From mboxrd@z Thu Jan 1 00:00:00 1970 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.subspace.kernel.org (Postfix) with ESMTPS id 5F6DE1E0B86; Mon, 19 May 2025 05:32:17 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.137.202.133 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1747632740; cv=none; b=f1sHgrybV4Qk+ykF+o4iy9oazHOBnttHsLAENqyyAIwcPNxdJugxRCuTxqVKyRo7OlTsQe4Um3jExul/HfLQMNDq8pBSqxMCV8+kcSsZWjuz1VWcz0nEWuj3HdJ0kL5O7XsimOcHT0SMY0fYFQ6r7KtLhzXuk3cV8tMhqbFhmco= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1747632740; c=relaxed/simple; bh=jWYI5g+vVLiBOzrfAXt/iaQKvkvYcWBSghpAXs28Q3U=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=q7KFArxSEsVLrsplWN8In3u+asRkTF6jAMwT5qJEMF3sx4PngNWLhNgNGkEASHogzGxdYtR/8C1bj+A13j0ZZWvpO+IXOecALvDHG8A/e5tboKYx9miPOkuvSf8wQWR2oYf01YY0mGBxRFtTtkr3omUWWdh3fxf4Q76E33siTas= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=bombadil.srs.infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=iUouCGxF; arc=none smtp.client-ip=198.137.202.133 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=bombadil.srs.infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="iUouCGxF" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=IEsfDykr8+4fWC+m7DpvjtvuBBE7sgNCtd1n2wYel9k=; b=iUouCGxFog+mPPutazH6N0pUPC Qr3eyxBur/7ohGjygeXPb4BBiG5JlNP1Y3KBG25V1lLRrDAOwUzG9deUNGeziJ1sw7YHXwv5dXGI/ idbgsmxcpnH5izAZUmaMQmG5y+oqFNfdngLCdSX+KU9r9KxE9XYqA1YDOSkJts56NE+liDH6kUHcg ImqHueG8Hgeu/TYOggPLmRxlGy4Y2tGescukkaiYbUaC7WYrAtJUT3blUZ81dJtquxjLmTEFDUvVN Q1laRD1UgMiz8BVSWKHm7eRKbiyg8xyQAkOblwDLkEMwmZlIYRR35C4iqyv2lr2e7f8TCEAidkosl HNuKvKAA==; Received: from hch by bombadil.infradead.org with local (Exim 4.98.2 #2 (Red Hat Linux)) id 1uGt6n-000000081xS-19vB; Mon, 19 May 2025 05:32:17 +0000 Date: Sun, 18 May 2025 22:32:17 -0700 From: Christoph Hellwig To: Benjamin Marzinski Cc: Christoph Hellwig , Kevin Wolf , Martin Wilck , dm-devel@lists.linux.dev, hreitz@redhat.com, mpatocka@redhat.com, snitzer@kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 0/2] dm mpath: Interface for explicit probing of active paths Message-ID: References: <20250429165018.112999-1-kwolf@redhat.com> <47dd225b433b0df585a25084a2e793344eeda239.camel@suse.com> Precedence: bulk X-Mailing-List: dm-devel@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html On Fri, May 16, 2025 at 12:06:21PM -0400, Benjamin Marzinski wrote: > I've run into SCSI arrays that always act like they were called with the > ALL_TG_PT flag set (or perhaps they were just configured that way, I > never could get a straight answer about that). Hmm, that's pretty strange. > libmpathpersist accepts > this flag, and only sends one registration per initiator & target device > when it's set, instead of one per initator & target port. With "this flag" you mean ALL_TG_PT? > dm-multipath > currently doesn't have the knowledge necessary to figure out which > devices it needs to send reservations to, even if the kernel PR API > supported this. > > But I supposed it could just send the registration normally down one > path and if that works, it could just ignore the existing key when it > sends the registration down all the other paths. We could add support for a similar flag to the kernel PR API. The problem is to figure out how to discover support for it. What does the library do for that currently?