[PATCH 5/7] docs: sysfs-block: document virt_boundary_mask

[Eric Biggers]

From: Eric Biggers <ebiggers@xxxxxxxxxx>

/sys/block/<disk>/queue/virt_boundary_mask is completely undocumented.
Document it.

Signed-off-by: Eric Biggers <ebiggers@xxxxxxxxxx>
---
 Documentation/ABI/testing/sysfs-block | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/Documentation/ABI/testing/sysfs-block b/Documentation/ABI/testing/sysfs-block
index 5d8b187e1ec54..8cc795476244c 100644
--- a/Documentation/ABI/testing/sysfs-block
+++ b/Documentation/ABI/testing/sysfs-block
@@ -536,6 +536,17 @@ Description:
 		CONFIG_BLK_DEV_THROTTLING_LOW is enabled.
 
 
+What:		/sys/block/<disk>/queue/virt_boundary_mask
+Date:		April 2021
+Contact:	linux-block@xxxxxxxxxxxxxxx
+Description:
+		[RO] This file shows the I/O segment alignment mask for the
+		block device.  I/O requests to this device will be split between
+		segments wherever either the end of the previous segment or the
+		beginning of the current segment is not aligned to
+		virt_boundary_mask + 1 bytes.
+
+
 What:		/sys/block/<disk>/queue/wbt_lat_usec
 Date:		November 2016
 Contact:	linux-block@xxxxxxxxxxxxxxx
-- 
2.34.1