diff options
Diffstat (limited to 'libblkid/llseek.c')
-rw-r--r-- | libblkid/llseek.c | 91 |
1 files changed, 91 insertions, 0 deletions
diff --git a/libblkid/llseek.c b/libblkid/llseek.c new file mode 100644 index 000000000..be4fdd323 --- /dev/null +++ b/libblkid/llseek.c @@ -0,0 +1,91 @@ +/* + * llseek.c -- stub calling the llseek system call + * + * Copyright (C) 1994, 1995, 1996, 1997 Theodore Ts'o. + * + * %Begin-Header% + * This file may be redistributed under the terms of the + * GNU Lesser General Public License. + * %End-Header% + */ + +#define _LARGEFILE_SOURCE +#define _LARGEFILE64_SOURCE + +#ifdef HAVE_SYS_TYPES_H +#include <sys/types.h> +#endif + +#ifdef HAVE_ERRNO_H +#include <errno.h> +#endif +#ifdef HAVE_UNISTD_H +#include <unistd.h> +#endif +#ifdef __MSDOS__ +#include <io.h> +#endif + +#include "blkidP.h" + +#ifdef __linux__ + +#define my_llseek lseek64 +#include <linux/unistd.h> + +#ifndef __NR__llseek +#define __NR__llseek 140 +#endif + +blkid_loff_t blkid_llseek(int fd, blkid_loff_t offset, int whence) +{ + blkid_loff_t result; + static int do_compat = 0; + + if ((sizeof(off_t) >= sizeof(blkid_loff_t)) || + (offset < ((blkid_loff_t) 1 << ((sizeof(off_t)*8) -1)))) + return lseek(fd, (off_t) offset, whence); + + if (do_compat) { + errno = EOVERFLOW; + return -1; + } + + if (result == -1 && errno == ENOSYS) { + /* + * Just in case this code runs on top of an old kernel + * which does not support the llseek system call + */ + do_compat++; + errno = EOVERFLOW; + } + return result; +} + +#else /* !linux */ + +#ifndef EOVERFLOW +#ifdef EXT2_ET_INVALID_ARGUMENT +#define EOVERFLOW EXT2_ET_INVALID_ARGUMENT +#else +#define EOVERFLOW 112 +#endif +#endif + +blkid_loff_t blkid_llseek(int fd, blkid_loff_t offset, int origin) +{ +#if defined(HAVE_LSEEK64) && defined(HAVE_LSEEK64_PROTOTYPE) + return lseek64 (fd, offset, origin); +#else + if ((sizeof(off_t) < sizeof(blkid_loff_t)) && + (offset >= ((blkid_loff_t) 1 << ((sizeof(off_t)*8) - 1)))) { + errno = EOVERFLOW; + return -1; + } + return lseek(fd, (off_t) offset, origin); +#endif +} + +#endif /* linux */ + + |