[PATCH v3] nvmet: handle rw's limited retry flag

[Keith Busch]

On Mon, Dec 09, 2024 at 09:53:44AM +0800, Guixin Liu wrote:
> In some scenarios, some multipath software setup places the
> REQ_FAILFAST_DEV flag on I/O to prevent retries and immediately
> switch to other paths for issuing I/O commands. This will reflect
> on the NVMe read and write commands with the limited retry flag.
> 
> However, the current NVMe target side does not handle the limited
> retry flag, and the target's underlying driver still retries the
> I/O. This will result in the I/O not being quickly switched to
> other paths, ultimately leading to increased I/O latency.
> 
> When the nvme target receive an rw command with limited retry flag,
> handle it in block backend by setting the REQ_FAILFAST_DEV flag to
> bio.

Thanks, applied to nvme-6.14.