dm snapshot: optimize track_chunk

track_chunk is always called with interrupts enabled. Consequently, we
do not need to save and restore interrupt state in "flags" variable.
This patch changes spin_lock_irqsave to spin_lock_irq and
spin_unlock_irqrestore to spin_unlock_irq.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>

1 files changed, 2 insertions, 3 deletions

diff --git a/drivers/md/dm-snap.c b/drivers/md/dm-snap.c
index a143921feaf..223e7ebf24f 100644
--- a/drivers/md/dm-snap.c
+++ b/drivers/md/dm-snap.c
@@ -198,14 +198,13 @@ static struct dm_snap_tracked_chunk *track_chunk(struct dm_snapshot *s,
 {
         struct dm_snap_tracked_chunk *c = mempool_alloc(s->tracked_chunk_pool,
                                                         GFP_NOIO);
-        unsigned long flags;
 
         c->chunk = chunk;
 
-        spin_lock_irqsave(&s->tracked_chunk_lock, flags);
+        spin_lock_irq(&s->tracked_chunk_lock);
         hlist_add_head(&c->node,
                        &s->tracked_chunk_hash[DM_TRACKED_CHUNK_HASH(chunk)]);
-        spin_unlock_irqrestore(&s->tracked_chunk_lock, flags);
+        spin_unlock_irq(&s->tracked_chunk_lock);
 
         return c;
 }