On Thu, Oct 03, 2019 at 09:53:35AM +0200, gregkh@xxxxxxxxxxxxxxxxxxx wrote:
The patch below does not apply to the 5.3-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@xxxxxxxxxxxxxxx>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From c84a1372df929033cb1a0441fb57bd3932f39ac9 Mon Sep 17 00:00:00 2001
From: NeilBrown <neilb@xxxxxxx>
Date: Mon, 9 Sep 2019 16:30:02 +1000
Subject: [PATCH] md/raid0: avoid RAID0 data corruption due to layout
confusion.
If the drives in a RAID0 are not all the same size, the array is
divided into zones.
The first zone covers all drives, to the size of the smallest.
The second zone covers all drives larger than the smallest, up to
the size of the second smallest - etc.
A change in Linux 3.14 unintentionally changed the layout for the
second and subsequent zones. All the correct data is still stored, but
each chunk may be assigned to a different device than in pre-3.14 kernels.
This can lead to data corruption.
It is not possible to determine what layout to use - it depends which
kernel the data was written by.
So we add a module parameter to allow the old (0) or new (1) layout to be
specified, and refused to assemble an affected array if that parameter is
not set.
Fixes: 20d0189b1012 ("block: Introduce new bio_split()")
cc: stable@xxxxxxxxxxxxxxx (3.14+)
Acked-by: Guoqing Jiang <guoqing.jiang@xxxxxxxxxxxxxxx>
Signed-off-by: NeilBrown <neilb@xxxxxxx>
Signed-off-by: Song Liu <songliubraving@xxxxxx>
Had to adjust context slightly due to missing 62f7b1989c02f ("md
raid0/linear: Mark array as 'broken' and fail BIOs if a member is
gone)" in 5.3-4.14.
On 4.9 and 4.4 we need a more complex backport which I didn't attempt
due to missing be306c2989804 ("md: define mddev flags, recovery flags
and r1bio state bits using enums") and a few fixes of that.
Queued up for 5.3-4.14.
--
Thanks,
Sasha
