xref: /illumos-gate/usr/src/uts/common/fs/ctfs/ctfs_sym.c (revision c559157643fef9f9afb0414e00a3579407ba3052)
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 http://www.opensolaris.org/os/licensing.
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 2007 Sun Microsystems, Inc.  All rights reserved.
23  * Use is subject to license terms.
24  */
25 
26 #pragma ident	"%Z%%M%	%I%	%E% SMI"
27 
28 #include <sys/types.h>
29 #include <sys/param.h>
30 #include <sys/time.h>
31 #include <sys/cred.h>
32 #include <sys/vfs.h>
33 #include <sys/vfs_opreg.h>
34 #include <sys/gfs.h>
35 #include <sys/vnode.h>
36 #include <sys/systm.h>
37 #include <sys/errno.h>
38 #include <sys/sysmacros.h>
39 #include <fs/fs_subr.h>
40 #include <sys/contract.h>
41 #include <sys/contract_impl.h>
42 #include <sys/ctfs.h>
43 #include <sys/ctfs_impl.h>
44 #include <sys/file.h>
45 #include <sys/cmn_err.h>
46 
47 /*
48  * CTFS routines for the /system/contract/all/<ctid> vnode.
49  */
50 
51 /*
52  * ctfs_create_symnode
53  *
54  * Creates and returns a symnode for the specified contract.
55  */
56 vnode_t *
57 ctfs_create_symnode(vnode_t *pvp, contract_t *ct)
58 {
59 	ctfs_symnode_t *symnode;
60 	vnode_t *vp;
61 	size_t len;
62 
63 	vp = gfs_file_create(sizeof (ctfs_symnode_t), pvp, ctfs_ops_sym);
64 	vp->v_type = VLNK;
65 	symnode = vp->v_data;
66 
67 	symnode->ctfs_sn_contract = ct;
68 	symnode->ctfs_sn_size = len = snprintf(NULL, 0, "../%s/%ld",
69 	    ct->ct_type->ct_type_name, (long)ct->ct_id) + 1;
70 	symnode->ctfs_sn_string = kmem_alloc(len, KM_SLEEP);
71 	VERIFY(snprintf(symnode->ctfs_sn_string, len, "../%s/%ld",
72 	    ct->ct_type->ct_type_name, (long)ct->ct_id) < len);
73 
74 	contract_hold(ct);
75 
76 	return (vp);
77 }
78 
79 /*
80  * ctfs_sym_getattr - VOP_GETATTR entry point
81  */
82 /* ARGSUSED */
83 static int
84 ctfs_sym_getattr(
85 	vnode_t *vp,
86 	vattr_t *vap,
87 	int flags,
88 	cred_t *cr,
89 	caller_context_t *ct)
90 {
91 	ctfs_symnode_t *symnode = vp->v_data;
92 
93 	vap->va_type = VLNK;
94 	vap->va_mode = 0444;
95 	vap->va_nlink = 1;
96 	vap->va_size = symnode->ctfs_sn_size - 1;
97 	vap->va_mtime = vap->va_atime = vap->va_ctime =
98 	    symnode->ctfs_sn_contract->ct_ctime;
99 	ctfs_common_getattr(vp, vap);
100 
101 	return (0);
102 }
103 
104 /*
105  * ctfs_sym_readlink - VOP_READLINK entry point
106  *
107  * Since we built the symlink string in ctfs_create_symnode, this is
108  * just a uiomove.
109  */
110 /* ARGSUSED */
111 int
112 ctfs_sym_readlink(vnode_t *vp, uio_t *uiop, cred_t *cr, caller_context_t *ct)
113 {
114 	ctfs_symnode_t *symnode = vp->v_data;
115 
116 	return (uiomove(symnode->ctfs_sn_string, symnode->ctfs_sn_size - 1,
117 	    UIO_READ, uiop));
118 }
119 
120 /*
121  * ctfs_sym_inactive - VOP_INACTIVE entry point
122  */
123 /* ARGSUSED */
124 static void
125 ctfs_sym_inactive(vnode_t *vp, cred_t *cr, caller_context_t *ct)
126 {
127 	ctfs_symnode_t *symnode;
128 
129 	if ((symnode = gfs_file_inactive(vp)) != NULL) {
130 		contract_rele(symnode->ctfs_sn_contract);
131 		kmem_free(symnode->ctfs_sn_string, symnode->ctfs_sn_size);
132 		kmem_free(symnode, sizeof (ctfs_symnode_t));
133 	}
134 }
135 
136 const fs_operation_def_t ctfs_tops_sym[] = {
137 	{ VOPNAME_OPEN,		{ .vop_open = ctfs_open } },
138 	{ VOPNAME_CLOSE,	{ .vop_close = ctfs_close } },
139 	{ VOPNAME_IOCTL,	{ .error = fs_inval } },
140 	{ VOPNAME_GETATTR,	{ .vop_getattr = ctfs_sym_getattr } },
141 	{ VOPNAME_READLINK,	{ .vop_readlink = ctfs_sym_readlink } },
142 	{ VOPNAME_ACCESS,	{ .vop_access = ctfs_access_readonly } },
143 	{ VOPNAME_READDIR,	{ .error = fs_notdir } },
144 	{ VOPNAME_LOOKUP,	{ .error = fs_notdir } },
145 	{ VOPNAME_INACTIVE,	{ .vop_inactive = ctfs_sym_inactive } },
146 	{ NULL, NULL }
147 };
148