leandrof/linux
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

target: Drop se_lun->lun_active for existing percpu lun_ref

Browse Source 
With se_port_t and t10_alua_tg_pt_gp_member being absored into se_lun,
there is no need for an extra atomic_t based reference count for PR
ALL_TG_PT=1 and ALUA access state transition.

Go ahead and use the existing percpu se_lun->lun_ref instead, and
convert the two special cases to percpu_ref_tryget_live() to avoid
se_lun if transport_clear_lun_ref() has already been invoked to
shutdown the se_lun.

Cc: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
This commit is contained in:
Nicholas Bellinger
2015-05-20 21:21:08 -07:00
parent 4cc987eaff
commit 9e37d042cf
4 changed files with 14 additions and 11 deletions
Download Patch File Download Diff File Expand all files Collapse all files

9
drivers/target/target_core_pr.c
View File

@@ -704,7 +704,8 @@ static struct t10_pr_registration *__core_scsi3_alloc_registration(
*/
spin_lock(&dev->se_port_lock);
list_for_each_entry_safe(lun_tmp, next, &dev->dev_sep_list, lun_dev_link) {
atomic_inc_mb(&lun_tmp->lun_active);
if (!percpu_ref_tryget_live(&lun_tmp->lun_ref))
continue;
spin_unlock(&dev->se_port_lock);
spin_lock_bh(&lun_tmp->lun_deve_lock);
@@ -751,7 +752,7 @@ static struct t10_pr_registration *__core_scsi3_alloc_registration(
if (ret < 0) {
pr_err("core_scsi3_lunacl_depend"
"_item() failed\n");
atomic_dec_mb(&lun->lun_active);
percpu_ref_put(&lun_tmp->lun_ref);
kref_put(&deve_tmp->pr_kref, target_pr_kref_release);
goto out;
}
@@ -770,7 +771,7 @@ static struct t10_pr_registration *__core_scsi3_alloc_registration(
deve_tmp->mapped_lun, NULL,
sa_res_key, all_tg_pt, aptpl);
if (!pr_reg_atp) {
atomic_dec_mb(&lun_tmp->lun_active);
percpu_ref_put(&lun_tmp->lun_ref);
core_scsi3_lunacl_undepend_item(deve_tmp);
goto out;
}
@@ -782,7 +783,7 @@ static struct t10_pr_registration *__core_scsi3_alloc_registration(
spin_unlock_bh(&lun_tmp->lun_deve_lock);
spin_lock(&dev->se_port_lock);
atomic_dec_mb(&lun_tmp->lun_active);
percpu_ref_put(&lun_tmp->lun_ref);
}
spin_unlock(&dev->se_port_lock);