[PATCH 3.16 099/133] bcache: do not subtract sectors_to_gc for bypassed IO

[Ben Hutchings]

3.16.51-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: Tang Junhui <tang.junhui@xxxxxxxxxx>

commit 69daf03adef5f7bc13e0ac86b4b8007df1767aab upstream.

Since bypassed IOs use no bucket, so do not subtract sectors_to_gc to
trigger gc thread.

Signed-off-by: tang.junhui <tang.junhui@xxxxxxxxxx>
Acked-by: Coly Li <colyli@xxxxxxx>
Reviewed-by: Eric Wheeler <bcache@xxxxxxxxxxxxxxxxxx>
Reviewed-by: Christoph Hellwig <hch@xxxxxx>
Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
 drivers/md/bcache/request.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

--- a/drivers/md/bcache/request.c
+++ b/drivers/md/bcache/request.c
@@ -193,14 +193,14 @@ static void bch_data_insert_start(struct
 	struct data_insert_op *op = container_of(cl, struct data_insert_op, cl);
 	struct bio *bio = op->bio, *n;
 
+	if (op->bypass)
+		return bch_data_invalidate(cl);
+
 	if (atomic_sub_return(bio_sectors(bio), &op->c->sectors_to_gc) < 0) {
 		set_gc_sectors(op->c);
 		wake_up_gc(op->c);
 	}
 
-	if (op->bypass)
-		return bch_data_invalidate(cl);
-
 	/*
 	 * Journal writes are marked REQ_FLUSH; if the original write was a
 	 * flush, it'll wait on the journal write.