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: Shaohua Li<shaohua.li@intel.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
diff --git a/include/linux/genhd.h b/include/linux/genhd.h
index c0d5f69..d764a42 100644
--- a/include/linux/genhd.h
+++ b/include/linux/genhd.h
@@ -109,7 +109,7 @@
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 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)