From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:35078 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751791AbdHABQc (ORCPT ); Mon, 31 Jul 2017 21:16:32 -0400 Subject: Patch "dm integrity: fix inefficient allocation of journal space" has been added to the 4.12-stable tree To: mpatocka@redhat.com, gregkh@linuxfoundation.org, snitzer@redhat.com Cc: , From: Date: Mon, 31 Jul 2017 18:16:26 -0700 Message-ID: <1501550186174211@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: This is a note to let you know that I've just added the patch titled dm integrity: fix inefficient allocation of journal space to the 4.12-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: dm-integrity-fix-inefficient-allocation-of-journal-space.patch and it can be found in the queue-4.12 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From 9dd59727dbc21d33a9add4c5b308a5775cd5a6ef Mon Sep 17 00:00:00 2001 From: Mikulas Patocka Date: Wed, 19 Jul 2017 11:23:40 -0400 Subject: dm integrity: fix inefficient allocation of journal space From: Mikulas Patocka commit 9dd59727dbc21d33a9add4c5b308a5775cd5a6ef upstream. When using a block size greater than 512 bytes, the dm-integrity target allocates journal space inefficiently. It allocates one journal entry for each 512-byte chunk of data, fills an entry for each block of data and leaves the remaining entries unused. This issue doesn't cause data corruption, but all the unused journal entries degrade performance severely. For example, with 4k blocks and an 8k bio, it would allocate 16 journal entries but only use 2 entries. The remaining 14 entries were left unused. Fix this by adding the missing 'log2_sectors_per_block' shifts that are required to have each journal entry map to a full block. Signed-off-by: Mikulas Patocka Fixes: 7eada909bfd7 ("dm: add integrity target") Signed-off-by: Mike Snitzer Signed-off-by: Greg Kroah-Hartman --- drivers/md/dm-integrity.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) --- a/drivers/md/dm-integrity.c +++ b/drivers/md/dm-integrity.c @@ -1587,16 +1587,18 @@ retry: if (likely(ic->mode == 'J')) { if (dio->write) { unsigned next_entry, i, pos; - unsigned ws, we; + unsigned ws, we, range_sectors; - dio->range.n_sectors = min(dio->range.n_sectors, ic->free_sectors); + dio->range.n_sectors = min(dio->range.n_sectors, + ic->free_sectors << ic->sb->log2_sectors_per_block); if (unlikely(!dio->range.n_sectors)) goto sleep; - ic->free_sectors -= dio->range.n_sectors; + range_sectors = dio->range.n_sectors >> ic->sb->log2_sectors_per_block; + ic->free_sectors -= range_sectors; journal_section = ic->free_section; journal_entry = ic->free_section_entry; - next_entry = ic->free_section_entry + dio->range.n_sectors; + next_entry = ic->free_section_entry + range_sectors; ic->free_section_entry = next_entry % ic->journal_section_entries; ic->free_section += next_entry / ic->journal_section_entries; ic->n_uncommitted_sections += next_entry / ic->journal_section_entries; Patches currently in stable-queue which might be from mpatocka@redhat.com are queue-4.12/dm-integrity-fix-inefficient-allocation-of-journal-space.patch queue-4.12/dm-integrity-test-for-corrupted-disk-format-during-table-load.patch