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_device.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_device.c')
| -rw-r--r-- | drivers/target/target_core_device.c | 10 |
1 files changed, 6 insertions, 4 deletions
diff --git a/drivers/target/target_core_device.c b/drivers/target/target_core_device.c index d90dbb0f1a6..569a3c7c9e5 100644 --- a/drivers/target/target_core_device.c +++ b/drivers/target/target_core_device.c @@ -92,6 +92,9 @@ transport_lookup_cmd_lun(struct se_cmd *se_cmd, u32 unpacked_lun) se_cmd->pr_res_key = deve->pr_res_key; se_cmd->orig_fe_lun = unpacked_lun; se_cmd->se_cmd_flags |= SCF_SE_LUN_CMD; + + percpu_ref_get(&se_lun->lun_ref); + se_cmd->lun_ref_active = true; } spin_unlock_irqrestore(&se_sess->se_node_acl->device_list_lock, flags); @@ -119,6 +122,9 @@ transport_lookup_cmd_lun(struct se_cmd *se_cmd, u32 unpacked_lun) se_cmd->se_lun = &se_sess->se_tpg->tpg_virt_lun0; se_cmd->orig_fe_lun = 0; se_cmd->se_cmd_flags |= SCF_SE_LUN_CMD; + + percpu_ref_get(&se_lun->lun_ref); + se_cmd->lun_ref_active = true; } /* Directly associate cmd with se_dev */ @@ -134,10 +140,6 @@ transport_lookup_cmd_lun(struct se_cmd *se_cmd, u32 unpacked_lun) dev->read_bytes += se_cmd->data_length; spin_unlock_irqrestore(&dev->stats_lock, flags); - spin_lock_irqsave(&se_lun->lun_cmd_lock, flags); - list_add_tail(&se_cmd->se_lun_node, &se_lun->lun_cmd_list); - spin_unlock_irqrestore(&se_lun->lun_cmd_lock, flags); - return 0; } EXPORT_SYMBOL(transport_lookup_cmd_lun); |