On 6/13/19 7:59 AM, 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().
Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@xxxxxxx>
---
include/linux/blkdev.h | 12 ++++++++++++
1 file changed, 12 insertions(+)
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 592669bcc536..1ae65107182a 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -1475,6 +1475,18 @@ 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)
+{
+ sector_t nr_sects;
+
+ rcu_read_lock();
+ nr_sects = part_nr_sects_read(bdev->bd_part);
+ rcu_read_unlock();
+
+ return nr_sects;
+}
+
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);
Please explain what makes you think that part_nr_sects_read() must be
protected by an RCU read lock.
Thanks,
Bart.
