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Diffstat (limited to '')
| -rw-r--r-- | util/copy_sparse.c | 228 |
1 files changed, 228 insertions, 0 deletions
diff --git a/util/copy_sparse.c b/util/copy_sparse.c new file mode 100644 index 0000000..cbab273 --- /dev/null +++ b/util/copy_sparse.c @@ -0,0 +1,228 @@ +/* + * copy_sparse.c -- copy a very large sparse files efficiently + * (requires root privileges) + * + * Copyright 2003, 2004 by Theodore Ts'o. + * + * %Begin-Header% + * This file may be redistributed under the terms of the GNU Public + * License. + * %End-Header% + */ + +#ifndef __linux__ +#include <stdio.h> +#include <stdlib.h> + +int main(void) { + fputs("This program is only supported on Linux!\n", stderr); + exit(EXIT_FAILURE); +} +#else +#define _LARGEFILE64_SOURCE + +#include <stdio.h> +#include <stdlib.h> +#include <unistd.h> +#include <string.h> +#include <time.h> +#include <fcntl.h> +#include <errno.h> +#ifdef HAVE_GETOPT_H +#include <getopt.h> +#else +extern char *optarg; +extern int optind; +#endif +#include <sys/types.h> +#include <sys/stat.h> +#include <sys/vfs.h> +#include <sys/ioctl.h> +#include <linux/fd.h> + +int verbose = 0; + +#define FIBMAP _IO(0x00,1) /* bmap access */ +#define FIGETBSZ _IO(0x00,2) /* get the block size used for bmap */ + +static unsigned long get_bmap(int fd, unsigned long block) +{ + int ret; + unsigned long b; + + b = block; + ret = ioctl(fd, FIBMAP, &b); + if (ret < 0) { + if (errno == EPERM) { + fprintf(stderr, "No permission to use FIBMAP ioctl; must have root privileges\n"); + exit(1); + } + perror("FIBMAP"); + } + return b; +} + +static int full_read(int fd, char *buf, size_t count) +{ + int got, total = 0; + int pass = 0; + + while (count > 0) { + got = read(fd, buf, count); + if (got == -1) { + if ((errno == EINTR) || (errno == EAGAIN)) + continue; + return total ? total : -1; + } + if (got == 0) { + if (pass++ >= 3) + return total; + continue; + } + pass = 0; + buf += got; + total += got; + count -= got; + } + return total; +} + +static void copy_sparse_file(const char *src, const char *dest) +{ + struct stat64 fileinfo; + long lb, i, fd, ofd, bs, block, numblocks; + ssize_t got, got2; + off64_t offset = 0, should_be; + char *buf; + + if (verbose) + printf("Copying sparse file from %s to %s\n", src, dest); + + if (strcmp(src, "-")) { + if (stat64(src, &fileinfo) < 0) { + perror("stat"); + exit(1); + } + if (!S_ISREG(fileinfo.st_mode)) { + printf("%s: Not a regular file\n", src); + exit(1); + } + fd = open(src, O_RDONLY | O_LARGEFILE); + if (fd < 0) { + perror("open"); + exit(1); + } + if (ioctl(fd, FIGETBSZ, &bs) < 0) { + perror("FIGETBSZ"); + close(fd); + exit(1); + } + if (bs < 0) { + printf("%s: Invalid block size: %ld\n", src, bs); + exit(1); + } + if (verbose) + printf("Blocksize of file %s is %ld\n", src, bs); + numblocks = (fileinfo.st_size + (bs-1)) / bs; + if (verbose) + printf("File size of %s is %lld (%ld blocks)\n", src, + (long long) fileinfo.st_size, numblocks); + } else { + fd = 0; + bs = 1024; + } + + ofd = open(dest, O_WRONLY|O_CREAT|O_TRUNC|O_LARGEFILE, 0777); + if (ofd < 0) { + perror(dest); + exit(1); + } + + buf = malloc(bs); + if (!buf) { + fprintf(stderr, "Couldn't allocate buffer"); + exit(1); + } + + for (lb = 0; !fd || lb < numblocks; lb++) { + if (fd) { + block = get_bmap(fd, lb); + if (!block) + continue; + should_be = ((off64_t) lb) * bs; + if (offset != should_be) { + if (verbose) + printf("Seeking to %lld\n", should_be); + if (lseek64(fd, should_be, SEEK_SET) == (off_t) -1) { + perror("lseek src"); + exit(1); + } + if (lseek64(ofd, should_be, SEEK_SET) == (off_t) -1) { + perror("lseek dest"); + exit(1); + } + offset = should_be; + } + } + got = full_read(fd, buf, bs); + + if (fd == 0 && got == 0) + break; + + if (got == bs) { + for (i=0; i < bs; i++) + if (buf[i]) + break; + if (i == bs) { + lseek(ofd, bs, SEEK_CUR); + offset += bs; + continue; + } + } + got2 = write(ofd, buf, got); + if (got != got2) { + printf("short write\n"); + exit(1); + } + offset += got; + } + offset = fileinfo.st_size; + if (fstat64(ofd, &fileinfo) < 0) { + perror("fstat"); + exit(1); + } + if (fileinfo.st_size != offset) { + lseek64(ofd, offset-1, SEEK_CUR); + buf[0] = 0; + write(ofd, buf, 1); + } + close(fd); + close(ofd); +} + +static void usage(const char *progname) +{ + fprintf(stderr, "Usage: %s [-v] source_file destination_file\n", progname); + exit(1); +} + +int main(int argc, char**argv) +{ + int c; + + while ((c = getopt(argc, argv, "v")) != EOF) + switch (c) { + case 'v': + verbose++; + break; + default: + usage(argv[0]); + break; + } + if (optind+2 != argc) + usage(argv[0]); + copy_sparse_file(argv[optind], argv[optind+1]); + + return 0; +} +#endif |