1 files changed, 118 insertions, 27 deletions

diff --git a/drivers/target/target_core_device.c b/drivers/target/target_core_device.c
index 8add07f387f9..e8dd6da164b2 100644
--- a/drivers/target/target_core_device.c
+++ b/drivers/target/target_core_device.c
@@ -49,8 +49,9 @@
 #include "target_core_pr.h"
 #include "target_core_ua.h"
 
-DEFINE_MUTEX(g_device_mutex);
-LIST_HEAD(g_device_list);
+static DEFINE_MUTEX(device_mutex);
+static LIST_HEAD(device_list);
+static DEFINE_IDR(devices_idr);
 
 static struct se_hba *lun0_hba;
 /* not static, needed by tpg.c */
@@ -168,11 +169,20 @@ int transport_lookup_tmr_lun(struct se_cmd *se_cmd, u64 unpacked_lun)
         rcu_read_lock();
         deve = target_nacl_find_deve(nacl, unpacked_lun);
         if (deve) {
-                se_cmd->se_lun = rcu_dereference(deve->se_lun);
                 se_lun = rcu_dereference(deve->se_lun);
+
+                if (!percpu_ref_tryget_live(&se_lun->lun_ref)) {
+                        se_lun = NULL;
+                        goto out_unlock;
+                }
+
+                se_cmd->se_lun = rcu_dereference(deve->se_lun);
                 se_cmd->pr_res_key = deve->pr_res_key;
                 se_cmd->orig_fe_lun = unpacked_lun;
+                se_cmd->se_cmd_flags |= SCF_SE_LUN_CMD;
+                se_cmd->lun_ref_active = true;
         }
+out_unlock:
         rcu_read_unlock();
 
         if (!se_lun) {
@@ -182,9 +192,6 @@ int transport_lookup_tmr_lun(struct se_cmd *se_cmd, u64 unpacked_lun)
                         unpacked_lun);
                 return -ENODEV;
         }
-        /*
-         * XXX: Add percpu se_lun->lun_ref reference count for TMR
-         */
         se_cmd->se_dev = rcu_dereference_raw(se_lun->lun_se_dev);
         se_tmr->tmr_dev = rcu_dereference_raw(se_lun->lun_se_dev);
 
@@ -756,19 +763,16 @@ struct se_device *target_alloc_device(struct se_hba *hba, const char *name)
         if (!dev)
                 return NULL;
 
-        dev->dev_link_magic = SE_DEV_LINK_MAGIC;
         dev->se_hba = hba;
         dev->transport = hba->backend->ops;
         dev->prot_length = sizeof(struct t10_pi_tuple);
         dev->hba_index = hba->hba_index;
 
-        INIT_LIST_HEAD(&dev->dev_list);
         INIT_LIST_HEAD(&dev->dev_sep_list);
         INIT_LIST_HEAD(&dev->dev_tmr_list);
         INIT_LIST_HEAD(&dev->delayed_cmd_list);
         INIT_LIST_HEAD(&dev->state_list);
         INIT_LIST_HEAD(&dev->qf_cmd_list);
-        INIT_LIST_HEAD(&dev->g_dev_node);
         spin_lock_init(&dev->execute_task_lock);
         spin_lock_init(&dev->delayed_cmd_lock);
         spin_lock_init(&dev->dev_reservation_lock);
@@ -851,7 +855,7 @@ bool target_configure_unmap_from_queue(struct se_dev_attrib *attrib,
         attrib->unmap_granularity = q->limits.discard_granularity / block_size;
         attrib->unmap_granularity_alignment = q->limits.discard_alignment /
                                                                 block_size;
-        attrib->unmap_zeroes_data = 0;
+        attrib->unmap_zeroes_data = (q->limits.max_write_zeroes_sectors);
         return true;
 }
 EXPORT_SYMBOL(target_configure_unmap_from_queue);
@@ -875,10 +879,79 @@ sector_t target_to_linux_sector(struct se_device *dev, sector_t lb)
 }
 EXPORT_SYMBOL(target_to_linux_sector);
 
+/**
+ * target_find_device - find a se_device by its dev_index
+ * @id: dev_index
+ * @do_depend: true if caller needs target_depend_item to be done
+ *
+ * If do_depend is true, the caller must do a target_undepend_item
+ * when finished using the device.
+ *
+ * If do_depend is false, the caller must be called in a configfs
+ * callback or during removal.
+ */
+struct se_device *target_find_device(int id, bool do_depend)
+{
+        struct se_device *dev;
+
+        mutex_lock(&device_mutex);
+        dev = idr_find(&devices_idr, id);
+        if (dev && do_depend && target_depend_item(&dev->dev_group.cg_item))
+                dev = NULL;
+        mutex_unlock(&device_mutex);
+        return dev;
+}
+EXPORT_SYMBOL(target_find_device);
+
+struct devices_idr_iter {
+        int (*fn)(struct se_device *dev, void *data);
+        void *data;
+};
+
+static int target_devices_idr_iter(int id, void *p, void *data)
+{
+        struct devices_idr_iter *iter = data;
+        struct se_device *dev = p;
+
+        /*
+         * We add the device early to the idr, so it can be used
+         * by backend modules during configuration. We do not want
+         * to allow other callers to access partially setup devices,
+         * so we skip them here.
+         */
+        if (!(dev->dev_flags & DF_CONFIGURED))
+                return 0;
+
+        return iter->fn(dev, iter->data);
+}
+
+/**
+ * target_for_each_device - iterate over configured devices
+ * @fn: iterator function
+ * @data: pointer to data that will be passed to fn
+ *
+ * fn must return 0 to continue looping over devices. non-zero will break
+ * from the loop and return that value to the caller.
+ */
+int target_for_each_device(int (*fn)(struct se_device *dev, void *data),
+                           void *data)
+{
+        struct devices_idr_iter iter;
+        int ret;
+
+        iter.fn = fn;
+        iter.data = data;
+
+        mutex_lock(&device_mutex);
+        ret = idr_for_each(&devices_idr, target_devices_idr_iter, &iter);
+        mutex_unlock(&device_mutex);
+        return ret;
+}
+
 int target_configure_device(struct se_device *dev)
 {
         struct se_hba *hba = dev->se_hba;
-        int ret;
+        int ret, id;
 
         if (dev->dev_flags & DF_CONFIGURED) {
                 pr_err("se_dev->se_dev_ptr already set for storage"
@@ -886,9 +959,26 @@ int target_configure_device(struct se_device *dev)
                 return -EEXIST;
         }
 
+        /*
+         * Add early so modules like tcmu can use during its
+         * configuration.
+         */
+        mutex_lock(&device_mutex);
+        /*
+         * Use cyclic to try and avoid collisions with devices
+         * that were recently removed.
+         */
+        id = idr_alloc_cyclic(&devices_idr, dev, 0, INT_MAX, GFP_KERNEL);
+        mutex_unlock(&device_mutex);
+        if (id < 0) {
+                ret = -ENOMEM;
+                goto out;
+        }
+        dev->dev_index = id;
+
         ret = dev->transport->configure_device(dev);
         if (ret)
-                goto out;
+                goto out_free_index;
         /*
          * XXX: there is not much point to have two different values here..
          */
@@ -903,12 +993,11 @@ int target_configure_device(struct se_device *dev)
                                          dev->dev_attrib.hw_block_size);
         dev->dev_attrib.optimal_sectors = dev->dev_attrib.hw_max_sectors;
 
-        dev->dev_index = scsi_get_new_index(SCSI_DEVICE_INDEX);
         dev->creation_time = get_jiffies_64();
 
         ret = core_setup_alua(dev);
         if (ret)
-                goto out;
+                goto out_free_index;
 
         /*
          * Startup the struct se_device processing thread
@@ -946,16 +1035,16 @@ int target_configure_device(struct se_device *dev)
         hba->dev_count++;
         spin_unlock(&hba->device_lock);
 
-        mutex_lock(&g_device_mutex);
-        list_add_tail(&dev->g_dev_node, &g_device_list);
-        mutex_unlock(&g_device_mutex);
-
         dev->dev_flags |= DF_CONFIGURED;
 
         return 0;
 
 out_free_alua:
         core_alua_free_lu_gp_mem(dev);
+out_free_index:
+        mutex_lock(&device_mutex);
+        idr_remove(&devices_idr, dev->dev_index);
+        mutex_unlock(&device_mutex);
 out:
         se_release_vpd_for_dev(dev);
         return ret;
@@ -970,9 +1059,11 @@ void target_free_device(struct se_device *dev)
         if (dev->dev_flags & DF_CONFIGURED) {
                 destroy_workqueue(dev->tmr_wq);
 
-                mutex_lock(&g_device_mutex);
-                list_del(&dev->g_dev_node);
-                mutex_unlock(&g_device_mutex);
+                dev->transport->destroy_device(dev);
+
+                mutex_lock(&device_mutex);
+                idr_remove(&devices_idr, dev->dev_index);
+                mutex_unlock(&device_mutex);
 
                 spin_lock(&hba->device_lock);
                 hba->dev_count--;
@@ -1087,19 +1178,19 @@ passthrough_parse_cdb(struct se_cmd *cmd,
               TRANSPORT_FLAG_PASSTHROUGH_PGR)) {
                 if (cdb[0] == PERSISTENT_RESERVE_IN) {
                         cmd->execute_cmd = target_scsi3_emulate_pr_in;
-                        size = (cdb[7] << 8) + cdb[8];
+                        size = get_unaligned_be16(&cdb[7]);
                         return target_cmd_size_check(cmd, size);
                 }
                 if (cdb[0] == PERSISTENT_RESERVE_OUT) {
                         cmd->execute_cmd = target_scsi3_emulate_pr_out;
-                        size = (cdb[7] << 8) + cdb[8];
+                        size = get_unaligned_be32(&cdb[5]);
                         return target_cmd_size_check(cmd, size);
                 }
 
                 if (cdb[0] == RELEASE || cdb[0] == RELEASE_10) {
                         cmd->execute_cmd = target_scsi2_reservation_release;
                         if (cdb[0] == RELEASE_10)
-                                size = (cdb[7] << 8) | cdb[8];
+                                size = get_unaligned_be16(&cdb[7]);
                         else
                                 size = cmd->data_length;
                         return target_cmd_size_check(cmd, size);
@@ -1107,7 +1198,7 @@ passthrough_parse_cdb(struct se_cmd *cmd,
                 if (cdb[0] == RESERVE || cdb[0] == RESERVE_10) {
                         cmd->execute_cmd = target_scsi2_reservation_reserve;
                         if (cdb[0] == RESERVE_10)
-                                size = (cdb[7] << 8) | cdb[8];
+                                size = get_unaligned_be16(&cdb[7]);
                         else
                                 size = cmd->data_length;
                         return target_cmd_size_check(cmd, size);
@@ -1126,7 +1217,7 @@ passthrough_parse_cdb(struct se_cmd *cmd,
         case WRITE_16:
         case WRITE_VERIFY:
         case WRITE_VERIFY_12:
-        case 0x8e: /* WRITE_VERIFY_16 */
+        case WRITE_VERIFY_16:
         case COMPARE_AND_WRITE:
         case XDWRITEREAD_10:
                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
@@ -1135,7 +1226,7 @@ passthrough_parse_cdb(struct se_cmd *cmd,
                 switch (get_unaligned_be16(&cdb[8])) {
                 case READ_32:
                 case WRITE_32:
-                case 0x0c: /* WRITE_VERIFY_32 */
+                case WRITE_VERIFY_32:
                 case XDWRITEREAD_32:
                         cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
                         break;