From 4a4b964f42fa5a70d0023d2f1d44a2764bd144f4 Mon Sep 17 00:00:00 2001 From: Filipe Manana Date: Thu, 27 Jul 2017 19:52:55 +0100 Subject: [PATCH] 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 Reviewed-by: Chris Mason Reviewed-by: Wang Shilong Signed-off-by: Chris Mason Signed-off-by: David Sterba --- fs/btrfs/inode.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index fa4b2563dfd7..6747292d437e 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -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); - spin_lock(&inode->lock); - if ((state->state & EXTENT_DEFRAG) && (*bits & EXTENT_DEFRAG)) + if ((state->state & EXTENT_DEFRAG) && (*bits & EXTENT_DEFRAG)) { + spin_lock(&inode->lock); inode->defrag_bytes -= len; - spin_unlock(&inode->lock); + spin_unlock(&inode->lock); + } /* * set_bit and clear bit hooks normally require _irqsave/restore