For some node operation is userspace we need to know
if previous suspend state of device really changed.

Patch add new flag to indicate suspend state change.

Signed-off-by: Milan Broz <mbroz@redhat.com>
---
drivers/md/dm-ioctl.c | 25 ++++++++++++++++++-------
include/linux/dm-ioctl.h | 11 ++++++++---
2 files changed, 26 insertions(+), 10 deletions(-)

diff --git a/drivers/md/dm-ioctl.c b/drivers/md/dm-ioctl.c
index b670922..5d33492 100644
--- a/drivers/md/dm-ioctl.c
+++ b/drivers/md/dm-ioctl.c
@@ -596,7 +596,7 @@ static int __dev_status(struct mapped_device *md, struct dm_ioctl *param)
struct dm_table *table;

param->flags &= ~(DM_SUSPEND_FLAG | DM_READONLY_FLAG |
- DM_ACTIVE_PRESENT_FLAG);
+ DM_SUSPEND_CHANGE_FLAG | DM_ACTIVE_PRESENT_FLAG);

if (dm_suspended_md(md))
param->flags |= DM_SUSPEND_FLAG;
@@ -846,7 +846,7 @@ out:

static int do_suspend(struct dm_ioctl *param)
{
- int r = 0;
+ int r = 0, suspended = 0;
unsigned suspend_flags = DM_SUSPEND_LOCKFS_FLAG;
struct mapped_device *md;

@@ -859,11 +859,17 @@ static int do_suspend(struct dm_ioctl *param)
if (param->flags & DM_NOFLUSH_FLAG)
suspend_flags |= DM_SUSPEND_NOFLUSH_FLAG;

- if (!dm_suspended_md(md))
+ if (!dm_suspended_md(md)) {
r = dm_suspend(md, suspend_flags);
+ if (!r)
+ suspended = 1;
+ }

- if (!r)
+ if (!r) {
r = __dev_status(md, param);
+ if (suspended)
+ param->flags |= DM_SUSPEND_CHANGE_FLAG;
+ }

dm_put(md);
return r;
@@ -871,7 +877,7 @@ static int do_suspend(struct dm_ioctl *param)

static int do_resume(struct dm_ioctl *param)
{
- int r = 0;
+ int r = 0, resumed = 0;
unsigned suspend_flags = DM_SUSPEND_LOCKFS_FLAG;
struct hash_cell *hc;
struct mapped_device *md;
@@ -919,16 +925,21 @@ static int do_resume(struct dm_ioctl *param)

if (dm_suspended_md(md)) {
r = dm_resume(md);
- if (!r)
+ if (!r) {
dm_ioctl_uevent(md, KOBJ_CHANGE, param->event_nr,
&param->flags);
+ resumed = 1;
+ }
}

if (old_map)
dm_table_destroy(old_map);

- if (!r)
+ if (!r) {
r = __dev_status(md, param);
+ if (resumed)
+ param->flags |= DM_SUSPEND_CHANGE_FLAG;
+ }

dm_put(md);
return r;
diff --git a/include/linux/dm-ioctl.h b/include/linux/dm-ioctl.h
index 2c445e1..ae957a3 100644
--- a/include/linux/dm-ioctl.h
+++ b/include/linux/dm-ioctl.h
@@ -1,6 +1,6 @@
/*
* Copyright (C) 2001 - 2003 Sistina Software (UK) Limited.
- * Copyright (C) 2004 - 2009 Red Hat, Inc. All rights reserved.
+ * Copyright (C) 2004 - 2010 Red Hat, Inc. All rights reserved.
*
* This file is released under the LGPL.
*/
@@ -266,9 +266,9 @@ enum {
#define DM_DEV_SET_GEOMETRY _IOWR(DM_IOCTL, DM_DEV_SET_GEOMETRY_CMD, struct dm_ioctl)

#define DM_VERSION_MAJOR 4
-#define DM_VERSION_MINOR 17
+#define DM_VERSION_MINOR 18
#define DM_VERSION_PATCHLEVEL 0
-#define DM_VERSION_EXTRA "-ioctl (2010-03-05)"
+#define DM_VERSION_EXTRA "-ioctl (2010-03-10)"

/* Status bits */
#define DM_READONLY_FLAG (1 << 0) /* In/Out */
@@ -321,4 +321,9 @@ enum {
*/
#define DM_UEVENT_GENERATED_FLAG (1 << 13) /* Out */

+/*
+ * If set, suspend state of device changed from previous state.
+ */
+#define DM_SUSPEND_CHANGE_FLAG (1 << 14) /* Out */
+
#endif /* _LINUX_DM_IOCTL_H */
--
1.7.0

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