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Diffstat (limited to '')
-rw-r--r-- | lib/blkid/llseek.c | 147 |
1 files changed, 147 insertions, 0 deletions
diff --git a/lib/blkid/llseek.c b/lib/blkid/llseek.c new file mode 100644 index 0000000..5929864 --- /dev/null +++ b/lib/blkid/llseek.c @@ -0,0 +1,147 @@ +/* + * 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% + */ + +#ifndef _LARGEFILE_SOURCE +#define _LARGEFILE_SOURCE +#endif +#ifndef _LARGEFILE64_SOURCE +#define _LARGEFILE64_SOURCE +#endif + +#include "config.h" +#if HAVE_SYS_TYPES_H +#include <sys/types.h> +#endif + +#if HAVE_ERRNO_H +#include <errno.h> +#endif +#if HAVE_UNISTD_H +#include <unistd.h> +#endif +#ifdef __MSDOS__ +#include <io.h> +#endif + +#include "blkidP.h" + +#ifdef __linux__ + +#if defined(HAVE_LSEEK64) && defined(HAVE_LSEEK64_PROTOTYPE) + +#define my_llseek lseek64 + +#elif defined(HAVE_LLSEEK) +#include <sys/syscall.h> + +#ifndef HAVE_LLSEEK_PROTOTYPE +extern long long llseek(int fd, long long offset, int origin); +#endif + +#define my_llseek llseek + +#else /* ! HAVE_LLSEEK */ + +#if SIZEOF_LONG == SIZEOF_LONG_LONG + +#define llseek lseek + +#else /* SIZEOF_LONG != SIZEOF_LONG_LONG */ + +#include <linux/unistd.h> + +#ifndef __NR__llseek +#define __NR__llseek 140 +#endif + +#ifndef __i386__ +static int _llseek(unsigned int, unsigned long, unsigned long, + blkid_loff_t *, unsigned int); + +static _syscall5(int, _llseek, unsigned int, fd, unsigned long, offset_high, + unsigned long, offset_low, blkid_loff_t *, result, + unsigned int, origin) +#endif + +static blkid_loff_t my_llseek(int fd, blkid_loff_t offset, int origin) +{ + blkid_loff_t result; + int retval; + +#ifndef __i386__ + retval = _llseek(fd, ((unsigned long long) offset) >> 32, + ((unsigned long long)offset) & 0xffffffff, + &result, origin); +#else + retval = syscall(__NR__llseek, fd, ((unsigned long long) offset) >> 32, + ((unsigned long long)offset) & 0xffffffff, + &result, origin); +#endif + return (retval == -1 ? (blkid_loff_t) retval : result); +} + +#endif /* __alpha__ || __ia64__ */ + +#endif /* HAVE_LLSEEK */ + +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; + } + + result = my_llseek(fd, offset, whence); + 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 */ + + |