diff options
author | Al Viro <viro@zeniv.linux.org.uk> | 2010-03-03 12:58:31 -0500 |
---|---|---|
committer | Al Viro <viro@zeniv.linux.org.uk> | 2010-03-03 12:58:31 -0500 |
commit | 4b1ae27a96d9860e6c4348673e8fb6a0322511fe (patch) | |
tree | d9d195bfef3e8e746ef68adb4364516633d27313 /fs/autofs4/root.c | |
parent | 60b341b778cc2929df16c0a504c91621b3c6a4ad (diff) |
Revert "autofs4: always use lookup for lookup"
This reverts commit 213614d583748d00967a91cacd656f417efb36ce.
Alas, ->d_revalidate() can't rely on ->lookup() finishing what
it's started; if d_alloc() in do_lookup() fails, we are not going
to call ->lookup() at all.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'fs/autofs4/root.c')
-rw-r--r-- | fs/autofs4/root.c | 474 |
1 files changed, 157 insertions, 317 deletions
diff --git a/fs/autofs4/root.c b/fs/autofs4/root.c index 30cc9ddf4b70..a015b49891df 100644 --- a/fs/autofs4/root.c +++ b/fs/autofs4/root.c | |||
@@ -104,99 +104,6 @@ static void autofs4_del_active(struct dentry *dentry) | |||
104 | return; | 104 | return; |
105 | } | 105 | } |
106 | 106 | ||
107 | static void autofs4_add_rehash_entry(struct autofs_info *ino, | ||
108 | struct rehash_entry *entry) | ||
109 | { | ||
110 | entry->task = current; | ||
111 | INIT_LIST_HEAD(&entry->list); | ||
112 | list_add(&entry->list, &ino->rehash_list); | ||
113 | return; | ||
114 | } | ||
115 | |||
116 | static void autofs4_remove_rehash_entry(struct autofs_info *ino) | ||
117 | { | ||
118 | struct list_head *head = &ino->rehash_list; | ||
119 | struct rehash_entry *entry; | ||
120 | list_for_each_entry(entry, head, list) { | ||
121 | if (entry->task == current) { | ||
122 | list_del(&entry->list); | ||
123 | kfree(entry); | ||
124 | break; | ||
125 | } | ||
126 | } | ||
127 | return; | ||
128 | } | ||
129 | |||
130 | static void autofs4_remove_rehash_entrys(struct autofs_info *ino) | ||
131 | { | ||
132 | struct autofs_sb_info *sbi = ino->sbi; | ||
133 | struct rehash_entry *entry, *next; | ||
134 | struct list_head *head; | ||
135 | |||
136 | spin_lock(&sbi->fs_lock); | ||
137 | spin_lock(&sbi->lookup_lock); | ||
138 | if (!(ino->flags & AUTOFS_INF_REHASH)) { | ||
139 | spin_unlock(&sbi->lookup_lock); | ||
140 | spin_unlock(&sbi->fs_lock); | ||
141 | return; | ||
142 | } | ||
143 | ino->flags &= ~AUTOFS_INF_REHASH; | ||
144 | head = &ino->rehash_list; | ||
145 | list_for_each_entry_safe(entry, next, head, list) { | ||
146 | list_del(&entry->list); | ||
147 | kfree(entry); | ||
148 | } | ||
149 | spin_unlock(&sbi->lookup_lock); | ||
150 | spin_unlock(&sbi->fs_lock); | ||
151 | dput(ino->dentry); | ||
152 | |||
153 | return; | ||
154 | } | ||
155 | |||
156 | static void autofs4_revalidate_drop(struct dentry *dentry, | ||
157 | struct rehash_entry *entry) | ||
158 | { | ||
159 | struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); | ||
160 | struct autofs_info *ino = autofs4_dentry_ino(dentry); | ||
161 | /* | ||
162 | * Add to the active list so we can pick this up in | ||
163 | * ->lookup(). Also add an entry to a rehash list so | ||
164 | * we know when there are no dentrys in flight so we | ||
165 | * know when we can rehash the dentry. | ||
166 | */ | ||
167 | spin_lock(&sbi->lookup_lock); | ||
168 | if (list_empty(&ino->active)) | ||
169 | list_add(&ino->active, &sbi->active_list); | ||
170 | autofs4_add_rehash_entry(ino, entry); | ||
171 | spin_unlock(&sbi->lookup_lock); | ||
172 | if (!(ino->flags & AUTOFS_INF_REHASH)) { | ||
173 | ino->flags |= AUTOFS_INF_REHASH; | ||
174 | dget(dentry); | ||
175 | spin_lock(&dentry->d_lock); | ||
176 | __d_drop(dentry); | ||
177 | spin_unlock(&dentry->d_lock); | ||
178 | } | ||
179 | return; | ||
180 | } | ||
181 | |||
182 | static void autofs4_revalidate_rehash(struct dentry *dentry) | ||
183 | { | ||
184 | struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); | ||
185 | struct autofs_info *ino = autofs4_dentry_ino(dentry); | ||
186 | if (ino->flags & AUTOFS_INF_REHASH) { | ||
187 | spin_lock(&sbi->lookup_lock); | ||
188 | autofs4_remove_rehash_entry(ino); | ||
189 | if (list_empty(&ino->rehash_list)) { | ||
190 | spin_unlock(&sbi->lookup_lock); | ||
191 | ino->flags &= ~AUTOFS_INF_REHASH; | ||
192 | d_rehash(dentry); | ||
193 | dput(ino->dentry); | ||
194 | } else | ||
195 | spin_unlock(&sbi->lookup_lock); | ||
196 | } | ||
197 | return; | ||
198 | } | ||
199 | |||
200 | static unsigned int autofs4_need_mount(unsigned int flags) | 107 | static unsigned int autofs4_need_mount(unsigned int flags) |
201 | { | 108 | { |
202 | unsigned int res = 0; | 109 | unsigned int res = 0; |
@@ -236,7 +143,7 @@ out: | |||
236 | return dcache_dir_open(inode, file); | 143 | return dcache_dir_open(inode, file); |
237 | } | 144 | } |
238 | 145 | ||
239 | static int try_to_fill_dentry(struct dentry *dentry) | 146 | static int try_to_fill_dentry(struct dentry *dentry, int flags) |
240 | { | 147 | { |
241 | struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); | 148 | struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); |
242 | struct autofs_info *ino = autofs4_dentry_ino(dentry); | 149 | struct autofs_info *ino = autofs4_dentry_ino(dentry); |
@@ -249,17 +156,55 @@ static int try_to_fill_dentry(struct dentry *dentry) | |||
249 | * Wait for a pending mount, triggering one if there | 156 | * Wait for a pending mount, triggering one if there |
250 | * isn't one already | 157 | * isn't one already |
251 | */ | 158 | */ |
252 | DPRINTK("waiting for mount name=%.*s", | 159 | if (dentry->d_inode == NULL) { |
253 | dentry->d_name.len, dentry->d_name.name); | 160 | DPRINTK("waiting for mount name=%.*s", |
161 | dentry->d_name.len, dentry->d_name.name); | ||
254 | 162 | ||
255 | status = autofs4_wait(sbi, dentry, NFY_MOUNT); | 163 | status = autofs4_wait(sbi, dentry, NFY_MOUNT); |
256 | 164 | ||
257 | DPRINTK("mount done status=%d", status); | 165 | DPRINTK("mount done status=%d", status); |
258 | 166 | ||
259 | /* Update expiry counter */ | 167 | /* Turn this into a real negative dentry? */ |
260 | ino->last_used = jiffies; | 168 | if (status == -ENOENT) { |
169 | spin_lock(&sbi->fs_lock); | ||
170 | ino->flags &= ~AUTOFS_INF_PENDING; | ||
171 | spin_unlock(&sbi->fs_lock); | ||
172 | return status; | ||
173 | } else if (status) { | ||
174 | /* Return a negative dentry, but leave it "pending" */ | ||
175 | return status; | ||
176 | } | ||
177 | /* Trigger mount for path component or follow link */ | ||
178 | } else if (ino->flags & AUTOFS_INF_PENDING || | ||
179 | autofs4_need_mount(flags) || | ||
180 | current->link_count) { | ||
181 | DPRINTK("waiting for mount name=%.*s", | ||
182 | dentry->d_name.len, dentry->d_name.name); | ||
261 | 183 | ||
262 | return status; | 184 | spin_lock(&sbi->fs_lock); |
185 | ino->flags |= AUTOFS_INF_PENDING; | ||
186 | spin_unlock(&sbi->fs_lock); | ||
187 | status = autofs4_wait(sbi, dentry, NFY_MOUNT); | ||
188 | |||
189 | DPRINTK("mount done status=%d", status); | ||
190 | |||
191 | if (status) { | ||
192 | spin_lock(&sbi->fs_lock); | ||
193 | ino->flags &= ~AUTOFS_INF_PENDING; | ||
194 | spin_unlock(&sbi->fs_lock); | ||
195 | return status; | ||
196 | } | ||
197 | } | ||
198 | |||
199 | /* Initialize expiry counter after successful mount */ | ||
200 | if (ino) | ||
201 | ino->last_used = jiffies; | ||
202 | |||
203 | spin_lock(&sbi->fs_lock); | ||
204 | ino->flags &= ~AUTOFS_INF_PENDING; | ||
205 | spin_unlock(&sbi->fs_lock); | ||
206 | |||
207 | return 0; | ||
263 | } | 208 | } |
264 | 209 | ||
265 | /* For autofs direct mounts the follow link triggers the mount */ | 210 | /* For autofs direct mounts the follow link triggers the mount */ |
@@ -313,16 +258,10 @@ static void *autofs4_follow_link(struct dentry *dentry, struct nameidata *nd) | |||
313 | */ | 258 | */ |
314 | if (ino->flags & AUTOFS_INF_PENDING || | 259 | if (ino->flags & AUTOFS_INF_PENDING || |
315 | (!d_mountpoint(dentry) && list_empty(&dentry->d_subdirs))) { | 260 | (!d_mountpoint(dentry) && list_empty(&dentry->d_subdirs))) { |
316 | ino->flags |= AUTOFS_INF_PENDING; | ||
317 | spin_unlock(&dcache_lock); | 261 | spin_unlock(&dcache_lock); |
318 | spin_unlock(&sbi->fs_lock); | 262 | spin_unlock(&sbi->fs_lock); |
319 | 263 | ||
320 | status = try_to_fill_dentry(dentry); | 264 | status = try_to_fill_dentry(dentry, 0); |
321 | |||
322 | spin_lock(&sbi->fs_lock); | ||
323 | ino->flags &= ~AUTOFS_INF_PENDING; | ||
324 | spin_unlock(&sbi->fs_lock); | ||
325 | |||
326 | if (status) | 265 | if (status) |
327 | goto out_error; | 266 | goto out_error; |
328 | 267 | ||
@@ -361,47 +300,18 @@ static int autofs4_revalidate(struct dentry *dentry, struct nameidata *nd) | |||
361 | { | 300 | { |
362 | struct inode *dir = dentry->d_parent->d_inode; | 301 | struct inode *dir = dentry->d_parent->d_inode; |
363 | struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb); | 302 | struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb); |
364 | struct autofs_info *ino = autofs4_dentry_ino(dentry); | 303 | int oz_mode = autofs4_oz_mode(sbi); |
365 | struct rehash_entry *entry; | ||
366 | int flags = nd ? nd->flags : 0; | 304 | int flags = nd ? nd->flags : 0; |
367 | unsigned int mutex_aquired; | 305 | int status = 1; |
368 | 306 | ||
369 | DPRINTK("name = %.*s oz_mode = %d", | ||
370 | dentry->d_name.len, dentry->d_name.name, oz_mode); | ||
371 | |||
372 | /* Daemon never causes a mount to trigger */ | ||
373 | if (autofs4_oz_mode(sbi)) | ||
374 | return 1; | ||
375 | |||
376 | entry = kmalloc(sizeof(struct rehash_entry), GFP_KERNEL); | ||
377 | if (!entry) | ||
378 | return -ENOMEM; | ||
379 | |||
380 | mutex_aquired = mutex_trylock(&dir->i_mutex); | ||
381 | |||
382 | spin_lock(&sbi->fs_lock); | ||
383 | spin_lock(&dcache_lock); | ||
384 | /* Pending dentry */ | 307 | /* Pending dentry */ |
308 | spin_lock(&sbi->fs_lock); | ||
385 | if (autofs4_ispending(dentry)) { | 309 | if (autofs4_ispending(dentry)) { |
386 | int status; | 310 | /* The daemon never causes a mount to trigger */ |
387 | |||
388 | /* | ||
389 | * We can only unhash and send this to ->lookup() if | ||
390 | * the directory mutex is held over d_revalidate() and | ||
391 | * ->lookup(). This prevents the VFS from incorrectly | ||
392 | * seeing the dentry as non-existent. | ||
393 | */ | ||
394 | ino->flags |= AUTOFS_INF_PENDING; | ||
395 | if (!mutex_aquired) { | ||
396 | autofs4_revalidate_drop(dentry, entry); | ||
397 | spin_unlock(&dcache_lock); | ||
398 | spin_unlock(&sbi->fs_lock); | ||
399 | return 0; | ||
400 | } | ||
401 | spin_unlock(&dcache_lock); | ||
402 | spin_unlock(&sbi->fs_lock); | 311 | spin_unlock(&sbi->fs_lock); |
403 | mutex_unlock(&dir->i_mutex); | 312 | |
404 | kfree(entry); | 313 | if (oz_mode) |
314 | return 1; | ||
405 | 315 | ||
406 | /* | 316 | /* |
407 | * If the directory has gone away due to an expire | 317 | * If the directory has gone away due to an expire |
@@ -415,82 +325,45 @@ static int autofs4_revalidate(struct dentry *dentry, struct nameidata *nd) | |||
415 | * A zero status is success otherwise we have a | 325 | * A zero status is success otherwise we have a |
416 | * negative error code. | 326 | * negative error code. |
417 | */ | 327 | */ |
418 | status = try_to_fill_dentry(dentry); | 328 | status = try_to_fill_dentry(dentry, flags); |
419 | |||
420 | spin_lock(&sbi->fs_lock); | ||
421 | ino->flags &= ~AUTOFS_INF_PENDING; | ||
422 | spin_unlock(&sbi->fs_lock); | ||
423 | |||
424 | if (status == 0) | 329 | if (status == 0) |
425 | return 1; | 330 | return 1; |
426 | 331 | ||
427 | return status; | 332 | return status; |
428 | } | 333 | } |
334 | spin_unlock(&sbi->fs_lock); | ||
335 | |||
336 | /* Negative dentry.. invalidate if "old" */ | ||
337 | if (dentry->d_inode == NULL) | ||
338 | return 0; | ||
429 | 339 | ||
430 | /* Check for a non-mountpoint directory with no contents */ | 340 | /* Check for a non-mountpoint directory with no contents */ |
341 | spin_lock(&dcache_lock); | ||
431 | if (S_ISDIR(dentry->d_inode->i_mode) && | 342 | if (S_ISDIR(dentry->d_inode->i_mode) && |
432 | !d_mountpoint(dentry) && list_empty(&dentry->d_subdirs)) { | 343 | !d_mountpoint(dentry) && list_empty(&dentry->d_subdirs)) { |
433 | DPRINTK("dentry=%p %.*s, emptydir", | 344 | DPRINTK("dentry=%p %.*s, emptydir", |
434 | dentry, dentry->d_name.len, dentry->d_name.name); | 345 | dentry, dentry->d_name.len, dentry->d_name.name); |
346 | spin_unlock(&dcache_lock); | ||
435 | 347 | ||
436 | if (autofs4_need_mount(flags) || current->link_count) { | 348 | /* The daemon never causes a mount to trigger */ |
437 | int status; | 349 | if (oz_mode) |
438 | 350 | return 1; | |
439 | /* | ||
440 | * We can only unhash and send this to ->lookup() if | ||
441 | * the directory mutex is held over d_revalidate() and | ||
442 | * ->lookup(). This prevents the VFS from incorrectly | ||
443 | * seeing the dentry as non-existent. | ||
444 | */ | ||
445 | ino->flags |= AUTOFS_INF_PENDING; | ||
446 | if (!mutex_aquired) { | ||
447 | autofs4_revalidate_drop(dentry, entry); | ||
448 | spin_unlock(&dcache_lock); | ||
449 | spin_unlock(&sbi->fs_lock); | ||
450 | return 0; | ||
451 | } | ||
452 | spin_unlock(&dcache_lock); | ||
453 | spin_unlock(&sbi->fs_lock); | ||
454 | mutex_unlock(&dir->i_mutex); | ||
455 | kfree(entry); | ||
456 | |||
457 | /* | ||
458 | * A zero status is success otherwise we have a | ||
459 | * negative error code. | ||
460 | */ | ||
461 | status = try_to_fill_dentry(dentry); | ||
462 | |||
463 | spin_lock(&sbi->fs_lock); | ||
464 | ino->flags &= ~AUTOFS_INF_PENDING; | ||
465 | spin_unlock(&sbi->fs_lock); | ||
466 | 351 | ||
467 | if (status == 0) | 352 | /* |
468 | return 1; | 353 | * A zero status is success otherwise we have a |
354 | * negative error code. | ||
355 | */ | ||
356 | status = try_to_fill_dentry(dentry, flags); | ||
357 | if (status == 0) | ||
358 | return 1; | ||
469 | 359 | ||
470 | return status; | 360 | return status; |
471 | } | ||
472 | } | 361 | } |
473 | spin_unlock(&dcache_lock); | 362 | spin_unlock(&dcache_lock); |
474 | spin_unlock(&sbi->fs_lock); | ||
475 | |||
476 | if (mutex_aquired) | ||
477 | mutex_unlock(&dir->i_mutex); | ||
478 | |||
479 | kfree(entry); | ||
480 | 363 | ||
481 | return 1; | 364 | return 1; |
482 | } | 365 | } |
483 | 366 | ||
484 | static void autofs4_free_rehash_entrys(struct autofs_info *inf) | ||
485 | { | ||
486 | struct list_head *head = &inf->rehash_list; | ||
487 | struct rehash_entry *entry, *next; | ||
488 | list_for_each_entry_safe(entry, next, head, list) { | ||
489 | list_del(&entry->list); | ||
490 | kfree(entry); | ||
491 | } | ||
492 | } | ||
493 | |||
494 | void autofs4_dentry_release(struct dentry *de) | 367 | void autofs4_dentry_release(struct dentry *de) |
495 | { | 368 | { |
496 | struct autofs_info *inf; | 369 | struct autofs_info *inf; |
@@ -509,8 +382,6 @@ void autofs4_dentry_release(struct dentry *de) | |||
509 | list_del(&inf->active); | 382 | list_del(&inf->active); |
510 | if (!list_empty(&inf->expiring)) | 383 | if (!list_empty(&inf->expiring)) |
511 | list_del(&inf->expiring); | 384 | list_del(&inf->expiring); |
512 | if (!list_empty(&inf->rehash_list)) | ||
513 | autofs4_free_rehash_entrys(inf); | ||
514 | spin_unlock(&sbi->lookup_lock); | 385 | spin_unlock(&sbi->lookup_lock); |
515 | } | 386 | } |
516 | 387 | ||
@@ -543,7 +414,6 @@ static struct dentry *autofs4_lookup_active(struct dentry *dentry) | |||
543 | const unsigned char *str = name->name; | 414 | const unsigned char *str = name->name; |
544 | struct list_head *p, *head; | 415 | struct list_head *p, *head; |
545 | 416 | ||
546 | restart: | ||
547 | spin_lock(&dcache_lock); | 417 | spin_lock(&dcache_lock); |
548 | spin_lock(&sbi->lookup_lock); | 418 | spin_lock(&sbi->lookup_lock); |
549 | head = &sbi->active_list; | 419 | head = &sbi->active_list; |
@@ -561,19 +431,6 @@ restart: | |||
561 | if (atomic_read(&active->d_count) == 0) | 431 | if (atomic_read(&active->d_count) == 0) |
562 | goto next; | 432 | goto next; |
563 | 433 | ||
564 | if (active->d_inode && IS_DEADDIR(active->d_inode)) { | ||
565 | if (!list_empty(&ino->rehash_list)) { | ||
566 | dget(active); | ||
567 | spin_unlock(&active->d_lock); | ||
568 | spin_unlock(&sbi->lookup_lock); | ||
569 | spin_unlock(&dcache_lock); | ||
570 | autofs4_remove_rehash_entrys(ino); | ||
571 | dput(active); | ||
572 | goto restart; | ||
573 | } | ||
574 | goto next; | ||
575 | } | ||
576 | |||
577 | qstr = &active->d_name; | 434 | qstr = &active->d_name; |
578 | 435 | ||
579 | if (active->d_name.hash != hash) | 436 | if (active->d_name.hash != hash) |
@@ -586,11 +443,13 @@ restart: | |||
586 | if (memcmp(qstr->name, str, len)) | 443 | if (memcmp(qstr->name, str, len)) |
587 | goto next; | 444 | goto next; |
588 | 445 | ||
589 | dget(active); | 446 | if (d_unhashed(active)) { |
590 | spin_unlock(&active->d_lock); | 447 | dget(active); |
591 | spin_unlock(&sbi->lookup_lock); | 448 | spin_unlock(&active->d_lock); |
592 | spin_unlock(&dcache_lock); | 449 | spin_unlock(&sbi->lookup_lock); |
593 | return active; | 450 | spin_unlock(&dcache_lock); |
451 | return active; | ||
452 | } | ||
594 | next: | 453 | next: |
595 | spin_unlock(&active->d_lock); | 454 | spin_unlock(&active->d_lock); |
596 | } | 455 | } |
@@ -639,11 +498,13 @@ static struct dentry *autofs4_lookup_expiring(struct dentry *dentry) | |||
639 | if (memcmp(qstr->name, str, len)) | 498 | if (memcmp(qstr->name, str, len)) |
640 | goto next; | 499 | goto next; |
641 | 500 | ||
642 | dget(expiring); | 501 | if (d_unhashed(expiring)) { |
643 | spin_unlock(&expiring->d_lock); | 502 | dget(expiring); |
644 | spin_unlock(&sbi->lookup_lock); | 503 | spin_unlock(&expiring->d_lock); |
645 | spin_unlock(&dcache_lock); | 504 | spin_unlock(&sbi->lookup_lock); |
646 | return expiring; | 505 | spin_unlock(&dcache_lock); |
506 | return expiring; | ||
507 | } | ||
647 | next: | 508 | next: |
648 | spin_unlock(&expiring->d_lock); | 509 | spin_unlock(&expiring->d_lock); |
649 | } | 510 | } |
@@ -653,48 +514,6 @@ next: | |||
653 | return NULL; | 514 | return NULL; |
654 | } | 515 | } |
655 | 516 | ||
656 | static struct autofs_info *init_new_dentry(struct autofs_sb_info *sbi, | ||
657 | struct dentry *dentry, int oz_mode) | ||
658 | { | ||
659 | struct autofs_info *ino; | ||
660 | |||
661 | /* | ||
662 | * Mark the dentry incomplete but don't hash it. We do this | ||
663 | * to serialize our inode creation operations (symlink and | ||
664 | * mkdir) which prevents deadlock during the callback to | ||
665 | * the daemon. Subsequent user space lookups for the same | ||
666 | * dentry are placed on the wait queue while the daemon | ||
667 | * itself is allowed passage unresticted so the create | ||
668 | * operation itself can then hash the dentry. Finally, | ||
669 | * we check for the hashed dentry and return the newly | ||
670 | * hashed dentry. | ||
671 | */ | ||
672 | dentry->d_op = &autofs4_root_dentry_operations; | ||
673 | |||
674 | /* | ||
675 | * And we need to ensure that the same dentry is used for | ||
676 | * all following lookup calls until it is hashed so that | ||
677 | * the dentry flags are persistent throughout the request. | ||
678 | */ | ||
679 | ino = autofs4_init_ino(NULL, sbi, 0555); | ||
680 | if (!ino) | ||
681 | return ERR_PTR(-ENOMEM); | ||
682 | |||
683 | dentry->d_fsdata = ino; | ||
684 | ino->dentry = dentry; | ||
685 | |||
686 | /* | ||
687 | * Only set the mount pending flag for new dentrys not created | ||
688 | * by the daemon. | ||
689 | */ | ||
690 | if (!oz_mode) | ||
691 | ino->flags |= AUTOFS_INF_PENDING; | ||
692 | |||
693 | d_instantiate(dentry, NULL); | ||
694 | |||
695 | return ino; | ||
696 | } | ||
697 | |||
698 | /* Lookups in the root directory */ | 517 | /* Lookups in the root directory */ |
699 | static struct dentry *autofs4_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd) | 518 | static struct dentry *autofs4_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd) |
700 | { | 519 | { |
@@ -702,7 +521,6 @@ static struct dentry *autofs4_lookup(struct inode *dir, struct dentry *dentry, s | |||
702 | struct autofs_info *ino; | 521 | struct autofs_info *ino; |
703 | struct dentry *expiring, *active; | 522 | struct dentry *expiring, *active; |
704 | int oz_mode; | 523 | int oz_mode; |
705 | int status = 0; | ||
706 | 524 | ||
707 | DPRINTK("name = %.*s", | 525 | DPRINTK("name = %.*s", |
708 | dentry->d_name.len, dentry->d_name.name); | 526 | dentry->d_name.len, dentry->d_name.name); |
@@ -717,26 +535,44 @@ static struct dentry *autofs4_lookup(struct inode *dir, struct dentry *dentry, s | |||
717 | DPRINTK("pid = %u, pgrp = %u, catatonic = %d, oz_mode = %d", | 535 | DPRINTK("pid = %u, pgrp = %u, catatonic = %d, oz_mode = %d", |
718 | current->pid, task_pgrp_nr(current), sbi->catatonic, oz_mode); | 536 | current->pid, task_pgrp_nr(current), sbi->catatonic, oz_mode); |
719 | 537 | ||
720 | spin_lock(&sbi->fs_lock); | ||
721 | active = autofs4_lookup_active(dentry); | 538 | active = autofs4_lookup_active(dentry); |
722 | if (active) { | 539 | if (active) { |
723 | dentry = active; | 540 | dentry = active; |
724 | ino = autofs4_dentry_ino(dentry); | 541 | ino = autofs4_dentry_ino(dentry); |
725 | /* If this came from revalidate, rehash it */ | ||
726 | autofs4_revalidate_rehash(dentry); | ||
727 | spin_unlock(&sbi->fs_lock); | ||
728 | } else { | 542 | } else { |
729 | spin_unlock(&sbi->fs_lock); | 543 | /* |
730 | ino = init_new_dentry(sbi, dentry, oz_mode); | 544 | * Mark the dentry incomplete but don't hash it. We do this |
731 | if (IS_ERR(ino)) | 545 | * to serialize our inode creation operations (symlink and |
732 | return (struct dentry *) ino; | 546 | * mkdir) which prevents deadlock during the callback to |
733 | } | 547 | * the daemon. Subsequent user space lookups for the same |
548 | * dentry are placed on the wait queue while the daemon | ||
549 | * itself is allowed passage unresticted so the create | ||
550 | * operation itself can then hash the dentry. Finally, | ||
551 | * we check for the hashed dentry and return the newly | ||
552 | * hashed dentry. | ||
553 | */ | ||
554 | dentry->d_op = &autofs4_root_dentry_operations; | ||
555 | |||
556 | /* | ||
557 | * And we need to ensure that the same dentry is used for | ||
558 | * all following lookup calls until it is hashed so that | ||
559 | * the dentry flags are persistent throughout the request. | ||
560 | */ | ||
561 | ino = autofs4_init_ino(NULL, sbi, 0555); | ||
562 | if (!ino) | ||
563 | return ERR_PTR(-ENOMEM); | ||
734 | 564 | ||
735 | autofs4_add_active(dentry); | 565 | dentry->d_fsdata = ino; |
566 | ino->dentry = dentry; | ||
567 | |||
568 | autofs4_add_active(dentry); | ||
569 | |||
570 | d_instantiate(dentry, NULL); | ||
571 | } | ||
736 | 572 | ||
737 | if (!oz_mode) { | 573 | if (!oz_mode) { |
738 | expiring = autofs4_lookup_expiring(dentry); | ||
739 | mutex_unlock(&dir->i_mutex); | 574 | mutex_unlock(&dir->i_mutex); |
575 | expiring = autofs4_lookup_expiring(dentry); | ||
740 | if (expiring) { | 576 | if (expiring) { |
741 | /* | 577 | /* |
742 | * If we are racing with expire the request might not | 578 | * If we are racing with expire the request might not |
@@ -744,22 +580,23 @@ static struct dentry *autofs4_lookup(struct inode *dir, struct dentry *dentry, s | |||
744 | * so it must have been successful, so just wait for it. | 580 | * so it must have been successful, so just wait for it. |
745 | */ | 581 | */ |
746 | autofs4_expire_wait(expiring); | 582 | autofs4_expire_wait(expiring); |
583 | autofs4_del_expiring(expiring); | ||
747 | dput(expiring); | 584 | dput(expiring); |
748 | } | 585 | } |
749 | status = try_to_fill_dentry(dentry); | 586 | |
750 | mutex_lock(&dir->i_mutex); | ||
751 | spin_lock(&sbi->fs_lock); | 587 | spin_lock(&sbi->fs_lock); |
752 | ino->flags &= ~AUTOFS_INF_PENDING; | 588 | ino->flags |= AUTOFS_INF_PENDING; |
753 | spin_unlock(&sbi->fs_lock); | 589 | spin_unlock(&sbi->fs_lock); |
590 | if (dentry->d_op && dentry->d_op->d_revalidate) | ||
591 | (dentry->d_op->d_revalidate)(dentry, nd); | ||
592 | mutex_lock(&dir->i_mutex); | ||
754 | } | 593 | } |
755 | 594 | ||
756 | autofs4_del_active(dentry); | ||
757 | |||
758 | /* | 595 | /* |
759 | * If we had a mount fail, check if we had to handle | 596 | * If we are still pending, check if we had to handle |
760 | * a signal. If so we can force a restart.. | 597 | * a signal. If so we can force a restart.. |
761 | */ | 598 | */ |
762 | if (status) { | 599 | if (ino->flags & AUTOFS_INF_PENDING) { |
763 | /* See if we were interrupted */ | 600 | /* See if we were interrupted */ |
764 | if (signal_pending(current)) { | 601 | if (signal_pending(current)) { |
765 | sigset_t *sigset = ¤t->pending.signal; | 602 | sigset_t *sigset = ¤t->pending.signal; |
@@ -771,46 +608,43 @@ static struct dentry *autofs4_lookup(struct inode *dir, struct dentry *dentry, s | |||
771 | return ERR_PTR(-ERESTARTNOINTR); | 608 | return ERR_PTR(-ERESTARTNOINTR); |
772 | } | 609 | } |
773 | } | 610 | } |
774 | } | 611 | if (!oz_mode) { |
775 | 612 | spin_lock(&sbi->fs_lock); | |
776 | /* | 613 | ino->flags &= ~AUTOFS_INF_PENDING; |
777 | * User space can (and has done in the past) remove and re-create | 614 | spin_unlock(&sbi->fs_lock); |
778 | * this directory during the callback. This can leave us with an | ||
779 | * unhashed dentry, but a successful mount! So we need to | ||
780 | * perform another cached lookup in case the dentry now exists. | ||
781 | */ | ||
782 | if (!oz_mode && !have_submounts(dentry)) { | ||
783 | struct dentry *new; | ||
784 | new = d_lookup(dentry->d_parent, &dentry->d_name); | ||
785 | if (new) { | ||
786 | if (active) | ||
787 | dput(active); | ||
788 | return new; | ||
789 | } else { | ||
790 | if (!status) | ||
791 | status = -ENOENT; | ||
792 | } | 615 | } |
793 | } | 616 | } |
794 | 617 | ||
795 | /* | 618 | /* |
796 | * If we had a mount failure, return status to user space. | 619 | * If this dentry is unhashed, then we shouldn't honour this |
797 | * If the mount succeeded and we used a dentry from the active queue | 620 | * lookup. Returning ENOENT here doesn't do the right thing |
798 | * return it. | 621 | * for all system calls, but it should be OK for the operations |
622 | * we permit from an autofs. | ||
799 | */ | 623 | */ |
800 | if (status) { | 624 | if (!oz_mode && d_unhashed(dentry)) { |
801 | dentry = ERR_PTR(status); | ||
802 | if (active) | ||
803 | dput(active); | ||
804 | return dentry; | ||
805 | } else { | ||
806 | /* | 625 | /* |
807 | * Valid successful mount, return active dentry or NULL | 626 | * A user space application can (and has done in the past) |
808 | * for a new dentry. | 627 | * remove and re-create this directory during the callback. |
628 | * This can leave us with an unhashed dentry, but a | ||
629 | * successful mount! So we need to perform another | ||
630 | * cached lookup in case the dentry now exists. | ||
809 | */ | 631 | */ |
632 | struct dentry *parent = dentry->d_parent; | ||
633 | struct dentry *new = d_lookup(parent, &dentry->d_name); | ||
634 | if (new != NULL) | ||
635 | dentry = new; | ||
636 | else | ||
637 | dentry = ERR_PTR(-ENOENT); | ||
638 | |||
810 | if (active) | 639 | if (active) |
811 | return active; | 640 | dput(active); |
641 | |||
642 | return dentry; | ||
812 | } | 643 | } |
813 | 644 | ||
645 | if (active) | ||
646 | return active; | ||
647 | |||
814 | return NULL; | 648 | return NULL; |
815 | } | 649 | } |
816 | 650 | ||
@@ -834,6 +668,8 @@ static int autofs4_dir_symlink(struct inode *dir, | |||
834 | if (!ino) | 668 | if (!ino) |
835 | return -ENOMEM; | 669 | return -ENOMEM; |
836 | 670 | ||
671 | autofs4_del_active(dentry); | ||
672 | |||
837 | ino->size = strlen(symname); | 673 | ino->size = strlen(symname); |
838 | cp = kmalloc(ino->size + 1, GFP_KERNEL); | 674 | cp = kmalloc(ino->size + 1, GFP_KERNEL); |
839 | if (!cp) { | 675 | if (!cp) { |
@@ -910,6 +746,7 @@ static int autofs4_dir_unlink(struct inode *dir, struct dentry *dentry) | |||
910 | dir->i_mtime = CURRENT_TIME; | 746 | dir->i_mtime = CURRENT_TIME; |
911 | 747 | ||
912 | spin_lock(&dcache_lock); | 748 | spin_lock(&dcache_lock); |
749 | autofs4_add_expiring(dentry); | ||
913 | spin_lock(&dentry->d_lock); | 750 | spin_lock(&dentry->d_lock); |
914 | __d_drop(dentry); | 751 | __d_drop(dentry); |
915 | spin_unlock(&dentry->d_lock); | 752 | spin_unlock(&dentry->d_lock); |
@@ -935,6 +772,7 @@ static int autofs4_dir_rmdir(struct inode *dir, struct dentry *dentry) | |||
935 | spin_unlock(&dcache_lock); | 772 | spin_unlock(&dcache_lock); |
936 | return -ENOTEMPTY; | 773 | return -ENOTEMPTY; |
937 | } | 774 | } |
775 | autofs4_add_expiring(dentry); | ||
938 | spin_lock(&dentry->d_lock); | 776 | spin_lock(&dentry->d_lock); |
939 | __d_drop(dentry); | 777 | __d_drop(dentry); |
940 | spin_unlock(&dentry->d_lock); | 778 | spin_unlock(&dentry->d_lock); |
@@ -972,6 +810,8 @@ static int autofs4_dir_mkdir(struct inode *dir, struct dentry *dentry, int mode) | |||
972 | if (!ino) | 810 | if (!ino) |
973 | return -ENOMEM; | 811 | return -ENOMEM; |
974 | 812 | ||
813 | autofs4_del_active(dentry); | ||
814 | |||
975 | inode = autofs4_get_inode(dir->i_sb, ino); | 815 | inode = autofs4_get_inode(dir->i_sb, ino); |
976 | if (!inode) { | 816 | if (!inode) { |
977 | if (!dentry->d_fsdata) | 817 | if (!dentry->d_fsdata) |