LDP: Update original to LDP v3.68

[linuxjm/LDP_man-pages.git] / original / man2 / lseek.2

diff --git a/original/man2/lseek.2 b/original/man2/lseek.2
index e10eb4a..93efb3d 100644 (file)
--- a/original/man2/lseek.2
+++ b/original/man2/lseek.2
@@ -44,7 +44,7 @@
 .\" Modified 2003-08-21 by Andries Brouwer <aeb@cwi.nl>
 .\" 2011-09-18, mtk, Added SEEK_DATA + SEEK_HOLE
 .\"
-.TH LSEEK 2 2011-09-25 "Linux" "Linux Programmer's Manual"
+.TH LSEEK 2 2014-01-22 "Linux" "Linux Programmer's Manual"
 .SH NAME
 lseek \- reposition read/write file offset
 .SH SYNOPSIS
@@ -130,13 +130,13 @@ if they have a mechanism for discovering holes.
 
 For the purposes of these operations, a hole is a sequence of zeros that
 (normally) has not been allocated in the underlying file storage.
-However, a file system is not obliged to report holes,
+However, a filesystem is not obliged to report holes,
 so these operations are not a guaranteed mechanism for
 mapping the storage space actually allocated to a file.
 (Furthermore, a sequence of zeros that actually has been written
 to the underlying storage may not be reported as a hole.)
 In the simplest implementation,
-a file system can support the operations by making
+a filesystem can support the operations by making
 .BR SEEK_HOLE
 always return the offset of the end of the file,
 and making
@@ -150,6 +150,32 @@ it can be considered to consist of data that is a sequence of zeros).
 .\" https://lkml.org/lkml/2011/4/22/79
 .\" http://lwn.net/Articles/440255/
 .\" http://blogs.oracle.com/bonwick/entry/seek_hole_and_seek_data
+
+The
+.BR _GNU_SOURCE
+feature test macro must be defined in order to obtain the definitions of
+.BR SEEK_DATA
+and
+.BR SEEK_HOLE
+from
+.IR <unistd.h> .
+
+The
+.BR SEEK_HOLE
+and
+.BR SEEK_DATA
+operations are supported for the following filesystems:
+.IP * 3
+Btrfs (since Linux 3.1)
+.IP * 3
+OCFS (since Linux 3.2)
+.\" commit 93862d5e1ab875664c6cc95254fc365028a48bb1
+.IP *
+XFS (since Linux 3.5)
+.IP *
+ext4 (since Linux 3.8)
+.IP *
+tmpfs (since Linux 3.8)
 .SH RETURN VALUE
 Upon successful completion,
 .BR lseek ()
@@ -170,7 +196,7 @@ is not valid.
 Or: the resulting file offset would be negative,
 or beyond the end of a seekable device.
 .\" Some systems may allow negative offsets for character devices
-.\" and/or for remote file systems.
+.\" and/or for remote filesystems.
 .TP
 .B EOVERFLOW
 .\" HP-UX 11 says EINVAL for this case (but POSIX.1 says EOVERFLOW)
@@ -240,3 +266,12 @@ subject to race conditions.
 .BR fseek (3),
 .BR lseek64 (3),
 .BR posix_fallocate (3)
+.SH COLOPHON
+This page is part of release 3.68 of the Linux
+.I man-pages
+project.
+A description of the project,
+information about reporting bugs,
+and the latest version of this page,
+can be found at
+\%http://www.kernel.org/doc/man\-pages/.