From d19c4643a52f0a56a7ccc86b145f207a57f40116 Mon Sep 17 00:00:00 2001 From: Mike Christie Date: Wed, 29 Mar 2017 00:19:24 -0500 Subject: target: Fix ALUA transition state race between multiple initiators Multiple threads could be writing to alua_access_state at the same time, or there could be multiple STPGs in flight (different initiators sending them or one initiator sending them to different ports), or a combo of both and the core_alua_do_transition_tg_pt calls will race with each other. Because from the last patches we no longer delay running core_alua_do_transition_tg_pt_work, there does not seem to be any point in running that in a workqueue. And, we always wait for it to complete one way or another, so we can sleep in this code path. So, this patch made over target-pending just adds a mutex and does the work core_alua_do_transition_tg_pt_work was doing in core_alua_do_transition_tg_pt. There is also no need to use an atomic for the tg_pt_gp_alua_access_state. In core_alua_do_transition_tg_pt we will test and set it under the transition mutex. And, it is a int/32 bits so in the other places where it is read, we will never see it partially updated. Signed-off-by: Mike Christie Signed-off-by: Nicholas Bellinger --- include/target/target_core_base.h | 8 ++------ 1 file changed, 2 insertions(+), 6 deletions(-) (limited to 'include') diff --git a/include/target/target_core_base.h b/include/target/target_core_base.h index 730ed3055336..ccfad0e9c2cd 100644 --- a/include/target/target_core_base.h +++ b/include/target/target_core_base.h @@ -280,8 +280,6 @@ struct t10_alua_tg_pt_gp { u16 tg_pt_gp_id; int tg_pt_gp_valid_id; int tg_pt_gp_alua_supported_states; - int tg_pt_gp_alua_pending_state; - int tg_pt_gp_alua_previous_state; int tg_pt_gp_alua_access_status; int tg_pt_gp_alua_access_type; int tg_pt_gp_nonop_delay_msecs; @@ -290,18 +288,16 @@ struct t10_alua_tg_pt_gp { int tg_pt_gp_pref; int tg_pt_gp_write_metadata; u32 tg_pt_gp_members; - atomic_t tg_pt_gp_alua_access_state; + int tg_pt_gp_alua_access_state; atomic_t tg_pt_gp_ref_cnt; spinlock_t tg_pt_gp_lock; - struct mutex tg_pt_gp_md_mutex; + struct mutex tg_pt_gp_transition_mutex; struct se_device *tg_pt_gp_dev; struct config_group tg_pt_gp_group; struct list_head tg_pt_gp_list; struct list_head tg_pt_gp_lun_list; struct se_lun *tg_pt_gp_alua_lun; struct se_node_acl *tg_pt_gp_alua_nacl; - struct work_struct tg_pt_gp_transition_work; - struct completion *tg_pt_gp_transition_complete; }; struct t10_vpd { -- cgit v1.2.3