merging pick_link() with get_link(), part 4

Move the call of get_link() into walk_component().  Change the
calling conventions for walk_component() to returning the link
body to follow (if any).

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

diff --git a/fs/namei.c b/fs/namei.c
index f844378..c8a933c 100644 (file)
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -1866,7 +1866,7 @@ static int step_into(struct nameidata *nd, int flags,
        return pick_link(nd, &path, inode, seq);
 }
 
-static int walk_component(struct nameidata *nd, int flags)
+static const char *walk_component(struct nameidata *nd, int flags)
 {
        struct dentry *dentry;
        struct inode *inode;
@@ -1881,19 +1881,24 @@ static int walk_component(struct nameidata *nd, int flags)
                if (!(flags & WALK_MORE) && nd->depth)
                        put_link(nd);
                err = handle_dots(nd, nd->last_type);
-               return err;
+               return ERR_PTR(err);
        }
        dentry = lookup_fast(nd, &inode, &seq);
        if (IS_ERR(dentry))
-               return PTR_ERR(dentry);
+               return ERR_CAST(dentry);
        if (unlikely(!dentry)) {
                dentry = lookup_slow(&nd->last, nd->path.dentry, nd->flags);
                if (IS_ERR(dentry))
-                       return PTR_ERR(dentry);
+                       return ERR_CAST(dentry);
        }
        if (!(flags & WALK_MORE) && nd->depth)
                put_link(nd);
-       return step_into(nd, flags, dentry, inode, seq);
+       err = step_into(nd, flags, dentry, inode, seq);
+       if (!err)
+               return NULL;
+       if (err > 0)
+               return get_link(nd);
+       return ERR_PTR(err);
 }
 
 /*
@@ -2145,6 +2150,7 @@ static int link_path_walk(const char *name, struct nameidata *nd)
 
        /* At this point we know we have a real path component. */
        for(;;) {
+               const char *link;
                u64 hash_len;
                int type;
 
@@ -2202,24 +2208,18 @@ OK:
                        if (!name)
                                return 0;
                        /* last component of nested symlink */
-                       err = walk_component(nd, WALK_FOLLOW);
+                       link = walk_component(nd, WALK_FOLLOW);
                } else {
                        /* not the last component */
-                       err = walk_component(nd, WALK_FOLLOW | WALK_MORE);
+                       link = walk_component(nd, WALK_FOLLOW | WALK_MORE);
                }
-               if (err < 0)
-                       return err;
-
-               if (err) {
-                       const char *s = get_link(nd);
-
-                       if (IS_ERR(s))
-                               return PTR_ERR(s);
-                       if (likely(s)) {
-                               nd->stack[nd->depth - 1].name = name;
-                               name = s;
-                               continue;
-                       }
+               if (unlikely(link)) {
+                       if (IS_ERR(link))
+                               return PTR_ERR(link);
+                       /* a symlink to follow */
+                       nd->stack[nd->depth - 1].name = name;
+                       name = link;
+                       continue;
                }
                if (unlikely(!d_can_lookup(nd->path.dentry))) {
                        if (nd->flags & LOOKUP_RCU) {
@@ -2335,24 +2335,17 @@ static const char *path_init(struct nameidata *nd, unsigned flags)
 
 static inline const char *lookup_last(struct nameidata *nd)
 {
-       int err;
+       const char *link;
        if (nd->last_type == LAST_NORM && nd->last.name[nd->last.len])
                nd->flags |= LOOKUP_FOLLOW | LOOKUP_DIRECTORY;
 
        nd->flags &= ~LOOKUP_PARENT;
-       err = walk_component(nd, 0);
-       if (unlikely(err)) {
-               const char *s;
-               if (err < 0)
-                       return PTR_ERR(err);
-               s = get_link(nd);
-               if (s) {
-                       nd->flags |= LOOKUP_PARENT;
-                       nd->stack[0].name = NULL;
-                       return s;
-               }
+       link = walk_component(nd, 0);
+       if (link) {
+               nd->flags |= LOOKUP_PARENT;
+               nd->stack[0].name = NULL;
        }
-       return NULL;
+       return link;
 }
 
 static int handle_lookup_down(struct nameidata *nd)