From 59d35c5171e65f3a208b6f44d028278f129bdeab Mon Sep 17 00:00:00 2001 From: Filipe Manana Date: Wed, 23 Mar 2022 16:19:28 +0000 Subject: [PATCH] btrfs: release path earlier at can_nocow_extent() At can_nocow_extent(), we are releasing the path only after checking if the block group that has the target extent is read only, and after checking if there's delalloc in the range in case our extent is a preallocated extent. The read only extent check can be expensive if we have a very large filesystem with many block groups, as well as the check for delalloc in the inode's io_tree in case the io_tree is big due to IO on other file ranges. Our path is holding a read lock on a leaf and there's no need to keep the lock while doing those two checks, so release the path before doing them, immediately after the last use of the leaf. Signed-off-by: Filipe Manana Reviewed-by: David Sterba Signed-off-by: David Sterba --- fs/btrfs/inode.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index b7a7a94..1922c70 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -7197,6 +7197,8 @@ noinline int can_nocow_extent(struct inode *inode, u64 offset, u64 *len, *ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi); } + btrfs_release_path(path); + if (btrfs_extent_readonly(fs_info, disk_bytenr)) goto out; @@ -7214,8 +7216,6 @@ noinline int can_nocow_extent(struct inode *inode, u64 offset, u64 *len, } } - btrfs_release_path(path); - /* * look for other files referencing this extent, if we * find any we must cow -- 2.7.4