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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#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
52static const struct inode_operations v9fs_dir_inode_operations;
53static const struct inode_operations v9fs_dir_inode_operations_dotu;
54static const struct inode_operations v9fs_file_inode_operations;
55static 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
64static 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 */
98static 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 */
125static 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 strlcpy(ext, stat->extension, sizeof(ext));
150 sscanf(ext, "%c %i %i", &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
175int 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 (extended) {
196 if (uflags & O_EXCL)
197 ret |= P9_OEXCL;
198
199 if (uflags & O_APPEND)
200 ret |= P9_OAPPEND;
201 }
202
203 return ret;
204}
205
206/**
207 * v9fs_blank_wstat - helper function to setup a 9P stat structure
208 * @wstat: structure to initialize
209 *
210 */
211
212void
213v9fs_blank_wstat(struct p9_wstat *wstat)
214{
215 wstat->type = ~0;
216 wstat->dev = ~0;
217 wstat->qid.type = ~0;
218 wstat->qid.version = ~0;
219 *((long long *)&wstat->qid.path) = ~0;
220 wstat->mode = ~0;
221 wstat->atime = ~0;
222 wstat->mtime = ~0;
223 wstat->length = ~0;
224 wstat->name = NULL;
225 wstat->uid = NULL;
226 wstat->gid = NULL;
227 wstat->muid = NULL;
228 wstat->n_uid = INVALID_UID;
229 wstat->n_gid = INVALID_GID;
230 wstat->n_muid = INVALID_UID;
231 wstat->extension = NULL;
232}
233
234/**
235 * v9fs_alloc_inode - helper function to allocate an inode
236 *
237 */
238struct inode *v9fs_alloc_inode(struct super_block *sb)
239{
240 struct v9fs_inode *v9inode;
241 v9inode = (struct v9fs_inode *)kmem_cache_alloc(v9fs_inode_cache,
242 GFP_KERNEL);
243 if (!v9inode)
244 return NULL;
245#ifdef CONFIG_9P_FSCACHE
246 v9inode->fscache = NULL;
247 mutex_init(&v9inode->fscache_lock);
248#endif
249 v9inode->writeback_fid = NULL;
250 v9inode->cache_validity = 0;
251 mutex_init(&v9inode->v_mutex);
252 return &v9inode->vfs_inode;
253}
254
255/**
256 * v9fs_destroy_inode - destroy an inode
257 *
258 */
259
260static void v9fs_i_callback(struct rcu_head *head)
261{
262 struct inode *inode = container_of(head, struct inode, i_rcu);
263 kmem_cache_free(v9fs_inode_cache, V9FS_I(inode));
264}
265
266void v9fs_destroy_inode(struct inode *inode)
267{
268 call_rcu(&inode->i_rcu, v9fs_i_callback);
269}
270
271int v9fs_init_inode(struct v9fs_session_info *v9ses,
272 struct inode *inode, umode_t mode, dev_t rdev)
273{
274 int err = 0;
275
276 inode_init_owner(inode, NULL, mode);
277 inode->i_blocks = 0;
278 inode->i_rdev = rdev;
279 inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
280 inode->i_mapping->a_ops = &v9fs_addr_operations;
281
282 switch (mode & S_IFMT) {
283 case S_IFIFO:
284 case S_IFBLK:
285 case S_IFCHR:
286 case S_IFSOCK:
287 if (v9fs_proto_dotl(v9ses)) {
288 inode->i_op = &v9fs_file_inode_operations_dotl;
289 } else if (v9fs_proto_dotu(v9ses)) {
290 inode->i_op = &v9fs_file_inode_operations;
291 } else {
292 p9_debug(P9_DEBUG_ERROR,
293 "special files without extended mode\n");
294 err = -EINVAL;
295 goto error;
296 }
297 init_special_inode(inode, inode->i_mode, inode->i_rdev);
298 break;
299 case S_IFREG:
300 if (v9fs_proto_dotl(v9ses)) {
301 inode->i_op = &v9fs_file_inode_operations_dotl;
302 if (v9ses->cache == CACHE_LOOSE ||
303 v9ses->cache == CACHE_FSCACHE)
304 inode->i_fop =
305 &v9fs_cached_file_operations_dotl;
306 else if (v9ses->cache == CACHE_MMAP)
307 inode->i_fop = &v9fs_mmap_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 == CACHE_LOOSE ||
313 v9ses->cache == CACHE_FSCACHE)
314 inode->i_fop =
315 &v9fs_cached_file_operations;
316 else if (v9ses->cache == CACHE_MMAP)
317 inode->i_fop = &v9fs_mmap_file_operations;
318 else
319 inode->i_fop = &v9fs_file_operations;
320 }
321
322 break;
323 case S_IFLNK:
324 if (!v9fs_proto_dotu(v9ses) && !v9fs_proto_dotl(v9ses)) {
325 p9_debug(P9_DEBUG_ERROR,
326 "extended modes used with legacy protocol\n");
327 err = -EINVAL;
328 goto error;
329 }
330
331 if (v9fs_proto_dotl(v9ses))
332 inode->i_op = &v9fs_symlink_inode_operations_dotl;
333 else
334 inode->i_op = &v9fs_symlink_inode_operations;
335
336 break;
337 case S_IFDIR:
338 inc_nlink(inode);
339 if (v9fs_proto_dotl(v9ses))
340 inode->i_op = &v9fs_dir_inode_operations_dotl;
341 else if (v9fs_proto_dotu(v9ses))
342 inode->i_op = &v9fs_dir_inode_operations_dotu;
343 else
344 inode->i_op = &v9fs_dir_inode_operations;
345
346 if (v9fs_proto_dotl(v9ses))
347 inode->i_fop = &v9fs_dir_operations_dotl;
348 else
349 inode->i_fop = &v9fs_dir_operations;
350
351 break;
352 default:
353 p9_debug(P9_DEBUG_ERROR, "BAD mode 0x%hx S_IFMT 0x%x\n",
354 mode, mode & S_IFMT);
355 err = -EINVAL;
356 goto error;
357 }
358error:
359 return err;
360
361}
362
363/**
364 * v9fs_get_inode - helper function to setup an inode
365 * @sb: superblock
366 * @mode: mode to setup inode with
367 *
368 */
369
370struct inode *v9fs_get_inode(struct super_block *sb, umode_t mode, dev_t rdev)
371{
372 int err;
373 struct inode *inode;
374 struct v9fs_session_info *v9ses = sb->s_fs_info;
375
376 p9_debug(P9_DEBUG_VFS, "super block: %p mode: %ho\n", sb, mode);
377
378 inode = new_inode(sb);
379 if (!inode) {
380 pr_warn("%s (%d): Problem allocating inode\n",
381 __func__, task_pid_nr(current));
382 return ERR_PTR(-ENOMEM);
383 }
384 err = v9fs_init_inode(v9ses, inode, mode, rdev);
385 if (err) {
386 iput(inode);
387 return ERR_PTR(err);
388 }
389 return inode;
390}
391
392/*
393static struct v9fs_fid*
394v9fs_clone_walk(struct v9fs_session_info *v9ses, u32 fid, struct dentry *dentry)
395{
396 int err;
397 int nfid;
398 struct v9fs_fid *ret;
399 struct v9fs_fcall *fcall;
400
401 nfid = v9fs_get_idpool(&v9ses->fidpool);
402 if (nfid < 0) {
403 eprintk(KERN_WARNING, "no free fids available\n");
404 return ERR_PTR(-ENOSPC);
405 }
406
407 err = v9fs_t_walk(v9ses, fid, nfid, (char *) dentry->d_name.name,
408 &fcall);
409
410 if (err < 0) {
411 if (fcall && fcall->id == RWALK)
412 goto clunk_fid;
413
414 PRINT_FCALL_ERROR("walk error", fcall);
415 v9fs_put_idpool(nfid, &v9ses->fidpool);
416 goto error;
417 }
418
419 kfree(fcall);
420 fcall = NULL;
421 ret = v9fs_fid_create(v9ses, nfid);
422 if (!ret) {
423 err = -ENOMEM;
424 goto clunk_fid;
425 }
426
427 err = v9fs_fid_insert(ret, dentry);
428 if (err < 0) {
429 v9fs_fid_destroy(ret);
430 goto clunk_fid;
431 }
432
433 return ret;
434
435clunk_fid:
436 v9fs_t_clunk(v9ses, nfid);
437
438error:
439 kfree(fcall);
440 return ERR_PTR(err);
441}
442*/
443
444
445/**
446 * v9fs_clear_inode - release an inode
447 * @inode: inode to release
448 *
449 */
450void v9fs_evict_inode(struct inode *inode)
451{
452 struct v9fs_inode *v9inode = V9FS_I(inode);
453
454 truncate_inode_pages_final(&inode->i_data);
455 clear_inode(inode);
456 filemap_fdatawrite(&inode->i_data);
457
458 v9fs_cache_inode_put_cookie(inode);
459 /* clunk the fid stashed in writeback_fid */
460 if (v9inode->writeback_fid) {
461 p9_client_clunk(v9inode->writeback_fid);
462 v9inode->writeback_fid = NULL;
463 }
464}
465
466static int v9fs_test_inode(struct inode *inode, void *data)
467{
468 int umode;
469 dev_t rdev;
470 struct v9fs_inode *v9inode = V9FS_I(inode);
471 struct p9_wstat *st = (struct p9_wstat *)data;
472 struct v9fs_session_info *v9ses = v9fs_inode2v9ses(inode);
473
474 umode = p9mode2unixmode(v9ses, st, &rdev);
475 /* don't match inode of different type */
476 if ((inode->i_mode & S_IFMT) != (umode & S_IFMT))
477 return 0;
478
479 /* compare qid details */
480 if (memcmp(&v9inode->qid.version,
481 &st->qid.version, sizeof(v9inode->qid.version)))
482 return 0;
483
484 if (v9inode->qid.type != st->qid.type)
485 return 0;
486 return 1;
487}
488
489static int v9fs_test_new_inode(struct inode *inode, void *data)
490{
491 return 0;
492}
493
494static int v9fs_set_inode(struct inode *inode, void *data)
495{
496 struct v9fs_inode *v9inode = V9FS_I(inode);
497 struct p9_wstat *st = (struct p9_wstat *)data;
498
499 memcpy(&v9inode->qid, &st->qid, sizeof(st->qid));
500 return 0;
501}
502
503static struct inode *v9fs_qid_iget(struct super_block *sb,
504 struct p9_qid *qid,
505 struct p9_wstat *st,
506 int new)
507{
508 dev_t rdev;
509 int retval;
510 umode_t umode;
511 unsigned long i_ino;
512 struct inode *inode;
513 struct v9fs_session_info *v9ses = sb->s_fs_info;
514 int (*test)(struct inode *, void *);
515
516 if (new)
517 test = v9fs_test_new_inode;
518 else
519 test = v9fs_test_inode;
520
521 i_ino = v9fs_qid2ino(qid);
522 inode = iget5_locked(sb, i_ino, test, v9fs_set_inode, st);
523 if (!inode)
524 return ERR_PTR(-ENOMEM);
525 if (!(inode->i_state & I_NEW))
526 return inode;
527 /*
528 * initialize the inode with the stat info
529 * FIXME!! we may need support for stale inodes
530 * later.
531 */
532 inode->i_ino = i_ino;
533 umode = p9mode2unixmode(v9ses, st, &rdev);
534 retval = v9fs_init_inode(v9ses, inode, umode, rdev);
535 if (retval)
536 goto error;
537
538 v9fs_stat2inode(st, inode, sb);
539 v9fs_cache_inode_get_cookie(inode);
540 unlock_new_inode(inode);
541 return inode;
542error:
543 iget_failed(inode);
544 return ERR_PTR(retval);
545
546}
547
548struct inode *
549v9fs_inode_from_fid(struct v9fs_session_info *v9ses, struct p9_fid *fid,
550 struct super_block *sb, int new)
551{
552 struct p9_wstat *st;
553 struct inode *inode = NULL;
554
555 st = p9_client_stat(fid);
556 if (IS_ERR(st))
557 return ERR_CAST(st);
558
559 inode = v9fs_qid_iget(sb, &st->qid, st, new);
560 p9stat_free(st);
561 kfree(st);
562 return inode;
563}
564
565/**
566 * v9fs_at_to_dotl_flags- convert Linux specific AT flags to
567 * plan 9 AT flag.
568 * @flags: flags to convert
569 */
570static int v9fs_at_to_dotl_flags(int flags)
571{
572 int rflags = 0;
573 if (flags & AT_REMOVEDIR)
574 rflags |= P9_DOTL_AT_REMOVEDIR;
575 return rflags;
576}
577
578/**
579 * v9fs_remove - helper function to remove files and directories
580 * @dir: directory inode that is being deleted
581 * @dentry: dentry that is being deleted
582 * @flags: removing a directory
583 *
584 */
585
586static int v9fs_remove(struct inode *dir, struct dentry *dentry, int flags)
587{
588 struct inode *inode;
589 int retval = -EOPNOTSUPP;
590 struct p9_fid *v9fid, *dfid;
591 struct v9fs_session_info *v9ses;
592
593 p9_debug(P9_DEBUG_VFS, "inode: %p dentry: %p rmdir: %x\n",
594 dir, dentry, flags);
595
596 v9ses = v9fs_inode2v9ses(dir);
597 inode = d_inode(dentry);
598 dfid = v9fs_fid_lookup(dentry->d_parent);
599 if (IS_ERR(dfid)) {
600 retval = PTR_ERR(dfid);
601 p9_debug(P9_DEBUG_VFS, "fid lookup failed %d\n", retval);
602 return retval;
603 }
604 if (v9fs_proto_dotl(v9ses))
605 retval = p9_client_unlinkat(dfid, dentry->d_name.name,
606 v9fs_at_to_dotl_flags(flags));
607 if (retval == -EOPNOTSUPP) {
608 /* Try the one based on path */
609 v9fid = v9fs_fid_clone(dentry);
610 if (IS_ERR(v9fid))
611 return PTR_ERR(v9fid);
612 retval = p9_client_remove(v9fid);
613 }
614 if (!retval) {
615 /*
616 * directories on unlink should have zero
617 * link count
618 */
619 if (flags & AT_REMOVEDIR) {
620 clear_nlink(inode);
621 drop_nlink(dir);
622 } else
623 drop_nlink(inode);
624
625 v9fs_invalidate_inode_attr(inode);
626 v9fs_invalidate_inode_attr(dir);
627 }
628 return retval;
629}
630
631/**
632 * v9fs_create - Create a file
633 * @v9ses: session information
634 * @dir: directory that dentry is being created in
635 * @dentry: dentry that is being created
636 * @extension: 9p2000.u extension string to support devices, etc.
637 * @perm: create permissions
638 * @mode: open mode
639 *
640 */
641static struct p9_fid *
642v9fs_create(struct v9fs_session_info *v9ses, struct inode *dir,
643 struct dentry *dentry, char *extension, u32 perm, u8 mode)
644{
645 int err;
646 char *name;
647 struct p9_fid *dfid, *ofid, *fid;
648 struct inode *inode;
649
650 p9_debug(P9_DEBUG_VFS, "name %pd\n", dentry);
651
652 err = 0;
653 ofid = NULL;
654 fid = NULL;
655 name = (char *) dentry->d_name.name;
656 dfid = v9fs_fid_lookup(dentry->d_parent);
657 if (IS_ERR(dfid)) {
658 err = PTR_ERR(dfid);
659 p9_debug(P9_DEBUG_VFS, "fid lookup failed %d\n", err);
660 return ERR_PTR(err);
661 }
662
663 /* clone a fid to use for creation */
664 ofid = p9_client_walk(dfid, 0, NULL, 1);
665 if (IS_ERR(ofid)) {
666 err = PTR_ERR(ofid);
667 p9_debug(P9_DEBUG_VFS, "p9_client_walk failed %d\n", err);
668 return ERR_PTR(err);
669 }
670
671 err = p9_client_fcreate(ofid, name, perm, mode, extension);
672 if (err < 0) {
673 p9_debug(P9_DEBUG_VFS, "p9_client_fcreate failed %d\n", err);
674 goto error;
675 }
676
677 if (!(perm & P9_DMLINK)) {
678 /* now walk from the parent so we can get unopened fid */
679 fid = p9_client_walk(dfid, 1, &name, 1);
680 if (IS_ERR(fid)) {
681 err = PTR_ERR(fid);
682 p9_debug(P9_DEBUG_VFS,
683 "p9_client_walk failed %d\n", err);
684 fid = NULL;
685 goto error;
686 }
687 /*
688 * instantiate inode and assign the unopened fid to the dentry
689 */
690 inode = v9fs_get_new_inode_from_fid(v9ses, fid, dir->i_sb);
691 if (IS_ERR(inode)) {
692 err = PTR_ERR(inode);
693 p9_debug(P9_DEBUG_VFS,
694 "inode creation failed %d\n", err);
695 goto error;
696 }
697 v9fs_fid_add(dentry, fid);
698 d_instantiate(dentry, inode);
699 }
700 return ofid;
701error:
702 if (ofid)
703 p9_client_clunk(ofid);
704
705 if (fid)
706 p9_client_clunk(fid);
707
708 return ERR_PTR(err);
709}
710
711/**
712 * v9fs_vfs_create - VFS hook to create a regular file
713 *
714 * open(.., O_CREAT) is handled in v9fs_vfs_atomic_open(). This is only called
715 * for mknod(2).
716 *
717 * @dir: directory inode that is being created
718 * @dentry: dentry that is being deleted
719 * @mode: create permissions
720 *
721 */
722
723static int
724v9fs_vfs_create(struct inode *dir, struct dentry *dentry, umode_t mode,
725 bool excl)
726{
727 struct v9fs_session_info *v9ses = v9fs_inode2v9ses(dir);
728 u32 perm = unixmode2p9mode(v9ses, mode);
729 struct p9_fid *fid;
730
731 /* P9_OEXCL? */
732 fid = v9fs_create(v9ses, dir, dentry, NULL, perm, P9_ORDWR);
733 if (IS_ERR(fid))
734 return PTR_ERR(fid);
735
736 v9fs_invalidate_inode_attr(dir);
737 p9_client_clunk(fid);
738
739 return 0;
740}
741
742/**
743 * v9fs_vfs_mkdir - VFS mkdir hook to create a directory
744 * @dir: inode that is being unlinked
745 * @dentry: dentry that is being unlinked
746 * @mode: mode for new directory
747 *
748 */
749
750static int v9fs_vfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
751{
752 int err;
753 u32 perm;
754 struct p9_fid *fid;
755 struct v9fs_session_info *v9ses;
756
757 p9_debug(P9_DEBUG_VFS, "name %pd\n", dentry);
758 err = 0;
759 v9ses = v9fs_inode2v9ses(dir);
760 perm = unixmode2p9mode(v9ses, mode | S_IFDIR);
761 fid = v9fs_create(v9ses, dir, dentry, NULL, perm, P9_OREAD);
762 if (IS_ERR(fid)) {
763 err = PTR_ERR(fid);
764 fid = NULL;
765 } else {
766 inc_nlink(dir);
767 v9fs_invalidate_inode_attr(dir);
768 }
769
770 if (fid)
771 p9_client_clunk(fid);
772
773 return err;
774}
775
776/**
777 * v9fs_vfs_lookup - VFS lookup hook to "walk" to a new inode
778 * @dir: inode that is being walked from
779 * @dentry: dentry that is being walked to?
780 * @flags: lookup flags (unused)
781 *
782 */
783
784struct dentry *v9fs_vfs_lookup(struct inode *dir, struct dentry *dentry,
785 unsigned int flags)
786{
787 struct dentry *res;
788 struct v9fs_session_info *v9ses;
789 struct p9_fid *dfid, *fid;
790 struct inode *inode;
791 char *name;
792
793 p9_debug(P9_DEBUG_VFS, "dir: %p dentry: (%pd) %p flags: %x\n",
794 dir, dentry, dentry, flags);
795
796 if (dentry->d_name.len > NAME_MAX)
797 return ERR_PTR(-ENAMETOOLONG);
798
799 v9ses = v9fs_inode2v9ses(dir);
800 /* We can walk d_parent because we hold the dir->i_mutex */
801 dfid = v9fs_fid_lookup(dentry->d_parent);
802 if (IS_ERR(dfid))
803 return ERR_CAST(dfid);
804
805 name = (char *) dentry->d_name.name;
806 fid = p9_client_walk(dfid, 1, &name, 1);
807 if (IS_ERR(fid)) {
808 if (fid == ERR_PTR(-ENOENT)) {
809 d_add(dentry, NULL);
810 return NULL;
811 }
812 return ERR_CAST(fid);
813 }
814 /*
815 * Make sure we don't use a wrong inode due to parallel
816 * unlink. For cached mode create calls request for new
817 * inode. But with cache disabled, lookup should do this.
818 */
819 if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE)
820 inode = v9fs_get_inode_from_fid(v9ses, fid, dir->i_sb);
821 else
822 inode = v9fs_get_new_inode_from_fid(v9ses, fid, dir->i_sb);
823 if (IS_ERR(inode)) {
824 p9_client_clunk(fid);
825 return ERR_CAST(inode);
826 }
827 /*
828 * If we had a rename on the server and a parallel lookup
829 * for the new name, then make sure we instantiate with
830 * the new name. ie look up for a/b, while on server somebody
831 * moved b under k and client parallely did a lookup for
832 * k/b.
833 */
834 res = d_splice_alias(inode, dentry);
835 if (!res)
836 v9fs_fid_add(dentry, fid);
837 else if (!IS_ERR(res))
838 v9fs_fid_add(res, fid);
839 else
840 p9_client_clunk(fid);
841 return res;
842}
843
844static int
845v9fs_vfs_atomic_open(struct inode *dir, struct dentry *dentry,
846 struct file *file, unsigned flags, umode_t mode,
847 int *opened)
848{
849 int err;
850 u32 perm;
851 struct v9fs_inode *v9inode;
852 struct v9fs_session_info *v9ses;
853 struct p9_fid *fid, *inode_fid;
854 struct dentry *res = NULL;
855
856 if (d_unhashed(dentry)) {
857 res = v9fs_vfs_lookup(dir, dentry, 0);
858 if (IS_ERR(res))
859 return PTR_ERR(res);
860
861 if (res)
862 dentry = res;
863 }
864
865 /* Only creates */
866 if (!(flags & O_CREAT) || d_really_is_positive(dentry))
867 return finish_no_open(file, res);
868
869 err = 0;
870
871 v9ses = v9fs_inode2v9ses(dir);
872 perm = unixmode2p9mode(v9ses, mode);
873 fid = v9fs_create(v9ses, dir, dentry, NULL, perm,
874 v9fs_uflags2omode(flags,
875 v9fs_proto_dotu(v9ses)));
876 if (IS_ERR(fid)) {
877 err = PTR_ERR(fid);
878 fid = NULL;
879 goto error;
880 }
881
882 v9fs_invalidate_inode_attr(dir);
883 v9inode = V9FS_I(d_inode(dentry));
884 mutex_lock(&v9inode->v_mutex);
885 if ((v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) &&
886 !v9inode->writeback_fid &&
887 ((flags & O_ACCMODE) != O_RDONLY)) {
888 /*
889 * clone a fid and add it to writeback_fid
890 * we do it during open time instead of
891 * page dirty time via write_begin/page_mkwrite
892 * because we want write after unlink usecase
893 * to work.
894 */
895 inode_fid = v9fs_writeback_fid(dentry);
896 if (IS_ERR(inode_fid)) {
897 err = PTR_ERR(inode_fid);
898 mutex_unlock(&v9inode->v_mutex);
899 goto error;
900 }
901 v9inode->writeback_fid = (void *) inode_fid;
902 }
903 mutex_unlock(&v9inode->v_mutex);
904 err = finish_open(file, dentry, generic_file_open, opened);
905 if (err)
906 goto error;
907
908 file->private_data = fid;
909 if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE)
910 v9fs_cache_inode_set_cookie(d_inode(dentry), file);
911
912 *opened |= FILE_CREATED;
913out:
914 dput(res);
915 return err;
916
917error:
918 if (fid)
919 p9_client_clunk(fid);
920 goto out;
921}
922
923/**
924 * v9fs_vfs_unlink - VFS unlink hook to delete an inode
925 * @i: inode that is being unlinked
926 * @d: dentry that is being unlinked
927 *
928 */
929
930int v9fs_vfs_unlink(struct inode *i, struct dentry *d)
931{
932 return v9fs_remove(i, d, 0);
933}
934
935/**
936 * v9fs_vfs_rmdir - VFS unlink hook to delete a directory
937 * @i: inode that is being unlinked
938 * @d: dentry that is being unlinked
939 *
940 */
941
942int v9fs_vfs_rmdir(struct inode *i, struct dentry *d)
943{
944 return v9fs_remove(i, d, AT_REMOVEDIR);
945}
946
947/**
948 * v9fs_vfs_rename - VFS hook to rename an inode
949 * @old_dir: old dir inode
950 * @old_dentry: old dentry
951 * @new_dir: new dir inode
952 * @new_dentry: new dentry
953 *
954 */
955
956int
957v9fs_vfs_rename(struct inode *old_dir, struct dentry *old_dentry,
958 struct inode *new_dir, struct dentry *new_dentry)
959{
960 int retval;
961 struct inode *old_inode;
962 struct inode *new_inode;
963 struct v9fs_session_info *v9ses;
964 struct p9_fid *oldfid;
965 struct p9_fid *olddirfid;
966 struct p9_fid *newdirfid;
967 struct p9_wstat wstat;
968
969 p9_debug(P9_DEBUG_VFS, "\n");
970 retval = 0;
971 old_inode = d_inode(old_dentry);
972 new_inode = d_inode(new_dentry);
973 v9ses = v9fs_inode2v9ses(old_inode);
974 oldfid = v9fs_fid_lookup(old_dentry);
975 if (IS_ERR(oldfid))
976 return PTR_ERR(oldfid);
977
978 olddirfid = v9fs_fid_clone(old_dentry->d_parent);
979 if (IS_ERR(olddirfid)) {
980 retval = PTR_ERR(olddirfid);
981 goto done;
982 }
983
984 newdirfid = v9fs_fid_clone(new_dentry->d_parent);
985 if (IS_ERR(newdirfid)) {
986 retval = PTR_ERR(newdirfid);
987 goto clunk_olddir;
988 }
989
990 down_write(&v9ses->rename_sem);
991 if (v9fs_proto_dotl(v9ses)) {
992 retval = p9_client_renameat(olddirfid, old_dentry->d_name.name,
993 newdirfid, new_dentry->d_name.name);
994 if (retval == -EOPNOTSUPP)
995 retval = p9_client_rename(oldfid, newdirfid,
996 new_dentry->d_name.name);
997 if (retval != -EOPNOTSUPP)
998 goto clunk_newdir;
999 }
1000 if (old_dentry->d_parent != new_dentry->d_parent) {
1001 /*
1002 * 9P .u can only handle file rename in the same directory
1003 */
1004
1005 p9_debug(P9_DEBUG_ERROR, "old dir and new dir are different\n");
1006 retval = -EXDEV;
1007 goto clunk_newdir;
1008 }
1009 v9fs_blank_wstat(&wstat);
1010 wstat.muid = v9ses->uname;
1011 wstat.name = (char *) new_dentry->d_name.name;
1012 retval = p9_client_wstat(oldfid, &wstat);
1013
1014clunk_newdir:
1015 if (!retval) {
1016 if (new_inode) {
1017 if (S_ISDIR(new_inode->i_mode))
1018 clear_nlink(new_inode);
1019 else
1020 drop_nlink(new_inode);
1021 }
1022 if (S_ISDIR(old_inode->i_mode)) {
1023 if (!new_inode)
1024 inc_nlink(new_dir);
1025 drop_nlink(old_dir);
1026 }
1027 v9fs_invalidate_inode_attr(old_inode);
1028 v9fs_invalidate_inode_attr(old_dir);
1029 v9fs_invalidate_inode_attr(new_dir);
1030
1031 /* successful rename */
1032 d_move(old_dentry, new_dentry);
1033 }
1034 up_write(&v9ses->rename_sem);
1035 p9_client_clunk(newdirfid);
1036
1037clunk_olddir:
1038 p9_client_clunk(olddirfid);
1039
1040done:
1041 return retval;
1042}
1043
1044/**
1045 * v9fs_vfs_getattr - retrieve file metadata
1046 * @mnt: mount information
1047 * @dentry: file to get attributes on
1048 * @stat: metadata structure to populate
1049 *
1050 */
1051
1052static int
1053v9fs_vfs_getattr(struct vfsmount *mnt, struct dentry *dentry,
1054 struct kstat *stat)
1055{
1056 struct v9fs_session_info *v9ses;
1057 struct p9_fid *fid;
1058 struct p9_wstat *st;
1059
1060 p9_debug(P9_DEBUG_VFS, "dentry: %p\n", dentry);
1061 v9ses = v9fs_dentry2v9ses(dentry);
1062 if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) {
1063 generic_fillattr(d_inode(dentry), stat);
1064 return 0;
1065 }
1066 fid = v9fs_fid_lookup(dentry);
1067 if (IS_ERR(fid))
1068 return PTR_ERR(fid);
1069
1070 st = p9_client_stat(fid);
1071 if (IS_ERR(st))
1072 return PTR_ERR(st);
1073
1074 v9fs_stat2inode(st, d_inode(dentry), d_inode(dentry)->i_sb);
1075 generic_fillattr(d_inode(dentry), stat);
1076
1077 p9stat_free(st);
1078 kfree(st);
1079 return 0;
1080}
1081
1082/**
1083 * v9fs_vfs_setattr - set file metadata
1084 * @dentry: file whose metadata to set
1085 * @iattr: metadata assignment structure
1086 *
1087 */
1088
1089static int v9fs_vfs_setattr(struct dentry *dentry, struct iattr *iattr)
1090{
1091 int retval;
1092 struct v9fs_session_info *v9ses;
1093 struct p9_fid *fid;
1094 struct p9_wstat wstat;
1095
1096 p9_debug(P9_DEBUG_VFS, "\n");
1097 retval = inode_change_ok(d_inode(dentry), iattr);
1098 if (retval)
1099 return retval;
1100
1101 retval = -EPERM;
1102 v9ses = v9fs_dentry2v9ses(dentry);
1103 fid = v9fs_fid_lookup(dentry);
1104 if(IS_ERR(fid))
1105 return PTR_ERR(fid);
1106
1107 v9fs_blank_wstat(&wstat);
1108 if (iattr->ia_valid & ATTR_MODE)
1109 wstat.mode = unixmode2p9mode(v9ses, iattr->ia_mode);
1110
1111 if (iattr->ia_valid & ATTR_MTIME)
1112 wstat.mtime = iattr->ia_mtime.tv_sec;
1113
1114 if (iattr->ia_valid & ATTR_ATIME)
1115 wstat.atime = iattr->ia_atime.tv_sec;
1116
1117 if (iattr->ia_valid & ATTR_SIZE)
1118 wstat.length = iattr->ia_size;
1119
1120 if (v9fs_proto_dotu(v9ses)) {
1121 if (iattr->ia_valid & ATTR_UID)
1122 wstat.n_uid = iattr->ia_uid;
1123
1124 if (iattr->ia_valid & ATTR_GID)
1125 wstat.n_gid = iattr->ia_gid;
1126 }
1127
1128 /* Write all dirty data */
1129 if (d_is_reg(dentry))
1130 filemap_write_and_wait(d_inode(dentry)->i_mapping);
1131
1132 retval = p9_client_wstat(fid, &wstat);
1133 if (retval < 0)
1134 return retval;
1135
1136 if ((iattr->ia_valid & ATTR_SIZE) &&
1137 iattr->ia_size != i_size_read(d_inode(dentry)))
1138 truncate_setsize(d_inode(dentry), iattr->ia_size);
1139
1140 v9fs_invalidate_inode_attr(d_inode(dentry));
1141
1142 setattr_copy(d_inode(dentry), iattr);
1143 mark_inode_dirty(d_inode(dentry));
1144 return 0;
1145}
1146
1147/**
1148 * v9fs_stat2inode - populate an inode structure with mistat info
1149 * @stat: Plan 9 metadata (mistat) structure
1150 * @inode: inode to populate
1151 * @sb: superblock of filesystem
1152 *
1153 */
1154
1155void
1156v9fs_stat2inode(struct p9_wstat *stat, struct inode *inode,
1157 struct super_block *sb)
1158{
1159 umode_t mode;
1160 char ext[32];
1161 char tag_name[14];
1162 unsigned int i_nlink;
1163 struct v9fs_session_info *v9ses = sb->s_fs_info;
1164 struct v9fs_inode *v9inode = V9FS_I(inode);
1165
1166 set_nlink(inode, 1);
1167
1168 inode->i_atime.tv_sec = stat->atime;
1169 inode->i_mtime.tv_sec = stat->mtime;
1170 inode->i_ctime.tv_sec = stat->mtime;
1171
1172 inode->i_uid = v9ses->dfltuid;
1173 inode->i_gid = v9ses->dfltgid;
1174
1175 if (v9fs_proto_dotu(v9ses)) {
1176 inode->i_uid = stat->n_uid;
1177 inode->i_gid = stat->n_gid;
1178 }
1179 if ((S_ISREG(inode->i_mode)) || (S_ISDIR(inode->i_mode))) {
1180 if (v9fs_proto_dotu(v9ses) && (stat->extension[0] != '\0')) {
1181 /*
1182 * Hadlink support got added later to
1183 * to the .u extension. So there can be
1184 * server out there that doesn't support
1185 * this even with .u extension. So check
1186 * for non NULL stat->extension
1187 */
1188 strlcpy(ext, stat->extension, sizeof(ext));
1189 /* HARDLINKCOUNT %u */
1190 sscanf(ext, "%13s %u", tag_name, &i_nlink);
1191 if (!strncmp(tag_name, "HARDLINKCOUNT", 13))
1192 set_nlink(inode, i_nlink);
1193 }
1194 }
1195 mode = p9mode2perm(v9ses, stat);
1196 mode |= inode->i_mode & ~S_IALLUGO;
1197 inode->i_mode = mode;
1198 i_size_write(inode, stat->length);
1199
1200 /* not real number of blocks, but 512 byte ones ... */
1201 inode->i_blocks = (i_size_read(inode) + 512 - 1) >> 9;
1202 v9inode->cache_validity &= ~V9FS_INO_INVALID_ATTR;
1203}
1204
1205/**
1206 * v9fs_qid2ino - convert qid into inode number
1207 * @qid: qid to hash
1208 *
1209 * BUG: potential for inode number collisions?
1210 */
1211
1212ino_t v9fs_qid2ino(struct p9_qid *qid)
1213{
1214 u64 path = qid->path + 2;
1215 ino_t i = 0;
1216
1217 if (sizeof(ino_t) == sizeof(path))
1218 memcpy(&i, &path, sizeof(ino_t));
1219 else
1220 i = (ino_t) (path ^ (path >> 32));
1221
1222 return i;
1223}
1224
1225/**
1226 * v9fs_vfs_get_link - follow a symlink path
1227 * @dentry: dentry for symlink
1228 * @inode: inode for symlink
1229 * @done: delayed call for when we are done with the return value
1230 */
1231
1232static const char *v9fs_vfs_get_link(struct dentry *dentry,
1233 struct inode *inode,
1234 struct delayed_call *done)
1235{
1236 struct v9fs_session_info *v9ses;
1237 struct p9_fid *fid;
1238 struct p9_wstat *st;
1239 char *res;
1240
1241 if (!dentry)
1242 return ERR_PTR(-ECHILD);
1243
1244 v9ses = v9fs_dentry2v9ses(dentry);
1245 fid = v9fs_fid_lookup(dentry);
1246 p9_debug(P9_DEBUG_VFS, "%pd\n", dentry);
1247
1248 if (IS_ERR(fid))
1249 return ERR_CAST(fid);
1250
1251 if (!v9fs_proto_dotu(v9ses))
1252 return ERR_PTR(-EBADF);
1253
1254 st = p9_client_stat(fid);
1255 if (IS_ERR(st))
1256 return ERR_CAST(st);
1257
1258 if (!(st->mode & P9_DMSYMLINK)) {
1259 p9stat_free(st);
1260 kfree(st);
1261 return ERR_PTR(-EINVAL);
1262 }
1263 res = st->extension;
1264 st->extension = NULL;
1265 if (strlen(res) >= PATH_MAX)
1266 res[PATH_MAX - 1] = '\0';
1267
1268 p9stat_free(st);
1269 kfree(st);
1270 set_delayed_call(done, kfree_link, res);
1271 return res;
1272}
1273
1274/**
1275 * v9fs_vfs_mkspecial - create a special file
1276 * @dir: inode to create special file in
1277 * @dentry: dentry to create
1278 * @perm: mode to create special file
1279 * @extension: 9p2000.u format extension string representing special file
1280 *
1281 */
1282
1283static int v9fs_vfs_mkspecial(struct inode *dir, struct dentry *dentry,
1284 u32 perm, const char *extension)
1285{
1286 struct p9_fid *fid;
1287 struct v9fs_session_info *v9ses;
1288
1289 v9ses = v9fs_inode2v9ses(dir);
1290 if (!v9fs_proto_dotu(v9ses)) {
1291 p9_debug(P9_DEBUG_ERROR, "not extended\n");
1292 return -EPERM;
1293 }
1294
1295 fid = v9fs_create(v9ses, dir, dentry, (char *) extension, perm,
1296 P9_OREAD);
1297 if (IS_ERR(fid))
1298 return PTR_ERR(fid);
1299
1300 v9fs_invalidate_inode_attr(dir);
1301 p9_client_clunk(fid);
1302 return 0;
1303}
1304
1305/**
1306 * v9fs_vfs_symlink - helper function to create symlinks
1307 * @dir: directory inode containing symlink
1308 * @dentry: dentry for symlink
1309 * @symname: symlink data
1310 *
1311 * See Also: 9P2000.u RFC for more information
1312 *
1313 */
1314
1315static int
1316v9fs_vfs_symlink(struct inode *dir, struct dentry *dentry, const char *symname)
1317{
1318 p9_debug(P9_DEBUG_VFS, " %lu,%pd,%s\n",
1319 dir->i_ino, dentry, symname);
1320
1321 return v9fs_vfs_mkspecial(dir, dentry, P9_DMSYMLINK, symname);
1322}
1323
1324#define U32_MAX_DIGITS 10
1325
1326/**
1327 * v9fs_vfs_link - create a hardlink
1328 * @old_dentry: dentry for file to link to
1329 * @dir: inode destination for new link
1330 * @dentry: dentry for link
1331 *
1332 */
1333
1334static int
1335v9fs_vfs_link(struct dentry *old_dentry, struct inode *dir,
1336 struct dentry *dentry)
1337{
1338 int retval;
1339 char name[1 + U32_MAX_DIGITS + 2]; /* sign + number + \n + \0 */
1340 struct p9_fid *oldfid;
1341
1342 p9_debug(P9_DEBUG_VFS, " %lu,%pd,%pd\n",
1343 dir->i_ino, dentry, old_dentry);
1344
1345 oldfid = v9fs_fid_clone(old_dentry);
1346 if (IS_ERR(oldfid))
1347 return PTR_ERR(oldfid);
1348
1349 sprintf(name, "%d\n", oldfid->fid);
1350 retval = v9fs_vfs_mkspecial(dir, dentry, P9_DMLINK, name);
1351 if (!retval) {
1352 v9fs_refresh_inode(oldfid, d_inode(old_dentry));
1353 v9fs_invalidate_inode_attr(dir);
1354 }
1355 p9_client_clunk(oldfid);
1356 return retval;
1357}
1358
1359/**
1360 * v9fs_vfs_mknod - create a special file
1361 * @dir: inode destination for new link
1362 * @dentry: dentry for file
1363 * @mode: mode for creation
1364 * @rdev: device associated with special file
1365 *
1366 */
1367
1368static int
1369v9fs_vfs_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t rdev)
1370{
1371 struct v9fs_session_info *v9ses = v9fs_inode2v9ses(dir);
1372 int retval;
1373 char name[2 + U32_MAX_DIGITS + 1 + U32_MAX_DIGITS + 1];
1374 u32 perm;
1375
1376 p9_debug(P9_DEBUG_VFS, " %lu,%pd mode: %hx MAJOR: %u MINOR: %u\n",
1377 dir->i_ino, dentry, mode,
1378 MAJOR(rdev), MINOR(rdev));
1379
1380 /* build extension */
1381 if (S_ISBLK(mode))
1382 sprintf(name, "b %u %u", MAJOR(rdev), MINOR(rdev));
1383 else if (S_ISCHR(mode))
1384 sprintf(name, "c %u %u", MAJOR(rdev), MINOR(rdev));
1385 else
1386 *name = 0;
1387
1388 perm = unixmode2p9mode(v9ses, mode);
1389 retval = v9fs_vfs_mkspecial(dir, dentry, perm, name);
1390
1391 return retval;
1392}
1393
1394int v9fs_refresh_inode(struct p9_fid *fid, struct inode *inode)
1395{
1396 int umode;
1397 dev_t rdev;
1398 loff_t i_size;
1399 struct p9_wstat *st;
1400 struct v9fs_session_info *v9ses;
1401
1402 v9ses = v9fs_inode2v9ses(inode);
1403 st = p9_client_stat(fid);
1404 if (IS_ERR(st))
1405 return PTR_ERR(st);
1406 /*
1407 * Don't update inode if the file type is different
1408 */
1409 umode = p9mode2unixmode(v9ses, st, &rdev);
1410 if ((inode->i_mode & S_IFMT) != (umode & S_IFMT))
1411 goto out;
1412
1413 spin_lock(&inode->i_lock);
1414 /*
1415 * We don't want to refresh inode->i_size,
1416 * because we may have cached data
1417 */
1418 i_size = inode->i_size;
1419 v9fs_stat2inode(st, inode, inode->i_sb);
1420 if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE)
1421 inode->i_size = i_size;
1422 spin_unlock(&inode->i_lock);
1423out:
1424 p9stat_free(st);
1425 kfree(st);
1426 return 0;
1427}
1428
1429static const struct inode_operations v9fs_dir_inode_operations_dotu = {
1430 .create = v9fs_vfs_create,
1431 .lookup = v9fs_vfs_lookup,
1432 .atomic_open = v9fs_vfs_atomic_open,
1433 .symlink = v9fs_vfs_symlink,
1434 .link = v9fs_vfs_link,
1435 .unlink = v9fs_vfs_unlink,
1436 .mkdir = v9fs_vfs_mkdir,
1437 .rmdir = v9fs_vfs_rmdir,
1438 .mknod = v9fs_vfs_mknod,
1439 .rename = v9fs_vfs_rename,
1440 .getattr = v9fs_vfs_getattr,
1441 .setattr = v9fs_vfs_setattr,
1442};
1443
1444static const struct inode_operations v9fs_dir_inode_operations = {
1445 .create = v9fs_vfs_create,
1446 .lookup = v9fs_vfs_lookup,
1447 .atomic_open = v9fs_vfs_atomic_open,
1448 .unlink = v9fs_vfs_unlink,
1449 .mkdir = v9fs_vfs_mkdir,
1450 .rmdir = v9fs_vfs_rmdir,
1451 .mknod = v9fs_vfs_mknod,
1452 .rename = v9fs_vfs_rename,
1453 .getattr = v9fs_vfs_getattr,
1454 .setattr = v9fs_vfs_setattr,
1455};
1456
1457static const struct inode_operations v9fs_file_inode_operations = {
1458 .getattr = v9fs_vfs_getattr,
1459 .setattr = v9fs_vfs_setattr,
1460};
1461
1462static const struct inode_operations v9fs_symlink_inode_operations = {
1463 .readlink = generic_readlink,
1464 .get_link = v9fs_vfs_get_link,
1465 .getattr = v9fs_vfs_getattr,
1466 .setattr = v9fs_vfs_setattr,
1467};
1468
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * This file contains vfs inode ops for the 9P2000 protocol.
4 *
5 * Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
6 * Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
7 */
8
9#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
10
11#include <linux/module.h>
12#include <linux/errno.h>
13#include <linux/fs.h>
14#include <linux/file.h>
15#include <linux/pagemap.h>
16#include <linux/stat.h>
17#include <linux/string.h>
18#include <linux/namei.h>
19#include <linux/sched.h>
20#include <linux/slab.h>
21#include <linux/xattr.h>
22#include <linux/posix_acl.h>
23#include <net/9p/9p.h>
24#include <net/9p/client.h>
25
26#include "v9fs.h"
27#include "v9fs_vfs.h"
28#include "fid.h"
29#include "cache.h"
30#include "xattr.h"
31#include "acl.h"
32
33static const struct inode_operations v9fs_dir_inode_operations;
34static const struct inode_operations v9fs_dir_inode_operations_dotu;
35static const struct inode_operations v9fs_file_inode_operations;
36static const struct inode_operations v9fs_symlink_inode_operations;
37
38/**
39 * unixmode2p9mode - convert unix mode bits to plan 9
40 * @v9ses: v9fs session information
41 * @mode: mode to convert
42 *
43 */
44
45static u32 unixmode2p9mode(struct v9fs_session_info *v9ses, umode_t mode)
46{
47 int res;
48
49 res = mode & 0777;
50 if (S_ISDIR(mode))
51 res |= P9_DMDIR;
52 if (v9fs_proto_dotu(v9ses)) {
53 if (v9ses->nodev == 0) {
54 if (S_ISSOCK(mode))
55 res |= P9_DMSOCKET;
56 if (S_ISFIFO(mode))
57 res |= P9_DMNAMEDPIPE;
58 if (S_ISBLK(mode))
59 res |= P9_DMDEVICE;
60 if (S_ISCHR(mode))
61 res |= P9_DMDEVICE;
62 }
63
64 if ((mode & S_ISUID) == S_ISUID)
65 res |= P9_DMSETUID;
66 if ((mode & S_ISGID) == S_ISGID)
67 res |= P9_DMSETGID;
68 if ((mode & S_ISVTX) == S_ISVTX)
69 res |= P9_DMSETVTX;
70 }
71 return res;
72}
73
74/**
75 * p9mode2perm- convert plan9 mode bits to unix permission bits
76 * @v9ses: v9fs session information
77 * @stat: p9_wstat from which mode need to be derived
78 *
79 */
80static int p9mode2perm(struct v9fs_session_info *v9ses,
81 struct p9_wstat *stat)
82{
83 int res;
84 int mode = stat->mode;
85
86 res = mode & 0777; /* S_IRWXUGO */
87 if (v9fs_proto_dotu(v9ses)) {
88 if ((mode & P9_DMSETUID) == P9_DMSETUID)
89 res |= S_ISUID;
90
91 if ((mode & P9_DMSETGID) == P9_DMSETGID)
92 res |= S_ISGID;
93
94 if ((mode & P9_DMSETVTX) == P9_DMSETVTX)
95 res |= S_ISVTX;
96 }
97 return res;
98}
99
100/**
101 * p9mode2unixmode- convert plan9 mode bits to unix mode bits
102 * @v9ses: v9fs session information
103 * @stat: p9_wstat from which mode need to be derived
104 * @rdev: major number, minor number in case of device files.
105 *
106 */
107static umode_t p9mode2unixmode(struct v9fs_session_info *v9ses,
108 struct p9_wstat *stat, dev_t *rdev)
109{
110 int res, r;
111 u32 mode = stat->mode;
112
113 *rdev = 0;
114 res = p9mode2perm(v9ses, stat);
115
116 if ((mode & P9_DMDIR) == P9_DMDIR)
117 res |= S_IFDIR;
118 else if ((mode & P9_DMSYMLINK) && (v9fs_proto_dotu(v9ses)))
119 res |= S_IFLNK;
120 else if ((mode & P9_DMSOCKET) && (v9fs_proto_dotu(v9ses))
121 && (v9ses->nodev == 0))
122 res |= S_IFSOCK;
123 else if ((mode & P9_DMNAMEDPIPE) && (v9fs_proto_dotu(v9ses))
124 && (v9ses->nodev == 0))
125 res |= S_IFIFO;
126 else if ((mode & P9_DMDEVICE) && (v9fs_proto_dotu(v9ses))
127 && (v9ses->nodev == 0)) {
128 char type = 0;
129 int major = -1, minor = -1;
130
131 r = sscanf(stat->extension, "%c %i %i", &type, &major, &minor);
132 if (r != 3) {
133 p9_debug(P9_DEBUG_ERROR,
134 "invalid device string, umode will be bogus: %s\n",
135 stat->extension);
136 return res;
137 }
138 switch (type) {
139 case 'c':
140 res |= S_IFCHR;
141 break;
142 case 'b':
143 res |= S_IFBLK;
144 break;
145 default:
146 p9_debug(P9_DEBUG_ERROR, "Unknown special type %c %s\n",
147 type, stat->extension);
148 }
149 *rdev = MKDEV(major, minor);
150 } else
151 res |= S_IFREG;
152
153 return res;
154}
155
156/**
157 * v9fs_uflags2omode- convert posix open flags to plan 9 mode bits
158 * @uflags: flags to convert
159 * @extended: if .u extensions are active
160 */
161
162int v9fs_uflags2omode(int uflags, int extended)
163{
164 int ret;
165
166 switch (uflags&3) {
167 default:
168 case O_RDONLY:
169 ret = P9_OREAD;
170 break;
171
172 case O_WRONLY:
173 ret = P9_OWRITE;
174 break;
175
176 case O_RDWR:
177 ret = P9_ORDWR;
178 break;
179 }
180
181 if (uflags & O_TRUNC)
182 ret |= P9_OTRUNC;
183
184 if (extended) {
185 if (uflags & O_EXCL)
186 ret |= P9_OEXCL;
187
188 if (uflags & O_APPEND)
189 ret |= P9_OAPPEND;
190 }
191
192 return ret;
193}
194
195/**
196 * v9fs_blank_wstat - helper function to setup a 9P stat structure
197 * @wstat: structure to initialize
198 *
199 */
200
201void
202v9fs_blank_wstat(struct p9_wstat *wstat)
203{
204 wstat->type = ~0;
205 wstat->dev = ~0;
206 wstat->qid.type = ~0;
207 wstat->qid.version = ~0;
208 *((long long *)&wstat->qid.path) = ~0;
209 wstat->mode = ~0;
210 wstat->atime = ~0;
211 wstat->mtime = ~0;
212 wstat->length = ~0;
213 wstat->name = NULL;
214 wstat->uid = NULL;
215 wstat->gid = NULL;
216 wstat->muid = NULL;
217 wstat->n_uid = INVALID_UID;
218 wstat->n_gid = INVALID_GID;
219 wstat->n_muid = INVALID_UID;
220 wstat->extension = NULL;
221}
222
223/**
224 * v9fs_alloc_inode - helper function to allocate an inode
225 * @sb: The superblock to allocate the inode from
226 */
227struct inode *v9fs_alloc_inode(struct super_block *sb)
228{
229 struct v9fs_inode *v9inode;
230
231 v9inode = alloc_inode_sb(sb, v9fs_inode_cache, GFP_KERNEL);
232 if (!v9inode)
233 return NULL;
234 v9inode->cache_validity = 0;
235 mutex_init(&v9inode->v_mutex);
236 return &v9inode->netfs.inode;
237}
238
239/**
240 * v9fs_free_inode - destroy an inode
241 * @inode: The inode to be freed
242 */
243
244void v9fs_free_inode(struct inode *inode)
245{
246 kmem_cache_free(v9fs_inode_cache, V9FS_I(inode));
247}
248
249/*
250 * Set parameters for the netfs library
251 */
252void v9fs_set_netfs_context(struct inode *inode)
253{
254 struct v9fs_inode *v9inode = V9FS_I(inode);
255 netfs_inode_init(&v9inode->netfs, &v9fs_req_ops, true);
256}
257
258int v9fs_init_inode(struct v9fs_session_info *v9ses,
259 struct inode *inode, struct p9_qid *qid, umode_t mode, dev_t rdev)
260{
261 int err = 0;
262 struct v9fs_inode *v9inode = V9FS_I(inode);
263
264 memcpy(&v9inode->qid, qid, sizeof(struct p9_qid));
265
266 inode_init_owner(&nop_mnt_idmap, inode, NULL, mode);
267 inode->i_blocks = 0;
268 inode->i_rdev = rdev;
269 simple_inode_init_ts(inode);
270 inode->i_mapping->a_ops = &v9fs_addr_operations;
271 inode->i_private = NULL;
272
273 switch (mode & S_IFMT) {
274 case S_IFIFO:
275 case S_IFBLK:
276 case S_IFCHR:
277 case S_IFSOCK:
278 if (v9fs_proto_dotl(v9ses)) {
279 inode->i_op = &v9fs_file_inode_operations_dotl;
280 } else if (v9fs_proto_dotu(v9ses)) {
281 inode->i_op = &v9fs_file_inode_operations;
282 } else {
283 p9_debug(P9_DEBUG_ERROR,
284 "special files without extended mode\n");
285 err = -EINVAL;
286 goto error;
287 }
288 init_special_inode(inode, inode->i_mode, inode->i_rdev);
289 break;
290 case S_IFREG:
291 if (v9fs_proto_dotl(v9ses)) {
292 inode->i_op = &v9fs_file_inode_operations_dotl;
293 inode->i_fop = &v9fs_file_operations_dotl;
294 } else {
295 inode->i_op = &v9fs_file_inode_operations;
296 inode->i_fop = &v9fs_file_operations;
297 }
298
299 break;
300 case S_IFLNK:
301 if (!v9fs_proto_dotu(v9ses) && !v9fs_proto_dotl(v9ses)) {
302 p9_debug(P9_DEBUG_ERROR,
303 "extended modes used with legacy protocol\n");
304 err = -EINVAL;
305 goto error;
306 }
307
308 if (v9fs_proto_dotl(v9ses))
309 inode->i_op = &v9fs_symlink_inode_operations_dotl;
310 else
311 inode->i_op = &v9fs_symlink_inode_operations;
312
313 break;
314 case S_IFDIR:
315 inc_nlink(inode);
316 if (v9fs_proto_dotl(v9ses))
317 inode->i_op = &v9fs_dir_inode_operations_dotl;
318 else if (v9fs_proto_dotu(v9ses))
319 inode->i_op = &v9fs_dir_inode_operations_dotu;
320 else
321 inode->i_op = &v9fs_dir_inode_operations;
322
323 if (v9fs_proto_dotl(v9ses))
324 inode->i_fop = &v9fs_dir_operations_dotl;
325 else
326 inode->i_fop = &v9fs_dir_operations;
327
328 break;
329 default:
330 p9_debug(P9_DEBUG_ERROR, "BAD mode 0x%hx S_IFMT 0x%x\n",
331 mode, mode & S_IFMT);
332 err = -EINVAL;
333 goto error;
334 }
335error:
336 return err;
337
338}
339
340/**
341 * v9fs_evict_inode - Remove an inode from the inode cache
342 * @inode: inode to release
343 *
344 */
345void v9fs_evict_inode(struct inode *inode)
346{
347 struct v9fs_inode __maybe_unused *v9inode = V9FS_I(inode);
348 __le32 __maybe_unused version;
349
350 if (!is_bad_inode(inode)) {
351 truncate_inode_pages_final(&inode->i_data);
352
353 version = cpu_to_le32(v9inode->qid.version);
354 netfs_clear_inode_writeback(inode, &version);
355
356 clear_inode(inode);
357 filemap_fdatawrite(&inode->i_data);
358
359#ifdef CONFIG_9P_FSCACHE
360 if (v9fs_inode_cookie(v9inode))
361 fscache_relinquish_cookie(v9fs_inode_cookie(v9inode), false);
362#endif
363 } else
364 clear_inode(inode);
365}
366
367struct inode *
368v9fs_fid_iget(struct super_block *sb, struct p9_fid *fid, bool new)
369{
370 dev_t rdev;
371 int retval;
372 umode_t umode;
373 struct inode *inode;
374 struct p9_wstat *st;
375 struct v9fs_session_info *v9ses = sb->s_fs_info;
376
377 inode = iget_locked(sb, QID2INO(&fid->qid));
378 if (unlikely(!inode))
379 return ERR_PTR(-ENOMEM);
380 if (!(inode->i_state & I_NEW)) {
381 if (!new) {
382 goto done;
383 } else {
384 p9_debug(P9_DEBUG_VFS, "WARNING: Inode collision %ld\n",
385 inode->i_ino);
386 iput(inode);
387 remove_inode_hash(inode);
388 inode = iget_locked(sb, QID2INO(&fid->qid));
389 WARN_ON(!(inode->i_state & I_NEW));
390 }
391 }
392
393 /*
394 * initialize the inode with the stat info
395 * FIXME!! we may need support for stale inodes
396 * later.
397 */
398 st = p9_client_stat(fid);
399 if (IS_ERR(st)) {
400 retval = PTR_ERR(st);
401 goto error;
402 }
403
404 umode = p9mode2unixmode(v9ses, st, &rdev);
405 retval = v9fs_init_inode(v9ses, inode, &fid->qid, umode, rdev);
406 v9fs_stat2inode(st, inode, sb, 0);
407 p9stat_free(st);
408 kfree(st);
409 if (retval)
410 goto error;
411
412 v9fs_set_netfs_context(inode);
413 v9fs_cache_inode_get_cookie(inode);
414 unlock_new_inode(inode);
415done:
416 return inode;
417error:
418 iget_failed(inode);
419 return ERR_PTR(retval);
420}
421
422/**
423 * v9fs_at_to_dotl_flags- convert Linux specific AT flags to
424 * plan 9 AT flag.
425 * @flags: flags to convert
426 */
427static int v9fs_at_to_dotl_flags(int flags)
428{
429 int rflags = 0;
430
431 if (flags & AT_REMOVEDIR)
432 rflags |= P9_DOTL_AT_REMOVEDIR;
433
434 return rflags;
435}
436
437/**
438 * v9fs_dec_count - helper functon to drop i_nlink.
439 *
440 * If a directory had nlink <= 2 (including . and ..), then we should not drop
441 * the link count, which indicates the underlying exported fs doesn't maintain
442 * nlink accurately. e.g.
443 * - overlayfs sets nlink to 1 for merged dir
444 * - ext4 (with dir_nlink feature enabled) sets nlink to 1 if a dir has more
445 * than EXT4_LINK_MAX (65000) links.
446 *
447 * @inode: inode whose nlink is being dropped
448 */
449static void v9fs_dec_count(struct inode *inode)
450{
451 if (!S_ISDIR(inode->i_mode) || inode->i_nlink > 2) {
452 if (inode->i_nlink) {
453 drop_nlink(inode);
454 } else {
455 p9_debug(P9_DEBUG_VFS,
456 "WARNING: unexpected i_nlink zero %d inode %ld\n",
457 inode->i_nlink, inode->i_ino);
458 }
459 }
460}
461
462/**
463 * v9fs_remove - helper function to remove files and directories
464 * @dir: directory inode that is being deleted
465 * @dentry: dentry that is being deleted
466 * @flags: removing a directory
467 *
468 */
469
470static int v9fs_remove(struct inode *dir, struct dentry *dentry, int flags)
471{
472 struct inode *inode;
473 int retval = -EOPNOTSUPP;
474 struct p9_fid *v9fid, *dfid;
475 struct v9fs_session_info *v9ses;
476
477 p9_debug(P9_DEBUG_VFS, "inode: %p dentry: %p rmdir: %x\n",
478 dir, dentry, flags);
479
480 v9ses = v9fs_inode2v9ses(dir);
481 inode = d_inode(dentry);
482 dfid = v9fs_parent_fid(dentry);
483 if (IS_ERR(dfid)) {
484 retval = PTR_ERR(dfid);
485 p9_debug(P9_DEBUG_VFS, "fid lookup failed %d\n", retval);
486 return retval;
487 }
488 if (v9fs_proto_dotl(v9ses))
489 retval = p9_client_unlinkat(dfid, dentry->d_name.name,
490 v9fs_at_to_dotl_flags(flags));
491 p9_fid_put(dfid);
492 if (retval == -EOPNOTSUPP) {
493 /* Try the one based on path */
494 v9fid = v9fs_fid_clone(dentry);
495 if (IS_ERR(v9fid))
496 return PTR_ERR(v9fid);
497 retval = p9_client_remove(v9fid);
498 }
499 if (!retval) {
500 /*
501 * directories on unlink should have zero
502 * link count
503 */
504 if (flags & AT_REMOVEDIR) {
505 clear_nlink(inode);
506 v9fs_dec_count(dir);
507 } else
508 v9fs_dec_count(inode);
509
510 if (inode->i_nlink <= 0) /* no more refs unhash it */
511 remove_inode_hash(inode);
512
513 v9fs_invalidate_inode_attr(inode);
514 v9fs_invalidate_inode_attr(dir);
515
516 /* invalidate all fids associated with dentry */
517 /* NOTE: This will not include open fids */
518 dentry->d_op->d_release(dentry);
519 }
520 return retval;
521}
522
523/**
524 * v9fs_create - Create a file
525 * @v9ses: session information
526 * @dir: directory that dentry is being created in
527 * @dentry: dentry that is being created
528 * @extension: 9p2000.u extension string to support devices, etc.
529 * @perm: create permissions
530 * @mode: open mode
531 *
532 */
533static struct p9_fid *
534v9fs_create(struct v9fs_session_info *v9ses, struct inode *dir,
535 struct dentry *dentry, char *extension, u32 perm, u8 mode)
536{
537 int err;
538 const unsigned char *name;
539 struct p9_fid *dfid, *ofid = NULL, *fid = NULL;
540 struct inode *inode;
541
542 p9_debug(P9_DEBUG_VFS, "name %pd\n", dentry);
543
544 name = dentry->d_name.name;
545 dfid = v9fs_parent_fid(dentry);
546 if (IS_ERR(dfid)) {
547 err = PTR_ERR(dfid);
548 p9_debug(P9_DEBUG_VFS, "fid lookup failed %d\n", err);
549 return ERR_PTR(err);
550 }
551
552 /* clone a fid to use for creation */
553 ofid = clone_fid(dfid);
554 if (IS_ERR(ofid)) {
555 err = PTR_ERR(ofid);
556 p9_debug(P9_DEBUG_VFS, "p9_client_walk failed %d\n", err);
557 goto error;
558 }
559
560 err = p9_client_fcreate(ofid, name, perm, mode, extension);
561 if (err < 0) {
562 p9_debug(P9_DEBUG_VFS, "p9_client_fcreate failed %d\n", err);
563 goto error;
564 }
565
566 if (!(perm & P9_DMLINK)) {
567 /* now walk from the parent so we can get unopened fid */
568 fid = p9_client_walk(dfid, 1, &name, 1);
569 if (IS_ERR(fid)) {
570 err = PTR_ERR(fid);
571 p9_debug(P9_DEBUG_VFS,
572 "p9_client_walk failed %d\n", err);
573 goto error;
574 }
575 /*
576 * instantiate inode and assign the unopened fid to the dentry
577 */
578 inode = v9fs_get_inode_from_fid(v9ses, fid, dir->i_sb, true);
579 if (IS_ERR(inode)) {
580 err = PTR_ERR(inode);
581 p9_debug(P9_DEBUG_VFS,
582 "inode creation failed %d\n", err);
583 goto error;
584 }
585 v9fs_fid_add(dentry, &fid);
586 d_instantiate(dentry, inode);
587 }
588 p9_fid_put(dfid);
589 return ofid;
590error:
591 p9_fid_put(dfid);
592 p9_fid_put(ofid);
593 p9_fid_put(fid);
594 return ERR_PTR(err);
595}
596
597/**
598 * v9fs_vfs_create - VFS hook to create a regular file
599 * @idmap: idmap of the mount
600 * @dir: The parent directory
601 * @dentry: The name of file to be created
602 * @mode: The UNIX file mode to set
603 * @excl: True if the file must not yet exist
604 *
605 * open(.., O_CREAT) is handled in v9fs_vfs_atomic_open(). This is only called
606 * for mknod(2).
607 *
608 */
609
610static int
611v9fs_vfs_create(struct mnt_idmap *idmap, struct inode *dir,
612 struct dentry *dentry, umode_t mode, bool excl)
613{
614 struct v9fs_session_info *v9ses = v9fs_inode2v9ses(dir);
615 u32 perm = unixmode2p9mode(v9ses, mode);
616 struct p9_fid *fid;
617
618 /* P9_OEXCL? */
619 fid = v9fs_create(v9ses, dir, dentry, NULL, perm, P9_ORDWR);
620 if (IS_ERR(fid))
621 return PTR_ERR(fid);
622
623 v9fs_invalidate_inode_attr(dir);
624 p9_fid_put(fid);
625
626 return 0;
627}
628
629/**
630 * v9fs_vfs_mkdir - VFS mkdir hook to create a directory
631 * @idmap: idmap of the mount
632 * @dir: inode that is being unlinked
633 * @dentry: dentry that is being unlinked
634 * @mode: mode for new directory
635 *
636 */
637
638static int v9fs_vfs_mkdir(struct mnt_idmap *idmap, struct inode *dir,
639 struct dentry *dentry, umode_t mode)
640{
641 int err;
642 u32 perm;
643 struct p9_fid *fid;
644 struct v9fs_session_info *v9ses;
645
646 p9_debug(P9_DEBUG_VFS, "name %pd\n", dentry);
647 err = 0;
648 v9ses = v9fs_inode2v9ses(dir);
649 perm = unixmode2p9mode(v9ses, mode | S_IFDIR);
650 fid = v9fs_create(v9ses, dir, dentry, NULL, perm, P9_OREAD);
651 if (IS_ERR(fid)) {
652 err = PTR_ERR(fid);
653 fid = NULL;
654 } else {
655 inc_nlink(dir);
656 v9fs_invalidate_inode_attr(dir);
657 }
658
659 if (fid)
660 p9_fid_put(fid);
661
662 return err;
663}
664
665/**
666 * v9fs_vfs_lookup - VFS lookup hook to "walk" to a new inode
667 * @dir: inode that is being walked from
668 * @dentry: dentry that is being walked to?
669 * @flags: lookup flags (unused)
670 *
671 */
672
673struct dentry *v9fs_vfs_lookup(struct inode *dir, struct dentry *dentry,
674 unsigned int flags)
675{
676 struct dentry *res;
677 struct v9fs_session_info *v9ses;
678 struct p9_fid *dfid, *fid;
679 struct inode *inode;
680 const unsigned char *name;
681
682 p9_debug(P9_DEBUG_VFS, "dir: %p dentry: (%pd) %p flags: %x\n",
683 dir, dentry, dentry, flags);
684
685 if (dentry->d_name.len > NAME_MAX)
686 return ERR_PTR(-ENAMETOOLONG);
687
688 v9ses = v9fs_inode2v9ses(dir);
689 /* We can walk d_parent because we hold the dir->i_mutex */
690 dfid = v9fs_parent_fid(dentry);
691 if (IS_ERR(dfid))
692 return ERR_CAST(dfid);
693
694 /*
695 * Make sure we don't use a wrong inode due to parallel
696 * unlink. For cached mode create calls request for new
697 * inode. But with cache disabled, lookup should do this.
698 */
699 name = dentry->d_name.name;
700 fid = p9_client_walk(dfid, 1, &name, 1);
701 p9_fid_put(dfid);
702 if (fid == ERR_PTR(-ENOENT))
703 inode = NULL;
704 else if (IS_ERR(fid))
705 inode = ERR_CAST(fid);
706 else
707 inode = v9fs_get_inode_from_fid(v9ses, fid, dir->i_sb, false);
708 /*
709 * If we had a rename on the server and a parallel lookup
710 * for the new name, then make sure we instantiate with
711 * the new name. ie look up for a/b, while on server somebody
712 * moved b under k and client parallely did a lookup for
713 * k/b.
714 */
715 res = d_splice_alias(inode, dentry);
716 if (!IS_ERR(fid)) {
717 if (!res)
718 v9fs_fid_add(dentry, &fid);
719 else if (!IS_ERR(res))
720 v9fs_fid_add(res, &fid);
721 else
722 p9_fid_put(fid);
723 }
724 return res;
725}
726
727static int
728v9fs_vfs_atomic_open(struct inode *dir, struct dentry *dentry,
729 struct file *file, unsigned int flags, umode_t mode)
730{
731 int err;
732 u32 perm;
733 struct v9fs_inode __maybe_unused *v9inode;
734 struct v9fs_session_info *v9ses;
735 struct p9_fid *fid;
736 struct dentry *res = NULL;
737 struct inode *inode;
738 int p9_omode;
739
740 if (d_in_lookup(dentry)) {
741 res = v9fs_vfs_lookup(dir, dentry, 0);
742 if (IS_ERR(res))
743 return PTR_ERR(res);
744
745 if (res)
746 dentry = res;
747 }
748
749 /* Only creates */
750 if (!(flags & O_CREAT) || d_really_is_positive(dentry))
751 return finish_no_open(file, res);
752
753 v9ses = v9fs_inode2v9ses(dir);
754 perm = unixmode2p9mode(v9ses, mode);
755 p9_omode = v9fs_uflags2omode(flags, v9fs_proto_dotu(v9ses));
756
757 if ((v9ses->cache & CACHE_WRITEBACK) && (p9_omode & P9_OWRITE)) {
758 p9_omode = (p9_omode & ~P9_OWRITE) | P9_ORDWR;
759 p9_debug(P9_DEBUG_CACHE,
760 "write-only file with writeback enabled, creating w/ O_RDWR\n");
761 }
762 fid = v9fs_create(v9ses, dir, dentry, NULL, perm, p9_omode);
763 if (IS_ERR(fid)) {
764 err = PTR_ERR(fid);
765 goto error;
766 }
767
768 v9fs_invalidate_inode_attr(dir);
769 inode = d_inode(dentry);
770 v9inode = V9FS_I(inode);
771 err = finish_open(file, dentry, generic_file_open);
772 if (err)
773 goto error;
774
775 file->private_data = fid;
776#ifdef CONFIG_9P_FSCACHE
777 if (v9ses->cache & CACHE_FSCACHE)
778 fscache_use_cookie(v9fs_inode_cookie(v9inode),
779 file->f_mode & FMODE_WRITE);
780#endif
781
782 v9fs_fid_add_modes(fid, v9ses->flags, v9ses->cache, file->f_flags);
783 v9fs_open_fid_add(inode, &fid);
784
785 file->f_mode |= FMODE_CREATED;
786out:
787 dput(res);
788 return err;
789
790error:
791 p9_fid_put(fid);
792 goto out;
793}
794
795/**
796 * v9fs_vfs_unlink - VFS unlink hook to delete an inode
797 * @i: inode that is being unlinked
798 * @d: dentry that is being unlinked
799 *
800 */
801
802int v9fs_vfs_unlink(struct inode *i, struct dentry *d)
803{
804 return v9fs_remove(i, d, 0);
805}
806
807/**
808 * v9fs_vfs_rmdir - VFS unlink hook to delete a directory
809 * @i: inode that is being unlinked
810 * @d: dentry that is being unlinked
811 *
812 */
813
814int v9fs_vfs_rmdir(struct inode *i, struct dentry *d)
815{
816 return v9fs_remove(i, d, AT_REMOVEDIR);
817}
818
819/**
820 * v9fs_vfs_rename - VFS hook to rename an inode
821 * @idmap: The idmap of the mount
822 * @old_dir: old dir inode
823 * @old_dentry: old dentry
824 * @new_dir: new dir inode
825 * @new_dentry: new dentry
826 * @flags: RENAME_* flags
827 *
828 */
829
830int
831v9fs_vfs_rename(struct mnt_idmap *idmap, struct inode *old_dir,
832 struct dentry *old_dentry, struct inode *new_dir,
833 struct dentry *new_dentry, unsigned int flags)
834{
835 int retval;
836 struct inode *old_inode;
837 struct inode *new_inode;
838 struct v9fs_session_info *v9ses;
839 struct p9_fid *oldfid = NULL, *dfid = NULL;
840 struct p9_fid *olddirfid = NULL;
841 struct p9_fid *newdirfid = NULL;
842 struct p9_wstat wstat;
843
844 if (flags)
845 return -EINVAL;
846
847 p9_debug(P9_DEBUG_VFS, "\n");
848 old_inode = d_inode(old_dentry);
849 new_inode = d_inode(new_dentry);
850 v9ses = v9fs_inode2v9ses(old_inode);
851 oldfid = v9fs_fid_lookup(old_dentry);
852 if (IS_ERR(oldfid))
853 return PTR_ERR(oldfid);
854
855 dfid = v9fs_parent_fid(old_dentry);
856 olddirfid = clone_fid(dfid);
857 p9_fid_put(dfid);
858 dfid = NULL;
859
860 if (IS_ERR(olddirfid)) {
861 retval = PTR_ERR(olddirfid);
862 goto error;
863 }
864
865 dfid = v9fs_parent_fid(new_dentry);
866 newdirfid = clone_fid(dfid);
867 p9_fid_put(dfid);
868 dfid = NULL;
869
870 if (IS_ERR(newdirfid)) {
871 retval = PTR_ERR(newdirfid);
872 goto error;
873 }
874
875 down_write(&v9ses->rename_sem);
876 if (v9fs_proto_dotl(v9ses)) {
877 retval = p9_client_renameat(olddirfid, old_dentry->d_name.name,
878 newdirfid, new_dentry->d_name.name);
879 if (retval == -EOPNOTSUPP)
880 retval = p9_client_rename(oldfid, newdirfid,
881 new_dentry->d_name.name);
882 if (retval != -EOPNOTSUPP)
883 goto error_locked;
884 }
885 if (old_dentry->d_parent != new_dentry->d_parent) {
886 /*
887 * 9P .u can only handle file rename in the same directory
888 */
889
890 p9_debug(P9_DEBUG_ERROR, "old dir and new dir are different\n");
891 retval = -EXDEV;
892 goto error_locked;
893 }
894 v9fs_blank_wstat(&wstat);
895 wstat.muid = v9ses->uname;
896 wstat.name = new_dentry->d_name.name;
897 retval = p9_client_wstat(oldfid, &wstat);
898
899error_locked:
900 if (!retval) {
901 if (new_inode) {
902 if (S_ISDIR(new_inode->i_mode))
903 clear_nlink(new_inode);
904 else
905 v9fs_dec_count(new_inode);
906 }
907 if (S_ISDIR(old_inode->i_mode)) {
908 if (!new_inode)
909 inc_nlink(new_dir);
910 v9fs_dec_count(old_dir);
911 }
912 v9fs_invalidate_inode_attr(old_inode);
913 v9fs_invalidate_inode_attr(old_dir);
914 v9fs_invalidate_inode_attr(new_dir);
915
916 /* successful rename */
917 d_move(old_dentry, new_dentry);
918 }
919 up_write(&v9ses->rename_sem);
920
921error:
922 p9_fid_put(newdirfid);
923 p9_fid_put(olddirfid);
924 p9_fid_put(oldfid);
925 return retval;
926}
927
928/**
929 * v9fs_vfs_getattr - retrieve file metadata
930 * @idmap: idmap of the mount
931 * @path: Object to query
932 * @stat: metadata structure to populate
933 * @request_mask: Mask of STATX_xxx flags indicating the caller's interests
934 * @flags: AT_STATX_xxx setting
935 *
936 */
937
938static int
939v9fs_vfs_getattr(struct mnt_idmap *idmap, const struct path *path,
940 struct kstat *stat, u32 request_mask, unsigned int flags)
941{
942 struct dentry *dentry = path->dentry;
943 struct inode *inode = d_inode(dentry);
944 struct v9fs_session_info *v9ses;
945 struct p9_fid *fid;
946 struct p9_wstat *st;
947
948 p9_debug(P9_DEBUG_VFS, "dentry: %p\n", dentry);
949 v9ses = v9fs_dentry2v9ses(dentry);
950 if (v9ses->cache & (CACHE_META|CACHE_LOOSE)) {
951 generic_fillattr(&nop_mnt_idmap, request_mask, inode, stat);
952 return 0;
953 } else if (v9ses->cache & CACHE_WRITEBACK) {
954 if (S_ISREG(inode->i_mode)) {
955 int retval = filemap_fdatawrite(inode->i_mapping);
956
957 if (retval)
958 p9_debug(P9_DEBUG_ERROR,
959 "flushing writeback during getattr returned %d\n", retval);
960 }
961 }
962 fid = v9fs_fid_lookup(dentry);
963 if (IS_ERR(fid))
964 return PTR_ERR(fid);
965
966 st = p9_client_stat(fid);
967 p9_fid_put(fid);
968 if (IS_ERR(st))
969 return PTR_ERR(st);
970
971 v9fs_stat2inode(st, d_inode(dentry), dentry->d_sb, 0);
972 generic_fillattr(&nop_mnt_idmap, request_mask, d_inode(dentry), stat);
973
974 p9stat_free(st);
975 kfree(st);
976 return 0;
977}
978
979/**
980 * v9fs_vfs_setattr - set file metadata
981 * @idmap: idmap of the mount
982 * @dentry: file whose metadata to set
983 * @iattr: metadata assignment structure
984 *
985 */
986
987static int v9fs_vfs_setattr(struct mnt_idmap *idmap,
988 struct dentry *dentry, struct iattr *iattr)
989{
990 int retval, use_dentry = 0;
991 struct inode *inode = d_inode(dentry);
992 struct v9fs_session_info *v9ses;
993 struct p9_fid *fid = NULL;
994 struct p9_wstat wstat;
995
996 p9_debug(P9_DEBUG_VFS, "\n");
997 retval = setattr_prepare(&nop_mnt_idmap, dentry, iattr);
998 if (retval)
999 return retval;
1000
1001 v9ses = v9fs_dentry2v9ses(dentry);
1002 if (iattr->ia_valid & ATTR_FILE) {
1003 fid = iattr->ia_file->private_data;
1004 WARN_ON(!fid);
1005 }
1006 if (!fid) {
1007 fid = v9fs_fid_lookup(dentry);
1008 use_dentry = 1;
1009 }
1010 if (IS_ERR(fid))
1011 return PTR_ERR(fid);
1012
1013 v9fs_blank_wstat(&wstat);
1014 if (iattr->ia_valid & ATTR_MODE)
1015 wstat.mode = unixmode2p9mode(v9ses, iattr->ia_mode);
1016
1017 if (iattr->ia_valid & ATTR_MTIME)
1018 wstat.mtime = iattr->ia_mtime.tv_sec;
1019
1020 if (iattr->ia_valid & ATTR_ATIME)
1021 wstat.atime = iattr->ia_atime.tv_sec;
1022
1023 if (iattr->ia_valid & ATTR_SIZE)
1024 wstat.length = iattr->ia_size;
1025
1026 if (v9fs_proto_dotu(v9ses)) {
1027 if (iattr->ia_valid & ATTR_UID)
1028 wstat.n_uid = iattr->ia_uid;
1029
1030 if (iattr->ia_valid & ATTR_GID)
1031 wstat.n_gid = iattr->ia_gid;
1032 }
1033
1034 /* Write all dirty data */
1035 if (d_is_reg(dentry)) {
1036 retval = filemap_fdatawrite(inode->i_mapping);
1037 if (retval)
1038 p9_debug(P9_DEBUG_ERROR,
1039 "flushing writeback during setattr returned %d\n", retval);
1040 }
1041
1042 retval = p9_client_wstat(fid, &wstat);
1043
1044 if (use_dentry)
1045 p9_fid_put(fid);
1046
1047 if (retval < 0)
1048 return retval;
1049
1050 if ((iattr->ia_valid & ATTR_SIZE) &&
1051 iattr->ia_size != i_size_read(inode)) {
1052 truncate_setsize(inode, iattr->ia_size);
1053 netfs_resize_file(netfs_inode(inode), iattr->ia_size, true);
1054
1055#ifdef CONFIG_9P_FSCACHE
1056 if (v9ses->cache & CACHE_FSCACHE) {
1057 struct v9fs_inode *v9inode = V9FS_I(inode);
1058
1059 fscache_resize_cookie(v9fs_inode_cookie(v9inode), iattr->ia_size);
1060 }
1061#endif
1062 }
1063
1064 v9fs_invalidate_inode_attr(inode);
1065
1066 setattr_copy(&nop_mnt_idmap, inode, iattr);
1067 mark_inode_dirty(inode);
1068 return 0;
1069}
1070
1071/**
1072 * v9fs_stat2inode - populate an inode structure with mistat info
1073 * @stat: Plan 9 metadata (mistat) structure
1074 * @inode: inode to populate
1075 * @sb: superblock of filesystem
1076 * @flags: control flags (e.g. V9FS_STAT2INODE_KEEP_ISIZE)
1077 *
1078 */
1079
1080void
1081v9fs_stat2inode(struct p9_wstat *stat, struct inode *inode,
1082 struct super_block *sb, unsigned int flags)
1083{
1084 umode_t mode;
1085 struct v9fs_session_info *v9ses = sb->s_fs_info;
1086 struct v9fs_inode *v9inode = V9FS_I(inode);
1087
1088 inode_set_atime(inode, stat->atime, 0);
1089 inode_set_mtime(inode, stat->mtime, 0);
1090 inode_set_ctime(inode, stat->mtime, 0);
1091
1092 inode->i_uid = v9ses->dfltuid;
1093 inode->i_gid = v9ses->dfltgid;
1094
1095 if (v9fs_proto_dotu(v9ses)) {
1096 inode->i_uid = stat->n_uid;
1097 inode->i_gid = stat->n_gid;
1098 }
1099 if ((S_ISREG(inode->i_mode)) || (S_ISDIR(inode->i_mode))) {
1100 if (v9fs_proto_dotu(v9ses)) {
1101 unsigned int i_nlink;
1102 /*
1103 * Hadlink support got added later to the .u extension.
1104 * So there can be a server out there that doesn't
1105 * support this even with .u extension. That would
1106 * just leave us with stat->extension being an empty
1107 * string, though.
1108 */
1109 /* HARDLINKCOUNT %u */
1110 if (sscanf(stat->extension,
1111 " HARDLINKCOUNT %u", &i_nlink) == 1)
1112 set_nlink(inode, i_nlink);
1113 }
1114 }
1115 mode = p9mode2perm(v9ses, stat);
1116 mode |= inode->i_mode & ~S_IALLUGO;
1117 inode->i_mode = mode;
1118
1119 v9inode->netfs.remote_i_size = stat->length;
1120 if (!(flags & V9FS_STAT2INODE_KEEP_ISIZE))
1121 v9fs_i_size_write(inode, stat->length);
1122 /* not real number of blocks, but 512 byte ones ... */
1123 inode->i_blocks = (stat->length + 512 - 1) >> 9;
1124 v9inode->cache_validity &= ~V9FS_INO_INVALID_ATTR;
1125}
1126
1127/**
1128 * v9fs_vfs_get_link - follow a symlink path
1129 * @dentry: dentry for symlink
1130 * @inode: inode for symlink
1131 * @done: delayed call for when we are done with the return value
1132 */
1133
1134static const char *v9fs_vfs_get_link(struct dentry *dentry,
1135 struct inode *inode,
1136 struct delayed_call *done)
1137{
1138 struct v9fs_session_info *v9ses;
1139 struct p9_fid *fid;
1140 struct p9_wstat *st;
1141 char *res;
1142
1143 if (!dentry)
1144 return ERR_PTR(-ECHILD);
1145
1146 v9ses = v9fs_dentry2v9ses(dentry);
1147 if (!v9fs_proto_dotu(v9ses))
1148 return ERR_PTR(-EBADF);
1149
1150 p9_debug(P9_DEBUG_VFS, "%pd\n", dentry);
1151 fid = v9fs_fid_lookup(dentry);
1152
1153 if (IS_ERR(fid))
1154 return ERR_CAST(fid);
1155
1156 st = p9_client_stat(fid);
1157 p9_fid_put(fid);
1158 if (IS_ERR(st))
1159 return ERR_CAST(st);
1160
1161 if (!(st->mode & P9_DMSYMLINK)) {
1162 p9stat_free(st);
1163 kfree(st);
1164 return ERR_PTR(-EINVAL);
1165 }
1166 res = st->extension;
1167 st->extension = NULL;
1168 if (strlen(res) >= PATH_MAX)
1169 res[PATH_MAX - 1] = '\0';
1170
1171 p9stat_free(st);
1172 kfree(st);
1173 set_delayed_call(done, kfree_link, res);
1174 return res;
1175}
1176
1177/**
1178 * v9fs_vfs_mkspecial - create a special file
1179 * @dir: inode to create special file in
1180 * @dentry: dentry to create
1181 * @perm: mode to create special file
1182 * @extension: 9p2000.u format extension string representing special file
1183 *
1184 */
1185
1186static int v9fs_vfs_mkspecial(struct inode *dir, struct dentry *dentry,
1187 u32 perm, const char *extension)
1188{
1189 struct p9_fid *fid;
1190 struct v9fs_session_info *v9ses;
1191
1192 v9ses = v9fs_inode2v9ses(dir);
1193 if (!v9fs_proto_dotu(v9ses)) {
1194 p9_debug(P9_DEBUG_ERROR, "not extended\n");
1195 return -EPERM;
1196 }
1197
1198 fid = v9fs_create(v9ses, dir, dentry, (char *) extension, perm,
1199 P9_OREAD);
1200 if (IS_ERR(fid))
1201 return PTR_ERR(fid);
1202
1203 v9fs_invalidate_inode_attr(dir);
1204 p9_fid_put(fid);
1205 return 0;
1206}
1207
1208/**
1209 * v9fs_vfs_symlink - helper function to create symlinks
1210 * @idmap: idmap of the mount
1211 * @dir: directory inode containing symlink
1212 * @dentry: dentry for symlink
1213 * @symname: symlink data
1214 *
1215 * See Also: 9P2000.u RFC for more information
1216 *
1217 */
1218
1219static int
1220v9fs_vfs_symlink(struct mnt_idmap *idmap, struct inode *dir,
1221 struct dentry *dentry, const char *symname)
1222{
1223 p9_debug(P9_DEBUG_VFS, " %lu,%pd,%s\n",
1224 dir->i_ino, dentry, symname);
1225
1226 return v9fs_vfs_mkspecial(dir, dentry, P9_DMSYMLINK, symname);
1227}
1228
1229#define U32_MAX_DIGITS 10
1230
1231/**
1232 * v9fs_vfs_link - create a hardlink
1233 * @old_dentry: dentry for file to link to
1234 * @dir: inode destination for new link
1235 * @dentry: dentry for link
1236 *
1237 */
1238
1239static int
1240v9fs_vfs_link(struct dentry *old_dentry, struct inode *dir,
1241 struct dentry *dentry)
1242{
1243 int retval;
1244 char name[1 + U32_MAX_DIGITS + 2]; /* sign + number + \n + \0 */
1245 struct p9_fid *oldfid;
1246
1247 p9_debug(P9_DEBUG_VFS, " %lu,%pd,%pd\n",
1248 dir->i_ino, dentry, old_dentry);
1249
1250 oldfid = v9fs_fid_clone(old_dentry);
1251 if (IS_ERR(oldfid))
1252 return PTR_ERR(oldfid);
1253
1254 sprintf(name, "%d\n", oldfid->fid);
1255 retval = v9fs_vfs_mkspecial(dir, dentry, P9_DMLINK, name);
1256 if (!retval) {
1257 v9fs_refresh_inode(oldfid, d_inode(old_dentry));
1258 v9fs_invalidate_inode_attr(dir);
1259 }
1260 p9_fid_put(oldfid);
1261 return retval;
1262}
1263
1264/**
1265 * v9fs_vfs_mknod - create a special file
1266 * @idmap: idmap of the mount
1267 * @dir: inode destination for new link
1268 * @dentry: dentry for file
1269 * @mode: mode for creation
1270 * @rdev: device associated with special file
1271 *
1272 */
1273
1274static int
1275v9fs_vfs_mknod(struct mnt_idmap *idmap, struct inode *dir,
1276 struct dentry *dentry, umode_t mode, dev_t rdev)
1277{
1278 struct v9fs_session_info *v9ses = v9fs_inode2v9ses(dir);
1279 int retval;
1280 char name[2 + U32_MAX_DIGITS + 1 + U32_MAX_DIGITS + 1];
1281 u32 perm;
1282
1283 p9_debug(P9_DEBUG_VFS, " %lu,%pd mode: %x MAJOR: %u MINOR: %u\n",
1284 dir->i_ino, dentry, mode,
1285 MAJOR(rdev), MINOR(rdev));
1286
1287 /* build extension */
1288 if (S_ISBLK(mode))
1289 sprintf(name, "b %u %u", MAJOR(rdev), MINOR(rdev));
1290 else if (S_ISCHR(mode))
1291 sprintf(name, "c %u %u", MAJOR(rdev), MINOR(rdev));
1292 else
1293 *name = 0;
1294
1295 perm = unixmode2p9mode(v9ses, mode);
1296 retval = v9fs_vfs_mkspecial(dir, dentry, perm, name);
1297
1298 return retval;
1299}
1300
1301int v9fs_refresh_inode(struct p9_fid *fid, struct inode *inode)
1302{
1303 int umode;
1304 dev_t rdev;
1305 struct p9_wstat *st;
1306 struct v9fs_session_info *v9ses;
1307 unsigned int flags;
1308
1309 v9ses = v9fs_inode2v9ses(inode);
1310 st = p9_client_stat(fid);
1311 if (IS_ERR(st))
1312 return PTR_ERR(st);
1313 /*
1314 * Don't update inode if the file type is different
1315 */
1316 umode = p9mode2unixmode(v9ses, st, &rdev);
1317 if (inode_wrong_type(inode, umode))
1318 goto out;
1319
1320 /*
1321 * We don't want to refresh inode->i_size,
1322 * because we may have cached data
1323 */
1324 flags = (v9ses->cache & CACHE_LOOSE) ?
1325 V9FS_STAT2INODE_KEEP_ISIZE : 0;
1326 v9fs_stat2inode(st, inode, inode->i_sb, flags);
1327out:
1328 p9stat_free(st);
1329 kfree(st);
1330 return 0;
1331}
1332
1333static const struct inode_operations v9fs_dir_inode_operations_dotu = {
1334 .create = v9fs_vfs_create,
1335 .lookup = v9fs_vfs_lookup,
1336 .atomic_open = v9fs_vfs_atomic_open,
1337 .symlink = v9fs_vfs_symlink,
1338 .link = v9fs_vfs_link,
1339 .unlink = v9fs_vfs_unlink,
1340 .mkdir = v9fs_vfs_mkdir,
1341 .rmdir = v9fs_vfs_rmdir,
1342 .mknod = v9fs_vfs_mknod,
1343 .rename = v9fs_vfs_rename,
1344 .getattr = v9fs_vfs_getattr,
1345 .setattr = v9fs_vfs_setattr,
1346};
1347
1348static const struct inode_operations v9fs_dir_inode_operations = {
1349 .create = v9fs_vfs_create,
1350 .lookup = v9fs_vfs_lookup,
1351 .atomic_open = v9fs_vfs_atomic_open,
1352 .unlink = v9fs_vfs_unlink,
1353 .mkdir = v9fs_vfs_mkdir,
1354 .rmdir = v9fs_vfs_rmdir,
1355 .mknod = v9fs_vfs_mknod,
1356 .rename = v9fs_vfs_rename,
1357 .getattr = v9fs_vfs_getattr,
1358 .setattr = v9fs_vfs_setattr,
1359};
1360
1361static const struct inode_operations v9fs_file_inode_operations = {
1362 .getattr = v9fs_vfs_getattr,
1363 .setattr = v9fs_vfs_setattr,
1364};
1365
1366static const struct inode_operations v9fs_symlink_inode_operations = {
1367 .get_link = v9fs_vfs_get_link,
1368 .getattr = v9fs_vfs_getattr,
1369 .setattr = v9fs_vfs_setattr,
1370};
1371