split the lookup-related parts of do_last() into a separate helper

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

diff --git a/fs/namei.c b/fs/namei.c
index 7986725..6530e3c 100644 (file)
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -3112,19 +3112,12 @@ out_dput:
        return ERR_PTR(error);
 }
 
-/*
- * Handle the last step of open()
- */
-static const char *do_last(struct nameidata *nd,
+static const char *open_last_lookups(struct nameidata *nd,
                   struct file *file, const struct open_flags *op)
 {
        struct dentry *dir = nd->path.dentry;
-       kuid_t dir_uid = nd->inode->i_uid;
-       umode_t dir_mode = nd->inode->i_mode;
        int open_flag = op->open_flag;
-       bool do_truncate;
        bool got_write = false;
-       int acc_mode;
        unsigned seq;
        struct inode *inode;
        struct dentry *dentry;
@@ -3137,9 +3130,9 @@ static const char *do_last(struct nameidata *nd,
                if (nd->depth)
                        put_link(nd);
                error = handle_dots(nd, nd->last_type);
-               if (unlikely(error))
-                       return ERR_PTR(error);
-               goto finish_open;
+               if (likely(!error))
+                       error = complete_walk(nd);
+               return ERR_PTR(error);
        }
 
        if (!(open_flag & O_CREAT)) {
@@ -3152,7 +3145,6 @@ static const char *do_last(struct nameidata *nd,
                if (likely(dentry))
                        goto finish_lookup;
 
-               BUG_ON(nd->inode != dir->d_inode);
                BUG_ON(nd->flags & LOOKUP_RCU);
        } else {
                /* create side of things */
@@ -3162,7 +3154,7 @@ static const char *do_last(struct nameidata *nd,
                 * about to look up
                 */
                error = complete_walk(nd);
-               if (error)
+               if (unlikely(error))
                        return ERR_PTR(error);
 
                audit_inode(nd->name, dir, AUDIT_INODE_PARENT);
@@ -3191,10 +3183,8 @@ static const char *do_last(struct nameidata *nd,
        else
                inode_unlock_shared(dir->d_inode);
 
-       if (got_write) {
+       if (got_write)
                mnt_drop_write(nd->path.mnt);
-               got_write = false;
-       }
 
        if (IS_ERR(dentry))
                return ERR_CAST(dentry);
@@ -3202,7 +3192,7 @@ static const char *do_last(struct nameidata *nd,
        if (file->f_mode & (FMODE_OPENED | FMODE_CREATED)) {
                dput(nd->path.dentry);
                nd->path.dentry = dentry;
-               goto finish_open_created;
+               return NULL;
        }
 
 finish_lookup:
@@ -3218,12 +3208,29 @@ finish_lookup:
                audit_inode(nd->name, nd->path.dentry, 0);
                return ERR_PTR(-EEXIST);
        }
-finish_open:
+
        /* Why this, you ask?  _Now_ we might have grown LOOKUP_JUMPED... */
-       error = complete_walk(nd);
-       if (error)
-               return ERR_PTR(error);
-finish_open_created:
+       return ERR_PTR(complete_walk(nd));
+}
+
+/*
+ * Handle the last step of open()
+ */
+static const char *do_last(struct nameidata *nd,
+                  struct file *file, const struct open_flags *op)
+{
+       kuid_t dir_uid = nd->inode->i_uid;
+       umode_t dir_mode = nd->inode->i_mode;
+       int open_flag = op->open_flag;
+       bool do_truncate;
+       int acc_mode;
+       const char *link;
+       int error;
+
+       link = open_last_lookups(nd, file, op);
+       if (unlikely(link))
+               return link;
+
        if (!(file->f_mode & FMODE_CREATED))
                audit_inode(nd->name, nd->path.dentry, 0);
        if (open_flag & O_CREAT) {