libata: implement ATA_QCFLAG_RETRY

Currently whether a command should be retried after failure is
determined inside ata_eh_finish().  Add ATA_QCFLAG_RETRY and move the
logic into ata_eh_autopsy().  This makes things clearer and helps
extending retry determination logic.

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

diff --git a/drivers/ata/libata-eh.c b/drivers/ata/libata-eh.c
index ec32082..cc8548e 100644 (file)
--- a/drivers/ata/libata-eh.c
+++ b/drivers/ata/libata-eh.c
@@ -1785,6 +1785,11 @@ static void ata_eh_link_autopsy(struct ata_link *link)
                if (qc->flags & ATA_QCFLAG_SENSE_VALID)
                        qc->err_mask &= ~(AC_ERR_DEV | AC_ERR_OTHER);
 
+               /* determine whether the command is worth retrying */
+               if (!(qc->err_mask & AC_ERR_INVALID) &&
+                   ((qc->flags & ATA_QCFLAG_IO) || qc->err_mask != AC_ERR_DEV))
+                       qc->flags |= ATA_QCFLAG_RETRY;
+
                /* accumulate error info */
                ehc->i.dev = qc->dev;
                all_err_mask |= qc->err_mask;
@@ -2783,18 +2788,11 @@ void ata_eh_finish(struct ata_port *ap)
                        /* FIXME: Once EH migration is complete,
                         * generate sense data in this function,
                         * considering both err_mask and tf.
-                        *
-                        * There's no point in retrying invalid
-                        * (detected by libata) and non-IO device
-                        * errors (rejected by device).  Finish them
-                        * immediately.
                         */
-                       if ((qc->err_mask & AC_ERR_INVALID) ||
-                           (!(qc->flags & ATA_QCFLAG_IO) &&
-                            qc->err_mask == AC_ERR_DEV))
-                               ata_eh_qc_complete(qc);
-                       else
+                       if (qc->flags & ATA_QCFLAG_RETRY)
                                ata_eh_qc_retry(qc);
+                       else
+                               ata_eh_qc_complete(qc);
                } else {
                        if (qc->flags & ATA_QCFLAG_SENSE_VALID) {
                                ata_eh_qc_complete(qc);

diff --git a/include/linux/libata.h b/include/linux/libata.h
index 61a7f8d..b25ea6a 100644 (file)
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -224,6 +224,7 @@ enum {
        ATA_QCFLAG_RESULT_TF    = (1 << 4), /* result TF requested */
        ATA_QCFLAG_CLEAR_EXCL   = (1 << 5), /* clear excl_link on completion */
        ATA_QCFLAG_QUIET        = (1 << 6), /* don't report device error */
+       ATA_QCFLAG_RETRY        = (1 << 7), /* retry after failure */
 
        ATA_QCFLAG_FAILED       = (1 << 16), /* cmd failed and is owned by EH */
        ATA_QCFLAG_SENSE_VALID  = (1 << 17), /* sense data valid */