1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * linux/fs/9p/vfs_inode.c
4 *
5 * This file contains vfs inode ops for the 9P2000 protocol.
6 *
7 * Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
8 * Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
9 */
10
11 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
12
13 #include <linux/module.h>
14 #include <linux/errno.h>
15 #include <linux/fs.h>
16 #include <linux/file.h>
17 #include <linux/pagemap.h>
18 #include <linux/stat.h>
19 #include <linux/string.h>
20 #include <linux/inet.h>
21 #include <linux/namei.h>
22 #include <linux/idr.h>
23 #include <linux/sched.h>
24 #include <linux/slab.h>
25 #include <linux/xattr.h>
26 #include <linux/posix_acl.h>
27 #include <net/9p/9p.h>
28 #include <net/9p/client.h>
29
30 #include "v9fs.h"
31 #include "v9fs_vfs.h"
32 #include "fid.h"
33 #include "cache.h"
34 #include "xattr.h"
35 #include "acl.h"
36
37 static const struct inode_operations v9fs_dir_inode_operations;
38 static const struct inode_operations v9fs_dir_inode_operations_dotu;
39 static const struct inode_operations v9fs_file_inode_operations;
40 static const struct inode_operations v9fs_symlink_inode_operations;
41
42 /**
43 * unixmode2p9mode - convert unix mode bits to plan 9
44 * @v9ses: v9fs session information
45 * @mode: mode to convert
46 *
47 */
48
unixmode2p9mode(struct v9fs_session_info * v9ses,umode_t mode)49 static u32 unixmode2p9mode(struct v9fs_session_info *v9ses, umode_t mode)
50 {
51 int res;
52
53 res = mode & 0777;
54 if (S_ISDIR(mode))
55 res |= P9_DMDIR;
56 if (v9fs_proto_dotu(v9ses)) {
57 if (v9ses->nodev == 0) {
58 if (S_ISSOCK(mode))
59 res |= P9_DMSOCKET;
60 if (S_ISFIFO(mode))
61 res |= P9_DMNAMEDPIPE;
62 if (S_ISBLK(mode))
63 res |= P9_DMDEVICE;
64 if (S_ISCHR(mode))
65 res |= P9_DMDEVICE;
66 }
67
68 if ((mode & S_ISUID) == S_ISUID)
69 res |= P9_DMSETUID;
70 if ((mode & S_ISGID) == S_ISGID)
71 res |= P9_DMSETGID;
72 if ((mode & S_ISVTX) == S_ISVTX)
73 res |= P9_DMSETVTX;
74 }
75 return res;
76 }
77
78 /**
79 * p9mode2perm- convert plan9 mode bits to unix permission bits
80 * @v9ses: v9fs session information
81 * @stat: p9_wstat from which mode need to be derived
82 *
83 */
p9mode2perm(struct v9fs_session_info * v9ses,struct p9_wstat * stat)84 static int p9mode2perm(struct v9fs_session_info *v9ses,
85 struct p9_wstat *stat)
86 {
87 int res;
88 int mode = stat->mode;
89
90 res = mode & S_IALLUGO;
91 if (v9fs_proto_dotu(v9ses)) {
92 if ((mode & P9_DMSETUID) == P9_DMSETUID)
93 res |= S_ISUID;
94
95 if ((mode & P9_DMSETGID) == P9_DMSETGID)
96 res |= S_ISGID;
97
98 if ((mode & P9_DMSETVTX) == P9_DMSETVTX)
99 res |= S_ISVTX;
100 }
101 return res;
102 }
103
104 /**
105 * p9mode2unixmode- convert plan9 mode bits to unix mode bits
106 * @v9ses: v9fs session information
107 * @stat: p9_wstat from which mode need to be derived
108 * @rdev: major number, minor number in case of device files.
109 *
110 */
p9mode2unixmode(struct v9fs_session_info * v9ses,struct p9_wstat * stat,dev_t * rdev)111 static umode_t p9mode2unixmode(struct v9fs_session_info *v9ses,
112 struct p9_wstat *stat, dev_t *rdev)
113 {
114 int res;
115 u32 mode = stat->mode;
116
117 *rdev = 0;
118 res = p9mode2perm(v9ses, stat);
119
120 if ((mode & P9_DMDIR) == P9_DMDIR)
121 res |= S_IFDIR;
122 else if ((mode & P9_DMSYMLINK) && (v9fs_proto_dotu(v9ses)))
123 res |= S_IFLNK;
124 else if ((mode & P9_DMSOCKET) && (v9fs_proto_dotu(v9ses))
125 && (v9ses->nodev == 0))
126 res |= S_IFSOCK;
127 else if ((mode & P9_DMNAMEDPIPE) && (v9fs_proto_dotu(v9ses))
128 && (v9ses->nodev == 0))
129 res |= S_IFIFO;
130 else if ((mode & P9_DMDEVICE) && (v9fs_proto_dotu(v9ses))
131 && (v9ses->nodev == 0)) {
132 char type = 0, ext[32];
133 int major = -1, minor = -1;
134
135 strlcpy(ext, stat->extension, sizeof(ext));
136 sscanf(ext, "%c %i %i", &type, &major, &minor);
137 switch (type) {
138 case 'c':
139 res |= S_IFCHR;
140 break;
141 case 'b':
142 res |= S_IFBLK;
143 break;
144 default:
145 p9_debug(P9_DEBUG_ERROR, "Unknown special type %c %s\n",
146 type, stat->extension);
147 }
148 *rdev = MKDEV(major, minor);
149 } else
150 res |= S_IFREG;
151
152 return res;
153 }
154
155 /**
156 * v9fs_uflags2omode- convert posix open flags to plan 9 mode bits
157 * @uflags: flags to convert
158 * @extended: if .u extensions are active
159 */
160
v9fs_uflags2omode(int uflags,int extended)161 int v9fs_uflags2omode(int uflags, int extended)
162 {
163 int ret;
164
165 ret = 0;
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 (extended) {
182 if (uflags & O_EXCL)
183 ret |= P9_OEXCL;
184
185 if (uflags & O_APPEND)
186 ret |= P9_OAPPEND;
187 }
188
189 return ret;
190 }
191
192 /**
193 * v9fs_blank_wstat - helper function to setup a 9P stat structure
194 * @wstat: structure to initialize
195 *
196 */
197
198 void
v9fs_blank_wstat(struct p9_wstat * wstat)199 v9fs_blank_wstat(struct p9_wstat *wstat)
200 {
201 wstat->type = ~0;
202 wstat->dev = ~0;
203 wstat->qid.type = ~0;
204 wstat->qid.version = ~0;
205 *((long long *)&wstat->qid.path) = ~0;
206 wstat->mode = ~0;
207 wstat->atime = ~0;
208 wstat->mtime = ~0;
209 wstat->length = ~0;
210 wstat->name = NULL;
211 wstat->uid = NULL;
212 wstat->gid = NULL;
213 wstat->muid = NULL;
214 wstat->n_uid = INVALID_UID;
215 wstat->n_gid = INVALID_GID;
216 wstat->n_muid = INVALID_UID;
217 wstat->extension = NULL;
218 }
219
220 /**
221 * v9fs_alloc_inode - helper function to allocate an inode
222 * @sb: The superblock to allocate the inode from
223 */
v9fs_alloc_inode(struct super_block * sb)224 struct inode *v9fs_alloc_inode(struct super_block *sb)
225 {
226 struct v9fs_inode *v9inode;
227
228 v9inode = kmem_cache_alloc(v9fs_inode_cache, GFP_KERNEL);
229 if (!v9inode)
230 return NULL;
231 #ifdef CONFIG_9P_FSCACHE
232 v9inode->fscache = NULL;
233 mutex_init(&v9inode->fscache_lock);
234 #endif
235 v9inode->writeback_fid = NULL;
236 v9inode->cache_validity = 0;
237 mutex_init(&v9inode->v_mutex);
238 return &v9inode->vfs_inode;
239 }
240
241 /**
242 * v9fs_free_inode - destroy an inode
243 * @inode: The inode to be freed
244 */
245
v9fs_free_inode(struct inode * inode)246 void v9fs_free_inode(struct inode *inode)
247 {
248 kmem_cache_free(v9fs_inode_cache, V9FS_I(inode));
249 }
250
v9fs_init_inode(struct v9fs_session_info * v9ses,struct inode * inode,umode_t mode,dev_t rdev)251 int v9fs_init_inode(struct v9fs_session_info *v9ses,
252 struct inode *inode, umode_t mode, dev_t rdev)
253 {
254 int err = 0;
255
256 inode_init_owner(&init_user_ns, inode, NULL, mode);
257 inode->i_blocks = 0;
258 inode->i_rdev = rdev;
259 inode->i_atime = inode->i_mtime = inode->i_ctime = current_time(inode);
260 inode->i_mapping->a_ops = &v9fs_addr_operations;
261 inode->i_private = NULL;
262
263 switch (mode & S_IFMT) {
264 case S_IFIFO:
265 case S_IFBLK:
266 case S_IFCHR:
267 case S_IFSOCK:
268 if (v9fs_proto_dotl(v9ses)) {
269 inode->i_op = &v9fs_file_inode_operations_dotl;
270 } else if (v9fs_proto_dotu(v9ses)) {
271 inode->i_op = &v9fs_file_inode_operations;
272 } else {
273 p9_debug(P9_DEBUG_ERROR,
274 "special files without extended mode\n");
275 err = -EINVAL;
276 goto error;
277 }
278 init_special_inode(inode, inode->i_mode, inode->i_rdev);
279 break;
280 case S_IFREG:
281 if (v9fs_proto_dotl(v9ses)) {
282 inode->i_op = &v9fs_file_inode_operations_dotl;
283 if (v9ses->cache == CACHE_LOOSE ||
284 v9ses->cache == CACHE_FSCACHE)
285 inode->i_fop =
286 &v9fs_cached_file_operations_dotl;
287 else if (v9ses->cache == CACHE_MMAP)
288 inode->i_fop = &v9fs_mmap_file_operations_dotl;
289 else
290 inode->i_fop = &v9fs_file_operations_dotl;
291 } else {
292 inode->i_op = &v9fs_file_inode_operations;
293 if (v9ses->cache == CACHE_LOOSE ||
294 v9ses->cache == CACHE_FSCACHE)
295 inode->i_fop =
296 &v9fs_cached_file_operations;
297 else if (v9ses->cache == CACHE_MMAP)
298 inode->i_fop = &v9fs_mmap_file_operations;
299 else
300 inode->i_fop = &v9fs_file_operations;
301 }
302
303 break;
304 case S_IFLNK:
305 if (!v9fs_proto_dotu(v9ses) && !v9fs_proto_dotl(v9ses)) {
306 p9_debug(P9_DEBUG_ERROR,
307 "extended modes used with legacy protocol\n");
308 err = -EINVAL;
309 goto error;
310 }
311
312 if (v9fs_proto_dotl(v9ses))
313 inode->i_op = &v9fs_symlink_inode_operations_dotl;
314 else
315 inode->i_op = &v9fs_symlink_inode_operations;
316
317 break;
318 case S_IFDIR:
319 inc_nlink(inode);
320 if (v9fs_proto_dotl(v9ses))
321 inode->i_op = &v9fs_dir_inode_operations_dotl;
322 else if (v9fs_proto_dotu(v9ses))
323 inode->i_op = &v9fs_dir_inode_operations_dotu;
324 else
325 inode->i_op = &v9fs_dir_inode_operations;
326
327 if (v9fs_proto_dotl(v9ses))
328 inode->i_fop = &v9fs_dir_operations_dotl;
329 else
330 inode->i_fop = &v9fs_dir_operations;
331
332 break;
333 default:
334 p9_debug(P9_DEBUG_ERROR, "BAD mode 0x%hx S_IFMT 0x%x\n",
335 mode, mode & S_IFMT);
336 err = -EINVAL;
337 goto error;
338 }
339 error:
340 return err;
341
342 }
343
344 /**
345 * v9fs_get_inode - helper function to setup an inode
346 * @sb: superblock
347 * @mode: mode to setup inode with
348 * @rdev: The device numbers to set
349 */
350
v9fs_get_inode(struct super_block * sb,umode_t mode,dev_t rdev)351 struct inode *v9fs_get_inode(struct super_block *sb, umode_t mode, dev_t rdev)
352 {
353 int err;
354 struct inode *inode;
355 struct v9fs_session_info *v9ses = sb->s_fs_info;
356
357 p9_debug(P9_DEBUG_VFS, "super block: %p mode: %ho\n", sb, mode);
358
359 inode = new_inode(sb);
360 if (!inode) {
361 pr_warn("%s (%d): Problem allocating inode\n",
362 __func__, task_pid_nr(current));
363 return ERR_PTR(-ENOMEM);
364 }
365 err = v9fs_init_inode(v9ses, inode, mode, rdev);
366 if (err) {
367 iput(inode);
368 return ERR_PTR(err);
369 }
370 return inode;
371 }
372
373 /**
374 * v9fs_evict_inode - Remove an inode from the inode cache
375 * @inode: inode to release
376 *
377 */
v9fs_evict_inode(struct inode * inode)378 void v9fs_evict_inode(struct inode *inode)
379 {
380 struct v9fs_inode *v9inode = V9FS_I(inode);
381
382 truncate_inode_pages_final(&inode->i_data);
383 clear_inode(inode);
384 filemap_fdatawrite(&inode->i_data);
385
386 v9fs_cache_inode_put_cookie(inode);
387 /* clunk the fid stashed in writeback_fid */
388 if (v9inode->writeback_fid) {
389 p9_client_clunk(v9inode->writeback_fid);
390 v9inode->writeback_fid = NULL;
391 }
392 }
393
v9fs_test_inode(struct inode * inode,void * data)394 static int v9fs_test_inode(struct inode *inode, void *data)
395 {
396 int umode;
397 dev_t rdev;
398 struct v9fs_inode *v9inode = V9FS_I(inode);
399 struct p9_wstat *st = (struct p9_wstat *)data;
400 struct v9fs_session_info *v9ses = v9fs_inode2v9ses(inode);
401
402 umode = p9mode2unixmode(v9ses, st, &rdev);
403 /* don't match inode of different type */
404 if (inode_wrong_type(inode, umode))
405 return 0;
406
407 /* compare qid details */
408 if (memcmp(&v9inode->qid.version,
409 &st->qid.version, sizeof(v9inode->qid.version)))
410 return 0;
411
412 if (v9inode->qid.type != st->qid.type)
413 return 0;
414
415 if (v9inode->qid.path != st->qid.path)
416 return 0;
417 return 1;
418 }
419
v9fs_test_new_inode(struct inode * inode,void * data)420 static int v9fs_test_new_inode(struct inode *inode, void *data)
421 {
422 return 0;
423 }
424
v9fs_set_inode(struct inode * inode,void * data)425 static int v9fs_set_inode(struct inode *inode, void *data)
426 {
427 struct v9fs_inode *v9inode = V9FS_I(inode);
428 struct p9_wstat *st = (struct p9_wstat *)data;
429
430 memcpy(&v9inode->qid, &st->qid, sizeof(st->qid));
431 return 0;
432 }
433
v9fs_qid_iget(struct super_block * sb,struct p9_qid * qid,struct p9_wstat * st,int new)434 static struct inode *v9fs_qid_iget(struct super_block *sb,
435 struct p9_qid *qid,
436 struct p9_wstat *st,
437 int new)
438 {
439 dev_t rdev;
440 int retval;
441 umode_t umode;
442 unsigned long i_ino;
443 struct inode *inode;
444 struct v9fs_session_info *v9ses = sb->s_fs_info;
445 int (*test)(struct inode *inode, void *data);
446
447 if (new)
448 test = v9fs_test_new_inode;
449 else
450 test = v9fs_test_inode;
451
452 i_ino = v9fs_qid2ino(qid);
453 inode = iget5_locked(sb, i_ino, test, v9fs_set_inode, st);
454 if (!inode)
455 return ERR_PTR(-ENOMEM);
456 if (!(inode->i_state & I_NEW))
457 return inode;
458 /*
459 * initialize the inode with the stat info
460 * FIXME!! we may need support for stale inodes
461 * later.
462 */
463 inode->i_ino = i_ino;
464 umode = p9mode2unixmode(v9ses, st, &rdev);
465 retval = v9fs_init_inode(v9ses, inode, umode, rdev);
466 if (retval)
467 goto error;
468
469 v9fs_stat2inode(st, inode, sb, 0);
470 v9fs_cache_inode_get_cookie(inode);
471 unlock_new_inode(inode);
472 return inode;
473 error:
474 iget_failed(inode);
475 return ERR_PTR(retval);
476
477 }
478
479 struct inode *
v9fs_inode_from_fid(struct v9fs_session_info * v9ses,struct p9_fid * fid,struct super_block * sb,int new)480 v9fs_inode_from_fid(struct v9fs_session_info *v9ses, struct p9_fid *fid,
481 struct super_block *sb, int new)
482 {
483 struct p9_wstat *st;
484 struct inode *inode = NULL;
485
486 st = p9_client_stat(fid);
487 if (IS_ERR(st))
488 return ERR_CAST(st);
489
490 inode = v9fs_qid_iget(sb, &st->qid, st, new);
491 p9stat_free(st);
492 kfree(st);
493 return inode;
494 }
495
496 /**
497 * v9fs_at_to_dotl_flags- convert Linux specific AT flags to
498 * plan 9 AT flag.
499 * @flags: flags to convert
500 */
v9fs_at_to_dotl_flags(int flags)501 static int v9fs_at_to_dotl_flags(int flags)
502 {
503 int rflags = 0;
504
505 if (flags & AT_REMOVEDIR)
506 rflags |= P9_DOTL_AT_REMOVEDIR;
507
508 return rflags;
509 }
510
511 /**
512 * v9fs_dec_count - helper functon to drop i_nlink.
513 *
514 * If a directory had nlink <= 2 (including . and ..), then we should not drop
515 * the link count, which indicates the underlying exported fs doesn't maintain
516 * nlink accurately. e.g.
517 * - overlayfs sets nlink to 1 for merged dir
518 * - ext4 (with dir_nlink feature enabled) sets nlink to 1 if a dir has more
519 * than EXT4_LINK_MAX (65000) links.
520 *
521 * @inode: inode whose nlink is being dropped
522 */
v9fs_dec_count(struct inode * inode)523 static void v9fs_dec_count(struct inode *inode)
524 {
525 if (!S_ISDIR(inode->i_mode) || inode->i_nlink > 2)
526 drop_nlink(inode);
527 }
528
529 /**
530 * v9fs_remove - helper function to remove files and directories
531 * @dir: directory inode that is being deleted
532 * @dentry: dentry that is being deleted
533 * @flags: removing a directory
534 *
535 */
536
v9fs_remove(struct inode * dir,struct dentry * dentry,int flags)537 static int v9fs_remove(struct inode *dir, struct dentry *dentry, int flags)
538 {
539 struct inode *inode;
540 int retval = -EOPNOTSUPP;
541 struct p9_fid *v9fid, *dfid;
542 struct v9fs_session_info *v9ses;
543
544 p9_debug(P9_DEBUG_VFS, "inode: %p dentry: %p rmdir: %x\n",
545 dir, dentry, flags);
546
547 v9ses = v9fs_inode2v9ses(dir);
548 inode = d_inode(dentry);
549 dfid = v9fs_parent_fid(dentry);
550 if (IS_ERR(dfid)) {
551 retval = PTR_ERR(dfid);
552 p9_debug(P9_DEBUG_VFS, "fid lookup failed %d\n", retval);
553 return retval;
554 }
555 if (v9fs_proto_dotl(v9ses))
556 retval = p9_client_unlinkat(dfid, dentry->d_name.name,
557 v9fs_at_to_dotl_flags(flags));
558 p9_client_clunk(dfid);
559 if (retval == -EOPNOTSUPP) {
560 /* Try the one based on path */
561 v9fid = v9fs_fid_clone(dentry);
562 if (IS_ERR(v9fid))
563 return PTR_ERR(v9fid);
564 retval = p9_client_remove(v9fid);
565 }
566 if (!retval) {
567 /*
568 * directories on unlink should have zero
569 * link count
570 */
571 if (flags & AT_REMOVEDIR) {
572 clear_nlink(inode);
573 v9fs_dec_count(dir);
574 } else
575 v9fs_dec_count(inode);
576
577 v9fs_invalidate_inode_attr(inode);
578 v9fs_invalidate_inode_attr(dir);
579
580 /* invalidate all fids associated with dentry */
581 /* NOTE: This will not include open fids */
582 dentry->d_op->d_release(dentry);
583 }
584 return retval;
585 }
586
587 /**
588 * v9fs_create - Create a file
589 * @v9ses: session information
590 * @dir: directory that dentry is being created in
591 * @dentry: dentry that is being created
592 * @extension: 9p2000.u extension string to support devices, etc.
593 * @perm: create permissions
594 * @mode: open mode
595 *
596 */
597 static struct p9_fid *
v9fs_create(struct v9fs_session_info * v9ses,struct inode * dir,struct dentry * dentry,char * extension,u32 perm,u8 mode)598 v9fs_create(struct v9fs_session_info *v9ses, struct inode *dir,
599 struct dentry *dentry, char *extension, u32 perm, u8 mode)
600 {
601 int err;
602 const unsigned char *name;
603 struct p9_fid *dfid, *ofid = NULL, *fid = NULL;
604 struct inode *inode;
605
606 p9_debug(P9_DEBUG_VFS, "name %pd\n", dentry);
607
608 err = 0;
609 name = dentry->d_name.name;
610 dfid = v9fs_parent_fid(dentry);
611 if (IS_ERR(dfid)) {
612 err = PTR_ERR(dfid);
613 p9_debug(P9_DEBUG_VFS, "fid lookup failed %d\n", err);
614 return ERR_PTR(err);
615 }
616
617 /* clone a fid to use for creation */
618 ofid = clone_fid(dfid);
619 if (IS_ERR(ofid)) {
620 err = PTR_ERR(ofid);
621 p9_debug(P9_DEBUG_VFS, "p9_client_walk failed %d\n", err);
622 p9_client_clunk(dfid);
623 return ERR_PTR(err);
624 }
625
626 err = p9_client_fcreate(ofid, name, perm, mode, extension);
627 if (err < 0) {
628 p9_debug(P9_DEBUG_VFS, "p9_client_fcreate failed %d\n", err);
629 p9_client_clunk(dfid);
630 goto error;
631 }
632
633 if (!(perm & P9_DMLINK)) {
634 /* now walk from the parent so we can get unopened fid */
635 fid = p9_client_walk(dfid, 1, &name, 1);
636 if (IS_ERR(fid)) {
637 err = PTR_ERR(fid);
638 p9_debug(P9_DEBUG_VFS,
639 "p9_client_walk failed %d\n", err);
640 fid = NULL;
641 p9_client_clunk(dfid);
642 goto error;
643 }
644 /*
645 * instantiate inode and assign the unopened fid to the dentry
646 */
647 inode = v9fs_get_new_inode_from_fid(v9ses, fid, dir->i_sb);
648 if (IS_ERR(inode)) {
649 err = PTR_ERR(inode);
650 p9_debug(P9_DEBUG_VFS,
651 "inode creation failed %d\n", err);
652 p9_client_clunk(dfid);
653 goto error;
654 }
655 v9fs_fid_add(dentry, fid);
656 d_instantiate(dentry, inode);
657 }
658 p9_client_clunk(dfid);
659 return ofid;
660 error:
661 if (ofid)
662 p9_client_clunk(ofid);
663
664 if (fid)
665 p9_client_clunk(fid);
666
667 return ERR_PTR(err);
668 }
669
670 /**
671 * v9fs_vfs_create - VFS hook to create a regular file
672 * @mnt_userns: The user namespace of the mount
673 * @dir: The parent directory
674 * @dentry: The name of file to be created
675 * @mode: The UNIX file mode to set
676 * @excl: True if the file must not yet exist
677 *
678 * open(.., O_CREAT) is handled in v9fs_vfs_atomic_open(). This is only called
679 * for mknod(2).
680 *
681 */
682
683 static int
v9fs_vfs_create(struct user_namespace * mnt_userns,struct inode * dir,struct dentry * dentry,umode_t mode,bool excl)684 v9fs_vfs_create(struct user_namespace *mnt_userns, struct inode *dir,
685 struct dentry *dentry, umode_t mode, bool excl)
686 {
687 struct v9fs_session_info *v9ses = v9fs_inode2v9ses(dir);
688 u32 perm = unixmode2p9mode(v9ses, mode);
689 struct p9_fid *fid;
690
691 /* P9_OEXCL? */
692 fid = v9fs_create(v9ses, dir, dentry, NULL, perm, P9_ORDWR);
693 if (IS_ERR(fid))
694 return PTR_ERR(fid);
695
696 v9fs_invalidate_inode_attr(dir);
697 p9_client_clunk(fid);
698
699 return 0;
700 }
701
702 /**
703 * v9fs_vfs_mkdir - VFS mkdir hook to create a directory
704 * @mnt_userns: The user namespace of the mount
705 * @dir: inode that is being unlinked
706 * @dentry: dentry that is being unlinked
707 * @mode: mode for new directory
708 *
709 */
710
v9fs_vfs_mkdir(struct user_namespace * mnt_userns,struct inode * dir,struct dentry * dentry,umode_t mode)711 static int v9fs_vfs_mkdir(struct user_namespace *mnt_userns, struct inode *dir,
712 struct dentry *dentry, umode_t mode)
713 {
714 int err;
715 u32 perm;
716 struct p9_fid *fid;
717 struct v9fs_session_info *v9ses;
718
719 p9_debug(P9_DEBUG_VFS, "name %pd\n", dentry);
720 err = 0;
721 v9ses = v9fs_inode2v9ses(dir);
722 perm = unixmode2p9mode(v9ses, mode | S_IFDIR);
723 fid = v9fs_create(v9ses, dir, dentry, NULL, perm, P9_OREAD);
724 if (IS_ERR(fid)) {
725 err = PTR_ERR(fid);
726 fid = NULL;
727 } else {
728 inc_nlink(dir);
729 v9fs_invalidate_inode_attr(dir);
730 }
731
732 if (fid)
733 p9_client_clunk(fid);
734
735 return err;
736 }
737
738 /**
739 * v9fs_vfs_lookup - VFS lookup hook to "walk" to a new inode
740 * @dir: inode that is being walked from
741 * @dentry: dentry that is being walked to?
742 * @flags: lookup flags (unused)
743 *
744 */
745
v9fs_vfs_lookup(struct inode * dir,struct dentry * dentry,unsigned int flags)746 struct dentry *v9fs_vfs_lookup(struct inode *dir, struct dentry *dentry,
747 unsigned int flags)
748 {
749 struct dentry *res;
750 struct v9fs_session_info *v9ses;
751 struct p9_fid *dfid, *fid;
752 struct inode *inode;
753 const unsigned char *name;
754
755 p9_debug(P9_DEBUG_VFS, "dir: %p dentry: (%pd) %p flags: %x\n",
756 dir, dentry, dentry, flags);
757
758 if (dentry->d_name.len > NAME_MAX)
759 return ERR_PTR(-ENAMETOOLONG);
760
761 v9ses = v9fs_inode2v9ses(dir);
762 /* We can walk d_parent because we hold the dir->i_mutex */
763 dfid = v9fs_parent_fid(dentry);
764 if (IS_ERR(dfid))
765 return ERR_CAST(dfid);
766
767 /*
768 * Make sure we don't use a wrong inode due to parallel
769 * unlink. For cached mode create calls request for new
770 * inode. But with cache disabled, lookup should do this.
771 */
772 name = dentry->d_name.name;
773 fid = p9_client_walk(dfid, 1, &name, 1);
774 p9_client_clunk(dfid);
775 if (fid == ERR_PTR(-ENOENT))
776 inode = NULL;
777 else if (IS_ERR(fid))
778 inode = ERR_CAST(fid);
779 else if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE)
780 inode = v9fs_get_inode_from_fid(v9ses, fid, dir->i_sb);
781 else
782 inode = v9fs_get_new_inode_from_fid(v9ses, fid, dir->i_sb);
783 /*
784 * If we had a rename on the server and a parallel lookup
785 * for the new name, then make sure we instantiate with
786 * the new name. ie look up for a/b, while on server somebody
787 * moved b under k and client parallely did a lookup for
788 * k/b.
789 */
790 res = d_splice_alias(inode, dentry);
791 if (!IS_ERR(fid)) {
792 if (!res)
793 v9fs_fid_add(dentry, fid);
794 else if (!IS_ERR(res))
795 v9fs_fid_add(res, fid);
796 else
797 p9_client_clunk(fid);
798 }
799 return res;
800 }
801
802 static int
v9fs_vfs_atomic_open(struct inode * dir,struct dentry * dentry,struct file * file,unsigned int flags,umode_t mode)803 v9fs_vfs_atomic_open(struct inode *dir, struct dentry *dentry,
804 struct file *file, unsigned int flags, umode_t mode)
805 {
806 int err;
807 u32 perm;
808 struct v9fs_inode *v9inode;
809 struct v9fs_session_info *v9ses;
810 struct p9_fid *fid, *inode_fid;
811 struct dentry *res = NULL;
812 struct inode *inode;
813
814 if (d_in_lookup(dentry)) {
815 res = v9fs_vfs_lookup(dir, dentry, 0);
816 if (IS_ERR(res))
817 return PTR_ERR(res);
818
819 if (res)
820 dentry = res;
821 }
822
823 /* Only creates */
824 if (!(flags & O_CREAT) || d_really_is_positive(dentry))
825 return finish_no_open(file, res);
826
827 err = 0;
828
829 v9ses = v9fs_inode2v9ses(dir);
830 perm = unixmode2p9mode(v9ses, mode);
831 fid = v9fs_create(v9ses, dir, dentry, NULL, perm,
832 v9fs_uflags2omode(flags,
833 v9fs_proto_dotu(v9ses)));
834 if (IS_ERR(fid)) {
835 err = PTR_ERR(fid);
836 fid = NULL;
837 goto error;
838 }
839
840 v9fs_invalidate_inode_attr(dir);
841 inode = d_inode(dentry);
842 v9inode = V9FS_I(inode);
843 mutex_lock(&v9inode->v_mutex);
844 if ((v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) &&
845 !v9inode->writeback_fid &&
846 ((flags & O_ACCMODE) != O_RDONLY)) {
847 /*
848 * clone a fid and add it to writeback_fid
849 * we do it during open time instead of
850 * page dirty time via write_begin/page_mkwrite
851 * because we want write after unlink usecase
852 * to work.
853 */
854 inode_fid = v9fs_writeback_fid(dentry);
855 if (IS_ERR(inode_fid)) {
856 err = PTR_ERR(inode_fid);
857 mutex_unlock(&v9inode->v_mutex);
858 goto error;
859 }
860 v9inode->writeback_fid = (void *) inode_fid;
861 }
862 mutex_unlock(&v9inode->v_mutex);
863 err = finish_open(file, dentry, generic_file_open);
864 if (err)
865 goto error;
866
867 file->private_data = fid;
868 if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE)
869 v9fs_cache_inode_set_cookie(d_inode(dentry), file);
870 v9fs_open_fid_add(inode, fid);
871
872 file->f_mode |= FMODE_CREATED;
873 out:
874 dput(res);
875 return err;
876
877 error:
878 if (fid)
879 p9_client_clunk(fid);
880 goto out;
881 }
882
883 /**
884 * v9fs_vfs_unlink - VFS unlink hook to delete an inode
885 * @i: inode that is being unlinked
886 * @d: dentry that is being unlinked
887 *
888 */
889
v9fs_vfs_unlink(struct inode * i,struct dentry * d)890 int v9fs_vfs_unlink(struct inode *i, struct dentry *d)
891 {
892 return v9fs_remove(i, d, 0);
893 }
894
895 /**
896 * v9fs_vfs_rmdir - VFS unlink hook to delete a directory
897 * @i: inode that is being unlinked
898 * @d: dentry that is being unlinked
899 *
900 */
901
v9fs_vfs_rmdir(struct inode * i,struct dentry * d)902 int v9fs_vfs_rmdir(struct inode *i, struct dentry *d)
903 {
904 return v9fs_remove(i, d, AT_REMOVEDIR);
905 }
906
907 /**
908 * v9fs_vfs_rename - VFS hook to rename an inode
909 * @mnt_userns: The user namespace of the mount
910 * @old_dir: old dir inode
911 * @old_dentry: old dentry
912 * @new_dir: new dir inode
913 * @new_dentry: new dentry
914 * @flags: RENAME_* flags
915 *
916 */
917
918 int
v9fs_vfs_rename(struct user_namespace * mnt_userns,struct inode * old_dir,struct dentry * old_dentry,struct inode * new_dir,struct dentry * new_dentry,unsigned int flags)919 v9fs_vfs_rename(struct user_namespace *mnt_userns, struct inode *old_dir,
920 struct dentry *old_dentry, struct inode *new_dir,
921 struct dentry *new_dentry, unsigned int flags)
922 {
923 int retval;
924 struct inode *old_inode;
925 struct inode *new_inode;
926 struct v9fs_session_info *v9ses;
927 struct p9_fid *oldfid, *dfid;
928 struct p9_fid *olddirfid;
929 struct p9_fid *newdirfid;
930 struct p9_wstat wstat;
931
932 if (flags)
933 return -EINVAL;
934
935 p9_debug(P9_DEBUG_VFS, "\n");
936 retval = 0;
937 old_inode = d_inode(old_dentry);
938 new_inode = d_inode(new_dentry);
939 v9ses = v9fs_inode2v9ses(old_inode);
940 oldfid = v9fs_fid_lookup(old_dentry);
941 if (IS_ERR(oldfid))
942 return PTR_ERR(oldfid);
943
944 dfid = v9fs_parent_fid(old_dentry);
945 olddirfid = clone_fid(dfid);
946 if (dfid && !IS_ERR(dfid))
947 p9_client_clunk(dfid);
948
949 if (IS_ERR(olddirfid)) {
950 retval = PTR_ERR(olddirfid);
951 goto done;
952 }
953
954 dfid = v9fs_parent_fid(new_dentry);
955 newdirfid = clone_fid(dfid);
956 p9_client_clunk(dfid);
957
958 if (IS_ERR(newdirfid)) {
959 retval = PTR_ERR(newdirfid);
960 goto clunk_olddir;
961 }
962
963 down_write(&v9ses->rename_sem);
964 if (v9fs_proto_dotl(v9ses)) {
965 retval = p9_client_renameat(olddirfid, old_dentry->d_name.name,
966 newdirfid, new_dentry->d_name.name);
967 if (retval == -EOPNOTSUPP)
968 retval = p9_client_rename(oldfid, newdirfid,
969 new_dentry->d_name.name);
970 if (retval != -EOPNOTSUPP)
971 goto clunk_newdir;
972 }
973 if (old_dentry->d_parent != new_dentry->d_parent) {
974 /*
975 * 9P .u can only handle file rename in the same directory
976 */
977
978 p9_debug(P9_DEBUG_ERROR, "old dir and new dir are different\n");
979 retval = -EXDEV;
980 goto clunk_newdir;
981 }
982 v9fs_blank_wstat(&wstat);
983 wstat.muid = v9ses->uname;
984 wstat.name = new_dentry->d_name.name;
985 retval = p9_client_wstat(oldfid, &wstat);
986
987 clunk_newdir:
988 if (!retval) {
989 if (new_inode) {
990 if (S_ISDIR(new_inode->i_mode))
991 clear_nlink(new_inode);
992 else
993 v9fs_dec_count(new_inode);
994 }
995 if (S_ISDIR(old_inode->i_mode)) {
996 if (!new_inode)
997 inc_nlink(new_dir);
998 v9fs_dec_count(old_dir);
999 }
1000 v9fs_invalidate_inode_attr(old_inode);
1001 v9fs_invalidate_inode_attr(old_dir);
1002 v9fs_invalidate_inode_attr(new_dir);
1003
1004 /* successful rename */
1005 d_move(old_dentry, new_dentry);
1006 }
1007 up_write(&v9ses->rename_sem);
1008 p9_client_clunk(newdirfid);
1009
1010 clunk_olddir:
1011 p9_client_clunk(olddirfid);
1012
1013 done:
1014 p9_client_clunk(oldfid);
1015 return retval;
1016 }
1017
1018 /**
1019 * v9fs_vfs_getattr - retrieve file metadata
1020 * @mnt_userns: The user namespace of the mount
1021 * @path: Object to query
1022 * @stat: metadata structure to populate
1023 * @request_mask: Mask of STATX_xxx flags indicating the caller's interests
1024 * @flags: AT_STATX_xxx setting
1025 *
1026 */
1027
1028 static int
v9fs_vfs_getattr(struct user_namespace * mnt_userns,const struct path * path,struct kstat * stat,u32 request_mask,unsigned int flags)1029 v9fs_vfs_getattr(struct user_namespace *mnt_userns, const struct path *path,
1030 struct kstat *stat, u32 request_mask, unsigned int flags)
1031 {
1032 struct dentry *dentry = path->dentry;
1033 struct v9fs_session_info *v9ses;
1034 struct p9_fid *fid;
1035 struct p9_wstat *st;
1036
1037 p9_debug(P9_DEBUG_VFS, "dentry: %p\n", dentry);
1038 v9ses = v9fs_dentry2v9ses(dentry);
1039 if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) {
1040 generic_fillattr(&init_user_ns, d_inode(dentry), stat);
1041 return 0;
1042 }
1043 fid = v9fs_fid_lookup(dentry);
1044 if (IS_ERR(fid))
1045 return PTR_ERR(fid);
1046
1047 st = p9_client_stat(fid);
1048 p9_client_clunk(fid);
1049 if (IS_ERR(st))
1050 return PTR_ERR(st);
1051
1052 v9fs_stat2inode(st, d_inode(dentry), dentry->d_sb, 0);
1053 generic_fillattr(&init_user_ns, d_inode(dentry), stat);
1054
1055 p9stat_free(st);
1056 kfree(st);
1057 return 0;
1058 }
1059
1060 /**
1061 * v9fs_vfs_setattr - set file metadata
1062 * @mnt_userns: The user namespace of the mount
1063 * @dentry: file whose metadata to set
1064 * @iattr: metadata assignment structure
1065 *
1066 */
1067
v9fs_vfs_setattr(struct user_namespace * mnt_userns,struct dentry * dentry,struct iattr * iattr)1068 static int v9fs_vfs_setattr(struct user_namespace *mnt_userns,
1069 struct dentry *dentry, struct iattr *iattr)
1070 {
1071 int retval, use_dentry = 0;
1072 struct v9fs_session_info *v9ses;
1073 struct p9_fid *fid = NULL;
1074 struct p9_wstat wstat;
1075
1076 p9_debug(P9_DEBUG_VFS, "\n");
1077 retval = setattr_prepare(&init_user_ns, dentry, iattr);
1078 if (retval)
1079 return retval;
1080
1081 retval = -EPERM;
1082 v9ses = v9fs_dentry2v9ses(dentry);
1083 if (iattr->ia_valid & ATTR_FILE) {
1084 fid = iattr->ia_file->private_data;
1085 WARN_ON(!fid);
1086 }
1087 if (!fid) {
1088 fid = v9fs_fid_lookup(dentry);
1089 use_dentry = 1;
1090 }
1091 if (IS_ERR(fid))
1092 return PTR_ERR(fid);
1093
1094 v9fs_blank_wstat(&wstat);
1095 if (iattr->ia_valid & ATTR_MODE)
1096 wstat.mode = unixmode2p9mode(v9ses, iattr->ia_mode);
1097
1098 if (iattr->ia_valid & ATTR_MTIME)
1099 wstat.mtime = iattr->ia_mtime.tv_sec;
1100
1101 if (iattr->ia_valid & ATTR_ATIME)
1102 wstat.atime = iattr->ia_atime.tv_sec;
1103
1104 if (iattr->ia_valid & ATTR_SIZE)
1105 wstat.length = iattr->ia_size;
1106
1107 if (v9fs_proto_dotu(v9ses)) {
1108 if (iattr->ia_valid & ATTR_UID)
1109 wstat.n_uid = iattr->ia_uid;
1110
1111 if (iattr->ia_valid & ATTR_GID)
1112 wstat.n_gid = iattr->ia_gid;
1113 }
1114
1115 /* Write all dirty data */
1116 if (d_is_reg(dentry))
1117 filemap_write_and_wait(d_inode(dentry)->i_mapping);
1118
1119 retval = p9_client_wstat(fid, &wstat);
1120
1121 if (use_dentry)
1122 p9_client_clunk(fid);
1123
1124 if (retval < 0)
1125 return retval;
1126
1127 if ((iattr->ia_valid & ATTR_SIZE) &&
1128 iattr->ia_size != i_size_read(d_inode(dentry)))
1129 truncate_setsize(d_inode(dentry), iattr->ia_size);
1130
1131 v9fs_invalidate_inode_attr(d_inode(dentry));
1132
1133 setattr_copy(&init_user_ns, d_inode(dentry), iattr);
1134 mark_inode_dirty(d_inode(dentry));
1135 return 0;
1136 }
1137
1138 /**
1139 * v9fs_stat2inode - populate an inode structure with mistat info
1140 * @stat: Plan 9 metadata (mistat) structure
1141 * @inode: inode to populate
1142 * @sb: superblock of filesystem
1143 * @flags: control flags (e.g. V9FS_STAT2INODE_KEEP_ISIZE)
1144 *
1145 */
1146
1147 void
v9fs_stat2inode(struct p9_wstat * stat,struct inode * inode,struct super_block * sb,unsigned int flags)1148 v9fs_stat2inode(struct p9_wstat *stat, struct inode *inode,
1149 struct super_block *sb, unsigned int flags)
1150 {
1151 umode_t mode;
1152 struct v9fs_session_info *v9ses = sb->s_fs_info;
1153 struct v9fs_inode *v9inode = V9FS_I(inode);
1154
1155 set_nlink(inode, 1);
1156
1157 inode->i_atime.tv_sec = stat->atime;
1158 inode->i_mtime.tv_sec = stat->mtime;
1159 inode->i_ctime.tv_sec = stat->mtime;
1160
1161 inode->i_uid = v9ses->dfltuid;
1162 inode->i_gid = v9ses->dfltgid;
1163
1164 if (v9fs_proto_dotu(v9ses)) {
1165 inode->i_uid = stat->n_uid;
1166 inode->i_gid = stat->n_gid;
1167 }
1168 if ((S_ISREG(inode->i_mode)) || (S_ISDIR(inode->i_mode))) {
1169 if (v9fs_proto_dotu(v9ses)) {
1170 unsigned int i_nlink;
1171 /*
1172 * Hadlink support got added later to the .u extension.
1173 * So there can be a server out there that doesn't
1174 * support this even with .u extension. That would
1175 * just leave us with stat->extension being an empty
1176 * string, though.
1177 */
1178 /* HARDLINKCOUNT %u */
1179 if (sscanf(stat->extension,
1180 " HARDLINKCOUNT %u", &i_nlink) == 1)
1181 set_nlink(inode, i_nlink);
1182 }
1183 }
1184 mode = p9mode2perm(v9ses, stat);
1185 mode |= inode->i_mode & ~S_IALLUGO;
1186 inode->i_mode = mode;
1187
1188 if (!(flags & V9FS_STAT2INODE_KEEP_ISIZE))
1189 v9fs_i_size_write(inode, stat->length);
1190 /* not real number of blocks, but 512 byte ones ... */
1191 inode->i_blocks = (stat->length + 512 - 1) >> 9;
1192 v9inode->cache_validity &= ~V9FS_INO_INVALID_ATTR;
1193 }
1194
1195 /**
1196 * v9fs_qid2ino - convert qid into inode number
1197 * @qid: qid to hash
1198 *
1199 * BUG: potential for inode number collisions?
1200 */
1201
v9fs_qid2ino(struct p9_qid * qid)1202 ino_t v9fs_qid2ino(struct p9_qid *qid)
1203 {
1204 u64 path = qid->path + 2;
1205 ino_t i = 0;
1206
1207 if (sizeof(ino_t) == sizeof(path))
1208 memcpy(&i, &path, sizeof(ino_t));
1209 else
1210 i = (ino_t) (path ^ (path >> 32));
1211
1212 return i;
1213 }
1214
1215 /**
1216 * v9fs_vfs_get_link - follow a symlink path
1217 * @dentry: dentry for symlink
1218 * @inode: inode for symlink
1219 * @done: delayed call for when we are done with the return value
1220 */
1221
v9fs_vfs_get_link(struct dentry * dentry,struct inode * inode,struct delayed_call * done)1222 static const char *v9fs_vfs_get_link(struct dentry *dentry,
1223 struct inode *inode,
1224 struct delayed_call *done)
1225 {
1226 struct v9fs_session_info *v9ses;
1227 struct p9_fid *fid;
1228 struct p9_wstat *st;
1229 char *res;
1230
1231 if (!dentry)
1232 return ERR_PTR(-ECHILD);
1233
1234 v9ses = v9fs_dentry2v9ses(dentry);
1235 if (!v9fs_proto_dotu(v9ses))
1236 return ERR_PTR(-EBADF);
1237
1238 p9_debug(P9_DEBUG_VFS, "%pd\n", dentry);
1239 fid = v9fs_fid_lookup(dentry);
1240
1241 if (IS_ERR(fid))
1242 return ERR_CAST(fid);
1243
1244 st = p9_client_stat(fid);
1245 p9_client_clunk(fid);
1246 if (IS_ERR(st))
1247 return ERR_CAST(st);
1248
1249 if (!(st->mode & P9_DMSYMLINK)) {
1250 p9stat_free(st);
1251 kfree(st);
1252 return ERR_PTR(-EINVAL);
1253 }
1254 res = st->extension;
1255 st->extension = NULL;
1256 if (strlen(res) >= PATH_MAX)
1257 res[PATH_MAX - 1] = '\0';
1258
1259 p9stat_free(st);
1260 kfree(st);
1261 set_delayed_call(done, kfree_link, res);
1262 return res;
1263 }
1264
1265 /**
1266 * v9fs_vfs_mkspecial - create a special file
1267 * @dir: inode to create special file in
1268 * @dentry: dentry to create
1269 * @perm: mode to create special file
1270 * @extension: 9p2000.u format extension string representing special file
1271 *
1272 */
1273
v9fs_vfs_mkspecial(struct inode * dir,struct dentry * dentry,u32 perm,const char * extension)1274 static int v9fs_vfs_mkspecial(struct inode *dir, struct dentry *dentry,
1275 u32 perm, const char *extension)
1276 {
1277 struct p9_fid *fid;
1278 struct v9fs_session_info *v9ses;
1279
1280 v9ses = v9fs_inode2v9ses(dir);
1281 if (!v9fs_proto_dotu(v9ses)) {
1282 p9_debug(P9_DEBUG_ERROR, "not extended\n");
1283 return -EPERM;
1284 }
1285
1286 fid = v9fs_create(v9ses, dir, dentry, (char *) extension, perm,
1287 P9_OREAD);
1288 if (IS_ERR(fid))
1289 return PTR_ERR(fid);
1290
1291 v9fs_invalidate_inode_attr(dir);
1292 p9_client_clunk(fid);
1293 return 0;
1294 }
1295
1296 /**
1297 * v9fs_vfs_symlink - helper function to create symlinks
1298 * @mnt_userns: The user namespace of the mount
1299 * @dir: directory inode containing symlink
1300 * @dentry: dentry for symlink
1301 * @symname: symlink data
1302 *
1303 * See Also: 9P2000.u RFC for more information
1304 *
1305 */
1306
1307 static int
v9fs_vfs_symlink(struct user_namespace * mnt_userns,struct inode * dir,struct dentry * dentry,const char * symname)1308 v9fs_vfs_symlink(struct user_namespace *mnt_userns, struct inode *dir,
1309 struct dentry *dentry, const char *symname)
1310 {
1311 p9_debug(P9_DEBUG_VFS, " %lu,%pd,%s\n",
1312 dir->i_ino, dentry, symname);
1313
1314 return v9fs_vfs_mkspecial(dir, dentry, P9_DMSYMLINK, symname);
1315 }
1316
1317 #define U32_MAX_DIGITS 10
1318
1319 /**
1320 * v9fs_vfs_link - create a hardlink
1321 * @old_dentry: dentry for file to link to
1322 * @dir: inode destination for new link
1323 * @dentry: dentry for link
1324 *
1325 */
1326
1327 static int
v9fs_vfs_link(struct dentry * old_dentry,struct inode * dir,struct dentry * dentry)1328 v9fs_vfs_link(struct dentry *old_dentry, struct inode *dir,
1329 struct dentry *dentry)
1330 {
1331 int retval;
1332 char name[1 + U32_MAX_DIGITS + 2]; /* sign + number + \n + \0 */
1333 struct p9_fid *oldfid;
1334
1335 p9_debug(P9_DEBUG_VFS, " %lu,%pd,%pd\n",
1336 dir->i_ino, dentry, old_dentry);
1337
1338 oldfid = v9fs_fid_clone(old_dentry);
1339 if (IS_ERR(oldfid))
1340 return PTR_ERR(oldfid);
1341
1342 sprintf(name, "%d\n", oldfid->fid);
1343 retval = v9fs_vfs_mkspecial(dir, dentry, P9_DMLINK, name);
1344 if (!retval) {
1345 v9fs_refresh_inode(oldfid, d_inode(old_dentry));
1346 v9fs_invalidate_inode_attr(dir);
1347 }
1348 p9_client_clunk(oldfid);
1349 return retval;
1350 }
1351
1352 /**
1353 * v9fs_vfs_mknod - create a special file
1354 * @mnt_userns: The user namespace of the mount
1355 * @dir: inode destination for new link
1356 * @dentry: dentry for file
1357 * @mode: mode for creation
1358 * @rdev: device associated with special file
1359 *
1360 */
1361
1362 static int
v9fs_vfs_mknod(struct user_namespace * mnt_userns,struct inode * dir,struct dentry * dentry,umode_t mode,dev_t rdev)1363 v9fs_vfs_mknod(struct user_namespace *mnt_userns, struct inode *dir,
1364 struct dentry *dentry, umode_t mode, dev_t rdev)
1365 {
1366 struct v9fs_session_info *v9ses = v9fs_inode2v9ses(dir);
1367 int retval;
1368 char name[2 + U32_MAX_DIGITS + 1 + U32_MAX_DIGITS + 1];
1369 u32 perm;
1370
1371 p9_debug(P9_DEBUG_VFS, " %lu,%pd mode: %x MAJOR: %u MINOR: %u\n",
1372 dir->i_ino, dentry, mode,
1373 MAJOR(rdev), MINOR(rdev));
1374
1375 /* build extension */
1376 if (S_ISBLK(mode))
1377 sprintf(name, "b %u %u", MAJOR(rdev), MINOR(rdev));
1378 else if (S_ISCHR(mode))
1379 sprintf(name, "c %u %u", MAJOR(rdev), MINOR(rdev));
1380 else
1381 *name = 0;
1382
1383 perm = unixmode2p9mode(v9ses, mode);
1384 retval = v9fs_vfs_mkspecial(dir, dentry, perm, name);
1385
1386 return retval;
1387 }
1388
v9fs_refresh_inode(struct p9_fid * fid,struct inode * inode)1389 int v9fs_refresh_inode(struct p9_fid *fid, struct inode *inode)
1390 {
1391 int umode;
1392 dev_t rdev;
1393 struct p9_wstat *st;
1394 struct v9fs_session_info *v9ses;
1395 unsigned int flags;
1396
1397 v9ses = v9fs_inode2v9ses(inode);
1398 st = p9_client_stat(fid);
1399 if (IS_ERR(st))
1400 return PTR_ERR(st);
1401 /*
1402 * Don't update inode if the file type is different
1403 */
1404 umode = p9mode2unixmode(v9ses, st, &rdev);
1405 if (inode_wrong_type(inode, umode))
1406 goto out;
1407
1408 /*
1409 * We don't want to refresh inode->i_size,
1410 * because we may have cached data
1411 */
1412 flags = (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) ?
1413 V9FS_STAT2INODE_KEEP_ISIZE : 0;
1414 v9fs_stat2inode(st, inode, inode->i_sb, flags);
1415 out:
1416 p9stat_free(st);
1417 kfree(st);
1418 return 0;
1419 }
1420
1421 static const struct inode_operations v9fs_dir_inode_operations_dotu = {
1422 .create = v9fs_vfs_create,
1423 .lookup = v9fs_vfs_lookup,
1424 .atomic_open = v9fs_vfs_atomic_open,
1425 .symlink = v9fs_vfs_symlink,
1426 .link = v9fs_vfs_link,
1427 .unlink = v9fs_vfs_unlink,
1428 .mkdir = v9fs_vfs_mkdir,
1429 .rmdir = v9fs_vfs_rmdir,
1430 .mknod = v9fs_vfs_mknod,
1431 .rename = v9fs_vfs_rename,
1432 .getattr = v9fs_vfs_getattr,
1433 .setattr = v9fs_vfs_setattr,
1434 };
1435
1436 static const struct inode_operations v9fs_dir_inode_operations = {
1437 .create = v9fs_vfs_create,
1438 .lookup = v9fs_vfs_lookup,
1439 .atomic_open = v9fs_vfs_atomic_open,
1440 .unlink = v9fs_vfs_unlink,
1441 .mkdir = v9fs_vfs_mkdir,
1442 .rmdir = v9fs_vfs_rmdir,
1443 .mknod = v9fs_vfs_mknod,
1444 .rename = v9fs_vfs_rename,
1445 .getattr = v9fs_vfs_getattr,
1446 .setattr = v9fs_vfs_setattr,
1447 };
1448
1449 static const struct inode_operations v9fs_file_inode_operations = {
1450 .getattr = v9fs_vfs_getattr,
1451 .setattr = v9fs_vfs_setattr,
1452 };
1453
1454 static const struct inode_operations v9fs_symlink_inode_operations = {
1455 .get_link = v9fs_vfs_get_link,
1456 .getattr = v9fs_vfs_getattr,
1457 .setattr = v9fs_vfs_setattr,
1458 };
1459
1460