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 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 0EBD7C433EF for ; Mon, 14 Mar 2022 07:17:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=5+nHjO0FlWSafR3YjpOT7rt4Z0HBx2CppoEaBPIpfN8=; b=HZPjykHe3qxfLBk/Zz0eyt4/PL 1iEPGCliFGgbY8OXj+WqXN+9K5GpFuQTDJTuKvBLR6XTajGJAs/t/X0KxEuOE0UAKoWthQHKh7Adm Pvt9AtI0JTtBFW/KHhH7MPwesVtmLrCCybYQGoKMM9rE2qkas2yiGMIeGEUlu8RqH7PMuPYQsD4zB sbiEkF7sdyWVwHXF1gmZ+i5tcJiRC3eGz3MEXCV6qnl+Im6nMRRuJJhCkAQWi90C5yr+O2w8gKZ19 77SivyuMgdmG2D9gRrcajMN+4nBpliCwlgXTMWdIqa9F/hQJiwnX2iizWGgP/tPv3GAp9KnusIQmZ 1jMjLyqg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1nTex6-0042eq-0Z; Mon, 14 Mar 2022 07:17:12 +0000 Received: from verein.lst.de ([213.95.11.211]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1nTex2-0042eA-NW for linux-nvme@lists.infradead.org; Mon, 14 Mar 2022 07:17:10 +0000 Received: by verein.lst.de (Postfix, from userid 2407) id 3CF0668AFE; Mon, 14 Mar 2022 08:17:05 +0100 (CET) Date: Mon, 14 Mar 2022 08:17:05 +0100 From: Christoph Hellwig To: Niels Dossche Cc: linux-nvme@lists.infradead.org, Christoph Hellwig , Sagi Grimberg , Chaitanya Kulkarni Subject: Re: [PATCH v4] nvmet: add missing lock around nvmet_ns_changed in nvmet_ns_revalidate Message-ID: <20220314071705.GA3903@lst.de> References: <20220313234114.37931-1-dossche.niels@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220313234114.37931-1-dossche.niels@gmail.com> User-Agent: Mutt/1.5.17 (2007-11-01) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220314_001709_086780_078B2E21 X-CRM114-Status: GOOD ( 16.13 ) X-BeenThere: linux-nvme@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "Linux-nvme" Errors-To: linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org On Mon, Mar 14, 2022 at 12:41:15AM +0100, Niels Dossche wrote: > - mutex_lock(&ns->subsys->lock); > if (!ns->enabled) { > pr_err("enable ns before revalidate.\n"); > - mutex_unlock(&ns->subsys->lock); > return -EINVAL; > } > nvmet_ns_revalidate(ns); > - mutex_unlock(&ns->subsys->lock); > return count; > } And now we lose the atomicy vs the enabled check. I think we'll need something like: diff --git a/drivers/nvme/target/admin-cmd.c b/drivers/nvme/target/admin-cmd.c index 6fb24746de069..46d0dab686dd6 100644 --- a/drivers/nvme/target/admin-cmd.c +++ b/drivers/nvme/target/admin-cmd.c @@ -511,7 +511,11 @@ static void nvmet_execute_identify_ns(struct nvmet_req *req) goto done; } - nvmet_ns_revalidate(req->ns); + if (nvmet_ns_revalidate(req->ns)) { + mutex_lock(&req->ns->subsys->lock); + nvmet_ns_changed(req->ns->subsys, req->ns->nsid); + mutex_unlock(&req->ns->subsys->lock); + } /* * nuse = ncap = nsze isn't always true, but we have no way to find diff --git a/drivers/nvme/target/configfs.c b/drivers/nvme/target/configfs.c index 091a0ca16361c..06ba477fbf771 100644 --- a/drivers/nvme/target/configfs.c +++ b/drivers/nvme/target/configfs.c @@ -586,7 +586,8 @@ static ssize_t nvmet_ns_revalidate_size_store(struct config_item *item, mutex_unlock(&ns->subsys->lock); return -EINVAL; } - nvmet_ns_revalidate(ns); + if (nvmet_ns_revalidate(ns)) + nvmet_ns_changed(ns->subsys, ns->nsid); mutex_unlock(&ns->subsys->lock); return count; } diff --git a/drivers/nvme/target/core.c b/drivers/nvme/target/core.c index 5119c687de683..17cc1cda836cc 100644 --- a/drivers/nvme/target/core.c +++ b/drivers/nvme/target/core.c @@ -531,7 +531,7 @@ static void nvmet_p2pmem_ns_add_p2p(struct nvmet_ctrl *ctrl, ns->nsid); } -void nvmet_ns_revalidate(struct nvmet_ns *ns) +bool nvmet_ns_revalidate(struct nvmet_ns *ns) { loff_t oldsize = ns->size; @@ -540,8 +540,7 @@ void nvmet_ns_revalidate(struct nvmet_ns *ns) else nvmet_file_ns_revalidate(ns); - if (oldsize != ns->size) - nvmet_ns_changed(ns->subsys, ns->nsid); + return oldsize != ns->size; } int nvmet_ns_enable(struct nvmet_ns *ns) diff --git a/drivers/nvme/target/nvmet.h b/drivers/nvme/target/nvmet.h index af193423c10bb..731f529e11a51 100644 --- a/drivers/nvme/target/nvmet.h +++ b/drivers/nvme/target/nvmet.h @@ -542,7 +542,7 @@ u16 nvmet_file_flush(struct nvmet_req *req); void nvmet_ns_changed(struct nvmet_subsys *subsys, u32 nsid); void nvmet_bdev_ns_revalidate(struct nvmet_ns *ns); int nvmet_file_ns_revalidate(struct nvmet_ns *ns); -void nvmet_ns_revalidate(struct nvmet_ns *ns); +bool nvmet_ns_revalidate(struct nvmet_ns *ns); u16 blk_to_nvme_status(struct nvmet_req *req, blk_status_t blk_sts); bool nvmet_bdev_zns_enable(struct nvmet_ns *ns); diff --git a/drivers/nvme/target/zns.c b/drivers/nvme/target/zns.c index 46bc30fe85d2b..56c20502b7ef3 100644 --- a/drivers/nvme/target/zns.c +++ b/drivers/nvme/target/zns.c @@ -123,7 +123,11 @@ void nvmet_execute_identify_cns_cs_ns(struct nvmet_req *req) goto done; } - nvmet_ns_revalidate(req->ns); + if (nvmet_ns_revalidate(req->ns)) { + mutex_lock(&req->ns->subsys->lock); + nvmet_ns_changed(req->ns->subsys, req->ns->nsid); + mutex_unlock(&req->ns->subsys->lock); + } zsze = (bdev_zone_sectors(req->ns->bdev) << 9) >> req->ns->blksize_shift; id_zns->lbafe[0].zsze = cpu_to_le64(zsze);