From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pf1-f199.google.com (mail-pf1-f199.google.com [209.85.210.199]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A28C2478E5B for ; Fri, 14 Aug 2026 14:33:15 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.210.199 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786718000; cv=none; b=Y9miEfRvmJdE8w+VVsILxSQc0lfhAxjRHpnvsVD17tzmTkeYrxaoXYusE8yXYLLkzTkwv5vYhztKnpsZtNIeeLht699uv4VI+zJXU/shXRTT5PeA2zV7Gg8+2gUO2LatId8AtitKKzU8OI+rDO23mDeIy+ALJMJ0uVzTjtea+v0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786718000; c=relaxed/simple; bh=ex6pRePhYMA39HcNB1bKP2BgdIOPCiqjQAlJZqxWR5c=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=LwiHOSGmzB5+RxDhoASEbDttOTHhDWtG1w8qhRRwCzOQ2Qg5zVFyqqSBMSBnf9rbEq9yHgiNcvuzPQ13TV34EYkI6zSQ5gvSgh+mzkIgsIzItauDiL/yGTjwSWCUKAF9bxfmnazLUdcmK2+Rz1mLywqNbdWBYdv8hcgvAWz1pkg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--praan.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=n210P0bC; arc=none smtp.client-ip=209.85.210.199 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--praan.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="n210P0bC" Received: by mail-pf1-f199.google.com with SMTP id d2e1a72fcca58-84e024d2129so1485324b3a.2 for ; Fri, 14 Aug 2026 07:33:15 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1786717993; x=1787322793; darn=vger.kernel.org; h=content-type:cc:to:from:subject:message-id:references:mime-version :in-reply-to:date:from:to:cc:subject:date:message-id:reply-to :content-type; bh=HTq2Yo3MiZtOH+LV5j9JTfmNCmFQW03NdlsC4mRN3vI=; b=n210P0bC1sT+9vl5QbuDFZxoQQkS5rXH6iPKyBBPPE+a8ZZ6rlYtvd9vew8JK8QZBd N87ngX8C+ebspYbYOLKrUYRQl8qhAXAlIE2jPMxI/h1wbsFMGiTd9QrG2T47DEQmurOy wjphxTK+H9D5+Ae/9P/onCp2pIuLuAMFFnR8dLHnAc4Vn2uLi6lHILn1s511m+WKciaQ AWYNFRD34zjOui7Paf5SSCxsy/xDa1GCmuiWsM9Oa70YZzdMhMrXff3OR54YJrd29akW Fe6H4eilx4caj6aIK0mmcAjgE7zqMuq0/Ma7izDv21gdAzYR0SEXIfcNIaO0/XGyKGZU K1eg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1786717993; x=1787322793; h=content-type:cc:to:from:subject:message-id:references:mime-version :in-reply-to:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to:content-type; bh=HTq2Yo3MiZtOH+LV5j9JTfmNCmFQW03NdlsC4mRN3vI=; b=YTf+CFDPYbDCvBEzKl76e8A3Q9O8rKum2zzmWrD24EZpAV5KWIKNpyi2egFpmH+Fg4 sfueiID2T5qdhOIhZIQCfljADEinfi2TNw7sU7vjnkYa79HvFKzppn/Ya1CVT4QR1B82 OttP4LGJdr+0VdEJT5hodgaj6aGt1yZDvgrhnttm2ygjGSQHFpOrgKhPOuwev1alpd9+ IrZ6mL5ymE9V0QvlUaMgRRCAZjlCZKFxFOkQBpZPpUc/h1YN0NIp82/bLQBn8x6cJn5G ELnGkX5xxNGt+Dbx+8QmSQxVEqeayAT/baMyrIjx4jcwftozShg0Tru5t7bqhC/VT9A9 YQ+A== X-Forwarded-Encrypted: i=1; AHgh+RqnyjuijIzqOOxHh4SW5zX523kDGmLbq27JIx+1HKSZtg/+fkM66M3QBGJu9Hc7ica3E4OytujNVndF@vger.kernel.org X-Gm-Message-State: AOJu0Yw946XwN9EBH5Q0geqztpdgTwR3V7DPpvkzOqSWamqHJFmGRTSE JqWiwSYf7+Gu7yeLL8kJ++QumZWV6MzME36KNybBunYBeGfe4QOFQ09JFSYZ3gcPZG0JznFMPnp +uw== X-Received: from pffy16.prod.google.com ([2002:aa7:93d0:0:b0:847:b0e2:92a3]) (user=praan job=prod-delivery.src-stubby-dispatcher) by 2002:a05:6a00:7487:b0:84f:dfce:966b with SMTP id d2e1a72fcca58-84fdfce99a7mr4924223b3a.8.1786717992732; Fri, 14 Aug 2026 07:33:12 -0700 (PDT) Date: Fri, 14 Aug 2026 14:32:54 +0000 In-Reply-To: <20260814143255.861084-1-praan@google.com> Precedence: bulk X-Mailing-List: linux-rdma@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260814143255.861084-1-praan@google.com> X-Mailer: git-send-email 2.55.0.691.gc56d675ccc-goog Message-ID: <20260814143255.861084-5-praan@google.com> Subject: [PATCH v6 4/5] nfs: migrate direct I/O to iov_iter_extract_pages From: Pranjal Shrivastava To: linux-nfs@vger.kernel.org, Trond Myklebust , Anna Schumaker 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 , Pranjal Shrivastava Content-Type: text/plain; charset="UTF-8" Migrate the NFS Direct I/O path away from the legacy iov_iter_get_pages_alloc2() API to the modern iov_iter_extract_pages API. The transition aligns NFS with the modern VFS extraction model and serves as a preparatory step for supporting requirements such as page pinning via GUP for DMA. The migration fixes a bug in the Direct I/O loop where pages were being unpinned immediately after request creation. With the new extraction model, pins are held until the I/O is complete. Manual release in the loop is correspondingly updated to only clean up failed pages. Signed-off-by: Pranjal Shrivastava Reviewed-by: Shivaji Kant Reviewed-by: Christoph Hellwig --- fs/nfs/direct.c | 37 +++++++++++++++++++------------------ 1 file changed, 19 insertions(+), 18 deletions(-) diff --git a/fs/nfs/direct.c b/fs/nfs/direct.c index 96995736fac2..a1479fbf4f9e 100644 --- a/fs/nfs/direct.c +++ b/fs/nfs/direct.c @@ -168,14 +168,8 @@ int nfs_swap_rw(struct kiocb *iocb, struct iov_iter *iter) static void nfs_direct_release_pages(struct page **pages, unsigned int npages, bool pinned) { - unsigned int i; - - if (pinned) { + if (pinned) unpin_user_pages(pages, npages); - } else { - for (i = 0; i < npages; i++) - put_page(pages[i]); - } } void nfs_init_cinfo_from_dreq(struct nfs_commit_info *cinfo, @@ -354,16 +348,17 @@ static ssize_t nfs_direct_read_schedule_iovec(struct nfs_direct_req *dreq, inode_dio_begin(inode); while (iov_iter_count(iter)) { - struct page **pagevec; + struct page **pagevec = NULL; size_t bytes; size_t pgbase; unsigned npages, i; + bool pinned = iov_iter_extract_will_pin(iter); - result = iov_iter_get_pages_alloc2(iter, &pagevec, - rsize, &pgbase); + result = iov_iter_extract_pages(iter, &pagevec, + rsize, ~0U, 0, &pgbase); if (result < 0) break; - + bytes = result; npages = (result + pgbase + PAGE_SIZE - 1) / PAGE_SIZE; for (i = 0; i < npages; i++) { @@ -371,7 +366,7 @@ static ssize_t nfs_direct_read_schedule_iovec(struct nfs_direct_req *dreq, unsigned int req_len = min_t(size_t, bytes, PAGE_SIZE - pgbase); /* XXX do we need to do the eof zeroing found in async_filler? */ req = nfs_page_create_from_page(dreq->ctx, pagevec[i], - false, pgbase, pos, + pinned, pgbase, pos, req_len); if (IS_ERR(req)) { result = PTR_ERR(req); @@ -380,6 +375,7 @@ static ssize_t nfs_direct_read_schedule_iovec(struct nfs_direct_req *dreq, if (!nfs_pageio_add_request(&desc, req)) { result = desc.pg_error; nfs_release_request(req); + i++; break; } pgbase = 0; @@ -387,7 +383,8 @@ static ssize_t nfs_direct_read_schedule_iovec(struct nfs_direct_req *dreq, requested_bytes += req_len; pos += req_len; } - nfs_direct_release_pages(pagevec, npages, false); + if (i < npages) + nfs_direct_release_pages(pagevec + i, npages - i, pinned); kvfree(pagevec); if (result < 0) break; @@ -891,13 +888,14 @@ static ssize_t nfs_direct_write_schedule_iovec(struct nfs_direct_req *dreq, NFS_I(inode)->write_io += iov_iter_count(iter); while (iov_iter_count(iter)) { - struct page **pagevec; + struct page **pagevec = NULL; size_t bytes; size_t pgbase; unsigned npages, i; + bool pinned = iov_iter_extract_will_pin(iter); - result = iov_iter_get_pages_alloc2(iter, &pagevec, - wsize, &pgbase); + result = iov_iter_extract_pages(iter, &pagevec, + wsize, ~0U, 0, &pgbase); if (result < 0) break; @@ -908,7 +906,7 @@ static ssize_t nfs_direct_write_schedule_iovec(struct nfs_direct_req *dreq, unsigned int req_len = min_t(size_t, bytes, PAGE_SIZE - pgbase); req = nfs_page_create_from_page(dreq->ctx, pagevec[i], - false, pgbase, pos, + pinned, pgbase, pos, req_len); if (IS_ERR(req)) { result = PTR_ERR(req); @@ -918,6 +916,7 @@ static ssize_t nfs_direct_write_schedule_iovec(struct nfs_direct_req *dreq, if (desc.pg_error < 0) { nfs_free_request(req); result = desc.pg_error; + i++; break; } @@ -939,6 +938,7 @@ static ssize_t nfs_direct_write_schedule_iovec(struct nfs_direct_req *dreq, if (desc.pg_error < 0 && desc.pg_error != -EAGAIN) { result = desc.pg_error; nfs_unlock_and_release_request(req); + i++; break; } @@ -952,7 +952,8 @@ static ssize_t nfs_direct_write_schedule_iovec(struct nfs_direct_req *dreq, desc.pg_error = 0; defer = true; } - nfs_direct_release_pages(pagevec, npages, false); + if (i < npages) + nfs_direct_release_pages(pagevec + i, npages - i, pinned); kvfree(pagevec); if (result < 0) break; -- 2.55.0.691.gc56d675ccc-goog