Commits
![Darrick J. Wong](https://secure.gravatar.com/avatar/adf7ddc62e9e4818594d54e4fe7adbb3.jpg?s=96&d=mm)
Darrick J. Wong committed b85f32481d9
xfs: forbid AG btrees with level == 0 commit d2a047f31e86941fa896e0e3271536d50aba415e upstream. There is no such thing as a zero-level AG btree since even a single-node zero-records btree has one level. Btree cursor constructors read cur_nlevels straight from disk and then access things like cur_bufs[cur_nlevels - 1] which is /really/ bad if cur_nlevels is zero! Therefore, strengthen the verifiers to prevent this possibility. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>