2 * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
3 * Copyright (C) 2004-2006 Red Hat, Inc. All rights reserved.
5 * This copyrighted material is made available to anyone wishing to use,
6 * modify, copy, or redistribute it subject to the terms and conditions
7 * of the GNU General Public License version 2.
10 #include <linux/module.h>
11 #include <linux/init.h>
12 #include <linux/string.h>
13 #include <linux/slab.h>
14 #include <linux/wait.h>
15 #include <linux/sched.h>
16 #include <linux/kmod.h>
18 #include <linux/delay.h>
20 #include "lm_interface.h"
23 struct list_head lw_list
;
24 const struct lm_lockops
*lw_ops
;
27 /* List of registered low-level locking protocols. A file system selects one
28 of them by name at mount time, e.g. lock_nolock, lock_dlm. */
30 static LIST_HEAD(lmh_list
);
31 static DEFINE_MUTEX(lmh_lock
);
34 * gfs2_register_lockproto - Register a low-level locking protocol
35 * @proto: the protocol definition
37 * Returns: 0 on success, -EXXX on failure
40 int gfs2_register_lockproto(const struct lm_lockops
*proto
)
42 struct lmh_wrapper
*lw
;
44 mutex_lock(&lmh_lock
);
46 list_for_each_entry(lw
, &lmh_list
, lw_list
) {
47 if (!strcmp(lw
->lw_ops
->lm_proto_name
, proto
->lm_proto_name
)) {
48 mutex_unlock(&lmh_lock
);
49 printk(KERN_INFO
"GFS2: protocol %s already exists\n",
50 proto
->lm_proto_name
);
55 lw
= kzalloc(sizeof(struct lmh_wrapper
), GFP_KERNEL
);
57 mutex_unlock(&lmh_lock
);
62 list_add(&lw
->lw_list
, &lmh_list
);
64 mutex_unlock(&lmh_lock
);
70 * gfs2_unregister_lockproto - Unregister a low-level locking protocol
71 * @proto: the protocol definition
75 void gfs2_unregister_lockproto(const struct lm_lockops
*proto
)
77 struct lmh_wrapper
*lw
;
79 mutex_lock(&lmh_lock
);
81 list_for_each_entry(lw
, &lmh_list
, lw_list
) {
82 if (!strcmp(lw
->lw_ops
->lm_proto_name
, proto
->lm_proto_name
)) {
83 list_del(&lw
->lw_list
);
84 mutex_unlock(&lmh_lock
);
90 mutex_unlock(&lmh_lock
);
92 printk(KERN_WARNING
"GFS2: can't unregister lock protocol %s\n",
93 proto
->lm_proto_name
);
97 * gfs2_mount_lockproto - Mount a lock protocol
98 * @proto_name - the name of the protocol
99 * @table_name - the name of the lock space
100 * @host_data - data specific to this host
101 * @cb - the callback to the code using the lock module
102 * @sdp - The GFS2 superblock
103 * @min_lvb_size - the mininum LVB size that the caller can deal with
104 * @flags - LM_MFLAG_*
105 * @lockstruct - a structure returned describing the mount
107 * Returns: 0 on success, -EXXX on failure
110 int gfs2_mount_lockproto(char *proto_name
, char *table_name
, char *host_data
,
111 lm_callback_t cb
, void *cb_data
,
112 unsigned int min_lvb_size
, int flags
,
113 struct lm_lockstruct
*lockstruct
,
114 struct kobject
*fskobj
)
116 struct lmh_wrapper
*lw
= NULL
;
121 mutex_lock(&lmh_lock
);
124 list_for_each_entry(lw
, &lmh_list
, lw_list
) {
125 if (!strcmp(lw
->lw_ops
->lm_proto_name
, proto_name
)) {
132 if (!try && capable(CAP_SYS_MODULE
)) {
134 mutex_unlock(&lmh_lock
);
135 request_module(proto_name
);
138 printk(KERN_INFO
"GFS2: can't find protocol %s\n", proto_name
);
143 if (!try_module_get(lw
->lw_ops
->lm_owner
)) {
145 mutex_unlock(&lmh_lock
);
150 error
= lw
->lw_ops
->lm_mount(table_name
, host_data
, cb
, cb_data
,
151 min_lvb_size
, flags
, lockstruct
, fskobj
);
153 module_put(lw
->lw_ops
->lm_owner
);
155 mutex_unlock(&lmh_lock
);
159 void gfs2_unmount_lockproto(struct lm_lockstruct
*lockstruct
)
161 mutex_lock(&lmh_lock
);
162 lockstruct
->ls_ops
->lm_unmount(lockstruct
->ls_lockspace
);
163 if (lockstruct
->ls_ops
->lm_owner
)
164 module_put(lockstruct
->ls_ops
->lm_owner
);
165 mutex_unlock(&lmh_lock
);
169 * gfs2_withdraw_lockproto - abnormally unmount a lock module
170 * @lockstruct: the lockstruct passed into mount
174 void gfs2_withdraw_lockproto(struct lm_lockstruct
*lockstruct
)
176 mutex_lock(&lmh_lock
);
177 lockstruct
->ls_ops
->lm_withdraw(lockstruct
->ls_lockspace
);
178 if (lockstruct
->ls_ops
->lm_owner
)
179 module_put(lockstruct
->ls_ops
->lm_owner
);
180 mutex_unlock(&lmh_lock
);
183 EXPORT_SYMBOL_GPL(gfs2_register_lockproto
);
184 EXPORT_SYMBOL_GPL(gfs2_unregister_lockproto
);