From: Eric Wheeler <git@xxxxxxxxxxxxxxxxxx> 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@xxxxxxxxxxxxxxxxxx> --- drivers/md/bcache/request.c | 7 +++++++ drivers/md/bcache/writeback.h | 3 ++- 2 files changed, 9 insertions(+), 1 deletion(-) diff --git a/drivers/md/bcache/request.c b/drivers/md/bcache/request.c index a95609f..859d08d 100644 --- a/drivers/md/bcache/request.c +++ b/drivers/md/bcache/request.c @@ -386,6 +386,13 @@ static bool check_should_bypass(struct cached_dev *dc, struct bio *bio) op_is_write(bio_op(bio)))) goto skip; + /* Flag for bypass if the IO is for read-ahead or background, + * unless the read-ahead request is for metadata (eg, for gfs2). + */ + if (bio->bi_opf & (REQ_RAHEAD|REQ_BACKGROUND) && + !(bio->bi_opf & REQ_META)) + goto skip; + /* If the ioprio already exists on the bio, use that. We assume that * the upper layer properly assigned the calling process's ioprio to * the bio being passed to bcache. Otherwise, use current's ioc. */ diff --git a/drivers/md/bcache/writeback.h b/drivers/md/bcache/writeback.h index cd82fe8..ea2f92e 100644 --- a/drivers/md/bcache/writeback.h +++ b/drivers/md/bcache/writeback.h @@ -81,7 +81,8 @@ static inline bool should_writeback(struct cached_dev *dc, struct bio *bio, return true; } - 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) -- 1.8.3.1
