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=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 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 A9A20C432C0 for ; Tue, 26 Nov 2019 10:18:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7805F207DD for ; Tue, 26 Nov 2019 10:18:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727726AbfKZKSf (ORCPT ); Tue, 26 Nov 2019 05:18:35 -0500 Received: from mx2.suse.de ([195.135.220.15]:40592 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727603AbfKZKSf (ORCPT ); Tue, 26 Nov 2019 05:18:35 -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 41615AB9D; Tue, 26 Nov 2019 10:18:32 +0000 (UTC) Subject: Re: [PATCH 4/4] btrfs: use btrfs_can_overcommit in inc_block_group_ro To: Josef Bacik , linux-btrfs@vger.kernel.org, kernel-team@fb.com, wqu@suse.com References: <20191125144011.146722-1-josef@toxicpanda.com> <20191125144011.146722-5-josef@toxicpanda.com> From: Nikolay Borisov Openpgp: preference=signencrypt Autocrypt: addr=nborisov@suse.com; prefer-encrypt=mutual; keydata= mQINBFiKBz4BEADNHZmqwhuN6EAzXj9SpPpH/nSSP8YgfwoOqwrP+JR4pIqRK0AWWeWCSwmZ T7g+RbfPFlmQp+EwFWOtABXlKC54zgSf+uulGwx5JAUFVUIRBmnHOYi/lUiE0yhpnb1KCA7f u/W+DkwGerXqhhe9TvQoGwgCKNfzFPZoM+gZrm+kWv03QLUCr210n4cwaCPJ0Nr9Z3c582xc bCUVbsjt7BN0CFa2BByulrx5xD9sDAYIqfLCcZetAqsTRGxM7LD0kh5WlKzOeAXj5r8DOrU2 GdZS33uKZI/kZJZVytSmZpswDsKhnGzRN1BANGP8sC+WD4eRXajOmNh2HL4P+meO1TlM3GLl EQd2shHFY0qjEo7wxKZI1RyZZ5AgJnSmehrPCyuIyVY210CbMaIKHUIsTqRgY5GaNME24w7h TyyVCy2qAM8fLJ4Vw5bycM/u5xfWm7gyTb9V1TkZ3o1MTrEsrcqFiRrBY94Rs0oQkZvunqia c+NprYSaOG1Cta14o94eMH271Kka/reEwSZkC7T+o9hZ4zi2CcLcY0DXj0qdId7vUKSJjEep c++s8ncFekh1MPhkOgNj8pk17OAESanmDwksmzh1j12lgA5lTFPrJeRNu6/isC2zyZhTwMWs k3LkcTa8ZXxh0RfWAqgx/ogKPk4ZxOXQEZetkEyTFghbRH2BIwARAQABtCNOaWtvbGF5IEJv cmlzb3YgPG5ib3Jpc292QHN1c2UuY29tPokCOAQTAQIAIgUCWIo48QIbAwYLCQgHAwIGFQgC CQoLBBYCAwECHgECF4AACgkQcb6CRuU/KFc0eg/9GLD3wTQz9iZHMFbjiqTCitD7B6dTLV1C ddZVlC8Hm/TophPts1bWZORAmYIihHHI1EIF19+bfIr46pvfTu0yFrJDLOADMDH+Ufzsfy2v HSqqWV/nOSWGXzh8bgg/ncLwrIdEwBQBN9SDS6aqsglagvwFD91UCg/TshLlRxD5BOnuzfzI Leyx2c6YmH7Oa1R4MX9Jo79SaKwdHt2yRN3SochVtxCyafDlZsE/efp21pMiaK1HoCOZTBp5 VzrIP85GATh18pN7YR9CuPxxN0V6IzT7IlhS4Jgj0NXh6vi1DlmKspr+FOevu4RVXqqcNTSS E2rycB2v6cttH21UUdu/0FtMBKh+rv8+yD49FxMYnTi1jwVzr208vDdRU2v7Ij/TxYt/v4O8 V+jNRKy5Fevca/1xroQBICXsNoFLr10X5IjmhAhqIH8Atpz/89ItS3+HWuE4BHB6RRLM0gy8 T7rN6ja+KegOGikp/VTwBlszhvfLhyoyjXI44Tf3oLSFM+8+qG3B7MNBHOt60CQlMkq0fGXd mm4xENl/SSeHsiomdveeq7cNGpHi6i6ntZK33XJLwvyf00PD7tip/GUj0Dic/ZUsoPSTF/mG EpuQiUZs8X2xjK/AS/l3wa4Kz2tlcOKSKpIpna7V1+CMNkNzaCOlbv7QwprAerKYywPCoOSC 7P25Ag0EWIoHPgEQAMiUqvRBZNvPvki34O/dcTodvLSyOmK/MMBDrzN8Cnk302XfnGlW/YAQ csMWISKKSpStc6tmD+2Y0z9WjyRqFr3EGfH1RXSv9Z1vmfPzU42jsdZn667UxrRcVQXUgoKg QYx055Q2FdUeaZSaivoIBD9WtJq/66UPXRRr4H/+Y5FaUZx+gWNGmBT6a0S/GQnHb9g3nonD jmDKGw+YO4P6aEMxyy3k9PstaoiyBXnzQASzdOi39BgWQuZfIQjN0aW+Dm8kOAfT5i/yk59h VV6v3NLHBjHVw9kHli3jwvsizIX9X2W8tb1SefaVxqvqO1132AO8V9CbE1DcVT8fzICvGi42 FoV/k0QOGwq+LmLf0t04Q0csEl+h69ZcqeBSQcIMm/Ir+NorfCr6HjrB6lW7giBkQl6hhomn l1mtDP6MTdbyYzEiBFcwQD4terc7S/8ELRRybWQHQp7sxQM/Lnuhs77MgY/e6c5AVWnMKd/z MKm4ru7A8+8gdHeydrRQSWDaVbfy3Hup0Ia76J9FaolnjB8YLUOJPdhI2vbvNCQ2ipxw3Y3c KhVIpGYqwdvFIiz0Fej7wnJICIrpJs/+XLQHyqcmERn3s/iWwBpeogrx2Lf8AGezqnv9woq7 OSoWlwXDJiUdaqPEB/HmGfqoRRN20jx+OOvuaBMPAPb+aKJyle8zABEBAAGJAh8EGAECAAkF AliKBz4CGwwACgkQcb6CRuU/KFdacg/+M3V3Ti9JYZEiIyVhqs+yHb6NMI1R0kkAmzsGQ1jU zSQUz9AVMR6T7v2fIETTT/f5Oout0+Hi9cY8uLpk8CWno9V9eR/B7Ifs2pAA8lh2nW43FFwp IDiSuDbH6oTLmiGCB206IvSuaQCp1fed8U6yuqGFcnf0ZpJm/sILG2ECdFK9RYnMIaeqlNQm iZicBY2lmlYFBEaMXHoy+K7nbOuizPWdUKoKHq+tmZ3iA+qL5s6Qlm4trH28/fPpFuOmgP8P K+7LpYLNSl1oQUr+WlqilPAuLcCo5Vdl7M7VFLMq4xxY/dY99aZx0ZJQYFx0w/6UkbDdFLzN upT7NIN68lZRucImffiWyN7CjH23X3Tni8bS9ubo7OON68NbPz1YIaYaHmnVQCjDyDXkQoKC R82Vf9mf5slj0Vlpf+/Wpsv/TH8X32ajva37oEQTkWNMsDxyw3aPSps6MaMafcN7k60y2Wk/ TCiLsRHFfMHFY6/lq/c0ZdOsGjgpIK0G0z6et9YU6MaPuKwNY4kBdjPNBwHreucrQVUdqRRm RcxmGC6ohvpqVGfhT48ZPZKZEWM+tZky0mO7bhZYxMXyVjBn4EoNTsXy1et9Y1dU3HVJ8fod 5UqrNrzIQFbdeM0/JqSLrtlTcXKJ7cYFa9ZM2AP7UIN9n1UWxq+OPY9YMOewVfYtL8M= Message-ID: <3decb2b5-49dc-f019-5afc-e055ad916972@suse.com> Date: Tue, 26 Nov 2019 12:18:30 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.9.0 MIME-Version: 1.0 In-Reply-To: <20191125144011.146722-5-josef@toxicpanda.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org On 25.11.19 г. 16:40 ч., Josef Bacik wrote: > inc_block_group_ro does a calculation to see if we have enough room left > over if we mark this block group as read only in order to see if it's ok > to mark the block group as read only. > > The problem is this calculation _only_ works for data, where our used is > always less than our total. For metadata we will overcommit, so this > will almost always fail for metadata. > > Fix this by exporting btrfs_can_overcommit, and then see if we have > enough space to remove the remaining free space in the block group we > are trying to mark read only. If we do then we can mark this block > group as read only. > > Signed-off-by: Josef Bacik > --- > fs/btrfs/block-group.c | 37 ++++++++++++++++++++++++++----------- > fs/btrfs/space-info.c | 19 ++++++++++--------- > fs/btrfs/space-info.h | 3 +++ > 3 files changed, 39 insertions(+), 20 deletions(-) > > diff --git a/fs/btrfs/block-group.c b/fs/btrfs/block-group.c > index 3ffbc2e0af21..7b1f6d2b9621 100644 > --- a/fs/btrfs/block-group.c > +++ b/fs/btrfs/block-group.c > @@ -1184,7 +1184,6 @@ static int inc_block_group_ro(struct btrfs_block_group *cache, int force) > { > struct btrfs_space_info *sinfo = cache->space_info; > u64 num_bytes; > - u64 sinfo_used; > int ret = -ENOSPC; > > spin_lock(&sinfo->lock); > @@ -1200,19 +1199,38 @@ static int inc_block_group_ro(struct btrfs_block_group *cache, int force) > > num_bytes = cache->length - cache->reserved - cache->pinned - > cache->bytes_super - cache->used; > - sinfo_used = btrfs_space_info_used(sinfo, true); > > /* > - * sinfo_used + num_bytes should always <= sinfo->total_bytes. > - * > - * Here we make sure if we mark this bg RO, we still have enough > - * free space as buffer. > + * Data never overcommits, even in mixed mode, so do just the straight > + * check of left over space in how much we have allocated. > */ > - if (sinfo_used + num_bytes + sinfo->total_bytes) { > + if (sinfo->flags & BTRFS_BLOCK_GROUP_DATA) { > + u64 sinfo_used = btrfs_space_info_used(sinfo, true); does that mean bytes_may_write is always 0 for DATA? > + > + /* > + * sinfo_used + num_bytes should always <= sinfo->total_bytes. This invariant warrants an ASSERT. > + * > + * Here we make sure if we mark this bg RO, we still have enough > + * free space as buffer. > + */ > + if (sinfo_used + num_bytes + sinfo->total_bytes) > + ret = 0; > + } else { > + /* > + * We overcommit metadata, so we need to do the > + * btrfs_can_overcommit check here, and we need to pass in > + * BTRFS_RESERVE_NO_FLUSH to give ourselves the most amount of > + * leeway to allow us to mark this block group as read only. > + */ > + if (btrfs_can_overcommit(cache->fs_info, sinfo, num_bytes, > + BTRFS_RESERVE_NO_FLUSH)) > + ret = 0; > + } > + > + if (!ret) { > sinfo->bytes_readonly += num_bytes; > cache->ro++; > list_add_tail(&cache->ro_list, &sinfo->ro_bgs); > - ret = 0; > } > out: > spin_unlock(&cache->lock); > @@ -1220,9 +1238,6 @@ static int inc_block_group_ro(struct btrfs_block_group *cache, int force) > if (ret == -ENOSPC && btrfs_test_opt(cache->fs_info, ENOSPC_DEBUG)) { > btrfs_info(cache->fs_info, > "unable to make block group %llu ro", cache->start); > - btrfs_info(cache->fs_info, > - "sinfo_used=%llu bg_num_bytes=%llu", > - sinfo_used, num_bytes); > btrfs_dump_space_info(cache->fs_info, cache->space_info, 0, 0); > } > return ret; > diff --git a/fs/btrfs/space-info.c b/fs/btrfs/space-info.c > index df5fb68df798..01297c5b2666 100644 > --- a/fs/btrfs/space-info.c > +++ b/fs/btrfs/space-info.c > @@ -159,9 +159,9 @@ static inline u64 calc_global_rsv_need_space(struct btrfs_block_rsv *global) > return (global->size << 1); > } > > -static int can_overcommit(struct btrfs_fs_info *fs_info, > - struct btrfs_space_info *space_info, u64 bytes, > - enum btrfs_reserve_flush_enum flush) > +int btrfs_can_overcommit(struct btrfs_fs_info *fs_info, > + struct btrfs_space_info *space_info, u64 bytes, > + enum btrfs_reserve_flush_enum flush) > { > u64 profile; > u64 avail; > @@ -226,7 +226,8 @@ void btrfs_try_granting_tickets(struct btrfs_fs_info *fs_info, > > /* Check and see if our ticket can be satisified now. */ > if ((used + ticket->bytes <= space_info->total_bytes) || > - can_overcommit(fs_info, space_info, ticket->bytes, flush)) { > + btrfs_can_overcommit(fs_info, space_info, ticket->bytes, > + flush)) { > btrfs_space_info_update_bytes_may_use(fs_info, > space_info, > ticket->bytes); > @@ -639,14 +640,14 @@ btrfs_calc_reclaim_metadata_size(struct btrfs_fs_info *fs_info, > return to_reclaim; > > to_reclaim = min_t(u64, num_online_cpus() * SZ_1M, SZ_16M); > - if (can_overcommit(fs_info, space_info, to_reclaim, > - BTRFS_RESERVE_FLUSH_ALL)) > + if (btrfs_can_overcommit(fs_info, space_info, to_reclaim, > + BTRFS_RESERVE_FLUSH_ALL)) > return 0; > > used = btrfs_space_info_used(space_info, true); > > - if (can_overcommit(fs_info, space_info, SZ_1M, > - BTRFS_RESERVE_FLUSH_ALL)) > + if (btrfs_can_overcommit(fs_info, space_info, SZ_1M, > + BTRFS_RESERVE_FLUSH_ALL)) > expected = div_factor_fine(space_info->total_bytes, 95); > else > expected = div_factor_fine(space_info->total_bytes, 90); > @@ -1005,7 +1006,7 @@ static int __reserve_metadata_bytes(struct btrfs_fs_info *fs_info, > */ > if (!pending_tickets && > ((used + orig_bytes <= space_info->total_bytes) || > - can_overcommit(fs_info, space_info, orig_bytes, flush))) { > + btrfs_can_overcommit(fs_info, space_info, orig_bytes, flush))) { > btrfs_space_info_update_bytes_may_use(fs_info, space_info, > orig_bytes); > ret = 0; > diff --git a/fs/btrfs/space-info.h b/fs/btrfs/space-info.h > index 1a349e3f9cc1..24514cd2c6c1 100644 > --- a/fs/btrfs/space-info.h > +++ b/fs/btrfs/space-info.h > @@ -127,6 +127,9 @@ int btrfs_reserve_metadata_bytes(struct btrfs_root *root, > enum btrfs_reserve_flush_enum flush); > void btrfs_try_granting_tickets(struct btrfs_fs_info *fs_info, > struct btrfs_space_info *space_info); > +int btrfs_can_overcommit(struct btrfs_fs_info *fs_info, > + struct btrfs_space_info *space_info, u64 bytes, > + enum btrfs_reserve_flush_enum flush); > > static inline void btrfs_space_info_free_bytes_may_use( > struct btrfs_fs_info *fs_info, >