[PATCH] libata: implement per-dev EH action mask eh_info->dev_action[]

Currently, the only per-dev EH action is REVALIDATE.  EH used to
exploit ehi->dev to do selective revalidation on a ATA bus.  However,
this is a bit hacky and makes it impossible to request selective
revalidation from outside of EH or add another per-dev EH action.

This patch adds per-dev EH action mask eh_info->dev_action[] and
update EH to use this field for REVALIDATE.  Note that per-dev actions
can still be specified at port-level and it has the same effect of
specifying the action for all devices on the port.

Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

1 files changed, 69 insertions, 16 deletions

diff --git a/drivers/scsi/libata-eh.c b/drivers/scsi/libata-eh.c
index 531a4e11c078..70b623988a9f 100644
--- a/drivers/scsi/libata-eh.c
+++ b/drivers/scsi/libata-eh.c
@@ -706,9 +706,35 @@ static void ata_eh_detach_dev(struct ata_device *dev)
         spin_unlock_irqrestore(&ap->host_set->lock, flags);
 }
 
+static void ata_eh_clear_action(struct ata_device *dev,
+                                struct ata_eh_info *ehi, unsigned int action)
+{
+        int i;
+
+        if (!dev) {
+                ehi->action &= ~action;
+                for (i = 0; i < ATA_MAX_DEVICES; i++)
+                        ehi->dev_action[i] &= ~action;
+        } else {
+                /* doesn't make sense for port-wide EH actions */
+                WARN_ON(!(action & ATA_EH_PERDEV_MASK));
+
+                /* break ehi->action into ehi->dev_action */
+                if (ehi->action & action) {
+                        for (i = 0; i < ATA_MAX_DEVICES; i++)
+                                ehi->dev_action[i] |= ehi->action & action;
+                        ehi->action &= ~action;
+                }
+
+                /* turn off the specified per-dev action */
+                ehi->dev_action[dev->devno] &= ~action;
+        }
+}
+
 /**
  *      ata_eh_about_to_do - about to perform eh_action
  *      @ap: target ATA port
+ *      @dev: target ATA dev for per-dev action (can be NULL)
  *      @action: action about to be performed
  *
  *      Called just before performing EH actions to clear related bits
@@ -718,17 +744,36 @@ static void ata_eh_detach_dev(struct ata_device *dev)
  *      LOCKING:
  *      None.
  */
-static void ata_eh_about_to_do(struct ata_port *ap, unsigned int action)
+static void ata_eh_about_to_do(struct ata_port *ap, struct ata_device *dev,
+                               unsigned int action)
 {
         unsigned long flags;
 
         spin_lock_irqsave(&ap->host_set->lock, flags);
-        ap->eh_info.action &= ~action;
+        ata_eh_clear_action(dev, &ap->eh_info, action);
         ap->flags |= ATA_FLAG_RECOVERED;
         spin_unlock_irqrestore(&ap->host_set->lock, flags);
 }
 
 /**
+ *      ata_eh_done - EH action complete
+ *      @ap: target ATA port
+ *      @dev: target ATA dev for per-dev action (can be NULL)
+ *      @action: action just completed
+ *
+ *      Called right after performing EH actions to clear related bits
+ *      in @ap->eh_context.
+ *
+ *      LOCKING:
+ *      None.
+ */
+static void ata_eh_done(struct ata_port *ap, struct ata_device *dev,
+                        unsigned int action)
+{
+        ata_eh_clear_action(dev, &ap->eh_context.i, action);
+}
+
+/**
  *      ata_err_string - convert err_mask to descriptive string
  *      @err_mask: error mask to convert to string
  *
@@ -1271,10 +1316,6 @@ static void ata_eh_autopsy(struct ata_port *ap)
                         is_io = 1;
         }
 
-        /* speed down iff command was in progress */
-        if (failed_dev)
-                action |= ata_eh_speed_down(failed_dev, is_io, all_err_mask);
-
         /* enforce default EH actions */
         if (ap->flags & ATA_FLAG_FROZEN ||
             all_err_mask & (AC_ERR_HSM | AC_ERR_TIMEOUT))
@@ -1282,6 +1323,17 @@ static void ata_eh_autopsy(struct ata_port *ap)
         else if (all_err_mask)
                 action |= ATA_EH_REVALIDATE;
 
+        /* if we have offending qcs and the associated failed device */
+        if (failed_dev) {
+                /* speed down */
+                action |= ata_eh_speed_down(failed_dev, is_io, all_err_mask);
+
+                /* perform per-dev EH action only on the offending device */
+                ehc->i.dev_action[failed_dev->devno] |=
+                        action & ATA_EH_PERDEV_MASK;
+                action &= ~ATA_EH_PERDEV_MASK;
+        }
+
         /* record autopsy result */
         ehc->i.dev = failed_dev;
         ehc->i.action = action;
@@ -1457,7 +1509,7 @@ static int ata_eh_reset(struct ata_port *ap, int classify,
                                 reset == softreset ? "soft" : "hard");
 
         /* reset */
-        ata_eh_about_to_do(ap, ATA_EH_RESET_MASK);
+        ata_eh_about_to_do(ap, NULL, ATA_EH_RESET_MASK);
         ehc->i.flags |= ATA_EHI_DID_RESET;
 
         rc = ata_do_reset(ap, reset, classes);
@@ -1476,7 +1528,7 @@ static int ata_eh_reset(struct ata_port *ap, int classify,
                         return -EINVAL;
                 }
 
-                ata_eh_about_to_do(ap, ATA_EH_RESET_MASK);
+                ata_eh_about_to_do(ap, NULL, ATA_EH_RESET_MASK);
                 rc = ata_do_reset(ap, reset, classes);
 
                 if (rc == 0 && classify &&
@@ -1520,8 +1572,7 @@ static int ata_eh_reset(struct ata_port *ap, int classify,
                         postreset(ap, classes);
 
                 /* reset successful, schedule revalidation */
-                ehc->i.dev = NULL;
-                ehc->i.action &= ~ATA_EH_RESET_MASK;
+                ata_eh_done(ap, NULL, ATA_EH_RESET_MASK);
                 ehc->i.action |= ATA_EH_REVALIDATE;
         }
 
@@ -1539,21 +1590,25 @@ static int ata_eh_revalidate_and_attach(struct ata_port *ap,
         DPRINTK("ENTER\n");
 
         for (i = 0; i < ATA_MAX_DEVICES; i++) {
+                unsigned int action;
+
                 dev = &ap->device[i];
+                action = ehc->i.action | ehc->i.dev_action[dev->devno];
 
-                if (ehc->i.action & ATA_EH_REVALIDATE && ata_dev_enabled(dev) &&
-                    (!ehc->i.dev || ehc->i.dev == dev)) {
+                if (action & ATA_EH_REVALIDATE && ata_dev_enabled(dev)) {
                         if (ata_port_offline(ap)) {
                                 rc = -EIO;
                                 break;
                         }
 
-                        ata_eh_about_to_do(ap, ATA_EH_REVALIDATE);
+                        ata_eh_about_to_do(ap, dev, ATA_EH_REVALIDATE);
                         rc = ata_dev_revalidate(dev,
                                         ehc->i.flags & ATA_EHI_DID_RESET);
                         if (rc)
                                 break;
 
+                        ata_eh_done(ap, dev, ATA_EH_REVALIDATE);
+
                         /* schedule the scsi_rescan_device() here */
                         queue_work(ata_aux_wq, &(ap->scsi_rescan_task));
                 } else if (dev->class == ATA_DEV_UNKNOWN &&
@@ -1576,9 +1631,7 @@ static int ata_eh_revalidate_and_attach(struct ata_port *ap,
                 }
         }
 
-        if (rc == 0)
-                ehc->i.action &= ~ATA_EH_REVALIDATE;
-        else
+        if (rc)
                 *r_failed_dev = dev;
 
         DPRINTK("EXIT\n");