From: Eric Wheeler <g...@linux.ewheeler.net>
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 <bca...@linux.ewheeler.net>
---
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
