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git.ipfire.org Git - thirdparty/systemd.git/blob - src/basic/copy.c
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. */
40 if (try_reflink
&& max_bytes
== (uint64_t) -1) {
41 r
= btrfs_reflink(fdf
, fdt
);
47 size_t m
= COPY_BUFFER_SIZE
;
50 if (max_bytes
!= (uint64_t) -1) {
55 if ((uint64_t) m
> max_bytes
)
56 m
= (size_t) max_bytes
;
59 /* First try sendfile(), unless we already tried */
62 n
= sendfile(fdt
, fdf
, NULL
, m
);
64 if (errno
!= EINVAL
&& errno
!= ENOSYS
)
68 /* use fallback below */
69 } else if (n
== 0) /* EOF */
76 /* The try splice, unless we already tried */
78 n
= splice(fdf
, NULL
, fdt
, NULL
, m
, 0);
80 if (errno
!= EINVAL
&& errno
!= ENOSYS
)
84 /* use fallback below */
85 } else if (n
== 0) /* EOF */
92 /* As a fallback just copy bits by hand */
96 n
= read(fdf
, buf
, m
);
102 r
= loop_write(fdt
, buf
, (size_t) n
, false);
108 if (max_bytes
!= (uint64_t) -1) {
109 assert(max_bytes
>= (uint64_t) n
);
117 static int fd_copy_symlink(int df
, const char *from
, const struct stat
*st
, int dt
, const char *to
) {
118 _cleanup_free_
char *target
= NULL
;
125 r
= readlinkat_malloc(df
, from
, &target
);
129 if (symlinkat(target
, dt
, to
) < 0)
132 if (fchownat(dt
, to
, st
->st_uid
, st
->st_gid
, AT_SYMLINK_NOFOLLOW
) < 0)
138 static int fd_copy_regular(int df
, const char *from
, const struct stat
*st
, int dt
, const char *to
) {
139 _cleanup_close_
int fdf
= -1, fdt
= -1;
140 struct timespec ts
[2];
147 fdf
= openat(df
, from
, O_RDONLY
|O_CLOEXEC
|O_NOCTTY
|O_NOFOLLOW
);
151 fdt
= openat(dt
, to
, O_WRONLY
|O_CREAT
|O_EXCL
|O_CLOEXEC
|O_NOCTTY
|O_NOFOLLOW
, st
->st_mode
& 07777);
155 r
= copy_bytes(fdf
, fdt
, (uint64_t) -1, true);
161 if (fchown(fdt
, st
->st_uid
, st
->st_gid
) < 0)
164 if (fchmod(fdt
, st
->st_mode
& 07777) < 0)
169 (void) futimens(fdt
, ts
);
171 (void) copy_xattr(fdf
, fdt
);
184 static int fd_copy_fifo(int df
, const char *from
, const struct stat
*st
, int dt
, const char *to
) {
191 r
= mkfifoat(dt
, to
, st
->st_mode
& 07777);
195 if (fchownat(dt
, to
, st
->st_uid
, st
->st_gid
, AT_SYMLINK_NOFOLLOW
) < 0)
198 if (fchmodat(dt
, to
, st
->st_mode
& 07777, 0) < 0)
204 static int fd_copy_node(int df
, const char *from
, const struct stat
*st
, int dt
, const char *to
) {
211 r
= mknodat(dt
, to
, st
->st_mode
, st
->st_rdev
);
215 if (fchownat(dt
, to
, st
->st_uid
, st
->st_gid
, AT_SYMLINK_NOFOLLOW
) < 0)
218 if (fchmodat(dt
, to
, st
->st_mode
& 07777, 0) < 0)
224 static int fd_copy_directory(
227 const struct stat
*st
,
230 dev_t original_device
,
233 _cleanup_close_
int fdf
= -1, fdt
= -1;
234 _cleanup_closedir_
DIR *d
= NULL
;
243 fdf
= openat(df
, from
, O_RDONLY
|O_DIRECTORY
|O_CLOEXEC
|O_NOCTTY
|O_NOFOLLOW
);
245 fdf
= fcntl(df
, F_DUPFD_CLOEXEC
, 3);
252 r
= mkdirat(dt
, to
, st
->st_mode
& 07777);
255 else if (errno
== EEXIST
&& merge
)
260 fdt
= openat(dt
, to
, O_RDONLY
|O_DIRECTORY
|O_CLOEXEC
|O_NOCTTY
|O_NOFOLLOW
);
267 struct timespec ut
[2] = {
272 if (fchown(fdt
, st
->st_uid
, st
->st_gid
) < 0)
275 if (fchmod(fdt
, st
->st_mode
& 07777) < 0)
278 (void) futimens(fdt
, ut
);
279 (void) copy_xattr(dirfd(d
), fdt
);
282 FOREACH_DIRENT_ALL(de
, d
, return -errno
) {
286 if (STR_IN_SET(de
->d_name
, ".", ".."))
289 if (fstatat(dirfd(d
), de
->d_name
, &buf
, AT_SYMLINK_NOFOLLOW
) < 0) {
294 if (buf
.st_dev
!= original_device
)
297 if (S_ISREG(buf
.st_mode
))
298 q
= fd_copy_regular(dirfd(d
), de
->d_name
, &buf
, fdt
, de
->d_name
);
299 else if (S_ISDIR(buf
.st_mode
))
300 q
= fd_copy_directory(dirfd(d
), de
->d_name
, &buf
, fdt
, de
->d_name
, original_device
, merge
);
301 else if (S_ISLNK(buf
.st_mode
))
302 q
= fd_copy_symlink(dirfd(d
), de
->d_name
, &buf
, fdt
, de
->d_name
);
303 else if (S_ISFIFO(buf
.st_mode
))
304 q
= fd_copy_fifo(dirfd(d
), de
->d_name
, &buf
, fdt
, de
->d_name
);
305 else if (S_ISBLK(buf
.st_mode
) || S_ISCHR(buf
.st_mode
))
306 q
= fd_copy_node(dirfd(d
), de
->d_name
, &buf
, fdt
, de
->d_name
);
310 if (q
== -EEXIST
&& merge
)
320 int copy_tree_at(int fdf
, const char *from
, int fdt
, const char *to
, bool merge
) {
326 if (fstatat(fdf
, from
, &st
, AT_SYMLINK_NOFOLLOW
) < 0)
329 if (S_ISREG(st
.st_mode
))
330 return fd_copy_regular(fdf
, from
, &st
, fdt
, to
);
331 else if (S_ISDIR(st
.st_mode
))
332 return fd_copy_directory(fdf
, from
, &st
, fdt
, to
, st
.st_dev
, merge
);
333 else if (S_ISLNK(st
.st_mode
))
334 return fd_copy_symlink(fdf
, from
, &st
, fdt
, to
);
335 else if (S_ISFIFO(st
.st_mode
))
336 return fd_copy_fifo(fdf
, from
, &st
, fdt
, to
);
337 else if (S_ISBLK(st
.st_mode
) || S_ISCHR(st
.st_mode
))
338 return fd_copy_node(fdf
, from
, &st
, fdt
, to
);
343 int copy_tree(const char *from
, const char *to
, bool merge
) {
344 return copy_tree_at(AT_FDCWD
, from
, AT_FDCWD
, to
, merge
);
347 int copy_directory_fd(int dirfd
, const char *to
, bool merge
) {
354 if (fstat(dirfd
, &st
) < 0)
357 if (!S_ISDIR(st
.st_mode
))
360 return fd_copy_directory(dirfd
, NULL
, &st
, AT_FDCWD
, to
, st
.st_dev
, merge
);
363 int copy_file_fd(const char *from
, int fdt
, bool try_reflink
) {
364 _cleanup_close_
int fdf
= -1;
370 fdf
= open(from
, O_RDONLY
|O_CLOEXEC
|O_NOCTTY
);
374 r
= copy_bytes(fdf
, fdt
, (uint64_t) -1, try_reflink
);
376 (void) copy_times(fdf
, fdt
);
377 (void) copy_xattr(fdf
, fdt
);
382 int copy_file(const char *from
, const char *to
, int flags
, mode_t mode
, unsigned chattr_flags
) {
388 RUN_WITH_UMASK(0000) {
389 fdt
= open(to
, flags
|O_WRONLY
|O_CREAT
|O_CLOEXEC
|O_NOCTTY
, mode
);
394 if (chattr_flags
!= 0)
395 (void) chattr_fd(fdt
, chattr_flags
, (unsigned) -1);
397 r
= copy_file_fd(from
, fdt
, true);
404 if (close(fdt
) < 0) {
412 int copy_file_atomic(const char *from
, const char *to
, mode_t mode
, bool replace
, unsigned chattr_flags
) {
413 _cleanup_free_
char *t
= NULL
;
419 r
= tempfn_random(to
, NULL
, &t
);
423 r
= copy_file(from
, t
, O_NOFOLLOW
|O_EXCL
, mode
, chattr_flags
);
428 r
= renameat(AT_FDCWD
, t
, AT_FDCWD
, to
);
432 r
= rename_noreplace(AT_FDCWD
, t
, AT_FDCWD
, to
);
434 (void) unlink_noerrno(t
);
441 int copy_times(int fdf
, int fdt
) {
442 struct timespec ut
[2];
449 if (fstat(fdf
, &st
) < 0)
455 if (futimens(fdt
, ut
) < 0)
458 if (fd_getcrtime(fdf
, &crtime
) >= 0)
459 (void) fd_setcrtime(fdt
, crtime
);
464 int copy_xattr(int fdf
, int fdt
) {
465 _cleanup_free_
char *bufa
= NULL
, *bufb
= NULL
;
466 size_t sza
= 100, szb
= 100;
476 n
= flistxattr(fdf
, bufa
, sza
);
494 assert(l
< (size_t) n
);
496 if (startswith(p
, "user.")) {
505 m
= fgetxattr(fdf
, p
, bufb
, szb
);
507 if (errno
== ERANGE
) {
516 if (fsetxattr(fdt
, p
, bufb
, m
, 0) < 0)