From: Max Gurtovoy <maxg@mellanox.com>
To: Christoph Hellwig <hch@lst.de>, Jens Axboe <axboe@kernel.dk>
Cc: keith.busch@intel.com, Sagi Grimberg <sagi@grimberg.me>,
martin.petersen@oracle.com, israelr@mellanox.com,
linux-nvme@lists.infradead.org, linux-block@vger.kernel.org,
shlomin@mellanox.com
Subject: Re: [PATCH 1/4] block: centrelize PI remapping logic to the block layer
Date: Wed, 4 Sep 2019 11:32:04 +0300 [thread overview]
Message-ID: <fd70d115-bb29-a8a7-83ae-7e3dcaa1dc1c@mellanox.com> (raw)
In-Reply-To: <20190904054956.GA10553@lst.de>
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)
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next prev parent reply other threads:[~2019-09-04 8:33 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-03 15:14 [PATCH 1/4] block: centrelize PI remapping logic to the block layer Max Gurtovoy
2019-09-03 15:14 ` [PATCH 2/4] nvme-rdma: simplify error flow in nvme_rdma_queue_rq Max Gurtovoy
2019-09-04 5:51 ` Christoph Hellwig
2019-09-03 15:14 ` [PATCH 3/4] nvme-tcp: introduce nvme_tcp_complete_rq callback Max Gurtovoy
2019-09-03 19:15 ` Sagi Grimberg
2019-09-04 5:54 ` Christoph Hellwig
2019-09-04 9:02 ` Max Gurtovoy
2019-09-03 15:14 ` [PATCH 4/4] nvmet-loop: fix possible leakage during error flow Max Gurtovoy
2019-09-04 5:50 ` Christoph Hellwig
2019-09-03 19:11 ` [PATCH 1/4] block: centrelize PI remapping logic to the block layer Sagi Grimberg
2019-09-03 19:21 ` Jens Axboe
2019-09-04 5:49 ` Christoph Hellwig
2019-09-04 8:32 ` Max Gurtovoy [this message]
2019-09-04 12:49 ` Christoph Hellwig
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