drbd: Implemented the disk-timeout option

When the disk-timeout is active, and it expires for a single request,
we consider the local disk as D_FAILED. Note: With this change,
I made both timeout based state transitions HARD state transitions.

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>

2 files changed, 6 insertions, 0 deletions

diff --git a/include/linux/drbd_limits.h b/include/linux/drbd_limits.h
index 928c84dfaf4..fb670bf603f 100644
--- a/include/linux/drbd_limits.h
+++ b/include/linux/drbd_limits.h
@@ -48,6 +48,11 @@
 #define DRBD_TIMEOUT_MAX 600
 #define DRBD_TIMEOUT_DEF 60       /* 6 seconds */
 
+ /* If backing disk takes longer than disk_timeout, mark the disk as failed */
+#define DRBD_DISK_TIMEOUT_MIN 0    /* 0 = disabled */
+#define DRBD_DISK_TIMEOUT_MAX 6000 /* 10 Minutes */
+#define DRBD_DISK_TIMEOUT_DEF 0    /* disabled */
+
   /* active connection retries when C_WF_CONNECTION */
 #define DRBD_CONNECT_INT_MIN 1
 #define DRBD_CONNECT_INT_MAX 120
diff --git a/include/linux/drbd_nl.h b/include/linux/drbd_nl.h
index 7203c9ead23..a8706f08ab3 100644
--- a/include/linux/drbd_nl.h
+++ b/include/linux/drbd_nl.h
@@ -31,6 +31,7 @@ NL_PACKET(disk_conf, 3,
         NL_INTEGER(     56,     T_MAY_IGNORE,   max_bio_bvecs)
         NL_BIT(         57,     T_MAY_IGNORE,   no_disk_barrier)
         NL_BIT(         58,     T_MAY_IGNORE,   no_disk_drain)
+        NL_INTEGER(     89,     T_MAY_IGNORE,   disk_timeout)
 )
 
 NL_PACKET(detach, 4,