1/*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or https://opensource.org/licenses/CDDL-1.0.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21/*
22 * Copyright (c) 2011 Gunnar Beutner
23 * Copyright (c) 2012 Cyril Plisko. All rights reserved.
24 */
25
26
27#include <sys/zfs_znode.h>
28#include <sys/zfs_vnops.h>
29#include <sys/zfs_ctldir.h>
30#include <sys/zpl.h>
31
32
33static int
34#ifdef HAVE_ENCODE_FH_WITH_INODE
35zpl_encode_fh(struct inode *ip, __u32 *fh, int *max_len, struct inode *parent)
36{
37#else
38zpl_encode_fh(struct dentry *dentry, __u32 *fh, int *max_len, int connectable)
39{
40	/* CSTYLED */
41	struct inode *ip = dentry->d_inode;
42#endif /* HAVE_ENCODE_FH_WITH_INODE */
43	fstrans_cookie_t cookie;
44	ushort_t empty_fid = 0;
45	fid_t *fid;
46	int len_bytes, rc;
47
48	len_bytes = *max_len * sizeof (__u32);
49
50	if (len_bytes < offsetof(fid_t, fid_data)) {
51		fid = (fid_t *)&empty_fid;
52	} else {
53		fid = (fid_t *)fh;
54		fid->fid_len = len_bytes - offsetof(fid_t, fid_data);
55	}
56
57	cookie = spl_fstrans_mark();
58
59	if (zfsctl_is_node(ip))
60		rc = zfsctl_fid(ip, fid);
61	else
62		rc = zfs_fid(ip, fid);
63
64	spl_fstrans_unmark(cookie);
65	len_bytes = offsetof(fid_t, fid_data) + fid->fid_len;
66	*max_len = roundup(len_bytes, sizeof (__u32)) / sizeof (__u32);
67
68	return (rc == 0 ? FILEID_INO32_GEN : 255);
69}
70
71static struct dentry *
72zpl_fh_to_dentry(struct super_block *sb, struct fid *fh,
73    int fh_len, int fh_type)
74{
75	fid_t *fid = (fid_t *)fh;
76	fstrans_cookie_t cookie;
77	struct inode *ip;
78	int len_bytes, rc;
79
80	len_bytes = fh_len * sizeof (__u32);
81
82	if (fh_type != FILEID_INO32_GEN ||
83	    len_bytes < offsetof(fid_t, fid_data) ||
84	    len_bytes < offsetof(fid_t, fid_data) + fid->fid_len)
85		return (ERR_PTR(-EINVAL));
86
87	cookie = spl_fstrans_mark();
88	rc = zfs_vget(sb, &ip, fid);
89	spl_fstrans_unmark(cookie);
90
91	if (rc) {
92		/*
93		 * If we see ENOENT it might mean that an NFSv4 * client
94		 * is using a cached inode value in a file handle and
95		 * that the sought after file has had its inode changed
96		 * by a third party.  So change the error to ESTALE
97		 * which will trigger a full lookup by the client and
98		 * will find the new filename/inode pair if it still
99		 * exists.
100		 */
101		if (rc == ENOENT)
102			rc = ESTALE;
103
104		return (ERR_PTR(-rc));
105	}
106
107	ASSERT((ip != NULL) && !IS_ERR(ip));
108
109	return (d_obtain_alias(ip));
110}
111
112static struct dentry *
113zpl_get_parent(struct dentry *child)
114{
115	cred_t *cr = CRED();
116	fstrans_cookie_t cookie;
117	znode_t *zp;
118	int error;
119
120	crhold(cr);
121	cookie = spl_fstrans_mark();
122	error = -zfs_lookup(ITOZ(child->d_inode), "..", &zp, 0, cr, NULL, NULL);
123	spl_fstrans_unmark(cookie);
124	crfree(cr);
125	ASSERT3S(error, <=, 0);
126
127	if (error)
128		return (ERR_PTR(error));
129
130	return (d_obtain_alias(ZTOI(zp)));
131}
132
133static int
134zpl_commit_metadata(struct inode *inode)
135{
136	cred_t *cr = CRED();
137	fstrans_cookie_t cookie;
138	int error;
139
140	if (zfsctl_is_node(inode))
141		return (0);
142
143	crhold(cr);
144	cookie = spl_fstrans_mark();
145	error = -zfs_fsync(ITOZ(inode), 0, cr);
146	spl_fstrans_unmark(cookie);
147	crfree(cr);
148	ASSERT3S(error, <=, 0);
149
150	return (error);
151}
152
153const struct export_operations zpl_export_operations = {
154	.encode_fh		= zpl_encode_fh,
155	.fh_to_dentry		= zpl_fh_to_dentry,
156	.get_parent		= zpl_get_parent,
157	.commit_metadata	= zpl_commit_metadata,
158};
159