From c2a9c7ab475bc3aaf06521a39ac65bc48c8cad4f Mon Sep 17 00:00:00 2001 From: Anand Jain Date: Thu, 6 Apr 2017 11:22:53 +0800 Subject: [PATCH] btrfs: check if the device is flush capable The block layer call chain from submit_bio will check if the write cache is enabled for the given queue before submitting the flush. This will add a code to fail fast if its not. Signed-off-by: Anand Jain Reviewed-by: David Sterba [ updated changelog to reflect current code stat, blkdev_issue_flush is not used yet ] Signed-off-by: David Sterba --- fs/btrfs/disk-io.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index e070e463ad8b..ba7bd65693a3 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -3518,9 +3518,13 @@ static void btrfs_end_empty_barrier(struct bio *bio) */ static int write_dev_flush(struct btrfs_device *device, int wait) { + struct request_queue *q = bdev_get_queue(device->bdev); struct bio *bio; int ret = 0; + if (!test_bit(QUEUE_FLAG_WC, &q->queue_flags)) + return 0; + if (wait) { bio = device->flush_bio; if (!bio)