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 AFE4A4501B; Tue, 13 Feb 2024 21:30:41 +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=1707859841; cv=none; b=UO9MHRXroS0L+mH5TjQsqCMLy7G5pXxetMtqM++1ghN5gHGoBJZ8/SISet/PI/HQsZZf5joocfAIl3GnP36QV95a3Wakjk5E4J3I2D3+v2QALTXGTdM9Ft018w7F9z+qfYvK02qOiwD0wlaF+748rk7W28Ow43IVwdrAqRxmaSc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1707859841; c=relaxed/simple; bh=9X9GQyhvkWNmvG1Gu8mRVXEfxB+77vFWQKzoIce99lQ=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=HXIqACJ6ev+pZPXnSDwZTCXT8fycjKmSi7iap0ZrlvLGbDd1pCiSSjzF0xNvmN/OGv8X2JeIrl0upag8PH0HNxQvLBhAs3WKWyt3ZdIW8fqyF/2PJfTZvROwgxwmp56K3Ie/Mxnaq7c0eyMgHLhEKWffw94EOgl5b3p/Y/VCPKc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=p7eXOBiu; 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="p7eXOBiu" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 21C8BC433C7; Tue, 13 Feb 2024 21:30:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1707859841; bh=9X9GQyhvkWNmvG1Gu8mRVXEfxB+77vFWQKzoIce99lQ=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=p7eXOBiuggM/wGeuiUFMm3PU3dXQ+ZLqQrv6ZQn/m/9yK7QHfgK6lhTagkIPxZBq6 bRlmV8vbS3wCXcSFKQeQO3MoXu0uu9s8uLiC6eEf09qYaFBybPdo9ZbcDvGT1ISe7a Ccn/2uag8Bvt60GxJhqjkPaleE9NshSYrPdF2Qi1dpW8OEgUDl1LrI4iKpm1UcpaYa oH6UglTMhfeRit7IDGYuG3wOUILzp6RrBwrXP5AVKx1N+vSlmpDfJP1pzEYZVrNRxS o0/DeMbvaCpPKCmmsq4sIMfsj0FNOkzy42gmHMJKDaIgCmSkhU7naIYnEQ1IegB34t DdxVA7WqDOJYw== Date: Tue, 13 Feb 2024 13:30:40 -0800 From: "Darrick J. Wong" To: "Pankaj Raghav (Samsung)" Cc: linux-xfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, mcgrof@kernel.org, gost.dev@samsung.com, akpm@linux-foundation.org, kbusch@kernel.org, chandan.babu@oracle.com, p.raghav@samsung.com, linux-kernel@vger.kernel.org, hare@suse.de, willy@infradead.org, linux-mm@kvack.org, david@fromorbit.com Subject: Re: [RFC v2 10/14] iomap: fix iomap_dio_zero() for fs bs > system page size Message-ID: <20240213213040.GX616564@frogsfrogsfrogs> References: <20240213093713.1753368-1-kernel@pankajraghav.com> <20240213093713.1753368-11-kernel@pankajraghav.com> <20240213163037.GR6184@frogsfrogsfrogs> <5kodxnrvjq5dsjgjfeps6wte774c2sl75bn3fg3hh46q3wkwk5@2tru4htvqmrq> Precedence: bulk X-Mailing-List: linux-xfs@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: <5kodxnrvjq5dsjgjfeps6wte774c2sl75bn3fg3hh46q3wkwk5@2tru4htvqmrq> On Tue, Feb 13, 2024 at 10:27:32PM +0100, Pankaj Raghav (Samsung) wrote: > On Tue, Feb 13, 2024 at 08:30:37AM -0800, Darrick J. Wong wrote: > > On Tue, Feb 13, 2024 at 10:37:09AM +0100, Pankaj Raghav (Samsung) wrote: > > > From: Pankaj Raghav > > > > > > iomap_dio_zero() will pad a fs block with zeroes if the direct IO size > > > < fs block size. iomap_dio_zero() has an implicit assumption that fs block > > > size < page_size. This is true for most filesystems at the moment. > > > > > > If the block size > page size, this will send the contents of the page > > > next to zero page(as len > PAGE_SIZE) to the underlying block device, > > > causing FS corruption. > > > > > > iomap is a generic infrastructure and it should not make any assumptions > > > about the fs block size and the page size of the system. > > > > > > Signed-off-by: Pankaj Raghav > > > --- > > > fs/iomap/direct-io.c | 13 +++++++++++-- > > > 1 file changed, 11 insertions(+), 2 deletions(-) > > > > > > diff --git a/fs/iomap/direct-io.c b/fs/iomap/direct-io.c > > > index bcd3f8cf5ea4..04f6c5548136 100644 > > > --- a/fs/iomap/direct-io.c > > > +++ b/fs/iomap/direct-io.c > > > @@ -239,14 +239,23 @@ static void iomap_dio_zero(const struct iomap_iter *iter, struct iomap_dio *dio, > > > struct page *page = ZERO_PAGE(0); > > > struct bio *bio; > > > > > > - bio = iomap_dio_alloc_bio(iter, dio, 1, REQ_OP_WRITE | REQ_SYNC | REQ_IDLE); > > > + WARN_ON_ONCE(len > (BIO_MAX_VECS * PAGE_SIZE)); > > > + > > > + bio = iomap_dio_alloc_bio(iter, dio, BIO_MAX_VECS, > > > + REQ_OP_WRITE | REQ_SYNC | REQ_IDLE); > > > fscrypt_set_bio_crypt_ctx(bio, inode, pos >> inode->i_blkbits, > > > GFP_KERNEL); > > > + > > > bio->bi_iter.bi_sector = iomap_sector(&iter->iomap, pos); > > > bio->bi_private = dio; > > > bio->bi_end_io = iomap_dio_bio_end_io; > > > > > > - __bio_add_page(bio, page, len, 0); > > > + while (len) { > > > + unsigned int io_len = min_t(unsigned int, len, PAGE_SIZE); > > > > What was the result of all that discussion about using the PMD-sized > > zero-folio the last time this patch was submitted? Did that prove to be > > unwieldly, or did it require enough extra surgery to become its own > > series? > > > > It proved a bit unwieldly to me at least as I did not know any straight > forward way to do it at the time. So I thought I will keep this approach > as it is, and add support for the PMD-sized zero folio for later > improvement. > > > (The code here looks good to me.) > > Thanks! In that case I'll throw it on the testing pile and let's ask brauner to merge this for 6.9 if nothing blows up. Reviewed-by: Darrick J. Wong --D > > > > --D > > > > > + > > > + __bio_add_page(bio, page, io_len, 0); > > > + len -= io_len; > > > + } > > > iomap_dio_submit_bio(iter, dio, bio, pos); > > > } > > > > > > -- > > > 2.43.0 > > > > > > >