1 /*
2 * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
3 * Copyright (C) 2004-2006 Red Hat, Inc. All rights reserved.
4 *
5 * This copyrighted material is made available to anyone wishing to use,
6 * modify, copy, or redistribute it subject to the terms and conditions
7 * of the GNU General Public License version 2.
8 */
9
10 #include <linux/slab.h>
11 #include <linux/spinlock.h>
12 #include <linux/completion.h>
13 #include <linux/buffer_head.h>
14 #include <linux/gfs2_ondisk.h>
15 #include <linux/crc32.h>
16 #include <linux/lm_interface.h>
17
18 #include "gfs2.h"
19 #include "incore.h"
20 #include "dir.h"
21 #include "glock.h"
22 #include "super.h"
23 #include "util.h"
24 #include "inode.h"
25
26 /**
27 * gfs2_drevalidate - Check directory lookup consistency
28 * @dentry: the mapping to check
29 * @nd:
30 *
31 * Check to make sure the lookup necessary to arrive at this inode from its
32 * parent is still good.
33 *
34 * Returns: 1 if the dentry is ok, 0 if it isn't
35 */
36
gfs2_drevalidate(struct dentry * dentry,struct nameidata * nd)37 static int gfs2_drevalidate(struct dentry *dentry, struct nameidata *nd)
38 {
39 struct dentry *parent = dget_parent(dentry);
40 struct gfs2_sbd *sdp = GFS2_SB(parent->d_inode);
41 struct gfs2_inode *dip = GFS2_I(parent->d_inode);
42 struct inode *inode = dentry->d_inode;
43 struct gfs2_holder d_gh;
44 struct gfs2_inode *ip = NULL;
45 int error;
46 int had_lock = 0;
47
48 if (inode) {
49 if (is_bad_inode(inode))
50 goto invalid;
51 ip = GFS2_I(inode);
52 }
53
54 if (sdp->sd_args.ar_localcaching)
55 goto valid;
56
57 had_lock = (gfs2_glock_is_locked_by_me(dip->i_gl) != NULL);
58 if (!had_lock) {
59 error = gfs2_glock_nq_init(dip->i_gl, LM_ST_SHARED, 0, &d_gh);
60 if (error)
61 goto fail;
62 }
63
64 error = gfs2_dir_check(parent->d_inode, &dentry->d_name, ip);
65 switch (error) {
66 case 0:
67 if (!inode)
68 goto invalid_gunlock;
69 break;
70 case -ENOENT:
71 if (!inode)
72 goto valid_gunlock;
73 goto invalid_gunlock;
74 default:
75 goto fail_gunlock;
76 }
77
78 valid_gunlock:
79 if (!had_lock)
80 gfs2_glock_dq_uninit(&d_gh);
81 valid:
82 dput(parent);
83 return 1;
84
85 invalid_gunlock:
86 if (!had_lock)
87 gfs2_glock_dq_uninit(&d_gh);
88 invalid:
89 if (inode && S_ISDIR(inode->i_mode)) {
90 if (have_submounts(dentry))
91 goto valid;
92 shrink_dcache_parent(dentry);
93 }
94 d_drop(dentry);
95 dput(parent);
96 return 0;
97
98 fail_gunlock:
99 gfs2_glock_dq_uninit(&d_gh);
100 fail:
101 dput(parent);
102 return 0;
103 }
104
gfs2_dhash(struct dentry * dentry,struct qstr * str)105 static int gfs2_dhash(struct dentry *dentry, struct qstr *str)
106 {
107 str->hash = gfs2_disk_hash(str->name, str->len);
108 return 0;
109 }
110
111 struct dentry_operations gfs2_dops = {
112 .d_revalidate = gfs2_drevalidate,
113 .d_hash = gfs2_dhash,
114 };
115
116