From patchwork Fri May 31 15:01:14 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Nikolay Borisov X-Patchwork-Id: 10970363 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 A43FD1398 for ; Fri, 31 May 2019 15:01:21 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 914CA28D56 for ; Fri, 31 May 2019 15:01:21 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 84DD228D53; Fri, 31 May 2019 15:01:21 +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 0509128AE3 for ; Fri, 31 May 2019 15:01:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726762AbfEaPBT (ORCPT ); Fri, 31 May 2019 11:01:19 -0400 Received: from mx2.suse.de ([195.135.220.15]:38374 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726421AbfEaPBT (ORCPT ); Fri, 31 May 2019 11:01:19 -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 BDE28AD7B for ; Fri, 31 May 2019 15:01:17 +0000 (UTC) From: Nikolay Borisov To: linux-btrfs@vger.kernel.org Cc: Nikolay Borisov Subject: [PATCH 1/2] btrfs: Introduce btrfs_io_geometry Date: Fri, 31 May 2019 18:01:14 +0300 Message-Id: <20190531150115.21003-1-nborisov@suse.com> X-Mailer: git-send-email 2.17.1 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 --- fs/btrfs/volumes.c | 98 ++++++++++++++++++++++++++++++++++++++++++++++ fs/btrfs/volumes.h | 2 + 2 files changed, 100 insertions(+) diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index 776f5c7ca7c5..b130f465ca6d 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -5907,6 +5907,104 @@ static bool need_full_stripe(enum btrfs_map_op op) return (op == BTRFS_MAP_WRITE || op == BTRFS_MAP_GET_READ_MIRRORS); } +/* + * btrfs_io_geometry - calculates the geomery of a particular (address, len) + * tuple. This information is used to calculate how big a + * particular bio can get before it straddles a stripe. + * + * @fs_info - The omnipresent btrfs structure + * @logical - Address that we want to figure out the geometry of + * @len - The length of IO we are going to perform, starting at @logical + * @op - Type of operation - Write or Read + * @io_geom - Pointer used to return values + * + * Returns < 0 in case a chunk for the given logical address cannot be found, + * usually shouldn't happen unless @logical is corrupted, 0 otherwise. + */ +int btrfs_io_geometry(struct btrfs_fs_info *fs_info, enum btrfs_map_op op, + u64 logical, u64 len, struct btrfs_io_geometry *io_geom) +{ + struct extent_map *em; + struct map_lookup *map; + u64 offset; + u64 stripe_offset; + u64 stripe_nr; + u64 stripe_len; + u64 raid56_full_stripe_start = (u64)-1; + int data_stripes; + + ASSERT(op != BTRFS_MAP_DISCARD); + + em = btrfs_get_chunk_map(fs_info, logical, len); + if (IS_ERR(em)) + return PTR_ERR(em); + + map = em->map_lookup; + /* Offset of this logical address in the chunk */ + offset = logical - em->start; + /* Len of a stripe in a chunk */ + stripe_len = map->stripe_len; + /* Stripe wher this block falls in */ + stripe_nr = div64_u64(offset, stripe_len); + /* Offset of stripe in the chunk */ + stripe_offset = stripe_nr * stripe_len; + if (offset < stripe_offset) { + btrfs_crit(fs_info, + "stripe math has gone wrong, stripe_offset=%llu, offset=%llu, start=%llu, logical=%llu, stripe_len=%llu", + stripe_offset, offset, em->start, logical, + stripe_len); + free_extent_map(em); + return -EINVAL; + } + + /* stripe_offset is the offset of this block in its stripe*/ + stripe_offset = offset - stripe_offset; + data_stripes = nr_data_stripes(map); + + + if (map->type & BTRFS_BLOCK_GROUP_PROFILE_MASK) { + u64 max_len = stripe_len - stripe_offset; + + /* + * In case of raid56, we need to know the stripe aligned start + */ + if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) { + unsigned long full_stripe_len = stripe_len * data_stripes; + raid56_full_stripe_start = offset; + + /* + * Allow a write of a full stripe, but make sure we + * don't allow straddling of stripes + */ + raid56_full_stripe_start = div64_u64(raid56_full_stripe_start, + full_stripe_len); + raid56_full_stripe_start *= full_stripe_len; + + /* + * For writes to RAID[56], allow a full stripeset across + * all disks. For other RAID types and for RAID[56] + * reads, just allow a single stripe (on a single disk). + */ + if (op == BTRFS_MAP_WRITE) { + max_len = stripe_len * data_stripes - + (offset - raid56_full_stripe_start); + } + } + len = min_t(u64, em->len - offset, max_len); + } else { + len = em->len - offset; + } + + io_geom->len = len; + io_geom->offset = offset; + io_geom->stripe_len = stripe_len; + io_geom->stripe_nr = stripe_nr; + io_geom->stripe_offset = stripe_offset; + io_geom->raid56_stripe_offset = raid56_full_stripe_start; + + return 0; +} + static int __btrfs_map_block(struct btrfs_fs_info *fs_info, enum btrfs_map_op op, u64 logical, u64 *length, diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h index 7c1ddf35b7d4..f3bdf768bbab 100644 --- a/fs/btrfs/volumes.h +++ b/fs/btrfs/volumes.h @@ -421,6 +421,8 @@ int btrfs_map_block(struct btrfs_fs_info *fs_info, enum btrfs_map_op op, int btrfs_map_sblock(struct btrfs_fs_info *fs_info, enum btrfs_map_op op, u64 logical, u64 *length, struct btrfs_bio **bbio_ret); +int btrfs_io_geometry(struct btrfs_fs_info *fs_info, enum btrfs_map_op op, + u64 logical, u64 len, struct btrfs_io_geometry *io_geom); int btrfs_rmap_block(struct btrfs_fs_info *fs_info, u64 chunk_start, u64 physical, u64 **logical, int *naddrs, int *stripe_len); int btrfs_read_sys_array(struct btrfs_fs_info *fs_info);