path: root/include/target/target_core_backend.h
diff options
authorNicholas Bellinger <nab@linux-iscsi.org>2015-03-22 20:42:19 -0700
committerNicholas Bellinger <nab@linux-iscsi.org>2015-06-01 00:23:46 -0700
commit29a05deebf6c2e3010934fb78ee65cab3d329470 (patch)
tree5b91d971e31c45919ef212513104350877807c3c /include/target/target_core_backend.h
parentd2c27f0d0b7eb18f40b9b1a0d793c8ba074e5c23 (diff)
target: Convert se_node_acl->device_list[] to RCU hlist
This patch converts se_node_acl->device_list[] table for mappedluns to modern RCU hlist_head usage in order to support an arbitrary number of node_acl lun mappings. It converts transport_lookup_*_lun() fast-path code to use RCU read path primitives when looking up se_dev_entry. It adds a new hlist_head at se_node_acl->lun_entry_hlist for this purpose. For transport_lookup_cmd_lun() code, it works with existing per-cpu se_lun->lun_ref when associating se_cmd with se_lun + se_device. Also, go ahead and update core_create_device_list_for_node() + core_free_device_list_for_node() to use ->lun_entry_hlist. It also converts se_dev_entry->pr_ref_count access to use modern struct kref counting, and updates core_disable_device_list_for_node() to kref_put() and block on se_deve->pr_comp waiting for outstanding PR special-case PR references to drop, then invoke kfree_rcu() to wait for the RCU grace period to complete before releasing memory. So now that se_node_acl->lun_entry_hlist fast path access uses RCU protected pointers, go ahead and convert remaining non-fast path RCU updater code using ->lun_entry_lock to struct mutex to allow callers to block while walking se_node_acl->lun_entry_hlist. Finally drop the left-over core_clear_initiator_node_from_tpg() that originally cleared lun_access during se_node_acl shutdown, as post RCU conversion it now becomes duplicated logic. Reviewed-by: Hannes Reinecke <hare@suse.de> Cc: Christoph Hellwig <hch@lst.de> Cc: Sagi Grimberg <sagig@mellanox.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Diffstat (limited to 'include/target/target_core_backend.h')
1 files changed, 1 insertions, 1 deletions
diff --git a/include/target/target_core_backend.h b/include/target/target_core_backend.h
index 47fafec556f8..80d9e486e33e 100644
--- a/include/target/target_core_backend.h
+++ b/include/target/target_core_backend.h
@@ -101,7 +101,7 @@ int target_alloc_sgl(struct scatterlist **, unsigned int *, u32, bool);
sense_reason_t transport_generic_map_mem_to_cmd(struct se_cmd *,
struct scatterlist *, u32, struct scatterlist *, u32);
-void array_free(void *array, int n);
+bool target_lun_is_rdonly(struct se_cmd *);
/* From target_core_configfs.c to setup default backend config_item_types */
void target_core_setup_sub_cits(struct se_subsystem_api *);