cifs: Deferred close performance improvements

During unlink/rename instead of closing all the deferred handles
under tcon, close only handles under the requested dentry.
Signed-off-by: Rohith Surabattula <rohiths@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

fs/cifs/cifsproto.h

@@ -267,6 +267,9 @@ extern void cifs_close_deferred_file(struct cifsInodeInfo *cifs_inode);
 
 extern void cifs_close_all_deferred_files(struct cifs_tcon *cifs_tcon);
 
+extern void cifs_close_deferred_file_under_dentry(struct cifs_tcon *cifs_tcon,
+				const char *path);
+
 extern struct TCP_Server_Info *cifs_get_tcp_session(struct smb3_fs_context *ctx);
 extern void cifs_put_tcp_session(struct TCP_Server_Info *server,
 				 int from_reconnect);

fs/cifs/inode.c

@@ -1624,7 +1624,7 @@ int cifs_unlink(struct inode *dir, struct dentry *dentry)
 		goto unlink_out;
 	}
 
-	cifs_close_deferred_file(CIFS_I(inode));
+	cifs_close_deferred_file_under_dentry(tcon, full_path);
 	if (cap_unix(tcon->ses) && (CIFS_UNIX_POSIX_PATH_OPS_CAP &
 				le64_to_cpu(tcon->fsUnixInfo.Capability))) {
 		rc = CIFSPOSIXDelFile(xid, tcon, full_path,
@@ -2113,9 +2113,9 @@ cifs_rename2(struct user_namespace *mnt_userns, struct inode *source_dir,
 		goto cifs_rename_exit;
 	}
 
-	cifs_close_deferred_file(CIFS_I(d_inode(source_dentry)));
+	cifs_close_deferred_file_under_dentry(tcon, from_name);
 	if (d_inode(target_dentry) != NULL)
-		cifs_close_deferred_file(CIFS_I(d_inode(target_dentry)));
+		cifs_close_deferred_file_under_dentry(tcon, to_name);
 
 	rc = cifs_do_rename(xid, source_dentry, from_name, target_dentry,
 			    to_name);

fs/cifs/misc.c

@@ -780,6 +780,43 @@ cifs_close_all_deferred_files(struct cifs_tcon *tcon)
 		kfree(tmp_list);
 	}
 }
+void
+cifs_close_deferred_file_under_dentry(struct cifs_tcon *tcon, const char *path)
+{
+	struct cifsFileInfo *cfile;
+	struct list_head *tmp;
+	struct file_list *tmp_list, *tmp_next_list;
+	struct list_head file_head;
+	void *page;
+	const char *full_path;
+
+	INIT_LIST_HEAD(&file_head);
+	page = alloc_dentry_path();
+	spin_lock(&tcon->open_file_lock);
+	list_for_each(tmp, &tcon->openFileList) {
+		cfile = list_entry(tmp, struct cifsFileInfo, tlist);
+		full_path = build_path_from_dentry(cfile->dentry, page);
+		if (strstr(full_path, path)) {
+			if (delayed_work_pending(&cfile->deferred)) {
+				if (cancel_delayed_work(&cfile->deferred)) {
+					tmp_list = kmalloc(sizeof(struct file_list), GFP_ATOMIC);
+					if (tmp_list == NULL)
+						break;
+					tmp_list->cfile = cfile;
+					list_add_tail(&tmp_list->list, &file_head);
+				}
+			}
+		}
+	}
+	spin_unlock(&tcon->open_file_lock);
+
+	list_for_each_entry_safe(tmp_list, tmp_next_list, &file_head, list) {
+		_cifsFileInfo_put(tmp_list->cfile, true, false);
+		list_del(&tmp_list->list);
+		kfree(tmp_list);
+	}
+	free_dentry_path(page);
+}
 
 /* parses DFS refferal V3 structure
  * caller is responsible for freeing target_nodes