include: add mount-api-utils.h

Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>

diff --git a/configure.ac b/configure.ac
index 7992236881072e84e6565c8301bd6e18bbd2cad7..432f7e72504f13c612ae3050d46c6db0681bcc98 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -498,6 +498,8 @@ AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
 [AC_DEFINE([HAVE_TM_GMTOFF], [1], [Does struct tm have a field tm_gmtoff?])
 ])
 
+AC_CHECK_TYPES([struct mount_attr], [], [], [[#include <sys/mount.h>]])
+
 AC_CHECK_MEMBERS([struct termios.c_line],,,
     [[#include <termios.h>]])
 
@@ -560,8 +562,11 @@ AC_CHECK_FUNCS([ \
        newlocale \
        mempcpy \
        mkostemp \
+       move_mount \
+       mount_setattr \
        nanosleep \
        ntp_gettime \
+       open_tree \
        personality \
        pidfd_open \
        pidfd_send_signal \

diff --git a/include/Makemodule.am b/include/Makemodule.am
index b7937b1c50e2bc24ef5c8f218d62005e25cf6886..7c6a7587f65a326aa892e7eee4456daa76562167 100644 (file)
--- a/include/Makemodule.am
+++ b/include/Makemodule.am
@@ -42,6 +42,7 @@ dist_noinst_HEADERS += \
        include/md5.h \
        include/minix.h \
        include/monotonic.h \
+       include/mount-api-utils.h \
        include/namespace.h \
        include/nls.h \
        include/optutils.h \

diff --git a/include/mount-api-utils.h b/include/mount-api-utils.h
new file mode 100644 (file)
index 0000000..4d3396e
--- /dev/null
+++ b/include/mount-api-utils.h
@@ -0,0 +1,132 @@
+#ifndef UTIL_LINUX_MOUNT_API_UTILS
+#define UTIL_LINUX_MOUNT_API_UTILS
+
+#if defined(__linux__)
+#include <sys/syscall.h>
+
+/*
+ * Scope all of this beneath mount_setattr(). If this syscall is available all
+ * other syscalls must as well. Otherwise we're dealing with a partial backport
+ * of syscalls.
+ */
+
+# if defined(SYS_mount_setattr)
+
+/* Accepted by both open_tree() and mount_setattr(). */
+#ifndef AT_RECURSIVE
+#define AT_RECURSIVE 0x8000
+#endif
+
+#ifndef OPEN_TREE_CLONE
+#define OPEN_TREE_CLONE 1
+#endif
+
+#ifndef OPEN_TREE_CLOEXEC
+#define OPEN_TREE_CLOEXEC O_CLOEXEC
+#endif
+
+#  ifndef HAVE_OPEN_TREE
+static inline int open_tree(int dfd, const char *filename, unsigned int flags)
+{
+       return syscall(__NR_open_tree, dfd, filename, flags);
+}
+#  endif
+
+#ifndef MOVE_MOUNT_F_SYMLINKS
+#define MOVE_MOUNT_F_SYMLINKS 0x00000001 /* Follow symlinks on from path */
+#endif
+
+#ifndef MOVE_MOUNT_F_AUTOMOUNTS
+#define MOVE_MOUNT_F_AUTOMOUNTS 0x00000002 /* Follow automounts on from path */
+#endif
+
+#ifndef MOVE_MOUNT_F_EMPTY_PATH
+#define MOVE_MOUNT_F_EMPTY_PATH 0x00000004 /* Empty from path permitted */
+#endif
+
+#ifndef MOVE_MOUNT_T_SYMLINKS
+#define MOVE_MOUNT_T_SYMLINKS 0x00000010 /* Follow symlinks on to path */
+#endif
+
+#ifndef MOVE_MOUNT_T_AUTOMOUNTS
+#define MOVE_MOUNT_T_AUTOMOUNTS 0x00000020 /* Follow automounts on to path */
+#endif
+
+#ifndef MOVE_MOUNT_T_EMPTY_PATH
+#define MOVE_MOUNT_T_EMPTY_PATH 0x00000040 /* Empty to path permitted */
+#endif
+
+#ifndef MOVE_MOUNT__MASK
+#define MOVE_MOUNT__MASK 0x00000077
+#endif
+
+#  ifndef HAVE_MOVE_MOUNT
+static inline int move_mount(int from_dfd, const char *from_pathname, int to_dfd,
+                            const char *to_pathname, unsigned int flags)
+{
+       return syscall(__NR_move_mount, from_dfd, from_pathname, to_dfd,
+                      to_pathname, flags);
+}
+#  endif
+
+#ifndef MOUNT_ATTR_RDONLY
+#define MOUNT_ATTR_RDONLY 0x00000001
+#endif
+
+#ifndef MOUNT_ATTR_NOSUID
+#define MOUNT_ATTR_NOSUID 0x00000002
+#endif
+
+#ifndef MOUNT_ATTR_NOEXEC
+#define MOUNT_ATTR_NOEXEC 0x00000008
+#endif
+
+#ifndef MOUNT_ATTR_NODIRATIME
+#define MOUNT_ATTR_NODIRATIME 0x00000080
+#endif
+
+#ifndef MOUNT_ATTR__ATIME
+#define MOUNT_ATTR__ATIME 0x00000070
+#endif
+
+#ifndef MOUNT_ATTR_RELATIME
+#define MOUNT_ATTR_RELATIME 0x00000000
+#endif
+
+#ifndef MOUNT_ATTR_NOATIME
+#define MOUNT_ATTR_NOATIME 0x00000010
+#endif
+
+#ifndef MOUNT_ATTR_STRICTATIME
+#define MOUNT_ATTR_STRICTATIME 0x00000020
+#endif
+
+#ifndef MOUNT_ATTR_IDMAP
+#define MOUNT_ATTR_IDMAP 0x00100000
+#endif
+
+#  ifndef HAVE_STRUCT_MOUNT_ATTR
+#  include <linux/types.h>
+struct mount_attr {
+       __u64 attr_set;
+       __u64 attr_clr;
+       __u64 propagation;
+       __u64 userns_fd;
+};
+#  endif
+
+#  ifndef HAVE_MOUNT_SETATTR
+static inline int mount_setattr(int dfd, const char *path, unsigned int flags,
+                               struct mount_attr *attr, size_t size)
+{
+       return syscall(__NR_mount_setattr, dfd, path, flags, attr, size);
+}
+#  endif
+
+#define UL_HAVE_MOUNT_API 1
+
+# endif
+
+#endif /* __linux__ */
+#endif /* UTIL_LINUX_MOUNT_API_UTILS */
+