| /* SPDX-License-Identifier: LGPL-2.1+ */ |
| |
| #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 later */ |
| #include <libmount.h> |
| |
| #include "alloc-util.h" |
| #include "escape.h" |
| #include "extract-word.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 = TAKE_PTR(h); |
| |
| 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|(flags & AT_SYMLINK_FOLLOW ? 0 : O_NOFOLLOW)); |
| 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, CHASE_TRAIL_SLASH, &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_simplify(cleaned, false); |
| |
| done = set_new(&path_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(&path_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", |
| "smb3", |
| "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 a corresponding inaccessible file node. These nodes are created during |
| * early boot by PID 1. In some cases we lacked the privs to create the character and block devices (maybe |
| * because we run in an userns environment, or miss CAP_SYS_MKNOD, or run with a devices policy that excludes |
| * device nodes with major and minor of 0), but that's fine, in that case we use an AF_UNIX file node instead, |
| * which is not the same, but close enough for most uses. And most importantly, the kernel allows bind mounts |
| * from socket nodes to any non-directory file nodes, and that's the most important thing that matters. */ |
| |
| 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; |
| } |