From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C2A10C43381 for ; Mon, 25 Mar 2019 12:31:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 976862085A for ; Mon, 25 Mar 2019 12:31:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731205AbfCYMbu (ORCPT ); Mon, 25 Mar 2019 08:31:50 -0400 Received: from mx2.suse.de ([195.135.220.15]:55626 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1731108AbfCYMbn (ORCPT ); Mon, 25 Mar 2019 08:31:43 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 04D42ACAC for ; Mon, 25 Mar 2019 12:31:42 +0000 (UTC) From: Nikolay Borisov To: linux-btrfs@vger.kernel.org Cc: Nikolay Borisov Subject: [PATCH v3 10/12] btrfs: Optimize unallocated chunks discard Date: Mon, 25 Mar 2019 14:31:30 +0200 Message-Id: <20190325123132.27835-11-nborisov@suse.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20190325123132.27835-1-nborisov@suse.com> References: <20190325123132.27835-1-nborisov@suse.com> Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org Currently unallocated chunks are always trimmed. For example 2 consecutive trims on large storage would trim freespace twice irrespective of whether the space was actually allocated or not between those trims. Optimise this behavior by exploiting the newly introduced alloc_state tree of btrfs_device. A new CHUNK_TRIMMED bit is used to mark those unallocated chunks which have been trimmed and have not been allocated afterwards. On chunk allocation the respective underlying devices' physical space will have its CHUNK_TRIMMED flag cleared. This avoids submitting discards for space which hasn't been changed since the last time discard was issued. Signed-off-by: Nikolay Borisov --- fs/btrfs/extent-tree.c | 57 +++++++++++++++++++++++++++++++++++++++++- fs/btrfs/extent_io.h | 8 +++++- fs/btrfs/extent_map.c | 4 ++- 3 files changed, 66 insertions(+), 3 deletions(-) diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index 574c73e0a7c0..503d68ba3f6a 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -11249,6 +11249,54 @@ int btrfs_error_unpin_extent_range(struct btrfs_fs_info *fs_info, return unpin_extent_range(fs_info, start, end, false); } +static bool should_skip_trim(struct btrfs_device *device, u64 *start, u64 *len) +{ + u64 trimmed_start = 0, trimmed_end = 0; + u64 end = *start + *len - 1; + + if (!find_first_extent_bit(&device->alloc_state, *start, &trimmed_start, + &trimmed_end, CHUNK_TRIMMED, NULL)) { + u64 trimmed_len = trimmed_end - trimmed_start + 1; + + if (*start < trimmed_start) { + if (in_range(end, trimmed_start, trimmed_len) || + end > trimmed_end) { + /* + * start|------|end + * ts|--|trimmed_len + * OR + * start|-----|end + * ts|-----|trimmed_len + */ + *len = trimmed_start - *start; + return false; + } else if (end < trimmed_start) { + /* + * start|------|end + * ts|--|trimmed_len + */ + return false; + } + } else if (in_range(*start, trimmed_start, trimmed_len)) { + if (in_range(end, trimmed_start, trimmed_len)) { + /* + * start|------|end + * ts|----------|trimmed_len + */ + return true; + } else { + /* + * start|-----------|end + * ts|----------|trimmed_len + */ + *start = trimmed_end + 1; + *len = end - *start + 1; + return false; + } + } + } + return false; +} /* * It used to be that old block groups would be left around forever. * Iterating over them would be enough to trim unused space. Since we @@ -11319,7 +11367,14 @@ static int btrfs_trim_free_extents(struct btrfs_device *device, start = max(range->start, start); len = min(range->len, len); - ret = btrfs_issue_discard(device->bdev, start, len, &bytes); + if (!should_skip_trim(device, &start, &len)) { + ret = btrfs_issue_discard(device->bdev, start, len, + &bytes); + if (!ret) + set_extent_bits(&device->alloc_state, start, + start + bytes - 1, + CHUNK_TRIMMED); + } mutex_unlock(&fs_info->chunk_mutex); if (ret) diff --git a/fs/btrfs/extent_io.h b/fs/btrfs/extent_io.h index 4bcc203b5431..9dd5190d9dd8 100644 --- a/fs/btrfs/extent_io.h +++ b/fs/btrfs/extent_io.h @@ -28,8 +28,14 @@ #define EXTENT_CTLBITS (EXTENT_DO_ACCOUNTING) -/* Redefined bits above which are used only in the device allocation tree */ +/* + * Redefined bits above which are used only in the device allocation tree, + * shouldn't be using EXTENT_IOBITS(EXTENT_LOCKED/EXTENT_WRITEBACK) / + * EXTENT_BOUNDARY / EXTENT_CLEAR_META_RESV / EXTENT_CLEAR_DATA_RESV because + * they have special meaning to the bit manipulation functions + */ #define CHUNK_ALLOCATED EXTENT_DIRTY +#define CHUNK_TRIMMED EXTENT_DEFRAG /* * flags for bio submission. The high bits indicate the compression diff --git a/fs/btrfs/extent_map.c b/fs/btrfs/extent_map.c index 0820f6fcf3a6..9e8c0904f623 100644 --- a/fs/btrfs/extent_map.c +++ b/fs/btrfs/extent_map.c @@ -389,8 +389,10 @@ int add_extent_mapping(struct extent_map_tree *tree, goto out; setup_extent_mapping(tree, em, modified); - if (test_bit(EXTENT_FLAG_FS_MAPPING, &em->flags)) + if (test_bit(EXTENT_FLAG_FS_MAPPING, &em->flags)) { extent_map_device_set_bits(em, CHUNK_ALLOCATED); + extent_map_device_clear_bits(em, CHUNK_TRIMMED); + } out: return ret; } -- 2.17.1