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target: split core_scsi2_emulate_crh
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Split core_scsi2_emulate_crh into one routine each for the reserve and
release side.  The common code now is in a helper called by both
routines.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
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Christoph Hellwig authored and Nicholas Bellinger committed Nov 4, 2011
1 parent a17f091 commit eacac00
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Showing 3 changed files with 102 additions and 106 deletions.
189 changes: 92 additions & 97 deletions drivers/target/target_core_pr.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -116,14 +116,99 @@ static int core_scsi2_reservation_check(struct se_cmd *cmd, u32 *pr_reg_type)
return ret;
}

static int core_scsi2_reservation_release(struct se_cmd *cmd)
static struct t10_pr_registration *core_scsi3_locate_pr_reg(struct se_device *,
struct se_node_acl *, struct se_session *);
static void core_scsi3_put_pr_reg(struct t10_pr_registration *);

static int target_check_scsi2_reservation_conflict(struct se_cmd *cmd, int *ret)
{
struct se_session *se_sess = cmd->se_sess;
struct se_subsystem_dev *su_dev = cmd->se_dev->se_sub_dev;
struct t10_pr_registration *pr_reg;
struct t10_reservation *pr_tmpl = &su_dev->t10_pr;
int crh = (su_dev->t10_pr.res_type == SPC3_PERSISTENT_RESERVATIONS);
int conflict = 0;

if (!crh)
return false;

pr_reg = core_scsi3_locate_pr_reg(cmd->se_dev, se_sess->se_node_acl,
se_sess);
if (pr_reg) {
/*
* From spc4r17 5.7.3 Exceptions to SPC-2 RESERVE and RELEASE
* behavior
*
* A RESERVE(6) or RESERVE(10) command shall complete with GOOD
* status, but no reservation shall be established and the
* persistent reservation shall not be changed, if the command
* is received from a) and b) below.
*
* A RELEASE(6) or RELEASE(10) command shall complete with GOOD
* status, but the persistent reservation shall not be released,
* if the command is received from a) and b)
*
* a) An I_T nexus that is a persistent reservation holder; or
* b) An I_T nexus that is registered if a registrants only or
* all registrants type persistent reservation is present.
*
* In all other cases, a RESERVE(6) command, RESERVE(10) command,
* RELEASE(6) command, or RELEASE(10) command shall be processed
* as defined in SPC-2.
*/
if (pr_reg->pr_res_holder) {
core_scsi3_put_pr_reg(pr_reg);
*ret = 0;
return false;
}
if ((pr_reg->pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_REGONLY) ||
(pr_reg->pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_REGONLY) ||
(pr_reg->pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG) ||
(pr_reg->pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG)) {
core_scsi3_put_pr_reg(pr_reg);
*ret = 0;
return true;
}
core_scsi3_put_pr_reg(pr_reg);
conflict = 1;
} else {
/*
* Following spc2r20 5.5.1 Reservations overview:
*
* If a logical unit has executed a PERSISTENT RESERVE OUT
* command with the REGISTER or the REGISTER AND IGNORE
* EXISTING KEY service action and is still registered by any
* initiator, all RESERVE commands and all RELEASE commands
* regardless of initiator shall conflict and shall terminate
* with a RESERVATION CONFLICT status.
*/
spin_lock(&pr_tmpl->registration_lock);
conflict = (list_empty(&pr_tmpl->registration_list)) ? 0 : 1;
spin_unlock(&pr_tmpl->registration_lock);
}

if (conflict) {
pr_err("Received legacy SPC-2 RESERVE/RELEASE"
" while active SPC-3 registrations exist,"
" returning RESERVATION_CONFLICT\n");
*ret = PYX_TRANSPORT_RESERVATION_CONFLICT;
return true;
}

return false;
}

int target_scsi2_reservation_release(struct se_cmd *cmd)
{
struct se_device *dev = cmd->se_dev;
struct se_session *sess = cmd->se_sess;
struct se_portal_group *tpg = sess->se_tpg;
int ret;

if (!sess || !tpg)
return 0;
if (target_check_scsi2_reservation_conflict(cmd, &ret))
return ret;

spin_lock(&dev->dev_reservation_lock);
if (!dev->dev_reserved_node_acl || !sess) {
Expand All @@ -150,11 +235,12 @@ static int core_scsi2_reservation_release(struct se_cmd *cmd)
return 0;
}

static int core_scsi2_reservation_reserve(struct se_cmd *cmd)
int target_scsi2_reservation_reserve(struct se_cmd *cmd)
{
struct se_device *dev = cmd->se_dev;
struct se_session *sess = cmd->se_sess;
struct se_portal_group *tpg = sess->se_tpg;
int ret;

if ((cmd->t_task_cdb[1] & 0x01) &&
(cmd->t_task_cdb[1] & 0x02)) {
Expand All @@ -168,6 +254,8 @@ static int core_scsi2_reservation_reserve(struct se_cmd *cmd)
*/
if (!sess || !tpg)
return 0;
if (target_check_scsi2_reservation_conflict(cmd, &ret))
return ret;

spin_lock(&dev->dev_reservation_lock);
if (dev->dev_reserved_node_acl &&
Expand Down Expand Up @@ -200,99 +288,6 @@ static int core_scsi2_reservation_reserve(struct se_cmd *cmd)
return 0;
}

static struct t10_pr_registration *core_scsi3_locate_pr_reg(struct se_device *,
struct se_node_acl *, struct se_session *);
static void core_scsi3_put_pr_reg(struct t10_pr_registration *);

/*
* Setup in target_core_transport.c:transport_generic_cmd_sequencer()
* and called via struct se_cmd->transport_emulate_cdb() in TCM processing
* thread context.
*/
int core_scsi2_emulate_crh(struct se_cmd *cmd)
{
struct se_session *se_sess = cmd->se_sess;
struct se_subsystem_dev *su_dev = cmd->se_dev->se_sub_dev;
struct t10_pr_registration *pr_reg;
struct t10_reservation *pr_tmpl = &su_dev->t10_pr;
unsigned char *cdb = &cmd->t_task_cdb[0];
int crh = (su_dev->t10_pr.res_type == SPC3_PERSISTENT_RESERVATIONS);
int conflict = 0;

if (!se_sess)
return 0;

if (!crh)
goto after_crh;

pr_reg = core_scsi3_locate_pr_reg(cmd->se_dev, se_sess->se_node_acl,
se_sess);
if (pr_reg) {
/*
* From spc4r17 5.7.3 Exceptions to SPC-2 RESERVE and RELEASE
* behavior
*
* A RESERVE(6) or RESERVE(10) command shall complete with GOOD
* status, but no reservation shall be established and the
* persistent reservation shall not be changed, if the command
* is received from a) and b) below.
*
* A RELEASE(6) or RELEASE(10) command shall complete with GOOD
* status, but the persistent reservation shall not be released,
* if the command is received from a) and b)
*
* a) An I_T nexus that is a persistent reservation holder; or
* b) An I_T nexus that is registered if a registrants only or
* all registrants type persistent reservation is present.
*
* In all other cases, a RESERVE(6) command, RESERVE(10) command,
* RELEASE(6) command, or RELEASE(10) command shall be processed
* as defined in SPC-2.
*/
if (pr_reg->pr_res_holder) {
core_scsi3_put_pr_reg(pr_reg);
return 0;
}
if ((pr_reg->pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_REGONLY) ||
(pr_reg->pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_REGONLY) ||
(pr_reg->pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG) ||
(pr_reg->pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG)) {
core_scsi3_put_pr_reg(pr_reg);
return 0;
}
core_scsi3_put_pr_reg(pr_reg);
conflict = 1;
} else {
/*
* Following spc2r20 5.5.1 Reservations overview:
*
* If a logical unit has executed a PERSISTENT RESERVE OUT
* command with the REGISTER or the REGISTER AND IGNORE
* EXISTING KEY service action and is still registered by any
* initiator, all RESERVE commands and all RELEASE commands
* regardless of initiator shall conflict and shall terminate
* with a RESERVATION CONFLICT status.
*/
spin_lock(&pr_tmpl->registration_lock);
conflict = (list_empty(&pr_tmpl->registration_list)) ? 0 : 1;
spin_unlock(&pr_tmpl->registration_lock);
}

if (conflict) {
pr_err("Received legacy SPC-2 RESERVE/RELEASE"
" while active SPC-3 registrations exist,"
" returning RESERVATION_CONFLICT\n");
return PYX_TRANSPORT_RESERVATION_CONFLICT;
}

after_crh:
if ((cdb[0] == RESERVE) || (cdb[0] == RESERVE_10))
return core_scsi2_reservation_reserve(cmd);
else if ((cdb[0] == RELEASE) || (cdb[0] == RELEASE_10))
return core_scsi2_reservation_release(cmd);
else
return PYX_TRANSPORT_INVALID_CDB_FIELD;
}

/*
* Begin SPC-3/SPC-4 Persistent Reservations emulation support
Expand Down Expand Up @@ -418,12 +413,12 @@ static int core_scsi3_pr_seq_non_holder(
break;
case RELEASE:
case RELEASE_10:
/* Handled by CRH=1 in core_scsi2_emulate_crh() */
/* Handled by CRH=1 in target_scsi2_reservation_release() */
ret = 0;
break;
case RESERVE:
case RESERVE_10:
/* Handled by CRH=1 in core_scsi2_emulate_crh() */
/* Handled by CRH=1 in target_scsi2_reservation_reserve() */
ret = 0;
break;
case TEST_UNIT_READY:
Expand Down
3 changes: 2 additions & 1 deletion drivers/target/target_core_pr.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -47,7 +47,8 @@ extern struct kmem_cache *t10_pr_reg_cache;

extern int core_pr_dump_initiator_port(struct t10_pr_registration *,
char *, u32);
extern int core_scsi2_emulate_crh(struct se_cmd *);
extern int target_scsi2_reservation_release(struct se_cmd *cmd);
extern int target_scsi2_reservation_reserve(struct se_cmd *cmd);
extern int core_scsi3_alloc_aptpl_registration(
struct t10_reservation *, u64,
unsigned char *, unsigned char *, u32,
Expand Down
16 changes: 8 additions & 8 deletions drivers/target/target_core_transport.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -2963,10 +2963,10 @@ static int transport_generic_cmd_sequencer(
* is running in SPC_PASSTHROUGH, and wants reservations
* emulation disabled.
*/
cmd->transport_emulate_cdb =
(su_dev->t10_pr.res_type !=
SPC_PASSTHROUGH) ?
core_scsi2_emulate_crh : NULL;
if (su_dev->t10_pr.res_type != SPC_PASSTHROUGH) {
cmd->transport_emulate_cdb =
target_scsi2_reservation_reserve;
}
cmd->se_cmd_flags |= SCF_SCSI_NON_DATA_CDB;
break;
case RELEASE:
Expand All @@ -2980,10 +2980,10 @@ static int transport_generic_cmd_sequencer(
else
size = cmd->data_length;

cmd->transport_emulate_cdb =
(su_dev->t10_pr.res_type !=
SPC_PASSTHROUGH) ?
core_scsi2_emulate_crh : NULL;
if (su_dev->t10_pr.res_type != SPC_PASSTHROUGH) {
cmd->transport_emulate_cdb =
target_scsi2_reservation_release;
}
cmd->se_cmd_flags |= SCF_SCSI_NON_DATA_CDB;
break;
case SYNCHRONIZE_CACHE:
Expand Down

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