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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 93608EE57DF for ; Mon, 11 Sep 2023 06:44:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234473AbjIKGoW (ORCPT ); Mon, 11 Sep 2023 02:44:22 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57244 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232031AbjIKGoV (ORCPT ); Mon, 11 Sep 2023 02:44:21 -0400 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9722F120; Sun, 10 Sep 2023 23:44:17 -0700 (PDT) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1724FC433CA; Mon, 11 Sep 2023 06:44:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1694414657; bh=BDtbK6skN/ze3p/6RlCNM57CdgzOGLa77e0zwF/NxHo=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=Tf8hBGkH4iSJC8ZGDF/62JApX9eZmV4gab645I5Oi8HIIcxKxrdsdYAK1SreH9VPd qrd+C89V2p2KgMflIUnc4aGz4o+YsEPExVl4x3drrEMFMwF43OATwGFTIA32mTzWx8 ESwSdrPgptWSvM+0q8GsSQMWBTNNYA84Xr086TmLAPCDiwXG3TK+RY0VNZVpteF5ay LBRekNDBt/Tt2yVozf/zsbuSkXG66OySDlDyqHeTFkpPFhrDUzDUElmVW5ajTUYci4 B4EfvMIPVT1gE4Pmrrg7oT4q5RPUfuRJuorfgKb6b0S/a2194doCOtEaZnjqtLqbuu hb9iDb3dZlTKg== Message-ID: Date: Mon, 11 Sep 2023 15:44:15 +0900 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.13.0 Subject: Re: [PATCH 02/19] ata: libata-core: Fix port and device removal Content-Language: en-US To: Hannes Reinecke , linux-ide@vger.kernel.org Cc: linux-scsi@vger.kernel.org, "Martin K . Petersen" , John Garry , Rodrigo Vivi , Paul Ausbeck , Kai-Heng Feng , Joe Breuer References: <20230911040217.253905-1-dlemoal@kernel.org> <20230911040217.253905-3-dlemoal@kernel.org> From: Damien Le Moal Organization: Western Digital Research In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-ide@vger.kernel.org On 9/11/23 15:37, Hannes Reinecke wrote: > On 9/11/23 06:02, Damien Le Moal wrote: >> Whenever an ATA adapter driver is removed (e.g. rmmod), >> ata_port_detach() is called repeatedly for all the adapter ports to >> remove (unload) the devices attached to the port and delete the port >> device itself. Removing of devices is done using libata EH with the >> ATA_PFLAG_UNLOADING port flag set. This causes libata EH to execute >> ata_eh_unload() which disables all devices attached to the port. >> >> ata_port_detach() finishes by calling scsi_remove_host() to remove the >> scsi host associated with the port. This function will trigger the >> removal of all scsi devices attached to the host and in the case of >> disks, calls to sd_shutdown() which will flush the device write cache >> and stop the device. However, given that the devices were already >> disabled by ata_eh_unload(), the synchronize write cache command and >> start stop unit commands fail. E.g. running "rmmod ahci" with first >> removing sd_mod results in error messages like: >> >> ata13.00: disable device >> sd 0:0:0:0: [sda] Synchronizing SCSI cache >> sd 0:0:0:0: [sda] Synchronize Cache(10) failed: Result: >> hostbyte=DID_BAD_TARGET driverbyte=DRIVER_OK >> sd 0:0:0:0: [sda] Stopping disk >> sd 0:0:0:0: [sda] Start/Stop Unit failed: Result: hostbyte=DID_BAD_TARGET >> driverbyte=DRIVER_OK >> >> Fix this by removing all scsi devices of the ata devices connected to >> the port before scheduling libata EH to disable the ATA devices. >> >> Fixes: 720ba12620ee ("[PATCH] libata-hp: update unload-unplug") >> Cc: stable@vger.kernel.org >> Signed-off-by: Damien Le Moal >> --- >>   drivers/ata/libata-core.c | 21 ++++++++++++++++++++- >>   1 file changed, 20 insertions(+), 1 deletion(-) >> >> diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c >> index c4898483d716..693cb3cd70cd 100644 >> --- a/drivers/ata/libata-core.c >> +++ b/drivers/ata/libata-core.c >> @@ -5952,11 +5952,30 @@ static void ata_port_detach(struct ata_port *ap) >>       struct ata_link *link; >>       struct ata_device *dev; >>   -    /* tell EH we're leaving & flush EH */ >> +    /* Wait for any ongoing EH */ >> +    ata_port_wait_eh(ap); >> + >> +    mutex_lock(&ap->scsi_scan_mutex); >>       spin_lock_irqsave(ap->lock, flags); >> + >> +    /* Remove scsi devices */ >> +    ata_for_each_link(link, ap, HOST_FIRST) { >> +        ata_for_each_dev(dev, link, ALL) { >> +            if (dev->sdev) { >> +                spin_unlock_irqrestore(ap->lock, flags); >> +                scsi_remove_device(dev->sdev); >> +                spin_lock_irqsave(ap->lock, flags); >> +                dev->sdev = NULL; >> +            } >> +        } >> +    } >> + >> +    /* Tell EH to disable all devices */ >>       ap->pflags |= ATA_PFLAG_UNLOADING; >>       ata_port_schedule_eh(ap); >> + >>       spin_unlock_irqrestore(ap->lock, flags); >> +    mutex_unlock(&ap->scsi_scan_mutex); >>   > Are you sure about releasing scan_mutex after ata_port_schedule_eh()? > Technically ata_port_schedule_eh() will be calling into SCSI rescan, which > would take scan_mutex ... > Not that it matter much, seeing that we've disconnected all devices, but still ... UNLOADING is set and in that case, EH does nothing else than removing the devices. So I think this is OK. > > Cheers, > > Hannes -- Damien Le Moal Western Digital Research