tests/zfs-tests/cmd/clone_mmap_cached.c

   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) 2024 by Pawel Jakub Dawidek
  24  */
  25
  26 #include <sys/mman.h>
  27 #include <sys/stat.h>
  28
  29 #include <assert.h>
  30 #include <errno.h>
  31 #include <fcntl.h>
  32 #include <stdbool.h>
  33 #include <stdio.h>
  34 #include <stdlib.h>
  35 #include <string.h>
  36 #include <unistd.h>
  37
  38 #ifdef __FreeBSD__
  39 #define loff_t  off_t
  40 #endif
  41
  42 ssize_t
  43 copy_file_range(int, loff_t *, int, loff_t *, size_t, unsigned int)
  44     __attribute__((weak));
  45
  46 static void *
  47 mmap_file(int fd, size_t size)
  48 {
  49         void *p;
  50
  51         p = mmap(NULL, size, PROT_READ, MAP_SHARED, fd, 0);
  52         if (p == MAP_FAILED) {
  53                 (void) fprintf(stderr, "mmap failed: %s\n", strerror(errno));
  54                 exit(2);
  55         }
  56
  57         return (p);
  58 }
  59
  60 static void
  61 usage(const char *progname)
  62 {
  63
  64         /*
  65          * -i cache input before copy_file_range(2).
  66          * -o cache input before copy_file_range(2).
  67          */
  68         (void) fprintf(stderr, "usage: %s [-io] <input> <output>\n", progname);
  69         exit(3);
  70 }
  71
  72 int
  73 main(int argc, char *argv[])
  74 {
  75         int dfd, sfd;
  76         size_t dsize, ssize;
  77         void *dmem, *smem, *ptr;
  78         off_t doff, soff;
  79         struct stat sb;
  80         bool cache_input, cache_output;
  81         const char *progname;
  82         int c;
  83
  84         progname = argv[0];
  85         cache_input = cache_output = false;
  86
  87         while ((c = getopt(argc, argv, "io")) != -1) {
  88                 switch (c) {
  89                 case 'i':
  90                         cache_input = true;
  91                         break;
  92                 case 'o':
  93                         cache_output = true;
  94                         break;
  95                 default:
  96                         usage(progname);
  97                 }
  98         }
  99         argc -= optind;
 100         argv += optind;
 101
 102         if (argc != 2) {
 103                 usage(progname);
 104         }
 105
 106         sfd = open(argv[0], O_RDONLY);
 107         if (fstat(sfd, &sb) == -1) {
 108                 (void) fprintf(stderr, "fstat failed: %s\n", strerror(errno));
 109                 exit(2);
 110         }
 111         ssize = sb.st_size;
 112         smem = mmap_file(sfd, ssize);
 113
 114         dfd = open(argv[1], O_RDWR);
 115         if (fstat(dfd, &sb) == -1) {
 116                 (void) fprintf(stderr, "fstat failed: %s\n", strerror(errno));
 117                 exit(2);
 118         }
 119         dsize = sb.st_size;
 120         dmem = mmap_file(dfd, dsize);
 121
 122         /*
 123          * Hopefully it won't be compiled out.
 124          */
 125         if (cache_input) {
 126                 ptr = malloc(ssize);
 127                 assert(ptr != NULL);
 128                 memcpy(ptr, smem, ssize);
 129                 free(ptr);
 130         }
 131         if (cache_output) {
 132                 ptr = malloc(ssize);
 133                 assert(ptr != NULL);
 134                 memcpy(ptr, dmem, dsize);
 135                 free(ptr);
 136         }
 137
 138         soff = doff = 0;
 139         if (copy_file_range(sfd, &soff, dfd, &doff, ssize, 0) < 0) {
 140                 (void) fprintf(stderr, "copy_file_range failed: %s\n",
 141                     strerror(errno));
 142                 exit(2);
 143         }
 144
 145         exit(memcmp(smem, dmem, ssize) == 0 ? 0 : 1);
 146 }