ublk: cleanup ublk_ctrl_uring_cmd

Move all per-command work into the per-command ublk_ctrl_* helpers
instead of being split over those, ublk_ctrl_cmd_validate, and the main
ublk_ctrl_uring_cmd handler.  To facilitate that, the old
ublk_ctrl_stop_dev function that just contained two function calls is
folded into both callers.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: ZiyangZhang <ZiyangZhang@linux.alibaba.com>
Link: https://lore.kernel.org/r/20220721130916.1869719-6-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c
index 1f7bbbc3276a2764f0df865c6c622568b048ee82..2032d677b9f18823e34e4877836b557da804c1db 100644 (file)
--- a/drivers/block/ublk_drv.c
+++ b/drivers/block/ublk_drv.c
@@ -813,13 +813,6 @@ static void ublk_stop_dev(struct ublk_device *ub)
        cancel_delayed_work_sync(&ub->monitor_work);
 }
 
-static int ublk_ctrl_stop_dev(struct ublk_device *ub)
-{
-       ublk_stop_dev(ub);
-       cancel_work_sync(&ub->stop_work);
-       return 0;
-}
-
 static inline bool ublk_queue_ready(struct ublk_queue *ubq)
 {
        return ubq->nr_io_ready == ubq->q_depth;
@@ -1205,8 +1198,8 @@ out_destroy_dev:
 
 static void ublk_remove(struct ublk_device *ub)
 {
-       ublk_ctrl_stop_dev(ub);
-
+       ublk_stop_dev(ub);
+       cancel_work_sync(&ub->stop_work);
        cdev_device_del(&ub->cdev, &ub->cdev_dev);
        put_device(&ub->cdev_dev);
 }
@@ -1227,36 +1220,45 @@ static struct ublk_device *ublk_get_device_from_id(int idx)
        return ub;
 }
 
-static int ublk_ctrl_start_dev(struct ublk_device *ub, struct io_uring_cmd *cmd)
+static int ublk_ctrl_start_dev(struct io_uring_cmd *cmd)
 {
        struct ublksrv_ctrl_cmd *header = (struct ublksrv_ctrl_cmd *)cmd->cmd;
-       int ret = -EINVAL;
        int ublksrv_pid = (int)header->data[0];
        unsigned long dev_blocks = header->data[1];
+       struct ublk_device *ub;
+       int ret = -EINVAL;
 
        if (ublksrv_pid <= 0)
-               return ret;
+               return -EINVAL;
+
+       ub = ublk_get_device_from_id(header->dev_id);
+       if (!ub)
+               return -EINVAL;
 
        wait_for_completion_interruptible(&ub->completion);
 
        schedule_delayed_work(&ub->monitor_work, UBLK_DAEMON_MONITOR_PERIOD);
 
        mutex_lock(&ub->mutex);
-       if (!disk_live(ub->ub_disk)) {
-               /* We may get disk size updated */
-               if (dev_blocks) {
-                       ub->dev_info.dev_blocks = dev_blocks;
-                       ublk_update_capacity(ub);
-               }
-               ub->dev_info.ublksrv_pid = ublksrv_pid;
-               ret = add_disk(ub->ub_disk);
-               if (!ret)
-                       ub->dev_info.state = UBLK_S_DEV_LIVE;
-       } else {
+       if (disk_live(ub->ub_disk)) {
                ret = -EEXIST;
+               goto out_unlock;
        }
-       mutex_unlock(&ub->mutex);
 
+       /* We may get disk size updated */
+       if (dev_blocks) {
+               ub->dev_info.dev_blocks = dev_blocks;
+               ublk_update_capacity(ub);
+       }
+       ub->dev_info.ublksrv_pid = ublksrv_pid;
+       ret = add_disk(ub->ub_disk);
+       if (ret)
+               goto out_unlock;
+
+       ub->dev_info.state = UBLK_S_DEV_LIVE;
+out_unlock:
+       mutex_unlock(&ub->mutex);
+       ublk_put_device(ub);
        return ret;
 }
 
@@ -1281,6 +1283,13 @@ static int ublk_ctrl_get_queue_affinity(struct io_uring_cmd *cmd)
        unsigned long queue;
        unsigned int retlen;
        int ret = -EINVAL;
+       
+       if (header->len * BITS_PER_BYTE < nr_cpu_ids)
+               return -EINVAL;
+       if (header->len & (sizeof(unsigned long)-1))
+               return -EINVAL;
+       if (!header->addr)
+               return -EINVAL;
 
        ub = ublk_get_device_from_id(header->dev_id);
        if (!ub)
@@ -1311,38 +1320,64 @@ static int ublk_ctrl_get_queue_affinity(struct io_uring_cmd *cmd)
        return ret;
 }
 
-static int ublk_ctrl_add_dev(const struct ublksrv_ctrl_dev_info *info,
-               void __user *argp, int idx)
+static inline void ublk_dump_dev_info(struct ublksrv_ctrl_dev_info *info)
 {
+       pr_devel("%s: dev id %d flags %llx\n", __func__,
+                       info->dev_id, info->flags[0]);
+       pr_devel("\t nr_hw_queues %d queue_depth %d block size %d dev_capacity %lld\n",
+                       info->nr_hw_queues, info->queue_depth,
+                       info->block_size, info->dev_blocks);
+}
+
+static int ublk_ctrl_add_dev(struct io_uring_cmd *cmd)
+{
+       struct ublksrv_ctrl_cmd *header = (struct ublksrv_ctrl_cmd *)cmd->cmd;
+       void __user *argp = (void __user *)(unsigned long)header->addr;
+       struct ublksrv_ctrl_dev_info info;
        struct ublk_device *ub;
-       int ret;
+       int ret = -EINVAL;
+
+       if (header->len < sizeof(info) || !header->addr)
+               return -EINVAL;
+       if (header->queue_id != (u16)-1) {
+               pr_warn("%s: queue_id is wrong %x\n",
+                       __func__, header->queue_id);
+               return -EINVAL;
+       }
+       if (copy_from_user(&info, argp, sizeof(info)))
+               return -EFAULT;
+       ublk_dump_dev_info(&info);
+       if (header->dev_id != info.dev_id) {
+               pr_warn("%s: dev id not match %u %u\n",
+                       __func__, header->dev_id, info.dev_id);
+               return -EINVAL;
+       }
 
        ret = mutex_lock_killable(&ublk_ctl_mutex);
        if (ret)
                return ret;
 
-       ub = __ublk_create_dev(idx);
-       if (!IS_ERR_OR_NULL(ub)) {
-               memcpy(&ub->dev_info, info, sizeof(*info));
+       ub = __ublk_create_dev(header->dev_id);
+       if (IS_ERR(ub)) {
+               ret = PTR_ERR(ub);
+               goto out_unlock;
+       }
 
-               /* update device id */
-               ub->dev_info.dev_id = ub->ub_number;
+       memcpy(&ub->dev_info, &info, sizeof(info));
 
-               ret = ublk_add_dev(ub);
-               if (!ret) {
-                       if (copy_to_user(argp, &ub->dev_info, sizeof(*info))) {
-                               ublk_remove(ub);
-                               ret = -EFAULT;
-                       }
-               }
-       } else {
-               if (IS_ERR(ub))
-                       ret = PTR_ERR(ub);
-               else
-                       ret = -ENOMEM;
+       /* update device id */
+       ub->dev_info.dev_id = ub->ub_number;
+
+       ret = ublk_add_dev(ub);
+       if (ret)
+               goto out_unlock;
+
+       if (copy_to_user(argp, &ub->dev_info, sizeof(info))) {
+               ublk_remove(ub);
+               ret = -EFAULT;
        }
+out_unlock:
        mutex_unlock(&ublk_ctl_mutex);
-
        return ret;
 }
 
@@ -1386,16 +1421,6 @@ static int ublk_ctrl_del_dev(int idx)
        return ret;
 }
 
-
-static inline void ublk_dump_dev_info(struct ublksrv_ctrl_dev_info *info)
-{
-       pr_devel("%s: dev id %d flags %llx\n", __func__,
-                       info->dev_id, info->flags[0]);
-       pr_devel("\t nr_hw_queues %d queue_depth %d block size %d dev_capacity %lld\n",
-                       info->nr_hw_queues, info->queue_depth,
-                       info->block_size, info->dev_blocks);
-}
-
 static inline void ublk_ctrl_cmd_dump(struct io_uring_cmd *cmd)
 {
        struct ublksrv_ctrl_cmd *header = (struct ublksrv_ctrl_cmd *)cmd->cmd;
@@ -1405,59 +1430,47 @@ static inline void ublk_ctrl_cmd_dump(struct io_uring_cmd *cmd)
                        header->data[0], header->addr, header->len);
 }
 
-static int ublk_ctrl_cmd_validate(struct io_uring_cmd *cmd,
-               struct ublksrv_ctrl_dev_info *info)
+static int ublk_ctrl_stop_dev(struct io_uring_cmd *cmd)
 {
        struct ublksrv_ctrl_cmd *header = (struct ublksrv_ctrl_cmd *)cmd->cmd;
-       u32 cmd_op = cmd->cmd_op;
-       void __user *argp = (void __user *)(unsigned long)header->addr;
+       struct ublk_device *ub;
 
-       if (!capable(CAP_SYS_ADMIN))
-               return -EPERM;
+       ub = ublk_get_device_from_id(header->dev_id);
+       if (!ub)
+               return -EINVAL;
 
-       switch (cmd_op) {
-       case UBLK_CMD_GET_DEV_INFO:
-               if (header->len < sizeof(*info) || !header->addr)
-                       return -EINVAL;
-               break;
-       case UBLK_CMD_ADD_DEV:
-               if (header->len < sizeof(*info) || !header->addr)
-                       return -EINVAL;
-               if (copy_from_user(info, argp, sizeof(*info)) != 0)
-                       return -EFAULT;
-               ublk_dump_dev_info(info);
-               if (header->dev_id != info->dev_id) {
-                       printk(KERN_WARNING "%s: cmd %x, dev id not match %u %u\n",
-                                       __func__, cmd_op, header->dev_id,
-                                       info->dev_id);
-                       return -EINVAL;
-               }
-               if (header->queue_id != (u16)-1) {
-                       printk(KERN_WARNING "%s: cmd %x queue_id is wrong %x\n",
-                                       __func__, cmd_op, header->queue_id);
-                       return -EINVAL;
-               }
-               break;
-       case UBLK_CMD_GET_QUEUE_AFFINITY:
-               if ((header->len * BITS_PER_BYTE) < nr_cpu_ids)
-                       return -EINVAL;
-               if (header->len & (sizeof(unsigned long)-1))
-                       return -EINVAL;
-               if (!header->addr)
-                       return -EINVAL;
-       }
+       ublk_stop_dev(ub);
+       cancel_work_sync(&ub->stop_work);
 
+       ublk_put_device(ub);
        return 0;
 }
 
-static int ublk_ctrl_uring_cmd(struct io_uring_cmd *cmd,
-               unsigned int issue_flags)
+static int ublk_ctrl_get_dev_info(struct io_uring_cmd *cmd)
 {
        struct ublksrv_ctrl_cmd *header = (struct ublksrv_ctrl_cmd *)cmd->cmd;
        void __user *argp = (void __user *)(unsigned long)header->addr;
-       struct ublksrv_ctrl_dev_info info;
-       u32 cmd_op = cmd->cmd_op;
        struct ublk_device *ub;
+       int ret = 0;
+
+       if (header->len < sizeof(struct ublksrv_ctrl_dev_info) || !header->addr)
+               return -EINVAL;
+
+       ub = ublk_get_device_from_id(header->dev_id);
+       if (!ub)
+               return -EINVAL;
+
+       if (copy_to_user(argp, &ub->dev_info, sizeof(ub->dev_info)))
+               ret = -EFAULT;
+       ublk_put_device(ub);
+
+       return ret;
+}
+
+static int ublk_ctrl_uring_cmd(struct io_uring_cmd *cmd,
+               unsigned int issue_flags)
+{
+       struct ublksrv_ctrl_cmd *header = (struct ublksrv_ctrl_cmd *)cmd->cmd;
        int ret = -EINVAL;
 
        ublk_ctrl_cmd_dump(cmd);
@@ -1465,38 +1478,23 @@ static int ublk_ctrl_uring_cmd(struct io_uring_cmd *cmd,
        if (!(issue_flags & IO_URING_F_SQE128))
                goto out;
 
-       ret = ublk_ctrl_cmd_validate(cmd, &info);
-       if (ret)
+       ret = -EPERM;
+       if (!capable(CAP_SYS_ADMIN))
                goto out;
 
        ret = -ENODEV;
-       switch (cmd_op) {
+       switch (cmd->cmd_op) {
        case UBLK_CMD_START_DEV:
-               ub = ublk_get_device_from_id(header->dev_id);
-               if (ub) {
-                       ret = ublk_ctrl_start_dev(ub, cmd);
-                       ublk_put_device(ub);
-               }
+               ret = ublk_ctrl_start_dev(cmd);
                break;
        case UBLK_CMD_STOP_DEV:
-               ub = ublk_get_device_from_id(header->dev_id);
-               if (ub) {
-                       ret = ublk_ctrl_stop_dev(ub);
-                       ublk_put_device(ub);
-               }
+               ret = ublk_ctrl_stop_dev(cmd);
                break;
        case UBLK_CMD_GET_DEV_INFO:
-               ub = ublk_get_device_from_id(header->dev_id);
-               if (ub) {
-                       if (copy_to_user(argp, &ub->dev_info, sizeof(info)))
-                               ret = -EFAULT;
-                       else
-                               ret = 0;
-                       ublk_put_device(ub);
-               }
+               ret = ublk_ctrl_get_dev_info(cmd);
                break;
        case UBLK_CMD_ADD_DEV:
-               ret = ublk_ctrl_add_dev(&info, argp, header->dev_id);
+               ret = ublk_ctrl_add_dev(cmd);
                break;
        case UBLK_CMD_DEL_DEV:
                ret = ublk_ctrl_del_dev(header->dev_id);