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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, 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
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * linux/fs/9p/vfs_inode.c
4 *
5 * This file contains vfs inode ops for the 9P2000 protocol.
6 *
7 * Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
8 * Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
9 */
10
11#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
12
13#include <linux/module.h>
14#include <linux/errno.h>
15#include <linux/fs.h>
16#include <linux/file.h>
17#include <linux/pagemap.h>
18#include <linux/stat.h>
19#include <linux/string.h>
20#include <linux/inet.h>
21#include <linux/namei.h>
22#include <linux/idr.h>
23#include <linux/sched.h>
24#include <linux/slab.h>
25#include <linux/xattr.h>
26#include <linux/posix_acl.h>
27#include <net/9p/9p.h>
28#include <net/9p/client.h>
29
30#include "v9fs.h"
31#include "v9fs_vfs.h"
32#include "fid.h"
33#include "cache.h"
34#include "xattr.h"
35#include "acl.h"
36
37static const struct inode_operations v9fs_dir_inode_operations;
38static const struct inode_operations v9fs_dir_inode_operations_dotu;
39static const struct inode_operations v9fs_file_inode_operations;
40static const struct inode_operations v9fs_symlink_inode_operations;
41
42/**
43 * unixmode2p9mode - convert unix mode bits to plan 9
44 * @v9ses: v9fs session information
45 * @mode: mode to convert
46 *
47 */
48
49static u32 unixmode2p9mode(struct v9fs_session_info *v9ses, umode_t mode)
50{
51 int res;
52 res = mode & 0777;
53 if (S_ISDIR(mode))
54 res |= P9_DMDIR;
55 if (v9fs_proto_dotu(v9ses)) {
56 if (v9ses->nodev == 0) {
57 if (S_ISSOCK(mode))
58 res |= P9_DMSOCKET;
59 if (S_ISFIFO(mode))
60 res |= P9_DMNAMEDPIPE;
61 if (S_ISBLK(mode))
62 res |= P9_DMDEVICE;
63 if (S_ISCHR(mode))
64 res |= P9_DMDEVICE;
65 }
66
67 if ((mode & S_ISUID) == S_ISUID)
68 res |= P9_DMSETUID;
69 if ((mode & S_ISGID) == S_ISGID)
70 res |= P9_DMSETGID;
71 if ((mode & S_ISVTX) == S_ISVTX)
72 res |= P9_DMSETVTX;
73 }
74 return res;
75}
76
77/**
78 * p9mode2perm- convert plan9 mode bits to unix permission bits
79 * @v9ses: v9fs session information
80 * @stat: p9_wstat from which mode need to be derived
81 *
82 */
83static int p9mode2perm(struct v9fs_session_info *v9ses,
84 struct p9_wstat *stat)
85{
86 int res;
87 int mode = stat->mode;
88
89 res = mode & S_IALLUGO;
90 if (v9fs_proto_dotu(v9ses)) {
91 if ((mode & P9_DMSETUID) == P9_DMSETUID)
92 res |= S_ISUID;
93
94 if ((mode & P9_DMSETGID) == P9_DMSETGID)
95 res |= S_ISGID;
96
97 if ((mode & P9_DMSETVTX) == P9_DMSETVTX)
98 res |= S_ISVTX;
99 }
100 return res;
101}
102
103/**
104 * p9mode2unixmode- convert plan9 mode bits to unix mode bits
105 * @v9ses: v9fs session information
106 * @stat: p9_wstat from which mode need to be derived
107 * @rdev: major number, minor number in case of device files.
108 *
109 */
110static umode_t p9mode2unixmode(struct v9fs_session_info *v9ses,
111 struct p9_wstat *stat, dev_t *rdev)
112{
113 int res;
114 u32 mode = stat->mode;
115
116 *rdev = 0;
117 res = p9mode2perm(v9ses, stat);
118
119 if ((mode & P9_DMDIR) == P9_DMDIR)
120 res |= S_IFDIR;
121 else if ((mode & P9_DMSYMLINK) && (v9fs_proto_dotu(v9ses)))
122 res |= S_IFLNK;
123 else if ((mode & P9_DMSOCKET) && (v9fs_proto_dotu(v9ses))
124 && (v9ses->nodev == 0))
125 res |= S_IFSOCK;
126 else if ((mode & P9_DMNAMEDPIPE) && (v9fs_proto_dotu(v9ses))
127 && (v9ses->nodev == 0))
128 res |= S_IFIFO;
129 else if ((mode & P9_DMDEVICE) && (v9fs_proto_dotu(v9ses))
130 && (v9ses->nodev == 0)) {
131 char type = 0, ext[32];
132 int major = -1, minor = -1;
133
134 strlcpy(ext, stat->extension, sizeof(ext));
135 sscanf(ext, "%c %i %i", &type, &major, &minor);
136 switch (type) {
137 case 'c':
138 res |= S_IFCHR;
139 break;
140 case 'b':
141 res |= S_IFBLK;
142 break;
143 default:
144 p9_debug(P9_DEBUG_ERROR, "Unknown special type %c %s\n",
145 type, stat->extension);
146 }
147 *rdev = MKDEV(major, minor);
148 } else
149 res |= S_IFREG;
150
151 return res;
152}
153
154/**
155 * v9fs_uflags2omode- convert posix open flags to plan 9 mode bits
156 * @uflags: flags to convert
157 * @extended: if .u extensions are active
158 */
159
160int v9fs_uflags2omode(int uflags, int extended)
161{
162 int ret;
163
164 ret = 0;
165 switch (uflags&3) {
166 default:
167 case O_RDONLY:
168 ret = P9_OREAD;
169 break;
170
171 case O_WRONLY:
172 ret = P9_OWRITE;
173 break;
174
175 case O_RDWR:
176 ret = P9_ORDWR;
177 break;
178 }
179
180 if (extended) {
181 if (uflags & O_EXCL)
182 ret |= P9_OEXCL;
183
184 if (uflags & O_APPEND)
185 ret |= P9_OAPPEND;
186 }
187
188 return ret;
189}
190
191/**
192 * v9fs_blank_wstat - helper function to setup a 9P stat structure
193 * @wstat: structure to initialize
194 *
195 */
196
197void
198v9fs_blank_wstat(struct p9_wstat *wstat)
199{
200 wstat->type = ~0;
201 wstat->dev = ~0;
202 wstat->qid.type = ~0;
203 wstat->qid.version = ~0;
204 *((long long *)&wstat->qid.path) = ~0;
205 wstat->mode = ~0;
206 wstat->atime = ~0;
207 wstat->mtime = ~0;
208 wstat->length = ~0;
209 wstat->name = NULL;
210 wstat->uid = NULL;
211 wstat->gid = NULL;
212 wstat->muid = NULL;
213 wstat->n_uid = INVALID_UID;
214 wstat->n_gid = INVALID_GID;
215 wstat->n_muid = INVALID_UID;
216 wstat->extension = NULL;
217}
218
219/**
220 * v9fs_alloc_inode - helper function to allocate an inode
221 *
222 */
223struct inode *v9fs_alloc_inode(struct super_block *sb)
224{
225 struct v9fs_inode *v9inode;
226 v9inode = kmem_cache_alloc(v9fs_inode_cache, GFP_KERNEL);
227 if (!v9inode)
228 return NULL;
229#ifdef CONFIG_9P_FSCACHE
230 v9inode->fscache = NULL;
231 mutex_init(&v9inode->fscache_lock);
232#endif
233 v9inode->writeback_fid = NULL;
234 v9inode->cache_validity = 0;
235 mutex_init(&v9inode->v_mutex);
236 return &v9inode->vfs_inode;
237}
238
239/**
240 * v9fs_free_inode - destroy an inode
241 *
242 */
243
244void v9fs_free_inode(struct inode *inode)
245{
246 kmem_cache_free(v9fs_inode_cache, V9FS_I(inode));
247}
248
249int v9fs_init_inode(struct v9fs_session_info *v9ses,
250 struct inode *inode, umode_t mode, dev_t rdev)
251{
252 int err = 0;
253
254 inode_init_owner(inode, NULL, mode);
255 inode->i_blocks = 0;
256 inode->i_rdev = rdev;
257 inode->i_atime = inode->i_mtime = inode->i_ctime = current_time(inode);
258 inode->i_mapping->a_ops = &v9fs_addr_operations;
259
260 switch (mode & S_IFMT) {
261 case S_IFIFO:
262 case S_IFBLK:
263 case S_IFCHR:
264 case S_IFSOCK:
265 if (v9fs_proto_dotl(v9ses)) {
266 inode->i_op = &v9fs_file_inode_operations_dotl;
267 } else if (v9fs_proto_dotu(v9ses)) {
268 inode->i_op = &v9fs_file_inode_operations;
269 } else {
270 p9_debug(P9_DEBUG_ERROR,
271 "special files without extended mode\n");
272 err = -EINVAL;
273 goto error;
274 }
275 init_special_inode(inode, inode->i_mode, inode->i_rdev);
276 break;
277 case S_IFREG:
278 if (v9fs_proto_dotl(v9ses)) {
279 inode->i_op = &v9fs_file_inode_operations_dotl;
280 if (v9ses->cache == CACHE_LOOSE ||
281 v9ses->cache == CACHE_FSCACHE)
282 inode->i_fop =
283 &v9fs_cached_file_operations_dotl;
284 else if (v9ses->cache == CACHE_MMAP)
285 inode->i_fop = &v9fs_mmap_file_operations_dotl;
286 else
287 inode->i_fop = &v9fs_file_operations_dotl;
288 } else {
289 inode->i_op = &v9fs_file_inode_operations;
290 if (v9ses->cache == CACHE_LOOSE ||
291 v9ses->cache == CACHE_FSCACHE)
292 inode->i_fop =
293 &v9fs_cached_file_operations;
294 else if (v9ses->cache == CACHE_MMAP)
295 inode->i_fop = &v9fs_mmap_file_operations;
296 else
297 inode->i_fop = &v9fs_file_operations;
298 }
299
300 break;
301 case S_IFLNK:
302 if (!v9fs_proto_dotu(v9ses) && !v9fs_proto_dotl(v9ses)) {
303 p9_debug(P9_DEBUG_ERROR,
304 "extended modes used with legacy protocol\n");
305 err = -EINVAL;
306 goto error;
307 }
308
309 if (v9fs_proto_dotl(v9ses))
310 inode->i_op = &v9fs_symlink_inode_operations_dotl;
311 else
312 inode->i_op = &v9fs_symlink_inode_operations;
313
314 break;
315 case S_IFDIR:
316 inc_nlink(inode);
317 if (v9fs_proto_dotl(v9ses))
318 inode->i_op = &v9fs_dir_inode_operations_dotl;
319 else if (v9fs_proto_dotu(v9ses))
320 inode->i_op = &v9fs_dir_inode_operations_dotu;
321 else
322 inode->i_op = &v9fs_dir_inode_operations;
323
324 if (v9fs_proto_dotl(v9ses))
325 inode->i_fop = &v9fs_dir_operations_dotl;
326 else
327 inode->i_fop = &v9fs_dir_operations;
328
329 break;
330 default:
331 p9_debug(P9_DEBUG_ERROR, "BAD mode 0x%hx S_IFMT 0x%x\n",
332 mode, mode & S_IFMT);
333 err = -EINVAL;
334 goto error;
335 }
336error:
337 return err;
338
339}
340
341/**
342 * v9fs_get_inode - helper function to setup an inode
343 * @sb: superblock
344 * @mode: mode to setup inode with
345 *
346 */
347
348struct inode *v9fs_get_inode(struct super_block *sb, umode_t mode, dev_t rdev)
349{
350 int err;
351 struct inode *inode;
352 struct v9fs_session_info *v9ses = sb->s_fs_info;
353
354 p9_debug(P9_DEBUG_VFS, "super block: %p mode: %ho\n", sb, mode);
355
356 inode = new_inode(sb);
357 if (!inode) {
358 pr_warn("%s (%d): Problem allocating inode\n",
359 __func__, task_pid_nr(current));
360 return ERR_PTR(-ENOMEM);
361 }
362 err = v9fs_init_inode(v9ses, inode, mode, rdev);
363 if (err) {
364 iput(inode);
365 return ERR_PTR(err);
366 }
367 return inode;
368}
369
370/**
371 * v9fs_clear_inode - release an inode
372 * @inode: inode to release
373 *
374 */
375void v9fs_evict_inode(struct inode *inode)
376{
377 struct v9fs_inode *v9inode = V9FS_I(inode);
378
379 truncate_inode_pages_final(&inode->i_data);
380 clear_inode(inode);
381 filemap_fdatawrite(&inode->i_data);
382
383 v9fs_cache_inode_put_cookie(inode);
384 /* clunk the fid stashed in writeback_fid */
385 if (v9inode->writeback_fid) {
386 p9_client_clunk(v9inode->writeback_fid);
387 v9inode->writeback_fid = NULL;
388 }
389}
390
391static int v9fs_test_inode(struct inode *inode, void *data)
392{
393 int umode;
394 dev_t rdev;
395 struct v9fs_inode *v9inode = V9FS_I(inode);
396 struct p9_wstat *st = (struct p9_wstat *)data;
397 struct v9fs_session_info *v9ses = v9fs_inode2v9ses(inode);
398
399 umode = p9mode2unixmode(v9ses, st, &rdev);
400 /* don't match inode of different type */
401 if ((inode->i_mode & S_IFMT) != (umode & S_IFMT))
402 return 0;
403
404 /* compare qid details */
405 if (memcmp(&v9inode->qid.version,
406 &st->qid.version, sizeof(v9inode->qid.version)))
407 return 0;
408
409 if (v9inode->qid.type != st->qid.type)
410 return 0;
411
412 if (v9inode->qid.path != st->qid.path)
413 return 0;
414 return 1;
415}
416
417static int v9fs_test_new_inode(struct inode *inode, void *data)
418{
419 return 0;
420}
421
422static int v9fs_set_inode(struct inode *inode, void *data)
423{
424 struct v9fs_inode *v9inode = V9FS_I(inode);
425 struct p9_wstat *st = (struct p9_wstat *)data;
426
427 memcpy(&v9inode->qid, &st->qid, sizeof(st->qid));
428 return 0;
429}
430
431static struct inode *v9fs_qid_iget(struct super_block *sb,
432 struct p9_qid *qid,
433 struct p9_wstat *st,
434 int new)
435{
436 dev_t rdev;
437 int retval;
438 umode_t umode;
439 unsigned long i_ino;
440 struct inode *inode;
441 struct v9fs_session_info *v9ses = sb->s_fs_info;
442 int (*test)(struct inode *, void *);
443
444 if (new)
445 test = v9fs_test_new_inode;
446 else
447 test = v9fs_test_inode;
448
449 i_ino = v9fs_qid2ino(qid);
450 inode = iget5_locked(sb, i_ino, test, v9fs_set_inode, st);
451 if (!inode)
452 return ERR_PTR(-ENOMEM);
453 if (!(inode->i_state & I_NEW))
454 return inode;
455 /*
456 * initialize the inode with the stat info
457 * FIXME!! we may need support for stale inodes
458 * later.
459 */
460 inode->i_ino = i_ino;
461 umode = p9mode2unixmode(v9ses, st, &rdev);
462 retval = v9fs_init_inode(v9ses, inode, umode, rdev);
463 if (retval)
464 goto error;
465
466 v9fs_stat2inode(st, inode, sb, 0);
467 v9fs_cache_inode_get_cookie(inode);
468 unlock_new_inode(inode);
469 return inode;
470error:
471 iget_failed(inode);
472 return ERR_PTR(retval);
473
474}
475
476struct inode *
477v9fs_inode_from_fid(struct v9fs_session_info *v9ses, struct p9_fid *fid,
478 struct super_block *sb, int new)
479{
480 struct p9_wstat *st;
481 struct inode *inode = NULL;
482
483 st = p9_client_stat(fid);
484 if (IS_ERR(st))
485 return ERR_CAST(st);
486
487 inode = v9fs_qid_iget(sb, &st->qid, st, new);
488 p9stat_free(st);
489 kfree(st);
490 return inode;
491}
492
493/**
494 * v9fs_at_to_dotl_flags- convert Linux specific AT flags to
495 * plan 9 AT flag.
496 * @flags: flags to convert
497 */
498static int v9fs_at_to_dotl_flags(int flags)
499{
500 int rflags = 0;
501 if (flags & AT_REMOVEDIR)
502 rflags |= P9_DOTL_AT_REMOVEDIR;
503 return rflags;
504}
505
506/**
507 * v9fs_dec_count - helper functon to drop i_nlink.
508 *
509 * If a directory had nlink <= 2 (including . and ..), then we should not drop
510 * the link count, which indicates the underlying exported fs doesn't maintain
511 * nlink accurately. e.g.
512 * - overlayfs sets nlink to 1 for merged dir
513 * - ext4 (with dir_nlink feature enabled) sets nlink to 1 if a dir has more
514 * than EXT4_LINK_MAX (65000) links.
515 *
516 * @inode: inode whose nlink is being dropped
517 */
518static void v9fs_dec_count(struct inode *inode)
519{
520 if (!S_ISDIR(inode->i_mode) || inode->i_nlink > 2)
521 drop_nlink(inode);
522}
523
524/**
525 * v9fs_remove - helper function to remove files and directories
526 * @dir: directory inode that is being deleted
527 * @dentry: dentry that is being deleted
528 * @flags: removing a directory
529 *
530 */
531
532static int v9fs_remove(struct inode *dir, struct dentry *dentry, int flags)
533{
534 struct inode *inode;
535 int retval = -EOPNOTSUPP;
536 struct p9_fid *v9fid, *dfid;
537 struct v9fs_session_info *v9ses;
538
539 p9_debug(P9_DEBUG_VFS, "inode: %p dentry: %p rmdir: %x\n",
540 dir, dentry, flags);
541
542 v9ses = v9fs_inode2v9ses(dir);
543 inode = d_inode(dentry);
544 dfid = v9fs_parent_fid(dentry);
545 if (IS_ERR(dfid)) {
546 retval = PTR_ERR(dfid);
547 p9_debug(P9_DEBUG_VFS, "fid lookup failed %d\n", retval);
548 return retval;
549 }
550 if (v9fs_proto_dotl(v9ses))
551 retval = p9_client_unlinkat(dfid, dentry->d_name.name,
552 v9fs_at_to_dotl_flags(flags));
553 if (retval == -EOPNOTSUPP) {
554 /* Try the one based on path */
555 v9fid = v9fs_fid_clone(dentry);
556 if (IS_ERR(v9fid))
557 return PTR_ERR(v9fid);
558 retval = p9_client_remove(v9fid);
559 }
560 if (!retval) {
561 /*
562 * directories on unlink should have zero
563 * link count
564 */
565 if (flags & AT_REMOVEDIR) {
566 clear_nlink(inode);
567 v9fs_dec_count(dir);
568 } else
569 v9fs_dec_count(inode);
570
571 v9fs_invalidate_inode_attr(inode);
572 v9fs_invalidate_inode_attr(dir);
573 }
574 return retval;
575}
576
577/**
578 * v9fs_create - Create a file
579 * @v9ses: session information
580 * @dir: directory that dentry is being created in
581 * @dentry: dentry that is being created
582 * @extension: 9p2000.u extension string to support devices, etc.
583 * @perm: create permissions
584 * @mode: open mode
585 *
586 */
587static struct p9_fid *
588v9fs_create(struct v9fs_session_info *v9ses, struct inode *dir,
589 struct dentry *dentry, char *extension, u32 perm, u8 mode)
590{
591 int err;
592 const unsigned char *name;
593 struct p9_fid *dfid, *ofid, *fid;
594 struct inode *inode;
595
596 p9_debug(P9_DEBUG_VFS, "name %pd\n", dentry);
597
598 err = 0;
599 ofid = NULL;
600 fid = NULL;
601 name = dentry->d_name.name;
602 dfid = v9fs_parent_fid(dentry);
603 if (IS_ERR(dfid)) {
604 err = PTR_ERR(dfid);
605 p9_debug(P9_DEBUG_VFS, "fid lookup failed %d\n", err);
606 return ERR_PTR(err);
607 }
608
609 /* clone a fid to use for creation */
610 ofid = clone_fid(dfid);
611 if (IS_ERR(ofid)) {
612 err = PTR_ERR(ofid);
613 p9_debug(P9_DEBUG_VFS, "p9_client_walk failed %d\n", err);
614 return ERR_PTR(err);
615 }
616
617 err = p9_client_fcreate(ofid, name, perm, mode, extension);
618 if (err < 0) {
619 p9_debug(P9_DEBUG_VFS, "p9_client_fcreate failed %d\n", err);
620 goto error;
621 }
622
623 if (!(perm & P9_DMLINK)) {
624 /* now walk from the parent so we can get unopened fid */
625 fid = p9_client_walk(dfid, 1, &name, 1);
626 if (IS_ERR(fid)) {
627 err = PTR_ERR(fid);
628 p9_debug(P9_DEBUG_VFS,
629 "p9_client_walk failed %d\n", err);
630 fid = NULL;
631 goto error;
632 }
633 /*
634 * instantiate inode and assign the unopened fid to the dentry
635 */
636 inode = v9fs_get_new_inode_from_fid(v9ses, fid, dir->i_sb);
637 if (IS_ERR(inode)) {
638 err = PTR_ERR(inode);
639 p9_debug(P9_DEBUG_VFS,
640 "inode creation failed %d\n", err);
641 goto error;
642 }
643 v9fs_fid_add(dentry, fid);
644 d_instantiate(dentry, inode);
645 }
646 return ofid;
647error:
648 if (ofid)
649 p9_client_clunk(ofid);
650
651 if (fid)
652 p9_client_clunk(fid);
653
654 return ERR_PTR(err);
655}
656
657/**
658 * v9fs_vfs_create - VFS hook to create a regular file
659 *
660 * open(.., O_CREAT) is handled in v9fs_vfs_atomic_open(). This is only called
661 * for mknod(2).
662 *
663 * @dir: directory inode that is being created
664 * @dentry: dentry that is being deleted
665 * @mode: create permissions
666 *
667 */
668
669static int
670v9fs_vfs_create(struct inode *dir, struct dentry *dentry, umode_t mode,
671 bool excl)
672{
673 struct v9fs_session_info *v9ses = v9fs_inode2v9ses(dir);
674 u32 perm = unixmode2p9mode(v9ses, mode);
675 struct p9_fid *fid;
676
677 /* P9_OEXCL? */
678 fid = v9fs_create(v9ses, dir, dentry, NULL, perm, P9_ORDWR);
679 if (IS_ERR(fid))
680 return PTR_ERR(fid);
681
682 v9fs_invalidate_inode_attr(dir);
683 p9_client_clunk(fid);
684
685 return 0;
686}
687
688/**
689 * v9fs_vfs_mkdir - VFS mkdir hook to create a directory
690 * @dir: inode that is being unlinked
691 * @dentry: dentry that is being unlinked
692 * @mode: mode for new directory
693 *
694 */
695
696static int v9fs_vfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
697{
698 int err;
699 u32 perm;
700 struct p9_fid *fid;
701 struct v9fs_session_info *v9ses;
702
703 p9_debug(P9_DEBUG_VFS, "name %pd\n", dentry);
704 err = 0;
705 v9ses = v9fs_inode2v9ses(dir);
706 perm = unixmode2p9mode(v9ses, mode | S_IFDIR);
707 fid = v9fs_create(v9ses, dir, dentry, NULL, perm, P9_OREAD);
708 if (IS_ERR(fid)) {
709 err = PTR_ERR(fid);
710 fid = NULL;
711 } else {
712 inc_nlink(dir);
713 v9fs_invalidate_inode_attr(dir);
714 }
715
716 if (fid)
717 p9_client_clunk(fid);
718
719 return err;
720}
721
722/**
723 * v9fs_vfs_lookup - VFS lookup hook to "walk" to a new inode
724 * @dir: inode that is being walked from
725 * @dentry: dentry that is being walked to?
726 * @flags: lookup flags (unused)
727 *
728 */
729
730struct dentry *v9fs_vfs_lookup(struct inode *dir, struct dentry *dentry,
731 unsigned int flags)
732{
733 struct dentry *res;
734 struct v9fs_session_info *v9ses;
735 struct p9_fid *dfid, *fid;
736 struct inode *inode;
737 const unsigned char *name;
738
739 p9_debug(P9_DEBUG_VFS, "dir: %p dentry: (%pd) %p flags: %x\n",
740 dir, dentry, dentry, flags);
741
742 if (dentry->d_name.len > NAME_MAX)
743 return ERR_PTR(-ENAMETOOLONG);
744
745 v9ses = v9fs_inode2v9ses(dir);
746 /* We can walk d_parent because we hold the dir->i_mutex */
747 dfid = v9fs_parent_fid(dentry);
748 if (IS_ERR(dfid))
749 return ERR_CAST(dfid);
750
751 /*
752 * Make sure we don't use a wrong inode due to parallel
753 * unlink. For cached mode create calls request for new
754 * inode. But with cache disabled, lookup should do this.
755 */
756 name = dentry->d_name.name;
757 fid = p9_client_walk(dfid, 1, &name, 1);
758 if (fid == ERR_PTR(-ENOENT))
759 inode = NULL;
760 else if (IS_ERR(fid))
761 inode = ERR_CAST(fid);
762 else if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE)
763 inode = v9fs_get_inode_from_fid(v9ses, fid, dir->i_sb);
764 else
765 inode = v9fs_get_new_inode_from_fid(v9ses, fid, dir->i_sb);
766 /*
767 * If we had a rename on the server and a parallel lookup
768 * for the new name, then make sure we instantiate with
769 * the new name. ie look up for a/b, while on server somebody
770 * moved b under k and client parallely did a lookup for
771 * k/b.
772 */
773 res = d_splice_alias(inode, dentry);
774 if (!IS_ERR(fid)) {
775 if (!res)
776 v9fs_fid_add(dentry, fid);
777 else if (!IS_ERR(res))
778 v9fs_fid_add(res, fid);
779 else
780 p9_client_clunk(fid);
781 }
782 return res;
783}
784
785static int
786v9fs_vfs_atomic_open(struct inode *dir, struct dentry *dentry,
787 struct file *file, unsigned flags, umode_t mode)
788{
789 int err;
790 u32 perm;
791 struct v9fs_inode *v9inode;
792 struct v9fs_session_info *v9ses;
793 struct p9_fid *fid, *inode_fid;
794 struct dentry *res = NULL;
795
796 if (d_in_lookup(dentry)) {
797 res = v9fs_vfs_lookup(dir, dentry, 0);
798 if (IS_ERR(res))
799 return PTR_ERR(res);
800
801 if (res)
802 dentry = res;
803 }
804
805 /* Only creates */
806 if (!(flags & O_CREAT) || d_really_is_positive(dentry))
807 return finish_no_open(file, res);
808
809 err = 0;
810
811 v9ses = v9fs_inode2v9ses(dir);
812 perm = unixmode2p9mode(v9ses, mode);
813 fid = v9fs_create(v9ses, dir, dentry, NULL, perm,
814 v9fs_uflags2omode(flags,
815 v9fs_proto_dotu(v9ses)));
816 if (IS_ERR(fid)) {
817 err = PTR_ERR(fid);
818 fid = NULL;
819 goto error;
820 }
821
822 v9fs_invalidate_inode_attr(dir);
823 v9inode = V9FS_I(d_inode(dentry));
824 mutex_lock(&v9inode->v_mutex);
825 if ((v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) &&
826 !v9inode->writeback_fid &&
827 ((flags & O_ACCMODE) != O_RDONLY)) {
828 /*
829 * clone a fid and add it to writeback_fid
830 * we do it during open time instead of
831 * page dirty time via write_begin/page_mkwrite
832 * because we want write after unlink usecase
833 * to work.
834 */
835 inode_fid = v9fs_writeback_fid(dentry);
836 if (IS_ERR(inode_fid)) {
837 err = PTR_ERR(inode_fid);
838 mutex_unlock(&v9inode->v_mutex);
839 goto error;
840 }
841 v9inode->writeback_fid = (void *) inode_fid;
842 }
843 mutex_unlock(&v9inode->v_mutex);
844 err = finish_open(file, dentry, generic_file_open);
845 if (err)
846 goto error;
847
848 file->private_data = fid;
849 if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE)
850 v9fs_cache_inode_set_cookie(d_inode(dentry), file);
851
852 file->f_mode |= FMODE_CREATED;
853out:
854 dput(res);
855 return err;
856
857error:
858 if (fid)
859 p9_client_clunk(fid);
860 goto out;
861}
862
863/**
864 * v9fs_vfs_unlink - VFS unlink hook to delete an inode
865 * @i: inode that is being unlinked
866 * @d: dentry that is being unlinked
867 *
868 */
869
870int v9fs_vfs_unlink(struct inode *i, struct dentry *d)
871{
872 return v9fs_remove(i, d, 0);
873}
874
875/**
876 * v9fs_vfs_rmdir - VFS unlink hook to delete a directory
877 * @i: inode that is being unlinked
878 * @d: dentry that is being unlinked
879 *
880 */
881
882int v9fs_vfs_rmdir(struct inode *i, struct dentry *d)
883{
884 return v9fs_remove(i, d, AT_REMOVEDIR);
885}
886
887/**
888 * v9fs_vfs_rename - VFS hook to rename an inode
889 * @old_dir: old dir inode
890 * @old_dentry: old dentry
891 * @new_dir: new dir inode
892 * @new_dentry: new dentry
893 *
894 */
895
896int
897v9fs_vfs_rename(struct inode *old_dir, struct dentry *old_dentry,
898 struct inode *new_dir, struct dentry *new_dentry,
899 unsigned int flags)
900{
901 int retval;
902 struct inode *old_inode;
903 struct inode *new_inode;
904 struct v9fs_session_info *v9ses;
905 struct p9_fid *oldfid;
906 struct p9_fid *olddirfid;
907 struct p9_fid *newdirfid;
908 struct p9_wstat wstat;
909
910 if (flags)
911 return -EINVAL;
912
913 p9_debug(P9_DEBUG_VFS, "\n");
914 retval = 0;
915 old_inode = d_inode(old_dentry);
916 new_inode = d_inode(new_dentry);
917 v9ses = v9fs_inode2v9ses(old_inode);
918 oldfid = v9fs_fid_lookup(old_dentry);
919 if (IS_ERR(oldfid))
920 return PTR_ERR(oldfid);
921
922 olddirfid = clone_fid(v9fs_parent_fid(old_dentry));
923 if (IS_ERR(olddirfid)) {
924 retval = PTR_ERR(olddirfid);
925 goto done;
926 }
927
928 newdirfid = clone_fid(v9fs_parent_fid(new_dentry));
929 if (IS_ERR(newdirfid)) {
930 retval = PTR_ERR(newdirfid);
931 goto clunk_olddir;
932 }
933
934 down_write(&v9ses->rename_sem);
935 if (v9fs_proto_dotl(v9ses)) {
936 retval = p9_client_renameat(olddirfid, old_dentry->d_name.name,
937 newdirfid, new_dentry->d_name.name);
938 if (retval == -EOPNOTSUPP)
939 retval = p9_client_rename(oldfid, newdirfid,
940 new_dentry->d_name.name);
941 if (retval != -EOPNOTSUPP)
942 goto clunk_newdir;
943 }
944 if (old_dentry->d_parent != new_dentry->d_parent) {
945 /*
946 * 9P .u can only handle file rename in the same directory
947 */
948
949 p9_debug(P9_DEBUG_ERROR, "old dir and new dir are different\n");
950 retval = -EXDEV;
951 goto clunk_newdir;
952 }
953 v9fs_blank_wstat(&wstat);
954 wstat.muid = v9ses->uname;
955 wstat.name = new_dentry->d_name.name;
956 retval = p9_client_wstat(oldfid, &wstat);
957
958clunk_newdir:
959 if (!retval) {
960 if (new_inode) {
961 if (S_ISDIR(new_inode->i_mode))
962 clear_nlink(new_inode);
963 else
964 v9fs_dec_count(new_inode);
965 }
966 if (S_ISDIR(old_inode->i_mode)) {
967 if (!new_inode)
968 inc_nlink(new_dir);
969 v9fs_dec_count(old_dir);
970 }
971 v9fs_invalidate_inode_attr(old_inode);
972 v9fs_invalidate_inode_attr(old_dir);
973 v9fs_invalidate_inode_attr(new_dir);
974
975 /* successful rename */
976 d_move(old_dentry, new_dentry);
977 }
978 up_write(&v9ses->rename_sem);
979 p9_client_clunk(newdirfid);
980
981clunk_olddir:
982 p9_client_clunk(olddirfid);
983
984done:
985 return retval;
986}
987
988/**
989 * v9fs_vfs_getattr - retrieve file metadata
990 * @path: Object to query
991 * @stat: metadata structure to populate
992 * @request_mask: Mask of STATX_xxx flags indicating the caller's interests
993 * @flags: AT_STATX_xxx setting
994 *
995 */
996
997static int
998v9fs_vfs_getattr(const struct path *path, struct kstat *stat,
999 u32 request_mask, unsigned int flags)
1000{
1001 struct dentry *dentry = path->dentry;
1002 struct v9fs_session_info *v9ses;
1003 struct p9_fid *fid;
1004 struct p9_wstat *st;
1005
1006 p9_debug(P9_DEBUG_VFS, "dentry: %p\n", dentry);
1007 v9ses = v9fs_dentry2v9ses(dentry);
1008 if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) {
1009 generic_fillattr(d_inode(dentry), stat);
1010 return 0;
1011 }
1012 fid = v9fs_fid_lookup(dentry);
1013 if (IS_ERR(fid))
1014 return PTR_ERR(fid);
1015
1016 st = p9_client_stat(fid);
1017 if (IS_ERR(st))
1018 return PTR_ERR(st);
1019
1020 v9fs_stat2inode(st, d_inode(dentry), dentry->d_sb, 0);
1021 generic_fillattr(d_inode(dentry), stat);
1022
1023 p9stat_free(st);
1024 kfree(st);
1025 return 0;
1026}
1027
1028/**
1029 * v9fs_vfs_setattr - set file metadata
1030 * @dentry: file whose metadata to set
1031 * @iattr: metadata assignment structure
1032 *
1033 */
1034
1035static int v9fs_vfs_setattr(struct dentry *dentry, struct iattr *iattr)
1036{
1037 int retval;
1038 struct v9fs_session_info *v9ses;
1039 struct p9_fid *fid = NULL;
1040 struct p9_wstat wstat;
1041
1042 p9_debug(P9_DEBUG_VFS, "\n");
1043 retval = setattr_prepare(dentry, iattr);
1044 if (retval)
1045 return retval;
1046
1047 retval = -EPERM;
1048 v9ses = v9fs_dentry2v9ses(dentry);
1049 if (iattr->ia_valid & ATTR_FILE) {
1050 fid = iattr->ia_file->private_data;
1051 WARN_ON(!fid);
1052 }
1053 if (!fid)
1054 fid = v9fs_fid_lookup(dentry);
1055 if(IS_ERR(fid))
1056 return PTR_ERR(fid);
1057
1058 v9fs_blank_wstat(&wstat);
1059 if (iattr->ia_valid & ATTR_MODE)
1060 wstat.mode = unixmode2p9mode(v9ses, iattr->ia_mode);
1061
1062 if (iattr->ia_valid & ATTR_MTIME)
1063 wstat.mtime = iattr->ia_mtime.tv_sec;
1064
1065 if (iattr->ia_valid & ATTR_ATIME)
1066 wstat.atime = iattr->ia_atime.tv_sec;
1067
1068 if (iattr->ia_valid & ATTR_SIZE)
1069 wstat.length = iattr->ia_size;
1070
1071 if (v9fs_proto_dotu(v9ses)) {
1072 if (iattr->ia_valid & ATTR_UID)
1073 wstat.n_uid = iattr->ia_uid;
1074
1075 if (iattr->ia_valid & ATTR_GID)
1076 wstat.n_gid = iattr->ia_gid;
1077 }
1078
1079 /* Write all dirty data */
1080 if (d_is_reg(dentry))
1081 filemap_write_and_wait(d_inode(dentry)->i_mapping);
1082
1083 retval = p9_client_wstat(fid, &wstat);
1084 if (retval < 0)
1085 return retval;
1086
1087 if ((iattr->ia_valid & ATTR_SIZE) &&
1088 iattr->ia_size != i_size_read(d_inode(dentry)))
1089 truncate_setsize(d_inode(dentry), iattr->ia_size);
1090
1091 v9fs_invalidate_inode_attr(d_inode(dentry));
1092
1093 setattr_copy(d_inode(dentry), iattr);
1094 mark_inode_dirty(d_inode(dentry));
1095 return 0;
1096}
1097
1098/**
1099 * v9fs_stat2inode - populate an inode structure with mistat info
1100 * @stat: Plan 9 metadata (mistat) structure
1101 * @inode: inode to populate
1102 * @sb: superblock of filesystem
1103 * @flags: control flags (e.g. V9FS_STAT2INODE_KEEP_ISIZE)
1104 *
1105 */
1106
1107void
1108v9fs_stat2inode(struct p9_wstat *stat, struct inode *inode,
1109 struct super_block *sb, unsigned int flags)
1110{
1111 umode_t mode;
1112 char ext[32];
1113 char tag_name[14];
1114 unsigned int i_nlink;
1115 struct v9fs_session_info *v9ses = sb->s_fs_info;
1116 struct v9fs_inode *v9inode = V9FS_I(inode);
1117
1118 set_nlink(inode, 1);
1119
1120 inode->i_atime.tv_sec = stat->atime;
1121 inode->i_mtime.tv_sec = stat->mtime;
1122 inode->i_ctime.tv_sec = stat->mtime;
1123
1124 inode->i_uid = v9ses->dfltuid;
1125 inode->i_gid = v9ses->dfltgid;
1126
1127 if (v9fs_proto_dotu(v9ses)) {
1128 inode->i_uid = stat->n_uid;
1129 inode->i_gid = stat->n_gid;
1130 }
1131 if ((S_ISREG(inode->i_mode)) || (S_ISDIR(inode->i_mode))) {
1132 if (v9fs_proto_dotu(v9ses) && (stat->extension[0] != '\0')) {
1133 /*
1134 * Hadlink support got added later to
1135 * to the .u extension. So there can be
1136 * server out there that doesn't support
1137 * this even with .u extension. So check
1138 * for non NULL stat->extension
1139 */
1140 strlcpy(ext, stat->extension, sizeof(ext));
1141 /* HARDLINKCOUNT %u */
1142 sscanf(ext, "%13s %u", tag_name, &i_nlink);
1143 if (!strncmp(tag_name, "HARDLINKCOUNT", 13))
1144 set_nlink(inode, i_nlink);
1145 }
1146 }
1147 mode = p9mode2perm(v9ses, stat);
1148 mode |= inode->i_mode & ~S_IALLUGO;
1149 inode->i_mode = mode;
1150
1151 if (!(flags & V9FS_STAT2INODE_KEEP_ISIZE))
1152 v9fs_i_size_write(inode, stat->length);
1153 /* not real number of blocks, but 512 byte ones ... */
1154 inode->i_blocks = (stat->length + 512 - 1) >> 9;
1155 v9inode->cache_validity &= ~V9FS_INO_INVALID_ATTR;
1156}
1157
1158/**
1159 * v9fs_qid2ino - convert qid into inode number
1160 * @qid: qid to hash
1161 *
1162 * BUG: potential for inode number collisions?
1163 */
1164
1165ino_t v9fs_qid2ino(struct p9_qid *qid)
1166{
1167 u64 path = qid->path + 2;
1168 ino_t i = 0;
1169
1170 if (sizeof(ino_t) == sizeof(path))
1171 memcpy(&i, &path, sizeof(ino_t));
1172 else
1173 i = (ino_t) (path ^ (path >> 32));
1174
1175 return i;
1176}
1177
1178/**
1179 * v9fs_vfs_get_link - follow a symlink path
1180 * @dentry: dentry for symlink
1181 * @inode: inode for symlink
1182 * @done: delayed call for when we are done with the return value
1183 */
1184
1185static const char *v9fs_vfs_get_link(struct dentry *dentry,
1186 struct inode *inode,
1187 struct delayed_call *done)
1188{
1189 struct v9fs_session_info *v9ses;
1190 struct p9_fid *fid;
1191 struct p9_wstat *st;
1192 char *res;
1193
1194 if (!dentry)
1195 return ERR_PTR(-ECHILD);
1196
1197 v9ses = v9fs_dentry2v9ses(dentry);
1198 fid = v9fs_fid_lookup(dentry);
1199 p9_debug(P9_DEBUG_VFS, "%pd\n", dentry);
1200
1201 if (IS_ERR(fid))
1202 return ERR_CAST(fid);
1203
1204 if (!v9fs_proto_dotu(v9ses))
1205 return ERR_PTR(-EBADF);
1206
1207 st = p9_client_stat(fid);
1208 if (IS_ERR(st))
1209 return ERR_CAST(st);
1210
1211 if (!(st->mode & P9_DMSYMLINK)) {
1212 p9stat_free(st);
1213 kfree(st);
1214 return ERR_PTR(-EINVAL);
1215 }
1216 res = st->extension;
1217 st->extension = NULL;
1218 if (strlen(res) >= PATH_MAX)
1219 res[PATH_MAX - 1] = '\0';
1220
1221 p9stat_free(st);
1222 kfree(st);
1223 set_delayed_call(done, kfree_link, res);
1224 return res;
1225}
1226
1227/**
1228 * v9fs_vfs_mkspecial - create a special file
1229 * @dir: inode to create special file in
1230 * @dentry: dentry to create
1231 * @perm: mode to create special file
1232 * @extension: 9p2000.u format extension string representing special file
1233 *
1234 */
1235
1236static int v9fs_vfs_mkspecial(struct inode *dir, struct dentry *dentry,
1237 u32 perm, const char *extension)
1238{
1239 struct p9_fid *fid;
1240 struct v9fs_session_info *v9ses;
1241
1242 v9ses = v9fs_inode2v9ses(dir);
1243 if (!v9fs_proto_dotu(v9ses)) {
1244 p9_debug(P9_DEBUG_ERROR, "not extended\n");
1245 return -EPERM;
1246 }
1247
1248 fid = v9fs_create(v9ses, dir, dentry, (char *) extension, perm,
1249 P9_OREAD);
1250 if (IS_ERR(fid))
1251 return PTR_ERR(fid);
1252
1253 v9fs_invalidate_inode_attr(dir);
1254 p9_client_clunk(fid);
1255 return 0;
1256}
1257
1258/**
1259 * v9fs_vfs_symlink - helper function to create symlinks
1260 * @dir: directory inode containing symlink
1261 * @dentry: dentry for symlink
1262 * @symname: symlink data
1263 *
1264 * See Also: 9P2000.u RFC for more information
1265 *
1266 */
1267
1268static int
1269v9fs_vfs_symlink(struct inode *dir, struct dentry *dentry, const char *symname)
1270{
1271 p9_debug(P9_DEBUG_VFS, " %lu,%pd,%s\n",
1272 dir->i_ino, dentry, symname);
1273
1274 return v9fs_vfs_mkspecial(dir, dentry, P9_DMSYMLINK, symname);
1275}
1276
1277#define U32_MAX_DIGITS 10
1278
1279/**
1280 * v9fs_vfs_link - create a hardlink
1281 * @old_dentry: dentry for file to link to
1282 * @dir: inode destination for new link
1283 * @dentry: dentry for link
1284 *
1285 */
1286
1287static int
1288v9fs_vfs_link(struct dentry *old_dentry, struct inode *dir,
1289 struct dentry *dentry)
1290{
1291 int retval;
1292 char name[1 + U32_MAX_DIGITS + 2]; /* sign + number + \n + \0 */
1293 struct p9_fid *oldfid;
1294
1295 p9_debug(P9_DEBUG_VFS, " %lu,%pd,%pd\n",
1296 dir->i_ino, dentry, old_dentry);
1297
1298 oldfid = v9fs_fid_clone(old_dentry);
1299 if (IS_ERR(oldfid))
1300 return PTR_ERR(oldfid);
1301
1302 sprintf(name, "%d\n", oldfid->fid);
1303 retval = v9fs_vfs_mkspecial(dir, dentry, P9_DMLINK, name);
1304 if (!retval) {
1305 v9fs_refresh_inode(oldfid, d_inode(old_dentry));
1306 v9fs_invalidate_inode_attr(dir);
1307 }
1308 p9_client_clunk(oldfid);
1309 return retval;
1310}
1311
1312/**
1313 * v9fs_vfs_mknod - create a special file
1314 * @dir: inode destination for new link
1315 * @dentry: dentry for file
1316 * @mode: mode for creation
1317 * @rdev: device associated with special file
1318 *
1319 */
1320
1321static int
1322v9fs_vfs_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t rdev)
1323{
1324 struct v9fs_session_info *v9ses = v9fs_inode2v9ses(dir);
1325 int retval;
1326 char name[2 + U32_MAX_DIGITS + 1 + U32_MAX_DIGITS + 1];
1327 u32 perm;
1328
1329 p9_debug(P9_DEBUG_VFS, " %lu,%pd mode: %hx MAJOR: %u MINOR: %u\n",
1330 dir->i_ino, dentry, mode,
1331 MAJOR(rdev), MINOR(rdev));
1332
1333 /* build extension */
1334 if (S_ISBLK(mode))
1335 sprintf(name, "b %u %u", MAJOR(rdev), MINOR(rdev));
1336 else if (S_ISCHR(mode))
1337 sprintf(name, "c %u %u", MAJOR(rdev), MINOR(rdev));
1338 else
1339 *name = 0;
1340
1341 perm = unixmode2p9mode(v9ses, mode);
1342 retval = v9fs_vfs_mkspecial(dir, dentry, perm, name);
1343
1344 return retval;
1345}
1346
1347int v9fs_refresh_inode(struct p9_fid *fid, struct inode *inode)
1348{
1349 int umode;
1350 dev_t rdev;
1351 struct p9_wstat *st;
1352 struct v9fs_session_info *v9ses;
1353 unsigned int flags;
1354
1355 v9ses = v9fs_inode2v9ses(inode);
1356 st = p9_client_stat(fid);
1357 if (IS_ERR(st))
1358 return PTR_ERR(st);
1359 /*
1360 * Don't update inode if the file type is different
1361 */
1362 umode = p9mode2unixmode(v9ses, st, &rdev);
1363 if ((inode->i_mode & S_IFMT) != (umode & S_IFMT))
1364 goto out;
1365
1366 /*
1367 * We don't want to refresh inode->i_size,
1368 * because we may have cached data
1369 */
1370 flags = (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) ?
1371 V9FS_STAT2INODE_KEEP_ISIZE : 0;
1372 v9fs_stat2inode(st, inode, inode->i_sb, flags);
1373out:
1374 p9stat_free(st);
1375 kfree(st);
1376 return 0;
1377}
1378
1379static const struct inode_operations v9fs_dir_inode_operations_dotu = {
1380 .create = v9fs_vfs_create,
1381 .lookup = v9fs_vfs_lookup,
1382 .atomic_open = v9fs_vfs_atomic_open,
1383 .symlink = v9fs_vfs_symlink,
1384 .link = v9fs_vfs_link,
1385 .unlink = v9fs_vfs_unlink,
1386 .mkdir = v9fs_vfs_mkdir,
1387 .rmdir = v9fs_vfs_rmdir,
1388 .mknod = v9fs_vfs_mknod,
1389 .rename = v9fs_vfs_rename,
1390 .getattr = v9fs_vfs_getattr,
1391 .setattr = v9fs_vfs_setattr,
1392};
1393
1394static const struct inode_operations v9fs_dir_inode_operations = {
1395 .create = v9fs_vfs_create,
1396 .lookup = v9fs_vfs_lookup,
1397 .atomic_open = v9fs_vfs_atomic_open,
1398 .unlink = v9fs_vfs_unlink,
1399 .mkdir = v9fs_vfs_mkdir,
1400 .rmdir = v9fs_vfs_rmdir,
1401 .mknod = v9fs_vfs_mknod,
1402 .rename = v9fs_vfs_rename,
1403 .getattr = v9fs_vfs_getattr,
1404 .setattr = v9fs_vfs_setattr,
1405};
1406
1407static const struct inode_operations v9fs_file_inode_operations = {
1408 .getattr = v9fs_vfs_getattr,
1409 .setattr = v9fs_vfs_setattr,
1410};
1411
1412static const struct inode_operations v9fs_symlink_inode_operations = {
1413 .get_link = v9fs_vfs_get_link,
1414 .getattr = v9fs_vfs_getattr,
1415 .setattr = v9fs_vfs_setattr,
1416};
1417