| /* SPDX-License-Identifier: LGPL-2.1+ */ |
| |
| #include <dirent.h> |
| #include <errno.h> |
| #include <fcntl.h> |
| #include <stddef.h> |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <string.h> |
| #include <sys/sendfile.h> |
| #include <sys/stat.h> |
| #include <sys/xattr.h> |
| #include <time.h> |
| #include <unistd.h> |
| |
| #include "alloc-util.h" |
| #include "btrfs-util.h" |
| #include "chattr-util.h" |
| #include "copy.h" |
| #include "dirent-util.h" |
| #include "fd-util.h" |
| #include "fileio.h" |
| #include "fs-util.h" |
| #include "io-util.h" |
| #include "macro.h" |
| #include "missing.h" |
| #include "mount-util.h" |
| #include "string-util.h" |
| #include "strv.h" |
| #include "time-util.h" |
| #include "umask-util.h" |
| #include "user-util.h" |
| #include "xattr-util.h" |
| |
| #define COPY_BUFFER_SIZE (16U*1024U) |
| |
| /* A safety net for descending recursively into file system trees to copy. On Linux PATH_MAX is 4096, which means the |
| * deepest valid path one can build is around 2048, which we hence use as a safety net here, to not spin endlessly in |
| * case of bind mount cycles and suchlike. */ |
| #define COPY_DEPTH_MAX 2048U |
| |
| static ssize_t try_copy_file_range( |
| int fd_in, loff_t *off_in, |
| int fd_out, loff_t *off_out, |
| size_t len, |
| unsigned int flags) { |
| |
| static int have = -1; |
| ssize_t r; |
| |
| if (have == 0) |
| return -ENOSYS; |
| |
| r = copy_file_range(fd_in, off_in, fd_out, off_out, len, flags); |
| if (have < 0) |
| have = r >= 0 || errno != ENOSYS; |
| if (r < 0) |
| return -errno; |
| |
| return r; |
| } |
| |
| enum { |
| FD_IS_NO_PIPE, |
| FD_IS_BLOCKING_PIPE, |
| FD_IS_NONBLOCKING_PIPE, |
| }; |
| |
| static int fd_is_nonblock_pipe(int fd) { |
| struct stat st; |
| int flags; |
| |
| /* Checks whether the specified file descriptor refers to a pipe, and if so if O_NONBLOCK is set. */ |
| |
| if (fstat(fd, &st) < 0) |
| return -errno; |
| |
| if (!S_ISFIFO(st.st_mode)) |
| return FD_IS_NO_PIPE; |
| |
| flags = fcntl(fd, F_GETFL); |
| if (flags < 0) |
| return -errno; |
| |
| return FLAGS_SET(flags, O_NONBLOCK) ? FD_IS_NONBLOCKING_PIPE : FD_IS_BLOCKING_PIPE; |
| } |
| |
| int copy_bytes_full( |
| int fdf, int fdt, |
| uint64_t max_bytes, |
| CopyFlags copy_flags, |
| void **ret_remains, |
| size_t *ret_remains_size) { |
| |
| bool try_cfr = true, try_sendfile = true, try_splice = true; |
| int r, nonblock_pipe = -1; |
| size_t m = SSIZE_MAX; /* that is the maximum that sendfile and c_f_r accept */ |
| |
| assert(fdf >= 0); |
| assert(fdt >= 0); |
| |
| /* Tries to copy bytes from the file descriptor 'fdf' to 'fdt' in the smartest possible way. Copies a maximum |
| * of 'max_bytes', which may be specified as UINT64_MAX, in which no maximum is applied. Returns negative on |
| * error, zero if EOF is hit before the bytes limit is hit and positive otherwise. If the copy fails for some |
| * reason but we read but didn't yet write some data an ret_remains/ret_remains_size is not NULL, then it will |
| * be initialized with an allocated buffer containing this "remaining" data. Note that these two parameters are |
| * initialized with a valid buffer only on failure and only if there's actually data already read. Otherwise |
| * these parameters if non-NULL are set to NULL. */ |
| |
| if (ret_remains) |
| *ret_remains = NULL; |
| if (ret_remains_size) |
| *ret_remains_size = 0; |
| |
| /* Try btrfs reflinks first. This only works on regular, seekable files, hence let's check the file offsets of |
| * source and destination first. */ |
| if ((copy_flags & COPY_REFLINK)) { |
| off_t foffset; |
| |
| foffset = lseek(fdf, 0, SEEK_CUR); |
| if (foffset >= 0) { |
| off_t toffset; |
| |
| toffset = lseek(fdt, 0, SEEK_CUR); |
| if (toffset >= 0) { |
| |
| if (foffset == 0 && toffset == 0 && max_bytes == UINT64_MAX) |
| r = btrfs_reflink(fdf, fdt); /* full file reflink */ |
| else |
| r = btrfs_clone_range(fdf, foffset, fdt, toffset, max_bytes == UINT64_MAX ? 0 : max_bytes); /* partial reflink */ |
| if (r >= 0) { |
| off_t t; |
| |
| /* This worked, yay! Now — to be fully correct — let's adjust the file pointers */ |
| if (max_bytes == UINT64_MAX) { |
| |
| /* We cloned to the end of the source file, let's position the read |
| * pointer there, and query it at the same time. */ |
| t = lseek(fdf, 0, SEEK_END); |
| if (t < 0) |
| return -errno; |
| if (t < foffset) |
| return -ESPIPE; |
| |
| /* Let's adjust the destination file write pointer by the same number |
| * of bytes. */ |
| t = lseek(fdt, toffset + (t - foffset), SEEK_SET); |
| if (t < 0) |
| return -errno; |
| |
| return 0; /* we copied the whole thing, hence hit EOF, return 0 */ |
| } else { |
| t = lseek(fdf, foffset + max_bytes, SEEK_SET); |
| if (t < 0) |
| return -errno; |
| |
| t = lseek(fdt, toffset + max_bytes, SEEK_SET); |
| if (t < 0) |
| return -errno; |
| |
| return 1; /* we copied only some number of bytes, which worked, but this means we didn't hit EOF, return 1 */ |
| } |
| } |
| |
| log_debug_errno(r, "Reflinking didn't work, falling back to non-reflink copying: %m"); |
| } |
| } |
| } |
| |
| for (;;) { |
| ssize_t n; |
| |
| if (max_bytes <= 0) |
| return 1; /* return > 0 if we hit the max_bytes limit */ |
| |
| if (max_bytes != UINT64_MAX && m > max_bytes) |
| m = max_bytes; |
| |
| /* First try copy_file_range(), unless we already tried */ |
| if (try_cfr) { |
| n = try_copy_file_range(fdf, NULL, fdt, NULL, m, 0u); |
| if (n < 0) { |
| if (!IN_SET(n, -EINVAL, -ENOSYS, -EXDEV, -EBADF)) |
| return n; |
| |
| try_cfr = false; |
| /* use fallback below */ |
| } else if (n == 0) /* EOF */ |
| break; |
| else |
| /* Success! */ |
| goto next; |
| } |
| |
| /* First try sendfile(), unless we already tried */ |
| if (try_sendfile) { |
| n = sendfile(fdt, fdf, NULL, m); |
| if (n < 0) { |
| if (!IN_SET(errno, EINVAL, ENOSYS)) |
| return -errno; |
| |
| try_sendfile = false; |
| /* use fallback below */ |
| } else if (n == 0) /* EOF */ |
| break; |
| else |
| /* Success! */ |
| goto next; |
| } |
| |
| /* Then try splice, unless we already tried. */ |
| if (try_splice) { |
| |
| /* splice()'s asynchronous I/O support is a bit weird. When it encounters a pipe file |
| * descriptor, then it will ignore its O_NONBLOCK flag and instead only honour the |
| * SPLICE_F_NONBLOCK flag specified in its flag parameter. Let's hide this behaviour here, and |
| * check if either of the specified fds are a pipe, and if so, let's pass the flag |
| * automatically, depending on O_NONBLOCK being set. |
| * |
| * Here's a twist though: when we use it to move data between two pipes of which one has |
| * O_NONBLOCK set and the other has not, then we have no individual control over O_NONBLOCK |
| * behaviour. Hence in that case we can't use splice() and still guarantee systematic |
| * O_NONBLOCK behaviour, hence don't. */ |
| |
| if (nonblock_pipe < 0) { |
| int a, b; |
| |
| /* Check if either of these fds is a pipe, and if so non-blocking or not */ |
| a = fd_is_nonblock_pipe(fdf); |
| if (a < 0) |
| return a; |
| |
| b = fd_is_nonblock_pipe(fdt); |
| if (b < 0) |
| return b; |
| |
| if ((a == FD_IS_NO_PIPE && b == FD_IS_NO_PIPE) || |
| (a == FD_IS_BLOCKING_PIPE && b == FD_IS_NONBLOCKING_PIPE) || |
| (a == FD_IS_NONBLOCKING_PIPE && b == FD_IS_BLOCKING_PIPE)) |
| |
| /* splice() only works if one of the fds is a pipe. If neither is, let's skip |
| * this step right-away. As mentioned above, if one of the two fds refers to a |
| * blocking pipe and the other to a non-blocking pipe, we can't use splice() |
| * either, hence don't try either. This hence means we can only use splice() if |
| * either only one of the two fds is a pipe, or if both are pipes with the same |
| * nonblocking flag setting. */ |
| |
| try_splice = false; |
| else |
| nonblock_pipe = a == FD_IS_NONBLOCKING_PIPE || b == FD_IS_NONBLOCKING_PIPE; |
| } |
| } |
| |
| if (try_splice) { |
| n = splice(fdf, NULL, fdt, NULL, m, nonblock_pipe ? SPLICE_F_NONBLOCK : 0); |
| if (n < 0) { |
| if (!IN_SET(errno, EINVAL, ENOSYS)) |
| return -errno; |
| |
| try_splice = false; |
| /* use fallback below */ |
| } else if (n == 0) /* EOF */ |
| break; |
| else |
| /* Success! */ |
| goto next; |
| } |
| |
| /* As a fallback just copy bits by hand */ |
| { |
| uint8_t buf[MIN(m, COPY_BUFFER_SIZE)], *p = buf; |
| ssize_t z; |
| |
| n = read(fdf, buf, sizeof buf); |
| if (n < 0) |
| return -errno; |
| if (n == 0) /* EOF */ |
| break; |
| |
| z = (size_t) n; |
| do { |
| ssize_t k; |
| |
| k = write(fdt, p, z); |
| if (k < 0) { |
| r = -errno; |
| |
| if (ret_remains) { |
| void *copy; |
| |
| copy = memdup(p, z); |
| if (!copy) |
| return -ENOMEM; |
| |
| *ret_remains = copy; |
| } |
| |
| if (ret_remains_size) |
| *ret_remains_size = z; |
| |
| return r; |
| } |
| |
| assert(k <= z); |
| z -= k; |
| p += k; |
| } while (z > 0); |
| } |
| |
| next: |
| if (max_bytes != (uint64_t) -1) { |
| assert(max_bytes >= (uint64_t) n); |
| max_bytes -= n; |
| } |
| /* sendfile accepts at most SSIZE_MAX-offset bytes to copy, |
| * so reduce our maximum by the amount we already copied, |
| * but don't go below our copy buffer size, unless we are |
| * close the limit of bytes we are allowed to copy. */ |
| m = MAX(MIN(COPY_BUFFER_SIZE, max_bytes), m - n); |
| } |
| |
| return 0; /* return 0 if we hit EOF earlier than the size limit */ |
| } |
| |
| static int fd_copy_symlink( |
| int df, |
| const char *from, |
| const struct stat *st, |
| int dt, |
| const char *to, |
| uid_t override_uid, |
| gid_t override_gid, |
| CopyFlags copy_flags) { |
| |
| _cleanup_free_ char *target = NULL; |
| int r; |
| |
| assert(from); |
| assert(st); |
| assert(to); |
| |
| r = readlinkat_malloc(df, from, &target); |
| if (r < 0) |
| return r; |
| |
| if (symlinkat(target, dt, to) < 0) |
| return -errno; |
| |
| if (fchownat(dt, to, |
| uid_is_valid(override_uid) ? override_uid : st->st_uid, |
| gid_is_valid(override_gid) ? override_gid : st->st_gid, |
| AT_SYMLINK_NOFOLLOW) < 0) |
| return -errno; |
| |
| return 0; |
| } |
| |
| static int fd_copy_regular( |
| int df, |
| const char *from, |
| const struct stat *st, |
| int dt, |
| const char *to, |
| uid_t override_uid, |
| gid_t override_gid, |
| CopyFlags copy_flags) { |
| |
| _cleanup_close_ int fdf = -1, fdt = -1; |
| struct timespec ts[2]; |
| int r, q; |
| |
| assert(from); |
| assert(st); |
| assert(to); |
| |
| fdf = openat(df, from, O_RDONLY|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW); |
| if (fdf < 0) |
| return -errno; |
| |
| fdt = openat(dt, to, O_WRONLY|O_CREAT|O_EXCL|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW, st->st_mode & 07777); |
| if (fdt < 0) |
| return -errno; |
| |
| r = copy_bytes(fdf, fdt, (uint64_t) -1, copy_flags); |
| if (r < 0) { |
| (void) unlinkat(dt, to, 0); |
| return r; |
| } |
| |
| if (fchown(fdt, |
| uid_is_valid(override_uid) ? override_uid : st->st_uid, |
| gid_is_valid(override_gid) ? override_gid : st->st_gid) < 0) |
| r = -errno; |
| |
| if (fchmod(fdt, st->st_mode & 07777) < 0) |
| r = -errno; |
| |
| ts[0] = st->st_atim; |
| ts[1] = st->st_mtim; |
| (void) futimens(fdt, ts); |
| (void) copy_xattr(fdf, fdt); |
| |
| q = close(fdt); |
| fdt = -1; |
| |
| if (q < 0) { |
| r = -errno; |
| (void) unlinkat(dt, to, 0); |
| } |
| |
| return r; |
| } |
| |
| static int fd_copy_fifo( |
| int df, |
| const char *from, |
| const struct stat *st, |
| int dt, |
| const char *to, |
| uid_t override_uid, |
| gid_t override_gid, |
| CopyFlags copy_flags) { |
| int r; |
| |
| assert(from); |
| assert(st); |
| assert(to); |
| |
| r = mkfifoat(dt, to, st->st_mode & 07777); |
| if (r < 0) |
| return -errno; |
| |
| if (fchownat(dt, to, |
| uid_is_valid(override_uid) ? override_uid : st->st_uid, |
| gid_is_valid(override_gid) ? override_gid : st->st_gid, |
| AT_SYMLINK_NOFOLLOW) < 0) |
| r = -errno; |
| |
| if (fchmodat(dt, to, st->st_mode & 07777, 0) < 0) |
| r = -errno; |
| |
| return r; |
| } |
| |
| static int fd_copy_node( |
| int df, |
| const char *from, |
| const struct stat *st, |
| int dt, |
| const char *to, |
| uid_t override_uid, |
| gid_t override_gid, |
| CopyFlags copy_flags) { |
| int r; |
| |
| assert(from); |
| assert(st); |
| assert(to); |
| |
| r = mknodat(dt, to, st->st_mode, st->st_rdev); |
| if (r < 0) |
| return -errno; |
| |
| if (fchownat(dt, to, |
| uid_is_valid(override_uid) ? override_uid : st->st_uid, |
| gid_is_valid(override_gid) ? override_gid : st->st_gid, |
| AT_SYMLINK_NOFOLLOW) < 0) |
| r = -errno; |
| |
| if (fchmodat(dt, to, st->st_mode & 07777, 0) < 0) |
| r = -errno; |
| |
| return r; |
| } |
| |
| static int fd_copy_directory( |
| int df, |
| const char *from, |
| const struct stat *st, |
| int dt, |
| const char *to, |
| dev_t original_device, |
| unsigned depth_left, |
| uid_t override_uid, |
| gid_t override_gid, |
| CopyFlags copy_flags) { |
| |
| _cleanup_close_ int fdf = -1, fdt = -1; |
| _cleanup_closedir_ DIR *d = NULL; |
| struct dirent *de; |
| bool created; |
| int r; |
| |
| assert(st); |
| assert(to); |
| |
| if (depth_left == 0) |
| return -ENAMETOOLONG; |
| |
| if (from) |
| fdf = openat(df, from, O_RDONLY|O_DIRECTORY|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW); |
| else |
| fdf = fcntl(df, F_DUPFD_CLOEXEC, 3); |
| if (fdf < 0) |
| return -errno; |
| |
| d = fdopendir(fdf); |
| if (!d) |
| return -errno; |
| fdf = -1; |
| |
| r = mkdirat(dt, to, st->st_mode & 07777); |
| if (r >= 0) |
| created = true; |
| else if (errno == EEXIST && (copy_flags & COPY_MERGE)) |
| created = false; |
| else |
| return -errno; |
| |
| fdt = openat(dt, to, O_RDONLY|O_DIRECTORY|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW); |
| if (fdt < 0) |
| return -errno; |
| |
| r = 0; |
| |
| FOREACH_DIRENT_ALL(de, d, return -errno) { |
| struct stat buf; |
| int q; |
| |
| if (dot_or_dot_dot(de->d_name)) |
| continue; |
| |
| if (fstatat(dirfd(d), de->d_name, &buf, AT_SYMLINK_NOFOLLOW) < 0) { |
| r = -errno; |
| continue; |
| } |
| |
| if (S_ISDIR(buf.st_mode)) { |
| /* |
| * Don't descend into directories on other file systems, if this is requested. We do a simple |
| * .st_dev check here, which basically comes for free. Note that we do this check only on |
| * directories, not other kind of file system objects, for two reason: |
| * |
| * • The kernel's overlayfs pseudo file system that overlays multiple real file systems |
| * propagates the .st_dev field of the file system a file originates from all the way up |
| * through the stack to stat(). It doesn't do that for directories however. This means that |
| * comparing .st_dev on non-directories suggests that they all are mount points. To avoid |
| * confusion we hence avoid relying on this check for regular files. |
| * |
| * • The main reason we do this check at all is to protect ourselves from bind mount cycles, |
| * where we really want to avoid descending down in all eternity. However the .st_dev check |
| * is usually not sufficient for this protection anyway, as bind mount cycles from the same |
| * file system onto itself can't be detected that way. (Note we also do a recursion depth |
| * check, which is probably the better protection in this regard, which is why |
| * COPY_SAME_MOUNT is optional). |
| */ |
| |
| if (FLAGS_SET(copy_flags, COPY_SAME_MOUNT)) { |
| if (buf.st_dev != original_device) |
| continue; |
| |
| r = fd_is_mount_point(dirfd(d), de->d_name, 0); |
| if (r < 0) |
| return r; |
| if (r > 0) |
| continue; |
| } |
| |
| q = fd_copy_directory(dirfd(d), de->d_name, &buf, fdt, de->d_name, original_device, depth_left-1, override_uid, override_gid, copy_flags); |
| } else if (S_ISREG(buf.st_mode)) |
| q = fd_copy_regular(dirfd(d), de->d_name, &buf, fdt, de->d_name, override_uid, override_gid, copy_flags); |
| else if (S_ISLNK(buf.st_mode)) |
| q = fd_copy_symlink(dirfd(d), de->d_name, &buf, fdt, de->d_name, override_uid, override_gid, copy_flags); |
| else if (S_ISFIFO(buf.st_mode)) |
| q = fd_copy_fifo(dirfd(d), de->d_name, &buf, fdt, de->d_name, override_uid, override_gid, copy_flags); |
| else if (S_ISBLK(buf.st_mode) || S_ISCHR(buf.st_mode) || S_ISSOCK(buf.st_mode)) |
| q = fd_copy_node(dirfd(d), de->d_name, &buf, fdt, de->d_name, override_uid, override_gid, copy_flags); |
| else |
| q = -EOPNOTSUPP; |
| |
| if (q == -EEXIST && (copy_flags & COPY_MERGE)) |
| q = 0; |
| |
| if (q < 0) |
| r = q; |
| } |
| |
| if (created) { |
| struct timespec ut[2] = { |
| st->st_atim, |
| st->st_mtim |
| }; |
| |
| if (fchown(fdt, |
| uid_is_valid(override_uid) ? override_uid : st->st_uid, |
| gid_is_valid(override_gid) ? override_gid : st->st_gid) < 0) |
| r = -errno; |
| |
| if (fchmod(fdt, st->st_mode & 07777) < 0) |
| r = -errno; |
| |
| (void) copy_xattr(dirfd(d), fdt); |
| (void) futimens(fdt, ut); |
| } |
| |
| return r; |
| } |
| |
| int copy_tree_at(int fdf, const char *from, int fdt, const char *to, uid_t override_uid, gid_t override_gid, CopyFlags copy_flags) { |
| struct stat st; |
| |
| assert(from); |
| assert(to); |
| |
| if (fstatat(fdf, from, &st, AT_SYMLINK_NOFOLLOW) < 0) |
| return -errno; |
| |
| if (S_ISREG(st.st_mode)) |
| return fd_copy_regular(fdf, from, &st, fdt, to, override_uid, override_gid, copy_flags); |
| else if (S_ISDIR(st.st_mode)) |
| return fd_copy_directory(fdf, from, &st, fdt, to, st.st_dev, COPY_DEPTH_MAX, override_uid, override_gid, copy_flags); |
| else if (S_ISLNK(st.st_mode)) |
| return fd_copy_symlink(fdf, from, &st, fdt, to, override_uid, override_gid, copy_flags); |
| else if (S_ISFIFO(st.st_mode)) |
| return fd_copy_fifo(fdf, from, &st, fdt, to, override_uid, override_gid, copy_flags); |
| else if (S_ISBLK(st.st_mode) || S_ISCHR(st.st_mode) || S_ISSOCK(st.st_mode)) |
| return fd_copy_node(fdf, from, &st, fdt, to, override_uid, override_gid, copy_flags); |
| else |
| return -EOPNOTSUPP; |
| } |
| |
| int copy_tree(const char *from, const char *to, uid_t override_uid, gid_t override_gid, CopyFlags copy_flags) { |
| return copy_tree_at(AT_FDCWD, from, AT_FDCWD, to, override_uid, override_gid, copy_flags); |
| } |
| |
| int copy_directory_fd(int dirfd, const char *to, CopyFlags copy_flags) { |
| struct stat st; |
| |
| assert(dirfd >= 0); |
| assert(to); |
| |
| if (fstat(dirfd, &st) < 0) |
| return -errno; |
| |
| if (!S_ISDIR(st.st_mode)) |
| return -ENOTDIR; |
| |
| return fd_copy_directory(dirfd, NULL, &st, AT_FDCWD, to, st.st_dev, COPY_DEPTH_MAX, UID_INVALID, GID_INVALID, copy_flags); |
| } |
| |
| int copy_directory(const char *from, const char *to, CopyFlags copy_flags) { |
| struct stat st; |
| |
| assert(from); |
| assert(to); |
| |
| if (lstat(from, &st) < 0) |
| return -errno; |
| |
| if (!S_ISDIR(st.st_mode)) |
| return -ENOTDIR; |
| |
| return fd_copy_directory(AT_FDCWD, from, &st, AT_FDCWD, to, st.st_dev, COPY_DEPTH_MAX, UID_INVALID, GID_INVALID, copy_flags); |
| } |
| |
| int copy_file_fd(const char *from, int fdt, CopyFlags copy_flags) { |
| _cleanup_close_ int fdf = -1; |
| int r; |
| |
| assert(from); |
| assert(fdt >= 0); |
| |
| fdf = open(from, O_RDONLY|O_CLOEXEC|O_NOCTTY); |
| if (fdf < 0) |
| return -errno; |
| |
| r = copy_bytes(fdf, fdt, (uint64_t) -1, copy_flags); |
| |
| (void) copy_times(fdf, fdt); |
| (void) copy_xattr(fdf, fdt); |
| |
| return r; |
| } |
| |
| int copy_file(const char *from, const char *to, int flags, mode_t mode, unsigned chattr_flags, CopyFlags copy_flags) { |
| int fdt = -1, r; |
| |
| assert(from); |
| assert(to); |
| |
| RUN_WITH_UMASK(0000) { |
| fdt = open(to, flags|O_WRONLY|O_CREAT|O_CLOEXEC|O_NOCTTY, mode); |
| if (fdt < 0) |
| return -errno; |
| } |
| |
| if (chattr_flags != 0) |
| (void) chattr_fd(fdt, chattr_flags, (unsigned) -1); |
| |
| r = copy_file_fd(from, fdt, copy_flags); |
| if (r < 0) { |
| close(fdt); |
| (void) unlink(to); |
| return r; |
| } |
| |
| if (close(fdt) < 0) { |
| unlink_noerrno(to); |
| return -errno; |
| } |
| |
| return 0; |
| } |
| |
| int copy_file_atomic(const char *from, const char *to, mode_t mode, unsigned chattr_flags, CopyFlags copy_flags) { |
| _cleanup_(unlink_and_freep) char *t = NULL; |
| _cleanup_close_ int fdt = -1; |
| int r; |
| |
| assert(from); |
| assert(to); |
| |
| /* We try to use O_TMPFILE here to create the file if we can. Note that that only works if COPY_REPLACE is not |
| * set though as we need to use linkat() for linking the O_TMPFILE file into the file system but that system |
| * call can't replace existing files. Hence, if COPY_REPLACE is set we create a temporary name in the file |
| * system right-away and unconditionally which we then can renameat() to the right name after we completed |
| * writing it. */ |
| |
| if (copy_flags & COPY_REPLACE) { |
| r = tempfn_random(to, NULL, &t); |
| if (r < 0) |
| return r; |
| |
| fdt = open(t, O_CREAT|O_EXCL|O_NOFOLLOW|O_NOCTTY|O_WRONLY|O_CLOEXEC, 0600); |
| if (fdt < 0) { |
| t = mfree(t); |
| return -errno; |
| } |
| } else { |
| fdt = open_tmpfile_linkable(to, O_WRONLY|O_CLOEXEC, &t); |
| if (fdt < 0) |
| return fdt; |
| } |
| |
| if (chattr_flags != 0) |
| (void) chattr_fd(fdt, chattr_flags, (unsigned) -1); |
| |
| r = copy_file_fd(from, fdt, copy_flags); |
| if (r < 0) |
| return r; |
| |
| if (fchmod(fdt, mode) < 0) |
| return -errno; |
| |
| if (copy_flags & COPY_REPLACE) { |
| if (renameat(AT_FDCWD, t, AT_FDCWD, to) < 0) |
| return -errno; |
| } else { |
| r = link_tmpfile(fdt, t, to); |
| if (r < 0) |
| return r; |
| } |
| |
| t = mfree(t); |
| return 0; |
| } |
| |
| int copy_times(int fdf, int fdt) { |
| struct timespec ut[2]; |
| struct stat st; |
| usec_t crtime = 0; |
| |
| assert(fdf >= 0); |
| assert(fdt >= 0); |
| |
| if (fstat(fdf, &st) < 0) |
| return -errno; |
| |
| ut[0] = st.st_atim; |
| ut[1] = st.st_mtim; |
| |
| if (futimens(fdt, ut) < 0) |
| return -errno; |
| |
| if (fd_getcrtime(fdf, &crtime) >= 0) |
| (void) fd_setcrtime(fdt, crtime); |
| |
| return 0; |
| } |
| |
| int copy_xattr(int fdf, int fdt) { |
| _cleanup_free_ char *bufa = NULL, *bufb = NULL; |
| size_t sza = 100, szb = 100; |
| ssize_t n; |
| int ret = 0; |
| const char *p; |
| |
| for (;;) { |
| bufa = malloc(sza); |
| if (!bufa) |
| return -ENOMEM; |
| |
| n = flistxattr(fdf, bufa, sza); |
| if (n == 0) |
| return 0; |
| if (n > 0) |
| break; |
| if (errno != ERANGE) |
| return -errno; |
| |
| sza *= 2; |
| |
| bufa = mfree(bufa); |
| } |
| |
| p = bufa; |
| while (n > 0) { |
| size_t l; |
| |
| l = strlen(p); |
| assert(l < (size_t) n); |
| |
| if (startswith(p, "user.")) { |
| ssize_t m; |
| |
| if (!bufb) { |
| bufb = malloc(szb); |
| if (!bufb) |
| return -ENOMEM; |
| } |
| |
| m = fgetxattr(fdf, p, bufb, szb); |
| if (m < 0) { |
| if (errno == ERANGE) { |
| szb *= 2; |
| bufb = mfree(bufb); |
| continue; |
| } |
| |
| return -errno; |
| } |
| |
| if (fsetxattr(fdt, p, bufb, m, 0) < 0) |
| ret = -errno; |
| } |
| |
| p += l + 1; |
| n -= l + 1; |
| } |
| |
| return ret; |
| } |