Initialize local variable trans_support before it is used rather
than after. It is supposed to contain the value of a register on the
controller containing bits that describe which transport modes the
controller supports (e.g. "performant", "ioaccel1", "ioaccel2"). A
NULL pointer dereference will almost certainly occur if trans_support
is not initialized at the right point. If for example the uninitialized
trans_support value does not have the bit set for ioaccel2 support when it
should be, then ioaccel2_alloc_cmds_and_bft() will not get called as it
should be and the h->ioaccel2_blockFetchTable array will remain NULL
instead of being allocated. Too late, trans_support finally gets
initialized with the correct value with ioaccel2 mode bit set,
which later causes calc_bucket_map() to be called to fill in
h->ioaccel2_blockFetchTable[]. However h->ioaccel2_blockFetchTable
is NULL because it didn't get allocated because earlier trans_support
wasn't initialized at the right point.
Fixes: e1f7de0cdd
Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Reported-by: Baoquan He <bhe@redhat.com>
Tested-by: Baoquan He <bhe@redhat.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
