diff options
author | Nicholas Bellinger <nab@linux-iscsi.org> | 2014-12-15 11:50:26 -0800 |
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committer | Nicholas Bellinger <nab@linux-iscsi.org> | 2014-12-15 20:38:34 -0800 |
commit | 6c3c9baa0debeb4bcc52a78c4463a0a97518de10 (patch) | |
tree | 73ff0c1adb684784f2e2d6ca4ca2977ccc2e5a93 | |
parent | d16ca7c5198fd668db10d2c7b048ed3359c12c54 (diff) | |
download | op-kernel-dev-6c3c9baa0debeb4bcc52a78c4463a0a97518de10.zip op-kernel-dev-6c3c9baa0debeb4bcc52a78c4463a0a97518de10.tar.gz |
target: Avoid dropping AllRegistrants reservation during unregister
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@gmail.com>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
-rw-r--r-- | drivers/target/target_core_pr.c | 87 |
1 files changed, 65 insertions, 22 deletions
diff --git a/drivers/target/target_core_pr.c b/drivers/target/target_core_pr.c index c4a8da5..703890c 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) @@ -1177,7 +1177,7 @@ static int core_scsi3_check_implicit_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 @@ -1219,7 +1219,8 @@ 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. @@ -1271,6 +1272,7 @@ 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. @@ -1278,13 +1280,18 @@ 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) { @@ -1307,7 +1314,7 @@ 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); @@ -2103,13 +2110,13 @@ 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_implicit_release( - cmd->se_dev, pr_reg); + type = pr_reg->pr_res_type; + pr_holder = core_scsi3_check_implicit_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); /* @@ -2383,23 +2390,59 @@ static void __core_scsi3_complete_pro_release( struct se_device *dev, struct se_node_acl *se_nacl, struct t10_pr_registration *pr_reg, - int explicit) + int explicit, + 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(), (explicit) ? "explicit" : "implicit", - 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(), (explicit) ? "explicit" : + "implicit", 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); @@ -2530,7 +2573,7 @@ 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); @@ -2618,7 +2661,7 @@ 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); /* @@ -2677,7 +2720,7 @@ 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; @@ -2922,8 +2965,8 @@ 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 @@ -3386,7 +3429,7 @@ 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 |