On Tue, Aug 13, 2013 at 05:13:31PM -0500, Mark Tinguely wrote:
> Adding the lost+found in phase 6 could allocate an inode from
> a new inode chunk. That newly created chunk was not around in
> the scan phase, and is not in the avl tree which will result
> in a NULL dereference.
>
> This patch adds the newly created inode chunk and inodes as if
> found in the scan phase.
>
> Metadata dump available for future tests.
>
> Signed-off-by: Mark Tinguely <tinguely@xxxxxxx>
> ---
> repair/incore_ino.c | 2 +-
> repair/phase6.c | 15 +++++++++++++++
> 2 files changed, 16 insertions(+), 1 deletion(-)
>
> Index: b/repair/incore_ino.c
> ===================================================================
> --- a/repair/incore_ino.c
> +++ b/repair/incore_ino.c
> @@ -700,7 +700,7 @@ get_inode_parent(ino_tree_node_t *irec,
> return(0LL);
> }
>
> -static void
> +void
> alloc_ex_data(ino_tree_node_t *irec)
> {
> parent_list_t *ptbl;
> Index: b/repair/phase6.c
> ===================================================================
> --- a/repair/phase6.c
> +++ b/repair/phase6.c
> @@ -930,6 +930,21 @@ mk_orphanage(xfs_mount_t *mp)
> irec = find_inode_rec(mp,
> XFS_INO_TO_AGNO(mp, ino),
> XFS_INO_TO_AGINO(mp, ino));
> +
> + if (irec == NULL && XFS_INO_TO_AGNO(mp, ino) < mp->m_sb.sb_agcount &&
> + ip != NULL && ip->i_d.di_magic == XFS_DINODE_MAGIC) {
I don't understand this check.
We've already dereferenced ip several lines above to increment the
link count and get the inode number stored in ino, so the ip != NULL
is unnecessary.
We've just allocated the inode, so why would the magic number be
wrong? And why would the inode number lie in a non-existent
allocation group?
> + /*
> + * add the newly allocated inode chunk to the avl tree.
> + */
I can see from the code we are allocating and irec, inserting it
into the AVL tree and marking all the inodes in the chunk as free.
The comment should explain *why* we need to do this.
Cheers,
Dave.
--
Dave Chinner
david@xxxxxxxxxxxxx
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