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/inet.h>
19 #include <linux/namei.h>
20 #include <linux/sched.h>
21 #include <linux/slab.h>
22 #include <linux/xattr.h>
23 #include <linux/posix_acl.h>
24 #include <net/9p/9p.h>
25 #include <net/9p/client.h>
26
27 #include "v9fs.h"
28 #include "v9fs_vfs.h"
29 #include "fid.h"
30 #include "cache.h"
31 #include "xattr.h"
32 #include "acl.h"
33
34 static const struct inode_operations v9fs_dir_inode_operations;
35 static const struct inode_operations v9fs_dir_inode_operations_dotu;
36 static const struct inode_operations v9fs_file_inode_operations;
37 static const struct inode_operations v9fs_symlink_inode_operations;
38
39 /**
40 * unixmode2p9mode - convert unix mode bits to plan 9
41 * @v9ses: v9fs session information
42 * @mode: mode to convert
43 *
44 */
45
unixmode2p9mode(struct v9fs_session_info * v9ses,umode_t mode)46 static u32 unixmode2p9mode(struct v9fs_session_info *v9ses, umode_t mode)
47 {
48 int res;
49
50 res = mode & 0777;
51 if (S_ISDIR(mode))
52 res |= P9_DMDIR;
53 if (v9fs_proto_dotu(v9ses)) {
54 if (v9ses->nodev == 0) {
55 if (S_ISSOCK(mode))
56 res |= P9_DMSOCKET;
57 if (S_ISFIFO(mode))
58 res |= P9_DMNAMEDPIPE;
59 if (S_ISBLK(mode))
60 res |= P9_DMDEVICE;
61 if (S_ISCHR(mode))
62 res |= P9_DMDEVICE;
63 }
64
65 if ((mode & S_ISUID) == S_ISUID)
66 res |= P9_DMSETUID;
67 if ((mode & S_ISGID) == S_ISGID)
68 res |= P9_DMSETGID;
69 if ((mode & S_ISVTX) == S_ISVTX)
70 res |= P9_DMSETVTX;
71 }
72 return res;
73 }
74
75 /**
76 * p9mode2perm- convert plan9 mode bits to unix permission bits
77 * @v9ses: v9fs session information
78 * @stat: p9_wstat from which mode need to be derived
79 *
80 */
p9mode2perm(struct v9fs_session_info * v9ses,struct p9_wstat * stat)81 static int p9mode2perm(struct v9fs_session_info *v9ses,
82 struct p9_wstat *stat)
83 {
84 int res;
85 int mode = stat->mode;
86
87 res = mode & S_IALLUGO;
88 if (v9fs_proto_dotu(v9ses)) {
89 if ((mode & P9_DMSETUID) == P9_DMSETUID)
90 res |= S_ISUID;
91
92 if ((mode & P9_DMSETGID) == P9_DMSETGID)
93 res |= S_ISGID;
94
95 if ((mode & P9_DMSETVTX) == P9_DMSETVTX)
96 res |= S_ISVTX;
97 }
98 return res;
99 }
100
101 /**
102 * p9mode2unixmode- convert plan9 mode bits to unix mode bits
103 * @v9ses: v9fs session information
104 * @stat: p9_wstat from which mode need to be derived
105 * @rdev: major number, minor number in case of device files.
106 *
107 */
p9mode2unixmode(struct v9fs_session_info * v9ses,struct p9_wstat * stat,dev_t * rdev)108 static umode_t p9mode2unixmode(struct v9fs_session_info *v9ses,
109 struct p9_wstat *stat, dev_t *rdev)
110 {
111 int res, r;
112 u32 mode = stat->mode;
113
114 *rdev = 0;
115 res = p9mode2perm(v9ses, stat);
116
117 if ((mode & P9_DMDIR) == P9_DMDIR)
118 res |= S_IFDIR;
119 else if ((mode & P9_DMSYMLINK) && (v9fs_proto_dotu(v9ses)))
120 res |= S_IFLNK;
121 else if ((mode & P9_DMSOCKET) && (v9fs_proto_dotu(v9ses))
122 && (v9ses->nodev == 0))
123 res |= S_IFSOCK;
124 else if ((mode & P9_DMNAMEDPIPE) && (v9fs_proto_dotu(v9ses))
125 && (v9ses->nodev == 0))
126 res |= S_IFIFO;
127 else if ((mode & P9_DMDEVICE) && (v9fs_proto_dotu(v9ses))
128 && (v9ses->nodev == 0)) {
129 char type = 0;
130 int major = -1, minor = -1;
131
132 r = sscanf(stat->extension, "%c %i %i", &type, &major, &minor);
133 if (r != 3) {
134 p9_debug(P9_DEBUG_ERROR,
135 "invalid device string, umode will be bogus: %s\n",
136 stat->extension);
137 return res;
138 }
139 switch (type) {
140 case 'c':
141 res |= S_IFCHR;
142 break;
143 case 'b':
144 res |= S_IFBLK;
145 break;
146 default:
147 p9_debug(P9_DEBUG_ERROR, "Unknown special type %c %s\n",
148 type, stat->extension);
149 }
150 *rdev = MKDEV(major, minor);
151 } else
152 res |= S_IFREG;
153
154 return res;
155 }
156
157 /**
158 * v9fs_uflags2omode- convert posix open flags to plan 9 mode bits
159 * @uflags: flags to convert
160 * @extended: if .u extensions are active
161 */
162
v9fs_uflags2omode(int uflags,int extended)163 int v9fs_uflags2omode(int uflags, int extended)
164 {
165 int ret;
166
167 ret = 0;
168 switch (uflags&3) {
169 default:
170 case O_RDONLY:
171 ret = P9_OREAD;
172 break;
173
174 case O_WRONLY:
175 ret = P9_OWRITE;
176 break;
177
178 case O_RDWR:
179 ret = P9_ORDWR;
180 break;
181 }
182
183 if (extended) {
184 if (uflags & O_EXCL)
185 ret |= P9_OEXCL;
186
187 if (uflags & O_APPEND)
188 ret |= P9_OAPPEND;
189 }
190
191 return ret;
192 }
193
194 /**
195 * v9fs_blank_wstat - helper function to setup a 9P stat structure
196 * @wstat: structure to initialize
197 *
198 */
199
200 void
v9fs_blank_wstat(struct p9_wstat * wstat)201 v9fs_blank_wstat(struct p9_wstat *wstat)
202 {
203 wstat->type = ~0;
204 wstat->dev = ~0;
205 wstat->qid.type = ~0;
206 wstat->qid.version = ~0;
207 *((long long *)&wstat->qid.path) = ~0;
208 wstat->mode = ~0;
209 wstat->atime = ~0;
210 wstat->mtime = ~0;
211 wstat->length = ~0;
212 wstat->name = NULL;
213 wstat->uid = NULL;
214 wstat->gid = NULL;
215 wstat->muid = NULL;
216 wstat->n_uid = INVALID_UID;
217 wstat->n_gid = INVALID_GID;
218 wstat->n_muid = INVALID_UID;
219 wstat->extension = NULL;
220 }
221
222 /**
223 * v9fs_alloc_inode - helper function to allocate an inode
224 * @sb: The superblock to allocate the inode from
225 */
v9fs_alloc_inode(struct super_block * sb)226 struct inode *v9fs_alloc_inode(struct super_block *sb)
227 {
228 struct v9fs_inode *v9inode;
229
230 v9inode = alloc_inode_sb(sb, v9fs_inode_cache, GFP_KERNEL);
231 if (!v9inode)
232 return NULL;
233 v9inode->writeback_fid = 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
v9fs_free_inode(struct inode * inode)244 void 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 */
v9fs_set_netfs_context(struct inode * inode)252 static void 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);
256 }
257
v9fs_init_inode(struct v9fs_session_info * v9ses,struct inode * inode,umode_t mode,dev_t rdev)258 int v9fs_init_inode(struct v9fs_session_info *v9ses,
259 struct inode *inode, umode_t mode, dev_t rdev)
260 {
261 int err = 0;
262
263 inode_init_owner(&nop_mnt_idmap, inode, NULL, mode);
264 inode->i_blocks = 0;
265 inode->i_rdev = rdev;
266 inode->i_atime = inode->i_mtime = inode->i_ctime = current_time(inode);
267 inode->i_mapping->a_ops = &v9fs_addr_operations;
268 inode->i_private = NULL;
269
270 switch (mode & S_IFMT) {
271 case S_IFIFO:
272 case S_IFBLK:
273 case S_IFCHR:
274 case S_IFSOCK:
275 if (v9fs_proto_dotl(v9ses)) {
276 inode->i_op = &v9fs_file_inode_operations_dotl;
277 } else if (v9fs_proto_dotu(v9ses)) {
278 inode->i_op = &v9fs_file_inode_operations;
279 } else {
280 p9_debug(P9_DEBUG_ERROR,
281 "special files without extended mode\n");
282 err = -EINVAL;
283 goto error;
284 }
285 init_special_inode(inode, inode->i_mode, inode->i_rdev);
286 break;
287 case S_IFREG:
288 if (v9fs_proto_dotl(v9ses)) {
289 inode->i_op = &v9fs_file_inode_operations_dotl;
290 if (v9ses->cache == CACHE_LOOSE ||
291 v9ses->cache == CACHE_FSCACHE)
292 inode->i_fop =
293 &v9fs_cached_file_operations_dotl;
294 else if (v9ses->cache == CACHE_MMAP)
295 inode->i_fop = &v9fs_mmap_file_operations_dotl;
296 else
297 inode->i_fop = &v9fs_file_operations_dotl;
298 } else {
299 inode->i_op = &v9fs_file_inode_operations;
300 if (v9ses->cache == CACHE_LOOSE ||
301 v9ses->cache == CACHE_FSCACHE)
302 inode->i_fop =
303 &v9fs_cached_file_operations;
304 else if (v9ses->cache == CACHE_MMAP)
305 inode->i_fop = &v9fs_mmap_file_operations;
306 else
307 inode->i_fop = &v9fs_file_operations;
308 }
309
310 break;
311 case S_IFLNK:
312 if (!v9fs_proto_dotu(v9ses) && !v9fs_proto_dotl(v9ses)) {
313 p9_debug(P9_DEBUG_ERROR,
314 "extended modes used with legacy protocol\n");
315 err = -EINVAL;
316 goto error;
317 }
318
319 if (v9fs_proto_dotl(v9ses))
320 inode->i_op = &v9fs_symlink_inode_operations_dotl;
321 else
322 inode->i_op = &v9fs_symlink_inode_operations;
323
324 break;
325 case S_IFDIR:
326 inc_nlink(inode);
327 if (v9fs_proto_dotl(v9ses))
328 inode->i_op = &v9fs_dir_inode_operations_dotl;
329 else if (v9fs_proto_dotu(v9ses))
330 inode->i_op = &v9fs_dir_inode_operations_dotu;
331 else
332 inode->i_op = &v9fs_dir_inode_operations;
333
334 if (v9fs_proto_dotl(v9ses))
335 inode->i_fop = &v9fs_dir_operations_dotl;
336 else
337 inode->i_fop = &v9fs_dir_operations;
338
339 break;
340 default:
341 p9_debug(P9_DEBUG_ERROR, "BAD mode 0x%hx S_IFMT 0x%x\n",
342 mode, mode & S_IFMT);
343 err = -EINVAL;
344 goto error;
345 }
346
347 v9fs_set_netfs_context(inode);
348 error:
349 return err;
350
351 }
352
353 /**
354 * v9fs_get_inode - helper function to setup an inode
355 * @sb: superblock
356 * @mode: mode to setup inode with
357 * @rdev: The device numbers to set
358 */
359
v9fs_get_inode(struct super_block * sb,umode_t mode,dev_t rdev)360 struct inode *v9fs_get_inode(struct super_block *sb, umode_t mode, dev_t rdev)
361 {
362 int err;
363 struct inode *inode;
364 struct v9fs_session_info *v9ses = sb->s_fs_info;
365
366 p9_debug(P9_DEBUG_VFS, "super block: %p mode: %ho\n", sb, mode);
367
368 inode = new_inode(sb);
369 if (!inode) {
370 pr_warn("%s (%d): Problem allocating inode\n",
371 __func__, task_pid_nr(current));
372 return ERR_PTR(-ENOMEM);
373 }
374 err = v9fs_init_inode(v9ses, inode, mode, rdev);
375 if (err) {
376 iput(inode);
377 return ERR_PTR(err);
378 }
379 return inode;
380 }
381
382 /**
383 * v9fs_evict_inode - Remove an inode from the inode cache
384 * @inode: inode to release
385 *
386 */
v9fs_evict_inode(struct inode * inode)387 void v9fs_evict_inode(struct inode *inode)
388 {
389 struct v9fs_inode *v9inode = V9FS_I(inode);
390 __le32 version;
391
392 truncate_inode_pages_final(&inode->i_data);
393 version = cpu_to_le32(v9inode->qid.version);
394 fscache_clear_inode_writeback(v9fs_inode_cookie(v9inode), inode,
395 &version);
396 clear_inode(inode);
397 filemap_fdatawrite(&inode->i_data);
398
399 fscache_relinquish_cookie(v9fs_inode_cookie(v9inode), false);
400 /* clunk the fid stashed in writeback_fid */
401 p9_fid_put(v9inode->writeback_fid);
402 v9inode->writeback_fid = NULL;
403 }
404
v9fs_test_inode(struct inode * inode,void * data)405 static int v9fs_test_inode(struct inode *inode, void *data)
406 {
407 int umode;
408 dev_t rdev;
409 struct v9fs_inode *v9inode = V9FS_I(inode);
410 struct p9_wstat *st = (struct p9_wstat *)data;
411 struct v9fs_session_info *v9ses = v9fs_inode2v9ses(inode);
412
413 umode = p9mode2unixmode(v9ses, st, &rdev);
414 /* don't match inode of different type */
415 if (inode_wrong_type(inode, umode))
416 return 0;
417
418 /* compare qid details */
419 if (memcmp(&v9inode->qid.version,
420 &st->qid.version, sizeof(v9inode->qid.version)))
421 return 0;
422
423 if (v9inode->qid.type != st->qid.type)
424 return 0;
425
426 if (v9inode->qid.path != st->qid.path)
427 return 0;
428 return 1;
429 }
430
v9fs_test_new_inode(struct inode * inode,void * data)431 static int v9fs_test_new_inode(struct inode *inode, void *data)
432 {
433 return 0;
434 }
435
v9fs_set_inode(struct inode * inode,void * data)436 static int v9fs_set_inode(struct inode *inode, void *data)
437 {
438 struct v9fs_inode *v9inode = V9FS_I(inode);
439 struct p9_wstat *st = (struct p9_wstat *)data;
440
441 memcpy(&v9inode->qid, &st->qid, sizeof(st->qid));
442 return 0;
443 }
444
v9fs_qid_iget(struct super_block * sb,struct p9_qid * qid,struct p9_wstat * st,int new)445 static struct inode *v9fs_qid_iget(struct super_block *sb,
446 struct p9_qid *qid,
447 struct p9_wstat *st,
448 int new)
449 {
450 dev_t rdev;
451 int retval;
452 umode_t umode;
453 unsigned long i_ino;
454 struct inode *inode;
455 struct v9fs_session_info *v9ses = sb->s_fs_info;
456 int (*test)(struct inode *inode, void *data);
457
458 if (new)
459 test = v9fs_test_new_inode;
460 else
461 test = v9fs_test_inode;
462
463 i_ino = v9fs_qid2ino(qid);
464 inode = iget5_locked(sb, i_ino, test, v9fs_set_inode, st);
465 if (!inode)
466 return ERR_PTR(-ENOMEM);
467 if (!(inode->i_state & I_NEW))
468 return inode;
469 /*
470 * initialize the inode with the stat info
471 * FIXME!! we may need support for stale inodes
472 * later.
473 */
474 inode->i_ino = i_ino;
475 umode = p9mode2unixmode(v9ses, st, &rdev);
476 retval = v9fs_init_inode(v9ses, inode, umode, rdev);
477 if (retval)
478 goto error;
479
480 v9fs_stat2inode(st, inode, sb, 0);
481 v9fs_cache_inode_get_cookie(inode);
482 unlock_new_inode(inode);
483 return inode;
484 error:
485 iget_failed(inode);
486 return ERR_PTR(retval);
487
488 }
489
490 struct inode *
v9fs_inode_from_fid(struct v9fs_session_info * v9ses,struct p9_fid * fid,struct super_block * sb,int new)491 v9fs_inode_from_fid(struct v9fs_session_info *v9ses, struct p9_fid *fid,
492 struct super_block *sb, int new)
493 {
494 struct p9_wstat *st;
495 struct inode *inode = NULL;
496
497 st = p9_client_stat(fid);
498 if (IS_ERR(st))
499 return ERR_CAST(st);
500
501 inode = v9fs_qid_iget(sb, &st->qid, st, new);
502 p9stat_free(st);
503 kfree(st);
504 return inode;
505 }
506
507 /**
508 * v9fs_at_to_dotl_flags- convert Linux specific AT flags to
509 * plan 9 AT flag.
510 * @flags: flags to convert
511 */
v9fs_at_to_dotl_flags(int flags)512 static int v9fs_at_to_dotl_flags(int flags)
513 {
514 int rflags = 0;
515
516 if (flags & AT_REMOVEDIR)
517 rflags |= P9_DOTL_AT_REMOVEDIR;
518
519 return rflags;
520 }
521
522 /**
523 * v9fs_dec_count - helper functon to drop i_nlink.
524 *
525 * If a directory had nlink <= 2 (including . and ..), then we should not drop
526 * the link count, which indicates the underlying exported fs doesn't maintain
527 * nlink accurately. e.g.
528 * - overlayfs sets nlink to 1 for merged dir
529 * - ext4 (with dir_nlink feature enabled) sets nlink to 1 if a dir has more
530 * than EXT4_LINK_MAX (65000) links.
531 *
532 * @inode: inode whose nlink is being dropped
533 */
v9fs_dec_count(struct inode * inode)534 static void v9fs_dec_count(struct inode *inode)
535 {
536 if (!S_ISDIR(inode->i_mode) || inode->i_nlink > 2)
537 drop_nlink(inode);
538 }
539
540 /**
541 * v9fs_remove - helper function to remove files and directories
542 * @dir: directory inode that is being deleted
543 * @dentry: dentry that is being deleted
544 * @flags: removing a directory
545 *
546 */
547
v9fs_remove(struct inode * dir,struct dentry * dentry,int flags)548 static int v9fs_remove(struct inode *dir, struct dentry *dentry, int flags)
549 {
550 struct inode *inode;
551 int retval = -EOPNOTSUPP;
552 struct p9_fid *v9fid, *dfid;
553 struct v9fs_session_info *v9ses;
554
555 p9_debug(P9_DEBUG_VFS, "inode: %p dentry: %p rmdir: %x\n",
556 dir, dentry, flags);
557
558 v9ses = v9fs_inode2v9ses(dir);
559 inode = d_inode(dentry);
560 dfid = v9fs_parent_fid(dentry);
561 if (IS_ERR(dfid)) {
562 retval = PTR_ERR(dfid);
563 p9_debug(P9_DEBUG_VFS, "fid lookup failed %d\n", retval);
564 return retval;
565 }
566 if (v9fs_proto_dotl(v9ses))
567 retval = p9_client_unlinkat(dfid, dentry->d_name.name,
568 v9fs_at_to_dotl_flags(flags));
569 p9_fid_put(dfid);
570 if (retval == -EOPNOTSUPP) {
571 /* Try the one based on path */
572 v9fid = v9fs_fid_clone(dentry);
573 if (IS_ERR(v9fid))
574 return PTR_ERR(v9fid);
575 retval = p9_client_remove(v9fid);
576 }
577 if (!retval) {
578 /*
579 * directories on unlink should have zero
580 * link count
581 */
582 if (flags & AT_REMOVEDIR) {
583 clear_nlink(inode);
584 v9fs_dec_count(dir);
585 } else
586 v9fs_dec_count(inode);
587
588 v9fs_invalidate_inode_attr(inode);
589 v9fs_invalidate_inode_attr(dir);
590
591 /* invalidate all fids associated with dentry */
592 /* NOTE: This will not include open fids */
593 dentry->d_op->d_release(dentry);
594 }
595 return retval;
596 }
597
598 /**
599 * v9fs_create - Create a file
600 * @v9ses: session information
601 * @dir: directory that dentry is being created in
602 * @dentry: dentry that is being created
603 * @extension: 9p2000.u extension string to support devices, etc.
604 * @perm: create permissions
605 * @mode: open mode
606 *
607 */
608 static struct p9_fid *
v9fs_create(struct v9fs_session_info * v9ses,struct inode * dir,struct dentry * dentry,char * extension,u32 perm,u8 mode)609 v9fs_create(struct v9fs_session_info *v9ses, struct inode *dir,
610 struct dentry *dentry, char *extension, u32 perm, u8 mode)
611 {
612 int err;
613 const unsigned char *name;
614 struct p9_fid *dfid, *ofid = NULL, *fid = NULL;
615 struct inode *inode;
616
617 p9_debug(P9_DEBUG_VFS, "name %pd\n", dentry);
618
619 err = 0;
620 name = dentry->d_name.name;
621 dfid = v9fs_parent_fid(dentry);
622 if (IS_ERR(dfid)) {
623 err = PTR_ERR(dfid);
624 p9_debug(P9_DEBUG_VFS, "fid lookup failed %d\n", err);
625 return ERR_PTR(err);
626 }
627
628 /* clone a fid to use for creation */
629 ofid = clone_fid(dfid);
630 if (IS_ERR(ofid)) {
631 err = PTR_ERR(ofid);
632 p9_debug(P9_DEBUG_VFS, "p9_client_walk failed %d\n", err);
633 goto error;
634 }
635
636 err = p9_client_fcreate(ofid, name, perm, mode, extension);
637 if (err < 0) {
638 p9_debug(P9_DEBUG_VFS, "p9_client_fcreate failed %d\n", err);
639 goto error;
640 }
641
642 if (!(perm & P9_DMLINK)) {
643 /* now walk from the parent so we can get unopened fid */
644 fid = p9_client_walk(dfid, 1, &name, 1);
645 if (IS_ERR(fid)) {
646 err = PTR_ERR(fid);
647 p9_debug(P9_DEBUG_VFS,
648 "p9_client_walk failed %d\n", err);
649 goto error;
650 }
651 /*
652 * instantiate inode and assign the unopened fid to the dentry
653 */
654 inode = v9fs_get_new_inode_from_fid(v9ses, fid, dir->i_sb);
655 if (IS_ERR(inode)) {
656 err = PTR_ERR(inode);
657 p9_debug(P9_DEBUG_VFS,
658 "inode creation failed %d\n", err);
659 goto error;
660 }
661 v9fs_fid_add(dentry, &fid);
662 d_instantiate(dentry, inode);
663 }
664 p9_fid_put(dfid);
665 return ofid;
666 error:
667 p9_fid_put(dfid);
668 p9_fid_put(ofid);
669 p9_fid_put(fid);
670 return ERR_PTR(err);
671 }
672
673 /**
674 * v9fs_vfs_create - VFS hook to create a regular file
675 * @idmap: idmap of the mount
676 * @dir: The parent directory
677 * @dentry: The name of file to be created
678 * @mode: The UNIX file mode to set
679 * @excl: True if the file must not yet exist
680 *
681 * open(.., O_CREAT) is handled in v9fs_vfs_atomic_open(). This is only called
682 * for mknod(2).
683 *
684 */
685
686 static int
v9fs_vfs_create(struct mnt_idmap * idmap,struct inode * dir,struct dentry * dentry,umode_t mode,bool excl)687 v9fs_vfs_create(struct mnt_idmap *idmap, struct inode *dir,
688 struct dentry *dentry, umode_t mode, bool excl)
689 {
690 struct v9fs_session_info *v9ses = v9fs_inode2v9ses(dir);
691 u32 perm = unixmode2p9mode(v9ses, mode);
692 struct p9_fid *fid;
693
694 /* P9_OEXCL? */
695 fid = v9fs_create(v9ses, dir, dentry, NULL, perm, P9_ORDWR);
696 if (IS_ERR(fid))
697 return PTR_ERR(fid);
698
699 v9fs_invalidate_inode_attr(dir);
700 p9_fid_put(fid);
701
702 return 0;
703 }
704
705 /**
706 * v9fs_vfs_mkdir - VFS mkdir hook to create a directory
707 * @idmap: idmap of the mount
708 * @dir: inode that is being unlinked
709 * @dentry: dentry that is being unlinked
710 * @mode: mode for new directory
711 *
712 */
713
v9fs_vfs_mkdir(struct mnt_idmap * idmap,struct inode * dir,struct dentry * dentry,umode_t mode)714 static int v9fs_vfs_mkdir(struct mnt_idmap *idmap, struct inode *dir,
715 struct dentry *dentry, umode_t mode)
716 {
717 int err;
718 u32 perm;
719 struct p9_fid *fid;
720 struct v9fs_session_info *v9ses;
721
722 p9_debug(P9_DEBUG_VFS, "name %pd\n", dentry);
723 err = 0;
724 v9ses = v9fs_inode2v9ses(dir);
725 perm = unixmode2p9mode(v9ses, mode | S_IFDIR);
726 fid = v9fs_create(v9ses, dir, dentry, NULL, perm, P9_OREAD);
727 if (IS_ERR(fid)) {
728 err = PTR_ERR(fid);
729 fid = NULL;
730 } else {
731 inc_nlink(dir);
732 v9fs_invalidate_inode_attr(dir);
733 }
734
735 if (fid)
736 p9_fid_put(fid);
737
738 return err;
739 }
740
741 /**
742 * v9fs_vfs_lookup - VFS lookup hook to "walk" to a new inode
743 * @dir: inode that is being walked from
744 * @dentry: dentry that is being walked to?
745 * @flags: lookup flags (unused)
746 *
747 */
748
v9fs_vfs_lookup(struct inode * dir,struct dentry * dentry,unsigned int flags)749 struct dentry *v9fs_vfs_lookup(struct inode *dir, struct dentry *dentry,
750 unsigned int flags)
751 {
752 struct dentry *res;
753 struct v9fs_session_info *v9ses;
754 struct p9_fid *dfid, *fid;
755 struct inode *inode;
756 const unsigned char *name;
757
758 p9_debug(P9_DEBUG_VFS, "dir: %p dentry: (%pd) %p flags: %x\n",
759 dir, dentry, dentry, flags);
760
761 if (dentry->d_name.len > NAME_MAX)
762 return ERR_PTR(-ENAMETOOLONG);
763
764 v9ses = v9fs_inode2v9ses(dir);
765 /* We can walk d_parent because we hold the dir->i_mutex */
766 dfid = v9fs_parent_fid(dentry);
767 if (IS_ERR(dfid))
768 return ERR_CAST(dfid);
769
770 /*
771 * Make sure we don't use a wrong inode due to parallel
772 * unlink. For cached mode create calls request for new
773 * inode. But with cache disabled, lookup should do this.
774 */
775 name = dentry->d_name.name;
776 fid = p9_client_walk(dfid, 1, &name, 1);
777 p9_fid_put(dfid);
778 if (fid == ERR_PTR(-ENOENT))
779 inode = NULL;
780 else if (IS_ERR(fid))
781 inode = ERR_CAST(fid);
782 else if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE)
783 inode = v9fs_get_inode_from_fid(v9ses, fid, dir->i_sb);
784 else
785 inode = v9fs_get_new_inode_from_fid(v9ses, fid, dir->i_sb);
786 /*
787 * If we had a rename on the server and a parallel lookup
788 * for the new name, then make sure we instantiate with
789 * the new name. ie look up for a/b, while on server somebody
790 * moved b under k and client parallely did a lookup for
791 * k/b.
792 */
793 res = d_splice_alias(inode, dentry);
794 if (!IS_ERR(fid)) {
795 if (!res)
796 v9fs_fid_add(dentry, &fid);
797 else if (!IS_ERR(res))
798 v9fs_fid_add(res, &fid);
799 else
800 p9_fid_put(fid);
801 }
802 return res;
803 }
804
805 static int
v9fs_vfs_atomic_open(struct inode * dir,struct dentry * dentry,struct file * file,unsigned int flags,umode_t mode)806 v9fs_vfs_atomic_open(struct inode *dir, struct dentry *dentry,
807 struct file *file, unsigned int flags, umode_t mode)
808 {
809 int err;
810 u32 perm;
811 struct v9fs_inode *v9inode;
812 struct v9fs_session_info *v9ses;
813 struct p9_fid *fid, *inode_fid;
814 struct dentry *res = NULL;
815 struct inode *inode;
816
817 if (d_in_lookup(dentry)) {
818 res = v9fs_vfs_lookup(dir, dentry, 0);
819 if (IS_ERR(res))
820 return PTR_ERR(res);
821
822 if (res)
823 dentry = res;
824 }
825
826 /* Only creates */
827 if (!(flags & O_CREAT) || d_really_is_positive(dentry))
828 return finish_no_open(file, res);
829
830 err = 0;
831
832 v9ses = v9fs_inode2v9ses(dir);
833 perm = unixmode2p9mode(v9ses, mode);
834 fid = v9fs_create(v9ses, dir, dentry, NULL, perm,
835 v9fs_uflags2omode(flags,
836 v9fs_proto_dotu(v9ses)));
837 if (IS_ERR(fid)) {
838 err = PTR_ERR(fid);
839 goto error;
840 }
841
842 v9fs_invalidate_inode_attr(dir);
843 inode = d_inode(dentry);
844 v9inode = V9FS_I(inode);
845 mutex_lock(&v9inode->v_mutex);
846 if ((v9ses->cache) && !v9inode->writeback_fid &&
847 ((flags & O_ACCMODE) != O_RDONLY)) {
848 /*
849 * clone a fid and add it to writeback_fid
850 * we do it during open time instead of
851 * page dirty time via write_begin/page_mkwrite
852 * because we want write after unlink usecase
853 * to work.
854 */
855 inode_fid = v9fs_writeback_fid(dentry);
856 if (IS_ERR(inode_fid)) {
857 err = PTR_ERR(inode_fid);
858 mutex_unlock(&v9inode->v_mutex);
859 goto error;
860 }
861 v9inode->writeback_fid = (void *) inode_fid;
862 }
863 mutex_unlock(&v9inode->v_mutex);
864 err = finish_open(file, dentry, generic_file_open);
865 if (err)
866 goto error;
867
868 file->private_data = fid;
869 if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE)
870 fscache_use_cookie(v9fs_inode_cookie(v9inode),
871 file->f_mode & FMODE_WRITE);
872 v9fs_open_fid_add(inode, &fid);
873
874 file->f_mode |= FMODE_CREATED;
875 out:
876 dput(res);
877 return err;
878
879 error:
880 p9_fid_put(fid);
881 goto out;
882 }
883
884 /**
885 * v9fs_vfs_unlink - VFS unlink hook to delete an inode
886 * @i: inode that is being unlinked
887 * @d: dentry that is being unlinked
888 *
889 */
890
v9fs_vfs_unlink(struct inode * i,struct dentry * d)891 int v9fs_vfs_unlink(struct inode *i, struct dentry *d)
892 {
893 return v9fs_remove(i, d, 0);
894 }
895
896 /**
897 * v9fs_vfs_rmdir - VFS unlink hook to delete a directory
898 * @i: inode that is being unlinked
899 * @d: dentry that is being unlinked
900 *
901 */
902
v9fs_vfs_rmdir(struct inode * i,struct dentry * d)903 int v9fs_vfs_rmdir(struct inode *i, struct dentry *d)
904 {
905 return v9fs_remove(i, d, AT_REMOVEDIR);
906 }
907
908 /**
909 * v9fs_vfs_rename - VFS hook to rename an inode
910 * @idmap: The idmap of the mount
911 * @old_dir: old dir inode
912 * @old_dentry: old dentry
913 * @new_dir: new dir inode
914 * @new_dentry: new dentry
915 * @flags: RENAME_* flags
916 *
917 */
918
919 int
v9fs_vfs_rename(struct mnt_idmap * idmap,struct inode * old_dir,struct dentry * old_dentry,struct inode * new_dir,struct dentry * new_dentry,unsigned int flags)920 v9fs_vfs_rename(struct mnt_idmap *idmap, struct inode *old_dir,
921 struct dentry *old_dentry, struct inode *new_dir,
922 struct dentry *new_dentry, unsigned int flags)
923 {
924 int retval;
925 struct inode *old_inode;
926 struct inode *new_inode;
927 struct v9fs_session_info *v9ses;
928 struct p9_fid *oldfid = NULL, *dfid = NULL;
929 struct p9_fid *olddirfid = NULL;
930 struct p9_fid *newdirfid = NULL;
931 struct p9_wstat wstat;
932
933 if (flags)
934 return -EINVAL;
935
936 p9_debug(P9_DEBUG_VFS, "\n");
937 retval = 0;
938 old_inode = d_inode(old_dentry);
939 new_inode = d_inode(new_dentry);
940 v9ses = v9fs_inode2v9ses(old_inode);
941 oldfid = v9fs_fid_lookup(old_dentry);
942 if (IS_ERR(oldfid))
943 return PTR_ERR(oldfid);
944
945 dfid = v9fs_parent_fid(old_dentry);
946 olddirfid = clone_fid(dfid);
947 p9_fid_put(dfid);
948 dfid = NULL;
949
950 if (IS_ERR(olddirfid)) {
951 retval = PTR_ERR(olddirfid);
952 goto error;
953 }
954
955 dfid = v9fs_parent_fid(new_dentry);
956 newdirfid = clone_fid(dfid);
957 p9_fid_put(dfid);
958 dfid = NULL;
959
960 if (IS_ERR(newdirfid)) {
961 retval = PTR_ERR(newdirfid);
962 goto error;
963 }
964
965 down_write(&v9ses->rename_sem);
966 if (v9fs_proto_dotl(v9ses)) {
967 retval = p9_client_renameat(olddirfid, old_dentry->d_name.name,
968 newdirfid, new_dentry->d_name.name);
969 if (retval == -EOPNOTSUPP)
970 retval = p9_client_rename(oldfid, newdirfid,
971 new_dentry->d_name.name);
972 if (retval != -EOPNOTSUPP)
973 goto error_locked;
974 }
975 if (old_dentry->d_parent != new_dentry->d_parent) {
976 /*
977 * 9P .u can only handle file rename in the same directory
978 */
979
980 p9_debug(P9_DEBUG_ERROR, "old dir and new dir are different\n");
981 retval = -EXDEV;
982 goto error_locked;
983 }
984 v9fs_blank_wstat(&wstat);
985 wstat.muid = v9ses->uname;
986 wstat.name = new_dentry->d_name.name;
987 retval = p9_client_wstat(oldfid, &wstat);
988
989 error_locked:
990 if (!retval) {
991 if (new_inode) {
992 if (S_ISDIR(new_inode->i_mode))
993 clear_nlink(new_inode);
994 else
995 v9fs_dec_count(new_inode);
996 }
997 if (S_ISDIR(old_inode->i_mode)) {
998 if (!new_inode)
999 inc_nlink(new_dir);
1000 v9fs_dec_count(old_dir);
1001 }
1002 v9fs_invalidate_inode_attr(old_inode);
1003 v9fs_invalidate_inode_attr(old_dir);
1004 v9fs_invalidate_inode_attr(new_dir);
1005
1006 /* successful rename */
1007 d_move(old_dentry, new_dentry);
1008 }
1009 up_write(&v9ses->rename_sem);
1010
1011 error:
1012 p9_fid_put(newdirfid);
1013 p9_fid_put(olddirfid);
1014 p9_fid_put(oldfid);
1015 return retval;
1016 }
1017
1018 /**
1019 * v9fs_vfs_getattr - retrieve file metadata
1020 * @idmap: idmap 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 mnt_idmap * idmap,const struct path * path,struct kstat * stat,u32 request_mask,unsigned int flags)1029 v9fs_vfs_getattr(struct mnt_idmap *idmap, 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(&nop_mnt_idmap, 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_fid_put(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(&nop_mnt_idmap, 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 * @idmap: idmap of the mount
1063 * @dentry: file whose metadata to set
1064 * @iattr: metadata assignment structure
1065 *
1066 */
1067
v9fs_vfs_setattr(struct mnt_idmap * idmap,struct dentry * dentry,struct iattr * iattr)1068 static int v9fs_vfs_setattr(struct mnt_idmap *idmap,
1069 struct dentry *dentry, struct iattr *iattr)
1070 {
1071 int retval, use_dentry = 0;
1072 struct inode *inode = d_inode(dentry);
1073 struct v9fs_inode *v9inode = V9FS_I(inode);
1074 struct v9fs_session_info *v9ses;
1075 struct p9_fid *fid = NULL;
1076 struct p9_wstat wstat;
1077
1078 p9_debug(P9_DEBUG_VFS, "\n");
1079 retval = setattr_prepare(&nop_mnt_idmap, dentry, iattr);
1080 if (retval)
1081 return retval;
1082
1083 retval = -EPERM;
1084 v9ses = v9fs_dentry2v9ses(dentry);
1085 if (iattr->ia_valid & ATTR_FILE) {
1086 fid = iattr->ia_file->private_data;
1087 WARN_ON(!fid);
1088 }
1089 if (!fid) {
1090 fid = v9fs_fid_lookup(dentry);
1091 use_dentry = 1;
1092 }
1093 if (IS_ERR(fid))
1094 return PTR_ERR(fid);
1095
1096 v9fs_blank_wstat(&wstat);
1097 if (iattr->ia_valid & ATTR_MODE)
1098 wstat.mode = unixmode2p9mode(v9ses, iattr->ia_mode);
1099
1100 if (iattr->ia_valid & ATTR_MTIME)
1101 wstat.mtime = iattr->ia_mtime.tv_sec;
1102
1103 if (iattr->ia_valid & ATTR_ATIME)
1104 wstat.atime = iattr->ia_atime.tv_sec;
1105
1106 if (iattr->ia_valid & ATTR_SIZE)
1107 wstat.length = iattr->ia_size;
1108
1109 if (v9fs_proto_dotu(v9ses)) {
1110 if (iattr->ia_valid & ATTR_UID)
1111 wstat.n_uid = iattr->ia_uid;
1112
1113 if (iattr->ia_valid & ATTR_GID)
1114 wstat.n_gid = iattr->ia_gid;
1115 }
1116
1117 /* Write all dirty data */
1118 if (d_is_reg(dentry))
1119 filemap_write_and_wait(inode->i_mapping);
1120
1121 retval = p9_client_wstat(fid, &wstat);
1122
1123 if (use_dentry)
1124 p9_fid_put(fid);
1125
1126 if (retval < 0)
1127 return retval;
1128
1129 if ((iattr->ia_valid & ATTR_SIZE) &&
1130 iattr->ia_size != i_size_read(inode)) {
1131 truncate_setsize(inode, iattr->ia_size);
1132 fscache_resize_cookie(v9fs_inode_cookie(v9inode), iattr->ia_size);
1133 }
1134
1135 v9fs_invalidate_inode_attr(inode);
1136
1137 setattr_copy(&nop_mnt_idmap, inode, iattr);
1138 mark_inode_dirty(inode);
1139 return 0;
1140 }
1141
1142 /**
1143 * v9fs_stat2inode - populate an inode structure with mistat info
1144 * @stat: Plan 9 metadata (mistat) structure
1145 * @inode: inode to populate
1146 * @sb: superblock of filesystem
1147 * @flags: control flags (e.g. V9FS_STAT2INODE_KEEP_ISIZE)
1148 *
1149 */
1150
1151 void
v9fs_stat2inode(struct p9_wstat * stat,struct inode * inode,struct super_block * sb,unsigned int flags)1152 v9fs_stat2inode(struct p9_wstat *stat, struct inode *inode,
1153 struct super_block *sb, unsigned int flags)
1154 {
1155 umode_t mode;
1156 struct v9fs_session_info *v9ses = sb->s_fs_info;
1157 struct v9fs_inode *v9inode = V9FS_I(inode);
1158
1159 set_nlink(inode, 1);
1160
1161 inode->i_atime.tv_sec = stat->atime;
1162 inode->i_mtime.tv_sec = stat->mtime;
1163 inode->i_ctime.tv_sec = stat->mtime;
1164
1165 inode->i_uid = v9ses->dfltuid;
1166 inode->i_gid = v9ses->dfltgid;
1167
1168 if (v9fs_proto_dotu(v9ses)) {
1169 inode->i_uid = stat->n_uid;
1170 inode->i_gid = stat->n_gid;
1171 }
1172 if ((S_ISREG(inode->i_mode)) || (S_ISDIR(inode->i_mode))) {
1173 if (v9fs_proto_dotu(v9ses)) {
1174 unsigned int i_nlink;
1175 /*
1176 * Hadlink support got added later to the .u extension.
1177 * So there can be a server out there that doesn't
1178 * support this even with .u extension. That would
1179 * just leave us with stat->extension being an empty
1180 * string, though.
1181 */
1182 /* HARDLINKCOUNT %u */
1183 if (sscanf(stat->extension,
1184 " HARDLINKCOUNT %u", &i_nlink) == 1)
1185 set_nlink(inode, i_nlink);
1186 }
1187 }
1188 mode = p9mode2perm(v9ses, stat);
1189 mode |= inode->i_mode & ~S_IALLUGO;
1190 inode->i_mode = mode;
1191
1192 if (!(flags & V9FS_STAT2INODE_KEEP_ISIZE))
1193 v9fs_i_size_write(inode, stat->length);
1194 /* not real number of blocks, but 512 byte ones ... */
1195 inode->i_blocks = (stat->length + 512 - 1) >> 9;
1196 v9inode->cache_validity &= ~V9FS_INO_INVALID_ATTR;
1197 }
1198
1199 /**
1200 * v9fs_qid2ino - convert qid into inode number
1201 * @qid: qid to hash
1202 *
1203 * BUG: potential for inode number collisions?
1204 */
1205
v9fs_qid2ino(struct p9_qid * qid)1206 ino_t v9fs_qid2ino(struct p9_qid *qid)
1207 {
1208 u64 path = qid->path + 2;
1209 ino_t i = 0;
1210
1211 if (sizeof(ino_t) == sizeof(path))
1212 memcpy(&i, &path, sizeof(ino_t));
1213 else
1214 i = (ino_t) (path ^ (path >> 32));
1215
1216 return i;
1217 }
1218
1219 /**
1220 * v9fs_vfs_get_link - follow a symlink path
1221 * @dentry: dentry for symlink
1222 * @inode: inode for symlink
1223 * @done: delayed call for when we are done with the return value
1224 */
1225
v9fs_vfs_get_link(struct dentry * dentry,struct inode * inode,struct delayed_call * done)1226 static const char *v9fs_vfs_get_link(struct dentry *dentry,
1227 struct inode *inode,
1228 struct delayed_call *done)
1229 {
1230 struct v9fs_session_info *v9ses;
1231 struct p9_fid *fid;
1232 struct p9_wstat *st;
1233 char *res;
1234
1235 if (!dentry)
1236 return ERR_PTR(-ECHILD);
1237
1238 v9ses = v9fs_dentry2v9ses(dentry);
1239 if (!v9fs_proto_dotu(v9ses))
1240 return ERR_PTR(-EBADF);
1241
1242 p9_debug(P9_DEBUG_VFS, "%pd\n", dentry);
1243 fid = v9fs_fid_lookup(dentry);
1244
1245 if (IS_ERR(fid))
1246 return ERR_CAST(fid);
1247
1248 st = p9_client_stat(fid);
1249 p9_fid_put(fid);
1250 if (IS_ERR(st))
1251 return ERR_CAST(st);
1252
1253 if (!(st->mode & P9_DMSYMLINK)) {
1254 p9stat_free(st);
1255 kfree(st);
1256 return ERR_PTR(-EINVAL);
1257 }
1258 res = st->extension;
1259 st->extension = NULL;
1260 if (strlen(res) >= PATH_MAX)
1261 res[PATH_MAX - 1] = '\0';
1262
1263 p9stat_free(st);
1264 kfree(st);
1265 set_delayed_call(done, kfree_link, res);
1266 return res;
1267 }
1268
1269 /**
1270 * v9fs_vfs_mkspecial - create a special file
1271 * @dir: inode to create special file in
1272 * @dentry: dentry to create
1273 * @perm: mode to create special file
1274 * @extension: 9p2000.u format extension string representing special file
1275 *
1276 */
1277
v9fs_vfs_mkspecial(struct inode * dir,struct dentry * dentry,u32 perm,const char * extension)1278 static int v9fs_vfs_mkspecial(struct inode *dir, struct dentry *dentry,
1279 u32 perm, const char *extension)
1280 {
1281 struct p9_fid *fid;
1282 struct v9fs_session_info *v9ses;
1283
1284 v9ses = v9fs_inode2v9ses(dir);
1285 if (!v9fs_proto_dotu(v9ses)) {
1286 p9_debug(P9_DEBUG_ERROR, "not extended\n");
1287 return -EPERM;
1288 }
1289
1290 fid = v9fs_create(v9ses, dir, dentry, (char *) extension, perm,
1291 P9_OREAD);
1292 if (IS_ERR(fid))
1293 return PTR_ERR(fid);
1294
1295 v9fs_invalidate_inode_attr(dir);
1296 p9_fid_put(fid);
1297 return 0;
1298 }
1299
1300 /**
1301 * v9fs_vfs_symlink - helper function to create symlinks
1302 * @idmap: idmap of the mount
1303 * @dir: directory inode containing symlink
1304 * @dentry: dentry for symlink
1305 * @symname: symlink data
1306 *
1307 * See Also: 9P2000.u RFC for more information
1308 *
1309 */
1310
1311 static int
v9fs_vfs_symlink(struct mnt_idmap * idmap,struct inode * dir,struct dentry * dentry,const char * symname)1312 v9fs_vfs_symlink(struct mnt_idmap *idmap, struct inode *dir,
1313 struct dentry *dentry, const char *symname)
1314 {
1315 p9_debug(P9_DEBUG_VFS, " %lu,%pd,%s\n",
1316 dir->i_ino, dentry, symname);
1317
1318 return v9fs_vfs_mkspecial(dir, dentry, P9_DMSYMLINK, symname);
1319 }
1320
1321 #define U32_MAX_DIGITS 10
1322
1323 /**
1324 * v9fs_vfs_link - create a hardlink
1325 * @old_dentry: dentry for file to link to
1326 * @dir: inode destination for new link
1327 * @dentry: dentry for link
1328 *
1329 */
1330
1331 static int
v9fs_vfs_link(struct dentry * old_dentry,struct inode * dir,struct dentry * dentry)1332 v9fs_vfs_link(struct dentry *old_dentry, struct inode *dir,
1333 struct dentry *dentry)
1334 {
1335 int retval;
1336 char name[1 + U32_MAX_DIGITS + 2]; /* sign + number + \n + \0 */
1337 struct p9_fid *oldfid;
1338
1339 p9_debug(P9_DEBUG_VFS, " %lu,%pd,%pd\n",
1340 dir->i_ino, dentry, old_dentry);
1341
1342 oldfid = v9fs_fid_clone(old_dentry);
1343 if (IS_ERR(oldfid))
1344 return PTR_ERR(oldfid);
1345
1346 sprintf(name, "%d\n", oldfid->fid);
1347 retval = v9fs_vfs_mkspecial(dir, dentry, P9_DMLINK, name);
1348 if (!retval) {
1349 v9fs_refresh_inode(oldfid, d_inode(old_dentry));
1350 v9fs_invalidate_inode_attr(dir);
1351 }
1352 p9_fid_put(oldfid);
1353 return retval;
1354 }
1355
1356 /**
1357 * v9fs_vfs_mknod - create a special file
1358 * @idmap: idmap of the mount
1359 * @dir: inode destination for new link
1360 * @dentry: dentry for file
1361 * @mode: mode for creation
1362 * @rdev: device associated with special file
1363 *
1364 */
1365
1366 static int
v9fs_vfs_mknod(struct mnt_idmap * idmap,struct inode * dir,struct dentry * dentry,umode_t mode,dev_t rdev)1367 v9fs_vfs_mknod(struct mnt_idmap *idmap, struct inode *dir,
1368 struct dentry *dentry, umode_t mode, dev_t rdev)
1369 {
1370 struct v9fs_session_info *v9ses = v9fs_inode2v9ses(dir);
1371 int retval;
1372 char name[2 + U32_MAX_DIGITS + 1 + U32_MAX_DIGITS + 1];
1373 u32 perm;
1374
1375 p9_debug(P9_DEBUG_VFS, " %lu,%pd mode: %x MAJOR: %u MINOR: %u\n",
1376 dir->i_ino, dentry, mode,
1377 MAJOR(rdev), MINOR(rdev));
1378
1379 /* build extension */
1380 if (S_ISBLK(mode))
1381 sprintf(name, "b %u %u", MAJOR(rdev), MINOR(rdev));
1382 else if (S_ISCHR(mode))
1383 sprintf(name, "c %u %u", MAJOR(rdev), MINOR(rdev));
1384 else
1385 *name = 0;
1386
1387 perm = unixmode2p9mode(v9ses, mode);
1388 retval = v9fs_vfs_mkspecial(dir, dentry, perm, name);
1389
1390 return retval;
1391 }
1392
v9fs_refresh_inode(struct p9_fid * fid,struct inode * inode)1393 int v9fs_refresh_inode(struct p9_fid *fid, struct inode *inode)
1394 {
1395 int umode;
1396 dev_t rdev;
1397 struct p9_wstat *st;
1398 struct v9fs_session_info *v9ses;
1399 unsigned int flags;
1400
1401 v9ses = v9fs_inode2v9ses(inode);
1402 st = p9_client_stat(fid);
1403 if (IS_ERR(st))
1404 return PTR_ERR(st);
1405 /*
1406 * Don't update inode if the file type is different
1407 */
1408 umode = p9mode2unixmode(v9ses, st, &rdev);
1409 if (inode_wrong_type(inode, umode))
1410 goto out;
1411
1412 /*
1413 * We don't want to refresh inode->i_size,
1414 * because we may have cached data
1415 */
1416 flags = (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) ?
1417 V9FS_STAT2INODE_KEEP_ISIZE : 0;
1418 v9fs_stat2inode(st, inode, inode->i_sb, flags);
1419 out:
1420 p9stat_free(st);
1421 kfree(st);
1422 return 0;
1423 }
1424
1425 static const struct inode_operations v9fs_dir_inode_operations_dotu = {
1426 .create = v9fs_vfs_create,
1427 .lookup = v9fs_vfs_lookup,
1428 .atomic_open = v9fs_vfs_atomic_open,
1429 .symlink = v9fs_vfs_symlink,
1430 .link = v9fs_vfs_link,
1431 .unlink = v9fs_vfs_unlink,
1432 .mkdir = v9fs_vfs_mkdir,
1433 .rmdir = v9fs_vfs_rmdir,
1434 .mknod = v9fs_vfs_mknod,
1435 .rename = v9fs_vfs_rename,
1436 .getattr = v9fs_vfs_getattr,
1437 .setattr = v9fs_vfs_setattr,
1438 };
1439
1440 static const struct inode_operations v9fs_dir_inode_operations = {
1441 .create = v9fs_vfs_create,
1442 .lookup = v9fs_vfs_lookup,
1443 .atomic_open = v9fs_vfs_atomic_open,
1444 .unlink = v9fs_vfs_unlink,
1445 .mkdir = v9fs_vfs_mkdir,
1446 .rmdir = v9fs_vfs_rmdir,
1447 .mknod = v9fs_vfs_mknod,
1448 .rename = v9fs_vfs_rename,
1449 .getattr = v9fs_vfs_getattr,
1450 .setattr = v9fs_vfs_setattr,
1451 };
1452
1453 static const struct inode_operations v9fs_file_inode_operations = {
1454 .getattr = v9fs_vfs_getattr,
1455 .setattr = v9fs_vfs_setattr,
1456 };
1457
1458 static const struct inode_operations v9fs_symlink_inode_operations = {
1459 .get_link = v9fs_vfs_get_link,
1460 .getattr = v9fs_vfs_getattr,
1461 .setattr = v9fs_vfs_setattr,
1462 };
1463
1464