From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 551473D5C23; Wed, 5 Aug 2026 20:12:29 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785960750; cv=none; b=P4m3Mfd6r8JEOsD3LXwEb0p8cNZA8RlCDT6sN5t/wa2AdLRQUA7JqVK+AuV+Ho5xPBeRO6nIq+0DzoqGZVyLFLvec5Vz92CAgTuCbEb+3U4Z75uSSW52fmz0GTMwWHU4cEXrn0yBugRUDspxJk6G0m+az4MOfOXhkrKxpZN+jMk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785960750; c=relaxed/simple; bh=HpPe5n1hdt+tdtFIiHbWgETDQGeqXLmppg4EelkUM3g=; h=Message-ID:Subject:From:To:Cc:Date:In-Reply-To:References: Content-Type:MIME-Version; b=cO9DpV5tU1CtAQiKvGwiH3L+FDIJJkhYJQOnm/vFtswrZCddOHsYYbYQ/Z/FdsytpGpjB8rFyEyNz3bN4vjnA5HYVeOunDH9gLw4BRVGCPFkjP2oQbqY8P7G+vNm1sHeQpx0ogsTJM6pGi5cPxwLxgltbHxhqfSHf2lOt6cwoYM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=mT+XTq2B; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="mT+XTq2B" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 834D11F000E9; Wed, 5 Aug 2026 20:12:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1785960748; bh=qKhFZjwoh9Z7eU7u5SE3stvRd+5tWHmU3iujv6Zqs9o=; h=Subject:From:To:Cc:Date:In-Reply-To:References; b=mT+XTq2BfoSjPDlU9PyzvB/WtaP3b68LUWHOQJXMFIbiI7NOPxSmb38BPMhlBg1OJ urrSbyln5OArGUsMad+g7iB3f8FeTYULIrs87MlqNJzaHF+Gzxy/h8XRlsI25BHBwQ YJq2oxxs6qJInAoMUR44sdNNjikbXHW5BgCxi4Mzlyh8s8Vzbd3derZbGrDlliQpcL B58XbcZGE1s/a8zi2D7+VRUoOOIxndMbaxkYaGKUd6ZtvrH0CrLEv38GqBmlhoa4lq 9CwWzvbJ2GtuGi927kivy1AHfPZDYkcK/bfp5lyIpLVH4sed4b8sWuFCtIwVSlgCL2 Al1My28izQvzA== Message-ID: Subject: Re: [PATCH v3 5/5] nfs: introduce nfs_direct_extract_pages helper From: Trond Myklebust To: Pranjal Shrivastava , Anna Schumaker , linux-nfs@vger.kernel.org Cc: Chuck Lever , Jeff Layton , linux-kernel@vger.kernel.org, Christoph Hellwig , Logan Gunthorpe , Jason Gunthorpe , linux-pci@vger.kernel.org, linux-rdma@vger.kernel.org, Shivaji Kant Date: Wed, 05 Aug 2026 13:12:28 -0700 In-Reply-To: <20260715143540.3597616-6-praan@google.com> References: <20260715143540.3597616-1-praan@google.com> <20260715143540.3597616-6-praan@google.com> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable User-Agent: Evolution 3.60.2 (3.60.2-1.fc44) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 On Wed, 2026-07-15 at 14:35 +0000, Pranjal Shrivastava wrote: > Introduce nfs_direct_extract_pages() in direct.c to centralize page > extraction and request creation for the Direct I/O path. The helper > manages extraction from the iters and builds a list of nfs_page > requests >=20 > Refactor nfs_direct_read_schedule_iovec() and > nfs_direct_write_schedule_iovec() to utilize the new helper, unifying > the extraction logic on both paths. >=20 > Signed-off-by: Pranjal Shrivastava > --- > =C2=A0fs/nfs/direct.c | 127 ++++++++++++++++++++++++---------------------= - > -- > =C2=A01 file changed, 64 insertions(+), 63 deletions(-) >=20 > diff --git a/fs/nfs/direct.c b/fs/nfs/direct.c > index b9ac0a67693c..d31e4720ffff 100644 > --- a/fs/nfs/direct.c > +++ b/fs/nfs/direct.c > @@ -178,6 +178,50 @@ static void nfs_direct_release_pages(struct page > **pages, unsigned int npages, > =C2=A0 } > =C2=A0} > =C2=A0 > +static ssize_t nfs_direct_extract_pages(struct nfs_direct_req *dreq, > + struct iov_iter *iter, > + size_t size, loff_t *pos, > + struct list_head *list) > +{ > + bool pinned =3D iov_iter_extract_will_pin(iter); > + struct page **pagevec =3D NULL; > + ssize_t result, bytes =3D 0; > + unsigned int npages, i; > + size_t pgbase; > + > + result =3D iov_iter_extract_pages(iter, &pagevec, size, ~0U, > 0, &pgbase); > + if (result <=3D 0) > + return result; > + > + npages =3D (result + pgbase + PAGE_SIZE - 1) >> PAGE_SHIFT; > + for (i =3D 0; i < npages; i++) { > + struct nfs_page *req; > + unsigned int req_len =3D min_t(size_t, result - bytes, > PAGE_SIZE - pgbase); > + > + req =3D nfs_page_create_from_page(dreq->ctx, > pagevec[i], > + pinned, pgbase, > *pos, > + req_len); > + if (IS_ERR(req)) { > + if (!bytes) > + bytes =3D PTR_ERR(req); > + break; > + } > + > + list_add_tail(&req->wb_list, list); > + pgbase =3D 0; > + bytes +=3D req_len; > + *pos +=3D req_len; > + } > + > + if (i < npages) { > + iov_iter_revert(iter, result - bytes); Oopsable if bytes =3D=3D PTR_ERR(req) > + nfs_direct_release_pages(pagevec + i, npages - i, > pinned); See what happens above with swap over NFS (which sets pinned =3D false). > + } > + > + kvfree(pagevec); > + return bytes; > +} > + > =C2=A0void nfs_init_cinfo_from_dreq(struct nfs_commit_info *cinfo, > =C2=A0 =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 struct nfs_direct_req *dreq) > =C2=A0{ > @@ -346,6 +390,7 @@ static ssize_t > nfs_direct_read_schedule_iovec(struct nfs_direct_req *dreq, > =C2=A0 ssize_t result =3D -EINVAL; > =C2=A0 size_t requested_bytes =3D 0; > =C2=A0 size_t rsize =3D max_t(size_t, NFS_SERVER(inode)->rsize, > PAGE_SIZE); > + LIST_HEAD(nfs_page_list); > =C2=A0 > =C2=A0 nfs_pageio_init_read(&desc, dreq->inode, false, > =C2=A0 =C2=A0=C2=A0=C2=A0=C2=A0 &nfs_direct_read_completion_ops); > @@ -354,43 +399,23 @@ static ssize_t > nfs_direct_read_schedule_iovec(struct nfs_direct_req *dreq, > =C2=A0 inode_dio_begin(inode); > =C2=A0 > =C2=A0 while (iov_iter_count(iter)) { > - struct page **pagevec =3D NULL; > - size_t bytes; > - size_t pgbase; > - unsigned npages, i; > - bool pinned =3D iov_iter_extract_will_pin(iter); > - > - result =3D iov_iter_extract_pages(iter, &pagevec, > - rsize, ~0U, 0, > &pgbase); > + result =3D nfs_direct_extract_pages(dreq, iter, rsize, > &pos, &nfs_page_list); > =C2=A0 if (result < 0) > =C2=A0 break; > =C2=A0 > - bytes =3D result; > - npages =3D (result + pgbase + PAGE_SIZE - 1) / > PAGE_SIZE; > - for (i =3D 0; i < npages; i++) { > - struct nfs_page *req; > - unsigned int req_len =3D min_t(size_t, bytes, > PAGE_SIZE - pgbase); > - /* XXX do we need to do the eof zeroing > found in async_filler? */ > - req =3D nfs_page_create_from_page(dreq->ctx, > pagevec[i], > - pinned, > pgbase, pos, > - req_len); > - if (IS_ERR(req)) { > - result =3D PTR_ERR(req); > - break; > - } > + while (!list_empty(&nfs_page_list)) { > + struct nfs_page *req =3D > nfs_list_entry(nfs_page_list.next); > + size_t req_len =3D req->wb_bytes; > + > + nfs_list_remove_request(req); > =C2=A0 if (!nfs_pageio_add_request(&desc, req)) { > =C2=A0 result =3D desc.pg_error; > =C2=A0 nfs_release_request(req); > + nfs_release_request_list(&nfs_page_l > ist); > =C2=A0 break; > =C2=A0 } > - pgbase =3D 0; > - bytes -=3D req_len; > =C2=A0 requested_bytes +=3D req_len; > - pos +=3D req_len; > =C2=A0 } > - if (i < npages) > - nfs_direct_release_pages(pagevec + i, npages > - i, pinned); > - kvfree(pagevec); > =C2=A0 if (result < 0) > =C2=A0 break; > =C2=A0 } > @@ -881,6 +906,7 @@ static ssize_t > nfs_direct_write_schedule_iovec(struct nfs_direct_req *dreq, > =C2=A0 ssize_t result =3D 0; > =C2=A0 size_t requested_bytes =3D 0; > =C2=A0 size_t wsize =3D max_t(size_t, NFS_SERVER(inode)->wsize, > PAGE_SIZE); > + LIST_HEAD(nfs_page_list); > =C2=A0 bool defer =3D false; > =C2=A0 > =C2=A0 trace_nfs_direct_write_schedule_iovec(dreq); > @@ -893,55 +919,32 @@ static ssize_t > nfs_direct_write_schedule_iovec(struct nfs_direct_req *dreq, > =C2=A0 > =C2=A0 NFS_I(inode)->write_io +=3D iov_iter_count(iter); > =C2=A0 while (iov_iter_count(iter)) { > - struct page **pagevec =3D NULL; > - size_t bytes; > - size_t pgbase; > - unsigned npages, i; > - bool pinned =3D iov_iter_extract_will_pin(iter); > - > - result =3D iov_iter_extract_pages(iter, &pagevec, > - wsize, ~0U, 0, > &pgbase); > + result =3D nfs_direct_extract_pages(dreq, iter, wsize, > &pos, &nfs_page_list); > =C2=A0 if (result < 0) > =C2=A0 break; > =C2=A0 > - bytes =3D result; > - npages =3D (result + pgbase + PAGE_SIZE - 1) / > PAGE_SIZE; > - for (i =3D 0; i < npages; i++) { > - struct nfs_page *req; > - unsigned int req_len =3D min_t(size_t, bytes, > PAGE_SIZE - pgbase); > - > - req =3D nfs_page_create_from_page(dreq->ctx, > pagevec[i], > - pinned, > pgbase, pos, > - req_len); > - if (IS_ERR(req)) { > - result =3D PTR_ERR(req); > - break; > - } > - > - if (desc.pg_error < 0) { > - nfs_free_request(req); > - result =3D desc.pg_error; > - break; > - } > - > - pgbase =3D 0; > - bytes -=3D req_len; > - requested_bytes +=3D req_len; > - pos +=3D req_len; > + while (!list_empty(&nfs_page_list)) { > + struct nfs_page *req =3D > nfs_list_entry(nfs_page_list.next); > + size_t req_len =3D req->wb_bytes; > =C2=A0 > + nfs_list_remove_request(req); > =C2=A0 if (defer) { > =C2=A0 nfs_mark_request_commit(req, NULL, > &cinfo, 0); > + requested_bytes +=3D req_len; > =C2=A0 continue; > =C2=A0 } > =C2=A0 > =C2=A0 nfs_lock_request(req); > - if (nfs_pageio_add_request(&desc, req)) > + if (nfs_pageio_add_request(&desc, req)) { > + requested_bytes +=3D req_len; > =C2=A0 continue; > + } > =C2=A0 > =C2=A0 /* Exit on hard errors */ > =C2=A0 if (desc.pg_error < 0 && desc.pg_error !=3D - > EAGAIN) { > =C2=A0 result =3D desc.pg_error; > =C2=A0 nfs_unlock_and_release_request(req); > + nfs_release_request_list(&nfs_page_l > ist); > =C2=A0 break; > =C2=A0 } > =C2=A0 > @@ -952,12 +955,10 @@ static ssize_t > nfs_direct_write_schedule_iovec(struct nfs_direct_req *dreq, > =C2=A0 spin_unlock(&dreq->lock); > =C2=A0 nfs_unlock_request(req); > =C2=A0 nfs_mark_request_commit(req, NULL, &cinfo, > 0); > + requested_bytes +=3D req_len; > =C2=A0 desc.pg_error =3D 0; > =C2=A0 defer =3D true; > =C2=A0 } > - if (i < npages) > - nfs_direct_release_pages(pagevec + i, npages > - i, pinned); > - kvfree(pagevec); > =C2=A0 if (result < 0) > =C2=A0 break; > =C2=A0 } --=20 Trond Myklebust Linux NFS client maintainer, Hammerspace trondmy@kernel.org, trond.myklebust@hammerspace.com