From 7e895409421534bc7a0d8d79a81be4533d70ba8f Mon Sep 17 00:00:00 2001 From: Naohiro Aota Date: Tue, 25 Feb 2020 12:56:26 +0900 Subject: [PATCH] btrfs: factor out prepare_allocation() for extent allocation This function finally factor out prepare_allocation() form find_free_extent(). This function is called before the allocation loop and a specific allocator function like prepare_allocation_clustered() should initialize their private information and can set proper hint_byte to indicate where to start the allocation with. Reviewed-by: Josef Bacik Signed-off-by: Naohiro Aota Reviewed-by: David Sterba Signed-off-by: David Sterba --- fs/btrfs/extent-tree.c | 110 +++++++++++++++++++++++++---------------- 1 file changed, 68 insertions(+), 42 deletions(-) diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index 1d895df67b3b60..36374b86529c3e 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -3853,6 +3853,71 @@ static int find_free_extent_update_loop(struct btrfs_fs_info *fs_info, return -ENOSPC; } +static int prepare_allocation_clustered(struct btrfs_fs_info *fs_info, + struct find_free_extent_ctl *ffe_ctl, + struct btrfs_space_info *space_info, + struct btrfs_key *ins) +{ + /* + * If our free space is heavily fragmented we may not be able to make + * big contiguous allocations, so instead of doing the expensive search + * for free space, simply return ENOSPC with our max_extent_size so we + * can go ahead and search for a more manageable chunk. + * + * If our max_extent_size is large enough for our allocation simply + * disable clustering since we will likely not be able to find enough + * space to create a cluster and induce latency trying. + */ + if (space_info->max_extent_size) { + spin_lock(&space_info->lock); + if (space_info->max_extent_size && + ffe_ctl->num_bytes > space_info->max_extent_size) { + ins->offset = space_info->max_extent_size; + spin_unlock(&space_info->lock); + return -ENOSPC; + } else if (space_info->max_extent_size) { + ffe_ctl->use_cluster = false; + } + spin_unlock(&space_info->lock); + } + + ffe_ctl->last_ptr = fetch_cluster_info(fs_info, space_info, + &ffe_ctl->empty_cluster); + if (ffe_ctl->last_ptr) { + struct btrfs_free_cluster *last_ptr = ffe_ctl->last_ptr; + + spin_lock(&last_ptr->lock); + if (last_ptr->block_group) + ffe_ctl->hint_byte = last_ptr->window_start; + if (last_ptr->fragmented) { + /* + * We still set window_start so we can keep track of the + * last place we found an allocation to try and save + * some time. + */ + ffe_ctl->hint_byte = last_ptr->window_start; + ffe_ctl->use_cluster = false; + } + spin_unlock(&last_ptr->lock); + } + + return 0; +} + +static int prepare_allocation(struct btrfs_fs_info *fs_info, + struct find_free_extent_ctl *ffe_ctl, + struct btrfs_space_info *space_info, + struct btrfs_key *ins) +{ + switch (ffe_ctl->policy) { + case BTRFS_EXTENT_ALLOC_CLUSTERED: + return prepare_allocation_clustered(fs_info, ffe_ctl, + space_info, ins); + default: + BUG(); + } +} + /* * walks the btree of allocated extents and find a hole of a given size. * The key ins is changed to record the hole: @@ -3922,48 +3987,9 @@ static noinline int find_free_extent(struct btrfs_fs_info *fs_info, return -ENOSPC; } - /* - * If our free space is heavily fragmented we may not be able to make - * big contiguous allocations, so instead of doing the expensive search - * for free space, simply return ENOSPC with our max_extent_size so we - * can go ahead and search for a more manageable chunk. - * - * If our max_extent_size is large enough for our allocation simply - * disable clustering since we will likely not be able to find enough - * space to create a cluster and induce latency trying. - */ - if (unlikely(space_info->max_extent_size)) { - spin_lock(&space_info->lock); - if (space_info->max_extent_size && - num_bytes > space_info->max_extent_size) { - ins->offset = space_info->max_extent_size; - spin_unlock(&space_info->lock); - return -ENOSPC; - } else if (space_info->max_extent_size) { - ffe_ctl.use_cluster = false; - } - spin_unlock(&space_info->lock); - } - - ffe_ctl.last_ptr = fetch_cluster_info(fs_info, space_info, - &ffe_ctl.empty_cluster); - if (ffe_ctl.last_ptr) { - struct btrfs_free_cluster *last_ptr = ffe_ctl.last_ptr; - - spin_lock(&last_ptr->lock); - if (last_ptr->block_group) - ffe_ctl.hint_byte = last_ptr->window_start; - if (last_ptr->fragmented) { - /* - * We still set window_start so we can keep track of the - * last place we found an allocation to try and save - * some time. - */ - ffe_ctl.hint_byte = last_ptr->window_start; - ffe_ctl.use_cluster = false; - } - spin_unlock(&last_ptr->lock); - } + ret = prepare_allocation(fs_info, &ffe_ctl, space_info, ins); + if (ret < 0) + return ret; ffe_ctl.search_start = max(ffe_ctl.search_start, first_logical_byte(fs_info, 0));