Messages in this thread Patch in this message | | | From | "Paul E. McKenney" <> | Subject | [PATCH tip/core/rcu 12/22] nvme: Avoid flush dependency in delete controller flow | Date | Sun, 22 Apr 2018 19:32:17 -0700 |
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From: Nitzan Carmi <nitzanc@mellanox.com>
The nvme_delete_ctrl() function queues a work item on a MEM_RECLAIM queue (nvme_delete_wq), which eventually calls cleanup_srcu_struct(), which in turn flushes a delayed work from an !MEM_RECLAIM queue. This is unsafe as we might trigger deadlocks under severe memory pressure.
Since we don't ever invoke call_srcu(), it is safe to use the shiny new _quiesced() version of srcu cleanup, thus avoiding that flush dependency. This commit makes that change.
Signed-off-by: Nitzan Carmi <nitzanc@mellanox.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Max Gurtovoy <maxg@mellanox.com> --- drivers/nvme/host/core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c index 9df4f71e58ca..c3cea8a29843 100644 --- a/drivers/nvme/host/core.c +++ b/drivers/nvme/host/core.c @@ -349,7 +349,7 @@ static void nvme_free_ns_head(struct kref *ref) nvme_mpath_remove_disk(head); ida_simple_remove(&head->subsys->ns_ida, head->instance); list_del_init(&head->entry); - cleanup_srcu_struct(&head->srcu); + cleanup_srcu_struct_quiesced(&head->srcu); kfree(head); } -- 2.5.2
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