This is a note to let you know that I've just added the patch titled
block: blkdev_get() should access ->bd_disk only after
to the 2.6.39-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
block-blkdev_get-should-access-bd_disk-only-after.patch
and it can be found in the queue-2.6.39 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <[email protected]> know about it.
>From 4c49ff3fe128ca68dabd07537415c419ad7f82f9 Mon Sep 17 00:00:00 2001
From: Tejun Heo <[email protected]>
Date: Wed, 1 Jun 2011 08:27:41 +0200
Subject: block: blkdev_get() should access ->bd_disk only after
success
From: Tejun Heo <[email protected]>
commit 4c49ff3fe128ca68dabd07537415c419ad7f82f9 upstream.
d4dc210f69 (block: don't block events on excl write for non-optical
devices) added dereferencing of bdev->bd_disk to test
GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE; however, bdev->bd_disk can be
%NULL if open failed which can lead to an oops.
Test the flag after testing open was successful, not before.
Signed-off-by: Tejun Heo <[email protected]>
Reported-by: David Miller <[email protected]>
Tested-by: David Miller <[email protected]>
Signed-off-by: Jens Axboe <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
fs/block_dev.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -1272,8 +1272,8 @@ int blkdev_get(struct block_device *bdev
* individual writeable reference is too fragile given the
* way @mode is used in blkdev_get/put().
*/
- if ((disk->flags & GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE) &&
- !res && (mode & FMODE_WRITE) && !bdev->bd_write_holder) {
+ if (!res && (mode & FMODE_WRITE) && !bdev->bd_write_holder &&
+ (disk->flags & GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE)) {
bdev->bd_write_holder = true;
disk_block_events(disk);
}
Patches currently in stable-queue which might be from [email protected] are
queue-2.6.39/block-blkdev_get-should-access-bd_disk-only-after.patch
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