[PATCH] libata-eh: implement dev->ering

This patch implements ata_ering and uses it to define dev->ering.

ata_ering is a ring buffer which records libata errors - whether a
command was for normar IO request, err_mask and timestamp.  Errors are
recorded per-device in dev->ering.  This will be used by EH to
determine recovery actions.

Signed-off-by: Tejun Heo <htejun@gmail.com>

1 files changed, 17 insertions, 0 deletions

diff --git a/include/linux/libata.h b/include/linux/libata.h
index 6fe5ed8eabf5..f5cea13599c3 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -226,6 +226,9 @@ enum {
         ATA_PORT_PRIMARY        = (1 << 0),
         ATA_PORT_SECONDARY      = (1 << 1),
 
+        /* ering size */
+        ATA_ERING_SIZE          = 32,
+
         /* reset / recovery action types */
         ATA_EH_REVALIDATE       = (1 << 0),
         ATA_EH_SOFTRESET        = (1 << 1),
@@ -375,6 +378,17 @@ struct ata_host_stats {
         unsigned long           rw_reqbuf;
 };
 
+struct ata_ering_entry {
+        int                     is_io;
+        unsigned int            err_mask;
+        u64                     timestamp;
+};
+
+struct ata_ering {
+        int                     cursor;
+        struct ata_ering_entry  ring[ATA_ERING_SIZE];
+};
+
 struct ata_device {
         struct ata_port         *ap;
         u64                     n_sectors;      /* size of device, if ATA */
@@ -401,6 +415,9 @@ struct ata_device {
         u16                     cylinders;      /* Number of cylinders */
         u16                     heads;          /* Number of heads */
         u16                     sectors;        /* Number of sectors per track */
+
+        /* error history */
+        struct ata_ering        ering;
 };
 
 struct ata_port {