From 29a05deebf6c2e3010934fb78ee65cab3d329470 Mon Sep 17 00:00:00 2001 From: Nicholas Bellinger Date: Sun, 22 Mar 2015 20:42:19 -0700 Subject: 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 Cc: Christoph Hellwig Cc: Sagi Grimberg Cc: Paul E. McKenney Signed-off-by: Nicholas Bellinger --- include/target/target_core_backend.h | 2 +- include/target/target_core_base.h | 27 +++++++++++++++------------ 2 files changed, 16 insertions(+), 13 deletions(-) (limited to 'include') 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 *); diff --git a/include/target/target_core_base.h b/include/target/target_core_base.h index 042a73464966..b518523cba7b 100644 --- a/include/target/target_core_base.h +++ b/include/target/target_core_base.h @@ -160,10 +160,8 @@ enum se_cmd_flags_table { /* struct se_dev_entry->lun_flags and struct se_lun->lun_access */ enum transport_lunflags_table { - TRANSPORT_LUNFLAGS_NO_ACCESS = 0x00, - TRANSPORT_LUNFLAGS_INITIATOR_ACCESS = 0x01, - TRANSPORT_LUNFLAGS_READ_ONLY = 0x02, - TRANSPORT_LUNFLAGS_READ_WRITE = 0x04, + TRANSPORT_LUNFLAGS_READ_ONLY = 0x01, + TRANSPORT_LUNFLAGS_READ_WRITE = 0x02, }; /* @@ -584,10 +582,10 @@ struct se_node_acl { char acl_tag[MAX_ACL_TAG_SIZE]; /* Used for PR SPEC_I_PT=1 and REGISTER_AND_MOVE */ atomic_t acl_pr_ref_count; - struct se_dev_entry **device_list; + struct hlist_head lun_entry_hlist; struct se_session *nacl_sess; struct se_portal_group *se_tpg; - spinlock_t device_list_lock; + struct mutex lun_entry_mutex; spinlock_t nacl_sess_lock; struct config_group acl_group; struct config_group acl_attrib_group; @@ -644,20 +642,23 @@ struct se_dev_entry { /* See transport_lunflags_table */ u32 lun_flags; u32 mapped_lun; - u32 total_cmds; u64 pr_res_key; u64 creation_time; u32 attach_count; - u64 read_bytes; - u64 write_bytes; + atomic_long_t total_cmds; + atomic_long_t read_bytes; + atomic_long_t write_bytes; atomic_t ua_count; /* Used for PR SPEC_I_PT=1 and REGISTER_AND_MOVE */ - atomic_t pr_ref_count; - struct se_lun_acl *se_lun_acl; + struct kref pr_kref; + struct completion pr_comp; + struct se_lun_acl __rcu *se_lun_acl; spinlock_t ua_lock; - struct se_lun *se_lun; + struct se_lun __rcu *se_lun; struct list_head alua_port_list; struct list_head ua_list; + struct hlist_node link; + struct rcu_head rcu_head; }; struct se_dev_attrib { @@ -703,6 +704,7 @@ struct se_port_stat_grps { }; struct se_lun { + u16 lun_rtpi; #define SE_LUN_LINK_MAGIC 0xffff7771 u32 lun_link_magic; /* See transport_lun_status_table */ @@ -710,6 +712,7 @@ struct se_lun { u32 lun_access; u32 lun_flags; u32 unpacked_lun; + u32 lun_index; atomic_t lun_acl_count; spinlock_t lun_acl_lock; spinlock_t lun_sep_lock; -- cgit v1.2.3