diff options
| author | Nicholas Bellinger <nab@linux-iscsi.org> | 2013-11-06 21:03:43 -0800 |
|---|---|---|
| committer | Nicholas Bellinger <nab@linux-iscsi.org> | 2013-11-07 14:24:52 -0800 |
| commit | 5277797dc4ed873d067477d84e910b39d113f649 (patch) | |
| tree | 5e2aa87dec2cbcb5bbdfadd697c92e86b0e5aa11 /drivers/target/target_core_tpg.c | |
| parent | c9e8d128fe316751230ee0c53478740c64f58436 (diff) | |
target: Add percpu refcounting for se_lun access
This patch adds percpu refcounting for se_lun access that allows the
association of an se_lun + se_cmd in transport_lookup_cmd_lun() to
occur without an extra list_head for tracking outstanding I/O during
se_lun shutdown.
This effectively changes se_lun shutdown logic to wait for outstanding
I/O percpu references to complete in transport_lun_remove_cmd() using
se_lun->lun_ref_comp, instead of explicitly draining the per se_lun
command list and waiting for individual se_cmd descriptor processing
to complete.
Cc: Kent Overstreet <kmo@daterainc.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Diffstat (limited to 'drivers/target/target_core_tpg.c')
| -rw-r--r-- | drivers/target/target_core_tpg.c | 27 |
1 files changed, 24 insertions, 3 deletions
diff --git a/drivers/target/target_core_tpg.c b/drivers/target/target_core_tpg.c index ec992208dc55..f321af04ef03 100644 --- a/drivers/target/target_core_tpg.c +++ b/drivers/target/target_core_tpg.c @@ -634,6 +634,13 @@ int core_tpg_set_initiator_node_tag( } EXPORT_SYMBOL(core_tpg_set_initiator_node_tag); +static void core_tpg_lun_ref_release(struct percpu_ref *ref) +{ + struct se_lun *lun = container_of(ref, struct se_lun, lun_ref); + + complete(&lun->lun_ref_comp); +} + static int core_tpg_setup_virtual_lun0(struct se_portal_group *se_tpg) { /* Set in core_dev_setup_virtual_lun0() */ @@ -651,11 +658,18 @@ static int core_tpg_setup_virtual_lun0(struct se_portal_group *se_tpg) spin_lock_init(&lun->lun_acl_lock); spin_lock_init(&lun->lun_cmd_lock); spin_lock_init(&lun->lun_sep_lock); + init_completion(&lun->lun_ref_comp); - ret = core_tpg_post_addlun(se_tpg, lun, lun_access, dev); + ret = percpu_ref_init(&lun->lun_ref, core_tpg_lun_ref_release); if (ret < 0) return ret; + ret = core_tpg_post_addlun(se_tpg, lun, lun_access, dev); + if (ret < 0) { + percpu_ref_cancel_init(&lun->lun_ref); + return ret; + } + return 0; } @@ -696,6 +710,7 @@ int core_tpg_register( spin_lock_init(&lun->lun_acl_lock); spin_lock_init(&lun->lun_cmd_lock); spin_lock_init(&lun->lun_sep_lock); + init_completion(&lun->lun_ref_comp); } se_tpg->se_tpg_type = se_tpg_type; @@ -816,10 +831,16 @@ int core_tpg_post_addlun( { int ret; - ret = core_dev_export(lun_ptr, tpg, lun); + ret = percpu_ref_init(&lun->lun_ref, core_tpg_lun_ref_release); if (ret < 0) return ret; + ret = core_dev_export(lun_ptr, tpg, lun); + if (ret < 0) { + percpu_ref_cancel_init(&lun->lun_ref); + return ret; + } + spin_lock(&tpg->tpg_lun_lock); lun->lun_access = lun_access; lun->lun_status = TRANSPORT_LUN_STATUS_ACTIVE; @@ -833,7 +854,7 @@ static void core_tpg_shutdown_lun( struct se_lun *lun) { core_clear_lun_from_tpg(lun, tpg); - transport_clear_lun_from_sessions(lun); + transport_clear_lun_ref(lun); } struct se_lun *core_tpg_pre_dellun( |