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
38#include "debug.h"
39#include "v9fs.h"
40#include "9p.h"
41#include "v9fs_vfs.h"
42#include "fid.h"
43
44static const struct inode_operations v9fs_dir_inode_operations;
45static const struct inode_operations v9fs_dir_inode_operations_ext;
46static const struct inode_operations v9fs_file_inode_operations;
47static const struct inode_operations v9fs_symlink_inode_operations;
48
49/**
50 * unixmode2p9mode - convert unix mode bits to plan 9
51 * @v9ses: v9fs session information
52 * @mode: mode to convert
53 *
54 */
55
56static int unixmode2p9mode(struct v9fs_session_info *v9ses, int mode)
57{
58	int res;
59	res = mode & 0777;
60	if (S_ISDIR(mode))
61		res |= V9FS_DMDIR;
62	if (v9ses->extended) {
63		if (S_ISLNK(mode))
64			res |= V9FS_DMSYMLINK;
65		if (v9ses->nodev == 0) {
66			if (S_ISSOCK(mode))
67				res |= V9FS_DMSOCKET;
68			if (S_ISFIFO(mode))
69				res |= V9FS_DMNAMEDPIPE;
70			if (S_ISBLK(mode))
71				res |= V9FS_DMDEVICE;
72			if (S_ISCHR(mode))
73				res |= V9FS_DMDEVICE;
74		}
75
76		if ((mode & S_ISUID) == S_ISUID)
77			res |= V9FS_DMSETUID;
78		if ((mode & S_ISGID) == S_ISGID)
79			res |= V9FS_DMSETGID;
80		if ((mode & V9FS_DMLINK))
81			res |= V9FS_DMLINK;
82	}
83
84	return res;
85}
86
87/**
88 * p9mode2unixmode- convert plan9 mode bits to unix mode bits
89 * @v9ses: v9fs session information
90 * @mode: mode to convert
91 *
92 */
93
94static int p9mode2unixmode(struct v9fs_session_info *v9ses, int mode)
95{
96	int res;
97
98	res = mode & 0777;
99
100	if ((mode & V9FS_DMDIR) == V9FS_DMDIR)
101		res |= S_IFDIR;
102	else if ((mode & V9FS_DMSYMLINK) && (v9ses->extended))
103		res |= S_IFLNK;
104	else if ((mode & V9FS_DMSOCKET) && (v9ses->extended)
105		 && (v9ses->nodev == 0))
106		res |= S_IFSOCK;
107	else if ((mode & V9FS_DMNAMEDPIPE) && (v9ses->extended)
108		 && (v9ses->nodev == 0))
109		res |= S_IFIFO;
110	else if ((mode & V9FS_DMDEVICE) && (v9ses->extended)
111		 && (v9ses->nodev == 0))
112		res |= S_IFBLK;
113	else
114		res |= S_IFREG;
115
116	if (v9ses->extended) {
117		if ((mode & V9FS_DMSETUID) == V9FS_DMSETUID)
118			res |= S_ISUID;
119
120		if ((mode & V9FS_DMSETGID) == V9FS_DMSETGID)
121			res |= S_ISGID;
122	}
123
124	return res;
125}
126
127int v9fs_uflags2omode(int uflags)
128{
129	int ret;
130
131	ret = 0;
132	switch (uflags&3) {
133	default:
134	case O_RDONLY:
135		ret = V9FS_OREAD;
136		break;
137
138	case O_WRONLY:
139		ret = V9FS_OWRITE;
140		break;
141
142	case O_RDWR:
143		ret = V9FS_ORDWR;
144		break;
145	}
146
147	if (uflags & O_EXCL)
148		ret |= V9FS_OEXCL;
149
150	if (uflags & O_TRUNC)
151		ret |= V9FS_OTRUNC;
152
153	if (uflags & O_APPEND)
154		ret |= V9FS_OAPPEND;
155
156	return ret;
157}
158
159/**
160 * v9fs_blank_wstat - helper function to setup a 9P stat structure
161 * @v9ses: 9P session info (for determining extended mode)
162 * @wstat: structure to initialize
163 *
164 */
165
166static void
167v9fs_blank_wstat(struct v9fs_wstat *wstat)
168{
169	wstat->type = ~0;
170	wstat->dev = ~0;
171	wstat->qid.type = ~0;
172	wstat->qid.version = ~0;
173	*((long long *)&wstat->qid.path) = ~0;
174	wstat->mode = ~0;
175	wstat->atime = ~0;
176	wstat->mtime = ~0;
177	wstat->length = ~0;
178	wstat->name = NULL;
179	wstat->uid = NULL;
180	wstat->gid = NULL;
181	wstat->muid = NULL;
182	wstat->n_uid = ~0;
183	wstat->n_gid = ~0;
184	wstat->n_muid = ~0;
185	wstat->extension = NULL;
186}
187
188/**
189 * v9fs_get_inode - helper function to setup an inode
190 * @sb: superblock
191 * @mode: mode to setup inode with
192 *
193 */
194
195struct inode *v9fs_get_inode(struct super_block *sb, int mode)
196{
197	struct inode *inode;
198	struct v9fs_session_info *v9ses = sb->s_fs_info;
199
200	dprintk(DEBUG_VFS, "super block: %p mode: %o\n", sb, mode);
201
202	inode = new_inode(sb);
203	if (inode) {
204		inode->i_mode = mode;
205		inode->i_uid = current->fsuid;
206		inode->i_gid = current->fsgid;
207		inode->i_blocks = 0;
208		inode->i_rdev = 0;
209		inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
210		inode->i_mapping->a_ops = &v9fs_addr_operations;
211
212		switch (mode & S_IFMT) {
213		case S_IFIFO:
214		case S_IFBLK:
215		case S_IFCHR:
216		case S_IFSOCK:
217			if(!v9ses->extended) {
218				dprintk(DEBUG_ERROR, "special files without extended mode\n");
219				return ERR_PTR(-EINVAL);
220			}
221			init_special_inode(inode, inode->i_mode,
222					   inode->i_rdev);
223			break;
224		case S_IFREG:
225			inode->i_op = &v9fs_file_inode_operations;
226			inode->i_fop = &v9fs_file_operations;
227			break;
228		case S_IFLNK:
229			if(!v9ses->extended) {
230				dprintk(DEBUG_ERROR, "extended modes used w/o 9P2000.u\n");
231				return ERR_PTR(-EINVAL);
232			}
233			inode->i_op = &v9fs_symlink_inode_operations;
234			break;
235		case S_IFDIR:
236			inc_nlink(inode);
237			if(v9ses->extended)
238				inode->i_op = &v9fs_dir_inode_operations_ext;
239			else
240				inode->i_op = &v9fs_dir_inode_operations;
241			inode->i_fop = &v9fs_dir_operations;
242			break;
243		default:
244			dprintk(DEBUG_ERROR, "BAD mode 0x%x S_IFMT 0x%x\n",
245				mode, mode & S_IFMT);
246			return ERR_PTR(-EINVAL);
247		}
248	} else {
249		eprintk(KERN_WARNING, "Problem allocating inode\n");
250		return ERR_PTR(-ENOMEM);
251	}
252	return inode;
253}
254
255static int
256v9fs_create(struct v9fs_session_info *v9ses, u32 pfid, char *name, u32 perm,
257	u8 mode, char *extension, u32 *fidp, struct v9fs_qid *qid, u32 *iounit)
258{
259	int fid;
260	int err;
261	struct v9fs_fcall *fcall;
262
263	fid = v9fs_get_idpool(&v9ses->fidpool);
264	if (fid < 0) {
265		eprintk(KERN_WARNING, "no free fids available\n");
266		return -ENOSPC;
267	}
268
269	err = v9fs_t_walk(v9ses, pfid, fid, NULL, &fcall);
270	if (err < 0) {
271		PRINT_FCALL_ERROR("clone error", fcall);
272		if (fcall && fcall->id == RWALK)
273			goto clunk_fid;
274		else
275			goto put_fid;
276	}
277	kfree(fcall);
278
279	err = v9fs_t_create(v9ses, fid, name, perm, mode, extension, &fcall);
280	if (err < 0) {
281		PRINT_FCALL_ERROR("create fails", fcall);
282		goto clunk_fid;
283	}
284
285	if (iounit)
286		*iounit = fcall->params.rcreate.iounit;
287
288	if (qid)
289		*qid = fcall->params.rcreate.qid;
290
291	if (fidp)
292		*fidp = fid;
293
294	kfree(fcall);
295	return 0;
296
297clunk_fid:
298	v9fs_t_clunk(v9ses, fid);
299	fid = V9FS_NOFID;
300
301put_fid:
302	if (fid != V9FS_NOFID)
303		v9fs_put_idpool(fid, &v9ses->fidpool);
304
305	kfree(fcall);
306	return err;
307}
308
309static struct v9fs_fid*
310v9fs_clone_walk(struct v9fs_session_info *v9ses, u32 fid, struct dentry *dentry)
311{
312	int err;
313	int nfid;
314	struct v9fs_fid *ret;
315	struct v9fs_fcall *fcall;
316
317	nfid = v9fs_get_idpool(&v9ses->fidpool);
318	if (nfid < 0) {
319		eprintk(KERN_WARNING, "no free fids available\n");
320		return ERR_PTR(-ENOSPC);
321	}
322
323	err = v9fs_t_walk(v9ses, fid, nfid, (char *) dentry->d_name.name,
324		&fcall);
325
326	if (err < 0) {
327		if (fcall && fcall->id == RWALK)
328			goto clunk_fid;
329
330		PRINT_FCALL_ERROR("walk error", fcall);
331		v9fs_put_idpool(nfid, &v9ses->fidpool);
332		goto error;
333	}
334
335	kfree(fcall);
336	fcall = NULL;
337	ret = v9fs_fid_create(v9ses, nfid);
338	if (!ret) {
339		err = -ENOMEM;
340		goto clunk_fid;
341	}
342
343	err = v9fs_fid_insert(ret, dentry);
344	if (err < 0) {
345		v9fs_fid_destroy(ret);
346		goto clunk_fid;
347	}
348
349	return ret;
350
351clunk_fid:
352	v9fs_t_clunk(v9ses, nfid);
353
354error:
355	kfree(fcall);
356	return ERR_PTR(err);
357}
358
359static struct inode *
360v9fs_inode_from_fid(struct v9fs_session_info *v9ses, u32 fid,
361	struct super_block *sb)
362{
363	int err, umode;
364	struct inode *ret;
365	struct v9fs_fcall *fcall;
366
367	ret = NULL;
368	err = v9fs_t_stat(v9ses, fid, &fcall);
369	if (err) {
370		PRINT_FCALL_ERROR("stat error", fcall);
371		goto error;
372	}
373
374	umode = p9mode2unixmode(v9ses, fcall->params.rstat.stat.mode);
375	ret = v9fs_get_inode(sb, umode);
376	if (IS_ERR(ret)) {
377		err = PTR_ERR(ret);
378		ret = NULL;
379		goto error;
380	}
381
382	v9fs_stat2inode(&fcall->params.rstat.stat, ret, sb);
383	kfree(fcall);
384	return ret;
385
386error:
387	kfree(fcall);
388	if (ret)
389		iput(ret);
390
391	return ERR_PTR(err);
392}
393
394/**
395 * v9fs_remove - helper function to remove files and directories
396 * @dir: directory inode that is being deleted
397 * @file:  dentry that is being deleted
398 * @rmdir: removing a directory
399 *
400 */
401
402static int v9fs_remove(struct inode *dir, struct dentry *file, int rmdir)
403{
404	struct v9fs_fcall *fcall = NULL;
405	struct super_block *sb = NULL;
406	struct v9fs_session_info *v9ses = NULL;
407	struct v9fs_fid *v9fid = NULL;
408	struct inode *file_inode = NULL;
409	int fid = -1;
410	int result = 0;
411
412	dprintk(DEBUG_VFS, "inode: %p dentry: %p rmdir: %d\n", dir, file,
413		rmdir);
414
415	file_inode = file->d_inode;
416	sb = file_inode->i_sb;
417	v9ses = v9fs_inode2v9ses(file_inode);
418	v9fid = v9fs_fid_clone(file);
419	if(IS_ERR(v9fid))
420		return PTR_ERR(v9fid);
421
422	fid = v9fid->fid;
423	if (fid < 0) {
424		dprintk(DEBUG_ERROR, "inode #%lu, no fid!\n",
425			file_inode->i_ino);
426		return -EBADF;
427	}
428
429	result = v9fs_t_remove(v9ses, fid, &fcall);
430	if (result < 0) {
431		PRINT_FCALL_ERROR("remove fails", fcall);
432		goto Error;
433	}
434
435	v9fs_put_idpool(fid, &v9ses->fidpool);
436	v9fs_fid_destroy(v9fid);
437
438Error:
439	kfree(fcall);
440	return result;
441}
442
443static int
444v9fs_open_created(struct inode *inode, struct file *file)
445{
446	return 0;
447}
448
449/**
450 * v9fs_vfs_create - VFS hook to create files
451 * @inode: directory inode that is being deleted
452 * @dentry:  dentry that is being deleted
453 * @mode: create permissions
454 * @nd: path information
455 *
456 */
457
458static int
459v9fs_vfs_create(struct inode *dir, struct dentry *dentry, int mode,
460		struct nameidata *nd)
461{
462	int err;
463	u32 fid, perm, iounit;
464	int flags;
465	struct v9fs_session_info *v9ses;
466	struct v9fs_fid *dfid, *vfid, *ffid;
467	struct inode *inode;
468	struct v9fs_qid qid;
469	struct file *filp;
470
471	inode = NULL;
472	vfid = NULL;
473	v9ses = v9fs_inode2v9ses(dir);
474	dfid = v9fs_fid_clone(dentry->d_parent);
475	if(IS_ERR(dfid)) {
476		err = PTR_ERR(dfid);
477		goto error;
478	}
479
480	perm = unixmode2p9mode(v9ses, mode);
481	if (nd && nd->flags & LOOKUP_OPEN)
482		flags = nd->intent.open.flags - 1;
483	else
484		flags = O_RDWR;
485
486	err = v9fs_create(v9ses, dfid->fid, (char *) dentry->d_name.name,
487		perm, v9fs_uflags2omode(flags), NULL, &fid, &qid, &iounit);
488
489	if (err)
490		goto clunk_dfid;
491
492	vfid = v9fs_clone_walk(v9ses, dfid->fid, dentry);
493	v9fs_fid_clunk(v9ses, dfid);
494	if (IS_ERR(vfid)) {
495		err = PTR_ERR(vfid);
496		vfid = NULL;
497		goto error;
498	}
499
500	inode = v9fs_inode_from_fid(v9ses, vfid->fid, dir->i_sb);
501	if (IS_ERR(inode)) {
502		err = PTR_ERR(inode);
503		inode = NULL;
504		goto error;
505	}
506
507	if(v9ses->cache)
508		dentry->d_op = &v9fs_cached_dentry_operations;
509	else
510		dentry->d_op = &v9fs_dentry_operations;
511	d_instantiate(dentry, inode);
512
513	if (nd && nd->flags & LOOKUP_OPEN) {
514		ffid = v9fs_fid_create(v9ses, fid);
515		if (!ffid)
516			return -ENOMEM;
517
518		filp = lookup_instantiate_filp(nd, dentry, v9fs_open_created);
519		if (IS_ERR(filp)) {
520			v9fs_fid_destroy(ffid);
521			return PTR_ERR(filp);
522		}
523
524		ffid->rdir_pos = 0;
525		ffid->rdir_fcall = NULL;
526		ffid->fidopen = 1;
527		ffid->iounit = iounit;
528		ffid->filp = filp;
529		filp->private_data = ffid;
530	}
531
532	return 0;
533
534clunk_dfid:
535	v9fs_fid_clunk(v9ses, dfid);
536
537error:
538	if (vfid)
539		v9fs_fid_destroy(vfid);
540
541	return err;
542}
543
544/**
545 * v9fs_vfs_mkdir - VFS mkdir hook to create a directory
546 * @inode:  inode that is being unlinked
547 * @dentry: dentry that is being unlinked
548 * @mode: mode for new directory
549 *
550 */
551
552static int v9fs_vfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
553{
554	int err;
555	u32 fid, perm;
556	struct v9fs_session_info *v9ses;
557	struct v9fs_fid *dfid, *vfid;
558	struct inode *inode;
559
560	inode = NULL;
561	vfid = NULL;
562	v9ses = v9fs_inode2v9ses(dir);
563	dfid = v9fs_fid_clone(dentry->d_parent);
564	if(IS_ERR(dfid)) {
565		err = PTR_ERR(dfid);
566		goto error;
567	}
568
569	perm = unixmode2p9mode(v9ses, mode | S_IFDIR);
570
571	err = v9fs_create(v9ses, dfid->fid, (char *) dentry->d_name.name,
572		perm, V9FS_OREAD, NULL, &fid, NULL, NULL);
573
574	if (err) {
575		dprintk(DEBUG_ERROR, "create error %d\n", err);
576		goto clean_up_dfid;
577	}
578
579	vfid = v9fs_clone_walk(v9ses, dfid->fid, dentry);
580	if (IS_ERR(vfid)) {
581		err = PTR_ERR(vfid);
582		vfid = NULL;
583		goto clean_up_dfid;
584	}
585
586	v9fs_fid_clunk(v9ses, dfid);
587	inode = v9fs_inode_from_fid(v9ses, vfid->fid, dir->i_sb);
588	if (IS_ERR(inode)) {
589		err = PTR_ERR(inode);
590		inode = NULL;
591		v9fs_fid_destroy(vfid);
592		goto error;
593	}
594
595	if(v9ses->cache)
596		dentry->d_op = &v9fs_cached_dentry_operations;
597	else
598		dentry->d_op = &v9fs_dentry_operations;
599	d_instantiate(dentry, inode);
600	return 0;
601
602clean_up_dfid:
603	v9fs_fid_clunk(v9ses, dfid);
604
605error:
606	return err;
607}
608
609/**
610 * v9fs_vfs_lookup - VFS lookup hook to "walk" to a new inode
611 * @dir:  inode that is being walked from
612 * @dentry: dentry that is being walked to?
613 * @nameidata: path data
614 *
615 */
616
617static struct dentry *v9fs_vfs_lookup(struct inode *dir, struct dentry *dentry,
618				      struct nameidata *nameidata)
619{
620	struct super_block *sb;
621	struct v9fs_session_info *v9ses;
622	struct v9fs_fid *dirfid;
623	struct v9fs_fid *fid;
624	struct inode *inode;
625	struct v9fs_fcall *fcall = NULL;
626	int dirfidnum = -1;
627	int newfid = -1;
628	int result = 0;
629
630	dprintk(DEBUG_VFS, "dir: %p dentry: (%s) %p nameidata: %p\n",
631		dir, dentry->d_name.name, dentry, nameidata);
632
633	sb = dir->i_sb;
634	v9ses = v9fs_inode2v9ses(dir);
635	dirfid = v9fs_fid_lookup(dentry->d_parent);
636
637	if(IS_ERR(dirfid))
638		return ERR_PTR(PTR_ERR(dirfid));
639
640	dirfidnum = dirfid->fid;
641
642	newfid = v9fs_get_idpool(&v9ses->fidpool);
643	if (newfid < 0) {
644		eprintk(KERN_WARNING, "newfid fails!\n");
645		result = -ENOSPC;
646		goto Release_Dirfid;
647	}
648
649	result = v9fs_t_walk(v9ses, dirfidnum, newfid,
650		(char *)dentry->d_name.name, &fcall);
651
652	up(&dirfid->lock);
653
654	if (result < 0) {
655		if (fcall && fcall->id == RWALK)
656			v9fs_t_clunk(v9ses, newfid);
657		else
658			v9fs_put_idpool(newfid, &v9ses->fidpool);
659
660		if (result == -ENOENT) {
661			d_add(dentry, NULL);
662			dprintk(DEBUG_VFS,
663				"Return negative dentry %p count %d\n",
664				dentry, atomic_read(&dentry->d_count));
665			kfree(fcall);
666			return NULL;
667		}
668		dprintk(DEBUG_ERROR, "walk error:%d\n", result);
669		goto FreeFcall;
670	}
671	kfree(fcall);
672
673	result = v9fs_t_stat(v9ses, newfid, &fcall);
674	if (result < 0) {
675		dprintk(DEBUG_ERROR, "stat error\n");
676		goto FreeFcall;
677	}
678
679	inode = v9fs_get_inode(sb, p9mode2unixmode(v9ses,
680		fcall->params.rstat.stat.mode));
681
682	if (IS_ERR(inode) && (PTR_ERR(inode) == -ENOSPC)) {
683		eprintk(KERN_WARNING, "inode alloc failes, returns %ld\n",
684			PTR_ERR(inode));
685
686		result = -ENOSPC;
687		goto FreeFcall;
688	}
689
690	inode->i_ino = v9fs_qid2ino(&fcall->params.rstat.stat.qid);
691
692	fid = v9fs_fid_create(v9ses, newfid);
693	if (fid == NULL) {
694		dprintk(DEBUG_ERROR, "couldn't insert\n");
695		result = -ENOMEM;
696		goto FreeFcall;
697	}
698
699	result = v9fs_fid_insert(fid, dentry);
700	if (result < 0)
701		goto FreeFcall;
702
703	fid->qid = fcall->params.rstat.stat.qid;
704	v9fs_stat2inode(&fcall->params.rstat.stat, inode, inode->i_sb);
705	if((fid->qid.version)&&(v9ses->cache))
706		dentry->d_op = &v9fs_cached_dentry_operations;
707	else
708		dentry->d_op = &v9fs_dentry_operations;
709
710	d_add(dentry, inode);
711	kfree(fcall);
712
713	return NULL;
714
715Release_Dirfid:
716	up(&dirfid->lock);
717
718FreeFcall:
719	kfree(fcall);
720
721	return ERR_PTR(result);
722}
723
724/**
725 * v9fs_vfs_unlink - VFS unlink hook to delete an inode
726 * @i:  inode that is being unlinked
727 * @d: dentry that is being unlinked
728 *
729 */
730
731static int v9fs_vfs_unlink(struct inode *i, struct dentry *d)
732{
733	return v9fs_remove(i, d, 0);
734}
735
736/**
737 * v9fs_vfs_rmdir - VFS unlink hook to delete a directory
738 * @i:  inode that is being unlinked
739 * @d: dentry that is being unlinked
740 *
741 */
742
743static int v9fs_vfs_rmdir(struct inode *i, struct dentry *d)
744{
745	return v9fs_remove(i, d, 1);
746}
747
748/**
749 * v9fs_vfs_rename - VFS hook to rename an inode
750 * @old_dir:  old dir inode
751 * @old_dentry: old dentry
752 * @new_dir: new dir inode
753 * @new_dentry: new dentry
754 *
755 */
756
757static int
758v9fs_vfs_rename(struct inode *old_dir, struct dentry *old_dentry,
759		struct inode *new_dir, struct dentry *new_dentry)
760{
761	struct inode *old_inode = old_dentry->d_inode;
762	struct v9fs_session_info *v9ses = v9fs_inode2v9ses(old_inode);
763	struct v9fs_fid *oldfid = v9fs_fid_lookup(old_dentry);
764	struct v9fs_fid *olddirfid;
765	struct v9fs_fid *newdirfid;
766	struct v9fs_wstat wstat;
767	struct v9fs_fcall *fcall = NULL;
768	int fid = -1;
769	int olddirfidnum = -1;
770	int newdirfidnum = -1;
771	int retval = 0;
772
773	dprintk(DEBUG_VFS, "\n");
774
775	if(IS_ERR(oldfid))
776		return PTR_ERR(oldfid);
777
778	olddirfid = v9fs_fid_clone(old_dentry->d_parent);
779	if(IS_ERR(olddirfid)) {
780		retval = PTR_ERR(olddirfid);
781		goto Release_lock;
782	}
783
784	newdirfid = v9fs_fid_clone(new_dentry->d_parent);
785	if(IS_ERR(newdirfid)) {
786		retval = PTR_ERR(newdirfid);
787		goto Clunk_olddir;
788	}
789
790	/* 9P can only handle file rename in the same directory */
791	if (memcmp(&olddirfid->qid, &newdirfid->qid, sizeof(newdirfid->qid))) {
792		dprintk(DEBUG_ERROR, "old dir and new dir are different\n");
793		retval = -EXDEV;
794		goto Clunk_newdir;
795	}
796
797	fid = oldfid->fid;
798	olddirfidnum = olddirfid->fid;
799	newdirfidnum = newdirfid->fid;
800
801	if (fid < 0) {
802		dprintk(DEBUG_ERROR, "no fid for old file #%lu\n",
803			old_inode->i_ino);
804		retval = -EBADF;
805		goto Clunk_newdir;
806	}
807
808	v9fs_blank_wstat(&wstat);
809	wstat.muid = v9ses->name;
810	wstat.name = (char *) new_dentry->d_name.name;
811
812	retval = v9fs_t_wstat(v9ses, fid, &wstat, &fcall);
813
814	if (retval < 0)
815		PRINT_FCALL_ERROR("wstat error", fcall);
816
817	kfree(fcall);
818
819Clunk_newdir:
820	v9fs_fid_clunk(v9ses, newdirfid);
821
822Clunk_olddir:
823	v9fs_fid_clunk(v9ses, olddirfid);
824
825Release_lock:
826	up(&oldfid->lock);
827
828	return retval;
829}
830
831/**
832 * v9fs_vfs_getattr - retrieve file metadata
833 * @mnt - mount information
834 * @dentry - file to get attributes on
835 * @stat - metadata structure to populate
836 *
837 */
838
839static int
840v9fs_vfs_getattr(struct vfsmount *mnt, struct dentry *dentry,
841		 struct kstat *stat)
842{
843	struct v9fs_fcall *fcall = NULL;
844	struct v9fs_session_info *v9ses = v9fs_inode2v9ses(dentry->d_inode);
845	struct v9fs_fid *fid = v9fs_fid_clone(dentry);
846	int err = -EPERM;
847
848	dprintk(DEBUG_VFS, "dentry: %p\n", dentry);
849	if(IS_ERR(fid))
850		return PTR_ERR(fid);
851
852	err = v9fs_t_stat(v9ses, fid->fid, &fcall);
853
854	if (err < 0)
855		dprintk(DEBUG_ERROR, "stat error\n");
856	else {
857		v9fs_stat2inode(&fcall->params.rstat.stat, dentry->d_inode,
858				  dentry->d_inode->i_sb);
859		generic_fillattr(dentry->d_inode, stat);
860	}
861
862	kfree(fcall);
863	v9fs_fid_clunk(v9ses, fid);
864	return err;
865}
866
867/**
868 * v9fs_vfs_setattr - set file metadata
869 * @dentry: file whose metadata to set
870 * @iattr: metadata assignment structure
871 *
872 */
873
874static int v9fs_vfs_setattr(struct dentry *dentry, struct iattr *iattr)
875{
876	struct v9fs_session_info *v9ses = v9fs_inode2v9ses(dentry->d_inode);
877	struct v9fs_fid *fid = v9fs_fid_clone(dentry);
878	struct v9fs_fcall *fcall = NULL;
879	struct v9fs_wstat wstat;
880	int res = -EPERM;
881
882	dprintk(DEBUG_VFS, "\n");
883	if(IS_ERR(fid))
884		return PTR_ERR(fid);
885
886	v9fs_blank_wstat(&wstat);
887	if (iattr->ia_valid & ATTR_MODE)
888		wstat.mode = unixmode2p9mode(v9ses, iattr->ia_mode);
889
890	if (iattr->ia_valid & ATTR_MTIME)
891		wstat.mtime = iattr->ia_mtime.tv_sec;
892
893	if (iattr->ia_valid & ATTR_ATIME)
894		wstat.atime = iattr->ia_atime.tv_sec;
895
896	if (iattr->ia_valid & ATTR_SIZE)
897		wstat.length = iattr->ia_size;
898
899	if (v9ses->extended) {
900		if (iattr->ia_valid & ATTR_UID)
901			wstat.n_uid = iattr->ia_uid;
902
903		if (iattr->ia_valid & ATTR_GID)
904			wstat.n_gid = iattr->ia_gid;
905	}
906
907	res = v9fs_t_wstat(v9ses, fid->fid, &wstat, &fcall);
908
909	if (res < 0)
910		PRINT_FCALL_ERROR("wstat error", fcall);
911
912	kfree(fcall);
913	if (res >= 0)
914		res = inode_setattr(dentry->d_inode, iattr);
915
916	v9fs_fid_clunk(v9ses, fid);
917	return res;
918}
919
920/**
921 * v9fs_stat2inode - populate an inode structure with mistat info
922 * @stat: Plan 9 metadata (mistat) structure
923 * @inode: inode to populate
924 * @sb: superblock of filesystem
925 *
926 */
927
928void
929v9fs_stat2inode(struct v9fs_stat *stat, struct inode *inode,
930	struct super_block *sb)
931{
932	int n;
933	char ext[32];
934	struct v9fs_session_info *v9ses = sb->s_fs_info;
935
936	inode->i_nlink = 1;
937
938	inode->i_atime.tv_sec = stat->atime;
939	inode->i_mtime.tv_sec = stat->mtime;
940	inode->i_ctime.tv_sec = stat->mtime;
941
942	inode->i_uid = v9ses->uid;
943	inode->i_gid = v9ses->gid;
944
945	if (v9ses->extended) {
946		inode->i_uid = stat->n_uid;
947		inode->i_gid = stat->n_gid;
948	}
949
950	inode->i_mode = p9mode2unixmode(v9ses, stat->mode);
951	if ((S_ISBLK(inode->i_mode)) || (S_ISCHR(inode->i_mode))) {
952		char type = 0;
953		int major = -1;
954		int minor = -1;
955
956		n = stat->extension.len;
957		if (n > sizeof(ext)-1)
958			n = sizeof(ext)-1;
959		memmove(ext, stat->extension.str, n);
960		ext[n] = 0;
961		sscanf(ext, "%c %u %u", &type, &major, &minor);
962		switch (type) {
963		case 'c':
964			inode->i_mode &= ~S_IFBLK;
965			inode->i_mode |= S_IFCHR;
966			break;
967		case 'b':
968			break;
969		default:
970			dprintk(DEBUG_ERROR, "Unknown special type %c (%.*s)\n",
971				type, stat->extension.len, stat->extension.str);
972		};
973		inode->i_rdev = MKDEV(major, minor);
974	} else
975		inode->i_rdev = 0;
976
977	inode->i_size = stat->length;
978
979	inode->i_blocks =
980	    (inode->i_size + sb->s_blocksize - 1) >> sb->s_blocksize_bits;
981}
982
983/**
984 * v9fs_qid2ino - convert qid into inode number
985 * @qid: qid to hash
986 *
987 * BUG: potential for inode number collisions?
988 */
989
990ino_t v9fs_qid2ino(struct v9fs_qid *qid)
991{
992	u64 path = qid->path + 2;
993	ino_t i = 0;
994
995	if (sizeof(ino_t) == sizeof(path))
996		memcpy(&i, &path, sizeof(ino_t));
997	else
998		i = (ino_t) (path ^ (path >> 32));
999
1000	return i;
1001}
1002
1003/**
1004 * v9fs_readlink - read a symlink's location (internal version)
1005 * @dentry: dentry for symlink
1006 * @buffer: buffer to load symlink location into
1007 * @buflen: length of buffer
1008 *
1009 */
1010
1011static int v9fs_readlink(struct dentry *dentry, char *buffer, int buflen)
1012{
1013	int retval = -EPERM;
1014
1015	struct v9fs_fcall *fcall = NULL;
1016	struct v9fs_session_info *v9ses = v9fs_inode2v9ses(dentry->d_inode);
1017	struct v9fs_fid *fid = v9fs_fid_clone(dentry);
1018
1019	if(IS_ERR(fid))
1020		return PTR_ERR(fid);
1021
1022	if (!v9ses->extended) {
1023		retval = -EBADF;
1024		dprintk(DEBUG_ERROR, "not extended\n");
1025		goto ClunkFid;
1026	}
1027
1028	dprintk(DEBUG_VFS, " %s\n", dentry->d_name.name);
1029	retval = v9fs_t_stat(v9ses, fid->fid, &fcall);
1030
1031	if (retval < 0) {
1032		dprintk(DEBUG_ERROR, "stat error\n");
1033		goto FreeFcall;
1034	}
1035
1036	if (!fcall) {
1037		retval = -EIO;
1038		goto ClunkFid;
1039	}
1040
1041	if (!(fcall->params.rstat.stat.mode & V9FS_DMSYMLINK)) {
1042		retval = -EINVAL;
1043		goto FreeFcall;
1044	}
1045
1046	/* copy extension buffer into buffer */
1047	if (fcall->params.rstat.stat.extension.len < buflen)
1048		buflen = fcall->params.rstat.stat.extension.len + 1;
1049
1050	memmove(buffer, fcall->params.rstat.stat.extension.str, buflen - 1);
1051	buffer[buflen-1] = 0;
1052
1053	dprintk(DEBUG_ERROR, "%s -> %.*s (%s)\n", dentry->d_name.name, fcall->params.rstat.stat.extension.len,
1054		fcall->params.rstat.stat.extension.str, buffer);
1055	retval = buflen;
1056
1057FreeFcall:
1058	kfree(fcall);
1059
1060ClunkFid:
1061	v9fs_fid_clunk(v9ses, fid);
1062
1063	return retval;
1064}
1065
1066/**
1067 * v9fs_vfs_readlink - read a symlink's location
1068 * @dentry: dentry for symlink
1069 * @buf: buffer to load symlink location into
1070 * @buflen: length of buffer
1071 *
1072 */
1073
1074static int v9fs_vfs_readlink(struct dentry *dentry, char __user * buffer,
1075			     int buflen)
1076{
1077	int retval;
1078	int ret;
1079	char *link = __getname();
1080
1081	if (unlikely(!link))
1082		return -ENOMEM;
1083
1084	if (buflen > PATH_MAX)
1085		buflen = PATH_MAX;
1086
1087	dprintk(DEBUG_VFS, " dentry: %s (%p)\n", dentry->d_iname, dentry);
1088
1089	retval = v9fs_readlink(dentry, link, buflen);
1090
1091	if (retval > 0) {
1092		if ((ret = copy_to_user(buffer, link, retval)) != 0) {
1093			dprintk(DEBUG_ERROR, "problem copying to user: %d\n",
1094				ret);
1095			retval = ret;
1096		}
1097	}
1098
1099	__putname(link);
1100	return retval;
1101}
1102
1103/**
1104 * v9fs_vfs_follow_link - follow a symlink path
1105 * @dentry: dentry for symlink
1106 * @nd: nameidata
1107 *
1108 */
1109
1110static void *v9fs_vfs_follow_link(struct dentry *dentry, struct nameidata *nd)
1111{
1112	int len = 0;
1113	char *link = __getname();
1114
1115	dprintk(DEBUG_VFS, "%s n", dentry->d_name.name);
1116
1117	if (!link)
1118		link = ERR_PTR(-ENOMEM);
1119	else {
1120		len = v9fs_readlink(dentry, link, PATH_MAX);
1121
1122		if (len < 0) {
1123			__putname(link);
1124			link = ERR_PTR(len);
1125		} else
1126			link[len] = 0;
1127	}
1128	nd_set_link(nd, link);
1129
1130	return NULL;
1131}
1132
1133/**
1134 * v9fs_vfs_put_link - release a symlink path
1135 * @dentry: dentry for symlink
1136 * @nd: nameidata
1137 *
1138 */
1139
1140static void v9fs_vfs_put_link(struct dentry *dentry, struct nameidata *nd, void *p)
1141{
1142	char *s = nd_get_link(nd);
1143
1144	dprintk(DEBUG_VFS, " %s %s\n", dentry->d_name.name, s);
1145	if (!IS_ERR(s))
1146		__putname(s);
1147}
1148
1149static int v9fs_vfs_mkspecial(struct inode *dir, struct dentry *dentry,
1150	int mode, const char *extension)
1151{
1152	int err;
1153	u32 fid, perm;
1154	struct v9fs_session_info *v9ses;
1155	struct v9fs_fid *dfid, *vfid = NULL;
1156	struct inode *inode = NULL;
1157
1158	v9ses = v9fs_inode2v9ses(dir);
1159	if (!v9ses->extended) {
1160		dprintk(DEBUG_ERROR, "not extended\n");
1161		return -EPERM;
1162	}
1163
1164	dfid = v9fs_fid_clone(dentry->d_parent);
1165	if(IS_ERR(dfid)) {
1166		err = PTR_ERR(dfid);
1167		goto error;
1168	}
1169
1170	perm = unixmode2p9mode(v9ses, mode);
1171
1172	err = v9fs_create(v9ses, dfid->fid, (char *) dentry->d_name.name,
1173		perm, V9FS_OREAD, (char *) extension, &fid, NULL, NULL);
1174
1175	if (err)
1176		goto clunk_dfid;
1177
1178	err = v9fs_t_clunk(v9ses, fid);
1179	if (err)
1180		goto clunk_dfid;
1181
1182	vfid = v9fs_clone_walk(v9ses, dfid->fid, dentry);
1183	if (IS_ERR(vfid)) {
1184		err = PTR_ERR(vfid);
1185		vfid = NULL;
1186		goto clunk_dfid;
1187	}
1188
1189	inode = v9fs_inode_from_fid(v9ses, vfid->fid, dir->i_sb);
1190	if (IS_ERR(inode)) {
1191		err = PTR_ERR(inode);
1192		inode = NULL;
1193		goto free_vfid;
1194	}
1195
1196	if(v9ses->cache)
1197		dentry->d_op = &v9fs_cached_dentry_operations;
1198	else
1199		dentry->d_op = &v9fs_dentry_operations;
1200	d_instantiate(dentry, inode);
1201	return 0;
1202
1203free_vfid:
1204	v9fs_fid_destroy(vfid);
1205
1206clunk_dfid:
1207	v9fs_fid_clunk(v9ses, dfid);
1208
1209error:
1210	return err;
1211
1212}
1213
1214/**
1215 * v9fs_vfs_symlink - helper function to create symlinks
1216 * @dir: directory inode containing symlink
1217 * @dentry: dentry for symlink
1218 * @symname: symlink data
1219 *
1220 * See 9P2000.u RFC for more information
1221 *
1222 */
1223
1224static int
1225v9fs_vfs_symlink(struct inode *dir, struct dentry *dentry, const char *symname)
1226{
1227	dprintk(DEBUG_VFS, " %lu,%s,%s\n", dir->i_ino, dentry->d_name.name,
1228		symname);
1229
1230	return v9fs_vfs_mkspecial(dir, dentry, S_IFLNK, symname);
1231}
1232
1233/**
1234 * v9fs_vfs_link - create a hardlink
1235 * @old_dentry: dentry for file to link to
1236 * @dir: inode destination for new link
1237 * @dentry: dentry for link
1238 *
1239 */
1240
1241
1242static int
1243v9fs_vfs_link(struct dentry *old_dentry, struct inode *dir,
1244	      struct dentry *dentry)
1245{
1246	int retval;
1247	struct v9fs_session_info *v9ses = v9fs_inode2v9ses(dir);
1248	struct v9fs_fid *oldfid;
1249	char *name;
1250
1251	dprintk(DEBUG_VFS, " %lu,%s,%s\n", dir->i_ino, dentry->d_name.name,
1252		old_dentry->d_name.name);
1253
1254	oldfid = v9fs_fid_clone(old_dentry);
1255	if(IS_ERR(oldfid))
1256		return PTR_ERR(oldfid);
1257
1258	name = __getname();
1259	if (unlikely(!name)) {
1260		retval = -ENOMEM;
1261		goto clunk_fid;
1262	}
1263
1264	sprintf(name, "%d\n", oldfid->fid);
1265	retval = v9fs_vfs_mkspecial(dir, dentry, V9FS_DMLINK, name);
1266	__putname(name);
1267
1268clunk_fid:
1269	v9fs_fid_clunk(v9ses, oldfid);
1270	return retval;
1271}
1272
1273/**
1274 * v9fs_vfs_mknod - create a special file
1275 * @dir: inode destination for new link
1276 * @dentry: dentry for file
1277 * @mode: mode for creation
1278 * @dev_t: device associated with special file
1279 *
1280 */
1281
1282static int
1283v9fs_vfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t rdev)
1284{
1285	int retval;
1286	char *name;
1287
1288	dprintk(DEBUG_VFS, " %lu,%s mode: %x MAJOR: %u MINOR: %u\n", dir->i_ino,
1289		dentry->d_name.name, mode, MAJOR(rdev), MINOR(rdev));
1290
1291	if (!new_valid_dev(rdev))
1292		return -EINVAL;
1293
1294	name = __getname();
1295	if (!name)
1296		return -ENOMEM;
1297	/* build extension */
1298	if (S_ISBLK(mode))
1299		sprintf(name, "b %u %u", MAJOR(rdev), MINOR(rdev));
1300	else if (S_ISCHR(mode))
1301		sprintf(name, "c %u %u", MAJOR(rdev), MINOR(rdev));
1302	else if (S_ISFIFO(mode))
1303		*name = 0;
1304	else {
1305		__putname(name);
1306		return -EINVAL;
1307	}
1308
1309	retval = v9fs_vfs_mkspecial(dir, dentry, mode, name);
1310	__putname(name);
1311
1312	return retval;
1313}
1314
1315static const struct inode_operations v9fs_dir_inode_operations_ext = {
1316	.create = v9fs_vfs_create,
1317	.lookup = v9fs_vfs_lookup,
1318	.symlink = v9fs_vfs_symlink,
1319	.link = v9fs_vfs_link,
1320	.unlink = v9fs_vfs_unlink,
1321	.mkdir = v9fs_vfs_mkdir,
1322	.rmdir = v9fs_vfs_rmdir,
1323	.mknod = v9fs_vfs_mknod,
1324	.rename = v9fs_vfs_rename,
1325	.readlink = v9fs_vfs_readlink,
1326	.getattr = v9fs_vfs_getattr,
1327	.setattr = v9fs_vfs_setattr,
1328};
1329
1330static const struct inode_operations v9fs_dir_inode_operations = {
1331	.create = v9fs_vfs_create,
1332	.lookup = v9fs_vfs_lookup,
1333	.unlink = v9fs_vfs_unlink,
1334	.mkdir = v9fs_vfs_mkdir,
1335	.rmdir = v9fs_vfs_rmdir,
1336	.mknod = v9fs_vfs_mknod,
1337	.rename = v9fs_vfs_rename,
1338	.getattr = v9fs_vfs_getattr,
1339	.setattr = v9fs_vfs_setattr,
1340};
1341
1342static const struct inode_operations v9fs_file_inode_operations = {
1343	.getattr = v9fs_vfs_getattr,
1344	.setattr = v9fs_vfs_setattr,
1345};
1346
1347static const struct inode_operations v9fs_symlink_inode_operations = {
1348	.readlink = v9fs_vfs_readlink,
1349	.follow_link = v9fs_vfs_follow_link,
1350	.put_link = v9fs_vfs_put_link,
1351	.getattr = v9fs_vfs_getattr,
1352	.setattr = v9fs_vfs_setattr,
1353};
1354