* [PATCH] block/bio-integrity: simplify the way of calculate nr_pages
@ 2020-02-24 13:12 Bob Liu
2020-02-24 16:40 ` Jens Axboe
0 siblings, 1 reply; 2+ messages in thread
From: Bob Liu @ 2020-02-24 13:12 UTC (permalink / raw)
To: linux-block; +Cc: axboe, martin.petersen, Bob Liu
Remove unnecessary start/end variables.
Signed-off-by: Bob Liu <bob.liu@oracle.com>
---
block/bio-integrity.c | 5 +----
1 file changed, 1 insertion(+), 4 deletions(-)
diff --git a/block/bio-integrity.c b/block/bio-integrity.c
index bf62c25..575df98 100644
--- a/block/bio-integrity.c
+++ b/block/bio-integrity.c
@@ -202,7 +202,6 @@ bool bio_integrity_prep(struct bio *bio)
struct blk_integrity *bi = blk_get_integrity(bio->bi_disk);
struct request_queue *q = bio->bi_disk->queue;
void *buf;
- unsigned long start, end;
unsigned int len, nr_pages;
unsigned int bytes, offset, i;
unsigned int intervals;
@@ -241,9 +240,7 @@ bool bio_integrity_prep(struct bio *bio)
goto err_end_io;
}
- end = (((unsigned long) buf) + len + PAGE_SIZE - 1) >> PAGE_SHIFT;
- start = ((unsigned long) buf) >> PAGE_SHIFT;
- nr_pages = end - start;
+ nr_pages = (len + PAGE_SIZE - 1) >> PAGE_SHIFT;
/* Allocate bio integrity payload and integrity vectors */
bip = bio_integrity_alloc(bio, GFP_NOIO, nr_pages);
--
2.9.5
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH] block/bio-integrity: simplify the way of calculate nr_pages
2020-02-24 13:12 [PATCH] block/bio-integrity: simplify the way of calculate nr_pages Bob Liu
@ 2020-02-24 16:40 ` Jens Axboe
0 siblings, 0 replies; 2+ messages in thread
From: Jens Axboe @ 2020-02-24 16:40 UTC (permalink / raw)
To: Bob Liu, linux-block; +Cc: martin.petersen
On 2/24/20 6:12 AM, Bob Liu wrote:
> Remove unnecessary start/end variables.
>
> Signed-off-by: Bob Liu <bob.liu@oracle.com>
> ---
> block/bio-integrity.c | 5 +----
> 1 file changed, 1 insertion(+), 4 deletions(-)
>
> diff --git a/block/bio-integrity.c b/block/bio-integrity.c
> index bf62c25..575df98 100644
> --- a/block/bio-integrity.c
> +++ b/block/bio-integrity.c
> @@ -202,7 +202,6 @@ bool bio_integrity_prep(struct bio *bio)
> struct blk_integrity *bi = blk_get_integrity(bio->bi_disk);
> struct request_queue *q = bio->bi_disk->queue;
> void *buf;
> - unsigned long start, end;
> unsigned int len, nr_pages;
> unsigned int bytes, offset, i;
> unsigned int intervals;
> @@ -241,9 +240,7 @@ bool bio_integrity_prep(struct bio *bio)
> goto err_end_io;
> }
>
> - end = (((unsigned long) buf) + len + PAGE_SIZE - 1) >> PAGE_SHIFT;
> - start = ((unsigned long) buf) >> PAGE_SHIFT;
> - nr_pages = end - start;
> + nr_pages = (len + PAGE_SIZE - 1) >> PAGE_SHIFT;
This is incorrect if you straddle a page boundary, the existing code is
correct.
--
Jens Axboe
^ permalink raw reply [flat|nested] 2+ messages in thread
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