From 771ed689d2cd53439e28e095bc38fbe40a71429e Mon Sep 17 00:00:00 2001 From: Chris Mason Date: Thu, 6 Nov 2008 22:02:51 -0500 Subject: Btrfs: Optimize compressed writeback and reads When reading compressed extents, try to put pages into the page cache for any pages covered by the compressed extent that readpages didn't already preload. Add an async work queue to handle transformations at delayed allocation processing time. Right now this is just compression. The workflow is: 1) Find offsets in the file marked for delayed allocation 2) Lock the pages 3) Lock the state bits 4) Call the async delalloc code The async delalloc code clears the state lock bits and delalloc bits. It is important this happens before the range goes into the work queue because otherwise it might deadlock with other work queue items that try to lock those extent bits. The file pages are compressed, and if the compression doesn't work the pages are written back directly. An ordered work queue is used to make sure the inodes are written in the same order that pdflush or writepages sent them down. This changes extent_write_cache_pages to let the writepage function update the wbc nr_written count. Signed-off-by: Chris Mason --- fs/btrfs/extent-tree.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) (limited to 'fs/btrfs/extent-tree.c') diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index 8af3952..ebd8275 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -768,7 +768,11 @@ static int __btrfs_inc_extent_ref(struct btrfs_trans_handle *trans, l = path->nodes[0]; btrfs_item_key_to_cpu(l, &key, path->slots[0]); - BUG_ON(key.objectid != bytenr); + if (key.objectid != bytenr) { + btrfs_print_leaf(root->fs_info->extent_root, path->nodes[0]); + printk("wanted %Lu found %Lu\n", bytenr, key.objectid); + BUG(); + } BUG_ON(key.type != BTRFS_EXTENT_ITEM_KEY); item = btrfs_item_ptr(l, path->slots[0], struct btrfs_extent_item); -- cgit v1.1