On Thu, Feb 1, 2018 at 2:27 AM, Amir Goldstein <amir73il@xxxxxxxxx> wrote:
> 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.
>
Now really CC stable.
Amir.
