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 * @dir: expected parent directory inode
25 * @name: expexted name
26 * @dentry: dentry to check
27 * @flags: lookup flags
28 *
29 * Check to make sure the lookup necessary to arrive at this inode from its
30 * parent is still good.
31 *
32 * Returns: 1 if the dentry is ok, 0 if it isn't
33 */
34
gfs2_drevalidate(struct inode * dir,const struct qstr * name,struct dentry * dentry,unsigned int flags)35 static int gfs2_drevalidate(struct inode *dir, const struct qstr *name,
36 struct dentry *dentry, unsigned int flags)
37 {
38 struct gfs2_sbd *sdp = GFS2_SB(dir);
39 struct gfs2_inode *dip = GFS2_I(dir);
40 struct inode *inode;
41 struct gfs2_holder d_gh;
42 struct gfs2_inode *ip = NULL;
43 int error, valid;
44 int had_lock = 0;
45
46 if (flags & LOOKUP_RCU)
47 return -ECHILD;
48
49 inode = d_inode(dentry);
50
51 if (inode) {
52 if (is_bad_inode(inode))
53 return 0;
54 ip = GFS2_I(inode);
55 }
56
57 if (sdp->sd_lockstruct.ls_ops->lm_mount == NULL)
58 return 1;
59
60 had_lock = (gfs2_glock_is_locked_by_me(dip->i_gl) != NULL);
61 if (!had_lock) {
62 error = gfs2_glock_nq_init(dip->i_gl, LM_ST_SHARED, 0, &d_gh);
63 if (error)
64 return 0;
65 }
66
67 error = gfs2_dir_check(dir, name, ip);
68 valid = inode ? !error : (error == -ENOENT);
69
70 if (!had_lock)
71 gfs2_glock_dq_uninit(&d_gh);
72 return valid;
73 }
74
gfs2_dhash(const struct dentry * dentry,struct qstr * str)75 static int gfs2_dhash(const struct dentry *dentry, struct qstr *str)
76 {
77 str->hash = gfs2_disk_hash(str->name, str->len);
78 return 0;
79 }
80
gfs2_dentry_delete(const struct dentry * dentry)81 static int gfs2_dentry_delete(const struct dentry *dentry)
82 {
83 struct gfs2_inode *ginode;
84
85 if (d_really_is_negative(dentry))
86 return 0;
87
88 ginode = GFS2_I(d_inode(dentry));
89 if (!gfs2_holder_initialized(&ginode->i_iopen_gh))
90 return 0;
91
92 if (test_bit(GLF_DEMOTE, &ginode->i_iopen_gh.gh_gl->gl_flags))
93 return 1;
94
95 return 0;
96 }
97
98 const struct dentry_operations gfs2_dops = {
99 .d_revalidate = gfs2_drevalidate,
100 .d_hash = gfs2_dhash,
101 .d_delete = gfs2_dentry_delete,
102 };
103
104