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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 | ||
276 | if (!logfs_empty_dir(inode)) | |
277 | return -ENOTEMPTY; | |
278 | ||
279 | return logfs_unlink(dir, dentry); | |
280 | } | |
281 | ||
282 | /* FIXME: readdir currently has it's own dir_walk code. I don't see a good | |
283 | * way to combine the two copies */ | |
284 | #define IMPLICIT_NODES 2 | |
285 | static int __logfs_readdir(struct file *file, void *buf, filldir_t filldir) | |
286 | { | |
287 | struct inode *dir = file->f_dentry->d_inode; | |
288 | loff_t pos = file->f_pos - IMPLICIT_NODES; | |
289 | struct page *page; | |
290 | struct logfs_disk_dentry *dd; | |
291 | int full; | |
292 | ||
293 | BUG_ON(pos < 0); | |
294 | for (;; pos++) { | |
295 | if (beyond_eof(dir, pos)) | |
296 | break; | |
297 | if (!logfs_exist_block(dir, pos)) { | |
298 | /* deleted dentry */ | |
299 | pos = dir_seek_data(dir, pos); | |
300 | continue; | |
301 | } | |
302 | page = read_cache_page(dir->i_mapping, pos, | |
303 | (filler_t *)logfs_readpage, NULL); | |
304 | if (IS_ERR(page)) | |
305 | return PTR_ERR(page); | |
e3260688 | 306 | dd = kmap(page); |
5db53f3e JE |
307 | BUG_ON(dd->namelen == 0); |
308 | ||
309 | full = filldir(buf, (char *)dd->name, be16_to_cpu(dd->namelen), | |
310 | pos, be64_to_cpu(dd->ino), dd->type); | |
e3260688 | 311 | kunmap(page); |
5db53f3e JE |
312 | page_cache_release(page); |
313 | if (full) | |
314 | break; | |
315 | } | |
316 | ||
317 | file->f_pos = pos + IMPLICIT_NODES; | |
318 | return 0; | |
319 | } | |
320 | ||
321 | static int logfs_readdir(struct file *file, void *buf, filldir_t filldir) | |
322 | { | |
323 | struct inode *inode = file->f_dentry->d_inode; | |
324 | ino_t pino = parent_ino(file->f_dentry); | |
325 | int err; | |
326 | ||
327 | if (file->f_pos < 0) | |
328 | return -EINVAL; | |
329 | ||
330 | if (file->f_pos == 0) { | |
331 | if (filldir(buf, ".", 1, 1, inode->i_ino, DT_DIR) < 0) | |
332 | return 0; | |
333 | file->f_pos++; | |
334 | } | |
335 | if (file->f_pos == 1) { | |
336 | if (filldir(buf, "..", 2, 2, pino, DT_DIR) < 0) | |
337 | return 0; | |
338 | file->f_pos++; | |
339 | } | |
340 | ||
341 | err = __logfs_readdir(file, buf, filldir); | |
342 | return err; | |
343 | } | |
344 | ||
345 | static void logfs_set_name(struct logfs_disk_dentry *dd, struct qstr *name) | |
346 | { | |
347 | dd->namelen = cpu_to_be16(name->len); | |
348 | memcpy(dd->name, name->name, name->len); | |
349 | } | |
350 | ||
351 | static struct dentry *logfs_lookup(struct inode *dir, struct dentry *dentry, | |
352 | struct nameidata *nd) | |
353 | { | |
354 | struct page *page; | |
355 | struct logfs_disk_dentry *dd; | |
356 | pgoff_t index; | |
357 | u64 ino = 0; | |
358 | struct inode *inode; | |
359 | ||
360 | page = logfs_get_dd_page(dir, dentry); | |
361 | if (IS_ERR(page)) | |
362 | return ERR_CAST(page); | |
363 | if (!page) { | |
364 | d_add(dentry, NULL); | |
365 | return NULL; | |
366 | } | |
367 | index = page->index; | |
368 | dd = kmap_atomic(page, KM_USER0); | |
369 | ino = be64_to_cpu(dd->ino); | |
370 | kunmap_atomic(dd, KM_USER0); | |
371 | page_cache_release(page); | |
372 | ||
373 | inode = logfs_iget(dir->i_sb, ino); | |
a9049376 | 374 | if (IS_ERR(inode)) |
5db53f3e JE |
375 | printk(KERN_ERR"LogFS: Cannot read inode #%llx for dentry (%lx, %lx)n", |
376 | ino, dir->i_ino, index); | |
5db53f3e JE |
377 | return d_splice_alias(inode, dentry); |
378 | } | |
379 | ||
380 | static void grow_dir(struct inode *dir, loff_t index) | |
381 | { | |
382 | index = (index + 1) << dir->i_sb->s_blocksize_bits; | |
383 | if (i_size_read(dir) < index) | |
384 | i_size_write(dir, index); | |
385 | } | |
386 | ||
387 | static int logfs_write_dir(struct inode *dir, struct dentry *dentry, | |
388 | struct inode *inode) | |
389 | { | |
390 | struct page *page; | |
391 | struct logfs_disk_dentry *dd; | |
392 | u32 hash = hash_32(dentry->d_name.name, dentry->d_name.len, 0); | |
393 | pgoff_t index; | |
394 | int round, err; | |
395 | ||
396 | for (round = 0; round < 20; round++) { | |
397 | index = hash_index(hash, round); | |
398 | ||
399 | if (logfs_exist_block(dir, index)) | |
400 | continue; | |
401 | page = find_or_create_page(dir->i_mapping, index, GFP_KERNEL); | |
402 | if (!page) | |
403 | return -ENOMEM; | |
404 | ||
405 | dd = kmap_atomic(page, KM_USER0); | |
406 | memset(dd, 0, sizeof(*dd)); | |
407 | dd->ino = cpu_to_be64(inode->i_ino); | |
408 | dd->type = logfs_type(inode); | |
409 | logfs_set_name(dd, &dentry->d_name); | |
410 | kunmap_atomic(dd, KM_USER0); | |
411 | ||
412 | err = logfs_write_buf(dir, page, WF_LOCK); | |
413 | unlock_page(page); | |
414 | page_cache_release(page); | |
415 | if (!err) | |
416 | grow_dir(dir, index); | |
417 | return err; | |
418 | } | |
419 | /* FIXME: Is there a better return value? In most cases neither | |
420 | * the filesystem nor the directory are full. But we have had | |
421 | * too many collisions for this particular hash and no fallback. | |
422 | */ | |
423 | return -ENOSPC; | |
424 | } | |
425 | ||
426 | static int __logfs_create(struct inode *dir, struct dentry *dentry, | |
427 | struct inode *inode, const char *dest, long destlen) | |
428 | { | |
429 | struct logfs_super *super = logfs_super(dir->i_sb); | |
430 | struct logfs_inode *li = logfs_inode(inode); | |
431 | struct logfs_transaction *ta; | |
432 | int ret; | |
433 | ||
434 | ta = kzalloc(sizeof(*ta), GFP_KERNEL); | |
25624958 AV |
435 | if (!ta) { |
436 | inode->i_nlink--; | |
437 | iput(inode); | |
5db53f3e | 438 | return -ENOMEM; |
25624958 | 439 | } |
5db53f3e JE |
440 | |
441 | ta->state = CREATE_1; | |
442 | ta->ino = inode->i_ino; | |
443 | mutex_lock(&super->s_dirop_mutex); | |
444 | logfs_add_transaction(inode, ta); | |
445 | ||
446 | if (dest) { | |
447 | /* symlink */ | |
448 | ret = logfs_inode_write(inode, dest, destlen, 0, WF_LOCK, NULL); | |
449 | if (!ret) | |
450 | ret = write_inode(inode); | |
451 | } else { | |
452 | /* creat/mkdir/mknod */ | |
453 | ret = write_inode(inode); | |
454 | } | |
455 | if (ret) { | |
456 | abort_transaction(inode, ta); | |
457 | li->li_flags |= LOGFS_IF_STILLBORN; | |
458 | /* FIXME: truncate symlink */ | |
459 | inode->i_nlink--; | |
460 | iput(inode); | |
461 | goto out; | |
462 | } | |
463 | ||
464 | ta->state = CREATE_2; | |
465 | logfs_add_transaction(dir, ta); | |
466 | ret = logfs_write_dir(dir, dentry, inode); | |
467 | /* sync directory */ | |
468 | if (!ret) | |
469 | ret = write_inode(dir); | |
470 | ||
471 | if (ret) { | |
472 | logfs_del_transaction(dir, ta); | |
473 | ta->state = CREATE_2; | |
474 | logfs_add_transaction(inode, ta); | |
475 | logfs_remove_inode(inode); | |
476 | iput(inode); | |
477 | goto out; | |
478 | } | |
479 | d_instantiate(dentry, inode); | |
480 | out: | |
481 | mutex_unlock(&super->s_dirop_mutex); | |
482 | return ret; | |
483 | } | |
484 | ||
485 | static int logfs_mkdir(struct inode *dir, struct dentry *dentry, int mode) | |
486 | { | |
487 | struct inode *inode; | |
488 | ||
489 | /* | |
490 | * FIXME: why do we have to fill in S_IFDIR, while the mode is | |
491 | * correct for mknod, creat, etc.? Smells like the vfs *should* | |
492 | * do it for us but for some reason fails to do so. | |
493 | */ | |
494 | inode = logfs_new_inode(dir, S_IFDIR | mode); | |
495 | if (IS_ERR(inode)) | |
496 | return PTR_ERR(inode); | |
497 | ||
498 | inode->i_op = &logfs_dir_iops; | |
499 | inode->i_fop = &logfs_dir_fops; | |
500 | ||
501 | return __logfs_create(dir, dentry, inode, NULL, 0); | |
502 | } | |
503 | ||
504 | static int logfs_create(struct inode *dir, struct dentry *dentry, int mode, | |
505 | struct nameidata *nd) | |
506 | { | |
507 | struct inode *inode; | |
508 | ||
509 | inode = logfs_new_inode(dir, mode); | |
510 | if (IS_ERR(inode)) | |
511 | return PTR_ERR(inode); | |
512 | ||
513 | inode->i_op = &logfs_reg_iops; | |
514 | inode->i_fop = &logfs_reg_fops; | |
515 | inode->i_mapping->a_ops = &logfs_reg_aops; | |
516 | ||
517 | return __logfs_create(dir, dentry, inode, NULL, 0); | |
518 | } | |
519 | ||
520 | static int logfs_mknod(struct inode *dir, struct dentry *dentry, int mode, | |
521 | dev_t rdev) | |
522 | { | |
523 | struct inode *inode; | |
524 | ||
525 | if (dentry->d_name.len > LOGFS_MAX_NAMELEN) | |
526 | return -ENAMETOOLONG; | |
527 | ||
528 | inode = logfs_new_inode(dir, mode); | |
529 | if (IS_ERR(inode)) | |
530 | return PTR_ERR(inode); | |
531 | ||
532 | init_special_inode(inode, mode, rdev); | |
533 | ||
534 | return __logfs_create(dir, dentry, inode, NULL, 0); | |
535 | } | |
536 | ||
537 | static int logfs_symlink(struct inode *dir, struct dentry *dentry, | |
538 | const char *target) | |
539 | { | |
540 | struct inode *inode; | |
541 | size_t destlen = strlen(target) + 1; | |
542 | ||
543 | if (destlen > dir->i_sb->s_blocksize) | |
544 | return -ENAMETOOLONG; | |
545 | ||
546 | inode = logfs_new_inode(dir, S_IFLNK | 0777); | |
547 | if (IS_ERR(inode)) | |
548 | return PTR_ERR(inode); | |
549 | ||
550 | inode->i_op = &logfs_symlink_iops; | |
551 | inode->i_mapping->a_ops = &logfs_reg_aops; | |
552 | ||
553 | return __logfs_create(dir, dentry, inode, target, destlen); | |
554 | } | |
555 | ||
5db53f3e JE |
556 | static int logfs_link(struct dentry *old_dentry, struct inode *dir, |
557 | struct dentry *dentry) | |
558 | { | |
559 | struct inode *inode = old_dentry->d_inode; | |
560 | ||
561 | if (inode->i_nlink >= LOGFS_LINK_MAX) | |
562 | return -EMLINK; | |
563 | ||
564 | inode->i_ctime = dir->i_ctime = dir->i_mtime = CURRENT_TIME; | |
7de9c6ee | 565 | ihold(inode); |
5db53f3e JE |
566 | inode->i_nlink++; |
567 | mark_inode_dirty_sync(inode); | |
568 | ||
569 | return __logfs_create(dir, dentry, inode, NULL, 0); | |
570 | } | |
571 | ||
572 | static int logfs_get_dd(struct inode *dir, struct dentry *dentry, | |
573 | struct logfs_disk_dentry *dd, loff_t *pos) | |
574 | { | |
575 | struct page *page; | |
576 | void *map; | |
577 | ||
578 | page = logfs_get_dd_page(dir, dentry); | |
579 | if (IS_ERR(page)) | |
580 | return PTR_ERR(page); | |
581 | *pos = page->index; | |
582 | map = kmap_atomic(page, KM_USER0); | |
583 | memcpy(dd, map, sizeof(*dd)); | |
584 | kunmap_atomic(map, KM_USER0); | |
585 | page_cache_release(page); | |
586 | return 0; | |
587 | } | |
588 | ||
589 | static int logfs_delete_dd(struct inode *dir, loff_t pos) | |
590 | { | |
591 | /* | |
592 | * Getting called with pos somewhere beyond eof is either a goofup | |
593 | * within this file or means someone maliciously edited the | |
594 | * (crc-protected) journal. | |
595 | */ | |
596 | BUG_ON(beyond_eof(dir, pos)); | |
597 | dir->i_ctime = dir->i_mtime = CURRENT_TIME; | |
598 | log_dir(" Delete dentry (%lx, %llx)\n", dir->i_ino, pos); | |
599 | return logfs_delete(dir, pos, NULL); | |
600 | } | |
601 | ||
602 | /* | |
603 | * Cross-directory rename, target does not exist. Just a little nasty. | |
604 | * Create a new dentry in the target dir, then remove the old dentry, | |
605 | * all the while taking care to remember our operation in the journal. | |
606 | */ | |
607 | static int logfs_rename_cross(struct inode *old_dir, struct dentry *old_dentry, | |
608 | struct inode *new_dir, struct dentry *new_dentry) | |
609 | { | |
610 | struct logfs_super *super = logfs_super(old_dir->i_sb); | |
611 | struct logfs_disk_dentry dd; | |
612 | struct logfs_transaction *ta; | |
613 | loff_t pos; | |
614 | int err; | |
615 | ||
616 | /* 1. locate source dd */ | |
617 | err = logfs_get_dd(old_dir, old_dentry, &dd, &pos); | |
618 | if (err) | |
619 | return err; | |
620 | ||
621 | ta = kzalloc(sizeof(*ta), GFP_KERNEL); | |
622 | if (!ta) | |
623 | return -ENOMEM; | |
624 | ||
625 | ta->state = CROSS_RENAME_1; | |
626 | ta->dir = old_dir->i_ino; | |
627 | ta->pos = pos; | |
628 | ||
629 | /* 2. write target dd */ | |
630 | mutex_lock(&super->s_dirop_mutex); | |
631 | logfs_add_transaction(new_dir, ta); | |
632 | err = logfs_write_dir(new_dir, new_dentry, old_dentry->d_inode); | |
633 | if (!err) | |
634 | err = write_inode(new_dir); | |
635 | ||
636 | if (err) { | |
637 | super->s_rename_dir = 0; | |
638 | super->s_rename_pos = 0; | |
639 | abort_transaction(new_dir, ta); | |
640 | goto out; | |
641 | } | |
642 | ||
643 | /* 3. remove source dd */ | |
644 | ta->state = CROSS_RENAME_2; | |
645 | logfs_add_transaction(old_dir, ta); | |
646 | err = logfs_delete_dd(old_dir, pos); | |
647 | if (!err) | |
648 | err = write_inode(old_dir); | |
649 | LOGFS_BUG_ON(err, old_dir->i_sb); | |
650 | out: | |
651 | mutex_unlock(&super->s_dirop_mutex); | |
652 | return err; | |
653 | } | |
654 | ||
655 | static int logfs_replace_inode(struct inode *dir, struct dentry *dentry, | |
656 | struct logfs_disk_dentry *dd, struct inode *inode) | |
657 | { | |
658 | loff_t pos; | |
659 | int err; | |
660 | ||
661 | err = logfs_get_dd(dir, dentry, dd, &pos); | |
662 | if (err) | |
663 | return err; | |
664 | dd->ino = cpu_to_be64(inode->i_ino); | |
665 | dd->type = logfs_type(inode); | |
666 | ||
667 | err = write_dir(dir, dd, pos); | |
668 | if (err) | |
669 | return err; | |
670 | log_dir("Replace dentry (%lx, %llx) %s -> %llx\n", dir->i_ino, pos, | |
671 | dd->name, be64_to_cpu(dd->ino)); | |
672 | return write_inode(dir); | |
673 | } | |
674 | ||
675 | /* Target dentry exists - the worst case. We need to attach the source | |
676 | * inode to the target dentry, then remove the orphaned target inode and | |
677 | * source dentry. | |
678 | */ | |
679 | static int logfs_rename_target(struct inode *old_dir, struct dentry *old_dentry, | |
680 | struct inode *new_dir, struct dentry *new_dentry) | |
681 | { | |
682 | struct logfs_super *super = logfs_super(old_dir->i_sb); | |
683 | struct inode *old_inode = old_dentry->d_inode; | |
684 | struct inode *new_inode = new_dentry->d_inode; | |
685 | int isdir = S_ISDIR(old_inode->i_mode); | |
686 | struct logfs_disk_dentry dd; | |
687 | struct logfs_transaction *ta; | |
688 | loff_t pos; | |
689 | int err; | |
690 | ||
691 | BUG_ON(isdir != S_ISDIR(new_inode->i_mode)); | |
692 | if (isdir) { | |
693 | if (!logfs_empty_dir(new_inode)) | |
694 | return -ENOTEMPTY; | |
695 | } | |
696 | ||
697 | /* 1. locate source dd */ | |
698 | err = logfs_get_dd(old_dir, old_dentry, &dd, &pos); | |
699 | if (err) | |
700 | return err; | |
701 | ||
702 | ta = kzalloc(sizeof(*ta), GFP_KERNEL); | |
703 | if (!ta) | |
704 | return -ENOMEM; | |
705 | ||
706 | ta->state = TARGET_RENAME_1; | |
707 | ta->dir = old_dir->i_ino; | |
708 | ta->pos = pos; | |
709 | ta->ino = new_inode->i_ino; | |
710 | ||
711 | /* 2. attach source inode to target dd */ | |
712 | mutex_lock(&super->s_dirop_mutex); | |
713 | logfs_add_transaction(new_dir, ta); | |
714 | err = logfs_replace_inode(new_dir, new_dentry, &dd, old_inode); | |
715 | if (err) { | |
716 | super->s_rename_dir = 0; | |
717 | super->s_rename_pos = 0; | |
718 | super->s_victim_ino = 0; | |
719 | abort_transaction(new_dir, ta); | |
720 | goto out; | |
721 | } | |
722 | ||
723 | /* 3. remove source dd */ | |
724 | ta->state = TARGET_RENAME_2; | |
725 | logfs_add_transaction(old_dir, ta); | |
726 | err = logfs_delete_dd(old_dir, pos); | |
727 | if (!err) | |
728 | err = write_inode(old_dir); | |
729 | LOGFS_BUG_ON(err, old_dir->i_sb); | |
730 | ||
731 | /* 4. remove target inode */ | |
732 | ta->state = TARGET_RENAME_3; | |
733 | logfs_add_transaction(new_inode, ta); | |
734 | err = logfs_remove_inode(new_inode); | |
735 | ||
736 | out: | |
737 | mutex_unlock(&super->s_dirop_mutex); | |
738 | return err; | |
739 | } | |
740 | ||
741 | static int logfs_rename(struct inode *old_dir, struct dentry *old_dentry, | |
742 | struct inode *new_dir, struct dentry *new_dentry) | |
743 | { | |
744 | if (new_dentry->d_inode) | |
745 | return logfs_rename_target(old_dir, old_dentry, | |
746 | new_dir, new_dentry); | |
747 | return logfs_rename_cross(old_dir, old_dentry, new_dir, new_dentry); | |
748 | } | |
749 | ||
750 | /* No locking done here, as this is called before .get_sb() returns. */ | |
751 | int logfs_replay_journal(struct super_block *sb) | |
752 | { | |
753 | struct logfs_super *super = logfs_super(sb); | |
754 | struct inode *inode; | |
755 | u64 ino, pos; | |
756 | int err; | |
757 | ||
758 | if (super->s_victim_ino) { | |
759 | /* delete victim inode */ | |
760 | ino = super->s_victim_ino; | |
761 | printk(KERN_INFO"LogFS: delete unmapped inode #%llx\n", ino); | |
762 | inode = logfs_iget(sb, ino); | |
763 | if (IS_ERR(inode)) | |
764 | goto fail; | |
765 | ||
766 | LOGFS_BUG_ON(i_size_read(inode) > 0, sb); | |
767 | super->s_victim_ino = 0; | |
768 | err = logfs_remove_inode(inode); | |
769 | iput(inode); | |
770 | if (err) { | |
771 | super->s_victim_ino = ino; | |
772 | goto fail; | |
773 | } | |
774 | } | |
775 | if (super->s_rename_dir) { | |
776 | /* delete old dd from rename */ | |
777 | ino = super->s_rename_dir; | |
778 | pos = super->s_rename_pos; | |
779 | printk(KERN_INFO"LogFS: delete unbacked dentry (%llx, %llx)\n", | |
780 | ino, pos); | |
781 | inode = logfs_iget(sb, ino); | |
782 | if (IS_ERR(inode)) | |
783 | goto fail; | |
784 | ||
785 | super->s_rename_dir = 0; | |
786 | super->s_rename_pos = 0; | |
787 | err = logfs_delete_dd(inode, pos); | |
788 | iput(inode); | |
789 | if (err) { | |
790 | super->s_rename_dir = ino; | |
791 | super->s_rename_pos = pos; | |
792 | goto fail; | |
793 | } | |
794 | } | |
795 | return 0; | |
796 | fail: | |
797 | LOGFS_BUG(sb); | |
798 | return -EIO; | |
799 | } | |
800 | ||
801 | const struct inode_operations logfs_symlink_iops = { | |
802 | .readlink = generic_readlink, | |
803 | .follow_link = page_follow_link_light, | |
804 | }; | |
805 | ||
806 | const struct inode_operations logfs_dir_iops = { | |
807 | .create = logfs_create, | |
808 | .link = logfs_link, | |
809 | .lookup = logfs_lookup, | |
810 | .mkdir = logfs_mkdir, | |
811 | .mknod = logfs_mknod, | |
812 | .rename = logfs_rename, | |
813 | .rmdir = logfs_rmdir, | |
5db53f3e JE |
814 | .symlink = logfs_symlink, |
815 | .unlink = logfs_unlink, | |
816 | }; | |
817 | const struct file_operations logfs_dir_fops = { | |
818 | .fsync = logfs_fsync, | |
02d6d685 | 819 | .unlocked_ioctl = logfs_ioctl, |
5db53f3e JE |
820 | .readdir = logfs_readdir, |
821 | .read = generic_read_dir, | |
6038f373 | 822 | .llseek = default_llseek, |
5db53f3e | 823 | }; |