ino = 0; | |
779 | err = logfs_remove_inode(inode); | |
780 | iput(inode); | |
781 | if (err) { | |
782 | super->s_victim_ino = ino; | |
783 | goto fail; | |
784 | } | |
785 | } | |
786 | if (super->s_rename_dir) { | |
787 | /* delete old dd from rename */ | |
788 | ino = super->s_rename_dir; | |
789 | pos = super->s_rename_pos; | |
790 | printk(KERN_INFO"LogFS: delete unbacked dentry (%llx, %llx)\n", | |
791 | ino, pos); | |
792 | inode = logfs_iget(sb, ino); | |
793 | if (IS_ERR(inode)) | |
794 | goto fail; | |
795 | ||
796 | super->s_rename_dir = 0; | |
797 | super->s_rename_pos = 0; | |
798 | err = logfs_delete_dd(inode, pos); | |
799 | iput(inode); | |
800 | if (err) { | |
801 | super->s_rename_dir = ino; | |
802 | super->s_rename_pos = pos; | |
803 | goto fail; | |
804 | } | |
805 | } | |
806 | return 0; | |
807 | fail: | |
808 | LOGFS_BUG(sb); | |
809 | return -EIO; | |
810 | } | |
811 | ||
812 | const struct inode_operations logfs_symlink_iops = { | |
813 | .readlink = generic_readlink, | |
814 | .follow_link = page_follow_link_light, | |
815 | }; | |
816 | ||
817 | const struct inode_operations logfs_dir_iops = { | |
818 | .create = logfs_create, | |
819 | .link = logfs_link, | |
820 | .lookup = logfs_lookup, | |
821 | .mkdir = logfs_mkdir, | |
822 | .mknod = logfs_mknod, | |
823 | .rename = logfs_rename, | |
824 | .rmdir = logfs_rmdir, | |
825 | .permission = logfs_permission, | |
826 | .symlink = logfs_symlink, | |
827 | .unlink = logfs_unlink, | |
828 | }; | |
829 | const struct file_operations logfs_dir_fops = { | |
830 | .fsync = logfs_fsync, | |
02d6d685 | 831 | .unlocked_ioctl = logfs_ioctl, |
5db53f3e JE |
832 | .readdir = logfs_readdir, |
833 | .read = generic_read_dir, | |
6038f373 | 834 | .llseek = default_llseek, |
5db53f3e | 835 | }; |