From: Eric Whitney Subject: [PATCH V2] e2fsck: fix multiply-claimed block quota accounting when deleting files Date: Thu, 11 May 2017 11:46:32 -0400 Message-ID: <20170511154632.GB11505@localhost.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: tytso@mit.edu To: linux-ext4@vger.kernel.org Return-path: Received: from mail-qk0-f194.google.com ([209.85.220.194]:35972 "EHLO mail-qk0-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757186AbdEKPoi (ORCPT ); Thu, 11 May 2017 11:44:38 -0400 Received: by mail-qk0-f194.google.com with SMTP id y128so4181683qka.3 for ; Thu, 11 May 2017 08:44:38 -0700 (PDT) Content-Disposition: inline Sender: linux-ext4-owner@vger.kernel.org List-ID: As e2fsck processes each file in pass1, the actual file system quota is increased by the number of blocks discovered in the file. This can include both non-multiply-claimed and multiply-claimed blocks, if the latter exist. However, if a file containing multiply-claimed blocks is then deleted in pass1b, those blocks are not taken into account when decreasing the actual quota. In this case, the new quota values written to the file system by e2fsck overstate the space actually consumed. And, e2fsck must be run twice on the file system to fully correct quota. Fix this by counting multiply-claimed blocks as a debit to quota when deleting files in pass1b. [V2] Correct a dangling else bug in the original patch. Signed-off-by: Eric Whitney --- e2fsck/pass1b.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/e2fsck/pass1b.c b/e2fsck/pass1b.c index b40f026..d22cffd 100644 --- a/e2fsck/pass1b.c +++ b/e2fsck/pass1b.c @@ -637,9 +637,11 @@ static int delete_file_block(ext2_filsys fs, if (ext2fs_test_block_bitmap2(ctx->block_dup_map, *block_nr)) { n = dict_lookup(&clstr_dict, INT_TO_VOIDPTR(c)); if (n) { - p = (struct dup_cluster *) dnode_get(n); - if (lc != pb->cur_cluster) + if (lc != pb->cur_cluster) { + p = (struct dup_cluster *) dnode_get(n); decrement_badcount(ctx, *block_nr, p); + pb->dup_blocks++; + } } else com_err("delete_file_block", 0, _("internal error: can't find dup_blk for %llu\n"), -- 2.1.4