| /* |
| * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved. |
| * Copyright (C) 2004-2005 Red Hat, Inc. All rights reserved. |
| * |
| * This copyrighted material is made available to anyone wishing to use, |
| * modify, copy, or redistribute it subject to the terms and conditions |
| * of the GNU General Public License version 2. |
| */ |
| |
| #include <linux/module.h> |
| #include <linux/slab.h> |
| #include <linux/module.h> |
| #include <linux/init.h> |
| #include <linux/types.h> |
| #include <linux/fs.h> |
| #include <linux/smp_lock.h> |
| #include <linux/lm_interface.h> |
| |
| struct nolock_lockspace { |
| unsigned int nl_lvb_size; |
| }; |
| |
| static const struct lm_lockops nolock_ops; |
| |
| static int nolock_mount(char *table_name, char *host_data, |
| lm_callback_t cb, void *cb_data, |
| unsigned int min_lvb_size, int flags, |
| struct lm_lockstruct *lockstruct, |
| struct kobject *fskobj) |
| { |
| char *c; |
| unsigned int jid; |
| struct nolock_lockspace *nl; |
| |
| c = strstr(host_data, "jid="); |
| if (!c) |
| jid = 0; |
| else { |
| c += 4; |
| sscanf(c, "%u", &jid); |
| } |
| |
| nl = kzalloc(sizeof(struct nolock_lockspace), GFP_KERNEL); |
| if (!nl) |
| return -ENOMEM; |
| |
| nl->nl_lvb_size = min_lvb_size; |
| |
| lockstruct->ls_jid = jid; |
| lockstruct->ls_first = 1; |
| lockstruct->ls_lvb_size = min_lvb_size; |
| lockstruct->ls_lockspace = nl; |
| lockstruct->ls_ops = &nolock_ops; |
| lockstruct->ls_flags = LM_LSFLAG_LOCAL; |
| |
| return 0; |
| } |
| |
| static void nolock_others_may_mount(void *lockspace) |
| { |
| } |
| |
| static void nolock_unmount(void *lockspace) |
| { |
| struct nolock_lockspace *nl = lockspace; |
| kfree(nl); |
| } |
| |
| static void nolock_withdraw(void *lockspace) |
| { |
| } |
| |
| /** |
| * nolock_get_lock - get a lm_lock_t given a descripton of the lock |
| * @lockspace: the lockspace the lock lives in |
| * @name: the name of the lock |
| * @lockp: return the lm_lock_t here |
| * |
| * Returns: 0 on success, -EXXX on failure |
| */ |
| |
| static int nolock_get_lock(void *lockspace, struct lm_lockname *name, |
| void **lockp) |
| { |
| *lockp = lockspace; |
| return 0; |
| } |
| |
| /** |
| * nolock_put_lock - get rid of a lock structure |
| * @lock: the lock to throw away |
| * |
| */ |
| |
| static void nolock_put_lock(void *lock) |
| { |
| } |
| |
| /** |
| * nolock_lock - acquire a lock |
| * @lock: the lock to manipulate |
| * @cur_state: the current state |
| * @req_state: the requested state |
| * @flags: modifier flags |
| * |
| * Returns: A bitmap of LM_OUT_* |
| */ |
| |
| static unsigned int nolock_lock(void *lock, unsigned int cur_state, |
| unsigned int req_state, unsigned int flags) |
| { |
| return req_state | LM_OUT_CACHEABLE; |
| } |
| |
| /** |
| * nolock_unlock - unlock a lock |
| * @lock: the lock to manipulate |
| * @cur_state: the current state |
| * |
| * Returns: 0 |
| */ |
| |
| static unsigned int nolock_unlock(void *lock, unsigned int cur_state) |
| { |
| return 0; |
| } |
| |
| static void nolock_cancel(void *lock) |
| { |
| } |
| |
| /** |
| * nolock_hold_lvb - hold on to a lock value block |
| * @lock: the lock the LVB is associated with |
| * @lvbp: return the lm_lvb_t here |
| * |
| * Returns: 0 on success, -EXXX on failure |
| */ |
| |
| static int nolock_hold_lvb(void *lock, char **lvbp) |
| { |
| struct nolock_lockspace *nl = lock; |
| int error = 0; |
| |
| *lvbp = kzalloc(nl->nl_lvb_size, GFP_KERNEL); |
| if (!*lvbp) |
| error = -ENOMEM; |
| |
| return error; |
| } |
| |
| /** |
| * nolock_unhold_lvb - release a LVB |
| * @lock: the lock the LVB is associated with |
| * @lvb: the lock value block |
| * |
| */ |
| |
| static void nolock_unhold_lvb(void *lock, char *lvb) |
| { |
| kfree(lvb); |
| } |
| |
| static int nolock_plock_get(void *lockspace, struct lm_lockname *name, |
| struct file *file, struct file_lock *fl) |
| { |
| posix_test_lock(file, fl); |
| |
| return 0; |
| } |
| |
| static int nolock_plock(void *lockspace, struct lm_lockname *name, |
| struct file *file, int cmd, struct file_lock *fl) |
| { |
| int error; |
| error = posix_lock_file_wait(file, fl); |
| return error; |
| } |
| |
| static int nolock_punlock(void *lockspace, struct lm_lockname *name, |
| struct file *file, struct file_lock *fl) |
| { |
| int error; |
| error = posix_lock_file_wait(file, fl); |
| return error; |
| } |
| |
| static void nolock_recovery_done(void *lockspace, unsigned int jid, |
| unsigned int message) |
| { |
| } |
| |
| static const struct lm_lockops nolock_ops = { |
| .lm_proto_name = "lock_nolock", |
| .lm_mount = nolock_mount, |
| .lm_others_may_mount = nolock_others_may_mount, |
| .lm_unmount = nolock_unmount, |
| .lm_withdraw = nolock_withdraw, |
| .lm_get_lock = nolock_get_lock, |
| .lm_put_lock = nolock_put_lock, |
| .lm_lock = nolock_lock, |
| .lm_unlock = nolock_unlock, |
| .lm_cancel = nolock_cancel, |
| .lm_hold_lvb = nolock_hold_lvb, |
| .lm_unhold_lvb = nolock_unhold_lvb, |
| .lm_plock_get = nolock_plock_get, |
| .lm_plock = nolock_plock, |
| .lm_punlock = nolock_punlock, |
| .lm_recovery_done = nolock_recovery_done, |
| .lm_owner = THIS_MODULE, |
| }; |
| |
| static int __init init_nolock(void) |
| { |
| int error; |
| |
| error = gfs2_register_lockproto(&nolock_ops); |
| if (error) { |
| printk(KERN_WARNING |
| "lock_nolock: can't register protocol: %d\n", error); |
| return error; |
| } |
| |
| printk(KERN_INFO |
| "Lock_Nolock (built %s %s) installed\n", __DATE__, __TIME__); |
| return 0; |
| } |
| |
| static void __exit exit_nolock(void) |
| { |
| gfs2_unregister_lockproto(&nolock_ops); |
| } |
| |
| module_init(init_nolock); |
| module_exit(exit_nolock); |
| |
| MODULE_DESCRIPTION("GFS Nolock Locking Module"); |
| MODULE_AUTHOR("Red Hat, Inc."); |
| MODULE_LICENSE("GPL"); |
| |