| From | Greg Kroah-Hartman <> | Subject | [PATCH 3.18 24/84] dm cache: only use overwrite optimisation for promotion when in writeback mode | Date | Tue, 6 Jan 2015 17:49:27 -0800 |
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3.18-stable review patch. If anyone has any objections, please let me know.
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From: Joe Thornber <ejt@redhat.com>
commit f29a3147e251d7ae20d3194ff67f109d71e501b4 upstream.
Overwrite causes the cache block and origin blocks to diverge, which is only allowed in writeback mode.
Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- drivers/md/dm-cache-target.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
--- a/drivers/md/dm-cache-target.c +++ b/drivers/md/dm-cache-target.c @@ -1070,7 +1070,8 @@ static void issue_copy(struct dm_cache_m avoid = is_discarded_oblock(cache, mg->new_oblock); - if (!avoid && bio_writes_complete_block(cache, bio)) { + if (writeback_mode(&cache->features) && + !avoid && bio_writes_complete_block(cache, bio)) { issue_overwrite(mg, bio); return; }
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