[SCSI] st: add st_scsi_kern_execute helper function (ffb43494) · Commits · 戴 / test

st_scsi_kern_execute is a helper function to perform SCSI commands synchronously. It supports data transfer with a liner in-kernel buffer (not scatter gather). st_scsi_kern_execute internally uses scsi_execute(). The majority of st_do_scsi can be replaced with st_scsi_kern_execute. This is a preparation for rewriting st_do_scsi to remove obsolete scsi_execute_async(). Signed-off-by:

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

James Bottomley <James.Bottomley@HansenPartnership.com>

drivers/scsi/st.c

+22 −0

Original line number	Diff line number	Diff line
		@@ -533,6 +533,28 @@ st_do_scsi(struct st_request * SRpnt, struct scsi_tape * STp, unsigned char *cmd
		return SRpnt;
		}

		static int st_scsi_kern_execute(struct st_request *streq,
		const unsigned char *cmd, int data_direction,
		void *buffer, unsigned bufflen, int timeout,
		int retries)
		{
		struct scsi_tape *stp = streq->stp;
		int ret, resid;

		stp->buffer->cmdstat.have_sense = 0;
		memcpy(streq->cmd, cmd, sizeof(streq->cmd));

		ret = scsi_execute(stp->device, cmd, data_direction, buffer, bufflen,
		streq->sense, timeout, retries, 0, &resid);
		if (driver_byte(ret) & DRIVER_ERROR)
		return -EBUSY;

		stp->buffer->cmdstat.midlevel_result = streq->result = ret;
		stp->buffer->cmdstat.residual = resid;
		stp->buffer->syscall_result = st_chk_result(stp, streq);

		return 0;
		}

		/* Handle the write-behind checking (waits for completion). Returns -ENOSPC if
		write has been correct but EOM early warning reached, -EIO if write ended in

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