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 */
v9fs_cached_dentry_delete(const struct dentry * dentry)50 static 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
v9fs_dentry_release(struct dentry * dentry)67 static 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
v9fs_lookup_revalidate(struct dentry * dentry,unsigned int flags)77 static 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 }
108 out_valid:
109 return 1;
110 }
111
112 const 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
119 const struct dentry_operations v9fs_dentry_operations = {
120 .d_delete = always_delete_dentry,
121 .d_release = v9fs_dentry_release,
122 };
123