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authorShaohua Li <shaohua.li@intel.com>2011-03-22 10:35:35 +0300
committerJens Axboe <jaxboe@fusionio.com>2011-03-22 10:35:35 +0300
commit1e9bb8808ac11094d711d20d580e7b45a4992d0c (patch)
treed0e228b619664b7f507e37e5eba4a5ebeef103a0
parent5e84ea3a9c662dc2d7a48703a4468fad954a3b7f (diff)
downloadlinux-1e9bb8808ac11094d711d20d580e7b45a4992d0c.tar.xz
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>
-rw-r--r--drivers/md/dm.c7
-rw-r--r--fs/partitions/check.c3
-rw-r--r--include/linux/genhd.h12
3 files changed, 12 insertions, 10 deletions
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index 88820704a191..0cf68b478878 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -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 */
diff --git a/fs/partitions/check.c b/fs/partitions/check.c
index 9c21119512b9..ac546975031f 100644
--- a/fs/partitions/check.c
+++ b/fs/partitions/check.c
@@ -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
diff --git a/include/linux/genhd.h b/include/linux/genhd.h
index c0d5f6945c1e..d764a426e9fd 100644
--- a/include/linux/genhd.h
+++ b/include/linux/genhd.h
@@ -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)