On 11/27/2017 09:45 AM, Eddie Chapman wrote:
On 27/11/17 16:06, gregkh@linuxfoundation.org wrote:
This is a note to let you know that I've just added the patch titled
bcache: only permit to recovery read error when cache device is cleanto the 4.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...
The filename of the patch is: bcache-only-permit-to-recovery-read-error-when-cache-device-is-clean.patch and it can be found in the queue-4.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.
Hi Greg,
This patch is an important fix for a possible data corruption issue, but it also introduces a bug that can produce read errors under certain circumstances. The issue introduced by this patch is not as severe as the issue it fixes, but can lead to e.g. upper layer fs remounting read only. In my environment upper layer handled it badly and indirectly resulted in data loss (not directly bcache's fault of course).
Michael Lyle CC'd the stable list with a follow up fix for the issue introduced by this patch, on 24th Nov, subject "bcache: recover data from backing when data is clean".
However, the followup fix is not in Linus' tree yet, only in Michael's. I guess that means you can't pick it up yet. Never-the-less I felt it important to point this out here.
It's commit e393aa2446150536929140739f09c6ecbcbea7f0 in my tree and will go upstream shortly - but yes, probably should not add this one, before both can be pulled in.