[PATCH] scsi: core: Rate limit "rejecting I/O" messages

From: Daniel Wagner
Date: Wed Apr 08 2020 - 13:10:18 EST


Prevent excessive logging by rate limiting the "rejecting I/O"
messages. For example in setups where remote syslog is used the link
is saturated by those messages when a storage controller/disk
misbehaves.

Cc: "James E.J. Bottomley" <jejb@xxxxxxxxxxxxx>
Cc: "Martin K. Petersen" <martin.petersen@xxxxxxxxxx>
Signed-off-by: Daniel Wagner <dwagner@xxxxxxx>
---
drivers/scsi/scsi_lib.c | 4 ++--
include/scsi/scsi_device.h | 10 ++++++++++
2 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 47835c4b4ee0..01c35c58c6f3 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -1217,7 +1217,7 @@ scsi_prep_state_check(struct scsi_device *sdev, struct request *req)
*/
if (!sdev->offline_already) {
sdev->offline_already = true;
- sdev_printk(KERN_ERR, sdev,
+ sdev_printk_ratelimited(KERN_ERR, sdev,
"rejecting I/O to offline device\n");
}
return BLK_STS_IOERR;
@@ -1226,7 +1226,7 @@ scsi_prep_state_check(struct scsi_device *sdev, struct request *req)
* If the device is fully deleted, we refuse to
* process any commands as well.
*/
- sdev_printk(KERN_ERR, sdev,
+ sdev_printk_ratelimited(KERN_ERR, sdev,
"rejecting I/O to dead device\n");
return BLK_STS_IOERR;
case SDEV_BLOCK:
diff --git a/include/scsi/scsi_device.h b/include/scsi/scsi_device.h
index c3cba2aaf934..8be40b0e1b8f 100644
--- a/include/scsi/scsi_device.h
+++ b/include/scsi/scsi_device.h
@@ -257,6 +257,16 @@ sdev_prefix_printk(const char *, const struct scsi_device *, const char *,
#define sdev_printk(l, sdev, fmt, a...) \
sdev_prefix_printk(l, sdev, NULL, fmt, ##a)

+#define sdev_printk_ratelimited(l, sdev, fmt, a...) \
+({ \
+ static DEFINE_RATELIMIT_STATE(_rs, \
+ DEFAULT_RATELIMIT_INTERVAL, \
+ DEFAULT_RATELIMIT_BURST); \
+ \
+ if (__ratelimit(&_rs)) \
+ sdev_prefix_printk(l, sdev, NULL, fmt, ##a); \
+})
+
__printf(3, 4) void
scmd_printk(const char *, const struct scsi_cmnd *, const char *, ...);

--
2.16.4