scsi: use REQ_TYPE_FS for flush request (e96f6abe) · Commits · 戴 / test

scsi-ml uses REQ_TYPE_BLOCK_PC for flush requests from file systems. The definition of REQ_TYPE_BLOCK_PC is that we don't retry requests even when we can (e.g. UNIT ATTENTION) and we send the response to the callers (then the callers can decide what they want). We need a workaround such as the commit to retry BLOCK_PC flush requests. We will need the similar workaround for discard requests too since SCSI-ml handle them as BLOCK_PC internally. This uses REQ_TYPE_FS for flush requests from file systems instead of REQ_TYPE_BLOCK_PC. scsi-ml retries only REQ_TYPE_FS requests that have data to transfer when we can retry them (e.g. UNIT_ATTENTION). However, we also need to retry REQ_TYPE_FS requests without data because the callers don't. This also changes scsi_check_sense() to retry all the REQ_TYPE_FS requests when appropriate. Thanks to scsi_noretry_cmd(), REQ_TYPE_BLOCK_PC requests don't be retried as before. Note that basically, this reverts the commit since now we use REQ_TYPE_FS for flush requests. Signed-off-by:

FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Signed-off-by:

Jens Axboe <jaxboe@fusionio.com>

drivers/scsi/scsi_error.c

+4 −15

Original line number	Diff line number	Diff line
		@@ -307,20 +307,7 @@ static int scsi_check_sense(struct scsi_cmnd *scmd)
		(sshdr.asc == 0x04) && (sshdr.ascq == 0x02))
		return FAILED;

		if (scmd->request->cmd_flags & REQ_HARDBARRIER)
		/*
		* barrier requests should always retry on UA
		* otherwise block will get a spurious error
		*/
		return NEEDS_RETRY;
		else
		/*
		* for normal (non barrier) commands, pass the
		* UA upwards for a determination in the
		* completion functions
		*/
		return SUCCESS;

		/* these three are not supported */
		case COPY_ABORTED:
		case VOLUME_OVERFLOW:
		@@ -1336,7 +1323,9 @@ int scsi_noretry_cmd(struct scsi_cmnd *scmd)
		* assume caller has checked sense and determinted
		* the check condition was retryable.
		*/
		return (scmd->request->cmd_flags & REQ_FAILFAST_DEV);
		if (scmd->request->cmd_flags & REQ_FAILFAST_DEV \|\|
		scmd->request->cmd_type == REQ_TYPE_BLOCK_PC)
		return 1;
		}

		return 0;

drivers/scsi/sd.c

+0 −2

Original line number	Diff line number	Diff line
		@@ -477,8 +477,6 @@ static int scsi_setup_discard_cmnd(struct scsi_device sdp, struct request rq)

		static int scsi_setup_flush_cmnd(struct scsi_device sdp, struct request rq)
		{
		/* for now, we use REQ_TYPE_BLOCK_PC. */
		rq->cmd_type = REQ_TYPE_BLOCK_PC;
		rq->timeout = SD_TIMEOUT;
		rq->retries = SD_MAX_RETRIES;
		rq->cmd[0] = SYNCHRONIZE_CACHE;

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