From patchwork Mon Oct 7 18:24:15 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Uday Shankar X-Patchwork-Id: 13825119 Received: from mail-lf1-f98.google.com (mail-lf1-f98.google.com [209.85.167.98]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 123E71DDC3A for ; Mon, 7 Oct 2024 18:24:33 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.167.98 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1728325476; cv=none; b=IJ774hOotVDsDk0TZC6KFDe4jSKt0Mj5sp4I5wUqeLgKYP2huz28Z2Qmca3Cbn7dxJMmJ72Qkij63a5scaZAaG3ka3RI+HtUFrPVJc6lTWH3ez4oYDJZD+9sx5EIoqGnRQAtq0/BKF//xdRUBd15BNZDU/Twg1nwmbpeC8rFmuc= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1728325476; c=relaxed/simple; bh=5BAYvcjKwAx/J4GvPz/qFxxZnbBXgXOpB5dJOP8thhE=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=R/PoBFq6tEFjBqm6ymi5zA7UCRaSB7Nk9GkeYgnuA7etRatIsaMuugqQuhYrr5lku++AAxGlralAo2t5hEO9T5fIRLWiKhzHX6ltZG+pXql8qFj3lW1t6wihUa0RQWEUViDVVvJRqSh+f72Lz3aERAuHGr82/ON9TYATXtCYgSQ= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=purestorage.com; spf=fail smtp.mailfrom=purestorage.com; dkim=pass (2048-bit key) header.d=purestorage.com header.i=@purestorage.com header.b=BqZLsFp6; arc=none smtp.client-ip=209.85.167.98 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=purestorage.com Authentication-Results: smtp.subspace.kernel.org; spf=fail smtp.mailfrom=purestorage.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=purestorage.com header.i=@purestorage.com header.b="BqZLsFp6" Received: by mail-lf1-f98.google.com with SMTP id 2adb3069b0e04-5399675e14cso5437157e87.3 for ; Mon, 07 Oct 2024 11:24:33 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=purestorage.com; s=google2022; t=1728325472; x=1728930272; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=Lzfa3TD2aAJu1t8Ngs41AQfKWfztgMT258K/19H9wjE=; b=BqZLsFp6JUwEzCNj0BsBHNjrmTjqtbFzzBtuankZJXP9dlyGBjTiPaoLYp3B8ohbX/ UCIKKTXKHsPVbxiNmowfMtr0XZ4zlRiRWWEDB/DyL+pY4q+4TjNUn9hAQFsTsoY2o5eF S8h4wgpJELTVUmMymeekZ9/5rQkeNKT2P0JXKo0q680MZYWGAfUGjopeZDxgNzi22x+e u5OIJo+MrJx6lw5lsT00ZRBaqEDMja7Jt5er4Z9gNCCs7TX43KNGmHkVbzsVE0HWWzXn EkjjbXqyrZDTSuoRD9WTnsdpTbLXPgyeLNn8WpvnOJt6nsnPJ0zaN/THtWmgMHw16ffE iwzA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1728325472; x=1728930272; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=Lzfa3TD2aAJu1t8Ngs41AQfKWfztgMT258K/19H9wjE=; b=VZW9BLUFtChm/fLDmBWThboDKJzNPR1HCm7cfc2+DgYmbMGV+vBxYFaiMxMiu+SUXj DQ8O6E03HwvdcrMGzOkBinw1Eg0iojiUhJFJ1cp/PlskhFdI47nam0RcE5NG3LargsCb 1s7kPZLJcRgEwIxZdmzXj7pwkymeh66y0HoWovAnE+v9nczCit0BJReMdFnzR6NIXTFN atSkQCQiNpw9gMG5u7DrzkUB4IyPyWOtaW8+YUbX1gAqwGr1OMFTcoAR4vGB8oHNPddU lM2if8a9GK4xYCkvHBhoa0PPPHDt0PnnsrypNrxeNW7GqLaDJm7js4964vHLJTTUOPx1 Td+w== X-Forwarded-Encrypted: i=1; AJvYcCUgp2Ujv6tGruyLzAObL/xbNCqJtizoZR08nV4Bjic4f68Bo8zk9TOpBVE0A5OuTfEv6p+T/i8ov0GR5w==@vger.kernel.org X-Gm-Message-State: AOJu0YydVKV9u46xNXEUnNIby4GNf32czsZriX+dUJwHb9k5h/r9Wb53 pW2esMhVlcRu6YCFbx5WKFExhTG9SRWaH3C8PWA2XaHNwfJTFbqmQPxpAcce9GiWEQboNx1nASU yFkepNH2bUuCayO4wznSVuUl3q6brPP3jrYnQ22aYlm4IZweN X-Google-Smtp-Source: AGHT+IF56kfSHWsxoYRfjsv+axS1dCXzXR57XmJZl3oM4t2HjUaDqW8lZ1RTGPGWRTXX/ON22nysZbHvl8ND X-Received: by 2002:a05:6512:3d0c:b0:533:d3e:16f5 with SMTP id 2adb3069b0e04-539ab9cf3cemr6353568e87.38.1728325471969; Mon, 07 Oct 2024 11:24:31 -0700 (PDT) Received: from c7-smtp-2023.dev.purestorage.com ([2620:125:9017:12:36:3:5:0]) by smtp-relay.gmail.com with ESMTPS id 2adb3069b0e04-539aff1f1aesm161333e87.82.2024.10.07.11.24.31 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 07 Oct 2024 11:24:31 -0700 (PDT) X-Relaying-Domain: purestorage.com Received: from dev-ushankar.dev.purestorage.com (dev-ushankar.dev.purestorage.com [10.7.70.36]) by c7-smtp-2023.dev.purestorage.com (Postfix) with ESMTP id 3662534022F; Mon, 7 Oct 2024 12:24:30 -0600 (MDT) Received: by dev-ushankar.dev.purestorage.com (Postfix, from userid 1557716368) id 2DCA2E413A4; Mon, 7 Oct 2024 12:24:30 -0600 (MDT) From: Uday Shankar To: Ming Lei , Jens Axboe , Jonathan Corbet Cc: Uday Shankar , linux-block@vger.kernel.org, linux-doc@vger.kernel.org Subject: [PATCH v4 2/5] ublk: refactor recovery configuration flag helpers Date: Mon, 7 Oct 2024 12:24:15 -0600 Message-Id: <20241007182419.3263186-3-ushankar@purestorage.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20241007182419.3263186-1-ushankar@purestorage.com> References: <20241007182419.3263186-1-ushankar@purestorage.com> Precedence: bulk X-Mailing-List: linux-block@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 ublk currently supports the following behaviors on ublk server exit: A: outstanding I/Os get errors, subsequently issued I/Os get errors B: outstanding I/Os get errors, subsequently issued I/Os queue C: outstanding I/Os get reissued, subsequently issued I/Os queue and the following behaviors for recovery of preexisting block devices by a future incarnation of the ublk server: 1: ublk devices stopped on ublk server exit (no recovery possible) 2: ublk devices are recoverable using start/end_recovery commands The userspace interface allows selection of combinations of these behaviors using flags specified at device creation time, namely: default behavior: A + 1 UBLK_F_USER_RECOVERY: B + 2 UBLK_F_USER_RECOVERY|UBLK_F_USER_RECOVERY_REISSUE: C + 2 We can't easily change the userspace interface to allow independent selection of one of {A, B, C} and one of {1, 2}, but we can refactor the internal helpers which test for the flags. Replace the existing helpers with the following set: ublk_nosrv_should_reissue_outstanding: tests for behavior C ublk_nosrv_[dev_]should_queue_io: tests for behavior B ublk_nosrv_should_stop_dev: tests for behavior 1 Signed-off-by: Uday Shankar Reviewed-by: Ming Lei --- drivers/block/ublk_drv.c | 62 +++++++++++++++++++++++++++------------- 1 file changed, 42 insertions(+), 20 deletions(-) diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c index 318a4dfe8266..a838ba809445 100644 --- a/drivers/block/ublk_drv.c +++ b/drivers/block/ublk_drv.c @@ -675,22 +675,44 @@ static inline int ublk_queue_cmd_buf_size(struct ublk_device *ub, int q_id) PAGE_SIZE); } -static inline bool ublk_queue_can_use_recovery_reissue( - struct ublk_queue *ubq) +/* + * Should I/O outstanding to the ublk server when it exits be reissued? + * If not, outstanding I/O will get errors. + */ +static inline bool ublk_nosrv_should_reissue_outstanding(struct ublk_device *ub) { - return (ubq->flags & UBLK_F_USER_RECOVERY) && - (ubq->flags & UBLK_F_USER_RECOVERY_REISSUE); + return (ub->dev_info.flags & UBLK_F_USER_RECOVERY) && + (ub->dev_info.flags & UBLK_F_USER_RECOVERY_REISSUE); } -static inline bool ublk_queue_can_use_recovery( - struct ublk_queue *ubq) +/* + * Should I/O issued while there is no ublk server queue? If not, I/O + * issued while there is no ublk server will get errors. + */ +static inline bool ublk_nosrv_dev_should_queue_io(struct ublk_device *ub) +{ + return ub->dev_info.flags & UBLK_F_USER_RECOVERY; +} + +/* + * Same as ublk_nosrv_dev_should_queue_io, but uses a queue-local copy + * of the device flags for smaller cache footprint - better for fast + * paths. + */ +static inline bool ublk_nosrv_should_queue_io(struct ublk_queue *ubq) { return ubq->flags & UBLK_F_USER_RECOVERY; } -static inline bool ublk_can_use_recovery(struct ublk_device *ub) +/* + * Should ublk devices be stopped (i.e. no recovery possible) when the + * ublk server exits? If not, devices can be used again by a future + * incarnation of a ublk server via the start_recovery/end_recovery + * commands. + */ +static inline bool ublk_nosrv_should_stop_dev(struct ublk_device *ub) { - return ub->dev_info.flags & UBLK_F_USER_RECOVERY; + return !(ub->dev_info.flags & UBLK_F_USER_RECOVERY); } static void ublk_free_disk(struct gendisk *disk) @@ -1066,7 +1088,7 @@ static void __ublk_fail_req(struct ublk_queue *ubq, struct ublk_io *io, { WARN_ON_ONCE(io->flags & UBLK_IO_FLAG_ACTIVE); - if (ublk_queue_can_use_recovery_reissue(ubq)) + if (ublk_nosrv_should_reissue_outstanding(ubq->dev)) blk_mq_requeue_request(req, false); else ublk_put_req_ref(ubq, req); @@ -1094,7 +1116,7 @@ static inline void __ublk_abort_rq(struct ublk_queue *ubq, struct request *rq) { /* We cannot process this rq so just requeue it. */ - if (ublk_queue_can_use_recovery(ubq)) + if (ublk_nosrv_dev_should_queue_io(ubq->dev)) blk_mq_requeue_request(rq, false); else blk_mq_end_request(rq, BLK_STS_IOERR); @@ -1239,10 +1261,10 @@ static enum blk_eh_timer_return ublk_timeout(struct request *rq) struct ublk_device *ub = ubq->dev; if (ublk_abort_requests(ub, ubq)) { - if (ublk_can_use_recovery(ub)) - schedule_work(&ub->quiesce_work); - else + if (ublk_nosrv_should_stop_dev(ub)) schedule_work(&ub->stop_work); + else + schedule_work(&ub->quiesce_work); } return BLK_EH_DONE; } @@ -1271,7 +1293,7 @@ static blk_status_t ublk_queue_rq(struct blk_mq_hw_ctx *hctx, * Note: force_abort is guaranteed to be seen because it is set * before request queue is unqiuesced. */ - if (ublk_queue_can_use_recovery(ubq) && unlikely(ubq->force_abort)) + if (ublk_nosrv_should_queue_io(ubq) && unlikely(ubq->force_abort)) return BLK_STS_IOERR; if (unlikely(ubq->canceling)) { @@ -1492,10 +1514,10 @@ static void ublk_uring_cmd_cancel_fn(struct io_uring_cmd *cmd, ublk_cancel_cmd(ubq, io, issue_flags); if (need_schedule) { - if (ublk_can_use_recovery(ub)) - schedule_work(&ub->quiesce_work); - else + if (ublk_nosrv_should_stop_dev(ub)) schedule_work(&ub->stop_work); + else + schedule_work(&ub->quiesce_work); } } @@ -1600,7 +1622,7 @@ static void ublk_stop_dev(struct ublk_device *ub) mutex_lock(&ub->mutex); if (ub->dev_info.state == UBLK_S_DEV_DEAD) goto unlock; - if (ublk_can_use_recovery(ub)) { + if (ublk_nosrv_dev_should_queue_io(ub)) { if (ub->dev_info.state == UBLK_S_DEV_LIVE) __ublk_quiesce_dev(ub); ublk_unquiesce_dev(ub); @@ -2701,7 +2723,7 @@ static int ublk_ctrl_start_recovery(struct ublk_device *ub, int i; mutex_lock(&ub->mutex); - if (!ublk_can_use_recovery(ub)) + if (ublk_nosrv_should_stop_dev(ub)) goto out_unlock; if (!ub->nr_queues_ready) goto out_unlock; @@ -2754,7 +2776,7 @@ static int ublk_ctrl_end_recovery(struct ublk_device *ub, __func__, ub->dev_info.nr_hw_queues, header->dev_id); mutex_lock(&ub->mutex); - if (!ublk_can_use_recovery(ub)) + if (ublk_nosrv_should_stop_dev(ub)) goto out_unlock; if (ub->dev_info.state != UBLK_S_DEV_QUIESCED) {