1/* 2 * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved. 3 * Copyright (C) 2004-2005 Red Hat, Inc. All rights reserved. 4 * 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. 8 */ 9 10#include <linux/module.h> 11#include <linux/slab.h> 12#include <linux/module.h> 13#include <linux/init.h> 14#include <linux/types.h> 15#include <linux/fs.h> 16#include <linux/lm_interface.h> 17 18struct nolock_lockspace { 19 unsigned int nl_lvb_size; 20}; 21 22static const struct lm_lockops nolock_ops; 23 24static int nolock_mount(char *table_name, char *host_data, 25 lm_callback_t cb, void *cb_data, 26 unsigned int min_lvb_size, int flags, 27 struct lm_lockstruct *lockstruct, 28 struct kobject *fskobj) 29{ 30 char *c; 31 unsigned int jid; 32 struct nolock_lockspace *nl; 33 34 c = strstr(host_data, "jid="); 35 if (!c) 36 jid = 0; 37 else { 38 c += 4; 39 sscanf(c, "%u", &jid); 40 } 41 42 nl = kzalloc(sizeof(struct nolock_lockspace), GFP_KERNEL); 43 if (!nl) 44 return -ENOMEM; 45 46 nl->nl_lvb_size = min_lvb_size; 47 48 lockstruct->ls_jid = jid; 49 lockstruct->ls_first = 1; 50 lockstruct->ls_lvb_size = min_lvb_size; 51 lockstruct->ls_lockspace = nl; 52 lockstruct->ls_ops = &nolock_ops; 53 lockstruct->ls_flags = LM_LSFLAG_LOCAL; 54 55 return 0; 56} 57 58static void nolock_others_may_mount(void *lockspace) 59{ 60} 61 62static void nolock_unmount(void *lockspace) 63{ 64 struct nolock_lockspace *nl = lockspace; 65 kfree(nl); 66} 67 68static void nolock_withdraw(void *lockspace) 69{ 70} 71 72/** 73 * nolock_get_lock - get a lm_lock_t given a descripton of the lock 74 * @lockspace: the lockspace the lock lives in 75 * @name: the name of the lock 76 * @lockp: return the lm_lock_t here 77 * 78 * Returns: 0 on success, -EXXX on failure 79 */ 80 81static int nolock_get_lock(void *lockspace, struct lm_lockname *name, 82 void **lockp) 83{ 84 *lockp = lockspace; 85 return 0; 86} 87 88/** 89 * nolock_put_lock - get rid of a lock structure 90 * @lock: the lock to throw away 91 * 92 */ 93 94static void nolock_put_lock(void *lock) 95{ 96} 97 98/** 99 * nolock_lock - acquire a lock 100 * @lock: the lock to manipulate 101 * @cur_state: the current state 102 * @req_state: the requested state 103 * @flags: modifier flags 104 * 105 * Returns: A bitmap of LM_OUT_* 106 */ 107 108static unsigned int nolock_lock(void *lock, unsigned int cur_state, 109 unsigned int req_state, unsigned int flags) 110{ 111 return req_state | LM_OUT_CACHEABLE; 112} 113 114/** 115 * nolock_unlock - unlock a lock 116 * @lock: the lock to manipulate 117 * @cur_state: the current state 118 * 119 * Returns: 0 120 */ 121 122static unsigned int nolock_unlock(void *lock, unsigned int cur_state) 123{ 124 return 0; 125} 126 127static void nolock_cancel(void *lock) 128{ 129} 130 131/** 132 * nolock_hold_lvb - hold on to a lock value block 133 * @lock: the lock the LVB is associated with 134 * @lvbp: return the lm_lvb_t here 135 * 136 * Returns: 0 on success, -EXXX on failure 137 */ 138 139static int nolock_hold_lvb(void *lock, char **lvbp) 140{ 141 struct nolock_lockspace *nl = lock; 142 int error = 0; 143 144 *lvbp = kzalloc(nl->nl_lvb_size, GFP_KERNEL); 145 if (!*lvbp) 146 error = -ENOMEM; 147 148 return error; 149} 150 151/** 152 * nolock_unhold_lvb - release a LVB 153 * @lock: the lock the LVB is associated with 154 * @lvb: the lock value block 155 * 156 */ 157 158static void nolock_unhold_lvb(void *lock, char *lvb) 159{ 160 kfree(lvb); 161} 162 163static int nolock_plock_get(void *lockspace, struct lm_lockname *name, 164 struct file *file, struct file_lock *fl) 165{ 166 posix_test_lock(file, fl); 167 168 return 0; 169} 170 171static int nolock_plock(void *lockspace, struct lm_lockname *name, 172 struct file *file, int cmd, struct file_lock *fl) 173{ 174 int error; 175 error = posix_lock_file_wait(file, fl); 176 return error; 177} 178 179static int nolock_punlock(void *lockspace, struct lm_lockname *name, 180 struct file *file, struct file_lock *fl) 181{ 182 int error; 183 error = posix_lock_file_wait(file, fl); 184 return error; 185} 186 187static void nolock_recovery_done(void *lockspace, unsigned int jid, 188 unsigned int message) 189{ 190} 191 192static const struct lm_lockops nolock_ops = { 193 .lm_proto_name = "lock_nolock", 194 .lm_mount = nolock_mount, 195 .lm_others_may_mount = nolock_others_may_mount, 196 .lm_unmount = nolock_unmount, 197 .lm_withdraw = nolock_withdraw, 198 .lm_get_lock = nolock_get_lock, 199 .lm_put_lock = nolock_put_lock, 200 .lm_lock = nolock_lock, 201 .lm_unlock = nolock_unlock, 202 .lm_cancel = nolock_cancel, 203 .lm_hold_lvb = nolock_hold_lvb, 204 .lm_unhold_lvb = nolock_unhold_lvb, 205 .lm_plock_get = nolock_plock_get, 206 .lm_plock = nolock_plock, 207 .lm_punlock = nolock_punlock, 208 .lm_recovery_done = nolock_recovery_done, 209 .lm_owner = THIS_MODULE, 210}; 211 212static int __init init_nolock(void) 213{ 214 int error; 215 216 error = gfs2_register_lockproto(&nolock_ops); 217 if (error) { 218 printk(KERN_WARNING 219 "lock_nolock: can't register protocol: %d\n", error); 220 return error; 221 } 222 223 printk(KERN_INFO 224 "Lock_Nolock (built %s %s) installed\n", __DATE__, __TIME__); 225 return 0; 226} 227 228static void __exit exit_nolock(void) 229{ 230 gfs2_unregister_lockproto(&nolock_ops); 231} 232 233module_init(init_nolock); 234module_exit(exit_nolock); 235 236MODULE_DESCRIPTION("GFS Nolock Locking Module"); 237MODULE_AUTHOR("Red Hat, Inc."); 238MODULE_LICENSE("GPL"); 239