From: "Martin K. Petersen" <martin.petersen@oracle.com>
To: Max Gurtovoy <mgurtovoy@nvidia.com>
Cc: <martin.petersen@oracle.com>, <hch@lst.de>, <sagi@grimberg.me>,
<linux-nvme@lists.infradead.org>, <hare@suse.de>,
<kbusch@kernel.org>, <axboe@kernel.dk>,
<linux-block@vger.kernel.org>, <oren@nvidia.com>,
<oevron@nvidia.com>, <israelr@nvidia.com>
Subject: Re: [PATCH v2 2/2] nvme-multipath: fix path failover for integrity ns
Date: Mon, 24 Apr 2023 22:12:52 -0400 [thread overview]
Message-ID: <yq1jzy0lnyl.fsf@ca-mkp.ca.oracle.com> (raw)
In-Reply-To: <20230424225442.18916-3-mgurtovoy@nvidia.com> (Max Gurtovoy's message of "Tue, 25 Apr 2023 01:54:42 +0300")
Hi Max!
> In case the integrity capabilities of the failed path and the failover
> path don't match, we may run into NULL dereference. Free the integrity
> context during the path failover and let the block layer prepare it
> again if needed during bio_submit.
This assumes that the protection information is just an ephemeral
checksum. However, that is not always the case. The application may
store values in the application or storage tags which must be returned
on a subsequent read.
In addition, in some overseas markets (financial, government), PI is a
regulatory requirement. It would be really bad for us to expose a device
claiming PI support and then it turns out the protection isn't actually
always active.
DM multipathing doesn't allow mismatched integrity profiles. I don't
think NVMe should either.
--
Martin K. Petersen Oracle Linux Engineering
next prev parent reply other threads:[~2023-04-25 2:13 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-04-24 22:54 [PATCH v2 0/2] Fix failover to non integrity NVMe path Max Gurtovoy
2023-04-24 22:54 ` [PATCH v2 1/2] block: bio-integrity: export bio_integrity_free func Max Gurtovoy
2023-04-24 22:54 ` [PATCH v2 2/2] nvme-multipath: fix path failover for integrity ns Max Gurtovoy
2023-04-25 2:12 ` Martin K. Petersen [this message]
2023-04-25 10:24 ` Max Gurtovoy
2023-04-25 22:39 ` Keith Busch
2023-04-26 1:22 ` Martin K. Petersen
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