nvmet: copy the hostid into the ctrl before creating PR pc_refs

Commit 6202783184 ("nvmet: Improve nvmet_alloc_ctrl() interface and
implementation") added a second uuid_copy() of args->hostid near the end
of nvmet_alloc_ctrl(), and commit 7b658153f1 ("nvmet: Remove duplicate
uuid_copy") removed the original copy that sat before
nvmet_ctrl_init_pr() instead of the new one.

Since then nvmet_ctrl_init_pr() snapshots ctrl->hostid into the
per-controller per-namespace reservation refs while the uuid_copy()
from the connect data runs later, after the controller is published.
The ctrl is allocated with kzalloc(), so every pc_ref created on this
path stores the nil UUID.

pc_ref->hostid has a single consumer: nvmet_pr_set_ctrl_to_abort()
matches it against the preempted registrant's hostid to kill and drain
the victim's in-flight I/O for Preempt and Abort.  The match can never
hit with the nil UUID, so whenever a namespace with reservations
enabled exists before a host connects, which includes every reconnect,
Preempt and Abort silently degrades into a plain Preempt: the
preempting host sees success while the victim's in-flight I/O is still
in the air.

Copy the hostid where the rest of the connect data is consumed, before
the controller is published and before nvmet_ctrl_init_pr() takes its
snapshot.

Fixes: 7b658153f1 ("nvmet: Remove duplicate uuid_copy")
Cc: stable@vger.kernel.org
Reviewed-by: Nilay Shroff <nilay@linux.ibm.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Guixin Liu <kanie@linux.alibaba.com>
Signed-off-by: Keith Busch <kbusch@kernel.org>
This commit is contained in:
Guixin Liu 2026-09-16 19:42:54 +08:00 committed by Keith Busch
parent fa6778e030
commit 5211fed41d

View File

@ -1648,6 +1648,8 @@ struct nvmet_ctrl *nvmet_alloc_ctrl(struct nvmet_alloc_ctrl_args *args)
INIT_DELAYED_WORK(&ctrl->ka_work, nvmet_keep_alive_timer);
memcpy(ctrl->hostnqn, args->hostnqn, NVMF_NQN_SIZE);
if (args->hostid)
uuid_copy(&ctrl->hostid, args->hostid);
kref_init(&ctrl->ref);
ctrl->subsys = subsys;
@ -1706,9 +1708,6 @@ struct nvmet_ctrl *nvmet_alloc_ctrl(struct nvmet_alloc_ctrl_args *args)
nvmet_start_keep_alive_timer(ctrl);
if (args->hostid)
uuid_copy(&ctrl->hostid, args->hostid);
dhchap_status = nvmet_setup_auth(ctrl, args->sq, false);
if (dhchap_status) {
pr_err("Failed to setup authentication, dhchap status %u\n",