target_core_alua: Allocate ALUA metadata on demand

We should only allocate ALUA metadata if we're actually going
to write them.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

diff --git a/drivers/target/target_core_alua.c b/drivers/target/target_core_alua.c
index 292ecce..738244b 100644 (file)
--- a/drivers/target/target_core_alua.c
+++ b/drivers/target/target_core_alua.c
@@ -770,16 +770,22 @@ static int core_alua_write_tpg_metadata(
  */
 static int core_alua_update_tpg_primary_metadata(
        struct t10_alua_tg_pt_gp *tg_pt_gp,
-       int primary_state,
-       unsigned char *md_buf)
+       int primary_state)
 {
+       unsigned char *md_buf;
        struct t10_wwn *wwn = &tg_pt_gp->tg_pt_gp_dev->t10_wwn;
        char path[ALUA_METADATA_PATH_LEN];
-       int len;
+       int len, rc;
+
+       md_buf = kzalloc(ALUA_MD_BUF_LEN, GFP_KERNEL);
+       if (!md_buf) {
+               pr_err("Unable to allocate buf for ALUA metadata\n");
+               return -ENOMEM;
+       }
 
        memset(path, 0, ALUA_METADATA_PATH_LEN);
 
-       len = snprintf(md_buf, tg_pt_gp->tg_pt_gp_md_buf_len,
+       len = snprintf(md_buf, ALUA_MD_BUF_LEN,
                        "tg_pt_gp_id=%hu\n"
                        "alua_access_state=0x%02x\n"
                        "alua_access_status=0x%02x\n",
@@ -790,14 +796,15 @@ static int core_alua_update_tpg_primary_metadata(
                "/var/target/alua/tpgs_%s/%s", &wwn->unit_serial[0],
                config_item_name(&tg_pt_gp->tg_pt_gp_group.cg_item));
 
-       return core_alua_write_tpg_metadata(path, md_buf, len);
+       rc = core_alua_write_tpg_metadata(path, md_buf, len);
+       kfree(md_buf);
+       return rc;
 }
 
 static int core_alua_do_transition_tg_pt(
        struct t10_alua_tg_pt_gp *tg_pt_gp,
        struct se_port *l_port,
        struct se_node_acl *nacl,
-       unsigned char *md_buf,
        int new_state,
        int explicit)
 {
@@ -885,8 +892,7 @@ static int core_alua_do_transition_tg_pt(
         */
        if (tg_pt_gp->tg_pt_gp_write_metadata) {
                mutex_lock(&tg_pt_gp->tg_pt_gp_md_mutex);
-               core_alua_update_tpg_primary_metadata(tg_pt_gp,
-                                       new_state, md_buf);
+               core_alua_update_tpg_primary_metadata(tg_pt_gp, new_state);
                mutex_unlock(&tg_pt_gp->tg_pt_gp_md_mutex);
        }
        /*
@@ -917,19 +923,12 @@ int core_alua_do_port_transition(
        struct t10_alua_lu_gp *lu_gp;
        struct t10_alua_lu_gp_member *lu_gp_mem, *local_lu_gp_mem;
        struct t10_alua_tg_pt_gp *tg_pt_gp;
-       unsigned char *md_buf;
        int primary, valid_states;
 
        valid_states = l_tg_pt_gp->tg_pt_gp_alua_supported_states;
        if (core_alua_check_transition(new_state, valid_states, &primary) != 0)
                return -EINVAL;
 
-       md_buf = kzalloc(l_tg_pt_gp->tg_pt_gp_md_buf_len, GFP_KERNEL);
-       if (!md_buf) {
-               pr_err("Unable to allocate buf for ALUA metadata\n");
-               return -ENOMEM;
-       }
-
        local_lu_gp_mem = l_dev->dev_alua_lu_gp_mem;
        spin_lock(&local_lu_gp_mem->lu_gp_mem_lock);
        lu_gp = local_lu_gp_mem->lu_gp;
@@ -947,10 +946,9 @@ int core_alua_do_port_transition(
                 * success.
                 */
                core_alua_do_transition_tg_pt(l_tg_pt_gp, l_port, l_nacl,
-                                       md_buf, new_state, explicit);
+                                       new_state, explicit);
                atomic_dec(&lu_gp->lu_gp_ref_cnt);
                smp_mb__after_atomic_dec();
-               kfree(md_buf);
                return 0;
        }
        /*
@@ -1000,7 +998,7 @@ int core_alua_do_port_transition(
                         * success.
                         */
                        core_alua_do_transition_tg_pt(tg_pt_gp, port,
-                                       nacl, md_buf, new_state, explicit);
+                                       nacl, new_state, explicit);
 
                        spin_lock(&dev->t10_alua.tg_pt_gps_lock);
                        atomic_dec(&tg_pt_gp->tg_pt_gp_ref_cnt);
@@ -1022,7 +1020,6 @@ int core_alua_do_port_transition(
 
        atomic_dec(&lu_gp->lu_gp_ref_cnt);
        smp_mb__after_atomic_dec();
-       kfree(md_buf);
        return 0;
 }
 
@@ -1031,13 +1028,18 @@ int core_alua_do_port_transition(
  */
 static int core_alua_update_tpg_secondary_metadata(
        struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem,
-       struct se_port *port,
-       unsigned char *md_buf,
-       u32 md_buf_len)
+       struct se_port *port)
 {
+       unsigned char *md_buf;
        struct se_portal_group *se_tpg = port->sep_tpg;
        char path[ALUA_METADATA_PATH_LEN], wwn[ALUA_SECONDARY_METADATA_WWN_LEN];
-       int len;
+       int len, rc;
+
+       md_buf = kzalloc(ALUA_MD_BUF_LEN, GFP_KERNEL);
+       if (!md_buf) {
+               pr_err("Unable to allocate buf for ALUA metadata\n");
+               return -ENOMEM;
+       }
 
        memset(path, 0, ALUA_METADATA_PATH_LEN);
        memset(wwn, 0, ALUA_SECONDARY_METADATA_WWN_LEN);
@@ -1049,7 +1051,7 @@ static int core_alua_update_tpg_secondary_metadata(
                snprintf(wwn+len, ALUA_SECONDARY_METADATA_WWN_LEN-len, "+%hu",
                                se_tpg->se_tpg_tfo->tpg_get_tag(se_tpg));
 
-       len = snprintf(md_buf, md_buf_len, "alua_tg_pt_offline=%d\n"
+       len = snprintf(md_buf, ALUA_MD_BUF_LEN, "alua_tg_pt_offline=%d\n"
                        "alua_tg_pt_status=0x%02x\n",
                        atomic_read(&port->sep_tg_pt_secondary_offline),
                        port->sep_tg_pt_secondary_stat);
@@ -1058,7 +1060,10 @@ static int core_alua_update_tpg_secondary_metadata(
                        se_tpg->se_tpg_tfo->get_fabric_name(), wwn,
                        port->sep_lun->unpacked_lun);
 
-       return core_alua_write_tpg_metadata(path, md_buf, len);
+       rc = core_alua_write_tpg_metadata(path, md_buf, len);
+       kfree(md_buf);
+
+       return rc;
 }
 
 static int core_alua_set_tg_pt_secondary_state(
@@ -1068,8 +1073,6 @@ static int core_alua_set_tg_pt_secondary_state(
        int offline)
 {
        struct t10_alua_tg_pt_gp *tg_pt_gp;
-       unsigned char *md_buf;
-       u32 md_buf_len;
        int trans_delay_msecs;
 
        spin_lock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
@@ -1090,7 +1093,6 @@ static int core_alua_set_tg_pt_secondary_state(
        else
                atomic_set(&port->sep_tg_pt_secondary_offline, 0);
 
-       md_buf_len = tg_pt_gp->tg_pt_gp_md_buf_len;
        port->sep_tg_pt_secondary_stat = (explicit) ?
                        ALUA_STATUS_ALTERED_BY_EXPLICIT_STPG :
                        ALUA_STATUS_ALTERED_BY_IMPLICIT_ALUA;
@@ -1112,18 +1114,9 @@ static int core_alua_set_tg_pt_secondary_state(
         * secondary state and status
         */
        if (port->sep_tg_pt_secondary_write_md) {
-               md_buf = kzalloc(md_buf_len, GFP_KERNEL);
-               if (!md_buf) {
-                       pr_err("Unable to allocate md_buf for"
-                               " secondary ALUA access metadata\n");
-                       return -ENOMEM;
-               }
                mutex_lock(&port->sep_tg_pt_md_mutex);
-               core_alua_update_tpg_secondary_metadata(tg_pt_gp_mem, port,
-                               md_buf, md_buf_len);
+               core_alua_update_tpg_secondary_metadata(tg_pt_gp_mem, port);
                mutex_unlock(&port->sep_tg_pt_md_mutex);
-
-               kfree(md_buf);
        }
 
        return 0;
@@ -1382,7 +1375,6 @@ struct t10_alua_tg_pt_gp *core_alua_allocate_tg_pt_gp(struct se_device *dev,
        spin_lock_init(&tg_pt_gp->tg_pt_gp_lock);
        atomic_set(&tg_pt_gp->tg_pt_gp_ref_cnt, 0);
        tg_pt_gp->tg_pt_gp_dev = dev;
-       tg_pt_gp->tg_pt_gp_md_buf_len = ALUA_MD_BUF_LEN;
        atomic_set(&tg_pt_gp->tg_pt_gp_alua_access_state,
                ALUA_ACCESS_STATE_ACTIVE_OPTIMIZED);
        /*

diff --git a/drivers/target/target_core_alua.h b/drivers/target/target_core_alua.h
index 88e2e83..1a152cd 100644 (file)
--- a/drivers/target/target_core_alua.h
+++ b/drivers/target/target_core_alua.h
@@ -78,6 +78,9 @@
  */
 #define ALUA_SECONDARY_METADATA_WWN_LEN                        256
 
+/* Used by core_alua_update_tpg_(primary,secondary)_metadata */
+#define ALUA_MD_BUF_LEN                                        1024
+
 extern struct kmem_cache *t10_alua_lu_gp_cache;
 extern struct kmem_cache *t10_alua_lu_gp_mem_cache;
 extern struct kmem_cache *t10_alua_tg_pt_gp_cache;

diff --git a/include/target/target_core_base.h b/include/target/target_core_base.h
index d6f96c7..bf9a4d6 100644 (file)
--- a/include/target/target_core_base.h
+++ b/include/target/target_core_base.h
@@ -291,9 +291,6 @@ struct t10_alua_tg_pt_gp {
        int     tg_pt_gp_implicit_trans_secs;
        int     tg_pt_gp_pref;
        int     tg_pt_gp_write_metadata;
-       /* Used by struct t10_alua_tg_pt_gp->tg_pt_gp_md_buf_len */
-#define ALUA_MD_BUF_LEN                                1024
-       u32     tg_pt_gp_md_buf_len;
        u32     tg_pt_gp_members;
        atomic_t tg_pt_gp_alua_access_state;
        atomic_t tg_pt_gp_ref_cnt;