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