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authorMike Christie <michael.christie@oracle.com>2022-04-08 03:13:09 +0300
committerMartin K. Petersen <martin.petersen@oracle.com>2022-04-12 05:09:34 +0300
commit7c6e99c18167ed89729bf167ccb4a7e3ab3115ba (patch)
tree7c2bb5c871a3f91d90701a62057f7acaf76bee9e /include/scsi
parent0aadafb5c34403a7cced1a8d61877048dc059f70 (diff)
downloadlinux-7c6e99c18167ed89729bf167ccb4a7e3ab3115ba.tar.xz
scsi: iscsi: Fix conn cleanup and stop race during iscsid restart
If iscsid is doing a stop_conn at the same time the kernel is starting error recovery we can hit a race that allows the cleanup work to run on a valid connection. In the race, iscsi_if_stop_conn sees the cleanup bit set, but it calls flush_work on the clean_work before iscsi_conn_error_event has queued it. The flush then returns before the queueing and so the cleanup_work can run later and disconnect/stop a conn while it's in a connected state. The patch: Commit 0ab710458da1 ("scsi: iscsi: Perform connection failure entirely in kernel space") added the late stop_conn call bug originally, and the patch: Commit 23d6fefbb3f6 ("scsi: iscsi: Fix in-kernel conn failure handling") attempted to fix it but only fixed the normal EH case and left the above race for the iscsid restart case. For the normal EH case we don't hit the race because we only signal userspace to start recovery after we have done the queueing, so the flush will always catch the queued work or see it completed. For iscsid restart cases like boot, we can hit the race because iscsid will call down to the kernel before the kernel has signaled any error, so both code paths can be running at the same time. This adds a lock around the setting of the cleanup bit and queueing so they happen together. Link: https://lore.kernel.org/r/20220408001314.5014-6-michael.christie@oracle.com Fixes: 0ab710458da1 ("scsi: iscsi: Perform connection failure entirely in kernel space") Tested-by: Manish Rangankar <mrangankar@marvell.com> Reviewed-by: Lee Duncan <lduncan@suse.com> Reviewed-by: Chris Leech <cleech@redhat.com> Signed-off-by: Mike Christie <michael.christie@oracle.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Diffstat (limited to 'include/scsi')
-rw-r--r--include/scsi/scsi_transport_iscsi.h2
1 files changed, 2 insertions, 0 deletions
diff --git a/include/scsi/scsi_transport_iscsi.h b/include/scsi/scsi_transport_iscsi.h
index fdd486047404..9acb8422f680 100644
--- a/include/scsi/scsi_transport_iscsi.h
+++ b/include/scsi/scsi_transport_iscsi.h
@@ -211,6 +211,8 @@ struct iscsi_cls_conn {
struct mutex ep_mutex;
struct iscsi_endpoint *ep;
+ /* Used when accessing flags and queueing work. */
+ spinlock_t lock;
unsigned long flags;
struct work_struct cleanup_work;