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 3FD067A730; Tue, 12 Mar 2024 22:12:57 +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=1710281578; cv=none; b=W0oyxVzim0r2B1An1LQOFGhldxS/ONrZAWp89n8rkP3Eo8MY29R6ExNt0yZuyNaPQtdSHR5I5sxqzSKo7ZgHj3gLe4AtImSg7i68AkNxMH3Apg2bqYmhs/Rfn1Cp6z3psbm7YS/dd3thFZpvcLxE1h3hjccjSl4HH9YZEMqYZhA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1710281578; c=relaxed/simple; bh=9uq/j3Hgz3Vttrm8luZzODCRNkQqejQaOuzuZQeBZnc=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=uMgL34GtXktYBiHPdaDPheyQOto3J6N2MMgYNLsUB6IUx++/mW2D+2GVA2mOyaNfoW9Qj2BszlqYlWk1hvgMXWRmC1nZWEjPCEED7/eQsVJPUV4AiBlilYjg1S+0XxIbfTW8Ckq0/19xO1m0TFbY0PAAsmt/jHvxpml49CHJy+Y= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=nT2NL4iy; 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="nT2NL4iy" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 549ACC433F1; Tue, 12 Mar 2024 22:12:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1710281577; bh=9uq/j3Hgz3Vttrm8luZzODCRNkQqejQaOuzuZQeBZnc=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=nT2NL4iyCmA0WNjwMrhLBIK3E4V5hxU/npyfBL3ZpzgemrK+gfAzrwixATP1A9cMm lqfxnfHWZwbnKIE+e9ZzN5u34fAjg1bicAZ4fok8DUBLlUzRN04UQDVR9ydFeJVfQI R2/+op6Tldx3OO5Y+weXXltAsTS1Nsv7mZJ7ARSQ4ZlRUqFj+y2HNovyoChWMprOmw kZBTB4viIZakkq9mCZyoNIFXAFOrrkf7e7OPa4kaEWeMhnTWRry91/oGDEi1dVdUON qpDdN8FWb9ma7yVsUTnESw4SoCeFknMHGAKsRyc2GeCYJteWUSqv4l0shIlmUnt2qw zrfRatW5y/H2g== Date: Tue, 12 Mar 2024 16:12:54 -0600 From: Keith Busch To: Christoph Hellwig Cc: Jens Axboe , Chandan Babu R , linux-block@vger.kernel.org, linux-nvme@lists.infradead.org, linux-xfs@vger.kernel.org Subject: Re: [PATCH 1/5] block: move discard checks into the ioctl handler Message-ID: References: <20240312144532.1044427-1-hch@lst.de> <20240312144532.1044427-2-hch@lst.de> Precedence: bulk X-Mailing-List: linux-block@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20240312144532.1044427-2-hch@lst.de> On Tue, Mar 12, 2024 at 08:45:27AM -0600, Christoph Hellwig wrote: > @@ -95,6 +95,8 @@ static int compat_blkpg_ioctl(struct block_device *bdev, > static int blk_ioctl_discard(struct block_device *bdev, blk_mode_t mode, > unsigned long arg) > { > + sector_t bs_mask = (bdev_logical_block_size(bdev) >> SECTOR_SHIFT) - 1; > + sector_t sector, nr_sects; > uint64_t range[2]; > uint64_t start, len; > struct inode *inode = bdev->bd_inode; > @@ -105,18 +107,21 @@ static int blk_ioctl_discard(struct block_device *bdev, blk_mode_t mode, > > if (!bdev_max_discard_sectors(bdev)) > return -EOPNOTSUPP; > + if (bdev_read_only(bdev)) > + return -EPERM; > > if (copy_from_user(range, (void __user *)arg, sizeof(range))) > return -EFAULT; > > start = range[0]; > len = range[1]; > + sector = start >> SECTOR_SHIFT; > + nr_sects = len >> SECTOR_SHIFT; > > - if (start & 511) > + if (!nr_sects) > return -EINVAL; > - if (len & 511) > + if ((sector | nr_sects) & bs_mask) > return -EINVAL; > - > if (start + len > bdev_nr_bytes(bdev)) > return -EINVAL; Maybe you want to shift lower bytes out of consideration, but it is different, right? For example, if I call this ioctl with start=5 and len=555, it would return EINVAL, but your change would let it succeed the same as if start=0, len=512.