c372cdd1ef
The largest allowed transfer is 4MB, which can use at most 1025 PRPs. Each PRP is 8 bytes, so the maximum number of 4k nvme pages needed for the iod_list is 3, which fits in an 's8' type. While modifying this field, change the name to "nr_allocations" to better represent that this is referring to the number of units allocated from a dma_pool. Also introduce a BUILD_BUG_ON to ensure we never accidently increase the largest transfer limit beyond 127 chained prp lists. Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com> Signed-off-by: Keith Busch <kbusch@kernel.org> Signed-off-by: Christoph Hellwig <hch@lst.de>