mount-util: Add a helper for remounting a bind mount

[thirdparty/systemd.git] / src / shared / mount-util.h

diff --git a/src/shared/mount-util.h b/src/shared/mount-util.h
index f06fd6de8c68ed1492b47602e93c11bc31ed3b48..26d96b27b7feb7fb3467714921195116845e0fe5 100644 (file)
--- a/src/shared/mount-util.h
+++ b/src/shared/mount-util.h
@@ -26,6 +26,7 @@ static inline int bind_remount_recursive(const char *prefix, unsigned long new_f
 }
 
 int bind_remount_one_with_mountinfo(const char *path, unsigned long new_flags, unsigned long flags_mask, FILE *proc_self_mountinfo);
+int bind_remount_one(const char *path, unsigned long new_flags, unsigned long flags_mask);
 
 int mount_switch_root_full(const char *path, unsigned long mount_propagation_flag, bool force_ms_move);
 static inline int mount_switch_root(const char *path, unsigned long mount_propagation_flag) {
@@ -116,16 +117,19 @@ typedef enum RemountIdmapping {
          * certain security implications defaults to off, and requires explicit opt-in. */
         REMOUNT_IDMAPPING_HOST_ROOT,
         /* Define a mapping from root user within the container to the owner of the bind mounted directory.
-         * This ensure no root-owned files will be written in a bind-mounted directory owned by a different
+         * This ensures no root-owned files will be written in a bind-mounted directory owned by a different
          * user. No other users are mapped. */
         REMOUNT_IDMAPPING_HOST_OWNER,
+        /* Define a mapping from bind-target owner within the container to the host owner of the bind mounted
+         * directory. No other users are mapped. */
+        REMOUNT_IDMAPPING_HOST_OWNER_TO_TARGET_OWNER,
         _REMOUNT_IDMAPPING_MAX,
         _REMOUNT_IDMAPPING_INVALID = -EINVAL,
 } RemountIdmapping;
 
-int make_userns(uid_t uid_shift, uid_t uid_range, uid_t owner, RemountIdmapping idmapping);
-int remount_idmap_fd(const char *p, int userns_fd);
-int remount_idmap(const char *p, uid_t uid_shift, uid_t uid_range, uid_t owner, RemountIdmapping idmapping);
+int make_userns(uid_t uid_shift, uid_t uid_range, uid_t host_owner, uid_t dest_owner, RemountIdmapping idmapping);
+int remount_idmap_fd(char **p, int userns_fd);
+int remount_idmap(char **p, uid_t uid_shift, uid_t uid_range, uid_t host_owner, uid_t dest_owner, RemountIdmapping idmapping);
 
 int bind_mount_submounts(
                 const char *source,