Commit 4a4b964f authored Jul 27, 2017 by Filipe Manana Committed by David Sterba Aug 18, 2017

Btrfs: avoid unnecessarily locking inode when clearing a range



If the range being cleared was not marked for defrag and we are not
about to clear the range from the defrag status, we don't need to
lock and unlock the inode.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: Chris Mason <clm@fb.com>
Reviewed-by: Wang Shilong <wangshilong1991@gmail.com>
Signed-off-by: Chris Mason <clm@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>

parent 938e1c77

fs/btrfs/inode.c

+4 −3

Original line number	Diff line number	Diff line
		@@ -1801,10 +1801,11 @@ static void btrfs_clear_bit_hook(void *private_data,
		u64 len = state->end + 1 - state->start;
		u32 num_extents = count_max_extents(len);

		if ((state->state & EXTENT_DEFRAG) && (*bits & EXTENT_DEFRAG)) {
		spin_lock(&inode->lock);
		if ((state->state & EXTENT_DEFRAG) && (*bits & EXTENT_DEFRAG))
		inode->defrag_bytes -= len;
		spin_unlock(&inode->lock);
		}

		/*
		* set_bit and clear bit hooks normally require _irqsave/restore

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