Return-Path: Received: from mail-wg0-f41.google.com ([74.125.82.41]:59914 "EHLO mail-wg0-f41.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754015AbaCKN4c (ORCPT ); Tue, 11 Mar 2014 09:56:32 -0400 Received: by mail-wg0-f41.google.com with SMTP id n12so10178099wgh.0 for ; Tue, 11 Mar 2014 06:56:31 -0700 (PDT) From: Filipe David Borba Manana To: linux-btrfs@vger.kernel.org Cc: Filipe David Borba Manana Subject: [PATCH 2/2] Btrfs: cache extent states in defrag code path Date: Tue, 11 Mar 2014 13:56:15 +0000 Message-Id: <1394546175-7370-2-git-send-email-fdmanana@gmail.com> In-Reply-To: <1394546175-7370-1-git-send-email-fdmanana@gmail.com> References: <1394546175-7370-1-git-send-email-fdmanana@gmail.com> Sender: linux-btrfs-owner@vger.kernel.org List-ID: When locking file ranges in the inode's io_tree, cache the first extent state that belongs to the target range, so that when unlocking the range we don't need to search in the io_tree again, reducing cpu time and making and therefore holding the io_tree's lock for a shorter period. Signed-off-by: Filipe David Borba Manana --- fs/btrfs/ioctl.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index 5239470..6de00ad 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -994,10 +994,13 @@ static struct extent_map *defrag_lookup_extent(struct inode *inode, u64 start) read_unlock(&em_tree->lock); if (!em) { + struct extent_state *cached = NULL; + u64 end = start + len - 1; + /* get the big lock and read metadata off disk */ - lock_extent(io_tree, start, start + len - 1); + lock_extent_bits(io_tree, start, end, 0, &cached); em = btrfs_get_extent(inode, NULL, 0, start, len, 0); - unlock_extent(io_tree, start, start + len - 1); + unlock_extent_cached(io_tree, start, end, &cached, GFP_NOFS); if (IS_ERR(em)) return NULL; @@ -1136,10 +1139,12 @@ again: page_start = page_offset(page); page_end = page_start + PAGE_CACHE_SIZE - 1; while (1) { - lock_extent(tree, page_start, page_end); + lock_extent_bits(tree, page_start, page_end, + 0, &cached_state); ordered = btrfs_lookup_ordered_extent(inode, page_start); - unlock_extent(tree, page_start, page_end); + unlock_extent_cached(tree, page_start, page_end, + &cached_state, GFP_NOFS); if (!ordered) break; -- 1.7.9.5