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1 /*
2 * linux/fs/9p/vfs_inode.c
3 *
4 * This file contains vfs inode ops for the 9P2000 protocol.
5 *
6 * Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
7 * Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License version 2
11 * as published by the Free Software Foundation.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to:
20 * Free Software Foundation
21 * 51 Franklin Street, Fifth Floor
22 * Boston, MA 02111-1301 USA
23 *
24 */
25
26 #include <linux/module.h>
27 #include <linux/errno.h>
28 #include <linux/fs.h>
29 #include <linux/file.h>
30 #include <linux/pagemap.h>
31 #include <linux/stat.h>
32 #include <linux/string.h>
33 #include <linux/inet.h>
34 #include <linux/namei.h>
35 #include <linux/idr.h>
36 #include <linux/sched.h>
37 #include <linux/slab.h>
38 #include <linux/xattr.h>
39 #include <linux/posix_acl.h>
40 #include <net/9p/9p.h>
41 #include <net/9p/client.h>
42
43 #include "v9fs.h"
44 #include "v9fs_vfs.h"
45 #include "fid.h"
46 #include "cache.h"
47 #include "xattr.h"
48 #include "acl.h"
49
50 static const struct inode_operations v9fs_dir_inode_operations;
51 static const struct inode_operations v9fs_dir_inode_operations_dotu;
52 static const struct inode_operations v9fs_file_inode_operations;
53 static const struct inode_operations v9fs_symlink_inode_operations;
54
55 /**
56 * unixmode2p9mode - convert unix mode bits to plan 9
57 * @v9ses: v9fs session information
58 * @mode: mode to convert
59 *
60 */
61
62 static int unixmode2p9mode(struct v9fs_session_info *v9ses, int mode)
63 {
64 int res;
65 res = mode & 0777;
66 if (S_ISDIR(mode))
67 res |= P9_DMDIR;
68 if (v9fs_proto_dotu(v9ses)) {
69 if (S_ISLNK(mode))
70 res |= P9_DMSYMLINK;
71 if (v9ses->nodev == 0) {
72 if (S_ISSOCK(mode))
73 res |= P9_DMSOCKET;
74 if (S_ISFIFO(mode))
75 res |= P9_DMNAMEDPIPE;
76 if (S_ISBLK(mode))
77 res |= P9_DMDEVICE;
78 if (S_ISCHR(mode))
79 res |= P9_DMDEVICE;
80 }
81
82 if ((mode & S_ISUID) == S_ISUID)
83 res |= P9_DMSETUID;
84 if ((mode & S_ISGID) == S_ISGID)
85 res |= P9_DMSETGID;
86 if ((mode & S_ISVTX) == S_ISVTX)
87 res |= P9_DMSETVTX;
88 if ((mode & P9_DMLINK))
89 res |= P9_DMLINK;
90 }
91
92 return res;
93 }
94
95 /**
96 * p9mode2unixmode- convert plan9 mode bits to unix mode bits
97 * @v9ses: v9fs session information
98 * @mode: mode to convert
99 *
100 */
101
102 static int p9mode2unixmode(struct v9fs_session_info *v9ses, int mode)
103 {
104 int res;
105
106 res = mode & 0777;
107
108 if ((mode & P9_DMDIR) == P9_DMDIR)
109 res |= S_IFDIR;
110 else if ((mode & P9_DMSYMLINK) && (v9fs_proto_dotu(v9ses)))
111 res |= S_IFLNK;
112 else if ((mode & P9_DMSOCKET) && (v9fs_proto_dotu(v9ses))
113 && (v9ses->nodev == 0))
114 res |= S_IFSOCK;
115 else if ((mode & P9_DMNAMEDPIPE) && (v9fs_proto_dotu(v9ses))
116 && (v9ses->nodev == 0))
117 res |= S_IFIFO;
118 else if ((mode & P9_DMDEVICE) && (v9fs_proto_dotu(v9ses))
119 && (v9ses->nodev == 0))
120 res |= S_IFBLK;
121 else
122 res |= S_IFREG;
123
124 if (v9fs_proto_dotu(v9ses)) {
125 if ((mode & P9_DMSETUID) == P9_DMSETUID)
126 res |= S_ISUID;
127
128 if ((mode & P9_DMSETGID) == P9_DMSETGID)
129 res |= S_ISGID;
130
131 if ((mode & P9_DMSETVTX) == P9_DMSETVTX)
132 res |= S_ISVTX;
133 }
134
135 return res;
136 }
137
138 /**
139 * v9fs_uflags2omode- convert posix open flags to plan 9 mode bits
140 * @uflags: flags to convert
141 * @extended: if .u extensions are active
142 */
143
144 int v9fs_uflags2omode(int uflags, int extended)
145 {
146 int ret;
147
148 ret = 0;
149 switch (uflags&3) {
150 default:
151 case O_RDONLY:
152 ret = P9_OREAD;
153 break;
154
155 case O_WRONLY:
156 ret = P9_OWRITE;
157 break;
158
159 case O_RDWR:
160 ret = P9_ORDWR;
161 break;
162 }
163
164 if (uflags & O_TRUNC)
165 ret |= P9_OTRUNC;
166
167 if (extended) {
168 if (uflags & O_EXCL)
169 ret |= P9_OEXCL;
170
171 if (uflags & O_APPEND)
172 ret |= P9_OAPPEND;
173 }
174
175 return ret;
176 }
177
178 /**
179 * v9fs_blank_wstat - helper function to setup a 9P stat structure
180 * @wstat: structure to initialize
181 *
182 */
183
184 void
185 v9fs_blank_wstat(struct p9_wstat *wstat)
186 {
187 wstat->type = ~0;
188 wstat->dev = ~0;
189 wstat->qid.type = ~0;
190 wstat->qid.version = ~0;
191 *((long long *)&wstat->qid.path) = ~0;
192 wstat->mode = ~0;
193 wstat->atime = ~0;
194 wstat->mtime = ~0;
195 wstat->length = ~0;
196 wstat->name = NULL;
197 wstat->uid = NULL;
198 wstat->gid = NULL;
199 wstat->muid = NULL;
200 wstat->n_uid = ~0;
201 wstat->n_gid = ~0;
202 wstat->n_muid = ~0;
203 wstat->extension = NULL;
204 }
205
206 /**
207 * v9fs_alloc_inode - helper function to allocate an inode
208 *
209 */
210 struct inode *v9fs_alloc_inode(struct super_block *sb)
211 {
212 struct v9fs_inode *v9inode;
213 v9inode = (struct v9fs_inode *)kmem_cache_alloc(v9fs_inode_cache,
214 GFP_KERNEL);
215 if (!v9inode)
216 return NULL;
217 #ifdef CONFIG_9P_FSCACHE
218 v9inode->fscache = NULL;
219 v9inode->fscache_key = NULL;
220 spin_lock_init(&v9inode->fscache_lock);
221 #endif
222 v9inode->writeback_fid = NULL;
223 v9inode->cache_validity = 0;
224 return &v9inode->vfs_inode;
225 }
226
227 /**
228 * v9fs_destroy_inode - destroy an inode
229 *
230 */
231
232 static void v9fs_i_callback(struct rcu_head *head)
233 {
234 struct inode *inode = container_of(head, struct inode, i_rcu);
235 INIT_LIST_HEAD(&inode->i_dentry);
236 kmem_cache_free(v9fs_inode_cache, V9FS_I(inode));
237 }
238
239 void v9fs_destroy_inode(struct inode *inode)
240 {
241 call_rcu(&inode->i_rcu, v9fs_i_callback);
242 }
243
244 int v9fs_init_inode(struct v9fs_session_info *v9ses,
245 struct inode *inode, int mode)
246 {
247 int err = 0;
248
249 inode_init_owner(inode, NULL, mode);
250 inode->i_blocks = 0;
251 inode->i_rdev = 0;
252 inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
253 inode->i_mapping->a_ops = &v9fs_addr_operations;
254
255 switch (mode & S_IFMT) {
256 case S_IFIFO:
257 case S_IFBLK:
258 case S_IFCHR:
259 case S_IFSOCK:
260 if (v9fs_proto_dotl(v9ses)) {
261 inode->i_op = &v9fs_file_inode_operations_dotl;
262 inode->i_fop = &v9fs_file_operations_dotl;
263 } else if (v9fs_proto_dotu(v9ses)) {
264 inode->i_op = &v9fs_file_inode_operations;
265 inode->i_fop = &v9fs_file_operations;
266 } else {
267 P9_DPRINTK(P9_DEBUG_ERROR,
268 "special files without extended mode\n");
269 err = -EINVAL;
270 goto error;
271 }
272 init_special_inode(inode, inode->i_mode, inode->i_rdev);
273 break;
274 case S_IFREG:
275 if (v9fs_proto_dotl(v9ses)) {
276 inode->i_op = &v9fs_file_inode_operations_dotl;
277 if (v9ses->cache)
278 inode->i_fop =
279 &v9fs_cached_file_operations_dotl;
280 else
281 inode->i_fop = &v9fs_file_operations_dotl;
282 } else {
283 inode->i_op = &v9fs_file_inode_operations;
284 if (v9ses->cache)
285 inode->i_fop = &v9fs_cached_file_operations;
286 else
287 inode->i_fop = &v9fs_file_operations;
288 }
289
290 break;
291 case S_IFLNK:
292 if (!v9fs_proto_dotu(v9ses) && !v9fs_proto_dotl(v9ses)) {
293 P9_DPRINTK(P9_DEBUG_ERROR, "extended modes used with "
294 "legacy protocol.\n");
295 err = -EINVAL;
296 goto error;
297 }
298
299 if (v9fs_proto_dotl(v9ses))
300 inode->i_op = &v9fs_symlink_inode_operations_dotl;
301 else
302 inode->i_op = &v9fs_symlink_inode_operations;
303
304 break;
305 case S_IFDIR:
306 inc_nlink(inode);
307 if (v9fs_proto_dotl(v9ses))
308 inode->i_op = &v9fs_dir_inode_operations_dotl;
309 else if (v9fs_proto_dotu(v9ses))
310 inode->i_op = &v9fs_dir_inode_operations_dotu;
311 else
312 inode->i_op = &v9fs_dir_inode_operations;
313
314 if (v9fs_proto_dotl(v9ses))
315 inode->i_fop = &v9fs_dir_operations_dotl;
316 else
317 inode->i_fop = &v9fs_dir_operations;
318
319 break;
320 default:
321 P9_DPRINTK(P9_DEBUG_ERROR, "BAD mode 0x%x S_IFMT 0x%x\n",
322 mode, mode & S_IFMT);
323 err = -EINVAL;
324 goto error;
325 }
326 error:
327 return err;
328
329 }
330
331 /**
332 * v9fs_get_inode - helper function to setup an inode
333 * @sb: superblock
334 * @mode: mode to setup inode with
335 *
336 */
337
338 struct inode *v9fs_get_inode(struct super_block *sb, int mode)
339 {
340 int err;
341 struct inode *inode;
342 struct v9fs_session_info *v9ses = sb->s_fs_info;
343
344 P9_DPRINTK(P9_DEBUG_VFS, "super block: %p mode: %o\n", sb, mode);
345
346 inode = new_inode(sb);
347 if (!inode) {
348 P9_EPRINTK(KERN_WARNING, "Problem allocating inode\n");
349 return ERR_PTR(-ENOMEM);
350 }
351 err = v9fs_init_inode(v9ses, inode, mode);
352 if (err) {
353 iput(inode);
354 return ERR_PTR(err);
355 }
356 return inode;
357 }
358
359 /*
360 static struct v9fs_fid*
361 v9fs_clone_walk(struct v9fs_session_info *v9ses, u32 fid, struct dentry *dentry)
362 {
363 int err;
364 int nfid;
365 struct v9fs_fid *ret;
366 struct v9fs_fcall *fcall;
367
368 nfid = v9fs_get_idpool(&v9ses->fidpool);
369 if (nfid < 0) {
370 eprintk(KERN_WARNING, "no free fids available\n");
371 return ERR_PTR(-ENOSPC);
372 }
373
374 err = v9fs_t_walk(v9ses, fid, nfid, (char *) dentry->d_name.name,
375 &fcall);
376
377 if (err < 0) {
378 if (fcall && fcall->id == RWALK)
379 goto clunk_fid;
380
381 PRINT_FCALL_ERROR("walk error", fcall);
382 v9fs_put_idpool(nfid, &v9ses->fidpool);
383 goto error;
384 }
385
386 kfree(fcall);
387 fcall = NULL;
388 ret = v9fs_fid_create(v9ses, nfid);
389 if (!ret) {
390 err = -ENOMEM;
391 goto clunk_fid;
392 }
393
394 err = v9fs_fid_insert(ret, dentry);
395 if (err < 0) {
396 v9fs_fid_destroy(ret);
397 goto clunk_fid;
398 }
399
400 return ret;
401
402 clunk_fid:
403 v9fs_t_clunk(v9ses, nfid);
404
405 error:
406 kfree(fcall);
407 return ERR_PTR(err);
408 }
409 */
410
411
412 /**
413 * v9fs_clear_inode - release an inode
414 * @inode: inode to release
415 *
416 */
417 void v9fs_evict_inode(struct inode *inode)
418 {
419 struct v9fs_inode *v9inode = V9FS_I(inode);
420
421 truncate_inode_pages(inode->i_mapping, 0);
422 end_writeback(inode);
423 filemap_fdatawrite(inode->i_mapping);
424
425 #ifdef CONFIG_9P_FSCACHE
426 v9fs_cache_inode_put_cookie(inode);
427 #endif
428 /* clunk the fid stashed in writeback_fid */
429 if (v9inode->writeback_fid) {
430 p9_client_clunk(v9inode->writeback_fid);
431 v9inode->writeback_fid = NULL;
432 }
433 }
434
435 static struct inode *v9fs_qid_iget(struct super_block *sb,
436 struct p9_qid *qid,
437 struct p9_wstat *st)
438 {
439 int retval, umode;
440 unsigned long i_ino;
441 struct inode *inode;
442 struct v9fs_session_info *v9ses = sb->s_fs_info;
443
444 i_ino = v9fs_qid2ino(qid);
445 inode = iget_locked(sb, i_ino);
446 if (!inode)
447 return ERR_PTR(-ENOMEM);
448 if (!(inode->i_state & I_NEW))
449 return inode;
450 /*
451 * initialize the inode with the stat info
452 * FIXME!! we may need support for stale inodes
453 * later.
454 */
455 umode = p9mode2unixmode(v9ses, st->mode);
456 retval = v9fs_init_inode(v9ses, inode, umode);
457 if (retval)
458 goto error;
459
460 v9fs_stat2inode(st, inode, sb);
461 #ifdef CONFIG_9P_FSCACHE
462 v9fs_fscache_set_key(inode, &st->qid);
463 v9fs_cache_inode_get_cookie(inode);
464 #endif
465 unlock_new_inode(inode);
466 return inode;
467 error:
468 unlock_new_inode(inode);
469 iput(inode);
470 return ERR_PTR(retval);
471
472 }
473
474 struct inode *
475 v9fs_inode_from_fid(struct v9fs_session_info *v9ses, struct p9_fid *fid,
476 struct super_block *sb)
477 {
478 struct p9_wstat *st;
479 struct inode *inode = NULL;
480
481 st = p9_client_stat(fid);
482 if (IS_ERR(st))
483 return ERR_CAST(st);
484
485 inode = v9fs_qid_iget(sb, &st->qid, st);
486 p9stat_free(st);
487 kfree(st);
488 return inode;
489 }
490
491 /**
492 * v9fs_remove - helper function to remove files and directories
493 * @dir: directory inode that is being deleted
494 * @file: dentry that is being deleted
495 * @rmdir: removing a directory
496 *
497 */
498
499 static int v9fs_remove(struct inode *dir, struct dentry *file, int rmdir)
500 {
501 int retval;
502 struct p9_fid *v9fid;
503 struct inode *file_inode;
504
505 P9_DPRINTK(P9_DEBUG_VFS, "inode: %p dentry: %p rmdir: %d\n", dir, file,
506 rmdir);
507
508 file_inode = file->d_inode;
509 v9fid = v9fs_fid_clone(file);
510 if (IS_ERR(v9fid))
511 return PTR_ERR(v9fid);
512
513 retval = p9_client_remove(v9fid);
514 if (!retval) {
515 /*
516 * directories on unlink should have zero
517 * link count
518 */
519 if (rmdir) {
520 clear_nlink(file_inode);
521 drop_nlink(dir);
522 } else
523 drop_nlink(file_inode);
524
525 v9fs_invalidate_inode_attr(file_inode);
526 v9fs_invalidate_inode_attr(dir);
527 }
528 return retval;
529 }
530
531 /**
532 * v9fs_create - Create a file
533 * @v9ses: session information
534 * @dir: directory that dentry is being created in
535 * @dentry: dentry that is being created
536 * @extension: 9p2000.u extension string to support devices, etc.
537 * @perm: create permissions
538 * @mode: open mode
539 *
540 */
541 static struct p9_fid *
542 v9fs_create(struct v9fs_session_info *v9ses, struct inode *dir,
543 struct dentry *dentry, char *extension, u32 perm, u8 mode)
544 {
545 int err;
546 char *name;
547 struct p9_fid *dfid, *ofid, *fid;
548 struct inode *inode;
549
550 P9_DPRINTK(P9_DEBUG_VFS, "name %s\n", dentry->d_name.name);
551
552 err = 0;
553 ofid = NULL;
554 fid = NULL;
555 name = (char *) dentry->d_name.name;
556 dfid = v9fs_fid_lookup(dentry->d_parent);
557 if (IS_ERR(dfid)) {
558 err = PTR_ERR(dfid);
559 P9_DPRINTK(P9_DEBUG_VFS, "fid lookup failed %d\n", err);
560 return ERR_PTR(err);
561 }
562
563 /* clone a fid to use for creation */
564 ofid = p9_client_walk(dfid, 0, NULL, 1);
565 if (IS_ERR(ofid)) {
566 err = PTR_ERR(ofid);
567 P9_DPRINTK(P9_DEBUG_VFS, "p9_client_walk failed %d\n", err);
568 return ERR_PTR(err);
569 }
570
571 err = p9_client_fcreate(ofid, name, perm, mode, extension);
572 if (err < 0) {
573 P9_DPRINTK(P9_DEBUG_VFS, "p9_client_fcreate failed %d\n", err);
574 goto error;
575 }
576
577 /* now walk from the parent so we can get unopened fid */
578 fid = p9_client_walk(dfid, 1, &name, 1);
579 if (IS_ERR(fid)) {
580 err = PTR_ERR(fid);
581 P9_DPRINTK(P9_DEBUG_VFS, "p9_client_walk failed %d\n", err);
582 fid = NULL;
583 goto error;
584 }
585
586 /* instantiate inode and assign the unopened fid to the dentry */
587 inode = v9fs_get_inode_from_fid(v9ses, fid, dir->i_sb);
588 if (IS_ERR(inode)) {
589 err = PTR_ERR(inode);
590 P9_DPRINTK(P9_DEBUG_VFS, "inode creation failed %d\n", err);
591 goto error;
592 }
593 d_instantiate(dentry, inode);
594 err = v9fs_fid_add(dentry, fid);
595 if (err < 0)
596 goto error;
597
598 return ofid;
599
600 error:
601 if (ofid)
602 p9_client_clunk(ofid);
603
604 if (fid)
605 p9_client_clunk(fid);
606
607 return ERR_PTR(err);
608 }
609
610 /**
611 * v9fs_vfs_create - VFS hook to create files
612 * @dir: directory inode that is being created
613 * @dentry: dentry that is being deleted
614 * @mode: create permissions
615 * @nd: path information
616 *
617 */
618
619 static int
620 v9fs_vfs_create(struct inode *dir, struct dentry *dentry, int mode,
621 struct nameidata *nd)
622 {
623 int err;
624 u32 perm;
625 int flags;
626 struct file *filp;
627 struct v9fs_inode *v9inode;
628 struct v9fs_session_info *v9ses;
629 struct p9_fid *fid, *inode_fid;
630
631 err = 0;
632 fid = NULL;
633 v9ses = v9fs_inode2v9ses(dir);
634 perm = unixmode2p9mode(v9ses, mode);
635 if (nd && nd->flags & LOOKUP_OPEN)
636 flags = nd->intent.open.flags - 1;
637 else
638 flags = O_RDWR;
639
640 fid = v9fs_create(v9ses, dir, dentry, NULL, perm,
641 v9fs_uflags2omode(flags,
642 v9fs_proto_dotu(v9ses)));
643 if (IS_ERR(fid)) {
644 err = PTR_ERR(fid);
645 fid = NULL;
646 goto error;
647 }
648
649 v9fs_invalidate_inode_attr(dir);
650 /* if we are opening a file, assign the open fid to the file */
651 if (nd && nd->flags & LOOKUP_OPEN) {
652 v9inode = V9FS_I(dentry->d_inode);
653 if (v9ses->cache && !v9inode->writeback_fid) {
654 /*
655 * clone a fid and add it to writeback_fid
656 * we do it during open time instead of
657 * page dirty time via write_begin/page_mkwrite
658 * because we want write after unlink usecase
659 * to work.
660 */
661 inode_fid = v9fs_writeback_fid(dentry);
662 if (IS_ERR(inode_fid)) {
663 err = PTR_ERR(inode_fid);
664 goto error;
665 }
666 v9inode->writeback_fid = (void *) inode_fid;
667 }
668 filp = lookup_instantiate_filp(nd, dentry, generic_file_open);
669 if (IS_ERR(filp)) {
670 err = PTR_ERR(filp);
671 goto error;
672 }
673
674 filp->private_data = fid;
675 #ifdef CONFIG_9P_FSCACHE
676 if (v9ses->cache)
677 v9fs_cache_inode_set_cookie(dentry->d_inode, filp);
678 #endif
679 } else
680 p9_client_clunk(fid);
681
682 return 0;
683
684 error:
685 if (fid)
686 p9_client_clunk(fid);
687
688 return err;
689 }
690
691 /**
692 * v9fs_vfs_mkdir - VFS mkdir hook to create a directory
693 * @dir: inode that is being unlinked
694 * @dentry: dentry that is being unlinked
695 * @mode: mode for new directory
696 *
697 */
698
699 static int v9fs_vfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
700 {
701 int err;
702 u32 perm;
703 struct p9_fid *fid;
704 struct v9fs_session_info *v9ses;
705
706 P9_DPRINTK(P9_DEBUG_VFS, "name %s\n", dentry->d_name.name);
707 err = 0;
708 v9ses = v9fs_inode2v9ses(dir);
709 perm = unixmode2p9mode(v9ses, mode | S_IFDIR);
710 fid = v9fs_create(v9ses, dir, dentry, NULL, perm, P9_OREAD);
711 if (IS_ERR(fid)) {
712 err = PTR_ERR(fid);
713 fid = NULL;
714 } else {
715 inc_nlink(dir);
716 v9fs_invalidate_inode_attr(dir);
717 }
718
719 if (fid)
720 p9_client_clunk(fid);
721
722 return err;
723 }
724
725 /**
726 * v9fs_vfs_lookup - VFS lookup hook to "walk" to a new inode
727 * @dir: inode that is being walked from
728 * @dentry: dentry that is being walked to?
729 * @nameidata: path data
730 *
731 */
732
733 struct dentry *v9fs_vfs_lookup(struct inode *dir, struct dentry *dentry,
734 struct nameidata *nameidata)
735 {
736 struct super_block *sb;
737 struct v9fs_session_info *v9ses;
738 struct p9_fid *dfid, *fid;
739 struct inode *inode;
740 char *name;
741 int result = 0;
742
743 P9_DPRINTK(P9_DEBUG_VFS, "dir: %p dentry: (%s) %p nameidata: %p\n",
744 dir, dentry->d_name.name, dentry, nameidata);
745
746 if (dentry->d_name.len > NAME_MAX)
747 return ERR_PTR(-ENAMETOOLONG);
748
749 sb = dir->i_sb;
750 v9ses = v9fs_inode2v9ses(dir);
751 /* We can walk d_parent because we hold the dir->i_mutex */
752 dfid = v9fs_fid_lookup(dentry->d_parent);
753 if (IS_ERR(dfid))
754 return ERR_CAST(dfid);
755
756 name = (char *) dentry->d_name.name;
757 fid = p9_client_walk(dfid, 1, &name, 1);
758 if (IS_ERR(fid)) {
759 result = PTR_ERR(fid);
760 if (result == -ENOENT) {
761 inode = NULL;
762 goto inst_out;
763 }
764
765 return ERR_PTR(result);
766 }
767
768 inode = v9fs_get_inode_from_fid(v9ses, fid, dir->i_sb);
769 if (IS_ERR(inode)) {
770 result = PTR_ERR(inode);
771 inode = NULL;
772 goto error;
773 }
774
775 result = v9fs_fid_add(dentry, fid);
776 if (result < 0)
777 goto error_iput;
778
779 inst_out:
780 d_add(dentry, inode);
781 return NULL;
782
783 error_iput:
784 iput(inode);
785 error:
786 p9_client_clunk(fid);
787
788 return ERR_PTR(result);
789 }
790
791 /**
792 * v9fs_vfs_unlink - VFS unlink hook to delete an inode
793 * @i: inode that is being unlinked
794 * @d: dentry that is being unlinked
795 *
796 */
797
798 int v9fs_vfs_unlink(struct inode *i, struct dentry *d)
799 {
800 return v9fs_remove(i, d, 0);
801 }
802
803 /**
804 * v9fs_vfs_rmdir - VFS unlink hook to delete a directory
805 * @i: inode that is being unlinked
806 * @d: dentry that is being unlinked
807 *
808 */
809
810 int v9fs_vfs_rmdir(struct inode *i, struct dentry *d)
811 {
812 return v9fs_remove(i, d, 1);
813 }
814
815 /**
816 * v9fs_vfs_rename - VFS hook to rename an inode
817 * @old_dir: old dir inode
818 * @old_dentry: old dentry
819 * @new_dir: new dir inode
820 * @new_dentry: new dentry
821 *
822 */
823
824 int
825 v9fs_vfs_rename(struct inode *old_dir, struct dentry *old_dentry,
826 struct inode *new_dir, struct dentry *new_dentry)
827 {
828 int retval;
829 struct inode *old_inode;
830 struct inode *new_inode;
831 struct v9fs_session_info *v9ses;
832 struct p9_fid *oldfid;
833 struct p9_fid *olddirfid;
834 struct p9_fid *newdirfid;
835 struct p9_wstat wstat;
836
837 P9_DPRINTK(P9_DEBUG_VFS, "\n");
838 retval = 0;
839 old_inode = old_dentry->d_inode;
840 new_inode = new_dentry->d_inode;
841 v9ses = v9fs_inode2v9ses(old_inode);
842 oldfid = v9fs_fid_lookup(old_dentry);
843 if (IS_ERR(oldfid))
844 return PTR_ERR(oldfid);
845
846 olddirfid = v9fs_fid_clone(old_dentry->d_parent);
847 if (IS_ERR(olddirfid)) {
848 retval = PTR_ERR(olddirfid);
849 goto done;
850 }
851
852 newdirfid = v9fs_fid_clone(new_dentry->d_parent);
853 if (IS_ERR(newdirfid)) {
854 retval = PTR_ERR(newdirfid);
855 goto clunk_olddir;
856 }
857
858 down_write(&v9ses->rename_sem);
859 if (v9fs_proto_dotl(v9ses)) {
860 retval = p9_client_rename(oldfid, newdirfid,
861 (char *) new_dentry->d_name.name);
862 if (retval != -ENOSYS)
863 goto clunk_newdir;
864 }
865 if (old_dentry->d_parent != new_dentry->d_parent) {
866 /*
867 * 9P .u can only handle file rename in the same directory
868 */
869
870 P9_DPRINTK(P9_DEBUG_ERROR,
871 "old dir and new dir are different\n");
872 retval = -EXDEV;
873 goto clunk_newdir;
874 }
875 v9fs_blank_wstat(&wstat);
876 wstat.muid = v9ses->uname;
877 wstat.name = (char *) new_dentry->d_name.name;
878 retval = p9_client_wstat(oldfid, &wstat);
879
880 clunk_newdir:
881 if (!retval) {
882 if (new_inode) {
883 if (S_ISDIR(new_inode->i_mode))
884 clear_nlink(new_inode);
885 else
886 drop_nlink(new_inode);
887 }
888 if (S_ISDIR(old_inode->i_mode)) {
889 if (!new_inode)
890 inc_nlink(new_dir);
891 drop_nlink(old_dir);
892 }
893 v9fs_invalidate_inode_attr(old_inode);
894 v9fs_invalidate_inode_attr(old_dir);
895 v9fs_invalidate_inode_attr(new_dir);
896
897 /* successful rename */
898 d_move(old_dentry, new_dentry);
899 }
900 up_write(&v9ses->rename_sem);
901 p9_client_clunk(newdirfid);
902
903 clunk_olddir:
904 p9_client_clunk(olddirfid);
905
906 done:
907 return retval;
908 }
909
910 /**
911 * v9fs_vfs_getattr - retrieve file metadata
912 * @mnt: mount information
913 * @dentry: file to get attributes on
914 * @stat: metadata structure to populate
915 *
916 */
917
918 static int
919 v9fs_vfs_getattr(struct vfsmount *mnt, struct dentry *dentry,
920 struct kstat *stat)
921 {
922 int err;
923 struct v9fs_session_info *v9ses;
924 struct p9_fid *fid;
925 struct p9_wstat *st;
926
927 P9_DPRINTK(P9_DEBUG_VFS, "dentry: %p\n", dentry);
928 err = -EPERM;
929 v9ses = v9fs_inode2v9ses(dentry->d_inode);
930 if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) {
931 generic_fillattr(dentry->d_inode, stat);
932 return 0;
933 }
934 fid = v9fs_fid_lookup(dentry);
935 if (IS_ERR(fid))
936 return PTR_ERR(fid);
937
938 st = p9_client_stat(fid);
939 if (IS_ERR(st))
940 return PTR_ERR(st);
941
942 v9fs_stat2inode(st, dentry->d_inode, dentry->d_inode->i_sb);
943 generic_fillattr(dentry->d_inode, stat);
944
945 p9stat_free(st);
946 kfree(st);
947 return 0;
948 }
949
950 /**
951 * v9fs_vfs_setattr - set file metadata
952 * @dentry: file whose metadata to set
953 * @iattr: metadata assignment structure
954 *
955 */
956
957 static int v9fs_vfs_setattr(struct dentry *dentry, struct iattr *iattr)
958 {
959 int retval;
960 struct v9fs_session_info *v9ses;
961 struct p9_fid *fid;
962 struct p9_wstat wstat;
963
964 P9_DPRINTK(P9_DEBUG_VFS, "\n");
965 retval = -EPERM;
966 v9ses = v9fs_inode2v9ses(dentry->d_inode);
967 fid = v9fs_fid_lookup(dentry);
968 if(IS_ERR(fid))
969 return PTR_ERR(fid);
970
971 v9fs_blank_wstat(&wstat);
972 if (iattr->ia_valid & ATTR_MODE)
973 wstat.mode = unixmode2p9mode(v9ses, iattr->ia_mode);
974
975 if (iattr->ia_valid & ATTR_MTIME)
976 wstat.mtime = iattr->ia_mtime.tv_sec;
977
978 if (iattr->ia_valid & ATTR_ATIME)
979 wstat.atime = iattr->ia_atime.tv_sec;
980
981 if (iattr->ia_valid & ATTR_SIZE)
982 wstat.length = iattr->ia_size;
983
984 if (v9fs_proto_dotu(v9ses)) {
985 if (iattr->ia_valid & ATTR_UID)
986 wstat.n_uid = iattr->ia_uid;
987
988 if (iattr->ia_valid & ATTR_GID)
989 wstat.n_gid = iattr->ia_gid;
990 }
991
992 retval = p9_client_wstat(fid, &wstat);
993 if (retval < 0)
994 return retval;
995
996 v9fs_invalidate_inode_attr(dentry->d_inode);
997 if ((iattr->ia_valid & ATTR_SIZE) &&
998 iattr->ia_size != i_size_read(dentry->d_inode)) {
999 retval = vmtruncate(dentry->d_inode, iattr->ia_size);
1000 if (retval)
1001 return retval;
1002 }
1003
1004 setattr_copy(dentry->d_inode, iattr);
1005 mark_inode_dirty(dentry->d_inode);
1006 return 0;
1007 }
1008
1009 /**
1010 * v9fs_stat2inode - populate an inode structure with mistat info
1011 * @stat: Plan 9 metadata (mistat) structure
1012 * @inode: inode to populate
1013 * @sb: superblock of filesystem
1014 *
1015 */
1016
1017 void
1018 v9fs_stat2inode(struct p9_wstat *stat, struct inode *inode,
1019 struct super_block *sb)
1020 {
1021 char ext[32];
1022 char tag_name[14];
1023 unsigned int i_nlink;
1024 struct v9fs_session_info *v9ses = sb->s_fs_info;
1025 struct v9fs_inode *v9inode = V9FS_I(inode);
1026
1027 inode->i_nlink = 1;
1028
1029 inode->i_atime.tv_sec = stat->atime;
1030 inode->i_mtime.tv_sec = stat->mtime;
1031 inode->i_ctime.tv_sec = stat->mtime;
1032
1033 inode->i_uid = v9ses->dfltuid;
1034 inode->i_gid = v9ses->dfltgid;
1035
1036 if (v9fs_proto_dotu(v9ses)) {
1037 inode->i_uid = stat->n_uid;
1038 inode->i_gid = stat->n_gid;
1039 }
1040 if ((S_ISREG(inode->i_mode)) || (S_ISDIR(inode->i_mode))) {
1041 if (v9fs_proto_dotu(v9ses) && (stat->extension[0] != '\0')) {
1042 /*
1043 * Hadlink support got added later to
1044 * to the .u extension. So there can be
1045 * server out there that doesn't support
1046 * this even with .u extension. So check
1047 * for non NULL stat->extension
1048 */
1049 strncpy(ext, stat->extension, sizeof(ext));
1050 /* HARDLINKCOUNT %u */
1051 sscanf(ext, "%13s %u", tag_name, &i_nlink);
1052 if (!strncmp(tag_name, "HARDLINKCOUNT", 13))
1053 inode->i_nlink = i_nlink;
1054 }
1055 }
1056 inode->i_mode = p9mode2unixmode(v9ses, stat->mode);
1057 if ((S_ISBLK(inode->i_mode)) || (S_ISCHR(inode->i_mode))) {
1058 char type = 0;
1059 int major = -1;
1060 int minor = -1;
1061
1062 strncpy(ext, stat->extension, sizeof(ext));
1063 sscanf(ext, "%c %u %u", &type, &major, &minor);
1064 switch (type) {
1065 case 'c':
1066 inode->i_mode &= ~S_IFBLK;
1067 inode->i_mode |= S_IFCHR;
1068 break;
1069 case 'b':
1070 break;
1071 default:
1072 P9_DPRINTK(P9_DEBUG_ERROR,
1073 "Unknown special type %c %s\n", type,
1074 stat->extension);
1075 };
1076 inode->i_rdev = MKDEV(major, minor);
1077 init_special_inode(inode, inode->i_mode, inode->i_rdev);
1078 } else
1079 inode->i_rdev = 0;
1080
1081 i_size_write(inode, stat->length);
1082
1083 /* not real number of blocks, but 512 byte ones ... */
1084 inode->i_blocks = (i_size_read(inode) + 512 - 1) >> 9;
1085 v9inode->cache_validity &= ~V9FS_INO_INVALID_ATTR;
1086 }
1087
1088 /**
1089 * v9fs_qid2ino - convert qid into inode number
1090 * @qid: qid to hash
1091 *
1092 * BUG: potential for inode number collisions?
1093 */
1094
1095 ino_t v9fs_qid2ino(struct p9_qid *qid)
1096 {
1097 u64 path = qid->path + 2;
1098 ino_t i = 0;
1099
1100 if (sizeof(ino_t) == sizeof(path))
1101 memcpy(&i, &path, sizeof(ino_t));
1102 else
1103 i = (ino_t) (path ^ (path >> 32));
1104
1105 return i;
1106 }
1107
1108 /**
1109 * v9fs_readlink - read a symlink's location (internal version)
1110 * @dentry: dentry for symlink
1111 * @buffer: buffer to load symlink location into
1112 * @buflen: length of buffer
1113 *
1114 */
1115
1116 static int v9fs_readlink(struct dentry *dentry, char *buffer, int buflen)
1117 {
1118 int retval;
1119
1120 struct v9fs_session_info *v9ses;
1121 struct p9_fid *fid;
1122 struct p9_wstat *st;
1123
1124 P9_DPRINTK(P9_DEBUG_VFS, " %s\n", dentry->d_name.name);
1125 retval = -EPERM;
1126 v9ses = v9fs_inode2v9ses(dentry->d_inode);
1127 fid = v9fs_fid_lookup(dentry);
1128 if (IS_ERR(fid))
1129 return PTR_ERR(fid);
1130
1131 if (!v9fs_proto_dotu(v9ses))
1132 return -EBADF;
1133
1134 st = p9_client_stat(fid);
1135 if (IS_ERR(st))
1136 return PTR_ERR(st);
1137
1138 if (!(st->mode & P9_DMSYMLINK)) {
1139 retval = -EINVAL;
1140 goto done;
1141 }
1142
1143 /* copy extension buffer into buffer */
1144 strncpy(buffer, st->extension, buflen);
1145
1146 P9_DPRINTK(P9_DEBUG_VFS,
1147 "%s -> %s (%s)\n", dentry->d_name.name, st->extension, buffer);
1148
1149 retval = strnlen(buffer, buflen);
1150 done:
1151 p9stat_free(st);
1152 kfree(st);
1153 return retval;
1154 }
1155
1156 /**
1157 * v9fs_vfs_follow_link - follow a symlink path
1158 * @dentry: dentry for symlink
1159 * @nd: nameidata
1160 *
1161 */
1162
1163 static void *v9fs_vfs_follow_link(struct dentry *dentry, struct nameidata *nd)
1164 {
1165 int len = 0;
1166 char *link = __getname();
1167
1168 P9_DPRINTK(P9_DEBUG_VFS, "%s n", dentry->d_name.name);
1169
1170 if (!link)
1171 link = ERR_PTR(-ENOMEM);
1172 else {
1173 len = v9fs_readlink(dentry, link, PATH_MAX);
1174
1175 if (len < 0) {
1176 __putname(link);
1177 link = ERR_PTR(len);
1178 } else
1179 link[min(len, PATH_MAX-1)] = 0;
1180 }
1181 nd_set_link(nd, link);
1182
1183 return NULL;
1184 }
1185
1186 /**
1187 * v9fs_vfs_put_link - release a symlink path
1188 * @dentry: dentry for symlink
1189 * @nd: nameidata
1190 * @p: unused
1191 *
1192 */
1193
1194 void
1195 v9fs_vfs_put_link(struct dentry *dentry, struct nameidata *nd, void *p)
1196 {
1197 char *s = nd_get_link(nd);
1198
1199 P9_DPRINTK(P9_DEBUG_VFS, " %s %s\n", dentry->d_name.name,
1200 IS_ERR(s) ? "<error>" : s);
1201 if (!IS_ERR(s))
1202 __putname(s);
1203 }
1204
1205 /**
1206 * v9fs_vfs_mkspecial - create a special file
1207 * @dir: inode to create special file in
1208 * @dentry: dentry to create
1209 * @mode: mode to create special file
1210 * @extension: 9p2000.u format extension string representing special file
1211 *
1212 */
1213
1214 static int v9fs_vfs_mkspecial(struct inode *dir, struct dentry *dentry,
1215 int mode, const char *extension)
1216 {
1217 u32 perm;
1218 struct p9_fid *fid;
1219 struct v9fs_session_info *v9ses;
1220
1221 v9ses = v9fs_inode2v9ses(dir);
1222 if (!v9fs_proto_dotu(v9ses)) {
1223 P9_DPRINTK(P9_DEBUG_ERROR, "not extended\n");
1224 return -EPERM;
1225 }
1226
1227 perm = unixmode2p9mode(v9ses, mode);
1228 fid = v9fs_create(v9ses, dir, dentry, (char *) extension, perm,
1229 P9_OREAD);
1230 if (IS_ERR(fid))
1231 return PTR_ERR(fid);
1232
1233 v9fs_invalidate_inode_attr(dir);
1234 p9_client_clunk(fid);
1235 return 0;
1236 }
1237
1238 /**
1239 * v9fs_vfs_symlink - helper function to create symlinks
1240 * @dir: directory inode containing symlink
1241 * @dentry: dentry for symlink
1242 * @symname: symlink data
1243 *
1244 * See Also: 9P2000.u RFC for more information
1245 *
1246 */
1247
1248 static int
1249 v9fs_vfs_symlink(struct inode *dir, struct dentry *dentry, const char *symname)
1250 {
1251 P9_DPRINTK(P9_DEBUG_VFS, " %lu,%s,%s\n", dir->i_ino,
1252 dentry->d_name.name, symname);
1253
1254 return v9fs_vfs_mkspecial(dir, dentry, S_IFLNK, symname);
1255 }
1256
1257 /**
1258 * v9fs_vfs_link - create a hardlink
1259 * @old_dentry: dentry for file to link to
1260 * @dir: inode destination for new link
1261 * @dentry: dentry for link
1262 *
1263 */
1264
1265 static int
1266 v9fs_vfs_link(struct dentry *old_dentry, struct inode *dir,
1267 struct dentry *dentry)
1268 {
1269 int retval;
1270 char *name;
1271 struct p9_fid *oldfid;
1272
1273 P9_DPRINTK(P9_DEBUG_VFS,
1274 " %lu,%s,%s\n", dir->i_ino, dentry->d_name.name,
1275 old_dentry->d_name.name);
1276
1277 oldfid = v9fs_fid_clone(old_dentry);
1278 if (IS_ERR(oldfid))
1279 return PTR_ERR(oldfid);
1280
1281 name = __getname();
1282 if (unlikely(!name)) {
1283 retval = -ENOMEM;
1284 goto clunk_fid;
1285 }
1286
1287 sprintf(name, "%d\n", oldfid->fid);
1288 retval = v9fs_vfs_mkspecial(dir, dentry, P9_DMLINK, name);
1289 __putname(name);
1290 if (!retval)
1291 v9fs_invalidate_inode_attr(dir);
1292 clunk_fid:
1293 p9_client_clunk(oldfid);
1294 return retval;
1295 }
1296
1297 /**
1298 * v9fs_vfs_mknod - create a special file
1299 * @dir: inode destination for new link
1300 * @dentry: dentry for file
1301 * @mode: mode for creation
1302 * @rdev: device associated with special file
1303 *
1304 */
1305
1306 static int
1307 v9fs_vfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t rdev)
1308 {
1309 int retval;
1310 char *name;
1311
1312 P9_DPRINTK(P9_DEBUG_VFS,
1313 " %lu,%s mode: %x MAJOR: %u MINOR: %u\n", dir->i_ino,
1314 dentry->d_name.name, mode, MAJOR(rdev), MINOR(rdev));
1315
1316 if (!new_valid_dev(rdev))
1317 return -EINVAL;
1318
1319 name = __getname();
1320 if (!name)
1321 return -ENOMEM;
1322 /* build extension */
1323 if (S_ISBLK(mode))
1324 sprintf(name, "b %u %u", MAJOR(rdev), MINOR(rdev));
1325 else if (S_ISCHR(mode))
1326 sprintf(name, "c %u %u", MAJOR(rdev), MINOR(rdev));
1327 else if (S_ISFIFO(mode))
1328 *name = 0;
1329 else if (S_ISSOCK(mode))
1330 *name = 0;
1331 else {
1332 __putname(name);
1333 return -EINVAL;
1334 }
1335
1336 retval = v9fs_vfs_mkspecial(dir, dentry, mode, name);
1337 __putname(name);
1338
1339 return retval;
1340 }
1341
1342 int v9fs_refresh_inode(struct p9_fid *fid, struct inode *inode)
1343 {
1344 loff_t i_size;
1345 struct p9_wstat *st;
1346 struct v9fs_session_info *v9ses;
1347
1348 v9ses = v9fs_inode2v9ses(inode);
1349 st = p9_client_stat(fid);
1350 if (IS_ERR(st))
1351 return PTR_ERR(st);
1352
1353 spin_lock(&inode->i_lock);
1354 /*
1355 * We don't want to refresh inode->i_size,
1356 * because we may have cached data
1357 */
1358 i_size = inode->i_size;
1359 v9fs_stat2inode(st, inode, inode->i_sb);
1360 if (v9ses->cache)
1361 inode->i_size = i_size;
1362 spin_unlock(&inode->i_lock);
1363 p9stat_free(st);
1364 kfree(st);
1365 return 0;
1366 }
1367
1368 static const struct inode_operations v9fs_dir_inode_operations_dotu = {
1369 .create = v9fs_vfs_create,
1370 .lookup = v9fs_vfs_lookup,
1371 .symlink = v9fs_vfs_symlink,
1372 .link = v9fs_vfs_link,
1373 .unlink = v9fs_vfs_unlink,
1374 .mkdir = v9fs_vfs_mkdir,
1375 .rmdir = v9fs_vfs_rmdir,
1376 .mknod = v9fs_vfs_mknod,
1377 .rename = v9fs_vfs_rename,
1378 .getattr = v9fs_vfs_getattr,
1379 .setattr = v9fs_vfs_setattr,
1380 };
1381
1382 static const struct inode_operations v9fs_dir_inode_operations = {
1383 .create = v9fs_vfs_create,
1384 .lookup = v9fs_vfs_lookup,
1385 .unlink = v9fs_vfs_unlink,
1386 .mkdir = v9fs_vfs_mkdir,
1387 .rmdir = v9fs_vfs_rmdir,
1388 .mknod = v9fs_vfs_mknod,
1389 .rename = v9fs_vfs_rename,
1390 .getattr = v9fs_vfs_getattr,
1391 .setattr = v9fs_vfs_setattr,
1392 };
1393
1394 static const struct inode_operations v9fs_file_inode_operations = {
1395 .getattr = v9fs_vfs_getattr,
1396 .setattr = v9fs_vfs_setattr,
1397 };
1398
1399 static const struct inode_operations v9fs_symlink_inode_operations = {
1400 .readlink = generic_readlink,
1401 .follow_link = v9fs_vfs_follow_link,
1402 .put_link = v9fs_vfs_put_link,
1403 .getattr = v9fs_vfs_getattr,
1404 .setattr = v9fs_vfs_setattr,
1405 };
1406