From: John Meneghini <jmeneghi@redhat.com>
To: "linux-nvme@lists.infradead.org" <linux-nvme@lists.infradead.org>
Subject: nvme/pcie hot plug results in /dev name change
Date: Fri, 20 Jan 2023 14:50:46 -0500 [thread overview]
Message-ID: <472fe309-f0f9-65bf-1ad1-8a92a349e973@redhat.com> (raw)
We have a customer complaining that when they hot unplug/plug their nvme-pci device the device name changes.
For example, when they hot remove /dev/nvme1n1 physically, then reinsert it, it gets identified as /dev/nvme4n1.
IIRC there is nothing about nvme_init_ctrl that guarantees the ctrl->instance will be the same because
ida_alloc() will only return the next free id in the bitmap.
The fact that nvme_remove -> nvme_init_ctrl many times results in the same ctrl->instance is just a happen stance and there is
nothing that guarantees /dev name consistency in Linux. Especially in the case of hot unplug/plug where the controller may very
well be marked NVME_CTRL_DEAD due to the ungraceful disconnect.
True?
--
John A. Meneghini
Senior Principal Platform Storage Engineer
RHEL SST - Platform Storage Group
jmeneghi@redhat.com
next reply other threads:[~2023-01-20 19:52 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-01-20 19:50 John Meneghini [this message]
2023-01-20 21:42 ` nvme/pcie hot plug results in /dev name change Keith Busch
2023-01-21 7:01 ` Christoph Hellwig
2023-01-29 10:28 ` Ming Lei
2023-01-31 16:38 ` Keith Busch
2023-02-01 2:33 ` Ming Lei
2023-02-01 6:27 ` Christoph Hellwig
2023-02-01 16:31 ` Keith Busch
2023-02-13 14:01 ` Sagi Grimberg
2023-02-13 16:32 ` Keith Busch
2023-02-14 0:04 ` Ming Lei
2023-02-14 9:18 ` Sagi Grimberg
2023-02-15 1:04 ` Ming Lei
2023-02-14 16:17 ` Keith Busch
2023-02-15 1:11 ` Ming Lei
2023-02-14 9:04 ` Sagi Grimberg
2023-02-15 6:18 ` Christoph Hellwig
2023-02-15 8:56 ` Sagi Grimberg
2023-02-15 22:18 ` Keith Busch
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