From patchwork Wed Jan 30 14:50:59 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Nikolay Borisov X-Patchwork-Id: 10788735 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 4A8F26C2 for ; Wed, 30 Jan 2019 14:51:13 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 351552F419 for ; Wed, 30 Jan 2019 14:51:13 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 32AE82F436; Wed, 30 Jan 2019 14:51:13 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id A931D2F419 for ; Wed, 30 Jan 2019 14:51:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731461AbfA3OvM (ORCPT ); Wed, 30 Jan 2019 09:51:12 -0500 Received: from mx2.suse.de ([195.135.220.15]:38158 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1731439AbfA3OvK (ORCPT ); Wed, 30 Jan 2019 09:51:10 -0500 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 CF16CB06A for ; Wed, 30 Jan 2019 14:51:07 +0000 (UTC) From: Nikolay Borisov To: linux-btrfs@vger.kernel.org Cc: jeffm@suse.com, Nikolay Borisov Subject: [PATCH 12/15] btrfs: Optimize unallocated chunks discard Date: Wed, 30 Jan 2019 16:50:59 +0200 Message-Id: <20190130145102.4708-13-nborisov@suse.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20190130145102.4708-1-nborisov@suse.com> References: <20190130145102.4708-1-nborisov@suse.com> Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP 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 610bed028511..f5005ef39f98 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -11127,6 +11127,54 @@ 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 @@ -11197,7 +11245,14 @@ 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 d4227e40c8ee..d238efd628cf 100644 --- a/fs/btrfs/extent_io.h +++ b/fs/btrfs/extent_io.h @@ -30,8 +30,14 @@ #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; }