pid1: stop limiting size of /dev/shm

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

diff --git a/src/shared/mount-util.h b/src/shared/mount-util.h
index 8649fca39b67a5e0aebbe3cb01c7db694c9e7279..8fb597e7c039de33ba61a04b5ee5692d61c91153 100644 (file)
--- a/src/shared/mount-util.h
+++ b/src/shared/mount-util.h
@@ -3,13 +3,40 @@
 
 #include <mntent.h>
 #include <stdio.h>
+#include <unistd.h>
 
+#include "errno-util.h"
 #include "macro.h"
 
+/* 4MB for contents of regular files, 64k inodes for directories, symbolic links and device specials, using
+ * large storage array systems as a baseline */
+#define TMPFS_LIMITS_DEV             ",size=4m,nr_inodes=64k"
+
+/* Very little, if any use expected */
+#define TMPFS_LIMITS_EMPTY_OR_ALMOST ",size=4m,nr_inodes=1k"
+#define TMPFS_LIMITS_SYS             TMPFS_LIMITS_EMPTY_OR_ALMOST
+#define TMPFS_LIMITS_SYS_FS_CGROUP   TMPFS_LIMITS_EMPTY_OR_ALMOST
+
+/* On an extremely small device with only 256MB of RAM, 20% of RAM should be enough for the re-execution of
+ * PID1 because 16MB of free space is required. */
+#define TMPFS_LIMITS_RUN             ",size=20%,nr_inodes=800k"
+
+/* The limit used for various nested tmpfs mounts, in paricular for guests started by systemd-nspawn.
+ * 10% of RAM (using 16GB of RAM as a baseline) translates to 400k inodes (assuming 4k each) and 25%
+ * translates to 1M inodes.
+ * (On the host, /tmp is configured through a .mount unit file.) */
+#define NESTED_TMPFS_LIMITS          ",size=10%,nr_inodes=400k"
+
+/* More space for volatile root and /var */
+#define TMPFS_LIMITS_VAR             ",size=25%,nr_inodes=1m"
+#define TMPFS_LIMITS_ROOTFS          TMPFS_LIMITS_VAR
+#define TMPFS_LIMITS_VOLATILE_STATE  TMPFS_LIMITS_VAR
+
 int repeat_unmount(const char *path, int flags);
 int umount_recursive(const char *target, int flags);
-int bind_remount_recursive(const char *prefix, unsigned long new_flags, unsigned long flags_mask, char **blacklist);
-int bind_remount_recursive_with_mountinfo(const char *prefix, unsigned long new_flags, unsigned long flags_mask, char **blacklist, FILE *proc_self_mountinfo);
+int bind_remount_recursive(const char *prefix, unsigned long new_flags, unsigned long flags_mask, char **deny_list);
+int bind_remount_recursive_with_mountinfo(const char *prefix, unsigned long new_flags, unsigned long flags_mask, char **deny_list, FILE *proc_self_mountinfo);
+int bind_remount_one_with_mountinfo(const char *path, unsigned long new_flags, unsigned long flags_mask, FILE *proc_self_mountinfo);
 
 int mount_move_root(const char *path);
 
@@ -31,4 +58,13 @@ int mount_option_mangle(
                 unsigned long *ret_mount_flags,
                 char **ret_remaining_options);
 
-const char* mode_to_inaccessible_node(mode_t mode);
+int mode_to_inaccessible_node(const char *runtime_dir, mode_t mode, char **dest);
+
+/* Useful for usage with _cleanup_(), unmounts, removes a directory and frees the pointer */
+static inline void umount_and_rmdir_and_free(char *p) {
+        PROTECT_ERRNO;
+        (void) umount_recursive(p, 0);
+        (void) rmdir(p);
+        free(p);
+}
+DEFINE_TRIVIAL_CLEANUP_FUNC(char*, umount_and_rmdir_and_free);