From: Zhao Lei <zhaolei@cn.fujitsu.com>
Date: Tue, 1 Dec 2015 10:39:40 +0000 (+0800)
Subject: btrfs: Fix no_space in write and rm loop
X-Git-Tag: v4.1.22~155
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=d5b55a7aae08c0e0785430126bcc4a9ae7f5c737;p=platform%2Fkernel%2Flinux-exynos.git

btrfs: Fix no_space in write and rm loop

[ Upstream commit 08acfd9dd845dc052c5eae33e6c3976338070069 ]

commit e1746e8381cd2af421f75557b5cae3604fc18b35 upstream.

I see no_space in v4.4-rc1 again in xfstests generic/102.
It happened randomly in some node only.
(one of 4 phy-node, and a kvm with non-virtio block driver)

By bisect, we can found the first-bad is:
 commit bdced438acd8 ("block: setup bi_phys_segments after splitting")'
But above patch only triggered the bug by making bio operation
faster(or slower).

Main reason is in our space_allocating code, we need to commit
page writeback before wait it complish, this patch fixed above
bug.

BTW, there is another reason for generic/102 fail, caused by
disable default mixed-blockgroup, I'll fix it in xfstests.

Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
---

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 98a4d52..d1ae132 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -3975,8 +3975,10 @@ commit_trans:
 		    !atomic_read(&root->fs_info->open_ioctl_trans)) {
 			need_commit--;
 
-			if (need_commit > 0)
+			if (need_commit > 0) {
+				btrfs_start_delalloc_roots(fs_info, 0, -1);
 				btrfs_wait_ordered_roots(fs_info, -1);
+			}
 
 			trans = btrfs_join_transaction(root);
 			if (IS_ERR(trans))