Re: [PATCH v2 4/7] scsi: scsi_debug: Add read support and update locate for tapes

John Meneghini
2025-02-19T21:56:25Z

Reviewed-by: John Meneghini <jmeneghi@redhat.com>
Tested-by: John Meneghini <jmeneghi@redhat.com>

After this patch it looks like fsr and bsr are working well.

Before this patch... forget it. Don't even try if you are using the scsi_debug driver.

[root@to-be-determined ~]# mt -f /dev/nst1 rewind
[Wed Feb 19 16:46:03 2025] st 8:0:0:0: [st1] check_tape: 1087: pos_unknown 0 was_reset 0/0 ready 0
[Wed Feb 19 16:46:03 2025] st 8:0:0:0: [st1] Block limits 512 - 1048576 bytes.
[Wed Feb 19 16:46:03 2025] st 8:0:0:0: [st1] Mode sense. Length 11, medium 0, WBS 0, BLL 8
[Wed Feb 19 16:46:03 2025] st 8:0:0:0: [st1] Density 0, tape length: 388000, drv buffer: 0
[Wed Feb 19 16:46:03 2025] st 8:0:0:0: [st1] Block size: 0, buffer size: 4096 (1 blocks).
[Wed Feb 19 16:46:03 2025] st 8:0:0:0: [st1] check_tape: 1287: CHKRES_READY pos_unknown 0 was_reset 0/0 ready 0
[Wed Feb 19 16:46:03 2025] st 8:0:0:0: [st1] flush_buffer: 852: pos_unknown 0 was_reset 0/0 ready 0
[Wed Feb 19 16:46:03 2025] st 8:0:0:0: [st1] Rewinding tape.
[Wed Feb 19 16:46:03 2025] st 8:0:0:0: [st1] st_flush: 1409: pos_unknown 0 was_reset 0/0 ready 0
[Wed Feb 19 16:46:03 2025] st 8:0:0:0: [st1] flush_buffer: 852: pos_unknown 0 was_reset 0/0 ready 0
[root@to-be-determined ~]# mt -f /dev/nst1 fsr 2
[Wed Feb 19 16:46:41 2025] st 8:0:0:0: [st1] check_tape: 1087: pos_unknown 0 was_reset 0/0 ready 0
[Wed Feb 19 16:46:41 2025] st 8:0:0:0: [st1] Block limits 512 - 1048576 bytes.
[Wed Feb 19 16:46:41 2025] st 8:0:0:0: [st1] Mode sense. Length 11, medium 0, WBS 0, BLL 8
[Wed Feb 19 16:46:41 2025] st 8:0:0:0: [st1] Density 0, tape length: 388000, drv buffer: 0
[Wed Feb 19 16:46:41 2025] st 8:0:0:0: [st1] Block size: 0, buffer size: 4096 (1 blocks).
[Wed Feb 19 16:46:41 2025] st 8:0:0:0: [st1] check_tape: 1287: CHKRES_READY pos_unknown 0 was_reset 0/0 ready 0
[Wed Feb 19 16:46:41 2025] st 8:0:0:0: [st1] flush_buffer: 852: pos_unknown 0 was_reset 0/0 ready 0
[Wed Feb 19 16:46:41 2025] st 8:0:0:0: [st1] Spacing tape forward over 2 blocks.
[Wed Feb 19 16:46:41 2025] st 8:0:0:0: [st1] st_flush: 1409: pos_unknown 0 was_reset 0/0 ready 0
[Wed Feb 19 16:46:41 2025] st 8:0:0:0: [st1] flush_buffer: 852: pos_unknown 0 was_reset 0/0 ready 0
[root@to-be-determined ~]# mt -f /dev/nst1 status
[Wed Feb 19 16:46:54 2025] st 8:0:0:0: [st1] check_tape: 1087: pos_unknown 0 was_reset 0/0 ready 0
[Wed Feb 19 16:46:54 2025] st 8:0:0:0: [st1] Block limits 512 - 1048576 bytes.
SCSI 2 tape drive:
File number=0, block number=2, partition=0.
Tape block size 0 bytes. Density code 0x0 (default).
Soft error count since last status=0
General status bits on (1010000):
ONLINE IM_REP_EN
[Wed Feb 19 16:46:54 2025] st 8:0:0:0: [st1] Mode sense. Length 11, medium 0, WBS 0, BLL 8
[Wed Feb 19 16:46:54 2025] st 8:0:0:0: [st1] Density 0, tape length: 388000, drv buffer: 0
[Wed Feb 19 16:46:54 2025] st 8:0:0:0: [st1] Block size: 0, buffer size: 4096 (1 blocks).
[Wed Feb 19 16:46:54 2025] st 8:0:0:0: [st1] check_tape: 1287: CHKRES_READY pos_unknown 0 was_reset 0/0 ready 0
[Wed Feb 19 16:46:54 2025] st 8:0:0:0: [st1] flush_buffer: 852: pos_unknown 0 was_reset 0/0 ready 0
[Wed Feb 19 16:46:54 2025] st 8:0:0:0: [st1] st_flush: 1409: pos_unknown 0 was_reset 0/0 ready 0
[Wed Feb 19 16:46:54 2025] st 8:0:0:0: [st1] flush_buffer: 852: pos_unknown 0 was_reset 0/0 ready 0

[root@to-be-determined ~]# mt -f /dev/nst1 bsr 2
[Wed Feb 19 16:47:35 2025] st 8:0:0:0: [st1] check_tape: 1087: pos_unknown 0 was_reset 0/0 ready 0
[Wed Feb 19 16:47:35 2025] st 8:0:0:0: [st1] Block limits 512 - 1048576 bytes.
[Wed Feb 19 16:47:35 2025] st 8:0:0:0: [st1] Mode sense. Length 11, medium 0, WBS 0, BLL 8
[Wed Feb 19 16:47:35 2025] st 8:0:0:0: [st1] Density 0, tape length: 388000, drv buffer: 0
[Wed Feb 19 16:47:35 2025] st 8:0:0:0: [st1] Block size: 0, buffer size: 4096 (1 blocks).
[Wed Feb 19 16:47:35 2025] st 8:0:0:0: [st1] check_tape: 1287: CHKRES_READY pos_unknown 0 was_reset 0/0 ready 0
[Wed Feb 19 16:47:35 2025] st 8:0:0:0: [st1] flush_buffer: 852: pos_unknown 0 was_reset 0/0 ready 0
[Wed Feb 19 16:47:35 2025] st 8:0:0:0: [st1] Spacing tape backward over 2 blocks.
[Wed Feb 19 16:47:35 2025] st 8:0:0:0: [st1] st_flush: 1409: pos_unknown 0 was_reset 0/0 ready 0
[Wed Feb 19 16:47:35 2025] st 8:0:0:0: [st1] flush_buffer: 852: pos_unknown 0 was_reset 0/0 ready 0

[root@to-be-determined ~]# mt -f /dev/nst1 status
[Wed Feb 19 16:47:40 2025] st 8:0:0:0: [st1] check_tape: 1087: pos_unknown 0 was_reset 0/0 ready 0
[Wed Feb 19 16:47:40 2025] st 8:0:0:0: [st1] Block limits 512 - 1048576 bytes.
[Wed Feb 19 16:47:40 2025] st 8:0:0:0: [st1] Mode sense. Length 11, medium 0, WBS 0, BLL 8
[Wed Feb 19 16:47:40 2025] st 8:0:0:0: [st1] Density 0, tape length: 388000, drv buffer: 0
[Wed Feb 19 16:47:40 2025] st 8:0:0:0: [st1] Block size: 0, buffer size: 4096 (1 blocks).
[Wed Feb 19 16:47:40 2025] st 8:0:0:0: [st1] check_tape: 1287: CHKRES_READY pos_unknown 0 was_reset 0/0 ready 0
[Wed Feb 19 16:47:40 2025] st 8:0:0:0: [st1] flush_buffer: 852: pos_unknown 0 was_reset 0/0 ready 0
SCSI 2 tape drive:
File number=0, block number=0, partition=0.
Tape block size 0 bytes. Density code 0x0 (default).
Soft error count since last status=0
General status bits on (41010000):
BOT ONLINE IM_REP_EN
[Wed Feb 19 16:47:40 2025] st 8:0:0:0: [st1] st_flush: 1409: pos_unknown 0 was_reset 0/0 ready 0
[Wed Feb 19 16:47:40 2025] st 8:0:0:0: [st1] flush_buffer: 852: pos_unknown 0 was_reset 0/0 ready 0

On 2/13/25 4:26 AM, Kai Mäkisara wrote:
> Support for the READ (6) and SPACE (6) commands for tapes based on the
> previous write patch is added. The LOCATE (10) command is updated to use
> the written data.
>
> Signed-off-by: Kai Mäkisara <Kai.Makisara@kolumbus.fi>
> ---
> v1 -> v2:
> - initialized i to zero in resp_space() to fix the bug reported by
> the Kernel Test Robot
>
> drivers/scsi/scsi_debug.c | 240 +++++++++++++++++++++++++++++++++++++-
> 1 file changed, 235 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/scsi/scsi_debug.c b/drivers/scsi/scsi_debug.c
> index 69cae4c1712a..29a9aea30d22 100644
> --- a/drivers/scsi/scsi_debug.c
> +++ b/drivers/scsi/scsi_debug.c
> @@ -532,7 +532,8 @@ enum sdeb_opcode_index {
> SDEB_I_READ_BLOCK_LIMITS = 33,
> SDEB_I_LOCATE = 34,
> SDEB_I_WRITE_FILEMARKS = 35,
> - SDEB_I_LAST_ELEM_P1 = 36, /* keep this last (previous + 1) */
> + SDEB_I_SPACE = 36,
> + SDEB_I_LAST_ELEM_P1 = 37, /* keep this last (previous + 1) */
> };
>
>
> @@ -541,7 +542,7 @@ static const unsigned char opcode_ind_arr[256] = {
> SDEB_I_TEST_UNIT_READY, SDEB_I_REZERO_UNIT, 0, SDEB_I_REQUEST_SENSE,
> 0, SDEB_I_READ_BLOCK_LIMITS, 0, 0,
> SDEB_I_READ, 0, SDEB_I_WRITE, 0, 0, 0, 0, 0,
> - SDEB_I_WRITE_FILEMARKS, 0, SDEB_I_INQUIRY, 0, 0,
> + SDEB_I_WRITE_FILEMARKS, SDEB_I_SPACE, SDEB_I_INQUIRY, 0, 0,
> SDEB_I_MODE_SELECT, SDEB_I_RESERVE, SDEB_I_RELEASE,
> 0, 0, SDEB_I_MODE_SENSE, SDEB_I_START_STOP, 0, SDEB_I_SEND_DIAG,
> SDEB_I_ALLOW_REMOVAL, 0,
> @@ -625,6 +626,7 @@ static int resp_rwp_zone(struct scsi_cmnd *, struct sdebug_dev_info *);
> static int resp_read_blklimits(struct scsi_cmnd *, struct sdebug_dev_info *);
> static int resp_locate(struct scsi_cmnd *, struct sdebug_dev_info *);
> static int resp_write_filemarks(struct scsi_cmnd *, struct sdebug_dev_info *);
> +static int resp_space(struct scsi_cmnd *, struct sdebug_dev_info *);
> static int resp_rewind(struct scsi_cmnd *, struct sdebug_dev_info *);
>
> static int sdebug_do_add_host(bool mk_new_store);
> @@ -872,10 +874,12 @@ static const struct opcode_info_t opcode_info_arr[SDEB_I_LAST_ELEM_P1 + 1] = {
> {0, 0x05, 0, F_D_IN, resp_read_blklimits, NULL, /* READ BLOCK LIMITS (6) */
> {6, 0, 0, 0, 0, 0xc7, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0} },
> {0, 0x2b, 0, F_D_UNKN, resp_locate, NULL, /* LOCATE (10) */
> - {10, 0x2, 0xff, 0xff, 0xff, 0xff, 0x3f, 0xff, 0xff, 0xc7, 0, 0,
> + {10, 0x07, 0, 0xff, 0xff, 0xff, 0xff, 0, 0xff, 0xc7, 0, 0,
> 0, 0, 0, 0} },
> {0, 0x10, 0, F_D_IN, resp_write_filemarks, NULL, /* WRITE FILEMARKS (6) */
> {6, 0x01, 0xff, 0xff, 0xff, 0xc7, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0} },
> + {0, 0x11, 0, F_D_IN, resp_space, NULL, /* SPACE (6) */
> + {6, 0x07, 0xff, 0xff, 0xff, 0xc7, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0} },
>
> /* sentinel */
> {0xff, 0, 0, 0, NULL, NULL, /* terminating element */
> @@ -3309,6 +3313,9 @@ static int resp_locate(struct scsi_cmnd *scp,
> struct sdebug_dev_info *devip)
> {
> unsigned char *cmd = scp->cmnd;
> + unsigned int i, pos;
> + struct tape_block *blp;
> + int partition;
>
> if ((cmd[1] & 0x02) != 0) {
> if (cmd[8] >= devip->tape_nbr_partitions) {
> @@ -3317,8 +3324,19 @@ static int resp_locate(struct scsi_cmnd *scp,
> }
> devip->tape_partition = cmd[8];
> }
> - devip->tape_location[devip->tape_partition] =
> - get_unaligned_be32(cmd + 3);
> + pos = get_unaligned_be32(cmd + 3);
> + partition = devip->tape_partition;
> +
> + for (i = 0, blp = devip->tape_blocks[partition];
> + i < pos && i < devip->tape_eop[partition]; i++, blp++)
> + if (IS_TAPE_BLOCK_EOD(blp->fl_size))
> + break;
> + if (i < pos) {
> + devip->tape_location[partition] = i;
> + mk_sense_buffer(scp, BLANK_CHECK, 0x05, 0);
> + return check_condition_result;
> + }
> + devip->tape_location[partition] = pos;
>
> return 0;
> }
> @@ -3353,6 +3371,123 @@ static int resp_write_filemarks(struct scsi_cmnd *scp,
> return 0;
> }
>
> +static int resp_space(struct scsi_cmnd *scp,
> + struct sdebug_dev_info *devip)
> +{
> + unsigned char *cmd = scp->cmnd, code;
> + int i = 0, pos, count;
> + struct tape_block *blp;
> + int partition = devip->tape_partition;
> +
> + count = get_unaligned_be24(cmd + 2);
> + if ((count & 0x800000) != 0) /* extend negative to 32-bit count */
> + count |= 0xff000000;
> + code = cmd[1] & 0x0f;
> +
> + pos = devip->tape_location[partition];
> + if (code == 0) { /* blocks */
> + if (count < 0) {
> + count = (-count);
> + pos -= 1;
> + for (i = 0, blp = devip->tape_blocks[partition] + pos; i < count;
> + i++) {
> + if (pos < 0)
> + goto is_bop;
> + else if (IS_TAPE_BLOCK_FM(blp->fl_size))
> + goto is_fm;
> + if (i > 0) {
> + pos--;
> + blp--;
> + }
> + }
> + } else if (count > 0) {
> + for (i = 0, blp = devip->tape_blocks[partition] + pos; i < count;
> + i++, pos++, blp++) {
> + if (IS_TAPE_BLOCK_EOD(blp->fl_size))
> + goto is_eod;
> + if (IS_TAPE_BLOCK_FM(blp->fl_size)) {
> + pos += 1;
> + goto is_fm;
> + }
> + if (pos >= devip->tape_eop[partition])
> + goto is_eop;
> + }
> + }
> + } else if (code == 1) { /* filemarks */
> + if (count < 0) {
> + count = (-count);
> + if (pos == 0)
> + goto is_bop;
> + else {
> + for (i = 0, blp = devip->tape_blocks[partition] + pos;
> + i < count && pos >= 0; i++, pos--, blp--) {
> + for (pos--, blp-- ; !IS_TAPE_BLOCK_FM(blp->fl_size) &&
> + pos >= 0; pos--, blp--)
> + ; /* empty */
> + if (pos < 0)
> + goto is_bop;
> + }
> + }
> + pos += 1;
> + } else if (count > 0) {
> + for (i = 0, blp = devip->tape_blocks[partition] + pos;
> + i < count; i++, pos++, blp++) {
> + for ( ; !IS_TAPE_BLOCK_FM(blp->fl_size) &&
> + !IS_TAPE_BLOCK_EOD(blp->fl_size) &&
> + pos < devip->tape_eop[partition];
> + pos++, blp++)
> + ; /* empty */
> + if (IS_TAPE_BLOCK_EOD(blp->fl_size))
> + goto is_eod;
> + if (pos >= devip->tape_eop[partition])
> + goto is_eop;
> + }
> + }
> + } else if (code == 3) { /* EOD */
> + for (blp = devip->tape_blocks[partition] + pos;
> + !IS_TAPE_BLOCK_EOD(blp->fl_size) && pos < devip->tape_eop[partition];
> + pos++, blp++)
> + ; /* empty */
> + if (pos >= devip->tape_eop[partition])
> + goto is_eop;
> + } else {
> + /* sequential filemarks not supported */
> + mk_sense_invalid_fld(scp, SDEB_IN_CDB, 8, -1);
> + return check_condition_result;
> + }
> + devip->tape_location[partition] = pos;
> + return 0;
> +
> +is_fm:
> + devip->tape_location[partition] = pos;
> + mk_sense_info_tape(scp, NO_SENSE, NO_ADDITIONAL_SENSE,
> + FILEMARK_DETECTED_ASCQ, count - i,
> + SENSE_FLAG_FILEMARK);
> + return check_condition_result;
> +
> +is_eod:
> + devip->tape_location[partition] = pos;
> + mk_sense_info_tape(scp, BLANK_CHECK, NO_ADDITIONAL_SENSE,
> + EOD_DETECTED_ASCQ, count - i,
> + 0);
> + return check_condition_result;
> +
> +is_bop:
> + devip->tape_location[partition] = 0;
> + mk_sense_info_tape(scp, NO_SENSE, NO_ADDITIONAL_SENSE,
> + BEGINNING_OF_P_M_DETECTED_ASCQ, count - i,
> + SENSE_FLAG_EOM);
> + devip->tape_location[partition] = 0;
> + return check_condition_result;
> +
> +is_eop:
> + devip->tape_location[partition] = devip->tape_eop[partition] - 1;
> + mk_sense_info_tape(scp, MEDIUM_ERROR, NO_ADDITIONAL_SENSE,
> + EOP_EOM_DETECTED_ASCQ, (unsigned int)i,
> + SENSE_FLAG_EOM);
> + return check_condition_result;
> +}
> +
> static int resp_rewind(struct scsi_cmnd *scp,
> struct sdebug_dev_info *devip)
> {
> @@ -4121,6 +4256,98 @@ static int prot_verify_read(struct scsi_cmnd *scp, sector_t start_sec,
> return ret;
> }
>
> +static int resp_read_tape(struct scsi_cmnd *scp, struct sdebug_dev_info *devip)
> +{
> + u32 i, num, transfer, size;
> + u8 *cmd = scp->cmnd;
> + struct scsi_data_buffer *sdb = &scp->sdb;
> + int partition = devip->tape_partition;
> + u32 pos = devip->tape_location[partition];
> + struct tape_block *blp;
> + bool fixed, sili;
> +
> + if (cmd[0] != READ_6) { /* Only Read(6) supported */
> + mk_sense_invalid_opcode(scp);
> + return illegal_condition_result;
> + }
> + fixed = (cmd[1] & 0x1) != 0;
> + sili = (cmd[1] & 0x2) != 0;
> + if (fixed && sili) {
> + mk_sense_invalid_fld(scp, SDEB_IN_CDB, 1, 1);
> + return check_condition_result;
> + }
> +
> + transfer = get_unaligned_be24(cmd + 2);
> + if (fixed) {
> + num = transfer;
> + size = devip->tape_blksize;
> + } else {
> + if (transfer < TAPE_MIN_BLKSIZE ||
> + transfer > TAPE_MAX_BLKSIZE) {
> + mk_sense_invalid_fld(scp, SDEB_IN_CDB, 2, -1);
> + return check_condition_result;
> + }
> + num = 1;
> + size = transfer;
> + }
> +
> + for (i = 0, blp = devip->tape_blocks[partition] + pos;
> + i < num && pos < devip->tape_eop[partition];
> + i++, pos++, blp++) {
> + devip->tape_location[partition] = pos + 1;
> + if (IS_TAPE_BLOCK_FM(blp->fl_size)) {
> + mk_sense_info_tape(scp, NO_SENSE, NO_ADDITIONAL_SENSE,
> + FILEMARK_DETECTED_ASCQ, fixed ? num - i : size,
> + SENSE_FLAG_FILEMARK);
> + scsi_set_resid(scp, (num - i) * size);
> + return check_condition_result;
> + }
> + /* Assume no REW */
> + if (IS_TAPE_BLOCK_EOD(blp->fl_size)) {
> + mk_sense_info_tape(scp, BLANK_CHECK, NO_ADDITIONAL_SENSE,
> + EOD_DETECTED_ASCQ, fixed ? num - i : size,
> + 0);
> + devip->tape_location[partition] = pos;
> + scsi_set_resid(scp, (num - i) * size);
> + return check_condition_result;
> + }
> + sg_zero_buffer(sdb->table.sgl, sdb->table.nents,
> + size, i * size);
> + sg_copy_buffer(sdb->table.sgl, sdb->table.nents,
> + &(blp->data), 4, i * size, false);
> + if (fixed) {
> + if (blp->fl_size != devip->tape_blksize) {
> + scsi_set_resid(scp, (num - i) * size);
> + mk_sense_info_tape(scp, NO_SENSE, NO_ADDITIONAL_SENSE,
> + 0, num - i,
> + SENSE_FLAG_ILI);
> + return check_condition_result;
> + }
> + } else {
> + if (blp->fl_size != size) {
> + if (blp->fl_size < size)
> + scsi_set_resid(scp, size - blp->fl_size);
> + if (!sili) {
> + mk_sense_info_tape(scp, NO_SENSE, NO_ADDITIONAL_SENSE,
> + 0, size - blp->fl_size,
> + SENSE_FLAG_ILI);
> + return check_condition_result;
> + }
> + }
> + }
> + }
> + if (pos >= devip->tape_eop[partition]) {
> + mk_sense_info_tape(scp, NO_SENSE, NO_ADDITIONAL_SENSE,
> + EOP_EOM_DETECTED_ASCQ, fixed ? num - i : size,
> + SENSE_FLAG_EOM);
> + devip->tape_location[partition] = pos - 1;
> + return check_condition_result;
> + }
> + devip->tape_location[partition] = pos;
> +
> + return 0;
> +}
> +
> static int resp_read_dt0(struct scsi_cmnd *scp, struct sdebug_dev_info *devip)
> {
> bool check_prot;
> @@ -4132,6 +4359,9 @@ static int resp_read_dt0(struct scsi_cmnd *scp, struct sdebug_dev_info *devip)
> u8 *cmd = scp->cmnd;
> bool meta_data_locked = false;
>
> + if (sdebug_ptype == TYPE_TAPE)
> + return resp_read_tape(scp, devip);
> +
> switch (cmd[0]) {
> case READ_16:
> ei_lba = 0;