tgt/0001-Remove-dummy-RAID-controller-from-LUN-0.patch

   1 From 0d204bda91efaeda3f73c9e7ce932869e63a8545 Mon Sep 17 00:00:00 2001
   2 From: Arne Redlich <arne.redlich@googlemail.com>
   3 Date: Sun, 20 Mar 2011 20:37:08 +0100
   4 Subject: [PATCH] Remove dummy RAID controller from LUN 0
   5
   6 The dummy RAID controller serves 2 purposes:
   7 (1) commands that are addressed to an inexistent LUN are redirected to it
   8 (2) it provides a LUN 0 by default which is required by the SCSI spec
   9 .
  10
  11 (1) is obviously wrong because instead of "wrong lun" "invalid cdb" is returned
  12 to the initiator. A "shadow LUN" of type NO_LUN is now used for this purpose.
  13 This LU uses bs_null as backingstore, so there are no idle threads spawned for
  14 it (in contrast to the previous dummy raid controller at LUN 0).
  15
  16 (2) confuses some OSes / users (Windows prompts for drivers,
  17 Solaris repeatedly tries to online the LU, but does not succeed).
  18
  19 It's now the user's responsibility to attach a LU to LUN 0 to adhere to the
  20 SCSI spec (Solaris / WinXP don't insist, Linux does!).
  21
  22 Signed-off-by: Arne Redlich <arne.redlich@googlemail.com>
  23 ---
  24  usr/Makefile |    2 +-
  25  usr/list.h   |    3 ++
  26  usr/nolun.c  |   95 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
  27  usr/spc.c    |   10 ++++++
  28  usr/spc.h    |    1 +
  29  usr/target.c |   28 +++++++++--------
  30  usr/target.h |    2 +
  31  7 files changed, 127 insertions(+), 14 deletions(-)
  32  create mode 100644 usr/nolun.c
  33
  34 diff --git a/usr/Makefile b/usr/Makefile
  35 index ea175cd..9ac79c0 100644
  36 --- a/usr/Makefile
  37 +++ b/usr/Makefile
  38 @@ -53,7 +53,7 @@ LIBS += -lpthread
  39
  40  PROGRAMS += tgtd tgtadm tgtimg
  41  TGTD_OBJS += tgtd.o mgmt.o target.o scsi.o log.o driver.o util.o work.o \
  42 -               parser.o spc.o sbc.o mmc.o osd.o scc.o smc.o \
  43 +               parser.o spc.o sbc.o mmc.o nolun.o osd.o scc.o smc.o \
  44                 ssc.o bs_ssc.o libssc.o \
  45                 bs_null.o bs_sg.o bs.o libcrc32c.o
  46
  47 diff --git a/usr/list.h b/usr/list.h
  48 index 2f80a56..698a684 100644
  49 --- a/usr/list.h
  50 +++ b/usr/list.h
  51 @@ -32,6 +32,9 @@ static inline void INIT_LIST_HEAD(struct list_head *list)
  52  #define list_first_entry(ptr, type, member) \
  53         list_entry((ptr)->next, type, member)
  54
  55 +#define list_last_entry(ptr, type, member) \
  56 +       list_entry((ptr)->prev, type, member)
  57 +
  58  static inline int list_empty(const struct list_head *head)
  59  {
  60         return head->next == head;
  61 diff --git a/usr/nolun.c b/usr/nolun.c
  62 new file mode 100644
  63 index 0000000..0f516a0
  64 --- /dev/null
  65 +++ b/usr/nolun.c
  66 @@ -0,0 +1,95 @@
  67 +/*
  68 + * Processing of SCSI commands addressed to inexistent LUNs.
  69 + *
  70 + * Based on scc.c:
  71 + *
  72 + * Copyright (C) 2007 FUJITA Tomonori <tomof@acm.org>
  73 + * Copyright (C) 2007 Mike Christie <michaelc@cs.wisc.edu>
  74 + *
  75 + * This program is free software; you can redistribute it and/or
  76 + * modify it under the terms of the GNU General Public License as
  77 + * published by the Free Software Foundation, version 2 of the
  78 + * License.
  79 + *
  80 + * This program is distributed in the hope that it will be useful, but
  81 + * WITHOUT ANY WARRANTY; without even the implied warranty of
  82 + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  83 + * General Public License for more details.
  84 + *
  85 + * You should have received a copy of the GNU General Public License
  86 + * along with this program; if not, write to the Free Software
  87 + * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
  88 + * 02110-1301 USA
  89 + */
  90 +#include <errno.h>
  91 +#include <stdio.h>
  92 +#include <stdlib.h>
  93 +#include <string.h>
  94 +#include <stdint.h>
  95 +#include <unistd.h>
  96 +#include <linux/fs.h>
  97 +
  98 +#include "list.h"
  99 +#include "util.h"
 100 +#include "tgtd.h"
 101 +#include "target.h"
 102 +#include "driver.h"
 103 +#include "scsi.h"
 104 +#include "tgtadm_error.h"
 105 +#include "spc.h"
 106 +
 107 +static int nolun_lu_init(struct scsi_lu *lu)
 108 +{
 109 +       memset(&lu->attrs, 0x0, sizeof(lu->attrs));
 110 +       /*
 111 +        * TODO: use PQ 11b (per. dev. supp but not connected) and dev type 0x0
 112 +        * (SBC-2) instead?
 113 +        */
 114 +       lu->attrs.device_type = 0x1f; /* unknown / no device type */
 115 +       lu->attrs.qualifier = 0x3; /* peripheral dev. not supp. on this LU */
 116 +
 117 +       return 0;
 118 +}
 119 +
 120 +static int nolun_lu_config(struct scsi_lu *lu __attribute__((unused)),
 121 +                          char *params __attribute__((unused)))
 122 +{
 123 +       return TGTADM_NO_LUN;
 124 +}
 125 +
 126 +static int nolun_lu_online(struct scsi_lu *lu __attribute__((unused)))
 127 +{
 128 +       /* TODO: correct return value? most consumers don't check at all ... */
 129 +       return -ENOENT;
 130 +}
 131 +
 132 +static int nolun_lu_offline(struct scsi_lu *lu __attribute__((unused)))
 133 +{
 134 +       return 0;
 135 +}
 136 +
 137 +static void nolun_lu_exit(struct scsi_lu *lu __attribute__((unused)))
 138 +{
 139 +       return;
 140 +}
 141 +
 142 +static struct device_type_template nolun_template = {
 143 +       .type           = TYPE_NO_LUN,
 144 +       .lu_init        = nolun_lu_init,
 145 +       .lu_config      = nolun_lu_config,
 146 +       .lu_online      = nolun_lu_online,
 147 +       .lu_offline     = nolun_lu_offline,
 148 +       .lu_exit        = nolun_lu_exit,
 149 +       .ops            = {
 150 +               [0x0 ... 0x11] =  {spc_invalid_lun,},
 151 +               {spc_inquiry,}, /* 0x12 */
 152 +               [ 0x13 ... 0x9f] =  {spc_invalid_lun},
 153 +               {spc_report_luns,}, /* 0xA0 */
 154 +               [0xa1 ... 0xff] = {spc_invalid_lun},
 155 +       }
 156 +};
 157 +
 158 +__attribute__((constructor)) static void nolun_init(void)
 159 +{
 160 +       device_type_register(&nolun_template);
 161 +}
 162 diff --git a/usr/spc.c b/usr/spc.c
 163 index ea901e2..94fa1f9 100644
 164 --- a/usr/spc.c
 165 +++ b/usr/spc.c
 166 @@ -270,6 +270,8 @@ int spc_report_luns(int host_no, struct scsi_cmd *cmd)
 167         nr_luns = 0;
 168
 169         list_for_each_entry(lu, dev_list, device_siblings) {
 170 +               if (lu->lun == TGT_SHADOW_LUN)
 171 +                       continue;
 172                 nr_luns++;
 173
 174                 if (!alen)
 175 @@ -1590,6 +1592,14 @@ int spc_illegal_op(int host_no, struct scsi_cmd *cmd)
 176         return SAM_STAT_CHECK_CONDITION;
 177  }
 178
 179 +int spc_invalid_lun(int host_no, struct scsi_cmd *cmd)
 180 +{
 181 +       dump_cdb(cmd);
 182 +       scsi_set_in_resid_by_actual(cmd, 0);
 183 +       sense_data_build(cmd, ILLEGAL_REQUEST, ASC_LUN_NOT_SUPPORTED);
 184 +       return SAM_STAT_CHECK_CONDITION;
 185 +}
 186 +
 187  enum {
 188         Opt_scsi_id, Opt_scsi_sn,
 189         Opt_vendor_id, Opt_product_id,
 190 diff --git a/usr/spc.h b/usr/spc.h
 191 index 430a882..23fab97 100644
 192 --- a/usr/spc.h
 193 +++ b/usr/spc.h
 194 @@ -12,6 +12,7 @@ extern int spc_test_unit(int host_no, struct scsi_cmd *cmd);
 195  extern int spc_request_sense(int host_no, struct scsi_cmd *cmd);
 196  extern int spc_prevent_allow_media_removal(int host_no, struct scsi_cmd *cmd);
 197  extern int spc_illegal_op(int host_no, struct scsi_cmd *cmd);
 198 +extern int spc_invalid_lun(int host_no, struct scsi_cmd *cmd);
 199  extern int spc_lu_init(struct scsi_lu *lu);
 200
 201  typedef int (match_fn_t)(struct scsi_lu *lu, char *params);
 202 diff --git a/usr/target.c b/usr/target.c
 203 index b8b8715..79319df 100644
 204 --- a/usr/target.c
 205 +++ b/usr/target.c
 206 @@ -510,7 +510,10 @@ int tgt_device_create(int tid, int dev_type, uint64_t lun, char *params,
 207                 goto out;
 208         }
 209
 210 -       bst = target->bst;
 211 +       bst = (lun == TGT_SHADOW_LUN) ?
 212 +               get_backingstore_template("null") :
 213 +               target->bst;
 214 +
 215         if (backing) {
 216                 if (bstype) {
 217                         bst = get_backingstore_template(bstype);
 218 @@ -675,10 +678,6 @@ int tgt_device_destroy(int tid, uint64_t lun, int force)
 219
 220         dprintf("%u %" PRIu64 "\n", tid, lun);
 221
 222 -       /* lun0 is special */
 223 -       if (!lun && !force)
 224 -               return TGTADM_INVALID_REQUEST;
 225 -
 226         lu = __device_lookup(tid, lun, &target);
 227         if (!lu) {
 228                 eprintf("device %" PRIu64 " not found\n", lun);
 229 @@ -934,11 +933,11 @@ int target_cmd_queue(int tid, struct scsi_cmd *cmd)
 230         cmd->dev_id = dev_id;
 231         dprintf("%p %x %" PRIx64 "\n", cmd, cmd->scb[0], dev_id);
 232         cmd->dev = device_lookup(target, dev_id);
 233 -       /* use LUN0 */
 234 +       /* use TGT_SHADOW_LUN */
 235         if (!cmd->dev)
 236 -               cmd->dev = list_first_entry(&target->device_list,
 237 -                                           struct scsi_lu,
 238 -                                           device_siblings);
 239 +               cmd->dev = list_last_entry(&target->device_list,
 240 +                                          struct scsi_lu,
 241 +                                          device_siblings);
 242
 243         cmd->itn_lu_info = it_nexus_lu_info_lookup(itn, cmd->dev->lun);
 244
 245 @@ -1767,7 +1766,9 @@ int tgt_target_show_all(char *buf, int rest)
 246                 }
 247
 248                 shprintf(total, buf, rest, _TAB1 "LUN information:\n");
 249 -               list_for_each_entry(lu, &target->device_list, device_siblings)
 250 +               list_for_each_entry(lu, &target->device_list, device_siblings) {
 251 +                       if (lu->lun == TGT_SHADOW_LUN)
 252 +                               continue;
 253                         shprintf(total, buf, rest,
 254                                  _TAB2 "LUN: %" PRIu64 "\n"
 255                                  _TAB3 "Type: %s\n"
 256 @@ -1794,6 +1795,7 @@ int tgt_target_show_all(char *buf, int rest)
 257                                         "None",
 258                                  lu->path ? : "None",
 259                                  open_flags_to_str(strflags, lu->bsoflags));
 260 +               }
 261
 262                 if (!strcmp(tgt_drivers[target->lid]->name, "iscsi") ||
 263                     !strcmp(tgt_drivers[target->lid]->name, "iser")) {
 264 @@ -1911,7 +1913,7 @@ int tgt_target_create(int lld, int tid, char *args)
 265         INIT_LIST_HEAD(&target->acl_list);
 266         INIT_LIST_HEAD(&target->it_nexus_list);
 267
 268 -       tgt_device_create(tid, TYPE_RAID, 0, NULL, 0);
 269 +       tgt_device_create(tid, TYPE_NO_LUN, TGT_SHADOW_LUN, NULL, 0);
 270
 271         if (tgt_drivers[lld]->target_create)
 272                 tgt_drivers[lld]->target_create(target);
 273 @@ -1938,8 +1940,8 @@ int tgt_target_destroy(int lld_no, int tid)
 274         }
 275
 276         while (!list_empty(&target->device_list)) {
 277 -               /* we remove lun0 last */
 278 -               lu = list_entry(target->device_list.prev, struct scsi_lu,
 279 +               /* we remove TGT_SHADOW_LUN last */
 280 +               lu = list_entry(target->device_list.next, struct scsi_lu,
 281                                 device_siblings);
 282                 ret = tgt_device_destroy(tid, lu->lun, 1);
 283                 if (ret)
 284 diff --git a/usr/target.h b/usr/target.h
 285 index 9283431..5cb102f 100644
 286 --- a/usr/target.h
 287 +++ b/usr/target.h
 288 @@ -8,6 +8,8 @@
 289  #define        HASH_ORDER      4
 290  #define        hashfn(val)     hash_long((unsigned long) (val), HASH_ORDER)
 291
 292 +#define TGT_SHADOW_LUN 0xffffffffffffffffULL
 293 +
 294  struct acl_entry {
 295         char *address;
 296         struct list_head aclent_list;
 297 --
 298 1.7.1
 299