9p: Reduce object size with CONFIG_NET_9P_DEBUG
[linux-3.10.git] / fs / 9p / vfs_dentry.c
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_dentry_delete - called when dentry refcount equals 0
47  * @dentry:  dentry in question
48  *
49  * By returning 1 here we should remove cacheing of unused
50  * dentry components.
51  *
52  */
53
54 static int v9fs_dentry_delete(const struct dentry *dentry)
55 {
56         p9_debug(P9_DEBUG_VFS, " dentry: %s (%p)\n",
57                  dentry->d_name.name, dentry);
58
59         return 1;
60 }
61
62 /**
63  * v9fs_cached_dentry_delete - called when dentry refcount equals 0
64  * @dentry:  dentry in question
65  *
66  */
67 static int v9fs_cached_dentry_delete(const struct dentry *dentry)
68 {
69         p9_debug(P9_DEBUG_VFS, " dentry: %s (%p)\n",
70                  dentry->d_name.name, dentry);
71
72         /* Don't cache negative dentries */
73         if (!dentry->d_inode)
74                 return 1;
75         return 0;
76 }
77
78 /**
79  * v9fs_dentry_release - called when dentry is going to be freed
80  * @dentry:  dentry that is being release
81  *
82  */
83
84 static void v9fs_dentry_release(struct dentry *dentry)
85 {
86         struct v9fs_dentry *dent;
87         struct p9_fid *temp, *current_fid;
88
89         p9_debug(P9_DEBUG_VFS, " dentry: %s (%p)\n",
90                  dentry->d_name.name, dentry);
91         dent = dentry->d_fsdata;
92         if (dent) {
93                 list_for_each_entry_safe(current_fid, temp, &dent->fidlist,
94                                                                         dlist) {
95                         p9_client_clunk(current_fid);
96                 }
97
98                 kfree(dent);
99                 dentry->d_fsdata = NULL;
100         }
101 }
102
103 static int v9fs_lookup_revalidate(struct dentry *dentry, struct nameidata *nd)
104 {
105         struct p9_fid *fid;
106         struct inode *inode;
107         struct v9fs_inode *v9inode;
108
109         if (nd->flags & LOOKUP_RCU)
110                 return -ECHILD;
111
112         inode = dentry->d_inode;
113         if (!inode)
114                 goto out_valid;
115
116         v9inode = V9FS_I(inode);
117         if (v9inode->cache_validity & V9FS_INO_INVALID_ATTR) {
118                 int retval;
119                 struct v9fs_session_info *v9ses;
120                 fid = v9fs_fid_lookup(dentry);
121                 if (IS_ERR(fid))
122                         return PTR_ERR(fid);
123
124                 v9ses = v9fs_inode2v9ses(inode);
125                 if (v9fs_proto_dotl(v9ses))
126                         retval = v9fs_refresh_inode_dotl(fid, inode);
127                 else
128                         retval = v9fs_refresh_inode(fid, inode);
129                 if (retval == -ENOENT)
130                         return 0;
131                 if (retval < 0)
132                         return retval;
133         }
134 out_valid:
135         return 1;
136 }
137
138 const struct dentry_operations v9fs_cached_dentry_operations = {
139         .d_revalidate = v9fs_lookup_revalidate,
140         .d_delete = v9fs_cached_dentry_delete,
141         .d_release = v9fs_dentry_release,
142 };
143
144 const struct dentry_operations v9fs_dentry_operations = {
145         .d_delete = v9fs_dentry_delete,
146         .d_release = v9fs_dentry_release,
147 };