[PATCH 15/16] GFS2: The "nolock" module The "nolock" locking module provides locking services for single node GFS2 set ups and is also useful for testing. Signed-off-by: Steven Whitehouse Signed-off-by: David Teigland fs/gfs2/locking/nolock/Makefile | 3 fs/gfs2/locking/nolock/main.c | 259 ++++++++++++++++++++++++++++++++++++++++ 2 files changed, 262 insertions(+) --- /dev/null +++ b/fs/gfs2/locking/nolock/main.c @@ -0,0 +1,259 @@ +/* + * 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 v.2. + */ + +#include +#include +#include +#include +#include +#include +#include + +#include "../../lm_interface.h" + +struct nolock_lockspace { + unsigned int nl_lvb_size; +}; + +struct lm_lockops nolock_ops; + +static int nolock_mount(char *table_name, char *host_data, + lm_callback_t cb, lm_fsdata_t *fsdata, + 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 = (lm_lockspace_t *)nl; + lockstruct->ls_ops = &nolock_ops; + lockstruct->ls_flags = LM_LSFLAG_LOCAL; + + return 0; +} + +static void nolock_others_may_mount(lm_lockspace_t *lockspace) +{ +} + +static void nolock_unmount(lm_lockspace_t *lockspace) +{ + struct nolock_lockspace *nl = (struct nolock_lockspace *)lockspace; + kfree(nl); +} + +static void nolock_withdraw(lm_lockspace_t *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(lm_lockspace_t *lockspace, struct lm_lockname *name, + lm_lock_t **lockp) +{ + *lockp = (lm_lock_t *)lockspace; + return 0; +} + +/** + * nolock_put_lock - get rid of a lock structure + * @lock: the lock to throw away + * + */ + +static void nolock_put_lock(lm_lock_t *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(lm_lock_t *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(lm_lock_t *lock, unsigned int cur_state) +{ + return 0; +} + +static void nolock_cancel(lm_lock_t *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(lm_lock_t *lock, char **lvbp) +{ + struct nolock_lockspace *nl = (struct nolock_lockspace *)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(lm_lock_t *lock, char *lvb) +{ + kfree(lvb); +} + +/** + * nolock_sync_lvb - sync out the value of a lvb + * @lock: the lock the LVB is associated with + * @lvb: the lock value block + * + */ + +static void nolock_sync_lvb(lm_lock_t *lock, char *lvb) +{ +} + +static int nolock_plock_get(lm_lockspace_t *lockspace, struct lm_lockname *name, + struct file *file, struct file_lock *fl) +{ + struct file_lock tmp; + int ret; + + ret = posix_test_lock(file, fl, &tmp); + fl->fl_type = F_UNLCK; + if (ret) + memcpy(fl, &tmp, sizeof(struct file_lock)); + + return 0; +} + +static int nolock_plock(lm_lockspace_t *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(lm_lockspace_t *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(lm_lockspace_t *lockspace, unsigned int jid, + unsigned int message) +{ +} + +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_sync_lvb = nolock_sync_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, +}; + +int __init init_nolock(void) +{ + int error; + + error = gfs_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; +} + +void __exit exit_nolock(void) +{ + gfs_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"); + --- /dev/null +++ b/fs/gfs2/locking/nolock/Makefile @@ -0,0 +1,3 @@ +obj-$(CONFIG_GFS2_FS) += lock_nolock.o +lock_nolock-y := main.o + - To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html