On 9/4/2019 8:49 AM, Christoph Hellwig wrote:
On Tue, Sep 03, 2019 at 01:21:59PM -0600, Jens Axboe wrote:
On 9/3/19 1:11 PM, Sagi Grimberg wrote:
+ if (blk_integrity_rq(req) && req_op(req) == REQ_OP_READ &&
+ error == BLK_STS_OK)
+ t10_pi_complete(req,
+ nr_bytes / queue_logical_block_size(req->q));
+
div in this path? better to use >> ilog2(block_size).
Also, would be better to have a wrapper in place like:
static inline unsigned short blk_integrity_interval(struct request *rq)
{
return queue_logical_block_size(rq->q);
}
If it's a hot path thing that matters, I'd strongly suggest to add
a queue block size shift instead.
Make that a protection_interval_shift, please. While that currently
is the same as the logical block size the concepts are a little
different, and that makes it clear. Except for that this patch looks
very nice to me, it is great to avoid having drivers to deal with the
PI remapping.
Christoph,
I was thinking about the following addition to the code (combination of
all the suggestions):
diff --git a/block/blk-core.c b/block/blk-core.c
index 58ecfd3..cef604c 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -1409,7 +1409,7 @@ bool blk_update_request(struct request *req,
blk_status_t error,
if (blk_integrity_rq(req) && req_op(req) == REQ_OP_READ &&
error == BLK_STS_OK)
t10_pi_complete(req,
- nr_bytes /
queue_logical_block_size(req->q));
+ nr_bytes >>
queue_logical_block_shift(req->q));
if (unlikely(error && !blk_rq_is_passthrough(req) &&
!(req->rq_flags & RQF_QUIET)))
diff --git a/block/blk-settings.c b/block/blk-settings.c
index 2c18312..8183ffc 100644
--- a/block/blk-settings.c
+++ b/block/blk-settings.c
@@ -330,6 +330,7 @@ void blk_queue_max_segment_size(struct request_queue
*q, unsigned int max_size)
void blk_queue_logical_block_size(struct request_queue *q, unsigned
short size)
{
q->limits.logical_block_size = size;
+ q->limits.logical_block_shift = ilog2(size);
if (q->limits.physical_block_size < size)
q->limits.physical_block_size = size;
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 1ef375d..4a0115e 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -332,6 +332,7 @@ struct queue_limits {
unsigned int discard_alignment;
unsigned short logical_block_size;
+ unsigned short logical_block_shift;
unsigned short max_segments;
unsigned short max_integrity_segments;
unsigned short max_discard_segments;
@@ -1267,6 +1268,16 @@ static inline unsigned int
queue_max_segment_size(struct request_queue *q)
return q->limits.max_segment_size;
}
+static inline unsigned short queue_logical_block_shift(struct
request_queue *q)
+{
+ unsigned short retval = 9;
+
+ if (q && q->limits.logical_block_shift)
+ retval = q->limits.logical_block_shift;
+
+ return retval;
+}
+
static inline unsigned short queue_logical_block_size(struct
request_queue *q)
