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1/*
2 * 2007+ Copyright (c) Evgeniy Polyakov <zbr@ioremap.net>
3 * All rights reserved.
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 */
15
16#include <linux/kernel.h>
17#include <linux/fs.h>
18#include <linux/jhash.h>
19#include <linux/namei.h>
20#include <linux/slab.h>
21#include <linux/pagemap.h>
22
23#include "netfs.h"
24
25static int pohmelfs_cmp_hash(struct pohmelfs_name *n, u32 hash)
26{
27 if (n->hash > hash)
28 return -1;
29 if (n->hash < hash)
30 return 1;
31
32 return 0;
33}
34
35static struct pohmelfs_name *pohmelfs_search_hash_unprecise(struct pohmelfs_inode *pi, u32 hash)
36{
37 struct rb_node *n = pi->hash_root.rb_node;
38 struct pohmelfs_name *tmp = NULL;
39 int cmp;
40
41 while (n) {
42 tmp = rb_entry(n, struct pohmelfs_name, hash_node);
43
44 cmp = pohmelfs_cmp_hash(tmp, hash);
45 if (cmp < 0)
46 n = n->rb_left;
47 else if (cmp > 0)
48 n = n->rb_right;
49 else
50 break;
51
52 }
53
54 return tmp;
55}
56
57struct pohmelfs_name *pohmelfs_search_hash(struct pohmelfs_inode *pi, u32 hash)
58{
59 struct pohmelfs_name *tmp;
60
61 tmp = pohmelfs_search_hash_unprecise(pi, hash);
62 if (tmp && (tmp->hash == hash))
63 return tmp;
64
65 return NULL;
66}
67
68static void __pohmelfs_name_del(struct pohmelfs_inode *parent, struct pohmelfs_name *node)
69{
70 rb_erase(&node->hash_node, &parent->hash_root);
71}
72
73/*
74 * Remove name cache entry from its caches and free it.
75 */
76static void pohmelfs_name_free(struct pohmelfs_inode *parent, struct pohmelfs_name *node)
77{
78 __pohmelfs_name_del(parent, node);
79 list_del(&node->sync_create_entry);
80 kfree(node);
81}
82
83static struct pohmelfs_name *pohmelfs_insert_hash(struct pohmelfs_inode *pi,
84 struct pohmelfs_name *new)
85{
86 struct rb_node **n = &pi->hash_root.rb_node, *parent = NULL;
87 struct pohmelfs_name *ret = NULL, *tmp;
88 int cmp;
89
90 while (*n) {
91 parent = *n;
92
93 tmp = rb_entry(parent, struct pohmelfs_name, hash_node);
94
95 cmp = pohmelfs_cmp_hash(tmp, new->hash);
96 if (cmp < 0)
97 n = &parent->rb_left;
98 else if (cmp > 0)
99 n = &parent->rb_right;
100 else {
101 ret = tmp;
102 break;
103 }
104 }
105
106 if (ret) {
107 printk("%s: exist: parent: %llu, ino: %llu, hash: %x, len: %u, data: '%s', "
108 "new: ino: %llu, hash: %x, len: %u, data: '%s'.\n",
109 __func__, pi->ino,
110 ret->ino, ret->hash, ret->len, ret->data,
111 new->ino, new->hash, new->len, new->data);
112 ret->ino = new->ino;
113 return ret;
114 }
115
116 rb_link_node(&new->hash_node, parent, n);
117 rb_insert_color(&new->hash_node, &pi->hash_root);
118
119 return NULL;
120}
121
122/*
123 * Free name cache for given inode.
124 */
125void pohmelfs_free_names(struct pohmelfs_inode *parent)
126{
127 struct rb_node *rb_node;
128 struct pohmelfs_name *n;
129
130 for (rb_node = rb_first(&parent->hash_root); rb_node;) {
131 n = rb_entry(rb_node, struct pohmelfs_name, hash_node);
132 rb_node = rb_next(rb_node);
133
134 pohmelfs_name_free(parent, n);
135 }
136}
137
138static void pohmelfs_fix_offset(struct pohmelfs_inode *parent, struct pohmelfs_name *node)
139{
140 parent->total_len -= node->len;
141}
142
143/*
144 * Free name cache entry helper.
145 */
146void pohmelfs_name_del(struct pohmelfs_inode *parent, struct pohmelfs_name *node)
147{
148 pohmelfs_fix_offset(parent, node);
149 pohmelfs_name_free(parent, node);
150}
151
152/*
153 * Insert new name cache entry into all hash cache.
154 */
155static int pohmelfs_insert_name(struct pohmelfs_inode *parent, struct pohmelfs_name *n)
156{
157 struct pohmelfs_name *name;
158
159 name = pohmelfs_insert_hash(parent, n);
160 if (name)
161 return -EEXIST;
162
163 parent->total_len += n->len;
164 list_add_tail(&n->sync_create_entry, &parent->sync_create_list);
165
166 return 0;
167}
168
169/*
170 * Allocate new name cache entry.
171 */
172static struct pohmelfs_name *pohmelfs_name_alloc(unsigned int len)
173{
174 struct pohmelfs_name *n;
175
176 n = kzalloc(sizeof(struct pohmelfs_name) + len, GFP_KERNEL);
177 if (!n)
178 return NULL;
179
180 INIT_LIST_HEAD(&n->sync_create_entry);
181
182 n->data = (char *)(n+1);
183
184 return n;
185}
186
187/*
188 * Add new name entry into directory's cache.
189 */
190static int pohmelfs_add_dir(struct pohmelfs_sb *psb, struct pohmelfs_inode *parent,
191 struct pohmelfs_inode *npi, struct qstr *str, unsigned int mode, int link)
192{
193 int err = -ENOMEM;
194 struct pohmelfs_name *n;
195
196 n = pohmelfs_name_alloc(str->len + 1);
197 if (!n)
198 goto err_out_exit;
199
200 n->ino = npi->ino;
201 n->mode = mode;
202 n->len = str->len;
203 n->hash = str->hash;
204 sprintf(n->data, "%s", str->name);
205
206 mutex_lock(&parent->offset_lock);
207 err = pohmelfs_insert_name(parent, n);
208 mutex_unlock(&parent->offset_lock);
209
210 if (err) {
211 if (err != -EEXIST)
212 goto err_out_free;
213 kfree(n);
214 }
215
216 return 0;
217
218err_out_free:
219 kfree(n);
220err_out_exit:
221 return err;
222}
223
224/*
225 * Create new inode for given parameters (name, inode info, parent).
226 * This does not create object on the server, it will be synced there during writeback.
227 */
228struct pohmelfs_inode *pohmelfs_new_inode(struct pohmelfs_sb *psb,
229 struct pohmelfs_inode *parent, struct qstr *str,
230 struct netfs_inode_info *info, int link)
231{
232 struct inode *new = NULL;
233 struct pohmelfs_inode *npi;
234 int err = -EEXIST;
235
236 dprintk("%s: creating inode: parent: %llu, ino: %llu, str: %p.\n",
237 __func__, (parent) ? parent->ino : 0, info->ino, str);
238
239 err = -ENOMEM;
240 new = iget_locked(psb->sb, info->ino);
241 if (!new)
242 goto err_out_exit;
243
244 npi = POHMELFS_I(new);
245 npi->ino = info->ino;
246 err = 0;
247
248 if (new->i_state & I_NEW) {
249 dprintk("%s: filling VFS inode: %lu/%llu.\n",
250 __func__, new->i_ino, info->ino);
251 pohmelfs_fill_inode(new, info);
252
253 if (S_ISDIR(info->mode)) {
254 struct qstr s;
255
256 s.name = ".";
257 s.len = 1;
258 s.hash = jhash(s.name, s.len, 0);
259
260 err = pohmelfs_add_dir(psb, npi, npi, &s, info->mode, 0);
261 if (err)
262 goto err_out_put;
263
264 s.name = "..";
265 s.len = 2;
266 s.hash = jhash(s.name, s.len, 0);
267
268 err = pohmelfs_add_dir(psb, npi, (parent) ? parent : npi, &s,
269 (parent) ? parent->vfs_inode.i_mode : npi->vfs_inode.i_mode, 0);
270 if (err)
271 goto err_out_put;
272 }
273 }
274
275 if (str) {
276 if (parent) {
277 err = pohmelfs_add_dir(psb, parent, npi, str, info->mode, link);
278
279 dprintk("%s: %s inserted name: '%s', new_offset: %llu, ino: %llu, parent: %llu.\n",
280 __func__, (err) ? "unsuccessfully" : "successfully",
281 str->name, parent->total_len, info->ino, parent->ino);
282
283 if (err && err != -EEXIST)
284 goto err_out_put;
285 }
286 }
287
288 if (new->i_state & I_NEW) {
289 if (parent)
290 mark_inode_dirty(&parent->vfs_inode);
291 mark_inode_dirty(new);
292 }
293
294 set_bit(NETFS_INODE_OWNED, &npi->state);
295 npi->lock_type = POHMELFS_WRITE_LOCK;
296 unlock_new_inode(new);
297
298 return npi;
299
300err_out_put:
301 printk("%s: putting inode: %p, npi: %p, error: %d.\n", __func__, new, npi, err);
302 iput(new);
303err_out_exit:
304 return ERR_PTR(err);
305}
306
307static int pohmelfs_remote_sync_complete(struct page **pages, unsigned int page_num,
308 void *private, int err)
309{
310 struct pohmelfs_inode *pi = private;
311 struct pohmelfs_sb *psb = POHMELFS_SB(pi->vfs_inode.i_sb);
312
313 dprintk("%s: ino: %llu, err: %d.\n", __func__, pi->ino, err);
314
315 if (err)
316 pi->error = err;
317 wake_up(&psb->wait);
318 pohmelfs_put_inode(pi);
319
320 return err;
321}
322
323/*
324 * Receive directory content from the server.
325 * This should be only done for objects, which were not created locally,
326 * and which were not synced previously.
327 */
328static int pohmelfs_sync_remote_dir(struct pohmelfs_inode *pi)
329{
330 struct inode *inode = &pi->vfs_inode;
331 struct pohmelfs_sb *psb = POHMELFS_SB(inode->i_sb);
332 long ret = psb->wait_on_page_timeout;
333 int err;
334
335 dprintk("%s: dir: %llu, state: %lx: remote_synced: %d.\n",
336 __func__, pi->ino, pi->state, test_bit(NETFS_INODE_REMOTE_SYNCED, &pi->state));
337
338 if (test_bit(NETFS_INODE_REMOTE_DIR_SYNCED, &pi->state))
339 return 0;
340
341 if (!igrab(inode)) {
342 err = -ENOENT;
343 goto err_out_exit;
344 }
345
346 err = pohmelfs_meta_command(pi, NETFS_READDIR, NETFS_TRANS_SINGLE_DST,
347 pohmelfs_remote_sync_complete, pi, 0);
348 if (err)
349 goto err_out_exit;
350
351 pi->error = 0;
352 ret = wait_event_interruptible_timeout(psb->wait,
353 test_bit(NETFS_INODE_REMOTE_DIR_SYNCED, &pi->state) || pi->error, ret);
354 dprintk("%s: awake dir: %llu, ret: %ld, err: %d.\n", __func__, pi->ino, ret, pi->error);
355 if (ret <= 0) {
356 err = ret;
357 if (!err)
358 err = -ETIMEDOUT;
359 goto err_out_exit;
360 }
361
362 if (pi->error)
363 return pi->error;
364
365 return 0;
366
367err_out_exit:
368 clear_bit(NETFS_INODE_REMOTE_SYNCED, &pi->state);
369
370 return err;
371}
372
373static int pohmelfs_dir_open(struct inode *inode, struct file *file)
374{
375 file->private_data = NULL;
376 return 0;
377}
378
379/*
380 * VFS readdir callback. Syncs directory content from server if needed,
381 * and provides direntry info to the userspace.
382 */
383static int pohmelfs_readdir(struct file *file, void *dirent, filldir_t filldir)
384{
385 struct inode *inode = file->f_path.dentry->d_inode;
386 struct pohmelfs_inode *pi = POHMELFS_I(inode);
387 struct pohmelfs_name *n;
388 struct rb_node *rb_node;
389 int err = 0, mode;
390 u64 len;
391
392 dprintk("%s: parent: %llu, fpos: %llu, hash: %08lx.\n",
393 __func__, pi->ino, (u64)file->f_pos,
394 (unsigned long)file->private_data);
395#if 0
396 err = pohmelfs_data_lock(pi, 0, ~0, POHMELFS_READ_LOCK);
397 if (err)
398 return err;
399#endif
400 err = pohmelfs_sync_remote_dir(pi);
401 if (err)
402 return err;
403
404 if (file->private_data && (file->private_data == (void *)(unsigned long)file->f_pos))
405 return 0;
406
407 mutex_lock(&pi->offset_lock);
408 n = pohmelfs_search_hash_unprecise(pi, (unsigned long)file->private_data);
409
410 while (n) {
411 mode = (n->mode >> 12) & 15;
412
413 dprintk("%s: offset: %llu, parent ino: %llu, name: '%s', len: %u, ino: %llu, "
414 "mode: %o/%o, fpos: %llu, hash: %08x.\n",
415 __func__, file->f_pos, pi->ino, n->data, n->len,
416 n->ino, n->mode, mode, file->f_pos, n->hash);
417
418 file->private_data = (void *)(unsigned long)n->hash;
419
420 len = n->len;
421 err = filldir(dirent, n->data, n->len, file->f_pos, n->ino, mode);
422
423 if (err < 0) {
424 dprintk("%s: err: %d.\n", __func__, err);
425 err = 0;
426 break;
427 }
428
429 file->f_pos += len;
430
431 rb_node = rb_next(&n->hash_node);
432
433 if (!rb_node || (rb_node == &n->hash_node)) {
434 file->private_data = (void *)(unsigned long)file->f_pos;
435 break;
436 }
437
438 n = rb_entry(rb_node, struct pohmelfs_name, hash_node);
439 }
440 mutex_unlock(&pi->offset_lock);
441
442 return err;
443}
444
445static loff_t pohmelfs_dir_lseek(struct file *file, loff_t offset, int origin)
446{
447 file->f_pos = offset;
448 file->private_data = NULL;
449 return offset;
450}
451
452const struct file_operations pohmelfs_dir_fops = {
453 .open = pohmelfs_dir_open,
454 .read = generic_read_dir,
455 .llseek = pohmelfs_dir_lseek,
456 .readdir = pohmelfs_readdir,
457};
458
459/*
460 * Lookup single object on server.
461 */
462static int pohmelfs_lookup_single(struct pohmelfs_inode *parent,
463 struct qstr *str, u64 ino)
464{
465 struct pohmelfs_sb *psb = POHMELFS_SB(parent->vfs_inode.i_sb);
466 long ret = msecs_to_jiffies(5000);
467 int err;
468
469 set_bit(NETFS_COMMAND_PENDING, &parent->state);
470 err = pohmelfs_meta_command_data(parent, parent->ino, NETFS_LOOKUP,
471 (char *)str->name, NETFS_TRANS_SINGLE_DST, NULL, NULL, ino);
472 if (err)
473 goto err_out_exit;
474
475 err = 0;
476 ret = wait_event_interruptible_timeout(psb->wait,
477 !test_bit(NETFS_COMMAND_PENDING, &parent->state), ret);
478 if (ret <= 0) {
479 err = ret;
480 if (!err)
481 err = -ETIMEDOUT;
482 }
483
484 if (err)
485 goto err_out_exit;
486
487 return 0;
488
489err_out_exit:
490 clear_bit(NETFS_COMMAND_PENDING, &parent->state);
491
492 printk("%s: failed: parent: %llu, ino: %llu, name: '%s', err: %d.\n",
493 __func__, parent->ino, ino, str->name, err);
494
495 return err;
496}
497
498/*
499 * VFS lookup callback.
500 * We first try to get inode number from local name cache, if we have one,
501 * then inode can be found in inode cache. If there is no inode or no object in
502 * local cache, try to lookup it on server. This only should be done for directories,
503 * which were not created locally, otherwise remote server does not know about dir at all,
504 * so no need to try to know that.
505 */
506struct dentry *pohmelfs_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd)
507{
508 struct pohmelfs_inode *parent = POHMELFS_I(dir);
509 struct pohmelfs_name *n;
510 struct inode *inode = NULL;
511 unsigned long ino = 0;
512 int err, lock_type = POHMELFS_READ_LOCK, need_lock = 1;
513 struct qstr str = dentry->d_name;
514
515 if ((nd->intent.open.flags & O_ACCMODE) != O_RDONLY)
516 lock_type = POHMELFS_WRITE_LOCK;
517
518 if (test_bit(NETFS_INODE_OWNED, &parent->state)) {
519 if (lock_type == parent->lock_type)
520 need_lock = 0;
521 if ((lock_type == POHMELFS_READ_LOCK) && (parent->lock_type == POHMELFS_WRITE_LOCK))
522 need_lock = 0;
523 }
524
525 if ((lock_type == POHMELFS_READ_LOCK) && !test_bit(NETFS_INODE_REMOTE_DIR_SYNCED, &parent->state))
526 need_lock = 1;
527
528 str.hash = jhash(dentry->d_name.name, dentry->d_name.len, 0);
529
530 mutex_lock(&parent->offset_lock);
531 n = pohmelfs_search_hash(parent, str.hash);
532 if (n)
533 ino = n->ino;
534 mutex_unlock(&parent->offset_lock);
535
536 dprintk("%s: start ino: %lu, inode: %p, name: '%s', hash: %x, parent_state: %lx, need_lock: %d.\n",
537 __func__, ino, inode, str.name, str.hash, parent->state, need_lock);
538
539 if (ino) {
540 inode = ilookup(dir->i_sb, ino);
541 if (inode)
542 goto out;
543 }
544
545 dprintk("%s: no inode dir: %p, dir_ino: %llu, name: '%s', len: %u, dir_state: %lx, ino: %lu.\n",
546 __func__, dir, parent->ino,
547 str.name, str.len, parent->state, ino);
548
549 if (!ino) {
550 if (!need_lock)
551 goto out;
552 }
553
554 err = pohmelfs_data_lock(parent, 0, ~0, lock_type);
555 if (err)
556 goto out;
557
558 err = pohmelfs_lookup_single(parent, &str, ino);
559 if (err)
560 goto out;
561
562 if (!ino) {
563 mutex_lock(&parent->offset_lock);
564 n = pohmelfs_search_hash(parent, str.hash);
565 if (n)
566 ino = n->ino;
567 mutex_unlock(&parent->offset_lock);
568 }
569
570 if (ino) {
571 inode = ilookup(dir->i_sb, ino);
572 dprintk("%s: second lookup ino: %lu, inode: %p, name: '%s', hash: %x.\n",
573 __func__, ino, inode, str.name, str.hash);
574 if (!inode) {
575 dprintk("%s: No inode for ino: %lu, name: '%s', hash: %x.\n",
576 __func__, ino, str.name, str.hash);
577 /* return NULL; */
578 return ERR_PTR(-EACCES);
579 }
580 } else {
581 printk("%s: No inode number : name: '%s', hash: %x.\n",
582 __func__, str.name, str.hash);
583 }
584out:
585 return d_splice_alias(inode, dentry);
586}
587
588/*
589 * Create new object in local cache. Object will be synced to server
590 * during writeback for given inode.
591 */
592struct pohmelfs_inode *pohmelfs_create_entry_local(struct pohmelfs_sb *psb,
593 struct pohmelfs_inode *parent, struct qstr *str, u64 start, int mode)
594{
595 struct pohmelfs_inode *npi;
596 int err = -ENOMEM;
597 struct netfs_inode_info info;
598
599 dprintk("%s: name: '%s', mode: %o, start: %llu.\n",
600 __func__, str->name, mode, start);
601
602 info.mode = mode;
603 info.ino = start;
604
605 if (!start)
606 info.ino = pohmelfs_new_ino(psb);
607
608 info.nlink = S_ISDIR(mode) ? 2 : 1;
609 info.uid = current_fsuid();
610 info.gid = current_fsgid();
611 info.size = 0;
612 info.blocksize = 512;
613 info.blocks = 0;
614 info.rdev = 0;
615 info.version = 0;
616
617 npi = pohmelfs_new_inode(psb, parent, str, &info, !!start);
618 if (IS_ERR(npi)) {
619 err = PTR_ERR(npi);
620 goto err_out_unlock;
621 }
622
623 return npi;
624
625err_out_unlock:
626 dprintk("%s: err: %d.\n", __func__, err);
627 return ERR_PTR(err);
628}
629
630/*
631 * Create local object and bind it to dentry.
632 */
633static int pohmelfs_create_entry(struct inode *dir, struct dentry *dentry, u64 start, int mode)
634{
635 struct pohmelfs_sb *psb = POHMELFS_SB(dir->i_sb);
636 struct pohmelfs_inode *npi, *parent;
637 struct qstr str = dentry->d_name;
638 int err;
639
640 parent = POHMELFS_I(dir);
641
642 err = pohmelfs_data_lock(parent, 0, ~0, POHMELFS_WRITE_LOCK);
643 if (err)
644 return err;
645
646 str.hash = jhash(dentry->d_name.name, dentry->d_name.len, 0);
647
648 npi = pohmelfs_create_entry_local(psb, parent, &str, start, mode);
649 if (IS_ERR(npi))
650 return PTR_ERR(npi);
651
652 d_instantiate(dentry, &npi->vfs_inode);
653
654 dprintk("%s: parent: %llu, inode: %llu, name: '%s', parent_nlink: %d, nlink: %d.\n",
655 __func__, parent->ino, npi->ino, dentry->d_name.name,
656 (signed)dir->i_nlink, (signed)npi->vfs_inode.i_nlink);
657
658 return 0;
659}
660
661/*
662 * VFS create and mkdir callbacks.
663 */
664static int pohmelfs_create(struct inode *dir, struct dentry *dentry, int mode,
665 struct nameidata *nd)
666{
667 return pohmelfs_create_entry(dir, dentry, 0, mode);
668}
669
670static int pohmelfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
671{
672 int err;
673
674 inode_inc_link_count(dir);
675 err = pohmelfs_create_entry(dir, dentry, 0, mode | S_IFDIR);
676 if (err)
677 inode_dec_link_count(dir);
678
679 return err;
680}
681
682static int pohmelfs_remove_entry(struct inode *dir, struct dentry *dentry)
683{
684 struct pohmelfs_sb *psb = POHMELFS_SB(dir->i_sb);
685 struct inode *inode = dentry->d_inode;
686 struct pohmelfs_inode *parent = POHMELFS_I(dir), *pi = POHMELFS_I(inode);
687 struct pohmelfs_name *n;
688 int err = -ENOENT;
689 struct qstr str = dentry->d_name;
690
691 err = pohmelfs_data_lock(parent, 0, ~0, POHMELFS_WRITE_LOCK);
692 if (err)
693 return err;
694
695 str.hash = jhash(dentry->d_name.name, dentry->d_name.len, 0);
696
697 dprintk("%s: dir_ino: %llu, inode: %llu, name: '%s', nlink: %d.\n",
698 __func__, parent->ino, pi->ino,
699 str.name, (signed)inode->i_nlink);
700
701 BUG_ON(!inode);
702
703 mutex_lock(&parent->offset_lock);
704 n = pohmelfs_search_hash(parent, str.hash);
705 if (n) {
706 pohmelfs_fix_offset(parent, n);
707 if (test_bit(NETFS_INODE_REMOTE_SYNCED, &pi->state))
708 pohmelfs_remove_child(pi, n);
709
710 pohmelfs_name_free(parent, n);
711 err = 0;
712 }
713 mutex_unlock(&parent->offset_lock);
714
715 if (!err) {
716 psb->avail_size += inode->i_size;
717
718 pohmelfs_inode_del_inode(psb, pi);
719
720 mark_inode_dirty(dir);
721
722 inode->i_ctime = dir->i_ctime;
723 if (inode->i_nlink)
724 inode_dec_link_count(inode);
725 }
726
727 return err;
728}
729
730/*
731 * Unlink and rmdir VFS callbacks.
732 */
733static int pohmelfs_unlink(struct inode *dir, struct dentry *dentry)
734{
735 return pohmelfs_remove_entry(dir, dentry);
736}
737
738static int pohmelfs_rmdir(struct inode *dir, struct dentry *dentry)
739{
740 int err;
741 struct inode *inode = dentry->d_inode;
742
743 dprintk("%s: parent: %llu, inode: %llu, name: '%s', parent_nlink: %d, nlink: %d.\n",
744 __func__, POHMELFS_I(dir)->ino, POHMELFS_I(inode)->ino,
745 dentry->d_name.name, (signed)dir->i_nlink, (signed)inode->i_nlink);
746
747 err = pohmelfs_remove_entry(dir, dentry);
748 if (!err) {
749 inode_dec_link_count(dir);
750 inode_dec_link_count(inode);
751 }
752
753 return err;
754}
755
756/*
757 * Link creation is synchronous.
758 * I'm lazy.
759 * Earth is somewhat round.
760 */
761static int pohmelfs_create_link(struct pohmelfs_inode *parent, struct qstr *obj,
762 struct pohmelfs_inode *target, struct qstr *tstr)
763{
764 struct super_block *sb = parent->vfs_inode.i_sb;
765 struct pohmelfs_sb *psb = POHMELFS_SB(sb);
766 struct netfs_cmd *cmd;
767 struct netfs_trans *t;
768 void *data;
769 int err, parent_len, target_len = 0, cur_len, path_size = 0;
770
771 err = pohmelfs_data_lock(parent, 0, ~0, POHMELFS_WRITE_LOCK);
772 if (err)
773 return err;
774
775 err = sb->s_op->write_inode(&parent->vfs_inode, 0);
776 if (err)
777 goto err_out_exit;
778
779 if (tstr)
780 target_len = tstr->len;
781
782 parent_len = pohmelfs_path_length(parent);
783 if (target)
784 target_len += pohmelfs_path_length(target);
785
786 if (parent_len < 0) {
787 err = parent_len;
788 goto err_out_exit;
789 }
790
791 if (target_len < 0) {
792 err = target_len;
793 goto err_out_exit;
794 }
795
796 t = netfs_trans_alloc(psb, parent_len + target_len + obj->len + 2, 0, 0);
797 if (!t) {
798 err = -ENOMEM;
799 goto err_out_exit;
800 }
801 cur_len = netfs_trans_cur_len(t);
802
803 cmd = netfs_trans_current(t);
804 if (IS_ERR(cmd)) {
805 err = PTR_ERR(cmd);
806 goto err_out_free;
807 }
808
809 data = (void *)(cmd + 1);
810 cur_len -= sizeof(struct netfs_cmd);
811
812 err = pohmelfs_construct_path_string(parent, data, parent_len);
813 if (err > 0) {
814 /* Do not place null-byte before the slash */
815 path_size = err - 1;
816 cur_len -= path_size;
817
818 err = snprintf(data + path_size, cur_len, "/%s|", obj->name);
819
820 path_size += err;
821 cur_len -= err;
822
823 cmd->ext = path_size - 1; /* No | symbol */
824
825 if (target) {
826 err = pohmelfs_construct_path_string(target, data + path_size, target_len);
827 if (err > 0) {
828 path_size += err;
829 cur_len -= err;
830 }
831 }
832 }
833
834 if (err < 0)
835 goto err_out_free;
836
837 cmd->start = 0;
838
839 if (!target && tstr) {
840 if (tstr->len > cur_len - 1) {
841 err = -ENAMETOOLONG;
842 goto err_out_free;
843 }
844
845 err = snprintf(data + path_size, cur_len, "%s", tstr->name) + 1; /* 0-byte */
846 path_size += err;
847 cur_len -= err;
848 cmd->start = 1;
849 }
850
851 dprintk("%s: parent: %llu, obj: '%s', target_inode: %llu, target_str: '%s', full: '%s'.\n",
852 __func__, parent->ino, obj->name, (target) ? target->ino : 0, (tstr) ? tstr->name : NULL,
853 (char *)data);
854
855 cmd->cmd = NETFS_LINK;
856 cmd->size = path_size;
857 cmd->id = parent->ino;
858
859 netfs_convert_cmd(cmd);
860
861 netfs_trans_update(cmd, t, path_size);
862
863 err = netfs_trans_finish(t, psb);
864 if (err)
865 goto err_out_exit;
866
867 return 0;
868
869err_out_free:
870 t->result = err;
871 netfs_trans_put(t);
872err_out_exit:
873 return err;
874}
875
876/*
877 * VFS hard and soft link callbacks.
878 */
879static int pohmelfs_link(struct dentry *old_dentry, struct inode *dir,
880 struct dentry *dentry)
881{
882 struct inode *inode = old_dentry->d_inode;
883 struct pohmelfs_inode *pi = POHMELFS_I(inode);
884 int err;
885 struct qstr str = dentry->d_name;
886
887 str.hash = jhash(dentry->d_name.name, dentry->d_name.len, 0);
888
889 err = inode->i_sb->s_op->write_inode(inode, 0);
890 if (err)
891 return err;
892
893 err = pohmelfs_create_link(POHMELFS_I(dir), &str, pi, NULL);
894 if (err)
895 return err;
896
897 return pohmelfs_create_entry(dir, dentry, pi->ino, inode->i_mode);
898}
899
900static int pohmelfs_symlink(struct inode *dir, struct dentry *dentry, const char *symname)
901{
902 struct qstr sym_str;
903 struct qstr str = dentry->d_name;
904 struct inode *inode;
905 int err;
906
907 str.hash = jhash(dentry->d_name.name, dentry->d_name.len, 0);
908
909 sym_str.name = symname;
910 sym_str.len = strlen(symname);
911
912 err = pohmelfs_create_link(POHMELFS_I(dir), &str, NULL, &sym_str);
913 if (err)
914 goto err_out_exit;
915
916 err = pohmelfs_create_entry(dir, dentry, 0, S_IFLNK | S_IRWXU | S_IRWXG | S_IRWXO);
917 if (err)
918 goto err_out_exit;
919
920 inode = dentry->d_inode;
921
922 err = page_symlink(inode, symname, sym_str.len + 1);
923 if (err)
924 goto err_out_put;
925
926 return 0;
927
928err_out_put:
929 iput(inode);
930err_out_exit:
931 return err;
932}
933
934static int pohmelfs_send_rename(struct pohmelfs_inode *pi, struct pohmelfs_inode *parent,
935 struct qstr *str)
936{
937 int path_len, err, total_len = 0, inode_len, parent_len;
938 char *path;
939 struct netfs_trans *t;
940 struct netfs_cmd *cmd;
941 struct pohmelfs_sb *psb = POHMELFS_SB(pi->vfs_inode.i_sb);
942
943 parent_len = pohmelfs_path_length(parent);
944 inode_len = pohmelfs_path_length(pi);
945
946 if (parent_len < 0 || inode_len < 0)
947 return -EINVAL;
948
949 path_len = parent_len + inode_len + str->len + 3;
950
951 t = netfs_trans_alloc(psb, path_len, 0, 0);
952 if (!t)
953 return -ENOMEM;
954
955 cmd = netfs_trans_current(t);
956 path = (char *)(cmd + 1);
957
958 err = pohmelfs_construct_path_string(pi, path, inode_len);
959 if (err < 0)
960 goto err_out_unlock;
961
962 cmd->ext = err;
963
964 path += err;
965 total_len += err;
966 path_len -= err;
967
968 *path = '|';
969 path++;
970 total_len++;
971 path_len--;
972
973 err = pohmelfs_construct_path_string(parent, path, parent_len);
974 if (err < 0)
975 goto err_out_unlock;
976
977 /*
978 * Do not place a null-byte before the final slash and the name.
979 */
980 err--;
981 path += err;
982 total_len += err;
983 path_len -= err;
984
985 err = snprintf(path, path_len - 1, "/%s", str->name);
986
987 total_len += err + 1; /* 0 symbol */
988 path_len -= err + 1;
989
990 cmd->cmd = NETFS_RENAME;
991 cmd->id = pi->ino;
992 cmd->start = parent->ino;
993 cmd->size = total_len;
994
995 netfs_convert_cmd(cmd);
996
997 netfs_trans_update(cmd, t, total_len);
998
999 return netfs_trans_finish(t, psb);
1000
1001err_out_unlock:
1002 netfs_trans_free(t);
1003 return err;
1004}
1005
1006static int pohmelfs_rename(struct inode *old_dir, struct dentry *old_dentry,
1007 struct inode *new_dir, struct dentry *new_dentry)
1008{
1009 struct inode *inode = old_dentry->d_inode;
1010 struct pohmelfs_inode *old_parent, *pi, *new_parent;
1011 struct qstr str = new_dentry->d_name;
1012 struct pohmelfs_name *n;
1013 unsigned int old_hash;
1014 int err = -ENOENT;
1015
1016 pi = POHMELFS_I(inode);
1017 old_parent = POHMELFS_I(old_dir);
1018
1019 if (new_dir)
1020 new_dir->i_sb->s_op->write_inode(new_dir, 0);
1021
1022 old_hash = jhash(old_dentry->d_name.name, old_dentry->d_name.len, 0);
1023 str.hash = jhash(new_dentry->d_name.name, new_dentry->d_name.len, 0);
1024
1025 str.len = new_dentry->d_name.len;
1026 str.name = new_dentry->d_name.name;
1027 str.hash = jhash(new_dentry->d_name.name, new_dentry->d_name.len, 0);
1028
1029 if (new_dir) {
1030 new_parent = POHMELFS_I(new_dir);
1031 err = -ENOTEMPTY;
1032
1033 if (S_ISDIR(inode->i_mode) &&
1034 new_parent->total_len <= 3)
1035 goto err_out_exit;
1036 } else {
1037 new_parent = old_parent;
1038 }
1039
1040 dprintk("%s: ino: %llu, parent: %llu, name: '%s' -> parent: %llu, name: '%s', i_size: %llu.\n",
1041 __func__, pi->ino, old_parent->ino, old_dentry->d_name.name,
1042 new_parent->ino, new_dentry->d_name.name, inode->i_size);
1043
1044 if (test_bit(NETFS_INODE_REMOTE_SYNCED, &pi->state) &&
1045 test_bit(NETFS_INODE_OWNED, &pi->state)) {
1046 err = pohmelfs_send_rename(pi, new_parent, &str);
1047 if (err)
1048 goto err_out_exit;
1049 }
1050
1051 n = pohmelfs_name_alloc(str.len + 1);
1052 if (!n)
1053 goto err_out_exit;
1054
1055 mutex_lock(&new_parent->offset_lock);
1056 n->ino = pi->ino;
1057 n->mode = inode->i_mode;
1058 n->len = str.len;
1059 n->hash = str.hash;
1060 sprintf(n->data, "%s", str.name);
1061
1062 err = pohmelfs_insert_name(new_parent, n);
1063 mutex_unlock(&new_parent->offset_lock);
1064
1065 if (err)
1066 goto err_out_exit;
1067
1068 mutex_lock(&old_parent->offset_lock);
1069 n = pohmelfs_search_hash(old_parent, old_hash);
1070 if (n)
1071 pohmelfs_name_del(old_parent, n);
1072 mutex_unlock(&old_parent->offset_lock);
1073
1074 mark_inode_dirty(inode);
1075 mark_inode_dirty(&new_parent->vfs_inode);
1076
1077 WARN_ON_ONCE(list_empty(&inode->i_dentry));
1078
1079 return 0;
1080
1081err_out_exit:
1082
1083 clear_bit(NETFS_INODE_REMOTE_SYNCED, &pi->state);
1084
1085 return err;
1086}
1087
1088/*
1089 * POHMELFS directory inode operations.
1090 */
1091const struct inode_operations pohmelfs_dir_inode_ops = {
1092 .link = pohmelfs_link,
1093 .symlink = pohmelfs_symlink,
1094 .unlink = pohmelfs_unlink,
1095 .mkdir = pohmelfs_mkdir,
1096 .rmdir = pohmelfs_rmdir,
1097 .create = pohmelfs_create,
1098 .lookup = pohmelfs_lookup,
1099 .setattr = pohmelfs_setattr,
1100 .rename = pohmelfs_rename,
1101};