blob: 6bdc347008f5eb15d2d60ea9750202e72d380f18 [file] [log] [blame]
Joern Engel5db53f32009-11-20 20:13:39 +01001/*
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"
Tejun Heo5a0e3ad2010-03-24 17:04:11 +09009#include <linux/slab.h>
Joern Engel5db53f32009-11-20 20:13:39 +010010
11/*
12 * Atomic dir operations
13 *
14 * Directory operations are by default not atomic. Dentries and Inodes are
Anand Gadiyara8cd4562010-05-10 14:51:19 +053015 * created/removed/altered in separate operations. Therefore we need to do
Joern Engel5db53f32009-11-20 20:13:39 +010016 * 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
66static 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
72static int write_inode(struct inode *inode)
73{
Prasad Joshi0bd90382011-10-02 23:46:51 +053074 return __logfs_write_inode(inode, NULL, WF_LOCK);
Joern Engel5db53f32009-11-20 20:13:39 +010075}
76
77static 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
84static 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
Lucas De Marchi25985ed2011-03-30 22:57:33 -030095 * of each character and pick a prime nearby, preferably a bit-sparse
Joern Engel5db53f32009-11-20 20:13:39 +010096 * one.
97 */
98static 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 */
134static pgoff_t hash_index(u32 hash, int round)
135{
Joern Engel30835cd2009-11-28 13:14:08 +0100136 u32 i0_blocks = I0_BLOCKS;
137 u32 i1_blocks = I1_BLOCKS;
138 u32 i2_blocks = I2_BLOCKS;
139 u32 i3_blocks = I3_BLOCKS;
140
Joern Engel5db53f32009-11-20 20:13:39 +0100141 switch (round) {
142 case 0:
Joern Engel30835cd2009-11-28 13:14:08 +0100143 return hash % i0_blocks;
Joern Engel5db53f32009-11-20 20:13:39 +0100144 case 1:
Joern Engel30835cd2009-11-28 13:14:08 +0100145 return i0_blocks + hash % (i1_blocks - i0_blocks);
Joern Engel5db53f32009-11-20 20:13:39 +0100146 case 2:
Joern Engel30835cd2009-11-28 13:14:08 +0100147 return i1_blocks + hash % (i2_blocks - i1_blocks);
Joern Engel5db53f32009-11-20 20:13:39 +0100148 case 3:
Joern Engel30835cd2009-11-28 13:14:08 +0100149 return i2_blocks + hash % (i3_blocks - i2_blocks);
Joern Engel5db53f32009-11-20 20:13:39 +0100150 case 4 ... 19:
Joern Engel30835cd2009-11-28 13:14:08 +0100151 return i3_blocks + 16 * (hash % (((1<<31) - i3_blocks) / 16))
Joern Engel5db53f32009-11-20 20:13:39 +0100152 + round - 4;
153 }
154 BUG();
155}
156
157static 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;
Cong Wang50bc9b62011-11-25 23:14:31 +0800180 dd = kmap_atomic(page);
Joern Engel5db53f32009-11-20 20:13:39 +0100181 BUG_ON(dd->namelen == 0);
182
183 if (name->len != be16_to_cpu(dd->namelen) ||
184 memcmp(name->name, dd->name, name->len)) {
Cong Wang50bc9b62011-11-25 23:14:31 +0800185 kunmap_atomic(dd);
Joern Engel5db53f32009-11-20 20:13:39 +0100186 page_cache_release(page);
187 continue;
188 }
189
Cong Wang50bc9b62011-11-25 23:14:31 +0800190 kunmap_atomic(dd);
Joern Engel5db53f32009-11-20 20:13:39 +0100191 return page;
192 }
193 return NULL;
194}
195
196static int logfs_remove_inode(struct inode *inode)
197{
198 int ret;
199
Miklos Szeredi6d6b77f2011-10-28 14:13:28 +0200200 drop_nlink(inode);
Joern Engel5db53f32009-11-20 20:13:39 +0100201 ret = write_inode(inode);
202 LOGFS_BUG_ON(ret, inode->i_sb);
203 return ret;
204}
205
206static 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
213static 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);
Joern Engelddfd1f02009-11-23 14:29:12 +0100232 if (!page) {
233 kfree(ta);
Joern Engel5db53f32009-11-20 20:13:39 +0100234 return -ENOENT;
Joern Engelddfd1f02009-11-23 14:29:12 +0100235 }
236 if (IS_ERR(page)) {
237 kfree(ta);
Joern Engel5db53f32009-11-20 20:13:39 +0100238 return PTR_ERR(page);
Joern Engelddfd1f02009-11-23 14:29:12 +0100239 }
Joern Engel5db53f32009-11-20 20:13:39 +0100240 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);
259out:
260 mutex_unlock(&super->s_dirop_mutex);
261 return ret;
262}
263
264static 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
272static 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 */
Al Viro46d07332013-05-17 17:06:34 -0400284static int logfs_readdir(struct file *file, struct dir_context *ctx)
Joern Engel5db53f32009-11-20 20:13:39 +0100285{
Al Viro496ad9a2013-01-23 17:07:38 -0500286 struct inode *dir = file_inode(file);
Al Viro46d07332013-05-17 17:06:34 -0400287 loff_t pos;
Joern Engel5db53f32009-11-20 20:13:39 +0100288 struct page *page;
289 struct logfs_disk_dentry *dd;
Joern Engel5db53f32009-11-20 20:13:39 +0100290
Al Viro46d07332013-05-17 17:06:34 -0400291 if (ctx->pos < 0)
292 return -EINVAL;
293
294 if (!dir_emit_dots(file, ctx))
295 return 0;
296
297 pos = ctx->pos - 2;
Joern Engel5db53f32009-11-20 20:13:39 +0100298 BUG_ON(pos < 0);
Al Viro46d07332013-05-17 17:06:34 -0400299 for (;; pos++, ctx->pos++) {
300 bool full;
Joern Engel5db53f32009-11-20 20:13:39 +0100301 if (beyond_eof(dir, pos))
302 break;
303 if (!logfs_exist_block(dir, pos)) {
304 /* deleted dentry */
305 pos = dir_seek_data(dir, pos);
306 continue;
307 }
308 page = read_cache_page(dir->i_mapping, pos,
309 (filler_t *)logfs_readpage, NULL);
310 if (IS_ERR(page))
311 return PTR_ERR(page);
Joern Engele3260682010-03-17 16:00:07 +0100312 dd = kmap(page);
Joern Engel5db53f32009-11-20 20:13:39 +0100313 BUG_ON(dd->namelen == 0);
314
Al Viro46d07332013-05-17 17:06:34 -0400315 full = !dir_emit(ctx, (char *)dd->name,
316 be16_to_cpu(dd->namelen),
317 be64_to_cpu(dd->ino), dd->type);
Joern Engele3260682010-03-17 16:00:07 +0100318 kunmap(page);
Joern Engel5db53f32009-11-20 20:13:39 +0100319 page_cache_release(page);
320 if (full)
321 break;
322 }
Joern Engel5db53f32009-11-20 20:13:39 +0100323 return 0;
324}
325
Joern Engel5db53f32009-11-20 20:13:39 +0100326static void logfs_set_name(struct logfs_disk_dentry *dd, struct qstr *name)
327{
328 dd->namelen = cpu_to_be16(name->len);
329 memcpy(dd->name, name->name, name->len);
330}
331
332static struct dentry *logfs_lookup(struct inode *dir, struct dentry *dentry,
Al Viro00cd8dd2012-06-10 17:13:09 -0400333 unsigned int flags)
Joern Engel5db53f32009-11-20 20:13:39 +0100334{
335 struct page *page;
336 struct logfs_disk_dentry *dd;
337 pgoff_t index;
338 u64 ino = 0;
339 struct inode *inode;
340
341 page = logfs_get_dd_page(dir, dentry);
342 if (IS_ERR(page))
343 return ERR_CAST(page);
344 if (!page) {
345 d_add(dentry, NULL);
346 return NULL;
347 }
348 index = page->index;
Cong Wang50bc9b62011-11-25 23:14:31 +0800349 dd = kmap_atomic(page);
Joern Engel5db53f32009-11-20 20:13:39 +0100350 ino = be64_to_cpu(dd->ino);
Cong Wang50bc9b62011-11-25 23:14:31 +0800351 kunmap_atomic(dd);
Joern Engel5db53f32009-11-20 20:13:39 +0100352 page_cache_release(page);
353
354 inode = logfs_iget(dir->i_sb, ino);
Al Viroa9049372011-07-08 21:20:11 -0400355 if (IS_ERR(inode))
Joern Engel5db53f32009-11-20 20:13:39 +0100356 printk(KERN_ERR"LogFS: Cannot read inode #%llx for dentry (%lx, %lx)n",
357 ino, dir->i_ino, index);
Joern Engel5db53f32009-11-20 20:13:39 +0100358 return d_splice_alias(inode, dentry);
359}
360
361static void grow_dir(struct inode *dir, loff_t index)
362{
363 index = (index + 1) << dir->i_sb->s_blocksize_bits;
364 if (i_size_read(dir) < index)
365 i_size_write(dir, index);
366}
367
368static int logfs_write_dir(struct inode *dir, struct dentry *dentry,
369 struct inode *inode)
370{
371 struct page *page;
372 struct logfs_disk_dentry *dd;
373 u32 hash = hash_32(dentry->d_name.name, dentry->d_name.len, 0);
374 pgoff_t index;
375 int round, err;
376
377 for (round = 0; round < 20; round++) {
378 index = hash_index(hash, round);
379
380 if (logfs_exist_block(dir, index))
381 continue;
382 page = find_or_create_page(dir->i_mapping, index, GFP_KERNEL);
383 if (!page)
384 return -ENOMEM;
385
Cong Wang50bc9b62011-11-25 23:14:31 +0800386 dd = kmap_atomic(page);
Joern Engel5db53f32009-11-20 20:13:39 +0100387 memset(dd, 0, sizeof(*dd));
388 dd->ino = cpu_to_be64(inode->i_ino);
389 dd->type = logfs_type(inode);
390 logfs_set_name(dd, &dentry->d_name);
Cong Wang50bc9b62011-11-25 23:14:31 +0800391 kunmap_atomic(dd);
Joern Engel5db53f32009-11-20 20:13:39 +0100392
393 err = logfs_write_buf(dir, page, WF_LOCK);
394 unlock_page(page);
395 page_cache_release(page);
396 if (!err)
397 grow_dir(dir, index);
398 return err;
399 }
400 /* FIXME: Is there a better return value? In most cases neither
401 * the filesystem nor the directory are full. But we have had
402 * too many collisions for this particular hash and no fallback.
403 */
404 return -ENOSPC;
405}
406
407static int __logfs_create(struct inode *dir, struct dentry *dentry,
408 struct inode *inode, const char *dest, long destlen)
409{
410 struct logfs_super *super = logfs_super(dir->i_sb);
411 struct logfs_inode *li = logfs_inode(inode);
412 struct logfs_transaction *ta;
413 int ret;
414
415 ta = kzalloc(sizeof(*ta), GFP_KERNEL);
Al Viro25624952010-07-04 12:23:11 +0400416 if (!ta) {
Miklos Szeredi6d6b77f2011-10-28 14:13:28 +0200417 drop_nlink(inode);
Al Viro25624952010-07-04 12:23:11 +0400418 iput(inode);
Joern Engel5db53f32009-11-20 20:13:39 +0100419 return -ENOMEM;
Al Viro25624952010-07-04 12:23:11 +0400420 }
Joern Engel5db53f32009-11-20 20:13:39 +0100421
422 ta->state = CREATE_1;
423 ta->ino = inode->i_ino;
424 mutex_lock(&super->s_dirop_mutex);
425 logfs_add_transaction(inode, ta);
426
427 if (dest) {
428 /* symlink */
429 ret = logfs_inode_write(inode, dest, destlen, 0, WF_LOCK, NULL);
430 if (!ret)
431 ret = write_inode(inode);
432 } else {
433 /* creat/mkdir/mknod */
434 ret = write_inode(inode);
435 }
436 if (ret) {
437 abort_transaction(inode, ta);
438 li->li_flags |= LOGFS_IF_STILLBORN;
439 /* FIXME: truncate symlink */
Miklos Szeredi6d6b77f2011-10-28 14:13:28 +0200440 drop_nlink(inode);
Joern Engel5db53f32009-11-20 20:13:39 +0100441 iput(inode);
442 goto out;
443 }
444
445 ta->state = CREATE_2;
446 logfs_add_transaction(dir, ta);
447 ret = logfs_write_dir(dir, dentry, inode);
448 /* sync directory */
449 if (!ret)
450 ret = write_inode(dir);
451
452 if (ret) {
453 logfs_del_transaction(dir, ta);
454 ta->state = CREATE_2;
455 logfs_add_transaction(inode, ta);
456 logfs_remove_inode(inode);
457 iput(inode);
458 goto out;
459 }
460 d_instantiate(dentry, inode);
461out:
462 mutex_unlock(&super->s_dirop_mutex);
463 return ret;
464}
465
Al Viro18bb1db2011-07-26 01:41:39 -0400466static int logfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
Joern Engel5db53f32009-11-20 20:13:39 +0100467{
468 struct inode *inode;
469
470 /*
471 * FIXME: why do we have to fill in S_IFDIR, while the mode is
472 * correct for mknod, creat, etc.? Smells like the vfs *should*
473 * do it for us but for some reason fails to do so.
474 */
475 inode = logfs_new_inode(dir, S_IFDIR | mode);
476 if (IS_ERR(inode))
477 return PTR_ERR(inode);
478
479 inode->i_op = &logfs_dir_iops;
480 inode->i_fop = &logfs_dir_fops;
481
482 return __logfs_create(dir, dentry, inode, NULL, 0);
483}
484
Al Viro4acdaf22011-07-26 01:42:34 -0400485static int logfs_create(struct inode *dir, struct dentry *dentry, umode_t mode,
Al Viroebfc3b42012-06-10 18:05:36 -0400486 bool excl)
Joern Engel5db53f32009-11-20 20:13:39 +0100487{
488 struct inode *inode;
489
490 inode = logfs_new_inode(dir, mode);
491 if (IS_ERR(inode))
492 return PTR_ERR(inode);
493
494 inode->i_op = &logfs_reg_iops;
495 inode->i_fop = &logfs_reg_fops;
496 inode->i_mapping->a_ops = &logfs_reg_aops;
497
498 return __logfs_create(dir, dentry, inode, NULL, 0);
499}
500
Al Viro1a67aaf2011-07-26 01:52:52 -0400501static int logfs_mknod(struct inode *dir, struct dentry *dentry, umode_t mode,
Joern Engel5db53f32009-11-20 20:13:39 +0100502 dev_t rdev)
503{
504 struct inode *inode;
505
506 if (dentry->d_name.len > LOGFS_MAX_NAMELEN)
507 return -ENAMETOOLONG;
508
509 inode = logfs_new_inode(dir, mode);
510 if (IS_ERR(inode))
511 return PTR_ERR(inode);
512
513 init_special_inode(inode, mode, rdev);
514
515 return __logfs_create(dir, dentry, inode, NULL, 0);
516}
517
518static int logfs_symlink(struct inode *dir, struct dentry *dentry,
519 const char *target)
520{
521 struct inode *inode;
522 size_t destlen = strlen(target) + 1;
523
524 if (destlen > dir->i_sb->s_blocksize)
525 return -ENAMETOOLONG;
526
527 inode = logfs_new_inode(dir, S_IFLNK | 0777);
528 if (IS_ERR(inode))
529 return PTR_ERR(inode);
530
531 inode->i_op = &logfs_symlink_iops;
532 inode->i_mapping->a_ops = &logfs_reg_aops;
533
534 return __logfs_create(dir, dentry, inode, target, destlen);
535}
536
Joern Engel5db53f32009-11-20 20:13:39 +0100537static int logfs_link(struct dentry *old_dentry, struct inode *dir,
538 struct dentry *dentry)
539{
540 struct inode *inode = old_dentry->d_inode;
541
Joern Engel5db53f32009-11-20 20:13:39 +0100542 inode->i_ctime = dir->i_ctime = dir->i_mtime = CURRENT_TIME;
Al Viro7de9c6ee2010-10-23 11:11:40 -0400543 ihold(inode);
Miklos Szeredi6d6b77f2011-10-28 14:13:28 +0200544 inc_nlink(inode);
Joern Engel5db53f32009-11-20 20:13:39 +0100545 mark_inode_dirty_sync(inode);
546
547 return __logfs_create(dir, dentry, inode, NULL, 0);
548}
549
550static int logfs_get_dd(struct inode *dir, struct dentry *dentry,
551 struct logfs_disk_dentry *dd, loff_t *pos)
552{
553 struct page *page;
554 void *map;
555
556 page = logfs_get_dd_page(dir, dentry);
557 if (IS_ERR(page))
558 return PTR_ERR(page);
559 *pos = page->index;
Cong Wang50bc9b62011-11-25 23:14:31 +0800560 map = kmap_atomic(page);
Joern Engel5db53f32009-11-20 20:13:39 +0100561 memcpy(dd, map, sizeof(*dd));
Cong Wang50bc9b62011-11-25 23:14:31 +0800562 kunmap_atomic(map);
Joern Engel5db53f32009-11-20 20:13:39 +0100563 page_cache_release(page);
564 return 0;
565}
566
567static int logfs_delete_dd(struct inode *dir, loff_t pos)
568{
569 /*
570 * Getting called with pos somewhere beyond eof is either a goofup
571 * within this file or means someone maliciously edited the
572 * (crc-protected) journal.
573 */
574 BUG_ON(beyond_eof(dir, pos));
575 dir->i_ctime = dir->i_mtime = CURRENT_TIME;
576 log_dir(" Delete dentry (%lx, %llx)\n", dir->i_ino, pos);
577 return logfs_delete(dir, pos, NULL);
578}
579
580/*
581 * Cross-directory rename, target does not exist. Just a little nasty.
582 * Create a new dentry in the target dir, then remove the old dentry,
583 * all the while taking care to remember our operation in the journal.
584 */
585static int logfs_rename_cross(struct inode *old_dir, struct dentry *old_dentry,
586 struct inode *new_dir, struct dentry *new_dentry)
587{
588 struct logfs_super *super = logfs_super(old_dir->i_sb);
589 struct logfs_disk_dentry dd;
590 struct logfs_transaction *ta;
591 loff_t pos;
592 int err;
593
594 /* 1. locate source dd */
595 err = logfs_get_dd(old_dir, old_dentry, &dd, &pos);
596 if (err)
597 return err;
598
599 ta = kzalloc(sizeof(*ta), GFP_KERNEL);
600 if (!ta)
601 return -ENOMEM;
602
603 ta->state = CROSS_RENAME_1;
604 ta->dir = old_dir->i_ino;
605 ta->pos = pos;
606
607 /* 2. write target dd */
608 mutex_lock(&super->s_dirop_mutex);
609 logfs_add_transaction(new_dir, ta);
610 err = logfs_write_dir(new_dir, new_dentry, old_dentry->d_inode);
611 if (!err)
612 err = write_inode(new_dir);
613
614 if (err) {
615 super->s_rename_dir = 0;
616 super->s_rename_pos = 0;
617 abort_transaction(new_dir, ta);
618 goto out;
619 }
620
621 /* 3. remove source dd */
622 ta->state = CROSS_RENAME_2;
623 logfs_add_transaction(old_dir, ta);
624 err = logfs_delete_dd(old_dir, pos);
625 if (!err)
626 err = write_inode(old_dir);
627 LOGFS_BUG_ON(err, old_dir->i_sb);
628out:
629 mutex_unlock(&super->s_dirop_mutex);
630 return err;
631}
632
633static int logfs_replace_inode(struct inode *dir, struct dentry *dentry,
634 struct logfs_disk_dentry *dd, struct inode *inode)
635{
636 loff_t pos;
637 int err;
638
639 err = logfs_get_dd(dir, dentry, dd, &pos);
640 if (err)
641 return err;
642 dd->ino = cpu_to_be64(inode->i_ino);
643 dd->type = logfs_type(inode);
644
645 err = write_dir(dir, dd, pos);
646 if (err)
647 return err;
648 log_dir("Replace dentry (%lx, %llx) %s -> %llx\n", dir->i_ino, pos,
649 dd->name, be64_to_cpu(dd->ino));
650 return write_inode(dir);
651}
652
653/* Target dentry exists - the worst case. We need to attach the source
654 * inode to the target dentry, then remove the orphaned target inode and
655 * source dentry.
656 */
657static int logfs_rename_target(struct inode *old_dir, struct dentry *old_dentry,
658 struct inode *new_dir, struct dentry *new_dentry)
659{
660 struct logfs_super *super = logfs_super(old_dir->i_sb);
661 struct inode *old_inode = old_dentry->d_inode;
662 struct inode *new_inode = new_dentry->d_inode;
663 int isdir = S_ISDIR(old_inode->i_mode);
664 struct logfs_disk_dentry dd;
665 struct logfs_transaction *ta;
666 loff_t pos;
667 int err;
668
669 BUG_ON(isdir != S_ISDIR(new_inode->i_mode));
670 if (isdir) {
671 if (!logfs_empty_dir(new_inode))
672 return -ENOTEMPTY;
673 }
674
675 /* 1. locate source dd */
676 err = logfs_get_dd(old_dir, old_dentry, &dd, &pos);
677 if (err)
678 return err;
679
680 ta = kzalloc(sizeof(*ta), GFP_KERNEL);
681 if (!ta)
682 return -ENOMEM;
683
684 ta->state = TARGET_RENAME_1;
685 ta->dir = old_dir->i_ino;
686 ta->pos = pos;
687 ta->ino = new_inode->i_ino;
688
689 /* 2. attach source inode to target dd */
690 mutex_lock(&super->s_dirop_mutex);
691 logfs_add_transaction(new_dir, ta);
692 err = logfs_replace_inode(new_dir, new_dentry, &dd, old_inode);
693 if (err) {
694 super->s_rename_dir = 0;
695 super->s_rename_pos = 0;
696 super->s_victim_ino = 0;
697 abort_transaction(new_dir, ta);
698 goto out;
699 }
700
701 /* 3. remove source dd */
702 ta->state = TARGET_RENAME_2;
703 logfs_add_transaction(old_dir, ta);
704 err = logfs_delete_dd(old_dir, pos);
705 if (!err)
706 err = write_inode(old_dir);
707 LOGFS_BUG_ON(err, old_dir->i_sb);
708
709 /* 4. remove target inode */
710 ta->state = TARGET_RENAME_3;
711 logfs_add_transaction(new_inode, ta);
712 err = logfs_remove_inode(new_inode);
713
714out:
715 mutex_unlock(&super->s_dirop_mutex);
716 return err;
717}
718
719static int logfs_rename(struct inode *old_dir, struct dentry *old_dentry,
720 struct inode *new_dir, struct dentry *new_dentry)
721{
722 if (new_dentry->d_inode)
723 return logfs_rename_target(old_dir, old_dentry,
724 new_dir, new_dentry);
725 return logfs_rename_cross(old_dir, old_dentry, new_dir, new_dentry);
726}
727
728/* No locking done here, as this is called before .get_sb() returns. */
729int logfs_replay_journal(struct super_block *sb)
730{
731 struct logfs_super *super = logfs_super(sb);
732 struct inode *inode;
733 u64 ino, pos;
734 int err;
735
736 if (super->s_victim_ino) {
737 /* delete victim inode */
738 ino = super->s_victim_ino;
739 printk(KERN_INFO"LogFS: delete unmapped inode #%llx\n", ino);
740 inode = logfs_iget(sb, ino);
741 if (IS_ERR(inode))
742 goto fail;
743
744 LOGFS_BUG_ON(i_size_read(inode) > 0, sb);
745 super->s_victim_ino = 0;
746 err = logfs_remove_inode(inode);
747 iput(inode);
748 if (err) {
749 super->s_victim_ino = ino;
750 goto fail;
751 }
752 }
753 if (super->s_rename_dir) {
754 /* delete old dd from rename */
755 ino = super->s_rename_dir;
756 pos = super->s_rename_pos;
757 printk(KERN_INFO"LogFS: delete unbacked dentry (%llx, %llx)\n",
758 ino, pos);
759 inode = logfs_iget(sb, ino);
760 if (IS_ERR(inode))
761 goto fail;
762
763 super->s_rename_dir = 0;
764 super->s_rename_pos = 0;
765 err = logfs_delete_dd(inode, pos);
766 iput(inode);
767 if (err) {
768 super->s_rename_dir = ino;
769 super->s_rename_pos = pos;
770 goto fail;
771 }
772 }
773 return 0;
774fail:
775 LOGFS_BUG(sb);
776 return -EIO;
777}
778
779const struct inode_operations logfs_symlink_iops = {
780 .readlink = generic_readlink,
781 .follow_link = page_follow_link_light,
782};
783
784const struct inode_operations logfs_dir_iops = {
785 .create = logfs_create,
786 .link = logfs_link,
787 .lookup = logfs_lookup,
788 .mkdir = logfs_mkdir,
789 .mknod = logfs_mknod,
790 .rename = logfs_rename,
791 .rmdir = logfs_rmdir,
Joern Engel5db53f32009-11-20 20:13:39 +0100792 .symlink = logfs_symlink,
793 .unlink = logfs_unlink,
794};
795const struct file_operations logfs_dir_fops = {
796 .fsync = logfs_fsync,
Arnd Bergmann02d6d682010-04-27 22:30:06 +0200797 .unlocked_ioctl = logfs_ioctl,
Al Viro46d07332013-05-17 17:06:34 -0400798 .iterate = logfs_readdir,
Joern Engel5db53f32009-11-20 20:13:39 +0100799 .read = generic_read_dir,
Arnd Bergmann6038f372010-08-15 18:52:59 +0200800 .llseek = default_llseek,
Joern Engel5db53f32009-11-20 20:13:39 +0100801};