1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or https://opensource.org/licenses/CDDL-1.0. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21 22 /* 23 * Copyright (c) 2021 by Lawrence Livermore National Security, LLC. 24 */ 25 26 #include <unistd.h> 27 #include <fcntl.h> 28 #include <stdio.h> 29 #include <stdlib.h> 30 #include <string.h> 31 #include <sys/mman.h> 32 #include <sys/sysmacros.h> 33 #include <errno.h> 34 #ifdef __linux__ 35 #include <linux/fs.h> 36 #endif 37 38 /* some older uClibc's lack the defines, so we'll manually define them */ 39 #ifdef __UCLIBC__ 40 #ifndef SEEK_DATA 41 #define SEEK_DATA 3 42 #endif 43 #ifndef SEEK_HOLE 44 #define SEEK_HOLE 4 45 #endif 46 #endif 47 48 static void 49 seek_data(int fd, off_t offset, off_t expected) 50 { 51 off_t data_offset = lseek(fd, offset, SEEK_DATA); 52 if (data_offset != expected) { 53 fprintf(stderr, "lseek(fd, %d, SEEK_DATA) = %d (expected %d)\n", 54 (int)offset, (int)data_offset, (int)expected); 55 exit(2); 56 } 57 } 58 59 static void 60 seek_hole(int fd, off_t offset, off_t expected) 61 { 62 off_t hole_offset = lseek(fd, offset, SEEK_HOLE); 63 if (hole_offset != expected) { 64 fprintf(stderr, "lseek(fd, %d, SEEK_HOLE) = %d (expected %d)\n", 65 (int)offset, (int)hole_offset, (int)expected); 66 exit(2); 67 } 68 } 69 70 int 71 main(int argc, char **argv) 72 { 73 char *execname = argv[0]; 74 char *file_path = argv[1]; 75 char *buf = NULL; 76 int err; 77 78 if (argc != 4) { 79 (void) printf("usage: %s <file name> <file size> " 80 "<block size>\n", argv[0]); 81 exit(1); 82 } 83 84 int fd = open(file_path, O_RDWR | O_CREAT, 0666); 85 if (fd == -1) { 86 (void) fprintf(stderr, "%s: %s: ", execname, file_path); 87 perror("open"); 88 exit(2); 89 } 90 91 off_t file_size = atoi(argv[2]); 92 off_t block_size = atoi(argv[3]); 93 94 if (block_size * 2 > file_size) { 95 (void) fprintf(stderr, "file size must be at least " 96 "double the block size\n"); 97 exit(2); 98 } 99 100 err = ftruncate(fd, file_size); 101 if (err == -1) { 102 perror("ftruncate"); 103 exit(2); 104 } 105 106 if ((buf = mmap(NULL, file_size, PROT_READ | PROT_WRITE, 107 MAP_SHARED, fd, 0)) == MAP_FAILED) { 108 perror("mmap"); 109 exit(2); 110 } 111 112 /* Verify the file is sparse and reports no data. */ 113 seek_data(fd, 0, -1); 114 115 /* Verify the file is reported as a hole. */ 116 seek_hole(fd, 0, 0); 117 118 /* Verify search beyond end of file is an error. */ 119 seek_data(fd, 2 * file_size, -1); 120 seek_hole(fd, 2 * file_size, -1); 121 122 /* Dirty the first byte. */ 123 memset(buf, 'a', 1); 124 seek_data(fd, 0, 0); 125 seek_data(fd, block_size, -1); 126 seek_hole(fd, 0, block_size); 127 seek_hole(fd, block_size, block_size); 128 129 /* Dirty the first half of the file. */ 130 memset(buf, 'b', file_size / 2); 131 seek_data(fd, 0, 0); 132 seek_data(fd, block_size, block_size); 133 seek_hole(fd, 0, P2ROUNDUP(file_size / 2, block_size)); 134 seek_hole(fd, block_size, P2ROUNDUP(file_size / 2, block_size)); 135 136 /* Dirty the whole file. */ 137 memset(buf, 'c', file_size); 138 seek_data(fd, 0, 0); 139 seek_data(fd, file_size * 3 / 4, 140 P2ROUNDUP(file_size * 3 / 4, block_size)); 141 seek_hole(fd, 0, file_size); 142 seek_hole(fd, file_size / 2, file_size); 143 144 /* Punch a hole (required compression be enabled). */ 145 memset(buf + block_size, 0, block_size); 146 seek_data(fd, 0, 0); 147 seek_data(fd, block_size, 2 * block_size); 148 seek_hole(fd, 0, block_size); 149 seek_hole(fd, block_size, block_size); 150 seek_hole(fd, 2 * block_size, file_size); 151 152 err = munmap(buf, file_size); 153 if (err == -1) { 154 perror("munmap"); 155 exit(2); 156 } 157 158 close(fd); 159 160 return (0); 161 } 162