This is a note to let you know that I've just added the patch titled
md: fix two bugs when attempting to resize RAID0 array.
to the 3.8-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:
md-fix-two-bugs-when-attempting-to-resize-raid0-array.patch
and it can be found in the queue-3.8 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From a64685399181780998281fe07309a94b25dd24c3 Mon Sep 17 00:00:00 2001
From: NeilBrown <neilb@xxxxxxx>
Date: Thu, 21 Feb 2013 14:33:17 +1100
Subject: md: fix two bugs when attempting to resize RAID0 array.
From: NeilBrown <neilb@xxxxxxx>
commit a64685399181780998281fe07309a94b25dd24c3 upstream.
You cannot resize a RAID0 array (in terms of making the devices
bigger), but the code doesn't entirely stop you.
So:
disable setting of the available size on each device for
RAID0 and Linear devices. This must not change as doing so
can change the effective layout of data.
Make sure that the size that raid0_size() reports is accurate,
but rounding devices sizes to chunk sizes. As the device sizes
cannot change now, this isn't so important, but it is best to be
safe.
Without this change:
mdadm --grow /dev/md0 -z max
mdadm --grow /dev/md0 -Z max
then read to the end of the array
can cause a BUG in a RAID0 array.
These bugs have been present ever since it became possible
to resize any device, which is a long time. So the fix is
suitable for any -stable kerenl.
Signed-off-by: NeilBrown <neilb@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/md/md.c | 3 +++
drivers/md/raid0.c | 3 ++-
2 files changed, 5 insertions(+), 1 deletion(-)
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -2998,6 +2998,9 @@ rdev_size_store(struct md_rdev *rdev, co
} else if (!sectors)
sectors = (i_size_read(rdev->bdev->bd_inode) >> 9) -
rdev->data_offset;
+ if (!my_mddev->pers->resize)
+ /* Cannot change size for RAID0 or Linear etc */
+ return -EINVAL;
}
if (sectors < my_mddev->dev_sectors)
return -EINVAL; /* component must fit device */
--- a/drivers/md/raid0.c
+++ b/drivers/md/raid0.c
@@ -411,7 +411,8 @@ static sector_t raid0_size(struct mddev
"%s does not support generic reshape\n", __func__);
rdev_for_each(rdev, mddev)
- array_sectors += rdev->sectors;
+ array_sectors += (rdev->sectors &
+ ~(sector_t)(mddev->chunk_sectors-1));
return array_sectors;
}
Patches currently in stable-queue which might be from neilb@xxxxxxx are
queue-3.8/md-raid1-raid10-fix-deadlock-with-freeze_array.patch
queue-3.8/md-fix-two-bugs-when-attempting-to-resize-raid0-array.patch
queue-3.8/md-raid0-fix-error-return-from-create_stripe_zones.patch
queue-3.8/md-protect-against-crash-upon-fsync-on-ro-array.patch
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