untangling do_lookup() - expand the area under ->i_mutex
Al Viro [Fri, 30 Mar 2012 18:08:28 +0000 (14:08 -0400)]
keep holding ->i_mutex over revalidation parts

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

fs/namei.c

index 157f3de..48fc0fb 100644 (file)
@@ -1173,6 +1173,7 @@ retry:
                BUG_ON(nd->inode != dir);
 
                mutex_lock(&dir->i_mutex);
+l:
                dentry = d_lookup(parent, name);
                if (likely(!dentry)) {
                        dentry = d_alloc_and_lookup(parent, name, nd);
@@ -1193,11 +1194,11 @@ retry:
                        need_reval = 0;
                        status = 1;
                }
-               mutex_unlock(&dir->i_mutex);
                if (unlikely(dentry->d_flags & DCACHE_OP_REVALIDATE) && need_reval)
                        status = d_revalidate(dentry, nd);
                if (unlikely(status <= 0)) {
                        if (status < 0) {
+                               mutex_unlock(&dir->i_mutex);
                                dput(dentry);
                                return status;
                        }
@@ -1205,9 +1206,10 @@ retry:
                                dput(dentry);
                                dentry = NULL;
                                need_reval = 1;
-                               goto retry;
+                               goto l;
                        }
                }
+               mutex_unlock(&dir->i_mutex);
                goto done;
        }
        if (unlikely(dentry->d_flags & DCACHE_OP_REVALIDATE) && need_reval)