On Sat, 23 Jul 2022 09:42:12 +0200,
Joe Perches wrote:
>
> On Fri, 2022-07-22 at 16:29 +0200, Takashi Iwai wrote:
> > Currently the error and info messages handled by exfat_err() and co
> > are tossed to exfat_msg() function that does nothing but passes the
> > strings with printk() invocation. Not only that this is more overhead
> > by the indirect calls, but also this makes harder to extend for the
> > debug print usage; because of the direct printk() call, you cannot
> > make it for dynamic debug or without debug like the standard helpers
> > such as pr_debug() or dev_dbg().
> >
> > For addressing the problem, this patch replaces exfat_msg() function
> > with a macro to expand to pr_*() directly. This allows us to create
> > exfat_debug() macro that is expanded to pr_debug() (which output can
> > gracefully suppressed via dyndbg).
> []
> > diff --git a/fs/exfat/exfat_fs.h b/fs/exfat/exfat_fs.h
> []
> > @@ -508,14 +508,19 @@ void __exfat_fs_error(struct super_block *sb, int report, const char *fmt, ...)
> > #define exfat_fs_error_ratelimit(sb, fmt, args...) \
> > __exfat_fs_error(sb, __ratelimit(&EXFAT_SB(sb)->ratelimit), \
> > fmt, ## args)
> > -void exfat_msg(struct super_block *sb, const char *lv, const char *fmt, ...)
> > - __printf(3, 4) __cold;
> > +
> > +/* expand to pr_xxx() with prefix */
> > +#define exfat_msg(sb, lv, fmt, ...) \
> > + pr_##lv("exFAT-fs (%s): " fmt "\n", (sb)->s_id, ##__VA_ARGS__)
> > +
> > #define exfat_err(sb, fmt, ...) \
> > - exfat_msg(sb, KERN_ERR, fmt, ##__VA_ARGS__)
> > + exfat_msg(sb, err, fmt, ##__VA_ARGS__)
> > #define exfat_warn(sb, fmt, ...) \
> > - exfat_msg(sb, KERN_WARNING, fmt, ##__VA_ARGS__)
> > + exfat_msg(sb, warn, fmt, ##__VA_ARGS__)
> > #define exfat_info(sb, fmt, ...) \
> > - exfat_msg(sb, KERN_INFO, fmt, ##__VA_ARGS__)
> > + exfat_msg(sb, info, fmt, ##__VA_ARGS__)
> > +#define exfat_debug(sb, fmt, ...) \
> > + exfat_msg(sb, debug, fmt, ##__VA_ARGS__)
>
> I think this would be clearer using pr_<level> directly instead
> of an indirecting macro that uses concatenation of <level> that
> obscures the actual use of pr_<level>
>
> Either: (and this first option would be my preference)
>
> #define exfat_err(sb, fmt, ...) \
> pr_err("exFAT-fs (%s): " fmt "\n", (sb)->s_id, ##__VA_ARGS__)
> #define exfat_warn(sb, fmt, ...) \
> pr_warn("exFAT-fs (%s): " fmt "\n", (sb)->s_id, ##__VA_ARGS__)
> etc...
IMO, it's a matter of taste, and I don't mind either way.
Just let me know.
> or using an indirecting macro:
>
> #define exfat_printk(pr_level, sb, fmt, ...) \
> pr_level("exFAT-fs (%s): " fmt "\n", (sb)->s_id, ##__VA_ARGS__)
Is pr_level() defined anywhere...?
>
> and btw, there are multiple uses of exfat_<level> output with a
> unnecessary and duplicated '\n' that the macro already adds that
> should be removed:
>
> $ git grep -P -n '\bexfat_(err|warn|info).*\\n' fs/exfat/
> fs/exfat/fatent.c:334: exfat_err(sb, "sbi->clu_srch_ptr is invalid (%u)\n",
> fs/exfat/nls.c:674: exfat_err(sb, "failed to read sector(0x%llx)\n",
> fs/exfat/super.c:467: exfat_err(sb, "bogus sector size bits : %u\n",
> fs/exfat/super.c:476: exfat_err(sb, "bogus sectors bits per cluster : %u\n",
Right, that should be addressed in another patch.
thanks,
Takashi
