From: Omar Sandoval <osandov@fb.com>
Date: Fri, 11 May 2018 13:13:40 -0700
Subject: Btrfs: reserve space for O_TMPFILE orphan item deletion
Git-commit: 399b0bbf5f680797d3599fa14f16706ffc470145
Patch-mainline: v4.18-rc1
References: bsc#1111469

btrfs_link() calls btrfs_orphan_del() if it's linking an O_TMPFILE but
it doesn't reserve space to do so. Even before the removal of the
orphan_block_rsv it wasn't using it.

Fixes: ef3b9af50bfa ("Btrfs: implement inode_operations callback tmpfile")
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Acked-by: Nikolay Borisov <nborisov@suse.com>
---
 fs/btrfs/inode.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index b247ea31c436..6e9cb5338964 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -6658,8 +6658,9 @@ static int btrfs_link(struct dentry *old_dentry, struct inode *dir,
 	 * 2 items for inode and inode ref
 	 * 2 items for dir items
 	 * 1 item for parent inode
+	 * 1 item for orphan item deletion if O_TMPFILE
 	 */
-	trans = btrfs_start_transaction(root, 5);
+	trans = btrfs_start_transaction(root, inode->i_nlink ? 5 : 6);
 	if (IS_ERR(trans)) {
 		err = PTR_ERR(trans);
 		trans = NULL;