On Thu, Mar 14, 2024 at 9:54 AM Qu Wenruo <wqu@xxxxxxxx> wrote: > > Currently when we increase the device statistics, it would always lead > to an error message in the kernel log. > > I would argue this behavior is not ideal: > > - It would flood the dmesg and bury real important messages > One common scenario is scrub. > If scrub hit some errors, it would cause both scrub and > btrfs_dev_stat_inc_and_print() to print error messages. > > And in that case, btrfs_dev_stat_inc_and_print() is completely > useless. > > - The results of btrfs_dev_stat_inc_and_print() is mostly for history > monitoring, doesn't has enough details > > If we trigger the errors during regular read, such messages from > btrfs_dev_stat_inc_and_print() won't help us to locate the cause > either. > > The real usage for the btrfs device statistics is for some user space > daemon to check if there is any new errors, acting like some checks on > SMART, thus we don't really need/want those messages in dmesg. > > This patch would reduce the log level to debug (disabled by default) for > btrfs_dev_stat_inc_and_print(). > For users really want to utilize btrfs devices statistics, they should > go check "btrfs device stats" periodically, and we should focus the > kernel error messages to more important things. Not sure if this is the right thing to do. In the scrub context it can be annoying for sure. Other cases I'm not so sure about, because having error messages in dmesg/syslog may help notice issues more quickly. > > CC: stable@xxxxxxxxxxxxxxx > Signed-off-by: Qu Wenruo <wqu@xxxxxxxx> > --- > fs/btrfs/volumes.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c > index e49935a54da0..126145950ed3 100644 > --- a/fs/btrfs/volumes.c > +++ b/fs/btrfs/volumes.c > @@ -7828,7 +7828,7 @@ void btrfs_dev_stat_inc_and_print(struct btrfs_device *dev, int index) > > if (!dev->dev_stats_valid) > return; > - btrfs_err_rl_in_rcu(dev->fs_info, > + btrfs_debug_rl_in_rcu(dev->fs_info, > "bdev %s errs: wr %u, rd %u, flush %u, corrupt %u, gen %u", > btrfs_dev_name(dev), > btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_WRITE_ERRS), > -- > 2.44.0 > >
