From: Max Gurtovoy <maxg@mellanox.com>
To: Christoph Hellwig <hch@lst.de>
Cc: Marta Rybczynska <mrybczyn@kalray.eu>, <kbusch@kernel.org>,
<axboe@fb.com>, <sagi@grimberg.me>,
<linux-nvme@lists.infradead.org>, <linux-kernel@vger.kernel.org>,
Samuel Jones <sjones@kalray.eu>,
Jean-Baptiste Riaux <jbriaux@kalray.eu>
Subject: Re: [PATCH v2] nvme: fix multipath crash when ANA desactivated
Date: Wed, 10 Jul 2019 11:53:40 +0300 [thread overview]
Message-ID: <0d113713-0198-0dc2-2a8f-a9fbcabbf05a@mellanox.com> (raw)
In-Reply-To: <20190709212904.GB9636@lst.de>
On 7/10/2019 12:29 AM, Christoph Hellwig wrote:
> On Sat, Jul 06, 2019 at 01:06:44PM +0300, Max Gurtovoy wrote:
>>> + /* check if multipath is enabled and we have the capability */
>>> + if (!multipath)
>>> + return 0;
>>> + if (!ctrl->subsys || ((ctrl->subsys->cmic & (1 << 3)) != 0))
>> shouldn't it be:
>>
>> if (!ctrl->subsys || ((ctrl->subsys->cmic & (1 << 3)) == 0))
>>
>> or
>>
>> if (!ctrl->subsys || !(ctrl->subsys->cmic & (1 << 3)))
>>
>>
>> Otherwise, you don't really do any initialization and return 0 in case you have the capability, right ?
> Yes. FYI, my idea how to fix this would be something like:
>
> diff --git a/drivers/nvme/host/multipath.c b/drivers/nvme/host/multipath.c
> index a9a927677970..cdb3e5baa329 100644
> --- a/drivers/nvme/host/multipath.c
> +++ b/drivers/nvme/host/multipath.c
> @@ -12,11 +12,6 @@ module_param(multipath, bool, 0444);
> MODULE_PARM_DESC(multipath,
> "turn on native support for multiple controllers per subsystem");
>
> -inline bool nvme_ctrl_use_ana(struct nvme_ctrl *ctrl)
> -{
> - return multipath && ctrl->subsys && (ctrl->subsys->cmic & (1 << 3));
> -}
> -
> /*
> * If multipathing is enabled we need to always use the subsystem instance
> * number for numbering our devices to avoid conflicts between subsystems that
> @@ -622,7 +617,7 @@ int nvme_mpath_init(struct nvme_ctrl *ctrl, struct nvme_id_ctrl *id)
> {
> int error;
>
> - if (!nvme_ctrl_use_ana(ctrl))
> + if (!multipath || !ctrl->subsys || !(ctrl->subsys->cmic & (1 << 3)))
> return 0;
>
> ctrl->anacap = id->anacap;
> diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h
> index 716a876119c8..14eca76bec5c 100644
> --- a/drivers/nvme/host/nvme.h
> +++ b/drivers/nvme/host/nvme.h
> @@ -485,7 +485,10 @@ extern const struct attribute_group *nvme_ns_id_attr_groups[];
> extern const struct block_device_operations nvme_ns_head_ops;
>
> #ifdef CONFIG_NVME_MULTIPATH
> -bool nvme_ctrl_use_ana(struct nvme_ctrl *ctrl);
> +static inline bool nvme_ctrl_use_ana(struct nvme_ctrl *ctrl)
> +{
> + return ctrl->ana_log_buf != NULL;
> +}
> void nvme_set_disk_name(char *disk_name, struct nvme_ns *ns,
> struct nvme_ctrl *ctrl, int *flags);
> void nvme_failover_req(struct request *req);
Yes this looks good.
prev parent reply other threads:[~2019-07-10 8:54 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-05 14:05 [PATCH v2] nvme: fix multipath crash when ANA desactivated Marta Rybczynska
2019-07-06 10:06 ` Max Gurtovoy
2019-07-09 21:29 ` Christoph Hellwig
2019-07-10 5:26 ` Marta Rybczynska
2019-07-10 16:38 ` Christoph Hellwig
2019-07-12 13:08 ` Marta Rybczynska
2019-07-10 8:53 ` Max Gurtovoy [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=0d113713-0198-0dc2-2a8f-a9fbcabbf05a@mellanox.com \
--to=maxg@mellanox.com \
--cc=axboe@fb.com \
--cc=hch@lst.de \
--cc=jbriaux@kalray.eu \
--cc=kbusch@kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-nvme@lists.infradead.org \
--cc=mrybczyn@kalray.eu \
--cc=sagi@grimberg.me \
--cc=sjones@kalray.eu \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).