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Message-ID: <e33c1a36-2b8e-8331-5f36-54dc47ab02d1@grimberg.me>
Date:   Tue, 8 Aug 2023 11:47:14 +0300
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Subject: Re: [PATCH libnvme v2 2/2] fabrics: Do not pass disable_sqflow if not
 supported
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To:     Daniel Wagner <dwagner@suse.de>, linux-nvme@lists.infradead.org
Cc:     linux-kernel@vger.kernel.org,
        Caleb Sander <csander@purestorage.com>,
        Keith Busch <kbusch@kernel.org>
References: <20230808070907.18834-1-dwagner@suse.de>
 <20230808070907.18834-3-dwagner@suse.de>
From:   Sagi Grimberg <sagi@grimberg.me>
In-Reply-To: <20230808070907.18834-3-dwagner@suse.de>
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> Only retry a connect attempt with disable_sqflow if the kernel
> actually supports this option.
> 
> Reported-by: Sagi Grimberg <sagi@grimberg.me>
> Signed-off-by: Daniel Wagner <dwagner@suse.de>
> ---
>   src/nvme/fabrics.c | 3 ++-
>   1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/src/nvme/fabrics.c b/src/nvme/fabrics.c
> index 9725eeb3cda8..f0e85d3b766d 100644
> --- a/src/nvme/fabrics.c
> +++ b/src/nvme/fabrics.c
> @@ -1043,7 +1043,8 @@ nvme_ctrl_t nvmf_connect_disc_entry(nvme_host_t h,
>   	if (!ret)
>   		return c;
>   
> -	if (errno == EINVAL && c->cfg.disable_sqflow) {
> +	if (errno == EINVAL && c->cfg.disable_sqflow &&
> +	    nvmf_check_option(h->r, disable_sqflow)) {
>   		errno = 0;
>   		/* disable_sqflow is unrecognized option on older kernels */
>   		nvme_msg(h->r, LOG_INFO, "failed to connect controller, "

I think you want to check this before the initial call
and avoid the retry altogether.
--
-       if (e->treq & NVMF_TREQ_DISABLE_SQFLOW)
+       if (e->treq & NVMF_TREQ_DISABLE_SQFLOW &&
+           nvmf_check_option(h->r, disable_sqflow))
                 c->cfg.disable_sqflow = true;
+       else
+               c->cfg.disable_sqflow = false;

         if (e->trtype == NVMF_TRTYPE_TCP &&
             (e->treq & NVMF_TREQ_REQUIRED ||
--