From 6bb826121be244a5a3c8bd8b7d45c47df18810b7 Mon Sep 17 00:00:00 2001 From: Nicholas Bellinger Date: Sun, 10 May 2015 19:31:10 -0700 Subject: target: Convert se_portal_group->tpg_lun_list[] to RCU hlist This patch converts the fixed size se_portal_group->tpg_lun_list[] to use modern RCU with hlist_head in order to support an arbitary number of se_lun ports per target endpoint. It includes dropping core_tpg_alloc_lun() from core_dev_add_lun(), and calling it directly from target_fabric_make_lun() to allocate a new se_lun. And add a new target_fabric_port_release() configfs item callback to invoke kfree_rcu() to release memory during se_lun->lun_group shutdown. Also now that se_node_acl->lun_entry_hlist is using RCU, convert existing tpg_lun_lock to struct mutex so core_tpg_add_node_to_devs() can perform RCU updater logic without releasing ->tpg_lun_mutex. Also, drop core_tpg_clear_object_luns() and it's single consumer in iscsi-target, which is duplicating TPG LUN shutdown logic and is current code results in a NOP. Finally, sbp-target and xen-scsiback fabric driver conversions are included, which are required due to the non-standard way they use ->tpg_lun_hlist. Reviewed-by: Hannes Reinecke Cc: Christoph Hellwig Cc: Sagi Grimberg Cc: Paul E. McKenney Cc: Chris Boot Signed-off-by: Nicholas Bellinger --- drivers/target/target_core_fabric_configfs.c | 34 ++++++++++++++++------------ 1 file changed, 20 insertions(+), 14 deletions(-) (limited to 'drivers/target/target_core_fabric_configfs.c') diff --git a/drivers/target/target_core_fabric_configfs.c b/drivers/target/target_core_fabric_configfs.c index 0939a5492c16..9be8030e016f 100644 --- a/drivers/target/target_core_fabric_configfs.c +++ b/drivers/target/target_core_fabric_configfs.c @@ -81,7 +81,7 @@ static int target_fabric_mappedlun_link( struct se_lun_acl, se_lun_group); struct se_portal_group *se_tpg; struct config_item *nacl_ci, *tpg_ci, *tpg_ci_s, *wwn_ci, *wwn_ci_s; - int ret = 0, lun_access; + int lun_access; if (lun->lun_link_magic != SE_LUN_LINK_MAGIC) { pr_err("Bad lun->lun_link_magic, not a valid lun_ci pointer:" @@ -137,12 +137,9 @@ static int target_fabric_mappedlun_link( * Determine the actual mapped LUN value user wants.. * * This value is what the SCSI Initiator actually sees the - * iscsi/$IQN/$TPGT/lun/lun_* as on their SCSI Initiator Ports. + * $FABRIC/$WWPN/$TPGT/lun/lun_* as on their SCSI Initiator Ports. */ - ret = core_dev_add_initiator_node_lun_acl(se_tpg, lacl, - lun->unpacked_lun, lun_access); - - return (ret < 0) ? -EINVAL : 0; + return core_dev_add_initiator_node_lun_acl(se_tpg, lacl, lun, lun_access); } static int target_fabric_mappedlun_unlink( @@ -761,7 +758,6 @@ static int target_fabric_port_link( struct config_item *tpg_ci; struct se_lun *lun = container_of(to_config_group(lun_ci), struct se_lun, lun_group); - struct se_lun *lun_p; struct se_portal_group *se_tpg; struct se_device *dev = container_of(to_config_group(se_dev_ci), struct se_device, dev_group); @@ -789,10 +785,9 @@ static int target_fabric_port_link( return -EEXIST; } - lun_p = core_dev_add_lun(se_tpg, dev, lun->unpacked_lun); - if (IS_ERR(lun_p)) { - pr_err("core_dev_add_lun() failed\n"); - ret = PTR_ERR(lun_p); + ret = core_dev_add_lun(se_tpg, dev, lun); + if (ret) { + pr_err("core_dev_add_lun() failed: %d\n", ret); goto out; } @@ -832,9 +827,18 @@ static int target_fabric_port_unlink( return 0; } +static void target_fabric_port_release(struct config_item *item) +{ + struct se_lun *lun = container_of(to_config_group(item), + struct se_lun, lun_group); + + kfree_rcu(lun, rcu_head); +} + static struct configfs_item_operations target_fabric_port_item_ops = { .show_attribute = target_fabric_port_attr_show, .store_attribute = target_fabric_port_attr_store, + .release = target_fabric_port_release, .allow_link = target_fabric_port_link, .drop_link = target_fabric_port_unlink, }; @@ -893,15 +897,16 @@ static struct config_group *target_fabric_make_lun( if (unpacked_lun > UINT_MAX) return ERR_PTR(-EINVAL); - lun = core_get_lun_from_tpg(se_tpg, unpacked_lun); - if (!lun) - return ERR_PTR(-EINVAL); + lun = core_tpg_alloc_lun(se_tpg, unpacked_lun); + if (IS_ERR(lun)) + return ERR_CAST(lun); lun_cg = &lun->lun_group; lun_cg->default_groups = kmalloc(sizeof(struct config_group *) * 2, GFP_KERNEL); if (!lun_cg->default_groups) { pr_err("Unable to allocate lun_cg->default_groups\n"); + kfree(lun); return ERR_PTR(-ENOMEM); } @@ -918,6 +923,7 @@ static struct config_group *target_fabric_make_lun( if (!port_stat_grp->default_groups) { pr_err("Unable to allocate port_stat_grp->default_groups\n"); kfree(lun_cg->default_groups); + kfree(lun); return ERR_PTR(-ENOMEM); } target_stat_setup_port_default_groups(lun); -- cgit v1.2.3-59-g8ed1b