]>
Commit | Line | Data |
---|---|---|
e69e7fe5 EVH |
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 as published by | |
11 | * the Free Software Foundation; either version 2 of the License, or | |
12 | * (at your option) any later version. | |
13 | * | |
14 | * This program is distributed in the hope that it will be useful, | |
15 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
16 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
17 | * GNU General Public License for more details. | |
18 | * | |
19 | * You should have received a copy of the GNU General Public License | |
20 | * along with this program; if not, write to: | |
21 | * Free Software Foundation | |
22 | * 51 Franklin Street, Fifth Floor | |
23 | * Boston, MA 02111-1301 USA | |
24 | * | |
25 | */ | |
26 | ||
27 | #include <linux/module.h> | |
28 | #include <linux/errno.h> | |
29 | #include <linux/fs.h> | |
30 | #include <linux/file.h> | |
31 | #include <linux/pagemap.h> | |
32 | #include <linux/stat.h> | |
33 | #include <linux/string.h> | |
34 | #include <linux/smp_lock.h> | |
35 | #include <linux/inet.h> | |
36 | #include <linux/namei.h> | |
37 | #include <linux/idr.h> | |
38 | ||
39 | #include "debug.h" | |
40 | #include "v9fs.h" | |
41 | #include "9p.h" | |
42 | #include "v9fs_vfs.h" | |
43 | #include "conv.h" | |
44 | #include "fid.h" | |
45 | ||
46 | /** | |
47 | * v9fs_dentry_validate - VFS dcache hook to validate cache | |
48 | * @dentry: dentry that is being validated | |
49 | * @nd: path data | |
50 | * | |
51 | * dcache really shouldn't be used for 9P2000 as at all due to | |
52 | * potential attached semantics to directory traversal (walk). | |
53 | * | |
54 | * FUTURE: look into how to use dcache to allow multi-stage | |
55 | * walks in Plan 9 & potential for better dcache operation which | |
56 | * would remain valid for Plan 9 semantics. Older versions | |
57 | * had validation via stat for those interested. However, since | |
58 | * stat has the same approximate overhead as walk there really | |
59 | * is no difference. The only improvement would be from a | |
60 | * time-decay cache like NFS has and that undermines the | |
61 | * synchronous nature of 9P2000. | |
62 | * | |
63 | */ | |
64 | ||
65 | static int v9fs_dentry_validate(struct dentry *dentry, struct nameidata *nd) | |
66 | { | |
67 | struct dentry *dc = current->fs->pwd; | |
68 | ||
69 | dprintk(DEBUG_VFS, "dentry: %s (%p)\n", dentry->d_iname, dentry); | |
70 | if (v9fs_fid_lookup(dentry, FID_OP)) { | |
71 | dprintk(DEBUG_VFS, "VALID\n"); | |
72 | return 1; | |
73 | } | |
74 | ||
75 | while (dc != NULL) { | |
76 | if (dc == dentry) { | |
77 | dprintk(DEBUG_VFS, "VALID\n"); | |
78 | return 1; | |
79 | } | |
80 | if (dc == dc->d_parent) | |
81 | break; | |
82 | ||
83 | dc = dc->d_parent; | |
84 | } | |
85 | ||
86 | dprintk(DEBUG_VFS, "INVALID\n"); | |
87 | return 0; | |
88 | } | |
89 | ||
90 | /** | |
91 | * v9fs_dentry_release - called when dentry is going to be freed | |
92 | * @dentry: dentry that is being release | |
93 | * | |
94 | */ | |
95 | ||
96 | void v9fs_dentry_release(struct dentry *dentry) | |
97 | { | |
98 | dprintk(DEBUG_VFS, " dentry: %s (%p)\n", dentry->d_iname, dentry); | |
99 | ||
100 | if (dentry->d_fsdata != NULL) { | |
101 | struct list_head *fid_list = dentry->d_fsdata; | |
102 | struct v9fs_fid *temp = NULL; | |
103 | struct v9fs_fid *current_fid = NULL; | |
104 | struct v9fs_fcall *fcall = NULL; | |
105 | ||
106 | list_for_each_entry_safe(current_fid, temp, fid_list, list) { | |
107 | if (v9fs_t_clunk | |
108 | (current_fid->v9ses, current_fid->fid, &fcall)) | |
109 | dprintk(DEBUG_ERROR, "clunk failed: %s\n", | |
110 | FCALL_ERROR(fcall)); | |
111 | ||
112 | v9fs_put_idpool(current_fid->fid, | |
113 | ¤t_fid->v9ses->fidpool); | |
114 | ||
115 | kfree(fcall); | |
116 | v9fs_fid_destroy(current_fid); | |
117 | } | |
118 | ||
119 | kfree(dentry->d_fsdata); /* free the list_head */ | |
120 | } | |
121 | } | |
122 | ||
123 | struct dentry_operations v9fs_dentry_operations = { | |
124 | .d_revalidate = v9fs_dentry_validate, | |
125 | .d_release = v9fs_dentry_release, | |
126 | }; |