From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-oo1-f46.google.com (mail-oo1-f46.google.com [209.85.161.46]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1418B378838 for ; Thu, 3 Sep 2026 17:41:39 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.161.46 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788457301; cv=none; b=tGbE48jf1Mybp2qiFWXoB1vxNLPJHkB1uzM3sUFadjzr+VK8rU+0LcT0NozTEjefTCahP+v/2j3hu0vbjyPhNV3w/vYeKQGhdqjeJO05NdGemyU+DGxzTsnUCJELFM4bDvSKwcFgt5SlaQHn0FLXy6YKobw0FPNUo3KHR4xaXCc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788457301; c=relaxed/simple; bh=pWSElYc8vth469p/p45Q3vrajNYvKALRapQG0DOJD5c=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=LDc6YQm5FVLlCAfgo9NKYIe1iFoexVJhVo8riARmKaJzrfkcwrGCP757uqHuzEdXVGI8lWOIXMYIY3OYm9csu097nU3Pt7NvIMNKg9ZvMoi/CadmRROqCBotl4M5QLJFFqJZkBt+7DKubyq9fWOrW/88AdEQdIbQKtV2kk3Z7Lc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=VW0pjsgA; arc=none smtp.client-ip=209.85.161.46 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="VW0pjsgA" Received: by mail-oo1-f46.google.com with SMTP id 006d021491bc7-6b1c75f0049so60764eaf.3 for ; Thu, 03 Sep 2026 10:41:39 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1788457299; x=1789062099; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to:content-type; bh=ykwTaa6ygXsfYqfQ8E8HUJuFa56MBU+sp0H1tR5irQM=; b=VW0pjsgAhOnEXoABdJX0LSb+sMnJDPixNllCbrjJD3bhhkzVdNRHRjyM1jfBc3LC1i DHfmAzoJiJ0nrxX/W6glocopx6Of4VNS+MQlUSJUkDSYF0yfuXyscS95/FJ20eITF9/e XjUU3dm4Srj6zHaxx0hKVhLQ3liXe4lpKyD5GSVles3RR6NUc+H+jRFZH65s+xw86r3p RkIlFqGZSaqjS4crqChPYj3NJ819/1yScIsOEhRLIIev8pXLeF7w0hDCfL8LdPYDpPNo Bau6wQhsM6ZHCuPaKKLuiITvUc7hXh1490Hlacq1rmcZIzSgid2ShitqkhaynLQp0rFE 0wJw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1788457299; x=1789062099; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-gg:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to:content-type; bh=ykwTaa6ygXsfYqfQ8E8HUJuFa56MBU+sp0H1tR5irQM=; b=eYEKFbcSWR/GSbov6Gdpi8Dc71I5Vaq6xzrHl6c07VLZQlU4o1uTw0rKLl3bznAwxv 29PkqencOOwDDVaNkEDO4FJl9YZwrRKPoZqFdYk8T+wQMl8pfUhNcKB6vv9ieacW9Ba/ AalRiORh1PudtkrlqgcQuSQ4ywbbBfCQGTDBVOS3h0agOHxoacypSMClZec9oY8rAGL/ CQGgWsatBW3pVk9wKpIlCTXoG5GtAt2gZXDkmI7oGzYthBixlj5V4gukjEN5rRrEsrFe s7INm+s6RDF99Z/P0AxaNPQTfIqcabQHzT78Krnn6G1ezfbFKihC/GTMHpFUd50fjO9P ncRQ== X-Gm-Message-State: AFuF++lRd1QS+AV0Ry8mZ8jpa8Q2BkjhqVI8sQv6iQEO66mPPdqltwNJ cCkUFkgjhcIp49H1nb/PejtuiErNZl4iJN52Fkzet0iC+Wheqfg5IpQQk8CPya/VfflZaw== X-Gm-Gg: AYBFou2I7nfzjBpDeFf+zpxhWvwsO/YY/850bYDIQO7lU1p+8Dy5iDEq3gmQOZCyRcf EyaSyGlbd2/0no60yPw2Oec+tl7HwGf/ZKJVjHhBMMGbgLqztFEFZrlcgL0T1DusfOpJeONUH+g serRA7na+lVOqlIS1yl3rimg3bIfu+P6kg3JhWOR/3Kpn5koVfUoTH3FmUv0CSRjM8k88Jjg+CS UGWlVNPSh2snqzlfZJa2HTOXDwqgJhCmO+TRKIABKEl+CuEnFbkfyzRNTqXeMsspokhX+G9UXfS pPOmWKODqoBx93zerULph0EVDcjJy7SEDxb8npAstaR0h64nncJEFt3bla82XkxSCHrSU8mHoKu Uqaz4QCGGt6LktzvV8mVZCge1rrspDkwPtB4kNNWWwjyxopN2PkQ5qCsqPnEnCGjG1vjYW12y0T HWYnTvsYCY6L7xv3+lKSTgEvcnJU77pWXlYzTdvE9f2jh/EDAucDrhCXbivw== X-Received: by 2002:a05:6820:1524:b0:6ae:a950:9fb4 with SMTP id 006d021491bc7-6b6fe0b8574mr263503eaf.33.1788457298656; Thu, 03 Sep 2026 10:41:38 -0700 (PDT) Received: from debian.lan ([172.245.89.240]) by smtp.gmail.com with ESMTPSA id 006d021491bc7-6b6de522bb0sm568133eaf.13.2026.09.03.10.41.36 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 03 Sep 2026 10:41:38 -0700 (PDT) From: Maks To: linux-block@vger.kernel.org Cc: Jens Axboe Subject: block: zero logical block size leads to infinite loop in set_init_blocksize() Date: Thu, 3 Sep 2026 20:41:24 +0300 Message-ID: <20260903174124.51009-1-mi9992828@gmail.com> X-Mailer: git-send-email 2.47.3 Precedence: bulk X-Mailing-List: linux-block@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Hi, I hit a soft lockup in set_init_blocksize() with a block device whose logical_block_size was zero. I understand that logical_block_size == 0 violates the block layer contract and that the driver which allowed this value needs to be fixed. However, the generic block code currently turns this invariant violation into a non-terminating loop: while (bsize < PAGE_SIZE) { if (size & bsize) break; bsize <<= 1; } With bsize == 0, the value never changes. In my case this resulted in: watchdog: BUG: soft lockup - CPU#0 stuck for 26s! [(udev-worker):...] RIP: set_init_blocksize+0x28/0x60 Call Trace: blkdev_get_whole+... bdev_open+... Is this considered acceptable behavior for a broken driver, or should the generic block layer defensively detect this case and fail the open instead of spinning indefinitely? If adding such a check is considered worthwhile, I can prepare a patch. Thanks, Maks