Break out several interwined paths when cmd->result is non zero and place them in scsi_io_completion_nz_result helper function. The logic is not changed.
Signed-off-by: Douglas Gilbert <[email protected]> --- A reviewer requested the original helper function's two return values be reduced to one: the blk_stat variable. This required a hack to differentiate the default setting of blk_stat (BLK_STS_OK) from the case when the helper assigns BLK_STS_OK as the return value. The hack is to return the otherwise unused BLK_STS_NOTSUPP value as an indication that the helper didn't change anything. drivers/scsi/scsi_lib.c | 134 +++++++++++++++++++++++++++++------------------- 1 file changed, 82 insertions(+), 52 deletions(-) diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c index a4da5773d42d..9731d0d3cc80 100644 --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -751,6 +751,77 @@ static blk_status_t __scsi_error_from_host_byte(struct scsi_cmnd *cmd, } } +/* + * Helper for scsi_io_completion() when cmd->result is non-zero. Returns + * BLK_STS_NOTSUPP if this function does not change blk_status . + */ +static blk_status_t scsi_io_completion_nz_result(struct scsi_cmnd *cmd, + int result) +{ + bool sense_valid; + bool about_current; + /* __scsi_error_from_host_byte() does not return BLK_STS_NOTSUPP */ + blk_status_t blk_stat = BLK_STS_NOTSUPP; + struct request *req = cmd->request; + struct scsi_sense_hdr sshdr; + + sense_valid = scsi_command_normalize_sense(cmd, &sshdr); + about_current = sense_valid ? !scsi_sense_is_deferred(&sshdr) : true; + + 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 (about_current) + blk_stat = __scsi_error_from_host_byte(cmd, result); + } else if (blk_rq_bytes(req) == 0 && about_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_error_from_host_byte(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); + /* 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)) + blk_stat = BLK_STS_OK; + + return blk_stat; +} + /* * Function: scsi_io_completion() * @@ -794,26 +865,23 @@ 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); + blk_stat = scsi_io_completion_nz_result(cmd, result); + if (blk_stat == BLK_STS_OK) + result = 0; /* suppress error processing now */ + /* + * if scsi_io_completion_nz_result() made no change, + * re-instate initial blk_stat value. + */ + if (blk_stat == BLK_STS_NOTSUPP) + blk_stat = BLK_STS_OK; + } 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_error_from_host_byte(cmd, - result); - } /* * __scsi_error_from_host_byte may have reset the host_byte */ @@ -831,13 +899,6 @@ 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_error_from_host_byte(cmd, result); } /* no bidi support for !blk_rq_is_passthrough yet */ @@ -851,37 +912,6 @@ 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)) { - /* 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)) - ; - else if (!(req->rq_flags & RQF_QUIET)) - 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 -- 2.14.1
