--- IO-AIO/AIO.pm	2012/06/17 17:07:25	1.228
+++ IO-AIO/AIO.pm	2012/07/30 16:46:30	1.232
@@ -204,8 +204,8 @@
 
 =head2 QUICK OVERVIEW
 
-This section simply lists the prototypes of the most important functions
-for quick reference. See the following sections for function-by-function
+This section simply lists the prototypes most of the functions for
+quick reference. See the following sections for function-by-function
 documentation.
 
    aio_wd $pathname, $callback->($wd)
@@ -223,6 +223,8 @@
    aio_chown $fh_or_path, $uid, $gid, $callback->($status)
    aio_chmod $fh_or_path, $mode, $callback->($status)
    aio_truncate $fh_or_path, $offset, $callback->($status)
+   aio_allocate $fh, $mode, $offset, $len, $callback->($status)
+   aio_fiemap $fh, $start, $length, $flags, $count, $cb->(\@extents)
    aio_unlink $pathname, $callback->($status)
    aio_mknod $pathname, $mode, $dev, $callback->($status)
    aio_link $srcpath, $dstpath, $callback->($status)
@@ -640,6 +642,22 @@
 Works like truncate(2) or ftruncate(2).
 
 
+=item aio_allocate $fh, $mode, $offset, $len, $callback->($status)
+
+Allocates or freed disk space according to the C<$mode> argument. See the
+linux C<fallocate> docuemntation for details.
+
+C<$mode> can currently be C<0> or C<IO::AIO::FALLOC_FL_KEEP_SIZE>
+to allocate space, or C<IO::AIO::FALLOC_FL_PUNCH_HOLE |
+IO::AIO::FALLOC_FL_KEEP_SIZE>, to deallocate a file range.
+
+The file system block size used by C<fallocate> is presumably the
+C<f_bsize> returned by C<statvfs>.
+
+If C<fallocate> isn't available or cannot be emulated (currently no
+emulation will be attempted), passes C<-1> and sets C<$!> to C<ENOSYS>.
+
+
 =item aio_chmod $fh_or_path, $mode, $callback->($status)
 
 Works like perl's C<chmod> function.
@@ -1263,7 +1281,7 @@
 
 Queries the extents of the given file (by calling the Linux FIEMAP ioctl,
 see L<http://cvs.schmorp.de/IO-AIO/doc/fiemap.txt> for details). If the
-C<ioctl> is not available on your OS, then this rquiest will fail with
+C<ioctl> is not available on your OS, then this request will fail with
 C<ENOSYS>.
 
 C<$start> is the starting offset to query extents for, C<$length> is the
@@ -1276,9 +1294,9 @@
 the data portion.
 
 C<$count> is the maximum number of extent records to return. If it is
-C<undef>, then IO::AIO queries all extents of the file. As a very special
+C<undef>, then IO::AIO queries all extents of the range. As a very special
 case, if it is C<0>, then the callback receives the number of extents
-instead of the extents themselves.
+instead of the extents themselves (which is unreliable, see below).
 
 If an error occurs, the callback receives no arguments. The special
 C<errno> value C<IO::AIO::EBADR> is available to test for flag errors.
@@ -1290,7 +1308,7 @@
    [$logical, $physical, $length, $flags]
 
 Flags is any combination of the following flag values (typically either C<0>
-or C<IO::AIO::FIEMAP_EXTENT_LAST>):
+or C<IO::AIO::FIEMAP_EXTENT_LAST> (1)):
 
 C<IO::AIO::FIEMAP_EXTENT_LAST>, C<IO::AIO::FIEMAP_EXTENT_UNKNOWN>,
 C<IO::AIO::FIEMAP_EXTENT_DELALLOC>, C<IO::AIO::FIEMAP_EXTENT_ENCODED>,
@@ -1299,6 +1317,11 @@
 C<IO::AIO::FIEMAP_EXTENT_UNWRITTEN>, C<IO::AIO::FIEMAP_EXTENT_MERGED> or
 C<IO::AIO::FIEMAP_EXTENT_SHARED>.
 
+At the time of this writing (Linux 3.2), this requets is unreliable unless
+C<$count> is C<undef>, as the kernel has all sorts of bugs preventing
+it to return all extents of a range for files with large number of
+extents. The code works around all these issues if C<$count> is undef.
+
 =item aio_group $callback->(...)
 
 This is a very special aio request: Instead of doing something, it is a