[PATCH] dm: suspend: parameter change

Change the interface of dm_suspend() so that we can pass several options
without increasing the number of parameters.  The existing 'do_lockfs' integer
parameter is replaced by a flag DM_SUSPEND_LOCKFS_FLAG.

There is no functional change to the code.

Test results:
I have tested 'dmsetup suspend' command with/without the '--nolockfs'
option and confirmed the do_lockfs value is correctly set.
Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Cc: dm-devel@redhat.com
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

drivers/md/dm-ioctl.c

@@ -765,7 +765,7 @@ out:
 static int do_suspend(struct dm_ioctl *param)
 {
 	int r = 0;
-	int do_lockfs = 1;
+	unsigned suspend_flags = DM_SUSPEND_LOCKFS_FLAG;
 	struct mapped_device *md;
 
 	md = find_device(param);
@@ -773,10 +773,10 @@ static int do_suspend(struct dm_ioctl *param)
 		return -ENXIO;
 
 	if (param->flags & DM_SKIP_LOCKFS_FLAG)
-		do_lockfs = 0;
+		suspend_flags &= ~DM_SUSPEND_LOCKFS_FLAG;
 
 	if (!dm_suspended(md))
-		r = dm_suspend(md, do_lockfs);
+		r = dm_suspend(md, suspend_flags);
 
 	if (!r)
 		r = __dev_status(md, param);
@@ -788,7 +788,7 @@ static int do_suspend(struct dm_ioctl *param)
 static int do_resume(struct dm_ioctl *param)
 {
 	int r = 0;
-	int do_lockfs = 1;
+	unsigned suspend_flags = DM_SUSPEND_LOCKFS_FLAG;
 	struct hash_cell *hc;
 	struct mapped_device *md;
 	struct dm_table *new_map;
@@ -814,9 +814,9 @@ static int do_resume(struct dm_ioctl *param)
 	if (new_map) {
 		/* Suspend if it isn't already suspended */
 		if (param->flags & DM_SKIP_LOCKFS_FLAG)
-			do_lockfs = 0;
+			suspend_flags &= ~DM_SUSPEND_LOCKFS_FLAG;
 		if (!dm_suspended(md))
-			dm_suspend(md, do_lockfs);
+			dm_suspend(md, suspend_flags);
 
 		r = dm_swap_table(md, new_map);
 		if (r) {

drivers/md/dm.c

@@ -1272,12 +1272,13 @@ static void unlock_fs(struct mapped_device *md)
  * dm_bind_table, dm_suspend must be called to flush any in
  * flight bios and ensure that any further io gets deferred.
  */
-int dm_suspend(struct mapped_device *md, int do_lockfs)
+int dm_suspend(struct mapped_device *md, unsigned suspend_flags)
 {
 	struct dm_table *map = NULL;
 	DECLARE_WAITQUEUE(wait, current);
 	struct bio *def;
 	int r = -EINVAL;
+	int do_lockfs = suspend_flags & DM_SUSPEND_LOCKFS_FLAG ? 1 : 0;
 
 	down(&md->suspend_lock);
 

drivers/md/dm.h

@@ -32,6 +32,11 @@
 
 #define SECTOR_SHIFT 9
 
+/*
+ * Suspend feature flags
+ */
+#define DM_SUSPEND_LOCKFS_FLAG		(1 << 0)
+
 /*
  * List of devices that a metadevice uses and should open/close.
  */

include/linux/device-mapper.h

@@ -173,7 +173,7 @@ void *dm_get_mdptr(struct mapped_device *md);
 /*
  * A device can still be used while suspended, but I/O is deferred.
  */
-int dm_suspend(struct mapped_device *md, int with_lockfs);
+int dm_suspend(struct mapped_device *md, unsigned suspend_flags);
 int dm_resume(struct mapped_device *md);
 
 /*