[GFS2] The lock modules for GFS2
This patch contains the pluggable locking modules
for GFS2.
Signed-off-by: David Teigland <teigland@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
diff --git a/fs/gfs2/locking/nolock/main.c b/fs/gfs2/locking/nolock/main.c
new file mode 100644
index 0000000..d3919e4
--- /dev/null
+++ b/fs/gfs2/locking/nolock/main.c
@@ -0,0 +1,357 @@
+/******************************************************************************
+*******************************************************************************
+**
+** 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 <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 "../../lm_interface.h"
+
+struct nolock_lockspace {
+ unsigned int nl_lvb_size;
+};
+
+struct lm_lockops nolock_ops;
+
+/**
+ * nolock_mount - mount a nolock lockspace
+ * @table_name: the name of the space to mount
+ * @host_data: host specific data
+ * @cb: the callback
+ * @fsdata:
+ * @min_lvb_size:
+ * @flags:
+ * @lockstruct: the structure of crap to fill in
+ *
+ * Returns: 0 on success, -EXXX on failure
+ */
+
+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)
+{
+ char *c;
+ unsigned int jid;
+ struct nolock_lockspace *nl;
+
+ /* If there is a "jid=" in the hostdata, return that jid.
+ Otherwise, return zero. */
+
+ c = strstr(host_data, "jid=");
+ if (!c)
+ jid = 0;
+ else {
+ c += 4;
+ sscanf(c, "%u", &jid);
+ }
+
+ nl = kmalloc(sizeof(struct nolock_lockspace), GFP_KERNEL);
+ if (!nl)
+ return -ENOMEM;
+
+ memset(nl, 0, sizeof(struct nolock_lockspace));
+ 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;
+}
+
+/**
+ * nolock_others_may_mount - unmount a lock space
+ * @lockspace: the lockspace to unmount
+ *
+ */
+
+static void nolock_others_may_mount(lm_lockspace_t *lockspace)
+{
+}
+
+/**
+ * nolock_unmount - unmount a lock space
+ * @lockspace: the lockspace to unmount
+ *
+ */
+
+static void nolock_unmount(lm_lockspace_t *lockspace)
+{
+ struct nolock_lockspace *nl = (struct nolock_lockspace *)lockspace;
+ kfree(nl);
+}
+
+/**
+ * nolock_withdraw - withdraw from a lock space
+ * @lockspace: the lockspace
+ *
+ */
+
+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;
+}
+
+/**
+ * nolock_cancel - cancel a request on a lock
+ * @lock: the lock to cancel request for
+ *
+ */
+
+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 = kmalloc(nl->nl_lvb_size, GFP_KERNEL);
+ if (*lvbp)
+ memset(*lvbp, 0, nl->nl_lvb_size);
+ else
+ 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)
+{
+}
+
+/**
+ * nolock_plock_get -
+ * @lockspace: the lockspace
+ * @name:
+ * @file:
+ * @fl:
+ *
+ * Returns: errno
+ */
+
+static int nolock_plock_get(lm_lockspace_t *lockspace, struct lm_lockname *name,
+ struct file *file, struct file_lock *fl)
+{
+ struct file_lock *tmp;
+
+ lock_kernel();
+ tmp = posix_test_lock(file, fl);
+ fl->fl_type = F_UNLCK;
+ if (tmp)
+ memcpy(fl, tmp, sizeof(struct file_lock));
+ unlock_kernel();
+
+ return 0;
+}
+
+/**
+ * nolock_plock -
+ * @lockspace: the lockspace
+ * @name:
+ * @file:
+ * @cmd:
+ * @fl:
+ *
+ * Returns: errno
+ */
+
+static int nolock_plock(lm_lockspace_t *lockspace, struct lm_lockname *name,
+ struct file *file, int cmd, struct file_lock *fl)
+{
+ int error;
+ lock_kernel();
+ error = posix_lock_file_wait(file, fl);
+ unlock_kernel();
+ return error;
+}
+
+/**
+ * nolock_punlock -
+ * @lockspace: the lockspace
+ * @name:
+ * @file:
+ * @fl:
+ *
+ * Returns: errno
+ */
+
+static int nolock_punlock(lm_lockspace_t *lockspace, struct lm_lockname *name,
+ struct file *file, struct file_lock *fl)
+{
+ int error;
+ lock_kernel();
+ error = posix_lock_file_wait(file, fl);
+ unlock_kernel();
+ return error;
+}
+
+/**
+ * nolock_recovery_done - reset the expired locks for a given jid
+ * @lockspace: the lockspace
+ * @jid: the jid
+ *
+ */
+
+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,
+};
+
+/**
+ * init_nolock - Initialize the nolock module
+ *
+ * Returns: 0 on success, -EXXX on failure
+ */
+
+int __init init_nolock(void)
+{
+ int error;
+
+ error = lm_register_proto(&nolock_ops);
+ if (error) {
+ printk("lock_nolock: can't register protocol: %d\n", error);
+ return error;
+ }
+
+ printk("Lock_Nolock (built %s %s) installed\n", __DATE__, __TIME__);
+ return 0;
+}
+
+/**
+ * exit_nolock - cleanup the nolock module
+ *
+ */
+
+void __exit exit_nolock(void)
+{
+ lm_unregister_proto(&nolock_ops);
+}
+
+module_init(init_nolock);
+module_exit(exit_nolock);
+
+MODULE_DESCRIPTION("GFS Nolock Locking Module");
+MODULE_AUTHOR("Red Hat, Inc.");
+MODULE_LICENSE("GPL");
+