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scsi: core: add scsi_io_completion_nz_result function

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Break out several intertwined paths when cmd->result is non zero and place
them in the scsi_io_completion_nz_result helper function. The logic is not
changed.

Signed-off-by: Douglas Gilbert <dgilbert@interlog.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Bart Van Assche <bart.vanassche@wdc.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
This commit is contained in:
Douglas Gilbert 2018-06-23 12:22:16 +02:00 committed by Martin K. Petersen
parent 1f7cbb8e4b
commit ab83108460
1 changed files with 75 additions and 57 deletions
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132
drivers/scsi/scsi_lib.c
View File

@ -761,6 +761,79 @@ static blk_status_t scsi_result_to_blk_status(struct scsi_cmnd *cmd, int result)
}
}
/*
* Helper for scsi_io_completion() when cmd->result is non-zero. Returns a
* new result that may suppress further error checking. Also modifies
* *blk_statp in some cases.
*/
static int scsi_io_completion_nz_result(struct scsi_cmnd *cmd, int result,
blk_status_t *blk_statp)
{
bool sense_valid;
bool sense_current = true; /* false implies "deferred sense" */
struct request *req = cmd->request;
struct scsi_sense_hdr sshdr;
sense_valid = scsi_command_normalize_sense(cmd, &sshdr);
if (sense_valid)
sense_current = !scsi_sense_is_deferred(&sshdr);
if (blk_rq_is_passthrough(req)) {
if (sense_valid) {
/*
* SG_IO wants current and deferred errors
*/
scsi_req(req)->sense_len =
min(8 + cmd->sense_buffer[7],
SCSI_SENSE_BUFFERSIZE);
}
if (sense_current)
*blk_statp = scsi_result_to_blk_status(cmd, result);
} else if (blk_rq_bytes(req) == 0 && sense_current) {
/*
* Flush commands do not transfers any data, and thus cannot use
* good_bytes != blk_rq_bytes(req) as the signal for an error.
* This sets *blk_statp explicitly for the problem case.
*/
*blk_statp = scsi_result_to_blk_status(cmd, result);
}
/*
* Recovered errors need reporting, but they're always treated as
* success, so fiddle the result code here. For passthrough requests
* we already took a copy of the original into sreq->result which
* is what gets returned to the user
*/
if (sense_valid && (sshdr.sense_key == RECOVERED_ERROR)) {
bool do_print = true;
/*
* if ATA PASS-THROUGH INFORMATION AVAILABLE [0x0, 0x1d]
* skip print since caller wants ATA registers. Only occurs
* on SCSI ATA PASS_THROUGH commands when CK_COND=1
*/
if ((sshdr.asc == 0x0) && (sshdr.ascq == 0x1d))
do_print = false;
else if (req->rq_flags & RQF_QUIET)
do_print = false;
if (do_print)
scsi_print_sense(cmd);
result = 0;
/* for passthrough, *blk_statp may be set */
*blk_statp = BLK_STS_OK;
}
/*
* Another corner case: the SCSI status byte is non-zero but 'good'.
* Example: PRE-FETCH command returns SAM_STAT_CONDITION_MET when
* it is able to fit nominated LBs in its cache (and SAM_STAT_GOOD
* if it can't fit). Treat SAM_STAT_CONDITION_MET and the related
* intermediate statuses (both obsolete in SAM-4) as good.
*/
if (status_byte(result) && scsi_status_is_good(result)) {
result = 0;
*blk_statp = BLK_STS_OK;
}
return result;
}
/*
* Function: scsi_io_completion()
*
@ -804,26 +877,14 @@ void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes)
ACTION_DELAYED_RETRY} action;
unsigned long wait_for = (cmd->allowed + 1) * req->timeout;
if (result) {
if (result) { /* does not necessarily mean there is an error */
sense_valid = scsi_command_normalize_sense(cmd, &sshdr);
if (sense_valid)
sense_current = !scsi_sense_is_deferred(&sshdr);
result = scsi_io_completion_nz_result(cmd, result, &blk_stat);
}
if (blk_rq_is_passthrough(req)) {
if (result) {
if (sense_valid) {
/*
* SG_IO wants current and deferred errors
*/
scsi_req(req)->sense_len =
min(8 + cmd->sense_buffer[7],
SCSI_SENSE_BUFFERSIZE);
}
if (sense_current)
blk_stat = scsi_result_to_blk_status(cmd,
result);
}
/*
* scsi_result_to_blk_status may have reset the host_byte
*/
@ -841,13 +902,6 @@ void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes)
BUG();
return;
}
} else if (blk_rq_bytes(req) == 0 && result && sense_current) {
/*
* Flush commands do not transfers any data, and thus cannot use
* good_bytes != blk_rq_bytes(req) as the signal for an error.
* This sets blk_stat explicitly for the problem case.
*/
blk_stat = scsi_result_to_blk_status(cmd, result);
}
/* no bidi support for !blk_rq_is_passthrough yet */
@ -861,42 +915,6 @@ void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes)
"%u sectors total, %d bytes done.\n",
blk_rq_sectors(req), good_bytes));
/*
* Recovered errors need reporting, but they're always treated as
* success, so fiddle the result code here. For passthrough requests
* we already took a copy of the original into sreq->result which
* is what gets returned to the user
*/
if (sense_valid && (sshdr.sense_key == RECOVERED_ERROR)) {
bool do_print = true;
/*
* If ATA PASS-THROUGH INFORMATION AVAILABLE skip
* print since caller wants ATA registers. Only occurs on
* SCSI ATA PASS_THROUGH commands when CK_COND=1
*/
if ((sshdr.asc == 0x0) && (sshdr.ascq == 0x1d))
do_print = false;
else if (req->rq_flags & RQF_QUIET)
do_print = false;
if (do_print)
scsi_print_sense(cmd);
result = 0;
/* for passthrough, blk_stat may be set */
blk_stat = BLK_STS_OK;
}
/*
* Another corner case: the SCSI status byte is non-zero but 'good'.
* Example: PRE-FETCH command returns SAM_STAT_CONDITION_MET when
* it is able to fit nominated LBs in its cache (and SAM_STAT_GOOD
* if it can't fit). Treat SAM_STAT_CONDITION_MET and the related
* intermediate statuses (both obsolete in SAM-4) as good.
*/
if (status_byte(result) && scsi_status_is_good(result)) {
result = 0;
blk_stat = BLK_STS_OK;
}
/*
* Next deal with any sectors which we were able to correctly
* handle. Failed, zero length commands always need to drop down