From 848b89778ed53e6c9f9e3ed01c90109ee970b3d1 Mon Sep 17 00:00:00 2001 From: Davidlohr Bueso Date: Fri, 6 May 2022 12:57:55 +0200 Subject: scsi: fcoe: Add a local_lock to fcoe_percpu fcoe_get_paged_crc_eof() relies on the caller having preemption disabled to ensure the per-CPU fcoe_percpu context remains valid throughout the call. This is done by either holding spinlocks (such as bnx2fc_global_lock or qedf_global_lock) or the get_cpu() from fcoe_alloc_paged_crc_eof(). This last one breaks PREEMPT_RT semantics as there can be memory allocation and end up sleeping in atomic contexts. Introduce a local_lock_t to struct fcoe_percpu that will keep the non-RT case the same, mapping to preempt_disable/enable, while RT will use a per-CPU spinlock allowing the region to be preemptible but still maintain CPU locality. The other users of fcoe_percpu are already safe in this regard and do not require local_lock()ing. Link: https://lore.kernel.org/r/20211117025956.79616-3-dave@stgolabs.net Link: https://lore.kernel.org/r/20220506105758.283887-2-bigeasy@linutronix.de Acked-by: Sebastian Andrzej Siewior Signed-off-by: Davidlohr Bueso Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Martin K. Petersen --- include/scsi/libfcoe.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'include/scsi') diff --git a/include/scsi/libfcoe.h b/include/scsi/libfcoe.h index fac8e89aed81..6e79fb87fea2 100644 --- a/include/scsi/libfcoe.h +++ b/include/scsi/libfcoe.h @@ -14,6 +14,7 @@ #include #include #include +#include #include #include #include @@ -326,6 +327,7 @@ struct fcoe_percpu_s { struct sk_buff_head fcoe_rx_list; struct page *crc_eof_page; int crc_eof_offset; + local_lock_t lock; }; /** -- cgit v1.2.3