kernel-ark/drivers/target/target_core_ua.c
Linus Torvalds 5c755fe142 Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending
Pull SCSI target updates from Nicholas Bellinger:
 "It's been a busy development cycle for target-core in a number of
  different areas.

  The fabric API usage for se_node_acl allocation is now within
  target-core code, dropping the external API callers for all fabric
  drivers tree-wide.

  There is a new conversion to RCU hlists for se_node_acl and
  se_portal_group LUN mappings, that turns fast-past LUN lookup into a
  completely lockless code-path.  It also removes the original
  hard-coded limitation of 256 LUNs per fabric endpoint.

  The configfs attributes for backends can now be shared between core
  and driver code, allowing existing drivers to use common code while
  still allowing flexibility for new backend provided attributes.

  The highlights include:

   - Merge sbc_verify_dif_* into common code (sagi)
   - Remove iscsi-target support for obsolete IFMarker/OFMarker
     (Christophe Vu-Brugier)
   - Add bidi support in target/user backend (ilias + vangelis + agover)
   - Move se_node_acl allocation into target-core code (hch)
   - Add crc_t10dif_update common helper (akinobu + mkp)
   - Handle target-core odd SGL mapping for data transfer memory
     (akinobu)
   - Move transport ID handling into target-core (hch)
   - Move task tag into struct se_cmd + support 64-bit tags (bart)
   - Convert se_node_acl->device_list[] to RCU hlist (nab + hch +
     paulmck)
   - Convert se_portal_group->tpg_lun_list[] to RCU hlist (nab + hch +
     paulmck)
   - Simplify target backend driver registration (hch)
   - Consolidate + simplify target backend attribute implementations
     (hch + nab)
   - Subsume se_port + t10_alua_tg_pt_gp_member into se_lun (hch)
   - Drop lun_sep_lock for se_lun->lun_se_dev RCU usage (hch + nab)
   - Drop unnecessary core_tpg_register TFO parameter (nab)
   - Use 64-bit LUNs tree-wide (hannes)
   - Drop left-over TARGET_MAX_LUNS_PER_TRANSPORT limit (hannes)"

* 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending: (76 commits)
  target: Bump core version to v5.0
  target: remove target_core_configfs.h
  target: remove unused TARGET_CORE_CONFIG_ROOT define
  target: consolidate version defines
  target: implement WRITE_SAME with UNMAP bit using ->execute_unmap
  target: simplify UNMAP handling
  target: replace se_cmd->execute_rw with a protocol_data field
  target/user: Fix inconsistent kmap_atomic/kunmap_atomic
  target: Send UA when changing LUN inventory
  target: Send UA upon LUN RESET tmr completion
  target: Send UA on ALUA target port group change
  target: Convert se_lun->lun_deve_lock to normal spinlock
  target: use 'se_dev_entry' when allocating UAs
  target: Remove 'ua_nacl' pointer from se_ua structure
  target_core_alua: Correct UA handling when switching states
  xen-scsiback: Fix compile warning for 64-bit LUN
  target: Remove TARGET_MAX_LUNS_PER_TRANSPORT
  target: use 64-bit LUNs
  target: Drop duplicate + unused se_dev_check_wce
  target: Drop unnecessary core_tpg_register TFO parameter
  ...
2015-07-04 14:13:43 -07:00

338 lines
8.8 KiB
C

/*******************************************************************************
* Filename: target_core_ua.c
*
* This file contains logic for SPC-3 Unit Attention emulation
*
* (c) Copyright 2009-2013 Datera, Inc.
*
* Nicholas A. Bellinger <nab@kernel.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*
******************************************************************************/
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <scsi/scsi_proto.h>
#include <target/target_core_base.h>
#include <target/target_core_fabric.h>
#include "target_core_internal.h"
#include "target_core_alua.h"
#include "target_core_pr.h"
#include "target_core_ua.h"
sense_reason_t
target_scsi3_ua_check(struct se_cmd *cmd)
{
struct se_dev_entry *deve;
struct se_session *sess = cmd->se_sess;
struct se_node_acl *nacl;
if (!sess)
return 0;
nacl = sess->se_node_acl;
if (!nacl)
return 0;
rcu_read_lock();
deve = target_nacl_find_deve(nacl, cmd->orig_fe_lun);
if (!deve) {
rcu_read_unlock();
return 0;
}
if (!atomic_read(&deve->ua_count)) {
rcu_read_unlock();
return 0;
}
rcu_read_unlock();
/*
* From sam4r14, section 5.14 Unit attention condition:
*
* a) if an INQUIRY command enters the enabled command state, the
* device server shall process the INQUIRY command and shall neither
* report nor clear any unit attention condition;
* b) if a REPORT LUNS command enters the enabled command state, the
* device server shall process the REPORT LUNS command and shall not
* report any unit attention condition;
* e) if a REQUEST SENSE command enters the enabled command state while
* a unit attention condition exists for the SCSI initiator port
* associated with the I_T nexus on which the REQUEST SENSE command
* was received, then the device server shall process the command
* and either:
*/
switch (cmd->t_task_cdb[0]) {
case INQUIRY:
case REPORT_LUNS:
case REQUEST_SENSE:
return 0;
default:
return TCM_CHECK_CONDITION_UNIT_ATTENTION;
}
}
int core_scsi3_ua_allocate(
struct se_dev_entry *deve,
u8 asc,
u8 ascq)
{
struct se_ua *ua, *ua_p, *ua_tmp;
ua = kmem_cache_zalloc(se_ua_cache, GFP_ATOMIC);
if (!ua) {
pr_err("Unable to allocate struct se_ua\n");
return -ENOMEM;
}
INIT_LIST_HEAD(&ua->ua_nacl_list);
ua->ua_asc = asc;
ua->ua_ascq = ascq;
spin_lock(&deve->ua_lock);
list_for_each_entry_safe(ua_p, ua_tmp, &deve->ua_list, ua_nacl_list) {
/*
* Do not report the same UNIT ATTENTION twice..
*/
if ((ua_p->ua_asc == asc) && (ua_p->ua_ascq == ascq)) {
spin_unlock(&deve->ua_lock);
kmem_cache_free(se_ua_cache, ua);
return 0;
}
/*
* Attach the highest priority Unit Attention to
* the head of the list following sam4r14,
* Section 5.14 Unit Attention Condition:
*
* POWER ON, RESET, OR BUS DEVICE RESET OCCURRED highest
* POWER ON OCCURRED or
* DEVICE INTERNAL RESET
* SCSI BUS RESET OCCURRED or
* MICROCODE HAS BEEN CHANGED or
* protocol specific
* BUS DEVICE RESET FUNCTION OCCURRED
* I_T NEXUS LOSS OCCURRED
* COMMANDS CLEARED BY POWER LOSS NOTIFICATION
* all others Lowest
*
* Each of the ASCQ codes listed above are defined in
* the 29h ASC family, see spc4r17 Table D.1
*/
if (ua_p->ua_asc == 0x29) {
if ((asc == 0x29) && (ascq > ua_p->ua_ascq))
list_add(&ua->ua_nacl_list,
&deve->ua_list);
else
list_add_tail(&ua->ua_nacl_list,
&deve->ua_list);
} else if (ua_p->ua_asc == 0x2a) {
/*
* Incoming Family 29h ASCQ codes will override
* Family 2AHh ASCQ codes for Unit Attention condition.
*/
if ((asc == 0x29) || (ascq > ua_p->ua_asc))
list_add(&ua->ua_nacl_list,
&deve->ua_list);
else
list_add_tail(&ua->ua_nacl_list,
&deve->ua_list);
} else
list_add_tail(&ua->ua_nacl_list,
&deve->ua_list);
spin_unlock(&deve->ua_lock);
atomic_inc_mb(&deve->ua_count);
return 0;
}
list_add_tail(&ua->ua_nacl_list, &deve->ua_list);
spin_unlock(&deve->ua_lock);
pr_debug("Allocated UNIT ATTENTION, mapped LUN: %llu, ASC:"
" 0x%02x, ASCQ: 0x%02x\n", deve->mapped_lun,
asc, ascq);
atomic_inc_mb(&deve->ua_count);
return 0;
}
void target_ua_allocate_lun(struct se_node_acl *nacl,
u32 unpacked_lun, u8 asc, u8 ascq)
{
struct se_dev_entry *deve;
if (!nacl)
return;
rcu_read_lock();
deve = target_nacl_find_deve(nacl, unpacked_lun);
if (!deve) {
rcu_read_unlock();
return;
}
core_scsi3_ua_allocate(deve, asc, ascq);
rcu_read_unlock();
}
void core_scsi3_ua_release_all(
struct se_dev_entry *deve)
{
struct se_ua *ua, *ua_p;
spin_lock(&deve->ua_lock);
list_for_each_entry_safe(ua, ua_p, &deve->ua_list, ua_nacl_list) {
list_del(&ua->ua_nacl_list);
kmem_cache_free(se_ua_cache, ua);
atomic_dec_mb(&deve->ua_count);
}
spin_unlock(&deve->ua_lock);
}
void core_scsi3_ua_for_check_condition(
struct se_cmd *cmd,
u8 *asc,
u8 *ascq)
{
struct se_device *dev = cmd->se_dev;
struct se_dev_entry *deve;
struct se_session *sess = cmd->se_sess;
struct se_node_acl *nacl;
struct se_ua *ua = NULL, *ua_p;
int head = 1;
if (!sess)
return;
nacl = sess->se_node_acl;
if (!nacl)
return;
rcu_read_lock();
deve = target_nacl_find_deve(nacl, cmd->orig_fe_lun);
if (!deve) {
rcu_read_unlock();
return;
}
if (!atomic_read(&deve->ua_count)) {
rcu_read_unlock();
return;
}
/*
* The highest priority Unit Attentions are placed at the head of the
* struct se_dev_entry->ua_list, and will be returned in CHECK_CONDITION +
* sense data for the received CDB.
*/
spin_lock(&deve->ua_lock);
list_for_each_entry_safe(ua, ua_p, &deve->ua_list, ua_nacl_list) {
/*
* For ua_intlck_ctrl code not equal to 00b, only report the
* highest priority UNIT_ATTENTION and ASC/ASCQ without
* clearing it.
*/
if (dev->dev_attrib.emulate_ua_intlck_ctrl != 0) {
*asc = ua->ua_asc;
*ascq = ua->ua_ascq;
break;
}
/*
* Otherwise for the default 00b, release the UNIT ATTENTION
* condition. Return the ASC/ASCQ of the highest priority UA
* (head of the list) in the outgoing CHECK_CONDITION + sense.
*/
if (head) {
*asc = ua->ua_asc;
*ascq = ua->ua_ascq;
head = 0;
}
list_del(&ua->ua_nacl_list);
kmem_cache_free(se_ua_cache, ua);
atomic_dec_mb(&deve->ua_count);
}
spin_unlock(&deve->ua_lock);
rcu_read_unlock();
pr_debug("[%s]: %s UNIT ATTENTION condition with"
" INTLCK_CTRL: %d, mapped LUN: %llu, got CDB: 0x%02x"
" reported ASC: 0x%02x, ASCQ: 0x%02x\n",
nacl->se_tpg->se_tpg_tfo->get_fabric_name(),
(dev->dev_attrib.emulate_ua_intlck_ctrl != 0) ? "Reporting" :
"Releasing", dev->dev_attrib.emulate_ua_intlck_ctrl,
cmd->orig_fe_lun, cmd->t_task_cdb[0], *asc, *ascq);
}
int core_scsi3_ua_clear_for_request_sense(
struct se_cmd *cmd,
u8 *asc,
u8 *ascq)
{
struct se_dev_entry *deve;
struct se_session *sess = cmd->se_sess;
struct se_node_acl *nacl;
struct se_ua *ua = NULL, *ua_p;
int head = 1;
if (!sess)
return -EINVAL;
nacl = sess->se_node_acl;
if (!nacl)
return -EINVAL;
rcu_read_lock();
deve = target_nacl_find_deve(nacl, cmd->orig_fe_lun);
if (!deve) {
rcu_read_unlock();
return -EINVAL;
}
if (!atomic_read(&deve->ua_count)) {
rcu_read_unlock();
return -EPERM;
}
/*
* The highest priority Unit Attentions are placed at the head of the
* struct se_dev_entry->ua_list. The First (and hence highest priority)
* ASC/ASCQ will be returned in REQUEST_SENSE payload data for the
* matching struct se_lun.
*
* Once the returning ASC/ASCQ values are set, we go ahead and
* release all of the Unit Attention conditions for the associated
* struct se_lun.
*/
spin_lock(&deve->ua_lock);
list_for_each_entry_safe(ua, ua_p, &deve->ua_list, ua_nacl_list) {
if (head) {
*asc = ua->ua_asc;
*ascq = ua->ua_ascq;
head = 0;
}
list_del(&ua->ua_nacl_list);
kmem_cache_free(se_ua_cache, ua);
atomic_dec_mb(&deve->ua_count);
}
spin_unlock(&deve->ua_lock);
rcu_read_unlock();
pr_debug("[%s]: Released UNIT ATTENTION condition, mapped"
" LUN: %llu, got REQUEST_SENSE reported ASC: 0x%02x,"
" ASCQ: 0x%02x\n", nacl->se_tpg->se_tpg_tfo->get_fabric_name(),
cmd->orig_fe_lun, *asc, *ascq);
return (head) ? -EPERM : 0;
}