Hi,
In the current block layer implementation including drivers and fs
there are some places in the code where block device->hd_part->number
of sectors is accessed directly without any locking. There is an
existing accessor function present in the include/linux/genhd.h
which should be used to read the bdev->hd_part->nr_sects
with the help of appropriate locking.
>From ${KERN_DIR}/include/linux/genhd.h:-
<snip>
714 /*
715 * Any access of part->nr_sects which is not protected by partition
716 * bd_mutex or gendisk bdev bd_mutex, should be done using this
717 * accessor function.
718 *
719 * Code written along the lines of i_size_read() and i_size_write().
720 * CONFIG_PREEMPT case optimizes the case of UP kernel with preemption
721 * on.
722 */
723 static inline sector_t part_nr_sects_read(struct hd_struct *part)
724 {
<snip>
This patch series introduces a helper function on the top of the
part_nr_sects_read() with expected rcu locking and removes the direct
accesses to the bdev->hd_part->nr_sects.
This is based on :-
1. Repo :- git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux-block.git.
2. Branch :- for-next.
Regards,
Chaitanya
Chaitanya Kulkarni (8):
block: add a helper function to read nr_setcs
blk-zoned: update blkdev_nr_zones() with helper
blk-zoned: update blkdev_report_zone() with helper
blk-zoned: update blkdev_reset_zones() with helper
bcache: update cached_dev_init() with helper
target/pscsi: use helper in pscsi_get_blocks()
f2fs: use helper in init_blkz_info()
blktrace: use helper in blk_trace_setup_lba()
block/blk-zoned.c | 12 ++++++------
drivers/md/bcache/super.c | 2 +-
drivers/target/target_core_pscsi.c | 2 +-
fs/f2fs/super.c | 2 +-
include/linux/blkdev.h | 12 ++++++++++++
kernel/trace/blktrace.c | 2 +-
6 files changed, 22 insertions(+), 10 deletions(-)
--
2.19.1
