From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from aserp1040.oracle.com ([141.146.126.69]:49682 "EHLO aserp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753583AbbLSIzp (ORCPT ); Sat, 19 Dec 2015 03:55:45 -0500 Subject: [PATCH 4/9] vfs: Add vfs_copy_file_range() support for pagecache copies From: "Darrick J. Wong" To: david@fromorbit.com, darrick.wong@oracle.com Cc: linux-api@vger.kernel.org, Christoph Hellwig , xfs@oss.sgi.com, linux-fsdevel@vger.kernel.org, Padraig Brady , Anna Schumaker Date: Sat, 19 Dec 2015 00:55:32 -0800 Message-ID: <20151219085532.12478.20947.stgit@birch.djwong.org> In-Reply-To: <20151219085505.12478.71157.stgit@birch.djwong.org> References: <20151219085505.12478.71157.stgit@birch.djwong.org> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-fsdevel-owner@vger.kernel.org List-ID: >>>From : Anna Schumaker This allows us to have an in-kernel copy mechanism that avoids frequent switches between kernel and user space. This is especially useful so NFSD can support server-side copies. The default (flags=0) means to first attempt copy acceleration, but use the pagecache if that fails. I moved the rw_verify_area() calls into the fallback code since some filesystems can handle reflinking a large range. Signed-off-by: Anna Schumaker Reviewed-by: Darrick J. Wong Reviewed-by: Padraig Brady Reviewed-by: Christoph Hellwig --- fs/read_write.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) diff --git a/fs/read_write.c b/fs/read_write.c index 97c15ca..6f73af1 100644 --- a/fs/read_write.c +++ b/fs/read_write.c @@ -1354,8 +1354,7 @@ ssize_t vfs_copy_file_range(struct file *file_in, loff_t pos_in, if (!(file_in->f_mode & FMODE_READ) || !(file_out->f_mode & FMODE_WRITE) || - (file_out->f_flags & O_APPEND) || - !file_out->f_op->copy_file_range) + (file_out->f_flags & O_APPEND)) return -EBADF; /* this could be relaxed once a method supports cross-fs copies */ @@ -1369,8 +1368,14 @@ ssize_t vfs_copy_file_range(struct file *file_in, loff_t pos_in, if (ret) return ret; - ret = file_out->f_op->copy_file_range(file_in, pos_in, file_out, pos_out, - len, flags); + ret = -EOPNOTSUPP; + if (file_out->f_op->copy_file_range) + ret = file_out->f_op->copy_file_range(file_in, pos_in, file_out, + pos_out, len, flags); + if (ret == -EOPNOTSUPP) + ret = do_splice_direct(file_in, &pos_in, file_out, &pos_out, + len > MAX_RW_COUNT ? MAX_RW_COUNT : len, 0); + if (ret > 0) { fsnotify_access(file_in); add_rchar(current, ret);