From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mitch Harder Subject: Re: [PATCH v2] btrfs: fix oops on failure path Date: Mon, 27 Jun 2011 17:27:46 -0500 Message-ID: References: <20110623103109.GN12709@twin.jikos.cz> <20110623163640.GO12709@twin.jikos.cz> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 To: dave@jikos.cz, Daniel J Blueman , Chris Mason , Linux BTRFS Return-path: In-Reply-To: <20110623163640.GO12709@twin.jikos.cz> List-ID: On Thu, Jun 23, 2011 at 11:36 AM, David Sterba wrote: > On Thu, Jun 23, 2011 at 11:01:01PM +0800, Daniel J Blueman wrote: >> On 23 June 2011 18:31, David Sterba wrote: >> (how does one follow up an email in git send-email with the message = id?) > > git-send-email --in-reply-to=3D > > (if it does not ask for it) and paste identifier from mail header > In-Reply-To: > >> If lookup_extent_backref fails, path->nodes[0] reasonably could be >> null along with other callers of btrfs_print_leaf, so ensure we have= a >> valid extent buffer before dereferencing. > > ack. > > > thanks, > david > >> >> Signed-off-by: Daniel J Blueman >> >> diff --git a/fs/btrfs/print-tree.c b/fs/btrfs/print-tree.c >> index fb2605d..f38e452 100644 >> --- a/fs/btrfs/print-tree.c >> +++ b/fs/btrfs/print-tree.c >> @@ -158,8 +158,7 @@ static void print_extent_ref_v0(struct >> extent_buffer *eb, int slot) >> =A0void btrfs_print_leaf(struct btrfs_root *root, struct extent_buff= er *l) >> =A0{ >> =A0 =A0 =A0 int i; >> - =A0 =A0 u32 type; >> - =A0 =A0 u32 nr =3D btrfs_header_nritems(l); >> + =A0 =A0 u32 type, nr; >> =A0 =A0 =A0 struct btrfs_item *item; >> =A0 =A0 =A0 struct btrfs_root_item *ri; >> =A0 =A0 =A0 struct btrfs_dir_item *di; >> @@ -172,6 +171,11 @@ void btrfs_print_leaf(struct btrfs_root *root, >> struct extent_buffer *l) >> =A0 =A0 =A0 struct btrfs_key key; >> =A0 =A0 =A0 struct btrfs_key found_key; >> >> + =A0 =A0 if (!l) >> + =A0 =A0 =A0 =A0 =A0 =A0 return; >> + >> + =A0 =A0 nr =3D btrfs_header_nritems(l); >> + >> =A0 =A0 =A0 printk(KERN_INFO "leaf %llu total ptrs %d free space %d\= n", >> =A0 =A0 =A0 =A0 =A0 =A0 =A0 (unsigned long long)btrfs_header_bytenr(= l), nr, >> =A0 =A0 =A0 =A0 =A0 =A0 =A0 btrfs_leaf_free_space(root, l)); >> -- >> Daniel J Blueman > -- > To unsubscribe from this list: send the line "unsubscribe linux-btrfs= " in > the body of a message to majordomo@vger.kernel.org > More majordomo info at =A0http://vger.kernel.org/majordomo-info.html > I've also run into a corruption with spots where path->nodes[0] has a value of NULL. But, I'm getting the error showing up elsewhere when I try to mount the partition: [ 6168.790849] device fsid 7c35237f-d72a-4d65-bd01-b853d853c17a devid 1 transid 507394 /dev/sdb6 [ 6168.832825] attempt to access beyond end of device [ 6168.832831] sdb6: rw=3D0, want=3D20033720, limit=3D20016927 [ 6168.832843] Failed to read block groups: -5 [ 6168.833663] btrfs: open_ctree failed In my case, I need to handle the corruption earlier in order to properly handle the error. Btrfs-progs also has troubles handling this corruption (debugging btrfsck was how I discovered I was running into path->nodes[0] =3D=3D NULL). =46or reference, I'm using a 2.6.39.1 kernel with Chris' latest 'for-linus' branch merged in. -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" = in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html