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| /* SPDX-License-Identifier: LGPL-2.1+ */ | |
| /*** | |
| This file is part of systemd. | |
| Copyright 2010 Lennart Poettering | |
| systemd is free software; you can redistribute it and/or modify it | |
| under the terms of the GNU Lesser General Public License as published by | |
| the Free Software Foundation; either version 2.1 of the License, or | |
| (at your option) any later version. | |
| systemd is distributed in the hope that it will be useful, but | |
| WITHOUT ANY WARRANTY; without even the implied warranty of | |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
| Lesser General Public License for more details. | |
| You should have received a copy of the GNU Lesser General Public License | |
| along with systemd; If not, see <http://www.gnu.org/licenses/>. | |
| ***/ | |
| #include <errno.h> | |
| #include <stdio_ext.h> | |
| #include <stdlib.h> | |
| #include <string.h> | |
| #include <sys/mount.h> | |
| #include <sys/stat.h> | |
| #include <sys/statvfs.h> | |
| #include <unistd.h> | |
| #include "alloc-util.h" | |
| #include "escape.h" | |
| #include "fd-util.h" | |
| #include "fileio.h" | |
| #include "fs-util.h" | |
| #include "hashmap.h" | |
| #include "mount-util.h" | |
| #include "parse-util.h" | |
| #include "path-util.h" | |
| #include "set.h" | |
| #include "stdio-util.h" | |
| #include "string-util.h" | |
| #include "strv.h" | |
| /* This is the original MAX_HANDLE_SZ definition from the kernel, when the API was introduced. We use that in place of | |
| * any more currently defined value to future-proof things: if the size is increased in the API headers, and our code | |
| * is recompiled then it would cease working on old kernels, as those refuse any sizes larger than this value with | |
| * EINVAL right-away. Hence, let's disconnect ourselves from any such API changes, and stick to the original definition | |
| * from when it was introduced. We use it as a start value only anyway (see below), and hence should be able to deal | |
| * with large file handles anyway. */ | |
| #define ORIGINAL_MAX_HANDLE_SZ 128 | |
| int name_to_handle_at_loop( | |
| int fd, | |
| const char *path, | |
| struct file_handle **ret_handle, | |
| int *ret_mnt_id, | |
| int flags) { | |
| _cleanup_free_ struct file_handle *h = NULL; | |
| size_t n = ORIGINAL_MAX_HANDLE_SZ; | |
| /* We need to invoke name_to_handle_at() in a loop, given that it might return EOVERFLOW when the specified | |
| * buffer is too small. Note that in contrast to what the docs might suggest, MAX_HANDLE_SZ is only good as a | |
| * start value, it is not an upper bound on the buffer size required. | |
| * | |
| * This improves on raw name_to_handle_at() also in one other regard: ret_handle and ret_mnt_id can be passed | |
| * as NULL if there's no interest in either. */ | |
| for (;;) { | |
| int mnt_id = -1; | |
| h = malloc0(offsetof(struct file_handle, f_handle) + n); | |
| if (!h) | |
| return -ENOMEM; | |
| h->handle_bytes = n; | |
| if (name_to_handle_at(fd, path, h, &mnt_id, flags) >= 0) { | |
| if (ret_handle) { | |
| *ret_handle = h; | |
| h = NULL; | |
| } | |
| if (ret_mnt_id) | |
| *ret_mnt_id = mnt_id; | |
| return 0; | |
| } | |
| if (errno != EOVERFLOW) | |
| return -errno; | |
| if (!ret_handle && ret_mnt_id && mnt_id >= 0) { | |
| /* As it appears, name_to_handle_at() fills in mnt_id even when it returns EOVERFLOW when the | |
| * buffer is too small, but that's undocumented. Hence, let's make use of this if it appears to | |
| * be filled in, and the caller was interested in only the mount ID an nothing else. */ | |
| *ret_mnt_id = mnt_id; | |
| return 0; | |
| } | |
| /* If name_to_handle_at() didn't increase the byte size, then this EOVERFLOW is caused by something | |
| * else (apparently EOVERFLOW is returned for untriggered nfs4 mounts sometimes), not by the too small | |
| * buffer. In that case propagate EOVERFLOW */ | |
| if (h->handle_bytes <= n) | |
| return -EOVERFLOW; | |
| /* The buffer was too small. Size the new buffer by what name_to_handle_at() returned. */ | |
| n = h->handle_bytes; | |
| if (offsetof(struct file_handle, f_handle) + n < n) /* check for addition overflow */ | |
| return -EOVERFLOW; | |
| h = mfree(h); | |
| } | |
| } | |
| static int fd_fdinfo_mnt_id(int fd, const char *filename, int flags, int *mnt_id) { | |
| char path[STRLEN("/proc/self/fdinfo/") + DECIMAL_STR_MAX(int)]; | |
| _cleanup_free_ char *fdinfo = NULL; | |
| _cleanup_close_ int subfd = -1; | |
| char *p; | |
| int r; | |
| if ((flags & AT_EMPTY_PATH) && isempty(filename)) | |
| xsprintf(path, "/proc/self/fdinfo/%i", fd); | |
| else { | |
| subfd = openat(fd, filename, O_CLOEXEC|O_PATH); | |
| if (subfd < 0) | |
| return -errno; | |
| xsprintf(path, "/proc/self/fdinfo/%i", subfd); | |
| } | |
| r = read_full_file(path, &fdinfo, NULL); | |
| if (r == -ENOENT) /* The fdinfo directory is a relatively new addition */ | |
| return -EOPNOTSUPP; | |
| if (r < 0) | |
| return r; | |
| p = startswith(fdinfo, "mnt_id:"); | |
| if (!p) { | |
| p = strstr(fdinfo, "\nmnt_id:"); | |
| if (!p) /* The mnt_id field is a relatively new addition */ | |
| return -EOPNOTSUPP; | |
| p += 8; | |
| } | |
| p += strspn(p, WHITESPACE); | |
| p[strcspn(p, WHITESPACE)] = 0; | |
| return safe_atoi(p, mnt_id); | |
| } | |
| int fd_is_mount_point(int fd, const char *filename, int flags) { | |
| _cleanup_free_ struct file_handle *h = NULL, *h_parent = NULL; | |
| int mount_id = -1, mount_id_parent = -1; | |
| bool nosupp = false, check_st_dev = true; | |
| struct stat a, b; | |
| int r; | |
| assert(fd >= 0); | |
| assert(filename); | |
| /* First we will try the name_to_handle_at() syscall, which | |
| * tells us the mount id and an opaque file "handle". It is | |
| * not supported everywhere though (kernel compile-time | |
| * option, not all file systems are hooked up). If it works | |
| * the mount id is usually good enough to tell us whether | |
| * something is a mount point. | |
| * | |
| * If that didn't work we will try to read the mount id from | |
| * /proc/self/fdinfo/<fd>. This is almost as good as | |
| * name_to_handle_at(), however, does not return the | |
| * opaque file handle. The opaque file handle is pretty useful | |
| * to detect the root directory, which we should always | |
| * consider a mount point. Hence we use this only as | |
| * fallback. Exporting the mnt_id in fdinfo is a pretty recent | |
| * kernel addition. | |
| * | |
| * As last fallback we do traditional fstat() based st_dev | |
| * comparisons. This is how things were traditionally done, | |
| * but unionfs breaks this since it exposes file | |
| * systems with a variety of st_dev reported. Also, btrfs | |
| * subvolumes have different st_dev, even though they aren't | |
| * real mounts of their own. */ | |
| r = name_to_handle_at_loop(fd, filename, &h, &mount_id, flags); | |
| if (IN_SET(r, -ENOSYS, -EACCES, -EPERM, -EOVERFLOW, -EINVAL)) | |
| /* This kernel does not support name_to_handle_at() at all (ENOSYS), or the syscall was blocked | |
| * (EACCES/EPERM; maybe through seccomp, because we are running inside of a container?), or the mount | |
| * point is not triggered yet (EOVERFLOW, think nfs4), or some general name_to_handle_at() flakiness | |
| * (EINVAL): fall back to simpler logic. */ | |
| goto fallback_fdinfo; | |
| else if (r == -EOPNOTSUPP) | |
| /* This kernel or file system does not support name_to_handle_at(), hence let's see if the upper fs | |
| * supports it (in which case it is a mount point), otherwise fallback to the traditional stat() | |
| * logic */ | |
| nosupp = true; | |
| else if (r < 0) | |
| return r; | |
| r = name_to_handle_at_loop(fd, "", &h_parent, &mount_id_parent, AT_EMPTY_PATH); | |
| if (r == -EOPNOTSUPP) { | |
| if (nosupp) | |
| /* Neither parent nor child do name_to_handle_at()? We have no choice but to fall back. */ | |
| goto fallback_fdinfo; | |
| else | |
| /* The parent can't do name_to_handle_at() but the directory we are interested in can? If so, | |
| * it must be a mount point. */ | |
| return 1; | |
| } else if (r < 0) | |
| return r; | |
| /* The parent can do name_to_handle_at() but the | |
| * directory we are interested in can't? If so, it | |
| * must be a mount point. */ | |
| if (nosupp) | |
| return 1; | |
| /* If the file handle for the directory we are | |
| * interested in and its parent are identical, we | |
| * assume this is the root directory, which is a mount | |
| * point. */ | |
| if (h->handle_bytes == h_parent->handle_bytes && | |
| h->handle_type == h_parent->handle_type && | |
| memcmp(h->f_handle, h_parent->f_handle, h->handle_bytes) == 0) | |
| return 1; | |
| return mount_id != mount_id_parent; | |
| fallback_fdinfo: | |
| r = fd_fdinfo_mnt_id(fd, filename, flags, &mount_id); | |
| if (IN_SET(r, -EOPNOTSUPP, -EACCES, -EPERM)) | |
| goto fallback_fstat; | |
| if (r < 0) | |
| return r; | |
| r = fd_fdinfo_mnt_id(fd, "", AT_EMPTY_PATH, &mount_id_parent); | |
| if (r < 0) | |
| return r; | |
| if (mount_id != mount_id_parent) | |
| return 1; | |
| /* Hmm, so, the mount ids are the same. This leaves one | |
| * special case though for the root file system. For that, | |
| * let's see if the parent directory has the same inode as we | |
| * are interested in. Hence, let's also do fstat() checks now, | |
| * too, but avoid the st_dev comparisons, since they aren't | |
| * that useful on unionfs mounts. */ | |
| check_st_dev = false; | |
| fallback_fstat: | |
| /* yay for fstatat() taking a different set of flags than the other | |
| * _at() above */ | |
| if (flags & AT_SYMLINK_FOLLOW) | |
| flags &= ~AT_SYMLINK_FOLLOW; | |
| else | |
| flags |= AT_SYMLINK_NOFOLLOW; | |
| if (fstatat(fd, filename, &a, flags) < 0) | |
| return -errno; | |
| if (fstatat(fd, "", &b, AT_EMPTY_PATH) < 0) | |
| return -errno; | |
| /* A directory with same device and inode as its parent? Must | |
| * be the root directory */ | |
| if (a.st_dev == b.st_dev && | |
| a.st_ino == b.st_ino) | |
| return 1; | |
| return check_st_dev && (a.st_dev != b.st_dev); | |
| } | |
| /* flags can be AT_SYMLINK_FOLLOW or 0 */ | |
| int path_is_mount_point(const char *t, const char *root, int flags) { | |
| _cleanup_free_ char *canonical = NULL, *parent = NULL; | |
| _cleanup_close_ int fd = -1; | |
| int r; | |
| assert(t); | |
| assert((flags & ~AT_SYMLINK_FOLLOW) == 0); | |
| if (path_equal(t, "/")) | |
| return 1; | |
| /* we need to resolve symlinks manually, we can't just rely on | |
| * fd_is_mount_point() to do that for us; if we have a structure like | |
| * /bin -> /usr/bin/ and /usr is a mount point, then the parent that we | |
| * look at needs to be /usr, not /. */ | |
| if (flags & AT_SYMLINK_FOLLOW) { | |
| r = chase_symlinks(t, root, 0, &canonical); | |
| if (r < 0) | |
| return r; | |
| t = canonical; | |
| } | |
| parent = dirname_malloc(t); | |
| if (!parent) | |
| return -ENOMEM; | |
| fd = openat(AT_FDCWD, parent, O_DIRECTORY|O_CLOEXEC|O_PATH); | |
| if (fd < 0) | |
| return -errno; | |
| return fd_is_mount_point(fd, last_path_component(t), flags); | |
| } | |
| int path_get_mnt_id(const char *path, int *ret) { | |
| int r; | |
| r = name_to_handle_at_loop(AT_FDCWD, path, NULL, ret, 0); | |
| 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 */ | |
| return fd_fdinfo_mnt_id(AT_FDCWD, path, 0, ret); | |
| return r; | |
| } | |
| int umount_recursive(const char *prefix, int flags) { | |
| bool again; | |
| int n = 0, r; | |
| /* Try to umount everything recursively below a | |
| * directory. Also, take care of stacked mounts, and keep | |
| * unmounting them until they are gone. */ | |
| do { | |
| _cleanup_fclose_ FILE *proc_self_mountinfo = NULL; | |
| again = false; | |
| r = 0; | |
| proc_self_mountinfo = fopen("/proc/self/mountinfo", "re"); | |
| if (!proc_self_mountinfo) | |
| return -errno; | |
| (void) __fsetlocking(proc_self_mountinfo, FSETLOCKING_BYCALLER); | |
| for (;;) { | |
| _cleanup_free_ char *path = NULL, *p = NULL; | |
| int k; | |
| k = fscanf(proc_self_mountinfo, | |
| "%*s " /* (1) mount id */ | |
| "%*s " /* (2) parent id */ | |
| "%*s " /* (3) major:minor */ | |
| "%*s " /* (4) root */ | |
| "%ms " /* (5) mount point */ | |
| "%*s" /* (6) mount options */ | |
| "%*[^-]" /* (7) optional fields */ | |
| "- " /* (8) separator */ | |
| "%*s " /* (9) file system type */ | |
| "%*s" /* (10) mount source */ | |
| "%*s" /* (11) mount options 2 */ | |
| "%*[^\n]", /* some rubbish at the end */ | |
| &path); | |
| if (k != 1) { | |
| if (k == EOF) | |
| break; | |
| continue; | |
| } | |
| r = cunescape(path, UNESCAPE_RELAX, &p); | |
| if (r < 0) | |
| return r; | |
| if (!path_startswith(p, prefix)) | |
| continue; | |
| if (umount2(p, flags) < 0) { | |
| r = log_debug_errno(errno, "Failed to umount %s: %m", p); | |
| continue; | |
| } | |
| log_debug("Successfully unmounted %s", p); | |
| again = true; | |
| n++; | |
| break; | |
| } | |
| } while (again); | |
| return r ? r : n; | |
| } | |
| static int get_mount_flags(const char *path, unsigned long *flags) { | |
| struct statvfs buf; | |
| if (statvfs(path, &buf) < 0) | |
| return -errno; | |
| *flags = buf.f_flag; | |
| return 0; | |
| } | |
| /* Use this function only if do you have direct access to /proc/self/mountinfo | |
| * and need the caller to open it for you. This is the case when /proc is | |
| * masked or not mounted. Otherwise, use bind_remount_recursive. */ | |
| int bind_remount_recursive_with_mountinfo(const char *prefix, bool ro, char **blacklist, FILE *proc_self_mountinfo) { | |
| _cleanup_set_free_free_ Set *done = NULL; | |
| _cleanup_free_ char *cleaned = NULL; | |
| int r; | |
| assert(proc_self_mountinfo); | |
| /* Recursively remount a directory (and all its submounts) read-only or read-write. If the directory is already | |
| * mounted, we reuse the mount and simply mark it MS_BIND|MS_RDONLY (or remove the MS_RDONLY for read-write | |
| * operation). If it isn't we first make it one. Afterwards we apply MS_BIND|MS_RDONLY (or remove MS_RDONLY) to | |
| * all submounts we can access, too. When mounts are stacked on the same mount point we only care for each | |
| * individual "top-level" mount on each point, as we cannot influence/access the underlying mounts anyway. We | |
| * do not have any effect on future submounts that might get propagated, they migt be writable. This includes | |
| * future submounts that have been triggered via autofs. | |
| * | |
| * If the "blacklist" parameter is specified it may contain a list of subtrees to exclude from the | |
| * remount operation. Note that we'll ignore the blacklist for the top-level path. */ | |
| cleaned = strdup(prefix); | |
| if (!cleaned) | |
| return -ENOMEM; | |
| path_kill_slashes(cleaned); | |
| done = set_new(&string_hash_ops); | |
| if (!done) | |
| return -ENOMEM; | |
| for (;;) { | |
| _cleanup_set_free_free_ Set *todo = NULL; | |
| bool top_autofs = false; | |
| char *x; | |
| unsigned long orig_flags; | |
| todo = set_new(&string_hash_ops); | |
| if (!todo) | |
| return -ENOMEM; | |
| rewind(proc_self_mountinfo); | |
| for (;;) { | |
| _cleanup_free_ char *path = NULL, *p = NULL, *type = NULL; | |
| int k; | |
| k = fscanf(proc_self_mountinfo, | |
| "%*s " /* (1) mount id */ | |
| "%*s " /* (2) parent id */ | |
| "%*s " /* (3) major:minor */ | |
| "%*s " /* (4) root */ | |
| "%ms " /* (5) mount point */ | |
| "%*s" /* (6) mount options (superblock) */ | |
| "%*[^-]" /* (7) optional fields */ | |
| "- " /* (8) separator */ | |
| "%ms " /* (9) file system type */ | |
| "%*s" /* (10) mount source */ | |
| "%*s" /* (11) mount options (bind mount) */ | |
| "%*[^\n]", /* some rubbish at the end */ | |
| &path, | |
| &type); | |
| if (k != 2) { | |
| if (k == EOF) | |
| break; | |
| continue; | |
| } | |
| r = cunescape(path, UNESCAPE_RELAX, &p); | |
| if (r < 0) | |
| return r; | |
| if (!path_startswith(p, cleaned)) | |
| continue; | |
| /* Ignore this mount if it is blacklisted, but only if it isn't the top-level mount we shall | |
| * operate on. */ | |
| if (!path_equal(cleaned, p)) { | |
| bool blacklisted = false; | |
| char **i; | |
| 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; | |
| fl = mount_flags_to_string(flags); | |
| if ((flags & MS_REMOUNT) && !what && !type) | |
| log_debug("Remounting %s (%s \"%s\")...", | |
| where, strnull(fl), strempty(options)); | |
| else if (!what && !type) | |
| log_debug("Mounting %s (%s \"%s\")...", | |
| where, strnull(fl), strempty(options)); | |
| else if ((flags & MS_BIND) && !type) | |
| log_debug("Bind-mounting %s on %s (%s \"%s\")...", | |
| what, where, strnull(fl), strempty(options)); | |
| else if (flags & MS_MOVE) | |
| log_debug("Moving mount %s → %s (%s \"%s\")...", | |
| what, where, strnull(fl), strempty(options)); | |
| else | |
| log_debug("Mounting %s on %s (%s \"%s\")...", | |
| strna(type), where, strnull(fl), strempty(options)); | |
| if (mount(what, where, type, flags, options) < 0) | |
| return log_full_errno(error_log_level, errno, | |
| "Failed to mount %s on %s (%s \"%s\"): %m", | |
| strna(type), where, strnull(fl), strempty(options)); | |
| 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; | |
| } |