reduce vfs_path_lookup() to do_path_lookup()
New lookup flag: LOOKUP_ROOT. nd->root is set (and held) by caller,
path_init() starts walking from that place and all pathname resolution
machinery never drops nd->root if that flag is set. That turns
vfs_path_lookup() into a special case of do_path_lookup() *and*
gets us down to 3 callers of link_path_walk(), making it finally
feasible to rip the handling of trailing symlink out of link_path_walk().
That will not only simply the living hell out of it, but make life
much simpler for unionfs merge. Trailing symlink handling will
become iterative, which is a good thing for stack footprint in
a lot of situations as well.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/include/linux/namei.h b/include/linux/namei.h
index 72ffd62..83cd6e5 100644
--- a/include/linux/namei.h
+++ b/include/linux/namei.h
@@ -63,6 +63,7 @@
#define LOOKUP_RENAME_TARGET 0x0800
#define LOOKUP_JUMPED 0x1000
+#define LOOKUP_ROOT 0x2000
extern int user_path_at(int, const char __user *, unsigned, struct path *);