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=-8.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,T_DKIMWL_WL_HIGH,USER_AGENT_MUTT 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 91D0BC282CE for ; Tue, 4 Jun 2019 18:36:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5DE8320848 for ; Tue, 4 Jun 2019 18:36:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1559673383; bh=OpBFA/0p9+w0NEMU26au/zRKP5suon4PQr4A2Jo+g50=; h=Date:From:To:Subject:References:In-Reply-To:List-ID:From; b=FQhAdzsX7FaqMdosPjOPK+64fpO+syRUhrGKisVLrpeQPKINv6qZQr71ez0Fgvp/t gzWaTa3ZiKnzrkwmiOQZYDqnOVlfuKss2srGH681n1heEutOHKXf43LGvnhzFwT9GZ XsQduDWJQM9JWqbYifE2IDp5N9pdBfBZobUfGN54= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726648AbfFDSgW (ORCPT ); Tue, 4 Jun 2019 14:36:22 -0400 Received: from mail.kernel.org ([198.145.29.99]:46104 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726317AbfFDSgW (ORCPT ); Tue, 4 Jun 2019 14:36:22 -0400 Received: from localhost (unknown [104.132.1.68]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 3C3892070B; Tue, 4 Jun 2019 18:36:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1559673380; bh=OpBFA/0p9+w0NEMU26au/zRKP5suon4PQr4A2Jo+g50=; h=Date:From:To:Subject:References:In-Reply-To:From; b=HAj+9ZFnb1BkyWHWv8gEYizpHbW3cEqqYvy68+UhruBwgHL15/4716SuBi+sIYGme q9Mcz85zX1LudvKYQlHaHWZooCTZlSd+V5euZ7jIL8eSjjC7ZK2f7DRKHK0UPv5BAu FKVvMko2tPo+Y503SqLTtQjVVAz6X9Z+24+1cIEg= Date: Tue, 4 Jun 2019 11:36:19 -0700 From: Jaegeuk Kim To: linux-kernel@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net Subject: Re: [f2fs-dev] [PATCH v3] f2fs: add a rw_sem to cover quota flag changes Message-ID: <20190604183619.GA8507@jaegeuk-macbookpro.roam.corp.google.com> References: <20190530033115.16853-1-jaegeuk@kernel.org> <20190530175714.GB28719@jaegeuk-macbookpro.roam.corp.google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190530175714.GB28719@jaegeuk-macbookpro.roam.corp.google.com> User-Agent: Mutt/1.8.2 (2017-04-18) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Two paths to update quota and f2fs_lock_op: 1. - lock_op | - quota_update `- unlock_op 2. - quota_update - lock_op `- unlock_op But, we need to make a transaction on quota_update + lock_op in #2 case. So, this patch introduces: 1. lock_op 2. down_write 3. check __need_flush 4. up_write 5. if there is dirty quota entries, flush them 6. otherwise, good to go Signed-off-by: Jaegeuk Kim --- v3 from v2: - refactor to fix quota corruption issue : it seems that the previous scenario is not real and no deadlock case was encountered. fs/f2fs/checkpoint.c | 41 +++++++++++++++++++---------------------- fs/f2fs/f2fs.h | 1 + fs/f2fs/super.c | 26 +++++++++++++++++++++----- 3 files changed, 41 insertions(+), 27 deletions(-) diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c index 89825261d474..43f65f0962e5 100644 --- a/fs/f2fs/checkpoint.c +++ b/fs/f2fs/checkpoint.c @@ -1131,17 +1131,24 @@ static void __prepare_cp_block(struct f2fs_sb_info *sbi) static bool __need_flush_quota(struct f2fs_sb_info *sbi) { + bool ret = false; + if (!is_journalled_quota(sbi)) return false; - if (is_sbi_flag_set(sbi, SBI_QUOTA_SKIP_FLUSH)) - return false; - if (is_sbi_flag_set(sbi, SBI_QUOTA_NEED_REPAIR)) - return false; - if (is_sbi_flag_set(sbi, SBI_QUOTA_NEED_FLUSH)) - return true; - if (get_pages(sbi, F2FS_DIRTY_QDATA)) - return true; - return false; + + down_write(&sbi->quota_sem); + if (is_sbi_flag_set(sbi, SBI_QUOTA_SKIP_FLUSH)) { + ret = false; + } else if (is_sbi_flag_set(sbi, SBI_QUOTA_NEED_REPAIR)) { + ret = false; + } else if (is_sbi_flag_set(sbi, SBI_QUOTA_NEED_FLUSH)) { + clear_sbi_flag(sbi, SBI_QUOTA_NEED_FLUSH); + ret = true; + } else if (get_pages(sbi, F2FS_DIRTY_QDATA)) { + ret = true; + } + up_write(&sbi->quota_sem); + return ret; } /* @@ -1160,26 +1167,22 @@ static int block_operations(struct f2fs_sb_info *sbi) blk_start_plug(&plug); retry_flush_quotas: + f2fs_lock_all(sbi); if (__need_flush_quota(sbi)) { int locked; if (++cnt > DEFAULT_RETRY_QUOTA_FLUSH_COUNT) { set_sbi_flag(sbi, SBI_QUOTA_SKIP_FLUSH); - f2fs_lock_all(sbi); + set_sbi_flag(sbi, SBI_QUOTA_NEED_FLUSH); goto retry_flush_dents; } - clear_sbi_flag(sbi, SBI_QUOTA_NEED_FLUSH); + f2fs_unlock_all(sbi); /* only failed during mount/umount/freeze/quotactl */ locked = down_read_trylock(&sbi->sb->s_umount); f2fs_quota_sync(sbi->sb, -1); if (locked) up_read(&sbi->sb->s_umount); - } - - f2fs_lock_all(sbi); - if (__need_flush_quota(sbi)) { - f2fs_unlock_all(sbi); cond_resched(); goto retry_flush_quotas; } @@ -1201,12 +1204,6 @@ static int block_operations(struct f2fs_sb_info *sbi) */ down_write(&sbi->node_change); - if (__need_flush_quota(sbi)) { - up_write(&sbi->node_change); - f2fs_unlock_all(sbi); - goto retry_flush_quotas; - } - if (get_pages(sbi, F2FS_DIRTY_IMETA)) { up_write(&sbi->node_change); f2fs_unlock_all(sbi); diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h index 9674a85154b2..9bd2bf0f559b 100644 --- a/fs/f2fs/f2fs.h +++ b/fs/f2fs/f2fs.h @@ -1253,6 +1253,7 @@ struct f2fs_sb_info { block_t unusable_block_count; /* # of blocks saved by last cp */ unsigned int nquota_files; /* # of quota sysfile */ + struct rw_semaphore quota_sem; /* blocking cp for flags */ /* # of pages, see count_type */ atomic_t nr_pages[NR_COUNT_TYPE]; diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c index 15d7e30bfc72..5a318399a2fa 100644 --- a/fs/f2fs/super.c +++ b/fs/f2fs/super.c @@ -1964,6 +1964,7 @@ int f2fs_quota_sync(struct super_block *sb, int type) int cnt; int ret; + down_read(&sbi->quota_sem); ret = dquot_writeback_dquots(sb, type); if (ret) goto out; @@ -2001,6 +2002,7 @@ int f2fs_quota_sync(struct super_block *sb, int type) out: if (ret) set_sbi_flag(F2FS_SB(sb), SBI_QUOTA_NEED_REPAIR); + up_read(&sbi->quota_sem); return ret; } @@ -2094,32 +2096,40 @@ static void f2fs_truncate_quota_inode_pages(struct super_block *sb) static int f2fs_dquot_commit(struct dquot *dquot) { + struct f2fs_sb_info *sbi = F2FS_SB(dquot->dq_sb); int ret; + down_read(&sbi->quota_sem); ret = dquot_commit(dquot); if (ret < 0) - set_sbi_flag(F2FS_SB(dquot->dq_sb), SBI_QUOTA_NEED_REPAIR); + set_sbi_flag(sbi, SBI_QUOTA_NEED_REPAIR); + up_read(&sbi->quota_sem); return ret; } static int f2fs_dquot_acquire(struct dquot *dquot) { + struct f2fs_sb_info *sbi = F2FS_SB(dquot->dq_sb); int ret; + down_read(&sbi->quota_sem); ret = dquot_acquire(dquot); if (ret < 0) - set_sbi_flag(F2FS_SB(dquot->dq_sb), SBI_QUOTA_NEED_REPAIR); - + set_sbi_flag(sbi, SBI_QUOTA_NEED_REPAIR); + up_read(&sbi->quota_sem); return ret; } static int f2fs_dquot_release(struct dquot *dquot) { + struct f2fs_sb_info *sbi = F2FS_SB(dquot->dq_sb); int ret; + down_read(&sbi->quota_sem); ret = dquot_release(dquot); if (ret < 0) - set_sbi_flag(F2FS_SB(dquot->dq_sb), SBI_QUOTA_NEED_REPAIR); + set_sbi_flag(sbi, SBI_QUOTA_NEED_REPAIR); + up_read(&sbi->quota_sem); return ret; } @@ -2129,22 +2139,27 @@ static int f2fs_dquot_mark_dquot_dirty(struct dquot *dquot) struct f2fs_sb_info *sbi = F2FS_SB(sb); int ret; + down_read(&sbi->quota_sem); ret = dquot_mark_dquot_dirty(dquot); /* if we are using journalled quota */ if (is_journalled_quota(sbi)) set_sbi_flag(sbi, SBI_QUOTA_NEED_FLUSH); + up_read(&sbi->quota_sem); return ret; } static int f2fs_dquot_commit_info(struct super_block *sb, int type) { + struct f2fs_sb_info *sbi = F2FS_SB(sb); int ret; + down_read(&sbi->quota_sem); ret = dquot_commit_info(sb, type); if (ret < 0) - set_sbi_flag(F2FS_SB(sb), SBI_QUOTA_NEED_REPAIR); + set_sbi_flag(sbi, SBI_QUOTA_NEED_REPAIR); + up_read(&sbi->quota_sem); return ret; } @@ -3253,6 +3268,7 @@ static int f2fs_fill_super(struct super_block *sb, void *data, int silent) } init_rwsem(&sbi->cp_rwsem); + init_rwsem(&sbi->quota_sem); init_waitqueue_head(&sbi->cp_wait); init_sb_info(sbi); -- 2.19.0.605.g01d371f741-goog