From 9de3a1ef032a5ad5d7b642d625b6bd362b1989d6 Mon Sep 17 00:00:00 2001 From: Mike Christie Date: Fri, 22 Jun 2018 16:40:20 -0500 Subject: [PATCH] scsi: tcmu: simplify nl interface Just return EBUSY if a nl request comes in while processing one. The upper layers do not support sending multiple create/remove requests at the same time (you cannot have a create and remove at the same time or do multiple creates or removes at the same time) and doing a reconfig while a create/remove is still executing does not make sense. Signed-off-by: Mike Christie Tested-by: Xiubo Li Signed-off-by: Martin K. Petersen --- drivers/target/target_core_user.c | 26 ++++++++++++-------------- 1 file changed, 12 insertions(+), 14 deletions(-) diff --git a/drivers/target/target_core_user.c b/drivers/target/target_core_user.c index 73a5768..9835ea3 100644 --- a/drivers/target/target_core_user.c +++ b/drivers/target/target_core_user.c @@ -165,8 +165,6 @@ struct tcmu_dev { struct list_head timedout_entry; struct tcmu_nl_cmd curr_nl_cmd; - /* wake up threads waiting on curr_nl_cmd */ - wait_queue_head_t nl_cmd_wq; char dev_config[TCMU_CONFIG_LEN]; @@ -1264,8 +1262,6 @@ static struct se_device *tcmu_alloc_device(struct se_hba *hba, const char *name) timer_setup(&udev->qfull_timer, tcmu_qfull_timedout, 0); timer_setup(&udev->cmd_timer, tcmu_cmd_timedout, 0); - init_waitqueue_head(&udev->nl_cmd_wq); - INIT_RADIX_TREE(&udev->data_blocks, GFP_KERNEL); return &udev->se_dev; @@ -1539,24 +1535,23 @@ static int tcmu_release(struct uio_info *info, struct inode *inode) return 0; } -static void tcmu_init_genl_cmd_reply(struct tcmu_dev *udev, int cmd) +static int tcmu_init_genl_cmd_reply(struct tcmu_dev *udev, int cmd) { struct tcmu_nl_cmd *nl_cmd = &udev->curr_nl_cmd; if (!tcmu_kern_cmd_reply_supported) - return; + return 0; if (udev->nl_reply_supported <= 0) - return; + return 0; -relock: mutex_lock(&tcmu_nl_cmd_mutex); if (nl_cmd->cmd != TCMU_CMD_UNSPEC) { mutex_unlock(&tcmu_nl_cmd_mutex); - pr_debug("sleeping for open nl cmd\n"); - wait_event(udev->nl_cmd_wq, (nl_cmd->cmd == TCMU_CMD_UNSPEC)); - goto relock; + pr_warn("netlink cmd %d already executing on %s\n", + nl_cmd->cmd, udev->name); + return -EBUSY; } memset(nl_cmd, 0, sizeof(*nl_cmd)); @@ -1568,6 +1563,7 @@ relock: list_add_tail(&nl_cmd->nl_list, &tcmu_nl_cmd_list); mutex_unlock(&tcmu_nl_cmd_mutex); + return 0; } static int tcmu_wait_genl_cmd_reply(struct tcmu_dev *udev) @@ -1590,8 +1586,6 @@ static int tcmu_wait_genl_cmd_reply(struct tcmu_dev *udev) nl_cmd->status = 0; mutex_unlock(&tcmu_nl_cmd_mutex); - wake_up_all(&udev->nl_cmd_wq); - return ret; } @@ -1642,7 +1636,11 @@ static int tcmu_netlink_event_send(struct tcmu_dev *udev, genlmsg_end(skb, msg_header); - tcmu_init_genl_cmd_reply(udev, cmd); + ret = tcmu_init_genl_cmd_reply(udev, cmd); + if (ret) { + nlmsg_free(skb); + return ret; + } ret = genlmsg_multicast_allns(&tcmu_genl_family, skb, 0, TCMU_MCGRP_CONFIG, GFP_KERNEL); -- 2.7.4