mirror of
https://sourceware.org/git/glibc.git
synced 2024-11-18 02:50:09 +00:00
72 lines
2.0 KiB
C
72 lines
2.0 KiB
C
|
/* Copyright (C) 2000 Free Software Foundation, Inc.
|
|||
|
This file is part of the GNU C Library.
|
|||
|
|
|||
|
The GNU C Library is free software; you can redistribute it and/or
|
|||
|
modify it under the terms of the GNU Library General Public License as
|
|||
|
published by the Free Software Foundation; either version 2 of the
|
|||
|
License, or (at your option) any later version.
|
|||
|
|
|||
|
The GNU C Library is distributed in the hope that it will be useful,
|
|||
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|||
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|||
|
Library General Public License for more details.
|
|||
|
|
|||
|
You should have received a copy of the GNU Library General Public
|
|||
|
License along with the GNU C Library; see the file COPYING.LIB. If not,
|
|||
|
write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
|
|||
|
Boston, MA 02111-1307, USA. */
|
|||
|
|
|||
|
#include <errno.h>
|
|||
|
#include <fcntl.h>
|
|||
|
#include <unistd.h>
|
|||
|
#include <sys/stat.h>
|
|||
|
#include <sys/statfs.h>
|
|||
|
|
|||
|
/* Reserve storage for the data of the file associated with FD. */
|
|||
|
|
|||
|
int
|
|||
|
posix_fallocate (int fd, __off_t offset, size_t len)
|
|||
|
{
|
|||
|
struct stat st;
|
|||
|
struct statfs f;
|
|||
|
size_t step;
|
|||
|
|
|||
|
/* `off_t<5F> is a signed type. Therefore we can determine whether
|
|||
|
OFFSET + LEN is too large if it is a negative value. */
|
|||
|
if (offset < 0 || len == 0)
|
|||
|
return EINVAL;
|
|||
|
if (offset + len < 0)
|
|||
|
return EFBIG;
|
|||
|
|
|||
|
/* First thing we have to make sure is that this is really a regular
|
|||
|
file. */
|
|||
|
if (__fxstat (_STAT_VER, fd, &st) != 0)
|
|||
|
return EBADF;
|
|||
|
if (S_ISFIFO (st.st_mode))
|
|||
|
return ESPIPE;
|
|||
|
if (! S_ISREG (st.st_mode))
|
|||
|
return ENODEV;
|
|||
|
|
|||
|
/* We have to know the block size of the filesystem to get at least some
|
|||
|
sort of performance. */
|
|||
|
if (__fstatfs (fd, &f) != 0)
|
|||
|
return errno;
|
|||
|
|
|||
|
/* Align OFFSET to block size and adjust LEN. */
|
|||
|
step = (offset + f.f_bsize - 1) % ~f.f_bsize;
|
|||
|
offset += step;
|
|||
|
|
|||
|
/* Write something to every block. */
|
|||
|
while (len > step)
|
|||
|
{
|
|||
|
len -= step;
|
|||
|
|
|||
|
if (pwrite (fd, "", 1, offset) != 1)
|
|||
|
return errno;
|
|||
|
|
|||
|
offset += step;
|
|||
|
}
|
|||
|
|
|||
|
return 0;
|
|||
|
}
|