From patchwork Thu Oct 22 21:22:23 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Matthew Wilcox X-Patchwork-Id: 11851921 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 7788B6A2 for ; Thu, 22 Oct 2020 21:22:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4E85324655 for ; Thu, 22 Oct 2020 21:22:58 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="j0gytLMN" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S372254AbgJVVWd (ORCPT ); Thu, 22 Oct 2020 17:22:33 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40964 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2897727AbgJVVWc (ORCPT ); Thu, 22 Oct 2020 17:22:32 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1895EC0613CE; Thu, 22 Oct 2020 14:22:31 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=Content-Transfer-Encoding:MIME-Version: References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From:Sender:Reply-To: Content-Type:Content-ID:Content-Description; bh=/Sk507X/XJRZb80wAXzDRfdLw7egwWlksVqiUNUiyjs=; b=j0gytLMNDZRI40meEo4hRH0jPx MaadKOoRAPi5awBfQX5VgWUV5s2w/Vq8fLZU7MEYAZpA6hWI36nO0Yyy87RMst0MaWjYFrDwDYkmY 1Mmm67OCuN6KpXH2OEfhgTkkLEX2rnoG1L5KxXBqM5t6ocYmlKBJYQ/KA3fq64qupBiiNHa1+eBp3 kns7bcC2TbVAOpW6oKEFdQmtxu79GBBw0QBR/Xz/d9YDOUs65+/sr7Eg55SFiCgJlHLYA5qGL7xkq WRRCEoB7yu1gIVj8FVkelOahlDSNLRO/ULvcB2rU3q4Haps42hFd+dyKw3WMTHvndlWFGTwarGCc0 DCgHAx1A==; Received: from willy by casper.infradead.org with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1kVi2Y-00046F-AE; Thu, 22 Oct 2020 21:22:30 +0000 From: "Matthew Wilcox (Oracle)" To: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-block@vger.kernel.org, linux-fscrypt@vger.kernel.org Cc: "Matthew Wilcox (Oracle)" Subject: [PATCH 1/6] block: Add blk_completion Date: Thu, 22 Oct 2020 22:22:23 +0100 Message-Id: <20201022212228.15703-2-willy@infradead.org> X-Mailer: git-send-email 2.21.3 In-Reply-To: <20201022212228.15703-1-willy@infradead.org> References: <20201022212228.15703-1-willy@infradead.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-fscrypt@vger.kernel.org This new data structure allows a task to wait for N things to complete. Usually the submitting task will handle cleanup, but if it is killed, the last completer will take care of it. Signed-off-by: Matthew Wilcox (Oracle) --- block/blk-core.c | 61 +++++++++++++++++++++++++++++++++++++++++++++ include/linux/bio.h | 11 ++++++++ 2 files changed, 72 insertions(+) diff --git a/block/blk-core.c b/block/blk-core.c index 10c08ac50697..2892246f2176 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -1900,6 +1900,67 @@ void blk_io_schedule(void) } EXPORT_SYMBOL_GPL(blk_io_schedule); +void blk_completion_init(struct blk_completion *cmpl, int n) +{ + spin_lock_init(&cmpl->cmpl_lock); + cmpl->cmpl_count = n; + cmpl->cmpl_task = current; + cmpl->cmpl_status = BLK_STS_OK; +} + +int blk_completion_sub(struct blk_completion *cmpl, blk_status_t status, int n) +{ + int ret = 0; + + spin_lock_bh(&cmpl->cmpl_lock); + if (cmpl->cmpl_status == BLK_STS_OK && status != BLK_STS_OK) + cmpl->cmpl_status = status; + cmpl->cmpl_count -= n; + BUG_ON(cmpl->cmpl_count < 0); + if (cmpl->cmpl_count == 0) { + if (cmpl->cmpl_task) + wake_up_process(cmpl->cmpl_task); + else + ret = -EINTR; + } + spin_unlock_bh(&cmpl->cmpl_lock); + if (ret < 0) + kfree(cmpl); + return ret; +} + +int blk_completion_wait_killable(struct blk_completion *cmpl) +{ + int err = 0; + + for (;;) { + set_current_state(TASK_KILLABLE); + spin_lock_bh(&cmpl->cmpl_lock); + if (cmpl->cmpl_count == 0) + break; + spin_unlock_bh(&cmpl->cmpl_lock); + blk_io_schedule(); + if (fatal_signal_pending(current)) { + spin_lock_bh(&cmpl->cmpl_lock); + cmpl->cmpl_task = NULL; + if (cmpl->cmpl_count != 0) { + spin_unlock_bh(&cmpl->cmpl_lock); + cmpl = NULL; + } + err = -ERESTARTSYS; + break; + } + } + set_current_state(TASK_RUNNING); + if (cmpl) { + spin_unlock_bh(&cmpl->cmpl_lock); + err = blk_status_to_errno(cmpl->cmpl_status); + kfree(cmpl); + } + + return err; +} + int __init blk_dev_init(void) { BUILD_BUG_ON(REQ_OP_LAST >= (1 << REQ_OP_BITS)); diff --git a/include/linux/bio.h b/include/linux/bio.h index f254bc79bb3a..0bde05f5548c 100644 --- a/include/linux/bio.h +++ b/include/linux/bio.h @@ -814,4 +814,15 @@ static inline void bio_set_polled(struct bio *bio, struct kiocb *kiocb) bio->bi_opf |= REQ_NOWAIT; } +struct blk_completion { + struct task_struct *cmpl_task; + spinlock_t cmpl_lock; + int cmpl_count; + blk_status_t cmpl_status; +}; + +void blk_completion_init(struct blk_completion *, int n); +int blk_completion_sub(struct blk_completion *, blk_status_t status, int n); +int blk_completion_wait_killable(struct blk_completion *); + #endif /* __LINUX_BIO_H */