1 /*
2 * This file and its contents are supplied under the terms of the
3 * Common Development and Distribution License ("CDDL"), version 1.0.
4 * You may only use this file in accordance with the terms of version
5 * 1.0 of the CDDL.
6 *
7 * A full copy of the text of the CDDL should have accompanied this
8 * source. A copy of the CDDL is also available via the Internet at
9 * http://www.illumos.org/license/CDDL.
10 */
11
12 /*
13 * Copyright 2012 Jilin Xpd <jilinxpd@gmail.com>
14 * Copyright 2018 Nexenta Systems, Inc.
15 */
16
17 /*
18 * Copy a file from src to dest, using mmap to copy the data,
19 * with either contiguous or discontiguous mappings.
20 * (Jilin calls discontiguous "discrete" below.)
21 */
22
23 #include <sys/mman.h>
24 #include <sys/types.h>
25 #include <sys/stat.h>
26 #include <limits.h>
27 #include <fcntl.h>
28 #include <stdio.h>
29 #include <stdlib.h>
30 #include <unistd.h>
31 #include <string.h>
32 #include <errno.h>
33
34 void
35 usage(void)
36 {
37 fprintf(stderr,
38 "usage: cp_mmap -t {d|c} -f <srcfile> <desfile>\n");
39 exit(1);
40 }
41
42 int
43 main(int argc, char **argv)
44 {
45 struct stat sb;
46 char *src_addr, *des_addr;
47 char *src_file = NULL, *des_file = NULL;
48 off_t offset;
49 size_t filesize;
50 size_t blksize;
51 size_t pagesize;
52 size_t len;
53 size_t numblks;
54 int src_fid, des_fid;
55 int mret = 0;
56 size_t i;
57 size_t stride;
58 boolean_t discrete = B_FALSE; /* discontiguous mappings */
59
60 /*
61 * parse arguments
62 * Not getopt because -f has two optargs
63 */
64 if (argc != 6)
65 usage();
66
67 for (i = 1; i < argc; ) {
68 switch (argv[i][1]) {
69 case 't': /* copy type */
70 i++;
71 discrete = (argv[i][0] == 'd');
72 i++;
73 break;
74 case 'f': /* src file and des file */
75 i++;
76 src_file = argv[i];
77 i++;
78 des_file = argv[i];
79 i++;
80 break;
81 default:
82 usage();
83 break;
84 }
85 }
86
87 pagesize = sysconf(_SC_PAGESIZE); /* mmap one page each time */
88 if (pagesize < 4096) {
89 fprintf(stderr, "sysconf error=%d\n", errno);
90 return (1);
91 }
92 if (discrete) {
93 /*
94 * Use discontiguous mappings, and only mmap
95 * one page each time
96 */
97 blksize = pagesize;
98 stride = 3;
99 } else {
100 /* will do contiguous mmap */
101 blksize = 64 * 1024 * 1024; /* mmap a block each time */
102 stride = 1;
103 }
104
105 /* source file */
106 src_fid = open(src_file, O_RDONLY);
107 if (src_fid == -1) {
108 fprintf(stderr, "open %s error=%d\n", src_file, errno);
109 return (1);
110 }
111 /* destination file */
112 des_fid = open(des_file, O_RDWR | O_CREAT | O_TRUNC,
113 S_IRUSR | S_IWUSR | S_IROTH | S_IWOTH);
114 if (des_fid == -1) {
115 fprintf(stderr, "open %s error=%d\n", des_file, errno);
116 mret = 1;
117 goto exit3;
118 }
119
120 /* get src file size */
121 if (fstat(src_fid, &sb) == -1) {
122 fprintf(stderr, "fstat %s error=%d\n", src_file, errno);
123 mret = 1;
124 goto exit2;
125 }
126 filesize = sb.st_size;
127 if (filesize < pagesize) {
128 fprintf(stderr, "src file size < %d\n", (int)pagesize);
129 mret = 1;
130 goto exit2;
131 }
132
133 /* extend des file */
134 if (ftruncate(des_fid, filesize) == -1) {
135 fprintf(stderr, "ftrunc %s error=%d\n", des_file, errno);
136 mret = 1;
137 goto exit2;
138 }
139
140 /* copy data */
141 numblks = (filesize + blksize - 1) / blksize;
142 for (i = 0; i < stride * numblks && mret == 0; i += stride) {
143
144 offset = (i % numblks) * blksize;
145 if (offset + blksize > filesize)
146 len = filesize - offset;
147 else
148 len = blksize;
149
150 /* map file */
151 src_addr = mmap(NULL, len, PROT_READ, MAP_SHARED,
152 src_fid, offset);
153 if (src_addr == MAP_FAILED) {
154 fprintf(stderr, "mmap %s error=%d\n", src_file, errno);
155 mret = 1;
156 break;
157 }
158 des_addr = mmap(NULL, len, PROT_READ | PROT_WRITE, MAP_SHARED,
159 des_fid, offset);
160 if (des_addr == MAP_FAILED) {
161 fprintf(stderr, "mmap %s error=%d\n", des_file, errno);
162 mret = 1;
163 goto exit1;
164 }
165
166 /* cp data from src addr to des addr */
167 memcpy(des_addr, src_addr, len);
168 /* sync mapped pages to file */
169 if (msync(des_addr, len, MS_SYNC) == -1) {
170 fprintf(stderr, "msync %s error=%d\n", des_file, errno);
171 mret = 1;
172 }
173
174 /* unmap file */
175 if (munmap(des_addr, len) == -1) {
176 fprintf(stderr, "munmap %s error=%d\n",
177 des_file, errno);
178 mret = 1;
179 }
180 exit1:
181 if (munmap(src_addr, len) == -1) {
182 fprintf(stderr, "munmap %s error=%d\n",
183 src_file, errno);
184 mret = 1;
185 }
186 }
187
188 exit2:
189 close(des_fid);
190 exit3:
191 close(src_fid);
192
193 return (mret);
194 }