[PATCH v2] ubifs: respect MS_SILENT mount flag

[hujianyang]

Hi Artem,

> 
> Or even introduce a new version of the error macro, something like
> 'ubifs_errc(), and use that in the relevant places. Not sure what is
> going to look better, though. Here is a sketch:
> 
> 
> diff --git a/fs/ubifs/ubifs.h b/fs/ubifs/ubifs.h
> index e8c8cfe..60cffa7 100644
> --- a/fs/ubifs/ubifs.h
> +++ b/fs/ubifs/ubifs.h
> @@ -52,6 +52,14 @@
>         pr_warn("UBIFS warning (pid %d): %s: " fmt "\n",            \
>                 current->pid, __func__, ##__VA_ARGS__)
>  
> +/*
> + * A variant of 'ubifs_err()' which takes the UBIFS file-sytem description
> + * object as an argument.
> + */
> +#define ubifs_errc(c, fmt, ...)                                    \
> +       if (!(c)->probing)                                          \
> +               ubifs_err(fmt, ##__VA_ARGS__)
> +
>  /* UBIFS file system VFS magic number */
>  #define UBIFS_SUPER_MAGIC 0x24051905
> 

I have to say I was just writing to you about adding a new marco to instead.
Ha~

In this way we can disable unnecessary messages during mount if we use "slient"
flag. I have a simple question，Is this @probing safe during mount? Are there
some probably race conditions of it? I have no experiences of these.

I think you should find out which ubifs_err should be replace into your
"ubifs_errc" in the next step.

Thank you very much!


Hu