[PATCH] NVMe: Abstract out sector to block number conversion

[Matthew Wilcox]

From: Matthew Wilcox <matthew.r.wilcox at intel.com>

Introduce nvme_block_nr() to help convert sectors to block numbers.
This fixes an integer overflow in the SCSI conversion layer, and it's
slightly less typing than opencoding it.

Signed-off-by: Matthew Wilcox <matthew.r.wilcox at intel.com>
---
 drivers/block/nvme-core.c |    4 ++--
 drivers/block/nvme-scsi.c |    2 +-
 include/linux/nvme.h      |    5 +++++
 3 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/drivers/block/nvme-core.c b/drivers/block/nvme-core.c
index a89f7db..20fe3e5 100644
--- a/drivers/block/nvme-core.c
+++ b/drivers/block/nvme-core.c
@@ -477,7 +477,7 @@ static int nvme_submit_discard(struct nvme_queue *nvmeq, struct nvme_ns *ns,
 
 	range->cattr = cpu_to_le32(0);
 	range->nlb = cpu_to_le32(bio->bi_size >> ns->lba_shift);
-	range->slba = cpu_to_le64(bio->bi_sector >> (ns->lba_shift - 9));
+	range->slba = cpu_to_le64(nvme_block_nr(ns, bio->bi_sector));
 
 	memset(cmnd, 0, sizeof(*cmnd));
 	cmnd->dsm.opcode = nvme_cmd_dsm;
@@ -590,7 +590,7 @@ static int nvme_submit_bio_queue(struct nvme_queue *nvmeq, struct nvme_ns *ns,
 	cmnd->rw.nsid = cpu_to_le32(ns->ns_id);
 	length = nvme_setup_prps(nvmeq->dev, &cmnd->common, iod, length,
 								GFP_ATOMIC);
-	cmnd->rw.slba = cpu_to_le64(bio->bi_sector >> (ns->lba_shift - 9));
+	cmnd->rw.slba = cpu_to_le64(nvme_block_nr(ns, bio->bi_sector));
 	cmnd->rw.length = cpu_to_le16((length >> ns->lba_shift) - 1);
 	cmnd->rw.control = cpu_to_le16(control);
 	cmnd->rw.dsmgmt = cpu_to_le32(dsmgmt);
diff --git a/drivers/block/nvme-scsi.c b/drivers/block/nvme-scsi.c
index d5b3afe..eeb3320 100644
--- a/drivers/block/nvme-scsi.c
+++ b/drivers/block/nvme-scsi.c
@@ -2040,7 +2040,7 @@ static int nvme_trans_do_nvme_io(struct nvme_ns *ns, struct sg_io_hdr *hdr,
 	struct nvme_command c;
 	u8 opcode = (is_write ? nvme_cmd_write : nvme_cmd_read);
 	u16 control;
-	u32 max_blocks = (dev->max_hw_sectors << 9) >> ns->lba_shift;
+	u32 max_blocks = nvme_block_nr(ns, dev->max_hw_sectors);
 
 	num_cmds = nvme_trans_io_get_num_cmds(hdr, cdb_info, max_blocks);
 
diff --git a/include/linux/nvme.h b/include/linux/nvme.h
index aa57503..09f419d 100644
--- a/include/linux/nvme.h
+++ b/include/linux/nvme.h
@@ -566,6 +566,11 @@ struct nvme_iod {
 	struct scatterlist sg[0];
 };
 
+static inline u64 nvme_block_nr(struct nvme_ns *ns, sector_t sector)
+{
+	return (sector >> (ns->lba_shift - 9));
+}
+
 /**
  * nvme_free_iod - frees an nvme_iod
  * @dev: The device that the I/O was submitted to
-- 
1.7.10.4