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, 12 insertions, 2 deletions

diff --git a/drivers/scsi/libata-core.c b/drivers/scsi/libata-core.c
index 157a3e914cb7..ec7bff73ae18 100644
--- a/drivers/scsi/libata-core.c
+++ b/drivers/scsi/libata-core.c
@@ -2388,12 +2388,13 @@ static int ata_sg_setup(struct ata_queued_cmd *qc)
 void ata_poll_qc_complete(struct ata_queued_cmd *qc, u8 drv_stat)
 {
         struct ata_port *ap = qc->ap;
+        unsigned long flags;
 
-        spin_lock_irq(&ap->host_set->lock);
+        spin_lock_irqsave(&ap->host_set->lock, flags);
         ap->flags &= ~ATA_FLAG_NOINTR;
         ata_irq_on(ap);
         ata_qc_complete(qc, drv_stat);
-        spin_unlock_irq(&ap->host_set->lock);
+        spin_unlock_irqrestore(&ap->host_set->lock, flags);
 }
 
 /**
@@ -2973,8 +2974,10 @@ static void atapi_request_sense(struct ata_port *ap, struct ata_device *dev,
 static void ata_qc_timeout(struct ata_queued_cmd *qc)
 {
         struct ata_port *ap = qc->ap;
+        struct ata_host_set *host_set = ap->host_set;
         struct ata_device *dev = qc->dev;
         u8 host_stat = 0, drv_stat;
+        unsigned long flags;
 
         DPRINTK("ENTER\n");
 
@@ -2985,7 +2988,9 @@ static void ata_qc_timeout(struct ata_queued_cmd *qc)
                 if (!(cmd->eh_eflags & SCSI_EH_CANCEL_CMD)) {
 
                         /* finish completing original command */
+                        spin_lock_irqsave(&host_set->lock, flags);
                         __ata_qc_complete(qc);
+                        spin_unlock_irqrestore(&host_set->lock, flags);
 
                         atapi_request_sense(ap, dev, cmd);
 
@@ -2996,6 +3001,8 @@ static void ata_qc_timeout(struct ata_queued_cmd *qc)
                 }
         }
 
+        spin_lock_irqsave(&host_set->lock, flags);
+
         /* hack alert!  We cannot use the supplied completion
          * function from inside the ->eh_strategy_handler() thread.
          * libata is the only user of ->eh_strategy_handler() in
@@ -3029,6 +3036,9 @@ static void ata_qc_timeout(struct ata_queued_cmd *qc)
                 ata_qc_complete(qc, drv_stat);
                 break;
         }
+
+        spin_unlock_irqrestore(&host_set->lock, flags);
+
 out:
         DPRINTK("EXIT\n");
 }