From patchwork Mon Sep 9 18:27:22 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christoph Hellwig X-Patchwork-Id: 11138469 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 8F7471709 for ; Mon, 9 Sep 2019 18:28:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6DC7C218AF for ; Mon, 9 Sep 2019 18:28:17 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="k3TD321Z" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731668AbfIIS2Q (ORCPT ); Mon, 9 Sep 2019 14:28:16 -0400 Received: from bombadil.infradead.org ([198.137.202.133]:36026 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730720AbfIIS2Q (ORCPT ); Mon, 9 Sep 2019 14:28:16 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-Id:Date:Subject:To:From:Sender: Reply-To:Cc:Content-Type:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=gGnxwHEkKmU3nZb6jslCTcVoCflOHLwGWJm5yNVFVAM=; b=k3TD321ZlIl3HAcRZhXy+ionW PuI50dHpesFITp2Ss1G6a4BtSH6LvsF5Z/ls+uRh8YnzS+4MdbGgDgmfO7RWuq0hwHS4CT9+QLuDj NoR8gqH20KyAHfJEiPIzzohs+TzZ9I9MtRFC8awCmGhPRfFL7USofUt672LASM2Zr7+K4z121rI/R gFGkmLTSSRhRKMU/IEgWvuaFjALHd+2zXW25e7ZKAKKbADJ4BWPmpBkWtX653U/JVLEt4yMc+oikf JTnwnSQgU8+eohSMDFGyEaZ19KIHLvHT7nZmiWE97tirZ/tsRP75g/oS3jeMkhR2ZQ0xjB2X+yVtV EpOd4FWDQ==; Received: from [2001:4bb8:180:57ff:412:4333:4bf9:9db2] (helo=localhost) by bombadil.infradead.org with esmtpsa (Exim 4.92 #3 (Red Hat Linux)) id 1i7OOd-00029p-J9; Mon, 09 Sep 2019 18:28:15 +0000 From: Christoph Hellwig To: Goldwyn Rodrigues , linux-xfs@vger.kernel.org, linux-fsdevel@vger.kernel.org Subject: [PATCH 19/19] xfs: improve the IOMAP_NOWAIT check for COW inodes Date: Mon, 9 Sep 2019 20:27:22 +0200 Message-Id: <20190909182722.16783-20-hch@lst.de> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190909182722.16783-1-hch@lst.de> References: <20190909182722.16783-1-hch@lst.de> MIME-Version: 1.0 X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Only bail out once we know that a COW allocation is actually required, similar to how we handle normal data fork allocations. Signed-off-by: Christoph Hellwig Reviewed-by: Darrick J. Wong --- fs/xfs/xfs_iomap.c | 23 +++++------------------ 1 file changed, 5 insertions(+), 18 deletions(-) diff --git a/fs/xfs/xfs_iomap.c b/fs/xfs/xfs_iomap.c index e4e79aa5b695..9e1b4b94acac 100644 --- a/fs/xfs/xfs_iomap.c +++ b/fs/xfs/xfs_iomap.c @@ -693,15 +693,8 @@ xfs_ilock_for_iomap( * COW writes may allocate delalloc space or convert unwritten COW * extents, so we need to make sure to take the lock exclusively here. */ - if (xfs_is_cow_inode(ip) && is_write) { - /* - * FIXME: It could still overwrite on unshared extents and not - * need allocation. - */ - if (flags & IOMAP_NOWAIT) - return -EAGAIN; + if (xfs_is_cow_inode(ip) && is_write) mode = XFS_ILOCK_EXCL; - } /* * Extents not yet cached requires exclusive access, don't block. This @@ -760,12 +753,6 @@ xfs_direct_write_iomap_begin( if (XFS_FORCED_SHUTDOWN(mp)) return -EIO; - /* - * Lock the inode in the manner required for the specified operation and - * check for as many conditions that would result in blocking as - * possible. This removes most of the non-blocking checks from the - * mapping code below. - */ error = xfs_ilock_for_iomap(ip, flags, &lockmode); if (error) return error; @@ -775,11 +762,11 @@ xfs_direct_write_iomap_begin( if (error) goto out_unlock; - /* - * Break shared extents if necessary. Checks for non-blocking IO have - * been done up front, so we don't need to do them here. - */ if (imap_needs_cow(ip, &imap, flags, nimaps)) { + error = -EAGAIN; + if (flags & IOMAP_NOWAIT) + goto out_unlock; + /* may drop and re-acquire the ilock */ error = xfs_reflink_allocate_cow(ip, &imap, &cmap, &shared, &lockmode, flags & IOMAP_DIRECT);