aboutsummaryrefslogtreecommitdiffstats
path: root/module/os/linux/zfs/zpl_export.c
blob: eaf048c38db11f53a5e160ad064aa07911c02eb8 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright (c) 2011 Gunnar Beutner
 * Copyright (c) 2012 Cyril Plisko. All rights reserved.
 */


#include <sys/zfs_znode.h>
#include <sys/zfs_vnops.h>
#include <sys/zfs_ctldir.h>
#include <sys/zpl.h>


static int
#ifdef HAVE_ENCODE_FH_WITH_INODE
zpl_encode_fh(struct inode *ip, __u32 *fh, int *max_len, struct inode *parent)
{
#else
zpl_encode_fh(struct dentry *dentry, __u32 *fh, int *max_len, int connectable)
{
	/* CSTYLED */
	struct inode *ip = dentry->d_inode;
#endif /* HAVE_ENCODE_FH_WITH_INODE */
	fstrans_cookie_t cookie;
	fid_t *fid = (fid_t *)fh;
	int len_bytes, rc;

	len_bytes = *max_len * sizeof (__u32);

	if (len_bytes < offsetof(fid_t, fid_data))
		return (255);

	fid->fid_len = len_bytes - offsetof(fid_t, fid_data);
	cookie = spl_fstrans_mark();

	if (zfsctl_is_node(ip))
		rc = zfsctl_fid(ip, fid);
	else
		rc = zfs_fid(ip, fid);

	spl_fstrans_unmark(cookie);
	len_bytes = offsetof(fid_t, fid_data) + fid->fid_len;
	*max_len = roundup(len_bytes, sizeof (__u32)) / sizeof (__u32);

	return (rc == 0 ? FILEID_INO32_GEN : 255);
}

static struct dentry *
zpl_fh_to_dentry(struct super_block *sb, struct fid *fh,
    int fh_len, int fh_type)
{
	fid_t *fid = (fid_t *)fh;
	fstrans_cookie_t cookie;
	struct inode *ip;
	int len_bytes, rc;

	len_bytes = fh_len * sizeof (__u32);

	if (fh_type != FILEID_INO32_GEN ||
	    len_bytes < offsetof(fid_t, fid_data) ||
	    len_bytes < offsetof(fid_t, fid_data) + fid->fid_len)
		return (ERR_PTR(-EINVAL));

	cookie = spl_fstrans_mark();
	rc = zfs_vget(sb, &ip, fid);
	spl_fstrans_unmark(cookie);

	if (rc) {
		/*
		 * If we see ENOENT it might mean that an NFSv4 * client
		 * is using a cached inode value in a file handle and
		 * that the sought after file has had its inode changed
		 * by a third party.  So change the error to ESTALE
		 * which will trigger a full lookup by the client and
		 * will find the new filename/inode pair if it still
		 * exists.
		 */
		if (rc == ENOENT)
			rc = ESTALE;

		return (ERR_PTR(-rc));
	}

	ASSERT((ip != NULL) && !IS_ERR(ip));

	return (d_obtain_alias(ip));
}

static struct dentry *
zpl_get_parent(struct dentry *child)
{
	cred_t *cr = CRED();
	fstrans_cookie_t cookie;
	znode_t *zp;
	int error;

	crhold(cr);
	cookie = spl_fstrans_mark();
	error = -zfs_lookup(ITOZ(child->d_inode), "..", &zp, 0, cr, NULL, NULL);
	spl_fstrans_unmark(cookie);
	crfree(cr);
	ASSERT3S(error, <=, 0);

	if (error)
		return (ERR_PTR(error));

	return (d_obtain_alias(ZTOI(zp)));
}

static int
zpl_commit_metadata(struct inode *inode)
{
	cred_t *cr = CRED();
	fstrans_cookie_t cookie;
	int error;

	if (zfsctl_is_node(inode))
		return (0);

	crhold(cr);
	cookie = spl_fstrans_mark();
	error = -zfs_fsync(ITOZ(inode), 0, cr);
	spl_fstrans_unmark(cookie);
	crfree(cr);
	ASSERT3S(error, <=, 0);

	return (error);
}

const struct export_operations zpl_export_operations = {
	.encode_fh		= zpl_encode_fh,
	.fh_to_dentry		= zpl_fh_to_dentry,
	.get_parent		= zpl_get_parent,
	.commit_metadata	= zpl_commit_metadata,
};