[v3] block: use right accessor to read nr_sects

[Xen-devel] [PATCH V3 1/9] block: add a helper function to read nr_setcs

Posted by Chaitanya Kulkarni 6 years, 7 months ago

This patch introduces helper function to read the number of sectors
from struct block_device->bd_part member. For more details Please refer
to the comment in the include/linux/genhd.h for part_nr_sects_read().

Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
---
 include/linux/blkdev.h | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 592669bcc536..be7ee5a0b0dd 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -1475,6 +1475,12 @@ static inline void put_dev_sector(Sector p)
 	put_page(p.v);
 }
 
+/* Helper function to read the bdev->bd_part->nr_sects */
+static inline sector_t bdev_nr_sects(struct block_device *bdev)
+{
+	return part_nr_sects_read(bdev->bd_part);
+}
+
 int kblockd_schedule_work(struct work_struct *work);
 int kblockd_schedule_work_on(int cpu, struct work_struct *work);
 int kblockd_mod_delayed_work_on(int cpu, struct delayed_work *dwork, unsigned long delay);
-- 
2.19.1


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Re: [Xen-devel] [PATCH V3 1/9] block: add a helper function to read nr_setcs

Posted by Minwoo Im 6 years, 7 months ago

On 19-07-02 10:42:27, Chaitanya Kulkarni wrote:
> This patch introduces helper function to read the number of sectors
> from struct block_device->bd_part member. For more details Please refer
> to the comment in the include/linux/genhd.h for part_nr_sects_read().

Without bd_mutex locked, this helper seems useful to have.

Reviewed-by: Minwoo Im <minwoo.im.dev@gmail.com>

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Re: [Xen-devel] [PATCH V3 1/9] block: add a helper function to read nr_setcs

Posted by Bart Van Assche 6 years, 7 months ago

On 7/2/19 10:42 AM, Chaitanya Kulkarni wrote:
> +/* Helper function to read the bdev->bd_part->nr_sects */
> +static inline sector_t bdev_nr_sects(struct block_device *bdev)
> +{
> +	return part_nr_sects_read(bdev->bd_part);
> +}

Is the comment above bdev_nr_sects() really useful or should it be left out?

Thanks,

Bart.

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