On Wed, Aug 05, 2020 at 03:34:09PM -0400, Mike Snitzer wrote: > On Wed, Aug 05 2020 at 10:32am -0400, > Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx> wrote: > > > On Tue, Aug 04, 2020 at 02:20:38PM -0400, Mike Snitzer wrote: > > > On Tue, Aug 04 2020 at 8:47am -0400, > > > Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx> wrote: > > > > > > > On Tue, Aug 04, 2020 at 07:33:05AM -0500, John Donnelly wrote: > > > > > From: Mike Snitzer <snitzer@xxxxxxxxxx> > > > > > > > > > > Discontinue issuing writethrough write IO in series to the origin and > > > > > then cache. > > > > > > > > > > Use bio_clone_fast() to create a new origin clone bio that will be > > > > > mapped to the origin device and then bio_chain() it to the bio that gets > > > > > remapped to the cache device. The origin clone bio does _not_ have a > > > > > copy of the per_bio_data -- as such check_if_tick_bio_needed() will not > > > > > be called. > > > > > > > > > > The cache bio (parent bio) will not complete until the origin bio has > > > > > completed -- this fulfills bio_clone_fast()'s requirements as well as > > > > > the requirement to not complete the original IO until the write IO has > > > > > completed to both the origin and cache device. > > > > > > > > > > Signed-off-by: Mike Snitzer <snitzer@xxxxxxxxxx> > > > > > > > > > > (cherry picked from commit 2df3bae9a6543e90042291707b8db0cbfbae9ee9) > > > > > > > > > > Fixes: 4ec34f2196d125ff781170ddc6c3058c08ec5e73 (dm bio record: > > > > > save/restore bi_end_io and bi_integrity ) > > > > > > > > > > 4ec34f21 introduced a mkfs.ext4 hang on a LVM device that has been > > > > > modified with lvconvert --cachemode=writethrough. > > > > > > > > > > CC:stable@xxxxxxxxxxxxxxx for 4.14.y > > > > > > > > > > Signed-off-by: John Donnelly <john.p.donnelly@xxxxxxxxxx> > > > > > Reviewed-by: Somasundaram Krishnasamy <somasundaram.krishnasamy@xxxxxxxxxx> > > > > > > > > > > conflicts: > > > > > drivers/md/dm-cache-target.c. - Corrected usage of > > > > > writethrough_mode(&cache->feature) that was caught by > > > > > compiler, and removed unused static functions : writethrough_endio(), > > > > > defer_writethrough_bio(), wake_deferred_writethrough_worker() > > > > > that generated warnings. > > > > > > > > What is this "conflicts nonsense"? You don't see that in any other > > > > kernel patch changelog, do you? > > > > > > > > > --- > > > > > drivers/md/dm-cache-target.c | 92 ++++++++++++++++++-------------------------- > > > > > 1 file changed, 37 insertions(+), 55 deletions(-) > > > > > > > > Please fix your email client up, it's totally broken and this does not > > > > work at all and is getting frustrating from my side here. > > > > > > > > Try sending emails to yourself and see if you can apply the patches, as > > > > the one you sent here does not work, again: > > > > > > John's inability to submit a patch that can apply aside: I do not like > > > how this patch header is constructed (yet attributed "From" me). It is > > > devoid of detail as it relates to stable@. > > > > > > Greg, please don't apply the v4 of this patch either. I'll craft a > > > proper stable@ patch that explains the reason for change and why we're > > > left having to resolve conflicts in stable@. > > > > > > But first I need to focus on sending DM changes to Linus for v5.9 merge. > > > > Ok, no worries, I'll drop all of these from my review queue and wait for > > something from you sometime in the future. > > Hey Greg, > > SO I've looked this required 4.14 stable@ backport over. Because 4.14 > already has these commits (to fix a dm integrity issue): > 1b17159e52b dm bio record: save/restore bi_end_io and bi_integrity > 248aa2645aa dm integrity: use dm_bio_record and dm_bio_restore > > DM-cache's 4.14 writethrough mode got broken because its implementation > (ab)used dm_hook_bio+dm_bio_record and predates 4.15's switch to using > bio_chain() via commit 2df3bae9a654. Without commit 2df3bae9a654 the > dm_hook_bio+dm_bio_record changes from commit 1b17159e52b break > dm-cache's writethrough support. > > So 4.14-stable now needs these 3 upstream 4.15 commits: > 8e3c3827776f dm cache: pass cache structure to mode functions > 2df3bae9a654 dm cache: submit writethrough writes in parallel to origin and cache > 9958f1d9a04e dm cache: remove all obsolete writethrough-specific code > > Applying those commits to v4.14.190 with: > git cherry-pick -x 8e3c3827776f^..9958f1d9a04e > > results in a kernel that successfully builds and should fix > 4.14-stable's broken dm-cache writethrough support. > > Are you ok with queueing up applying these 3 upstream commits to > 4.14-stable or do you need me to send a patchset? This is good enough, now all queued up, thanks! greg k-h -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
