From ab83108460a2a0d71c5bb22830036c4646e94e63 Mon Sep 17 00:00:00 2001 From: Douglas Gilbert Date: Sat, 23 Jun 2018 12:22:16 +0200 Subject: [PATCH] scsi: core: add scsi_io_completion_nz_result function 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 Reviewed-by: Johannes Thumshirn Reviewed-by: Bart Van Assche Reviewed-by: Hannes Reinecke Signed-off-by: Martin K. Petersen --- drivers/scsi/scsi_lib.c | 132 +++++++++++++++++++++++++++--------------------- 1 file changed, 75 insertions(+), 57 deletions(-) diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c index 1da1ff46c496..02892408962b 100644 --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -762,6 +762,79 @@ 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() * * Purpose: Completion processing for block device I/O requests. @@ -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 */ @@ -862,42 +916,6 @@ void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes) 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 * to retry code. Fast path should return in this block. -- 2.11.0