From: Namjae Jeon <namjae.jeon@xxxxxxxxxxx> Update FALLOC_FL_COLLAPSE_RANGE flag in fallocate. Signed-off-by: Namjae Jeon <namjae.jeon@xxxxxxxxxxx> Signed-off-by: Ashish Sangwan <a.sangwan@xxxxxxxxxxx> --- 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 <dgc@xxxxxxx> +.\" Updated by Namjae Jeon <namjae.jeon@xxxxxxxxxxx> .\" .\" %%%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 -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
