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 4D7FB3A9DB9; Thu, 5 Mar 2026 14:51:08 +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=1772722268; cv=none; b=pB0KvsEnJcRuzLKd6Hpk9SnEUSSz9KDGLNqJZiErc7+up8DRg//MRL+ScxDsBppTA21OvKJAFCYku6sYUDtJzIjS8nk4iCnSecMP7CaklZ2MDSwaAQXGvDTbGjSzGcYYEhy8BnrhLfgPrj3BbHCoIQSCDLf1g3FulPoniczEzIo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772722268; c=relaxed/simple; bh=rq4BHiiCcabo7gcPdEWEW+x1M5J6IKn6QNtDOWZqR+M=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=oTIko3VCzsYyp4sRtf1hKCmOhCL7RPyXoYCWIGviNY1i5f3oKfrYDgCVJD4oLeEqDss6wsN0Kjy712VPj19XYVjADhK46Q8h5nDEy0svh1CLasGX9h47RWxTwEOIIPC5kxugkzt+oA1LmRws9QjXIEICme3pe9du6meFtgyScx8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=PT0DPgiO; 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="PT0DPgiO" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8BE91C2BC9E; Thu, 5 Mar 2026 14:51:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1772722268; bh=rq4BHiiCcabo7gcPdEWEW+x1M5J6IKn6QNtDOWZqR+M=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=PT0DPgiO6mTSVTxCQqrErAcTahHho7meC0z7pDd856PFhyYho7fdxywOYk2Qq8k8+ zG1WRvpHmeoG3pY4fmNfb1TFP1rmbMa2weBFlnmEc/ZjvRug/bIghMmZX7WM7HK9bn eI18ce7guZDGMivzKKACG49XxvYOQmOmXxoDpLo6zfF7vUVbn7p/rhXgGUUEx7RWYU oYXWqay14Jax3p53BQeVsUFGyKeuTu2v6dRonmfaM7cgT41ZdfBZhnB1E7R6yKLSX4 eyef3Mv3DFO3SlAf5slkEBQY2nlZHE35tv97wLc74xXl/rus3CQVlOSioRloFadbiz zgmnpXTxP6vpQ== From: Chuck Lever To: Anna Schumaker Cc: Trond Myklebust , , , Eric Badger Subject: [PATCH v2 1/8] xprtrdma: Decrement re_receiving on the early exit paths Date: Thu, 5 Mar 2026 09:50:56 -0500 Message-ID: <20260305145054.7096-11-cel@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260305145054.7096-10-cel@kernel.org> References: <20260305145054.7096-10-cel@kernel.org> Precedence: bulk X-Mailing-List: linux-rdma@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=2769; i=chuck.lever@oracle.com; h=from:subject; bh=DbTWoaOmC5YvD/uexMHeuzEaauOPfSsyhH5uSNXM2Nw=; b=owEBbQKS/ZANAwAKATNqszNvZn+XAcsmYgBpqZhVaMy/ag2q2q990/xkdywo3Ej4TnZm0fWQs 4ovj2gD3oOJAjMEAAEKAB0WIQQosuWwEobfJDzyPv4zarMzb2Z/lwUCaamYVQAKCRAzarMzb2Z/ l4wbEACKByQbr1LpSlymm5jD6u6uDhBrJ697xgz1arVGGyevk4aaXn1N8YHOnaPxDNYWOJIQR+b 86l//PaleIYtdHzciMEgJBp09OcbTziNCxTQV8FvjkYHwF+H7xh+8fsDK7S3cP7l4vNSch/CZ53 I/JzJ0d2zpojuK+ZTbCURtACXvyk9xTQ5jCW8BHF4G5dGM2oJd04rpHFMb77M4xm/rmDz+zQZn1 GYSXVhzIkxJfGA+77w863sc91LOmOMNMZrf0e8g5k5fXHOgRmvwhcdyEWPvv2ivkANMwu+jozoA R4H83QhqlxNRTqaYQtGqE5rnG/crE/XgReTgvaadLxQqIEr+Qf/sgklf4YjFi5FHxYxahSBippi w5GsnwrU2SNj4a3qwqicDnaKdZEnBNnWDTc+OludbuQtD12Fl0CNEO4o/pdqJ00cIVN8jSpf4Ax XUOEmOWIFr0sJyhb54M5AmgIqGPcG58ydqvaNh021gN9pstO2yZNqpGNt+hSKFEw3VWLKjuTK13 AzKyTPA7QJ/8RFnQli8iR/gQephz1cvED2Qwclwj/Wz/RYVZMMlmeyq+6XOB1sQh+p4ScSaee3h pCLCKuFDYWivmqjJaUohnxrkoCSKCSuZB13uzYYVeauP4kXq/ZYVOOQmtG7SWcpHOm3pgC/dKFa 4QFQMt1S900eS1A== X-Developer-Key: i=chuck.lever@oracle.com; a=openpgp; fpr=28B2E5B01286DF243CF23EFE336AB3336F667F97 Content-Transfer-Encoding: 8bit From: Eric Badger In the event that rpcrdma_post_recvs() fails to create a work request (due to memory allocation failure, say) or otherwise exits early, we should decrement ep->re_receiving before returning. Otherwise we will hang in rpcrdma_xprt_drain() as re_receiving will never reach zero and the completion will never be triggered. On a system with high memory pressure, this can appear as the following hung task: INFO: task kworker/u385:17:8393 blocked for more than 122 seconds. Tainted: G S E 6.19.0 #3 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u385:17 state:D stack:0 pid:8393 tgid:8393 ppid:2 task_flags:0x4248060 flags:0x00080000 Workqueue: xprtiod xprt_autoclose [sunrpc] Call Trace: __schedule+0x48b/0x18b0 ? ib_post_send_mad+0x247/0xae0 [ib_core] schedule+0x27/0xf0 schedule_timeout+0x104/0x110 __wait_for_common+0x98/0x180 ? __pfx_schedule_timeout+0x10/0x10 wait_for_completion+0x24/0x40 rpcrdma_xprt_disconnect+0x444/0x460 [rpcrdma] xprt_rdma_close+0x12/0x40 [rpcrdma] xprt_autoclose+0x5f/0x120 [sunrpc] process_one_work+0x191/0x3e0 worker_thread+0x2e3/0x420 ? __pfx_worker_thread+0x10/0x10 kthread+0x10d/0x230 ? __pfx_kthread+0x10/0x10 ret_from_fork+0x273/0x2b0 ? __pfx_kthread+0x10/0x10 ret_from_fork_asm+0x1a/0x30 Fixes: 15788d1d1077 ("xprtrdma: Do not refresh Receive Queue while it is draining") Signed-off-by: Eric Badger Signed-off-by: Chuck Lever --- net/sunrpc/xprtrdma/verbs.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/net/sunrpc/xprtrdma/verbs.c b/net/sunrpc/xprtrdma/verbs.c index 15bbf953dfad..b51a162885bb 100644 --- a/net/sunrpc/xprtrdma/verbs.c +++ b/net/sunrpc/xprtrdma/verbs.c @@ -1362,7 +1362,7 @@ void rpcrdma_post_recvs(struct rpcrdma_xprt *r_xprt, int needed) needed += RPCRDMA_MAX_RECV_BATCH; if (atomic_inc_return(&ep->re_receiving) > 1) - goto out; + goto out_dec; /* fast path: all needed reps can be found on the free list */ wr = NULL; @@ -1385,7 +1385,7 @@ void rpcrdma_post_recvs(struct rpcrdma_xprt *r_xprt, int needed) ++count; } if (!wr) - goto out; + goto out_dec; rc = ib_post_recv(ep->re_id->qp, wr, (const struct ib_recv_wr **)&bad_wr); @@ -1400,9 +1400,10 @@ void rpcrdma_post_recvs(struct rpcrdma_xprt *r_xprt, int needed) --count; } } + +out_dec: if (atomic_dec_return(&ep->re_receiving) > 0) complete(&ep->re_done); - out: trace_xprtrdma_post_recvs(r_xprt, count); ep->re_receive_count += count; -- 2.53.0