bcache: update bio->bi_opf bypass/writeback REQ_ flag hints
Flag for bypass if the IO is for read-ahead or background, unless the
read-ahead request is for metadata (eg, from gfs2).
Bypass if:
bio->bi_opf & (REQ_RAHEAD|REQ_BACKGROUND) &&
!(bio->bi_opf & REQ_META))
Writeback if:
op_is_sync(bio->bi_opf) ||
bio->bi_opf & (REQ_META|REQ_PRIO)
Signed-off-by: Eric Wheeler <bcache@linux.ewheeler.net>
Reviewed-by: Coly Li <colyli@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/drivers/md/bcache/writeback.h b/drivers/md/bcache/writeback.h
index e35421d..34bcf49 100644
--- a/drivers/md/bcache/writeback.h
+++ b/drivers/md/bcache/writeback.h
@@ -76,7 +76,9 @@ static inline bool should_writeback(struct cached_dev *dc, struct bio *bio,
if (would_skip)
return false;
- return op_is_sync(bio->bi_opf) || in_use <= CUTOFF_WRITEBACK;
+ return (op_is_sync(bio->bi_opf) ||
+ bio->bi_opf & (REQ_META|REQ_PRIO) ||
+ in_use <= CUTOFF_WRITEBACK);
}
static inline void bch_writeback_queue(struct cached_dev *dc)