libata: fix EH locking

Wrap ata_qc_complete() calls in EH context in spinlocks, to prevent
races (mainly in ATAPI code paths).

1 files changed, 6 insertions, 1 deletions

diff --git a/drivers/scsi/ahci.c b/drivers/scsi/ahci.c
index 348493982b56..841f4e2cfe08 100644
--- a/drivers/scsi/ahci.c
+++ b/drivers/scsi/ahci.c
@@ -586,12 +586,16 @@ static void ahci_intr_error(struct ata_port *ap, u32 irq_stat)
 
 static void ahci_eng_timeout(struct ata_port *ap)
 {
-        void *mmio = ap->host_set->mmio_base;
+        struct ata_host_set *host_set = ap->host_set;
+        void *mmio = host_set->mmio_base;
         void *port_mmio = ahci_port_base(mmio, ap->port_no);
         struct ata_queued_cmd *qc;
+        unsigned long flags;
 
         DPRINTK("ENTER\n");
 
+        spin_lock_irqsave(&host_set->lock, flags);
+
         ahci_intr_error(ap, readl(port_mmio + PORT_IRQ_STAT));
 
         qc = ata_qc_from_tag(ap, ap->active_tag);
@@ -609,6 +613,7 @@ static void ahci_eng_timeout(struct ata_port *ap)
                 ata_qc_complete(qc, ATA_ERR);
         }
 
+        spin_unlock_irqrestore(&host_set->lock, flags);
 }
 
 static inline int ahci_host_intr(struct ata_port *ap, struct ata_queued_cmd *qc)