The patch below does not apply to the 4.19-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 stable@vger.kernel.org.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From fd2b007eaec898564e269d1f478a2da0380ecf51 Mon Sep 17 00:00:00 2001

From: Qu Wenruo wqu@suse.com Date: Thu, 17 Oct 2019 10:38:36 +0800 Subject: [PATCH] btrfs: tracepoints: Fix wrong parameter order for qgroup events

[BUG] For btrfs:qgroup_meta_reserve event, the trace event can output garbage:

qgroup_meta_reserve: 9c7f6acc-b342-4037-bc47-7f6e4d2232d7: refroot=5(FS_TREE) type=DATA diff=2

The diff should always be alinged to sector size (4k), so there is definitely something wrong.

[CAUSE] For the wrong @diff, it's caused by wrong parameter order. The correct parameters are:

struct btrfs_root, s64 diff, int type.

However the parameters used are:

struct btrfs_root, int type, s64 diff.

Fixes: 4ee0d8832c2e ("btrfs: qgroup: Update trace events for metadata reservation") CC: stable@vger.kernel.org # 4.19+ Reviewed-by: Nikolay Borisov nborisov@suse.com Signed-off-by: Qu Wenruo wqu@suse.com Reviewed-by: David Sterba dsterba@suse.com Signed-off-by: David Sterba dsterba@suse.com

diff --git a/fs/btrfs/qgroup.c b/fs/btrfs/qgroup.c index c4bb69941c77..3ad151655eb8 100644 --- a/fs/btrfs/qgroup.c +++ b/fs/btrfs/qgroup.c @@ -3629,7 +3629,7 @@ int __btrfs_qgroup_reserve_meta(struct btrfs_root *root, int num_bytes, return 0;

BUG_ON(num_bytes != round_down(num_bytes, fs_info->nodesize)); - trace_qgroup_meta_reserve(root, type, (s64)num_bytes); + trace_qgroup_meta_reserve(root, (s64)num_bytes, type); ret = qgroup_reserve(root, num_bytes, enforce, type); if (ret < 0) return ret; @@ -3676,7 +3676,7 @@ void __btrfs_qgroup_free_meta(struct btrfs_root *root, int num_bytes, */ num_bytes = sub_root_meta_rsv(root, num_bytes, type); BUG_ON(num_bytes != round_down(num_bytes, fs_info->nodesize)); - trace_qgroup_meta_reserve(root, type, -(s64)num_bytes); + trace_qgroup_meta_reserve(root, -(s64)num_bytes, type); btrfs_qgroup_free_refroot(fs_info, root->root_key.objectid, num_bytes, type); }