From: Nikolay Borisov <nborisov@suse.com>
Date: Fri, 15 Dec 2017 12:05:37 +0200
Subject: btrfs: Add enospc_debug printing in metadata_reserve_bytes
Git-commit: 9a3daff320260723b9e64b5b3b9c6592a0cd006a
Patch-mainline: v4.17-rc1
References: bsc#1165949

Currently when enospc_debug mount option is turned on we do not print
any debug info in case metadata reservation failures happen. Fix this
by adding the necessary hook in reserve_metadata_bytes.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
---
 fs/btrfs/extent-tree.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 9a677860f64d..85258e85a030 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -5394,10 +5394,15 @@ static int reserve_metadata_bytes(struct btrfs_root *root,
 		    !block_rsv_use_bytes(global_rsv, orig_bytes))
 			ret = 0;
 	}
-	if (ret == -ENOSPC)
+	if (ret == -ENOSPC) {
 		trace_btrfs_space_reservation(fs_info, "space_info:enospc",
 					      block_rsv->space_info->flags,
 					      orig_bytes, 1);
+
+		if (btrfs_test_opt(fs_info, ENOSPC_DEBUG))
+			dump_space_info(fs_info, block_rsv->space_info,
+					orig_bytes, 0);
+	}
 	return ret;
 }