From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8AF8CC433EF for ; Tue, 16 Nov 2021 01:47:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 797F661265 for ; Tue, 16 Nov 2021 01:47:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1351537AbhKPBuI (ORCPT ); Mon, 15 Nov 2021 20:50:08 -0500 Received: from mail.kernel.org ([198.145.29.99]:60610 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241470AbhKOSUi (ORCPT ); Mon, 15 Nov 2021 13:20:38 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id C406463275; Mon, 15 Nov 2021 17:52:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1636998758; bh=D2tkhKgc+aknwoFkPJgK9qqGGn2tCgSWZ9boUPL98ZM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=PEviLEllZoxw72xMrXXX1jtCuiBP1KHCC1O13/ilLOTCs/qEyeDNELVaVTdFYe0TO V7K7DBU/TkRf0BZ67foUDTLZg2HjPgbt9m6/8A32DasKYW/MLI2HSH2dLsCNewCMHn ikEKGhIj/NTH5TBJD4xI+YK6vW2Jz7qR8dhbn4IQ= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, stable@kernel.org, yangerkun , Theodore Tso Subject: [PATCH 5.14 050/849] ext4: refresh the ext4_ext_path struct after dropping i_data_sem. Date: Mon, 15 Nov 2021 17:52:13 +0100 Message-Id: <20211115165421.697911536@linuxfoundation.org> X-Mailer: git-send-email 2.33.1 In-Reply-To: <20211115165419.961798833@linuxfoundation.org> References: <20211115165419.961798833@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: yangerkun commit 1811bc401aa58c7bdb0df3205aa6613b49d32127 upstream. After we drop i_data sem, we need to reload the ext4_ext_path structure since the extent tree can change once i_data_sem is released. This addresses the BUG: [52117.465187] ------------[ cut here ]------------ [52117.465686] kernel BUG at fs/ext4/extents.c:1756! ... [52117.478306] Call Trace: [52117.478565] ext4_ext_shift_extents+0x3ee/0x710 [52117.479020] ext4_fallocate+0x139c/0x1b40 [52117.479405] ? __do_sys_newfstat+0x6b/0x80 [52117.479805] vfs_fallocate+0x151/0x4b0 [52117.480177] ksys_fallocate+0x4a/0xa0 [52117.480533] __x64_sys_fallocate+0x22/0x30 [52117.480930] do_syscall_64+0x35/0x80 [52117.481277] entry_SYSCALL_64_after_hwframe+0x44/0xae [52117.481769] RIP: 0033:0x7fa062f855ca Cc: stable@kernel.org Link: https://lore.kernel.org/r/20210903062748.4118886-4-yangerkun@huawei.com Signed-off-by: yangerkun Signed-off-by: Theodore Ts'o Signed-off-by: Greg Kroah-Hartman --- fs/ext4/extents.c | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-) --- a/fs/ext4/extents.c +++ b/fs/ext4/extents.c @@ -5006,8 +5006,11 @@ ext4_ext_shift_path_extents(struct ext4_ restart_credits = ext4_writepage_trans_blocks(inode); err = ext4_datasem_ensure_credits(handle, inode, credits, restart_credits, 0); - if (err) + if (err) { + if (err > 0) + err = -EAGAIN; goto out; + } err = ext4_ext_get_access(handle, inode, path + depth); if (err) @@ -5081,6 +5084,7 @@ ext4_ext_shift_extents(struct inode *ino int ret = 0, depth; struct ext4_extent *extent; ext4_lblk_t stop, *iterator, ex_start, ex_end; + ext4_lblk_t tmp = EXT_MAX_BLOCKS; /* Let path point to the last extent */ path = ext4_find_extent(inode, EXT_MAX_BLOCKS - 1, NULL, @@ -5134,11 +5138,15 @@ ext4_ext_shift_extents(struct inode *ino * till we reach stop. In case of right shift, iterator points to stop * and it is decreased till we reach start. */ +again: if (SHIFT == SHIFT_LEFT) iterator = &start; else iterator = &stop; + if (tmp != EXT_MAX_BLOCKS) + *iterator = tmp; + /* * Its safe to start updating extents. Start and stop are unsigned, so * in case of right shift if extent with 0 block is reached, iterator @@ -5167,6 +5175,7 @@ ext4_ext_shift_extents(struct inode *ino } } + tmp = *iterator; if (SHIFT == SHIFT_LEFT) { extent = EXT_LAST_EXTENT(path[depth].p_hdr); *iterator = le32_to_cpu(extent->ee_block) + @@ -5185,6 +5194,9 @@ ext4_ext_shift_extents(struct inode *ino } ret = ext4_ext_shift_path_extents(path, shift, inode, handle, SHIFT); + /* iterator can be NULL which means we should break */ + if (ret == -EAGAIN) + goto again; if (ret) break; }