From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:57070 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751586AbdKFJZI (ORCPT ); Mon, 6 Nov 2017 04:25:08 -0500 Subject: Patch "ext4: fix stripe-unaligned allocations" has been added to the 4.4-stable tree To: jack@suse.cz, alexander.levin@verizon.com, gregkh@linuxfoundation.org, ross.zwisler@linux.intel.com, tytso@mit.edu Cc: , From: Date: Mon, 06 Nov 2017 10:25:06 +0100 Message-ID: <150996030613398@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 ext4: fix stripe-unaligned allocations to the 4.4-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: ext4-fix-stripe-unaligned-allocations.patch and it can be found in the queue-4.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From foo@baz Mon Nov 6 10:22:56 CET 2017 From: Jan Kara Date: Sat, 7 Oct 2017 22:37:45 +0000 Subject: ext4: fix stripe-unaligned allocations From: Jan Kara [ Upstream commit d9b22cf9f5466a057f2a4f1e642b469fa9d73117 ] When a filesystem is created using: mkfs.ext4 -b 4096 -E stride=512 and we try to allocate 64MB extent, we will end up directly in ext4_mb_complex_scan_group(). This is because the request is detected as power-of-two allocation (so we start in ext4_mb_regular_allocator() with ac_criteria == 0) however the check before ext4_mb_simple_scan_group() refuses the direct buddy scan because the allocation request is too large. Since cr == 0, the check whether we should use ext4_mb_scan_aligned() fails as well and we fall back to ext4_mb_complex_scan_group(). Fix the problem by checking for upper limit on power-of-two requests directly when detecting them. Reported-by: Ross Zwisler Signed-off-by: Jan Kara Signed-off-by: Theodore Ts'o Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- fs/ext4/mballoc.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) --- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c @@ -2136,8 +2136,10 @@ ext4_mb_regular_allocator(struct ext4_al * We search using buddy data only if the order of the request * is greater than equal to the sbi_s_mb_order2_reqs * You can tune it via /sys/fs/ext4//mb_order2_req + * We also support searching for power-of-two requests only for + * requests upto maximum buddy size we have constructed. */ - if (i >= sbi->s_mb_order2_reqs) { + if (i >= sbi->s_mb_order2_reqs && i <= sb->s_blocksize_bits + 2) { /* * This should tell if fe_len is exactly power of 2 */ @@ -2207,7 +2209,7 @@ repeat: } ac->ac_groups_scanned++; - if (cr == 0 && ac->ac_2order < sb->s_blocksize_bits+2) + if (cr == 0) ext4_mb_simple_scan_group(ac, &e4b); else if (cr == 1 && sbi->s_stripe && !(ac->ac_g_ex.fe_len % sbi->s_stripe)) Patches currently in stable-queue which might be from jack@suse.cz are queue-4.4/ext4-fix-stripe-unaligned-allocations.patch queue-4.4/ext4-do-not-use-stripe_width-if-it-is-not-set.patch