From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pj1-f72.google.com (mail-pj1-f72.google.com [209.85.216.72]) (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 735BF4446E1 for ; Mon, 10 Aug 2026 19:50:52 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.216.72 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786391454; cv=none; b=TeCfIlzZ2IGOvRaXFIOd0kktq31FrQR4X6oueExCobb9CYwAESE1Jtl99LWMNqQ46BnnI/rkAcQJij3DMsrwA3dH16BdepGTEKinieMNWTmrhzqn3q37YdDOdcS5RfuDFu40AXSUvYIHRk/9ZfKgbMY3bJVPtFznBK+VdeaDwLM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786391454; c=relaxed/simple; bh=DpoLih1PcP1k7ATY/YpwCBeYW+iX+D+/PGns6KtbHsg=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=XDNMELuSJ+aSDokTXRa5SLctRvd9YYej0OIyjOhAx3rr2HRFz5sTesSB36IbpZJBnD9VxHxrmN9z5mUScWOR98QrYeI3dJubtMi3wsiQMLoy7H5+MUVJn+WgzHJwnlN0vr9ps+hDchYAtoJdBecqMQxX6dqx1juOC5roBgblF00= 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=dbc59f1P; arc=none smtp.client-ip=209.85.216.72 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="dbc59f1P" Received: by mail-pj1-f72.google.com with SMTP id 98e67ed59e1d1-38e5a616d07so2661229a91.2 for ; Mon, 10 Aug 2026 12:50:52 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1786391452; x=1786996252; 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=VcYKmOJeHZ340ymkvpq1SUtt9jjLj7DE6k/D4ssp5QU=; b=dbc59f1P4KzBA4hLzz0lEZa6t6X47EK1J5yXcYG+NCVB5Y8oSdjjzShOEcz5QKk0Et kxrmSzCoPs9e6QJhoPIXgWF9T+7Gu34NFVoUiZJTpZClKbGlatN2vsxybtoeBGyAtEoE 2p3IKfnusvhvgkRnnjrHAr1zA94V+PE1sFpwiDNrD6ovLHEqtcnbgpq9gl5WYJK06zk3 Cpm1o2RYleWSq4mwzqnE9Eue91QGFeRNK/9S48vvCvRqItRhzMtvWfEjc7BrozEu95ni k9bcZXW6r9YHsHpK3gi0/vJrwZNM1yjoSY4teDfd6NaURy1v4Ja287fNAN74drGnsYjC RtOQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1786391452; x=1786996252; 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=VcYKmOJeHZ340ymkvpq1SUtt9jjLj7DE6k/D4ssp5QU=; b=geyUUe2IIph7a9OoaSE/JwCJxbG431BWekmgm8GDyH5l9B+EHXertaV7yo7SEeFRoc fxdLJpJD3pvrX4cmrVlvGZfWihn9QGBj4S0SsM33RkyFlFkCrCVN5t/+h4qrSETJ2B0q oGcjh13X5q7gSYjKTtbTNLvneDgopjcCBD7crj5ROZ4vDA5vxdNxiuJRUDn/VINZbolh Sypgps9SuZtZSZ7MSOExiwJq03Iga0wbhfneHZevcpWkUtfNNtk07Zur8E2PDuxsJmJG q8oOPrrt0kK+dZQbvY0kXJCntZwYIyT37+uoDJRB6UpYnzsrDloxiEXUqdmRVRH0uLQI /eAQ== X-Forwarded-Encrypted: i=1; AHgh+RrYhUDXhP5l2YQw46XW1Y+9qwEv3CBvXitrMJbF7I1eNFVTlhqD4BYlJY4YP2aYZYlW4Lain+555OuFJf0=@vger.kernel.org X-Gm-Message-State: AOJu0Yx7RHLniWhxjdMyIOWKx+Ury08w/AhOybU3Zg2Rei1Qhoz9LzWv ZpDMIWC5fr5NZu8/Djkc+LVOeCFCE/MjyRwysEBAQWvcSlxsvIiH+/f1r/pkc1HdT91Cl/v0TDa b+g== X-Received: from dybrq15.prod.google.com ([2002:a05:7301:468f:b0:313:d984:da01]) (user=praan job=prod-delivery.src-stubby-dispatcher) by 2002:a17:90b:5444:b0:381:1f51:1ff0 with SMTP id 98e67ed59e1d1-392821fc107mr22534242a91.2.1786391451507; Mon, 10 Aug 2026 12:50:51 -0700 (PDT) Date: Mon, 10 Aug 2026 19:50:38 +0000 In-Reply-To: <20260810195040.2877784-1-praan@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260810195040.2877784-1-praan@google.com> X-Mailer: git-send-email 2.55.0.679.g6767b8d81c-goog Message-ID: <20260810195040.2877784-5-praan@google.com> Subject: [PATCH v5 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 | 34 ++++++++++++++++------------------ 1 file changed, 16 insertions(+), 18 deletions(-) diff --git a/fs/nfs/direct.c b/fs/nfs/direct.c index 96995736fac2..a1caef90f2f1 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); @@ -387,7 +382,8 @@ 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 +887,14 @@ 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 +905,7 @@ 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 +949,8 @@ 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; -- 2.55.0.679.g6767b8d81c-goog