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authorNicholas Bellinger <nab@linux-iscsi.org>2015-05-11 05:31:10 +0300
committerNicholas Bellinger <nab@linux-iscsi.org>2015-06-01 10:24:33 +0300
commit6bb826121be244a5a3c8bd8b7d45c47df18810b7 (patch)
tree7a75624e4801567a4133bc5b373ed67dd1db1cbb /drivers/target/sbp
parent9fcb57f39c0cde70bcccdc1d998d3060297e911c (diff)
downloadlinux-6bb826121be244a5a3c8bd8b7d45c47df18810b7.tar.xz
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 <hare@suse.de> Cc: Christoph Hellwig <hch@lst.de> Cc: Sagi Grimberg <sagig@mellanox.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Chris Boot <bootc@bootc.net> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Diffstat (limited to 'drivers/target/sbp')
-rw-r--r--drivers/target/sbp/sbp_target.c97
-rw-r--r--drivers/target/sbp/sbp_target.h2
2 files changed, 43 insertions, 56 deletions
diff --git a/drivers/target/sbp/sbp_target.c b/drivers/target/sbp/sbp_target.c
index 5d7755edc668..47fb12fbaf47 100644
--- a/drivers/target/sbp/sbp_target.c
+++ b/drivers/target/sbp/sbp_target.c
@@ -108,13 +108,13 @@ static struct sbp_session *sbp_session_find_by_guid(
}
static struct sbp_login_descriptor *sbp_login_find_by_lun(
- struct sbp_session *session, struct se_lun *lun)
+ struct sbp_session *session, u32 unpacked_lun)
{
struct sbp_login_descriptor *login, *found = NULL;
spin_lock_bh(&session->lock);
list_for_each_entry(login, &session->login_list, link) {
- if (login->lun == lun)
+ if (login->login_lun == unpacked_lun)
found = login;
}
spin_unlock_bh(&session->lock);
@@ -124,7 +124,7 @@ static struct sbp_login_descriptor *sbp_login_find_by_lun(
static int sbp_login_count_all_by_lun(
struct sbp_tpg *tpg,
- struct se_lun *lun,
+ u32 unpacked_lun,
int exclusive)
{
struct se_session *se_sess;
@@ -138,7 +138,7 @@ static int sbp_login_count_all_by_lun(
spin_lock_bh(&sess->lock);
list_for_each_entry(login, &sess->login_list, link) {
- if (login->lun != lun)
+ if (login->login_lun != unpacked_lun)
continue;
if (!exclusive || login->exclusive)
@@ -174,23 +174,23 @@ static struct sbp_login_descriptor *sbp_login_find_by_id(
return found;
}
-static struct se_lun *sbp_get_lun_from_tpg(struct sbp_tpg *tpg, int lun)
+static u32 sbp_get_lun_from_tpg(struct sbp_tpg *tpg, u32 login_lun, int *err)
{
struct se_portal_group *se_tpg = &tpg->se_tpg;
struct se_lun *se_lun;
- if (lun >= TRANSPORT_MAX_LUNS_PER_TPG)
- return ERR_PTR(-EINVAL);
-
- spin_lock(&se_tpg->tpg_lun_lock);
- se_lun = se_tpg->tpg_lun_list[lun];
-
- if (se_lun->lun_status != TRANSPORT_LUN_STATUS_ACTIVE)
- se_lun = ERR_PTR(-ENODEV);
-
- spin_unlock(&se_tpg->tpg_lun_lock);
+ rcu_read_lock();
+ hlist_for_each_entry_rcu(se_lun, &se_tpg->tpg_lun_hlist, link) {
+ if (se_lun->unpacked_lun == login_lun) {
+ rcu_read_unlock();
+ *err = 0;
+ return login_lun;
+ }
+ }
+ rcu_read_unlock();
- return se_lun;
+ *err = -ENODEV;
+ return login_lun;
}
static struct sbp_session *sbp_session_create(
@@ -294,17 +294,16 @@ static void sbp_management_request_login(
{
struct sbp_tport *tport = agent->tport;
struct sbp_tpg *tpg = tport->tpg;
- struct se_lun *se_lun;
- int ret;
- u64 guid;
struct sbp_session *sess;
struct sbp_login_descriptor *login;
struct sbp_login_response_block *response;
- int login_response_len;
+ u64 guid;
+ u32 unpacked_lun;
+ int login_response_len, ret;
- se_lun = sbp_get_lun_from_tpg(tpg,
- LOGIN_ORB_LUN(be32_to_cpu(req->orb.misc)));
- if (IS_ERR(se_lun)) {
+ unpacked_lun = sbp_get_lun_from_tpg(tpg,
+ LOGIN_ORB_LUN(be32_to_cpu(req->orb.misc)), &ret);
+ if (ret) {
pr_notice("login to unknown LUN: %d\n",
LOGIN_ORB_LUN(be32_to_cpu(req->orb.misc)));
@@ -325,11 +324,11 @@ static void sbp_management_request_login(
}
pr_notice("mgt_agent LOGIN to LUN %d from %016llx\n",
- se_lun->unpacked_lun, guid);
+ unpacked_lun, guid);
sess = sbp_session_find_by_guid(tpg, guid);
if (sess) {
- login = sbp_login_find_by_lun(sess, se_lun);
+ login = sbp_login_find_by_lun(sess, unpacked_lun);
if (login) {
pr_notice("initiator already logged-in\n");
@@ -357,7 +356,7 @@ static void sbp_management_request_login(
* reject with access_denied if any logins present
*/
if (LOGIN_ORB_EXCLUSIVE(be32_to_cpu(req->orb.misc)) &&
- sbp_login_count_all_by_lun(tpg, se_lun, 0)) {
+ sbp_login_count_all_by_lun(tpg, unpacked_lun, 0)) {
pr_warn("refusing exclusive login with other active logins\n");
req->status.status = cpu_to_be32(
@@ -370,7 +369,7 @@ static void sbp_management_request_login(
* check exclusive bit in any existing login descriptor
* reject with access_denied if any exclusive logins present
*/
- if (sbp_login_count_all_by_lun(tpg, se_lun, 1)) {
+ if (sbp_login_count_all_by_lun(tpg, unpacked_lun, 1)) {
pr_warn("refusing login while another exclusive login present\n");
req->status.status = cpu_to_be32(
@@ -383,7 +382,7 @@ static void sbp_management_request_login(
* check we haven't exceeded the number of allowed logins
* reject with resources_unavailable if we have
*/
- if (sbp_login_count_all_by_lun(tpg, se_lun, 0) >=
+ if (sbp_login_count_all_by_lun(tpg, unpacked_lun, 0) >=
tport->max_logins_per_lun) {
pr_warn("max number of logins reached\n");
@@ -439,7 +438,7 @@ static void sbp_management_request_login(
}
login->sess = sess;
- login->lun = se_lun;
+ login->login_lun = unpacked_lun;
login->status_fifo_addr = sbp2_pointer_to_addr(&req->orb.status_fifo);
login->exclusive = LOGIN_ORB_EXCLUSIVE(be32_to_cpu(req->orb.misc));
login->login_id = atomic_inc_return(&login_id);
@@ -601,7 +600,7 @@ static void sbp_management_request_logout(
}
pr_info("mgt_agent LOGOUT from LUN %d session %d\n",
- login->lun->unpacked_lun, login->login_id);
+ login->login_lun, login->login_id);
if (req->node_addr != login->sess->node_id) {
pr_warn("logout from different node ID\n");
@@ -1227,7 +1226,7 @@ static void sbp_handle_command(struct sbp_target_request *req)
goto err;
}
- unpacked_lun = req->login->lun->unpacked_lun;
+ unpacked_lun = req->login->login_lun;
sbp_calc_data_length_direction(req, &data_length, &data_dir);
pr_debug("sbp_handle_command ORB:0x%llx unpacked_lun:%d data_len:%d data_dir:%d\n",
@@ -1826,25 +1825,21 @@ static int sbp_check_stop_free(struct se_cmd *se_cmd)
static int sbp_count_se_tpg_luns(struct se_portal_group *tpg)
{
- int i, count = 0;
-
- spin_lock(&tpg->tpg_lun_lock);
- for (i = 0; i < TRANSPORT_MAX_LUNS_PER_TPG; i++) {
- struct se_lun *se_lun = tpg->tpg_lun_list[i];
-
- if (se_lun->lun_status == TRANSPORT_LUN_STATUS_FREE)
- continue;
+ struct se_lun *lun;
+ int count = 0;
+ rcu_read_lock();
+ hlist_for_each_entry_rcu(lun, &tpg->tpg_lun_hlist, link)
count++;
- }
- spin_unlock(&tpg->tpg_lun_lock);
+ rcu_read_unlock();
return count;
}
static int sbp_update_unit_directory(struct sbp_tport *tport)
{
- int num_luns, num_entries, idx = 0, mgt_agt_addr, ret, i;
+ struct se_lun *lun;
+ int num_luns, num_entries, idx = 0, mgt_agt_addr, ret;
u32 *data;
if (tport->unit_directory.data) {
@@ -1906,28 +1901,20 @@ static int sbp_update_unit_directory(struct sbp_tport *tport)
/* unit unique ID (leaf is just after LUNs) */
data[idx++] = 0x8d000000 | (num_luns + 1);
- spin_lock(&tport->tpg->se_tpg.tpg_lun_lock);
- for (i = 0; i < TRANSPORT_MAX_LUNS_PER_TPG; i++) {
- struct se_lun *se_lun = tport->tpg->se_tpg.tpg_lun_list[i];
+ rcu_read_lock();
+ hlist_for_each_entry_rcu(lun, &tport->tpg->se_tpg.tpg_lun_hlist, link) {
struct se_device *dev;
int type;
- if (se_lun->lun_status == TRANSPORT_LUN_STATUS_FREE)
- continue;
-
- spin_unlock(&tport->tpg->se_tpg.tpg_lun_lock);
-
- dev = se_lun->lun_se_dev;
+ dev = lun->lun_se_dev;
type = dev->transport->get_device_type(dev);
/* logical_unit_number */
data[idx++] = 0x14000000 |
((type << 16) & 0x1f0000) |
- (se_lun->unpacked_lun & 0xffff);
-
- spin_lock(&tport->tpg->se_tpg.tpg_lun_lock);
+ (lun->unpacked_lun & 0xffff);
}
- spin_unlock(&tport->tpg->se_tpg.tpg_lun_lock);
+ rcu_read_unlock();
/* unit unique ID leaf */
data[idx++] = 2 << 16;
diff --git a/drivers/target/sbp/sbp_target.h b/drivers/target/sbp/sbp_target.h
index e1b0b84f7379..73bcb1208832 100644
--- a/drivers/target/sbp/sbp_target.h
+++ b/drivers/target/sbp/sbp_target.h
@@ -125,7 +125,7 @@ struct sbp_login_descriptor {
struct sbp_session *sess;
struct list_head link;
- struct se_lun *lun;
+ u32 login_lun;
u64 status_fifo_addr;
int exclusive;