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 6FD1CEE645A for ; Fri, 15 Sep 2023 12:30:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234772AbjIOMaE (ORCPT ); Fri, 15 Sep 2023 08:30:04 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36838 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229841AbjIOMaD (ORCPT ); Fri, 15 Sep 2023 08:30:03 -0400 Received: from smtp-out1.suse.de (smtp-out1.suse.de [IPv6:2001:67c:2178:6::1c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 21FE4A1; Fri, 15 Sep 2023 05:29:58 -0700 (PDT) Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out1.suse.de (Postfix) with ESMTPS id D195C21887; Fri, 15 Sep 2023 12:29:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1694780996; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:autocrypt:autocrypt; bh=GyoxUOFAPJdcF6p4rmOuD/KvaHZmxy13Vmq8t+ZZgZs=; b=aiUsKAEsWsFfXdCldCAvfrIdDd+lqqeqlJEbnSFIrePG9XUoz3sq8j02+drNbbGa07aAkx 2bUkY2+S4Z8ih2ldpo1UzZqW7puwv2/AMgTlyrLJPK0SabuksuLMX/SRqHqSD/NUIR7hRC gnV6ah8oElSO3d3oKBzBDWPuypwqzpo= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1694780996; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:autocrypt:autocrypt; bh=GyoxUOFAPJdcF6p4rmOuD/KvaHZmxy13Vmq8t+ZZgZs=; b=yRvrTqiy84I3ySCPsNm5e1vFKrWU61iMsP5mBRK824OMLv9iiCSgtSLdCr1+73XdjBup55 Ll85JfjORfJXDaAA== Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id 92F8513251; Fri, 15 Sep 2023 12:29:56 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id qB7LIkROBGX6PwAAMHmgww (envelope-from ); Fri, 15 Sep 2023 12:29:56 +0000 Message-ID: <085acf14-d9c3-0187-e25f-965152bb6209@suse.de> Date: Fri, 15 Sep 2023 14:29:56 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v3 07/23] ata: libata-scsi: Fix delayed scsi_rescan_device() execution Content-Language: en-US To: Damien Le Moal , 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 , Geert Uytterhoeven , Chia-Lin Kao References: <20230915081507.761711-1-dlemoal@kernel.org> <20230915081507.761711-8-dlemoal@kernel.org> From: Hannes Reinecke Autocrypt: addr=hare@suse.de; keydata= xsFNBE6KyREBEACwRN6XKClPtxPiABx5GW+Yr1snfhjzExxkTYaINHsWHlsLg13kiemsS6o7 qrc+XP8FmhcnCOts9e2jxZxtmpB652lxRB9jZE40mcSLvYLM7S6aH0WXKn8bOqpqOGJiY2bc 6qz6rJuqkOx3YNuUgiAxjuoYauEl8dg4bzex3KGkGRuxzRlC8APjHlwmsr+ETxOLBfUoRNuE b4nUtaseMPkNDwM4L9+n9cxpGbdwX0XwKFhlQMbG3rWA3YqQYWj1erKIPpgpfM64hwsdk9zZ QO1krgfULH4poPQFpl2+yVeEMXtsSou915jn/51rBelXeLq+cjuK5+B/JZUXPnNDoxOG3j3V VSZxkxLJ8RO1YamqZZbVP6jhDQ/bLcAI3EfjVbxhw9KWrh8MxTcmyJPn3QMMEp3wpVX9nSOQ tzG72Up/Py67VQe0x8fqmu7R4MmddSbyqgHrab/Nu+ak6g2RRn3QHXAQ7PQUq55BDtj85hd9 W2iBiROhkZ/R+Q14cJkWhzaThN1sZ1zsfBNW0Im8OVn/J8bQUaS0a/NhpXJWv6J1ttkX3S0c QUratRfX4D1viAwNgoS0Joq7xIQD+CfJTax7pPn9rT////hSqJYUoMXkEz5IcO+hptCH1HF3 qz77aA5njEBQrDRlslUBkCZ5P+QvZgJDy0C3xRGdg6ZVXEXJOQARAQABzSpIYW5uZXMgUmVp bmVja2UgKFN1U0UgTGFicykgPGhhcmVAc3VzZS5kZT7CwZgEEwECAEICGwMGCwkIBwMCBhUI AgkKCwQWAgMBAh4BAheAAhkBFiEEmusOw9rHmm3C+nirbPjKL07IqM8FAmGvIo0FCRyKWvwA CgkQbPjKL07IqM8Ocg/8Dt2h8G8prHk6lONEKoUekljoiOTcpdrZZ6oJpykUQ2UewDBt2MtT fgfKgz741lC0q5j1+XCIZsGd3xhpFNt+20F94TNMi8pwg06GS/nkWsefmvG4VnIchqA4rD/A obfJpkAHQwfQgDbYL44oSLIyPXAprlEKhEImyLBBx5mnJhpR8TCiBipcSuLwWtrAM+q4RpF3 mhlXhuATwhENs+yiHPhuu4sbDNbJ6juah3Y0YC30DW4S1oUm97zgzvDIcaPnSCe/F11UD770 G+lgZU/8XaAgGYstvrV6fASCom42GVuhXgJYOqdnXTgogLudQhTvbdpyq5wiVJWA8zhTuZXF 7Yz5tHRJutDTSEaibWnLVFR/KsjB2xmtTV8Ztb/xsZklHiq3cSco8GS21fOtte1KMJlSiEIg 8kATAosigjHlmMF8j+w8bUxSvJ9ljpjS4sK8J77YeEdi/kTDUg7TxaruqgSwQYLEgxYrUtga DeP3bGzvAwavHz0DFRatSQ0UwBaqugLBLt0VsKjpXO8g61mdZTEG3huvOg2Ko7yY6RFC0rcI nxsi9nzkuWOxVt/IzZIdctge01jGPHOuH9qc5m/gVEq5lz6vCc5h4FT30xNxH2j/vneSgbsm SXIQXnOsRCb1U3zlrSSP+oYwHsqjsPywu4WYSp0VWwImcP3VInbFrgTOwU0ETorJEQEQAK8Q mCCQYLjaG4UColw5wuqeMrze3hNXASclGKxtj9V15kgdMa1wYuqwAsPOT5sQBxlqmC7N+ntz JLO+5HofKruEoSMQcBmYj/cgNz2dt2ESB0KIVq1qHRdn+ni+nsoB6Vipu/xgX85EvKUB0uH2 vMtHrIcWpVpHhYvimXiQRbAWE1IcvF7nkbnr93EG6iPhGsWhffKd6td9unh0fYoCs9zQ1+hq ap5u4Y18RCYNu2cIYTnMpxHTO+ZexGmpTv5xq5+55nIvCNNT7LmnfhTg+U47ZDv9t1o8R1d+ mC9KlaTWjcffou+Q9X88YYMIvNo2fTgF2KKI8QfCgiMJc4BxH7j56ozhNLBWlOfpI2BscuMC ELAIPKCAr7eoQYmmH5Y201Tu4V+xxI+TiOqXFzw/6Gf0ipoxZp5f2cERqIp99Hs4qMx20UWc FFJeJb+Q4q65F14OMvmBYmNj4il1p88qGO9QW19LAZ2sNSHdK8HmSdKLETepvFuFs3GaoNXP LMzC6cUA26PLJWLNLfUOdYLq0rMA2QKTXkLJ4ULqwUW75alHG8Lp/NBMsjkJEYAHoUDHPwe7 muk01kextiz1V+v8Em5JR9Ej/XZ44Isi/FE+mYw6VwjhYNbcQOTOo0Befk6fH9vSsUYWkzga ZI+uIQl0FvgzilIPp83pj8mueD8F3CRJABEBAAHCwXwEGAECACYCGwwWIQSa6w7D2seabcL6 eKts+MovTsiozwUCYa8jtQUJHIpcJAAKCRBs+MovTsiozxFbEACGvsjoL9Tmi1Kk4BQcyTY9 A3WuFr27fTFVc/RTKAblIH9CYWcGvzJ5HBQMrD9uKwKkXxhmsSmYO0QCMvh0kEysOASNGVPv WciYZXU7apv5715KNJ+KzZpruSohqG2tmDPjfCTQ7kj2BC9HOMo0BcdpXB0r8KfKKUvfIbSW 4JsJubJrL+FDY4xxYko4t3gfTiFqUEf8hvtX9QbC5m1S58N9KXwOFR7333jsA+sqa6L2hEth i/7hcTuKi0U1MDC5WsASFbhbe+yOjPvquHYCcQrFOO+tLvuXSCNCumFcpvDiteNSZUUTD/QB 0Y/U167yjgktS/hZuuCbrUb+E4TG7EL5+IQGRcAJtQduE2jrCSlN547einmB4vQi4G3ToEk/ wr5DwYiNEZyO0pJsh85VNLlgnYpzDi3WC5cqePMueogFZDEjMvUeTzwSTM8+scTw6YAcwoHw h/Zc/Zqi7mdqcWnNg8WfMcKutB6CaFtJhzShfib+D90F/+r3KGzZdLp1QqLYkfXD3to7XCnR QuSHPtufr0nWz7vC3IackvoFHNjQ92ZbHhFbOqLYFHvqaBu8N2PE0YhPh0y0/sjmHM9DHUQh jbCcdMlwO54T4hHLBbuR/lU6locuDn9SsF5lFeoPtfnztU0+GtqTw+cRSo0g2ARonLsydcQ0 YwtooKEemPj2lg== In-Reply-To: <20230915081507.761711-8-dlemoal@kernel.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org On 9/15/23 10:14, Damien Le Moal wrote: > Commit 6aa0365a3c85 ("ata: libata-scsi: Avoid deadlock on rescan after > device resume") modified ata_scsi_dev_rescan() to check the scsi device > "is_suspended" power field to ensure that the scsi device associated > with an ATA device is fully resumed when scsi_rescan_device() is > executed. However, this fix is problematic as: > 1) It relies on a PM internal field that should not be used without PM > device locking protection. > 2) The check for is_suspended and the call to scsi_rescan_device() are > not atomic and a suspend PM event may be triggered between them, > casuing scsi_rescan_device() to be called on a suspended device and > in that function blocking while holding the scsi device lock. This > would deadlock a following resume operation. > These problems can trigger PM deadlocks on resume, especially with > resume operations triggered quickly after or during suspend operations. > E.g., a simple bash script like: > > for (( i=0; i<10; i++ )); do > echo "+2 > /sys/class/rtc/rtc0/wakealarm > echo mem > /sys/power/state > done > > that triggers a resume 2 seconds after starting suspending a system can > quickly lead to a PM deadlock preventing the system from correctly > resuming. > > Fix this by replacing the check on is_suspended with a check on the > return value given by scsi_rescan_device() as that function will fail if > called against a suspended device. Also make sure rescan tasks already > scheduled are first cancelled before suspending an ata port. > > Fixes: 6aa0365a3c85 ("ata: libata-scsi: Avoid deadlock on rescan after device resume") > Cc: stable@vger.kernel.org > Signed-off-by: Damien Le Moal > --- > drivers/ata/libata-core.c | 16 ++++++++++++++++ > drivers/ata/libata-scsi.c | 33 +++++++++++++++------------------ > 2 files changed, 31 insertions(+), 18 deletions(-) > Reviewed-by: Hannes Reinecke Cheers, Hannes -- Dr. Hannes Reinecke Kernel Storage Architect hare@suse.de +49 911 74053 688 SUSE Software Solutions Germany GmbH, Frankenstr. 146, 90461 Nürnberg Managing Directors: I. Totev, A. Myers, A. McDonald, M. B. Moerman (HRB 36809, AG Nürnberg)