teach filename_lookup() to treat NULL filename as ""

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

diff --git a/fs/namei.c b/fs/namei.c
index 4a4a22a08ac20df0e2cbe4b242d47eb4bc630faa..aaf3cd6c802f5a20ff935a577aa9091c4189290a 100644 (file)
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -588,6 +588,7 @@ struct nameidata {
                unsigned seq;
        } *stack, internal[EMBEDDED_LEVELS];
        struct filename *name;
+       const char *pathname;
        struct nameidata *saved;
        unsigned        root_seq;
        int             dfd;
@@ -606,6 +607,7 @@ static void __set_nameidata(struct nameidata *p, int dfd, struct filename *name)
        p->depth = 0;
        p->dfd = dfd;
        p->name = name;
+       p->pathname = likely(name) ? name->name : "";
        p->path.mnt = NULL;
        p->path.dentry = NULL;
        p->total_link_count = old ? old->total_link_count : 0;
@@ -2439,7 +2441,7 @@ OK:
 static const char *path_init(struct nameidata *nd, unsigned flags)
 {
        int error;
-       const char *s = nd->name->name;
+       const char *s = nd->pathname;
 
        /* LOOKUP_CACHED requires RCU, ask caller to retry */
        if ((flags & (LOOKUP_RCU | LOOKUP_CACHED)) == LOOKUP_CACHED)