From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-f65.google.com ([74.125.82.65]:35294 "EHLO mail-wm0-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932752AbcILPH1 (ORCPT ); Mon, 12 Sep 2016 11:07:27 -0400 From: Amir Goldstein Subject: [PATCH v2 3/4] vfs: allow vfs_copy_file_range() across file systems Date: Mon, 12 Sep 2016 18:06:42 +0300 Message-Id: <1473692803-11964-4-git-send-email-amir73il@gmail.com> In-Reply-To: <1473692803-11964-1-git-send-email-amir73il@gmail.com> References: <1473348594-31425-1-git-send-email-amir73il@gmail.com> <1473692803-11964-1-git-send-email-amir73il@gmail.com> Sender: linux-xfs-owner@vger.kernel.org List-ID: List-Id: xfs To: Miklos Szeredi , Dave Chinner , linux-unionfs@vger.kernel.org Cc: Christoph Hellwig , linux-xfs@vger.kernel.org, "Darrick J . Wong" , linux-fsdevel@vger.kernel.org copy_file_range syscall returns -EXDEV if src and dest file are not on the same file system. The vfs_copy_file_range() helper, however, knows how to copy across file systems with do_splice_direct(). Move the enforcement of same file system from the vfs helper to the syscall code. A following patch is going to use the vfs_copy_file_range() helper in overlayfs to copy up between lower and upper not on the same file system. Signed-off-by: Amir Goldstein --- fs/read_write.c | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-) diff --git a/fs/read_write.c b/fs/read_write.c index 9dc6e52..c4675c6 100644 --- a/fs/read_write.c +++ b/fs/read_write.c @@ -1502,10 +1502,6 @@ ssize_t vfs_copy_file_range(struct file *file_in, loff_t pos_in, (file_out->f_flags & O_APPEND)) return -EBADF; - /* this could be relaxed once a method supports cross-fs copies */ - if (inode_in->i_sb != inode_out->i_sb) - return -EXDEV; - if (len == 0) return 0; @@ -1514,7 +1510,8 @@ ssize_t vfs_copy_file_range(struct file *file_in, loff_t pos_in, return ret; ret = -EOPNOTSUPP; - if (file_out->f_op->copy_file_range) + if (inode_in->i_sb == inode_out->i_sb && + 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) @@ -1569,6 +1566,14 @@ SYSCALL_DEFINE6(copy_file_range, int, fd_in, loff_t __user *, off_in, pos_out = f_out.file->f_pos; } + /* + * FIXME: should copy_file_range syscall enforce that src and + * dest files are on the same mount point or only on the same + * file system? none of the above? + */ + if (file_inode(f_in.file)->i_sb != file_inode(f_out.file)->i_sb) + return -EXDEV; + ret = vfs_copy_file_range(f_in.file, pos_in, f_out.file, pos_out, len, flags); if (ret > 0) { -- 2.7.4