[PATCH RESEND 10/10] manpage: update FALLOC_FL_COLLAPSE_RANGE flag in fallocate

@@ -1,5 +1,6 @@
 .\" Copyright (c) 2007 Silicon Graphics, Inc. All Rights Reserved
 .\" Written by Dave Chinner <dgc@sgi.com>
+.\" Updated by Namjae Jeon <namjae.jeon@samsung.com>
 .\"
 .\" %%%LICENSE_START(GPLv2_ONELINE)
 .\" May be distributed as per GNU General Public License version 2.

@@ -7,6 +8,7 @@
 .\"
 .\" 2011-09-19: Added FALLOC_FL_PUNCH_HOLE
 .\" 2011-09-19: Substantial restructuring of the page
+.\" 2013-11-10: Added FALLOC_FL_COLLAPSE_RANGE
 .\"
 .TH FALLOCATE 2 2013-11-08 "Linux" "Linux Programmer's Manual"
 .SH NAME

@@ -113,6 +115,25 @@ does not change.
 Not all filesystems support
 .BR FALLOC_FL_PUNCH_HOLE ;
 if a filesystem doesn't support the operation, an error is returned.
+.SS Collapsing file space
+Specifiying the
+.BR FALLOC_FL_COLLAPSE_RANGE
+flag in
+.I mode
+collpse space in the byte range starting at
+.I offset
+and continuing for
+.I len
+bytes. Within the specified range, it first de-allocates blocks and eliminates
+the hole created in this process by shifting data blocks into the hole.
+
+Different filesystem may implement different limitatios on the granularity of
+the operation. Most filesystem will limit operations to filesystem block size
+boundaries, but this boundary may be larger or smaller depending
+on the filesystem and/or the configuration of the filesystem or file.
+
+If filesystem has such limitation on granularity, It will return error(EINVAL).
+
 .SH RETURN VALUE
 On success,
 .BR fallocate ()