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 (c) 2007, 2010, Oracle and/or its affiliates. All rights reserved.
23 * Copyright 2013 Nexenta Systems, Inc. All rights reserved.
24 */
25
26 #include <sys/vfs.h>
27 #include <smbsrv/smb_ktypes.h>
28 #include <smbsrv/smb_kproto.h>
29
30 static smb_vfs_t *smb_vfs_find(smb_export_t *, vfs_t *);
31 static void smb_vfs_destroy(smb_vfs_t *);
32
33 /*
34 * If a hold on the specified VFS has already been taken
35 * then only increment the reference count of the corresponding
36 * smb_vfs_t structure. If no smb_vfs_t structure has been created
37 * yet for the specified VFS then create one and take a hold on
38 * the VFS.
39 */
40 int
41 smb_vfs_hold(smb_export_t *se, vfs_t *vfsp)
42 {
43 smb_vfs_t *smb_vfs;
44 vnode_t *rootvp;
45 int rc;
46
47 if (se == NULL || vfsp == NULL)
48 return (EINVAL);
49
50 smb_llist_enter(&se->e_vfs_list, RW_WRITER);
51
52 if ((smb_vfs = smb_vfs_find(se, vfsp)) != NULL) {
53 smb_vfs->sv_refcnt++;
54 DTRACE_PROBE1(smb_vfs_hold_hit, smb_vfs_t *, smb_vfs);
55 smb_llist_exit(&se->e_vfs_list);
56 return (0);
57 }
58
59 if ((rc = VFS_ROOT(vfsp, &rootvp)) != 0) {
60 smb_llist_exit(&se->e_vfs_list);
61 return (rc);
62 }
63
64 smb_vfs = kmem_cache_alloc(smb_kshare_cache_vfs, KM_SLEEP);
65
66 bzero(smb_vfs, sizeof (smb_vfs_t));
67
68 smb_vfs->sv_magic = SMB_VFS_MAGIC;
69 smb_vfs->sv_refcnt = 1;
70 smb_vfs->sv_vfsp = vfsp;
71 /*
72 * We have a hold on the root vnode of the file system
73 * from the VFS_ROOT call above.
74 */
75 smb_vfs->sv_rootvp = rootvp;
76
77 smb_llist_insert_head(&se->e_vfs_list, smb_vfs);
78 DTRACE_PROBE1(smb_vfs_hold_miss, smb_vfs_t *, smb_vfs);
79 smb_llist_exit(&se->e_vfs_list);
80
81 return (0);
82 }
83
84 /*
85 * smb_vfs_rele
86 *
87 * Decrements the reference count of the fs passed in. If the reference count
88 * drops to zero the smb_vfs_t structure associated with the fs is freed.
89 */
90 void
91 smb_vfs_rele(smb_export_t *se, vfs_t *vfsp)
92 {
93 smb_vfs_t *smb_vfs;
94
95 ASSERT(vfsp);
96
97 smb_llist_enter(&se->e_vfs_list, RW_WRITER);
98 smb_vfs = smb_vfs_find(se, vfsp);
99 DTRACE_PROBE1(smb_vfs_release, smb_vfs_t *, smb_vfs);
100 if (smb_vfs) {
101 ASSERT(smb_vfs->sv_refcnt);
102 if (--smb_vfs->sv_refcnt == 0) {
103 smb_llist_remove(&se->e_vfs_list, smb_vfs);
104 smb_llist_exit(&se->e_vfs_list);
105 smb_vfs_destroy(smb_vfs);
106 return;
107 }
108 }
109 smb_llist_exit(&se->e_vfs_list);
110 }
111
112 /*
113 * smb_vfs_rele_all()
114 *
115 * Release all holds on root vnodes of file systems which were taken
116 * due to the existence of at least one enabled share on the file system.
117 * Called at driver close time.
118 */
119 void
120 smb_vfs_rele_all(smb_export_t *se)
121 {
122 smb_vfs_t *smb_vfs;
123
124 smb_llist_enter(&se->e_vfs_list, RW_WRITER);
125 while ((smb_vfs = smb_llist_head(&se->e_vfs_list)) != NULL) {
126
127 ASSERT(smb_vfs->sv_magic == SMB_VFS_MAGIC);
128 DTRACE_PROBE1(smb_vfs_rele_all_hit, smb_vfs_t *, smb_vfs);
129 smb_llist_remove(&se->e_vfs_list, smb_vfs);
130 smb_vfs_destroy(smb_vfs);
131 }
132 smb_llist_exit(&se->e_vfs_list);
133 }
134
135 /*
136 * Goes through the list of smb_vfs_t structure and returns the one matching
137 * the vnode passed in. If no match is found a NULL pointer is returned.
138 *
139 * The list of smb_vfs_t structures has to have been entered prior calling
140 * this function.
141 */
142 static smb_vfs_t *
143 smb_vfs_find(smb_export_t *se, vfs_t *vfsp)
144 {
145 smb_vfs_t *smb_vfs;
146
147 smb_vfs = smb_llist_head(&se->e_vfs_list);
148 while (smb_vfs) {
149 ASSERT(smb_vfs->sv_magic == SMB_VFS_MAGIC);
150 if (smb_vfs->sv_vfsp == vfsp)
151 return (smb_vfs);
152 smb_vfs = smb_llist_next(&se->e_vfs_list, smb_vfs);
153 }
154
155 return (NULL);
156 }
157
158 static void
159 smb_vfs_destroy(smb_vfs_t *smb_vfs)
160 {
161 VN_RELE(smb_vfs->sv_rootvp);
162 smb_vfs->sv_magic = (uint32_t)~SMB_VFS_MAGIC;
163 kmem_cache_free(smb_kshare_cache_vfs, smb_vfs);
164 }