[SCSI] st: add st_scsi_kern_execute helper function
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>
diff --git a/drivers/scsi/st.c b/drivers/scsi/st.c
index 203f22e..11341b7 100644
--- a/drivers/scsi/st.c
+++ b/drivers/scsi/st.c
@@ -533,6 +533,28 @@
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