From: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx>
This patch has been added to the 3.12 stable tree. If you have any
objections, please let us know.
===============
commit 6c3c9baa0debeb4bcc52a78c4463a0a97518de10 upstream.
This patch fixes an issue with AllRegistrants reservations where
an unregister operation by the I_T nexus reservation holder would
incorrectly drop the reservation, instead of waiting until the
last active I_T nexus is unregistered as per SPC-4.
This includes updating __core_scsi3_complete_pro_release() to reset
dev->dev_pr_res_holder with another pr_reg for this special case,
as well as a new 'unreg' parameter to determine when the release
is occuring from an implicit unregister, vs. explicit RELEASE.
It also adds special handling in core_scsi3_free_pr_reg_from_nacl()
to release the left-over pr_res_holder, now that pr_reg is deleted
from pr_reg_list within __core_scsi3_complete_pro_release().
Reported-by: Ilias Tsitsimpis <i.tsitsimpis@xxxxxxxxx>
Cc: James Bottomley <James.Bottomley@xxxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx>
Signed-off-by: Jiri Slaby <jslaby@xxxxxxx>
---
drivers/target/target_core_pr.c | 87 ++++++++++++++++++++++++++++++-----------
1 file changed, 65 insertions(+), 22 deletions(-)
diff --git a/drivers/target/target_core_pr.c b/drivers/target/target_core_pr.c
index 39f0e32c77e7..13a4836765ea 100644
--- a/drivers/target/target_core_pr.c
+++ b/drivers/target/target_core_pr.c
@@ -76,7 +76,7 @@ enum preempt_type {
};
static void __core_scsi3_complete_pro_release(struct se_device *, struct se_node_acl *,
- struct t10_pr_registration *, int);
+ struct t10_pr_registration *, int, int);
static sense_reason_t
target_scsi2_reservation_check(struct se_cmd *cmd)
@@ -1186,7 +1186,7 @@ static int core_scsi3_check_implict_release(
* service action with the SERVICE ACTION RESERVATION KEY
* field set to zero (see 5.7.11.3).
*/
- __core_scsi3_complete_pro_release(dev, nacl, pr_reg, 0);
+ __core_scsi3_complete_pro_release(dev, nacl, pr_reg, 0, 1);
ret = 1;
/*
* For 'All Registrants' reservation types, all existing
@@ -1228,7 +1228,8 @@ static void __core_scsi3_free_registration(
pr_reg->pr_reg_deve->def_pr_registered = 0;
pr_reg->pr_reg_deve->pr_res_key = 0;
- list_del(&pr_reg->pr_reg_list);
+ if (!list_empty(&pr_reg->pr_reg_list))
+ list_del(&pr_reg->pr_reg_list);
/*
* Caller accessing *pr_reg using core_scsi3_locate_pr_reg(),
* so call core_scsi3_put_pr_reg() to decrement our reference.
@@ -1280,6 +1281,7 @@ void core_scsi3_free_pr_reg_from_nacl(
{
struct t10_reservation *pr_tmpl = &dev->t10_pr;
struct t10_pr_registration *pr_reg, *pr_reg_tmp, *pr_res_holder;
+ bool free_reg = false;
/*
* If the passed se_node_acl matches the reservation holder,
* release the reservation.
@@ -1287,13 +1289,18 @@ void core_scsi3_free_pr_reg_from_nacl(
spin_lock(&dev->dev_reservation_lock);
pr_res_holder = dev->dev_pr_res_holder;
if ((pr_res_holder != NULL) &&
- (pr_res_holder->pr_reg_nacl == nacl))
- __core_scsi3_complete_pro_release(dev, nacl, pr_res_holder, 0);
+ (pr_res_holder->pr_reg_nacl == nacl)) {
+ __core_scsi3_complete_pro_release(dev, nacl, pr_res_holder, 0, 1);
+ free_reg = true;
+ }
spin_unlock(&dev->dev_reservation_lock);
/*
* Release any registration associated with the struct se_node_acl.
*/
spin_lock(&pr_tmpl->registration_lock);
+ if (pr_res_holder && free_reg)
+ __core_scsi3_free_registration(dev, pr_res_holder, NULL, 0);
+
list_for_each_entry_safe(pr_reg, pr_reg_tmp,
&pr_tmpl->registration_list, pr_reg_list) {
@@ -1316,7 +1323,7 @@ void core_scsi3_free_all_registrations(
if (pr_res_holder != NULL) {
struct se_node_acl *pr_res_nacl = pr_res_holder->pr_reg_nacl;
__core_scsi3_complete_pro_release(dev, pr_res_nacl,
- pr_res_holder, 0);
+ pr_res_holder, 0, 0);
}
spin_unlock(&dev->dev_reservation_lock);
@@ -2126,13 +2133,13 @@ core_scsi3_emulate_pro_register(struct se_cmd *cmd, u64 res_key, u64 sa_res_key,
/*
* sa_res_key=0 Unregister Reservation Key for registered I_T Nexus.
*/
- pr_holder = core_scsi3_check_implict_release(
- cmd->se_dev, pr_reg);
+ type = pr_reg->pr_res_type;
+ pr_holder = core_scsi3_check_implict_release(cmd->se_dev,
+ pr_reg);
if (pr_holder < 0) {
ret = TCM_RESERVATION_CONFLICT;
goto out;
}
- type = pr_reg->pr_res_type;
spin_lock(&pr_tmpl->registration_lock);
/*
@@ -2406,23 +2413,59 @@ static void __core_scsi3_complete_pro_release(
struct se_device *dev,
struct se_node_acl *se_nacl,
struct t10_pr_registration *pr_reg,
- int explict)
+ int explict,
+ int unreg)
{
struct target_core_fabric_ops *tfo = se_nacl->se_tpg->se_tpg_tfo;
char i_buf[PR_REG_ISID_ID_LEN];
+ int pr_res_type = 0, pr_res_scope = 0;
memset(i_buf, 0, PR_REG_ISID_ID_LEN);
core_pr_dump_initiator_port(pr_reg, i_buf, PR_REG_ISID_ID_LEN);
/*
* Go ahead and release the current PR reservation holder.
+ * If an All Registrants reservation is currently active and
+ * a unregister operation is requested, replace the current
+ * dev_pr_res_holder with another active registration.
*/
- dev->dev_pr_res_holder = NULL;
+ if (dev->dev_pr_res_holder) {
+ pr_res_type = dev->dev_pr_res_holder->pr_res_type;
+ pr_res_scope = dev->dev_pr_res_holder->pr_res_scope;
+ dev->dev_pr_res_holder->pr_res_type = 0;
+ dev->dev_pr_res_holder->pr_res_scope = 0;
+ dev->dev_pr_res_holder->pr_res_holder = 0;
+ dev->dev_pr_res_holder = NULL;
+ }
+ if (!unreg)
+ goto out;
- pr_debug("SPC-3 PR [%s] Service Action: %s RELEASE cleared"
- " reservation holder TYPE: %s ALL_TG_PT: %d\n",
- tfo->get_fabric_name(), (explict) ? "explict" : "implict",
- core_scsi3_pr_dump_type(pr_reg->pr_res_type),
- (pr_reg->pr_reg_all_tg_pt) ? 1 : 0);
+ spin_lock(&dev->t10_pr.registration_lock);
+ list_del_init(&pr_reg->pr_reg_list);
+ /*
+ * If the I_T nexus is a reservation holder, the persistent reservation
+ * is of an all registrants type, and the I_T nexus is the last remaining
+ * registered I_T nexus, then the device server shall also release the
+ * persistent reservation.
+ */
+ if (!list_empty(&dev->t10_pr.registration_list) &&
+ ((pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG) ||
+ (pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG))) {
+ dev->dev_pr_res_holder =
+ list_entry(dev->t10_pr.registration_list.next,
+ struct t10_pr_registration, pr_reg_list);
+ dev->dev_pr_res_holder->pr_res_type = pr_res_type;
+ dev->dev_pr_res_holder->pr_res_scope = pr_res_scope;
+ dev->dev_pr_res_holder->pr_res_holder = 1;
+ }
+ spin_unlock(&dev->t10_pr.registration_lock);
+out:
+ if (!dev->dev_pr_res_holder) {
+ pr_debug("SPC-3 PR [%s] Service Action: %s RELEASE cleared"
+ " reservation holder TYPE: %s ALL_TG_PT: %d\n",
+ tfo->get_fabric_name(), (explict) ? "explict" :
+ "implict", core_scsi3_pr_dump_type(pr_res_type),
+ (pr_reg->pr_reg_all_tg_pt) ? 1 : 0);
+ }
pr_debug("SPC-3 PR [%s] RELEASE Node: %s%s\n",
tfo->get_fabric_name(), se_nacl->initiatorname,
i_buf);
@@ -2553,7 +2596,7 @@ core_scsi3_emulate_pro_release(struct se_cmd *cmd, int type, int scope,
* server shall not establish a unit attention condition.
*/
__core_scsi3_complete_pro_release(dev, se_sess->se_node_acl,
- pr_reg, 1);
+ pr_reg, 1, 0);
spin_unlock(&dev->dev_reservation_lock);
@@ -2641,7 +2684,7 @@ core_scsi3_emulate_pro_clear(struct se_cmd *cmd, u64 res_key)
if (pr_res_holder) {
struct se_node_acl *pr_res_nacl = pr_res_holder->pr_reg_nacl;
__core_scsi3_complete_pro_release(dev, pr_res_nacl,
- pr_res_holder, 0);
+ pr_res_holder, 0, 0);
}
spin_unlock(&dev->dev_reservation_lock);
/*
@@ -2700,7 +2743,7 @@ static void __core_scsi3_complete_pro_preempt(
*/
if (dev->dev_pr_res_holder)
__core_scsi3_complete_pro_release(dev, nacl,
- dev->dev_pr_res_holder, 0);
+ dev->dev_pr_res_holder, 0, 0);
dev->dev_pr_res_holder = pr_reg;
pr_reg->pr_res_holder = 1;
@@ -2944,8 +2987,8 @@ core_scsi3_pro_preempt(struct se_cmd *cmd, int type, int scope, u64 res_key,
*/
if (pr_reg_n != pr_res_holder)
__core_scsi3_complete_pro_release(dev,
- pr_res_holder->pr_reg_nacl,
- dev->dev_pr_res_holder, 0);
+ pr_res_holder->pr_reg_nacl,
+ dev->dev_pr_res_holder, 0, 0);
/*
* b) Remove the registrations for all I_T nexuses identified
* by the SERVICE ACTION RESERVATION KEY field, except the
@@ -3415,7 +3458,7 @@ after_iport_check:
* holder (i.e., the I_T nexus on which the
*/
__core_scsi3_complete_pro_release(dev, pr_res_nacl,
- dev->dev_pr_res_holder, 0);
+ dev->dev_pr_res_holder, 0, 0);
/*
* g) Move the persistent reservation to the specified I_T nexus using
* the same scope and type as the persistent reservation released in
--
2.3.3
--
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