diff options
author | Nicholas Bellinger <nab@linux-iscsi.org> | 2015-03-22 20:42:19 -0700 |
---|---|---|
committer | Nicholas Bellinger <nab@linux-iscsi.org> | 2015-06-01 00:23:46 -0700 |
commit | 29a05deebf6c2e3010934fb78ee65cab3d329470 (patch) | |
tree | 5b91d971e31c45919ef212513104350877807c3c /drivers/target/target_core_tpg.c | |
parent | d2c27f0d0b7eb18f40b9b1a0d793c8ba074e5c23 (diff) | |
download | linux-29a05deebf6c2e3010934fb78ee65cab3d329470.tar.bz2 |
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 'drivers/target/target_core_tpg.c')
-rw-r--r-- | drivers/target/target_core_tpg.c | 75 |
1 files changed, 3 insertions, 72 deletions
diff --git a/drivers/target/target_core_tpg.c b/drivers/target/target_core_tpg.c index c0c1f67facb5..0519923ef930 100644 --- a/drivers/target/target_core_tpg.c +++ b/drivers/target/target_core_tpg.c @@ -47,42 +47,6 @@ extern struct se_device *g_lun0_dev; static DEFINE_SPINLOCK(tpg_lock); static LIST_HEAD(tpg_list); -/* core_clear_initiator_node_from_tpg(): - * - * - */ -static void core_clear_initiator_node_from_tpg( - struct se_node_acl *nacl, - struct se_portal_group *tpg) -{ - int i; - struct se_dev_entry *deve; - struct se_lun *lun; - - spin_lock_irq(&nacl->device_list_lock); - for (i = 0; i < TRANSPORT_MAX_LUNS_PER_TPG; i++) { - deve = nacl->device_list[i]; - - if (!(deve->lun_flags & TRANSPORT_LUNFLAGS_INITIATOR_ACCESS)) - continue; - - if (!deve->se_lun) { - pr_err("%s device entries device pointer is" - " NULL, but Initiator has access.\n", - tpg->se_tpg_tfo->get_fabric_name()); - continue; - } - - lun = deve->se_lun; - spin_unlock_irq(&nacl->device_list_lock); - core_disable_device_list_for_node(lun, NULL, deve->mapped_lun, - TRANSPORT_LUNFLAGS_NO_ACCESS, nacl, tpg); - - spin_lock_irq(&nacl->device_list_lock); - } - spin_unlock_irq(&nacl->device_list_lock); -} - /* __core_tpg_get_initiator_node_acl(): * * spin_lock_bh(&tpg->acl_node_lock); must be held when calling @@ -225,35 +189,6 @@ static void *array_zalloc(int n, size_t size, gfp_t flags) return a; } -/* core_create_device_list_for_node(): - * - * - */ -static int core_create_device_list_for_node(struct se_node_acl *nacl) -{ - struct se_dev_entry *deve; - int i; - - nacl->device_list = array_zalloc(TRANSPORT_MAX_LUNS_PER_TPG, - sizeof(struct se_dev_entry), GFP_KERNEL); - if (!nacl->device_list) { - pr_err("Unable to allocate memory for" - " struct se_node_acl->device_list\n"); - return -ENOMEM; - } - for (i = 0; i < TRANSPORT_MAX_LUNS_PER_TPG; i++) { - deve = nacl->device_list[i]; - - atomic_set(&deve->ua_count, 0); - atomic_set(&deve->pr_ref_count, 0); - spin_lock_init(&deve->ua_lock); - INIT_LIST_HEAD(&deve->alua_port_list); - INIT_LIST_HEAD(&deve->ua_list); - } - - return 0; -} - static struct se_node_acl *target_alloc_node_acl(struct se_portal_group *tpg, const unsigned char *initiatorname) { @@ -266,10 +201,11 @@ static struct se_node_acl *target_alloc_node_acl(struct se_portal_group *tpg, INIT_LIST_HEAD(&acl->acl_list); INIT_LIST_HEAD(&acl->acl_sess_list); + INIT_HLIST_HEAD(&acl->lun_entry_hlist); kref_init(&acl->acl_kref); init_completion(&acl->acl_free_comp); - spin_lock_init(&acl->device_list_lock); spin_lock_init(&acl->nacl_sess_lock); + mutex_init(&acl->lun_entry_mutex); atomic_set(&acl->acl_pr_ref_count, 0); if (tpg->se_tpg_tfo->tpg_get_default_depth) acl->queue_depth = tpg->se_tpg_tfo->tpg_get_default_depth(tpg); @@ -281,15 +217,11 @@ static struct se_node_acl *target_alloc_node_acl(struct se_portal_group *tpg, tpg->se_tpg_tfo->set_default_node_attributes(acl); - if (core_create_device_list_for_node(acl) < 0) - goto out_free_acl; if (core_set_queue_depth_for_node(tpg, acl) < 0) - goto out_free_device_list; + goto out_free_acl; return acl; -out_free_device_list: - core_free_device_list_for_node(acl, tpg); out_free_acl: kfree(acl); return NULL; @@ -454,7 +386,6 @@ void core_tpg_del_initiator_node_acl(struct se_node_acl *acl) wait_for_completion(&acl->acl_free_comp); core_tpg_wait_for_nacl_pr_ref(acl); - core_clear_initiator_node_from_tpg(acl, tpg); core_free_device_list_for_node(acl, tpg); pr_debug("%s_TPG[%hu] - Deleted ACL with TCQ Depth: %d for %s" |