From 55944e5e40b1be2afc4855d8d2baf4b73d1876b5 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Wed, 10 Apr 2024 22:49:52 +0200 Subject: Adding upstream version 255.4. Signed-off-by: Daniel Baumann --- src/shared/copy.c | 1635 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 1635 insertions(+) create mode 100644 src/shared/copy.c (limited to 'src/shared/copy.c') 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 +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#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) { + /* 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)); +} -- cgit v1.2.3