This is a note to let you know that I've just added the patch titled
fs/block_dev.c: page cache wrongly left invalidated after revalidate_disk()
to the 3.7-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:
fs-block_dev.c-page-cache-wrongly-left-invalidated-after-revalidate_disk.patch
and it can be found in the queue-3.7 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <[email protected]> know about it.
>From 7630b661da330b35dd57b6f5d6d62b386f2dd751 Mon Sep 17 00:00:00 2001
From: MITSUNARI Shigeo <[email protected]>
Date: Thu, 21 Feb 2013 16:42:01 -0800
Subject: fs/block_dev.c: page cache wrongly left invalidated after
revalidate_disk()
From: MITSUNARI Shigeo <[email protected]>
commit 7630b661da330b35dd57b6f5d6d62b386f2dd751 upstream.
We found that bdev->bd_invalidated was left set once revalidate_disk()
is called, which results in page cache flush every time that device is
open.
Specifically, we found this problem in MD block device. Once we resize
a MD device, mdadm --monitor periodically flush all page cache for that
device every 60 or 1000 seconds when it opens the device.
This bug lies since at least 3.2.0 till the latest kernel(3.6.2). Patch
is attached.
The following steps will reproduce the problem.
1. prepair a block device (eg /dev/sdb).
2. create two partitions:
sudo parted /dev/sdb
mklabel gpt
mkpart primary 0% 50%
mkpart primary 50% 100%
3. create a md device.
sudo mdadm -C /dev/md/hoge -l 1 -n 2 -e 1.2 --assume-clean --auto=md
--symlink=no /dev/sdb1 /dev/sdb2
4. create file system and mount it
sudo mkfs.ext3 /dev/md/hoge
sudo mkdir /mnt/test
sudo mount /dev/md/hoge /mnt/test
5. try to resize the device
sudo mdadm -G /dev/md/hoge --size=max
6. create a file to fill file cache.
sudo dd if=/dev/urandom of=/mnt/test/data bs=1M count=10
and verify the current status of file by free command.
7. mdadm monitor will open the md device every 1000 seconds and you
will find all file cache on the device are cleared.
The timing can be reduced by the following steps.
a) kill mdadm and restart it with --delay option
/sbin/mdadm --monitor --delay=30 --pid-file /var/run/mdadm/monitor.pid
--daemonise --scan --syslog
or open the md device directly.
sudo dd if=/dev/md/hoge of=/dev/null bs=4096 count=1
Signed-off-by: MITSUNARI Shigeo <[email protected]>
Cc: Al Viro <[email protected]>
Cc: Jeff Moyer <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
fs/block_dev.c | 1 +
1 file changed, 1 insertion(+)
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -994,6 +994,7 @@ int revalidate_disk(struct gendisk *disk
mutex_lock(&bdev->bd_mutex);
check_disk_size_change(disk, bdev);
+ bdev->bd_invalidated = 0;
mutex_unlock(&bdev->bd_mutex);
bdput(bdev);
return ret;
Patches currently in stable-queue which might be from [email protected] are
queue-3.7/fs-block_dev.c-page-cache-wrongly-left-invalidated-after-revalidate_disk.patch
--
To unsubscribe from this list: send the line "unsubscribe stable" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
