md/bitmap: remove some pointless locking.

There is nothing gained by holding a lock while we check if a pointer
is NULL or not.  If there could be a race, then it could become NULL
immediately after the unlock - but there is no race here.

So just remove the locking.

Signed-off-by: NeilBrown <neilb@suse.de>

1 files changed, 2 insertions, 12 deletions

diff --git a/drivers/md/bitmap.c b/drivers/md/bitmap.c
index fcf3c9465fd8..e12b515bd471 100644
--- a/drivers/md/bitmap.c
+++ b/drivers/md/bitmap.c
@@ -446,18 +446,13 @@ out:
 void bitmap_update_sb(struct bitmap *bitmap)
 {
         bitmap_super_t *sb;
-        unsigned long flags;
 
         if (!bitmap || !bitmap->mddev) /* no bitmap for this array */
                 return;
         if (bitmap->mddev->bitmap_info.external)
                 return;
-        spin_lock_irqsave(&bitmap->lock, flags);
-        if (!bitmap->sb_page) { /* no superblock */
-                spin_unlock_irqrestore(&bitmap->lock, flags);
+        if (!bitmap->sb_page) /* no superblock */
                 return;
-        }
-        spin_unlock_irqrestore(&bitmap->lock, flags);
         sb = kmap_atomic(bitmap->sb_page, KM_USER0);
         sb->events = cpu_to_le64(bitmap->mddev->events);
         if (bitmap->mddev->events < bitmap->events_cleared)
@@ -683,15 +678,10 @@ static int bitmap_mask_state(struct bitmap *bitmap, enum bitmap_state bits,
                              enum bitmap_mask_op op)
 {
         bitmap_super_t *sb;
-        unsigned long flags;
         int old;
 
-        spin_lock_irqsave(&bitmap->lock, flags);
-        if (!bitmap->sb_page) { /* can't set the state */
-                spin_unlock_irqrestore(&bitmap->lock, flags);
+        if (!bitmap->sb_page) /* can't set the state */
                 return 0;
-        }
-        spin_unlock_irqrestore(&bitmap->lock, flags);
         sb = kmap_atomic(bitmap->sb_page, KM_USER0);
         old = le32_to_cpu(sb->state) & bits;
         switch (op) {