+/* SPDX-License-Identifier: LGPL-2.1+ */
/***
This file is part of systemd.
#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 "set.h"
#include "stdio-util.h"
#include "string-util.h"
+#include "strv.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)];
return safe_atoi(p, mnt_id);
}
-
int fd_is_mount_point(int fd, const char *filename, int flags) {
union file_handle_union h = FILE_HANDLE_INIT, h_parent = FILE_HANDLE_INIT;
int mount_id = -1, mount_id_parent = -1;
*
* As last fallback we do traditional fstat() based st_dev
* comparisons. This is how things were traditionally done,
- * but unionfs breaks breaks this since it exposes file
+ * 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(fd, filename, &h.handle, &mount_id, flags);
if (r < 0) {
- if (errno == ENOSYS)
- /* This kernel does not support name_to_handle_at()
- * fall back to simpler logic. */
+ if (IN_SET(errno, ENOSYS, EACCES, EPERM))
+ /* This kernel does not support name_to_handle_at() at all, or the syscall was blocked (maybe
+ * through seccomp, because we are running inside of a container?): fall back to simpler
+ * logic. */
goto fallback_fdinfo;
else if (errno == EOPNOTSUPP)
/* This kernel or file system does not support
fallback_fdinfo:
r = fd_fdinfo_mnt_id(fd, filename, flags, &mount_id);
- if (r == -EOPNOTSUPP)
+ if (IN_SET(r, -EOPNOTSUPP, -EACCES, -EPERM))
goto fallback_fstat;
if (r < 0)
return r;
}
/* flags can be AT_SYMLINK_FOLLOW or 0 */
-int path_is_mount_point(const char *t, int flags) {
- _cleanup_close_ int fd = -1;
+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);
* /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) {
- canonical = canonicalize_file_name(t);
- if (!canonical)
- return -errno;
+ r = chase_symlinks(t, root, 0, &canonical);
+ if (r < 0)
+ return r;
t = canonical;
}
continue;
if (umount2(p, flags) < 0) {
- r = -errno;
+ r = log_debug_errno(errno, "Failed to umount %s: %m", p);
continue;
}
+ log_debug("Successfully unmounted %s", p);
+
again = true;
n++;
return 0;
}
-int bind_remount_recursive(const char *prefix, bool ro) {
+/* 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;
- /* 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. */
+ 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;
for (;;) {
- _cleanup_fclose_ FILE *proc_self_mountinfo = NULL;
_cleanup_set_free_free_ Set *todo = NULL;
bool top_autofs = false;
char *x;
if (!todo)
return -ENOMEM;
- proc_self_mountinfo = fopen("/proc/self/mountinfo", "re");
- if (!proc_self_mountinfo)
- return -errno;
+ rewind(proc_self_mountinfo);
for (;;) {
_cleanup_free_ char *path = NULL, *p = NULL, *type = NULL;
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
continue;
}
- if (path_startswith(p, cleaned) &&
- !set_contains(done, p)) {
-
+ if (!set_contains(done, p)) {
r = set_consume(todo, p);
p = NULL;
-
if (r == -EEXIST)
continue;
if (r < 0)
if (!set_contains(done, cleaned) &&
!set_contains(todo, cleaned)) {
- /* The prefix directory itself is not yet a
- * mount, make it one. */
+ /* 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;
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;
while ((x = set_steal_first(todo))) {
r = set_consume(done, x);
- if (r == -EEXIST || r == 0)
+ 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, but
- * don't care for errors, in case of
- * obstructed mounts */
+ /* 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) {
-
- /* Deal with mount points that are
- * obstructed by a later mount */
-
- if (errno != ENOENT)
- return -errno;
- }
+ 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;
+
+ return bind_remount_recursive_with_mountinfo(prefix, ro, blacklist, proc_self_mountinfo);
+}
+
int mount_move_root(const char *path) {
assert(path);
}
bool fstype_is_network(const char *fstype) {
- static const char table[] =
- "afs\0"
- "cifs\0"
- "smbfs\0"
- "sshfs\0"
- "ncpfs\0"
- "ncp\0"
- "nfs\0"
- "nfs4\0"
- "gfs\0"
- "gfs2\0"
- "glusterfs\0";
-
const char *x;
x = startswith(fstype, "fuse.");
if (x)
fstype = x;
- return nulstr_contains(table, fstype);
+ 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");
}
int repeat_unmount(const char *path, int flags) {
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;
+}
projects / thirdparty / systemd.git / blobdiff