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>
23 #include <sys/xattr.h>
26 // #include "btrfs-util.h"
30 #define COPY_BUFFER_SIZE (16*1024)
32 int copy_bytes(int fdf, int fdt, uint64_t max_bytes, bool try_reflink) {
33 bool try_sendfile = true, try_splice = true;
39 /* Try btrfs reflinks first. */
41 max_bytes == (uint64_t) -1 &&
42 lseek(fdf, 0, SEEK_CUR) == 0 &&
43 lseek(fdt, 0, SEEK_CUR) == 0) {
45 r = btrfs_reflink(fdf, fdt);
47 return 0; /* we copied the whole thing, hence hit EOF, return 0 */
51 size_t m = COPY_BUFFER_SIZE;
54 if (max_bytes != (uint64_t) -1) {
59 if ((uint64_t) m > max_bytes)
60 m = (size_t) max_bytes;
63 /* First try sendfile(), unless we already tried */
66 n = sendfile(fdt, fdf, NULL, m);
68 if (errno != EINVAL && errno != ENOSYS)
72 /* use fallback below */
73 } else if (n == 0) /* EOF */
80 /* The try splice, unless we already tried */
82 n = splice(fdf, NULL, fdt, NULL, m, 0);
84 if (errno != EINVAL && errno != ENOSYS)
88 /* use fallback below */
89 } else if (n == 0) /* EOF */
96 /* As a fallback just copy bits by hand */
100 n = read(fdf, buf, m);
103 if (n == 0) /* EOF */
106 r = loop_write(fdt, buf, (size_t) n, false);
112 if (max_bytes != (uint64_t) -1) {
113 assert(max_bytes >= (uint64_t) n);
118 return 0; /* return 0 if we hit EOF earlier than the size limit */
121 // UNNEEDED by elogind
123 static int fd_copy_symlink(int df, const char *from, const struct stat *st, int dt, const char *to) {
124 _cleanup_free_ char *target = NULL;
131 r = readlinkat_malloc(df, from, &target);
135 if (symlinkat(target, dt, to) < 0)
138 if (fchownat(dt, to, st->st_uid, st->st_gid, AT_SYMLINK_NOFOLLOW) < 0)
144 static int fd_copy_regular(int df, const char *from, const struct stat *st, int dt, const char *to) {
145 _cleanup_close_ int fdf = -1, fdt = -1;
146 struct timespec ts[2];
153 fdf = openat(df, from, O_RDONLY|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW);
157 fdt = openat(dt, to, O_WRONLY|O_CREAT|O_EXCL|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW, st->st_mode & 07777);
161 r = copy_bytes(fdf, fdt, (uint64_t) -1, true);
167 if (fchown(fdt, st->st_uid, st->st_gid) < 0)
170 if (fchmod(fdt, st->st_mode & 07777) < 0)
175 (void) futimens(fdt, ts);
177 (void) copy_xattr(fdf, fdt);
190 static int fd_copy_fifo(int df, const char *from, const struct stat *st, int dt, const char *to) {
197 r = mkfifoat(dt, to, st->st_mode & 07777);
201 if (fchownat(dt, to, st->st_uid, st->st_gid, AT_SYMLINK_NOFOLLOW) < 0)
204 if (fchmodat(dt, to, st->st_mode & 07777, 0) < 0)
210 static int fd_copy_node(int df, const char *from, const struct stat *st, int dt, const char *to) {
217 r = mknodat(dt, to, st->st_mode, st->st_rdev);
221 if (fchownat(dt, to, st->st_uid, st->st_gid, AT_SYMLINK_NOFOLLOW) < 0)
224 if (fchmodat(dt, to, st->st_mode & 07777, 0) < 0)
230 static int fd_copy_directory(
233 const struct stat *st,
236 dev_t original_device,
239 _cleanup_close_ int fdf = -1, fdt = -1;
240 _cleanup_closedir_ DIR *d = NULL;
249 fdf = openat(df, from, O_RDONLY|O_DIRECTORY|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW);
251 fdf = fcntl(df, F_DUPFD_CLOEXEC, 3);
258 r = mkdirat(dt, to, st->st_mode & 07777);
261 else if (errno == EEXIST && merge)
266 fdt = openat(dt, to, O_RDONLY|O_DIRECTORY|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW);
273 struct timespec ut[2] = {
278 if (fchown(fdt, st->st_uid, st->st_gid) < 0)
281 if (fchmod(fdt, st->st_mode & 07777) < 0)
284 (void) futimens(fdt, ut);
285 (void) copy_xattr(dirfd(d), fdt);
288 FOREACH_DIRENT_ALL(de, d, return -errno) {
292 if (STR_IN_SET(de->d_name, ".", ".."))
295 if (fstatat(dirfd(d), de->d_name, &buf, AT_SYMLINK_NOFOLLOW) < 0) {
300 if (buf.st_dev != original_device)
303 if (S_ISREG(buf.st_mode))
304 q = fd_copy_regular(dirfd(d), de->d_name, &buf, fdt, de->d_name);
305 else if (S_ISDIR(buf.st_mode))
306 q = fd_copy_directory(dirfd(d), de->d_name, &buf, fdt, de->d_name, original_device, merge);
307 else if (S_ISLNK(buf.st_mode))
308 q = fd_copy_symlink(dirfd(d), de->d_name, &buf, fdt, de->d_name);
309 else if (S_ISFIFO(buf.st_mode))
310 q = fd_copy_fifo(dirfd(d), de->d_name, &buf, fdt, de->d_name);
311 else if (S_ISBLK(buf.st_mode) || S_ISCHR(buf.st_mode))
312 q = fd_copy_node(dirfd(d), de->d_name, &buf, fdt, de->d_name);
316 if (q == -EEXIST && merge)
326 int copy_tree_at(int fdf, const char *from, int fdt, const char *to, bool merge) {
332 if (fstatat(fdf, from, &st, AT_SYMLINK_NOFOLLOW) < 0)
335 if (S_ISREG(st.st_mode))
336 return fd_copy_regular(fdf, from, &st, fdt, to);
337 else if (S_ISDIR(st.st_mode))
338 return fd_copy_directory(fdf, from, &st, fdt, to, st.st_dev, merge);
339 else if (S_ISLNK(st.st_mode))
340 return fd_copy_symlink(fdf, from, &st, fdt, to);
341 else if (S_ISFIFO(st.st_mode))
342 return fd_copy_fifo(fdf, from, &st, fdt, to);
343 else if (S_ISBLK(st.st_mode) || S_ISCHR(st.st_mode))
344 return fd_copy_node(fdf, from, &st, fdt, to);
349 int copy_tree(const char *from, const char *to, bool merge) {
350 return copy_tree_at(AT_FDCWD, from, AT_FDCWD, to, merge);
353 int copy_directory_fd(int dirfd, const char *to, bool merge) {
360 if (fstat(dirfd, &st) < 0)
363 if (!S_ISDIR(st.st_mode))
366 return fd_copy_directory(dirfd, NULL, &st, AT_FDCWD, to, st.st_dev, merge);
369 int copy_file_fd(const char *from, int fdt, bool try_reflink) {
370 _cleanup_close_ int fdf = -1;
376 fdf = open(from, O_RDONLY|O_CLOEXEC|O_NOCTTY);
380 r = copy_bytes(fdf, fdt, (uint64_t) -1, try_reflink);
382 (void) copy_times(fdf, fdt);
383 (void) copy_xattr(fdf, fdt);
388 int copy_file(const char *from, const char *to, int flags, mode_t mode, unsigned chattr_flags) {
394 RUN_WITH_UMASK(0000) {
395 fdt = open(to, flags|O_WRONLY|O_CREAT|O_CLOEXEC|O_NOCTTY, mode);
400 if (chattr_flags != 0)
401 (void) chattr_fd(fdt, chattr_flags, (unsigned) -1);
403 r = copy_file_fd(from, fdt, true);
410 if (close(fdt) < 0) {
418 int copy_file_atomic(const char *from, const char *to, mode_t mode, bool replace, unsigned chattr_flags) {
419 _cleanup_free_ char *t = NULL;
425 r = tempfn_random(to, NULL, &t);
429 r = copy_file(from, t, O_NOFOLLOW|O_EXCL, mode, chattr_flags);
434 r = renameat(AT_FDCWD, t, AT_FDCWD, to);
438 r = rename_noreplace(AT_FDCWD, t, AT_FDCWD, to);
440 (void) unlink_noerrno(t);
447 int copy_times(int fdf, int fdt) {
448 struct timespec ut[2];
455 if (fstat(fdf, &st) < 0)
461 if (futimens(fdt, ut) < 0)
464 if (fd_getcrtime(fdf, &crtime) >= 0)
465 (void) fd_setcrtime(fdt, crtime);
470 int copy_xattr(int fdf, int fdt) {
471 _cleanup_free_ char *bufa = NULL, *bufb = NULL;
472 size_t sza = 100, szb = 100;
482 n = flistxattr(fdf, bufa, sza);
500 assert(l < (size_t) n);
502 if (startswith(p, "user.")) {
511 m = fgetxattr(fdf, p, bufb, szb);
513 if (errno == ERANGE) {
522 if (fsetxattr(fdt, p, bufb, m, 0) < 0)