[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>

3 files changed, 404 insertions, 0 deletions

diff --git a/fs/gfs2/locking/nolock/Makefile b/fs/gfs2/locking/nolock/Makefile
new file mode 100644
index 000000000000..cdadf956c831
--- /dev/null
+++ b/fs/gfs2/locking/nolock/Makefile
@@ -0,0 +1,3 @@
+obj-$(CONFIG_GFS2_FS) += lock_nolock.o
+lock_nolock-y := main.o
+
diff --git a/fs/gfs2/locking/nolock/lock_nolock.mod.c b/fs/gfs2/locking/nolock/lock_nolock.mod.c
new file mode 100644
index 000000000000..ae92522b2182
--- /dev/null
+++ b/fs/gfs2/locking/nolock/lock_nolock.mod.c
@@ -0,0 +1,44 @@
+#include <linux/module.h>
+#include <linux/vermagic.h>
+#include <linux/compiler.h>
+
+MODULE_INFO(vermagic, VERMAGIC_STRING);
+
+#undef unix
+struct module __this_module
+__attribute__((section(".gnu.linkonce.this_module"))) = {
+ .name = __stringify(KBUILD_MODNAME),
+ .init = init_module,
+#ifdef CONFIG_MODULE_UNLOAD
+ .exit = cleanup_module,
+#endif
+};
+
+static const struct modversion_info ____versions[]
+__attribute_used__
+__attribute__((section("__versions"))) = {
+        { 0x316962fc, "struct_module" },
+        { 0x5a34a45c, "__kmalloc" },
+        { 0x724beef2, "malloc_sizes" },
+        { 0x3fa03a97, "memset" },
+        { 0xc16fe12d, "__memcpy" },
+        { 0xdd132261, "printk" },
+        { 0x859204af, "sscanf" },
+        { 0x3656bf5a, "lock_kernel" },
+        { 0x1e6d26a8, "strstr" },
+        { 0x41ede9df, "lm_register_proto" },
+        { 0xb1f975aa, "unlock_kernel" },
+        { 0x87b0b01f, "posix_lock_file_wait" },
+        { 0x75f29cfd, "kmem_cache_alloc" },
+        { 0x69384280, "lm_unregister_proto" },
+        { 0x37a0cba, "kfree" },
+        { 0x5d16bfe6, "posix_test_lock" },
+};
+
+static const char __module_depends[]
+__attribute_used__
+__attribute__((section(".modinfo"))) =
+"depends=gfs2";
+
+
+MODULE_INFO(srcversion, "123E446F965A386A0C017C4");
diff --git a/fs/gfs2/locking/nolock/main.c b/fs/gfs2/locking/nolock/main.c
new file mode 100644
index 000000000000..d3919e471163
--- /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");
+