[PATCH 01/12] vfs: Document the effect of d_revalidate on d_find_alias

[ebiederm@xmission.com (Eric W. Biederman)]

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 <miklos@szeredi.hu>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
---
 fs/dcache.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)

diff --git a/fs/dcache.c b/fs/dcache.c
index 265e0ce9769c..c71c86f7780e 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -726,7 +726,8 @@ 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 unless @want_discon is set,
-- 
1.7.5.4