[PATCH] nvmet: use IOCB_NOWAIT only if the filesystem supports it.

[Sagi Grimberg]

On 11/22/21 12:08 PM, Maurizio Lombardi wrote:
> Submit I/O requests with the IOCB_NOWAIT flag set only if
> the underlying filesystem supports it.
> 
> Fixes: 50a909db36f2 ("nvmet: use IOCB_NOWAIT for file-ns buffered I/O")
> 
> Signed-off-by: Maurizio Lombardi <mlombard at redhat.com>
> ---
>   drivers/nvme/target/io-cmd-file.c | 2 ++
>   1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/nvme/target/io-cmd-file.c b/drivers/nvme/target/io-cmd-file.c
> index 6aa30f30b572..136b14853ed7 100644
> --- a/drivers/nvme/target/io-cmd-file.c
> +++ b/drivers/nvme/target/io-cmd-file.c
> @@ -8,6 +8,7 @@
>   #include <linux/uio.h>
>   #include <linux/falloc.h>
>   #include <linux/file.h>
> +#include <linux/fs.h>
>   #include "nvmet.h"
>   
>   #define NVMET_MAX_MPOOL_BVEC		16
> @@ -266,6 +267,7 @@ static void nvmet_file_execute_rw(struct nvmet_req *req)
>   
>   	if (req->ns->buffered_io) {
>   		if (likely(!req->f.mpool_alloc) &&
> +				req->ns->file->f_mode & FMODE_NOWAIT &&
>   				nvmet_file_execute_io(req, IOCB_NOWAIT))

I'd suggest to fix the alignment if we are touching this.
    		if (likely(!req->f.mpool_alloc) &&
		    req->ns->file->f_mode & FMODE_NOWAIT &&
  		    nvmet_file_execute_io(req, IOCB_NOWAIT))

>   			return;
>   		nvmet_file_submit_buffered_io(req);
>