1 files changed, 27 insertions, 11 deletions

diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c
index 76440feb79f6..e3d5fb651f9a 100644
--- a/fs/overlayfs/super.c
+++ b/fs/overlayfs/super.c
@@ -211,6 +211,7 @@ static void ovl_destroy_inode(struct inode *inode)
 	struct ovl_inode *oi = OVL_I(inode);
 
 	dput(oi->__upperdentry);
+	iput(oi->lower);
 	kfree(oi->redirect);
 	ovl_dir_cache_free(inode);
 	mutex_destroy(&oi->lock);
@@ -520,10 +521,6 @@ static struct dentry *ovl_workdir_create(struct ovl_fs *ofs,
 	bool retried = false;
 	bool locked = false;
 
-	err = mnt_want_write(mnt);
-	if (err)
-		goto out_err;
-
 	inode_lock_nested(dir, I_MUTEX_PARENT);
 	locked = true;
 
@@ -588,7 +585,6 @@ retry:
 		goto out_err;
 	}
 out_unlock:
-	mnt_drop_write(mnt);
 	if (locked)
 		inode_unlock(dir);
 
@@ -703,7 +699,8 @@ static int ovl_lower_dir(const char *name, struct path *path,
 	 * The inodes index feature needs to encode and decode file
 	 * handles, so it requires that all layers support them.
 	 */
-	if (ofs->config.index && !ovl_can_decode_fh(path->dentry->d_sb)) {
+	if (ofs->config.index && ofs->config.upperdir &&
+	    !ovl_can_decode_fh(path->dentry->d_sb)) {
 		ofs->config.index = false;
 		pr_warn("overlayfs: fs on '%s' does not support file handles, falling back to index=off.\n", name);
 	}
@@ -929,12 +926,17 @@ out:
 
 static int ovl_make_workdir(struct ovl_fs *ofs, struct path *workpath)
 {
+	struct vfsmount *mnt = ofs->upper_mnt;
 	struct dentry *temp;
 	int err;
 
+	err = mnt_want_write(mnt);
+	if (err)
+		return err;
+
 	ofs->workdir = ovl_workdir_create(ofs, OVL_WORKDIR_NAME, false);
 	if (!ofs->workdir)
-		return 0;
+		goto out;
 
 	/*
 	 * Upper should support d_type, else whiteouts are visible.  Given
@@ -944,7 +946,7 @@ static int ovl_make_workdir(struct ovl_fs *ofs, struct path *workpath)
 	 */
 	err = ovl_check_d_type_supported(workpath);
 	if (err < 0)
-		return err;
+		goto out;
 
 	/*
 	 * We allowed this configuration and don't want to break users over
@@ -968,6 +970,7 @@ static int ovl_make_workdir(struct ovl_fs *ofs, struct path *workpath)
 	if (err) {
 		ofs->noxattr = true;
 		pr_warn("overlayfs: upper fs does not support xattr.\n");
+		err = 0;
 	} else {
 		vfs_removexattr(ofs->workdir, OVL_XATTR_OPAQUE);
 	}
@@ -979,7 +982,9 @@ static int ovl_make_workdir(struct ovl_fs *ofs, struct path *workpath)
 		pr_warn("overlayfs: upper fs does not support file handles, falling back to index=off.\n");
 	}
 
-	return 0;
+out:
+	mnt_drop_write(mnt);
+	return err;
 }
 
 static int ovl_get_workdir(struct ovl_fs *ofs, struct path *upperpath)
@@ -1026,8 +1031,13 @@ out:
 static int ovl_get_indexdir(struct ovl_fs *ofs, struct ovl_entry *oe,
 			    struct path *upperpath)
 {
+	struct vfsmount *mnt = ofs->upper_mnt;
 	int err;
 
+	err = mnt_want_write(mnt);
+	if (err)
+		return err;
+
 	/* Verify lower root is upper root origin */
 	err = ovl_verify_origin(upperpath->dentry, oe->lowerstack[0].dentry,
 				false, true);
@@ -1055,6 +1065,7 @@ static int ovl_get_indexdir(struct ovl_fs *ofs, struct ovl_entry *oe,
 		pr_warn("overlayfs: try deleting index dir or mounting with '-o index=off' to disable inodes index.\n");
 
 out:
+	mnt_drop_write(mnt);
 	return err;
 }
 
@@ -1257,11 +1268,16 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent)
 		if (err)
 			goto out_free_oe;
 
-		if (!ofs->indexdir)
+		/* Force r/o mount with no index dir */
+		if (!ofs->indexdir) {
+			dput(ofs->workdir);
+			ofs->workdir = NULL;
 			sb->s_flags |= SB_RDONLY;
+		}
+
 	}
 
-	/* Show index=off/on in /proc/mounts for any of the reasons above */
+	/* Show index=off in /proc/mounts for forced r/o mount */
 	if (!ofs->indexdir)
 		ofs->config.index = false;