Return-Path: linux-nfs-owner@vger.kernel.org Received: from mail-pd0-f171.google.com ([209.85.192.171]:44905 "EHLO mail-pd0-f171.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750876AbaLOF10 (ORCPT ); Mon, 15 Dec 2014 00:27:26 -0500 Received: by mail-pd0-f171.google.com with SMTP id y13so10996837pdi.2 for ; Sun, 14 Dec 2014 21:27:25 -0800 (PST) From: Omar Sandoval To: Alexander Viro , Andrew Morton , Trond Myklebust , Christoph Hellwig , David Sterba , linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-nfs@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Omar Sandoval Subject: [PATCH 1/8] nfs: follow direct I/O write locking convention Date: Sun, 14 Dec 2014 21:26:55 -0800 Message-Id: <7561c096c7de603ac39fcfcff7bd2ec80589cae1.1418618044.git.osandov@osandov.com> In-Reply-To: References: In-Reply-To: References: Sender: linux-nfs-owner@vger.kernel.org List-ID: The generic callers of direct_IO lock i_mutex before doing a write. NFS doesn't use the generic write code, so it doesn't follow this convention. This is now a problem because the interface introduced for swap-over-NFS calls direct_IO for a write without holding i_mutex, but other implementations of direct_IO will expect to have it locked. Signed-off-by: Omar Sandoval --- fs/nfs/direct.c | 12 +++++------- fs/nfs/file.c | 8 ++++++-- 2 files changed, 11 insertions(+), 9 deletions(-) diff --git a/fs/nfs/direct.c b/fs/nfs/direct.c index 10bf072..9402b96 100644 --- a/fs/nfs/direct.c +++ b/fs/nfs/direct.c @@ -906,17 +906,15 @@ ssize_t nfs_file_direct_write(struct kiocb *iocb, struct iov_iter *iter, if (!count) goto out; - mutex_lock(&inode->i_mutex); - result = nfs_sync_mapping(mapping); if (result) - goto out_unlock; + goto out; if (mapping->nrpages) { result = invalidate_inode_pages2_range(mapping, pos >> PAGE_CACHE_SHIFT, end); if (result) - goto out_unlock; + goto out; } task_io_account_write(count); @@ -924,7 +922,7 @@ ssize_t nfs_file_direct_write(struct kiocb *iocb, struct iov_iter *iter, result = -ENOMEM; dreq = nfs_direct_req_alloc(); if (!dreq) - goto out_unlock; + goto out; dreq->inode = inode; dreq->bytes_left = count; @@ -960,12 +958,12 @@ ssize_t nfs_file_direct_write(struct kiocb *iocb, struct iov_iter *iter, } } nfs_direct_req_release(dreq); + + mutex_lock(&inode->i_mutex); return result; out_release: nfs_direct_req_release(dreq); -out_unlock: - mutex_unlock(&inode->i_mutex); out: return result; } diff --git a/fs/nfs/file.c b/fs/nfs/file.c index 2ab6f00..8b80276 100644 --- a/fs/nfs/file.c +++ b/fs/nfs/file.c @@ -675,8 +675,12 @@ ssize_t nfs_file_write(struct kiocb *iocb, struct iov_iter *from) if (result) return result; - if (file->f_flags & O_DIRECT) - return nfs_file_direct_write(iocb, from, pos); + if (file->f_flags & O_DIRECT) { + mutex_lock(&inode->i_mutex); + result = nfs_file_direct_write(iocb, from, pos); + mutex_unlock(&inode->i_mutex); + return result; + } dprintk("NFS: write(%pD2, %zu@%Ld)\n", file, count, (long long) pos); -- 2.1.3