[V4,1/9] block: add a helper function to read nr_setcs
diff mbox series

Message ID 20190708184711.2984-2-chaitanya.kulkarni@wdc.com
State New
Headers show
Series
  • block: use right accessor to read nr_sects
Related show

Commit Message

Chaitanya Kulkarni July 8, 2019, 6:47 p.m. UTC
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 | 5 +++++
 1 file changed, 5 insertions(+)

Comments

Martin K. Petersen July 12, 2019, 1:59 a.m. UTC | #1
Hi Chaitanya,

> +static inline sector_t bdev_nr_sects(struct block_device *bdev)
> +{
> +	return part_nr_sects_read(bdev->bd_part);
> +}

Can bdev end up being NULL in any of the call sites?

Otherwise no objections.
Chaitanya Kulkarni July 12, 2019, 4:09 p.m. UTC | #2
On 7/11/19 6:59 PM, Martin K. Petersen wrote:
> Hi Chaitanya,
>
>> +static inline sector_t bdev_nr_sects(struct block_device *bdev)
>> +{
>> +	return part_nr_sects_read(bdev->bd_part);
>> +}
> Can bdev end up being NULL in any of the call sites?
>
> Otherwise no objections.
>
Thanks for mentioning that. Initial version which was not posted had
that check.

This series just replaces the existing accesses without changing anything.

So if any of the exiting code has that bug then it will blow up nicely.

For future callers I don't mind adding a new check and resend the series.

Would you prefer adding a check  ?
Martin K. Petersen July 17, 2019, 2:28 a.m. UTC | #3
Chaitanya,

> This series just replaces the existing accesses without changing
> anything.
>
> So if any of the exiting code has that bug then it will blow up
> nicely.
>
> For future callers I don't mind adding a new check and resend the
> series.
>
> Would you prefer adding a check ?

I checked your call sites and they look fine. Also, I don't think
returning a capacity of 0 on error is going to help us much.

Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>

Patch
diff mbox series

diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 0c482371c8b3..578383712093 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -1464,6 +1464,11 @@  static inline void put_dev_sector(Sector p)
 	put_page(p.v);
 }
 
+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);