From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.openvz.org (unknown [69.168.225.77]) by lore.virtuozzo.com (Postfix) with ESMTPS id 00512808A3 for ; Mon, 12 Oct 2026 13:28:24 +0000 (UTC) Received: from mail.openvz.org (localhost [127.0.0.1]) by mail.openvz.org (8.14.4/8.14.4) with ESMTP id 69CDRAjF022900; Mon, 12 Oct 2026 16:27:11 +0300 DKIM-Filter: OpenDKIM Filter v2.11.0 mail.openvz.org 69CDRAjF022900 Authentication-Results: mail.openvz.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=virtuozzo.com header.i=@virtuozzo.com header.b="ohfjwOLk" Received: from mail-wr1-f69.google.com (mail-wr1-f69.google.com [209.85.221.69]) by mail.openvz.org (8.14.4/8.14.4) with ESMTP id 69CDQtDk022845 (version=TLSv1/SSLv3 cipher=AES128-GCM-SHA256 bits=128 verify=FAIL) for ; Mon, 12 Oct 2026 16:26:55 +0300 DKIM-Filter: OpenDKIM Filter v2.11.0 mail.openvz.org 69CDQtDk022845 Received: by mail-wr1-f69.google.com with SMTP id ffacd0b85a97d-47f2de3ba47so1253500f8f.1 for ; Mon, 12 Oct 2026 06:26:55 -0700 (PDT) X-Gm-Message-State: AFq9FYJp0c9pfSoHeGOJ8HDvW3tiEEq5GkLnMY6Tei9F6AMU14O+0+oL S/+mOkk917JXiqMb+N2u/eEmBZwjAHK9Bvl+xjBDg57ZPCTWUTYxt2hMk4VOx4I61g83cZzmwlP HfX1L+ZRPY+peLA6xXmjw2SF3GI8qQ8uhNJCEF/Y0hvrrQlk9+GTcJw== X-Gm-Gg: AYBFou2VMsv4ETfrteXSYrlsAKg9G0W32oWk/70cYwxczqSlGZLYFW2urb9wV6Fp+Ne j2F79Q/uxLIsNYKrYluFkPEBriYItEG6c5XvLYzlshKKdUhJaqEzkEcURQ01JpnTaYvTio966HJ aHLVtGdqwKi+ZHo4b5Fq8ZVq0l6AVbHNAI2VMHDrJaX6PRNYUXtA/NVqG8GCc0aQkkIJI3Bddkm ghmtuS/9LT2fInEGP7yXujYYil9D15bF0R9u6z4XlryWTt853Bk7otPceeWna8jIruGl7zu5zV/ YygxLK+0SvZevVL9XW67YtVMSJRNMSEwW42Kfy6P4ejbRnyl3jHHvYczDdNhlvqWVWYm0Mu1BD1 bXodVgGFlELmi6XPpnC7W/lNUuAQ= X-Received: by 2002:adf:e184:0:b0:488:7bdc:6032 with SMTP id ffacd0b85a97d-48dbace4711mr17836613f8f.43.1791811615359; Mon, 12 Oct 2026 06:26:55 -0700 (PDT) X-Received: by 2002:adf:e184:0:b0:488:7bdc:6032 with SMTP id ffacd0b85a97d-48dbace4711mr17836536f8f.43.1791811614457; Mon, 12 Oct 2026 06:26:54 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1791811614; cv=none; d=google.com; s=arc-20260327; b=SCb79OLAK3FFhLYfqM7Cmxw2Xbz4NfoxiBSHFIJHx1IGCTTdvqCjbLINCR3qgcQA2/ 0IVIb+JehgJQuFOfp7QAtqWPi6gS6rZYNwrgveDXNKjzecd7AcLat3hIQC+aLxAPo4C2 ix4zpuZ0X7b3qT6Ms3yQtLv/dF76P69AwL8jF/Oy3Gvz+WKWcwzg5o1/VNM897ehqk/F bvhjBz5eDNE7Yy0Ui6P6iPg7f5aihDyP9/4wIGXnV0XzD6YUDk/mIZ/EGm11hCLQAYOR KmN7RDRU8LgwUKjytR+F38D0JDW+hdFdL3JznnSteMTuTjWa7EgD8ZvEApHsq+npJeIq PWJg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20260327; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:dkim-signature; bh=tj9oV5sudd4onI61vAo7lfIUu5DtFQHB0f29SE0KHMo=; fh=M+TyAUhAp4+t7uzAVeqNdLHW5eNz2FQXSv4TjrRhpCk=; b=RtCY1x+7g3Ka/qO09hVWtCtwjLJGhZ7rkleYyjj4DzaO98umOdSbABjWH8y8NMosxN YjEBo1uB6vG5m4lVUzholnIBzYTV6vP7Lkt9+OWJr3zKfS/MyF+6byTgEs1AnajsMrku yoE7s4DzPk6vzFCtJtxerk51dqg9gMEWx/r3N/5ef2obIV+tHnTfOhVUkeMizV5oZHJg A83OcG1hIjEFIB0xfUmu5iWLAm9esnVNcWV4SBntsYox59Au/A45FPBq2U7dyJ8Phevr ZdSSH9fAk319Zk9BUTkdcyR6DZp5UV/I9kWnPVTxkKhvJxjVkxWrDfc2PnIXLjihxsc7 KGRQ==; dara=google.com ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@virtuozzo.com header.s=relay header.b=ohfjwOLk; spf=pass (google.com: domain of alexander.ivanov@virtuozzo.com designates 130.117.225.111 as permitted sender) smtp.mailfrom=alexander.ivanov@virtuozzo.com; dmarc=pass (p=QUARANTINE sp=QUARANTINE dis=NONE) header.from=virtuozzo.com Received: from relay.virtuozzo.com (relay.virtuozzo.com. [130.117.225.111]) by mx.google.com with ESMTPS id ffacd0b85a97d-48db9ac447dsi17961287f8f.211.2026.10.12.06.26.53 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 12 Oct 2026 06:26:54 -0700 (PDT) Received-SPF: pass (google.com: domain of alexander.ivanov@virtuozzo.com designates 130.117.225.111 as permitted sender) client-ip=130.117.225.111; Authentication-Results: mx.google.com; dkim=pass header.i=@virtuozzo.com header.s=relay header.b=ohfjwOLk; spf=pass (google.com: domain of alexander.ivanov@virtuozzo.com designates 130.117.225.111 as permitted sender) smtp.mailfrom=alexander.ivanov@virtuozzo.com; dmarc=pass (p=QUARANTINE sp=QUARANTINE dis=NONE) header.from=virtuozzo.com DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=virtuozzo.com; s=relay; h=MIME-Version:Message-ID:Date:Subject:From: Content-Type; bh=tj9oV5sudd4onI61vAo7lfIUu5DtFQHB0f29SE0KHMo=; b=ohfjwOLkNGzG H+z39njzxj/C1Zlc712Q6Yi3bmnuRBOg7pkZRfFo9egIBZL8HqAAad0sOPwfJOS6Vt5g5yz8j7iwK xwSrc19G0IEmLpWX0oLGUB7cAJpDTGJ1XC4Uyqbcx3+bAICdp1/DGcqJhSlg0q1zk8zfz2yMuKZ6G 1e0GqX46tov2xWM1qLoSgF3TyY5ZPF5vjwO/mbNY/qG1QPUZ60j48Z7vUxu2RJ7atYOZvpCuDUr5b OAJAEfM9nVDAhsYg5uosYAfQLbH3By7CodA0OoXor7zBWO9a/P3X5IbNEApxwEVY+1kgfI0otqNBx G1DnIWpIC7N1v3U2uWyu6w==; Received: from ch-vpn.virtuozzo.com ([130.117.225.6] helo=sky) by relay.virtuozzo.com with esmtps (TLS1.3) tls TLS_AES_256_GCM_SHA384 (Exim 4.96) (envelope-from ) id 1xGFzv-001WAY-1p; Mon, 12 Oct 2026 15:26:45 +0200 From: Alexander Ivanov To: den@openvz.org Date: Mon, 12 Oct 2026 15:26:37 +0200 Message-ID: <20261012132646.41494-3-alexander.ivanov@virtuozzo.com> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20261012132646.41494-1-alexander.ivanov@virtuozzo.com> References: <20261012132646.41494-1-alexander.ivanov@virtuozzo.com> MIME-Version: 1.0 X-OZ-Fwd: true Cc: devel@openvz.org Subject: [Devel] [PATCH hci-8.1 v4 02/11] dm-ploop: fix lost wakeup in ploop_allocator() X-BeenThere: devel@openvz.org X-Mailman-Version: 2.1.12 Precedence: list List-Id: OpenVZ development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: devel-bounces@openvz.org Errors-To: devel-bounces@openvz.org ploop_allocator() checks prealloc_size and kthread_should_stop() before setting TASK_INTERRUPTIBLE. If ploop_req_prealloc() sets prealloc_size and calls wake_up_process() in between, the wakeup finds the task running and is lost, so the allocator goes to sleep with a pending preallocation request. Later requests for the same size return early without waking it up, so the request may stay pending forever and waiters on dispatcher_wq_prealloc hang. The same applies to kthread_stop(). Set the task state before checking the conditions, as the canonical kthread loop does. set_current_state() implies a full barrier, which pairs with the one in try_to_wake_up(). https://virtuozzo.atlassian.net/browse/VSTOR-148171 Feature: dm-ploop: ploop target driver Signed-off-by: Alexander Ivanov Reviewed-by: Denis V. Lunev --- drivers/md/dm-ploop-map.c | 44 ++++++++++++++++++++------------------- 1 file changed, 23 insertions(+), 21 deletions(-) diff --git a/drivers/md/dm-ploop-map.c b/drivers/md/dm-ploop-map.c index 48466435dd19..92ceadf41b42 100644 --- a/drivers/md/dm-ploop-map.c +++ b/drivers/md/dm-ploop-map.c @@ -2347,31 +2347,33 @@ int ploop_allocator(void *data) struct file *file; for (;;) { - /* we do not care about exact number here - risk one extra schedule wrt taking the lock */ - if (ploop->prealloc_size) { - __set_current_state(TASK_RUNNING); - file = ploop_top_delta(ploop)->file; - current->flags |= PLOOP_PFLAGS; - ret = ploop_preallocate_cluster(ploop, file); - if (ret) { - /* - * threads requesting prealloc must check - * if size actually changed - */ - /* ENOSPC is only for fallocate */ - pr_err_ratelimited( - PL_FMT("failed to allocate space: %d\n"), - ploop_device_name(ploop), ret); - } - wake_up_interruptible(&ploop->dispatcher_wq_prealloc); - current_restore_flags(old_flags, PLOOP_PFLAGS); - } + set_current_state(TASK_INTERRUPTIBLE); if (kthread_should_stop()) { __set_current_state(TASK_RUNNING); break; } - set_current_state(TASK_INTERRUPTIBLE); - schedule(); + /* we do not care about exact number here - risk one extra schedule wrt taking the lock */ + if (!READ_ONCE(ploop->prealloc_size)) { + schedule(); + continue; + } + __set_current_state(TASK_RUNNING); + + file = ploop_top_delta(ploop)->file; + current->flags |= PLOOP_PFLAGS; + ret = ploop_preallocate_cluster(ploop, file); + if (ret) { + /* + * threads requesting prealloc must check + * if size actually changed + */ + /* ENOSPC is only for fallocate */ + pr_err_ratelimited( + PL_FMT("failed to allocate space: %d\n"), + ploop_device_name(ploop), ret); + } + wake_up_interruptible(&ploop->dispatcher_wq_prealloc); + current_restore_flags(old_flags, PLOOP_PFLAGS); } return 0; -- 2.53.0 _______________________________________________ Devel mailing list Devel@openvz.org https://lists.openvz.org/mailman/listinfo/devel