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/idr.h>
21 #include <linux/sched.h>
22 #include <linux/slab.h>
23 #include <linux/xattr.h>
24 #include <linux/posix_acl.h>
25 #include <net/9p/9p.h>
26 #include <net/9p/client.h>
27
28 #include "v9fs.h"
29 #include "v9fs_vfs.h"
30 #include "fid.h"
31 #include "cache.h"
32 #include "xattr.h"
33 #include "acl.h"
34
35 static const struct inode_operations v9fs_dir_inode_operations;
36 static const struct inode_operations v9fs_dir_inode_operations_dotu;
37 static const struct inode_operations v9fs_file_inode_operations;
38 static const struct inode_operations v9fs_symlink_inode_operations;
39
40 /**
41 * unixmode2p9mode - convert unix mode bits to plan 9
42 * @v9ses: v9fs session information
43 * @mode: mode to convert
44 *
45 */
46
unixmode2p9mode(struct v9fs_session_info * v9ses,umode_t mode)47 static u32 unixmode2p9mode(struct v9fs_session_info *v9ses, umode_t mode)
48 {
49 int res;
50
51 res = mode & 0777;
52 if (S_ISDIR(mode))
53 res |= P9_DMDIR;
54 if (v9fs_proto_dotu(v9ses)) {
55 if (v9ses->nodev == 0) {
56 if (S_ISSOCK(mode))
57 res |= P9_DMSOCKET;
58 if (S_ISFIFO(mode))
59 res |= P9_DMNAMEDPIPE;
60 if (S_ISBLK(mode))
61 res |= P9_DMDEVICE;
62 if (S_ISCHR(mode))
63 res |= P9_DMDEVICE;
64 }
65
66 if ((mode & S_ISUID) == S_ISUID)
67 res |= P9_DMSETUID;
68 if ((mode & S_ISGID) == S_ISGID)
69 res |= P9_DMSETGID;
70 if ((mode & S_ISVTX) == S_ISVTX)
71 res |= P9_DMSETVTX;
72 }
73 return res;
74 }
75
76 /**
77 * p9mode2perm- convert plan9 mode bits to unix permission bits
78 * @v9ses: v9fs session information
79 * @stat: p9_wstat from which mode need to be derived
80 *
81 */
p9mode2perm(struct v9fs_session_info * v9ses,struct p9_wstat * stat)82 static int p9mode2perm(struct v9fs_session_info *v9ses,
83 struct p9_wstat *stat)
84 {
85 int res;
86 int mode = stat->mode;
87
88 res = mode & S_IALLUGO;
89 if (v9fs_proto_dotu(v9ses)) {
90 if ((mode & P9_DMSETUID) == P9_DMSETUID)
91 res |= S_ISUID;
92
93 if ((mode & P9_DMSETGID) == P9_DMSETGID)
94 res |= S_ISGID;
95
96 if ((mode & P9_DMSETVTX) == P9_DMSETVTX)
97 res |= S_ISVTX;
98 }
99 return res;
100 }
101
102 /**
103 * p9mode2unixmode- convert plan9 mode bits to unix mode bits
104 * @v9ses: v9fs session information
105 * @stat: p9_wstat from which mode need to be derived
106 * @rdev: major number, minor number in case of device files.
107 *
108 */
p9mode2unixmode(struct v9fs_session_info * v9ses,struct p9_wstat * stat,dev_t * rdev)109 static umode_t p9mode2unixmode(struct v9fs_session_info *v9ses,
110 struct p9_wstat *stat, dev_t *rdev)
111 {
112 int res, r;
113 u32 mode = stat->mode;
114
115 *rdev = 0;
116 res = p9mode2perm(v9ses, stat);
117
118 if ((mode & P9_DMDIR) == P9_DMDIR)
119 res |= S_IFDIR;
120 else if ((mode & P9_DMSYMLINK) && (v9fs_proto_dotu(v9ses)))
121 res |= S_IFLNK;
122 else if ((mode & P9_DMSOCKET) && (v9fs_proto_dotu(v9ses))
123 && (v9ses->nodev == 0))
124 res |= S_IFSOCK;
125 else if ((mode & P9_DMNAMEDPIPE) && (v9fs_proto_dotu(v9ses))
126 && (v9ses->nodev == 0))
127 res |= S_IFIFO;
128 else if ((mode & P9_DMDEVICE) && (v9fs_proto_dotu(v9ses))
129 && (v9ses->nodev == 0)) {
130 char type = 0;
131 int major = -1, minor = -1;
132
133 r = sscanf(stat->extension, "%c %i %i", &type, &major, &minor);
134 if (r != 3) {
135 p9_debug(P9_DEBUG_ERROR,
136 "invalid device string, umode will be bogus: %s\n",
137 stat->extension);
138 return res;
139 }
140 switch (type) {
141 case 'c':
142 res |= S_IFCHR;
143 break;
144 case 'b':
145 res |= S_IFBLK;
146 break;
147 default:
148 p9_debug(P9_DEBUG_ERROR, "Unknown special type %c %s\n",
149 type, stat->extension);
150 }
151 *rdev = MKDEV(major, minor);
152 } else
153 res |= S_IFREG;
154
155 return res;
156 }
157
158 /**
159 * v9fs_uflags2omode- convert posix open flags to plan 9 mode bits
160 * @uflags: flags to convert
161 * @extended: if .u extensions are active
162 */
163
v9fs_uflags2omode(int uflags,int extended)164 int v9fs_uflags2omode(int uflags, int extended)
165 {
166 int ret;
167
168 ret = 0;
169 switch (uflags&3) {
170 default:
171 case O_RDONLY:
172 ret = P9_OREAD;
173 break;
174
175 case O_WRONLY:
176 ret = P9_OWRITE;
177 break;
178
179 case O_RDWR:
180 ret = P9_ORDWR;
181 break;
182 }
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->writeback_fid = NULL;
235 v9inode->cache_validity = 0;
236 mutex_init(&v9inode->v_mutex);
237 return &v9inode->netfs.inode;
238 }
239
240 /**
241 * v9fs_free_inode - destroy an inode
242 * @inode: The inode to be freed
243 */
244
v9fs_free_inode(struct inode * inode)245 void v9fs_free_inode(struct inode *inode)
246 {
247 kmem_cache_free(v9fs_inode_cache, V9FS_I(inode));
248 }
249
250 /*
251 * Set parameters for the netfs library
252 */
v9fs_set_netfs_context(struct inode * inode)253 static void v9fs_set_netfs_context(struct inode *inode)
254 {
255 struct v9fs_inode *v9inode = V9FS_I(inode);
256 netfs_inode_init(&v9inode->netfs, &v9fs_req_ops);
257 }
258
v9fs_init_inode(struct v9fs_session_info * v9ses,struct inode * inode,umode_t mode,dev_t rdev)259 int v9fs_init_inode(struct v9fs_session_info *v9ses,
260 struct inode *inode, umode_t mode, dev_t rdev)
261 {
262 int err = 0;
263
264 inode_init_owner(&init_user_ns, inode, NULL, mode);
265 inode->i_blocks = 0;
266 inode->i_rdev = rdev;
267 inode->i_atime = inode->i_mtime = inode->i_ctime = current_time(inode);
268 inode->i_mapping->a_ops = &v9fs_addr_operations;
269 inode->i_private = NULL;
270
271 switch (mode & S_IFMT) {
272 case S_IFIFO:
273 case S_IFBLK:
274 case S_IFCHR:
275 case S_IFSOCK:
276 if (v9fs_proto_dotl(v9ses)) {
277 inode->i_op = &v9fs_file_inode_operations_dotl;
278 } else if (v9fs_proto_dotu(v9ses)) {
279 inode->i_op = &v9fs_file_inode_operations;
280 } else {
281 p9_debug(P9_DEBUG_ERROR,
282 "special files without extended mode\n");
283 err = -EINVAL;
284 goto error;
285 }
286 init_special_inode(inode, inode->i_mode, inode->i_rdev);
287 break;
288 case S_IFREG:
289 if (v9fs_proto_dotl(v9ses)) {
290 inode->i_op = &v9fs_file_inode_operations_dotl;
291 if (v9ses->cache == CACHE_LOOSE ||
292 v9ses->cache == CACHE_FSCACHE)
293 inode->i_fop =
294 &v9fs_cached_file_operations_dotl;
295 else if (v9ses->cache == CACHE_MMAP)
296 inode->i_fop = &v9fs_mmap_file_operations_dotl;
297 else
298 inode->i_fop = &v9fs_file_operations_dotl;
299 } else {
300 inode->i_op = &v9fs_file_inode_operations;
301 if (v9ses->cache == CACHE_LOOSE ||
302 v9ses->cache == CACHE_FSCACHE)
303 inode->i_fop =
304 &v9fs_cached_file_operations;
305 else if (v9ses->cache == CACHE_MMAP)
306 inode->i_fop = &v9fs_mmap_file_operations;
307 else
308 inode->i_fop = &v9fs_file_operations;
309 }
310
311 break;
312 case S_IFLNK:
313 if (!v9fs_proto_dotu(v9ses) && !v9fs_proto_dotl(v9ses)) {
314 p9_debug(P9_DEBUG_ERROR,
315 "extended modes used with legacy protocol\n");
316 err = -EINVAL;
317 goto error;
318 }
319
320 if (v9fs_proto_dotl(v9ses))
321 inode->i_op = &v9fs_symlink_inode_operations_dotl;
322 else
323 inode->i_op = &v9fs_symlink_inode_operations;
324
325 break;
326 case S_IFDIR:
327 inc_nlink(inode);
328 if (v9fs_proto_dotl(v9ses))
329 inode->i_op = &v9fs_dir_inode_operations_dotl;
330 else if (v9fs_proto_dotu(v9ses))
331 inode->i_op = &v9fs_dir_inode_operations_dotu;
332 else
333 inode->i_op = &v9fs_dir_inode_operations;
334
335 if (v9fs_proto_dotl(v9ses))
336 inode->i_fop = &v9fs_dir_operations_dotl;
337 else
338 inode->i_fop = &v9fs_dir_operations;
339
340 break;
341 default:
342 p9_debug(P9_DEBUG_ERROR, "BAD mode 0x%hx S_IFMT 0x%x\n",
343 mode, mode & S_IFMT);
344 err = -EINVAL;
345 goto error;
346 }
347
348 v9fs_set_netfs_context(inode);
349 error:
350 return err;
351
352 }
353
354 /**
355 * v9fs_get_inode - helper function to setup an inode
356 * @sb: superblock
357 * @mode: mode to setup inode with
358 * @rdev: The device numbers to set
359 */
360
v9fs_get_inode(struct super_block * sb,umode_t mode,dev_t rdev)361 struct inode *v9fs_get_inode(struct super_block *sb, umode_t mode, dev_t rdev)
362 {
363 int err;
364 struct inode *inode;
365 struct v9fs_session_info *v9ses = sb->s_fs_info;
366
367 p9_debug(P9_DEBUG_VFS, "super block: %p mode: %ho\n", sb, mode);
368
369 inode = new_inode(sb);
370 if (!inode) {
371 pr_warn("%s (%d): Problem allocating inode\n",
372 __func__, task_pid_nr(current));
373 return ERR_PTR(-ENOMEM);
374 }
375 err = v9fs_init_inode(v9ses, inode, mode, rdev);
376 if (err) {
377 iput(inode);
378 return ERR_PTR(err);
379 }
380 return inode;
381 }
382
383 /**
384 * v9fs_evict_inode - Remove an inode from the inode cache
385 * @inode: inode to release
386 *
387 */
v9fs_evict_inode(struct inode * inode)388 void v9fs_evict_inode(struct inode *inode)
389 {
390 struct v9fs_inode *v9inode = V9FS_I(inode);
391 __le32 version;
392
393 truncate_inode_pages_final(&inode->i_data);
394 version = cpu_to_le32(v9inode->qid.version);
395 fscache_clear_inode_writeback(v9fs_inode_cookie(v9inode), inode,
396 &version);
397 clear_inode(inode);
398 filemap_fdatawrite(&inode->i_data);
399
400 fscache_relinquish_cookie(v9fs_inode_cookie(v9inode), false);
401 /* clunk the fid stashed in writeback_fid */
402 p9_fid_put(v9inode->writeback_fid);
403 v9inode->writeback_fid = NULL;
404 }
405
v9fs_test_inode(struct inode * inode,void * data)406 static int v9fs_test_inode(struct inode *inode, void *data)
407 {
408 int umode;
409 dev_t rdev;
410 struct v9fs_inode *v9inode = V9FS_I(inode);
411 struct p9_wstat *st = (struct p9_wstat *)data;
412 struct v9fs_session_info *v9ses = v9fs_inode2v9ses(inode);
413
414 umode = p9mode2unixmode(v9ses, st, &rdev);
415 /* don't match inode of different type */
416 if (inode_wrong_type(inode, umode))
417 return 0;
418
419 /* compare qid details */
420 if (memcmp(&v9inode->qid.version,
421 &st->qid.version, sizeof(v9inode->qid.version)))
422 return 0;
423
424 if (v9inode->qid.type != st->qid.type)
425 return 0;
426
427 if (v9inode->qid.path != st->qid.path)
428 return 0;
429 return 1;
430 }
431
v9fs_test_new_inode(struct inode * inode,void * data)432 static int v9fs_test_new_inode(struct inode *inode, void *data)
433 {
434 return 0;
435 }
436
v9fs_set_inode(struct inode * inode,void * data)437 static int v9fs_set_inode(struct inode *inode, void *data)
438 {
439 struct v9fs_inode *v9inode = V9FS_I(inode);
440 struct p9_wstat *st = (struct p9_wstat *)data;
441
442 memcpy(&v9inode->qid, &st->qid, sizeof(st->qid));
443 return 0;
444 }
445
v9fs_qid_iget(struct super_block * sb,struct p9_qid * qid,struct p9_wstat * st,int new)446 static struct inode *v9fs_qid_iget(struct super_block *sb,
447 struct p9_qid *qid,
448 struct p9_wstat *st,
449 int new)
450 {
451 dev_t rdev;
452 int retval;
453 umode_t umode;
454 unsigned long i_ino;
455 struct inode *inode;
456 struct v9fs_session_info *v9ses = sb->s_fs_info;
457 int (*test)(struct inode *inode, void *data);
458
459 if (new)
460 test = v9fs_test_new_inode;
461 else
462 test = v9fs_test_inode;
463
464 i_ino = v9fs_qid2ino(qid);
465 inode = iget5_locked(sb, i_ino, test, v9fs_set_inode, st);
466 if (!inode)
467 return ERR_PTR(-ENOMEM);
468 if (!(inode->i_state & I_NEW))
469 return inode;
470 /*
471 * initialize the inode with the stat info
472 * FIXME!! we may need support for stale inodes
473 * later.
474 */
475 inode->i_ino = i_ino;
476 umode = p9mode2unixmode(v9ses, st, &rdev);
477 retval = v9fs_init_inode(v9ses, inode, umode, rdev);
478 if (retval)
479 goto error;
480
481 v9fs_stat2inode(st, inode, sb, 0);
482 v9fs_cache_inode_get_cookie(inode);
483 unlock_new_inode(inode);
484 return inode;
485 error:
486 iget_failed(inode);
487 return ERR_PTR(retval);
488
489 }
490
491 struct inode *
v9fs_inode_from_fid(struct v9fs_session_info * v9ses,struct p9_fid * fid,struct super_block * sb,int new)492 v9fs_inode_from_fid(struct v9fs_session_info *v9ses, struct p9_fid *fid,
493 struct super_block *sb, int new)
494 {
495 struct p9_wstat *st;
496 struct inode *inode = NULL;
497
498 st = p9_client_stat(fid);
499 if (IS_ERR(st))
500 return ERR_CAST(st);
501
502 inode = v9fs_qid_iget(sb, &st->qid, st, new);
503 p9stat_free(st);
504 kfree(st);
505 return inode;
506 }
507
508 /**
509 * v9fs_at_to_dotl_flags- convert Linux specific AT flags to
510 * plan 9 AT flag.
511 * @flags: flags to convert
512 */
v9fs_at_to_dotl_flags(int flags)513 static int v9fs_at_to_dotl_flags(int flags)
514 {
515 int rflags = 0;
516
517 if (flags & AT_REMOVEDIR)
518 rflags |= P9_DOTL_AT_REMOVEDIR;
519
520 return rflags;
521 }
522
523 /**
524 * v9fs_dec_count - helper functon to drop i_nlink.
525 *
526 * If a directory had nlink <= 2 (including . and ..), then we should not drop
527 * the link count, which indicates the underlying exported fs doesn't maintain
528 * nlink accurately. e.g.
529 * - overlayfs sets nlink to 1 for merged dir
530 * - ext4 (with dir_nlink feature enabled) sets nlink to 1 if a dir has more
531 * than EXT4_LINK_MAX (65000) links.
532 *
533 * @inode: inode whose nlink is being dropped
534 */
v9fs_dec_count(struct inode * inode)535 static void v9fs_dec_count(struct inode *inode)
536 {
537 if (!S_ISDIR(inode->i_mode) || inode->i_nlink > 2)
538 drop_nlink(inode);
539 }
540
541 /**
542 * v9fs_remove - helper function to remove files and directories
543 * @dir: directory inode that is being deleted
544 * @dentry: dentry that is being deleted
545 * @flags: removing a directory
546 *
547 */
548
v9fs_remove(struct inode * dir,struct dentry * dentry,int flags)549 static int v9fs_remove(struct inode *dir, struct dentry *dentry, int flags)
550 {
551 struct inode *inode;
552 int retval = -EOPNOTSUPP;
553 struct p9_fid *v9fid, *dfid;
554 struct v9fs_session_info *v9ses;
555
556 p9_debug(P9_DEBUG_VFS, "inode: %p dentry: %p rmdir: %x\n",
557 dir, dentry, flags);
558
559 v9ses = v9fs_inode2v9ses(dir);
560 inode = d_inode(dentry);
561 dfid = v9fs_parent_fid(dentry);
562 if (IS_ERR(dfid)) {
563 retval = PTR_ERR(dfid);
564 p9_debug(P9_DEBUG_VFS, "fid lookup failed %d\n", retval);
565 return retval;
566 }
567 if (v9fs_proto_dotl(v9ses))
568 retval = p9_client_unlinkat(dfid, dentry->d_name.name,
569 v9fs_at_to_dotl_flags(flags));
570 p9_fid_put(dfid);
571 if (retval == -EOPNOTSUPP) {
572 /* Try the one based on path */
573 v9fid = v9fs_fid_clone(dentry);
574 if (IS_ERR(v9fid))
575 return PTR_ERR(v9fid);
576 retval = p9_client_remove(v9fid);
577 }
578 if (!retval) {
579 /*
580 * directories on unlink should have zero
581 * link count
582 */
583 if (flags & AT_REMOVEDIR) {
584 clear_nlink(inode);
585 v9fs_dec_count(dir);
586 } else
587 v9fs_dec_count(inode);
588
589 v9fs_invalidate_inode_attr(inode);
590 v9fs_invalidate_inode_attr(dir);
591
592 /* invalidate all fids associated with dentry */
593 /* NOTE: This will not include open fids */
594 dentry->d_op->d_release(dentry);
595 }
596 return retval;
597 }
598
599 /**
600 * v9fs_create - Create a file
601 * @v9ses: session information
602 * @dir: directory that dentry is being created in
603 * @dentry: dentry that is being created
604 * @extension: 9p2000.u extension string to support devices, etc.
605 * @perm: create permissions
606 * @mode: open mode
607 *
608 */
609 static struct p9_fid *
v9fs_create(struct v9fs_session_info * v9ses,struct inode * dir,struct dentry * dentry,char * extension,u32 perm,u8 mode)610 v9fs_create(struct v9fs_session_info *v9ses, struct inode *dir,
611 struct dentry *dentry, char *extension, u32 perm, u8 mode)
612 {
613 int err;
614 const unsigned char *name;
615 struct p9_fid *dfid, *ofid = NULL, *fid = NULL;
616 struct inode *inode;
617
618 p9_debug(P9_DEBUG_VFS, "name %pd\n", dentry);
619
620 err = 0;
621 name = dentry->d_name.name;
622 dfid = v9fs_parent_fid(dentry);
623 if (IS_ERR(dfid)) {
624 err = PTR_ERR(dfid);
625 p9_debug(P9_DEBUG_VFS, "fid lookup failed %d\n", err);
626 return ERR_PTR(err);
627 }
628
629 /* clone a fid to use for creation */
630 ofid = clone_fid(dfid);
631 if (IS_ERR(ofid)) {
632 err = PTR_ERR(ofid);
633 p9_debug(P9_DEBUG_VFS, "p9_client_walk failed %d\n", err);
634 goto error;
635 }
636
637 err = p9_client_fcreate(ofid, name, perm, mode, extension);
638 if (err < 0) {
639 p9_debug(P9_DEBUG_VFS, "p9_client_fcreate failed %d\n", err);
640 goto error;
641 }
642
643 if (!(perm & P9_DMLINK)) {
644 /* now walk from the parent so we can get unopened fid */
645 fid = p9_client_walk(dfid, 1, &name, 1);
646 if (IS_ERR(fid)) {
647 err = PTR_ERR(fid);
648 p9_debug(P9_DEBUG_VFS,
649 "p9_client_walk failed %d\n", err);
650 goto error;
651 }
652 /*
653 * instantiate inode and assign the unopened fid to the dentry
654 */
655 inode = v9fs_get_new_inode_from_fid(v9ses, fid, dir->i_sb);
656 if (IS_ERR(inode)) {
657 err = PTR_ERR(inode);
658 p9_debug(P9_DEBUG_VFS,
659 "inode creation failed %d\n", err);
660 goto error;
661 }
662 v9fs_fid_add(dentry, &fid);
663 d_instantiate(dentry, inode);
664 }
665 p9_fid_put(dfid);
666 return ofid;
667 error:
668 p9_fid_put(dfid);
669 p9_fid_put(ofid);
670 p9_fid_put(fid);
671 return ERR_PTR(err);
672 }
673
674 /**
675 * v9fs_vfs_create - VFS hook to create a regular file
676 * @mnt_userns: The user namespace of the mount
677 * @dir: The parent directory
678 * @dentry: The name of file to be created
679 * @mode: The UNIX file mode to set
680 * @excl: True if the file must not yet exist
681 *
682 * open(.., O_CREAT) is handled in v9fs_vfs_atomic_open(). This is only called
683 * for mknod(2).
684 *
685 */
686
687 static int
v9fs_vfs_create(struct user_namespace * mnt_userns,struct inode * dir,struct dentry * dentry,umode_t mode,bool excl)688 v9fs_vfs_create(struct user_namespace *mnt_userns, struct inode *dir,
689 struct dentry *dentry, umode_t mode, bool excl)
690 {
691 struct v9fs_session_info *v9ses = v9fs_inode2v9ses(dir);
692 u32 perm = unixmode2p9mode(v9ses, mode);
693 struct p9_fid *fid;
694
695 /* P9_OEXCL? */
696 fid = v9fs_create(v9ses, dir, dentry, NULL, perm, P9_ORDWR);
697 if (IS_ERR(fid))
698 return PTR_ERR(fid);
699
700 v9fs_invalidate_inode_attr(dir);
701 p9_fid_put(fid);
702
703 return 0;
704 }
705
706 /**
707 * v9fs_vfs_mkdir - VFS mkdir hook to create a directory
708 * @mnt_userns: The user namespace of the mount
709 * @dir: inode that is being unlinked
710 * @dentry: dentry that is being unlinked
711 * @mode: mode for new directory
712 *
713 */
714
v9fs_vfs_mkdir(struct user_namespace * mnt_userns,struct inode * dir,struct dentry * dentry,umode_t mode)715 static int v9fs_vfs_mkdir(struct user_namespace *mnt_userns, struct inode *dir,
716 struct dentry *dentry, umode_t mode)
717 {
718 int err;
719 u32 perm;
720 struct p9_fid *fid;
721 struct v9fs_session_info *v9ses;
722
723 p9_debug(P9_DEBUG_VFS, "name %pd\n", dentry);
724 err = 0;
725 v9ses = v9fs_inode2v9ses(dir);
726 perm = unixmode2p9mode(v9ses, mode | S_IFDIR);
727 fid = v9fs_create(v9ses, dir, dentry, NULL, perm, P9_OREAD);
728 if (IS_ERR(fid)) {
729 err = PTR_ERR(fid);
730 fid = NULL;
731 } else {
732 inc_nlink(dir);
733 v9fs_invalidate_inode_attr(dir);
734 }
735
736 if (fid)
737 p9_fid_put(fid);
738
739 return err;
740 }
741
742 /**
743 * v9fs_vfs_lookup - VFS lookup hook to "walk" to a new inode
744 * @dir: inode that is being walked from
745 * @dentry: dentry that is being walked to?
746 * @flags: lookup flags (unused)
747 *
748 */
749
v9fs_vfs_lookup(struct inode * dir,struct dentry * dentry,unsigned int flags)750 struct dentry *v9fs_vfs_lookup(struct inode *dir, struct dentry *dentry,
751 unsigned int flags)
752 {
753 struct dentry *res;
754 struct v9fs_session_info *v9ses;
755 struct p9_fid *dfid, *fid;
756 struct inode *inode;
757 const unsigned char *name;
758
759 p9_debug(P9_DEBUG_VFS, "dir: %p dentry: (%pd) %p flags: %x\n",
760 dir, dentry, dentry, flags);
761
762 if (dentry->d_name.len > NAME_MAX)
763 return ERR_PTR(-ENAMETOOLONG);
764
765 v9ses = v9fs_inode2v9ses(dir);
766 /* We can walk d_parent because we hold the dir->i_mutex */
767 dfid = v9fs_parent_fid(dentry);
768 if (IS_ERR(dfid))
769 return ERR_CAST(dfid);
770
771 /*
772 * Make sure we don't use a wrong inode due to parallel
773 * unlink. For cached mode create calls request for new
774 * inode. But with cache disabled, lookup should do this.
775 */
776 name = dentry->d_name.name;
777 fid = p9_client_walk(dfid, 1, &name, 1);
778 p9_fid_put(dfid);
779 if (fid == ERR_PTR(-ENOENT))
780 inode = NULL;
781 else if (IS_ERR(fid))
782 inode = ERR_CAST(fid);
783 else if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE)
784 inode = v9fs_get_inode_from_fid(v9ses, fid, dir->i_sb);
785 else
786 inode = v9fs_get_new_inode_from_fid(v9ses, fid, dir->i_sb);
787 /*
788 * If we had a rename on the server and a parallel lookup
789 * for the new name, then make sure we instantiate with
790 * the new name. ie look up for a/b, while on server somebody
791 * moved b under k and client parallely did a lookup for
792 * k/b.
793 */
794 res = d_splice_alias(inode, dentry);
795 if (!IS_ERR(fid)) {
796 if (!res)
797 v9fs_fid_add(dentry, &fid);
798 else if (!IS_ERR(res))
799 v9fs_fid_add(res, &fid);
800 else
801 p9_fid_put(fid);
802 }
803 return res;
804 }
805
806 static int
v9fs_vfs_atomic_open(struct inode * dir,struct dentry * dentry,struct file * file,unsigned int flags,umode_t mode)807 v9fs_vfs_atomic_open(struct inode *dir, struct dentry *dentry,
808 struct file *file, unsigned int flags, umode_t mode)
809 {
810 int err;
811 u32 perm;
812 struct v9fs_inode *v9inode;
813 struct v9fs_session_info *v9ses;
814 struct p9_fid *fid, *inode_fid;
815 struct dentry *res = NULL;
816 struct inode *inode;
817
818 if (d_in_lookup(dentry)) {
819 res = v9fs_vfs_lookup(dir, dentry, 0);
820 if (IS_ERR(res))
821 return PTR_ERR(res);
822
823 if (res)
824 dentry = res;
825 }
826
827 /* Only creates */
828 if (!(flags & O_CREAT) || d_really_is_positive(dentry))
829 return finish_no_open(file, res);
830
831 err = 0;
832
833 v9ses = v9fs_inode2v9ses(dir);
834 perm = unixmode2p9mode(v9ses, mode);
835 fid = v9fs_create(v9ses, dir, dentry, NULL, perm,
836 v9fs_uflags2omode(flags,
837 v9fs_proto_dotu(v9ses)));
838 if (IS_ERR(fid)) {
839 err = PTR_ERR(fid);
840 goto error;
841 }
842
843 v9fs_invalidate_inode_attr(dir);
844 inode = d_inode(dentry);
845 v9inode = V9FS_I(inode);
846 mutex_lock(&v9inode->v_mutex);
847 if ((v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) &&
848 !v9inode->writeback_fid &&
849 ((flags & O_ACCMODE) != O_RDONLY)) {
850 /*
851 * clone a fid and add it to writeback_fid
852 * we do it during open time instead of
853 * page dirty time via write_begin/page_mkwrite
854 * because we want write after unlink usecase
855 * to work.
856 */
857 inode_fid = v9fs_writeback_fid(dentry);
858 if (IS_ERR(inode_fid)) {
859 err = PTR_ERR(inode_fid);
860 mutex_unlock(&v9inode->v_mutex);
861 goto error;
862 }
863 v9inode->writeback_fid = (void *) inode_fid;
864 }
865 mutex_unlock(&v9inode->v_mutex);
866 err = finish_open(file, dentry, generic_file_open);
867 if (err)
868 goto error;
869
870 file->private_data = fid;
871 if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE)
872 fscache_use_cookie(v9fs_inode_cookie(v9inode),
873 file->f_mode & FMODE_WRITE);
874 v9fs_open_fid_add(inode, &fid);
875
876 file->f_mode |= FMODE_CREATED;
877 out:
878 dput(res);
879 return err;
880
881 error:
882 p9_fid_put(fid);
883 goto out;
884 }
885
886 /**
887 * v9fs_vfs_unlink - VFS unlink hook to delete an inode
888 * @i: inode that is being unlinked
889 * @d: dentry that is being unlinked
890 *
891 */
892
v9fs_vfs_unlink(struct inode * i,struct dentry * d)893 int v9fs_vfs_unlink(struct inode *i, struct dentry *d)
894 {
895 return v9fs_remove(i, d, 0);
896 }
897
898 /**
899 * v9fs_vfs_rmdir - VFS unlink hook to delete a directory
900 * @i: inode that is being unlinked
901 * @d: dentry that is being unlinked
902 *
903 */
904
v9fs_vfs_rmdir(struct inode * i,struct dentry * d)905 int v9fs_vfs_rmdir(struct inode *i, struct dentry *d)
906 {
907 return v9fs_remove(i, d, AT_REMOVEDIR);
908 }
909
910 /**
911 * v9fs_vfs_rename - VFS hook to rename an inode
912 * @mnt_userns: The user namespace of the mount
913 * @old_dir: old dir inode
914 * @old_dentry: old dentry
915 * @new_dir: new dir inode
916 * @new_dentry: new dentry
917 * @flags: RENAME_* flags
918 *
919 */
920
921 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)922 v9fs_vfs_rename(struct user_namespace *mnt_userns, struct inode *old_dir,
923 struct dentry *old_dentry, struct inode *new_dir,
924 struct dentry *new_dentry, unsigned int flags)
925 {
926 int retval;
927 struct inode *old_inode;
928 struct inode *new_inode;
929 struct v9fs_session_info *v9ses;
930 struct p9_fid *oldfid = NULL, *dfid = NULL;
931 struct p9_fid *olddirfid = NULL;
932 struct p9_fid *newdirfid = NULL;
933 struct p9_wstat wstat;
934
935 if (flags)
936 return -EINVAL;
937
938 p9_debug(P9_DEBUG_VFS, "\n");
939 retval = 0;
940 old_inode = d_inode(old_dentry);
941 new_inode = d_inode(new_dentry);
942 v9ses = v9fs_inode2v9ses(old_inode);
943 oldfid = v9fs_fid_lookup(old_dentry);
944 if (IS_ERR(oldfid))
945 return PTR_ERR(oldfid);
946
947 dfid = v9fs_parent_fid(old_dentry);
948 olddirfid = clone_fid(dfid);
949 p9_fid_put(dfid);
950 dfid = NULL;
951
952 if (IS_ERR(olddirfid)) {
953 retval = PTR_ERR(olddirfid);
954 goto error;
955 }
956
957 dfid = v9fs_parent_fid(new_dentry);
958 newdirfid = clone_fid(dfid);
959 p9_fid_put(dfid);
960 dfid = NULL;
961
962 if (IS_ERR(newdirfid)) {
963 retval = PTR_ERR(newdirfid);
964 goto error;
965 }
966
967 down_write(&v9ses->rename_sem);
968 if (v9fs_proto_dotl(v9ses)) {
969 retval = p9_client_renameat(olddirfid, old_dentry->d_name.name,
970 newdirfid, new_dentry->d_name.name);
971 if (retval == -EOPNOTSUPP)
972 retval = p9_client_rename(oldfid, newdirfid,
973 new_dentry->d_name.name);
974 if (retval != -EOPNOTSUPP)
975 goto error_locked;
976 }
977 if (old_dentry->d_parent != new_dentry->d_parent) {
978 /*
979 * 9P .u can only handle file rename in the same directory
980 */
981
982 p9_debug(P9_DEBUG_ERROR, "old dir and new dir are different\n");
983 retval = -EXDEV;
984 goto error_locked;
985 }
986 v9fs_blank_wstat(&wstat);
987 wstat.muid = v9ses->uname;
988 wstat.name = new_dentry->d_name.name;
989 retval = p9_client_wstat(oldfid, &wstat);
990
991 error_locked:
992 if (!retval) {
993 if (new_inode) {
994 if (S_ISDIR(new_inode->i_mode))
995 clear_nlink(new_inode);
996 else
997 v9fs_dec_count(new_inode);
998 }
999 if (S_ISDIR(old_inode->i_mode)) {
1000 if (!new_inode)
1001 inc_nlink(new_dir);
1002 v9fs_dec_count(old_dir);
1003 }
1004 v9fs_invalidate_inode_attr(old_inode);
1005 v9fs_invalidate_inode_attr(old_dir);
1006 v9fs_invalidate_inode_attr(new_dir);
1007
1008 /* successful rename */
1009 d_move(old_dentry, new_dentry);
1010 }
1011 up_write(&v9ses->rename_sem);
1012
1013 error:
1014 p9_fid_put(newdirfid);
1015 p9_fid_put(olddirfid);
1016 p9_fid_put(oldfid);
1017 return retval;
1018 }
1019
1020 /**
1021 * v9fs_vfs_getattr - retrieve file metadata
1022 * @mnt_userns: The user namespace of the mount
1023 * @path: Object to query
1024 * @stat: metadata structure to populate
1025 * @request_mask: Mask of STATX_xxx flags indicating the caller's interests
1026 * @flags: AT_STATX_xxx setting
1027 *
1028 */
1029
1030 static int
v9fs_vfs_getattr(struct user_namespace * mnt_userns,const struct path * path,struct kstat * stat,u32 request_mask,unsigned int flags)1031 v9fs_vfs_getattr(struct user_namespace *mnt_userns, const struct path *path,
1032 struct kstat *stat, u32 request_mask, unsigned int flags)
1033 {
1034 struct dentry *dentry = path->dentry;
1035 struct v9fs_session_info *v9ses;
1036 struct p9_fid *fid;
1037 struct p9_wstat *st;
1038
1039 p9_debug(P9_DEBUG_VFS, "dentry: %p\n", dentry);
1040 v9ses = v9fs_dentry2v9ses(dentry);
1041 if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) {
1042 generic_fillattr(&init_user_ns, d_inode(dentry), stat);
1043 return 0;
1044 }
1045 fid = v9fs_fid_lookup(dentry);
1046 if (IS_ERR(fid))
1047 return PTR_ERR(fid);
1048
1049 st = p9_client_stat(fid);
1050 p9_fid_put(fid);
1051 if (IS_ERR(st))
1052 return PTR_ERR(st);
1053
1054 v9fs_stat2inode(st, d_inode(dentry), dentry->d_sb, 0);
1055 generic_fillattr(&init_user_ns, d_inode(dentry), stat);
1056
1057 p9stat_free(st);
1058 kfree(st);
1059 return 0;
1060 }
1061
1062 /**
1063 * v9fs_vfs_setattr - set file metadata
1064 * @mnt_userns: The user namespace of the mount
1065 * @dentry: file whose metadata to set
1066 * @iattr: metadata assignment structure
1067 *
1068 */
1069
v9fs_vfs_setattr(struct user_namespace * mnt_userns,struct dentry * dentry,struct iattr * iattr)1070 static int v9fs_vfs_setattr(struct user_namespace *mnt_userns,
1071 struct dentry *dentry, struct iattr *iattr)
1072 {
1073 int retval, use_dentry = 0;
1074 struct inode *inode = d_inode(dentry);
1075 struct v9fs_inode *v9inode = V9FS_I(inode);
1076 struct v9fs_session_info *v9ses;
1077 struct p9_fid *fid = NULL;
1078 struct p9_wstat wstat;
1079
1080 p9_debug(P9_DEBUG_VFS, "\n");
1081 retval = setattr_prepare(&init_user_ns, dentry, iattr);
1082 if (retval)
1083 return retval;
1084
1085 retval = -EPERM;
1086 v9ses = v9fs_dentry2v9ses(dentry);
1087 if (iattr->ia_valid & ATTR_FILE) {
1088 fid = iattr->ia_file->private_data;
1089 WARN_ON(!fid);
1090 }
1091 if (!fid) {
1092 fid = v9fs_fid_lookup(dentry);
1093 use_dentry = 1;
1094 }
1095 if (IS_ERR(fid))
1096 return PTR_ERR(fid);
1097
1098 v9fs_blank_wstat(&wstat);
1099 if (iattr->ia_valid & ATTR_MODE)
1100 wstat.mode = unixmode2p9mode(v9ses, iattr->ia_mode);
1101
1102 if (iattr->ia_valid & ATTR_MTIME)
1103 wstat.mtime = iattr->ia_mtime.tv_sec;
1104
1105 if (iattr->ia_valid & ATTR_ATIME)
1106 wstat.atime = iattr->ia_atime.tv_sec;
1107
1108 if (iattr->ia_valid & ATTR_SIZE)
1109 wstat.length = iattr->ia_size;
1110
1111 if (v9fs_proto_dotu(v9ses)) {
1112 if (iattr->ia_valid & ATTR_UID)
1113 wstat.n_uid = iattr->ia_uid;
1114
1115 if (iattr->ia_valid & ATTR_GID)
1116 wstat.n_gid = iattr->ia_gid;
1117 }
1118
1119 /* Write all dirty data */
1120 if (d_is_reg(dentry))
1121 filemap_write_and_wait(inode->i_mapping);
1122
1123 retval = p9_client_wstat(fid, &wstat);
1124
1125 if (use_dentry)
1126 p9_fid_put(fid);
1127
1128 if (retval < 0)
1129 return retval;
1130
1131 if ((iattr->ia_valid & ATTR_SIZE) &&
1132 iattr->ia_size != i_size_read(inode)) {
1133 truncate_setsize(inode, iattr->ia_size);
1134 fscache_resize_cookie(v9fs_inode_cookie(v9inode), iattr->ia_size);
1135 }
1136
1137 v9fs_invalidate_inode_attr(inode);
1138
1139 setattr_copy(&init_user_ns, inode, iattr);
1140 mark_inode_dirty(inode);
1141 return 0;
1142 }
1143
1144 /**
1145 * v9fs_stat2inode - populate an inode structure with mistat info
1146 * @stat: Plan 9 metadata (mistat) structure
1147 * @inode: inode to populate
1148 * @sb: superblock of filesystem
1149 * @flags: control flags (e.g. V9FS_STAT2INODE_KEEP_ISIZE)
1150 *
1151 */
1152
1153 void
v9fs_stat2inode(struct p9_wstat * stat,struct inode * inode,struct super_block * sb,unsigned int flags)1154 v9fs_stat2inode(struct p9_wstat *stat, struct inode *inode,
1155 struct super_block *sb, unsigned int flags)
1156 {
1157 umode_t mode;
1158 struct v9fs_session_info *v9ses = sb->s_fs_info;
1159 struct v9fs_inode *v9inode = V9FS_I(inode);
1160
1161 set_nlink(inode, 1);
1162
1163 inode->i_atime.tv_sec = stat->atime;
1164 inode->i_mtime.tv_sec = stat->mtime;
1165 inode->i_ctime.tv_sec = stat->mtime;
1166
1167 inode->i_uid = v9ses->dfltuid;
1168 inode->i_gid = v9ses->dfltgid;
1169
1170 if (v9fs_proto_dotu(v9ses)) {
1171 inode->i_uid = stat->n_uid;
1172 inode->i_gid = stat->n_gid;
1173 }
1174 if ((S_ISREG(inode->i_mode)) || (S_ISDIR(inode->i_mode))) {
1175 if (v9fs_proto_dotu(v9ses)) {
1176 unsigned int i_nlink;
1177 /*
1178 * Hadlink support got added later to the .u extension.
1179 * So there can be a server out there that doesn't
1180 * support this even with .u extension. That would
1181 * just leave us with stat->extension being an empty
1182 * string, though.
1183 */
1184 /* HARDLINKCOUNT %u */
1185 if (sscanf(stat->extension,
1186 " HARDLINKCOUNT %u", &i_nlink) == 1)
1187 set_nlink(inode, i_nlink);
1188 }
1189 }
1190 mode = p9mode2perm(v9ses, stat);
1191 mode |= inode->i_mode & ~S_IALLUGO;
1192 inode->i_mode = mode;
1193
1194 if (!(flags & V9FS_STAT2INODE_KEEP_ISIZE))
1195 v9fs_i_size_write(inode, stat->length);
1196 /* not real number of blocks, but 512 byte ones ... */
1197 inode->i_blocks = (stat->length + 512 - 1) >> 9;
1198 v9inode->cache_validity &= ~V9FS_INO_INVALID_ATTR;
1199 }
1200
1201 /**
1202 * v9fs_qid2ino - convert qid into inode number
1203 * @qid: qid to hash
1204 *
1205 * BUG: potential for inode number collisions?
1206 */
1207
v9fs_qid2ino(struct p9_qid * qid)1208 ino_t v9fs_qid2ino(struct p9_qid *qid)
1209 {
1210 u64 path = qid->path + 2;
1211 ino_t i = 0;
1212
1213 if (sizeof(ino_t) == sizeof(path))
1214 memcpy(&i, &path, sizeof(ino_t));
1215 else
1216 i = (ino_t) (path ^ (path >> 32));
1217
1218 return i;
1219 }
1220
1221 /**
1222 * v9fs_vfs_get_link - follow a symlink path
1223 * @dentry: dentry for symlink
1224 * @inode: inode for symlink
1225 * @done: delayed call for when we are done with the return value
1226 */
1227
v9fs_vfs_get_link(struct dentry * dentry,struct inode * inode,struct delayed_call * done)1228 static const char *v9fs_vfs_get_link(struct dentry *dentry,
1229 struct inode *inode,
1230 struct delayed_call *done)
1231 {
1232 struct v9fs_session_info *v9ses;
1233 struct p9_fid *fid;
1234 struct p9_wstat *st;
1235 char *res;
1236
1237 if (!dentry)
1238 return ERR_PTR(-ECHILD);
1239
1240 v9ses = v9fs_dentry2v9ses(dentry);
1241 if (!v9fs_proto_dotu(v9ses))
1242 return ERR_PTR(-EBADF);
1243
1244 p9_debug(P9_DEBUG_VFS, "%pd\n", dentry);
1245 fid = v9fs_fid_lookup(dentry);
1246
1247 if (IS_ERR(fid))
1248 return ERR_CAST(fid);
1249
1250 st = p9_client_stat(fid);
1251 p9_fid_put(fid);
1252 if (IS_ERR(st))
1253 return ERR_CAST(st);
1254
1255 if (!(st->mode & P9_DMSYMLINK)) {
1256 p9stat_free(st);
1257 kfree(st);
1258 return ERR_PTR(-EINVAL);
1259 }
1260 res = st->extension;
1261 st->extension = NULL;
1262 if (strlen(res) >= PATH_MAX)
1263 res[PATH_MAX - 1] = '\0';
1264
1265 p9stat_free(st);
1266 kfree(st);
1267 set_delayed_call(done, kfree_link, res);
1268 return res;
1269 }
1270
1271 /**
1272 * v9fs_vfs_mkspecial - create a special file
1273 * @dir: inode to create special file in
1274 * @dentry: dentry to create
1275 * @perm: mode to create special file
1276 * @extension: 9p2000.u format extension string representing special file
1277 *
1278 */
1279
v9fs_vfs_mkspecial(struct inode * dir,struct dentry * dentry,u32 perm,const char * extension)1280 static int v9fs_vfs_mkspecial(struct inode *dir, struct dentry *dentry,
1281 u32 perm, const char *extension)
1282 {
1283 struct p9_fid *fid;
1284 struct v9fs_session_info *v9ses;
1285
1286 v9ses = v9fs_inode2v9ses(dir);
1287 if (!v9fs_proto_dotu(v9ses)) {
1288 p9_debug(P9_DEBUG_ERROR, "not extended\n");
1289 return -EPERM;
1290 }
1291
1292 fid = v9fs_create(v9ses, dir, dentry, (char *) extension, perm,
1293 P9_OREAD);
1294 if (IS_ERR(fid))
1295 return PTR_ERR(fid);
1296
1297 v9fs_invalidate_inode_attr(dir);
1298 p9_fid_put(fid);
1299 return 0;
1300 }
1301
1302 /**
1303 * v9fs_vfs_symlink - helper function to create symlinks
1304 * @mnt_userns: The user namespace of the mount
1305 * @dir: directory inode containing symlink
1306 * @dentry: dentry for symlink
1307 * @symname: symlink data
1308 *
1309 * See Also: 9P2000.u RFC for more information
1310 *
1311 */
1312
1313 static int
v9fs_vfs_symlink(struct user_namespace * mnt_userns,struct inode * dir,struct dentry * dentry,const char * symname)1314 v9fs_vfs_symlink(struct user_namespace *mnt_userns, struct inode *dir,
1315 struct dentry *dentry, const char *symname)
1316 {
1317 p9_debug(P9_DEBUG_VFS, " %lu,%pd,%s\n",
1318 dir->i_ino, dentry, symname);
1319
1320 return v9fs_vfs_mkspecial(dir, dentry, P9_DMSYMLINK, symname);
1321 }
1322
1323 #define U32_MAX_DIGITS 10
1324
1325 /**
1326 * v9fs_vfs_link - create a hardlink
1327 * @old_dentry: dentry for file to link to
1328 * @dir: inode destination for new link
1329 * @dentry: dentry for link
1330 *
1331 */
1332
1333 static int
v9fs_vfs_link(struct dentry * old_dentry,struct inode * dir,struct dentry * dentry)1334 v9fs_vfs_link(struct dentry *old_dentry, struct inode *dir,
1335 struct dentry *dentry)
1336 {
1337 int retval;
1338 char name[1 + U32_MAX_DIGITS + 2]; /* sign + number + \n + \0 */
1339 struct p9_fid *oldfid;
1340
1341 p9_debug(P9_DEBUG_VFS, " %lu,%pd,%pd\n",
1342 dir->i_ino, dentry, old_dentry);
1343
1344 oldfid = v9fs_fid_clone(old_dentry);
1345 if (IS_ERR(oldfid))
1346 return PTR_ERR(oldfid);
1347
1348 sprintf(name, "%d\n", oldfid->fid);
1349 retval = v9fs_vfs_mkspecial(dir, dentry, P9_DMLINK, name);
1350 if (!retval) {
1351 v9fs_refresh_inode(oldfid, d_inode(old_dentry));
1352 v9fs_invalidate_inode_attr(dir);
1353 }
1354 p9_fid_put(oldfid);
1355 return retval;
1356 }
1357
1358 /**
1359 * v9fs_vfs_mknod - create a special file
1360 * @mnt_userns: The user namespace of the mount
1361 * @dir: inode destination for new link
1362 * @dentry: dentry for file
1363 * @mode: mode for creation
1364 * @rdev: device associated with special file
1365 *
1366 */
1367
1368 static int
v9fs_vfs_mknod(struct user_namespace * mnt_userns,struct inode * dir,struct dentry * dentry,umode_t mode,dev_t rdev)1369 v9fs_vfs_mknod(struct user_namespace *mnt_userns, struct inode *dir,
1370 struct dentry *dentry, umode_t mode, dev_t rdev)
1371 {
1372 struct v9fs_session_info *v9ses = v9fs_inode2v9ses(dir);
1373 int retval;
1374 char name[2 + U32_MAX_DIGITS + 1 + U32_MAX_DIGITS + 1];
1375 u32 perm;
1376
1377 p9_debug(P9_DEBUG_VFS, " %lu,%pd mode: %x MAJOR: %u MINOR: %u\n",
1378 dir->i_ino, dentry, mode,
1379 MAJOR(rdev), MINOR(rdev));
1380
1381 /* build extension */
1382 if (S_ISBLK(mode))
1383 sprintf(name, "b %u %u", MAJOR(rdev), MINOR(rdev));
1384 else if (S_ISCHR(mode))
1385 sprintf(name, "c %u %u", MAJOR(rdev), MINOR(rdev));
1386 else
1387 *name = 0;
1388
1389 perm = unixmode2p9mode(v9ses, mode);
1390 retval = v9fs_vfs_mkspecial(dir, dentry, perm, name);
1391
1392 return retval;
1393 }
1394
v9fs_refresh_inode(struct p9_fid * fid,struct inode * inode)1395 int v9fs_refresh_inode(struct p9_fid *fid, struct inode *inode)
1396 {
1397 int umode;
1398 dev_t rdev;
1399 struct p9_wstat *st;
1400 struct v9fs_session_info *v9ses;
1401 unsigned int flags;
1402
1403 v9ses = v9fs_inode2v9ses(inode);
1404 st = p9_client_stat(fid);
1405 if (IS_ERR(st))
1406 return PTR_ERR(st);
1407 /*
1408 * Don't update inode if the file type is different
1409 */
1410 umode = p9mode2unixmode(v9ses, st, &rdev);
1411 if (inode_wrong_type(inode, umode))
1412 goto out;
1413
1414 /*
1415 * We don't want to refresh inode->i_size,
1416 * because we may have cached data
1417 */
1418 flags = (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) ?
1419 V9FS_STAT2INODE_KEEP_ISIZE : 0;
1420 v9fs_stat2inode(st, inode, inode->i_sb, flags);
1421 out:
1422 p9stat_free(st);
1423 kfree(st);
1424 return 0;
1425 }
1426
1427 static const struct inode_operations v9fs_dir_inode_operations_dotu = {
1428 .create = v9fs_vfs_create,
1429 .lookup = v9fs_vfs_lookup,
1430 .atomic_open = v9fs_vfs_atomic_open,
1431 .symlink = v9fs_vfs_symlink,
1432 .link = v9fs_vfs_link,
1433 .unlink = v9fs_vfs_unlink,
1434 .mkdir = v9fs_vfs_mkdir,
1435 .rmdir = v9fs_vfs_rmdir,
1436 .mknod = v9fs_vfs_mknod,
1437 .rename = v9fs_vfs_rename,
1438 .getattr = v9fs_vfs_getattr,
1439 .setattr = v9fs_vfs_setattr,
1440 };
1441
1442 static const struct inode_operations v9fs_dir_inode_operations = {
1443 .create = v9fs_vfs_create,
1444 .lookup = v9fs_vfs_lookup,
1445 .atomic_open = v9fs_vfs_atomic_open,
1446 .unlink = v9fs_vfs_unlink,
1447 .mkdir = v9fs_vfs_mkdir,
1448 .rmdir = v9fs_vfs_rmdir,
1449 .mknod = v9fs_vfs_mknod,
1450 .rename = v9fs_vfs_rename,
1451 .getattr = v9fs_vfs_getattr,
1452 .setattr = v9fs_vfs_setattr,
1453 };
1454
1455 static const struct inode_operations v9fs_file_inode_operations = {
1456 .getattr = v9fs_vfs_getattr,
1457 .setattr = v9fs_vfs_setattr,
1458 };
1459
1460 static const struct inode_operations v9fs_symlink_inode_operations = {
1461 .get_link = v9fs_vfs_get_link,
1462 .getattr = v9fs_vfs_getattr,
1463 .setattr = v9fs_vfs_setattr,
1464 };
1465
1466