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, cache: 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(s: v9fs_inode_cache, objp: 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(ctx: &v9inode->netfs, ops: &v9fs_req_ops, use_zero_point: 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(idmap: &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, aux: &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(cookie: v9fs_inode_cookie(v9inode), retire: false);
362#endif
363 } else
364 clear_inode(inode);
365}
366
367struct inode *v9fs_fid_iget(struct super_block *sb, struct p9_fid *fid)
368{
369 dev_t rdev;
370 int retval;
371 umode_t umode;
372 struct inode *inode;
373 struct p9_wstat *st;
374 struct v9fs_session_info *v9ses = sb->s_fs_info;
375
376 inode = iget_locked(sb, QID2INO(&fid->qid));
377 if (unlikely(!inode))
378 return ERR_PTR(error: -ENOMEM);
379 if (!(inode->i_state & I_NEW))
380 return inode;
381
382 /*
383 * initialize the inode with the stat info
384 * FIXME!! we may need support for stale inodes
385 * later.
386 */
387 st = p9_client_stat(fid);
388 if (IS_ERR(ptr: st)) {
389 retval = PTR_ERR(ptr: st);
390 goto error;
391 }
392
393 umode = p9mode2unixmode(v9ses, stat: st, rdev: &rdev);
394 retval = v9fs_init_inode(v9ses, inode, qid: &fid->qid, mode: umode, rdev);
395 v9fs_stat2inode(stat: st, inode, sb, flags: 0);
396 p9stat_free(stbuf: st);
397 kfree(objp: st);
398 if (retval)
399 goto error;
400
401 v9fs_set_netfs_context(inode);
402 v9fs_cache_inode_get_cookie(inode);
403 unlock_new_inode(inode);
404 return inode;
405error:
406 iget_failed(inode);
407 return ERR_PTR(error: retval);
408
409}
410
411/**
412 * v9fs_at_to_dotl_flags- convert Linux specific AT flags to
413 * plan 9 AT flag.
414 * @flags: flags to convert
415 */
416static int v9fs_at_to_dotl_flags(int flags)
417{
418 int rflags = 0;
419
420 if (flags & AT_REMOVEDIR)
421 rflags |= P9_DOTL_AT_REMOVEDIR;
422
423 return rflags;
424}
425
426/**
427 * v9fs_dec_count - helper functon to drop i_nlink.
428 *
429 * If a directory had nlink <= 2 (including . and ..), then we should not drop
430 * the link count, which indicates the underlying exported fs doesn't maintain
431 * nlink accurately. e.g.
432 * - overlayfs sets nlink to 1 for merged dir
433 * - ext4 (with dir_nlink feature enabled) sets nlink to 1 if a dir has more
434 * than EXT4_LINK_MAX (65000) links.
435 *
436 * @inode: inode whose nlink is being dropped
437 */
438static void v9fs_dec_count(struct inode *inode)
439{
440 if (!S_ISDIR(inode->i_mode) || inode->i_nlink > 2)
441 drop_nlink(inode);
442}
443
444/**
445 * v9fs_remove - helper function to remove files and directories
446 * @dir: directory inode that is being deleted
447 * @dentry: dentry that is being deleted
448 * @flags: removing a directory
449 *
450 */
451
452static int v9fs_remove(struct inode *dir, struct dentry *dentry, int flags)
453{
454 struct inode *inode;
455 int retval = -EOPNOTSUPP;
456 struct p9_fid *v9fid, *dfid;
457 struct v9fs_session_info *v9ses;
458
459 p9_debug(P9_DEBUG_VFS, "inode: %p dentry: %p rmdir: %x\n",
460 dir, dentry, flags);
461
462 v9ses = v9fs_inode2v9ses(inode: dir);
463 inode = d_inode(dentry);
464 dfid = v9fs_parent_fid(dentry);
465 if (IS_ERR(ptr: dfid)) {
466 retval = PTR_ERR(ptr: dfid);
467 p9_debug(P9_DEBUG_VFS, "fid lookup failed %d\n", retval);
468 return retval;
469 }
470 if (v9fs_proto_dotl(v9ses))
471 retval = p9_client_unlinkat(dfid, name: dentry->d_name.name,
472 flags: v9fs_at_to_dotl_flags(flags));
473 p9_fid_put(fid: dfid);
474 if (retval == -EOPNOTSUPP) {
475 /* Try the one based on path */
476 v9fid = v9fs_fid_clone(dentry);
477 if (IS_ERR(ptr: v9fid))
478 return PTR_ERR(ptr: v9fid);
479 retval = p9_client_remove(fid: v9fid);
480 }
481 if (!retval) {
482 /*
483 * directories on unlink should have zero
484 * link count
485 */
486 if (flags & AT_REMOVEDIR) {
487 clear_nlink(inode);
488 v9fs_dec_count(inode: dir);
489 } else
490 v9fs_dec_count(inode);
491
492 v9fs_invalidate_inode_attr(inode);
493 v9fs_invalidate_inode_attr(inode: dir);
494
495 /* invalidate all fids associated with dentry */
496 /* NOTE: This will not include open fids */
497 dentry->d_op->d_release(dentry);
498 }
499 return retval;
500}
501
502/**
503 * v9fs_create - Create a file
504 * @v9ses: session information
505 * @dir: directory that dentry is being created in
506 * @dentry: dentry that is being created
507 * @extension: 9p2000.u extension string to support devices, etc.
508 * @perm: create permissions
509 * @mode: open mode
510 *
511 */
512static struct p9_fid *
513v9fs_create(struct v9fs_session_info *v9ses, struct inode *dir,
514 struct dentry *dentry, char *extension, u32 perm, u8 mode)
515{
516 int err;
517 const unsigned char *name;
518 struct p9_fid *dfid, *ofid = NULL, *fid = NULL;
519 struct inode *inode;
520
521 p9_debug(P9_DEBUG_VFS, "name %pd\n", dentry);
522
523 name = dentry->d_name.name;
524 dfid = v9fs_parent_fid(dentry);
525 if (IS_ERR(ptr: dfid)) {
526 err = PTR_ERR(ptr: dfid);
527 p9_debug(P9_DEBUG_VFS, "fid lookup failed %d\n", err);
528 return ERR_PTR(error: err);
529 }
530
531 /* clone a fid to use for creation */
532 ofid = clone_fid(fid: dfid);
533 if (IS_ERR(ptr: ofid)) {
534 err = PTR_ERR(ptr: ofid);
535 p9_debug(P9_DEBUG_VFS, "p9_client_walk failed %d\n", err);
536 goto error;
537 }
538
539 err = p9_client_fcreate(fid: ofid, name, perm, mode, extension);
540 if (err < 0) {
541 p9_debug(P9_DEBUG_VFS, "p9_client_fcreate failed %d\n", err);
542 goto error;
543 }
544
545 if (!(perm & P9_DMLINK)) {
546 /* now walk from the parent so we can get unopened fid */
547 fid = p9_client_walk(oldfid: dfid, nwname: 1, wnames: &name, clone: 1);
548 if (IS_ERR(ptr: fid)) {
549 err = PTR_ERR(ptr: fid);
550 p9_debug(P9_DEBUG_VFS,
551 "p9_client_walk failed %d\n", err);
552 goto error;
553 }
554 /*
555 * instantiate inode and assign the unopened fid to the dentry
556 */
557 inode = v9fs_get_inode_from_fid(v9ses, fid, sb: dir->i_sb);
558 if (IS_ERR(ptr: inode)) {
559 err = PTR_ERR(ptr: inode);
560 p9_debug(P9_DEBUG_VFS,
561 "inode creation failed %d\n", err);
562 goto error;
563 }
564 v9fs_fid_add(dentry, fid: &fid);
565 d_instantiate(dentry, inode);
566 }
567 p9_fid_put(fid: dfid);
568 return ofid;
569error:
570 p9_fid_put(fid: dfid);
571 p9_fid_put(fid: ofid);
572 p9_fid_put(fid);
573 return ERR_PTR(error: err);
574}
575
576/**
577 * v9fs_vfs_create - VFS hook to create a regular file
578 * @idmap: idmap of the mount
579 * @dir: The parent directory
580 * @dentry: The name of file to be created
581 * @mode: The UNIX file mode to set
582 * @excl: True if the file must not yet exist
583 *
584 * open(.., O_CREAT) is handled in v9fs_vfs_atomic_open(). This is only called
585 * for mknod(2).
586 *
587 */
588
589static int
590v9fs_vfs_create(struct mnt_idmap *idmap, struct inode *dir,
591 struct dentry *dentry, umode_t mode, bool excl)
592{
593 struct v9fs_session_info *v9ses = v9fs_inode2v9ses(inode: dir);
594 u32 perm = unixmode2p9mode(v9ses, mode);
595 struct p9_fid *fid;
596
597 /* P9_OEXCL? */
598 fid = v9fs_create(v9ses, dir, dentry, NULL, perm, mode: P9_ORDWR);
599 if (IS_ERR(ptr: fid))
600 return PTR_ERR(ptr: fid);
601
602 v9fs_invalidate_inode_attr(inode: dir);
603 p9_fid_put(fid);
604
605 return 0;
606}
607
608/**
609 * v9fs_vfs_mkdir - VFS mkdir hook to create a directory
610 * @idmap: idmap of the mount
611 * @dir: inode that is being unlinked
612 * @dentry: dentry that is being unlinked
613 * @mode: mode for new directory
614 *
615 */
616
617static int v9fs_vfs_mkdir(struct mnt_idmap *idmap, struct inode *dir,
618 struct dentry *dentry, umode_t mode)
619{
620 int err;
621 u32 perm;
622 struct p9_fid *fid;
623 struct v9fs_session_info *v9ses;
624
625 p9_debug(P9_DEBUG_VFS, "name %pd\n", dentry);
626 err = 0;
627 v9ses = v9fs_inode2v9ses(inode: dir);
628 perm = unixmode2p9mode(v9ses, mode: mode | S_IFDIR);
629 fid = v9fs_create(v9ses, dir, dentry, NULL, perm, mode: P9_OREAD);
630 if (IS_ERR(ptr: fid)) {
631 err = PTR_ERR(ptr: fid);
632 fid = NULL;
633 } else {
634 inc_nlink(inode: dir);
635 v9fs_invalidate_inode_attr(inode: dir);
636 }
637
638 if (fid)
639 p9_fid_put(fid);
640
641 return err;
642}
643
644/**
645 * v9fs_vfs_lookup - VFS lookup hook to "walk" to a new inode
646 * @dir: inode that is being walked from
647 * @dentry: dentry that is being walked to?
648 * @flags: lookup flags (unused)
649 *
650 */
651
652struct dentry *v9fs_vfs_lookup(struct inode *dir, struct dentry *dentry,
653 unsigned int flags)
654{
655 struct dentry *res;
656 struct v9fs_session_info *v9ses;
657 struct p9_fid *dfid, *fid;
658 struct inode *inode;
659 const unsigned char *name;
660
661 p9_debug(P9_DEBUG_VFS, "dir: %p dentry: (%pd) %p flags: %x\n",
662 dir, dentry, dentry, flags);
663
664 if (dentry->d_name.len > NAME_MAX)
665 return ERR_PTR(error: -ENAMETOOLONG);
666
667 v9ses = v9fs_inode2v9ses(inode: dir);
668 /* We can walk d_parent because we hold the dir->i_mutex */
669 dfid = v9fs_parent_fid(dentry);
670 if (IS_ERR(ptr: dfid))
671 return ERR_CAST(ptr: dfid);
672
673 /*
674 * Make sure we don't use a wrong inode due to parallel
675 * unlink. For cached mode create calls request for new
676 * inode. But with cache disabled, lookup should do this.
677 */
678 name = dentry->d_name.name;
679 fid = p9_client_walk(oldfid: dfid, nwname: 1, wnames: &name, clone: 1);
680 p9_fid_put(fid: dfid);
681 if (fid == ERR_PTR(error: -ENOENT))
682 inode = NULL;
683 else if (IS_ERR(ptr: fid))
684 inode = ERR_CAST(ptr: fid);
685 else
686 inode = v9fs_get_inode_from_fid(v9ses, fid, sb: dir->i_sb);
687 /*
688 * If we had a rename on the server and a parallel lookup
689 * for the new name, then make sure we instantiate with
690 * the new name. ie look up for a/b, while on server somebody
691 * moved b under k and client parallely did a lookup for
692 * k/b.
693 */
694 res = d_splice_alias(inode, dentry);
695 if (!IS_ERR(ptr: fid)) {
696 if (!res)
697 v9fs_fid_add(dentry, fid: &fid);
698 else if (!IS_ERR(ptr: res))
699 v9fs_fid_add(dentry: res, fid: &fid);
700 else
701 p9_fid_put(fid);
702 }
703 return res;
704}
705
706static int
707v9fs_vfs_atomic_open(struct inode *dir, struct dentry *dentry,
708 struct file *file, unsigned int flags, umode_t mode)
709{
710 int err;
711 u32 perm;
712 struct v9fs_inode __maybe_unused *v9inode;
713 struct v9fs_session_info *v9ses;
714 struct p9_fid *fid;
715 struct dentry *res = NULL;
716 struct inode *inode;
717 int p9_omode;
718
719 if (d_in_lookup(dentry)) {
720 res = v9fs_vfs_lookup(dir, dentry, flags: 0);
721 if (IS_ERR(ptr: res))
722 return PTR_ERR(ptr: res);
723
724 if (res)
725 dentry = res;
726 }
727
728 /* Only creates */
729 if (!(flags & O_CREAT) || d_really_is_positive(dentry))
730 return finish_no_open(file, dentry: res);
731
732 v9ses = v9fs_inode2v9ses(inode: dir);
733 perm = unixmode2p9mode(v9ses, mode);
734 p9_omode = v9fs_uflags2omode(uflags: flags, extended: v9fs_proto_dotu(v9ses));
735
736 if ((v9ses->cache & CACHE_WRITEBACK) && (p9_omode & P9_OWRITE)) {
737 p9_omode = (p9_omode & ~P9_OWRITE) | P9_ORDWR;
738 p9_debug(P9_DEBUG_CACHE,
739 "write-only file with writeback enabled, creating w/ O_RDWR\n");
740 }
741 fid = v9fs_create(v9ses, dir, dentry, NULL, perm, mode: p9_omode);
742 if (IS_ERR(ptr: fid)) {
743 err = PTR_ERR(ptr: fid);
744 goto error;
745 }
746
747 v9fs_invalidate_inode_attr(inode: dir);
748 inode = d_inode(dentry);
749 v9inode = V9FS_I(inode);
750 err = finish_open(file, dentry, open: generic_file_open);
751 if (err)
752 goto error;
753
754 file->private_data = fid;
755#ifdef CONFIG_9P_FSCACHE
756 if (v9ses->cache & CACHE_FSCACHE)
757 fscache_use_cookie(cookie: v9fs_inode_cookie(v9inode),
758 will_modify: file->f_mode & FMODE_WRITE);
759#endif
760
761 v9fs_fid_add_modes(fid, s_flags: v9ses->flags, s_cache: v9ses->cache, f_flags: file->f_flags);
762 v9fs_open_fid_add(inode, fid: &fid);
763
764 file->f_mode |= FMODE_CREATED;
765out:
766 dput(res);
767 return err;
768
769error:
770 p9_fid_put(fid);
771 goto out;
772}
773
774/**
775 * v9fs_vfs_unlink - VFS unlink hook to delete an inode
776 * @i: inode that is being unlinked
777 * @d: dentry that is being unlinked
778 *
779 */
780
781int v9fs_vfs_unlink(struct inode *i, struct dentry *d)
782{
783 return v9fs_remove(dir: i, dentry: d, flags: 0);
784}
785
786/**
787 * v9fs_vfs_rmdir - VFS unlink hook to delete a directory
788 * @i: inode that is being unlinked
789 * @d: dentry that is being unlinked
790 *
791 */
792
793int v9fs_vfs_rmdir(struct inode *i, struct dentry *d)
794{
795 return v9fs_remove(dir: i, dentry: d, AT_REMOVEDIR);
796}
797
798/**
799 * v9fs_vfs_rename - VFS hook to rename an inode
800 * @idmap: The idmap of the mount
801 * @old_dir: old dir inode
802 * @old_dentry: old dentry
803 * @new_dir: new dir inode
804 * @new_dentry: new dentry
805 * @flags: RENAME_* flags
806 *
807 */
808
809int
810v9fs_vfs_rename(struct mnt_idmap *idmap, struct inode *old_dir,
811 struct dentry *old_dentry, struct inode *new_dir,
812 struct dentry *new_dentry, unsigned int flags)
813{
814 int retval;
815 struct inode *old_inode;
816 struct inode *new_inode;
817 struct v9fs_session_info *v9ses;
818 struct p9_fid *oldfid = NULL, *dfid = NULL;
819 struct p9_fid *olddirfid = NULL;
820 struct p9_fid *newdirfid = NULL;
821 struct p9_wstat wstat;
822
823 if (flags)
824 return -EINVAL;
825
826 p9_debug(P9_DEBUG_VFS, "\n");
827 old_inode = d_inode(dentry: old_dentry);
828 new_inode = d_inode(dentry: new_dentry);
829 v9ses = v9fs_inode2v9ses(inode: old_inode);
830 oldfid = v9fs_fid_lookup(dentry: old_dentry);
831 if (IS_ERR(ptr: oldfid))
832 return PTR_ERR(ptr: oldfid);
833
834 dfid = v9fs_parent_fid(dentry: old_dentry);
835 olddirfid = clone_fid(fid: dfid);
836 p9_fid_put(fid: dfid);
837 dfid = NULL;
838
839 if (IS_ERR(ptr: olddirfid)) {
840 retval = PTR_ERR(ptr: olddirfid);
841 goto error;
842 }
843
844 dfid = v9fs_parent_fid(dentry: new_dentry);
845 newdirfid = clone_fid(fid: dfid);
846 p9_fid_put(fid: dfid);
847 dfid = NULL;
848
849 if (IS_ERR(ptr: newdirfid)) {
850 retval = PTR_ERR(ptr: newdirfid);
851 goto error;
852 }
853
854 down_write(sem: &v9ses->rename_sem);
855 if (v9fs_proto_dotl(v9ses)) {
856 retval = p9_client_renameat(olddirfid, old_name: old_dentry->d_name.name,
857 newdirfid, new_name: new_dentry->d_name.name);
858 if (retval == -EOPNOTSUPP)
859 retval = p9_client_rename(fid: oldfid, newdirfid,
860 name: new_dentry->d_name.name);
861 if (retval != -EOPNOTSUPP)
862 goto error_locked;
863 }
864 if (old_dentry->d_parent != new_dentry->d_parent) {
865 /*
866 * 9P .u can only handle file rename in the same directory
867 */
868
869 p9_debug(P9_DEBUG_ERROR, "old dir and new dir are different\n");
870 retval = -EXDEV;
871 goto error_locked;
872 }
873 v9fs_blank_wstat(wstat: &wstat);
874 wstat.muid = v9ses->uname;
875 wstat.name = new_dentry->d_name.name;
876 retval = p9_client_wstat(fid: oldfid, wst: &wstat);
877
878error_locked:
879 if (!retval) {
880 if (new_inode) {
881 if (S_ISDIR(new_inode->i_mode))
882 clear_nlink(inode: new_inode);
883 else
884 v9fs_dec_count(inode: new_inode);
885 }
886 if (S_ISDIR(old_inode->i_mode)) {
887 if (!new_inode)
888 inc_nlink(inode: new_dir);
889 v9fs_dec_count(inode: old_dir);
890 }
891 v9fs_invalidate_inode_attr(inode: old_inode);
892 v9fs_invalidate_inode_attr(inode: old_dir);
893 v9fs_invalidate_inode_attr(inode: new_dir);
894
895 /* successful rename */
896 d_move(old_dentry, new_dentry);
897 }
898 up_write(sem: &v9ses->rename_sem);
899
900error:
901 p9_fid_put(fid: newdirfid);
902 p9_fid_put(fid: olddirfid);
903 p9_fid_put(fid: oldfid);
904 return retval;
905}
906
907/**
908 * v9fs_vfs_getattr - retrieve file metadata
909 * @idmap: idmap of the mount
910 * @path: Object to query
911 * @stat: metadata structure to populate
912 * @request_mask: Mask of STATX_xxx flags indicating the caller's interests
913 * @flags: AT_STATX_xxx setting
914 *
915 */
916
917static int
918v9fs_vfs_getattr(struct mnt_idmap *idmap, const struct path *path,
919 struct kstat *stat, u32 request_mask, unsigned int flags)
920{
921 struct dentry *dentry = path->dentry;
922 struct inode *inode = d_inode(dentry);
923 struct v9fs_session_info *v9ses;
924 struct p9_fid *fid;
925 struct p9_wstat *st;
926
927 p9_debug(P9_DEBUG_VFS, "dentry: %p\n", dentry);
928 v9ses = v9fs_dentry2v9ses(dentry);
929 if (v9ses->cache & (CACHE_META|CACHE_LOOSE)) {
930 generic_fillattr(&nop_mnt_idmap, request_mask, inode, stat);
931 return 0;
932 } else if (v9ses->cache & CACHE_WRITEBACK) {
933 if (S_ISREG(inode->i_mode)) {
934 int retval = filemap_fdatawrite(inode->i_mapping);
935
936 if (retval)
937 p9_debug(P9_DEBUG_ERROR,
938 "flushing writeback during getattr returned %d\n", retval);
939 }
940 }
941 fid = v9fs_fid_lookup(dentry);
942 if (IS_ERR(ptr: fid))
943 return PTR_ERR(ptr: fid);
944
945 st = p9_client_stat(fid);
946 p9_fid_put(fid);
947 if (IS_ERR(ptr: st))
948 return PTR_ERR(ptr: st);
949
950 v9fs_stat2inode(stat: st, inode: d_inode(dentry), sb: dentry->d_sb, flags: 0);
951 generic_fillattr(&nop_mnt_idmap, request_mask, d_inode(dentry), stat);
952
953 p9stat_free(stbuf: st);
954 kfree(objp: st);
955 return 0;
956}
957
958/**
959 * v9fs_vfs_setattr - set file metadata
960 * @idmap: idmap of the mount
961 * @dentry: file whose metadata to set
962 * @iattr: metadata assignment structure
963 *
964 */
965
966static int v9fs_vfs_setattr(struct mnt_idmap *idmap,
967 struct dentry *dentry, struct iattr *iattr)
968{
969 int retval, use_dentry = 0;
970 struct inode *inode = d_inode(dentry);
971 struct v9fs_session_info *v9ses;
972 struct p9_fid *fid = NULL;
973 struct p9_wstat wstat;
974
975 p9_debug(P9_DEBUG_VFS, "\n");
976 retval = setattr_prepare(&nop_mnt_idmap, dentry, iattr);
977 if (retval)
978 return retval;
979
980 v9ses = v9fs_dentry2v9ses(dentry);
981 if (iattr->ia_valid & ATTR_FILE) {
982 fid = iattr->ia_file->private_data;
983 WARN_ON(!fid);
984 }
985 if (!fid) {
986 fid = v9fs_fid_lookup(dentry);
987 use_dentry = 1;
988 }
989 if (IS_ERR(ptr: fid))
990 return PTR_ERR(ptr: fid);
991
992 v9fs_blank_wstat(wstat: &wstat);
993 if (iattr->ia_valid & ATTR_MODE)
994 wstat.mode = unixmode2p9mode(v9ses, mode: iattr->ia_mode);
995
996 if (iattr->ia_valid & ATTR_MTIME)
997 wstat.mtime = iattr->ia_mtime.tv_sec;
998
999 if (iattr->ia_valid & ATTR_ATIME)
1000 wstat.atime = iattr->ia_atime.tv_sec;
1001
1002 if (iattr->ia_valid & ATTR_SIZE)
1003 wstat.length = iattr->ia_size;
1004
1005 if (v9fs_proto_dotu(v9ses)) {
1006 if (iattr->ia_valid & ATTR_UID)
1007 wstat.n_uid = iattr->ia_uid;
1008
1009 if (iattr->ia_valid & ATTR_GID)
1010 wstat.n_gid = iattr->ia_gid;
1011 }
1012
1013 /* Write all dirty data */
1014 if (d_is_reg(dentry)) {
1015 retval = filemap_fdatawrite(inode->i_mapping);
1016 if (retval)
1017 p9_debug(P9_DEBUG_ERROR,
1018 "flushing writeback during setattr returned %d\n", retval);
1019 }
1020
1021 retval = p9_client_wstat(fid, wst: &wstat);
1022
1023 if (use_dentry)
1024 p9_fid_put(fid);
1025
1026 if (retval < 0)
1027 return retval;
1028
1029 if ((iattr->ia_valid & ATTR_SIZE) &&
1030 iattr->ia_size != i_size_read(inode)) {
1031 truncate_setsize(inode, newsize: iattr->ia_size);
1032 netfs_resize_file(ctx: netfs_inode(inode), new_i_size: iattr->ia_size, changed_on_server: true);
1033
1034#ifdef CONFIG_9P_FSCACHE
1035 if (v9ses->cache & CACHE_FSCACHE) {
1036 struct v9fs_inode *v9inode = V9FS_I(inode);
1037
1038 fscache_resize_cookie(cookie: v9fs_inode_cookie(v9inode), new_size: iattr->ia_size);
1039 }
1040#endif
1041 }
1042
1043 v9fs_invalidate_inode_attr(inode);
1044
1045 setattr_copy(&nop_mnt_idmap, inode, attr: iattr);
1046 mark_inode_dirty(inode);
1047 return 0;
1048}
1049
1050/**
1051 * v9fs_stat2inode - populate an inode structure with mistat info
1052 * @stat: Plan 9 metadata (mistat) structure
1053 * @inode: inode to populate
1054 * @sb: superblock of filesystem
1055 * @flags: control flags (e.g. V9FS_STAT2INODE_KEEP_ISIZE)
1056 *
1057 */
1058
1059void
1060v9fs_stat2inode(struct p9_wstat *stat, struct inode *inode,
1061 struct super_block *sb, unsigned int flags)
1062{
1063 umode_t mode;
1064 struct v9fs_session_info *v9ses = sb->s_fs_info;
1065 struct v9fs_inode *v9inode = V9FS_I(inode);
1066
1067 inode_set_atime(inode, sec: stat->atime, nsec: 0);
1068 inode_set_mtime(inode, sec: stat->mtime, nsec: 0);
1069 inode_set_ctime(inode, sec: stat->mtime, nsec: 0);
1070
1071 inode->i_uid = v9ses->dfltuid;
1072 inode->i_gid = v9ses->dfltgid;
1073
1074 if (v9fs_proto_dotu(v9ses)) {
1075 inode->i_uid = stat->n_uid;
1076 inode->i_gid = stat->n_gid;
1077 }
1078 if ((S_ISREG(inode->i_mode)) || (S_ISDIR(inode->i_mode))) {
1079 if (v9fs_proto_dotu(v9ses)) {
1080 unsigned int i_nlink;
1081 /*
1082 * Hadlink support got added later to the .u extension.
1083 * So there can be a server out there that doesn't
1084 * support this even with .u extension. That would
1085 * just leave us with stat->extension being an empty
1086 * string, though.
1087 */
1088 /* HARDLINKCOUNT %u */
1089 if (sscanf(stat->extension,
1090 " HARDLINKCOUNT %u", &i_nlink) == 1)
1091 set_nlink(inode, nlink: i_nlink);
1092 }
1093 }
1094 mode = p9mode2perm(v9ses, stat);
1095 mode |= inode->i_mode & ~S_IALLUGO;
1096 inode->i_mode = mode;
1097
1098 v9inode->netfs.remote_i_size = stat->length;
1099 if (!(flags & V9FS_STAT2INODE_KEEP_ISIZE))
1100 v9fs_i_size_write(inode, i_size: stat->length);
1101 /* not real number of blocks, but 512 byte ones ... */
1102 inode->i_blocks = (stat->length + 512 - 1) >> 9;
1103 v9inode->cache_validity &= ~V9FS_INO_INVALID_ATTR;
1104}
1105
1106/**
1107 * v9fs_vfs_get_link - follow a symlink path
1108 * @dentry: dentry for symlink
1109 * @inode: inode for symlink
1110 * @done: delayed call for when we are done with the return value
1111 */
1112
1113static const char *v9fs_vfs_get_link(struct dentry *dentry,
1114 struct inode *inode,
1115 struct delayed_call *done)
1116{
1117 struct v9fs_session_info *v9ses;
1118 struct p9_fid *fid;
1119 struct p9_wstat *st;
1120 char *res;
1121
1122 if (!dentry)
1123 return ERR_PTR(error: -ECHILD);
1124
1125 v9ses = v9fs_dentry2v9ses(dentry);
1126 if (!v9fs_proto_dotu(v9ses))
1127 return ERR_PTR(error: -EBADF);
1128
1129 p9_debug(P9_DEBUG_VFS, "%pd\n", dentry);
1130 fid = v9fs_fid_lookup(dentry);
1131
1132 if (IS_ERR(ptr: fid))
1133 return ERR_CAST(ptr: fid);
1134
1135 st = p9_client_stat(fid);
1136 p9_fid_put(fid);
1137 if (IS_ERR(ptr: st))
1138 return ERR_CAST(ptr: st);
1139
1140 if (!(st->mode & P9_DMSYMLINK)) {
1141 p9stat_free(stbuf: st);
1142 kfree(objp: st);
1143 return ERR_PTR(error: -EINVAL);
1144 }
1145 res = st->extension;
1146 st->extension = NULL;
1147 if (strlen(res) >= PATH_MAX)
1148 res[PATH_MAX - 1] = '\0';
1149
1150 p9stat_free(stbuf: st);
1151 kfree(objp: st);
1152 set_delayed_call(call: done, fn: kfree_link, arg: res);
1153 return res;
1154}
1155
1156/**
1157 * v9fs_vfs_mkspecial - create a special file
1158 * @dir: inode to create special file in
1159 * @dentry: dentry to create
1160 * @perm: mode to create special file
1161 * @extension: 9p2000.u format extension string representing special file
1162 *
1163 */
1164
1165static int v9fs_vfs_mkspecial(struct inode *dir, struct dentry *dentry,
1166 u32 perm, const char *extension)
1167{
1168 struct p9_fid *fid;
1169 struct v9fs_session_info *v9ses;
1170
1171 v9ses = v9fs_inode2v9ses(inode: dir);
1172 if (!v9fs_proto_dotu(v9ses)) {
1173 p9_debug(P9_DEBUG_ERROR, "not extended\n");
1174 return -EPERM;
1175 }
1176
1177 fid = v9fs_create(v9ses, dir, dentry, extension: (char *) extension, perm,
1178 mode: P9_OREAD);
1179 if (IS_ERR(ptr: fid))
1180 return PTR_ERR(ptr: fid);
1181
1182 v9fs_invalidate_inode_attr(inode: dir);
1183 p9_fid_put(fid);
1184 return 0;
1185}
1186
1187/**
1188 * v9fs_vfs_symlink - helper function to create symlinks
1189 * @idmap: idmap of the mount
1190 * @dir: directory inode containing symlink
1191 * @dentry: dentry for symlink
1192 * @symname: symlink data
1193 *
1194 * See Also: 9P2000.u RFC for more information
1195 *
1196 */
1197
1198static int
1199v9fs_vfs_symlink(struct mnt_idmap *idmap, struct inode *dir,
1200 struct dentry *dentry, const char *symname)
1201{
1202 p9_debug(P9_DEBUG_VFS, " %lu,%pd,%s\n",
1203 dir->i_ino, dentry, symname);
1204
1205 return v9fs_vfs_mkspecial(dir, dentry, perm: P9_DMSYMLINK, extension: symname);
1206}
1207
1208#define U32_MAX_DIGITS 10
1209
1210/**
1211 * v9fs_vfs_link - create a hardlink
1212 * @old_dentry: dentry for file to link to
1213 * @dir: inode destination for new link
1214 * @dentry: dentry for link
1215 *
1216 */
1217
1218static int
1219v9fs_vfs_link(struct dentry *old_dentry, struct inode *dir,
1220 struct dentry *dentry)
1221{
1222 int retval;
1223 char name[1 + U32_MAX_DIGITS + 2]; /* sign + number + \n + \0 */
1224 struct p9_fid *oldfid;
1225
1226 p9_debug(P9_DEBUG_VFS, " %lu,%pd,%pd\n",
1227 dir->i_ino, dentry, old_dentry);
1228
1229 oldfid = v9fs_fid_clone(dentry: old_dentry);
1230 if (IS_ERR(ptr: oldfid))
1231 return PTR_ERR(ptr: oldfid);
1232
1233 sprintf(buf: name, fmt: "%d\n", oldfid->fid);
1234 retval = v9fs_vfs_mkspecial(dir, dentry, perm: P9_DMLINK, extension: name);
1235 if (!retval) {
1236 v9fs_refresh_inode(fid: oldfid, inode: d_inode(dentry: old_dentry));
1237 v9fs_invalidate_inode_attr(inode: dir);
1238 }
1239 p9_fid_put(fid: oldfid);
1240 return retval;
1241}
1242
1243/**
1244 * v9fs_vfs_mknod - create a special file
1245 * @idmap: idmap of the mount
1246 * @dir: inode destination for new link
1247 * @dentry: dentry for file
1248 * @mode: mode for creation
1249 * @rdev: device associated with special file
1250 *
1251 */
1252
1253static int
1254v9fs_vfs_mknod(struct mnt_idmap *idmap, struct inode *dir,
1255 struct dentry *dentry, umode_t mode, dev_t rdev)
1256{
1257 struct v9fs_session_info *v9ses = v9fs_inode2v9ses(inode: dir);
1258 int retval;
1259 char name[2 + U32_MAX_DIGITS + 1 + U32_MAX_DIGITS + 1];
1260 u32 perm;
1261
1262 p9_debug(P9_DEBUG_VFS, " %lu,%pd mode: %x MAJOR: %u MINOR: %u\n",
1263 dir->i_ino, dentry, mode,
1264 MAJOR(rdev), MINOR(rdev));
1265
1266 /* build extension */
1267 if (S_ISBLK(mode))
1268 sprintf(buf: name, fmt: "b %u %u", MAJOR(rdev), MINOR(rdev));
1269 else if (S_ISCHR(mode))
1270 sprintf(buf: name, fmt: "c %u %u", MAJOR(rdev), MINOR(rdev));
1271 else
1272 *name = 0;
1273
1274 perm = unixmode2p9mode(v9ses, mode);
1275 retval = v9fs_vfs_mkspecial(dir, dentry, perm, extension: name);
1276
1277 return retval;
1278}
1279
1280int v9fs_refresh_inode(struct p9_fid *fid, struct inode *inode)
1281{
1282 int umode;
1283 dev_t rdev;
1284 struct p9_wstat *st;
1285 struct v9fs_session_info *v9ses;
1286 unsigned int flags;
1287
1288 v9ses = v9fs_inode2v9ses(inode);
1289 st = p9_client_stat(fid);
1290 if (IS_ERR(ptr: st))
1291 return PTR_ERR(ptr: st);
1292 /*
1293 * Don't update inode if the file type is different
1294 */
1295 umode = p9mode2unixmode(v9ses, stat: st, rdev: &rdev);
1296 if (inode_wrong_type(inode, mode: umode))
1297 goto out;
1298
1299 /*
1300 * We don't want to refresh inode->i_size,
1301 * because we may have cached data
1302 */
1303 flags = (v9ses->cache & CACHE_LOOSE) ?
1304 V9FS_STAT2INODE_KEEP_ISIZE : 0;
1305 v9fs_stat2inode(stat: st, inode, sb: inode->i_sb, flags);
1306out:
1307 p9stat_free(stbuf: st);
1308 kfree(objp: st);
1309 return 0;
1310}
1311
1312static const struct inode_operations v9fs_dir_inode_operations_dotu = {
1313 .create = v9fs_vfs_create,
1314 .lookup = v9fs_vfs_lookup,
1315 .atomic_open = v9fs_vfs_atomic_open,
1316 .symlink = v9fs_vfs_symlink,
1317 .link = v9fs_vfs_link,
1318 .unlink = v9fs_vfs_unlink,
1319 .mkdir = v9fs_vfs_mkdir,
1320 .rmdir = v9fs_vfs_rmdir,
1321 .mknod = v9fs_vfs_mknod,
1322 .rename = v9fs_vfs_rename,
1323 .getattr = v9fs_vfs_getattr,
1324 .setattr = v9fs_vfs_setattr,
1325};
1326
1327static const struct inode_operations v9fs_dir_inode_operations = {
1328 .create = v9fs_vfs_create,
1329 .lookup = v9fs_vfs_lookup,
1330 .atomic_open = v9fs_vfs_atomic_open,
1331 .unlink = v9fs_vfs_unlink,
1332 .mkdir = v9fs_vfs_mkdir,
1333 .rmdir = v9fs_vfs_rmdir,
1334 .mknod = v9fs_vfs_mknod,
1335 .rename = v9fs_vfs_rename,
1336 .getattr = v9fs_vfs_getattr,
1337 .setattr = v9fs_vfs_setattr,
1338};
1339
1340static const struct inode_operations v9fs_file_inode_operations = {
1341 .getattr = v9fs_vfs_getattr,
1342 .setattr = v9fs_vfs_setattr,
1343};
1344
1345static const struct inode_operations v9fs_symlink_inode_operations = {
1346 .get_link = v9fs_vfs_get_link,
1347 .getattr = v9fs_vfs_getattr,
1348 .setattr = v9fs_vfs_setattr,
1349};
1350
1351

source code of linux/fs/9p/vfs_inode.c