From: Namjae Jeon <[email protected]>
Update FALLOC_FL_COLLAPSE_RANGE flag in fallocate.
Signed-off-by: Namjae Jeon <[email protected]>
Signed-off-by: Ashish Sangwan <[email protected]>
---
man2/fallocate.2 | 21 +++++++++++++++++++++
1 file changed, 21 insertions(+)
diff --git a/man2/fallocate.2 b/man2/fallocate.2
index b31bbde..06a0b0c 100644
--- a/man2/fallocate.2
+++ b/man2/fallocate.2
@@ -1,5 +1,6 @@
.\" Copyright (c) 2007 Silicon Graphics, Inc. All Rights Reserved
.\" Written by Dave Chinner <[email protected]>
+.\" Updated by Namjae Jeon <[email protected]>
.\"
.\" %%%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
+.\" 2014-02-19: Added FALLOC_FL_COLLAPSE_RANGE
.\"
.TH FALLOCATE 2 2014-01-24 "Linux" "Linux Programmer's Manual"
.SH NAME
@@ -124,6 +126,25 @@ Btrfs (since Linux 3.7)
.IP *
tmpfs (since Linux 3.5)
.\" commit 83e4fa9c16e4af7122e31be3eca5d57881d236fe
+.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 ()
--
1.7.9.5