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path: root/drivers/scsi/scsi_lib.c
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Diffstat (limited to 'drivers/scsi/scsi_lib.c')
-rw-r--r--drivers/scsi/scsi_lib.c8
1 files changed, 8 insertions, 0 deletions
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index c7d6b76c86d2..4a902c9dfd8b 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -376,6 +376,14 @@ static void scsi_dec_host_busy(struct Scsi_Host *shost, struct scsi_cmnd *cmd)
rcu_read_lock();
__clear_bit(SCMD_STATE_INFLIGHT, &cmd->state);
if (unlikely(scsi_host_in_recovery(shost))) {
+ /*
+ * Ensure the clear of SCMD_STATE_INFLIGHT is visible to
+ * other CPUs before counting busy requests. Otherwise,
+ * reordering can cause CPUs to race and miss an eh wakeup
+ * when no CPU sees all busy requests as done or timed out.
+ */
+ smp_mb();
+
unsigned int busy = scsi_host_busy(shost);
spin_lock_irqsave(shost->host_lock, flags);