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/request.c b/drivers/md/bcache/request.c
index 681b4f12b05a0ceb2a23028bb8857b28e0ee86cd..9ee137e8d387b52ee5666ce2e720182480fda0cd 100644 (file)
--- a/drivers/md/bcache/request.c
+++ b/drivers/md/bcache/request.c
@@ -384,6 +384,14 @@ 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 (bio->bi_iter.bi_sector & (c->sb.block_size - 1) ||
            bio_sectors(bio) & (c->sb.block_size - 1)) {
                pr_debug("skipping unaligned io");

diff --git a/drivers/md/bcache/writeback.h b/drivers/md/bcache/writeback.h
index e35421d20d2eb32b75d48707fe00ecb7f4fdfb72..34bcf49d737bdfb1fc07d8fcea8f9f4f0840da8d 100644 (file)
--- 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)