From patchwork Wed Jul 31 20:22:57 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Bart Van Assche X-Patchwork-Id: 816190 Received: from 008.lax.mailroute.net (008.lax.mailroute.net [199.89.1.11]) (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 4EB9817579 for ; Wed, 31 Jul 2024 20:26:44 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=199.89.1.11 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1722457605; cv=none; b=mzJpLUYtxLbFua4p0GXMa+y0PQ+nqHQ871yVoat6uKjBKcVJiUnCzml4tzUhWoffHDvqLNEmzpAR7Frsao5xOZI90qzeSFnUf06QIVaElozx14GWOn+ci3tB8/pQm4G6GYaCNdJc7CF6ym2ZGnWhl6viM9PSSQ0YW0DnvkHRWhg= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1722457605; c=relaxed/simple; bh=H5ArDd+hq2jHQBtCRY2DdmowPeY5Q8QpQXJuMJrgP/c=; h=Message-ID:Date:MIME-Version:From:Subject:To:Cc:Content-Type; b=M383CVhJEvNBOhNJcRbDT7xrkXnUhzuEvoXZMExOYsJ7W0zGQwuqAUTGU7min4k+ROpBQlSKsFWLUpG5BWnI+1bOENhJC4l50t1VvDmTNR5PeYJkOBQ+YIYU1LG+lRv/3JOxfSbPDhaDYA/QNDn4xMgerxd1qfnjd8d7F0PmALM= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=acm.org; spf=pass smtp.mailfrom=acm.org; dkim=pass (2048-bit key) header.d=acm.org header.i=@acm.org header.b=b98uFmXR; arc=none smtp.client-ip=199.89.1.11 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=acm.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=acm.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=acm.org header.i=@acm.org header.b="b98uFmXR" Received: from localhost (localhost [127.0.0.1]) by 008.lax.mailroute.net (Postfix) with ESMTP id 4WZ3ST1mx2z6CmLxY; Wed, 31 Jul 2024 20:23:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=acm.org; h= content-transfer-encoding:content-type:content-type :content-language:subject:subject:from:from:user-agent :mime-version:date:date:message-id:received:received; s=mr01; t= 1722457381; x=1725049382; bh=Uuok3gItVhet6LmTYx4sbEjwn+unjYRnwLs mBGqO25g=; b=b98uFmXR7DgMPdjxczABqrr80xVsZGlFqsGnuDUfrcB3XLbL1AK SeMGlNoHUoxjjlkwB16a7hJ+dTjCw8A5JFAfZMzioSgIZA2RkyfbPQwq0sZ0xMdd tPe2z0CGyvJ3oN46i2Xc+0k+2jQjCESh8eKEQyvWo8LrgF9db9dhOR0tNdd/EGJB 33n6Z+1HEGEQM2iSWAI3mVitu1ljpr2fkqQl8//XmJzCdvga9CA5TAzQzyrHtslZ AtLx9W1pQ27FViF6CorDpvGOIHHh8amWSi5n+tFdSJOke9bZl3cprP6rwJ531xfk fPYcC/37PnbH6psSVFfKgqPLRkSaxG2TBfA== X-Virus-Scanned: by MailRoute Received: from 008.lax.mailroute.net ([127.0.0.1]) by localhost (008.lax [127.0.0.1]) (mroute_mailscanner, port 10029) with LMTP id Lp-8nHiRaPfG; Wed, 31 Jul 2024 20:23:01 +0000 (UTC) Received: from [100.66.154.22] (unknown [104.135.204.82]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) (Authenticated sender: bvanassche@acm.org) by 008.lax.mailroute.net (Postfix) with ESMTPSA id 4WZ3SM3jNyz6CmM6f; Wed, 31 Jul 2024 20:22:59 +0000 (UTC) Message-ID: Date: Wed, 31 Jul 2024 13:22:57 -0700 Precedence: bulk X-Mailing-List: linux-scsi@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird From: Bart Van Assche Subject: RFC: Retrying SCSI pass-through commands To: "Martin K . Petersen" , Damien Le Moal , Hannes Reinecke , Mike Christie Cc: "James E . J . Bottomley" , Jaegeuk Kim , Christoph Hellwig , "linux-scsi@vger.kernel.org" Content-Language: en-US Hi, Recently I noticed that a particular UFS-based device does not resume correctly. The logs of the device show that sd_start_stop_device() does not retry the START STOP UNIT command if the device reports a unit attention. I think that's a bug in the SCSI core. The following hack makes resume work again. I think this confirms my understanding of this issue (sd_start_stop_device() sets RQF_PM): Bart. diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c index da7dac77f8cd..e21becc5bcf9 100644 --- a/drivers/scsi/scsi_error.c +++ b/drivers/scsi/scsi_error.c @@ -1816,6 +1816,8 @@ bool scsi_noretry_cmd(struct scsi_cmnd *scmd) * assume caller has checked sense and determined * the check condition was retryable. */ + if (req->rq_flags & RQF_PM) + return false; if (req->cmd_flags & REQ_FAILFAST_DEV || blk_rq_is_passthrough(req)) return true; My understanding is that SCSI pass-through commands submitted from user space must not be retried. Are there any objections against modifying the behavior of the SCSI core such that it retries REQ_OP_DRV_* operations submitted by the SCSI core, as illustrated by the pseudo-code below? diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c index da7dac77f8cd..e21becc5bcf9 100644 --- a/drivers/scsi/scsi_error.c +++ b/drivers/scsi/scsi_error.c @@ -1816,6 +1816,12 @@ bool scsi_noretry_cmd(struct scsi_cmnd *scmd) * assume caller has checked sense and determined * the check condition was retryable. */ - if (req->cmd_flags & REQ_FAILFAST_DEV || blk_rq_is_passthrough(req)) - return true; + if (req->cmd_flags & REQ_FAILFAST_DEV) + return true; + if (/* submitted by the SCSI core */) + return false; + if (blk_rq_is_passthrough(req)) + return true; Thanks,