}
EXPORT_SYMBOL(scsi_execute);
-
-int scsi_execute_req(struct scsi_device *sdev, const unsigned char *cmd,
+int scsi_execute_req_flags(struct scsi_device *sdev, const unsigned char *cmd,
int data_direction, void *buffer, unsigned bufflen,
struct scsi_sense_hdr *sshdr, int timeout, int retries,
- int *resid)
+ int *resid, int flags)
{
char *sense = NULL;
int result;
return DRIVER_ERROR << 24;
}
result = scsi_execute(sdev, cmd, data_direction, buffer, bufflen,
- sense, timeout, retries, 0, resid);
+ sense, timeout, retries, flags, resid);
if (sshdr)
scsi_normalize_sense(sense, SCSI_SENSE_BUFFERSIZE, sshdr);
kfree(sense);
return result;
}
-EXPORT_SYMBOL(scsi_execute_req);
+EXPORT_SYMBOL(scsi_execute_req_flags);
/*
* Function: scsi_init_cmd_errh()
static void __scsi_release_buffers(struct scsi_cmnd *, int);
-/*
- * Function: scsi_end_request()
- *
- * Purpose: Post-processing of completed commands (usually invoked at end
- * of upper level post-processing and scsi_io_completion).
- *
- * Arguments: cmd - command that is complete.
- * error - 0 if I/O indicates success, < 0 for I/O error.
- * bytes - number of bytes of completed I/O
- * requeue - indicates whether we should requeue leftovers.
- *
- * Lock status: Assumed that lock is not held upon entry.
- *
- * Returns: cmd if requeue required, NULL otherwise.
- *
- * Notes: This is called for block device requests in order to
- * mark some number of sectors as complete.
- *
- * We are guaranteeing that the request queue will be goosed
- * at some point during this call.
- * Notes: If cmd was requeued, upon return it will be a stale pointer.
- */
-static struct scsi_cmnd *scsi_end_request(struct scsi_cmnd *cmd, int error,
- int bytes, int requeue)
-{
- struct request_queue *q = cmd->device->request_queue;
- struct request *req = cmd->request;
-
- /*
- * If there are blocks left over at the end, set up the command
- * to queue the remainder of them.
- */
- if (blk_end_request(req, error, bytes)) {
- /* kill remainder if no retrys */
- if (error && scsi_noretry_cmd(cmd))
- blk_end_request_all(req, error);
- else {
- if (requeue) {
- /*
- * Bleah. Leftovers again. Stick the
- * leftovers in the front of the
- * queue, and goose the queue again.
- */
- scsi_release_buffers(cmd);
- scsi_requeue_command(q, cmd);
- cmd = NULL;
- }
- return cmd;
- }
- }
-
- /*
- * This will goose the queue request function at the end, so we don't
- * need to worry about launching another command.
- */
- __scsi_release_buffers(cmd, 0);
- scsi_next_command(cmd);
- return NULL;
-}
-
static inline unsigned int scsi_sgtable_index(unsigned short nents)
{
unsigned int index;
*
* Returns: Nothing
*
- * Notes: This function is matched in terms of capabilities to
- * the function that created the scatter-gather list.
- * In other words, if there are no bounce buffers
- * (the normal case for most drivers), we don't need
- * the logic to deal with cleaning up afterwards.
- *
- * We must call scsi_end_request(). This will finish off
- * the specified number of sectors. If we are done, the
- * command block will be released and the queue function
- * will be goosed. If we are not done then we have to
+ * Notes: We will finish off the specified number of sectors. If we
+ * are done, the command block will be released and the queue
+ * function will be goosed. If we are not done then we have to
* figure out what to do next:
*
* a) We can call scsi_requeue_command(). The request
* be used if we made forward progress, or if we want
* to switch from READ(10) to READ(6) for example.
*
- * b) We can call scsi_queue_insert(). The request will
+ * b) We can call __scsi_queue_insert(). The request will
* be put back on the queue and retried using the same
* command as before, possibly after a delay.
*
scsi_next_command(cmd);
return;
}
+ } else if (blk_rq_bytes(req) == 0 && result && !sense_deferred) {
+ /*
+ * Certain non BLOCK_PC requests are commands that don't
+ * actually transfer anything (FLUSH), so cannot use
+ * good_bytes != blk_rq_bytes(req) as the signal for an error.
+ * This sets the error explicitly for the problem case.
+ */
+ error = __scsi_error_from_host_byte(cmd, result);
}
/* no bidi support for !REQ_TYPE_BLOCK_PC yet */
}
/*
- * A number of bytes were successfully read. If there
- * are leftovers and there is some kind of error
- * (result != 0), retry the rest.
+ * special case: failed zero length commands always need to
+ * drop down into the retry code. Otherwise, if we finished
+ * all bytes in the request we are done now.
*/
- if (scsi_end_request(cmd, error, good_bytes, result == 0) == NULL)
- return;
+ if (!(blk_rq_bytes(req) == 0 && error) &&
+ !blk_end_request(req, error, good_bytes))
+ goto next_command;
+
+ /*
+ * Kill remainder if no retrys.
+ */
+ if (error && scsi_noretry_cmd(cmd)) {
+ blk_end_request_all(req, error);
+ goto next_command;
+ }
+
+ /*
+ * If there had been no error, but we have leftover bytes in the
+ * requeues just queue the command up again.
+ */
+ if (result == 0)
+ goto requeue;
error = __scsi_error_from_host_byte(cmd, result);
switch (action) {
case ACTION_FAIL:
/* Give up and fail the remainder of the request */
- scsi_release_buffers(cmd);
if (!(req->cmd_flags & REQ_QUIET)) {
if (description)
scmd_printk(KERN_INFO, cmd, "%s\n",
scsi_print_sense("", cmd);
scsi_print_command(cmd);
}
- if (blk_end_request_err(req, error))
- scsi_requeue_command(q, cmd);
- else
- scsi_next_command(cmd);
- break;
+ if (!blk_end_request_err(req, error))
+ goto next_command;
+ /*FALLTHRU*/
case ACTION_REPREP:
+ requeue:
/* Unprep the request and put it back at the head of the queue.
* A new command will be prepared and issued.
*/
__scsi_queue_insert(cmd, SCSI_MLQUEUE_DEVICE_BUSY, 0);
break;
}
+ return;
+
+next_command:
+ __scsi_release_buffers(cmd, 0);
+ scsi_next_command(cmd);
}
static int scsi_init_sgtable(struct request *req, struct scsi_data_buffer *sdb,
int scsi_init_io(struct scsi_cmnd *cmd, gfp_t gfp_mask)
{
struct request *rq = cmd->request;
+ int error;
- int error = scsi_init_sgtable(rq, &cmd->sdb, gfp_mask);
+ if (WARN_ON_ONCE(!rq->nr_phys_segments))
+ return -EINVAL;
+
+ error = scsi_init_sgtable(rq, &cmd->sdb, gfp_mask);
if (error)
goto err_exit;
* submit a request without an attached bio.
*/
if (req->bio) {
- int ret;
-
- BUG_ON(!req->nr_phys_segments);
-
- ret = scsi_init_io(cmd, GFP_ATOMIC);
+ int ret = scsi_init_io(cmd, GFP_ATOMIC);
if (unlikely(ret))
return ret;
} else {
return ret;
}
- /*
- * Filesystem requests must transfer data.
- */
- BUG_ON(!req->nr_phys_segments);
-
cmd = scsi_get_cmd_from_req(sdev, req);
if (unlikely(!cmd))
return BLKPREP_DEFER;
"rejecting I/O to dead device\n");
ret = BLKPREP_KILL;
break;
- case SDEV_QUIESCE:
case SDEV_BLOCK:
case SDEV_CREATED_BLOCK:
+ ret = BLKPREP_DEFER;
+ break;
+ case SDEV_QUIESCE:
/*
* If the devices is blocked we defer normal commands.
*/