vfs: Document the effect of d_revalidate on d_find_alias

d_drop or check_submounts_and_drop called from d_revalidate can result in renamed directories with child dentries being unhashed. These renamed and drop directory dentries can be rehashed after d_materialise_unique uses d_find_alias to find them. Reviewed-by: Miklos Szeredi <[email protected]> Signed-off-by: "Eric W. Biederman" <[email protected]> Signed-off-by: Al Viro <[email protected]>
ambv · Oct 9, 2014 · 3ccb354 · 3ccb354
1 parent 9ea459e
commit 3ccb354
Showing 1 changed file with 2 additions and 1 deletion.
diff --git a/fs/dcache.c b/fs/dcache.c
@@ -761,7 +761,8 @@ EXPORT_SYMBOL(dget_parent);
  * acquire the reference to alias and return it. Otherwise return NULL.
  * Notice that if inode is a directory there can be only one alias and
  * it can be unhashed only if it has no children, or if it is the root
- * of a filesystem.
+ * of a filesystem, or if the directory was renamed and d_revalidate
+ * was the first vfs operation to notice.
  *
  * If the inode has an IS_ROOT, DCACHE_DISCONNECTED alias, then prefer
  * any other hashed alias over that one.