vfs: new internal helper: mnt_has_parent(mnt)
vfsmounts have ->mnt_parent pointing either to a different vfsmount
or to itself; it's never NULL and termination condition in loops
traversing the tree towards root is mnt == mnt->mnt_parent. At least
one place (see the next patch) is confused about what's going on;
let's add an explicit helper checking it right way and use it in
all places where we need it. Not that there had been too many,
but...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/dcache.c b/fs/dcache.c
index 89509b5..8a75e3b 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -38,6 +38,7 @@
#include <linux/prefetch.h>
#include <linux/ratelimit.h>
#include "internal.h"
+#include "mount.h"
/*
* Usage:
@@ -2460,9 +2461,8 @@
if (dentry == vfsmnt->mnt_root || IS_ROOT(dentry)) {
/* Global root? */
- if (vfsmnt->mnt_parent == vfsmnt) {
+ if (!mnt_has_parent(vfsmnt))
goto global_root;
- }
dentry = vfsmnt->mnt_mountpoint;
vfsmnt = vfsmnt->mnt_parent;
continue;
@@ -2862,7 +2862,7 @@
br_read_lock(vfsmount_lock);
if (mnt != path2->mnt) {
for (;;) {
- if (mnt->mnt_parent == mnt) {
+ if (!mnt_has_parent(mnt)) {
br_read_unlock(vfsmount_lock);
return 0;
}