From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx0b-00082601.pphosted.com ([67.231.153.30]:48786 "EHLO mx0a-00082601.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1754558AbbHLPQY (ORCPT ); Wed, 12 Aug 2015 11:16:24 -0400 Message-ID: <55CB631B.2080404@fb.com> Date: Wed, 12 Aug 2015 11:15:39 -0400 From: Josef Bacik MIME-Version: 1.0 To: Marc MERLIN CC: , , Subject: Re: kernel BUG at fs/btrfs/extent-tree.c:8113! (4.1.3 kernel) References: <20150706212156.GY17274@merlins.org> <20150710134348.GB15535@suse.cz> <20150712010229.GA5284@merlins.org> <20150723115558.GQ6306@suse.cz> <20150724162446.GH30815@merlins.org> <20150803035130.GL24824@merlins.org> <20150811050758.GF29259@merlins.org> <55CA177D.1050004@fb.com> <20150812144749.GY24824@merlins.org> In-Reply-To: <20150812144749.GY24824@merlins.org> Content-Type: text/plain; charset="windows-1252"; format=flowed Sender: linux-btrfs-owner@vger.kernel.org List-ID: On 08/12/2015 10:47 AM, Marc MERLIN wrote: > On Tue, Aug 11, 2015 at 11:40:45AM -0400, Josef Bacik wrote: >> From a48cf7a9ae44a17d927df5542c8b0be287aee9ed Mon Sep 17 00:00:00 2001 >> From: Josef Bacik >> Date: Tue, 11 Aug 2015 11:39:37 -0400 >> Subject: [PATCH] Btrfs: kill BUG_ON() in btrfs_lookup_extent_info() >> >> Replace it with an ASSERT(0) for the developers and an error for not the >> developers. > > Thanks. We knocked one down and now another BUG has been triggered :) > > if (unlikely(wc->refs[level - 1] == 0)) { > btrfs_err(root->fs_info, "Missing references."); > BUG(); > } > This is why you got your own branch, it's never just one. Here's the next bit From 07214b5294d2772682aba893de15ef8020994598 Mon Sep 17 00:00:00 2001 From: Josef Bacik Date: Wed, 12 Aug 2015 11:06:42 -0400 Subject: [PATCH] Btrfs: don't BUG() during drop snapshot Really there's lots of things that can go wrong here, kill all the BUG_ON()'s and replace the logic ones with ASSERT()'s and return EIO instead. Also fix the leak of next in one of the error conditions while we're at it. Thanks, Signed-off-by: Josef Bacik --- fs/btrfs/extent-tree.c | 27 +++++++++++++++++++++++---- 1 file changed, 23 insertions(+), 4 deletions(-) diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index f7fb120..6671faf 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -8196,12 +8196,15 @@ static noinline int do_walk_down(struct btrfs_trans_handle *trans, &wc->flags[level - 1]); if (ret < 0) { btrfs_tree_unlock(next); + free_extent_buffer(next); return ret; } if (unlikely(wc->refs[level - 1] == 0)) { btrfs_err(root->fs_info, "Missing references."); - BUG(); + btrfs_tree_unlock(next); + free_extent_buffer(next); + return -EIO; } *lookup_info = 0; @@ -8253,7 +8256,13 @@ static noinline int do_walk_down(struct btrfs_trans_handle *trans, } level--; - BUG_ON(level != btrfs_header_level(next)); + ASSERT(level == btrfs_header_level(next)); + if (level != btrfs_header_level(next)) { + printk(KERN_ERR "Mismatched level\n"); + btrfs_tree_unlock(next); + free_extent_buffer(next); + return -EIO; + } path->nodes[level] = next; path->slots[level] = 0; path->locks[level] = BTRFS_WRITE_LOCK_BLOCKING; @@ -8268,8 +8277,14 @@ skip: if (wc->flags[level] & BTRFS_BLOCK_FLAG_FULL_BACKREF) { parent = path->nodes[level]->start; } else { - BUG_ON(root->root_key.objectid != + ASSERT(root->root_key.objectid == btrfs_header_owner(path->nodes[level])); + if (root->root_key.objectid != + btrfs_header_owner(path->nodes[level])) { + printk(KERN_ERR "Mismatched block owner\n"); + btrfs_tree_unlock(next); + free_extent_buffer(next); + } parent = 0; } @@ -8285,7 +8300,11 @@ skip: } ret = btrfs_free_extent(trans, root, bytenr, blocksize, parent, root->root_key.objectid, level - 1, 0, 0); - BUG_ON(ret); /* -ENOMEM */ + if (ret) { + btrfs_tree_unlock(next); + free_extent_buffer(next); + return ret; + } } btrfs_tree_unlock(next); free_extent_buffer(next); -- 2.1.0