From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 EE46618D0B0; Mon, 17 Jun 2024 13:26:19 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1718630780; cv=none; b=J9RabjmRzUeYAxN486tVf89RMwrLoDDIoYon0PxyxQW9h066PCGe95wX3Y1ofHAW0e1atR9//Cuqvxrl11c6gp+hXzd8WDQYyOzRtRc6hBc+vVFogZsO7wUZ2Y60KtoPFOmg7apyOaJkMgbHmFqhHAq85ccMWJigP5N22MuRsWo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1718630780; c=relaxed/simple; bh=o1kRwwDvVU1rG3e8P5Z+WVP3KIo7hNw64Oqe8utbRqY=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=c0zLRxRsmtpY9zbK2A+O+ckx6HyLpeljk7PDGzzp3ZKsSoi1EeyVcs6z/fhKzcMYvBBFzMGiO9kDMZRoLvN38zn1Iq1iGoKsN5xB1aYbbaswt+W9dcOUwRuy7+2LV4FQgZ7ynOTUVd4HOP7rDsv2jCG6HpNRvc8S+UTH7bo+ZFw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=dIVEuZGO; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="dIVEuZGO" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7C044C2BD10; Mon, 17 Jun 2024 13:26:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1718630779; bh=o1kRwwDvVU1rG3e8P5Z+WVP3KIo7hNw64Oqe8utbRqY=; h=From:To:Cc:Subject:Date:From; b=dIVEuZGOO2N4vNi4l7SthBdNSZr4K4uQKbd1mPkZGMMv2eABLhhACZB+UhfqKOtRg DKkN9MRy8KkUkyWYMBDUpVn0qAohTlqdY2dWmy6OrWfmzz+mc4zkPylrrZ8IPhvQRk imo/0PErJI4eSmVziOlGq/9PpyUluVv3uQxeywiebpnDJA2zkgNfEjP8RkY8lYEFkN 3Y2FRD7S0XrTjqwnMl32pSugVCe/GZookhlXbX9JALyz4E4izrSLICUi1hK82EOwNz hC4o043gFemkSvWSPXu8dnk7+gsQD9EQ0AFh2kZxssb/csYdXmC1naQUKXxJeACJAF 7WglltTMTXsOw== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Martin Wilck , Rajashekhar M A , Hannes Reinecke , Damien Le Moal , Christoph Hellwig , Mike Christie , "Martin K . Petersen" , Sasha Levin , James.Bottomley@HansenPartnership.com, linux-scsi@vger.kernel.org Subject: [PATCH AUTOSEL 5.15 01/21] scsi: core: alua: I/O errors for ALUA state transitions Date: Mon, 17 Jun 2024 09:25:38 -0400 Message-ID: <20240617132617.2589631-1-sashal@kernel.org> X-Mailer: git-send-email 2.43.0 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 5.15.161 Content-Transfer-Encoding: 8bit From: Martin Wilck [ Upstream commit 10157b1fc1a762293381e9145041253420dfc6ad ] When a host is configured with a few LUNs and I/O is running, injecting FC faults repeatedly leads to path recovery problems. The LUNs have 4 paths each and 3 of them come back active after say an FC fault which makes 2 of the paths go down, instead of all 4. This happens after several iterations of continuous FC faults. Reason here is that we're returning an I/O error whenever we're encountering sense code 06/04/0a (LOGICAL UNIT NOT ACCESSIBLE, ASYMMETRIC ACCESS STATE TRANSITION) instead of retrying. [mwilck: The original patch was developed by Rajashekhar M A and Hannes Reinecke. I moved the code to alua_check_sense() as suggested by Mike Christie [1]. Evan Milne had raised the question whether pg->state should be set to transitioning in the UA case [2]. I believe that doing this is correct. SCSI_ACCESS_STATE_TRANSITIONING by itself doesn't cause I/O errors. Our handler schedules an RTPG, which will only result in an I/O error condition if the transitioning timeout expires.] [1] https://lore.kernel.org/all/0bc96e82-fdda-4187-148d-5b34f81d4942@oracle.com/ [2] https://lore.kernel.org/all/CAGtn9r=kicnTDE2o7Gt5Y=yoidHYD7tG8XdMHEBJTBraVEoOCw@mail.gmail.com/ Co-developed-by: Rajashekhar M A Co-developed-by: Hannes Reinecke Signed-off-by: Hannes Reinecke Signed-off-by: Martin Wilck Link: https://lore.kernel.org/r/20240514140344.19538-1-mwilck@suse.com Reviewed-by: Damien Le Moal Reviewed-by: Christoph Hellwig Reviewed-by: Mike Christie Signed-off-by: Martin K. Petersen Signed-off-by: Sasha Levin --- drivers/scsi/device_handler/scsi_dh_alua.c | 31 +++++++++++++++------- 1 file changed, 22 insertions(+), 9 deletions(-) diff --git a/drivers/scsi/device_handler/scsi_dh_alua.c b/drivers/scsi/device_handler/scsi_dh_alua.c index a9c4a5e2ccb90..60792f257c235 100644 --- a/drivers/scsi/device_handler/scsi_dh_alua.c +++ b/drivers/scsi/device_handler/scsi_dh_alua.c @@ -406,28 +406,40 @@ static char print_alua_state(unsigned char state) } } -static enum scsi_disposition alua_check_sense(struct scsi_device *sdev, - struct scsi_sense_hdr *sense_hdr) +static void alua_handle_state_transition(struct scsi_device *sdev) { struct alua_dh_data *h = sdev->handler_data; struct alua_port_group *pg; + rcu_read_lock(); + pg = rcu_dereference(h->pg); + if (pg) + pg->state = SCSI_ACCESS_STATE_TRANSITIONING; + rcu_read_unlock(); + alua_check(sdev, false); +} + +static enum scsi_disposition alua_check_sense(struct scsi_device *sdev, + struct scsi_sense_hdr *sense_hdr) +{ switch (sense_hdr->sense_key) { case NOT_READY: if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0x0a) { /* * LUN Not Accessible - ALUA state transition */ - rcu_read_lock(); - pg = rcu_dereference(h->pg); - if (pg) - pg->state = SCSI_ACCESS_STATE_TRANSITIONING; - rcu_read_unlock(); - alua_check(sdev, false); + alua_handle_state_transition(sdev); return NEEDS_RETRY; } break; case UNIT_ATTENTION: + if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0x0a) { + /* + * LUN Not Accessible - ALUA state transition + */ + alua_handle_state_transition(sdev); + return NEEDS_RETRY; + } if (sense_hdr->asc == 0x29 && sense_hdr->ascq == 0x00) { /* * Power On, Reset, or Bus Device Reset. @@ -494,7 +506,8 @@ static int alua_tur(struct scsi_device *sdev) retval = scsi_test_unit_ready(sdev, ALUA_FAILOVER_TIMEOUT * HZ, ALUA_FAILOVER_RETRIES, &sense_hdr); - if (sense_hdr.sense_key == NOT_READY && + if ((sense_hdr.sense_key == NOT_READY || + sense_hdr.sense_key == UNIT_ATTENTION) && sense_hdr.asc == 0x04 && sense_hdr.ascq == 0x0a) return SCSI_DH_RETRY; else if (retval) -- 2.43.0