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 681b4f1..9ee137e 100644
--- a/drivers/md/bcache/request.c
+++ b/drivers/md/bcache/request.c
@@ -384,6 +384,14 @@
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 e35421d..34bcf49 100644
--- a/drivers/md/bcache/writeback.h
+++ b/drivers/md/bcache/writeback.h
@@ -76,7 +76,9 @@
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)