Since we flush the data device as part of a metadata commit, it's redundant to then submit any deferred REQ_PREFLUSH bios.
Add a check in process_deferred_bios() for deferred REQ_PREFLUSH bios and complete them immediately. Signed-off-by: Nikos Tsironis <[email protected]> --- drivers/md/dm-thin.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) diff --git a/drivers/md/dm-thin.c b/drivers/md/dm-thin.c index e0be545080d0..40d8a255dbc3 100644 --- a/drivers/md/dm-thin.c +++ b/drivers/md/dm-thin.c @@ -2383,8 +2383,18 @@ static void process_deferred_bios(struct pool *pool) while ((bio = bio_list_pop(&bio_completions))) bio_endio(bio); - while ((bio = bio_list_pop(&bios))) - generic_make_request(bio); + while ((bio = bio_list_pop(&bios))) { + if (bio->bi_opf & REQ_PREFLUSH) { + /* + * We just flushed the data device as part of the + * metadata commit, so there is no reason to send + * another flush. + */ + bio_endio(bio); + } else { + generic_make_request(bio); + } + } } static void do_worker(struct work_struct *ws) -- 2.11.0 -- dm-devel mailing list [email protected] https://www.redhat.com/mailman/listinfo/dm-devel
