1 // SPDX-License-Identifier: CDDL-1.0 2 /* 3 * CDDL HEADER START 4 * 5 * The contents of this file are subject to the terms of the 6 * Common Development and Distribution License (the "License"). 7 * You may not use this file except in compliance with the License. 8 * 9 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 10 * or https://opensource.org/licenses/CDDL-1.0. 11 * See the License for the specific language governing permissions 12 * and limitations under the License. 13 * 14 * When distributing Covered Code, include this CDDL HEADER in each 15 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 16 * If applicable, add the following below this CDDL HEADER, with the 17 * fields enclosed by brackets "[]" replaced with your own identifying 18 * information: Portions Copyright [yyyy] [name of copyright owner] 19 * 20 * CDDL HEADER END 21 */ 22 23 /* 24 * Copyright (c) 2021 by Lawrence Livermore National Security, LLC. 25 */ 26 27 #include <unistd.h> 28 #include <fcntl.h> 29 #include <stdio.h> 30 #include <stdlib.h> 31 #include <string.h> 32 #include <sys/mman.h> 33 #include <sys/sysmacros.h> 34 #include <errno.h> 35 #ifdef __linux__ 36 #include <linux/fs.h> 37 #endif 38 39 /* some older uClibc's lack the defines, so we'll manually define them */ 40 #ifdef __UCLIBC__ 41 #ifndef SEEK_DATA 42 #define SEEK_DATA 3 43 #endif 44 #ifndef SEEK_HOLE 45 #define SEEK_HOLE 4 46 #endif 47 #endif 48 49 static void 50 seek_data(int fd, off_t offset, off_t expected) 51 { 52 off_t data_offset = lseek(fd, offset, SEEK_DATA); 53 if (data_offset != expected) { 54 fprintf(stderr, "lseek(fd, %d, SEEK_DATA) = %d (expected %d)\n", 55 (int)offset, (int)data_offset, (int)expected); 56 exit(2); 57 } 58 } 59 60 static void 61 seek_hole(int fd, off_t offset, off_t expected) 62 { 63 off_t hole_offset = lseek(fd, offset, SEEK_HOLE); 64 if (hole_offset != expected) { 65 fprintf(stderr, "lseek(fd, %d, SEEK_HOLE) = %d (expected %d)\n", 66 (int)offset, (int)hole_offset, (int)expected); 67 exit(2); 68 } 69 } 70 71 int 72 main(int argc, char **argv) 73 { 74 char *execname = argv[0]; 75 char *file_path = argv[1]; 76 char *buf = NULL; 77 int err; 78 79 if (argc != 4) { 80 (void) printf("usage: %s <file name> <file size> " 81 "<block size>\n", argv[0]); 82 exit(1); 83 } 84 85 int fd = open(file_path, O_RDWR | O_CREAT, 0666); 86 if (fd == -1) { 87 (void) fprintf(stderr, "%s: %s: ", execname, file_path); 88 perror("open"); 89 exit(2); 90 } 91 92 off_t file_size = atoi(argv[2]); 93 off_t block_size = atoi(argv[3]); 94 95 if (block_size * 2 > file_size) { 96 (void) fprintf(stderr, "file size must be at least " 97 "double the block size\n"); 98 exit(2); 99 } 100 101 err = ftruncate(fd, file_size); 102 if (err == -1) { 103 perror("ftruncate"); 104 exit(2); 105 } 106 107 if ((buf = mmap(NULL, file_size, PROT_READ | PROT_WRITE, 108 MAP_SHARED, fd, 0)) == MAP_FAILED) { 109 perror("mmap"); 110 exit(2); 111 } 112 113 /* Verify the file is sparse and reports no data. */ 114 seek_data(fd, 0, -1); 115 116 /* Verify the file is reported as a hole. */ 117 seek_hole(fd, 0, 0); 118 119 /* Verify search beyond end of file is an error. */ 120 seek_data(fd, 2 * file_size, -1); 121 seek_hole(fd, 2 * file_size, -1); 122 123 /* Dirty the first byte. */ 124 memset(buf, 'a', 1); 125 seek_data(fd, 0, 0); 126 seek_data(fd, block_size, -1); 127 seek_hole(fd, 0, block_size); 128 seek_hole(fd, block_size, block_size); 129 130 /* Dirty the first half of the file. */ 131 memset(buf, 'b', file_size / 2); 132 seek_data(fd, 0, 0); 133 seek_data(fd, block_size, block_size); 134 seek_hole(fd, 0, P2ROUNDUP(file_size / 2, block_size)); 135 seek_hole(fd, block_size, P2ROUNDUP(file_size / 2, block_size)); 136 137 /* Dirty the whole file. */ 138 memset(buf, 'c', file_size); 139 seek_data(fd, 0, 0); 140 seek_data(fd, file_size * 3 / 4, 141 P2ROUNDUP(file_size * 3 / 4, block_size)); 142 seek_hole(fd, 0, file_size); 143 seek_hole(fd, file_size / 2, file_size); 144 145 /* Punch a hole (required compression be enabled). */ 146 memset(buf + block_size, 0, block_size); 147 seek_data(fd, 0, 0); 148 seek_data(fd, block_size, 2 * block_size); 149 seek_hole(fd, 0, block_size); 150 seek_hole(fd, block_size, block_size); 151 seek_hole(fd, 2 * block_size, file_size); 152 153 err = munmap(buf, file_size); 154 if (err == -1) { 155 perror("munmap"); 156 exit(2); 157 } 158 159 close(fd); 160 161 return (0); 162 } 163