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 5CAEF25F780; Mon, 22 Sep 2025 19:36:52 +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=1758569812; cv=none; b=RRnz812ZzTvDYUvBOh2b/sAOc3K4zwA8HUM7Masyb4+9lrFVPCTT08HAt2erM/eCWdP+SKcU7er5U+h2EiAZUU1LnjMWMh5NEt79/ZqCUdSnhLJhRcld5NAnIt5hdOngAOIQR+bz+uz3Lp/U8/Ie1ZIBrbWe5cbxG30QWu8sCSE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758569812; c=relaxed/simple; bh=p4jryB07k7M5vKBTCrC4ou4exVH6wGIHL20RQE7fL9c=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=ospaCLxTW08EwDXSaAD9WKzgRlahWFH+kLMoswB/cBOEPvf1zxRGB32UsRKs7c8YWd1xuzBl9MFlgBad9yxwAkLzilUZEUvQ7UdUFBAFbbZFhqgdmAOL/GFLWU+h09e/ay2Lekfui3NRqrGAj0h6ZHPTuLHG0u7Tg04iFLI2WaY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=DnXWlzUD; 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="DnXWlzUD" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E0C8FC4CEF0; Mon, 22 Sep 2025 19:36:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1758569812; bh=p4jryB07k7M5vKBTCrC4ou4exVH6wGIHL20RQE7fL9c=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=DnXWlzUDNqYb//Og/ulau8DL0SssM6upbAac1qHnO0VgcihD7iLRWTa6T05mb8z94 GyDhHveiabFLALcAzWjVf/5NVGQeXJ9ouNpss1RFCrwntwjT2PfMCeTRrOc8yf3vvp CAGRLWwZ2zV4JN6JET1XpQo9bHhC50RGn0PPv3cE= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, "stable@vger.kernel.org, jack@suse.cz, Eric Hagberg" , Eric Hagberg Subject: [PATCH 6.6 70/70] Revert "loop: Avoid updating block size under exclusive owner" Date: Mon, 22 Sep 2025 21:30:10 +0200 Message-ID: <20250922192406.492614870@linuxfoundation.org> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20250922192404.455120315@linuxfoundation.org> References: <20250922192404.455120315@linuxfoundation.org> User-Agent: quilt/0.68 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Eric Hagberg Revert commit ce8da5d13d8c2a7b30b2fb376a22e8eb1a70b8bb which is commit 7e49538288e523427beedd26993d446afef1a6fb upstream. This reverts commit ce8da5d13d8c ("loop: Avoid updating block size under exclusive owner") for the 6.6 kernel, because if the LTP ioctl_loop06 test is run with this patch in place, the test will fail, it leaves the host unable to kexec into the kernel again (hangs forever) and "losetup -a" will hang on attempting to access the /dev/loopN device that the test has set up. The patch doesn't need to be reverted from 6.12, as it works fine there. Cc: stable@vger.kernel.org # 6.6.x Signed-off-by: Eric Hagberg Signed-off-by: Greg Kroah-Hartman --- drivers/block/loop.c | 38 ++++++++------------------------------ 1 file changed, 8 insertions(+), 30 deletions(-) --- a/drivers/block/loop.c +++ b/drivers/block/loop.c @@ -1472,36 +1472,19 @@ static int loop_set_dio(struct loop_devi return error; } -static int loop_set_block_size(struct loop_device *lo, blk_mode_t mode, - struct block_device *bdev, unsigned long arg) +static int loop_set_block_size(struct loop_device *lo, unsigned long arg) { int err = 0; - /* - * If we don't hold exclusive handle for the device, upgrade to it - * here to avoid changing device under exclusive owner. - */ - if (!(mode & BLK_OPEN_EXCL)) { - err = bd_prepare_to_claim(bdev, loop_set_block_size, NULL); - if (err) - return err; - } - - err = mutex_lock_killable(&lo->lo_mutex); - if (err) - goto abort_claim; - - if (lo->lo_state != Lo_bound) { - err = -ENXIO; - goto unlock; - } + if (lo->lo_state != Lo_bound) + return -ENXIO; err = blk_validate_block_size(arg); if (err) return err; if (lo->lo_queue->limits.logical_block_size == arg) - goto unlock; + return 0; sync_blockdev(lo->lo_device); invalidate_bdev(lo->lo_device); @@ -1513,11 +1496,6 @@ static int loop_set_block_size(struct lo loop_update_dio(lo); blk_mq_unfreeze_queue(lo->lo_queue); -unlock: - mutex_unlock(&lo->lo_mutex); -abort_claim: - if (!(mode & BLK_OPEN_EXCL)) - bd_abort_claiming(bdev, loop_set_block_size); return err; } @@ -1536,6 +1514,9 @@ static int lo_simple_ioctl(struct loop_d case LOOP_SET_DIRECT_IO: err = loop_set_dio(lo, arg); break; + case LOOP_SET_BLOCK_SIZE: + err = loop_set_block_size(lo, arg); + break; default: err = -EINVAL; } @@ -1590,12 +1571,9 @@ static int lo_ioctl(struct block_device break; case LOOP_GET_STATUS64: return loop_get_status64(lo, argp); - case LOOP_SET_BLOCK_SIZE: - if (!(mode & BLK_OPEN_WRITE) && !capable(CAP_SYS_ADMIN)) - return -EPERM; - return loop_set_block_size(lo, mode, bdev, arg); case LOOP_SET_CAPACITY: case LOOP_SET_DIRECT_IO: + case LOOP_SET_BLOCK_SIZE: if (!(mode & BLK_OPEN_WRITE) && !capable(CAP_SYS_ADMIN)) return -EPERM; fallthrough;