From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pl1-f198.google.com (mail-pl1-f198.google.com [209.85.214.198]) (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 17FC8418A38 for ; Mon, 20 Jul 2026 15:06:42 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.214.198 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784560004; cv=none; b=QEDmMrHlawqRIXU0wd0JE2wVcMALPRDDYYDD1Oqo385D0zbPWkG3vvyKxKVY9gNKilrveKXGoCW0aeDLsNzM23l1o0YgMgyer12mvg5qpojR/Ib++LiI1dkAJHlKWT2hkchXQs/1ml8mMiKvuWb0MmG6yK1IrBqackAK9cq5wNg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784560004; c=relaxed/simple; bh=lvGGPxUg6qqnndxGA/aNFDaANt0aJQwgdyiaT7mGbqM=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=aHwkmLv3NMnsbw5YGhsLtGCz+XdPw8GrvkPaVf/RxpPH1QGUUNhllJDNx1gQPxUhgYrg8o0oc+BNCH+pmS/tX8TtT/pxZC5WuxVWHHfRkEvrLErnAWVMkDt/r+wdKafpZj3loZ8SmIfpO3Dsw2wJ1Xms404XNaLU8dMfFOoLq4E= 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=lgP7VNqt; arc=none smtp.client-ip=209.85.214.198 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="lgP7VNqt" Received: by mail-pl1-f198.google.com with SMTP id d9443c01a7336-2cf7dd9fd91so1138085ad.1 for ; Mon, 20 Jul 2026 08:06:42 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1784560002; x=1785164802; 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=05o7VYUkCdAGSR73b2hzUktgrPZs5fUnpb2oWqFgEQo=; b=lgP7VNqtSYl9op/wKrWO6h2JAjjgXjNenX2D1nwhA86ObF3NQKd5fie/VKxTFiUsq6 kyd44Z9GhstHi771VC2cXK3ysHfnog788heITgUuH+N8rsurmtcgku2epJtDYAgYh6w2 Jdk9a2S7LuuxZaTB3D12o+AeWEK3lcWPt2bQDHE7quLvDWXSoe0TPqe+GtjCVIMXPOxF wxKQSjcd1VkKD07Qn/F2zCZMEiJ7ORsO7EnVHyReG5Bl0CxqhcVc8rNPo/nJQS8OBMSK UomPQGtx3DAxIKim0RyFN2SeGYSs62/e+4gwoJ7WCcUy5qM3y97Y6y0LheO3+7wvEy6q GJCQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1784560002; x=1785164802; 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=05o7VYUkCdAGSR73b2hzUktgrPZs5fUnpb2oWqFgEQo=; b=cij/Qtg6IbOmYPNa3BCRzDd0f3KsYzo8fgvb/n7AHPddrfy5PfIPYVNA7cGQn/1UNG /3xFrGUN055wrt9xP9Sj/4PRxbNvzxRO9/y6FYKGhLkqE4MOzipUPhjNpSA6rkO8ZEz7 7eUPIdD9C3cDmcTdodzy0SCKn57101dio9OYsZNLnyPI5y/joYoN8oWAKS7wmvTVMsQC zYVdutS1c2+AWPyQYyRvALd6fqPA/1CxW91CxRVVeEW5ZevkWY0Lx/XmKJc7Xduxr1cD qhIqyWEQQCYRvr7cxbmumicso0aXDZ7qkFITE0oBM43AZauXHN80bElF8GGOunsavwOV EYzQ== X-Gm-Message-State: AOJu0Yzzyp570wWZfjVJ03CnO97JTFupBVj9hdwnmp99oPrKGdeVXknf tL9EvaD7BVDte+KcpY5ebuS1CD7Y3rR3dGl8MkTGmb8Fxu1bgrXDwNBdcPR7UgTmwFHPwGF0J3i fd/6VsyU0yM/3iXIAjQ9Q+6+zuC9BHQP83jbXkMhSblNykYGt8igl3pMb8j6jM6XI3Qsd+NjfUJ M3gHrAbtQKXN+KXvgfS54RNIQ0sjK4SC8RXLs= X-Received: from plgn10.prod.google.com ([2002:a17:902:f60a:b0:2cc:cfa0:3117]) (user=praan job=prod-delivery.src-stubby-dispatcher) by 2002:a17:903:2441:b0:2c2:cf20:213 with SMTP id d9443c01a7336-2cf3499c666mr166695255ad.29.1784560001928; Mon, 20 Jul 2026 08:06:41 -0700 (PDT) Date: Mon, 20 Jul 2026 15:06:00 +0000 In-Reply-To: <20260720150601.2702700-1-praan@google.com> Precedence: bulk X-Mailing-List: linux-nfs@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260720150601.2702700-1-praan@google.com> X-Mailer: git-send-email 2.55.0.229.g6434b31f56-goog Message-ID: <20260720150601.2702700-5-praan@google.com> Subject: [PATCH v4 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 | 26 +++++++++++++++----------- 1 file changed, 15 insertions(+), 11 deletions(-) diff --git a/fs/nfs/direct.c b/fs/nfs/direct.c index 96995736fac2..b9ac0a67693c 100644 --- a/fs/nfs/direct.c +++ b/fs/nfs/direct.c @@ -354,16 +354,17 @@ 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 +372,7 @@ 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); @@ -387,7 +388,8 @@ 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 +893,14 @@ 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 +911,7 @@ 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); @@ -952,7 +955,8 @@ 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; -- 2.55.0.229.g6434b31f56-goog