projects / mirror_lxc.git / blame
| Commit | Line | Data |
|---|---|---|
| e3642c43 DL |
1 | /* |
| 2 | * lxc: linux Container library | |
| 3 | * | |
| 4 | * (C) Copyright IBM Corp. 2007, 2008 | |
| 5 | * | |
| 6 | * Authors: | |
| 7 | * Daniel Lezcano <dlezcano at fr.ibm.com> | |
| 8 | * | |
| 9 | * This library is free software; you can redistribute it and/or | |
| 10 | * modify it under the terms of the GNU Lesser General Public | |
| 11 | * License as published by the Free Software Foundation; either | |
| 12 | * version 2.1 of the License, or (at your option) any later version. | |
| 13 | * | |
| 14 | * This library is distributed in the hope that it will be useful, | |
| 15 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
| 16 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
| 17 | * Lesser General Public License for more details. | |
| 18 | * | |
| 19 | * You should have received a copy of the GNU Lesser General Public | |
| 20 | * License along with this library; if not, write to the Free Software | |
| 21 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA | |
| 22 | */ | |
| 23 | ||
| 24 | #include <fcntl.h> | |
| 25 | #include <errno.h> | |
| 26 | #include <unistd.h> | |
| 27 | #include <sys/types.h> | |
| 28 | #include <sys/stat.h> | |
| 29 | #include <sys/mman.h> | |
| 30 | ||
| 31 | #include "log.h" | |
| 32 | ||
| 33 | lxc_log_define(lxc_utils, lxc); | |
| 34 | ||
| 35 | int lxc_copy_file(const char *srcfile, const char *dstfile) | |
| 36 | { | |
| 37 | void *srcaddr = NULL, *dstaddr; | |
| 38 | struct stat stat; | |
| 39 | int srcfd, dstfd, ret = -1; | |
| 40 | char c = '\0'; | |
| 41 | ||
| 42 | dstfd = open(dstfile, O_CREAT | O_EXCL | O_RDWR, 0600); | |
| 43 | if (dstfd < 0) { | |
| 44 | SYSERROR("failed to creat '%s'", dstfile); | |
| 45 | goto out; | |
| 46 | } | |
| 47 | ||
| 48 | srcfd = open(srcfile, O_RDONLY); | |
| 49 | if (srcfd < 0) { | |
| 50 | SYSERROR("failed to open '%s'", srcfile); | |
| 51 | goto err; | |
| 52 | } | |
| 53 | ||
| 54 | if (fstat(srcfd, &stat)) { | |
| 55 | SYSERROR("failed to stat '%s'", srcfile); | |
| 56 | goto err; | |
| 57 | } | |
| 58 | ||
| 59 | if (!stat.st_size) { | |
| 60 | INFO("copy '%s' which is an empty file", srcfile); | |
| 61 | ret = 0; | |
| 62 | goto out_close; | |
| 63 | } | |
| 64 | ||
| 65 | if (lseek(dstfd, stat.st_size - 1, SEEK_SET) < 0) { | |
| 66 | SYSERROR("failed to seek dest file '%s'", dstfile); | |
| 67 | goto err; | |
| 68 | } | |
| 69 | ||
| 70 | /* fixup length */ | |
| 71 | if (write(dstfd, &c, 1) < 0) { | |
| 72 | SYSERROR("failed to write to '%s'", dstfile); | |
| 73 | goto err; | |
| 74 | } | |
| 75 | ||
| 76 | srcaddr = mmap(NULL, stat.st_size, PROT_READ, MAP_SHARED, srcfd, 0L); | |
| 77 | if (srcaddr == MAP_FAILED) { | |
| 78 | SYSERROR("failed to mmap '%s'", srcfile); | |
| 79 | goto err; | |
| 80 | } | |
| 81 | ||
| 82 | dstaddr = mmap(NULL, stat.st_size, PROT_WRITE, MAP_SHARED, dstfd, 0L); | |
| 83 | if (dstaddr == MAP_FAILED) { | |
| 84 | SYSERROR("failed to mmap '%s'", dstfile); | |
| 85 | goto err; | |
| 86 | } | |
| 87 | ||
| 88 | ret = 0; | |
| 89 | ||
| 90 | memcpy(dstaddr, srcaddr, stat.st_size); | |
| 91 | ||
| 92 | munmap(dstaddr, stat.st_size); | |
| 93 | out_mmap: | |
| 94 | if (srcaddr) | |
| 95 | munmap(srcaddr, stat.st_size); | |
| 96 | out_close: | |
| 97 | close(dstfd); | |
| 98 | close(srcfd); | |
| 99 | out: | |
| 100 | return ret; | |
| 101 | err: | |
| 102 | unlink(dstfile); | |
| 103 | goto out_mmap; | |
| 104 | } |