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authorMike Christie <michael.christie@oracle.com>2021-09-29 21:04:22 -0500
committerMartin K. Petersen <martin.petersen@oracle.com>2021-10-18 22:38:36 -0400
commitf9793d649c29bad86651620ec49888ee9743cbb6 (patch)
tree8e7fb9e52d3a43dddc1424ffc5d0d6342d69b5b6 /drivers/target
parent7324f47d4293ff50f489010735a4057defb1a5d6 (diff)
scsi: target: Perform ALUA group changes in one step
When userspace changes the LUN's ALUA group, it will set the LUN's group to NULL then to the new group. Before the new group is set, target_alua_state_check() will return 0 and allow the I/O to execute. This has us skip the NULL stage, and just swap in the new group. Link: https://lore.kernel.org/r/20210930020422.92578-6-michael.christie@oracle.com Signed-off-by: Mike Christie <michael.christie@oracle.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Diffstat (limited to 'drivers/target')
-rw-r--r--drivers/target/target_core_alua.c23
1 files changed, 16 insertions, 7 deletions
diff --git a/drivers/target/target_core_alua.c b/drivers/target/target_core_alua.c
index 74944b914b4e..b56ef8af66e7 100644
--- a/drivers/target/target_core_alua.c
+++ b/drivers/target/target_core_alua.c
@@ -1835,8 +1835,6 @@ static void __target_detach_tg_pt_gp(struct se_lun *lun,
list_del_init(&lun->lun_tg_pt_gp_link);
tg_pt_gp->tg_pt_gp_members--;
spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
-
- rcu_assign_pointer(lun->lun_tg_pt_gp, NULL);
}
void target_detach_tg_pt_gp(struct se_lun *lun)
@@ -1846,12 +1844,25 @@ void target_detach_tg_pt_gp(struct se_lun *lun)
spin_lock(&lun->lun_tg_pt_gp_lock);
tg_pt_gp = rcu_dereference_check(lun->lun_tg_pt_gp,
lockdep_is_held(&lun->lun_tg_pt_gp_lock));
- if (tg_pt_gp)
+ if (tg_pt_gp) {
__target_detach_tg_pt_gp(lun, tg_pt_gp);
+ rcu_assign_pointer(lun->lun_tg_pt_gp, NULL);
+ }
spin_unlock(&lun->lun_tg_pt_gp_lock);
synchronize_rcu();
}
+static void target_swap_tg_pt_gp(struct se_lun *lun,
+ struct t10_alua_tg_pt_gp *old_tg_pt_gp,
+ struct t10_alua_tg_pt_gp *new_tg_pt_gp)
+{
+ assert_spin_locked(&lun->lun_tg_pt_gp_lock);
+
+ if (old_tg_pt_gp)
+ __target_detach_tg_pt_gp(lun, old_tg_pt_gp);
+ __target_attach_tg_pt_gp(lun, new_tg_pt_gp);
+}
+
ssize_t core_alua_show_tg_pt_gp_info(struct se_lun *lun, char *page)
{
struct config_item *tg_pt_ci;
@@ -1941,18 +1952,16 @@ ssize_t core_alua_store_tg_pt_gp_info(
&tg_pt_gp->tg_pt_gp_group.cg_item),
tg_pt_gp->tg_pt_gp_id);
- __target_detach_tg_pt_gp(lun, tg_pt_gp);
- __target_attach_tg_pt_gp(lun,
+ target_swap_tg_pt_gp(lun, tg_pt_gp,
dev->t10_alua.default_tg_pt_gp);
spin_unlock(&lun->lun_tg_pt_gp_lock);
goto sync_rcu;
}
- __target_detach_tg_pt_gp(lun, tg_pt_gp);
move = 1;
}
- __target_attach_tg_pt_gp(lun, tg_pt_gp_new);
+ target_swap_tg_pt_gp(lun, tg_pt_gp, tg_pt_gp_new);
spin_unlock(&lun->lun_tg_pt_gp_lock);
pr_debug("Target_Core_ConfigFS: %s %s/tpgt_%hu/%s to ALUA"
" Target Port Group: alua/%s, ID: %hu\n", (move) ?