Commit 60440789 authored by Bart Van Assche's avatar Bart Van Assche Committed by Mike Snitzer
Browse files

dm: fix printk() rate limiting code 



Using the same rate limiting state for different kinds of messages
is wrong because this can cause a high frequency message to suppress
a report of a low frequency message. Hence use a unique rate limiting
state per message type.

Fixes: 71a16736 ("dm: use local printk ratelimit")
Cc: stable@vger.kernel.org
Signed-off-by: default avatarBart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: default avatarMike Snitzer <snitzer@redhat.com>
parent 68515cc7

drivers/md/dm.c

+0 −10
Original line number Diff line number Diff line
@@ -27,16 +27,6 @@ 


#define DM_MSG_PREFIX "core"



#ifdef CONFIG_PRINTK

/*

 * ratelimit state to be used in DMXXX_LIMIT().

 */

DEFINE_RATELIMIT_STATE(dm_ratelimit_state,

		       DEFAULT_RATELIMIT_INTERVAL,

		       DEFAULT_RATELIMIT_BURST);

EXPORT_SYMBOL(dm_ratelimit_state);

#endif



/*

 * Cookies are numeric values sent with CHANGE and REMOVE

 * uevents while resuming, removing or renaming the device.

include/linux/device-mapper.h

+12 −29
Original line number Diff line number Diff line
@@ -549,46 +549,29 @@ void *dm_vcalloc(unsigned long nmemb, unsigned long elem_size); 
 *---------------------------------------------------------------*/

#define DM_NAME "device-mapper"



#ifdef CONFIG_PRINTK

extern struct ratelimit_state dm_ratelimit_state;



#define dm_ratelimit()	__ratelimit(&dm_ratelimit_state)

#else

#define dm_ratelimit()	0

#endif

#define DM_RATELIMIT(pr_func, fmt, ...)					\

do {									\

	static DEFINE_RATELIMIT_STATE(rs, DEFAULT_RATELIMIT_INTERVAL,	\

				      DEFAULT_RATELIMIT_BURST);		\

									\

	if (__ratelimit(&rs))						\

		pr_func(DM_FMT(fmt), ##__VA_ARGS__);			\

} while (0)



#define DM_FMT(fmt) DM_NAME ": " DM_MSG_PREFIX ": " fmt "\n"



#define DMCRIT(fmt, ...) pr_crit(DM_FMT(fmt), ##__VA_ARGS__)



#define DMERR(fmt, ...) pr_err(DM_FMT(fmt), ##__VA_ARGS__)

#define DMERR_LIMIT(fmt, ...)						\

do {									\

	if (dm_ratelimit())						\

		DMERR(fmt, ##__VA_ARGS__);				\

} while (0)



#define DMERR_LIMIT(fmt, ...) DM_RATELIMIT(pr_err, fmt, ##__VA_ARGS__)

#define DMWARN(fmt, ...) pr_warn(DM_FMT(fmt), ##__VA_ARGS__)

#define DMWARN_LIMIT(fmt, ...)						\

do {									\

	if (dm_ratelimit())						\

		DMWARN(fmt, ##__VA_ARGS__);				\

} while (0)



#define DMWARN_LIMIT(fmt, ...) DM_RATELIMIT(pr_warn, fmt, ##__VA_ARGS__)

#define DMINFO(fmt, ...) pr_info(DM_FMT(fmt), ##__VA_ARGS__)

#define DMINFO_LIMIT(fmt, ...)						\

do {									\

	if (dm_ratelimit())						\

		DMINFO(fmt, ##__VA_ARGS__);				\

} while (0)

#define DMINFO_LIMIT(fmt, ...) DM_RATELIMIT(pr_info, fmt, ##__VA_ARGS__)



#ifdef CONFIG_DM_DEBUG

#define DMDEBUG(fmt, ...) printk(KERN_DEBUG DM_FMT(fmt), ##__VA_ARGS__)

#define DMDEBUG_LIMIT(fmt, ...)						\

do {									\

	if (dm_ratelimit())						\

		DMDEBUG(fmt, ##__VA_ARGS__);				\

} while (0)

#define DMDEBUG_LIMIT(fmt, ...) DM_RATELIMIT(pr_debug, fmt, ##__VA_ARGS__)

#else

#define DMDEBUG(fmt, ...) no_printk(fmt, ##__VA_ARGS__)

#define DMDEBUG_LIMIT(fmt, ...) no_printk(fmt, ##__VA_ARGS__)

CRA Git | Maintained and supported by SUSTech CRA and CCSE