Current ata_gen_passthru_sense() code performs two actions: 1. Generates sense data based on the ATA 'status' and ATA 'error' fields. 2. Populates "ATA Status Return sense data descriptor" / "Fixed format sense data" with ATA taskfile fields.

The problem is that #1 generates sense data even when a valid sense data is already present (ATA_QCFLAG_SENSE_VALID is set). Factoring out #2 into a separate function allows us to generate sense data only when there is no valid sense data (ATA_QCFLAG_SENSE_VALID is not set).

As a bonus, we can now delete a FIXME comment in atapi_qc_complete() which states that we don't want to translate taskfile registers into sense descriptors for ATAPI.

Additionally, always set SAM_STAT_CHECK_CONDITION when CK_COND=1 because SAT specification mandates that SATL shall return CHECK CONDITION if the CK_COND bit is set.

The ATA PASS-THROUGH handling logic in ata_scsi_qc_complete() is hard to read/understand. Improve the readability of the code by moving checks into self-explanatory boolean variables.

Cc: stable@vger.kernel.org # 4.19+ Co-developed-by: Niklas Cassel cassel@kernel.org Signed-off-by: Niklas Cassel cassel@kernel.org Reviewed-by: Hannes Reinecke hare@suse.de Reviewed-by: Damien Le Moal dlemoal@kernel.org Reviewed-by: Niklas Cassel cassel@kernel.org Signed-off-by: Igor Pylypiv ipylypiv@google.com --- drivers/ata/libata-scsi.c | 169 +++++++++++++++++++++----------------- 1 file changed, 92 insertions(+), 77 deletions(-)

diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c index a9e44ad4c2de..b59cbb5ce5a6 100644 --- a/drivers/ata/libata-scsi.c +++ b/drivers/ata/libata-scsi.c @@ -230,6 +230,80 @@ void ata_scsi_set_sense_information(struct ata_device *dev, SCSI_SENSE_BUFFERSIZE, information); }

+/** + * ata_scsi_set_passthru_sense_fields - Set ATA fields in sense buffer + * @qc: ATA PASS-THROUGH command. + * + * Populates "ATA Status Return sense data descriptor" / "Fixed format + * sense data" with ATA taskfile fields. + * + * LOCKING: + * None. + */ +static void ata_scsi_set_passthru_sense_fields(struct ata_queued_cmd *qc) +{ + struct scsi_cmnd *cmd = qc->scsicmd; + struct ata_taskfile *tf = &qc->result_tf; + unsigned char *sb = cmd->sense_buffer; + + if ((sb[0] & 0x7f) >= 0x72) { + unsigned char *desc; + u8 len; + + /* descriptor format */ + len = sb[7]; + desc = (char *)scsi_sense_desc_find(sb, len + 8, 9); + if (!desc) { + if (SCSI_SENSE_BUFFERSIZE < len + 14) + return; + sb[7] = len + 14; + desc = sb + 8 + len; + } + desc[0] = 9; + desc[1] = 12; + /* + * Copy registers into sense buffer. + */ + desc[2] = 0x00; + desc[3] = tf->error; + desc[5] = tf->nsect; + desc[7] = tf->lbal; + desc[9] = tf->lbam; + desc[11] = tf->lbah; + desc[12] = tf->device; + desc[13] = tf->status; + + /* + * Fill in Extend bit, and the high order bytes + * if applicable. + */ + if (tf->flags & ATA_TFLAG_LBA48) { + desc[2] |= 0x01; + desc[4] = tf->hob_nsect; + desc[6] = tf->hob_lbal; + desc[8] = tf->hob_lbam; + desc[10] = tf->hob_lbah; + } + } else { + /* Fixed sense format */ + sb[0] |= 0x80; + sb[3] = tf->error; + sb[4] = tf->status; + sb[5] = tf->device; + sb[6] = tf->nsect; + if (tf->flags & ATA_TFLAG_LBA48) { + sb[8] |= 0x80; + if (tf->hob_nsect) + sb[8] |= 0x40; + if (tf->hob_lbal || tf->hob_lbam || tf->hob_lbah) + sb[8] |= 0x20; + } + sb[9] = tf->lbal; + sb[10] = tf->lbam; + sb[11] = tf->lbah; + } +} + static void ata_scsi_set_invalid_field(struct ata_device *dev, struct scsi_cmnd *cmd, u16 field, u8 bit) { @@ -837,10 +911,8 @@ static void ata_to_sense_error(unsigned id, u8 drv_stat, u8 drv_err, u8 *sk, * ata_gen_passthru_sense - Generate check condition sense block. * @qc: Command that completed. * - * This function is specific to the ATA descriptor format sense - * block specified for the ATA pass through commands. Regardless - * of whether the command errored or not, return a sense - * block. Copy all controller registers into the sense + * This function is specific to the ATA pass through commands. + * Regardless of whether the command errored or not, return a sense * block. If there was no error, we get the request from an ATA * passthrough command, so we use the following sense data: * sk = RECOVERED ERROR @@ -875,63 +947,6 @@ static void ata_gen_passthru_sense(struct ata_queued_cmd *qc) */ scsi_build_sense(cmd, 1, RECOVERED_ERROR, 0, 0x1D); } - - if ((sb[0] & 0x7f) >= 0x72) { - unsigned char *desc; - u8 len; - - /* descriptor format */ - len = sb[7]; - desc = (char *)scsi_sense_desc_find(sb, len + 8, 9); - if (!desc) { - if (SCSI_SENSE_BUFFERSIZE < len + 14) - return; - sb[7] = len + 14; - desc = sb + 8 + len; - } - desc[0] = 9; - desc[1] = 12; - /* - * Copy registers into sense buffer. - */ - desc[2] = 0x00; - desc[3] = tf->error; - desc[5] = tf->nsect; - desc[7] = tf->lbal; - desc[9] = tf->lbam; - desc[11] = tf->lbah; - desc[12] = tf->device; - desc[13] = tf->status; - - /* - * Fill in Extend bit, and the high order bytes - * if applicable. - */ - if (tf->flags & ATA_TFLAG_LBA48) { - desc[2] |= 0x01; - desc[4] = tf->hob_nsect; - desc[6] = tf->hob_lbal; - desc[8] = tf->hob_lbam; - desc[10] = tf->hob_lbah; - } - } else { - /* Fixed sense format */ - sb[0] |= 0x80; - sb[3] = tf->error; - sb[4] = tf->status; - sb[5] = tf->device; - sb[6] = tf->nsect; - if (tf->flags & ATA_TFLAG_LBA48) { - sb[8] |= 0x80; - if (tf->hob_nsect) - sb[8] |= 0x40; - if (tf->hob_lbal || tf->hob_lbam || tf->hob_lbah) - sb[8] |= 0x20; - } - sb[9] = tf->lbal; - sb[10] = tf->lbam; - sb[11] = tf->lbah; - } }

/** @@ -1632,26 +1647,32 @@ static void ata_scsi_qc_complete(struct ata_queued_cmd *qc) { struct scsi_cmnd *cmd = qc->scsicmd; u8 *cdb = cmd->cmnd; - int need_sense = (qc->err_mask != 0) && - !(qc->flags & ATA_QCFLAG_SENSE_VALID); + bool have_sense = qc->flags & ATA_QCFLAG_SENSE_VALID; + bool is_ata_passthru = cdb[0] == ATA_16 || cdb[0] == ATA_12; + bool is_ck_cond_request = cdb[2] & 0x20; + bool is_error = qc->err_mask != 0;

/* For ATA pass thru (SAT) commands, generate a sense block if * user mandated it or if there's an error. Note that if we - * generate because the user forced us to [CK_COND =1], a check + * generate because the user forced us to [CK_COND=1], a check * condition is generated and the ATA register values are returned * whether the command completed successfully or not. If there - * was no error, we use the following sense data: + * was no error, and CK_COND=1, we use the following sense data: * sk = RECOVERED ERROR * asc,ascq = ATA PASS-THROUGH INFORMATION AVAILABLE */ - if (((cdb[0] == ATA_16) || (cdb[0] == ATA_12)) && - ((cdb[2] & 0x20) || need_sense)) - ata_gen_passthru_sense(qc); - else if (need_sense) + if (is_ata_passthru && (is_ck_cond_request || is_error || have_sense)) { + if (!have_sense) + ata_gen_passthru_sense(qc); + ata_scsi_set_passthru_sense_fields(qc); + if (is_ck_cond_request) + set_status_byte(qc->scsicmd, SAM_STAT_CHECK_CONDITION); + } else if (is_error && !have_sense) { ata_gen_ata_sense(qc); - else + } else { /* Keep the SCSI ML and status byte, clear host byte. */ cmd->result &= 0x0000ffff; + }

ata_qc_done(qc); } @@ -2590,14 +2611,8 @@ static void atapi_qc_complete(struct ata_queued_cmd *qc) /* handle completion from EH */ if (unlikely(err_mask || qc->flags & ATA_QCFLAG_SENSE_VALID)) {

- if (!(qc->flags & ATA_QCFLAG_SENSE_VALID)) { - /* FIXME: not quite right; we don't want the - * translation of taskfile registers into a - * sense descriptors, since that's only - * correct for ATA, not ATAPI - */ + if (!(qc->flags & ATA_QCFLAG_SENSE_VALID)) ata_gen_passthru_sense(qc); - }

/* SCSI EH automatically locks door if sdev->locked is * set. Sometimes door lock request continues to