From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id CD51EC43334 for ; Tue, 28 Jun 2022 11:47:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244356AbiF1Lrs (ORCPT ); Tue, 28 Jun 2022 07:47:48 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38440 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1345140AbiF1LrT (ORCPT ); Tue, 28 Jun 2022 07:47:19 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A1A422FFED for ; Tue, 28 Jun 2022 04:45:29 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 07C5EB81BEF for ; Tue, 28 Jun 2022 11:45:28 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id D6CECC3411D; Tue, 28 Jun 2022 11:45:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1656416726; bh=1MUvF4wrBkh16lmNSPkipbT+k8ENsVlDWCG2Q0tEloU=; h=Subject:From:To:Cc:Date:In-Reply-To:References:From; b=Qe45Qcsrw5dP7AKzkcAY9suJfTZ9kVSt8DIOMUg6GNphzBWyrqFuFgPj3GMZ8U00S ToWh7kdmjM8+wwHNz5husxXjn4ec3NnrZp5F81u8vcfHRWUV7swfhJyMGLJzlld71F YnLxaG/n105lWrvVWhoy7oqVz0o5rtOxvXwsQUr3pgUIZs3N1gvpx1xCgLI74UVrSh KmfnFtcNEt1yY0Xv2Q2bacg5G0sHY7ch3a9VcjiC9i1YjXEPn42Vn6HNaRhGxe6NIi exPV583Teu4Il24IdRtjKsv27Xo7d0mnuKqiknX4jKQY6d3KfZvef5PKx4/i8eP1vK 5HIm5Nd9PLx+A== Message-ID: <38dd6d58a7915bdc234db8f7c1082ca9da01b1df.camel@kernel.org> Subject: Re: [PATCH 24/44] iov_iter_get_pages_alloc(): lift freeing pages array on failure exits into wrapper From: Jeff Layton To: Al Viro , linux-fsdevel@vger.kernel.org Cc: Linus Torvalds , Jens Axboe , Christoph Hellwig , Matthew Wilcox , David Howells , Dominique Martinet , Christian Brauner Date: Tue, 28 Jun 2022 07:45:24 -0400 In-Reply-To: <20220622041552.737754-24-viro@zeniv.linux.org.uk> References: <20220622041552.737754-1-viro@zeniv.linux.org.uk> <20220622041552.737754-24-viro@zeniv.linux.org.uk> Content-Type: text/plain; charset="ISO-8859-15" Content-Transfer-Encoding: quoted-printable User-Agent: Evolution 3.44.2 (3.44.2-1.fc36) MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Wed, 2022-06-22 at 05:15 +0100, Al Viro wrote: > Incidentally, ITER_XARRAY did *not* free the sucker in case when > iter_xarray_populate_pages() returned 0... >=20 > Signed-off-by: Al Viro > --- > lib/iov_iter.c | 38 ++++++++++++++++++++++---------------- > 1 file changed, 22 insertions(+), 16 deletions(-) >=20 > diff --git a/lib/iov_iter.c b/lib/iov_iter.c > index c3fb7853dbe8..9c25661684c6 100644 > --- a/lib/iov_iter.c > +++ b/lib/iov_iter.c > @@ -1425,15 +1425,10 @@ static ssize_t pipe_get_pages_alloc(struct iov_it= er *i, > maxsize =3D n; > else > npages =3D DIV_ROUND_UP(maxsize + off, PAGE_SIZE); > - p =3D get_pages_array(npages); > + *pages =3D p =3D get_pages_array(npages); > if (!p) > return -ENOMEM; > - n =3D __pipe_get_pages(i, maxsize, p, off); > - if (n > 0) > - *pages =3D p; > - else > - kvfree(p); > - return n; > + return __pipe_get_pages(i, maxsize, p, off); > } > =20 > static ssize_t iter_xarray_get_pages_alloc(struct iov_iter *i, > @@ -1463,10 +1458,9 @@ static ssize_t iter_xarray_get_pages_alloc(struct = iov_iter *i, > count++; > } > =20 > - p =3D get_pages_array(count); > + *pages =3D p =3D get_pages_array(count); > if (!p) > return -ENOMEM; > - *pages =3D p; > =20 > nr =3D iter_xarray_populate_pages(p, i->xarray, index, count); > if (nr =3D=3D 0) > @@ -1475,7 +1469,7 @@ static ssize_t iter_xarray_get_pages_alloc(struct i= ov_iter *i, > return min_t(size_t, nr * PAGE_SIZE - offset, maxsize); > } > =20 > -ssize_t iov_iter_get_pages_alloc(struct iov_iter *i, > +static ssize_t __iov_iter_get_pages_alloc(struct iov_iter *i, > struct page ***pages, size_t maxsize, > size_t *start) > { > @@ -1501,16 +1495,12 @@ ssize_t iov_iter_get_pages_alloc(struct iov_iter = *i, > =20 > addr =3D first_iovec_segment(i, &len, start, maxsize, ~0U); > n =3D DIV_ROUND_UP(len, PAGE_SIZE); > - p =3D get_pages_array(n); > + *pages =3D p =3D get_pages_array(n); > if (!p) > return -ENOMEM; > res =3D get_user_pages_fast(addr, n, gup_flags, p); > - if (unlikely(res <=3D 0)) { > - kvfree(p); > - *pages =3D NULL; > + if (unlikely(res <=3D 0)) > return res; > - } > - *pages =3D p; > return (res =3D=3D n ? len : res * PAGE_SIZE) - *start; > } > if (iov_iter_is_bvec(i)) { > @@ -1531,6 +1521,22 @@ ssize_t iov_iter_get_pages_alloc(struct iov_iter *= i, > return iter_xarray_get_pages_alloc(i, pages, maxsize, start); > return -EFAULT; > } > + > +ssize_t iov_iter_get_pages_alloc(struct iov_iter *i, > + struct page ***pages, size_t maxsize, > + size_t *start) > +{ > + ssize_t len; > + > + *pages =3D NULL; > + > + len =3D __iov_iter_get_pages_alloc(i, pages, maxsize, start); > + if (len <=3D 0) { > + kvfree(*pages); > + *pages =3D NULL; > + } > + return len; > +} > EXPORT_SYMBOL(iov_iter_get_pages_alloc); > =20 > size_t csum_and_copy_from_iter(void *addr, size_t bytes, __wsum *csum, Reviewed-by: Jeff Layton