From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from cn.fujitsu.com ([59.151.112.132]:11500 "EHLO heian.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1750786AbbIKA1U (ORCPT ); Thu, 10 Sep 2015 20:27:20 -0400 Subject: Re: [PATCH] btrfs-progs: fix cross stripe boundary check To: David Sterba , References: <1441897376-5572-1-git-send-email-dsterba@suse.com> From: Qu Wenruo Message-ID: <55F21FE5.2030008@cn.fujitsu.com> Date: Fri, 11 Sep 2015 08:27:17 +0800 MIME-Version: 1.0 In-Reply-To: <1441897376-5572-1-git-send-email-dsterba@suse.com> Content-Type: text/plain; charset="utf-8"; format=flowed Sender: linux-btrfs-owner@vger.kernel.org List-ID: David Sterba wrote on 2015/09/10 17:02 +0200: > Commit 854437ca3c228d8ab3eb24d2efc1c21b5d56a635 ("btrfs-progs: > extent-tree: avoid allocating tree block that crosses stripe boundary") > does not work for 64k nodesize. Due to an off-by-one error, all queries > to check_crossing_stripes will return that all extents cross a stripe > and this will lead to a false ENOSPC. This crashes later > > $ ./mkfs.btrfs -n 64k image > > ./mkfs.btrfs(btrfs_reserve_extent+0xb77)[0x417f38] > ./mkfs.btrfs(btrfs_alloc_free_block+0x57)[0x417fe0] > ./mkfs.btrfs(__btrfs_cow_block+0x163)[0x408eb7] > ./mkfs.btrfs(btrfs_cow_block+0xd0)[0x4097c4] > ./mkfs.btrfs(btrfs_search_slot+0x16f)[0x40be4d] > ./mkfs.btrfs(btrfs_insert_empty_items+0xc0)[0x40d5f9] > ./mkfs.btrfs(btrfs_insert_item+0x99)[0x40da5f] > ./mkfs.btrfs(btrfs_make_block_group+0x4d)[0x41705c] > ./mkfs.btrfs(main+0xeef)[0x434b56] > > CC: Qu Wenruo > Signed-off-by: David Sterba Nice one, yep, my fault. BTW, any idea to add mkfs test? Reviewed-by: Qu Wenruo Thanks, Qu > --- > volumes.h | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/volumes.h b/volumes.h > index f7761311e8ce..4ecb99314a0c 100644 > --- a/volumes.h > +++ b/volumes.h > @@ -156,7 +156,7 @@ struct map_lookup { > static inline int check_crossing_stripes(u64 start, u64 len) > { > return (start / BTRFS_STRIPE_LEN) != > - ((start + len) / BTRFS_STRIPE_LEN); > + ((start + len - 1) / BTRFS_STRIPE_LEN); > } > > int __btrfs_map_block(struct btrfs_mapping_tree *map_tree, int rw, >