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git.proxmox.com Git - mirror_ubuntu-artful-kernel.git/blob - fs/gfs2/locking.c
2 * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
3 * Copyright (C) 2004-2005 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 v.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 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 struct list_head lmh_list
;
31 static struct semaphore lmh_lock
;
34 * gfs_register_lockproto - Register a low-level locking protocol
35 * @proto: the protocol definition
37 * Returns: 0 on success, -EXXX on failure
40 int gfs_register_lockproto(struct lm_lockops
*proto
)
42 struct lmh_wrapper
*lw
;
46 list_for_each_entry(lw
, &lmh_list
, lw_list
) {
47 if (!strcmp(lw
->lw_ops
->lm_proto_name
, proto
->lm_proto_name
)) {
49 printk("GFS2: protocol %s already exists\n",
50 proto
->lm_proto_name
);
55 lw
= kmalloc(sizeof(struct lmh_wrapper
), GFP_KERNEL
);
60 memset(lw
, 0, sizeof(struct lmh_wrapper
));
63 list_add(&lw
->lw_list
, &lmh_list
);
71 * gfs_unregister_lockproto - Unregister a low-level locking protocol
72 * @proto: the protocol definition
76 void gfs_unregister_lockproto(struct lm_lockops
*proto
)
78 struct lmh_wrapper
*lw
;
82 list_for_each_entry(lw
, &lmh_list
, lw_list
) {
83 if (!strcmp(lw
->lw_ops
->lm_proto_name
, proto
->lm_proto_name
)) {
84 list_del(&lw
->lw_list
);
93 printk("GFS2: can't unregister lock protocol %s\n",
94 proto
->lm_proto_name
);
98 * gfs2_mount_lockproto - Mount a lock protocol
99 * @proto_name - the name of the protocol
100 * @table_name - the name of the lock space
101 * @host_data - data specific to this host
102 * @cb - the callback to the code using the lock module
103 * @fsdata - data to pass back with the callback
104 * @min_lvb_size - the mininum LVB size that the caller can deal with
105 * @flags - LM_MFLAG_*
106 * @lockstruct - a structure returned describing the mount
108 * Returns: 0 on success, -EXXX on failure
111 int gfs2_mount_lockproto(char *proto_name
, char *table_name
, char *host_data
,
112 lm_callback_t cb
, lm_fsdata_t
*fsdata
,
113 unsigned int min_lvb_size
, int flags
,
114 struct lm_lockstruct
*lockstruct
,
115 struct kobject
*fskobj
)
117 struct lmh_wrapper
*lw
= NULL
;
125 list_for_each_entry(lw
, &lmh_list
, lw_list
) {
126 if (!strcmp(lw
->lw_ops
->lm_proto_name
, proto_name
)) {
133 if (!try && capable(CAP_SYS_MODULE
)) {
136 request_module(proto_name
);
139 printk("GFS2: can't find protocol %s\n", proto_name
);
144 if (!try_module_get(lw
->lw_ops
->lm_owner
)) {
151 error
= lw
->lw_ops
->lm_mount(table_name
, host_data
, cb
, fsdata
,
152 min_lvb_size
, flags
, lockstruct
, fskobj
);
154 module_put(lw
->lw_ops
->lm_owner
);
160 void gfs2_unmount_lockproto(struct lm_lockstruct
*lockstruct
)
163 lockstruct
->ls_ops
->lm_unmount(lockstruct
->ls_lockspace
);
164 if (lockstruct
->ls_ops
->lm_owner
)
165 module_put(lockstruct
->ls_ops
->lm_owner
);
170 * gfs2_withdraw_lockproto - abnormally unmount a lock module
171 * @lockstruct: the lockstruct passed into mount
175 void gfs2_withdraw_lockproto(struct lm_lockstruct
*lockstruct
)
178 lockstruct
->ls_ops
->lm_withdraw(lockstruct
->ls_lockspace
);
179 if (lockstruct
->ls_ops
->lm_owner
)
180 module_put(lockstruct
->ls_ops
->lm_owner
);
184 void __init
gfs2_init_lmh(void)
186 init_MUTEX(&lmh_lock
);
187 INIT_LIST_HEAD(&lmh_list
);
190 EXPORT_SYMBOL_GPL(gfs_register_lockproto
);
191 EXPORT_SYMBOL_GPL(gfs_unregister_lockproto
);