1 files changed, 46 insertions, 11 deletions

diff --git a/fs/overlayfs/readdir.c b/fs/overlayfs/readdir.c
index 8c98578d27a1..c11f5c0906c3 100644
--- a/fs/overlayfs/readdir.c
+++ b/fs/overlayfs/readdir.c
@@ -593,8 +593,15 @@ static struct ovl_dir_cache *ovl_cache_get_impure(struct path *path)
 		return ERR_PTR(res);
 	}
 	if (list_empty(&cache->entries)) {
-		/* Good oportunity to get rid of an unnecessary "impure" flag */
-		ovl_do_removexattr(ovl_dentry_upper(dentry), OVL_XATTR_IMPURE);
+		/*
+		 * A good opportunity to get rid of an unneeded "impure" flag.
+		 * Removing the "impure" xattr is best effort.
+		 */
+		if (!ovl_want_write(dentry)) {
+			ovl_do_removexattr(ovl_dentry_upper(dentry),
+					   OVL_XATTR_IMPURE);
+			ovl_drop_write(dentry);
+		}
 		ovl_clear_flag(OVL_IMPURE, d_inode(dentry));
 		kfree(cache);
 		return NULL;
@@ -769,10 +776,14 @@ static int ovl_dir_fsync(struct file *file, loff_t start, loff_t end,
 	struct dentry *dentry = file->f_path.dentry;
 	struct file *realfile = od->realfile;
 
+	/* Nothing to sync for lower */
+	if (!OVL_TYPE_UPPER(ovl_path_type(dentry)))
+		return 0;
+
 	/*
 	 * Need to check if we started out being a lower dir, but got copied up
 	 */
-	if (!od->is_upper && OVL_TYPE_UPPER(ovl_path_type(dentry))) {
+	if (!od->is_upper) {
 		struct inode *inode = file_inode(file);
 
 		realfile = READ_ONCE(od->upperfile);
@@ -858,8 +869,11 @@ int ovl_check_empty_dir(struct dentry *dentry, struct list_head *list)
 	int err;
 	struct ovl_cache_entry *p, *n;
 	struct rb_root root = RB_ROOT;
+	const struct cred *old_cred;
 
+	old_cred = ovl_override_creds(dentry->d_sb);
 	err = ovl_dir_read_merged(dentry, list, &root);
+	revert_creds(old_cred);
 	if (err)
 		return err;
 
@@ -1016,13 +1030,13 @@ void ovl_workdir_cleanup(struct inode *dir, struct vfsmount *mnt,
 	}
 }
 
-int ovl_indexdir_cleanup(struct dentry *dentry, struct vfsmount *mnt,
-			 struct ovl_path *lower, unsigned int numlower)
+int ovl_indexdir_cleanup(struct ovl_fs *ofs)
 {
 	int err;
+	struct dentry *indexdir = ofs->indexdir;
 	struct dentry *index = NULL;
-	struct inode *dir = dentry->d_inode;
-	struct path path = { .mnt = mnt, .dentry = dentry };
+	struct inode *dir = indexdir->d_inode;
+	struct path path = { .mnt = ofs->upper_mnt, .dentry = indexdir };
 	LIST_HEAD(list);
 	struct rb_root root = RB_ROOT;
 	struct ovl_cache_entry *p;
@@ -1046,19 +1060,40 @@ int ovl_indexdir_cleanup(struct dentry *dentry, struct vfsmount *mnt,
 			if (p->len == 2 && p->name[1] == '.')
 				continue;
 		}
-		index = lookup_one_len(p->name, dentry, p->len);
+		index = lookup_one_len(p->name, indexdir, p->len);
 		if (IS_ERR(index)) {
 			err = PTR_ERR(index);
 			index = NULL;
 			break;
 		}
-		err = ovl_verify_index(index, lower, numlower);
-		/* Cleanup stale and orphan index entries */
-		if (err && (err == -ESTALE || err == -ENOENT))
+		err = ovl_verify_index(ofs, index);
+		if (!err) {
+			goto next;
+		} else if (err == -ESTALE) {
+			/* Cleanup stale index entries */
+			err = ovl_cleanup(dir, index);
+		} else if (err != -ENOENT) {
+			/*
+			 * Abort mount to avoid corrupting the index if
+			 * an incompatible index entry was found or on out
+			 * of memory.
+			 */
+			break;
+		} else if (ofs->config.nfs_export) {
+			/*
+			 * Whiteout orphan index to block future open by
+			 * handle after overlay nlink dropped to zero.
+			 */
+			err = ovl_cleanup_and_whiteout(indexdir, dir, index);
+		} else {
+			/* Cleanup orphan index entries */
 			err = ovl_cleanup(dir, index);
+		}
+
 		if (err)
 			break;
 
+next:
 		dput(index);
 		index = NULL;
 	}