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authorNicholas Bellinger <nab@linux-iscsi.org>2013-11-07 06:03:43 +0100
committerNicholas Bellinger <nab@linux-iscsi.org>2013-11-07 23:24:52 +0100
commit5277797dc4ed873d067477d84e910b39d113f649 (patch)
tree5e2aa87dec2cbcb5bbdfadd697c92e86b0e5aa11 /include/target
parentpercpu-refcount: Add EXPORT_SYMBOL to use percpu_ref from modules (diff)
downloadlinux-5277797dc4ed873d067477d84e910b39d113f649.tar.xz
linux-5277797dc4ed873d067477d84e910b39d113f649.zip
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 'include/target')
-rw-r--r--include/target/target_core_base.h5
1 files changed, 5 insertions, 0 deletions
diff --git a/include/target/target_core_base.h b/include/target/target_core_base.h
index 22e752c4406d..4d16fd9330a6 100644
--- a/include/target/target_core_base.h
+++ b/include/target/target_core_base.h
@@ -499,6 +499,9 @@ struct se_cmd {
/* backend private data */
void *priv;
+
+ /* Used for lun->lun_ref counting */
+ bool lun_ref_active;
};
struct se_ua {
@@ -757,6 +760,8 @@ struct se_lun {
struct se_port *lun_sep;
struct config_group lun_group;
struct se_port_stat_grps port_stat_grps;
+ struct completion lun_ref_comp;
+ struct percpu_ref lun_ref;
};
struct scsi_port_stats {