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 static void 39 seek_data(int fd, off_t offset, off_t expected) 40 { 41 off_t data_offset = lseek(fd, offset, SEEK_DATA); 42 if (data_offset != expected) { 43 fprintf(stderr, "lseek(fd, %d, SEEK_DATA) = %d (expected %d)\n", 44 (int)offset, (int)data_offset, (int)expected); 45 exit(2); 46 } 47 } 48 49 static void 50 seek_hole(int fd, off_t offset, off_t expected) 51 { 52 off_t hole_offset = lseek(fd, offset, SEEK_HOLE); 53 if (hole_offset != expected) { 54 fprintf(stderr, "lseek(fd, %d, SEEK_HOLE) = %d (expected %d)\n", 55 (int)offset, (int)hole_offset, (int)expected); 56 exit(2); 57 } 58 } 59 60 int 61 main(int argc, char **argv) 62 { 63 char *execname = argv[0]; 64 char *file_path = argv[1]; 65 char *buf = NULL; 66 int err; 67 68 if (argc != 4) { 69 (void) printf("usage: %s <file name> <file size> " 70 "<block size>\n", argv[0]); 71 exit(1); 72 } 73 74 int fd = open(file_path, O_RDWR | O_CREAT, 0666); 75 if (fd == -1) { 76 (void) fprintf(stderr, "%s: %s: ", execname, file_path); 77 perror("open"); 78 exit(2); 79 } 80 81 off_t file_size = atoi(argv[2]); 82 off_t block_size = atoi(argv[3]); 83 84 if (block_size * 2 > file_size) { 85 (void) fprintf(stderr, "file size must be at least " 86 "double the block size\n"); 87 exit(2); 88 } 89 90 err = ftruncate(fd, file_size); 91 if (err == -1) { 92 perror("ftruncate"); 93 exit(2); 94 } 95 96 if ((buf = mmap(NULL, file_size, PROT_READ | PROT_WRITE, 97 MAP_SHARED, fd, 0)) == MAP_FAILED) { 98 perror("mmap"); 99 exit(2); 100 } 101 102 /* Verify the file is sparse and reports no data. */ 103 seek_data(fd, 0, -1); 104 105 /* Verify the file is reported as a hole. */ 106 seek_hole(fd, 0, 0); 107 108 /* Verify search beyond end of file is an error. */ 109 seek_data(fd, 2 * file_size, -1); 110 seek_hole(fd, 2 * file_size, -1); 111 112 /* Dirty the first byte. */ 113 memset(buf, 'a', 1); 114 seek_data(fd, 0, 0); 115 seek_data(fd, block_size, -1); 116 seek_hole(fd, 0, block_size); 117 seek_hole(fd, block_size, block_size); 118 119 /* Dirty the first half of the file. */ 120 memset(buf, 'b', file_size / 2); 121 seek_data(fd, 0, 0); 122 seek_data(fd, block_size, block_size); 123 seek_hole(fd, 0, P2ROUNDUP(file_size / 2, block_size)); 124 seek_hole(fd, block_size, P2ROUNDUP(file_size / 2, block_size)); 125 126 /* Dirty the whole file. */ 127 memset(buf, 'c', file_size); 128 seek_data(fd, 0, 0); 129 seek_data(fd, file_size * 3 / 4, 130 P2ROUNDUP(file_size * 3 / 4, block_size)); 131 seek_hole(fd, 0, file_size); 132 seek_hole(fd, file_size / 2, file_size); 133 134 /* Punch a hole (required compression be enabled). */ 135 memset(buf + block_size, 0, block_size); 136 seek_data(fd, 0, 0); 137 seek_data(fd, block_size, 2 * block_size); 138 seek_hole(fd, 0, block_size); 139 seek_hole(fd, block_size, block_size); 140 seek_hole(fd, 2 * block_size, file_size); 141 142 err = munmap(buf, file_size); 143 if (err == -1) { 144 perror("munmap"); 145 exit(2); 146 } 147 148 close(fd); 149 150 return (0); 151 } 152