1/*
2 *  linux/fs/9p/vfs_dentry.c
3 *
4 * This file contians vfs dentry 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 <net/9p/9p.h>
39#include <net/9p/client.h>
40
41#include "v9fs.h"
42#include "v9fs_vfs.h"
43#include "fid.h"
44
45/**
46 * v9fs_cached_dentry_delete - called when dentry refcount equals 0
47 * @dentry:  dentry in question
48 *
49 */
50static int v9fs_cached_dentry_delete(const struct dentry *dentry)
51{
52	p9_debug(P9_DEBUG_VFS, " dentry: %pd (%p)\n",
53		 dentry, dentry);
54
55	/* Don't cache negative dentries */
56	if (d_really_is_negative(dentry))
57		return 1;
58	return 0;
59}
60
61/**
62 * v9fs_dentry_release - called when dentry is going to be freed
63 * @dentry:  dentry that is being release
64 *
65 */
66
67static void v9fs_dentry_release(struct dentry *dentry)
68{
69	struct hlist_node *p, *n;
70	p9_debug(P9_DEBUG_VFS, " dentry: %pd (%p)\n",
71		 dentry, dentry);
72	hlist_for_each_safe(p, n, (struct hlist_head *)&dentry->d_fsdata)
73		p9_client_clunk(hlist_entry(p, struct p9_fid, dlist));
74	dentry->d_fsdata = NULL;
75}
76
77static int v9fs_lookup_revalidate(struct dentry *dentry, unsigned int flags)
78{
79	struct p9_fid *fid;
80	struct inode *inode;
81	struct v9fs_inode *v9inode;
82
83	if (flags & LOOKUP_RCU)
84		return -ECHILD;
85
86	inode = d_inode(dentry);
87	if (!inode)
88		goto out_valid;
89
90	v9inode = V9FS_I(inode);
91	if (v9inode->cache_validity & V9FS_INO_INVALID_ATTR) {
92		int retval;
93		struct v9fs_session_info *v9ses;
94		fid = v9fs_fid_lookup(dentry);
95		if (IS_ERR(fid))
96			return PTR_ERR(fid);
97
98		v9ses = v9fs_inode2v9ses(inode);
99		if (v9fs_proto_dotl(v9ses))
100			retval = v9fs_refresh_inode_dotl(fid, inode);
101		else
102			retval = v9fs_refresh_inode(fid, inode);
103		if (retval == -ENOENT)
104			return 0;
105		if (retval < 0)
106			return retval;
107	}
108out_valid:
109	return 1;
110}
111
112const struct dentry_operations v9fs_cached_dentry_operations = {
113	.d_revalidate = v9fs_lookup_revalidate,
114	.d_weak_revalidate = v9fs_lookup_revalidate,
115	.d_delete = v9fs_cached_dentry_delete,
116	.d_release = v9fs_dentry_release,
117};
118
119const struct dentry_operations v9fs_dentry_operations = {
120	.d_delete = always_delete_dentry,
121	.d_release = v9fs_dentry_release,
122};
123