On Thu, Jun 23, 2011 at 11:36 AM, David Sterba <[email protected]> wrote: > On Thu, Jun 23, 2011 at 11:01:01PM +0800, Daniel J Blueman wrote: >> On 23 June 2011 18:31, David Sterba <[email protected]> wrote: >> (how does one follow up an email in git send-email with the message id?) > > git-send-email --in-reply-to=<identifier> > > (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 <[email protected]> >> >> 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) >> void btrfs_print_leaf(struct btrfs_root *root, struct extent_buffer *l) >> { >> int i; >> - u32 type; >> - u32 nr = btrfs_header_nritems(l); >> + u32 type, nr; >> struct btrfs_item *item; >> struct btrfs_root_item *ri; >> struct btrfs_dir_item *di; >> @@ -172,6 +171,11 @@ void btrfs_print_leaf(struct btrfs_root *root, >> struct extent_buffer *l) >> struct btrfs_key key; >> struct btrfs_key found_key; >> >> + if (!l) >> + return; >> + >> + nr = btrfs_header_nritems(l); >> + >> printk(KERN_INFO "leaf %llu total ptrs %d free space %d\n", >> (unsigned long long)btrfs_header_bytenr(l), nr, >> 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 [email protected] > More majordomo info at http://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=0, want=20033720, limit=20016927 [ 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] == NULL). For 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 [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
