From 8fa3a867486f85df66eba8c4df85804d3309c6ad Mon Sep 17 00:00:00 2001 From: Nicholas Bellinger Date: Wed, 16 Sep 2015 20:23:53 -0700 Subject: [PATCH] target: Make TCM_WRITE_PROTECT failure honor D_SENSE bit This patch changes transport_lookup_cmd_lun() to obtain se_lun->lun_ref + se_cmd->se_device rcu_dereference during TCM_WRITE_PROTECT -> CHECK_CONDITION failure status. Do this to ensure the active control D_SENSE mode page bit is being honored. Reported-by: Sagi Grimberg Reviewed-by: Sagi Grimberg Signed-off-by: Nicholas Bellinger --- drivers/target/target_core_device.c | 40 +++++++++++++++++------------ 1 file changed, 23 insertions(+), 17 deletions(-) diff --git a/drivers/target/target_core_device.c b/drivers/target/target_core_device.c index abf20763b0b6..88ea4e4f124b 100644 --- a/drivers/target/target_core_device.c +++ b/drivers/target/target_core_device.c @@ -62,22 +62,13 @@ transport_lookup_cmd_lun(struct se_cmd *se_cmd, u64 unpacked_lun) struct se_session *se_sess = se_cmd->se_sess; struct se_node_acl *nacl = se_sess->se_node_acl; struct se_dev_entry *deve; + sense_reason_t ret = TCM_NO_SENSE; rcu_read_lock(); deve = target_nacl_find_deve(nacl, unpacked_lun); if (deve) { atomic_long_inc(&deve->total_cmds); - if ((se_cmd->data_direction == DMA_TO_DEVICE) && - (deve->lun_flags & TRANSPORT_LUNFLAGS_READ_ONLY)) { - pr_err("TARGET_CORE[%s]: Detected WRITE_PROTECTED LUN" - " Access for 0x%08llx\n", - se_cmd->se_tfo->get_fabric_name(), - unpacked_lun); - rcu_read_unlock(); - return TCM_WRITE_PROTECTED; - } - if (se_cmd->data_direction == DMA_TO_DEVICE) atomic_long_add(se_cmd->data_length, &deve->write_bytes); @@ -93,6 +84,17 @@ transport_lookup_cmd_lun(struct se_cmd *se_cmd, u64 unpacked_lun) percpu_ref_get(&se_lun->lun_ref); se_cmd->lun_ref_active = true; + + if ((se_cmd->data_direction == DMA_TO_DEVICE) && + (deve->lun_flags & TRANSPORT_LUNFLAGS_READ_ONLY)) { + pr_err("TARGET_CORE[%s]: Detected WRITE_PROTECTED LUN" + " Access for 0x%08llx\n", + se_cmd->se_tfo->get_fabric_name(), + unpacked_lun); + rcu_read_unlock(); + ret = TCM_WRITE_PROTECTED; + goto ref_dev; + } } rcu_read_unlock(); @@ -109,12 +111,6 @@ transport_lookup_cmd_lun(struct se_cmd *se_cmd, u64 unpacked_lun) unpacked_lun); return TCM_NON_EXISTENT_LUN; } - /* - * Force WRITE PROTECT for virtual LUN 0 - */ - if ((se_cmd->data_direction != DMA_FROM_DEVICE) && - (se_cmd->data_direction != DMA_NONE)) - return TCM_WRITE_PROTECTED; se_lun = se_sess->se_tpg->tpg_virt_lun0; se_cmd->se_lun = se_sess->se_tpg->tpg_virt_lun0; @@ -123,6 +119,15 @@ transport_lookup_cmd_lun(struct se_cmd *se_cmd, u64 unpacked_lun) percpu_ref_get(&se_lun->lun_ref); se_cmd->lun_ref_active = true; + + /* + * Force WRITE PROTECT for virtual LUN 0 + */ + if ((se_cmd->data_direction != DMA_FROM_DEVICE) && + (se_cmd->data_direction != DMA_NONE)) { + ret = TCM_WRITE_PROTECTED; + goto ref_dev; + } } /* * RCU reference protected by percpu se_lun->lun_ref taken above that @@ -130,6 +135,7 @@ transport_lookup_cmd_lun(struct se_cmd *se_cmd, u64 unpacked_lun) * pointer can be kfree_rcu() by the final se_lun->lun_group put via * target_core_fabric_configfs.c:target_fabric_port_release */ +ref_dev: se_cmd->se_dev = rcu_dereference_raw(se_lun->lun_se_dev); atomic_long_inc(&se_cmd->se_dev->num_cmds); @@ -140,7 +146,7 @@ transport_lookup_cmd_lun(struct se_cmd *se_cmd, u64 unpacked_lun) atomic_long_add(se_cmd->data_length, &se_cmd->se_dev->read_bytes); - return 0; + return ret; } EXPORT_SYMBOL(transport_lookup_cmd_lun); -- 2.20.1