1 files changed, 246 insertions, 0 deletions

diff --git a/fs/gfs2/locking/nolock/main.c b/fs/gfs2/locking/nolock/main.c
new file mode 100644
index 000000000000..acfbc941f319
--- /dev/null
+++ b/fs/gfs2/locking/nolock/main.c
@@ -0,0 +1,246 @@
+/*
+ * 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)
+{
+        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(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");
+