956 lines
36 KiB
C
956 lines
36 KiB
C
/* SPDX-License-Identifier: LGPL-2.1+ */
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/***
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This file is part of systemd.
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Copyright 2010 Lennart Poettering
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systemd is free software; you can redistribute it and/or modify it
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under the terms of the GNU Lesser General Public License as published by
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the Free Software Foundation; either version 2.1 of the License, or
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(at your option) any later version.
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systemd is distributed in the hope that it will be useful, but
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WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public License
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along with systemd; If not, see <http://www.gnu.org/licenses/>.
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***/
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#include <errno.h>
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#include <stdio_ext.h>
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#include <stdlib.h>
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#include <string.h>
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#include <sys/mount.h>
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#include <sys/stat.h>
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#include <sys/statvfs.h>
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#include <unistd.h>
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/* Include later */
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#include <libmount.h>
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#include "alloc-util.h"
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#include "escape.h"
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#include "extract-word.h"
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#include "fd-util.h"
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#include "fileio.h"
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#include "fs-util.h"
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#include "hashmap.h"
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#include "mount-util.h"
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#include "parse-util.h"
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#include "path-util.h"
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#include "set.h"
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#include "stdio-util.h"
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#include "string-util.h"
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#include "strv.h"
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/* This is the original MAX_HANDLE_SZ definition from the kernel, when the API was introduced. We use that in place of
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* any more currently defined value to future-proof things: if the size is increased in the API headers, and our code
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* is recompiled then it would cease working on old kernels, as those refuse any sizes larger than this value with
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* EINVAL right-away. Hence, let's disconnect ourselves from any such API changes, and stick to the original definition
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* from when it was introduced. We use it as a start value only anyway (see below), and hence should be able to deal
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* with large file handles anyway. */
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#define ORIGINAL_MAX_HANDLE_SZ 128
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int name_to_handle_at_loop(
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int fd,
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const char *path,
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struct file_handle **ret_handle,
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int *ret_mnt_id,
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int flags) {
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_cleanup_free_ struct file_handle *h = NULL;
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size_t n = ORIGINAL_MAX_HANDLE_SZ;
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/* We need to invoke name_to_handle_at() in a loop, given that it might return EOVERFLOW when the specified
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* buffer is too small. Note that in contrast to what the docs might suggest, MAX_HANDLE_SZ is only good as a
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* start value, it is not an upper bound on the buffer size required.
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*
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* This improves on raw name_to_handle_at() also in one other regard: ret_handle and ret_mnt_id can be passed
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* as NULL if there's no interest in either. */
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for (;;) {
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int mnt_id = -1;
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h = malloc0(offsetof(struct file_handle, f_handle) + n);
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if (!h)
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return -ENOMEM;
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h->handle_bytes = n;
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if (name_to_handle_at(fd, path, h, &mnt_id, flags) >= 0) {
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if (ret_handle)
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*ret_handle = TAKE_PTR(h);
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if (ret_mnt_id)
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*ret_mnt_id = mnt_id;
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return 0;
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}
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if (errno != EOVERFLOW)
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return -errno;
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if (!ret_handle && ret_mnt_id && mnt_id >= 0) {
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/* As it appears, name_to_handle_at() fills in mnt_id even when it returns EOVERFLOW when the
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* buffer is too small, but that's undocumented. Hence, let's make use of this if it appears to
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* be filled in, and the caller was interested in only the mount ID an nothing else. */
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*ret_mnt_id = mnt_id;
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return 0;
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}
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/* If name_to_handle_at() didn't increase the byte size, then this EOVERFLOW is caused by something
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* else (apparently EOVERFLOW is returned for untriggered nfs4 mounts sometimes), not by the too small
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* buffer. In that case propagate EOVERFLOW */
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if (h->handle_bytes <= n)
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return -EOVERFLOW;
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/* The buffer was too small. Size the new buffer by what name_to_handle_at() returned. */
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n = h->handle_bytes;
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if (offsetof(struct file_handle, f_handle) + n < n) /* check for addition overflow */
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return -EOVERFLOW;
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h = mfree(h);
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}
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}
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static int fd_fdinfo_mnt_id(int fd, const char *filename, int flags, int *mnt_id) {
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char path[STRLEN("/proc/self/fdinfo/") + DECIMAL_STR_MAX(int)];
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_cleanup_free_ char *fdinfo = NULL;
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_cleanup_close_ int subfd = -1;
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char *p;
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int r;
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if ((flags & AT_EMPTY_PATH) && isempty(filename))
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xsprintf(path, "/proc/self/fdinfo/%i", fd);
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else {
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subfd = openat(fd, filename, O_CLOEXEC|O_PATH);
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if (subfd < 0)
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return -errno;
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xsprintf(path, "/proc/self/fdinfo/%i", subfd);
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}
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r = read_full_file(path, &fdinfo, NULL);
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if (r == -ENOENT) /* The fdinfo directory is a relatively new addition */
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return -EOPNOTSUPP;
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if (r < 0)
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return r;
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p = startswith(fdinfo, "mnt_id:");
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if (!p) {
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p = strstr(fdinfo, "\nmnt_id:");
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if (!p) /* The mnt_id field is a relatively new addition */
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return -EOPNOTSUPP;
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p += 8;
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}
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p += strspn(p, WHITESPACE);
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p[strcspn(p, WHITESPACE)] = 0;
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return safe_atoi(p, mnt_id);
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}
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int fd_is_mount_point(int fd, const char *filename, int flags) {
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_cleanup_free_ struct file_handle *h = NULL, *h_parent = NULL;
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int mount_id = -1, mount_id_parent = -1;
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bool nosupp = false, check_st_dev = true;
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struct stat a, b;
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int r;
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assert(fd >= 0);
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assert(filename);
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/* First we will try the name_to_handle_at() syscall, which
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* tells us the mount id and an opaque file "handle". It is
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* not supported everywhere though (kernel compile-time
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* option, not all file systems are hooked up). If it works
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* the mount id is usually good enough to tell us whether
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* something is a mount point.
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*
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* If that didn't work we will try to read the mount id from
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* /proc/self/fdinfo/<fd>. This is almost as good as
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* name_to_handle_at(), however, does not return the
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* opaque file handle. The opaque file handle is pretty useful
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* to detect the root directory, which we should always
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* consider a mount point. Hence we use this only as
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* fallback. Exporting the mnt_id in fdinfo is a pretty recent
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* kernel addition.
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*
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* As last fallback we do traditional fstat() based st_dev
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* comparisons. This is how things were traditionally done,
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* but unionfs breaks this since it exposes file
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* systems with a variety of st_dev reported. Also, btrfs
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* subvolumes have different st_dev, even though they aren't
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* real mounts of their own. */
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r = name_to_handle_at_loop(fd, filename, &h, &mount_id, flags);
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if (IN_SET(r, -ENOSYS, -EACCES, -EPERM, -EOVERFLOW, -EINVAL))
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/* This kernel does not support name_to_handle_at() at all (ENOSYS), or the syscall was blocked
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* (EACCES/EPERM; maybe through seccomp, because we are running inside of a container?), or the mount
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* point is not triggered yet (EOVERFLOW, think nfs4), or some general name_to_handle_at() flakiness
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* (EINVAL): fall back to simpler logic. */
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goto fallback_fdinfo;
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else if (r == -EOPNOTSUPP)
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/* This kernel or file system does not support name_to_handle_at(), hence let's see if the upper fs
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* supports it (in which case it is a mount point), otherwise fallback to the traditional stat()
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* logic */
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nosupp = true;
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else if (r < 0)
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return r;
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r = name_to_handle_at_loop(fd, "", &h_parent, &mount_id_parent, AT_EMPTY_PATH);
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if (r == -EOPNOTSUPP) {
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if (nosupp)
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/* Neither parent nor child do name_to_handle_at()? We have no choice but to fall back. */
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goto fallback_fdinfo;
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else
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/* The parent can't do name_to_handle_at() but the directory we are interested in can? If so,
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* it must be a mount point. */
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return 1;
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} else if (r < 0)
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return r;
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/* The parent can do name_to_handle_at() but the
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* directory we are interested in can't? If so, it
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* must be a mount point. */
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if (nosupp)
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return 1;
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/* If the file handle for the directory we are
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* interested in and its parent are identical, we
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* assume this is the root directory, which is a mount
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* point. */
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if (h->handle_bytes == h_parent->handle_bytes &&
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h->handle_type == h_parent->handle_type &&
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memcmp(h->f_handle, h_parent->f_handle, h->handle_bytes) == 0)
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return 1;
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return mount_id != mount_id_parent;
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fallback_fdinfo:
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r = fd_fdinfo_mnt_id(fd, filename, flags, &mount_id);
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if (IN_SET(r, -EOPNOTSUPP, -EACCES, -EPERM))
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goto fallback_fstat;
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if (r < 0)
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return r;
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r = fd_fdinfo_mnt_id(fd, "", AT_EMPTY_PATH, &mount_id_parent);
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if (r < 0)
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return r;
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if (mount_id != mount_id_parent)
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return 1;
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/* Hmm, so, the mount ids are the same. This leaves one
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* special case though for the root file system. For that,
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* let's see if the parent directory has the same inode as we
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* are interested in. Hence, let's also do fstat() checks now,
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* too, but avoid the st_dev comparisons, since they aren't
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* that useful on unionfs mounts. */
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check_st_dev = false;
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fallback_fstat:
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/* yay for fstatat() taking a different set of flags than the other
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* _at() above */
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if (flags & AT_SYMLINK_FOLLOW)
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flags &= ~AT_SYMLINK_FOLLOW;
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else
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flags |= AT_SYMLINK_NOFOLLOW;
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if (fstatat(fd, filename, &a, flags) < 0)
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return -errno;
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if (fstatat(fd, "", &b, AT_EMPTY_PATH) < 0)
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return -errno;
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/* A directory with same device and inode as its parent? Must
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* be the root directory */
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if (a.st_dev == b.st_dev &&
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a.st_ino == b.st_ino)
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return 1;
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return check_st_dev && (a.st_dev != b.st_dev);
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}
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/* flags can be AT_SYMLINK_FOLLOW or 0 */
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int path_is_mount_point(const char *t, const char *root, int flags) {
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_cleanup_free_ char *canonical = NULL, *parent = NULL;
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_cleanup_close_ int fd = -1;
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int r;
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assert(t);
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assert((flags & ~AT_SYMLINK_FOLLOW) == 0);
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if (path_equal(t, "/"))
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return 1;
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/* we need to resolve symlinks manually, we can't just rely on
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* fd_is_mount_point() to do that for us; if we have a structure like
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* /bin -> /usr/bin/ and /usr is a mount point, then the parent that we
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* look at needs to be /usr, not /. */
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if (flags & AT_SYMLINK_FOLLOW) {
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r = chase_symlinks(t, root, 0, &canonical);
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if (r < 0)
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return r;
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t = canonical;
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}
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parent = dirname_malloc(t);
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if (!parent)
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return -ENOMEM;
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fd = openat(AT_FDCWD, parent, O_DIRECTORY|O_CLOEXEC|O_PATH);
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if (fd < 0)
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return -errno;
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return fd_is_mount_point(fd, last_path_component(t), flags);
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}
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int path_get_mnt_id(const char *path, int *ret) {
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int r;
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r = name_to_handle_at_loop(AT_FDCWD, path, NULL, ret, 0);
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if (IN_SET(r, -EOPNOTSUPP, -ENOSYS, -EACCES, -EPERM, -EOVERFLOW, -EINVAL)) /* kernel/fs don't support this, or seccomp blocks access, or untriggered mount, or name_to_handle_at() is flaky */
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return fd_fdinfo_mnt_id(AT_FDCWD, path, 0, ret);
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return r;
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}
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int umount_recursive(const char *prefix, int flags) {
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bool again;
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int n = 0, r;
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/* Try to umount everything recursively below a
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* directory. Also, take care of stacked mounts, and keep
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* unmounting them until they are gone. */
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do {
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_cleanup_fclose_ FILE *proc_self_mountinfo = NULL;
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again = false;
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r = 0;
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proc_self_mountinfo = fopen("/proc/self/mountinfo", "re");
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if (!proc_self_mountinfo)
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return -errno;
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(void) __fsetlocking(proc_self_mountinfo, FSETLOCKING_BYCALLER);
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for (;;) {
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_cleanup_free_ char *path = NULL, *p = NULL;
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int k;
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k = fscanf(proc_self_mountinfo,
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"%*s " /* (1) mount id */
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"%*s " /* (2) parent id */
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"%*s " /* (3) major:minor */
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"%*s " /* (4) root */
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"%ms " /* (5) mount point */
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"%*s" /* (6) mount options */
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"%*[^-]" /* (7) optional fields */
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"- " /* (8) separator */
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"%*s " /* (9) file system type */
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"%*s" /* (10) mount source */
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"%*s" /* (11) mount options 2 */
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"%*[^\n]", /* some rubbish at the end */
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&path);
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if (k != 1) {
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if (k == EOF)
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break;
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continue;
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}
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r = cunescape(path, UNESCAPE_RELAX, &p);
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if (r < 0)
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return r;
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if (!path_startswith(p, prefix))
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continue;
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if (umount2(p, flags) < 0) {
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r = log_debug_errno(errno, "Failed to umount %s: %m", p);
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continue;
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}
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log_debug("Successfully unmounted %s", p);
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again = true;
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n++;
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break;
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}
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} while (again);
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return r ? r : n;
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}
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static int get_mount_flags(const char *path, unsigned long *flags) {
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struct statvfs buf;
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if (statvfs(path, &buf) < 0)
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return -errno;
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*flags = buf.f_flag;
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return 0;
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}
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/* Use this function only if do you have direct access to /proc/self/mountinfo
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* and need the caller to open it for you. This is the case when /proc is
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* masked or not mounted. Otherwise, use bind_remount_recursive. */
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int bind_remount_recursive_with_mountinfo(const char *prefix, bool ro, char **blacklist, FILE *proc_self_mountinfo) {
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_cleanup_set_free_free_ Set *done = NULL;
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_cleanup_free_ char *cleaned = NULL;
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int r;
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assert(proc_self_mountinfo);
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/* Recursively remount a directory (and all its submounts) read-only or read-write. If the directory is already
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* mounted, we reuse the mount and simply mark it MS_BIND|MS_RDONLY (or remove the MS_RDONLY for read-write
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* operation). If it isn't we first make it one. Afterwards we apply MS_BIND|MS_RDONLY (or remove MS_RDONLY) to
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* all submounts we can access, too. When mounts are stacked on the same mount point we only care for each
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* individual "top-level" mount on each point, as we cannot influence/access the underlying mounts anyway. We
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* do not have any effect on future submounts that might get propagated, they migt be writable. This includes
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* future submounts that have been triggered via autofs.
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*
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* If the "blacklist" parameter is specified it may contain a list of subtrees to exclude from the
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* remount operation. Note that we'll ignore the blacklist for the top-level path. */
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cleaned = strdup(prefix);
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if (!cleaned)
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return -ENOMEM;
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path_kill_slashes(cleaned);
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done = set_new(&path_hash_ops);
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if (!done)
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return -ENOMEM;
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for (;;) {
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_cleanup_set_free_free_ Set *todo = NULL;
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bool top_autofs = false;
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char *x;
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unsigned long orig_flags;
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todo = set_new(&path_hash_ops);
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if (!todo)
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return -ENOMEM;
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rewind(proc_self_mountinfo);
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for (;;) {
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_cleanup_free_ char *path = NULL, *p = NULL, *type = NULL;
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int k;
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k = fscanf(proc_self_mountinfo,
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"%*s " /* (1) mount id */
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"%*s " /* (2) parent id */
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"%*s " /* (3) major:minor */
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"%*s " /* (4) root */
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"%ms " /* (5) mount point */
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"%*s" /* (6) mount options (superblock) */
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"%*[^-]" /* (7) optional fields */
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"- " /* (8) separator */
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"%ms " /* (9) file system type */
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"%*s" /* (10) mount source */
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"%*s" /* (11) mount options (bind mount) */
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"%*[^\n]", /* some rubbish at the end */
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&path,
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&type);
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if (k != 2) {
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if (k == EOF)
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break;
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continue;
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}
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r = cunescape(path, UNESCAPE_RELAX, &p);
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if (r < 0)
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return r;
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if (!path_startswith(p, cleaned))
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continue;
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/* Ignore this mount if it is blacklisted, but only if it isn't the top-level mount we shall
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* operate on. */
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if (!path_equal(cleaned, p)) {
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bool blacklisted = false;
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char **i;
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|
|
STRV_FOREACH(i, blacklist) {
|
|
|
|
if (path_equal(*i, cleaned))
|
|
continue;
|
|
|
|
if (!path_startswith(*i, cleaned))
|
|
continue;
|
|
|
|
if (path_startswith(p, *i)) {
|
|
blacklisted = true;
|
|
log_debug("Not remounting %s, because blacklisted by %s, called for %s", p, *i, cleaned);
|
|
break;
|
|
}
|
|
}
|
|
if (blacklisted)
|
|
continue;
|
|
}
|
|
|
|
/* Let's ignore autofs mounts. If they aren't
|
|
* triggered yet, we want to avoid triggering
|
|
* them, as we don't make any guarantees for
|
|
* future submounts anyway. If they are
|
|
* already triggered, then we will find
|
|
* another entry for this. */
|
|
if (streq(type, "autofs")) {
|
|
top_autofs = top_autofs || path_equal(cleaned, p);
|
|
continue;
|
|
}
|
|
|
|
if (!set_contains(done, p)) {
|
|
r = set_consume(todo, p);
|
|
p = NULL;
|
|
if (r == -EEXIST)
|
|
continue;
|
|
if (r < 0)
|
|
return r;
|
|
}
|
|
}
|
|
|
|
/* If we have no submounts to process anymore and if
|
|
* the root is either already done, or an autofs, we
|
|
* are done */
|
|
if (set_isempty(todo) &&
|
|
(top_autofs || set_contains(done, cleaned)))
|
|
return 0;
|
|
|
|
if (!set_contains(done, cleaned) &&
|
|
!set_contains(todo, cleaned)) {
|
|
/* The prefix directory itself is not yet a mount, make it one. */
|
|
if (mount(cleaned, cleaned, NULL, MS_BIND|MS_REC, NULL) < 0)
|
|
return -errno;
|
|
|
|
orig_flags = 0;
|
|
(void) get_mount_flags(cleaned, &orig_flags);
|
|
orig_flags &= ~MS_RDONLY;
|
|
|
|
if (mount(NULL, prefix, NULL, orig_flags|MS_BIND|MS_REMOUNT|(ro ? MS_RDONLY : 0), NULL) < 0)
|
|
return -errno;
|
|
|
|
log_debug("Made top-level directory %s a mount point.", prefix);
|
|
|
|
x = strdup(cleaned);
|
|
if (!x)
|
|
return -ENOMEM;
|
|
|
|
r = set_consume(done, x);
|
|
if (r < 0)
|
|
return r;
|
|
}
|
|
|
|
while ((x = set_steal_first(todo))) {
|
|
|
|
r = set_consume(done, x);
|
|
if (IN_SET(r, 0, -EEXIST))
|
|
continue;
|
|
if (r < 0)
|
|
return r;
|
|
|
|
/* Deal with mount points that are obstructed by a later mount */
|
|
r = path_is_mount_point(x, NULL, 0);
|
|
if (IN_SET(r, 0, -ENOENT))
|
|
continue;
|
|
if (r < 0)
|
|
return r;
|
|
|
|
/* Try to reuse the original flag set */
|
|
orig_flags = 0;
|
|
(void) get_mount_flags(x, &orig_flags);
|
|
orig_flags &= ~MS_RDONLY;
|
|
|
|
if (mount(NULL, x, NULL, orig_flags|MS_BIND|MS_REMOUNT|(ro ? MS_RDONLY : 0), NULL) < 0)
|
|
return -errno;
|
|
|
|
log_debug("Remounted %s read-only.", x);
|
|
}
|
|
}
|
|
}
|
|
|
|
int bind_remount_recursive(const char *prefix, bool ro, char **blacklist) {
|
|
_cleanup_fclose_ FILE *proc_self_mountinfo = NULL;
|
|
|
|
proc_self_mountinfo = fopen("/proc/self/mountinfo", "re");
|
|
if (!proc_self_mountinfo)
|
|
return -errno;
|
|
|
|
(void) __fsetlocking(proc_self_mountinfo, FSETLOCKING_BYCALLER);
|
|
|
|
return bind_remount_recursive_with_mountinfo(prefix, ro, blacklist, proc_self_mountinfo);
|
|
}
|
|
|
|
int mount_move_root(const char *path) {
|
|
assert(path);
|
|
|
|
if (chdir(path) < 0)
|
|
return -errno;
|
|
|
|
if (mount(path, "/", NULL, MS_MOVE, NULL) < 0)
|
|
return -errno;
|
|
|
|
if (chroot(".") < 0)
|
|
return -errno;
|
|
|
|
if (chdir("/") < 0)
|
|
return -errno;
|
|
|
|
return 0;
|
|
}
|
|
|
|
bool fstype_is_network(const char *fstype) {
|
|
const char *x;
|
|
|
|
x = startswith(fstype, "fuse.");
|
|
if (x)
|
|
fstype = x;
|
|
|
|
return STR_IN_SET(fstype,
|
|
"afs",
|
|
"cifs",
|
|
"smbfs",
|
|
"sshfs",
|
|
"ncpfs",
|
|
"ncp",
|
|
"nfs",
|
|
"nfs4",
|
|
"gfs",
|
|
"gfs2",
|
|
"glusterfs",
|
|
"pvfs2", /* OrangeFS */
|
|
"ocfs2",
|
|
"lustre");
|
|
}
|
|
|
|
bool fstype_is_api_vfs(const char *fstype) {
|
|
return STR_IN_SET(fstype,
|
|
"autofs",
|
|
"bpf",
|
|
"cgroup",
|
|
"cgroup2",
|
|
"configfs",
|
|
"cpuset",
|
|
"debugfs",
|
|
"devpts",
|
|
"devtmpfs",
|
|
"efivarfs",
|
|
"fusectl",
|
|
"hugetlbfs",
|
|
"mqueue",
|
|
"proc",
|
|
"pstore",
|
|
"ramfs",
|
|
"securityfs",
|
|
"sysfs",
|
|
"tmpfs",
|
|
"tracefs");
|
|
}
|
|
|
|
bool fstype_is_ro(const char *fstype) {
|
|
/* All Linux file systems that are necessarily read-only */
|
|
return STR_IN_SET(fstype,
|
|
"DM_verity_hash",
|
|
"iso9660",
|
|
"squashfs");
|
|
}
|
|
|
|
bool fstype_can_discard(const char *fstype) {
|
|
return STR_IN_SET(fstype,
|
|
"btrfs",
|
|
"ext4",
|
|
"vfat",
|
|
"xfs");
|
|
}
|
|
|
|
bool fstype_can_uid_gid(const char *fstype) {
|
|
|
|
/* All file systems that have a uid=/gid= mount option that fixates the owners of all files and directories,
|
|
* current and future. */
|
|
|
|
return STR_IN_SET(fstype,
|
|
"adfs",
|
|
"fat",
|
|
"hfs",
|
|
"hpfs",
|
|
"iso9660",
|
|
"msdos",
|
|
"ntfs",
|
|
"vfat");
|
|
}
|
|
|
|
int repeat_unmount(const char *path, int flags) {
|
|
bool done = false;
|
|
|
|
assert(path);
|
|
|
|
/* If there are multiple mounts on a mount point, this
|
|
* removes them all */
|
|
|
|
for (;;) {
|
|
if (umount2(path, flags) < 0) {
|
|
|
|
if (errno == EINVAL)
|
|
return done;
|
|
|
|
return -errno;
|
|
}
|
|
|
|
done = true;
|
|
}
|
|
}
|
|
|
|
const char* mode_to_inaccessible_node(mode_t mode) {
|
|
/* This function maps a node type to the correspondent inaccessible node type.
|
|
* Character and block inaccessible devices may not be created (because major=0 and minor=0),
|
|
* in such case we map character and block devices to the inaccessible node type socket. */
|
|
switch(mode & S_IFMT) {
|
|
case S_IFREG:
|
|
return "/run/systemd/inaccessible/reg";
|
|
case S_IFDIR:
|
|
return "/run/systemd/inaccessible/dir";
|
|
case S_IFCHR:
|
|
if (access("/run/systemd/inaccessible/chr", F_OK) == 0)
|
|
return "/run/systemd/inaccessible/chr";
|
|
return "/run/systemd/inaccessible/sock";
|
|
case S_IFBLK:
|
|
if (access("/run/systemd/inaccessible/blk", F_OK) == 0)
|
|
return "/run/systemd/inaccessible/blk";
|
|
return "/run/systemd/inaccessible/sock";
|
|
case S_IFIFO:
|
|
return "/run/systemd/inaccessible/fifo";
|
|
case S_IFSOCK:
|
|
return "/run/systemd/inaccessible/sock";
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
#define FLAG(name) (flags & name ? STRINGIFY(name) "|" : "")
|
|
static char* mount_flags_to_string(long unsigned flags) {
|
|
char *x;
|
|
_cleanup_free_ char *y = NULL;
|
|
long unsigned overflow;
|
|
|
|
overflow = flags & ~(MS_RDONLY |
|
|
MS_NOSUID |
|
|
MS_NODEV |
|
|
MS_NOEXEC |
|
|
MS_SYNCHRONOUS |
|
|
MS_REMOUNT |
|
|
MS_MANDLOCK |
|
|
MS_DIRSYNC |
|
|
MS_NOATIME |
|
|
MS_NODIRATIME |
|
|
MS_BIND |
|
|
MS_MOVE |
|
|
MS_REC |
|
|
MS_SILENT |
|
|
MS_POSIXACL |
|
|
MS_UNBINDABLE |
|
|
MS_PRIVATE |
|
|
MS_SLAVE |
|
|
MS_SHARED |
|
|
MS_RELATIME |
|
|
MS_KERNMOUNT |
|
|
MS_I_VERSION |
|
|
MS_STRICTATIME |
|
|
MS_LAZYTIME);
|
|
|
|
if (flags == 0 || overflow != 0)
|
|
if (asprintf(&y, "%lx", overflow) < 0)
|
|
return NULL;
|
|
|
|
x = strjoin(FLAG(MS_RDONLY),
|
|
FLAG(MS_NOSUID),
|
|
FLAG(MS_NODEV),
|
|
FLAG(MS_NOEXEC),
|
|
FLAG(MS_SYNCHRONOUS),
|
|
FLAG(MS_REMOUNT),
|
|
FLAG(MS_MANDLOCK),
|
|
FLAG(MS_DIRSYNC),
|
|
FLAG(MS_NOATIME),
|
|
FLAG(MS_NODIRATIME),
|
|
FLAG(MS_BIND),
|
|
FLAG(MS_MOVE),
|
|
FLAG(MS_REC),
|
|
FLAG(MS_SILENT),
|
|
FLAG(MS_POSIXACL),
|
|
FLAG(MS_UNBINDABLE),
|
|
FLAG(MS_PRIVATE),
|
|
FLAG(MS_SLAVE),
|
|
FLAG(MS_SHARED),
|
|
FLAG(MS_RELATIME),
|
|
FLAG(MS_KERNMOUNT),
|
|
FLAG(MS_I_VERSION),
|
|
FLAG(MS_STRICTATIME),
|
|
FLAG(MS_LAZYTIME),
|
|
y);
|
|
if (!x)
|
|
return NULL;
|
|
if (!y)
|
|
x[strlen(x) - 1] = '\0'; /* truncate the last | */
|
|
return x;
|
|
}
|
|
|
|
int mount_verbose(
|
|
int error_log_level,
|
|
const char *what,
|
|
const char *where,
|
|
const char *type,
|
|
unsigned long flags,
|
|
const char *options) {
|
|
|
|
_cleanup_free_ char *fl = NULL, *o = NULL;
|
|
unsigned long f;
|
|
int r;
|
|
|
|
r = mount_option_mangle(options, flags, &f, &o);
|
|
if (r < 0)
|
|
return log_full_errno(error_log_level, r,
|
|
"Failed to mangle mount options %s: %m",
|
|
strempty(options));
|
|
|
|
fl = mount_flags_to_string(f);
|
|
|
|
if ((f & MS_REMOUNT) && !what && !type)
|
|
log_debug("Remounting %s (%s \"%s\")...",
|
|
where, strnull(fl), strempty(o));
|
|
else if (!what && !type)
|
|
log_debug("Mounting %s (%s \"%s\")...",
|
|
where, strnull(fl), strempty(o));
|
|
else if ((f & MS_BIND) && !type)
|
|
log_debug("Bind-mounting %s on %s (%s \"%s\")...",
|
|
what, where, strnull(fl), strempty(o));
|
|
else if (f & MS_MOVE)
|
|
log_debug("Moving mount %s → %s (%s \"%s\")...",
|
|
what, where, strnull(fl), strempty(o));
|
|
else
|
|
log_debug("Mounting %s on %s (%s \"%s\")...",
|
|
strna(type), where, strnull(fl), strempty(o));
|
|
if (mount(what, where, type, f, o) < 0)
|
|
return log_full_errno(error_log_level, errno,
|
|
"Failed to mount %s on %s (%s \"%s\"): %m",
|
|
strna(type), where, strnull(fl), strempty(o));
|
|
return 0;
|
|
}
|
|
|
|
int umount_verbose(const char *what) {
|
|
log_debug("Umounting %s...", what);
|
|
if (umount(what) < 0)
|
|
return log_error_errno(errno, "Failed to unmount %s: %m", what);
|
|
return 0;
|
|
}
|
|
|
|
const char *mount_propagation_flags_to_string(unsigned long flags) {
|
|
|
|
switch (flags & (MS_SHARED|MS_SLAVE|MS_PRIVATE)) {
|
|
case 0:
|
|
return "";
|
|
case MS_SHARED:
|
|
return "shared";
|
|
case MS_SLAVE:
|
|
return "slave";
|
|
case MS_PRIVATE:
|
|
return "private";
|
|
}
|
|
|
|
return NULL;
|
|
}
|
|
|
|
|
|
int mount_propagation_flags_from_string(const char *name, unsigned long *ret) {
|
|
|
|
if (isempty(name))
|
|
*ret = 0;
|
|
else if (streq(name, "shared"))
|
|
*ret = MS_SHARED;
|
|
else if (streq(name, "slave"))
|
|
*ret = MS_SLAVE;
|
|
else if (streq(name, "private"))
|
|
*ret = MS_PRIVATE;
|
|
else
|
|
return -EINVAL;
|
|
return 0;
|
|
}
|
|
|
|
int mount_option_mangle(
|
|
const char *options,
|
|
unsigned long mount_flags,
|
|
unsigned long *ret_mount_flags,
|
|
char **ret_remaining_options) {
|
|
|
|
const struct libmnt_optmap *map;
|
|
_cleanup_free_ char *ret = NULL;
|
|
const char *p;
|
|
int r;
|
|
|
|
/* This extracts mount flags from the mount options, and store
|
|
* non-mount-flag options to '*ret_remaining_options'.
|
|
* E.g.,
|
|
* "rw,nosuid,nodev,relatime,size=1630748k,mode=700,uid=1000,gid=1000"
|
|
* is split to MS_NOSUID|MS_NODEV|MS_RELATIME and
|
|
* "size=1630748k,mode=700,uid=1000,gid=1000".
|
|
* See more examples in test-mount-utils.c.
|
|
*
|
|
* Note that if 'options' does not contain any non-mount-flag options,
|
|
* then '*ret_remaining_options' is set to NULL instread of empty string.
|
|
* Note that this does not check validity of options stored in
|
|
* '*ret_remaining_options'.
|
|
* Note that if 'options' is NULL, then this just copies 'mount_flags'
|
|
* to '*ret_mount_flags'. */
|
|
|
|
assert(ret_mount_flags);
|
|
assert(ret_remaining_options);
|
|
|
|
map = mnt_get_builtin_optmap(MNT_LINUX_MAP);
|
|
if (!map)
|
|
return -EINVAL;
|
|
|
|
p = options;
|
|
for (;;) {
|
|
_cleanup_free_ char *word = NULL;
|
|
const struct libmnt_optmap *ent;
|
|
|
|
r = extract_first_word(&p, &word, ",", EXTRACT_QUOTES);
|
|
if (r < 0)
|
|
return r;
|
|
if (r == 0)
|
|
break;
|
|
|
|
for (ent = map; ent->name; ent++) {
|
|
/* All entries in MNT_LINUX_MAP do not take any argument.
|
|
* Thus, ent->name does not contain "=" or "[=]". */
|
|
if (!streq(word, ent->name))
|
|
continue;
|
|
|
|
if (!(ent->mask & MNT_INVERT))
|
|
mount_flags |= ent->id;
|
|
else if (mount_flags & ent->id)
|
|
mount_flags ^= ent->id;
|
|
|
|
break;
|
|
}
|
|
|
|
/* If 'word' is not a mount flag, then store it in '*ret_remaining_options'. */
|
|
if (!ent->name && !strextend_with_separator(&ret, ",", word, NULL))
|
|
return -ENOMEM;
|
|
}
|
|
|
|
*ret_mount_flags = mount_flags;
|
|
*ret_remaining_options = TAKE_PTR(ret);
|
|
|
|
return 0;
|
|
}
|