2 This file is part of systemd.
4 Copyright 2014 Lennart Poettering
6 systemd is free software; you can redistribute it and/or modify it
7 under the terms of the GNU Lesser General Public License as published by
8 the Free Software Foundation; either version 2.1 of the License, or
9 (at your option) any later version.
11 systemd is distributed in the hope that it will be useful, but
12 WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 Lesser General Public License for more details.
16 You should have received a copy of the GNU Lesser General Public License
17 along with systemd; If not, see <http://www.gnu.org/licenses/>.
27 #include <sys/sendfile.h>
28 //#include <sys/stat.h>
29 #include <sys/xattr.h>
33 //#include "alloc-util.h"
34 //#include "btrfs-util.h"
35 //#include "chattr-util.h"
37 //#include "dirent-util.h"
38 //#include "fd-util.h"
40 //#include "fs-util.h"
43 //#include "string-util.h"
45 #include "time-util.h"
46 //#include "umask-util.h"
47 //#include "xattr-util.h"
49 #define COPY_BUFFER_SIZE (16*1024u)
51 static ssize_t try_copy_file_range(int fd_in, loff_t *off_in,
52 int fd_out, loff_t *off_out,
61 r = copy_file_range(fd_in, off_in, fd_out, off_out, len, flags);
62 if (_unlikely_(have < 0))
63 have = r >= 0 || errno != ENOSYS;
70 int copy_bytes(int fdf, int fdt, uint64_t max_bytes, bool try_reflink) {
71 bool try_cfr = true, try_sendfile = true, try_splice = true;
73 size_t m = SSIZE_MAX; /* that is the maximum that sendfile and c_f_r accept */
78 #if 0 /// UNNEEDED by elogind
79 /* Try btrfs reflinks first. */
81 max_bytes == (uint64_t) -1 &&
82 lseek(fdf, 0, SEEK_CUR) == 0 &&
83 lseek(fdt, 0, SEEK_CUR) == 0) {
85 r = btrfs_reflink(fdf, fdt);
87 return 0; /* we copied the whole thing, hence hit EOF, return 0 */
94 if (max_bytes != (uint64_t) -1) {
96 return 1; /* return > 0 if we hit the max_bytes limit */
102 /* First try copy_file_range(), unless we already tried */
104 n = try_copy_file_range(fdf, NULL, fdt, NULL, m, 0u);
106 if (!IN_SET(n, -EINVAL, -ENOSYS, -EXDEV, -EBADF))
110 /* use fallback below */
111 } else if (n == 0) /* EOF */
118 /* First try sendfile(), unless we already tried */
120 n = sendfile(fdt, fdf, NULL, m);
122 if (!IN_SET(errno, EINVAL, ENOSYS))
125 try_sendfile = false;
126 /* use fallback below */
127 } else if (n == 0) /* EOF */
134 /* Then try splice, unless we already tried */
136 n = splice(fdf, NULL, fdt, NULL, m, 0);
138 if (!IN_SET(errno, EINVAL, ENOSYS))
142 /* use fallback below */
143 } else if (n == 0) /* EOF */
150 /* As a fallback just copy bits by hand */
152 uint8_t buf[MIN(m, COPY_BUFFER_SIZE)];
154 n = read(fdf, buf, sizeof buf);
157 if (n == 0) /* EOF */
160 r = loop_write(fdt, buf, (size_t) n, false);
166 if (max_bytes != (uint64_t) -1) {
167 assert(max_bytes >= (uint64_t) n);
170 /* sendfile accepts at most SSIZE_MAX-offset bytes to copy,
171 * so reduce our maximum by the amount we already copied,
172 * but don't go below our copy buffer size, unless we are
173 * close the limit of bytes we are allowed to copy. */
174 m = MAX(MIN(COPY_BUFFER_SIZE, max_bytes), m - n);
177 return 0; /* return 0 if we hit EOF earlier than the size limit */
180 #if 0 /// UNNEEDED by elogind
181 static int fd_copy_symlink(int df, const char *from, const struct stat *st, int dt, const char *to) {
182 _cleanup_free_ char *target = NULL;
189 r = readlinkat_malloc(df, from, &target);
193 if (symlinkat(target, dt, to) < 0)
196 if (fchownat(dt, to, st->st_uid, st->st_gid, AT_SYMLINK_NOFOLLOW) < 0)
202 static int fd_copy_regular(int df, const char *from, const struct stat *st, int dt, const char *to) {
203 _cleanup_close_ int fdf = -1, fdt = -1;
204 struct timespec ts[2];
211 fdf = openat(df, from, O_RDONLY|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW);
215 fdt = openat(dt, to, O_WRONLY|O_CREAT|O_EXCL|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW, st->st_mode & 07777);
219 r = copy_bytes(fdf, fdt, (uint64_t) -1, true);
225 if (fchown(fdt, st->st_uid, st->st_gid) < 0)
228 if (fchmod(fdt, st->st_mode & 07777) < 0)
233 (void) futimens(fdt, ts);
235 (void) copy_xattr(fdf, fdt);
248 static int fd_copy_fifo(int df, const char *from, const struct stat *st, int dt, const char *to) {
255 r = mkfifoat(dt, to, st->st_mode & 07777);
259 if (fchownat(dt, to, st->st_uid, st->st_gid, AT_SYMLINK_NOFOLLOW) < 0)
262 if (fchmodat(dt, to, st->st_mode & 07777, 0) < 0)
268 static int fd_copy_node(int df, const char *from, const struct stat *st, int dt, const char *to) {
275 r = mknodat(dt, to, st->st_mode, st->st_rdev);
279 if (fchownat(dt, to, st->st_uid, st->st_gid, AT_SYMLINK_NOFOLLOW) < 0)
282 if (fchmodat(dt, to, st->st_mode & 07777, 0) < 0)
288 static int fd_copy_directory(
291 const struct stat *st,
294 dev_t original_device,
297 _cleanup_close_ int fdf = -1, fdt = -1;
298 _cleanup_closedir_ DIR *d = NULL;
307 fdf = openat(df, from, O_RDONLY|O_DIRECTORY|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW);
309 fdf = fcntl(df, F_DUPFD_CLOEXEC, 3);
318 r = mkdirat(dt, to, st->st_mode & 07777);
321 else if (errno == EEXIST && merge)
326 fdt = openat(dt, to, O_RDONLY|O_DIRECTORY|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW);
332 FOREACH_DIRENT_ALL(de, d, return -errno) {
336 if (STR_IN_SET(de->d_name, ".", ".."))
339 if (fstatat(dirfd(d), de->d_name, &buf, AT_SYMLINK_NOFOLLOW) < 0) {
344 if (buf.st_dev != original_device)
347 if (S_ISREG(buf.st_mode))
348 q = fd_copy_regular(dirfd(d), de->d_name, &buf, fdt, de->d_name);
349 else if (S_ISDIR(buf.st_mode))
350 q = fd_copy_directory(dirfd(d), de->d_name, &buf, fdt, de->d_name, original_device, merge);
351 else if (S_ISLNK(buf.st_mode))
352 q = fd_copy_symlink(dirfd(d), de->d_name, &buf, fdt, de->d_name);
353 else if (S_ISFIFO(buf.st_mode))
354 q = fd_copy_fifo(dirfd(d), de->d_name, &buf, fdt, de->d_name);
355 else if (S_ISBLK(buf.st_mode) || S_ISCHR(buf.st_mode) || S_ISSOCK(buf.st_mode))
356 q = fd_copy_node(dirfd(d), de->d_name, &buf, fdt, de->d_name);
360 if (q == -EEXIST && merge)
368 struct timespec ut[2] = {
373 if (fchown(fdt, st->st_uid, st->st_gid) < 0)
376 if (fchmod(fdt, st->st_mode & 07777) < 0)
379 (void) copy_xattr(dirfd(d), fdt);
380 (void) futimens(fdt, ut);
386 int copy_tree_at(int fdf, const char *from, int fdt, const char *to, bool merge) {
392 if (fstatat(fdf, from, &st, AT_SYMLINK_NOFOLLOW) < 0)
395 if (S_ISREG(st.st_mode))
396 return fd_copy_regular(fdf, from, &st, fdt, to);
397 else if (S_ISDIR(st.st_mode))
398 return fd_copy_directory(fdf, from, &st, fdt, to, st.st_dev, merge);
399 else if (S_ISLNK(st.st_mode))
400 return fd_copy_symlink(fdf, from, &st, fdt, to);
401 else if (S_ISFIFO(st.st_mode))
402 return fd_copy_fifo(fdf, from, &st, fdt, to);
403 else if (S_ISBLK(st.st_mode) || S_ISCHR(st.st_mode) || S_ISSOCK(st.st_mode))
404 return fd_copy_node(fdf, from, &st, fdt, to);
409 int copy_tree(const char *from, const char *to, bool merge) {
410 return copy_tree_at(AT_FDCWD, from, AT_FDCWD, to, merge);
413 int copy_directory_fd(int dirfd, const char *to, bool merge) {
419 if (fstat(dirfd, &st) < 0)
422 if (!S_ISDIR(st.st_mode))
425 return fd_copy_directory(dirfd, NULL, &st, AT_FDCWD, to, st.st_dev, merge);
428 int copy_directory(const char *from, const char *to, bool merge) {
434 if (lstat(from, &st) < 0)
437 if (!S_ISDIR(st.st_mode))
440 return fd_copy_directory(AT_FDCWD, from, &st, AT_FDCWD, to, st.st_dev, merge);
443 int copy_file_fd(const char *from, int fdt, bool try_reflink) {
444 _cleanup_close_ int fdf = -1;
450 fdf = open(from, O_RDONLY|O_CLOEXEC|O_NOCTTY);
454 r = copy_bytes(fdf, fdt, (uint64_t) -1, try_reflink);
456 (void) copy_times(fdf, fdt);
457 (void) copy_xattr(fdf, fdt);
462 int copy_file(const char *from, const char *to, int flags, mode_t mode, unsigned chattr_flags) {
468 RUN_WITH_UMASK(0000) {
469 fdt = open(to, flags|O_WRONLY|O_CREAT|O_CLOEXEC|O_NOCTTY, mode);
474 if (chattr_flags != 0)
475 (void) chattr_fd(fdt, chattr_flags, (unsigned) -1);
477 r = copy_file_fd(from, fdt, true);
484 if (close(fdt) < 0) {
492 int copy_file_atomic(const char *from, const char *to, mode_t mode, bool replace, unsigned chattr_flags) {
493 _cleanup_free_ char *t = NULL;
499 r = tempfn_random(to, NULL, &t);
503 r = copy_file(from, t, O_NOFOLLOW|O_EXCL, mode, chattr_flags);
508 r = renameat(AT_FDCWD, t, AT_FDCWD, to);
512 r = rename_noreplace(AT_FDCWD, t, AT_FDCWD, to);
514 (void) unlink_noerrno(t);
521 int copy_times(int fdf, int fdt) {
522 struct timespec ut[2];
529 if (fstat(fdf, &st) < 0)
535 if (futimens(fdt, ut) < 0)
538 if (fd_getcrtime(fdf, &crtime) >= 0)
539 (void) fd_setcrtime(fdt, crtime);
544 int copy_xattr(int fdf, int fdt) {
545 _cleanup_free_ char *bufa = NULL, *bufb = NULL;
546 size_t sza = 100, szb = 100;
556 n = flistxattr(fdf, bufa, sza);
574 assert(l < (size_t) n);
576 if (startswith(p, "user.")) {
585 m = fgetxattr(fdf, p, bufb, szb);
587 if (errno == ERANGE) {
596 if (fsetxattr(fdt, p, bufb, m, 0) < 0)