From 3819f24466fbd3a4c15814a8d374b63708f71dcc Mon Sep 17 00:00:00 2001 From: Chaitanya Kulkarni Date: Wed, 2 Feb 2022 01:04:45 -0800 Subject: [PATCH] nvmet: allow bdev in buffered_io mode Allow block device to be configured in the buffered I/O mode by using the file backend. In this way now we can use cache for the block device namespace which shows significant performance improvement. We update the block device ns enable function and return early when buffered_io flag is set. Signed-off-by: Chaitanya Kulkarni Signed-off-by: Christoph Hellwig --- drivers/nvme/target/io-cmd-bdev.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/drivers/nvme/target/io-cmd-bdev.c b/drivers/nvme/target/io-cmd-bdev.c index 95c2bbb0b2f5f..e9194804ddee4 100644 --- a/drivers/nvme/target/io-cmd-bdev.c +++ b/drivers/nvme/target/io-cmd-bdev.c @@ -76,6 +76,14 @@ int nvmet_bdev_ns_enable(struct nvmet_ns *ns) { int ret; + /* + * When buffered_io namespace attribute is enabled that means user want + * this block device to be used as a file, so block device can take + * an advantage of cache. + */ + if (ns->buffered_io) + return -ENOTBLK; + ns->bdev = blkdev_get_by_path(ns->device_path, FMODE_READ | FMODE_WRITE, NULL); if (IS_ERR(ns->bdev)) { -- 2.39.5