Commit 5a6c824e authored by NeilBrown's avatar NeilBrown
Browse files

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: default avatarNeilBrown <neilb@suse.de>
parent 278c1ca2

drivers/md/bitmap.c

+2 −12
Original line number Diff line number Diff line
@@ -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) {

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