From nobody Wed Dec 1 18:15:14 2021 X-Original-To: freebsd-stable@mlmmj.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mlmmj.nyi.freebsd.org (Postfix) with ESMTP id 140DF18C245F for ; Wed, 1 Dec 2021 18:15:33 +0000 (UTC) (envelope-from asomers@gmail.com) Received: from mail-oi1-f182.google.com (mail-oi1-f182.google.com [209.85.167.182]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (2048 bits) client-digest SHA256) (Client CN "smtp.gmail.com", Issuer "GTS CA 1D4" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4J46hM6XX8z3GbH for ; Wed, 1 Dec 2021 18:15:31 +0000 (UTC) (envelope-from asomers@gmail.com) Received: by mail-oi1-f182.google.com with SMTP id s139so50218179oie.13 for ; Wed, 01 Dec 2021 10:15:31 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:from:date:message-id:subject:to; bh=6yfDtFy8wspL7fZXjsOujF/4/m/SEIXbVts4OdTo+wk=; b=jxJBFOX44yhDPQTxVz8GCJaiOyNwOxrK9yVFZwuq4RXydGL1GdNdCDhixkiWwzOXAq iyYGAu4bqGlc8H9Odm+BO3682+eLJ5LYhjSwELluccTCwzJhTlk5k60vg0yL9AUj2gLa J4nQ/Ub15DKWnHyCeqm9EHC5+jMYKARMc+9Uf1kYnzn+VDFNU0hYZlXnEX2WQPyrx1oW jXs+QoWrAk7gvINxRH9sJFQj/RA2rqX19i9Q4MEmGezKMvyMOYPTrqayTdhr/iCldegU jq40/ChZIJnFwC4jkJfr6ZuVlhSPK2ZcVvRw23pWH0L3nfAydGBnyQWol/JrZ7wnO918 1tog== X-Gm-Message-State: AOAM530E5NihLDi8XWoj2CgI3t/O6Ump36xkC+F4dDV6O7fDGUc5qHtl 070Cx5sJNY0de2SRjYIWdeONHP1J58E6GHP4M57xPtRT X-Google-Smtp-Source: ABdhPJznvwVNnKYsn2GxbMXS4EHEV2fYTpPE4OzKpASlGw4xtcEqGgsmBqsOQ4D8mVIJYzK4Tc+JKck0MONfTVeV+8E= X-Received: by 2002:a05:6808:ec3:: with SMTP id q3mr7692800oiv.57.1638382525410; Wed, 01 Dec 2021 10:15:25 -0800 (PST) List-Id: Production branch of FreeBSD source code List-Archive: https://lists.freebsd.org/archives/freebsd-stable List-Help: List-Post: List-Subscribe: List-Unsubscribe: Sender: owner-freebsd-stable@freebsd.org X-BeenThere: freebsd-stable@freebsd.org MIME-Version: 1.0 From: Alan Somers Date: Wed, 1 Dec 2021 11:15:14 -0700 Message-ID: Subject: ZFS deadlocks triggered by HDD timeouts To: FreeBSD Content-Type: text/plain; charset="UTF-8" X-Rspamd-Queue-Id: 4J46hM6XX8z3GbH X-Spamd-Bar: / Authentication-Results: mx1.freebsd.org; dkim=none; dmarc=none; spf=pass (mx1.freebsd.org: domain of asomers@gmail.com designates 209.85.167.182 as permitted sender) smtp.mailfrom=asomers@gmail.com X-Spamd-Result: default: False [0.80 / 15.00]; ARC_NA(0.00)[]; RCVD_COUNT_TWO(0.00)[2]; FREEFALL_USER(0.00)[asomers]; FROM_HAS_DN(0.00)[]; R_SPF_ALLOW(-0.20)[+ip4:209.85.128.0/17:c]; TO_MATCH_ENVRCPT_ALL(0.00)[]; MIME_GOOD(-0.10)[text/plain]; PREVIOUSLY_DELIVERED(0.00)[freebsd-stable@freebsd.org]; DMARC_NA(0.00)[freebsd.org]; NEURAL_SPAM_MEDIUM(0.86)[0.860]; RCPT_COUNT_ONE(0.00)[1]; TO_DN_ALL(0.00)[]; NEURAL_HAM_SHORT(-0.95)[-0.951]; RCVD_TLS_ALL(0.00)[]; RCVD_IN_DNSWL_NONE(0.00)[209.85.167.182:from]; NEURAL_SPAM_LONG(0.89)[0.890]; FORGED_SENDER(0.30)[asomers@freebsd.org,asomers@gmail.com]; RWL_MAILSPIKE_POSSIBLE(0.00)[209.85.167.182:from]; R_DKIM_NA(0.00)[]; MIME_TRACE(0.00)[0:+]; ASN(0.00)[asn:15169, ipnet:209.85.128.0/17, country:US]; FROM_NEQ_ENVFROM(0.00)[asomers@freebsd.org,asomers@gmail.com]; FREEMAIL_ENVFROM(0.00)[gmail.com]; TO_DOM_EQ_FROM_DOM(0.00)[] X-ThisMailContainsUnwantedMimeParts: N On a stable/13 build from 16-Sep-2021 I see frequent ZFS deadlocks triggered by HDD timeouts. The timeouts are probably caused by genuine hardware faults, but they didn't lead to deadlocks in 12.2-RELEASE or 13.0-RELEASE. Unfortunately I don't have much additional information. ZFS's stack traces aren't very informative, and dmesg doesn't show anything besides the usual information about the disk timeout. I don't see anything obviously related in the commit history for that time range, either. Has anybody else observed this phenomenon? Or does anybody have a good way to deliberately inject timeouts? CAM makes it easy enough to inject an error, but not a timeout. If it did, then I could bisect the problem. As it is I can only reproduce it on production servers. -Alan