1/*
2 *  linux/fs/9p/vfs_inode.c
3 *
4 * This file contains vfs inode ops for the 9P2000 protocol.
5 *
6 *  Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
7 *  Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
8 *
9 *  This program is free software; you can redistribute it and/or modify
10 *  it under the terms of the GNU General Public License version 2
11 *  as published by the Free Software Foundation.
12 *
13 *  This program is distributed in the hope that it will be useful,
14 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
15 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16 *  GNU General Public License for more details.
17 *
18 *  You should have received a copy of the GNU General Public License
19 *  along with this program; if not, write to:
20 *  Free Software Foundation
21 *  51 Franklin Street, Fifth Floor
22 *  Boston, MA  02111-1301  USA
23 *
24 */
25
26#include <linux/module.h>
27#include <linux/errno.h>
28#include <linux/fs.h>
29#include <linux/file.h>
30#include <linux/pagemap.h>
31#include <linux/stat.h>
32#include <linux/string.h>
33#include <linux/inet.h>
34#include <linux/namei.h>
35#include <linux/idr.h>
36#include <linux/sched.h>
37#include <linux/slab.h>
38#include <linux/xattr.h>
39#include <net/9p/9p.h>
40#include <net/9p/client.h>
41
42#include "v9fs.h"
43#include "v9fs_vfs.h"
44#include "fid.h"
45#include "cache.h"
46#include "xattr.h"
47
48static const struct inode_operations v9fs_dir_inode_operations;
49static const struct inode_operations v9fs_dir_inode_operations_dotu;
50static const struct inode_operations v9fs_dir_inode_operations_dotl;
51static const struct inode_operations v9fs_file_inode_operations;
52static const struct inode_operations v9fs_file_inode_operations_dotl;
53static const struct inode_operations v9fs_symlink_inode_operations;
54static const struct inode_operations v9fs_symlink_inode_operations_dotl;
55
56/**
57 * unixmode2p9mode - convert unix mode bits to plan 9
58 * @v9ses: v9fs session information
59 * @mode: mode to convert
60 *
61 */
62
63static int unixmode2p9mode(struct v9fs_session_info *v9ses, int mode)
64{
65	int res;
66	res = mode & 0777;
67	if (S_ISDIR(mode))
68		res |= P9_DMDIR;
69	if (v9fs_proto_dotu(v9ses)) {
70		if (S_ISLNK(mode))
71			res |= P9_DMSYMLINK;
72		if (v9ses->nodev == 0) {
73			if (S_ISSOCK(mode))
74				res |= P9_DMSOCKET;
75			if (S_ISFIFO(mode))
76				res |= P9_DMNAMEDPIPE;
77			if (S_ISBLK(mode))
78				res |= P9_DMDEVICE;
79			if (S_ISCHR(mode))
80				res |= P9_DMDEVICE;
81		}
82
83		if ((mode & S_ISUID) == S_ISUID)
84			res |= P9_DMSETUID;
85		if ((mode & S_ISGID) == S_ISGID)
86			res |= P9_DMSETGID;
87		if ((mode & S_ISVTX) == S_ISVTX)
88			res |= P9_DMSETVTX;
89		if ((mode & P9_DMLINK))
90			res |= P9_DMLINK;
91	}
92
93	return res;
94}
95
96/**
97 * p9mode2unixmode- convert plan9 mode bits to unix mode bits
98 * @v9ses: v9fs session information
99 * @mode: mode to convert
100 *
101 */
102
103static int p9mode2unixmode(struct v9fs_session_info *v9ses, int mode)
104{
105	int res;
106
107	res = mode & 0777;
108
109	if ((mode & P9_DMDIR) == P9_DMDIR)
110		res |= S_IFDIR;
111	else if ((mode & P9_DMSYMLINK) && (v9fs_proto_dotu(v9ses)))
112		res |= S_IFLNK;
113	else if ((mode & P9_DMSOCKET) && (v9fs_proto_dotu(v9ses))
114		 && (v9ses->nodev == 0))
115		res |= S_IFSOCK;
116	else if ((mode & P9_DMNAMEDPIPE) && (v9fs_proto_dotu(v9ses))
117		 && (v9ses->nodev == 0))
118		res |= S_IFIFO;
119	else if ((mode & P9_DMDEVICE) && (v9fs_proto_dotu(v9ses))
120		 && (v9ses->nodev == 0))
121		res |= S_IFBLK;
122	else
123		res |= S_IFREG;
124
125	if (v9fs_proto_dotu(v9ses)) {
126		if ((mode & P9_DMSETUID) == P9_DMSETUID)
127			res |= S_ISUID;
128
129		if ((mode & P9_DMSETGID) == P9_DMSETGID)
130			res |= S_ISGID;
131
132		if ((mode & P9_DMSETVTX) == P9_DMSETVTX)
133			res |= S_ISVTX;
134	}
135
136	return res;
137}
138
139/**
140 * v9fs_uflags2omode- convert posix open flags to plan 9 mode bits
141 * @uflags: flags to convert
142 * @extended: if .u extensions are active
143 */
144
145int v9fs_uflags2omode(int uflags, int extended)
146{
147	int ret;
148
149	ret = 0;
150	switch (uflags&3) {
151	default:
152	case O_RDONLY:
153		ret = P9_OREAD;
154		break;
155
156	case O_WRONLY:
157		ret = P9_OWRITE;
158		break;
159
160	case O_RDWR:
161		ret = P9_ORDWR;
162		break;
163	}
164
165	if (uflags & O_TRUNC)
166		ret |= P9_OTRUNC;
167
168	if (extended) {
169		if (uflags & O_EXCL)
170			ret |= P9_OEXCL;
171
172		if (uflags & O_APPEND)
173			ret |= P9_OAPPEND;
174	}
175
176	return ret;
177}
178
179/**
180 * v9fs_blank_wstat - helper function to setup a 9P stat structure
181 * @wstat: structure to initialize
182 *
183 */
184
185void
186v9fs_blank_wstat(struct p9_wstat *wstat)
187{
188	wstat->type = ~0;
189	wstat->dev = ~0;
190	wstat->qid.type = ~0;
191	wstat->qid.version = ~0;
192	*((long long *)&wstat->qid.path) = ~0;
193	wstat->mode = ~0;
194	wstat->atime = ~0;
195	wstat->mtime = ~0;
196	wstat->length = ~0;
197	wstat->name = NULL;
198	wstat->uid = NULL;
199	wstat->gid = NULL;
200	wstat->muid = NULL;
201	wstat->n_uid = ~0;
202	wstat->n_gid = ~0;
203	wstat->n_muid = ~0;
204	wstat->extension = NULL;
205}
206
207#ifdef CONFIG_9P_FSCACHE
208/**
209 * v9fs_alloc_inode - helper function to allocate an inode
210 * This callback is executed before setting up the inode so that we
211 * can associate a vcookie with each inode.
212 *
213 */
214
215struct inode *v9fs_alloc_inode(struct super_block *sb)
216{
217	struct v9fs_cookie *vcookie;
218	vcookie = (struct v9fs_cookie *)kmem_cache_alloc(vcookie_cache,
219							 GFP_KERNEL);
220	if (!vcookie)
221		return NULL;
222
223	vcookie->fscache = NULL;
224	vcookie->qid = NULL;
225	spin_lock_init(&vcookie->lock);
226	return &vcookie->inode;
227}
228
229/**
230 * v9fs_destroy_inode - destroy an inode
231 *
232 */
233
234void v9fs_destroy_inode(struct inode *inode)
235{
236	kmem_cache_free(vcookie_cache, v9fs_inode2cookie(inode));
237}
238#endif
239
240/**
241 * v9fs_get_fsgid_for_create - Helper function to get the gid for creating a
242 * new file system object. This checks the S_ISGID to determine the owning
243 * group of the new file system object.
244 */
245
246static gid_t v9fs_get_fsgid_for_create(struct inode *dir_inode)
247{
248	BUG_ON(dir_inode == NULL);
249
250	if (dir_inode->i_mode & S_ISGID) {
251		/* set_gid bit is set.*/
252		return dir_inode->i_gid;
253	}
254	return current_fsgid();
255}
256
257/**
258 * v9fs_dentry_from_dir_inode - helper function to get the dentry from
259 * dir inode.
260 *
261 */
262
263static struct dentry *v9fs_dentry_from_dir_inode(struct inode *inode)
264{
265	struct dentry *dentry;
266
267	spin_lock(&dcache_lock);
268	/* Directory should have only one entry. */
269	BUG_ON(S_ISDIR(inode->i_mode) && !list_is_singular(&inode->i_dentry));
270	dentry = list_entry(inode->i_dentry.next, struct dentry, d_alias);
271	spin_unlock(&dcache_lock);
272	return dentry;
273}
274
275/**
276 * v9fs_get_inode - helper function to setup an inode
277 * @sb: superblock
278 * @mode: mode to setup inode with
279 *
280 */
281
282struct inode *v9fs_get_inode(struct super_block *sb, int mode)
283{
284	int err;
285	struct inode *inode;
286	struct v9fs_session_info *v9ses = sb->s_fs_info;
287
288	P9_DPRINTK(P9_DEBUG_VFS, "super block: %p mode: %o\n", sb, mode);
289
290	inode = new_inode(sb);
291	if (!inode) {
292		P9_EPRINTK(KERN_WARNING, "Problem allocating inode\n");
293		return ERR_PTR(-ENOMEM);
294	}
295
296	inode_init_owner(inode, NULL, mode);
297	inode->i_blocks = 0;
298	inode->i_rdev = 0;
299	inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
300	inode->i_mapping->a_ops = &v9fs_addr_operations;
301
302	switch (mode & S_IFMT) {
303	case S_IFIFO:
304	case S_IFBLK:
305	case S_IFCHR:
306	case S_IFSOCK:
307		if (v9fs_proto_dotl(v9ses)) {
308			inode->i_op = &v9fs_file_inode_operations_dotl;
309			inode->i_fop = &v9fs_file_operations_dotl;
310		} else if (v9fs_proto_dotu(v9ses)) {
311			inode->i_op = &v9fs_file_inode_operations;
312			inode->i_fop = &v9fs_file_operations;
313		} else {
314			P9_DPRINTK(P9_DEBUG_ERROR,
315				   "special files without extended mode\n");
316			err = -EINVAL;
317			goto error;
318		}
319		init_special_inode(inode, inode->i_mode, inode->i_rdev);
320		break;
321	case S_IFREG:
322		if (v9fs_proto_dotl(v9ses)) {
323			inode->i_op = &v9fs_file_inode_operations_dotl;
324			inode->i_fop = &v9fs_file_operations_dotl;
325		} else {
326			inode->i_op = &v9fs_file_inode_operations;
327			inode->i_fop = &v9fs_file_operations;
328		}
329
330		break;
331
332	case S_IFLNK:
333		if (!v9fs_proto_dotu(v9ses) && !v9fs_proto_dotl(v9ses)) {
334			P9_DPRINTK(P9_DEBUG_ERROR, "extended modes used with "
335						"legacy protocol.\n");
336			err = -EINVAL;
337			goto error;
338		}
339
340		if (v9fs_proto_dotl(v9ses))
341			inode->i_op = &v9fs_symlink_inode_operations_dotl;
342		else
343			inode->i_op = &v9fs_symlink_inode_operations;
344
345		break;
346	case S_IFDIR:
347		inc_nlink(inode);
348		if (v9fs_proto_dotl(v9ses))
349			inode->i_op = &v9fs_dir_inode_operations_dotl;
350		else if (v9fs_proto_dotu(v9ses))
351			inode->i_op = &v9fs_dir_inode_operations_dotu;
352		else
353			inode->i_op = &v9fs_dir_inode_operations;
354
355		if (v9fs_proto_dotl(v9ses))
356			inode->i_fop = &v9fs_dir_operations_dotl;
357		else
358			inode->i_fop = &v9fs_dir_operations;
359
360		break;
361	default:
362		P9_DPRINTK(P9_DEBUG_ERROR, "BAD mode 0x%x S_IFMT 0x%x\n",
363			   mode, mode & S_IFMT);
364		err = -EINVAL;
365		goto error;
366	}
367
368	return inode;
369
370error:
371	iput(inode);
372	return ERR_PTR(err);
373}
374
375/*
376static struct v9fs_fid*
377v9fs_clone_walk(struct v9fs_session_info *v9ses, u32 fid, struct dentry *dentry)
378{
379	int err;
380	int nfid;
381	struct v9fs_fid *ret;
382	struct v9fs_fcall *fcall;
383
384	nfid = v9fs_get_idpool(&v9ses->fidpool);
385	if (nfid < 0) {
386		eprintk(KERN_WARNING, "no free fids available\n");
387		return ERR_PTR(-ENOSPC);
388	}
389
390	err = v9fs_t_walk(v9ses, fid, nfid, (char *) dentry->d_name.name,
391		&fcall);
392
393	if (err < 0) {
394		if (fcall && fcall->id == RWALK)
395			goto clunk_fid;
396
397		PRINT_FCALL_ERROR("walk error", fcall);
398		v9fs_put_idpool(nfid, &v9ses->fidpool);
399		goto error;
400	}
401
402	kfree(fcall);
403	fcall = NULL;
404	ret = v9fs_fid_create(v9ses, nfid);
405	if (!ret) {
406		err = -ENOMEM;
407		goto clunk_fid;
408	}
409
410	err = v9fs_fid_insert(ret, dentry);
411	if (err < 0) {
412		v9fs_fid_destroy(ret);
413		goto clunk_fid;
414	}
415
416	return ret;
417
418clunk_fid:
419	v9fs_t_clunk(v9ses, nfid);
420
421error:
422	kfree(fcall);
423	return ERR_PTR(err);
424}
425*/
426
427
428/**
429 * v9fs_clear_inode - release an inode
430 * @inode: inode to release
431 *
432 */
433void v9fs_evict_inode(struct inode *inode)
434{
435	truncate_inode_pages(inode->i_mapping, 0);
436	end_writeback(inode);
437	filemap_fdatawrite(inode->i_mapping);
438
439#ifdef CONFIG_9P_FSCACHE
440	v9fs_cache_inode_put_cookie(inode);
441#endif
442}
443
444static struct inode *
445v9fs_inode(struct v9fs_session_info *v9ses, struct p9_fid *fid,
446	struct super_block *sb)
447{
448	int err, umode;
449	struct inode *ret = NULL;
450	struct p9_wstat *st;
451
452	st = p9_client_stat(fid);
453	if (IS_ERR(st))
454		return ERR_CAST(st);
455
456	umode = p9mode2unixmode(v9ses, st->mode);
457	ret = v9fs_get_inode(sb, umode);
458	if (IS_ERR(ret)) {
459		err = PTR_ERR(ret);
460		goto error;
461	}
462
463	v9fs_stat2inode(st, ret, sb);
464	ret->i_ino = v9fs_qid2ino(&st->qid);
465
466#ifdef CONFIG_9P_FSCACHE
467	v9fs_vcookie_set_qid(ret, &st->qid);
468	v9fs_cache_inode_get_cookie(ret);
469#endif
470	p9stat_free(st);
471	kfree(st);
472	return ret;
473error:
474	p9stat_free(st);
475	kfree(st);
476	return ERR_PTR(err);
477}
478
479static struct inode *
480v9fs_inode_dotl(struct v9fs_session_info *v9ses, struct p9_fid *fid,
481	struct super_block *sb)
482{
483	struct inode *ret = NULL;
484	int err;
485	struct p9_stat_dotl *st;
486
487	st = p9_client_getattr_dotl(fid, P9_STATS_BASIC);
488	if (IS_ERR(st))
489		return ERR_CAST(st);
490
491	ret = v9fs_get_inode(sb, st->st_mode);
492	if (IS_ERR(ret)) {
493		err = PTR_ERR(ret);
494		goto error;
495	}
496
497	v9fs_stat2inode_dotl(st, ret);
498	ret->i_ino = v9fs_qid2ino(&st->qid);
499#ifdef CONFIG_9P_FSCACHE
500	v9fs_vcookie_set_qid(ret, &st->qid);
501	v9fs_cache_inode_get_cookie(ret);
502#endif
503	kfree(st);
504	return ret;
505error:
506	kfree(st);
507	return ERR_PTR(err);
508}
509
510/**
511 * v9fs_inode_from_fid - Helper routine to populate an inode by
512 * issuing a attribute request
513 * @v9ses: session information
514 * @fid: fid to issue attribute request for
515 * @sb: superblock on which to create inode
516 *
517 */
518static inline struct inode *
519v9fs_inode_from_fid(struct v9fs_session_info *v9ses, struct p9_fid *fid,
520			struct super_block *sb)
521{
522	if (v9fs_proto_dotl(v9ses))
523		return v9fs_inode_dotl(v9ses, fid, sb);
524	else
525		return v9fs_inode(v9ses, fid, sb);
526}
527
528/**
529 * v9fs_remove - helper function to remove files and directories
530 * @dir: directory inode that is being deleted
531 * @file:  dentry that is being deleted
532 * @rmdir: removing a directory
533 *
534 */
535
536static int v9fs_remove(struct inode *dir, struct dentry *file, int rmdir)
537{
538	int retval;
539	struct inode *file_inode;
540	struct p9_fid *v9fid;
541
542	P9_DPRINTK(P9_DEBUG_VFS, "inode: %p dentry: %p rmdir: %d\n", dir, file,
543		rmdir);
544
545	file_inode = file->d_inode;
546	v9fid = v9fs_fid_clone(file);
547	if (IS_ERR(v9fid))
548		return PTR_ERR(v9fid);
549
550	retval = p9_client_remove(v9fid);
551	if (!retval)
552		drop_nlink(file_inode);
553	return retval;
554}
555
556static int
557v9fs_open_created(struct inode *inode, struct file *file)
558{
559	return 0;
560}
561
562
563/**
564 * v9fs_create - Create a file
565 * @v9ses: session information
566 * @dir: directory that dentry is being created in
567 * @dentry:  dentry that is being created
568 * @extension: 9p2000.u extension string to support devices, etc.
569 * @perm: create permissions
570 * @mode: open mode
571 *
572 */
573static struct p9_fid *
574v9fs_create(struct v9fs_session_info *v9ses, struct inode *dir,
575		struct dentry *dentry, char *extension, u32 perm, u8 mode)
576{
577	int err;
578	char *name;
579	struct p9_fid *dfid, *ofid, *fid;
580	struct inode *inode;
581
582	P9_DPRINTK(P9_DEBUG_VFS, "name %s\n", dentry->d_name.name);
583
584	err = 0;
585	ofid = NULL;
586	fid = NULL;
587	name = (char *) dentry->d_name.name;
588	dfid = v9fs_fid_lookup(dentry->d_parent);
589	if (IS_ERR(dfid)) {
590		err = PTR_ERR(dfid);
591		P9_DPRINTK(P9_DEBUG_VFS, "fid lookup failed %d\n", err);
592		return ERR_PTR(err);
593	}
594
595	/* clone a fid to use for creation */
596	ofid = p9_client_walk(dfid, 0, NULL, 1);
597	if (IS_ERR(ofid)) {
598		err = PTR_ERR(ofid);
599		P9_DPRINTK(P9_DEBUG_VFS, "p9_client_walk failed %d\n", err);
600		return ERR_PTR(err);
601	}
602
603	err = p9_client_fcreate(ofid, name, perm, mode, extension);
604	if (err < 0) {
605		P9_DPRINTK(P9_DEBUG_VFS, "p9_client_fcreate failed %d\n", err);
606		goto error;
607	}
608
609	/* now walk from the parent so we can get unopened fid */
610	fid = p9_client_walk(dfid, 1, &name, 1);
611	if (IS_ERR(fid)) {
612		err = PTR_ERR(fid);
613		P9_DPRINTK(P9_DEBUG_VFS, "p9_client_walk failed %d\n", err);
614		fid = NULL;
615		goto error;
616	}
617
618	/* instantiate inode and assign the unopened fid to the dentry */
619	inode = v9fs_inode_from_fid(v9ses, fid, dir->i_sb);
620	if (IS_ERR(inode)) {
621		err = PTR_ERR(inode);
622		P9_DPRINTK(P9_DEBUG_VFS, "inode creation failed %d\n", err);
623		goto error;
624	}
625
626	if (v9ses->cache)
627		dentry->d_op = &v9fs_cached_dentry_operations;
628	else
629		dentry->d_op = &v9fs_dentry_operations;
630
631	d_instantiate(dentry, inode);
632	err = v9fs_fid_add(dentry, fid);
633	if (err < 0)
634		goto error;
635
636	return ofid;
637
638error:
639	if (ofid)
640		p9_client_clunk(ofid);
641
642	if (fid)
643		p9_client_clunk(fid);
644
645	return ERR_PTR(err);
646}
647
648/**
649 * v9fs_vfs_create_dotl - VFS hook to create files for 9P2000.L protocol.
650 * @dir: directory inode that is being created
651 * @dentry:  dentry that is being deleted
652 * @mode: create permissions
653 * @nd: path information
654 *
655 */
656
657static int
658v9fs_vfs_create_dotl(struct inode *dir, struct dentry *dentry, int mode,
659		struct nameidata *nd)
660{
661	int err = 0;
662	char *name = NULL;
663	gid_t gid;
664	int flags;
665	struct v9fs_session_info *v9ses;
666	struct p9_fid *fid = NULL;
667	struct p9_fid *dfid, *ofid;
668	struct file *filp;
669	struct p9_qid qid;
670	struct inode *inode;
671
672	v9ses = v9fs_inode2v9ses(dir);
673	if (nd && nd->flags & LOOKUP_OPEN)
674		flags = nd->intent.open.flags - 1;
675	else
676		flags = O_RDWR;
677
678	name = (char *) dentry->d_name.name;
679	P9_DPRINTK(P9_DEBUG_VFS, "v9fs_vfs_create_dotl: name:%s flags:0x%x "
680			"mode:0x%x\n", name, flags, mode);
681
682	dfid = v9fs_fid_lookup(dentry->d_parent);
683	if (IS_ERR(dfid)) {
684		err = PTR_ERR(dfid);
685		P9_DPRINTK(P9_DEBUG_VFS, "fid lookup failed %d\n", err);
686		return err;
687	}
688
689	/* clone a fid to use for creation */
690	ofid = p9_client_walk(dfid, 0, NULL, 1);
691	if (IS_ERR(ofid)) {
692		err = PTR_ERR(ofid);
693		P9_DPRINTK(P9_DEBUG_VFS, "p9_client_walk failed %d\n", err);
694		return err;
695	}
696
697	gid = v9fs_get_fsgid_for_create(dir);
698	err = p9_client_create_dotl(ofid, name, flags, mode, gid, &qid);
699	if (err < 0) {
700		P9_DPRINTK(P9_DEBUG_VFS,
701				"p9_client_open_dotl failed in creat %d\n",
702				err);
703		goto error;
704	}
705
706	/* No need to populate the inode if we are not opening the file AND
707	 * not in cached mode.
708	 */
709	if (!v9ses->cache && !(nd && nd->flags & LOOKUP_OPEN)) {
710		/* Not in cached mode. No need to populate inode with stat */
711		dentry->d_op = &v9fs_dentry_operations;
712		p9_client_clunk(ofid);
713		d_instantiate(dentry, NULL);
714		return 0;
715	}
716
717	/* Now walk from the parent so we can get an unopened fid. */
718	fid = p9_client_walk(dfid, 1, &name, 1);
719	if (IS_ERR(fid)) {
720		err = PTR_ERR(fid);
721		P9_DPRINTK(P9_DEBUG_VFS, "p9_client_walk failed %d\n", err);
722		fid = NULL;
723		goto error;
724	}
725
726	/* instantiate inode and assign the unopened fid to dentry */
727	inode = v9fs_inode_from_fid(v9ses, fid, dir->i_sb);
728	if (IS_ERR(inode)) {
729		err = PTR_ERR(inode);
730		P9_DPRINTK(P9_DEBUG_VFS, "inode creation failed %d\n", err);
731		goto error;
732	}
733	if (v9ses->cache)
734		dentry->d_op = &v9fs_cached_dentry_operations;
735	else
736		dentry->d_op = &v9fs_dentry_operations;
737	d_instantiate(dentry, inode);
738	err = v9fs_fid_add(dentry, fid);
739	if (err < 0)
740		goto error;
741
742	/* if we are opening a file, assign the open fid to the file */
743	if (nd && nd->flags & LOOKUP_OPEN) {
744		filp = lookup_instantiate_filp(nd, dentry, v9fs_open_created);
745		if (IS_ERR(filp)) {
746			p9_client_clunk(ofid);
747			return PTR_ERR(filp);
748		}
749		filp->private_data = ofid;
750	} else
751		p9_client_clunk(ofid);
752
753	return 0;
754
755error:
756	if (ofid)
757		p9_client_clunk(ofid);
758	if (fid)
759		p9_client_clunk(fid);
760	return err;
761}
762
763/**
764 * v9fs_vfs_create - VFS hook to create files
765 * @dir: directory inode that is being created
766 * @dentry:  dentry that is being deleted
767 * @mode: create permissions
768 * @nd: path information
769 *
770 */
771
772static int
773v9fs_vfs_create(struct inode *dir, struct dentry *dentry, int mode,
774		struct nameidata *nd)
775{
776	int err;
777	u32 perm;
778	int flags;
779	struct v9fs_session_info *v9ses;
780	struct p9_fid *fid;
781	struct file *filp;
782
783	err = 0;
784	fid = NULL;
785	v9ses = v9fs_inode2v9ses(dir);
786	perm = unixmode2p9mode(v9ses, mode);
787	if (nd && nd->flags & LOOKUP_OPEN)
788		flags = nd->intent.open.flags - 1;
789	else
790		flags = O_RDWR;
791
792	fid = v9fs_create(v9ses, dir, dentry, NULL, perm,
793				v9fs_uflags2omode(flags,
794						v9fs_proto_dotu(v9ses)));
795	if (IS_ERR(fid)) {
796		err = PTR_ERR(fid);
797		fid = NULL;
798		goto error;
799	}
800
801	/* if we are opening a file, assign the open fid to the file */
802	if (nd && nd->flags & LOOKUP_OPEN) {
803		filp = lookup_instantiate_filp(nd, dentry, v9fs_open_created);
804		if (IS_ERR(filp)) {
805			err = PTR_ERR(filp);
806			goto error;
807		}
808
809		filp->private_data = fid;
810	} else
811		p9_client_clunk(fid);
812
813	return 0;
814
815error:
816	if (fid)
817		p9_client_clunk(fid);
818
819	return err;
820}
821
822/**
823 * v9fs_vfs_mkdir - VFS mkdir hook to create a directory
824 * @dir:  inode that is being unlinked
825 * @dentry: dentry that is being unlinked
826 * @mode: mode for new directory
827 *
828 */
829
830static int v9fs_vfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
831{
832	int err;
833	u32 perm;
834	struct v9fs_session_info *v9ses;
835	struct p9_fid *fid;
836
837	P9_DPRINTK(P9_DEBUG_VFS, "name %s\n", dentry->d_name.name);
838	err = 0;
839	v9ses = v9fs_inode2v9ses(dir);
840	perm = unixmode2p9mode(v9ses, mode | S_IFDIR);
841	fid = v9fs_create(v9ses, dir, dentry, NULL, perm, P9_OREAD);
842	if (IS_ERR(fid)) {
843		err = PTR_ERR(fid);
844		fid = NULL;
845	}
846
847	if (fid)
848		p9_client_clunk(fid);
849
850	return err;
851}
852
853
854/**
855 * v9fs_vfs_mkdir_dotl - VFS mkdir hook to create a directory
856 * @dir:  inode that is being unlinked
857 * @dentry: dentry that is being unlinked
858 * @mode: mode for new directory
859 *
860 */
861
862static int v9fs_vfs_mkdir_dotl(struct inode *dir, struct dentry *dentry,
863					int mode)
864{
865	int err;
866	struct v9fs_session_info *v9ses;
867	struct p9_fid *fid = NULL, *dfid = NULL;
868	gid_t gid;
869	char *name;
870	struct inode *inode;
871	struct p9_qid qid;
872	struct dentry *dir_dentry;
873
874	P9_DPRINTK(P9_DEBUG_VFS, "name %s\n", dentry->d_name.name);
875	err = 0;
876	v9ses = v9fs_inode2v9ses(dir);
877
878	mode |= S_IFDIR;
879	dir_dentry = v9fs_dentry_from_dir_inode(dir);
880	dfid = v9fs_fid_lookup(dir_dentry);
881	if (IS_ERR(dfid)) {
882		err = PTR_ERR(dfid);
883		P9_DPRINTK(P9_DEBUG_VFS, "fid lookup failed %d\n", err);
884		dfid = NULL;
885		goto error;
886	}
887
888	gid = v9fs_get_fsgid_for_create(dir);
889	if (gid < 0) {
890		P9_DPRINTK(P9_DEBUG_VFS, "v9fs_get_fsgid_for_create failed\n");
891		goto error;
892	}
893
894	name = (char *) dentry->d_name.name;
895	err = p9_client_mkdir_dotl(dfid, name, mode, gid, &qid);
896	if (err < 0)
897		goto error;
898
899	/* instantiate inode and assign the unopened fid to the dentry */
900	if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) {
901		fid = p9_client_walk(dfid, 1, &name, 1);
902		if (IS_ERR(fid)) {
903			err = PTR_ERR(fid);
904			P9_DPRINTK(P9_DEBUG_VFS, "p9_client_walk failed %d\n",
905				err);
906			fid = NULL;
907			goto error;
908		}
909
910		inode = v9fs_inode_from_fid(v9ses, fid, dir->i_sb);
911		if (IS_ERR(inode)) {
912			err = PTR_ERR(inode);
913			P9_DPRINTK(P9_DEBUG_VFS, "inode creation failed %d\n",
914				err);
915			goto error;
916		}
917		dentry->d_op = &v9fs_cached_dentry_operations;
918		d_instantiate(dentry, inode);
919		err = v9fs_fid_add(dentry, fid);
920		if (err < 0)
921			goto error;
922		fid = NULL;
923	}
924error:
925	if (fid)
926		p9_client_clunk(fid);
927	return err;
928}
929
930/**
931 * v9fs_vfs_lookup - VFS lookup hook to "walk" to a new inode
932 * @dir:  inode that is being walked from
933 * @dentry: dentry that is being walked to?
934 * @nameidata: path data
935 *
936 */
937
938static struct dentry *v9fs_vfs_lookup(struct inode *dir, struct dentry *dentry,
939				      struct nameidata *nameidata)
940{
941	struct super_block *sb;
942	struct v9fs_session_info *v9ses;
943	struct p9_fid *dfid, *fid;
944	struct inode *inode;
945	char *name;
946	int result = 0;
947
948	P9_DPRINTK(P9_DEBUG_VFS, "dir: %p dentry: (%s) %p nameidata: %p\n",
949		dir, dentry->d_name.name, dentry, nameidata);
950
951	if (dentry->d_name.len > NAME_MAX)
952		return ERR_PTR(-ENAMETOOLONG);
953
954	sb = dir->i_sb;
955	v9ses = v9fs_inode2v9ses(dir);
956	/* We can walk d_parent because we hold the dir->i_mutex */
957	dfid = v9fs_fid_lookup(dentry->d_parent);
958	if (IS_ERR(dfid))
959		return ERR_CAST(dfid);
960
961	name = (char *) dentry->d_name.name;
962	fid = p9_client_walk(dfid, 1, &name, 1);
963	if (IS_ERR(fid)) {
964		result = PTR_ERR(fid);
965		if (result == -ENOENT) {
966			inode = NULL;
967			goto inst_out;
968		}
969
970		return ERR_PTR(result);
971	}
972
973	inode = v9fs_inode_from_fid(v9ses, fid, dir->i_sb);
974	if (IS_ERR(inode)) {
975		result = PTR_ERR(inode);
976		inode = NULL;
977		goto error;
978	}
979
980	result = v9fs_fid_add(dentry, fid);
981	if (result < 0)
982		goto error;
983
984inst_out:
985	if (v9ses->cache)
986		dentry->d_op = &v9fs_cached_dentry_operations;
987	else
988		dentry->d_op = &v9fs_dentry_operations;
989
990	d_add(dentry, inode);
991	return NULL;
992
993error:
994	p9_client_clunk(fid);
995
996	return ERR_PTR(result);
997}
998
999/**
1000 * v9fs_vfs_unlink - VFS unlink hook to delete an inode
1001 * @i:  inode that is being unlinked
1002 * @d: dentry that is being unlinked
1003 *
1004 */
1005
1006static int v9fs_vfs_unlink(struct inode *i, struct dentry *d)
1007{
1008	return v9fs_remove(i, d, 0);
1009}
1010
1011/**
1012 * v9fs_vfs_rmdir - VFS unlink hook to delete a directory
1013 * @i:  inode that is being unlinked
1014 * @d: dentry that is being unlinked
1015 *
1016 */
1017
1018static int v9fs_vfs_rmdir(struct inode *i, struct dentry *d)
1019{
1020	return v9fs_remove(i, d, 1);
1021}
1022
1023/**
1024 * v9fs_vfs_rename - VFS hook to rename an inode
1025 * @old_dir:  old dir inode
1026 * @old_dentry: old dentry
1027 * @new_dir: new dir inode
1028 * @new_dentry: new dentry
1029 *
1030 */
1031
1032static int
1033v9fs_vfs_rename(struct inode *old_dir, struct dentry *old_dentry,
1034		struct inode *new_dir, struct dentry *new_dentry)
1035{
1036	struct inode *old_inode;
1037	struct v9fs_session_info *v9ses;
1038	struct p9_fid *oldfid;
1039	struct p9_fid *olddirfid;
1040	struct p9_fid *newdirfid;
1041	struct p9_wstat wstat;
1042	int retval;
1043
1044	P9_DPRINTK(P9_DEBUG_VFS, "\n");
1045	retval = 0;
1046	old_inode = old_dentry->d_inode;
1047	v9ses = v9fs_inode2v9ses(old_inode);
1048	oldfid = v9fs_fid_lookup(old_dentry);
1049	if (IS_ERR(oldfid))
1050		return PTR_ERR(oldfid);
1051
1052	olddirfid = v9fs_fid_clone(old_dentry->d_parent);
1053	if (IS_ERR(olddirfid)) {
1054		retval = PTR_ERR(olddirfid);
1055		goto done;
1056	}
1057
1058	newdirfid = v9fs_fid_clone(new_dentry->d_parent);
1059	if (IS_ERR(newdirfid)) {
1060		retval = PTR_ERR(newdirfid);
1061		goto clunk_olddir;
1062	}
1063
1064	down_write(&v9ses->rename_sem);
1065	if (v9fs_proto_dotl(v9ses)) {
1066		retval = p9_client_rename(oldfid, newdirfid,
1067					(char *) new_dentry->d_name.name);
1068		if (retval != -ENOSYS)
1069			goto clunk_newdir;
1070	}
1071	if (old_dentry->d_parent != new_dentry->d_parent) {
1072		/*
1073		 * 9P .u can only handle file rename in the same directory
1074		 */
1075
1076		P9_DPRINTK(P9_DEBUG_ERROR,
1077				"old dir and new dir are different\n");
1078		retval = -EXDEV;
1079		goto clunk_newdir;
1080	}
1081	v9fs_blank_wstat(&wstat);
1082	wstat.muid = v9ses->uname;
1083	wstat.name = (char *) new_dentry->d_name.name;
1084	retval = p9_client_wstat(oldfid, &wstat);
1085
1086clunk_newdir:
1087	if (!retval)
1088		/* successful rename */
1089		d_move(old_dentry, new_dentry);
1090	up_write(&v9ses->rename_sem);
1091	p9_client_clunk(newdirfid);
1092
1093clunk_olddir:
1094	p9_client_clunk(olddirfid);
1095
1096done:
1097	return retval;
1098}
1099
1100/**
1101 * v9fs_vfs_getattr - retrieve file metadata
1102 * @mnt: mount information
1103 * @dentry: file to get attributes on
1104 * @stat: metadata structure to populate
1105 *
1106 */
1107
1108static int
1109v9fs_vfs_getattr(struct vfsmount *mnt, struct dentry *dentry,
1110		 struct kstat *stat)
1111{
1112	int err;
1113	struct v9fs_session_info *v9ses;
1114	struct p9_fid *fid;
1115	struct p9_wstat *st;
1116
1117	P9_DPRINTK(P9_DEBUG_VFS, "dentry: %p\n", dentry);
1118	err = -EPERM;
1119	v9ses = v9fs_inode2v9ses(dentry->d_inode);
1120	if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE)
1121		return simple_getattr(mnt, dentry, stat);
1122
1123	fid = v9fs_fid_lookup(dentry);
1124	if (IS_ERR(fid))
1125		return PTR_ERR(fid);
1126
1127	st = p9_client_stat(fid);
1128	if (IS_ERR(st))
1129		return PTR_ERR(st);
1130
1131	v9fs_stat2inode(st, dentry->d_inode, dentry->d_inode->i_sb);
1132		generic_fillattr(dentry->d_inode, stat);
1133
1134	p9stat_free(st);
1135	kfree(st);
1136	return 0;
1137}
1138
1139static int
1140v9fs_vfs_getattr_dotl(struct vfsmount *mnt, struct dentry *dentry,
1141		 struct kstat *stat)
1142{
1143	int err;
1144	struct v9fs_session_info *v9ses;
1145	struct p9_fid *fid;
1146	struct p9_stat_dotl *st;
1147
1148	P9_DPRINTK(P9_DEBUG_VFS, "dentry: %p\n", dentry);
1149	err = -EPERM;
1150	v9ses = v9fs_inode2v9ses(dentry->d_inode);
1151	if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE)
1152		return simple_getattr(mnt, dentry, stat);
1153
1154	fid = v9fs_fid_lookup(dentry);
1155	if (IS_ERR(fid))
1156		return PTR_ERR(fid);
1157
1158	/* Ask for all the fields in stat structure. Server will return
1159	 * whatever it supports
1160	 */
1161
1162	st = p9_client_getattr_dotl(fid, P9_STATS_ALL);
1163	if (IS_ERR(st))
1164		return PTR_ERR(st);
1165
1166	v9fs_stat2inode_dotl(st, dentry->d_inode);
1167	generic_fillattr(dentry->d_inode, stat);
1168	/* Change block size to what the server returned */
1169	stat->blksize = st->st_blksize;
1170
1171	kfree(st);
1172	return 0;
1173}
1174
1175/**
1176 * v9fs_vfs_setattr - set file metadata
1177 * @dentry: file whose metadata to set
1178 * @iattr: metadata assignment structure
1179 *
1180 */
1181
1182static int v9fs_vfs_setattr(struct dentry *dentry, struct iattr *iattr)
1183{
1184	int retval;
1185	struct v9fs_session_info *v9ses;
1186	struct p9_fid *fid;
1187	struct p9_wstat wstat;
1188
1189	P9_DPRINTK(P9_DEBUG_VFS, "\n");
1190	retval = -EPERM;
1191	v9ses = v9fs_inode2v9ses(dentry->d_inode);
1192	fid = v9fs_fid_lookup(dentry);
1193	if(IS_ERR(fid))
1194		return PTR_ERR(fid);
1195
1196	v9fs_blank_wstat(&wstat);
1197	if (iattr->ia_valid & ATTR_MODE)
1198		wstat.mode = unixmode2p9mode(v9ses, iattr->ia_mode);
1199
1200	if (iattr->ia_valid & ATTR_MTIME)
1201		wstat.mtime = iattr->ia_mtime.tv_sec;
1202
1203	if (iattr->ia_valid & ATTR_ATIME)
1204		wstat.atime = iattr->ia_atime.tv_sec;
1205
1206	if (iattr->ia_valid & ATTR_SIZE)
1207		wstat.length = iattr->ia_size;
1208
1209	if (v9fs_proto_dotu(v9ses)) {
1210		if (iattr->ia_valid & ATTR_UID)
1211			wstat.n_uid = iattr->ia_uid;
1212
1213		if (iattr->ia_valid & ATTR_GID)
1214			wstat.n_gid = iattr->ia_gid;
1215	}
1216
1217	retval = p9_client_wstat(fid, &wstat);
1218	if (retval < 0)
1219		return retval;
1220
1221	if ((iattr->ia_valid & ATTR_SIZE) &&
1222	    iattr->ia_size != i_size_read(dentry->d_inode)) {
1223		retval = vmtruncate(dentry->d_inode, iattr->ia_size);
1224		if (retval)
1225			return retval;
1226	}
1227
1228	setattr_copy(dentry->d_inode, iattr);
1229	mark_inode_dirty(dentry->d_inode);
1230	return 0;
1231}
1232
1233/**
1234 * v9fs_vfs_setattr_dotl - set file metadata
1235 * @dentry: file whose metadata to set
1236 * @iattr: metadata assignment structure
1237 *
1238 */
1239
1240static int v9fs_vfs_setattr_dotl(struct dentry *dentry, struct iattr *iattr)
1241{
1242	int retval;
1243	struct v9fs_session_info *v9ses;
1244	struct p9_fid *fid;
1245	struct p9_iattr_dotl p9attr;
1246
1247	P9_DPRINTK(P9_DEBUG_VFS, "\n");
1248
1249	retval = inode_change_ok(dentry->d_inode, iattr);
1250	if (retval)
1251		return retval;
1252
1253	p9attr.valid = iattr->ia_valid;
1254	p9attr.mode = iattr->ia_mode;
1255	p9attr.uid = iattr->ia_uid;
1256	p9attr.gid = iattr->ia_gid;
1257	p9attr.size = iattr->ia_size;
1258	p9attr.atime_sec = iattr->ia_atime.tv_sec;
1259	p9attr.atime_nsec = iattr->ia_atime.tv_nsec;
1260	p9attr.mtime_sec = iattr->ia_mtime.tv_sec;
1261	p9attr.mtime_nsec = iattr->ia_mtime.tv_nsec;
1262
1263	retval = -EPERM;
1264	v9ses = v9fs_inode2v9ses(dentry->d_inode);
1265	fid = v9fs_fid_lookup(dentry);
1266	if (IS_ERR(fid))
1267		return PTR_ERR(fid);
1268
1269	retval = p9_client_setattr(fid, &p9attr);
1270	if (retval < 0)
1271		return retval;
1272
1273	if ((iattr->ia_valid & ATTR_SIZE) &&
1274	    iattr->ia_size != i_size_read(dentry->d_inode)) {
1275		retval = vmtruncate(dentry->d_inode, iattr->ia_size);
1276		if (retval)
1277			return retval;
1278	}
1279
1280	setattr_copy(dentry->d_inode, iattr);
1281	mark_inode_dirty(dentry->d_inode);
1282	return 0;
1283}
1284
1285/**
1286 * v9fs_stat2inode - populate an inode structure with mistat info
1287 * @stat: Plan 9 metadata (mistat) structure
1288 * @inode: inode to populate
1289 * @sb: superblock of filesystem
1290 *
1291 */
1292
1293void
1294v9fs_stat2inode(struct p9_wstat *stat, struct inode *inode,
1295	struct super_block *sb)
1296{
1297	char ext[32];
1298	char tag_name[14];
1299	unsigned int i_nlink;
1300	struct v9fs_session_info *v9ses = sb->s_fs_info;
1301
1302	inode->i_nlink = 1;
1303
1304	inode->i_atime.tv_sec = stat->atime;
1305	inode->i_mtime.tv_sec = stat->mtime;
1306	inode->i_ctime.tv_sec = stat->mtime;
1307
1308	inode->i_uid = v9ses->dfltuid;
1309	inode->i_gid = v9ses->dfltgid;
1310
1311	if (v9fs_proto_dotu(v9ses)) {
1312		inode->i_uid = stat->n_uid;
1313		inode->i_gid = stat->n_gid;
1314	}
1315	if ((S_ISREG(inode->i_mode)) || (S_ISDIR(inode->i_mode))) {
1316		if (v9fs_proto_dotu(v9ses) && (stat->extension[0] != '\0')) {
1317			/*
1318			 * Hadlink support got added later to
1319			 * to the .u extension. So there can be
1320			 * server out there that doesn't support
1321			 * this even with .u extension. So check
1322			 * for non NULL stat->extension
1323			 */
1324			strncpy(ext, stat->extension, sizeof(ext));
1325			/* HARDLINKCOUNT %u */
1326			sscanf(ext, "%13s %u", tag_name, &i_nlink);
1327			if (!strncmp(tag_name, "HARDLINKCOUNT", 13))
1328				inode->i_nlink = i_nlink;
1329		}
1330	}
1331	inode->i_mode = p9mode2unixmode(v9ses, stat->mode);
1332	if ((S_ISBLK(inode->i_mode)) || (S_ISCHR(inode->i_mode))) {
1333		char type = 0;
1334		int major = -1;
1335		int minor = -1;
1336
1337		strncpy(ext, stat->extension, sizeof(ext));
1338		sscanf(ext, "%c %u %u", &type, &major, &minor);
1339		switch (type) {
1340		case 'c':
1341			inode->i_mode &= ~S_IFBLK;
1342			inode->i_mode |= S_IFCHR;
1343			break;
1344		case 'b':
1345			break;
1346		default:
1347			P9_DPRINTK(P9_DEBUG_ERROR,
1348				"Unknown special type %c %s\n", type,
1349				stat->extension);
1350		};
1351		inode->i_rdev = MKDEV(major, minor);
1352		init_special_inode(inode, inode->i_mode, inode->i_rdev);
1353	} else
1354		inode->i_rdev = 0;
1355
1356	i_size_write(inode, stat->length);
1357
1358	/* not real number of blocks, but 512 byte ones ... */
1359	inode->i_blocks = (i_size_read(inode) + 512 - 1) >> 9;
1360}
1361
1362/**
1363 * v9fs_stat2inode_dotl - populate an inode structure with stat info
1364 * @stat: stat structure
1365 * @inode: inode to populate
1366 * @sb: superblock of filesystem
1367 *
1368 */
1369
1370void
1371v9fs_stat2inode_dotl(struct p9_stat_dotl *stat, struct inode *inode)
1372{
1373
1374	if ((stat->st_result_mask & P9_STATS_BASIC) == P9_STATS_BASIC) {
1375		inode->i_atime.tv_sec = stat->st_atime_sec;
1376		inode->i_atime.tv_nsec = stat->st_atime_nsec;
1377		inode->i_mtime.tv_sec = stat->st_mtime_sec;
1378		inode->i_mtime.tv_nsec = stat->st_mtime_nsec;
1379		inode->i_ctime.tv_sec = stat->st_ctime_sec;
1380		inode->i_ctime.tv_nsec = stat->st_ctime_nsec;
1381		inode->i_uid = stat->st_uid;
1382		inode->i_gid = stat->st_gid;
1383		inode->i_nlink = stat->st_nlink;
1384		inode->i_mode = stat->st_mode;
1385		inode->i_rdev = new_decode_dev(stat->st_rdev);
1386
1387		if ((S_ISBLK(inode->i_mode)) || (S_ISCHR(inode->i_mode)))
1388			init_special_inode(inode, inode->i_mode, inode->i_rdev);
1389
1390		i_size_write(inode, stat->st_size);
1391		inode->i_blocks = stat->st_blocks;
1392	} else {
1393		if (stat->st_result_mask & P9_STATS_ATIME) {
1394			inode->i_atime.tv_sec = stat->st_atime_sec;
1395			inode->i_atime.tv_nsec = stat->st_atime_nsec;
1396		}
1397		if (stat->st_result_mask & P9_STATS_MTIME) {
1398			inode->i_mtime.tv_sec = stat->st_mtime_sec;
1399			inode->i_mtime.tv_nsec = stat->st_mtime_nsec;
1400		}
1401		if (stat->st_result_mask & P9_STATS_CTIME) {
1402			inode->i_ctime.tv_sec = stat->st_ctime_sec;
1403			inode->i_ctime.tv_nsec = stat->st_ctime_nsec;
1404		}
1405		if (stat->st_result_mask & P9_STATS_UID)
1406			inode->i_uid = stat->st_uid;
1407		if (stat->st_result_mask & P9_STATS_GID)
1408			inode->i_gid = stat->st_gid;
1409		if (stat->st_result_mask & P9_STATS_NLINK)
1410			inode->i_nlink = stat->st_nlink;
1411		if (stat->st_result_mask & P9_STATS_MODE) {
1412			inode->i_mode = stat->st_mode;
1413			if ((S_ISBLK(inode->i_mode)) ||
1414						(S_ISCHR(inode->i_mode)))
1415				init_special_inode(inode, inode->i_mode,
1416								inode->i_rdev);
1417		}
1418		if (stat->st_result_mask & P9_STATS_RDEV)
1419			inode->i_rdev = new_decode_dev(stat->st_rdev);
1420		if (stat->st_result_mask & P9_STATS_SIZE)
1421			i_size_write(inode, stat->st_size);
1422		if (stat->st_result_mask & P9_STATS_BLOCKS)
1423			inode->i_blocks = stat->st_blocks;
1424	}
1425	if (stat->st_result_mask & P9_STATS_GEN)
1426			inode->i_generation = stat->st_gen;
1427
1428	/* Currently we don't support P9_STATS_BTIME and P9_STATS_DATA_VERSION
1429	 * because the inode structure does not have fields for them.
1430	 */
1431}
1432
1433/**
1434 * v9fs_qid2ino - convert qid into inode number
1435 * @qid: qid to hash
1436 *
1437 * BUG: potential for inode number collisions?
1438 */
1439
1440ino_t v9fs_qid2ino(struct p9_qid *qid)
1441{
1442	u64 path = qid->path + 2;
1443	ino_t i = 0;
1444
1445	if (sizeof(ino_t) == sizeof(path))
1446		memcpy(&i, &path, sizeof(ino_t));
1447	else
1448		i = (ino_t) (path ^ (path >> 32));
1449
1450	return i;
1451}
1452
1453/**
1454 * v9fs_readlink - read a symlink's location (internal version)
1455 * @dentry: dentry for symlink
1456 * @buffer: buffer to load symlink location into
1457 * @buflen: length of buffer
1458 *
1459 */
1460
1461static int v9fs_readlink(struct dentry *dentry, char *buffer, int buflen)
1462{
1463	int retval;
1464
1465	struct v9fs_session_info *v9ses;
1466	struct p9_fid *fid;
1467	struct p9_wstat *st;
1468
1469	P9_DPRINTK(P9_DEBUG_VFS, " %s\n", dentry->d_name.name);
1470	retval = -EPERM;
1471	v9ses = v9fs_inode2v9ses(dentry->d_inode);
1472	fid = v9fs_fid_lookup(dentry);
1473	if (IS_ERR(fid))
1474		return PTR_ERR(fid);
1475
1476	if (!v9fs_proto_dotu(v9ses) && !v9fs_proto_dotl(v9ses))
1477		return -EBADF;
1478
1479	st = p9_client_stat(fid);
1480	if (IS_ERR(st))
1481		return PTR_ERR(st);
1482
1483	if (!(st->mode & P9_DMSYMLINK)) {
1484		retval = -EINVAL;
1485		goto done;
1486	}
1487
1488	/* copy extension buffer into buffer */
1489	strncpy(buffer, st->extension, buflen);
1490
1491	P9_DPRINTK(P9_DEBUG_VFS,
1492		"%s -> %s (%s)\n", dentry->d_name.name, st->extension, buffer);
1493
1494	retval = strnlen(buffer, buflen);
1495done:
1496	p9stat_free(st);
1497	kfree(st);
1498	return retval;
1499}
1500
1501/**
1502 * v9fs_vfs_follow_link - follow a symlink path
1503 * @dentry: dentry for symlink
1504 * @nd: nameidata
1505 *
1506 */
1507
1508static void *v9fs_vfs_follow_link(struct dentry *dentry, struct nameidata *nd)
1509{
1510	int len = 0;
1511	char *link = __getname();
1512
1513	P9_DPRINTK(P9_DEBUG_VFS, "%s n", dentry->d_name.name);
1514
1515	if (!link)
1516		link = ERR_PTR(-ENOMEM);
1517	else {
1518		len = v9fs_readlink(dentry, link, PATH_MAX);
1519
1520		if (len < 0) {
1521			__putname(link);
1522			link = ERR_PTR(len);
1523		} else
1524			link[min(len, PATH_MAX-1)] = 0;
1525	}
1526	nd_set_link(nd, link);
1527
1528	return NULL;
1529}
1530
1531/**
1532 * v9fs_vfs_put_link - release a symlink path
1533 * @dentry: dentry for symlink
1534 * @nd: nameidata
1535 * @p: unused
1536 *
1537 */
1538
1539static void
1540v9fs_vfs_put_link(struct dentry *dentry, struct nameidata *nd, void *p)
1541{
1542	char *s = nd_get_link(nd);
1543
1544	P9_DPRINTK(P9_DEBUG_VFS, " %s %s\n", dentry->d_name.name,
1545		IS_ERR(s) ? "<error>" : s);
1546	if (!IS_ERR(s))
1547		__putname(s);
1548}
1549
1550/**
1551 * v9fs_vfs_mkspecial - create a special file
1552 * @dir: inode to create special file in
1553 * @dentry: dentry to create
1554 * @mode: mode to create special file
1555 * @extension: 9p2000.u format extension string representing special file
1556 *
1557 */
1558
1559static int v9fs_vfs_mkspecial(struct inode *dir, struct dentry *dentry,
1560	int mode, const char *extension)
1561{
1562	u32 perm;
1563	struct v9fs_session_info *v9ses;
1564	struct p9_fid *fid;
1565
1566	v9ses = v9fs_inode2v9ses(dir);
1567	if (!v9fs_proto_dotu(v9ses)) {
1568		P9_DPRINTK(P9_DEBUG_ERROR, "not extended\n");
1569		return -EPERM;
1570	}
1571
1572	perm = unixmode2p9mode(v9ses, mode);
1573	fid = v9fs_create(v9ses, dir, dentry, (char *) extension, perm,
1574								P9_OREAD);
1575	if (IS_ERR(fid))
1576		return PTR_ERR(fid);
1577
1578	p9_client_clunk(fid);
1579	return 0;
1580}
1581
1582/**
1583 * v9fs_vfs_symlink_dotl - helper function to create symlinks
1584 * @dir: directory inode containing symlink
1585 * @dentry: dentry for symlink
1586 * @symname: symlink data
1587 *
1588 * See Also: 9P2000.L RFC for more information
1589 *
1590 */
1591
1592static int
1593v9fs_vfs_symlink_dotl(struct inode *dir, struct dentry *dentry,
1594		const char *symname)
1595{
1596	struct v9fs_session_info *v9ses;
1597	struct p9_fid *dfid;
1598	struct p9_fid *fid = NULL;
1599	struct inode *inode;
1600	struct p9_qid qid;
1601	char *name;
1602	int err;
1603	gid_t gid;
1604
1605	name = (char *) dentry->d_name.name;
1606	P9_DPRINTK(P9_DEBUG_VFS, "v9fs_vfs_symlink_dotl : %lu,%s,%s\n",
1607			dir->i_ino, name, symname);
1608	v9ses = v9fs_inode2v9ses(dir);
1609
1610	dfid = v9fs_fid_lookup(dentry->d_parent);
1611	if (IS_ERR(dfid)) {
1612		err = PTR_ERR(dfid);
1613		P9_DPRINTK(P9_DEBUG_VFS, "fid lookup failed %d\n", err);
1614		return err;
1615	}
1616
1617	gid = v9fs_get_fsgid_for_create(dir);
1618
1619	if (gid < 0) {
1620		P9_DPRINTK(P9_DEBUG_VFS, "v9fs_get_egid failed %d\n", gid);
1621		goto error;
1622	}
1623
1624	/* Server doesn't alter fid on TSYMLINK. Hence no need to clone it. */
1625	err = p9_client_symlink(dfid, name, (char *)symname, gid, &qid);
1626
1627	if (err < 0) {
1628		P9_DPRINTK(P9_DEBUG_VFS, "p9_client_symlink failed %d\n", err);
1629		goto error;
1630	}
1631
1632	if (v9ses->cache) {
1633		/* Now walk from the parent so we can get an unopened fid. */
1634		fid = p9_client_walk(dfid, 1, &name, 1);
1635		if (IS_ERR(fid)) {
1636			err = PTR_ERR(fid);
1637			P9_DPRINTK(P9_DEBUG_VFS, "p9_client_walk failed %d\n",
1638					err);
1639			fid = NULL;
1640			goto error;
1641		}
1642
1643		/* instantiate inode and assign the unopened fid to dentry */
1644		inode = v9fs_inode_from_fid(v9ses, fid, dir->i_sb);
1645		if (IS_ERR(inode)) {
1646			err = PTR_ERR(inode);
1647			P9_DPRINTK(P9_DEBUG_VFS, "inode creation failed %d\n",
1648					err);
1649			goto error;
1650		}
1651		dentry->d_op = &v9fs_cached_dentry_operations;
1652		d_instantiate(dentry, inode);
1653		err = v9fs_fid_add(dentry, fid);
1654		if (err < 0)
1655			goto error;
1656		fid = NULL;
1657	} else {
1658		/* Not in cached mode. No need to populate inode with stat */
1659		inode = v9fs_get_inode(dir->i_sb, S_IFLNK);
1660		if (IS_ERR(inode)) {
1661			err = PTR_ERR(inode);
1662			goto error;
1663		}
1664		dentry->d_op = &v9fs_dentry_operations;
1665		d_instantiate(dentry, inode);
1666	}
1667
1668error:
1669	if (fid)
1670		p9_client_clunk(fid);
1671
1672	return err;
1673}
1674
1675/**
1676 * v9fs_vfs_symlink - helper function to create symlinks
1677 * @dir: directory inode containing symlink
1678 * @dentry: dentry for symlink
1679 * @symname: symlink data
1680 *
1681 * See Also: 9P2000.u RFC for more information
1682 *
1683 */
1684
1685static int
1686v9fs_vfs_symlink(struct inode *dir, struct dentry *dentry, const char *symname)
1687{
1688	P9_DPRINTK(P9_DEBUG_VFS, " %lu,%s,%s\n", dir->i_ino,
1689					dentry->d_name.name, symname);
1690
1691	return v9fs_vfs_mkspecial(dir, dentry, S_IFLNK, symname);
1692}
1693
1694/**
1695 * v9fs_vfs_link - create a hardlink
1696 * @old_dentry: dentry for file to link to
1697 * @dir: inode destination for new link
1698 * @dentry: dentry for link
1699 *
1700 */
1701
1702static int
1703v9fs_vfs_link(struct dentry *old_dentry, struct inode *dir,
1704	      struct dentry *dentry)
1705{
1706	int retval;
1707	struct p9_fid *oldfid;
1708	char *name;
1709
1710	P9_DPRINTK(P9_DEBUG_VFS,
1711		" %lu,%s,%s\n", dir->i_ino, dentry->d_name.name,
1712		old_dentry->d_name.name);
1713
1714	oldfid = v9fs_fid_clone(old_dentry);
1715	if (IS_ERR(oldfid))
1716		return PTR_ERR(oldfid);
1717
1718	name = __getname();
1719	if (unlikely(!name)) {
1720		retval = -ENOMEM;
1721		goto clunk_fid;
1722	}
1723
1724	sprintf(name, "%d\n", oldfid->fid);
1725	retval = v9fs_vfs_mkspecial(dir, dentry, P9_DMLINK, name);
1726	__putname(name);
1727
1728clunk_fid:
1729	p9_client_clunk(oldfid);
1730	return retval;
1731}
1732
1733/**
1734 * v9fs_vfs_link_dotl - create a hardlink for dotl
1735 * @old_dentry: dentry for file to link to
1736 * @dir: inode destination for new link
1737 * @dentry: dentry for link
1738 *
1739 */
1740
1741static int
1742v9fs_vfs_link_dotl(struct dentry *old_dentry, struct inode *dir,
1743		struct dentry *dentry)
1744{
1745	int err;
1746	struct p9_fid *dfid, *oldfid;
1747	char *name;
1748	struct v9fs_session_info *v9ses;
1749	struct dentry *dir_dentry;
1750
1751	P9_DPRINTK(P9_DEBUG_VFS, "dir ino: %lu, old_name: %s, new_name: %s\n",
1752			dir->i_ino, old_dentry->d_name.name,
1753			dentry->d_name.name);
1754
1755	v9ses = v9fs_inode2v9ses(dir);
1756	dir_dentry = v9fs_dentry_from_dir_inode(dir);
1757	dfid = v9fs_fid_lookup(dir_dentry);
1758	if (IS_ERR(dfid))
1759		return PTR_ERR(dfid);
1760
1761	oldfid = v9fs_fid_lookup(old_dentry);
1762	if (IS_ERR(oldfid))
1763		return PTR_ERR(oldfid);
1764
1765	name = (char *) dentry->d_name.name;
1766
1767	err = p9_client_link(dfid, oldfid, (char *)dentry->d_name.name);
1768
1769	if (err < 0) {
1770		P9_DPRINTK(P9_DEBUG_VFS, "p9_client_link failed %d\n", err);
1771		return err;
1772	}
1773
1774	if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) {
1775		/* Get the latest stat info from server. */
1776		struct p9_fid *fid;
1777		struct p9_stat_dotl *st;
1778
1779		fid = v9fs_fid_lookup(old_dentry);
1780		if (IS_ERR(fid))
1781			return PTR_ERR(fid);
1782
1783		st = p9_client_getattr_dotl(fid, P9_STATS_BASIC);
1784		if (IS_ERR(st))
1785			return PTR_ERR(st);
1786
1787		v9fs_stat2inode_dotl(st, old_dentry->d_inode);
1788
1789		kfree(st);
1790	} else {
1791		/* Caching disabled. No need to get upto date stat info.
1792		 * This dentry will be released immediately. So, just i_count++
1793		 */
1794		atomic_inc(&old_dentry->d_inode->i_count);
1795	}
1796
1797	dentry->d_op = old_dentry->d_op;
1798	d_instantiate(dentry, old_dentry->d_inode);
1799
1800	return err;
1801}
1802
1803/**
1804 * v9fs_vfs_mknod - create a special file
1805 * @dir: inode destination for new link
1806 * @dentry: dentry for file
1807 * @mode: mode for creation
1808 * @rdev: device associated with special file
1809 *
1810 */
1811
1812static int
1813v9fs_vfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t rdev)
1814{
1815	int retval;
1816	char *name;
1817
1818	P9_DPRINTK(P9_DEBUG_VFS,
1819		" %lu,%s mode: %x MAJOR: %u MINOR: %u\n", dir->i_ino,
1820		dentry->d_name.name, mode, MAJOR(rdev), MINOR(rdev));
1821
1822	if (!new_valid_dev(rdev))
1823		return -EINVAL;
1824
1825	name = __getname();
1826	if (!name)
1827		return -ENOMEM;
1828	/* build extension */
1829	if (S_ISBLK(mode))
1830		sprintf(name, "b %u %u", MAJOR(rdev), MINOR(rdev));
1831	else if (S_ISCHR(mode))
1832		sprintf(name, "c %u %u", MAJOR(rdev), MINOR(rdev));
1833	else if (S_ISFIFO(mode))
1834		*name = 0;
1835	else if (S_ISSOCK(mode))
1836		*name = 0;
1837	else {
1838		__putname(name);
1839		return -EINVAL;
1840	}
1841
1842	retval = v9fs_vfs_mkspecial(dir, dentry, mode, name);
1843	__putname(name);
1844
1845	return retval;
1846}
1847
1848/**
1849 * v9fs_vfs_mknod_dotl - create a special file
1850 * @dir: inode destination for new link
1851 * @dentry: dentry for file
1852 * @mode: mode for creation
1853 * @rdev: device associated with special file
1854 *
1855 */
1856static int
1857v9fs_vfs_mknod_dotl(struct inode *dir, struct dentry *dentry, int mode,
1858		dev_t rdev)
1859{
1860	int err;
1861	char *name;
1862	struct v9fs_session_info *v9ses;
1863	struct p9_fid *fid = NULL, *dfid = NULL;
1864	struct inode *inode;
1865	gid_t gid;
1866	struct p9_qid qid;
1867	struct dentry *dir_dentry;
1868
1869	P9_DPRINTK(P9_DEBUG_VFS,
1870		" %lu,%s mode: %x MAJOR: %u MINOR: %u\n", dir->i_ino,
1871		dentry->d_name.name, mode, MAJOR(rdev), MINOR(rdev));
1872
1873	if (!new_valid_dev(rdev))
1874		return -EINVAL;
1875
1876	v9ses = v9fs_inode2v9ses(dir);
1877	dir_dentry = v9fs_dentry_from_dir_inode(dir);
1878	dfid = v9fs_fid_lookup(dir_dentry);
1879	if (IS_ERR(dfid)) {
1880		err = PTR_ERR(dfid);
1881		P9_DPRINTK(P9_DEBUG_VFS, "fid lookup failed %d\n", err);
1882		dfid = NULL;
1883		goto error;
1884	}
1885
1886	gid = v9fs_get_fsgid_for_create(dir);
1887	if (gid < 0) {
1888		P9_DPRINTK(P9_DEBUG_VFS, "v9fs_get_fsgid_for_create failed\n");
1889		goto error;
1890	}
1891
1892	name = (char *) dentry->d_name.name;
1893
1894	err = p9_client_mknod_dotl(dfid, name, mode, rdev, gid, &qid);
1895	if (err < 0)
1896		goto error;
1897
1898	/* instantiate inode and assign the unopened fid to the dentry */
1899	if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) {
1900		fid = p9_client_walk(dfid, 1, &name, 1);
1901		if (IS_ERR(fid)) {
1902			err = PTR_ERR(fid);
1903			P9_DPRINTK(P9_DEBUG_VFS, "p9_client_walk failed %d\n",
1904				err);
1905			fid = NULL;
1906			goto error;
1907		}
1908
1909		inode = v9fs_inode_from_fid(v9ses, fid, dir->i_sb);
1910		if (IS_ERR(inode)) {
1911			err = PTR_ERR(inode);
1912			P9_DPRINTK(P9_DEBUG_VFS, "inode creation failed %d\n",
1913				err);
1914			goto error;
1915		}
1916		dentry->d_op = &v9fs_cached_dentry_operations;
1917		d_instantiate(dentry, inode);
1918		err = v9fs_fid_add(dentry, fid);
1919		if (err < 0)
1920			goto error;
1921		fid = NULL;
1922	} else {
1923		/*
1924		 * Not in cached mode. No need to populate inode with stat.
1925		 * socket syscall returns a fd, so we need instantiate
1926		 */
1927		inode = v9fs_get_inode(dir->i_sb, mode);
1928		if (IS_ERR(inode)) {
1929			err = PTR_ERR(inode);
1930			goto error;
1931		}
1932		dentry->d_op = &v9fs_dentry_operations;
1933		d_instantiate(dentry, inode);
1934	}
1935
1936error:
1937	if (fid)
1938		p9_client_clunk(fid);
1939	return err;
1940}
1941
1942static const struct inode_operations v9fs_dir_inode_operations_dotu = {
1943	.create = v9fs_vfs_create,
1944	.lookup = v9fs_vfs_lookup,
1945	.symlink = v9fs_vfs_symlink,
1946	.link = v9fs_vfs_link,
1947	.unlink = v9fs_vfs_unlink,
1948	.mkdir = v9fs_vfs_mkdir,
1949	.rmdir = v9fs_vfs_rmdir,
1950	.mknod = v9fs_vfs_mknod,
1951	.rename = v9fs_vfs_rename,
1952	.getattr = v9fs_vfs_getattr,
1953	.setattr = v9fs_vfs_setattr,
1954};
1955
1956static const struct inode_operations v9fs_dir_inode_operations_dotl = {
1957	.create = v9fs_vfs_create_dotl,
1958	.lookup = v9fs_vfs_lookup,
1959	.link = v9fs_vfs_link_dotl,
1960	.symlink = v9fs_vfs_symlink_dotl,
1961	.unlink = v9fs_vfs_unlink,
1962	.mkdir = v9fs_vfs_mkdir_dotl,
1963	.rmdir = v9fs_vfs_rmdir,
1964	.mknod = v9fs_vfs_mknod_dotl,
1965	.rename = v9fs_vfs_rename,
1966	.getattr = v9fs_vfs_getattr_dotl,
1967	.setattr = v9fs_vfs_setattr_dotl,
1968	.setxattr = generic_setxattr,
1969	.getxattr = generic_getxattr,
1970	.removexattr = generic_removexattr,
1971	.listxattr = v9fs_listxattr,
1972
1973};
1974
1975static const struct inode_operations v9fs_dir_inode_operations = {
1976	.create = v9fs_vfs_create,
1977	.lookup = v9fs_vfs_lookup,
1978	.unlink = v9fs_vfs_unlink,
1979	.mkdir = v9fs_vfs_mkdir,
1980	.rmdir = v9fs_vfs_rmdir,
1981	.mknod = v9fs_vfs_mknod,
1982	.rename = v9fs_vfs_rename,
1983	.getattr = v9fs_vfs_getattr,
1984	.setattr = v9fs_vfs_setattr,
1985};
1986
1987static const struct inode_operations v9fs_file_inode_operations = {
1988	.getattr = v9fs_vfs_getattr,
1989	.setattr = v9fs_vfs_setattr,
1990};
1991
1992static const struct inode_operations v9fs_file_inode_operations_dotl = {
1993	.getattr = v9fs_vfs_getattr_dotl,
1994	.setattr = v9fs_vfs_setattr_dotl,
1995	.setxattr = generic_setxattr,
1996	.getxattr = generic_getxattr,
1997	.removexattr = generic_removexattr,
1998	.listxattr = v9fs_listxattr,
1999};
2000
2001static const struct inode_operations v9fs_symlink_inode_operations = {
2002	.readlink = generic_readlink,
2003	.follow_link = v9fs_vfs_follow_link,
2004	.put_link = v9fs_vfs_put_link,
2005	.getattr = v9fs_vfs_getattr,
2006	.setattr = v9fs_vfs_setattr,
2007};
2008
2009static const struct inode_operations v9fs_symlink_inode_operations_dotl = {
2010	.readlink = generic_readlink,
2011	.follow_link = v9fs_vfs_follow_link,
2012	.put_link = v9fs_vfs_put_link,
2013	.getattr = v9fs_vfs_getattr_dotl,
2014	.setattr = v9fs_vfs_setattr_dotl,
2015	.setxattr = generic_setxattr,
2016	.getxattr = generic_getxattr,
2017	.removexattr = generic_removexattr,
2018	.listxattr = v9fs_listxattr,
2019};
2020