[PATCH] device-mapper ioctl: add skip lock_fs flag
Add ioctl DM_SKIP_LOCKFS_FLAG for userspace to request that lock_fs is
bypassed when suspending a device.
There's no change to the behaviour of existing code that doesn't know about
the new flag.
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/drivers/md/dm-ioctl.c b/drivers/md/dm-ioctl.c
index dbc07af..561bda5 100644
--- a/drivers/md/dm-ioctl.c
+++ b/drivers/md/dm-ioctl.c
@@ -693,14 +693,18 @@
static int do_suspend(struct dm_ioctl *param)
{
int r = 0;
+ int do_lockfs = 1;
struct mapped_device *md;
md = find_device(param);
if (!md)
return -ENXIO;
+ if (param->flags & DM_SKIP_LOCKFS_FLAG)
+ do_lockfs = 0;
+
if (!dm_suspended(md))
- r = dm_suspend(md, 1);
+ r = dm_suspend(md, do_lockfs);
if (!r)
r = __dev_status(md, param);
@@ -712,6 +716,7 @@
static int do_resume(struct dm_ioctl *param)
{
int r = 0;
+ int do_lockfs = 1;
struct hash_cell *hc;
struct mapped_device *md;
struct dm_table *new_map;
@@ -737,8 +742,10 @@
/* Do we need to load a new map ? */
if (new_map) {
/* Suspend if it isn't already suspended */
+ if (param->flags & DM_SKIP_LOCKFS_FLAG)
+ do_lockfs = 0;
if (!dm_suspended(md))
- dm_suspend(md, 1);
+ dm_suspend(md, do_lockfs);
r = dm_swap_table(md, new_map);
if (r) {
diff --git a/include/linux/dm-ioctl.h b/include/linux/dm-ioctl.h
index f5eb6b6..fa75ba0 100644
--- a/include/linux/dm-ioctl.h
+++ b/include/linux/dm-ioctl.h
@@ -272,9 +272,9 @@
#define DM_TARGET_MSG _IOWR(DM_IOCTL, DM_TARGET_MSG_CMD, struct dm_ioctl)
#define DM_VERSION_MAJOR 4
-#define DM_VERSION_MINOR 4
+#define DM_VERSION_MINOR 5
#define DM_VERSION_PATCHLEVEL 0
-#define DM_VERSION_EXTRA "-ioctl (2005-01-12)"
+#define DM_VERSION_EXTRA "-ioctl (2005-10-04)"
/* Status bits */
#define DM_READONLY_FLAG (1 << 0) /* In/Out */
@@ -301,8 +301,13 @@
#define DM_BUFFER_FULL_FLAG (1 << 8) /* Out */
/*
- * Set this to improve performance when you aren't going to use open_count
+ * Set this to improve performance when you aren't going to use open_count.
*/
#define DM_SKIP_BDGET_FLAG (1 << 9) /* In */
+/*
+ * Set this to avoid attempting to freeze any filesystem when suspending.
+ */
+#define DM_SKIP_LOCKFS_FLAG (1 << 10) /* In */
+
#endif /* _LINUX_DM_IOCTL_H */