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 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
27
28 #include <linux/module.h>
29 #include <linux/errno.h>
30 #include <linux/fs.h>
31 #include <linux/file.h>
32 #include <linux/pagemap.h>
33 #include <linux/stat.h>
34 #include <linux/string.h>
35 #include <linux/inet.h>
36 #include <linux/namei.h>
37 #include <linux/idr.h>
38 #include <linux/sched.h>
39 #include <linux/slab.h>
40 #include <linux/xattr.h>
41 #include <linux/posix_acl.h>
42 #include <net/9p/9p.h>
43 #include <net/9p/client.h>
44
45 #include "v9fs.h"
46 #include "v9fs_vfs.h"
47 #include "fid.h"
48 #include "cache.h"
49 #include "xattr.h"
50 #include "acl.h"
51
52 static const struct inode_operations v9fs_dir_inode_operations;
53 static const struct inode_operations v9fs_dir_inode_operations_dotu;
54 static const struct inode_operations v9fs_file_inode_operations;
55 static const struct inode_operations v9fs_symlink_inode_operations;
56
57 /**
58 * unixmode2p9mode - convert unix mode bits to plan 9
59 * @v9ses: v9fs session information
60 * @mode: mode to convert
61 *
62 */
63
unixmode2p9mode(struct v9fs_session_info * v9ses,umode_t mode)64 static u32 unixmode2p9mode(struct v9fs_session_info *v9ses, umode_t mode)
65 {
66 int res;
67 res = mode & 0777;
68 if (S_ISDIR(mode))
69 res |= P9_DMDIR;
70 if (v9fs_proto_dotu(v9ses)) {
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 }
89 return res;
90 }
91
92 /**
93 * p9mode2perm- convert plan9 mode bits to unix permission bits
94 * @v9ses: v9fs session information
95 * @stat: p9_wstat from which mode need to be derived
96 *
97 */
p9mode2perm(struct v9fs_session_info * v9ses,struct p9_wstat * stat)98 static int p9mode2perm(struct v9fs_session_info *v9ses,
99 struct p9_wstat *stat)
100 {
101 int res;
102 int mode = stat->mode;
103
104 res = mode & S_IALLUGO;
105 if (v9fs_proto_dotu(v9ses)) {
106 if ((mode & P9_DMSETUID) == P9_DMSETUID)
107 res |= S_ISUID;
108
109 if ((mode & P9_DMSETGID) == P9_DMSETGID)
110 res |= S_ISGID;
111
112 if ((mode & P9_DMSETVTX) == P9_DMSETVTX)
113 res |= S_ISVTX;
114 }
115 return res;
116 }
117
118 /**
119 * p9mode2unixmode- convert plan9 mode bits to unix mode bits
120 * @v9ses: v9fs session information
121 * @stat: p9_wstat from which mode need to be derived
122 * @rdev: major number, minor number in case of device files.
123 *
124 */
p9mode2unixmode(struct v9fs_session_info * v9ses,struct p9_wstat * stat,dev_t * rdev)125 static umode_t p9mode2unixmode(struct v9fs_session_info *v9ses,
126 struct p9_wstat *stat, dev_t *rdev)
127 {
128 int res;
129 u32 mode = stat->mode;
130
131 *rdev = 0;
132 res = p9mode2perm(v9ses, stat);
133
134 if ((mode & P9_DMDIR) == P9_DMDIR)
135 res |= S_IFDIR;
136 else if ((mode & P9_DMSYMLINK) && (v9fs_proto_dotu(v9ses)))
137 res |= S_IFLNK;
138 else if ((mode & P9_DMSOCKET) && (v9fs_proto_dotu(v9ses))
139 && (v9ses->nodev == 0))
140 res |= S_IFSOCK;
141 else if ((mode & P9_DMNAMEDPIPE) && (v9fs_proto_dotu(v9ses))
142 && (v9ses->nodev == 0))
143 res |= S_IFIFO;
144 else if ((mode & P9_DMDEVICE) && (v9fs_proto_dotu(v9ses))
145 && (v9ses->nodev == 0)) {
146 char type = 0, ext[32];
147 int major = -1, minor = -1;
148
149 strncpy(ext, stat->extension, sizeof(ext));
150 sscanf(ext, "%c %u %u", &type, &major, &minor);
151 switch (type) {
152 case 'c':
153 res |= S_IFCHR;
154 break;
155 case 'b':
156 res |= S_IFBLK;
157 break;
158 default:
159 p9_debug(P9_DEBUG_ERROR, "Unknown special type %c %s\n",
160 type, stat->extension);
161 };
162 *rdev = MKDEV(major, minor);
163 } else
164 res |= S_IFREG;
165
166 return res;
167 }
168
169 /**
170 * v9fs_uflags2omode- convert posix open flags to plan 9 mode bits
171 * @uflags: flags to convert
172 * @extended: if .u extensions are active
173 */
174
v9fs_uflags2omode(int uflags,int extended)175 int v9fs_uflags2omode(int uflags, int extended)
176 {
177 int ret;
178
179 ret = 0;
180 switch (uflags&3) {
181 default:
182 case O_RDONLY:
183 ret = P9_OREAD;
184 break;
185
186 case O_WRONLY:
187 ret = P9_OWRITE;
188 break;
189
190 case O_RDWR:
191 ret = P9_ORDWR;
192 break;
193 }
194
195 if (uflags & O_TRUNC)
196 ret |= P9_OTRUNC;
197
198 if (extended) {
199 if (uflags & O_EXCL)
200 ret |= P9_OEXCL;
201
202 if (uflags & O_APPEND)
203 ret |= P9_OAPPEND;
204 }
205
206 return ret;
207 }
208
209 /**
210 * v9fs_blank_wstat - helper function to setup a 9P stat structure
211 * @wstat: structure to initialize
212 *
213 */
214
215 void
v9fs_blank_wstat(struct p9_wstat * wstat)216 v9fs_blank_wstat(struct p9_wstat *wstat)
217 {
218 wstat->type = ~0;
219 wstat->dev = ~0;
220 wstat->qid.type = ~0;
221 wstat->qid.version = ~0;
222 *((long long *)&wstat->qid.path) = ~0;
223 wstat->mode = ~0;
224 wstat->atime = ~0;
225 wstat->mtime = ~0;
226 wstat->length = ~0;
227 wstat->name = NULL;
228 wstat->uid = NULL;
229 wstat->gid = NULL;
230 wstat->muid = NULL;
231 wstat->n_uid = ~0;
232 wstat->n_gid = ~0;
233 wstat->n_muid = ~0;
234 wstat->extension = NULL;
235 }
236
237 /**
238 * v9fs_alloc_inode - helper function to allocate an inode
239 *
240 */
v9fs_alloc_inode(struct super_block * sb)241 struct inode *v9fs_alloc_inode(struct super_block *sb)
242 {
243 struct v9fs_inode *v9inode;
244 v9inode = (struct v9fs_inode *)kmem_cache_alloc(v9fs_inode_cache,
245 GFP_KERNEL);
246 if (!v9inode)
247 return NULL;
248 #ifdef CONFIG_9P_FSCACHE
249 v9inode->fscache = NULL;
250 spin_lock_init(&v9inode->fscache_lock);
251 #endif
252 v9inode->writeback_fid = NULL;
253 v9inode->cache_validity = 0;
254 mutex_init(&v9inode->v_mutex);
255 return &v9inode->vfs_inode;
256 }
257
258 /**
259 * v9fs_destroy_inode - destroy an inode
260 *
261 */
262
v9fs_i_callback(struct rcu_head * head)263 static void v9fs_i_callback(struct rcu_head *head)
264 {
265 struct inode *inode = container_of(head, struct inode, i_rcu);
266 kmem_cache_free(v9fs_inode_cache, V9FS_I(inode));
267 }
268
v9fs_destroy_inode(struct inode * inode)269 void v9fs_destroy_inode(struct inode *inode)
270 {
271 call_rcu(&inode->i_rcu, v9fs_i_callback);
272 }
273
v9fs_init_inode(struct v9fs_session_info * v9ses,struct inode * inode,umode_t mode,dev_t rdev)274 int v9fs_init_inode(struct v9fs_session_info *v9ses,
275 struct inode *inode, umode_t mode, dev_t rdev)
276 {
277 int err = 0;
278
279 inode_init_owner(inode, NULL, mode);
280 inode->i_blocks = 0;
281 inode->i_rdev = rdev;
282 inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
283 inode->i_mapping->a_ops = &v9fs_addr_operations;
284
285 switch (mode & S_IFMT) {
286 case S_IFIFO:
287 case S_IFBLK:
288 case S_IFCHR:
289 case S_IFSOCK:
290 if (v9fs_proto_dotl(v9ses)) {
291 inode->i_op = &v9fs_file_inode_operations_dotl;
292 } else if (v9fs_proto_dotu(v9ses)) {
293 inode->i_op = &v9fs_file_inode_operations;
294 } else {
295 p9_debug(P9_DEBUG_ERROR,
296 "special files without extended mode\n");
297 err = -EINVAL;
298 goto error;
299 }
300 init_special_inode(inode, inode->i_mode, inode->i_rdev);
301 break;
302 case S_IFREG:
303 if (v9fs_proto_dotl(v9ses)) {
304 inode->i_op = &v9fs_file_inode_operations_dotl;
305 if (v9ses->cache)
306 inode->i_fop =
307 &v9fs_cached_file_operations_dotl;
308 else
309 inode->i_fop = &v9fs_file_operations_dotl;
310 } else {
311 inode->i_op = &v9fs_file_inode_operations;
312 if (v9ses->cache)
313 inode->i_fop = &v9fs_cached_file_operations;
314 else
315 inode->i_fop = &v9fs_file_operations;
316 }
317
318 break;
319 case S_IFLNK:
320 if (!v9fs_proto_dotu(v9ses) && !v9fs_proto_dotl(v9ses)) {
321 p9_debug(P9_DEBUG_ERROR,
322 "extended modes used with legacy protocol\n");
323 err = -EINVAL;
324 goto error;
325 }
326
327 if (v9fs_proto_dotl(v9ses))
328 inode->i_op = &v9fs_symlink_inode_operations_dotl;
329 else
330 inode->i_op = &v9fs_symlink_inode_operations;
331
332 break;
333 case S_IFDIR:
334 inc_nlink(inode);
335 if (v9fs_proto_dotl(v9ses))
336 inode->i_op = &v9fs_dir_inode_operations_dotl;
337 else if (v9fs_proto_dotu(v9ses))
338 inode->i_op = &v9fs_dir_inode_operations_dotu;
339 else
340 inode->i_op = &v9fs_dir_inode_operations;
341
342 if (v9fs_proto_dotl(v9ses))
343 inode->i_fop = &v9fs_dir_operations_dotl;
344 else
345 inode->i_fop = &v9fs_dir_operations;
346
347 break;
348 default:
349 p9_debug(P9_DEBUG_ERROR, "BAD mode 0x%hx S_IFMT 0x%x\n",
350 mode, mode & S_IFMT);
351 err = -EINVAL;
352 goto error;
353 }
354 error:
355 return err;
356
357 }
358
359 /**
360 * v9fs_get_inode - helper function to setup an inode
361 * @sb: superblock
362 * @mode: mode to setup inode with
363 *
364 */
365
v9fs_get_inode(struct super_block * sb,umode_t mode,dev_t rdev)366 struct inode *v9fs_get_inode(struct super_block *sb, umode_t mode, dev_t rdev)
367 {
368 int err;
369 struct inode *inode;
370 struct v9fs_session_info *v9ses = sb->s_fs_info;
371
372 p9_debug(P9_DEBUG_VFS, "super block: %p mode: %ho\n", sb, mode);
373
374 inode = new_inode(sb);
375 if (!inode) {
376 pr_warn("%s (%d): Problem allocating inode\n",
377 __func__, task_pid_nr(current));
378 return ERR_PTR(-ENOMEM);
379 }
380 err = v9fs_init_inode(v9ses, inode, mode, rdev);
381 if (err) {
382 iput(inode);
383 return ERR_PTR(err);
384 }
385 return inode;
386 }
387
388 /*
389 static struct v9fs_fid*
390 v9fs_clone_walk(struct v9fs_session_info *v9ses, u32 fid, struct dentry *dentry)
391 {
392 int err;
393 int nfid;
394 struct v9fs_fid *ret;
395 struct v9fs_fcall *fcall;
396
397 nfid = v9fs_get_idpool(&v9ses->fidpool);
398 if (nfid < 0) {
399 eprintk(KERN_WARNING, "no free fids available\n");
400 return ERR_PTR(-ENOSPC);
401 }
402
403 err = v9fs_t_walk(v9ses, fid, nfid, (char *) dentry->d_name.name,
404 &fcall);
405
406 if (err < 0) {
407 if (fcall && fcall->id == RWALK)
408 goto clunk_fid;
409
410 PRINT_FCALL_ERROR("walk error", fcall);
411 v9fs_put_idpool(nfid, &v9ses->fidpool);
412 goto error;
413 }
414
415 kfree(fcall);
416 fcall = NULL;
417 ret = v9fs_fid_create(v9ses, nfid);
418 if (!ret) {
419 err = -ENOMEM;
420 goto clunk_fid;
421 }
422
423 err = v9fs_fid_insert(ret, dentry);
424 if (err < 0) {
425 v9fs_fid_destroy(ret);
426 goto clunk_fid;
427 }
428
429 return ret;
430
431 clunk_fid:
432 v9fs_t_clunk(v9ses, nfid);
433
434 error:
435 kfree(fcall);
436 return ERR_PTR(err);
437 }
438 */
439
440
441 /**
442 * v9fs_clear_inode - release an inode
443 * @inode: inode to release
444 *
445 */
v9fs_evict_inode(struct inode * inode)446 void v9fs_evict_inode(struct inode *inode)
447 {
448 struct v9fs_inode *v9inode = V9FS_I(inode);
449
450 truncate_inode_pages(inode->i_mapping, 0);
451 end_writeback(inode);
452 filemap_fdatawrite(inode->i_mapping);
453
454 #ifdef CONFIG_9P_FSCACHE
455 v9fs_cache_inode_put_cookie(inode);
456 #endif
457 /* clunk the fid stashed in writeback_fid */
458 if (v9inode->writeback_fid) {
459 p9_client_clunk(v9inode->writeback_fid);
460 v9inode->writeback_fid = NULL;
461 }
462 }
463
v9fs_test_inode(struct inode * inode,void * data)464 static int v9fs_test_inode(struct inode *inode, void *data)
465 {
466 int umode;
467 dev_t rdev;
468 struct v9fs_inode *v9inode = V9FS_I(inode);
469 struct p9_wstat *st = (struct p9_wstat *)data;
470 struct v9fs_session_info *v9ses = v9fs_inode2v9ses(inode);
471
472 umode = p9mode2unixmode(v9ses, st, &rdev);
473 /* don't match inode of different type */
474 if ((inode->i_mode & S_IFMT) != (umode & S_IFMT))
475 return 0;
476
477 /* compare qid details */
478 if (memcmp(&v9inode->qid.version,
479 &st->qid.version, sizeof(v9inode->qid.version)))
480 return 0;
481
482 if (v9inode->qid.type != st->qid.type)
483 return 0;
484 return 1;
485 }
486
v9fs_test_new_inode(struct inode * inode,void * data)487 static int v9fs_test_new_inode(struct inode *inode, void *data)
488 {
489 return 0;
490 }
491
v9fs_set_inode(struct inode * inode,void * data)492 static int v9fs_set_inode(struct inode *inode, void *data)
493 {
494 struct v9fs_inode *v9inode = V9FS_I(inode);
495 struct p9_wstat *st = (struct p9_wstat *)data;
496
497 memcpy(&v9inode->qid, &st->qid, sizeof(st->qid));
498 return 0;
499 }
500
v9fs_qid_iget(struct super_block * sb,struct p9_qid * qid,struct p9_wstat * st,int new)501 static struct inode *v9fs_qid_iget(struct super_block *sb,
502 struct p9_qid *qid,
503 struct p9_wstat *st,
504 int new)
505 {
506 dev_t rdev;
507 int retval;
508 umode_t umode;
509 unsigned long i_ino;
510 struct inode *inode;
511 struct v9fs_session_info *v9ses = sb->s_fs_info;
512 int (*test)(struct inode *, void *);
513
514 if (new)
515 test = v9fs_test_new_inode;
516 else
517 test = v9fs_test_inode;
518
519 i_ino = v9fs_qid2ino(qid);
520 inode = iget5_locked(sb, i_ino, test, v9fs_set_inode, st);
521 if (!inode)
522 return ERR_PTR(-ENOMEM);
523 if (!(inode->i_state & I_NEW))
524 return inode;
525 /*
526 * initialize the inode with the stat info
527 * FIXME!! we may need support for stale inodes
528 * later.
529 */
530 inode->i_ino = i_ino;
531 umode = p9mode2unixmode(v9ses, st, &rdev);
532 retval = v9fs_init_inode(v9ses, inode, umode, rdev);
533 if (retval)
534 goto error;
535
536 v9fs_stat2inode(st, inode, sb);
537 #ifdef CONFIG_9P_FSCACHE
538 v9fs_cache_inode_get_cookie(inode);
539 #endif
540 unlock_new_inode(inode);
541 return inode;
542 error:
543 unlock_new_inode(inode);
544 iput(inode);
545 return ERR_PTR(retval);
546
547 }
548
549 struct inode *
v9fs_inode_from_fid(struct v9fs_session_info * v9ses,struct p9_fid * fid,struct super_block * sb,int new)550 v9fs_inode_from_fid(struct v9fs_session_info *v9ses, struct p9_fid *fid,
551 struct super_block *sb, int new)
552 {
553 struct p9_wstat *st;
554 struct inode *inode = NULL;
555
556 st = p9_client_stat(fid);
557 if (IS_ERR(st))
558 return ERR_CAST(st);
559
560 inode = v9fs_qid_iget(sb, &st->qid, st, new);
561 p9stat_free(st);
562 kfree(st);
563 return inode;
564 }
565
566 /**
567 * v9fs_at_to_dotl_flags- convert Linux specific AT flags to
568 * plan 9 AT flag.
569 * @flags: flags to convert
570 */
v9fs_at_to_dotl_flags(int flags)571 static int v9fs_at_to_dotl_flags(int flags)
572 {
573 int rflags = 0;
574 if (flags & AT_REMOVEDIR)
575 rflags |= P9_DOTL_AT_REMOVEDIR;
576 return rflags;
577 }
578
579 /**
580 * v9fs_remove - helper function to remove files and directories
581 * @dir: directory inode that is being deleted
582 * @dentry: dentry that is being deleted
583 * @rmdir: removing a directory
584 *
585 */
586
v9fs_remove(struct inode * dir,struct dentry * dentry,int flags)587 static int v9fs_remove(struct inode *dir, struct dentry *dentry, int flags)
588 {
589 struct inode *inode;
590 int retval = -EOPNOTSUPP;
591 struct p9_fid *v9fid, *dfid;
592 struct v9fs_session_info *v9ses;
593
594 p9_debug(P9_DEBUG_VFS, "inode: %p dentry: %p rmdir: %x\n",
595 dir, dentry, flags);
596
597 v9ses = v9fs_inode2v9ses(dir);
598 inode = dentry->d_inode;
599 dfid = v9fs_fid_lookup(dentry->d_parent);
600 if (IS_ERR(dfid)) {
601 retval = PTR_ERR(dfid);
602 p9_debug(P9_DEBUG_VFS, "fid lookup failed %d\n", retval);
603 return retval;
604 }
605 if (v9fs_proto_dotl(v9ses))
606 retval = p9_client_unlinkat(dfid, dentry->d_name.name,
607 v9fs_at_to_dotl_flags(flags));
608 if (retval == -EOPNOTSUPP) {
609 /* Try the one based on path */
610 v9fid = v9fs_fid_clone(dentry);
611 if (IS_ERR(v9fid))
612 return PTR_ERR(v9fid);
613 retval = p9_client_remove(v9fid);
614 }
615 if (!retval) {
616 /*
617 * directories on unlink should have zero
618 * link count
619 */
620 if (flags & AT_REMOVEDIR) {
621 clear_nlink(inode);
622 drop_nlink(dir);
623 } else
624 drop_nlink(inode);
625
626 v9fs_invalidate_inode_attr(inode);
627 v9fs_invalidate_inode_attr(dir);
628 }
629 return retval;
630 }
631
632 /**
633 * v9fs_create - Create a file
634 * @v9ses: session information
635 * @dir: directory that dentry is being created in
636 * @dentry: dentry that is being created
637 * @extension: 9p2000.u extension string to support devices, etc.
638 * @perm: create permissions
639 * @mode: open mode
640 *
641 */
642 static struct p9_fid *
v9fs_create(struct v9fs_session_info * v9ses,struct inode * dir,struct dentry * dentry,char * extension,u32 perm,u8 mode)643 v9fs_create(struct v9fs_session_info *v9ses, struct inode *dir,
644 struct dentry *dentry, char *extension, u32 perm, u8 mode)
645 {
646 int err;
647 char *name;
648 struct p9_fid *dfid, *ofid, *fid;
649 struct inode *inode;
650
651 p9_debug(P9_DEBUG_VFS, "name %s\n", dentry->d_name.name);
652
653 err = 0;
654 ofid = NULL;
655 fid = NULL;
656 name = (char *) dentry->d_name.name;
657 dfid = v9fs_fid_lookup(dentry->d_parent);
658 if (IS_ERR(dfid)) {
659 err = PTR_ERR(dfid);
660 p9_debug(P9_DEBUG_VFS, "fid lookup failed %d\n", err);
661 return ERR_PTR(err);
662 }
663
664 /* clone a fid to use for creation */
665 ofid = p9_client_walk(dfid, 0, NULL, 1);
666 if (IS_ERR(ofid)) {
667 err = PTR_ERR(ofid);
668 p9_debug(P9_DEBUG_VFS, "p9_client_walk failed %d\n", err);
669 return ERR_PTR(err);
670 }
671
672 err = p9_client_fcreate(ofid, name, perm, mode, extension);
673 if (err < 0) {
674 p9_debug(P9_DEBUG_VFS, "p9_client_fcreate failed %d\n", err);
675 goto error;
676 }
677
678 if (!(perm & P9_DMLINK)) {
679 /* now walk from the parent so we can get unopened fid */
680 fid = p9_client_walk(dfid, 1, &name, 1);
681 if (IS_ERR(fid)) {
682 err = PTR_ERR(fid);
683 p9_debug(P9_DEBUG_VFS,
684 "p9_client_walk failed %d\n", err);
685 fid = NULL;
686 goto error;
687 }
688 /*
689 * instantiate inode and assign the unopened fid to the dentry
690 */
691 inode = v9fs_get_new_inode_from_fid(v9ses, fid, dir->i_sb);
692 if (IS_ERR(inode)) {
693 err = PTR_ERR(inode);
694 p9_debug(P9_DEBUG_VFS,
695 "inode creation failed %d\n", err);
696 goto error;
697 }
698 err = v9fs_fid_add(dentry, fid);
699 if (err < 0)
700 goto error;
701 d_instantiate(dentry, inode);
702 }
703 return ofid;
704 error:
705 if (ofid)
706 p9_client_clunk(ofid);
707
708 if (fid)
709 p9_client_clunk(fid);
710
711 return ERR_PTR(err);
712 }
713
714 /**
715 * v9fs_vfs_create - VFS hook to create files
716 * @dir: directory inode that is being created
717 * @dentry: dentry that is being deleted
718 * @mode: create permissions
719 * @nd: path information
720 *
721 */
722
723 static int
v9fs_vfs_create(struct inode * dir,struct dentry * dentry,umode_t mode,struct nameidata * nd)724 v9fs_vfs_create(struct inode *dir, struct dentry *dentry, umode_t mode,
725 struct nameidata *nd)
726 {
727 int err;
728 u32 perm;
729 int flags;
730 struct file *filp;
731 struct v9fs_inode *v9inode;
732 struct v9fs_session_info *v9ses;
733 struct p9_fid *fid, *inode_fid;
734
735 err = 0;
736 fid = NULL;
737 v9ses = v9fs_inode2v9ses(dir);
738 perm = unixmode2p9mode(v9ses, mode);
739 if (nd)
740 flags = nd->intent.open.flags;
741 else
742 flags = O_RDWR;
743
744 fid = v9fs_create(v9ses, dir, dentry, NULL, perm,
745 v9fs_uflags2omode(flags,
746 v9fs_proto_dotu(v9ses)));
747 if (IS_ERR(fid)) {
748 err = PTR_ERR(fid);
749 fid = NULL;
750 goto error;
751 }
752
753 v9fs_invalidate_inode_attr(dir);
754 /* if we are opening a file, assign the open fid to the file */
755 if (nd) {
756 v9inode = V9FS_I(dentry->d_inode);
757 mutex_lock(&v9inode->v_mutex);
758 if (v9ses->cache && !v9inode->writeback_fid &&
759 ((flags & O_ACCMODE) != O_RDONLY)) {
760 /*
761 * clone a fid and add it to writeback_fid
762 * we do it during open time instead of
763 * page dirty time via write_begin/page_mkwrite
764 * because we want write after unlink usecase
765 * to work.
766 */
767 inode_fid = v9fs_writeback_fid(dentry);
768 if (IS_ERR(inode_fid)) {
769 err = PTR_ERR(inode_fid);
770 mutex_unlock(&v9inode->v_mutex);
771 goto error;
772 }
773 v9inode->writeback_fid = (void *) inode_fid;
774 }
775 mutex_unlock(&v9inode->v_mutex);
776 filp = lookup_instantiate_filp(nd, dentry, generic_file_open);
777 if (IS_ERR(filp)) {
778 err = PTR_ERR(filp);
779 goto error;
780 }
781
782 filp->private_data = fid;
783 #ifdef CONFIG_9P_FSCACHE
784 if (v9ses->cache)
785 v9fs_cache_inode_set_cookie(dentry->d_inode, filp);
786 #endif
787 } else
788 p9_client_clunk(fid);
789
790 return 0;
791
792 error:
793 if (fid)
794 p9_client_clunk(fid);
795
796 return err;
797 }
798
799 /**
800 * v9fs_vfs_mkdir - VFS mkdir hook to create a directory
801 * @dir: inode that is being unlinked
802 * @dentry: dentry that is being unlinked
803 * @mode: mode for new directory
804 *
805 */
806
v9fs_vfs_mkdir(struct inode * dir,struct dentry * dentry,umode_t mode)807 static int v9fs_vfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
808 {
809 int err;
810 u32 perm;
811 struct p9_fid *fid;
812 struct v9fs_session_info *v9ses;
813
814 p9_debug(P9_DEBUG_VFS, "name %s\n", dentry->d_name.name);
815 err = 0;
816 v9ses = v9fs_inode2v9ses(dir);
817 perm = unixmode2p9mode(v9ses, mode | S_IFDIR);
818 fid = v9fs_create(v9ses, dir, dentry, NULL, perm, P9_OREAD);
819 if (IS_ERR(fid)) {
820 err = PTR_ERR(fid);
821 fid = NULL;
822 } else {
823 inc_nlink(dir);
824 v9fs_invalidate_inode_attr(dir);
825 }
826
827 if (fid)
828 p9_client_clunk(fid);
829
830 return err;
831 }
832
833 /**
834 * v9fs_vfs_lookup - VFS lookup hook to "walk" to a new inode
835 * @dir: inode that is being walked from
836 * @dentry: dentry that is being walked to?
837 * @nameidata: path data
838 *
839 */
840
v9fs_vfs_lookup(struct inode * dir,struct dentry * dentry,struct nameidata * nameidata)841 struct dentry *v9fs_vfs_lookup(struct inode *dir, struct dentry *dentry,
842 struct nameidata *nameidata)
843 {
844 struct dentry *res;
845 struct super_block *sb;
846 struct v9fs_session_info *v9ses;
847 struct p9_fid *dfid, *fid;
848 struct inode *inode;
849 char *name;
850 int result = 0;
851
852 p9_debug(P9_DEBUG_VFS, "dir: %p dentry: (%s) %p nameidata: %p\n",
853 dir, dentry->d_name.name, dentry, nameidata);
854
855 if (dentry->d_name.len > NAME_MAX)
856 return ERR_PTR(-ENAMETOOLONG);
857
858 sb = dir->i_sb;
859 v9ses = v9fs_inode2v9ses(dir);
860 /* We can walk d_parent because we hold the dir->i_mutex */
861 dfid = v9fs_fid_lookup(dentry->d_parent);
862 if (IS_ERR(dfid))
863 return ERR_CAST(dfid);
864
865 name = (char *) dentry->d_name.name;
866 fid = p9_client_walk(dfid, 1, &name, 1);
867 if (IS_ERR(fid)) {
868 result = PTR_ERR(fid);
869 if (result == -ENOENT) {
870 inode = NULL;
871 goto inst_out;
872 }
873
874 return ERR_PTR(result);
875 }
876 /*
877 * Make sure we don't use a wrong inode due to parallel
878 * unlink. For cached mode create calls request for new
879 * inode. But with cache disabled, lookup should do this.
880 */
881 if (v9ses->cache)
882 inode = v9fs_get_inode_from_fid(v9ses, fid, dir->i_sb);
883 else
884 inode = v9fs_get_new_inode_from_fid(v9ses, fid, dir->i_sb);
885 if (IS_ERR(inode)) {
886 result = PTR_ERR(inode);
887 inode = NULL;
888 goto error;
889 }
890 result = v9fs_fid_add(dentry, fid);
891 if (result < 0)
892 goto error_iput;
893 inst_out:
894 /*
895 * If we had a rename on the server and a parallel lookup
896 * for the new name, then make sure we instantiate with
897 * the new name. ie look up for a/b, while on server somebody
898 * moved b under k and client parallely did a lookup for
899 * k/b.
900 */
901 res = d_materialise_unique(dentry, inode);
902 if (!IS_ERR(res))
903 return res;
904 result = PTR_ERR(res);
905 error_iput:
906 iput(inode);
907 error:
908 p9_client_clunk(fid);
909
910 return ERR_PTR(result);
911 }
912
913 /**
914 * v9fs_vfs_unlink - VFS unlink hook to delete an inode
915 * @i: inode that is being unlinked
916 * @d: dentry that is being unlinked
917 *
918 */
919
v9fs_vfs_unlink(struct inode * i,struct dentry * d)920 int v9fs_vfs_unlink(struct inode *i, struct dentry *d)
921 {
922 return v9fs_remove(i, d, 0);
923 }
924
925 /**
926 * v9fs_vfs_rmdir - VFS unlink hook to delete a directory
927 * @i: inode that is being unlinked
928 * @d: dentry that is being unlinked
929 *
930 */
931
v9fs_vfs_rmdir(struct inode * i,struct dentry * d)932 int v9fs_vfs_rmdir(struct inode *i, struct dentry *d)
933 {
934 return v9fs_remove(i, d, AT_REMOVEDIR);
935 }
936
937 /**
938 * v9fs_vfs_rename - VFS hook to rename an inode
939 * @old_dir: old dir inode
940 * @old_dentry: old dentry
941 * @new_dir: new dir inode
942 * @new_dentry: new dentry
943 *
944 */
945
946 int
v9fs_vfs_rename(struct inode * old_dir,struct dentry * old_dentry,struct inode * new_dir,struct dentry * new_dentry)947 v9fs_vfs_rename(struct inode *old_dir, struct dentry *old_dentry,
948 struct inode *new_dir, struct dentry *new_dentry)
949 {
950 int retval;
951 struct inode *old_inode;
952 struct inode *new_inode;
953 struct v9fs_session_info *v9ses;
954 struct p9_fid *oldfid;
955 struct p9_fid *olddirfid;
956 struct p9_fid *newdirfid;
957 struct p9_wstat wstat;
958
959 p9_debug(P9_DEBUG_VFS, "\n");
960 retval = 0;
961 old_inode = old_dentry->d_inode;
962 new_inode = new_dentry->d_inode;
963 v9ses = v9fs_inode2v9ses(old_inode);
964 oldfid = v9fs_fid_lookup(old_dentry);
965 if (IS_ERR(oldfid))
966 return PTR_ERR(oldfid);
967
968 olddirfid = v9fs_fid_clone(old_dentry->d_parent);
969 if (IS_ERR(olddirfid)) {
970 retval = PTR_ERR(olddirfid);
971 goto done;
972 }
973
974 newdirfid = v9fs_fid_clone(new_dentry->d_parent);
975 if (IS_ERR(newdirfid)) {
976 retval = PTR_ERR(newdirfid);
977 goto clunk_olddir;
978 }
979
980 down_write(&v9ses->rename_sem);
981 if (v9fs_proto_dotl(v9ses)) {
982 retval = p9_client_renameat(olddirfid, old_dentry->d_name.name,
983 newdirfid, new_dentry->d_name.name);
984 if (retval == -EOPNOTSUPP)
985 retval = p9_client_rename(oldfid, newdirfid,
986 new_dentry->d_name.name);
987 if (retval != -EOPNOTSUPP)
988 goto clunk_newdir;
989 }
990 if (old_dentry->d_parent != new_dentry->d_parent) {
991 /*
992 * 9P .u can only handle file rename in the same directory
993 */
994
995 p9_debug(P9_DEBUG_ERROR, "old dir and new dir are different\n");
996 retval = -EXDEV;
997 goto clunk_newdir;
998 }
999 v9fs_blank_wstat(&wstat);
1000 wstat.muid = v9ses->uname;
1001 wstat.name = (char *) new_dentry->d_name.name;
1002 retval = p9_client_wstat(oldfid, &wstat);
1003
1004 clunk_newdir:
1005 if (!retval) {
1006 if (new_inode) {
1007 if (S_ISDIR(new_inode->i_mode))
1008 clear_nlink(new_inode);
1009 else
1010 drop_nlink(new_inode);
1011 }
1012 if (S_ISDIR(old_inode->i_mode)) {
1013 if (!new_inode)
1014 inc_nlink(new_dir);
1015 drop_nlink(old_dir);
1016 }
1017 v9fs_invalidate_inode_attr(old_inode);
1018 v9fs_invalidate_inode_attr(old_dir);
1019 v9fs_invalidate_inode_attr(new_dir);
1020
1021 /* successful rename */
1022 d_move(old_dentry, new_dentry);
1023 }
1024 up_write(&v9ses->rename_sem);
1025 p9_client_clunk(newdirfid);
1026
1027 clunk_olddir:
1028 p9_client_clunk(olddirfid);
1029
1030 done:
1031 return retval;
1032 }
1033
1034 /**
1035 * v9fs_vfs_getattr - retrieve file metadata
1036 * @mnt: mount information
1037 * @dentry: file to get attributes on
1038 * @stat: metadata structure to populate
1039 *
1040 */
1041
1042 static int
v9fs_vfs_getattr(struct vfsmount * mnt,struct dentry * dentry,struct kstat * stat)1043 v9fs_vfs_getattr(struct vfsmount *mnt, struct dentry *dentry,
1044 struct kstat *stat)
1045 {
1046 int err;
1047 struct v9fs_session_info *v9ses;
1048 struct p9_fid *fid;
1049 struct p9_wstat *st;
1050
1051 p9_debug(P9_DEBUG_VFS, "dentry: %p\n", dentry);
1052 err = -EPERM;
1053 v9ses = v9fs_dentry2v9ses(dentry);
1054 if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) {
1055 generic_fillattr(dentry->d_inode, stat);
1056 return 0;
1057 }
1058 fid = v9fs_fid_lookup(dentry);
1059 if (IS_ERR(fid))
1060 return PTR_ERR(fid);
1061
1062 st = p9_client_stat(fid);
1063 if (IS_ERR(st))
1064 return PTR_ERR(st);
1065
1066 v9fs_stat2inode(st, dentry->d_inode, dentry->d_inode->i_sb);
1067 generic_fillattr(dentry->d_inode, stat);
1068
1069 p9stat_free(st);
1070 kfree(st);
1071 return 0;
1072 }
1073
1074 /**
1075 * v9fs_vfs_setattr - set file metadata
1076 * @dentry: file whose metadata to set
1077 * @iattr: metadata assignment structure
1078 *
1079 */
1080
v9fs_vfs_setattr(struct dentry * dentry,struct iattr * iattr)1081 static int v9fs_vfs_setattr(struct dentry *dentry, struct iattr *iattr)
1082 {
1083 int retval;
1084 struct v9fs_session_info *v9ses;
1085 struct p9_fid *fid;
1086 struct p9_wstat wstat;
1087
1088 p9_debug(P9_DEBUG_VFS, "\n");
1089 retval = inode_change_ok(dentry->d_inode, iattr);
1090 if (retval)
1091 return retval;
1092
1093 retval = -EPERM;
1094 v9ses = v9fs_dentry2v9ses(dentry);
1095 fid = v9fs_fid_lookup(dentry);
1096 if(IS_ERR(fid))
1097 return PTR_ERR(fid);
1098
1099 v9fs_blank_wstat(&wstat);
1100 if (iattr->ia_valid & ATTR_MODE)
1101 wstat.mode = unixmode2p9mode(v9ses, iattr->ia_mode);
1102
1103 if (iattr->ia_valid & ATTR_MTIME)
1104 wstat.mtime = iattr->ia_mtime.tv_sec;
1105
1106 if (iattr->ia_valid & ATTR_ATIME)
1107 wstat.atime = iattr->ia_atime.tv_sec;
1108
1109 if (iattr->ia_valid & ATTR_SIZE)
1110 wstat.length = iattr->ia_size;
1111
1112 if (v9fs_proto_dotu(v9ses)) {
1113 if (iattr->ia_valid & ATTR_UID)
1114 wstat.n_uid = iattr->ia_uid;
1115
1116 if (iattr->ia_valid & ATTR_GID)
1117 wstat.n_gid = iattr->ia_gid;
1118 }
1119
1120 /* Write all dirty data */
1121 if (S_ISREG(dentry->d_inode->i_mode))
1122 filemap_write_and_wait(dentry->d_inode->i_mapping);
1123
1124 retval = p9_client_wstat(fid, &wstat);
1125 if (retval < 0)
1126 return retval;
1127
1128 if ((iattr->ia_valid & ATTR_SIZE) &&
1129 iattr->ia_size != i_size_read(dentry->d_inode))
1130 truncate_setsize(dentry->d_inode, iattr->ia_size);
1131
1132 v9fs_invalidate_inode_attr(dentry->d_inode);
1133
1134 setattr_copy(dentry->d_inode, iattr);
1135 mark_inode_dirty(dentry->d_inode);
1136 return 0;
1137 }
1138
1139 /**
1140 * v9fs_stat2inode - populate an inode structure with mistat info
1141 * @stat: Plan 9 metadata (mistat) structure
1142 * @inode: inode to populate
1143 * @sb: superblock of filesystem
1144 *
1145 */
1146
1147 void
v9fs_stat2inode(struct p9_wstat * stat,struct inode * inode,struct super_block * sb)1148 v9fs_stat2inode(struct p9_wstat *stat, struct inode *inode,
1149 struct super_block *sb)
1150 {
1151 umode_t mode;
1152 char ext[32];
1153 char tag_name[14];
1154 unsigned int i_nlink;
1155 struct v9fs_session_info *v9ses = sb->s_fs_info;
1156 struct v9fs_inode *v9inode = V9FS_I(inode);
1157
1158 set_nlink(inode, 1);
1159
1160 inode->i_atime.tv_sec = stat->atime;
1161 inode->i_mtime.tv_sec = stat->mtime;
1162 inode->i_ctime.tv_sec = stat->mtime;
1163
1164 inode->i_uid = v9ses->dfltuid;
1165 inode->i_gid = v9ses->dfltgid;
1166
1167 if (v9fs_proto_dotu(v9ses)) {
1168 inode->i_uid = stat->n_uid;
1169 inode->i_gid = stat->n_gid;
1170 }
1171 if ((S_ISREG(inode->i_mode)) || (S_ISDIR(inode->i_mode))) {
1172 if (v9fs_proto_dotu(v9ses) && (stat->extension[0] != '\0')) {
1173 /*
1174 * Hadlink support got added later to
1175 * to the .u extension. So there can be
1176 * server out there that doesn't support
1177 * this even with .u extension. So check
1178 * for non NULL stat->extension
1179 */
1180 strncpy(ext, stat->extension, sizeof(ext));
1181 /* HARDLINKCOUNT %u */
1182 sscanf(ext, "%13s %u", tag_name, &i_nlink);
1183 if (!strncmp(tag_name, "HARDLINKCOUNT", 13))
1184 set_nlink(inode, i_nlink);
1185 }
1186 }
1187 mode = p9mode2perm(v9ses, stat);
1188 mode |= inode->i_mode & ~S_IALLUGO;
1189 inode->i_mode = mode;
1190 i_size_write(inode, stat->length);
1191
1192 /* not real number of blocks, but 512 byte ones ... */
1193 inode->i_blocks = (i_size_read(inode) + 512 - 1) >> 9;
1194 v9inode->cache_validity &= ~V9FS_INO_INVALID_ATTR;
1195 }
1196
1197 /**
1198 * v9fs_qid2ino - convert qid into inode number
1199 * @qid: qid to hash
1200 *
1201 * BUG: potential for inode number collisions?
1202 */
1203
v9fs_qid2ino(struct p9_qid * qid)1204 ino_t v9fs_qid2ino(struct p9_qid *qid)
1205 {
1206 u64 path = qid->path + 2;
1207 ino_t i = 0;
1208
1209 if (sizeof(ino_t) == sizeof(path))
1210 memcpy(&i, &path, sizeof(ino_t));
1211 else
1212 i = (ino_t) (path ^ (path >> 32));
1213
1214 return i;
1215 }
1216
1217 /**
1218 * v9fs_readlink - read a symlink's location (internal version)
1219 * @dentry: dentry for symlink
1220 * @buffer: buffer to load symlink location into
1221 * @buflen: length of buffer
1222 *
1223 */
1224
v9fs_readlink(struct dentry * dentry,char * buffer,int buflen)1225 static int v9fs_readlink(struct dentry *dentry, char *buffer, int buflen)
1226 {
1227 int retval;
1228
1229 struct v9fs_session_info *v9ses;
1230 struct p9_fid *fid;
1231 struct p9_wstat *st;
1232
1233 p9_debug(P9_DEBUG_VFS, " %s\n", dentry->d_name.name);
1234 retval = -EPERM;
1235 v9ses = v9fs_dentry2v9ses(dentry);
1236 fid = v9fs_fid_lookup(dentry);
1237 if (IS_ERR(fid))
1238 return PTR_ERR(fid);
1239
1240 if (!v9fs_proto_dotu(v9ses))
1241 return -EBADF;
1242
1243 st = p9_client_stat(fid);
1244 if (IS_ERR(st))
1245 return PTR_ERR(st);
1246
1247 if (!(st->mode & P9_DMSYMLINK)) {
1248 retval = -EINVAL;
1249 goto done;
1250 }
1251
1252 /* copy extension buffer into buffer */
1253 strncpy(buffer, st->extension, buflen);
1254
1255 p9_debug(P9_DEBUG_VFS, "%s -> %s (%s)\n",
1256 dentry->d_name.name, st->extension, buffer);
1257
1258 retval = strnlen(buffer, buflen);
1259 done:
1260 p9stat_free(st);
1261 kfree(st);
1262 return retval;
1263 }
1264
1265 /**
1266 * v9fs_vfs_follow_link - follow a symlink path
1267 * @dentry: dentry for symlink
1268 * @nd: nameidata
1269 *
1270 */
1271
v9fs_vfs_follow_link(struct dentry * dentry,struct nameidata * nd)1272 static void *v9fs_vfs_follow_link(struct dentry *dentry, struct nameidata *nd)
1273 {
1274 int len = 0;
1275 char *link = __getname();
1276
1277 p9_debug(P9_DEBUG_VFS, "%s\n", dentry->d_name.name);
1278
1279 if (!link)
1280 link = ERR_PTR(-ENOMEM);
1281 else {
1282 len = v9fs_readlink(dentry, link, PATH_MAX);
1283
1284 if (len < 0) {
1285 __putname(link);
1286 link = ERR_PTR(len);
1287 } else
1288 link[min(len, PATH_MAX-1)] = 0;
1289 }
1290 nd_set_link(nd, link);
1291
1292 return NULL;
1293 }
1294
1295 /**
1296 * v9fs_vfs_put_link - release a symlink path
1297 * @dentry: dentry for symlink
1298 * @nd: nameidata
1299 * @p: unused
1300 *
1301 */
1302
1303 void
v9fs_vfs_put_link(struct dentry * dentry,struct nameidata * nd,void * p)1304 v9fs_vfs_put_link(struct dentry *dentry, struct nameidata *nd, void *p)
1305 {
1306 char *s = nd_get_link(nd);
1307
1308 p9_debug(P9_DEBUG_VFS, " %s %s\n",
1309 dentry->d_name.name, IS_ERR(s) ? "<error>" : s);
1310 if (!IS_ERR(s))
1311 __putname(s);
1312 }
1313
1314 /**
1315 * v9fs_vfs_mkspecial - create a special file
1316 * @dir: inode to create special file in
1317 * @dentry: dentry to create
1318 * @mode: mode to create special file
1319 * @extension: 9p2000.u format extension string representing special file
1320 *
1321 */
1322
v9fs_vfs_mkspecial(struct inode * dir,struct dentry * dentry,u32 perm,const char * extension)1323 static int v9fs_vfs_mkspecial(struct inode *dir, struct dentry *dentry,
1324 u32 perm, const char *extension)
1325 {
1326 struct p9_fid *fid;
1327 struct v9fs_session_info *v9ses;
1328
1329 v9ses = v9fs_inode2v9ses(dir);
1330 if (!v9fs_proto_dotu(v9ses)) {
1331 p9_debug(P9_DEBUG_ERROR, "not extended\n");
1332 return -EPERM;
1333 }
1334
1335 fid = v9fs_create(v9ses, dir, dentry, (char *) extension, perm,
1336 P9_OREAD);
1337 if (IS_ERR(fid))
1338 return PTR_ERR(fid);
1339
1340 v9fs_invalidate_inode_attr(dir);
1341 p9_client_clunk(fid);
1342 return 0;
1343 }
1344
1345 /**
1346 * v9fs_vfs_symlink - helper function to create symlinks
1347 * @dir: directory inode containing symlink
1348 * @dentry: dentry for symlink
1349 * @symname: symlink data
1350 *
1351 * See Also: 9P2000.u RFC for more information
1352 *
1353 */
1354
1355 static int
v9fs_vfs_symlink(struct inode * dir,struct dentry * dentry,const char * symname)1356 v9fs_vfs_symlink(struct inode *dir, struct dentry *dentry, const char *symname)
1357 {
1358 p9_debug(P9_DEBUG_VFS, " %lu,%s,%s\n",
1359 dir->i_ino, dentry->d_name.name, symname);
1360
1361 return v9fs_vfs_mkspecial(dir, dentry, P9_DMSYMLINK, symname);
1362 }
1363
1364 /**
1365 * v9fs_vfs_link - create a hardlink
1366 * @old_dentry: dentry for file to link to
1367 * @dir: inode destination for new link
1368 * @dentry: dentry for link
1369 *
1370 */
1371
1372 static int
v9fs_vfs_link(struct dentry * old_dentry,struct inode * dir,struct dentry * dentry)1373 v9fs_vfs_link(struct dentry *old_dentry, struct inode *dir,
1374 struct dentry *dentry)
1375 {
1376 int retval;
1377 char *name;
1378 struct p9_fid *oldfid;
1379
1380 p9_debug(P9_DEBUG_VFS, " %lu,%s,%s\n",
1381 dir->i_ino, dentry->d_name.name, old_dentry->d_name.name);
1382
1383 oldfid = v9fs_fid_clone(old_dentry);
1384 if (IS_ERR(oldfid))
1385 return PTR_ERR(oldfid);
1386
1387 name = __getname();
1388 if (unlikely(!name)) {
1389 retval = -ENOMEM;
1390 goto clunk_fid;
1391 }
1392
1393 sprintf(name, "%d\n", oldfid->fid);
1394 retval = v9fs_vfs_mkspecial(dir, dentry, P9_DMLINK, name);
1395 __putname(name);
1396 if (!retval) {
1397 v9fs_refresh_inode(oldfid, old_dentry->d_inode);
1398 v9fs_invalidate_inode_attr(dir);
1399 }
1400 clunk_fid:
1401 p9_client_clunk(oldfid);
1402 return retval;
1403 }
1404
1405 /**
1406 * v9fs_vfs_mknod - create a special file
1407 * @dir: inode destination for new link
1408 * @dentry: dentry for file
1409 * @mode: mode for creation
1410 * @rdev: device associated with special file
1411 *
1412 */
1413
1414 static int
v9fs_vfs_mknod(struct inode * dir,struct dentry * dentry,umode_t mode,dev_t rdev)1415 v9fs_vfs_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t rdev)
1416 {
1417 struct v9fs_session_info *v9ses = v9fs_inode2v9ses(dir);
1418 int retval;
1419 char *name;
1420 u32 perm;
1421
1422 p9_debug(P9_DEBUG_VFS, " %lu,%s mode: %hx MAJOR: %u MINOR: %u\n",
1423 dir->i_ino, dentry->d_name.name, mode,
1424 MAJOR(rdev), MINOR(rdev));
1425
1426 if (!new_valid_dev(rdev))
1427 return -EINVAL;
1428
1429 name = __getname();
1430 if (!name)
1431 return -ENOMEM;
1432 /* build extension */
1433 if (S_ISBLK(mode))
1434 sprintf(name, "b %u %u", MAJOR(rdev), MINOR(rdev));
1435 else if (S_ISCHR(mode))
1436 sprintf(name, "c %u %u", MAJOR(rdev), MINOR(rdev));
1437 else if (S_ISFIFO(mode))
1438 *name = 0;
1439 else if (S_ISSOCK(mode))
1440 *name = 0;
1441 else {
1442 __putname(name);
1443 return -EINVAL;
1444 }
1445
1446 perm = unixmode2p9mode(v9ses, mode);
1447 retval = v9fs_vfs_mkspecial(dir, dentry, perm, name);
1448 __putname(name);
1449
1450 return retval;
1451 }
1452
v9fs_refresh_inode(struct p9_fid * fid,struct inode * inode)1453 int v9fs_refresh_inode(struct p9_fid *fid, struct inode *inode)
1454 {
1455 int umode;
1456 dev_t rdev;
1457 loff_t i_size;
1458 struct p9_wstat *st;
1459 struct v9fs_session_info *v9ses;
1460
1461 v9ses = v9fs_inode2v9ses(inode);
1462 st = p9_client_stat(fid);
1463 if (IS_ERR(st))
1464 return PTR_ERR(st);
1465 /*
1466 * Don't update inode if the file type is different
1467 */
1468 umode = p9mode2unixmode(v9ses, st, &rdev);
1469 if ((inode->i_mode & S_IFMT) != (umode & S_IFMT))
1470 goto out;
1471
1472 spin_lock(&inode->i_lock);
1473 /*
1474 * We don't want to refresh inode->i_size,
1475 * because we may have cached data
1476 */
1477 i_size = inode->i_size;
1478 v9fs_stat2inode(st, inode, inode->i_sb);
1479 if (v9ses->cache)
1480 inode->i_size = i_size;
1481 spin_unlock(&inode->i_lock);
1482 out:
1483 p9stat_free(st);
1484 kfree(st);
1485 return 0;
1486 }
1487
1488 static const struct inode_operations v9fs_dir_inode_operations_dotu = {
1489 .create = v9fs_vfs_create,
1490 .lookup = v9fs_vfs_lookup,
1491 .symlink = v9fs_vfs_symlink,
1492 .link = v9fs_vfs_link,
1493 .unlink = v9fs_vfs_unlink,
1494 .mkdir = v9fs_vfs_mkdir,
1495 .rmdir = v9fs_vfs_rmdir,
1496 .mknod = v9fs_vfs_mknod,
1497 .rename = v9fs_vfs_rename,
1498 .getattr = v9fs_vfs_getattr,
1499 .setattr = v9fs_vfs_setattr,
1500 };
1501
1502 static const struct inode_operations v9fs_dir_inode_operations = {
1503 .create = v9fs_vfs_create,
1504 .lookup = v9fs_vfs_lookup,
1505 .unlink = v9fs_vfs_unlink,
1506 .mkdir = v9fs_vfs_mkdir,
1507 .rmdir = v9fs_vfs_rmdir,
1508 .mknod = v9fs_vfs_mknod,
1509 .rename = v9fs_vfs_rename,
1510 .getattr = v9fs_vfs_getattr,
1511 .setattr = v9fs_vfs_setattr,
1512 };
1513
1514 static const struct inode_operations v9fs_file_inode_operations = {
1515 .getattr = v9fs_vfs_getattr,
1516 .setattr = v9fs_vfs_setattr,
1517 };
1518
1519 static const struct inode_operations v9fs_symlink_inode_operations = {
1520 .readlink = generic_readlink,
1521 .follow_link = v9fs_vfs_follow_link,
1522 .put_link = v9fs_vfs_put_link,
1523 .getattr = v9fs_vfs_getattr,
1524 .setattr = v9fs_vfs_setattr,
1525 };
1526
1527