1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
4 * Copyright (C) 2004-2006 Red Hat, Inc. All rights reserved.
5 */
6
7 #include <linux/spinlock.h>
8 #include <linux/completion.h>
9 #include <linux/buffer_head.h>
10 #include <linux/gfs2_ondisk.h>
11 #include <linux/namei.h>
12 #include <linux/crc32.h>
13
14 #include "gfs2.h"
15 #include "incore.h"
16 #include "dir.h"
17 #include "glock.h"
18 #include "super.h"
19 #include "util.h"
20 #include "inode.h"
21
22 /**
23 * gfs2_drevalidate - Check directory lookup consistency
24 * @dentry: the mapping to check
25 * @flags: lookup flags
26 *
27 * Check to make sure the lookup necessary to arrive at this inode from its
28 * parent is still good.
29 *
30 * Returns: 1 if the dentry is ok, 0 if it isn't
31 */
32
gfs2_drevalidate(struct dentry * dentry,unsigned int flags)33 static int gfs2_drevalidate(struct dentry *dentry, unsigned int flags)
34 {
35 struct dentry *parent;
36 struct gfs2_sbd *sdp;
37 struct gfs2_inode *dip;
38 struct inode *inode;
39 struct gfs2_holder d_gh;
40 struct gfs2_inode *ip = NULL;
41 int error, valid = 0;
42 int had_lock = 0;
43
44 if (flags & LOOKUP_RCU)
45 return -ECHILD;
46
47 parent = dget_parent(dentry);
48 sdp = GFS2_SB(d_inode(parent));
49 dip = GFS2_I(d_inode(parent));
50 inode = d_inode(dentry);
51
52 if (inode) {
53 if (is_bad_inode(inode))
54 goto out;
55 ip = GFS2_I(inode);
56 }
57
58 if (sdp->sd_lockstruct.ls_ops->lm_mount == NULL) {
59 valid = 1;
60 goto out;
61 }
62
63 had_lock = (gfs2_glock_is_locked_by_me(dip->i_gl) != NULL);
64 if (!had_lock) {
65 error = gfs2_glock_nq_init(dip->i_gl, LM_ST_SHARED, 0, &d_gh);
66 if (error)
67 goto out;
68 }
69
70 error = gfs2_dir_check(d_inode(parent), &dentry->d_name, ip);
71 valid = inode ? !error : (error == -ENOENT);
72
73 if (!had_lock)
74 gfs2_glock_dq_uninit(&d_gh);
75 out:
76 dput(parent);
77 return valid;
78 }
79
gfs2_dhash(const struct dentry * dentry,struct qstr * str)80 static int gfs2_dhash(const struct dentry *dentry, struct qstr *str)
81 {
82 str->hash = gfs2_disk_hash(str->name, str->len);
83 return 0;
84 }
85
86 const struct dentry_operations gfs2_dops = {
87 .d_revalidate = gfs2_drevalidate,
88 .d_hash = gfs2_dhash,
89 };
90
91