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 2A55614F9E9; Tue, 23 Jul 2024 11:24:11 +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=1721733852; cv=none; b=HL7Aok6OJ9093YczRnPgSts064/iOg4FqKwq/y3GJQHaPSBSC/zhiOYrxytRtb7Y/1ZHNhBq2dXaPCPCatBLpmqQB67RpiDqLD0yRAlMTySc985g4x6wKqPTln9TLEXWWfUKuFgewRZKrhn0jrnCYet22bAQh71eyZBp/97GQMw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1721733852; c=relaxed/simple; bh=WT1R4JXlAscYM9Eu3wRc2IO4UpVlARwdXG7i/HkXkj0=; h=Subject:To:Cc:From:Date:Message-ID:MIME-Version:Content-Type; b=uBNS4d+i+8mQ34bFCdSx6EhhXAk5DXMUwx6MDtzERAaHKMHnte/CMfeJ0U/MX/BiPwpo8sjqi8WRENiHo0XlncHZki3Tp79VD8WnT12iDwW4g24sKDE45BDlE4IqtKoM9LHn0c0rldnZMT53kJGzTbrzWkMmvDRHXJQTK5Zt45A= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=ODQ99rdO; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="ODQ99rdO" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 48327C4AF09; Tue, 23 Jul 2024 11:24:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1721733851; bh=WT1R4JXlAscYM9Eu3wRc2IO4UpVlARwdXG7i/HkXkj0=; h=Subject:To:Cc:From:Date:From; b=ODQ99rdOBV2iMXiylfwqVQ2ghPr0QXlAb4TrKxjkuJRO+SYfF0rL/VtwZRjHaidRU RBlrvHx1B6Nbzp1OfvyZIPcSR/9sn/yZzB6LVpU6KOQUCpim4Ug0js4avlR2upNN1F Ihh/q7I8uk4g5+a2aooMvvg/L9ww71f4ha+VyzJY= Subject: Patch "cifs: Fix server re-repick on subrequest retry" has been added to the 6.10-stable tree To: aaptel@suse.com,dhowells@redhat.com,gregkh@linuxfoundation.org,jlayton@kernel.org,netfs@lists.linux.dev,pc@manguebit.com,smfrench@gmail.com,stfrench@microsoft.com,tom@talpey.com Cc: From: Date: Tue, 23 Jul 2024 13:23:54 +0200 Message-ID: <2024072354-drained-vision-44ea@gregkh> Precedence: bulk X-Mailing-List: netfs@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit X-stable: commit X-Patchwork-Hint: ignore This is a note to let you know that I've just added the patch titled cifs: Fix server re-repick on subrequest retry to the 6.10-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: cifs-fix-server-re-repick-on-subrequest-retry.patch and it can be found in the queue-6.10 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >From de40579b903883274fe203865f29d66b168b7236 Mon Sep 17 00:00:00 2001 From: David Howells Date: Thu, 18 Jul 2024 20:19:32 +0100 Subject: cifs: Fix server re-repick on subrequest retry From: David Howells commit de40579b903883274fe203865f29d66b168b7236 upstream. When a subrequest is marked for needing retry, netfs will call cifs_prepare_write() which will make cifs repick the server for the op before renegotiating credits; it then calls cifs_issue_write() which invokes smb2_async_writev() - which re-repicks the server. If a different server is then selected, this causes the increment of server->in_flight to happen against one record and the decrement to happen against another, leading to misaccounting. Fix this by just removing the repick code in smb2_async_writev(). As this is only called from netfslib-driven code, cifs_prepare_write() should always have been called first, and so server should never be NULL and the preparatory step is repeated in the event that we do a retry. The problem manifests as a warning looking something like: WARNING: CPU: 4 PID: 72896 at fs/smb/client/smb2ops.c:97 smb2_add_credits+0x3f0/0x9e0 [cifs] ... RIP: 0010:smb2_add_credits+0x3f0/0x9e0 [cifs] ... smb2_writev_callback+0x334/0x560 [cifs] cifs_demultiplex_thread+0x77a/0x11b0 [cifs] kthread+0x187/0x1d0 ret_from_fork+0x34/0x60 ret_from_fork_asm+0x1a/0x30 Which may be triggered by a number of different xfstests running against an Azure server in multichannel mode. generic/249 seems the most repeatable, but generic/215, generic/249 and generic/308 may also show it. Fixes: 3ee1a1fc3981 ("cifs: Cut over to using netfslib") Cc: stable@vger.kernel.org Reported-by: Steve French Reviewed-by: Paulo Alcantara (Red Hat) Acked-by: Tom Talpey Signed-off-by: David Howells cc: Jeff Layton cc: Aurelien Aptel cc: linux-cifs@vger.kernel.org cc: netfs@lists.linux.dev cc: linux-fsdevel@vger.kernel.org Signed-off-by: Steve French Signed-off-by: Greg Kroah-Hartman --- fs/smb/client/smb2pdu.c | 3 --- 1 file changed, 3 deletions(-) diff --git a/fs/smb/client/smb2pdu.c b/fs/smb/client/smb2pdu.c index 2ae2dbb6202b..bb84a89e5905 100644 --- a/fs/smb/client/smb2pdu.c +++ b/fs/smb/client/smb2pdu.c @@ -4859,9 +4859,6 @@ smb2_async_writev(struct cifs_io_subrequest *wdata) struct cifs_io_parms *io_parms = NULL; int credit_request; - if (!wdata->server || test_bit(NETFS_SREQ_RETRYING, &wdata->subreq.flags)) - server = wdata->server = cifs_pick_channel(tcon->ses); - /* * in future we may get cifs_io_parms passed in from the caller, * but for now we construct it here... -- 2.45.2 Patches currently in stable-queue which might be from dhowells@redhat.com are queue-6.10/cifs-fix-server-re-repick-on-subrequest-retry.patch queue-6.10/cifs-fix-setting-of-zero_point-after-dio-write.patch queue-6.10/cifs-fix-missing-error-code-set.patch queue-6.10/cifs-fix-missing-fscache-invalidation.patch