1 /* 2 * getsectsize.c --- get the sector size of a device. 3 * 4 * Copyright (C) 1995, 1995 Theodore Ts'o. 5 * Copyright (C) 2003 VMware, Inc. 6 * 7 * %Begin-Header% 8 * This file may be redistributed under the terms of the GNU Library 9 * General Public License, version 2. 10 * %End-Header% 11 */ 12 13 #ifndef _LARGEFILE_SOURCE 14 #define _LARGEFILE_SOURCE 15 #endif 16 #ifndef _LARGEFILE64_SOURCE 17 #define _LARGEFILE64_SOURCE 18 #endif 19 20 #include "config.h" 21 #include <stdio.h> 22 #if HAVE_UNISTD_H 23 #include <unistd.h> 24 #endif 25 #if HAVE_ERRNO_H 26 #include <errno.h> 27 #endif 28 #include <fcntl.h> 29 #ifdef HAVE_LINUX_FD_H 30 #include <sys/ioctl.h> 31 #include <linux/fd.h> 32 #endif 33 34 #if defined(__linux__) && defined(_IO) 35 #if !defined(BLKSSZGET) 36 #define BLKSSZGET _IO(0x12,104)/* get block device sector size */ 37 #endif 38 #if !defined(BLKPBSZGET) 39 #define BLKPBSZGET _IO(0x12,123)/* get block physical sector size */ 40 #endif 41 #endif 42 43 #include "ext2_fs.h" 44 #include "ext2fs.h" 45 46 /* 47 * Returns the logical sector size of a device 48 */ 49 errcode_t ext2fs_get_device_sectsize(const char *file, int *sectsize) 50 { 51 int fd; 52 53 fd = ext2fs_open_file(file, O_RDONLY, 0); 54 if (fd < 0) 55 return errno; 56 57 #ifdef BLKSSZGET 58 if (ioctl(fd, BLKSSZGET, sectsize) >= 0) { 59 close(fd); 60 return 0; 61 } 62 #endif 63 *sectsize = 0; 64 close(fd); 65 return 0; 66 } 67 68 /* 69 * Return desired alignment for direct I/O 70 */ 71 int ext2fs_get_dio_alignment(int fd) 72 { 73 int align = 0; 74 75 #ifdef BLKSSZGET 76 if (ioctl(fd, BLKSSZGET, &align) < 0) 77 align = 0; 78 #endif 79 80 #ifdef _SC_PAGESIZE 81 if (align <= 0) 82 align = sysconf(_SC_PAGESIZE); 83 #endif 84 #ifdef HAVE_GETPAGESIZE 85 if (align <= 0) 86 align = getpagesize(); 87 #endif 88 if (align <= 0) 89 align = 4096; 90 91 return align; 92 } 93 94 /* 95 * Returns the physical sector size of a device 96 */ 97 errcode_t ext2fs_get_device_phys_sectsize(const char *file, int *sectsize) 98 { 99 int fd; 100 101 fd = ext2fs_open_file(file, O_RDONLY, 0); 102 if (fd < 0) 103 return errno; 104 105 #ifdef BLKPBSZGET 106 if (ioctl(fd, BLKPBSZGET, sectsize) >= 0) { 107 close(fd); 108 return 0; 109 } 110 #endif 111 *sectsize = 0; 112 close(fd); 113 return 0; 114 } 115
