From patchwork Thu May 27 00:19:42 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dave Chinner X-Patchwork-Id: 12283083 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8A97AC47082 for ; Thu, 27 May 2021 00:19:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5E911613CD for ; Thu, 27 May 2021 00:19:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232430AbhE0AVW (ORCPT ); Wed, 26 May 2021 20:21:22 -0400 Received: from mail106.syd.optusnet.com.au ([211.29.132.42]:51377 "EHLO mail106.syd.optusnet.com.au" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232381AbhE0AVV (ORCPT ); Wed, 26 May 2021 20:21:21 -0400 Received: from dread.disaster.area (pa49-180-230-185.pa.nsw.optusnet.com.au [49.180.230.185]) by mail106.syd.optusnet.com.au (Postfix) with ESMTPS id 0C5B080B96F for ; Thu, 27 May 2021 10:19:47 +1000 (AEST) Received: from discord.disaster.area ([192.168.253.110]) by dread.disaster.area with esmtp (Exim 4.92.3) (envelope-from ) id 1lm3kV-005ccV-3X for linux-xfs@vger.kernel.org; Thu, 27 May 2021 10:19:43 +1000 Received: from dave by discord.disaster.area with local (Exim 4.94) (envelope-from ) id 1lm3kU-004gE5-Pm for linux-xfs@vger.kernel.org; Thu, 27 May 2021 10:19:42 +1000 From: Dave Chinner To: linux-xfs@vger.kernel.org Subject: [PATCH] xfs: btree format inode forks can have zero extents Date: Thu, 27 May 2021 10:19:42 +1000 Message-Id: <20210527001942.1115586-1-david@fromorbit.com> X-Mailer: git-send-email 2.31.1 MIME-Version: 1.0 X-Optus-CM-Score: 0 X-Optus-CM-Analysis: v=2.3 cv=YKPhNiOx c=1 sm=1 tr=0 a=dUIOjvib2kB+GiIc1vUx8g==:117 a=dUIOjvib2kB+GiIc1vUx8g==:17 a=5FLXtPjwQuUA:10 a=20KFwNOVAAAA:8 a=RfcaFHgcWMp4lnFpylIA:9 Precedence: bulk List-ID: X-Mailing-List: linux-xfs@vger.kernel.org From: Dave Chinner xfs/538 is assert failing with this trace when testing with directory block sizes of 64kB: XFS: Assertion failed: !xfs_need_iread_extents(ifp), file: fs/xfs/libxfs/xfs_bmap.c, line: 608 .... Call Trace: xfs_bmap_btree_to_extents+0x2a9/0x470 ? kmem_cache_alloc+0xe7/0x220 __xfs_bunmapi+0x4ca/0xdf0 xfs_bunmapi+0x1a/0x30 xfs_dir2_shrink_inode+0x71/0x210 xfs_dir2_block_to_sf+0x2ae/0x410 xfs_dir2_block_removename+0x21a/0x280 xfs_dir_removename+0x195/0x1d0 xfs_remove+0x244/0x460 xfs_vn_unlink+0x53/0xa0 ? selinux_inode_unlink+0x13/0x20 vfs_unlink+0x117/0x220 do_unlinkat+0x1a2/0x2d0 __x64_sys_unlink+0x42/0x60 do_syscall_64+0x3a/0x70 entry_SYSCALL_64_after_hwframe+0x44/0xae This is a check to ensure that the extents have been read into memory before we are doing a ifork btree manipulation. This assert is bogus in the above case. We have a fragmented directory block that has more extents in it than can fit in extent format, so the inode data fork is in btree format. xfs_dir2_shrink_inode() asks to remove all remaining 16 filesystem blocks from the inode so it can convert to short form, and __xfs_bunmapi() removes all the extents. We now have a data fork in btree format but have zero extents in the fork. This incorrectly trips the xfs_need_iread_extents() assert because it assumes that an empty extent btree means the extent tree has not been read into memory yet. This is clearly not the case with xfs_bunmapi(), as it has an explicit call to xfs_iread_extents() in it to pull the extents into memory before it starts unmapping. Also, the assert directly after this bogus one is: ASSERT(ifp->if_format == XFS_DINODE_FMT_BTREE); Which covers the context in which it is legal to call xfs_bmap_btree_to_extents just fine. Hence we should just remove the bogus assert as it is clearly wrong and causes a regression. The returns the test behaviour to the pre-existing assert failure in xfs_dir2_shrink_inode() that indicates xfs_bunmapi() has failed to remove all the extents in the range it was asked to unmap. Signed-off-by: Dave Chinner Reviewed-by: Chandan Babu R --- fs/xfs/libxfs/xfs_bmap.c | 1 - 1 file changed, 1 deletion(-) diff --git a/fs/xfs/libxfs/xfs_bmap.c b/fs/xfs/libxfs/xfs_bmap.c index 7e3b9b01431e..3f8b6da09261 100644 --- a/fs/xfs/libxfs/xfs_bmap.c +++ b/fs/xfs/libxfs/xfs_bmap.c @@ -605,7 +605,6 @@ xfs_bmap_btree_to_extents( ASSERT(cur); ASSERT(whichfork != XFS_COW_FORK); - ASSERT(!xfs_need_iread_extents(ifp)); ASSERT(ifp->if_format == XFS_DINODE_FMT_BTREE); ASSERT(be16_to_cpu(rblock->bb_level) == 1); ASSERT(be16_to_cpu(rblock->bb_numrecs) == 1);