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-rw-r--r--src/shared/copy.c1635
1 files changed, 1635 insertions, 0 deletions
diff --git a/src/shared/copy.c b/src/shared/copy.c
new file mode 100644
index 0000000..c0e30cd
--- /dev/null
+++ b/src/shared/copy.c
@@ -0,0 +1,1635 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+
+#include <errno.h>
+#include <fcntl.h>
+#include <linux/btrfs.h>
+#include <stddef.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/file.h>
+#include <sys/ioctl.h>
+#include <sys/sendfile.h>
+#include <sys/xattr.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_fs.h"
+#include "missing_syscall.h"
+#include "mkdir-label.h"
+#include "mountpoint-util.h"
+#include "nulstr-util.h"
+#include "rm-rf.h"
+#include "selinux-util.h"
+#include "signal-util.h"
+#include "stat-util.h"
+#include "stdio-util.h"
+#include "string-util.h"
+#include "strv.h"
+#include "sync-util.h"
+#include "time-util.h"
+#include "tmpfile-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 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;
+}
+
+static int look_for_signals(CopyFlags copy_flags) {
+ int r;
+
+ if ((copy_flags & (COPY_SIGINT|COPY_SIGTERM)) == 0)
+ return 0;
+
+ r = pop_pending_signal(copy_flags & COPY_SIGINT ? SIGINT : 0,
+ copy_flags & COPY_SIGTERM ? SIGTERM : 0);
+ if (r < 0)
+ return r;
+ if (r != 0)
+ return log_debug_errno(SYNTHETIC_ERRNO(EINTR),
+ "Got %s, cancelling copy operation.", signal_to_string(r));
+
+ return 0;
+}
+
+static int create_hole(int fd, off_t size) {
+ off_t offset;
+ off_t end;
+
+ offset = lseek(fd, 0, SEEK_CUR);
+ if (offset < 0)
+ return -errno;
+
+ end = lseek(fd, 0, SEEK_END);
+ if (end < 0)
+ return -errno;
+
+ /* If we're not at the end of the target file, try to punch a hole in the existing space using fallocate(). */
+
+ if (offset < end &&
+ fallocate(fd, FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE, offset, MIN(size, end - offset)) < 0 &&
+ !ERRNO_IS_NOT_SUPPORTED(errno))
+ return -errno;
+
+ if (end - offset >= size) {
+ /* If we've created the full hole, set the file pointer to the end of the hole we created and exit. */
+ if (lseek(fd, offset + size, SEEK_SET) < 0)
+ return -errno;
+
+ return 0;
+ }
+
+ /* If we haven't created the full hole, use ftruncate() to grow the file (and the hole) to the
+ * required size and move the file pointer to the end of the file. */
+
+ size -= end - offset;
+
+ if (ftruncate(fd, end + size) < 0)
+ return -errno;
+
+ if (lseek(fd, 0, SEEK_END) < 0)
+ return -errno;
+
+ return 0;
+}
+
+int copy_bytes_full(
+ int fdf, int fdt,
+ uint64_t max_bytes,
+ CopyFlags copy_flags,
+ void **ret_remains,
+ size_t *ret_remains_size,
+ copy_progress_bytes_t progress,
+ void *userdata) {
+
+ _cleanup_close_ int fdf_opened = -EBADF, fdt_opened = -EBADF;
+ bool try_cfr = true, try_sendfile = true, try_splice = true, copied_something = false;
+ 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);
+ assert(!FLAGS_SET(copy_flags, COPY_LOCK_BSD));
+
+ /* 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;
+
+ fdf = fd_reopen_condition(fdf, O_CLOEXEC | O_NOCTTY | O_RDONLY, O_PATH, &fdf_opened);
+ if (fdf < 0)
+ return fdf;
+ fdt = fd_reopen_condition(fdt, O_CLOEXEC | O_NOCTTY | O_RDWR, O_PATH, &fdt_opened);
+ if (fdt < 0)
+ return fdt;
+
+ /* 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 = reflink(fdf, fdt); /* full file reflink */
+ else
+ r = reflink_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 */
+ }
+ }
+ }
+ }
+ }
+
+ for (;;) {
+ ssize_t n;
+
+ if (max_bytes <= 0)
+ break;
+
+ r = look_for_signals(copy_flags);
+ if (r < 0)
+ return r;
+
+ if (max_bytes != UINT64_MAX && m > max_bytes)
+ m = max_bytes;
+
+ if (copy_flags & COPY_HOLES) {
+ off_t c, e;
+
+ c = lseek(fdf, 0, SEEK_CUR);
+ if (c < 0)
+ return -errno;
+
+ /* To see if we're in a hole, we search for the next data offset. */
+ e = lseek(fdf, c, SEEK_DATA);
+ if (e < 0 && errno == ENXIO)
+ /* If errno == ENXIO, that means we've reached the final hole of the file and
+ * that hole isn't followed by more data. */
+ e = lseek(fdf, 0, SEEK_END);
+ if (e < 0)
+ return -errno;
+
+ /* If we're in a hole (current offset is not a data offset), create a hole of the
+ * same size in the target file. */
+ if (e > c) {
+ /* Make sure our new hole doesn't go over the maximum size we're allowed to copy. */
+ n = MIN(max_bytes, (uint64_t) e - c);
+ r = create_hole(fdt, n);
+ if (r < 0)
+ return r;
+
+ /* Make sure holes are taken into account in the maximum size we're supposed to copy. */
+ if (max_bytes != UINT64_MAX) {
+ max_bytes -= n;
+ if (max_bytes <= 0)
+ break;
+ }
+
+ /* Update the size we're supposed to copy in this iteration if needed. */
+ if (m > max_bytes)
+ m = max_bytes;
+ }
+
+ c = e; /* Set c to the start of the data segment. */
+
+ /* After copying a potential hole, find the end of the data segment by looking for
+ * the next hole. If we get ENXIO, we're at EOF. */
+ e = lseek(fdf, c, SEEK_HOLE);
+ if (e < 0) {
+ if (errno == ENXIO)
+ break;
+ return -errno;
+ }
+
+ /* SEEK_HOLE modifies the file offset so we need to move back to the initial offset. */
+ if (lseek(fdf, c, SEEK_SET) < 0)
+ return -errno;
+
+ /* Make sure we're not copying more than the current data segment. */
+ m = MIN(m, (size_t) e - c);
+ }
+
+ /* 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) { /* likely EOF */
+
+ if (copied_something)
+ break;
+
+ /* So, we hit EOF immediately, without having copied a single byte. This
+ * could indicate two things: the file is actually empty, or we are on some
+ * virtual file system such as procfs/sysfs where the syscall actually
+ * doesn't work but doesn't return an error. Try to handle that, by falling
+ * back to simple read()s in case we encounter empty files.
+ *
+ * See: https://lwn.net/Articles/846403/ */
+ try_cfr = try_sendfile = try_splice = false;
+ } 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) { /* likely EOF */
+
+ if (copied_something)
+ break;
+
+ try_sendfile = try_splice = false; /* same logic as above for copy_file_range() */
+ } 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) { /* likely EOF */
+
+ if (copied_something)
+ break;
+
+ try_splice = false; /* same logic as above for copy_file_range() + sendfile() */
+ } 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 (progress) {
+ r = progress(n, userdata);
+ if (r < 0)
+ return r;
+ }
+
+ if (max_bytes != UINT64_MAX) {
+ 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);
+
+ copied_something = true;
+ }
+
+ if (copy_flags & COPY_TRUNCATE) {
+ off_t off = lseek(fdt, 0, SEEK_CUR);
+ if (off < 0)
+ return -errno;
+
+ if (ftruncate(fdt, off) < 0)
+ return -errno;
+ }
+
+ return max_bytes <= 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 (copy_flags & COPY_MAC_CREATE) {
+ r = mac_selinux_create_file_prepare_at(dt, to, S_IFLNK);
+ if (r < 0)
+ return r;
+ }
+ r = RET_NERRNO(symlinkat(target, dt, to));
+ if (copy_flags & COPY_MAC_CREATE)
+ mac_selinux_create_file_clear();
+ if (r < 0) {
+ if (FLAGS_SET(copy_flags, COPY_GRACEFUL_WARN) && (ERRNO_IS_PRIVILEGE(r) || ERRNO_IS_NOT_SUPPORTED(r))) {
+ log_notice_errno(r, "Failed to copy symlink '%s', ignoring: %m", from);
+ return 0;
+ }
+
+ return r;
+ }
+
+ 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;
+
+ (void) copy_xattr(df, from, dt, to, copy_flags);
+ (void) utimensat(dt, to, (struct timespec[]) { st->st_atim, st->st_mtim }, AT_SYMLINK_NOFOLLOW);
+ return r;
+}
+
+/* Encapsulates the database we store potential hardlink targets in */
+typedef struct HardlinkContext {
+ int dir_fd; /* An fd to the directory we use as lookup table. Never AT_FDCWD. Lazily created, when
+ * we add the first entry. */
+
+ /* These two fields are used to create the hardlink repository directory above — via
+ * mkdirat(parent_fd, subdir) — and are kept so that we can automatically remove the directory again
+ * when we are done. */
+ int parent_fd; /* Possibly AT_FDCWD */
+ char *subdir;
+} HardlinkContext;
+
+static int hardlink_context_setup(
+ HardlinkContext *c,
+ int dt,
+ const char *to,
+ CopyFlags copy_flags) {
+
+ _cleanup_close_ int dt_copy = -EBADF;
+ int r;
+
+ assert(c);
+ assert(c->dir_fd < 0 && c->dir_fd != AT_FDCWD);
+ assert(c->parent_fd < 0);
+ assert(!c->subdir);
+
+ /* If hardlink recreation is requested we have to maintain a database of inodes that are potential
+ * hardlink sources. Given that generally disk sizes have to be assumed to be larger than what fits
+ * into physical RAM we cannot maintain that database in dynamic memory alone. Here we opt to
+ * maintain it on disk, to simplify things: inside the destination directory we'll maintain a
+ * temporary directory consisting of hardlinks of every inode we copied that might be subject of
+ * hardlinks. We can then use that as hardlink source later on. Yes, this means additional disk IO
+ * but thankfully Linux is optimized for this kind of thing. If this ever becomes a performance
+ * bottleneck we can certainly place an in-memory hash table in front of this, but for the beginning,
+ * let's keep things simple, and just use the disk as lookup table for inodes.
+ *
+ * Note that this should have zero performance impact as long as .n_link of all files copied remains
+ * <= 0, because in that case we will not actually allocate the hardlink inode lookup table directory
+ * on disk (we do so lazily, when the first candidate with .n_link > 1 is seen). This means, in the
+ * common case where hardlinks are not used at all or only for few files the fact that we store the
+ * table on disk shouldn't matter perfomance-wise. */
+
+ if (!FLAGS_SET(copy_flags, COPY_HARDLINKS))
+ return 0;
+
+ if (dt == AT_FDCWD)
+ dt_copy = AT_FDCWD;
+ else if (dt < 0)
+ return -EBADF;
+ else {
+ dt_copy = fcntl(dt, F_DUPFD_CLOEXEC, 3);
+ if (dt_copy < 0)
+ return -errno;
+ }
+
+ r = tempfn_random_child(to, "hardlink", &c->subdir);
+ if (r < 0)
+ return r;
+
+ c->parent_fd = TAKE_FD(dt_copy);
+
+ /* We don't actually create the directory we keep the table in here, that's done on-demand when the
+ * first entry is added, using hardlink_context_realize() below. */
+ return 1;
+}
+
+static int hardlink_context_realize(HardlinkContext *c) {
+ if (!c)
+ return 0;
+
+ if (c->dir_fd >= 0) /* Already realized */
+ return 1;
+
+ if (c->parent_fd < 0 && c->parent_fd != AT_FDCWD) /* Not configured */
+ return 0;
+
+ assert(c->subdir);
+
+ c->dir_fd = open_mkdir_at(c->parent_fd, c->subdir, O_EXCL|O_CLOEXEC, 0700);
+ if (c->dir_fd < 0)
+ return c->dir_fd;
+
+ return 1;
+}
+
+static void hardlink_context_destroy(HardlinkContext *c) {
+ int r;
+
+ assert(c);
+
+ /* Automatically remove the hardlink lookup table directory again after we are done. This is used via
+ * _cleanup_() so that we really delete this, even on failure. */
+
+ if (c->dir_fd >= 0) {
+ /* <dir_fd> might be have already been used for reading, so we need to rewind it. */
+ if (lseek(c->dir_fd, 0, SEEK_SET) < 0)
+ log_debug_errno(errno, "Failed to lseek on file descriptor, ignoring: %m");
+
+ r = rm_rf_children(TAKE_FD(c->dir_fd), REMOVE_PHYSICAL, NULL); /* consumes dir_fd in all cases, even on failure */
+ if (r < 0)
+ log_debug_errno(r, "Failed to remove hardlink store (%s) contents, ignoring: %m", c->subdir);
+
+ assert(c->parent_fd >= 0 || c->parent_fd == AT_FDCWD);
+ assert(c->subdir);
+
+ if (unlinkat(c->parent_fd, c->subdir, AT_REMOVEDIR) < 0)
+ log_debug_errno(errno, "Failed to remove hardlink store (%s) directory, ignoring: %m", c->subdir);
+ }
+
+ 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_tree_generic(
+ 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,
+ Hashmap *denylist,
+ Set *subvolumes,
+ HardlinkContext *hardlink_context,
+ const char *display_path,
+ copy_progress_path_t progress_path,
+ copy_progress_bytes_t progress_bytes,
+ void *userdata);
+
+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 = -EBADF, fdt = -EBADF;
+ 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_MAX, copy_flags, NULL, NULL, progress, userdata);
+ if (r < 0)
+ goto fail;
+
+ 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) futimens(fdt, (struct timespec[]) { st->st_atim, st->st_mtim });
+ (void) copy_xattr(fdf, NULL, fdt, NULL, copy_flags);
+
+ if (copy_flags & COPY_FSYNC) {
+ if (fsync(fdt) < 0) {
+ r = -errno;
+ goto fail;
+ }
+ }
+
+ q = close_nointr(TAKE_FD(fdt)); /* even if this fails, the fd is now invalidated */
+ if (q < 0) {
+ r = q;
+ goto fail;
+ }
+
+ (void) memorize_hardlink(hardlink_context, st, dt, to);
+ return r;
+
+fail:
+ (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,
+ 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 = RET_NERRNO(mkfifoat(dt, to, st->st_mode & 07777));
+ if (copy_flags & COPY_MAC_CREATE)
+ mac_selinux_create_file_clear();
+ if (FLAGS_SET(copy_flags, COPY_GRACEFUL_WARN) && (ERRNO_IS_NEG_PRIVILEGE(r) || ERRNO_IS_NEG_NOT_SUPPORTED(r))) {
+ log_notice_errno(r, "Failed to copy fifo '%s', ignoring: %m", from);
+ return 0;
+ } else if (r < 0)
+ return r;
+
+ 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) utimensat(dt, to, (struct timespec[]) { st->st_atim, st->st_mtim }, AT_SYMLINK_NOFOLLOW);
+
+ (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 = RET_NERRNO(mknodat(dt, to, st->st_mode, st->st_rdev));
+ if (copy_flags & COPY_MAC_CREATE)
+ mac_selinux_create_file_clear();
+ if (FLAGS_SET(copy_flags, COPY_GRACEFUL_WARN) && (ERRNO_IS_NEG_PRIVILEGE(r) || ERRNO_IS_NEG_NOT_SUPPORTED(r))) {
+ log_notice_errno(r, "Failed to copy node '%s', ignoring: %m", from);
+ return 0;
+ } else if (r < 0)
+ return r;
+
+ 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) utimensat(dt, to, (struct timespec[]) { st->st_atim, st->st_mtim }, AT_SYMLINK_NOFOLLOW);
+
+ (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,
+ Hashmap *denylist,
+ Set *subvolumes,
+ 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 = -EBADF,
+ .parent_fd = -EBADF,
+ };
+
+ _cleanup_close_ int fdf = -EBADF, fdt = -EBADF;
+ _cleanup_closedir_ DIR *d = NULL;
+ bool exists;
+ 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;
+
+ r = dir_is_empty_at(dt, to, /* ignore_hidden_or_backup= */ false);
+ if (r < 0 && r != -ENOENT)
+ return r;
+ if ((r > 0 && !(copy_flags & (COPY_MERGE|COPY_MERGE_EMPTY))) || (r == 0 && !FLAGS_SET(copy_flags, COPY_MERGE)))
+ return -EEXIST;
+
+ exists = r >= 0;
+
+ fdt = xopenat_lock(dt, to,
+ O_RDONLY|O_DIRECTORY|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW|(exists ? 0 : O_CREAT|O_EXCL),
+ (copy_flags & COPY_MAC_CREATE ? XO_LABEL : 0)|(set_contains(subvolumes, st) ? XO_SUBVOLUME : 0),
+ st->st_mode & 07777,
+ copy_flags & COPY_LOCK_BSD ? LOCK_BSD : LOCK_NONE,
+ LOCK_EX);
+ if (fdt < 0)
+ return fdt;
+
+ r = 0;
+
+ if (PTR_TO_INT(hashmap_get(denylist, st)) == DENY_CONTENTS) {
+ log_debug("%s is in the denylist, not recursing", from);
+ goto finish;
+ }
+
+ 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;
+
+ r = look_for_signals(copy_flags);
+ if (r < 0)
+ return r;
+
+ 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 (PTR_TO_INT(hashmap_get(denylist, &buf)) == DENY_INODE) {
+ log_debug("%s/%s is in the denylist, ignoring", from, de->d_name);
+ 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_tree_generic(dirfd(d), de->d_name, &buf, fdt, de->d_name, original_device,
+ depth_left-1, override_uid, override_gid, copy_flags & ~COPY_LOCK_BSD,
+ denylist, subvolumes, hardlink_context, child_display_path, progress_path,
+ progress_bytes, userdata);
+
+ if (q == -EINTR) /* Propagate SIGINT/SIGTERM up instantly */
+ return q;
+ if (q == -EEXIST && (copy_flags & COPY_MERGE))
+ q = 0;
+ if (q < 0)
+ r = q;
+ }
+
+finish:
+ if (!exists) {
+ 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), NULL, fdt, NULL, copy_flags);
+ (void) futimens(fdt, (struct timespec[]) { st->st_atim, st->st_mtim });
+ }
+
+ if (copy_flags & COPY_FSYNC_FULL) {
+ if (fsync(fdt) < 0)
+ return -errno;
+ }
+
+ if (r < 0)
+ return r;
+
+ return copy_flags & COPY_LOCK_BSD ? TAKE_FD(fdt) : 0;
+}
+
+static int fd_copy_leaf(
+ 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,
+ const char *display_path,
+ copy_progress_bytes_t progress_bytes,
+ void *userdata) {
+ int r;
+
+ if (S_ISREG(st->st_mode))
+ r = fd_copy_regular(df, from, st, dt, to, override_uid, override_gid, copy_flags, hardlink_context, progress_bytes, userdata);
+ else if (S_ISLNK(st->st_mode))
+ r = fd_copy_symlink(df, from, st, dt, to, override_uid, override_gid, copy_flags);
+ else if (S_ISFIFO(st->st_mode))
+ r = fd_copy_fifo(df, from, st, dt, to, override_uid, override_gid, copy_flags, hardlink_context);
+ else if (S_ISBLK(st->st_mode) || S_ISCHR(st->st_mode) || S_ISSOCK(st->st_mode))
+ r = fd_copy_node(df, from, st, dt, to, override_uid, override_gid, copy_flags, hardlink_context);
+ else
+ r = -EOPNOTSUPP;
+
+ return r;
+}
+
+static int fd_copy_tree_generic(
+ 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,
+ Hashmap *denylist,
+ Set *subvolumes,
+ HardlinkContext *hardlink_context,
+ const char *display_path,
+ copy_progress_path_t progress_path,
+ copy_progress_bytes_t progress_bytes,
+ void *userdata) {
+
+ int r;
+
+ assert(!FLAGS_SET(copy_flags, COPY_LOCK_BSD));
+
+ if (S_ISDIR(st->st_mode))
+ return fd_copy_directory(df, from, st, dt, to, original_device, depth_left-1, override_uid,
+ override_gid, copy_flags, denylist, subvolumes, hardlink_context,
+ display_path, progress_path, progress_bytes, userdata);
+
+ DenyType t = PTR_TO_INT(hashmap_get(denylist, st));
+ if (t == DENY_INODE) {
+ log_debug("%s is in the denylist, ignoring", from);
+ return 0;
+ } else if (t == DENY_CONTENTS)
+ log_debug("%s is configured to have its contents excluded, but is not a directory", from);
+
+ r = fd_copy_leaf(df, from, st, dt, to, override_uid, override_gid, copy_flags, hardlink_context, display_path, progress_bytes, userdata);
+ /* We just tried to copy a leaf node of the tree. If it failed because the node already exists *and* the COPY_REPLACE flag has been provided, we should unlink the node and re-copy. */
+ if (r == -EEXIST && (copy_flags & COPY_REPLACE)) {
+ /* This codepath is us trying to address an error to copy, if the unlink fails, lets just return the original error. */
+ if (unlinkat(dt, to, 0) < 0)
+ return r;
+
+ r = fd_copy_leaf(df, from, st, dt, to, override_uid, override_gid, copy_flags, hardlink_context, display_path, progress_bytes, userdata);
+ }
+
+ 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,
+ Hashmap *denylist,
+ Set *subvolumes,
+ copy_progress_path_t progress_path,
+ copy_progress_bytes_t progress_bytes,
+ void *userdata) {
+
+ struct stat st;
+ int r;
+
+ assert(from);
+ assert(to);
+ assert(!FLAGS_SET(copy_flags, COPY_LOCK_BSD));
+
+ if (fstatat(fdf, from, &st, AT_SYMLINK_NOFOLLOW) < 0)
+ return -errno;
+
+ r = fd_copy_tree_generic(fdf, from, &st, fdt, to, st.st_dev, COPY_DEPTH_MAX, override_uid,
+ override_gid, copy_flags, denylist, subvolumes, NULL, NULL, progress_path,
+ progress_bytes, userdata);
+ if (r < 0)
+ return r;
+
+ if (S_ISDIR(st.st_mode) && (copy_flags & COPY_SYNCFS)) {
+ /* If the top-level inode is a directory run syncfs() now. */
+ r = syncfs_path(fdt, to);
+ if (r < 0)
+ return r;
+ } else if ((copy_flags & (COPY_FSYNC_FULL|COPY_SYNCFS)) != 0) {
+ /* fsync() the parent dir of what we just copied if COPY_FSYNC_FULL is set. Also do this in
+ * case COPY_SYNCFS is set but the top-level inode wasn't actually a directory. We do this so that
+ * COPY_SYNCFS provides reasonable synchronization semantics on any kind of inode: when the
+ * copy operation is done the whole inode — regardless of its type — and all its children
+ * will be synchronized to disk. */
+ r = fsync_parent_at(fdt, to);
+ if (r < 0)
+ return r;
+ }
+
+ return 0;
+}
+
+static int sync_dir_by_flags(int dir_fd, const char *path, CopyFlags copy_flags) {
+ assert(dir_fd >= 0 || dir_fd == AT_FDCWD);
+ assert(path);
+
+ if (copy_flags & COPY_SYNCFS)
+ return syncfs_path(dir_fd, path);
+ if (copy_flags & COPY_FSYNC_FULL)
+ return fsync_parent_at(dir_fd, path);
+
+ return 0;
+}
+
+int copy_directory_at_full(
+ int dir_fdf,
+ const char *from,
+ int dir_fdt,
+ const char *to,
+ CopyFlags copy_flags,
+ copy_progress_path_t progress_path,
+ copy_progress_bytes_t progress_bytes,
+ void *userdata) {
+
+ _cleanup_close_ int fdt = -EBADF;
+ struct stat st;
+ int r;
+
+ assert(dir_fdf >= 0 || dir_fdf == AT_FDCWD);
+ assert(dir_fdt >= 0 || dir_fdt == AT_FDCWD);
+ assert(to);
+
+ if (fstatat(dir_fdf, strempty(from), &st, AT_SYMLINK_NOFOLLOW|(isempty(from) ? AT_EMPTY_PATH : 0)) < 0)
+ return -errno;
+
+ r = stat_verify_directory(&st);
+ if (r < 0)
+ return r;
+
+ r = fd_copy_directory(
+ dir_fdf, from,
+ &st,
+ dir_fdt, to,
+ st.st_dev,
+ COPY_DEPTH_MAX,
+ UID_INVALID, GID_INVALID,
+ copy_flags,
+ NULL, NULL, NULL, NULL,
+ progress_path,
+ progress_bytes,
+ userdata);
+ if (r < 0)
+ return r;
+
+ if (FLAGS_SET(copy_flags, COPY_LOCK_BSD))
+ fdt = r;
+
+ r = sync_dir_by_flags(dir_fdt, to, copy_flags);
+ if (r < 0)
+ return r;
+
+ return FLAGS_SET(copy_flags, COPY_LOCK_BSD) ? TAKE_FD(fdt) : 0;
+}
+
+int copy_file_fd_at_full(
+ int dir_fdf,
+ const char *from,
+ int fdt,
+ CopyFlags copy_flags,
+ copy_progress_bytes_t progress_bytes,
+ void *userdata) {
+
+ _cleanup_close_ int fdf = -EBADF;
+ struct stat st;
+ int r;
+
+ assert(dir_fdf >= 0 || dir_fdf == AT_FDCWD);
+ assert(from);
+ assert(fdt >= 0);
+ assert(!FLAGS_SET(copy_flags, COPY_LOCK_BSD));
+
+ fdf = openat(dir_fdf, from, O_RDONLY|O_CLOEXEC|O_NOCTTY);
+ if (fdf < 0)
+ return -errno;
+
+ r = fd_verify_regular(fdf);
+ if (r < 0)
+ return r;
+
+ if (fstat(fdt, &st) < 0)
+ return -errno;
+
+ r = copy_bytes_full(fdf, fdt, UINT64_MAX, copy_flags, NULL, NULL, progress_bytes, userdata);
+ if (r < 0)
+ return r;
+
+ /* Make sure to copy file attributes only over if target is a regular
+ * file (so that copying a file to /dev/null won't alter the access
+ * mode/ownership of that device node...) */
+ if (S_ISREG(st.st_mode)) {
+ (void) copy_times(fdf, fdt, copy_flags);
+ (void) copy_xattr(fdf, NULL, fdt, NULL, copy_flags);
+ }
+
+ if (copy_flags & COPY_FSYNC_FULL) {
+ r = fsync_full(fdt);
+ if (r < 0)
+ return r;
+ } else if (copy_flags & COPY_FSYNC) {
+ if (fsync(fdt) < 0)
+ return -errno;
+ }
+
+ return 0;
+}
+
+int copy_file_at_full(
+ int dir_fdf,
+ const char *from,
+ int dir_fdt,
+ 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 = -EBADF, fdt = -EBADF;
+ struct stat st;
+ int r;
+
+ assert(dir_fdf >= 0 || dir_fdf == AT_FDCWD);
+ assert(dir_fdt >= 0 || dir_fdt == AT_FDCWD);
+ assert(from);
+ assert(to);
+
+ fdf = openat(dir_fdf, from, O_RDONLY|O_CLOEXEC|O_NOCTTY);
+ if (fdf < 0)
+ return -errno;
+
+ if (fstat(fdf, &st) < 0)
+ return -errno;
+
+ r = stat_verify_regular(&st);
+ if (r < 0)
+ return r;
+
+ WITH_UMASK(0000) {
+ fdt = xopenat_lock(dir_fdt, to,
+ flags|O_WRONLY|O_CREAT|O_CLOEXEC|O_NOCTTY,
+ (copy_flags & COPY_MAC_CREATE ? XO_LABEL : 0),
+ mode != MODE_INVALID ? mode : st.st_mode,
+ copy_flags & COPY_LOCK_BSD ? LOCK_BSD : LOCK_NONE, LOCK_EX);
+ if (fdt < 0)
+ return fdt;
+ }
+
+ if (!FLAGS_SET(flags, O_EXCL)) { /* if O_EXCL was used we created the thing as regular file, no need to check again */
+ r = fd_verify_regular(fdt);
+ if (r < 0)
+ goto fail;
+ }
+
+ if (chattr_mask != 0)
+ (void) chattr_fd(fdt, chattr_flags, chattr_mask & CHATTR_EARLY_FL, NULL);
+
+ r = copy_bytes_full(fdf, fdt, UINT64_MAX, copy_flags & ~COPY_LOCK_BSD, NULL, NULL, progress_bytes, userdata);
+ if (r < 0)
+ goto fail;
+
+ (void) copy_times(fdf, fdt, copy_flags);
+ (void) copy_xattr(fdf, NULL, fdt, NULL, copy_flags);
+
+ if (chattr_mask != 0)
+ (void) chattr_fd(fdt, chattr_flags, chattr_mask & ~CHATTR_EARLY_FL, NULL);
+
+ if (copy_flags & (COPY_FSYNC|COPY_FSYNC_FULL)) {
+ if (fsync(fdt) < 0) {
+ r = -errno;
+ goto fail;
+ }
+ }
+
+ if (!FLAGS_SET(copy_flags, COPY_LOCK_BSD)) {
+ r = close_nointr(TAKE_FD(fdt)); /* even if this fails, the fd is now invalidated */
+ if (r < 0)
+ goto fail;
+ }
+
+ if (copy_flags & COPY_FSYNC_FULL) {
+ r = fsync_parent_at(dir_fdt, to);
+ if (r < 0)
+ goto fail;
+ }
+
+ return copy_flags & COPY_LOCK_BSD ? TAKE_FD(fdt) : 0;
+
+fail:
+ /* Only unlink if we definitely are the ones who created the file */
+ if (FLAGS_SET(flags, O_EXCL))
+ (void) unlinkat(dir_fdt, to, 0);
+
+ return r;
+}
+
+int copy_file_atomic_at_full(
+ int dir_fdf,
+ const char *from,
+ int dir_fdt,
+ 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 = -EBADF;
+ int r;
+
+ assert(from);
+ assert(to);
+ assert(!FLAGS_SET(copy_flags, COPY_LOCK_BSD));
+
+ if (copy_flags & COPY_MAC_CREATE) {
+ r = mac_selinux_create_file_prepare_at(dir_fdt, to, S_IFREG);
+ if (r < 0)
+ return r;
+ }
+ fdt = open_tmpfile_linkable_at(dir_fdt, 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_at_full(dir_fdf, from, fdt, copy_flags, progress_bytes, userdata);
+ if (r < 0)
+ return r;
+
+ if (fchmod(fdt, mode) < 0)
+ return -errno;
+
+ if ((copy_flags & (COPY_FSYNC|COPY_FSYNC_FULL))) {
+ /* Sync the file */
+ if (fsync(fdt) < 0)
+ return -errno;
+ }
+
+ r = link_tmpfile_at(fdt, dir_fdt, t, to, (copy_flags & COPY_REPLACE) ? LINK_TMPFILE_REPLACE : 0);
+ if (r < 0)
+ return r;
+
+ t = mfree(t);
+
+ if (chattr_mask != 0)
+ (void) chattr_fd(fdt, chattr_flags, chattr_mask & ~CHATTR_EARLY_FL, NULL);
+
+ r = close_nointr(TAKE_FD(fdt)); /* even if this fails, the fd is now invalidated */
+ if (r < 0)
+ goto fail;
+
+ if (copy_flags & COPY_FSYNC_FULL) {
+ /* Sync the parent directory */
+ r = fsync_parent_at(dir_fdt, to);
+ if (r < 0)
+ goto fail;
+ }
+
+ return 0;
+
+fail:
+ (void) unlinkat(dir_fdt, to, 0);
+ return r;
+}
+
+int copy_times(int fdf, int fdt, CopyFlags flags) {
+ struct stat st;
+
+ assert(fdf >= 0);
+ assert(fdt >= 0);
+
+ if (fstat(fdf, &st) < 0)
+ return -errno;
+
+ if (futimens(fdt, (struct timespec[2]) { st.st_atim, st.st_mtim }) < 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);
+
+ /* Copies just the access mode (and not the ownership) from fdf to fdt */
+
+ if (fstat(fdf, &st) < 0)
+ return -errno;
+
+ return RET_NERRNO(fchmod(fdt, st.st_mode & 07777));
+}
+
+int copy_rights_with_fallback(int fdf, int fdt, const char *patht) {
+ struct stat st;
+
+ assert(fdf >= 0);
+ assert(fdt >= 0);
+
+ /* Copies both access mode and ownership from fdf to fdt */
+
+ if (fstat(fdf, &st) < 0)
+ return -errno;
+
+ return fchmod_and_chown_with_fallback(fdt, patht, st.st_mode & 07777, st.st_uid, st.st_gid);
+}
+
+int copy_xattr(int df, const char *from, int dt, const char *to, CopyFlags copy_flags) {
+ _cleanup_free_ char *names = NULL;
+ int ret = 0, r;
+
+ r = listxattr_at_malloc(df, from, 0, &names);
+ if (r < 0)
+ return r;
+
+ NULSTR_FOREACH(p, names) {
+ _cleanup_free_ char *value = NULL;
+
+ if (!FLAGS_SET(copy_flags, COPY_ALL_XATTRS) && !startswith(p, "user."))
+ continue;
+
+ r = getxattr_at_malloc(df, from, p, 0, &value);
+ if (r == -ENODATA)
+ continue; /* gone by now */
+ if (r < 0)
+ return r;
+
+ if (xsetxattr(dt, to, p, value, r, 0) < 0)
+ ret = -errno;
+ }
+
+ return ret;
+}
+
+int reflink(int infd, int outfd) {
+ int r;
+
+ assert(infd >= 0);
+ assert(outfd >= 0);
+
+ /* Make sure we invoke the ioctl on a regular file, so that no device driver accidentally gets it. */
+
+ r = fd_verify_regular(outfd);
+ if (r < 0)
+ return r;
+
+ /* FICLONE was introduced in Linux 4.5 but it uses the same number as BTRFS_IOC_CLONE introduced earlier */
+
+ assert_cc(FICLONE == BTRFS_IOC_CLONE);
+
+ return RET_NERRNO(ioctl(outfd, FICLONE, infd));
+}
+
+assert_cc(sizeof(struct file_clone_range) == sizeof(struct btrfs_ioctl_clone_range_args));
+
+int reflink_range(int infd, uint64_t in_offset, int outfd, uint64_t out_offset, uint64_t sz) {
+ struct file_clone_range args = {
+ .src_fd = infd,
+ .src_offset = in_offset,
+ .src_length = sz,
+ .dest_offset = out_offset,
+ };
+ int r;
+
+ assert(infd >= 0);
+ assert(outfd >= 0);
+
+ /* Inside the kernel, FICLONE is identical to FICLONERANGE with offsets and size set to zero, let's
+ * simplify things and use the simple ioctl in that case. Also, do the same if the size is
+ * UINT64_MAX, which is how we usually encode "everything". */
+ if (in_offset == 0 && out_offset == 0 && IN_SET(sz, 0, UINT64_MAX))
+ return reflink(infd, outfd);
+
+ r = fd_verify_regular(outfd);
+ if (r < 0)
+ return r;
+
+ assert_cc(FICLONERANGE == BTRFS_IOC_CLONE_RANGE);
+
+ return RET_NERRNO(ioctl(outfd, FICLONERANGE, &args));
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-22 21:00:17 +0000