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Diffstat (limited to 'lib/ext2fs/getsectsize.c')
-rw-r--r-- | lib/ext2fs/getsectsize.c | 151 |
1 files changed, 151 insertions, 0 deletions
diff --git a/lib/ext2fs/getsectsize.c b/lib/ext2fs/getsectsize.c new file mode 100644 index 0000000..bd978c5 --- /dev/null +++ b/lib/ext2fs/getsectsize.c @@ -0,0 +1,151 @@ +/* + * getsectsize.c --- get the sector size of a device. + * + * Copyright (C) 1995, 1995 Theodore Ts'o. + * Copyright (C) 2003 VMware, Inc. + * + * %Begin-Header% + * This file may be redistributed under the terms of the GNU Library + * General Public License, version 2. + * %End-Header% + */ + +#ifndef _LARGEFILE_SOURCE +#define _LARGEFILE_SOURCE +#endif +#ifndef _LARGEFILE64_SOURCE +#define _LARGEFILE64_SOURCE +#endif + +#include "config.h" +#include <stdio.h> +#if HAVE_UNISTD_H +#include <unistd.h> +#endif +#if HAVE_ERRNO_H +#include <errno.h> +#endif +#include <fcntl.h> +#ifdef HAVE_SYS_DISK_H +#include <sys/disk.h> +#endif +#ifdef HAVE_LINUX_FD_H +#include <sys/ioctl.h> +#include <linux/fd.h> +#endif + +#if defined(__linux__) && defined(_IO) +#if !defined(BLKSSZGET) +#define BLKSSZGET _IO(0x12,104)/* get block device sector size */ +#endif +#if !defined(BLKPBSZGET) +#define BLKPBSZGET _IO(0x12,123)/* get block physical sector size */ +#endif +#endif + +#include "ext2_fs.h" +#include "ext2fs.h" + +/* + * Returns the logical sector size of a device + */ +errcode_t ext2fs_get_device_sectsize(const char *file, int *sectsize) +{ +#ifdef _WIN32 + *sectsize = 512; // just guessing + return 0; +#else // not _WIN32 + + int fd; + + fd = ext2fs_open_file(file, O_RDONLY, 0); + if (fd < 0) + return errno; + +#ifdef BLKSSZGET + if (ioctl(fd, BLKSSZGET, sectsize) >= 0) { + close(fd); + return 0; + } +#endif +#ifdef DIOCGSECTORSIZE + if (ioctl(fd, DIOCGSECTORSIZE, sectsize) >= 0) { + close(fd); + return 0; + } +#endif + *sectsize = 0; + close(fd); + return 0; + +#endif // ifdef _WIN32 +} + +/* + * Return desired alignment for direct I/O + */ +int ext2fs_get_dio_alignment(int fd) +{ + int align = 0; + +#ifdef BLKSSZGET + if (ioctl(fd, BLKSSZGET, &align) < 0) + align = 0; +#endif +#ifdef DIOCGSECTORSIZE + if (align <= 0 && + ioctl(fd, DIOCGSECTORSIZE, &align) < 0) + align = 0; +#endif + +#ifdef _SC_PAGESIZE + if (align <= 0) + align = sysconf(_SC_PAGESIZE); +#endif +#ifdef HAVE_GETPAGESIZE + if (align <= 0) + align = getpagesize(); +#endif + if (align <= 0) + align = 4096; + + return align; +} + +/* + * Returns the physical sector size of a device + */ +errcode_t ext2fs_get_device_phys_sectsize(const char *file, int *sectsize) +{ +#ifdef _WIN32 + + return ext2fs_get_device_sectsize(file, sectsize); + +#else // not _WIN32 + + int fd; + + fd = ext2fs_open_file(file, O_RDONLY, 0); + if (fd < 0) + return errno; + +#ifdef BLKPBSZGET + if (ioctl(fd, BLKPBSZGET, sectsize) >= 0) { + close(fd); + return 0; + } +#endif +#ifdef DIOCGSECTORSIZE + /* This isn't really the physical sector size, but FreeBSD + * doesn't seem to have this concept. */ + if (ioctl(fd, DIOCGSECTORSIZE, sectsize) >= 0) { + close(fd); + return 0; + } +#endif + *sectsize = 0; + close(fd); + return 0; + +#endif // ifdef _WIN32 +} |