diff --git a/Documentation/ABI/testing/sysfs-block b/Documentation/ABI/testing/sysfs-block
index 7710d4022b19ec5641d4f0983b73227452662680..dfad7427817c05135ed2554b64529944367f03f9 100644
--- a/Documentation/ABI/testing/sysfs-block
+++ b/Documentation/ABI/testing/sysfs-block
@@ -279,3 +279,12 @@ Description:
 		size in 512B sectors of the zones of the device, with
 		the eventual exception of the last zone of the device
 		which may be smaller.
+
+What:		/sys/block/<disk>/queue/io_timeout
+Date:		November 2018
+Contact:	Weiping Zhang <zhangweiping@didiglobal.com>
+Description:
+		io_timeout is the request timeout in milliseconds. If a request
+		does not complete in this time then the block driver timeout
+		handler is invoked. That timeout handler can decide to retry
+		the request, to fail it or to start a device recovery strategy.
diff --git a/Documentation/block/queue-sysfs.txt b/Documentation/block/queue-sysfs.txt
index 39e286d7afc90a94d4129da44a5fbb8e685c1ff9..83b457e24bbaecedc307d6649e6a2c574c568472 100644
--- a/Documentation/block/queue-sysfs.txt
+++ b/Documentation/block/queue-sysfs.txt
@@ -67,6 +67,13 @@ If set to a value larger than 0, the kernel will put the process issuing
 IO to sleep for this amount of microseconds before entering classic
 polling.
 
+io_timeout (RW)
+---------------
+io_timeout is the request timeout in milliseconds. If a request does not
+complete in this time then the block driver timeout handler is invoked.
+That timeout handler can decide to retry the request, to fail it or to start
+a device recovery strategy.
+
 iostats (RW)
 -------------
 This file is used to control (on/off) the iostats accounting of the