From: David Teigland <teigland@redhat.com>
Date: Thu, 5 Jun 2008 14:11:00 -0500
Subject: [dlm] move plock code from gfs2
Message-id: 20080605191100.GR18635@redhat.com
O-Subject: [RHEL5.3 PATCH 18/18] dlm: move plock code from gfs2
Bugzilla: 450138
RH-Acked-by: Bob Peterson <rpeterso@redhat.com>

bz 450138  dlm: move plock code from gfs2

Move the plock code from the lock_dlm module into the dlm so that it
can be used by both gfs1 and gfs2.  This is done because lock_dlm
is being duplicated for gfs1 and gfs2, but we still need to share the
plock code between them, i.e. maintain one instance of the plock code
instead of two.

This same shift was done upstream so that the plock code could be shared
with ocfs2.  The plock code is self-contained; its function does not
change when shifting the code into the different module.

brew build including this patch
http://brewweb.devel.redhat.com/brew/taskinfo?taskID=1344633

upstream commits:

>From 2402211a8389282fd2942fad4511f02c0eeeffc5 Mon Sep 17 00:00:00 2001
>From: David Teigland <teigland@redhat.com>
>Date: Fri, 14 Mar 2008 15:09:15 -0500
>Subject: [PATCH] dlm: move plock code from gfs2

Move the code that handles cluster posix locks from gfs2 into the dlm
so that it can be used by both gfs2 and ocfs2.

Signed-off-by: David Teigland <teigland@redhat.com>

>From 817d10bad56f2fdfa321b4a864a21295226b123a Mon Sep 17 00:00:00 2001
>From: David Teigland <teigland@redhat.com>
>Date: Tue, 13 May 2008 14:28:26 -0500
>Subject: [PATCH] dlm: fix plock dev_write return value

The return value on writes to the plock device should be
the number of bytes written.  It was returning 0 instead
when an nfs lock callback was involved.

Reported-by: Nathan Straz <nstraz@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>

diff --git a/fs/dlm/Makefile b/fs/dlm/Makefile
index c8b4207..fa82f48 100644
--- a/fs/dlm/Makefile
+++ b/fs/dlm/Makefile
@@ -10,6 +10,7 @@ dlm-y :=			ast.o \
 				midcomms.o \
 				netlink.o \
 				lowcomms.o \
+				plock.o \
 				rcom.o \
 				recover.o \
 				recoverd.o \
diff --git a/fs/dlm/dlm_internal.h b/fs/dlm/dlm_internal.h
index d2fc238..300583a 100644
--- a/fs/dlm/dlm_internal.h
+++ b/fs/dlm/dlm_internal.h
@@ -570,5 +570,8 @@ static inline int dlm_no_directory(struct dlm_ls *ls)
 	return (ls->ls_exflags & DLM_LSFL_NODIR) ? 1 : 0;
 }
 
+int dlm_plock_init(void);
+void dlm_plock_exit(void);
+
 #endif				/* __DLM_INTERNAL_DOT_H__ */
 
diff --git a/fs/dlm/main.c b/fs/dlm/main.c
index eca2907..b3fcf7f 100644
--- a/fs/dlm/main.c
+++ b/fs/dlm/main.c
@@ -56,10 +56,16 @@ static int __init init_dlm(void)
 	if (error)
 		goto out_user;
 
+	error = dlm_plock_init();
+	if (error)
+		goto out_netlink;
+
 	printk("DLM (built %s %s) installed\n", __DATE__, __TIME__);
 
 	return 0;
 
+ out_netlink:
+	dlm_netlink_exit();
  out_user:
 	dlm_user_exit();
  out_debug:
@@ -76,6 +82,7 @@ static int __init init_dlm(void)
 
 static void __exit exit_dlm(void)
 {
+	dlm_plock_exit();
 	dlm_netlink_exit();
 	dlm_user_exit();
 	dlm_config_exit();
diff --git a/fs/dlm/plock.c b/fs/dlm/plock.c
new file mode 100644
index 0000000..204f254
--- /dev/null
+++ b/fs/dlm/plock.c
@@ -0,0 +1,441 @@
+/*
+ * Copyright (C) 2005-2008 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/fs.h>
+#include <linux/miscdevice.h>
+#include <linux/poll.h>
+#include <linux/dlm.h>
+#include <linux/dlm_plock.h>
+
+#include "dlm_internal.h"
+#include "lockspace.h"
+
+static spinlock_t ops_lock;
+static struct list_head send_list;
+static struct list_head recv_list;
+static wait_queue_head_t send_wq;
+static wait_queue_head_t recv_wq;
+
+struct plock_op {
+	struct list_head list;
+	int done;
+	struct dlm_plock_info info;
+};
+
+struct plock_xop {
+	struct plock_op xop;
+	void *callback;
+	void *fl;
+	void *file;
+	struct file_lock flc;
+};
+
+
+static inline void set_version(struct dlm_plock_info *info)
+{
+	info->version[0] = DLM_PLOCK_VERSION_MAJOR;
+	info->version[1] = DLM_PLOCK_VERSION_MINOR;
+	info->version[2] = DLM_PLOCK_VERSION_PATCH;
+}
+
+static int check_version(struct dlm_plock_info *info)
+{
+	if ((DLM_PLOCK_VERSION_MAJOR != info->version[0]) ||
+	    (DLM_PLOCK_VERSION_MINOR < info->version[1])) {
+		log_print("plock device version mismatch: "
+			  "kernel (%u.%u.%u), user (%u.%u.%u)",
+			  DLM_PLOCK_VERSION_MAJOR,
+			  DLM_PLOCK_VERSION_MINOR,
+			  DLM_PLOCK_VERSION_PATCH,
+			  info->version[0],
+			  info->version[1],
+			  info->version[2]);
+		return -EINVAL;
+	}
+	return 0;
+}
+
+static void send_op(struct plock_op *op)
+{
+	set_version(&op->info);
+	INIT_LIST_HEAD(&op->list);
+	spin_lock(&ops_lock);
+	list_add_tail(&op->list, &send_list);
+	spin_unlock(&ops_lock);
+	wake_up(&send_wq);
+}
+
+int dlm_posix_lock(dlm_lockspace_t *lockspace, u64 number, struct file *file,
+		   int cmd, struct file_lock *fl)
+{
+	struct dlm_ls *ls;
+	struct plock_op *op;
+	struct plock_xop *xop;
+	int rv;
+
+	ls = dlm_find_lockspace_local(lockspace);
+	if (!ls)
+		return -EINVAL;
+
+	xop = kzalloc(sizeof(*xop), GFP_KERNEL);
+	if (!xop) {
+		rv = -ENOMEM;
+		goto out;
+	}
+
+	op = &xop->xop;
+	op->info.optype		= DLM_PLOCK_OP_LOCK;
+	op->info.pid		= fl->fl_pid;
+	op->info.ex		= (fl->fl_type == F_WRLCK);
+	op->info.wait		= IS_SETLKW(cmd);
+	op->info.fsid		= ls->ls_global_id;
+	op->info.number		= number;
+	op->info.start		= fl->fl_start;
+	op->info.end		= fl->fl_end;
+	if ((fl->fl_flags & FL_GRANT) &&
+		fl->fl_lmops && fl->fl_lmops->fl_grant) {
+		/* fl_owner is lockd which doesn't distinguish
+		   processes on the nfs client */
+		op->info.owner	= (__u64) fl->fl_pid;
+		xop->callback	= fl->fl_lmops->fl_grant;
+		locks_init_lock(&xop->flc);
+		locks_copy_lock(&xop->flc, fl);
+		xop->fl		= fl;
+		xop->file	= file;
+	} else {
+		op->info.owner	= (__u64)(long) fl->fl_owner;
+		xop->callback	= NULL;
+	}
+
+	send_op(op);
+
+	if (xop->callback == NULL)
+		wait_event(recv_wq, (op->done != 0));
+	else {
+		rv = -EINPROGRESS;
+		goto out;
+	}
+
+	spin_lock(&ops_lock);
+	if (!list_empty(&op->list)) {
+		log_error(ls, "dlm_posix_lock: op on list %llx",
+			  (unsigned long long)number);
+		list_del(&op->list);
+	}
+	spin_unlock(&ops_lock);
+
+	rv = op->info.rv;
+
+	if (!rv) {
+		if (posix_lock_file_wait(file, fl) < 0)
+			log_error(ls, "dlm_posix_lock: vfs lock error %llx",
+				  (unsigned long long)number);
+	}
+
+	kfree(xop);
+out:
+	dlm_put_lockspace(ls);
+	return rv;
+}
+EXPORT_SYMBOL_GPL(dlm_posix_lock);
+
+/* Returns failure iff a succesful lock operation should be canceled */
+static int dlm_plock_callback(struct plock_op *op)
+{
+	struct file *file;
+	struct file_lock *fl;
+	struct file_lock *flc;
+	int (*notify)(void *, void *, int) = NULL;
+	struct plock_xop *xop = (struct plock_xop *)op;
+	int rv = 0;
+
+	spin_lock(&ops_lock);
+	if (!list_empty(&op->list)) {
+		log_print("dlm_plock_callback: op on list %llx",
+			  (unsigned long long)op->info.number);
+		list_del(&op->list);
+	}
+	spin_unlock(&ops_lock);
+
+	/* check if the following 2 are still valid or make a copy */
+	file = xop->file;
+	flc = &xop->flc;
+	fl = xop->fl;
+	notify = xop->callback;
+
+	if (op->info.rv) {
+		notify(flc, NULL, op->info.rv);
+		goto out;
+	}
+
+	/* got fs lock; bookkeep locally as well: */
+	flc->fl_flags &= ~FL_SLEEP;
+	if (posix_lock_file(file, flc)) {
+		/*
+		 * This can only happen in the case of kmalloc() failure.
+		 * The filesystem's own lock is the authoritative lock,
+		 * so a failure to get the lock locally is not a disaster.
+		 * As long as the fs cannot reliably cancel locks (especially
+		 * in a low-memory situation), we're better off ignoring
+		 * this failure than trying to recover.
+		 */
+		log_print("dlm_plock_callback: vfs lock error %llx file %p fl %p",
+			  (unsigned long long)op->info.number, file, fl);
+	}
+
+	rv = notify(flc, NULL, 0);
+	if (rv) {
+		/* XXX: We need to cancel the fs lock here: */
+		log_print("dlm_plock_callback: lock granted after lock request "
+			  "failed; dangling lock!\n");
+		goto out;
+	}
+
+out:
+	kfree(xop);
+	return rv;
+}
+
+int dlm_posix_unlock(dlm_lockspace_t *lockspace, u64 number, struct file *file,
+		     struct file_lock *fl)
+{
+	struct dlm_ls *ls;
+	struct plock_op *op;
+	int rv;
+
+	ls = dlm_find_lockspace_local(lockspace);
+	if (!ls)
+		return -EINVAL;
+
+	op = kzalloc(sizeof(*op), GFP_KERNEL);
+	if (!op) {
+		rv = -ENOMEM;
+		goto out;
+	}
+
+	if (posix_lock_file_wait(file, fl) < 0)
+		log_error(ls, "dlm_posix_unlock: vfs unlock error %llx",
+			  (unsigned long long)number);
+
+	op->info.optype		= DLM_PLOCK_OP_UNLOCK;
+	op->info.pid		= fl->fl_pid;
+	op->info.fsid		= ls->ls_global_id;
+	op->info.number		= number;
+	op->info.start		= fl->fl_start;
+	op->info.end		= fl->fl_end;
+	if ((fl->fl_flags & FL_GRANT) &&
+		fl->fl_lmops && fl->fl_lmops->fl_grant)
+		op->info.owner	= (__u64) fl->fl_pid;
+	else
+		op->info.owner	= (__u64)(long) fl->fl_owner;
+
+	send_op(op);
+	wait_event(recv_wq, (op->done != 0));
+
+	spin_lock(&ops_lock);
+	if (!list_empty(&op->list)) {
+		log_error(ls, "dlm_posix_unlock: op on list %llx",
+			  (unsigned long long)number);
+		list_del(&op->list);
+	}
+	spin_unlock(&ops_lock);
+
+	rv = op->info.rv;
+
+	if (rv == -ENOENT)
+		rv = 0;
+
+	kfree(op);
+out:
+	dlm_put_lockspace(ls);
+	return rv;
+}
+EXPORT_SYMBOL_GPL(dlm_posix_unlock);
+
+int dlm_posix_get(dlm_lockspace_t *lockspace, u64 number, struct file *file,
+		  struct file_lock *fl)
+{
+	struct dlm_ls *ls;
+	struct plock_op *op;
+	int rv;
+
+	ls = dlm_find_lockspace_local(lockspace);
+	if (!ls)
+		return -EINVAL;
+
+	op = kzalloc(sizeof(*op), GFP_KERNEL);
+	if (!op) {
+		rv = -ENOMEM;
+		goto out;
+	}
+
+	op->info.optype		= DLM_PLOCK_OP_GET;
+	op->info.pid		= fl->fl_pid;
+	op->info.ex		= (fl->fl_type == F_WRLCK);
+	op->info.fsid		= ls->ls_global_id;
+	op->info.number		= number;
+	op->info.start		= fl->fl_start;
+	op->info.end		= fl->fl_end;
+	if ((fl->fl_flags & FL_GRANT) &&
+		fl->fl_lmops && fl->fl_lmops->fl_grant)
+		op->info.owner	= (__u64) fl->fl_pid;
+	else
+		op->info.owner	= (__u64)(long) fl->fl_owner;
+
+	send_op(op);
+	wait_event(recv_wq, (op->done != 0));
+
+	spin_lock(&ops_lock);
+	if (!list_empty(&op->list)) {
+		log_error(ls, "dlm_posix_get: op on list %llx",
+			  (unsigned long long)number);
+		list_del(&op->list);
+	}
+	spin_unlock(&ops_lock);
+
+	/* info.rv from userspace is 1 for conflict, 0 for no-conflict,
+	   -ENOENT if there are no locks on the file */
+
+	rv = op->info.rv;
+
+	fl->fl_type = F_UNLCK;
+	if (rv == -ENOENT)
+		rv = 0;
+	else if (rv > 0) {
+		fl->fl_type = (op->info.ex) ? F_WRLCK : F_RDLCK;
+		fl->fl_pid = op->info.pid;
+		fl->fl_start = op->info.start;
+		fl->fl_end = op->info.end;
+		rv = 0;
+	}
+
+	kfree(op);
+out:
+	dlm_put_lockspace(ls);
+	return rv;
+}
+EXPORT_SYMBOL_GPL(dlm_posix_get);
+
+/* a read copies out one plock request from the send list */
+static ssize_t dev_read(struct file *file, char __user *u, size_t count,
+			loff_t *ppos)
+{
+	struct dlm_plock_info info;
+	struct plock_op *op = NULL;
+
+	if (count < sizeof(info))
+		return -EINVAL;
+
+	spin_lock(&ops_lock);
+	if (!list_empty(&send_list)) {
+		op = list_entry(send_list.next, struct plock_op, list);
+		list_move(&op->list, &recv_list);
+		memcpy(&info, &op->info, sizeof(info));
+	}
+	spin_unlock(&ops_lock);
+
+	if (!op)
+		return -EAGAIN;
+
+	if (copy_to_user(u, &info, sizeof(info)))
+		return -EFAULT;
+	return sizeof(info);
+}
+
+/* a write copies in one plock result that should match a plock_op
+   on the recv list */
+static ssize_t dev_write(struct file *file, const char __user *u, size_t count,
+			 loff_t *ppos)
+{
+	struct dlm_plock_info info;
+	struct plock_op *op;
+	int found = 0;
+
+	if (count != sizeof(info))
+		return -EINVAL;
+
+	if (copy_from_user(&info, u, sizeof(info)))
+		return -EFAULT;
+
+	if (check_version(&info))
+		return -EINVAL;
+
+	spin_lock(&ops_lock);
+	list_for_each_entry(op, &recv_list, list) {
+		if (op->info.fsid == info.fsid && op->info.number == info.number &&
+		    op->info.owner == info.owner) {
+			list_del_init(&op->list);
+			found = 1;
+			op->done = 1;
+			memcpy(&op->info, &info, sizeof(info));
+			break;
+		}
+	}
+	spin_unlock(&ops_lock);
+
+	if (found) {
+		struct plock_xop *xop;
+		xop = (struct plock_xop *)op;
+		if (xop->callback)
+			dlm_plock_callback(op);
+		else
+			wake_up(&recv_wq);
+	} else
+		log_print("dev_write no op %x %llx", info.fsid,
+			  (unsigned long long)info.number);
+	return count;
+}
+
+static unsigned int dev_poll(struct file *file, poll_table *wait)
+{
+	poll_wait(file, &send_wq, wait);
+
+	spin_lock(&ops_lock);
+	if (!list_empty(&send_list)) {
+		spin_unlock(&ops_lock);
+		return POLLIN | POLLRDNORM;
+	}
+	spin_unlock(&ops_lock);
+	return 0;
+}
+
+static struct file_operations dev_fops = {
+	.read    = dev_read,
+	.write   = dev_write,
+	.poll    = dev_poll,
+	.owner   = THIS_MODULE
+};
+
+static struct miscdevice plock_dev_misc = {
+	.minor = MISC_DYNAMIC_MINOR,
+	.name = DLM_PLOCK_MISC_NAME,
+	.fops = &dev_fops
+};
+
+int dlm_plock_init(void)
+{
+	int rv;
+
+	spin_lock_init(&ops_lock);
+	INIT_LIST_HEAD(&send_list);
+	INIT_LIST_HEAD(&recv_list);
+	init_waitqueue_head(&send_wq);
+	init_waitqueue_head(&recv_wq);
+
+	rv = misc_register(&plock_dev_misc);
+	if (rv)
+		log_print("dlm_plock_init: misc_register failed %d", rv);
+	return rv;
+}
+
+void dlm_plock_exit(void)
+{
+	if (misc_deregister(&plock_dev_misc) < 0)
+		log_print("dlm_plock_exit: misc_deregister failed");
+}
+
diff --git a/fs/gfs2/locking/dlm/Makefile b/fs/gfs2/locking/dlm/Makefile
index 89b93b6..2609bb6 100644
--- a/fs/gfs2/locking/dlm/Makefile
+++ b/fs/gfs2/locking/dlm/Makefile
@@ -1,3 +1,3 @@
 obj-$(CONFIG_GFS2_FS_LOCKING_DLM) += lock_dlm.o
-lock_dlm-y := lock.o main.o mount.o sysfs.o thread.o plock.o
+lock_dlm-y := lock.o main.o mount.o sysfs.o thread.o
 
diff --git a/fs/gfs2/locking/dlm/lock_dlm.h b/fs/gfs2/locking/dlm/lock_dlm.h
index 24d70f7..e6e8ca2 100644
--- a/fs/gfs2/locking/dlm/lock_dlm.h
+++ b/fs/gfs2/locking/dlm/lock_dlm.h
@@ -26,6 +26,7 @@
 #include <net/sock.h>
 
 #include <linux/dlm.h>
+#include <linux/dlm_plock.h>
 #include <linux/lm_interface.h>
 
 /*
@@ -174,15 +175,5 @@ void gdlm_cancel(void *);
 int gdlm_hold_lvb(void *, char **);
 void gdlm_unhold_lvb(void *, char *);
 
-/* plock.c */
-
-int gdlm_plock_init(void);
-void gdlm_plock_exit(void);
-int gdlm_plock(void *, struct lm_lockname *, struct file *, int,
-		struct file_lock *);
-int gdlm_plock_get(void *, struct lm_lockname *, struct file *,
-		struct file_lock *);
-int gdlm_punlock(void *, struct lm_lockname *, struct file *,
-		struct file_lock *);
 #endif
 
diff --git a/fs/gfs2/locking/dlm/main.c b/fs/gfs2/locking/dlm/main.c
index a0e7eda..867763c 100644
--- a/fs/gfs2/locking/dlm/main.c
+++ b/fs/gfs2/locking/dlm/main.c
@@ -30,13 +30,6 @@ static int __init init_lock_dlm(void)
 		return error;
 	}
 
-	error = gdlm_plock_init();
-	if (error) {
-		gdlm_sysfs_exit();
-		gfs2_unregister_lockproto(&gdlm_ops);
-		return error;
-	}
-
 	printk(KERN_INFO
 	       "Lock_DLM (built %s %s) installed\n", __DATE__, __TIME__);
 	return 0;
@@ -44,7 +37,6 @@ static int __init init_lock_dlm(void)
 
 static void __exit exit_lock_dlm(void)
 {
-	gdlm_plock_exit();
 	gdlm_sysfs_exit();
 	gfs2_unregister_lockproto(&gdlm_ops);
 }
diff --git a/fs/gfs2/locking/dlm/mount.c b/fs/gfs2/locking/dlm/mount.c
index 41c5b04..d428b47 100644
--- a/fs/gfs2/locking/dlm/mount.c
+++ b/fs/gfs2/locking/dlm/mount.c
@@ -231,6 +231,27 @@ static void gdlm_withdraw(void *lockspace)
 	gdlm_kobject_release(ls);
 }
 
+static int gdlm_plock(void *lockspace, struct lm_lockname *name,
+		struct file *file, int cmd, struct file_lock *fl)
+{
+	struct gdlm_ls *ls = lockspace;
+	return dlm_posix_lock(ls->dlm_lockspace, name->ln_number, file, cmd, fl);
+}
+
+static int gdlm_punlock(void *lockspace, struct lm_lockname *name,
+		struct file *file, struct file_lock *fl)
+{
+	struct gdlm_ls *ls = lockspace;
+	return dlm_posix_unlock(ls->dlm_lockspace, name->ln_number, file, fl);
+}
+
+static int gdlm_plock_get(void *lockspace, struct lm_lockname *name,
+		struct file *file, struct file_lock *fl)
+{
+	struct gdlm_ls *ls = lockspace;
+	return dlm_posix_get(ls->dlm_lockspace, name->ln_number, file, fl);
+}
+
 const struct lm_lockops gdlm_ops = {
 	.lm_proto_name = "lock_dlm",
 	.lm_mount = gdlm_mount,
diff --git a/fs/gfs2/locking/dlm/plock.c b/fs/gfs2/locking/dlm/plock.c
deleted file mode 100644
index 7634bc9..0000000
--- a/fs/gfs2/locking/dlm/plock.c
+++ /dev/null
@@ -1,408 +0,0 @@
-/*
- * Copyright (C) 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/miscdevice.h>
-#include <linux/lock_dlm_plock.h>
-
-#include "lock_dlm.h"
-
-
-static spinlock_t ops_lock;
-static struct list_head send_list;
-static struct list_head recv_list;
-static wait_queue_head_t send_wq;
-static wait_queue_head_t recv_wq;
-
-struct plock_op {
-	struct list_head list;
-	int done;
-	struct gdlm_plock_info info;
-};
-
-struct plock_xop {
-	struct plock_op xop;
-	void *callback;
-	void *fl;
-	void *file;
-	struct file_lock flc;
-};
-
-
-static inline void set_version(struct gdlm_plock_info *info)
-{
-	info->version[0] = GDLM_PLOCK_VERSION_MAJOR;
-	info->version[1] = GDLM_PLOCK_VERSION_MINOR;
-	info->version[2] = GDLM_PLOCK_VERSION_PATCH;
-}
-
-static int check_version(struct gdlm_plock_info *info)
-{
-	if ((GDLM_PLOCK_VERSION_MAJOR != info->version[0]) ||
-	    (GDLM_PLOCK_VERSION_MINOR < info->version[1])) {
-		log_error("plock device version mismatch: "
-			  "kernel (%u.%u.%u), user (%u.%u.%u)",
-			  GDLM_PLOCK_VERSION_MAJOR,
-			  GDLM_PLOCK_VERSION_MINOR,
-			  GDLM_PLOCK_VERSION_PATCH,
-			  info->version[0],
-			  info->version[1],
-			  info->version[2]);
-		return -EINVAL;
-	}
-	return 0;
-}
-
-static void send_op(struct plock_op *op)
-{
-	set_version(&op->info);
-	INIT_LIST_HEAD(&op->list);
-	spin_lock(&ops_lock);
-	list_add_tail(&op->list, &send_list);
-	spin_unlock(&ops_lock);
-	wake_up(&send_wq);
-}
-
-int gdlm_plock(void *lockspace, struct lm_lockname *name,
-	       struct file *file, int cmd, struct file_lock *fl)
-{
-	struct gdlm_ls *ls = lockspace;
-	struct plock_op *op;
-	struct plock_xop *xop;
-	int rv;
-
-	xop = kzalloc(sizeof(*xop), GFP_KERNEL);
-	if (!xop)
-		return -ENOMEM;
-
-	op = &xop->xop;
-	op->info.optype		= GDLM_PLOCK_OP_LOCK;
-	op->info.pid		= fl->fl_pid;
-	op->info.ex		= (fl->fl_type == F_WRLCK);
-	op->info.wait		= IS_SETLKW(cmd);
-	op->info.fsid		= ls->id;
-	op->info.number		= name->ln_number;
-	op->info.start		= fl->fl_start;
-	op->info.end		= fl->fl_end;
-	if ((fl->fl_flags & FL_GRANT) &&
-		fl->fl_lmops && fl->fl_lmops->fl_grant) {
-		/* fl_owner is lockd which doesn't distinguish
-		processes on the nfs client */
-		op->info.owner  = (__u64) fl->fl_pid;
-		xop->callback	= fl->fl_lmops->fl_grant;
-		locks_init_lock(&xop->flc);
-		locks_copy_lock(&xop->flc, fl);
-		xop->fl		= fl;
-		xop->file	= file;
-	} else {
-		xop->callback	= NULL;
-		op->info.owner  = (__u64)(long) fl->fl_owner;
-	}
-
-	send_op(op);
-
-	if (xop->callback == NULL)
-		wait_event(recv_wq, (op->done != 0));
-	else
-		return -EINPROGRESS;
-
-	spin_lock(&ops_lock);
-	if (!list_empty(&op->list)) {
-		printk(KERN_INFO "plock op on list\n");
-		list_del(&op->list);
-	}
-	spin_unlock(&ops_lock);
-
-	rv = op->info.rv;
-
-	if (!rv) {
-		if (posix_lock_file_wait(file, fl) < 0)
-			log_error("gdlm_plock: vfs lock error %x,%llx",
-				  name->ln_type,
-				  (unsigned long long)name->ln_number);
-	}
-
-	kfree(xop);
-	return rv;
-}
-
-/* Returns failure iff a succesful lock operation should be canceled */
-static int gdlm_plock_callback(struct plock_op *op)
-{
-	struct file *file;
-	struct file_lock *fl;
-	struct file_lock *flc;
-	int (*notify)(void *, void *, int) = NULL;
-	struct plock_xop *xop = (struct plock_xop *)op;
-	int rv = 0;
-
-	spin_lock(&ops_lock);
-	if (!list_empty(&op->list)) {
-		printk(KERN_INFO "plock op on list\n");
-		list_del(&op->list);
-	}
-	spin_unlock(&ops_lock);
-
-	/* check if the following 2 are still valid or make a copy */
-	file = xop->file;
-	flc = &xop->flc;
-	fl = xop->fl;
-	notify = xop->callback;
-
-	if (op->info.rv) {
-		notify(flc, NULL, op->info.rv);
-		goto out;
-	}
-
-	/* got fs lock; bookkeep locally as well: */
-	flc->fl_flags &= ~FL_SLEEP;
-	if (posix_lock_file(file, flc)) {
-		/*
-		 * This can only happen in the case of kmalloc() failure.
-		 * The filesystem's own lock is the authoritative lock,
-		 * so a failure to get the lock locally is not a disaster.
-		 * As long as GFS cannot reliably cancel locks (especially
-		 * in a low-memory situation), we're better off ignoring
-		 * this failure than trying to recover.
-		 */
-		log_error("gdlm_plock: vfs lock error file %p fl %p",
-				file, fl);
-	}
-
-	rv = notify(flc, NULL, 0);
-	if (rv) {
-		/* XXX: We need to cancel the fs lock here: */
-		printk(KERN_ERR "gfs2 lock granted after lock request failed;"
-						" dangling lock!\n");
-		goto out;
-	}
-
-out:
-	kfree(xop);
-	return rv;
-}
-
-int gdlm_punlock(void *lockspace, struct lm_lockname *name,
-		 struct file *file, struct file_lock *fl)
-{
-	struct gdlm_ls *ls = lockspace;
-	struct plock_op *op;
-	int rv;
-
-	op = kzalloc(sizeof(*op), GFP_KERNEL);
-	if (!op)
-		return -ENOMEM;
-
-	if (posix_lock_file_wait(file, fl) < 0)
-		log_error("gdlm_punlock: vfs unlock error %x,%llx",
-			  name->ln_type, (unsigned long long)name->ln_number);
-
-	op->info.optype		= GDLM_PLOCK_OP_UNLOCK;
-	op->info.pid		= fl->fl_pid;
-	op->info.fsid		= ls->id;
-	op->info.number		= name->ln_number;
-	op->info.start		= fl->fl_start;
-	op->info.end		= fl->fl_end;
-	if ((fl->fl_flags & FL_GRANT) &&
-		fl->fl_lmops && fl->fl_lmops->fl_grant)
-		op->info.owner  = (__u64) fl->fl_pid;
-	else
-		op->info.owner	= (__u64)(long) fl->fl_owner;
-
-	send_op(op);
-	wait_event(recv_wq, (op->done != 0));
-
-	spin_lock(&ops_lock);
-	if (!list_empty(&op->list)) {
-		printk(KERN_INFO "punlock op on list\n");
-		list_del(&op->list);
-	}
-	spin_unlock(&ops_lock);
-
-	rv = op->info.rv;
-
-	if (rv == -ENOENT)
-		rv = 0;
-
-	kfree(op);
-	return rv;
-}
-
-int gdlm_plock_get(void *lockspace, struct lm_lockname *name,
-		   struct file *file, struct file_lock *fl)
-{
-	struct gdlm_ls *ls = lockspace;
-	struct plock_op *op;
-	int rv;
-
-	op = kzalloc(sizeof(*op), GFP_KERNEL);
-	if (!op)
-		return -ENOMEM;
-
-	op->info.optype		= GDLM_PLOCK_OP_GET;
-	op->info.pid		= fl->fl_pid;
-	op->info.ex		= (fl->fl_type == F_WRLCK);
-	op->info.fsid		= ls->id;
-	op->info.number		= name->ln_number;
-	op->info.start		= fl->fl_start;
-	op->info.end		= fl->fl_end;
-	if ((fl->fl_flags & FL_GRANT) &&
-		fl->fl_lmops && fl->fl_lmops->fl_grant)
-		op->info.owner  = (__u64) fl->fl_pid;
-	else
-		op->info.owner	= (__u64)(long) fl->fl_owner;
-
-
-	send_op(op);
-	wait_event(recv_wq, (op->done != 0));
-
-	spin_lock(&ops_lock);
-	if (!list_empty(&op->list)) {
-		printk(KERN_INFO "plock_get op on list\n");
-		list_del(&op->list);
-	}
-	spin_unlock(&ops_lock);
-
-	/* info.rv from userspace is 1 for conflict, 0 for no-conflict,
-	   -ENOENT if there are no locks on the file */
-
-	rv = op->info.rv;
-
-	fl->fl_type = F_UNLCK;
-	if (rv == -ENOENT)
-		rv = 0;
-	else if (rv > 0) {
-		fl->fl_type = (op->info.ex) ? F_WRLCK : F_RDLCK;
-		fl->fl_pid = op->info.pid;
-		fl->fl_start = op->info.start;
-		fl->fl_end = op->info.end;
-		rv = 0;
-	}
-
-	kfree(op);
-	return rv;
-}
-
-/* a read copies out one plock request from the send list */
-static ssize_t dev_read(struct file *file, char __user *u, size_t count,
-			loff_t *ppos)
-{
-	struct gdlm_plock_info info;
-	struct plock_op *op = NULL;
-
-	if (count < sizeof(info))
-		return -EINVAL;
-
-	spin_lock(&ops_lock);
-	if (!list_empty(&send_list)) {
-		op = list_entry(send_list.next, struct plock_op, list);
-		list_move(&op->list, &recv_list);
-		memcpy(&info, &op->info, sizeof(info));
-	}
-	spin_unlock(&ops_lock);
-
-	if (!op)
-		return -EAGAIN;
-
-	if (copy_to_user(u, &info, sizeof(info)))
-		return -EFAULT;
-	return sizeof(info);
-}
-
-/* a write copies in one plock result that should match a plock_op
-   on the recv list */
-static ssize_t dev_write(struct file *file, const char __user *u, size_t count,
-			 loff_t *ppos)
-{
-	struct gdlm_plock_info info;
-	struct plock_op *op;
-	int found = 0;
-
-	if (count != sizeof(info))
-		return -EINVAL;
-
-	if (copy_from_user(&info, u, sizeof(info)))
-		return -EFAULT;
-
-	if (check_version(&info))
-		return -EINVAL;
-
-	spin_lock(&ops_lock);
-	list_for_each_entry(op, &recv_list, list) {
-		if (op->info.fsid == info.fsid && op->info.number == info.number &&
-		    op->info.owner == info.owner) {
-			list_del_init(&op->list);
-			found = 1;
-			op->done = 1;
-			memcpy(&op->info, &info, sizeof(info));
-			break;
-		}
-	}
-	spin_unlock(&ops_lock);
-
-	if (found) {
-		struct plock_xop *xop;
-		xop = (struct plock_xop *)op;
-		if (xop->callback)
-			count = gdlm_plock_callback(op);
-		else
-			wake_up(&recv_wq);
-	} else
-		printk(KERN_INFO "gdlm dev_write no op %x %llx\n", info.fsid,
-			(unsigned long long)info.number);
-	return count;
-}
-
-static unsigned int dev_poll(struct file *file, poll_table *wait)
-{
-	poll_wait(file, &send_wq, wait);
-
-	spin_lock(&ops_lock);
-	if (!list_empty(&send_list)) {
-		spin_unlock(&ops_lock);
-		return POLLIN | POLLRDNORM;
-	}
-	spin_unlock(&ops_lock);
-	return 0;
-}
-
-static struct file_operations dev_fops = {
-	.read    = dev_read,
-	.write   = dev_write,
-	.poll    = dev_poll,
-	.owner   = THIS_MODULE
-};
-
-static struct miscdevice plock_dev_misc = {
-	.minor = MISC_DYNAMIC_MINOR,
-	.name = GDLM_PLOCK_MISC_NAME,
-	.fops = &dev_fops
-};
-
-int gdlm_plock_init(void)
-{
-	int rv;
-
-	spin_lock_init(&ops_lock);
-	INIT_LIST_HEAD(&send_list);
-	INIT_LIST_HEAD(&recv_list);
-	init_waitqueue_head(&send_wq);
-	init_waitqueue_head(&recv_wq);
-
-	rv = misc_register(&plock_dev_misc);
-	if (rv)
-		printk(KERN_INFO "gdlm_plock_init: misc_register failed %d",
-		       rv);
-	return rv;
-}
-
-void gdlm_plock_exit(void)
-{
-	if (misc_deregister(&plock_dev_misc) < 0)
-		printk(KERN_INFO "gdlm_plock_exit: misc_deregister failed");
-}
-
diff --git a/include/linux/Kbuild b/include/linux/Kbuild
index 571d6c2..7870517 100644
--- a/include/linux/Kbuild
+++ b/include/linux/Kbuild
@@ -200,6 +200,7 @@ unifdef-y += dccp.h
 unifdef-y += dirent.h
 unifdef-y += divert.h
 unifdef-y += dlm.h
+unifdef-y += dlm_plock.h
 unifdef-y += elfcore.h
 unifdef-y += errno.h
 unifdef-y += errqueue.h
diff --git a/include/linux/dlm_plock.h b/include/linux/dlm_plock.h
new file mode 100644
index 0000000..18d5fdb
--- /dev/null
+++ b/include/linux/dlm_plock.h
@@ -0,0 +1,50 @@
+/*
+ * Copyright (C) 2005-2008 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.
+ */
+
+#ifndef __DLM_PLOCK_DOT_H__
+#define __DLM_PLOCK_DOT_H__
+
+#define DLM_PLOCK_MISC_NAME		"dlm_plock"
+
+#define DLM_PLOCK_VERSION_MAJOR	1
+#define DLM_PLOCK_VERSION_MINOR	1
+#define DLM_PLOCK_VERSION_PATCH	0
+
+enum {
+	DLM_PLOCK_OP_LOCK = 1,
+	DLM_PLOCK_OP_UNLOCK,
+	DLM_PLOCK_OP_GET,
+};
+
+struct dlm_plock_info {
+	__u32 version[3];
+	__u8 optype;
+	__u8 ex;
+	__u8 wait;
+	__u8 pad;
+	__u32 pid;
+	__s32 nodeid;
+	__s32 rv;
+	__u32 fsid;
+	__u64 number;
+	__u64 start;
+	__u64 end;
+	__u64 owner;
+};
+
+#ifdef __KERNEL__
+int dlm_posix_lock(dlm_lockspace_t *lockspace, u64 number, struct file *file,
+		int cmd, struct file_lock *fl);
+int dlm_posix_unlock(dlm_lockspace_t *lockspace, u64 number, struct file *file,
+		struct file_lock *fl);
+int dlm_posix_get(dlm_lockspace_t *lockspace, u64 number, struct file *file,
+		struct file_lock *fl);
+#endif /* __KERNEL__ */
+
+#endif
+