Merge branch 'overlayfs-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs

Pull overlayfs fixes from Miklos Szeredi:
 "Overlayfs bug fixes.  All marked as -stable material"

* 'overlayfs-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs:
  ovl: copy new uid/gid into overlayfs runtime inode
  ovl: ignore lower entries when checking purity of non-directory entries
  ovl: fix getcwd() failure after unsuccessful rmdir
  ovl: fix working on distributed fs as lower layer

3 files changed, 19 insertions, 6 deletions

diff --git a/fs/overlayfs/dir.c b/fs/overlayfs/dir.c
index ed95272d57a6..52f6de5d40a9 100644
--- a/fs/overlayfs/dir.c
+++ b/fs/overlayfs/dir.c
@@ -618,7 +618,8 @@ static int ovl_remove_upper(struct dentry *dentry, bool is_dir)
          * sole user of this dentry.  Too tricky...  Just unhash for
          * now.
          */
-        d_drop(dentry);
+        if (!err)
+                d_drop(dentry);
         inode_unlock(dir);
 
         return err;
@@ -903,6 +904,13 @@ static int ovl_rename2(struct inode *olddir, struct dentry *old,
         if (!overwrite && new_is_dir && !old_opaque && new_opaque)
                 ovl_remove_opaque(newdentry);
 
+        /*
+         * Old dentry now lives in different location. Dentries in
+         * lowerstack are stale. We cannot drop them here because
+         * access to them is lockless. This could be only pure upper
+         * or opaque directory - numlower is zero. Or upper non-dir
+         * entry - its pureness is tracked by flag opaque.
+         */
         if (old_opaque != new_opaque) {
                 ovl_dentry_set_opaque(old, new_opaque);
                 if (!overwrite)
diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c
index 49e204560655..a4ff5d0d7db9 100644
--- a/fs/overlayfs/inode.c
+++ b/fs/overlayfs/inode.c
@@ -65,6 +65,8 @@ int ovl_setattr(struct dentry *dentry, struct iattr *attr)
 
                 inode_lock(upperdentry->d_inode);
                 err = notify_change(upperdentry, attr, NULL);
+                if (!err)
+                        ovl_copyattr(upperdentry->d_inode, dentry->d_inode);
                 inode_unlock(upperdentry->d_inode);
         }
         ovl_drop_write(dentry);
diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c
index 8d826bd56b26..619ad4b016d2 100644
--- a/fs/overlayfs/super.c
+++ b/fs/overlayfs/super.c
@@ -76,12 +76,14 @@ enum ovl_path_type ovl_path_type(struct dentry *dentry)
         if (oe->__upperdentry) {
                 type = __OVL_PATH_UPPER;
 
-                if (oe->numlower) {
-                        if (S_ISDIR(dentry->d_inode->i_mode))
-                                type |= __OVL_PATH_MERGE;
-                } else if (!oe->opaque) {
+                /*
+                 * Non-dir dentry can hold lower dentry from previous
+                 * location. Its purity depends only on opaque flag.
+                 */
+                if (oe->numlower && S_ISDIR(dentry->d_inode->i_mode))
+                        type |= __OVL_PATH_MERGE;
+                else if (!oe->opaque)
                         type |= __OVL_PATH_PURE;
-                }
         } else {
                 if (oe->numlower > 1)
                         type |= __OVL_PATH_MERGE;
@@ -341,6 +343,7 @@ static const struct dentry_operations ovl_dentry_operations = {
 
 static const struct dentry_operations ovl_reval_dentry_operations = {
         .d_release = ovl_dentry_release,
+        .d_select_inode = ovl_d_select_inode,
         .d_revalidate = ovl_dentry_revalidate,
         .d_weak_revalidate = ovl_dentry_weak_revalidate,
 };