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
33 static const struct inode_operations v9fs_dir_inode_operations;
34 static const struct inode_operations v9fs_dir_inode_operations_dotu;
35 static const struct inode_operations v9fs_file_inode_operations;
36 static 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
unixmode2p9mode(struct v9fs_session_info * v9ses,umode_t mode)45 static 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 */
p9mode2perm(struct v9fs_session_info * v9ses,struct p9_wstat * stat)80 static 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 */
p9mode2unixmode(struct v9fs_session_info * v9ses,struct p9_wstat * stat,dev_t * rdev)107 static 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
v9fs_uflags2omode(int uflags,int extended)162 int 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
201 void
v9fs_blank_wstat(struct p9_wstat * wstat)202 v9fs_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 */
v9fs_alloc_inode(struct super_block * sb)227 struct 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
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 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_set_ctime_current(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 inode->i_fop = &v9fs_file_operations_dotl;
291 } else {
292 inode->i_op = &v9fs_file_inode_operations;
293 inode->i_fop = &v9fs_file_operations;
294 }
295
296 break;
297 case S_IFLNK:
298 if (!v9fs_proto_dotu(v9ses) && !v9fs_proto_dotl(v9ses)) {
299 p9_debug(P9_DEBUG_ERROR,
300 "extended modes used with legacy protocol\n");
301 err = -EINVAL;
302 goto error;
303 }
304
305 if (v9fs_proto_dotl(v9ses))
306 inode->i_op = &v9fs_symlink_inode_operations_dotl;
307 else
308 inode->i_op = &v9fs_symlink_inode_operations;
309
310 break;
311 case S_IFDIR:
312 inc_nlink(inode);
313 if (v9fs_proto_dotl(v9ses))
314 inode->i_op = &v9fs_dir_inode_operations_dotl;
315 else if (v9fs_proto_dotu(v9ses))
316 inode->i_op = &v9fs_dir_inode_operations_dotu;
317 else
318 inode->i_op = &v9fs_dir_inode_operations;
319
320 if (v9fs_proto_dotl(v9ses))
321 inode->i_fop = &v9fs_dir_operations_dotl;
322 else
323 inode->i_fop = &v9fs_dir_operations;
324
325 break;
326 default:
327 p9_debug(P9_DEBUG_ERROR, "BAD mode 0x%hx S_IFMT 0x%x\n",
328 mode, mode & S_IFMT);
329 err = -EINVAL;
330 goto error;
331 }
332 error:
333 return err;
334
335 }
336
337 /**
338 * v9fs_get_inode - helper function to setup an inode
339 * @sb: superblock
340 * @mode: mode to setup inode with
341 * @rdev: The device numbers to set
342 */
343
v9fs_get_inode(struct super_block * sb,umode_t mode,dev_t rdev)344 struct inode *v9fs_get_inode(struct super_block *sb, umode_t mode, dev_t rdev)
345 {
346 int err;
347 struct inode *inode;
348 struct v9fs_session_info *v9ses = sb->s_fs_info;
349
350 p9_debug(P9_DEBUG_VFS, "super block: %p mode: %ho\n", sb, mode);
351
352 inode = new_inode(sb);
353 if (!inode) {
354 pr_warn("%s (%d): Problem allocating inode\n",
355 __func__, task_pid_nr(current));
356 return ERR_PTR(-ENOMEM);
357 }
358 err = v9fs_init_inode(v9ses, inode, mode, rdev);
359 if (err) {
360 iput(inode);
361 return ERR_PTR(err);
362 }
363 v9fs_set_netfs_context(inode);
364 return inode;
365 }
366
367 /**
368 * v9fs_evict_inode - Remove an inode from the inode cache
369 * @inode: inode to release
370 *
371 */
v9fs_evict_inode(struct inode * inode)372 void v9fs_evict_inode(struct inode *inode)
373 {
374 struct v9fs_inode __maybe_unused *v9inode = V9FS_I(inode);
375 __le32 __maybe_unused version;
376
377 if (!is_bad_inode(inode)) {
378 truncate_inode_pages_final(&inode->i_data);
379
380 #ifdef CONFIG_9P_FSCACHE
381 version = cpu_to_le32(v9inode->qid.version);
382 fscache_clear_inode_writeback(v9fs_inode_cookie(v9inode), inode,
383 &version);
384 #endif
385 clear_inode(inode);
386 filemap_fdatawrite(&inode->i_data);
387
388 #ifdef CONFIG_9P_FSCACHE
389 if (v9fs_inode_cookie(v9inode))
390 fscache_relinquish_cookie(v9fs_inode_cookie(v9inode), false);
391 #endif
392 } else
393 clear_inode(inode);
394 }
395
v9fs_test_inode(struct inode * inode,void * data)396 static int v9fs_test_inode(struct inode *inode, void *data)
397 {
398 int umode;
399 dev_t rdev;
400 struct v9fs_inode *v9inode = V9FS_I(inode);
401 struct p9_wstat *st = (struct p9_wstat *)data;
402 struct v9fs_session_info *v9ses = v9fs_inode2v9ses(inode);
403
404 umode = p9mode2unixmode(v9ses, st, &rdev);
405 /* don't match inode of different type */
406 if (inode_wrong_type(inode, umode))
407 return 0;
408
409 /* compare qid details */
410 if (memcmp(&v9inode->qid.version,
411 &st->qid.version, sizeof(v9inode->qid.version)))
412 return 0;
413
414 if (v9inode->qid.type != st->qid.type)
415 return 0;
416
417 if (v9inode->qid.path != st->qid.path)
418 return 0;
419 return 1;
420 }
421
v9fs_test_new_inode(struct inode * inode,void * data)422 static int v9fs_test_new_inode(struct inode *inode, void *data)
423 {
424 return 0;
425 }
426
v9fs_set_inode(struct inode * inode,void * data)427 static int v9fs_set_inode(struct inode *inode, void *data)
428 {
429 struct v9fs_inode *v9inode = V9FS_I(inode);
430 struct p9_wstat *st = (struct p9_wstat *)data;
431
432 memcpy(&v9inode->qid, &st->qid, sizeof(st->qid));
433 return 0;
434 }
435
v9fs_qid_iget(struct super_block * sb,struct p9_qid * qid,struct p9_wstat * st,int new)436 static struct inode *v9fs_qid_iget(struct super_block *sb,
437 struct p9_qid *qid,
438 struct p9_wstat *st,
439 int new)
440 {
441 dev_t rdev;
442 int retval;
443 umode_t umode;
444 unsigned long i_ino;
445 struct inode *inode;
446 struct v9fs_session_info *v9ses = sb->s_fs_info;
447 int (*test)(struct inode *inode, void *data);
448
449 if (new)
450 test = v9fs_test_new_inode;
451 else
452 test = v9fs_test_inode;
453
454 i_ino = v9fs_qid2ino(qid);
455 inode = iget5_locked(sb, i_ino, test, v9fs_set_inode, st);
456 if (!inode)
457 return ERR_PTR(-ENOMEM);
458 if (!(inode->i_state & I_NEW))
459 return inode;
460 /*
461 * initialize the inode with the stat info
462 * FIXME!! we may need support for stale inodes
463 * later.
464 */
465 inode->i_ino = i_ino;
466 umode = p9mode2unixmode(v9ses, st, &rdev);
467 retval = v9fs_init_inode(v9ses, inode, umode, rdev);
468 if (retval)
469 goto error;
470
471 v9fs_stat2inode(st, inode, sb, 0);
472 v9fs_set_netfs_context(inode);
473 v9fs_cache_inode_get_cookie(inode);
474 unlock_new_inode(inode);
475 return inode;
476 error:
477 iget_failed(inode);
478 return ERR_PTR(retval);
479
480 }
481
482 struct inode *
v9fs_inode_from_fid(struct v9fs_session_info * v9ses,struct p9_fid * fid,struct super_block * sb,int new)483 v9fs_inode_from_fid(struct v9fs_session_info *v9ses, struct p9_fid *fid,
484 struct super_block *sb, int new)
485 {
486 struct p9_wstat *st;
487 struct inode *inode = NULL;
488
489 st = p9_client_stat(fid);
490 if (IS_ERR(st))
491 return ERR_CAST(st);
492
493 inode = v9fs_qid_iget(sb, &st->qid, st, new);
494 p9stat_free(st);
495 kfree(st);
496 return inode;
497 }
498
499 /**
500 * v9fs_at_to_dotl_flags- convert Linux specific AT flags to
501 * plan 9 AT flag.
502 * @flags: flags to convert
503 */
v9fs_at_to_dotl_flags(int flags)504 static int v9fs_at_to_dotl_flags(int flags)
505 {
506 int rflags = 0;
507
508 if (flags & AT_REMOVEDIR)
509 rflags |= P9_DOTL_AT_REMOVEDIR;
510
511 return rflags;
512 }
513
514 /**
515 * v9fs_dec_count - helper functon to drop i_nlink.
516 *
517 * If a directory had nlink <= 2 (including . and ..), then we should not drop
518 * the link count, which indicates the underlying exported fs doesn't maintain
519 * nlink accurately. e.g.
520 * - overlayfs sets nlink to 1 for merged dir
521 * - ext4 (with dir_nlink feature enabled) sets nlink to 1 if a dir has more
522 * than EXT4_LINK_MAX (65000) links.
523 *
524 * @inode: inode whose nlink is being dropped
525 */
v9fs_dec_count(struct inode * inode)526 static void v9fs_dec_count(struct inode *inode)
527 {
528 if (!S_ISDIR(inode->i_mode) || inode->i_nlink > 2)
529 drop_nlink(inode);
530 }
531
532 /**
533 * v9fs_remove - helper function to remove files and directories
534 * @dir: directory inode that is being deleted
535 * @dentry: dentry that is being deleted
536 * @flags: removing a directory
537 *
538 */
539
v9fs_remove(struct inode * dir,struct dentry * dentry,int flags)540 static int v9fs_remove(struct inode *dir, struct dentry *dentry, int flags)
541 {
542 struct inode *inode;
543 int retval = -EOPNOTSUPP;
544 struct p9_fid *v9fid, *dfid;
545 struct v9fs_session_info *v9ses;
546
547 p9_debug(P9_DEBUG_VFS, "inode: %p dentry: %p rmdir: %x\n",
548 dir, dentry, flags);
549
550 v9ses = v9fs_inode2v9ses(dir);
551 inode = d_inode(dentry);
552 dfid = v9fs_parent_fid(dentry);
553 if (IS_ERR(dfid)) {
554 retval = PTR_ERR(dfid);
555 p9_debug(P9_DEBUG_VFS, "fid lookup failed %d\n", retval);
556 return retval;
557 }
558 if (v9fs_proto_dotl(v9ses))
559 retval = p9_client_unlinkat(dfid, dentry->d_name.name,
560 v9fs_at_to_dotl_flags(flags));
561 p9_fid_put(dfid);
562 if (retval == -EOPNOTSUPP) {
563 /* Try the one based on path */
564 v9fid = v9fs_fid_clone(dentry);
565 if (IS_ERR(v9fid))
566 return PTR_ERR(v9fid);
567 retval = p9_client_remove(v9fid);
568 }
569 if (!retval) {
570 /*
571 * directories on unlink should have zero
572 * link count
573 */
574 if (flags & AT_REMOVEDIR) {
575 clear_nlink(inode);
576 v9fs_dec_count(dir);
577 } else
578 v9fs_dec_count(inode);
579
580 v9fs_invalidate_inode_attr(inode);
581 v9fs_invalidate_inode_attr(dir);
582
583 /* invalidate all fids associated with dentry */
584 /* NOTE: This will not include open fids */
585 dentry->d_op->d_release(dentry);
586 }
587 return retval;
588 }
589
590 /**
591 * v9fs_create - Create a file
592 * @v9ses: session information
593 * @dir: directory that dentry is being created in
594 * @dentry: dentry that is being created
595 * @extension: 9p2000.u extension string to support devices, etc.
596 * @perm: create permissions
597 * @mode: open mode
598 *
599 */
600 static struct p9_fid *
v9fs_create(struct v9fs_session_info * v9ses,struct inode * dir,struct dentry * dentry,char * extension,u32 perm,u8 mode)601 v9fs_create(struct v9fs_session_info *v9ses, struct inode *dir,
602 struct dentry *dentry, char *extension, u32 perm, u8 mode)
603 {
604 int err;
605 const unsigned char *name;
606 struct p9_fid *dfid, *ofid = NULL, *fid = NULL;
607 struct inode *inode;
608
609 p9_debug(P9_DEBUG_VFS, "name %pd\n", dentry);
610
611 name = dentry->d_name.name;
612 dfid = v9fs_parent_fid(dentry);
613 if (IS_ERR(dfid)) {
614 err = PTR_ERR(dfid);
615 p9_debug(P9_DEBUG_VFS, "fid lookup failed %d\n", err);
616 return ERR_PTR(err);
617 }
618
619 /* clone a fid to use for creation */
620 ofid = clone_fid(dfid);
621 if (IS_ERR(ofid)) {
622 err = PTR_ERR(ofid);
623 p9_debug(P9_DEBUG_VFS, "p9_client_walk failed %d\n", err);
624 goto error;
625 }
626
627 err = p9_client_fcreate(ofid, name, perm, mode, extension);
628 if (err < 0) {
629 p9_debug(P9_DEBUG_VFS, "p9_client_fcreate failed %d\n", err);
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 goto error;
641 }
642 /*
643 * instantiate inode and assign the unopened fid to the dentry
644 */
645 inode = v9fs_get_new_inode_from_fid(v9ses, fid, dir->i_sb);
646 if (IS_ERR(inode)) {
647 err = PTR_ERR(inode);
648 p9_debug(P9_DEBUG_VFS,
649 "inode creation failed %d\n", err);
650 goto error;
651 }
652 v9fs_fid_add(dentry, &fid);
653 d_instantiate(dentry, inode);
654 }
655 p9_fid_put(dfid);
656 return ofid;
657 error:
658 p9_fid_put(dfid);
659 p9_fid_put(ofid);
660 p9_fid_put(fid);
661 return ERR_PTR(err);
662 }
663
664 /**
665 * v9fs_vfs_create - VFS hook to create a regular file
666 * @idmap: idmap of the mount
667 * @dir: The parent directory
668 * @dentry: The name of file to be created
669 * @mode: The UNIX file mode to set
670 * @excl: True if the file must not yet exist
671 *
672 * open(.., O_CREAT) is handled in v9fs_vfs_atomic_open(). This is only called
673 * for mknod(2).
674 *
675 */
676
677 static int
v9fs_vfs_create(struct mnt_idmap * idmap,struct inode * dir,struct dentry * dentry,umode_t mode,bool excl)678 v9fs_vfs_create(struct mnt_idmap *idmap, struct inode *dir,
679 struct dentry *dentry, umode_t mode, bool excl)
680 {
681 struct v9fs_session_info *v9ses = v9fs_inode2v9ses(dir);
682 u32 perm = unixmode2p9mode(v9ses, mode);
683 struct p9_fid *fid;
684
685 /* P9_OEXCL? */
686 fid = v9fs_create(v9ses, dir, dentry, NULL, perm, P9_ORDWR);
687 if (IS_ERR(fid))
688 return PTR_ERR(fid);
689
690 v9fs_invalidate_inode_attr(dir);
691 p9_fid_put(fid);
692
693 return 0;
694 }
695
696 /**
697 * v9fs_vfs_mkdir - VFS mkdir hook to create a directory
698 * @idmap: idmap of the mount
699 * @dir: inode that is being unlinked
700 * @dentry: dentry that is being unlinked
701 * @mode: mode for new directory
702 *
703 */
704
v9fs_vfs_mkdir(struct mnt_idmap * idmap,struct inode * dir,struct dentry * dentry,umode_t mode)705 static int v9fs_vfs_mkdir(struct mnt_idmap *idmap, struct inode *dir,
706 struct dentry *dentry, umode_t mode)
707 {
708 int err;
709 u32 perm;
710 struct p9_fid *fid;
711 struct v9fs_session_info *v9ses;
712
713 p9_debug(P9_DEBUG_VFS, "name %pd\n", dentry);
714 err = 0;
715 v9ses = v9fs_inode2v9ses(dir);
716 perm = unixmode2p9mode(v9ses, mode | S_IFDIR);
717 fid = v9fs_create(v9ses, dir, dentry, NULL, perm, P9_OREAD);
718 if (IS_ERR(fid)) {
719 err = PTR_ERR(fid);
720 fid = NULL;
721 } else {
722 inc_nlink(dir);
723 v9fs_invalidate_inode_attr(dir);
724 }
725
726 if (fid)
727 p9_fid_put(fid);
728
729 return err;
730 }
731
732 /**
733 * v9fs_vfs_lookup - VFS lookup hook to "walk" to a new inode
734 * @dir: inode that is being walked from
735 * @dentry: dentry that is being walked to?
736 * @flags: lookup flags (unused)
737 *
738 */
739
v9fs_vfs_lookup(struct inode * dir,struct dentry * dentry,unsigned int flags)740 struct dentry *v9fs_vfs_lookup(struct inode *dir, struct dentry *dentry,
741 unsigned int flags)
742 {
743 struct dentry *res;
744 struct v9fs_session_info *v9ses;
745 struct p9_fid *dfid, *fid;
746 struct inode *inode;
747 const unsigned char *name;
748
749 p9_debug(P9_DEBUG_VFS, "dir: %p dentry: (%pd) %p flags: %x\n",
750 dir, dentry, dentry, flags);
751
752 if (dentry->d_name.len > NAME_MAX)
753 return ERR_PTR(-ENAMETOOLONG);
754
755 v9ses = v9fs_inode2v9ses(dir);
756 /* We can walk d_parent because we hold the dir->i_mutex */
757 dfid = v9fs_parent_fid(dentry);
758 if (IS_ERR(dfid))
759 return ERR_CAST(dfid);
760
761 /*
762 * Make sure we don't use a wrong inode due to parallel
763 * unlink. For cached mode create calls request for new
764 * inode. But with cache disabled, lookup should do this.
765 */
766 name = dentry->d_name.name;
767 fid = p9_client_walk(dfid, 1, &name, 1);
768 p9_fid_put(dfid);
769 if (fid == ERR_PTR(-ENOENT))
770 inode = NULL;
771 else if (IS_ERR(fid))
772 inode = ERR_CAST(fid);
773 else if (v9ses->cache & (CACHE_META|CACHE_LOOSE))
774 inode = v9fs_get_inode_from_fid(v9ses, fid, dir->i_sb);
775 else
776 inode = v9fs_get_new_inode_from_fid(v9ses, fid, dir->i_sb);
777 /*
778 * If we had a rename on the server and a parallel lookup
779 * for the new name, then make sure we instantiate with
780 * the new name. ie look up for a/b, while on server somebody
781 * moved b under k and client parallely did a lookup for
782 * k/b.
783 */
784 res = d_splice_alias(inode, dentry);
785 if (!IS_ERR(fid)) {
786 if (!res)
787 v9fs_fid_add(dentry, &fid);
788 else if (!IS_ERR(res))
789 v9fs_fid_add(res, &fid);
790 else
791 p9_fid_put(fid);
792 }
793 return res;
794 }
795
796 static int
v9fs_vfs_atomic_open(struct inode * dir,struct dentry * dentry,struct file * file,unsigned int flags,umode_t mode)797 v9fs_vfs_atomic_open(struct inode *dir, struct dentry *dentry,
798 struct file *file, unsigned int flags, umode_t mode)
799 {
800 int err;
801 u32 perm;
802 struct v9fs_inode __maybe_unused *v9inode;
803 struct v9fs_session_info *v9ses;
804 struct p9_fid *fid;
805 struct dentry *res = NULL;
806 struct inode *inode;
807 int p9_omode;
808
809 if (d_in_lookup(dentry)) {
810 res = v9fs_vfs_lookup(dir, dentry, 0);
811 if (IS_ERR(res))
812 return PTR_ERR(res);
813
814 if (res)
815 dentry = res;
816 }
817
818 /* Only creates */
819 if (!(flags & O_CREAT) || d_really_is_positive(dentry))
820 return finish_no_open(file, res);
821
822 v9ses = v9fs_inode2v9ses(dir);
823 perm = unixmode2p9mode(v9ses, mode);
824 p9_omode = v9fs_uflags2omode(flags, v9fs_proto_dotu(v9ses));
825
826 if ((v9ses->cache & CACHE_WRITEBACK) && (p9_omode & P9_OWRITE)) {
827 p9_omode = (p9_omode & ~P9_OWRITE) | P9_ORDWR;
828 p9_debug(P9_DEBUG_CACHE,
829 "write-only file with writeback enabled, creating w/ O_RDWR\n");
830 }
831 fid = v9fs_create(v9ses, dir, dentry, NULL, perm, p9_omode);
832 if (IS_ERR(fid)) {
833 err = PTR_ERR(fid);
834 goto error;
835 }
836
837 v9fs_invalidate_inode_attr(dir);
838 inode = d_inode(dentry);
839 v9inode = V9FS_I(inode);
840 err = finish_open(file, dentry, generic_file_open);
841 if (err)
842 goto error;
843
844 file->private_data = fid;
845 #ifdef CONFIG_9P_FSCACHE
846 if (v9ses->cache & CACHE_FSCACHE)
847 fscache_use_cookie(v9fs_inode_cookie(v9inode),
848 file->f_mode & FMODE_WRITE);
849 #endif
850
851 v9fs_fid_add_modes(fid, v9ses->flags, v9ses->cache, file->f_flags);
852 v9fs_open_fid_add(inode, &fid);
853
854 file->f_mode |= FMODE_CREATED;
855 out:
856 dput(res);
857 return err;
858
859 error:
860 p9_fid_put(fid);
861 goto out;
862 }
863
864 /**
865 * v9fs_vfs_unlink - VFS unlink hook to delete an inode
866 * @i: inode that is being unlinked
867 * @d: dentry that is being unlinked
868 *
869 */
870
v9fs_vfs_unlink(struct inode * i,struct dentry * d)871 int v9fs_vfs_unlink(struct inode *i, struct dentry *d)
872 {
873 return v9fs_remove(i, d, 0);
874 }
875
876 /**
877 * v9fs_vfs_rmdir - VFS unlink hook to delete a directory
878 * @i: inode that is being unlinked
879 * @d: dentry that is being unlinked
880 *
881 */
882
v9fs_vfs_rmdir(struct inode * i,struct dentry * d)883 int v9fs_vfs_rmdir(struct inode *i, struct dentry *d)
884 {
885 return v9fs_remove(i, d, AT_REMOVEDIR);
886 }
887
888 /**
889 * v9fs_vfs_rename - VFS hook to rename an inode
890 * @idmap: The idmap of the mount
891 * @old_dir: old dir inode
892 * @old_dentry: old dentry
893 * @new_dir: new dir inode
894 * @new_dentry: new dentry
895 * @flags: RENAME_* flags
896 *
897 */
898
899 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)900 v9fs_vfs_rename(struct mnt_idmap *idmap, struct inode *old_dir,
901 struct dentry *old_dentry, struct inode *new_dir,
902 struct dentry *new_dentry, unsigned int flags)
903 {
904 int retval;
905 struct inode *old_inode;
906 struct inode *new_inode;
907 struct v9fs_session_info *v9ses;
908 struct p9_fid *oldfid = NULL, *dfid = NULL;
909 struct p9_fid *olddirfid = NULL;
910 struct p9_fid *newdirfid = NULL;
911 struct p9_wstat wstat;
912
913 if (flags)
914 return -EINVAL;
915
916 p9_debug(P9_DEBUG_VFS, "\n");
917 old_inode = d_inode(old_dentry);
918 new_inode = d_inode(new_dentry);
919 v9ses = v9fs_inode2v9ses(old_inode);
920 oldfid = v9fs_fid_lookup(old_dentry);
921 if (IS_ERR(oldfid))
922 return PTR_ERR(oldfid);
923
924 dfid = v9fs_parent_fid(old_dentry);
925 olddirfid = clone_fid(dfid);
926 p9_fid_put(dfid);
927 dfid = NULL;
928
929 if (IS_ERR(olddirfid)) {
930 retval = PTR_ERR(olddirfid);
931 goto error;
932 }
933
934 dfid = v9fs_parent_fid(new_dentry);
935 newdirfid = clone_fid(dfid);
936 p9_fid_put(dfid);
937 dfid = NULL;
938
939 if (IS_ERR(newdirfid)) {
940 retval = PTR_ERR(newdirfid);
941 goto error;
942 }
943
944 down_write(&v9ses->rename_sem);
945 if (v9fs_proto_dotl(v9ses)) {
946 retval = p9_client_renameat(olddirfid, old_dentry->d_name.name,
947 newdirfid, new_dentry->d_name.name);
948 if (retval == -EOPNOTSUPP)
949 retval = p9_client_rename(oldfid, newdirfid,
950 new_dentry->d_name.name);
951 if (retval != -EOPNOTSUPP)
952 goto error_locked;
953 }
954 if (old_dentry->d_parent != new_dentry->d_parent) {
955 /*
956 * 9P .u can only handle file rename in the same directory
957 */
958
959 p9_debug(P9_DEBUG_ERROR, "old dir and new dir are different\n");
960 retval = -EXDEV;
961 goto error_locked;
962 }
963 v9fs_blank_wstat(&wstat);
964 wstat.muid = v9ses->uname;
965 wstat.name = new_dentry->d_name.name;
966 retval = p9_client_wstat(oldfid, &wstat);
967
968 error_locked:
969 if (!retval) {
970 if (new_inode) {
971 if (S_ISDIR(new_inode->i_mode))
972 clear_nlink(new_inode);
973 else
974 v9fs_dec_count(new_inode);
975 }
976 if (S_ISDIR(old_inode->i_mode)) {
977 if (!new_inode)
978 inc_nlink(new_dir);
979 v9fs_dec_count(old_dir);
980 }
981 v9fs_invalidate_inode_attr(old_inode);
982 v9fs_invalidate_inode_attr(old_dir);
983 v9fs_invalidate_inode_attr(new_dir);
984
985 /* successful rename */
986 d_move(old_dentry, new_dentry);
987 }
988 up_write(&v9ses->rename_sem);
989
990 error:
991 p9_fid_put(newdirfid);
992 p9_fid_put(olddirfid);
993 p9_fid_put(oldfid);
994 return retval;
995 }
996
997 /**
998 * v9fs_vfs_getattr - retrieve file metadata
999 * @idmap: idmap of the mount
1000 * @path: Object to query
1001 * @stat: metadata structure to populate
1002 * @request_mask: Mask of STATX_xxx flags indicating the caller's interests
1003 * @flags: AT_STATX_xxx setting
1004 *
1005 */
1006
1007 static int
v9fs_vfs_getattr(struct mnt_idmap * idmap,const struct path * path,struct kstat * stat,u32 request_mask,unsigned int flags)1008 v9fs_vfs_getattr(struct mnt_idmap *idmap, const struct path *path,
1009 struct kstat *stat, u32 request_mask, unsigned int flags)
1010 {
1011 struct dentry *dentry = path->dentry;
1012 struct inode *inode = d_inode(dentry);
1013 struct v9fs_session_info *v9ses;
1014 struct p9_fid *fid;
1015 struct p9_wstat *st;
1016
1017 p9_debug(P9_DEBUG_VFS, "dentry: %p\n", dentry);
1018 v9ses = v9fs_dentry2v9ses(dentry);
1019 if (v9ses->cache & (CACHE_META|CACHE_LOOSE)) {
1020 generic_fillattr(&nop_mnt_idmap, request_mask, inode, stat);
1021 return 0;
1022 } else if (v9ses->cache & CACHE_WRITEBACK) {
1023 if (S_ISREG(inode->i_mode)) {
1024 int retval = filemap_fdatawrite(inode->i_mapping);
1025
1026 if (retval)
1027 p9_debug(P9_DEBUG_ERROR,
1028 "flushing writeback during getattr returned %d\n", retval);
1029 }
1030 }
1031 fid = v9fs_fid_lookup(dentry);
1032 if (IS_ERR(fid))
1033 return PTR_ERR(fid);
1034
1035 st = p9_client_stat(fid);
1036 p9_fid_put(fid);
1037 if (IS_ERR(st))
1038 return PTR_ERR(st);
1039
1040 v9fs_stat2inode(st, d_inode(dentry), dentry->d_sb, 0);
1041 generic_fillattr(&nop_mnt_idmap, request_mask, d_inode(dentry), stat);
1042
1043 p9stat_free(st);
1044 kfree(st);
1045 return 0;
1046 }
1047
1048 /**
1049 * v9fs_vfs_setattr - set file metadata
1050 * @idmap: idmap of the mount
1051 * @dentry: file whose metadata to set
1052 * @iattr: metadata assignment structure
1053 *
1054 */
1055
v9fs_vfs_setattr(struct mnt_idmap * idmap,struct dentry * dentry,struct iattr * iattr)1056 static int v9fs_vfs_setattr(struct mnt_idmap *idmap,
1057 struct dentry *dentry, struct iattr *iattr)
1058 {
1059 int retval, use_dentry = 0;
1060 struct inode *inode = d_inode(dentry);
1061 struct v9fs_session_info *v9ses;
1062 struct p9_fid *fid = NULL;
1063 struct p9_wstat wstat;
1064
1065 p9_debug(P9_DEBUG_VFS, "\n");
1066 retval = setattr_prepare(&nop_mnt_idmap, dentry, iattr);
1067 if (retval)
1068 return retval;
1069
1070 v9ses = v9fs_dentry2v9ses(dentry);
1071 if (iattr->ia_valid & ATTR_FILE) {
1072 fid = iattr->ia_file->private_data;
1073 WARN_ON(!fid);
1074 }
1075 if (!fid) {
1076 fid = v9fs_fid_lookup(dentry);
1077 use_dentry = 1;
1078 }
1079 if (IS_ERR(fid))
1080 return PTR_ERR(fid);
1081
1082 v9fs_blank_wstat(&wstat);
1083 if (iattr->ia_valid & ATTR_MODE)
1084 wstat.mode = unixmode2p9mode(v9ses, iattr->ia_mode);
1085
1086 if (iattr->ia_valid & ATTR_MTIME)
1087 wstat.mtime = iattr->ia_mtime.tv_sec;
1088
1089 if (iattr->ia_valid & ATTR_ATIME)
1090 wstat.atime = iattr->ia_atime.tv_sec;
1091
1092 if (iattr->ia_valid & ATTR_SIZE)
1093 wstat.length = iattr->ia_size;
1094
1095 if (v9fs_proto_dotu(v9ses)) {
1096 if (iattr->ia_valid & ATTR_UID)
1097 wstat.n_uid = iattr->ia_uid;
1098
1099 if (iattr->ia_valid & ATTR_GID)
1100 wstat.n_gid = iattr->ia_gid;
1101 }
1102
1103 /* Write all dirty data */
1104 if (d_is_reg(dentry)) {
1105 retval = filemap_fdatawrite(inode->i_mapping);
1106 if (retval)
1107 p9_debug(P9_DEBUG_ERROR,
1108 "flushing writeback during setattr returned %d\n", retval);
1109 }
1110
1111 retval = p9_client_wstat(fid, &wstat);
1112
1113 if (use_dentry)
1114 p9_fid_put(fid);
1115
1116 if (retval < 0)
1117 return retval;
1118
1119 if ((iattr->ia_valid & ATTR_SIZE) &&
1120 iattr->ia_size != i_size_read(inode)) {
1121 truncate_setsize(inode, iattr->ia_size);
1122 truncate_pagecache(inode, iattr->ia_size);
1123
1124 #ifdef CONFIG_9P_FSCACHE
1125 if (v9ses->cache & CACHE_FSCACHE) {
1126 struct v9fs_inode *v9inode = V9FS_I(inode);
1127
1128 fscache_resize_cookie(v9fs_inode_cookie(v9inode), iattr->ia_size);
1129 }
1130 #endif
1131 }
1132
1133 v9fs_invalidate_inode_attr(inode);
1134
1135 setattr_copy(&nop_mnt_idmap, inode, iattr);
1136 mark_inode_dirty(inode);
1137 return 0;
1138 }
1139
1140 /**
1141 * v9fs_stat2inode - populate an inode structure with mistat info
1142 * @stat: Plan 9 metadata (mistat) structure
1143 * @inode: inode to populate
1144 * @sb: superblock of filesystem
1145 * @flags: control flags (e.g. V9FS_STAT2INODE_KEEP_ISIZE)
1146 *
1147 */
1148
1149 void
v9fs_stat2inode(struct p9_wstat * stat,struct inode * inode,struct super_block * sb,unsigned int flags)1150 v9fs_stat2inode(struct p9_wstat *stat, struct inode *inode,
1151 struct super_block *sb, unsigned int flags)
1152 {
1153 umode_t mode;
1154 struct v9fs_session_info *v9ses = sb->s_fs_info;
1155 struct v9fs_inode *v9inode = V9FS_I(inode);
1156
1157 set_nlink(inode, 1);
1158
1159 inode->i_atime.tv_sec = stat->atime;
1160 inode->i_mtime.tv_sec = stat->mtime;
1161 inode_set_ctime(inode, stat->mtime, 0);
1162
1163 inode->i_uid = v9ses->dfltuid;
1164 inode->i_gid = v9ses->dfltgid;
1165
1166 if (v9fs_proto_dotu(v9ses)) {
1167 inode->i_uid = stat->n_uid;
1168 inode->i_gid = stat->n_gid;
1169 }
1170 if ((S_ISREG(inode->i_mode)) || (S_ISDIR(inode->i_mode))) {
1171 if (v9fs_proto_dotu(v9ses)) {
1172 unsigned int i_nlink;
1173 /*
1174 * Hadlink support got added later to the .u extension.
1175 * So there can be a server out there that doesn't
1176 * support this even with .u extension. That would
1177 * just leave us with stat->extension being an empty
1178 * string, though.
1179 */
1180 /* HARDLINKCOUNT %u */
1181 if (sscanf(stat->extension,
1182 " HARDLINKCOUNT %u", &i_nlink) == 1)
1183 set_nlink(inode, i_nlink);
1184 }
1185 }
1186 mode = p9mode2perm(v9ses, stat);
1187 mode |= inode->i_mode & ~S_IALLUGO;
1188 inode->i_mode = mode;
1189
1190 if (!(flags & V9FS_STAT2INODE_KEEP_ISIZE))
1191 v9fs_i_size_write(inode, stat->length);
1192 /* not real number of blocks, but 512 byte ones ... */
1193 inode->i_blocks = (stat->length + 512 - 1) >> 9;
1194 v9inode->cache_validity &= ~V9FS_INO_INVALID_ATTR;
1195 }
1196
1197 /**
1198 * v9fs_qid2ino - convert qid into inode number
1199 * @qid: qid to hash
1200 *
1201 * BUG: potential for inode number collisions?
1202 */
1203
v9fs_qid2ino(struct p9_qid * qid)1204 ino_t v9fs_qid2ino(struct p9_qid *qid)
1205 {
1206 u64 path = qid->path + 2;
1207 ino_t i = 0;
1208
1209 if (sizeof(ino_t) == sizeof(path))
1210 memcpy(&i, &path, sizeof(ino_t));
1211 else
1212 i = (ino_t) (path ^ (path >> 32));
1213
1214 return i;
1215 }
1216
1217 /**
1218 * v9fs_vfs_get_link - follow a symlink path
1219 * @dentry: dentry for symlink
1220 * @inode: inode for symlink
1221 * @done: delayed call for when we are done with the return value
1222 */
1223
v9fs_vfs_get_link(struct dentry * dentry,struct inode * inode,struct delayed_call * done)1224 static const char *v9fs_vfs_get_link(struct dentry *dentry,
1225 struct inode *inode,
1226 struct delayed_call *done)
1227 {
1228 struct v9fs_session_info *v9ses;
1229 struct p9_fid *fid;
1230 struct p9_wstat *st;
1231 char *res;
1232
1233 if (!dentry)
1234 return ERR_PTR(-ECHILD);
1235
1236 v9ses = v9fs_dentry2v9ses(dentry);
1237 if (!v9fs_proto_dotu(v9ses))
1238 return ERR_PTR(-EBADF);
1239
1240 p9_debug(P9_DEBUG_VFS, "%pd\n", dentry);
1241 fid = v9fs_fid_lookup(dentry);
1242
1243 if (IS_ERR(fid))
1244 return ERR_CAST(fid);
1245
1246 st = p9_client_stat(fid);
1247 p9_fid_put(fid);
1248 if (IS_ERR(st))
1249 return ERR_CAST(st);
1250
1251 if (!(st->mode & P9_DMSYMLINK)) {
1252 p9stat_free(st);
1253 kfree(st);
1254 return ERR_PTR(-EINVAL);
1255 }
1256 res = st->extension;
1257 st->extension = NULL;
1258 if (strlen(res) >= PATH_MAX)
1259 res[PATH_MAX - 1] = '\0';
1260
1261 p9stat_free(st);
1262 kfree(st);
1263 set_delayed_call(done, kfree_link, res);
1264 return res;
1265 }
1266
1267 /**
1268 * v9fs_vfs_mkspecial - create a special file
1269 * @dir: inode to create special file in
1270 * @dentry: dentry to create
1271 * @perm: mode to create special file
1272 * @extension: 9p2000.u format extension string representing special file
1273 *
1274 */
1275
v9fs_vfs_mkspecial(struct inode * dir,struct dentry * dentry,u32 perm,const char * extension)1276 static int v9fs_vfs_mkspecial(struct inode *dir, struct dentry *dentry,
1277 u32 perm, const char *extension)
1278 {
1279 struct p9_fid *fid;
1280 struct v9fs_session_info *v9ses;
1281
1282 v9ses = v9fs_inode2v9ses(dir);
1283 if (!v9fs_proto_dotu(v9ses)) {
1284 p9_debug(P9_DEBUG_ERROR, "not extended\n");
1285 return -EPERM;
1286 }
1287
1288 fid = v9fs_create(v9ses, dir, dentry, (char *) extension, perm,
1289 P9_OREAD);
1290 if (IS_ERR(fid))
1291 return PTR_ERR(fid);
1292
1293 v9fs_invalidate_inode_attr(dir);
1294 p9_fid_put(fid);
1295 return 0;
1296 }
1297
1298 /**
1299 * v9fs_vfs_symlink - helper function to create symlinks
1300 * @idmap: idmap of the mount
1301 * @dir: directory inode containing symlink
1302 * @dentry: dentry for symlink
1303 * @symname: symlink data
1304 *
1305 * See Also: 9P2000.u RFC for more information
1306 *
1307 */
1308
1309 static int
v9fs_vfs_symlink(struct mnt_idmap * idmap,struct inode * dir,struct dentry * dentry,const char * symname)1310 v9fs_vfs_symlink(struct mnt_idmap *idmap, struct inode *dir,
1311 struct dentry *dentry, const char *symname)
1312 {
1313 p9_debug(P9_DEBUG_VFS, " %lu,%pd,%s\n",
1314 dir->i_ino, dentry, symname);
1315
1316 return v9fs_vfs_mkspecial(dir, dentry, P9_DMSYMLINK, symname);
1317 }
1318
1319 #define U32_MAX_DIGITS 10
1320
1321 /**
1322 * v9fs_vfs_link - create a hardlink
1323 * @old_dentry: dentry for file to link to
1324 * @dir: inode destination for new link
1325 * @dentry: dentry for link
1326 *
1327 */
1328
1329 static int
v9fs_vfs_link(struct dentry * old_dentry,struct inode * dir,struct dentry * dentry)1330 v9fs_vfs_link(struct dentry *old_dentry, struct inode *dir,
1331 struct dentry *dentry)
1332 {
1333 int retval;
1334 char name[1 + U32_MAX_DIGITS + 2]; /* sign + number + \n + \0 */
1335 struct p9_fid *oldfid;
1336
1337 p9_debug(P9_DEBUG_VFS, " %lu,%pd,%pd\n",
1338 dir->i_ino, dentry, old_dentry);
1339
1340 oldfid = v9fs_fid_clone(old_dentry);
1341 if (IS_ERR(oldfid))
1342 return PTR_ERR(oldfid);
1343
1344 sprintf(name, "%d\n", oldfid->fid);
1345 retval = v9fs_vfs_mkspecial(dir, dentry, P9_DMLINK, name);
1346 if (!retval) {
1347 v9fs_refresh_inode(oldfid, d_inode(old_dentry));
1348 v9fs_invalidate_inode_attr(dir);
1349 }
1350 p9_fid_put(oldfid);
1351 return retval;
1352 }
1353
1354 /**
1355 * v9fs_vfs_mknod - create a special file
1356 * @idmap: idmap of the mount
1357 * @dir: inode destination for new link
1358 * @dentry: dentry for file
1359 * @mode: mode for creation
1360 * @rdev: device associated with special file
1361 *
1362 */
1363
1364 static int
v9fs_vfs_mknod(struct mnt_idmap * idmap,struct inode * dir,struct dentry * dentry,umode_t mode,dev_t rdev)1365 v9fs_vfs_mknod(struct mnt_idmap *idmap, struct inode *dir,
1366 struct dentry *dentry, umode_t mode, dev_t rdev)
1367 {
1368 struct v9fs_session_info *v9ses = v9fs_inode2v9ses(dir);
1369 int retval;
1370 char name[2 + U32_MAX_DIGITS + 1 + U32_MAX_DIGITS + 1];
1371 u32 perm;
1372
1373 p9_debug(P9_DEBUG_VFS, " %lu,%pd mode: %x MAJOR: %u MINOR: %u\n",
1374 dir->i_ino, dentry, mode,
1375 MAJOR(rdev), MINOR(rdev));
1376
1377 /* build extension */
1378 if (S_ISBLK(mode))
1379 sprintf(name, "b %u %u", MAJOR(rdev), MINOR(rdev));
1380 else if (S_ISCHR(mode))
1381 sprintf(name, "c %u %u", MAJOR(rdev), MINOR(rdev));
1382 else
1383 *name = 0;
1384
1385 perm = unixmode2p9mode(v9ses, mode);
1386 retval = v9fs_vfs_mkspecial(dir, dentry, perm, name);
1387
1388 return retval;
1389 }
1390
v9fs_refresh_inode(struct p9_fid * fid,struct inode * inode)1391 int v9fs_refresh_inode(struct p9_fid *fid, struct inode *inode)
1392 {
1393 int umode;
1394 dev_t rdev;
1395 struct p9_wstat *st;
1396 struct v9fs_session_info *v9ses;
1397 unsigned int flags;
1398
1399 v9ses = v9fs_inode2v9ses(inode);
1400 st = p9_client_stat(fid);
1401 if (IS_ERR(st))
1402 return PTR_ERR(st);
1403 /*
1404 * Don't update inode if the file type is different
1405 */
1406 umode = p9mode2unixmode(v9ses, st, &rdev);
1407 if (inode_wrong_type(inode, umode))
1408 goto out;
1409
1410 /*
1411 * We don't want to refresh inode->i_size,
1412 * because we may have cached data
1413 */
1414 flags = (v9ses->cache & CACHE_LOOSE) ?
1415 V9FS_STAT2INODE_KEEP_ISIZE : 0;
1416 v9fs_stat2inode(st, inode, inode->i_sb, flags);
1417 out:
1418 p9stat_free(st);
1419 kfree(st);
1420 return 0;
1421 }
1422
1423 static const struct inode_operations v9fs_dir_inode_operations_dotu = {
1424 .create = v9fs_vfs_create,
1425 .lookup = v9fs_vfs_lookup,
1426 .atomic_open = v9fs_vfs_atomic_open,
1427 .symlink = v9fs_vfs_symlink,
1428 .link = v9fs_vfs_link,
1429 .unlink = v9fs_vfs_unlink,
1430 .mkdir = v9fs_vfs_mkdir,
1431 .rmdir = v9fs_vfs_rmdir,
1432 .mknod = v9fs_vfs_mknod,
1433 .rename = v9fs_vfs_rename,
1434 .getattr = v9fs_vfs_getattr,
1435 .setattr = v9fs_vfs_setattr,
1436 };
1437
1438 static const struct inode_operations v9fs_dir_inode_operations = {
1439 .create = v9fs_vfs_create,
1440 .lookup = v9fs_vfs_lookup,
1441 .atomic_open = v9fs_vfs_atomic_open,
1442 .unlink = v9fs_vfs_unlink,
1443 .mkdir = v9fs_vfs_mkdir,
1444 .rmdir = v9fs_vfs_rmdir,
1445 .mknod = v9fs_vfs_mknod,
1446 .rename = v9fs_vfs_rename,
1447 .getattr = v9fs_vfs_getattr,
1448 .setattr = v9fs_vfs_setattr,
1449 };
1450
1451 static const struct inode_operations v9fs_file_inode_operations = {
1452 .getattr = v9fs_vfs_getattr,
1453 .setattr = v9fs_vfs_setattr,
1454 };
1455
1456 static const struct inode_operations v9fs_symlink_inode_operations = {
1457 .get_link = v9fs_vfs_get_link,
1458 .getattr = v9fs_vfs_getattr,
1459 .setattr = v9fs_vfs_setattr,
1460 };
1461
1462