On 2024/8/19 12:17, Damien Le Moal wrote:
On 8/19/24 13:07, Yihang Li wrote:
On 2024/8/19 7:55, Damien Le Moal wrote:
On 8/17/24 10:50, Yihang Li wrote:
If formatting a suspended disk (such as formatting with different DIF type), the disk will be resuming first, and then the format command will submit to the disk through SG_IO ioctl.
When the disk is processing the format command, the system does not submit other commands to the disk. Therefore, the system attempts to suspend the disk again and sends the SYNC CACHE command. However, the SYNC CACHE
Why would the system try to suspend the disk with a request in flight ? Sounds like there is a bug with PM reference counting, no ?
According to my understand and test, the format command request is finished, so it is not in flight for the kernel. And the command need a few time to processing in the disk while no other commands are being sent.
OK, fine. But I think that retrying SYNC CACHE if the drive is formatting makes absolutely no sense at all because there is nothing to flush in that case. So what about simply ignoring the error ? I.e. something like this:
diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c index 699f4f9674d9..1da267b8cd8a 100644 --- a/drivers/scsi/sd.c +++ b/drivers/scsi/sd.c @@ -1824,12 +1824,14 @@ static int sd_sync_cache(struct scsi_disk *sdkp) /* this is no error here */ return 0; /*
* This drive doesn't support sync and there's not much* we can do because this is called during shutdown* or suspend so just return success so those operations* can proceed.
* If a format is in progress (asc = LOGICAL UNIT NOT* READY, ascq = FORMAT IN PROGRESS) or if the drive* does not support sync, there is not much we can do* because this is called during shutdown or suspend. So* just return success so those operations can proceed. */
if (sshdr.sense_key == ILLEGAL_REQUEST)
if ((sshdr.asc == 0x04 && sshdr.ascq == 0x04) ||sshdr.sense_key == ILLEGAL_REQUEST) return 0; }
Thanks for your suggestion, it seems like good. I will send a new version based on this later.
Thanks,
Yihang.