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b8df25dcfe674e37ceb3d54e00a31e1d33e96057
systemd/src/shared/copy.c
Mike Yuan b8df25dcfe xattr-util: try new *xattrat() family syscalls first 
Added in 6140be90ec

However, when O_PATH fds are encountered we'd have to go by
/proc/self/fd/ still, since the kernel people are reluctant
to make the new syscalls work with them
(https://lore.kernel.org/linux-fsdevel/20250206-steril-raumplanung-733224062432@brauner/)
Hence getxattrat() and listxattrat() are not employed.

While at it, remove the discrepancy between path being NULL
and empty - I don't grok the "security issue" claimed earlier,
but nowadays even the kernel treats the two as identical:
e896474fe4
2025-02-09 14:51:04 +01:00

1735 lines
65 KiB
C
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/* 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"
/* If we copy via a userspace buffer, size it to 64K */
#define COPY_BUFFER_SIZE (64U*U64_KB)
/* If a byte progress function is specified during copying, never try to copy more than 1M, so that we can
* reasonably call the progress function still */
#define PROGRESS_STEP_SIZE (1U*U64_MB)
/* 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;
uint64_t copied_total = 0;
int r, nonblock_pipe = -1;
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 and
* 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;
int ret;
/* 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;
if (FLAGS_SET(copy_flags, COPY_VERIFY_LINKED)) {
r = fd_verify_linked(fdf);
if (r < 0)
return r;
}
/* We copied the whole thing, hence hit EOF, return 0. */
ret = 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;
/* We copied only some number of bytes, which worked, but
* this means we didn't hit EOF, return 1. */
ret = 1;
}
if (FLAGS_SET(copy_flags, COPY_VERIFY_LINKED)) {
r = fd_verify_linked(fdf);
if (r < 0)
return r;
}
return ret;
}
}
}
}
for (;;) {
ssize_t n;
size_t m;
if (max_bytes <= 0)
break;
r = look_for_signals(copy_flags);
if (r < 0)
return r;
/* sendfile() accepts at most SSIZE_MAX-offset bytes to copy, hence let's subtract how much
* copied so far from SSIZE_MAX as maximum of what we want to copy. */
if (try_sendfile) {
assert(copied_total < SSIZE_MAX);
m = (uint64_t) SSIZE_MAX - copied_total;
} else
m = SSIZE_MAX;
if (max_bytes != UINT64_MAX && m > max_bytes)
m = max_bytes;
if (progress && m > PROGRESS_STEP_SIZE)
m = PROGRESS_STEP_SIZE;
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);
if (m <= 0)
continue;
}
/* 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, -EOPNOTSUPP))
return n;
try_cfr = false;
/* use fallback below */
} else if (n == 0) { /* likely EOF */
if (copied_total > 0)
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_total > 0)
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_total > 0)
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:
copied_total += n;
/* Disable sendfile() in case we are getting too close to it's SSIZE_MAX-offset limit */
if (copied_total > SSIZE_MAX - COPY_BUFFER_SIZE)
try_sendfile = false;
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;
}
}
if (FLAGS_SET(copy_flags, COPY_VERIFY_LINKED)) {
r = fd_verify_linked(fdf);
if (r < 0)
return r;
}
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(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%s%s, ignoring: %m",
isempty(from) ? "" : " '",
strempty(from),
isempty(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 prepare_nocow(int fdf, const char *from, int fdt, unsigned *chattr_mask, unsigned *chattr_flags) {
unsigned attrs = 0;
int r;
assert(fdf >= 0 || fdf == AT_FDCWD);
assert(fdt >= 0);
assert(!!chattr_mask == !!chattr_flags);
/* If caller explicitly requested NOCOW to be set or unset, let's not interfere. */
if (chattr_mask && FLAGS_SET(*chattr_mask, FS_NOCOW_FL))
return 0;
r = read_attr_at(fdf, from, &attrs);
if (r < 0 && !ERRNO_IS_NOT_SUPPORTED(r) && r != -ELOOP) /* If the source is a symlink we get ELOOP */
return r;
if (FLAGS_SET(attrs, FS_NOCOW_FL)) {
if (chattr_mask && chattr_flags) {
*chattr_mask |= FS_NOCOW_FL;
*chattr_flags |= FS_NOCOW_FL;
} else
/* If the NOCOW flag is set on the source, make the copy NOCOW as well. If the source
* is not NOCOW, don't do anything in particular with the copy. */
(void) chattr_fd(fdt, FS_NOCOW_FL, FS_NOCOW_FL, /*previous=*/ NULL);
}
return 0;
}
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(st);
assert(to);
r = try_hardlink(hardlink_context, st, dt, to);
if (r < 0)
return r;
if (r > 0) /* worked! */
return 0;
fdf = xopenat_full(df, from, O_RDONLY|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW, XO_REGULAR, 0);
if (fdf < 0)
return fdf;
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 = prepare_nocow(fdf, /*from=*/ NULL, fdt, /*chattr_mask=*/ NULL, /*chattr_flags=*/ NULL);
if (r < 0)
return r;
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 (FLAGS_SET(copy_flags, COPY_VERIFY_LINKED)) {
r = fd_verify_linked(fdf);
if (r < 0)
return r;
}
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(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%s%s, ignoring: %m",
isempty(from) ? "" : " '",
strempty(from),
isempty(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(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%s%s, ignoring: %m",
isempty(from) ? "" : " '",
strempty(from),
isempty(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;
struct stat dt_st;
bool exists;
int r;
assert(st);
assert(to);
if (depth_left == 0)
return -ENAMETOOLONG;
fdf = xopenat(df, from, O_RDONLY|O_DIRECTORY|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW);
if (fdf < 0)
return fdf;
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_full(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;
if (exists && FLAGS_SET(copy_flags, COPY_RESTORE_DIRECTORY_TIMESTAMPS) && fstat(fdt, &dt_st) < 0)
return -errno;
r = 0;
if (PTR_TO_INT(hashmap_get(denylist, st)) == DENY_CONTENTS) {
log_debug("%s is in the denylist, not recursing", from ?: "file to copy");
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%s is in the denylist, ignoring",
strempty(from), isempty(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 = is_mount_point_at(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 });
} else if (FLAGS_SET(copy_flags, COPY_RESTORE_DIRECTORY_TIMESTAMPS))
/* If the directory already exists, make sure the timestamps stay the same as before. */
(void) futimens(fdt, (struct timespec[]) { dt_st.st_atim, dt_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 ?: "file to copy");
return 0;
} else if (t == DENY_CONTENTS)
log_debug("%s is configured to have its contents excluded, but is not a directory", from ?: "file to copy");
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(to);
assert(!FLAGS_SET(copy_flags, COPY_LOCK_BSD));
if (fstatat(fdf, strempty(from), &st, AT_SYMLINK_NOFOLLOW | (isempty(from) ? AT_EMPTY_PATH : 0)) < 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(fdt >= 0);
assert(!FLAGS_SET(copy_flags, COPY_LOCK_BSD));
fdf = xopenat_full(dir_fdf, from, O_RDONLY|O_CLOEXEC|O_NOCTTY, XO_REGULAR, 0);
if (fdf < 0)
return fdf;
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 (FLAGS_SET(copy_flags, COPY_VERIFY_LINKED)) {
r = fd_verify_linked(fdf);
if (r < 0)
return r;
}
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;
int r;
assert(dir_fdf >= 0 || dir_fdf == AT_FDCWD);
assert(dir_fdt >= 0 || dir_fdt == AT_FDCWD);
assert(to);
fdf = xopenat_full(dir_fdf, from, O_RDONLY|O_CLOEXEC|O_NOCTTY, XO_REGULAR, 0);
if (fdf < 0)
return fdf;
if (mode == MODE_INVALID) {
struct stat st;
if (fstat(fdf, &st) < 0)
return -errno;
mode = st.st_mode;
}
WITH_UMASK(0000) {
fdt = xopenat_lock_full(dir_fdt, to,
flags|O_WRONLY|O_CREAT|O_CLOEXEC|O_NOCTTY,
XO_REGULAR | (copy_flags & COPY_MAC_CREATE ? XO_LABEL : 0),
mode,
copy_flags & COPY_LOCK_BSD ? LOCK_BSD : LOCK_NONE, LOCK_EX);
if (fdt < 0)
return fdt;
}
r = prepare_nocow(fdf, /*from=*/ NULL, fdt, &chattr_mask, &chattr_flags);
if (r < 0)
return r;
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 (FLAGS_SET(copy_flags, COPY_VERIFY_LINKED)) {
r = fd_verify_linked(fdf);
if (r < 0)
goto fail;
}
unsigned nocow = FLAGS_SET(copy_flags, COPY_NOCOW_AFTER) ? FS_NOCOW_FL : 0;
if ((chattr_mask | nocow) != 0)
(void) chattr_fd(fdt, chattr_flags | nocow, (chattr_mask & ~CHATTR_EARLY_FL) | nocow, 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(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;
r = prepare_nocow(dir_fdf, from, fdt, &chattr_mask, &chattr_flags);
if (r < 0)
return r;
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);
unsigned nocow = FLAGS_SET(copy_flags, COPY_NOCOW_AFTER) ? FS_NOCOW_FL : 0;
if ((chattr_mask | nocow) != 0)
(void) chattr_fd(fdt, chattr_flags | nocow, (chattr_mask & ~CHATTR_EARLY_FL) | nocow, 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;
RET_GATHER(ret, xsetxattr_full(dt, to, /* at_flags = */ 0, p, value, r, /* xattr_flags = */ 0));
}
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));
}
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