f2fs: update documents and a MAINTAINERS entry

This patch adds missing some description of sysfs entries in
 - Documentation/ABI/testing/sysfs-fs-f2fs
 - Documentation/filesystems/f2fs.txt.

And it adds a maintained document entry of F2FS in MAINTAINERS.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
diff --git a/Documentation/ABI/testing/sysfs-fs-f2fs b/Documentation/ABI/testing/sysfs-fs-f2fs
index 31942ef..32b0809 100644
--- a/Documentation/ABI/testing/sysfs-fs-f2fs
+++ b/Documentation/ABI/testing/sysfs-fs-f2fs
@@ -24,3 +24,34 @@
 Contact:	"Namjae Jeon" <namjae.jeon@samsung.com>
 Description:
 		 Controls the victim selection policy for garbage collection.
+
+What:		/sys/fs/f2fs/<disk>/reclaim_segments
+Date:		October 2013
+Contact:	"Jaegeuk Kim" <jaegeuk.kim@samsung.com>
+Description:
+		 Controls the issue rate of segment discard commands.
+
+What:		/sys/fs/f2fs/<disk>/ipu_policy
+Date:		November 2013
+Contact:	"Jaegeuk Kim" <jaegeuk.kim@samsung.com>
+Description:
+		 Controls the in-place-update policy.
+
+What:		/sys/fs/f2fs/<disk>/min_ipu_util
+Date:		November 2013
+Contact:	"Jaegeuk Kim" <jaegeuk.kim@samsung.com>
+Description:
+		 Controls the FS utilization condition for the in-place-update
+		 policies.
+
+What:		/sys/fs/f2fs/<disk>/max_small_discards
+Date:		November 2013
+Contact:	"Jaegeuk Kim" <jaegeuk.kim@samsung.com>
+Description:
+		 Controls the issue rate of small discard commands.
+
+What:		/sys/fs/f2fs/<disk>/max_victim_search
+Date:		January 2014
+Contact:	"Jaegeuk Kim" <jaegeuk.kim@samsung.com>
+Description:
+		 Controls the number of trials to find a victim segment.