This is a note to let you know that I've just added the patch titled
nvme: use kref_get_unless_zero in nvme_find_get_ns
to the 4.14-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
nvme-use-kref_get_unless_zero-in-nvme_find_get_ns.patch
and it can be found in the queue-4.14 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From foo@baz Mon Dec 18 13:28:59 CET 2017
From: Christoph Hellwig <hch@xxxxxx>
Date: Wed, 18 Oct 2017 13:20:01 +0200
Subject: nvme: use kref_get_unless_zero in nvme_find_get_ns
From: Christoph Hellwig <hch@xxxxxx>
[ Upstream commit 2dd4122854f697afc777582d18548dded03ce5dd ]
For kref_get_unless_zero to protect against lookup vs free races we need
to use it in all places where we aren't guaranteed to already hold a
reference. There is no such guarantee in nvme_find_get_ns, so switch to
kref_get_unless_zero in this function.
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Reviewed-by: Sagi Grimberg <sagi@xxxxxxxxxxx>
Reviewed-by: Hannes Reinecke <hare@xxxxxxxx>
Reviewed-by: Johannes Thumshirn <jthumshirn@xxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/nvme/host/core.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -2299,7 +2299,8 @@ static struct nvme_ns *nvme_find_get_ns(
mutex_lock(&ctrl->namespaces_mutex);
list_for_each_entry(ns, &ctrl->namespaces, list) {
if (ns->ns_id == nsid) {
- kref_get(&ns->kref);
+ if (!kref_get_unless_zero(&ns->kref))
+ continue;
ret = ns;
break;
}
Patches currently in stable-queue which might be from hch@xxxxxx are
queue-4.14/xfs-fix-incorrect-extent-state-in-xfs_bmap_add_extent_unwritten_real.patch
queue-4.14/nvme-use-kref_get_unless_zero-in-nvme_find_get_ns.patch
queue-4.14/target-iscsi-detect-conn_cmd_list-corruption-early.patch
queue-4.14/target-iscsi-fix-a-race-condition-in-iscsit_add_reject_from_cmd.patch
queue-4.14/scsi-core-fix-a-scsi_show_rq-null-pointer-dereference.patch
queue-4.14/scsi-libsas-fix-length-error-in-sas_smp_handler.patch
queue-4.14/blk-mq-sched-dispatch-from-scheduler-iff-progress-is-made-in-dispatch.patch