Improve performance by optionally bypassing some code that uses bdget.
Signed-Off-By: Alasdair G Kergon <[EMAIL PROTECTED]>
--- diff/drivers/md/dm-ioctl.c 2005-01-12 20:50:16.000000000 +0000
+++ source/drivers/md/dm-ioctl.c 2005-01-12 20:50:07.000000000 +0000
@@ -1,6 +1,6 @@
/*
* Copyright (C) 2001, 2002 Sistina Software (UK) Limited.
- * Copyright (C) 2004 Red Hat, Inc. All rights reserved.
+ * Copyright (C) 2004 - 2005 Red Hat, Inc. All rights reserved.
*
* This file is released under the GPL.
*/
@@ -520,19 +520,22 @@
if (dm_suspended(md))
param->flags |= DM_SUSPEND_FLAG;
- bdev = bdget_disk(disk, 0);
- if (!bdev)
- return -ENXIO;
-
param->dev = huge_encode_dev(MKDEV(disk->major, disk->first_minor));
- /*
- * Yes, this will be out of date by the time it gets back
- * to userland, but it is still very useful ofr
- * debugging.
- */
- param->open_count = bdev->bd_openers;
- bdput(bdev);
+ if (!(param->flags & DM_SKIP_BDGET_FLAG)) {
+ bdev = bdget_disk(disk, 0);
+ if (!bdev)
+ return -ENXIO;
+
+ /*
+ * Yes, this will be out of date by the time it gets back
+ * to userland, but it is still very useful for
+ * debugging.
+ */
+ param->open_count = bdev->bd_openers;
+ bdput(bdev);
+ } else
+ param->open_count = -1;
if (disk->policy)
param->flags |= DM_READONLY_FLAG;
--- diff/include/linux/dm-ioctl.h 2005-01-12 20:50:16.000000000 +0000
+++ source/include/linux/dm-ioctl.h 2005-01-12 20:49:42.000000000 +0000
@@ -1,6 +1,6 @@
/*
* Copyright (C) 2001 - 2003 Sistina Software (UK) Limited.
- * Copyright (C) 2004 Red Hat, Inc. All rights reserved.
+ * Copyright (C) 2004 - 2005 Red Hat, Inc. All rights reserved.
*
* This file is released under the LGPL.
*/
@@ -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 3
+#define DM_VERSION_MINOR 4
#define DM_VERSION_PATCHLEVEL 0
-#define DM_VERSION_EXTRA "-ioctl (2004-09-30)"
+#define DM_VERSION_EXTRA "-ioctl (2005-01-12)"
/* Status bits */
#define DM_READONLY_FLAG (1 << 0) /* In/Out */
@@ -300,4 +300,9 @@
*/
#define DM_BUFFER_FULL_FLAG (1 << 8) /* Out */
+/*
+ * Set this to improve performance when you aren't going to use open_count
+ */
+#define DM_SKIP_BDGET_FLAG (1 << 9) /* In */
+
#endif /* _LINUX_DM_IOCTL_H */
-
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