1252 lines
45 KiB
C
1252 lines
45 KiB
C
/* SPDX-License-Identifier: LGPL-2.1-or-later */
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#include <errno.h>
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#include <fcntl.h>
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#include <stddef.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <sys/sendfile.h>
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#include <sys/xattr.h>
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#include <unistd.h>
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#include "alloc-util.h"
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#include "btrfs-util.h"
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#include "chattr-util.h"
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#include "copy.h"
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#include "dirent-util.h"
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#include "fd-util.h"
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#include "fileio.h"
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#include "fs-util.h"
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#include "io-util.h"
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#include "macro.h"
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#include "missing_syscall.h"
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#include "mountpoint-util.h"
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#include "nulstr-util.h"
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#include "rm-rf.h"
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#include "selinux-util.h"
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#include "stat-util.h"
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#include "stdio-util.h"
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#include "string-util.h"
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#include "strv.h"
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#include "time-util.h"
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#include "tmpfile-util.h"
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#include "umask-util.h"
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#include "user-util.h"
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#include "xattr-util.h"
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#define COPY_BUFFER_SIZE (16U*1024U)
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/* A safety net for descending recursively into file system trees to copy. On Linux PATH_MAX is 4096, which means the
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* deepest valid path one can build is around 2048, which we hence use as a safety net here, to not spin endlessly in
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* case of bind mount cycles and suchlike. */
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#define COPY_DEPTH_MAX 2048U
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static ssize_t try_copy_file_range(
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int fd_in, loff_t *off_in,
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int fd_out, loff_t *off_out,
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size_t len,
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unsigned flags) {
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static int have = -1;
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ssize_t r;
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if (have == 0)
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return -ENOSYS;
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r = copy_file_range(fd_in, off_in, fd_out, off_out, len, flags);
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if (have < 0)
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have = r >= 0 || errno != ENOSYS;
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if (r < 0)
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return -errno;
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return r;
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}
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enum {
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FD_IS_NO_PIPE,
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FD_IS_BLOCKING_PIPE,
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FD_IS_NONBLOCKING_PIPE,
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};
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static int fd_is_nonblock_pipe(int fd) {
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struct stat st;
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int flags;
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/* Checks whether the specified file descriptor refers to a pipe, and if so if O_NONBLOCK is set. */
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if (fstat(fd, &st) < 0)
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return -errno;
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if (!S_ISFIFO(st.st_mode))
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return FD_IS_NO_PIPE;
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flags = fcntl(fd, F_GETFL);
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if (flags < 0)
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return -errno;
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return FLAGS_SET(flags, O_NONBLOCK) ? FD_IS_NONBLOCKING_PIPE : FD_IS_BLOCKING_PIPE;
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}
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static int sigint_pending(void) {
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sigset_t ss;
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assert_se(sigemptyset(&ss) >= 0);
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assert_se(sigaddset(&ss, SIGINT) >= 0);
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if (sigtimedwait(&ss, NULL, &(struct timespec) { 0, 0 }) < 0) {
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if (errno == EAGAIN)
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return false;
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return -errno;
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}
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return true;
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}
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int copy_bytes_full(
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int fdf, int fdt,
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uint64_t max_bytes,
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CopyFlags copy_flags,
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void **ret_remains,
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size_t *ret_remains_size,
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copy_progress_bytes_t progress,
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void *userdata) {
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bool try_cfr = true, try_sendfile = true, try_splice = true;
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int r, nonblock_pipe = -1;
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size_t m = SSIZE_MAX; /* that is the maximum that sendfile and c_f_r accept */
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assert(fdf >= 0);
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assert(fdt >= 0);
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/* Tries to copy bytes from the file descriptor 'fdf' to 'fdt' in the smartest possible way. Copies a maximum
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* of 'max_bytes', which may be specified as UINT64_MAX, in which no maximum is applied. Returns negative on
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* error, zero if EOF is hit before the bytes limit is hit and positive otherwise. If the copy fails for some
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* reason but we read but didn't yet write some data an ret_remains/ret_remains_size is not NULL, then it will
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* be initialized with an allocated buffer containing this "remaining" data. Note that these two parameters are
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* initialized with a valid buffer only on failure and only if there's actually data already read. Otherwise
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* these parameters if non-NULL are set to NULL. */
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if (ret_remains)
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*ret_remains = NULL;
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if (ret_remains_size)
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*ret_remains_size = 0;
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/* Try btrfs reflinks first. This only works on regular, seekable files, hence let's check the file offsets of
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* source and destination first. */
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if ((copy_flags & COPY_REFLINK)) {
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off_t foffset;
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foffset = lseek(fdf, 0, SEEK_CUR);
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if (foffset >= 0) {
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off_t toffset;
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toffset = lseek(fdt, 0, SEEK_CUR);
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if (toffset >= 0) {
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if (foffset == 0 && toffset == 0 && max_bytes == UINT64_MAX)
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r = btrfs_reflink(fdf, fdt); /* full file reflink */
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else
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r = btrfs_clone_range(fdf, foffset, fdt, toffset, max_bytes == UINT64_MAX ? 0 : max_bytes); /* partial reflink */
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if (r >= 0) {
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off_t t;
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/* This worked, yay! Now — to be fully correct — let's adjust the file pointers */
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if (max_bytes == UINT64_MAX) {
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/* We cloned to the end of the source file, let's position the read
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* pointer there, and query it at the same time. */
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t = lseek(fdf, 0, SEEK_END);
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if (t < 0)
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return -errno;
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if (t < foffset)
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return -ESPIPE;
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/* Let's adjust the destination file write pointer by the same number
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* of bytes. */
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t = lseek(fdt, toffset + (t - foffset), SEEK_SET);
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if (t < 0)
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return -errno;
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return 0; /* we copied the whole thing, hence hit EOF, return 0 */
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} else {
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t = lseek(fdf, foffset + max_bytes, SEEK_SET);
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if (t < 0)
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return -errno;
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t = lseek(fdt, toffset + max_bytes, SEEK_SET);
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if (t < 0)
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return -errno;
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return 1; /* we copied only some number of bytes, which worked, but this means we didn't hit EOF, return 1 */
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}
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}
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}
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}
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}
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for (;;) {
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ssize_t n;
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if (max_bytes <= 0)
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return 1; /* return > 0 if we hit the max_bytes limit */
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if (FLAGS_SET(copy_flags, COPY_SIGINT)) {
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r = sigint_pending();
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if (r < 0)
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return r;
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if (r > 0)
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return -EINTR;
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}
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if (max_bytes != UINT64_MAX && m > max_bytes)
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m = max_bytes;
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/* First try copy_file_range(), unless we already tried */
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if (try_cfr) {
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n = try_copy_file_range(fdf, NULL, fdt, NULL, m, 0u);
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if (n < 0) {
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if (!IN_SET(n, -EINVAL, -ENOSYS, -EXDEV, -EBADF))
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return n;
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try_cfr = false;
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/* use fallback below */
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} else if (n == 0) /* EOF */
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break;
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else
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/* Success! */
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goto next;
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}
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/* First try sendfile(), unless we already tried */
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if (try_sendfile) {
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n = sendfile(fdt, fdf, NULL, m);
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if (n < 0) {
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if (!IN_SET(errno, EINVAL, ENOSYS))
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return -errno;
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try_sendfile = false;
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/* use fallback below */
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} else if (n == 0) /* EOF */
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break;
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else
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/* Success! */
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goto next;
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}
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/* Then try splice, unless we already tried. */
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if (try_splice) {
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/* splice()'s asynchronous I/O support is a bit weird. When it encounters a pipe file
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* descriptor, then it will ignore its O_NONBLOCK flag and instead only honour the
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* SPLICE_F_NONBLOCK flag specified in its flag parameter. Let's hide this behaviour here, and
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* check if either of the specified fds are a pipe, and if so, let's pass the flag
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* automatically, depending on O_NONBLOCK being set.
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*
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* Here's a twist though: when we use it to move data between two pipes of which one has
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* O_NONBLOCK set and the other has not, then we have no individual control over O_NONBLOCK
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* behaviour. Hence in that case we can't use splice() and still guarantee systematic
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* O_NONBLOCK behaviour, hence don't. */
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if (nonblock_pipe < 0) {
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int a, b;
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/* Check if either of these fds is a pipe, and if so non-blocking or not */
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a = fd_is_nonblock_pipe(fdf);
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if (a < 0)
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return a;
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b = fd_is_nonblock_pipe(fdt);
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if (b < 0)
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return b;
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if ((a == FD_IS_NO_PIPE && b == FD_IS_NO_PIPE) ||
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(a == FD_IS_BLOCKING_PIPE && b == FD_IS_NONBLOCKING_PIPE) ||
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(a == FD_IS_NONBLOCKING_PIPE && b == FD_IS_BLOCKING_PIPE))
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/* splice() only works if one of the fds is a pipe. If neither is, let's skip
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* this step right-away. As mentioned above, if one of the two fds refers to a
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* blocking pipe and the other to a non-blocking pipe, we can't use splice()
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* either, hence don't try either. This hence means we can only use splice() if
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* either only one of the two fds is a pipe, or if both are pipes with the same
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* nonblocking flag setting. */
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try_splice = false;
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else
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nonblock_pipe = a == FD_IS_NONBLOCKING_PIPE || b == FD_IS_NONBLOCKING_PIPE;
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}
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}
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if (try_splice) {
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n = splice(fdf, NULL, fdt, NULL, m, nonblock_pipe ? SPLICE_F_NONBLOCK : 0);
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if (n < 0) {
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if (!IN_SET(errno, EINVAL, ENOSYS))
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return -errno;
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try_splice = false;
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/* use fallback below */
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} else if (n == 0) /* EOF */
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break;
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else
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/* Success! */
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goto next;
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}
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/* As a fallback just copy bits by hand */
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{
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uint8_t buf[MIN(m, COPY_BUFFER_SIZE)], *p = buf;
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ssize_t z;
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n = read(fdf, buf, sizeof buf);
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if (n < 0)
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return -errno;
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if (n == 0) /* EOF */
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break;
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z = (size_t) n;
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do {
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ssize_t k;
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k = write(fdt, p, z);
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if (k < 0) {
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r = -errno;
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if (ret_remains) {
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void *copy;
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copy = memdup(p, z);
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if (!copy)
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return -ENOMEM;
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*ret_remains = copy;
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}
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if (ret_remains_size)
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*ret_remains_size = z;
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return r;
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}
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assert(k <= z);
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z -= k;
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p += k;
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} while (z > 0);
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}
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next:
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if (progress) {
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r = progress(n, userdata);
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if (r < 0)
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return r;
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}
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if (max_bytes != (uint64_t) -1) {
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assert(max_bytes >= (uint64_t) n);
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max_bytes -= n;
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}
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/* sendfile accepts at most SSIZE_MAX-offset bytes to copy,
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* so reduce our maximum by the amount we already copied,
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* but don't go below our copy buffer size, unless we are
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* close the limit of bytes we are allowed to copy. */
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m = MAX(MIN(COPY_BUFFER_SIZE, max_bytes), m - n);
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}
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return 0; /* return 0 if we hit EOF earlier than the size limit */
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}
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static int fd_copy_symlink(
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int df,
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const char *from,
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const struct stat *st,
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int dt,
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const char *to,
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uid_t override_uid,
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gid_t override_gid,
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CopyFlags copy_flags) {
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_cleanup_free_ char *target = NULL;
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int r;
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assert(from);
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assert(st);
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assert(to);
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r = readlinkat_malloc(df, from, &target);
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if (r < 0)
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return r;
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if (copy_flags & COPY_MAC_CREATE) {
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r = mac_selinux_create_file_prepare_at(dt, to, S_IFLNK);
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if (r < 0)
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return r;
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}
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r = symlinkat(target, dt, to);
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if (copy_flags & COPY_MAC_CREATE)
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mac_selinux_create_file_clear();
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if (r < 0)
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return -errno;
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if (fchownat(dt, to,
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uid_is_valid(override_uid) ? override_uid : st->st_uid,
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gid_is_valid(override_gid) ? override_gid : st->st_gid,
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AT_SYMLINK_NOFOLLOW) < 0)
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return -errno;
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return 0;
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}
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/* Encapsulates the database we store potential hardlink targets in */
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typedef struct HardlinkContext {
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int dir_fd; /* An fd to the directory we use as lookup table. Never AT_FDCWD. Lazily created, when
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* we add the first entry. */
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/* These two fields are used to create the hardlink repository directory above — via
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* mkdirat(parent_fd, subdir) — and are kept so that we can automatically remove the directory again
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* when we are done. */
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int parent_fd; /* Possibly AT_FDCWD */
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char *subdir;
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} HardlinkContext;
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static int hardlink_context_setup(
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HardlinkContext *c,
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int dt,
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const char *to,
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CopyFlags copy_flags) {
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_cleanup_close_ int dt_copy = -1;
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int r;
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assert(c);
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assert(c->dir_fd < 0 && c->dir_fd != AT_FDCWD);
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assert(c->parent_fd < 0);
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assert(!c->subdir);
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/* If hardlink recreation is requested we have to maintain a database of inodes that are potential
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* hardlink sources. Given that generally disk sizes have to be assumed to be larger than what fits
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* into physical RAM we cannot maintain that database in dynamic memory alone. Here we opt to
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* maintain it on disk, to simplify things: inside the destination directory we'll maintain a
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* temporary directory consisting of hardlinks of every inode we copied that might be subject of
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* hardlinks. We can then use that as hardlink source later on. Yes, this means additional disk IO
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* but thankfully Linux is optimized for this kind of thing. If this ever becomes a performance
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* bottleneck we can certainly place an in-memory hash table in front of this, but for the beginning,
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* let's keep things simple, and just use the disk as lookup table for inodes.
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*
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* Note that this should have zero performance impact as long as .n_link of all files copied remains
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* <= 0, because in that case we will not actually allocate the hardlink inode lookup table directory
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* on disk (we do so lazily, when the first candidate with .n_link > 1 is seen). This means, in the
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* common case where hardlinks are not used at all or only for few files the fact that we store the
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* table on disk shouldn't matter perfomance-wise. */
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if (!FLAGS_SET(copy_flags, COPY_HARDLINKS))
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return 0;
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if (dt == AT_FDCWD)
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dt_copy = AT_FDCWD;
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else if (dt < 0)
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return -EBADF;
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else {
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dt_copy = fcntl(dt, F_DUPFD_CLOEXEC, 3);
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if (dt_copy < 0)
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return -errno;
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}
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r = tempfn_random_child(to, "hardlink", &c->subdir);
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if (r < 0)
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return r;
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c->parent_fd = TAKE_FD(dt_copy);
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/* We don't actually create the directory we keep the table in here, that's done on-demand when the
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* first entry is added, using hardlink_context_realize() below. */
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return 1;
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}
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static int hardlink_context_realize(HardlinkContext *c) {
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int r;
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if (!c)
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return 0;
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if (c->dir_fd >= 0) /* Already realized */
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return 1;
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if (c->parent_fd < 0 && c->parent_fd != AT_FDCWD) /* Not configured */
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return 0;
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assert(c->subdir);
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if (mkdirat(c->parent_fd, c->subdir, 0700) < 0)
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return -errno;
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c->dir_fd = openat(c->parent_fd, c->subdir, O_RDONLY|O_DIRECTORY|O_CLOEXEC);
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if (c->dir_fd < 0) {
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r = -errno;
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(void) unlinkat(c->parent_fd, c->subdir, AT_REMOVEDIR);
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return r;
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}
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return 1;
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}
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static void hardlink_context_destroy(HardlinkContext *c) {
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int r;
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assert(c);
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/* Automatically remove the hardlink lookup table directory again after we are done. This is used via
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* _cleanup_() so that we really delete this, even on failure. */
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if (c->dir_fd >= 0) {
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r = rm_rf_children(TAKE_FD(c->dir_fd), REMOVE_PHYSICAL, NULL); /* consumes dir_fd in all cases, even on failure */
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if (r < 0)
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log_debug_errno(r, "Failed to remove hardlink store (%s) contents, ignoring: %m", c->subdir);
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assert(c->parent_fd >= 0 || c->parent_fd == AT_FDCWD);
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assert(c->subdir);
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if (unlinkat(c->parent_fd, c->subdir, AT_REMOVEDIR) < 0)
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log_debug_errno(errno, "Failed to remove hardlink store (%s) directory, ignoring: %m", c->subdir);
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}
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|
|
assert_cc(AT_FDCWD < 0);
|
|
c->parent_fd = safe_close(c->parent_fd);
|
|
|
|
c->subdir = mfree(c->subdir);
|
|
}
|
|
|
|
static int try_hardlink(
|
|
HardlinkContext *c,
|
|
const struct stat *st,
|
|
int dt,
|
|
const char *to) {
|
|
|
|
char dev_ino[DECIMAL_STR_MAX(dev_t)*2 + DECIMAL_STR_MAX(uint64_t) + 4];
|
|
|
|
assert(st);
|
|
assert(dt >= 0 || dt == AT_FDCWD);
|
|
assert(to);
|
|
|
|
if (!c) /* No temporary hardlink directory, don't bother */
|
|
return 0;
|
|
|
|
if (st->st_nlink <= 1) /* Source not hardlinked, don't bother */
|
|
return 0;
|
|
|
|
if (c->dir_fd < 0) /* not yet realized, hence empty */
|
|
return 0;
|
|
|
|
xsprintf(dev_ino, "%u:%u:%" PRIu64, major(st->st_dev), minor(st->st_dev), (uint64_t) st->st_ino);
|
|
if (linkat(c->dir_fd, dev_ino, dt, to, 0) < 0) {
|
|
if (errno != ENOENT) /* doesn't exist in store yet */
|
|
log_debug_errno(errno, "Failed to hardlink %s to %s, ignoring: %m", dev_ino, to);
|
|
return 0;
|
|
}
|
|
|
|
return 1;
|
|
}
|
|
|
|
static int memorize_hardlink(
|
|
HardlinkContext *c,
|
|
const struct stat *st,
|
|
int dt,
|
|
const char *to) {
|
|
|
|
char dev_ino[DECIMAL_STR_MAX(dev_t)*2 + DECIMAL_STR_MAX(uint64_t) + 4];
|
|
int r;
|
|
|
|
assert(st);
|
|
assert(dt >= 0 || dt == AT_FDCWD);
|
|
assert(to);
|
|
|
|
if (!c) /* No temporary hardlink directory, don't bother */
|
|
return 0;
|
|
|
|
if (st->st_nlink <= 1) /* Source not hardlinked, don't bother */
|
|
return 0;
|
|
|
|
r = hardlink_context_realize(c); /* Create the hardlink store lazily */
|
|
if (r < 0)
|
|
return r;
|
|
|
|
xsprintf(dev_ino, "%u:%u:%" PRIu64, major(st->st_dev), minor(st->st_dev), (uint64_t) st->st_ino);
|
|
if (linkat(dt, to, c->dir_fd, dev_ino, 0) < 0) {
|
|
log_debug_errno(errno, "Failed to hardlink %s to %s, ignoring: %m", to, dev_ino);
|
|
return 0;
|
|
}
|
|
|
|
return 1;
|
|
}
|
|
|
|
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,
|
|
HardlinkContext *hardlink_context,
|
|
copy_progress_bytes_t progress,
|
|
void *userdata) {
|
|
|
|
_cleanup_close_ int fdf = -1, fdt = -1;
|
|
struct timespec ts[2];
|
|
int r, q;
|
|
|
|
assert(from);
|
|
assert(st);
|
|
assert(to);
|
|
|
|
r = try_hardlink(hardlink_context, st, dt, to);
|
|
if (r < 0)
|
|
return r;
|
|
if (r > 0) /* worked! */
|
|
return 0;
|
|
|
|
fdf = openat(df, from, O_RDONLY|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW);
|
|
if (fdf < 0)
|
|
return -errno;
|
|
|
|
if (copy_flags & COPY_MAC_CREATE) {
|
|
r = mac_selinux_create_file_prepare_at(dt, to, S_IFREG);
|
|
if (r < 0)
|
|
return r;
|
|
}
|
|
fdt = openat(dt, to, O_WRONLY|O_CREAT|O_EXCL|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW, st->st_mode & 07777);
|
|
if (copy_flags & COPY_MAC_CREATE)
|
|
mac_selinux_create_file_clear();
|
|
if (fdt < 0)
|
|
return -errno;
|
|
|
|
r = copy_bytes_full(fdf, fdt, (uint64_t) -1, copy_flags, NULL, NULL, progress, userdata);
|
|
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);
|
|
}
|
|
|
|
(void) memorize_hardlink(hardlink_context, st, dt, to);
|
|
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,
|
|
HardlinkContext *hardlink_context) {
|
|
int r;
|
|
|
|
assert(from);
|
|
assert(st);
|
|
assert(to);
|
|
|
|
r = try_hardlink(hardlink_context, st, dt, to);
|
|
if (r < 0)
|
|
return r;
|
|
if (r > 0) /* worked! */
|
|
return 0;
|
|
|
|
if (copy_flags & COPY_MAC_CREATE) {
|
|
r = mac_selinux_create_file_prepare_at(dt, to, S_IFIFO);
|
|
if (r < 0)
|
|
return r;
|
|
}
|
|
r = mkfifoat(dt, to, st->st_mode & 07777);
|
|
if (copy_flags & COPY_MAC_CREATE)
|
|
mac_selinux_create_file_clear();
|
|
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;
|
|
|
|
(void) memorize_hardlink(hardlink_context, st, dt, to);
|
|
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,
|
|
HardlinkContext *hardlink_context) {
|
|
int r;
|
|
|
|
assert(from);
|
|
assert(st);
|
|
assert(to);
|
|
|
|
r = try_hardlink(hardlink_context, st, dt, to);
|
|
if (r < 0)
|
|
return r;
|
|
if (r > 0) /* worked! */
|
|
return 0;
|
|
|
|
if (copy_flags & COPY_MAC_CREATE) {
|
|
r = mac_selinux_create_file_prepare_at(dt, to, st->st_mode & S_IFMT);
|
|
if (r < 0)
|
|
return r;
|
|
}
|
|
r = mknodat(dt, to, st->st_mode, st->st_rdev);
|
|
if (copy_flags & COPY_MAC_CREATE)
|
|
mac_selinux_create_file_clear();
|
|
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;
|
|
|
|
(void) memorize_hardlink(hardlink_context, st, dt, to);
|
|
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,
|
|
HardlinkContext *hardlink_context,
|
|
const char *display_path,
|
|
copy_progress_path_t progress_path,
|
|
copy_progress_bytes_t progress_bytes,
|
|
void *userdata) {
|
|
|
|
_cleanup_(hardlink_context_destroy) HardlinkContext our_hardlink_context = {
|
|
.dir_fd = -1,
|
|
.parent_fd = -1,
|
|
};
|
|
|
|
_cleanup_close_ int fdf = -1, fdt = -1;
|
|
_cleanup_closedir_ DIR *d = NULL;
|
|
struct dirent *de;
|
|
bool exists, 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;
|
|
|
|
if (!hardlink_context) {
|
|
/* If recreating hardlinks is requested let's set up a context for that now. */
|
|
r = hardlink_context_setup(&our_hardlink_context, dt, to, copy_flags);
|
|
if (r < 0)
|
|
return r;
|
|
if (r > 0) /* It's enabled and allocated, let's now use the same context for all recursive
|
|
* invocations from here down */
|
|
hardlink_context = &our_hardlink_context;
|
|
}
|
|
|
|
d = take_fdopendir(&fdf);
|
|
if (!d)
|
|
return -errno;
|
|
|
|
exists = false;
|
|
if (copy_flags & COPY_MERGE_EMPTY) {
|
|
r = dir_is_empty_at(dt, to);
|
|
if (r < 0 && r != -ENOENT)
|
|
return r;
|
|
else if (r == 1)
|
|
exists = true;
|
|
}
|
|
|
|
if (exists)
|
|
created = false;
|
|
else {
|
|
if (copy_flags & COPY_MAC_CREATE)
|
|
r = mkdirat_label(dt, to, st->st_mode & 07777);
|
|
else
|
|
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) {
|
|
const char *child_display_path = NULL;
|
|
_cleanup_free_ char *dp = NULL;
|
|
struct stat buf;
|
|
int q;
|
|
|
|
if (dot_or_dot_dot(de->d_name))
|
|
continue;
|
|
|
|
if (FLAGS_SET(copy_flags, COPY_SIGINT)) {
|
|
r = sigint_pending();
|
|
if (r < 0)
|
|
return r;
|
|
if (r > 0)
|
|
return -EINTR;
|
|
}
|
|
|
|
if (fstatat(dirfd(d), de->d_name, &buf, AT_SYMLINK_NOFOLLOW) < 0) {
|
|
r = -errno;
|
|
continue;
|
|
}
|
|
|
|
if (progress_path) {
|
|
if (display_path)
|
|
child_display_path = dp = path_join(display_path, de->d_name);
|
|
else
|
|
child_display_path = de->d_name;
|
|
|
|
r = progress_path(child_display_path, &buf, userdata);
|
|
if (r < 0)
|
|
return r;
|
|
}
|
|
|
|
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, hardlink_context, child_display_path, progress_path, progress_bytes, userdata);
|
|
} 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, hardlink_context, progress_bytes, userdata);
|
|
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, hardlink_context);
|
|
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, hardlink_context);
|
|
else
|
|
q = -EOPNOTSUPP;
|
|
|
|
if (q == -EINTR) /* Propagate SIGINT up instantly */
|
|
return q;
|
|
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_full(
|
|
int fdf,
|
|
const char *from,
|
|
int fdt,
|
|
const char *to,
|
|
uid_t override_uid,
|
|
gid_t override_gid,
|
|
CopyFlags copy_flags,
|
|
copy_progress_path_t progress_path,
|
|
copy_progress_bytes_t progress_bytes,
|
|
void *userdata) {
|
|
|
|
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, NULL, progress_bytes, userdata);
|
|
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, NULL, NULL, progress_path, progress_bytes, userdata);
|
|
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, NULL);
|
|
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, NULL);
|
|
else
|
|
return -EOPNOTSUPP;
|
|
}
|
|
|
|
int copy_directory_fd_full(
|
|
int dirfd,
|
|
const char *to,
|
|
CopyFlags copy_flags,
|
|
copy_progress_path_t progress_path,
|
|
copy_progress_bytes_t progress_bytes,
|
|
void *userdata) {
|
|
|
|
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, NULL, NULL, progress_path, progress_bytes, userdata);
|
|
}
|
|
|
|
int copy_directory_full(
|
|
const char *from,
|
|
const char *to,
|
|
CopyFlags copy_flags,
|
|
copy_progress_path_t progress_path,
|
|
copy_progress_bytes_t progress_bytes,
|
|
void *userdata) {
|
|
|
|
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, NULL, NULL, progress_path, progress_bytes, userdata);
|
|
}
|
|
|
|
int copy_file_fd_full(
|
|
const char *from,
|
|
int fdt,
|
|
CopyFlags copy_flags,
|
|
copy_progress_bytes_t progress_bytes,
|
|
void *userdata) {
|
|
|
|
_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_full(fdf, fdt, (uint64_t) -1, copy_flags, NULL, NULL, progress_bytes, userdata);
|
|
|
|
(void) copy_times(fdf, fdt, copy_flags);
|
|
(void) copy_xattr(fdf, fdt);
|
|
|
|
return r;
|
|
}
|
|
|
|
int copy_file_full(
|
|
const char *from,
|
|
const char *to,
|
|
int flags,
|
|
mode_t mode,
|
|
unsigned chattr_flags,
|
|
unsigned chattr_mask,
|
|
CopyFlags copy_flags,
|
|
copy_progress_bytes_t progress_bytes,
|
|
void *userdata) {
|
|
|
|
_cleanup_close_ int fdf = -1;
|
|
struct stat st;
|
|
int fdt = -1, r;
|
|
|
|
assert(from);
|
|
assert(to);
|
|
|
|
fdf = open(from, O_RDONLY|O_CLOEXEC|O_NOCTTY);
|
|
if (fdf < 0)
|
|
return -errno;
|
|
|
|
if (mode == (mode_t) -1)
|
|
if (fstat(fdf, &st) < 0)
|
|
return -errno;
|
|
|
|
RUN_WITH_UMASK(0000) {
|
|
if (copy_flags & COPY_MAC_CREATE) {
|
|
r = mac_selinux_create_file_prepare(to, S_IFREG);
|
|
if (r < 0)
|
|
return r;
|
|
}
|
|
fdt = open(to, flags|O_WRONLY|O_CREAT|O_CLOEXEC|O_NOCTTY,
|
|
mode != (mode_t) -1 ? mode : st.st_mode);
|
|
if (copy_flags & COPY_MAC_CREATE)
|
|
mac_selinux_create_file_clear();
|
|
if (fdt < 0)
|
|
return -errno;
|
|
}
|
|
|
|
if (chattr_mask != 0)
|
|
(void) chattr_fd(fdt, chattr_flags, chattr_mask & CHATTR_EARLY_FL, NULL);
|
|
|
|
r = copy_bytes_full(fdf, fdt, (uint64_t) -1, copy_flags, NULL, NULL, progress_bytes, userdata);
|
|
if (r < 0) {
|
|
close(fdt);
|
|
(void) unlink(to);
|
|
return r;
|
|
}
|
|
|
|
(void) copy_times(fdf, fdt, copy_flags);
|
|
(void) copy_xattr(fdf, fdt);
|
|
|
|
if (chattr_mask != 0)
|
|
(void) chattr_fd(fdt, chattr_flags, chattr_mask & ~CHATTR_EARLY_FL, NULL);
|
|
|
|
if (close(fdt) < 0) {
|
|
unlink_noerrno(to);
|
|
return -errno;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
int copy_file_atomic_full(
|
|
const char *from,
|
|
const char *to,
|
|
mode_t mode,
|
|
unsigned chattr_flags,
|
|
unsigned chattr_mask,
|
|
CopyFlags copy_flags,
|
|
copy_progress_bytes_t progress_bytes,
|
|
void *userdata) {
|
|
|
|
_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 this 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;
|
|
|
|
if (copy_flags & COPY_MAC_CREATE) {
|
|
r = mac_selinux_create_file_prepare(to, S_IFREG);
|
|
if (r < 0) {
|
|
t = mfree(t);
|
|
return r;
|
|
}
|
|
}
|
|
fdt = open(t, O_CREAT|O_EXCL|O_NOFOLLOW|O_NOCTTY|O_WRONLY|O_CLOEXEC, 0600);
|
|
if (copy_flags & COPY_MAC_CREATE)
|
|
mac_selinux_create_file_clear();
|
|
if (fdt < 0) {
|
|
t = mfree(t);
|
|
return -errno;
|
|
}
|
|
} else {
|
|
if (copy_flags & COPY_MAC_CREATE) {
|
|
r = mac_selinux_create_file_prepare(to, S_IFREG);
|
|
if (r < 0)
|
|
return r;
|
|
}
|
|
fdt = open_tmpfile_linkable(to, O_WRONLY|O_CLOEXEC, &t);
|
|
if (copy_flags & COPY_MAC_CREATE)
|
|
mac_selinux_create_file_clear();
|
|
if (fdt < 0)
|
|
return fdt;
|
|
}
|
|
|
|
if (chattr_mask != 0)
|
|
(void) chattr_fd(fdt, chattr_flags, chattr_mask & CHATTR_EARLY_FL, NULL);
|
|
|
|
r = copy_file_fd_full(from, fdt, copy_flags, progress_bytes, userdata);
|
|
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;
|
|
}
|
|
|
|
if (chattr_mask != 0)
|
|
(void) chattr_fd(fdt, chattr_flags, chattr_mask & ~CHATTR_EARLY_FL, NULL);
|
|
|
|
t = mfree(t);
|
|
return 0;
|
|
}
|
|
|
|
int copy_times(int fdf, int fdt, CopyFlags flags) {
|
|
struct timespec ut[2];
|
|
struct stat st;
|
|
|
|
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 (FLAGS_SET(flags, COPY_CRTIME)) {
|
|
usec_t crtime;
|
|
|
|
if (fd_getcrtime(fdf, &crtime) >= 0)
|
|
(void) fd_setcrtime(fdt, crtime);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
int copy_access(int fdf, int fdt) {
|
|
struct stat st;
|
|
|
|
assert(fdf >= 0);
|
|
assert(fdt >= 0);
|
|
|
|
if (fstat(fdf, &st) < 0)
|
|
return -errno;
|
|
|
|
if (fchmod(fdt, st.st_mode & 07777) < 0)
|
|
return -errno;
|
|
|
|
return 0;
|
|
}
|
|
|
|
int copy_xattr(int fdf, int fdt) {
|
|
_cleanup_free_ char *names = NULL;
|
|
int ret = 0, r;
|
|
const char *p;
|
|
|
|
r = flistxattr_malloc(fdf, &names);
|
|
if (r < 0)
|
|
return r;
|
|
|
|
NULSTR_FOREACH(p, names) {
|
|
_cleanup_free_ char *value = NULL;
|
|
|
|
if (!startswith(p, "user."))
|
|
continue;
|
|
|
|
r = fgetxattr_malloc(fdf, p, &value);
|
|
if (r == -ENODATA)
|
|
continue; /* gone by now */
|
|
if (r < 0)
|
|
return r;
|
|
|
|
if (fsetxattr(fdt, p, value, r, 0) < 0)
|
|
ret = -errno;
|
|
}
|
|
|
|
return ret;
|
|
}
|