Commit 1e9bb880 authored by Shaohua Li's avatar Shaohua Li Committed by Jens Axboe
Browse files

block: fix non-atomic access to genhd inflight structures 



After the stack plugging introduction, these are called lockless.
Ensure that the counters are updated atomically.

Signed-off-by: default avatarShaohua <Li&lt;shaohua.li@intel.com>
Signed-off-by: default avatarJens Axboe <jaxboe@fusionio.com>
parent 5e84ea3a

drivers/md/dm.c

+4 −3
Original line number Diff line number Diff line
@@ -477,7 +477,8 @@ static void start_io_acct(struct dm_io *io) 
	cpu = part_stat_lock();

	part_round_stats(cpu, &dm_disk(md)->part0);

	part_stat_unlock();

	dm_disk(md)->part0.in_flight[rw] = atomic_inc_return(&md->pending[rw]);

	atomic_set(&dm_disk(md)->part0.in_flight[rw],

		atomic_inc_return(&md->pending[rw]));

}



static void end_io_acct(struct dm_io *io)
@@ -497,8 +498,8 @@ static void end_io_acct(struct dm_io *io) 
	 * After this is decremented the bio must not be touched if it is

	 * a flush.

	 */

	dm_disk(md)->part0.in_flight[rw] = pending =

		atomic_dec_return(&md->pending[rw]);

	pending = atomic_dec_return(&md->pending[rw]);

	atomic_set(&dm_disk(md)->part0.in_flight[rw], pending);

	pending += atomic_read(&md->pending[rw^0x1]);



	/* nudge anyone waiting on suspend queue */

fs/partitions/check.c

+2 −1
Original line number Diff line number Diff line
@@ -290,7 +290,8 @@ ssize_t part_inflight_show(struct device *dev, 
{

	struct hd_struct *p = dev_to_part(dev);



	return sprintf(buf, "%8u %8u\n", p->in_flight[0], p->in_flight[1]);

	return sprintf(buf, "%8u %8u\n", atomic_read(&p->in_flight[0]),

		atomic_read(&p->in_flight[1]));

}



#ifdef CONFIG_FAIL_MAKE_REQUEST

include/linux/genhd.h

+6 −6
Original line number Diff line number Diff line
@@ -109,7 +109,7 @@ struct hd_struct { 
	int make_it_fail;

#endif

	unsigned long stamp;

	int in_flight[2];

	atomic_t in_flight[2];

#ifdef	CONFIG_SMP

	struct disk_stats __percpu *dkstats;

#else
@@ -370,21 +370,21 @@ static inline void free_part_stats(struct hd_struct *part) 


static inline void part_inc_in_flight(struct hd_struct *part, int rw)

{

	part->in_flight[rw]++;

	atomic_inc(&part->in_flight[rw]);

	if (part->partno)

		part_to_disk(part)->part0.in_flight[rw]++;

		atomic_inc(&part_to_disk(part)->part0.in_flight[rw]);

}



static inline void part_dec_in_flight(struct hd_struct *part, int rw)

{

	part->in_flight[rw]--;

	atomic_dec(&part->in_flight[rw]);

	if (part->partno)

		part_to_disk(part)->part0.in_flight[rw]--;

		atomic_dec(&part_to_disk(part)->part0.in_flight[rw]);

}



static inline int part_in_flight(struct hd_struct *part)

{

	return part->in_flight[0] + part->in_flight[1];

	return atomic_read(&part->in_flight[0]) + atomic_read(&part->in_flight[1]);

}



static inline struct partition_meta_info *alloc_part_info(struct gendisk *disk)