On 11/27/2017 09:45 AM, Eddie Chapman wrote: > On 27/11/17 16:06, gregkh@xxxxxxxxxxxxxxxxxxx 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 clean >> >> to the 4.9-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: >> 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@xxxxxxxxxxxxxxx> 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. -- Jens Axboe