[PATCH] Re: [XFS] 2.6.29-rc2: XFS internal error XFS_WANT_CORRUPTED_GOTO

Dave Chinner
2009-01-20T23:08:50Z

On Wed, Jan 21, 2009 at 12:35:21AM +1100, Dave Chinner wrote:
> On Tue, Jan 20, 2009 at 06:49:06AM -0500, Christoph Hellwig wrote:
> > On Tue, Jan 20, 2009 at 12:47:16PM +0100, Jacek Luczak wrote:
> > > Christoph Hellwig pisze:
> > > > I'm doing about half of my testing on 32 bit x86, and I couldn't
> > > > reproduce the detailed receipe in the kernel.org bugzilla yet.
> > > >
> > > > Just curious: do you have CONFIG_LBD set?
> > >
> > > the answer is:
> > > $ grep LBD .config
> > > # CONFIG_LBD is not set
> >
> > Ok, let me reproduce it without that set..
>
> Good call, Christoph. I have a reproduce on ia32, CONFIG_LBD=n,
> 1k block size, 16 AGs in 4GB.

Christoph nailed it down to a problem with xf_fsblock_t last night.

> I'll see if this is reproducable, and if it is I'll start
> instrumenting in the morning during the LCA keynote. ;)

And here's the patch to fix it, posted direct from the keynote ;)

Cheers,

Dave.

------

[XFS] Long btree pointers are still 64 bit on disk

On 32 bit machines with CONFIG_LBD=n, XFS reduces the
in memory size of xfs_fsblock_t to 32 bits so that it
will fit within 32 bit addressing. However, the disk format
for long btree pointers are still 64 bits in size.

The recent btree rewrite failed to take this into account
when initialising new btree blocks, setting sibling pointers
to NULL and checking if they are NULL. Hence checking whether
a 64 bit NULL was the same as a 32 bit NULL was failingi
resulting in NULL sibling pointers failing to be detected
correctly. This showed up as WANT_CORRUPTED_GOTO shutdowns
in xfs_btree_delrec.

Fix this by making all the comparisons and setting of long
pointer btree NULL blocks to the disk format, not the
in memory format. i.e. use NULLDFSBNO.

Signed-off-by: Dave Chinner <david@fromorbit.com>
---
fs/xfs/xfs_btree.c | 10 +++++-----
1 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/fs/xfs/xfs_btree.c b/fs/xfs/xfs_btree.c
index 2c3ef20..6bc2136 100644
--- a/fs/xfs/xfs_btree.c
+++ b/fs/xfs/xfs_btree.c
@@ -843,7 +843,7 @@ xfs_btree_ptr_is_null(
union xfs_btree_ptr *ptr)
{
if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
- return be64_to_cpu(ptr->l) == NULLFSBLOCK;
+ return be64_to_cpu(ptr->l) == NULLDFSBNO;
else
return be32_to_cpu(ptr->s) == NULLAGBLOCK;
}
@@ -854,7 +854,7 @@ xfs_btree_set_ptr_null(
union xfs_btree_ptr *ptr)
{
if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
- ptr->l = cpu_to_be64(NULLFSBLOCK);
+ ptr->l = cpu_to_be64(NULLDFSBNO);
else
ptr->s = cpu_to_be32(NULLAGBLOCK);
}
@@ -918,8 +918,8 @@ xfs_btree_init_block(
new->bb_numrecs = cpu_to_be16(numrecs);

if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
- new->bb_u.l.bb_leftsib = cpu_to_be64(NULLFSBLOCK);
- new->bb_u.l.bb_rightsib = cpu_to_be64(NULLFSBLOCK);
+ new->bb_u.l.bb_leftsib = cpu_to_be64(NULLDFSBNO);
+ new->bb_u.l.bb_rightsib = cpu_to_be64(NULLDFSBNO);
} else {
new->bb_u.s.bb_leftsib = cpu_to_be32(NULLAGBLOCK);
new->bb_u.s.bb_rightsib = cpu_to_be32(NULLAGBLOCK);
@@ -971,7 +971,7 @@ xfs_btree_ptr_to_daddr(
union xfs_btree_ptr *ptr)
{
if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
- ASSERT(be64_to_cpu(ptr->l) != NULLFSBLOCK);
+ ASSERT(be64_to_cpu(ptr->l) != NULLDFSBNO);

return XFS_FSB_TO_DADDR(cur->bc_mp, be64_to_cpu(ptr->l));
} else {

--
Dave Chinner
david@fromorbit.com