On Mon, Jan 29, 2018 at 5:50 PM, Darrick J. Wong
<darrick.wong@xxxxxxxxxx> wrote:
> On Mon, Jan 29, 2018 at 01:07:36PM +0200, Amir Goldstein wrote:
>> On Fri, Jan 26, 2018 at 11:44 PM, Darrick J. Wong
>> <darrick.wong@xxxxxxxxxx> wrote:
>> > On Fri, Jan 26, 2018 at 09:44:29AM +0200, Amir Goldstein wrote:
>> >> Commit 66f364649d870 ("xfs: remove if_rdev") moved storing of rdev
>> >> value for special inodes to VFS inodes, but forgot to preserve the
>> >> value of i_rdev when recycling a reclaimable xfs_inode.
>> >>
>> >> This was detected by xfstest overlay/017 with inodex=on mount option
>> >> and xfs base fs. The test does a lookup of overlay chardev and blockdev
>> >> right after drop caches.
>> >>
>> >> Overlayfs inodes hold a reference on underlying xfs inodes when mount
>> >> option index=on is configured. If drop caches reclaim xfs inodes, before
>> >> it relclaims overlayfs inodes, that can sometimes leave a reclaimable xfs
>> >> inode and that test hits that case quite often.
>> >>
>> >> When that happens, the xfs inode cache remains broken (zere i_rdev)
>> >> until the next cycle mount or drop caches.
>> >>
>> >> Fixes: 66f364649d870 ("xfs: remove if_rdev")
>> >> Signed-off-by: Amir Goldstein <amir73il@xxxxxxxxx>
>> >
>> > Looks ok,
>> > Reviewed-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
>> >
>>
>> I recon that now we should now also strap:
>> Cc: <stable@xxxxxxxxxxxxxxx> #v4.15
>>
>> Can I assume, you'll add it on apply?
>
> I'll do a proper backport of this and a couple other critical cow
> fixes after I get the 4.16 stuff merged.
>
I am not sure what "proper backport" means in the context of
this patch.
This is a v4.15-rc1 regression fix that is based on v4.15-rc8.
It applied cleanly on v4.15.
CC'ing stable for attention.
This patch is now in master, but due to its timing it did not
get the CC: stable tag.
Thanks,
Amir.
