1 /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
4 This file is part of systemd.
6 Copyright 2014 Lennart Poettering
8 systemd is free software; you can redistribute it and/or modify it
9 under the terms of the GNU Lesser General Public License as published by
10 the Free Software Foundation; either version 2.1 of the License, or
11 (at your option) any later version.
13 systemd is distributed in the hope that it will be useful, but
14 WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 Lesser General Public License for more details.
18 You should have received a copy of the GNU Lesser General Public License
19 along with systemd; If not, see <http://www.gnu.org/licenses/>.
22 #include <sys/sendfile.h>
25 #include "btrfs-util.h"
28 int copy_bytes(int fdf, int fdt, off_t max_bytes) {
29 bool try_sendfile = true;
35 /* Try btrfs reflinks first. */
36 if (max_bytes == (off_t) -1) {
37 r = btrfs_reflink(fdf, fdt);
46 if (max_bytes != (off_t) -1) {
51 if ((off_t) m > max_bytes)
52 m = (size_t) max_bytes;
55 /* First try sendfile(), unless we already tried */
58 n = sendfile(fdt, fdf, NULL, m);
60 if (errno != EINVAL && errno != ENOSYS)
64 /* use fallback below */
65 } else if (n == 0) /* EOF */
72 /* As a fallback just copy bits by hand */
76 n = read(fdf, buf, m);
82 r = loop_write(fdt, buf, (size_t) n, false);
88 if (max_bytes != (off_t) -1) {
89 assert(max_bytes >= n);
97 static int fd_copy_symlink(int df, const char *from, const struct stat *st, int dt, const char *to) {
98 _cleanup_free_ char *target = NULL;
105 r = readlinkat_malloc(df, from, &target);
109 if (symlinkat(target, dt, to) < 0)
112 if (fchownat(dt, to, st->st_uid, st->st_gid, AT_SYMLINK_NOFOLLOW) < 0)
118 static int fd_copy_regular(int df, const char *from, const struct stat *st, int dt, const char *to) {
119 _cleanup_close_ int fdf = -1, fdt = -1;
126 fdf = openat(df, from, O_RDONLY|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW);
130 fdt = openat(dt, to, O_WRONLY|O_CREAT|O_EXCL|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW, st->st_mode & 07777);
134 r = copy_bytes(fdf, fdt, (off_t) -1);
140 if (fchown(fdt, st->st_uid, st->st_gid) < 0)
143 if (fchmod(fdt, st->st_mode & 07777) < 0)
157 static int fd_copy_fifo(int df, const char *from, const struct stat *st, int dt, const char *to) {
164 r = mkfifoat(dt, to, st->st_mode & 07777);
168 if (fchownat(dt, to, st->st_uid, st->st_gid, AT_SYMLINK_NOFOLLOW) < 0)
171 if (fchmodat(dt, to, st->st_mode & 07777, 0) < 0)
177 static int fd_copy_node(int df, const char *from, const struct stat *st, int dt, const char *to) {
184 r = mknodat(dt, to, st->st_mode, st->st_rdev);
188 if (fchownat(dt, to, st->st_uid, st->st_gid, AT_SYMLINK_NOFOLLOW) < 0)
191 if (fchmodat(dt, to, st->st_mode & 07777, 0) < 0)
197 static int fd_copy_directory(
200 const struct stat *st,
203 dev_t original_device,
206 _cleanup_close_ int fdf = -1, fdt = -1;
207 _cleanup_closedir_ DIR *d = NULL;
216 fdf = openat(df, from, O_RDONLY|O_DIRECTORY|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW);
218 fdf = fcntl(df, F_DUPFD_CLOEXEC, 3);
225 r = mkdirat(dt, to, st->st_mode & 07777);
228 else if (errno == EEXIST && merge)
233 fdt = openat(dt, to, O_RDONLY|O_DIRECTORY|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW);
240 if (fchown(fdt, st->st_uid, st->st_gid) < 0)
243 if (fchmod(fdt, st->st_mode & 07777) < 0)
247 FOREACH_DIRENT(de, d, return -errno) {
251 if (fstatat(dirfd(d), de->d_name, &buf, AT_SYMLINK_NOFOLLOW) < 0) {
256 if (buf.st_dev != original_device)
259 if (S_ISREG(buf.st_mode))
260 q = fd_copy_regular(dirfd(d), de->d_name, &buf, fdt, de->d_name);
261 else if (S_ISDIR(buf.st_mode))
262 q = fd_copy_directory(dirfd(d), de->d_name, &buf, fdt, de->d_name, original_device, merge);
263 else if (S_ISLNK(buf.st_mode))
264 q = fd_copy_symlink(dirfd(d), de->d_name, &buf, fdt, de->d_name);
265 else if (S_ISFIFO(buf.st_mode))
266 q = fd_copy_fifo(dirfd(d), de->d_name, &buf, fdt, de->d_name);
267 else if (S_ISBLK(buf.st_mode) || S_ISCHR(buf.st_mode))
268 q = fd_copy_node(dirfd(d), de->d_name, &buf, fdt, de->d_name);
272 if (q == -EEXIST && merge)
282 int copy_tree(const char *from, const char *to, bool merge) {
288 if (lstat(from, &st) < 0)
291 if (S_ISREG(st.st_mode))
292 return fd_copy_regular(AT_FDCWD, from, &st, AT_FDCWD, to);
293 else if (S_ISDIR(st.st_mode))
294 return fd_copy_directory(AT_FDCWD, from, &st, AT_FDCWD, to, st.st_dev, merge);
295 else if (S_ISLNK(st.st_mode))
296 return fd_copy_symlink(AT_FDCWD, from, &st, AT_FDCWD, to);
297 else if (S_ISFIFO(st.st_mode))
298 return fd_copy_fifo(AT_FDCWD, from, &st, AT_FDCWD, to);
299 else if (S_ISBLK(st.st_mode) || S_ISCHR(st.st_mode))
300 return fd_copy_node(AT_FDCWD, from, &st, AT_FDCWD, to);
305 int copy_tree_fd(int dirfd, const char *to, bool merge) {
312 if (fstat(dirfd, &st) < 0)
315 if (!S_ISDIR(st.st_mode))
318 return fd_copy_directory(dirfd, NULL, &st, AT_FDCWD, to, st.st_dev, merge);
321 int copy_file_fd(const char *from, int fdt) {
322 _cleanup_close_ int fdf = -1;
327 fdf = open(from, O_RDONLY|O_CLOEXEC|O_NOCTTY);
331 return copy_bytes(fdf, fdt, (off_t) -1);
334 int copy_file(const char *from, const char *to, int flags, mode_t mode) {
340 fdt = open(to, flags|O_WRONLY|O_CREAT|O_CLOEXEC|O_NOCTTY, mode);
344 r = copy_file_fd(from, fdt);
351 if (close(fdt) < 0) {