From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wr0-f193.google.com ([209.85.128.193]:34332 "EHLO mail-wr0-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751575AbeFXTBS (ORCPT ); Sun, 24 Jun 2018 15:01:18 -0400 Received: by mail-wr0-f193.google.com with SMTP id a12-v6so11425714wro.1 for ; Sun, 24 Jun 2018 12:01:18 -0700 (PDT) Date: Sun, 24 Jun 2018 20:01:00 +0100 From: Sudip Mukherjee To: gregkh@linuxfoundation.org Cc: bo.li.liu@oracle.com, dsterba@suse.com, stable@vger.kernel.org Subject: Re: FAILED: patch "[PATCH] Btrfs: fix unexpected cow in run_delalloc_nocow" failed to apply to 4.9-stable tree Message-ID: <20180624190100.ohl4unql6bnt4i5f@debian> References: <152299873711092@kroah.com> MIME-Version: 1.0 Content-Type: multipart/mixed; boundary="2izx22vqywi5543s" Content-Disposition: inline In-Reply-To: <152299873711092@kroah.com> Sender: stable-owner@vger.kernel.org List-ID: --2izx22vqywi5543s Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Hi Greg, On Fri, Apr 06, 2018 at 09:12:17AM +0200, gregkh@linuxfoundation.org wrote: > > The patch below does not apply to the 4.9-stable tree. > If someone wants it applied there, or to any other stable or longterm > tree, then please email the backport, including the original git commit > id to . The attached patch should now apply to v4.9-stable tree. -- Regards Sudip --2izx22vqywi5543s Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="0001-Btrfs-fix-unexpected-cow-in-run_delalloc_nocow.patch" >>From 898c00a307fb80cf2b18a5c84dd3c6ee61f037af Mon Sep 17 00:00:00 2001 From: Liu Bo Date: Wed, 31 Jan 2018 17:09:13 -0700 Subject: [PATCH] Btrfs: fix unexpected cow in run_delalloc_nocow commit 5811375325420052fcadd944792a416a43072b7f upstream Fstests generic/475 provides a way to fail metadata reads while checking if checksum exists for the inode inside run_delalloc_nocow(), and csum_exist_in_range() interprets error (-EIO) as inode having checksum and makes its caller enter the cow path. In case of free space inode, this ends up with a warning in cow_file_range(). The same problem applies to btrfs_cross_ref_exist() since it may also read metadata in between. With this, run_delalloc_nocow() bails out when errors occur at the two places. cc: v2.6.28+ Fixes: 17d217fe970d ("Btrfs: fix nodatasum handling in balancing code") Signed-off-by: Liu Bo Signed-off-by: David Sterba Signed-off-by: Sudip Mukherjee --- fs/btrfs/inode.c | 33 ++++++++++++++++++++++++++++++--- 1 file changed, 30 insertions(+), 3 deletions(-) diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index f073de65e818..e67c7da54604 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -1230,6 +1230,8 @@ static noinline int csum_exist_in_range(struct btrfs_root *root, list_del(&sums->list); kfree(sums); } + if (ret < 0) + return ret; return 1; } @@ -1381,10 +1383,23 @@ static noinline int run_delalloc_nocow(struct inode *inode, goto out_check; if (btrfs_extent_readonly(root, disk_bytenr)) goto out_check; - if (btrfs_cross_ref_exist(trans, root, ino, + ret = btrfs_cross_ref_exist(trans, root, ino, found_key.offset - - extent_offset, disk_bytenr)) + extent_offset, disk_bytenr); + if (ret) { + /* + * ret could be -EIO if the above fails to read + * metadata. + */ + if (ret < 0) { + if (cow_start != (u64)-1) + cur_offset = cow_start; + goto error; + } + + WARN_ON_ONCE(nolock); goto out_check; + } disk_bytenr += extent_offset; disk_bytenr += cur_offset - found_key.offset; num_bytes = min(end + 1, extent_end) - cur_offset; @@ -1402,8 +1417,20 @@ static noinline int run_delalloc_nocow(struct inode *inode, * this ensure that csum for a given extent are * either valid or do not exist. */ - if (csum_exist_in_range(root, disk_bytenr, num_bytes)) + ret = csum_exist_in_range(root, disk_bytenr, num_bytes); + if (ret) { + /* + * ret could be -EIO if the above fails to read + * metadata. + */ + if (ret < 0) { + if (cow_start != (u64)-1) + cur_offset = cow_start; + goto error; + } + WARN_ON_ONCE(nolock); goto out_check; + } if (!btrfs_inc_nocow_writers(root->fs_info, disk_bytenr)) goto out_check; -- 2.11.0 --2izx22vqywi5543s--