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authorKristen Carlson Accardi <kristen.c.accardi@intel.com>2007-05-23 13:57:38 -0700
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-05-23 20:14:11 -0700
commit86ce18d7b7925bfd6b64c061828ca2a857ee83b8 (patch)
treeb753b7fd6d195aa7ed9eebc5a3917c5f20786260 /Documentation/block
parent352823160613b65fdaa558be486720a71f75ed86 (diff)
genhd: expose AN to user space
Allow user space to determine if a disk supports Asynchronous Notification of media changes. This is done by adding a new sysfs file "capability_flags", which is documented in (insert file name). This sysfs file will export all disk capabilities flags to user space. We also define a new flag to define the media change notification capability. Signed-off-by: Kristen Carlson Accardi <kristen.c.accardi@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'Documentation/block')
-rw-r--r--Documentation/block/capability.txt15
1 files changed, 15 insertions, 0 deletions
diff --git a/Documentation/block/capability.txt b/Documentation/block/capability.txt
new file mode 100644
index 000000000000..2f1729424ef4
--- /dev/null
+++ b/Documentation/block/capability.txt
@@ -0,0 +1,15 @@
+Generic Block Device Capability
+===============================================================================
+This file documents the sysfs file block/<disk>/capability
+
+capability is a hex word indicating which capabilities a specific disk
+supports. For more information on bits not listed here, see
+include/linux/genhd.h
+
+Capability Value
+-------------------------------------------------------------------------------
+GENHD_FL_MEDIA_CHANGE_NOTIFY 4
+ When this bit is set, the disk supports Asynchronous Notification
+ of media change events. These events will be broadcast to user
+ space via kernel uevent.
+