On Mon, 23 Feb 2015, Arnd Bergmann wrote:

A patch that was added to 4.0-rc1 in the last minute caused a
build break in the NVMe driver unless integrity support is
also enabled:

drivers/block/nvme-core.c: In function 'nvme_dif_remap':
drivers/block/nvme-core.c:523:24: error: dereferencing pointer to incomplete type
 pmap = kmap_atomic(bip->bip_vec->bv_page) + bip->bip_vec->bv_offset;
                       ^
drivers/block/nvme-core.c:523:49: error: dereferencing pointer to incomplete type
 pmap = kmap_atomic(bip->bip_vec->bv_page) + bip->bip_vec->bv_offset;
                                                ^

This changes the Kconfig entry for NVMe to depend on that
support, to avoid the build error. Using 'select' would work
as well, but might have unintended side-effects when users
do not actually want the integerity support.

Thanks for the catch. We do want users to be able to use this with and
without blk-integrity, so I'll send a patch using conditional functions
between appropriate ifdef's like how scsi and block handle this.