Commit d2138eab authored by Easwar Hariharan's avatar Easwar Hariharan Committed by Martin K. Petersen
Browse files

scsi: storvsc: Ratelimit warning logs to prevent VM denial of service 

If there's a persistent error in the hypervisor, the SCSI warning for
failed I/O can flood the kernel log and max out CPU utilization,
preventing troubleshooting from the VM side. Ratelimit the warning so
it doesn't DoS the VM.

Closes: https://github.com/microsoft/WSL/issues/9173


Signed-off-by: default avatarEaswar Hariharan <eahariha@linux.microsoft.com>
Link: https://lore.kernel.org/r/20250107-eahariha-ratelimit-storvsc-v1-1-7fc193d1f2b0@linux.microsoft.com


Reviewed-by: default avatarMichael Kelley <mhklinux@outlook.com>
Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
parent 37d061e1

drivers/scsi/storvsc_drv.c

+7 −1
Original line number Diff line number Diff line
@@ -171,6 +171,12 @@ do { \ 
		dev_warn(&(dev)->device, fmt, ##__VA_ARGS__);	\

} while (0)



#define storvsc_log_ratelimited(dev, level, fmt, ...)				\

do {										\

	if (do_logging(level))							\

		dev_warn_ratelimited(&(dev)->device, fmt, ##__VA_ARGS__);	\

} while (0)



struct vmscsi_request {

	u16 length;

	u8 srb_status;
@@ -1176,7 +1182,7 @@ static void storvsc_on_io_completion(struct storvsc_device *stor_device, 
		int loglevel = (stor_pkt->vm_srb.cdb[0] == TEST_UNIT_READY) ?

			STORVSC_LOGGING_WARN : STORVSC_LOGGING_ERROR;



		storvsc_log(device, loglevel,

		storvsc_log_ratelimited(device, loglevel,

			"tag#%d cmd 0x%x status: scsi 0x%x srb 0x%x hv 0x%x\n",

			scsi_cmd_to_rq(request->cmd)->tag,

			stor_pkt->vm_srb.cdb[0],