On Thu, Jul 30, 2020 at 03:33:42PM -0500, John Donnelly wrote: > From: Mike Snitzer <snit...@redhat.com> > > 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 <snit...@redhat.com> > > (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:sta...@vger.kernel.org for 4.14.x . > > Signed-off-by: John Donnelly <john.p.donne...@oracle.com> > Reviewed-by: Somasundaram Krishnasamy <somasundaram.krishnas...@oracle.com> > > 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. > --- > drivers/md/dm-cache-target.c | 94 > ++++++++++++++++++--------------------------
Line wrapped? > 1 file changed, 38 insertions(+), 56 deletions(-) > > diff --git a/drivers/md/dm-cache-target.c b/drivers/md/dm-cache-target.c > index 69cdb29ef6be..2d9566bfe08b 100644 > --- a/drivers/md/dm-cache-target.c > +++ b/drivers/md/dm-cache-target.c > @@ -1,5 +1,5 @@ > /* > - * Copyright (C) 2012 Red Hat. All rights reserved. > + i Copyright (C) 2012 Red Hat. All rights reserved. What happened here? This patch can't be applied as-is :( greg k-h
