This patch adds the relevant documenation for using fallocate with the
FALLOC_FL_PUNCH_HOLE mode. This information comes from the implementation of
FALLOC_FL_PUNCH_HOLE that I've posted along with this man page update to outline
the definition for hole punching. Obviously this patch is dependant upon the
current implementation being accepted. Thanks,
Signed-off-by: Josef Bacik <[email protected]>
---
man2/fallocate.2 | 15 ++++++++++++---
1 files changed, 12 insertions(+), 3 deletions(-)
diff --git a/man2/fallocate.2 b/man2/fallocate.2
index 42eefbd..1b28916 100644
--- a/man2/fallocate.2
+++ b/man2/fallocate.2
@@ -31,9 +31,8 @@ bytes.
The
.I mode
-argument determines the operation to be performed on the given range.
-Currently only one flag is supported for
-.IR mode :
+argument determines the operation to be performed on the given range, the
+value can be one of the following:
.TP
.B FALLOC_FL_KEEP_SIZE
This flag allocates and initializes to zero the disk space
@@ -50,6 +49,16 @@ the file size (as reported by
.BR stat (2))
even if it is less than
.IR offset + len .
+.TP
+.B FALLOC_FL_PUNCH_HOLE
+This flag de-allocates the disk space within the range specified by
+.I offset
+and
+.IR len .
+This call preserves the file size (as reported by
+.BR stat (2)),
+the only change will be to the amount of space used by the file. After a
+successful call, subsequent reads from this range will return 0's.
.\"
.\" Note from Amit Arora:
.\" There were few more flags which were discussed, but none of
--
1.6.6.1