[stgt] RFC [PATCH] Implement PERSISTENT RESERVE IN/OUT

ronnie sahlberg ronniesahlberg at gmail.com
Wed Aug 20 07:18:26 CEST 2008


Hi Mark

Just one suggestion.
These two commands take service actions, and are thus reported in
"ReportSupportedOperactionCodes" with one entry for each
opcode/service_action combination.


Please have a look at how I implemented service actions by looking at
the maint_in_service_actions example :
sbc.c:          {spc_maint_in, maint_in_service_actions,},

If you add a similar structure for your service actions it means that
ReportedSupportedOperationCodes will return correct
data for your PersistentReservation opcode.

regards
ronnie sahlberg



On Wed, Aug 20, 2008 at 3:01 PM, Mark Harvey <markh794 at gmail.com> wrote:
> Apologies for sending as an attachment... gmail and all.
>
> This is an initial attempt to implement PERSISTENT RESERVE IN and
> PERSISTENT RESERVE OUT.
>
> Currently only READ KEY service action will actually return anything.
> It returns a hard-coded 'ABC1234'.
>
> This post is a request for comment before I get too far into coding effort.
>
> # lsscsi -g
> [3:0:0:0]    disk    USB-HS   HTS726060M9AT00  0.01  /dev/sda  /dev/sg0
> [7:0:0:0]    storage IET      Controller       0001  -         /dev/sg1
> [7:0:0:1]    disk    QUANTUM  HD100            0010  /dev/sdb  /dev/sg2
> [7:0:0:2]    tape    QUANTUM  DLT6000          0010  /dev/st0  /dev/sg3
> [7:0:0:3]    tape    QUANTUM  DLT6000          0010  /dev/st1  /dev/sg4
> [7:0:0:4]    tape    QUANTUM  DLT6000          0010  /dev/st2  /dev/sg5
> [7:0:0:5]    mediumx STK      L700             0010  -         /dev/sg6
>
> # sg_persist -i /dev/sg3
>>> No service action given; assume Persistent Reservations In command
>>> with Read Keys service action
>  QUANTUM  DLT6000  0010
>  Peripheral device type: tape
>  PR generation=0x0, 4 registered reservation keys follow:
>    0x4142433132333400
>    0x0
>    0x0
>    0x0
>
>
> I'll include in-line for viewing pleasure :)
>
> [PATCH 1/2]
> From 11ad9ee209708f51bd2884598d309b1e7079cdce Mon Sep 17 00:00:00 2001
> From: Mark Harvey <markh794 at gmail.com>
> Date: Wed, 20 Aug 2008 14:42:27 +1000
> Subject: RFC - Implement PERSISTENT RESERVE IN/OUT
>
> Implement service action 'READ KEY' which returns
> a hard-coded string 'ABC1234'
>
> Signed-off-by: Mark Harvey <markh794 at gmail.com>
> ---
>  usr/scsi.h |    5 ++
>  usr/spc.c  |  231 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
>  usr/spc.h  |    2 +
>  usr/tgtd.h |   13 ++++
>  4 files changed, 251 insertions(+), 0 deletions(-)
>
> diff --git a/usr/scsi.h b/usr/scsi.h
> index 84fadff..a9481a1 100644
> --- a/usr/scsi.h
> +++ b/usr/scsi.h
> @@ -208,6 +208,11 @@
>  #define ASC_POSITION_PAST_BOM                  0x3b0c
>  #define ASC_MEDIUM_REMOVAL_PREVENTED           0x5302
>  #define ASC_BAD_MICROCODE_DETECTED             0x8283
> +#define ASC_INSUFFICENT_RESERVE_RESOURCE       0x5502
> +#define ASC_INSUFFICENT_RESOURCE               0x5503
> +#define ASC_INSUFFICENT_REGISTRAT_RESOURCE     0x5504
> +#define ASC_INSUFFICENT_AC_RESOURCE            0x5505
> +#define ASC_AUX_MEMORY_OUT_OF_SPACE            0x5506
>
>  /* Key 6: Unit Attention */
>  #define ASC_NOT_READY_TO_TRANSITION            0x2800
> diff --git a/usr/spc.c b/usr/spc.c
> index bd2c975..cc088bf 100644
> --- a/usr/spc.c
> +++ b/usr/spc.c
> @@ -880,6 +880,237 @@ void dump_cdb(struct scsi_cmd *cmd)
>        }
>  }
>
> +/**
> + * SCSI Persistent Reservation
> + *
> + * Reference: spc4r16 Ch 5.7
> + *
> + * Interesting points:
> + *  - Persistent reservations are not reset by hard reset, lu reset ot I_T loss
> + *  - Optionally, may be retained when power to target is lost
> + */
> +
> +/**
> + * PERSISTENT RESERVE IN - 5Eh
> + * Ref: 6.13
> + *
> + */
> +#define PR_IN_READ_KEYS 0
> +#define PR_IN_READ_RESERVATION 1
> +#define PR_IN_REPORT_CAPABILITIES 2
> +#define PR_IN_READ_FULL_STATUS 3
> +static int spc_pr_read_keys(int host_no, struct scsi_cmd *cmd)
> +{
> +       uint8_t *buf;
> +       int len;
> +       int cdb_alloc_len;
> +       struct scsi_pr *pr;
> +
> +       cdb_alloc_len = ((cmd->scb[7] & 0xff) << 8) | (cmd->scb[8] & 0xff);
> +
> +       dprintf("**** Called ****\n");
> +       pr = &cmd->dev->pr;
> +
> +       buf = scsi_get_in_buffer(cmd);
> +       len = sizeof(cmd->dev->pr.pr_key);
> +       memset(buf, 0, len + 8);
> +
> +       dprintf("Buf: %p, len: %d, cdb_alloc_len: %d\n",
> +                        buf, len, cdb_alloc_len);
> +
> +       buf[0] = (pr->PRgeneration >> 24) & 0xff;
> +       buf[1] = (pr->PRgeneration >> 16) & 0xff;
> +       buf[2] = (pr->PRgeneration >>  8) & 0xff;
> +       buf[3] = pr->PRgeneration & 0xff;
> +       buf[4] = (len >> 24) & 0xff;
> +       buf[5] = (len >> 16) & 0xff;
> +       buf[6] = (len >>  8) & 0xff;
> +       buf[7] = len & 0xff;
> +
> +       strcpy(buf + 8, "ABC1234");
> +       memcpy(scsi_get_in_buffer(cmd), buf, min(cdb_alloc_len, len + 8));
> +
> +       scsi_set_in_resid_by_actual(cmd, len + 8);
> +
> +       return SAM_STAT_GOOD;
> +}
> +
> +static int spc_pr_read_reservation(int host_no, struct scsi_cmd *cmd)
> +{
> +       dprintf("**** Called ****\n");
> +       sense_data_build(cmd, ILLEGAL_REQUEST, ASC_INVALID_OP_CODE);
> +       return SAM_STAT_CHECK_CONDITION;
> +}
> +
> +static int spc_pr_report_capabilities(int host_no, struct scsi_cmd *cmd)
> +{
> +       dprintf("**** Called ****\n");
> +       sense_data_build(cmd, ILLEGAL_REQUEST, ASC_INVALID_OP_CODE);
> +       return SAM_STAT_CHECK_CONDITION;
> +}
> +
> +static int spc_pr_read_full_status(int host_no, struct scsi_cmd *cmd)
> +{
> +       dprintf("**** Called ****\n");
> +       sense_data_build(cmd, ILLEGAL_REQUEST, ASC_INVALID_OP_CODE);
> +       return SAM_STAT_CHECK_CONDITION;
> +}
> +
> +struct service_action pr_in_service_actions[] = {
> +       {PR_IN_READ_KEYS, spc_pr_read_keys},
> +       {PR_IN_READ_RESERVATION, spc_pr_read_reservation},
> +       {PR_IN_REPORT_CAPABILITIES, spc_pr_report_capabilities},
> +       {PR_IN_READ_FULL_STATUS, spc_pr_read_full_status},
> +       {0, NULL}
> +};
> +
> +int persistent_reserve_in(int host_no, struct scsi_cmd *cmd)
> +{
> +       uint8_t action;
> +       struct service_action *service_action;
> +
> +       action = cmd->scb[1] & 0x1f;
> +       service_action = find_service_action(pr_in_service_actions, action);
> +
> +       if (!service_action) {
> +               scsi_set_in_resid_by_actual(cmd, 0);
> +               sense_data_build(cmd, ILLEGAL_REQUEST,
> +                               ASC_INVALID_FIELD_IN_CDB);
> +               return SAM_STAT_CHECK_CONDITION;
> +       }
> +
> +       return service_action->cmd_perform(host_no, cmd);
> +}
> +
> +/**
> + * PERSISTENT RESERVE OUT - 5Fh
> + * Ref: 6.14
> + */
> +#define PR_OUT_REGISTER 0
> +#define PR_OUT_RESERVE 1
> +#define PR_OUT_RELEASE 2
> +#define PR_OUT_CLEAR 3
> +#define PR_OUT_PREEMPT 4
> +#define PR_OUT_PREEMPT_ABORT 5
> +#define PR_OUT_REGISTER_IGNORE 6
> +#define PR_OUT_REGISTER_MOVE 7
> +
> +static int spc_pr_register(int host_no, struct scsi_cmd *cmd)
> +{
> +       struct scsi_pr *pr;
> +
> +       dprintf("**** Called ****\n");
> +       pr = &cmd->dev->pr;
> +       pr->PRgeneration += 1;
> +
> +       sense_data_build(cmd, ILLEGAL_REQUEST, ASC_INVALID_OP_CODE);
> +       return SAM_STAT_CHECK_CONDITION;
> +}
> +
> +static int spc_pr_reserve(int host_no, struct scsi_cmd *cmd)
> +{
> +       dprintf("**** Called ****\n");
> +       sense_data_build(cmd, ILLEGAL_REQUEST, ASC_INVALID_OP_CODE);
> +       return SAM_STAT_CHECK_CONDITION;
> +}
> +
> +static int spc_pr_release(int host_no, struct scsi_cmd *cmd)
> +{
> +       dprintf("**** Called ****\n");
> +       sense_data_build(cmd, ILLEGAL_REQUEST, ASC_INVALID_OP_CODE);
> +       return SAM_STAT_CHECK_CONDITION;
> +}
> +
> +static int spc_pr_clear(int host_no, struct scsi_cmd *cmd)
> +{
> +       struct scsi_pr *pr;
> +
> +       dprintf("**** Called ****\n");
> +       pr = &cmd->dev->pr;
> +       pr->PRgeneration += 1;
> +
> +       sense_data_build(cmd, ILLEGAL_REQUEST, ASC_INVALID_OP_CODE);
> +       return SAM_STAT_CHECK_CONDITION;
> +}
> +
> +static int spc_pr_preempt(int host_no, struct scsi_cmd *cmd)
> +{
> +       struct scsi_pr *pr;
> +
> +       dprintf("**** Called ****\n");
> +       pr = &cmd->dev->pr;
> +       pr->PRgeneration += 1;
> +
> +       sense_data_build(cmd, ILLEGAL_REQUEST, ASC_INVALID_OP_CODE);
> +       return SAM_STAT_CHECK_CONDITION;
> +}
> +
> +static int spc_pr_preempt_abort(int host_no, struct scsi_cmd *cmd)
> +{
> +       struct scsi_pr *pr;
> +
> +       dprintf("**** Called ****\n");
> +       pr = &cmd->dev->pr;
> +       pr->PRgeneration += 1;
> +
> +       sense_data_build(cmd, ILLEGAL_REQUEST, ASC_INVALID_OP_CODE);
> +       return SAM_STAT_CHECK_CONDITION;
> +}
> +
> +static int spc_pr_register_ignore(int host_no, struct scsi_cmd *cmd)
> +{
> +       struct scsi_pr *pr;
> +
> +       dprintf("**** Called ****\n");
> +       pr = &cmd->dev->pr;
> +       pr->PRgeneration += 1;
> +
> +       sense_data_build(cmd, ILLEGAL_REQUEST, ASC_INVALID_OP_CODE);
> +       return SAM_STAT_CHECK_CONDITION;
> +}
> +
> +static int spc_pr_register_move(int host_no, struct scsi_cmd *cmd)
> +{
> +       struct scsi_pr *pr;
> +
> +       dprintf("**** Called ****\n");
> +       pr = &cmd->dev->pr;
> +       pr->PRgeneration += 1;
> +
> +       sense_data_build(cmd, ILLEGAL_REQUEST, ASC_INVALID_OP_CODE);
> +       return SAM_STAT_CHECK_CONDITION;
> +}
> +
> +struct service_action pr_out_service_actions[] = {
> +       {PR_OUT_REGISTER, spc_pr_register},
> +       {PR_OUT_RESERVE, spc_pr_reserve},
> +       {PR_OUT_RELEASE, spc_pr_release},
> +       {PR_OUT_CLEAR, spc_pr_clear},
> +       {PR_OUT_PREEMPT, spc_pr_preempt},
> +       {PR_OUT_PREEMPT_ABORT, spc_pr_preempt_abort},
> +       {PR_OUT_REGISTER_IGNORE, spc_pr_register_ignore},
> +       {PR_OUT_REGISTER_MOVE, spc_pr_register_move},
> +       {0, NULL}
> +};
> +
> +int persistent_reserve_out(int host_no, struct scsi_cmd *cmd)
> +{
> +       uint8_t action;
> +       struct service_action *service_action;
> +
> +       action = cmd->scb[1] & 0x1f;
> +       service_action = find_service_action(pr_out_service_actions, action);
> +
> +       if (!service_action) {
> +               scsi_set_in_resid_by_actual(cmd, 0);
> +               sense_data_build(cmd, ILLEGAL_REQUEST,
> +                               ASC_INVALID_FIELD_IN_CDB);
> +               return SAM_STAT_CHECK_CONDITION;
> +       }
> +
> +       return service_action->cmd_perform(host_no, cmd);
> +}
> +
>  int spc_illegal_op(int host_no, struct scsi_cmd *cmd)
>  {
>        dump_cdb(cmd);
> diff --git a/usr/spc.h b/usr/spc.h
> index 8fe3e3c..bdc3c1f 100644
> --- a/usr/spc.h
> +++ b/usr/spc.h
> @@ -9,6 +9,8 @@ extern int spc_start_stop(int host_no, struct scsi_cmd *cmd);
>  extern int spc_test_unit(int host_no, struct scsi_cmd *cmd);
>  extern int spc_request_sense(int host_no, struct scsi_cmd *cmd);
>  extern int spc_illegal_op(int host_no, struct scsi_cmd *cmd);
> +extern int persistent_reserve_in(int host_no, struct scsi_cmd *cmd);
> +extern int persistent_reserve_out(int host_no, struct scsi_cmd *cmd);
>  extern int spc_lu_init(struct scsi_lu *lu);
>
>  typedef int (match_fn_t)(struct scsi_lu *lu, char *params);
> diff --git a/usr/tgtd.h b/usr/tgtd.h
> index 4febcd3..d2c7135 100644
> --- a/usr/tgtd.h
> +++ b/usr/tgtd.h
> @@ -19,6 +19,11 @@
>
>  #define VENDOR_ID      "IET"
>
> +/* 8 byte reservation key size */
> +#define PR_KEY_SZ 8
> +/* Number of PR keys we can store at any one time */
> +#define PR_RESERVATION_SZ 4
> +
>  #define _TAB1 "    "
>  #define _TAB2 _TAB1 _TAB1
>  #define _TAB3 _TAB1 _TAB1 _TAB1
> @@ -126,6 +131,12 @@ struct mode_pg {
>        uint8_t mode_data[0];   /* Rest of mode page info */
>  };
>
> +struct scsi_pr {
> +       /* Persistent Reservation Generation */
> +       uint32_t PRgeneration;
> +       uint8_t pr_key[PR_RESERVATION_SZ][PR_KEY_SZ];
> +};
> +
>  struct scsi_lu {
>        int fd;
>        uint64_t addr; /* persistent mapped address */
> @@ -150,6 +161,8 @@ struct scsi_lu {
>        uint8_t mode_block_descriptor[BLOCK_DESCRIPTOR_LEN];
>        struct mode_pg *mode_pgs[0x3f];
>
> +       struct scsi_pr pr;
> +
>        struct lu_phy_attr attrs;
>
>        /* A pointer for each modules private use.
> --
> 1.5.6
>
> [PATCH 2/2]
> From 68c454d2d7f1b64f9dbce9410e5c2c8500d6ceb3 Mon Sep 17 00:00:00 2001
> From: Mark Harvey <markh794 at gmail.com>
> Date: Wed, 20 Aug 2008 14:45:30 +1000
> Subject: Add persistent reserve in/out to ssc module
>
> Signed-off-by: Mark Harvey <markh794 at gmail.com>
> ---
>  usr/ssc.c |    4 ++--
>  1 files changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/usr/ssc.c b/usr/ssc.c
> index 2630a6a..6dbdc0b 100644
> --- a/usr/ssc.c
> +++ b/usr/ssc.c
> @@ -251,8 +251,8 @@ static struct device_type_template ssc_template = {
>                {spc_illegal_op,},
>                {spc_illegal_op,},
>                {spc_illegal_op,},
> -               {spc_illegal_op,},
> -               {spc_illegal_op,},
> +               {persistent_reserve_in,},
> +               {persistent_reserve_out,},
>
>                [0x60 ... 0x7f] = {spc_illegal_op,},
>
> --
> 1.5.6
>
--
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