From patchwork Tue Oct 1 01:27:40 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Darrick Wong X-Patchwork-Id: 279288 Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 82FE02C0089 for ; Tue, 1 Oct 2013 11:27:45 +1000 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755426Ab3JAB1p (ORCPT ); Mon, 30 Sep 2013 21:27:45 -0400 Received: from aserp1040.oracle.com ([141.146.126.69]:22471 "EHLO aserp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755345Ab3JAB1o (ORCPT ); Mon, 30 Sep 2013 21:27:44 -0400 Received: from ucsinet21.oracle.com (ucsinet21.oracle.com [156.151.31.93]) by aserp1040.oracle.com (Sentrion-MTA-4.3.1/Sentrion-MTA-4.3.1) with ESMTP id r911RgwM021760 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Tue, 1 Oct 2013 01:27:43 GMT Received: from userz7021.oracle.com (userz7021.oracle.com [156.151.31.85]) by ucsinet21.oracle.com (8.14.4+Sun/8.14.4) with ESMTP id r911RgwS008363 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Tue, 1 Oct 2013 01:27:42 GMT Received: from abhmt109.oracle.com (abhmt109.oracle.com [141.146.116.61]) by userz7021.oracle.com (8.14.4+Sun/8.14.4) with ESMTP id r911RfAh008358; Tue, 1 Oct 2013 01:27:41 GMT Received: from localhost (/10.137.226.112) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Mon, 30 Sep 2013 18:27:41 -0700 Subject: [PATCH 09/31] libext2fs: Rewind extent pointer when totally deleting an extent To: tytso@mit.edu, darrick.wong@oracle.com From: "Darrick J. Wong" Cc: linux-ext4@vger.kernel.org Date: Mon, 30 Sep 2013 18:27:40 -0700 Message-ID: <20131001012740.28415.55304.stgit@birch.djwong.org> In-Reply-To: <20131001012642.28415.89353.stgit@birch.djwong.org> References: <20131001012642.28415.89353.stgit@birch.djwong.org> User-Agent: StGit/0.15 MIME-Version: 1.0 X-Source-IP: ucsinet21.oracle.com [156.151.31.93] Sender: linux-ext4-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-ext4@vger.kernel.org During a punch operation, if we decide to delete an extent out of the extent tree, the subsequent extents are moved on top of the current extent (that is to say, they're memmmove'd down one slot). Therefore it is not correct to advance to the next leaf because that means we miss half the extents in the range! Rereading the current pointer should be fine. Signed-off-by: Darrick J. Wong --- lib/ext2fs/punch.c | 22 ++++++++++++++++++++-- 1 file changed, 20 insertions(+), 2 deletions(-) -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html diff --git a/lib/ext2fs/punch.c b/lib/ext2fs/punch.c index b53653a..11c7668 100644 --- a/lib/ext2fs/punch.c +++ b/lib/ext2fs/punch.c @@ -186,6 +186,7 @@ static errcode_t ext2fs_punch_extent(ext2_filsys fs, ext2_ino_t ino, blk64_t free_start, next; __u32 free_count, newlen; int freed = 0; + int op; retval = ext2fs_extent_open2(fs, ino, inode, &handle); if (retval) @@ -195,6 +196,7 @@ static errcode_t ext2fs_punch_extent(ext2_filsys fs, ext2_ino_t ino, if (retval) goto errout; while (1) { + op = EXT2_EXTENT_NEXT_LEAF; dbg_print_extent("main loop", &extent); next = extent.e_lblk + extent.e_len; dbg_printf("start %llu, end %llu, next %llu\n", @@ -256,8 +258,23 @@ static errcode_t ext2fs_punch_extent(ext2_filsys fs, ext2_ino_t ino, dbg_print_extent("replacing", &extent); retval = ext2fs_extent_replace(handle, 0, &extent); } else { + struct ext2fs_extent newex; dbg_printf("deleting current extent%s\n", ""); retval = ext2fs_extent_delete(handle, 0); + if (retval) + goto errout; + /* + * We just moved the next extent into the current + * extent's position, so re-read the extent next time. + */ + retval = ext2fs_extent_get(handle, + EXT2_EXTENT_PREV_LEAF, + &newex); + /* Can't go back? Just reread current. */ + if (retval == EXT2_ET_EXTENT_NO_PREV) { + retval = 0; + op = EXT2_EXTENT_CURRENT; + } } if (retval) goto errout; @@ -268,9 +285,10 @@ static errcode_t ext2fs_punch_extent(ext2_filsys fs, ext2_ino_t ino, freed++; } next_extent: - retval = ext2fs_extent_get(handle, EXT2_EXTENT_NEXT_LEAF, + retval = ext2fs_extent_get(handle, op, &extent); - if (retval == EXT2_ET_EXTENT_NO_NEXT) + if (retval == EXT2_ET_EXTENT_NO_NEXT || + retval == EXT2_ET_NO_CURRENT_NODE) break; if (retval) goto errout;