finally fold get_link() into pick_link()

kill nd->link_inode, while we are at it

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

diff --git a/fs/namei.c b/fs/namei.c
index f5959f6..02f1481 100644 (file)
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -503,7 +503,6 @@ struct nameidata {
        } *stack, internal[EMBEDDED_LEVELS];
        struct filename *name;
        struct nameidata *saved;
-       struct inode    *link_inode;
        unsigned        root_seq;
        int             dfd;
 } __randomize_layout;
@@ -962,9 +961,8 @@ int sysctl_protected_regular __read_mostly;
  *
  * Returns 0 if following the symlink is allowed, -ve on error.
  */
-static inline int may_follow_link(struct nameidata *nd)
+static inline int may_follow_link(struct nameidata *nd, const struct inode *inode)
 {
-       const struct inode *inode;
        const struct inode *parent;
        kuid_t puid;
 
@@ -972,7 +970,6 @@ static inline int may_follow_link(struct nameidata *nd)
                return 0;
 
        /* Allowed if owner and follower match. */
-       inode = nd->link_inode;
        if (uid_eq(current_cred()->fsuid, inode->i_uid))
                return 0;
 
@@ -1106,73 +1103,6 @@ static int may_create_in_sticky(umode_t dir_mode, kuid_t dir_uid,
        return 0;
 }
 
-static __always_inline
-const char *get_link(struct nameidata *nd)
-{
-       struct saved *last = nd->stack + nd->depth - 1;
-       struct dentry *dentry = last->link.dentry;
-       struct inode *inode = nd->link_inode;
-       int error;
-       const char *res;
-
-       if (!(nd->flags & LOOKUP_PARENT)) {
-               error = may_follow_link(nd);
-               if (unlikely(error))
-                       return ERR_PTR(error);
-       }
-
-       if (unlikely(nd->flags & LOOKUP_NO_SYMLINKS))
-               return ERR_PTR(-ELOOP);
-
-       if (!(nd->flags & LOOKUP_RCU)) {
-               touch_atime(&last->link);
-               cond_resched();
-       } else if (atime_needs_update(&last->link, inode)) {
-               if (unlikely(unlazy_walk(nd)))
-                       return ERR_PTR(-ECHILD);
-               touch_atime(&last->link);
-       }
-
-       error = security_inode_follow_link(dentry, inode,
-                                          nd->flags & LOOKUP_RCU);
-       if (unlikely(error))
-               return ERR_PTR(error);
-
-       nd->last_type = LAST_BIND;
-       res = READ_ONCE(inode->i_link);
-       if (!res) {
-               const char * (*get)(struct dentry *, struct inode *,
-                               struct delayed_call *);
-               get = inode->i_op->get_link;
-               if (nd->flags & LOOKUP_RCU) {
-                       res = get(NULL, inode, &last->done);
-                       if (res == ERR_PTR(-ECHILD)) {
-                               if (unlikely(unlazy_walk(nd)))
-                                       return ERR_PTR(-ECHILD);
-                               res = get(dentry, inode, &last->done);
-                       }
-               } else {
-                       res = get(dentry, inode, &last->done);
-               }
-               if (!res)
-                       goto all_done;
-               if (IS_ERR(res))
-                       return res;
-       }
-       if (*res == '/') {
-               error = nd_jump_root(nd);
-               if (unlikely(error))
-                       return ERR_PTR(error);
-               while (unlikely(*++res == '/'))
-                       ;
-       }
-       if (*res)
-               return res;
-all_done: // pure jump
-       put_link(nd);
-       return NULL;
-}
-
 /*
  * follow_up - Find the mountpoint of path's vfsmount
  *
@@ -1796,8 +1726,10 @@ static inline int handle_dots(struct nameidata *nd, int type)
 static const char *pick_link(struct nameidata *nd, struct path *link,
                     struct inode *inode, unsigned seq)
 {
-       int error;
        struct saved *last;
+       const char *res;
+       int error;
+
        if (unlikely(nd->total_link_count++ >= MAXSYMLINKS)) {
                path_to_nameidata(link, nd);
                return ERR_PTR(-ELOOP);
@@ -1828,9 +1760,64 @@ static const char *pick_link(struct nameidata *nd, struct path *link,
        last = nd->stack + nd->depth++;
        last->link = *link;
        clear_delayed_call(&last->done);
-       nd->link_inode = inode;
        last->seq = seq;
-       return get_link(nd);
+
+       if (!(nd->flags & LOOKUP_PARENT)) {
+               error = may_follow_link(nd, inode);
+               if (unlikely(error))
+                       return ERR_PTR(error);
+       }
+
+       if (unlikely(nd->flags & LOOKUP_NO_SYMLINKS))
+               return ERR_PTR(-ELOOP);
+
+       if (!(nd->flags & LOOKUP_RCU)) {
+               touch_atime(&last->link);
+               cond_resched();
+       } else if (atime_needs_update(&last->link, inode)) {
+               if (unlikely(unlazy_walk(nd)))
+                       return ERR_PTR(-ECHILD);
+               touch_atime(&last->link);
+       }
+
+       error = security_inode_follow_link(link->dentry, inode,
+                                          nd->flags & LOOKUP_RCU);
+       if (unlikely(error))
+               return ERR_PTR(error);
+
+       nd->last_type = LAST_BIND;
+       res = READ_ONCE(inode->i_link);
+       if (!res) {
+               const char * (*get)(struct dentry *, struct inode *,
+                               struct delayed_call *);
+               get = inode->i_op->get_link;
+               if (nd->flags & LOOKUP_RCU) {
+                       res = get(NULL, inode, &last->done);
+                       if (res == ERR_PTR(-ECHILD)) {
+                               if (unlikely(unlazy_walk(nd)))
+                                       return ERR_PTR(-ECHILD);
+                               res = get(link->dentry, inode, &last->done);
+                       }
+               } else {
+                       res = get(link->dentry, inode, &last->done);
+               }
+               if (!res)
+                       goto all_done;
+               if (IS_ERR(res))
+                       return res;
+       }
+       if (*res == '/') {
+               error = nd_jump_root(nd);
+               if (unlikely(error))
+                       return ERR_PTR(error);
+               while (unlikely(*++res == '/'))
+                       ;
+       }
+       if (*res)
+               return res;
+all_done: // pure jump
+       put_link(nd);
+       return NULL;
 }
 
 enum {WALK_FOLLOW = 1, WALK_MORE = 2, WALK_NOFOLLOW = 4};