From 23c4f13702afa6e9f7a0a745859b961b76b79a35 Mon Sep 17 00:00:00 2001 From: Anand Jain Date: Fri, 10 Jan 2020 12:26:34 +0800 Subject: [PATCH] btrfs: device stats, log when stats are zeroed We had a report indicating that some read errors aren't reported by the device stats in the userland. It is important to have the errors reported in the device stat as user land scripts might depend on it to take the reasonable corrective actions. But to debug these issue we need to be really sure that request to reset the device stat did not come from the userland itself. So log an info message when device error reset happens. For example: BTRFS info (device sdc): device stats zeroed by btrfs(9223) Reported-by: philip@philip-seeger.de Link: https://www.spinics.net/lists/linux-btrfs/msg96528.html Reviewed-by: Josef Bacik Signed-off-by: Anand Jain Reviewed-by: David Sterba Signed-off-by: David Sterba --- fs/btrfs/volumes.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index d184a994c3929..9658c53eec7b1 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -7329,6 +7329,8 @@ int btrfs_get_dev_stats(struct btrfs_fs_info *fs_info, else btrfs_dev_stat_set(dev, i, 0); } + btrfs_info(fs_info, "device stats zeroed by %s (%d)", + current->comm, task_pid_nr(current)); } else { for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++) if (stats->nr_items > i) -- 2.39.5