[PATCH V2 3/6] ublk_drv: move ublk_get_device_from_id into ublk_ctrl_uring_cmd

Ming Lei
2022-11-24T03:06:27Z

It is annoying for each control command handler to get/put ublk
device and deal with failure.

Control command handler is simplified a lot by moving
ublk_get_device_from_id into ublk_ctrl_uring_cmd().

Signed-off-by: Ming Lei <ming.lei@redhat.com>
---
drivers/block/ublk_drv.c | 138 ++++++++++++++-------------------------
1 file changed, 49 insertions(+), 89 deletions(-)

diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c
index a3d776a1c2f5..9d1578384cba 100644
--- a/drivers/block/ublk_drv.c
+++ b/drivers/block/ublk_drv.c
@@ -1496,21 +1496,16 @@ static struct ublk_device *ublk_get_device_from_id(int idx)
return ub;
}

-static int ublk_ctrl_start_dev(struct io_uring_cmd *cmd)
+static int ublk_ctrl_start_dev(struct ublk_device *ub, struct io_uring_cmd *cmd)
{
struct ublksrv_ctrl_cmd *header = (struct ublksrv_ctrl_cmd *)cmd->cmd;
int ublksrv_pid = (int)header->data[0];
- struct ublk_device *ub;
struct gendisk *disk;
int ret = -EINVAL;

if (ublksrv_pid <= 0)
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);
@@ -1559,21 +1554,20 @@ static int ublk_ctrl_start_dev(struct io_uring_cmd *cmd)
put_disk(disk);
out_unlock:
mutex_unlock(&ub->mutex);
- ublk_put_device(ub);
return ret;
}

-static int ublk_ctrl_get_queue_affinity(struct io_uring_cmd *cmd)
+static int ublk_ctrl_get_queue_affinity(struct ublk_device *ub,
+ 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 ublk_device *ub;
cpumask_var_t cpumask;
unsigned long queue;
unsigned int retlen;
unsigned int i;
- int ret = -EINVAL;
-
+ int ret;
+
if (header->len * BITS_PER_BYTE < nr_cpu_ids)
return -EINVAL;
if (header->len & (sizeof(unsigned long)-1))
@@ -1581,17 +1575,12 @@ static int ublk_ctrl_get_queue_affinity(struct io_uring_cmd *cmd)
if (!header->addr)
return -EINVAL;

- ub = ublk_get_device_from_id(header->dev_id);
- if (!ub)
- return -EINVAL;
-
queue = header->data[0];
if (queue >= ub->dev_info.nr_hw_queues)
- goto out_put_device;
+ return -EINVAL;

- ret = -ENOMEM;
if (!zalloc_cpumask_var(&cpumask, GFP_KERNEL))
- goto out_put_device;
+ return -ENOMEM;

for_each_possible_cpu(i) {
if (ub->tag_set.map[HCTX_TYPE_DEFAULT].mq_map[i] == queue)
@@ -1609,8 +1598,6 @@ static int ublk_ctrl_get_queue_affinity(struct io_uring_cmd *cmd)
ret = 0;
out_free_cpumask:
free_cpumask_var(cpumask);
-out_put_device:
- ublk_put_device(ub);
return ret;
}

@@ -1731,30 +1718,27 @@ static inline bool ublk_idr_freed(int id)
return ptr == NULL;
}

-static int ublk_ctrl_del_dev(int idx)
+static int ublk_ctrl_del_dev(struct ublk_device **p_ub)
{
- struct ublk_device *ub;
+ struct ublk_device *ub = *p_ub;
+ int idx = ub->ub_number;
int ret;

ret = mutex_lock_killable(&ublk_ctl_mutex);
if (ret)
return ret;

- ub = ublk_get_device_from_id(idx);
- if (ub) {
- ublk_remove(ub);
- ublk_put_device(ub);
- ret = 0;
- } else {
- ret = -ENODEV;
- }
+ ublk_remove(ub);
+
+ /* Mark the reference as consumed */
+ *p_ub = NULL;
+ ublk_put_device(ub);

/*
* Wait until the idr is removed, then it can be reused after
* DEL_DEV command is returned.
*/
- if (!ret)
- wait_event(ublk_idr_wq, ublk_idr_freed(idx));
+ wait_event(ublk_idr_wq, ublk_idr_freed(idx));
mutex_unlock(&ublk_ctl_mutex);

return ret;
@@ -1769,50 +1753,36 @@ static inline void ublk_ctrl_cmd_dump(struct io_uring_cmd *cmd)
header->data[0], header->addr, header->len);
}

-static int ublk_ctrl_stop_dev(struct io_uring_cmd *cmd)
+static int ublk_ctrl_stop_dev(struct ublk_device *ub)
{
- struct ublksrv_ctrl_cmd *header = (struct ublksrv_ctrl_cmd *)cmd->cmd;
- struct ublk_device *ub;
-
- ub = ublk_get_device_from_id(header->dev_id);
- if (!ub)
- return -EINVAL;
-
ublk_stop_dev(ub);
cancel_work_sync(&ub->stop_work);
cancel_work_sync(&ub->quiesce_work);

- ublk_put_device(ub);
return 0;
}

-static int ublk_ctrl_get_dev_info(struct io_uring_cmd *cmd)
+static int ublk_ctrl_get_dev_info(struct ublk_device *ub,
+ 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 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 -EFAULT;

- return ret;
+ return 0;
}

-static int ublk_ctrl_get_params(struct io_uring_cmd *cmd)
+static int ublk_ctrl_get_params(struct ublk_device *ub,
+ 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 ublk_params_header ph;
- struct ublk_device *ub;
int ret;

if (header->len <= sizeof(ph) || !header->addr)
@@ -1827,10 +1797,6 @@ static int ublk_ctrl_get_params(struct io_uring_cmd *cmd)
if (ph.len > sizeof(struct ublk_params))
ph.len = sizeof(struct ublk_params);

- ub = ublk_get_device_from_id(header->dev_id);
- if (!ub)
- return -EINVAL;
-
mutex_lock(&ub->mutex);
if (copy_to_user(argp, &ub->params, ph.len))
ret = -EFAULT;
@@ -1838,16 +1804,15 @@ static int ublk_ctrl_get_params(struct io_uring_cmd *cmd)
ret = 0;
mutex_unlock(&ub->mutex);

- ublk_put_device(ub);
return ret;
}

-static int ublk_ctrl_set_params(struct io_uring_cmd *cmd)
+static int ublk_ctrl_set_params(struct ublk_device *ub,
+ 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 ublk_params_header ph;
- struct ublk_device *ub;
int ret = -EFAULT;

if (header->len <= sizeof(ph) || !header->addr)
@@ -1862,10 +1827,6 @@ static int ublk_ctrl_set_params(struct io_uring_cmd *cmd)
if (ph.len > sizeof(struct ublk_params))
ph.len = sizeof(struct ublk_params);

- ub = ublk_get_device_from_id(header->dev_id);
- if (!ub)
- return -EINVAL;
-
/* parameters can only be changed when device isn't live */
mutex_lock(&ub->mutex);
if (ub->dev_info.state == UBLK_S_DEV_LIVE) {
@@ -1878,7 +1839,6 @@ static int ublk_ctrl_set_params(struct io_uring_cmd *cmd)
ret = ublk_validate_params(ub);
}
mutex_unlock(&ub->mutex);
- ublk_put_device(ub);

return ret;
}
@@ -1905,17 +1865,13 @@ static void ublk_queue_reinit(struct ublk_device *ub, struct ublk_queue *ubq)
}
}

-static int ublk_ctrl_start_recovery(struct io_uring_cmd *cmd)
+static int ublk_ctrl_start_recovery(struct ublk_device *ub,
+ struct io_uring_cmd *cmd)
{
struct ublksrv_ctrl_cmd *header = (struct ublksrv_ctrl_cmd *)cmd->cmd;
- struct ublk_device *ub;
int ret = -EINVAL;
int i;

- ub = ublk_get_device_from_id(header->dev_id);
- if (!ub)
- return ret;
-
mutex_lock(&ub->mutex);
if (!ublk_can_use_recovery(ub))
goto out_unlock;
@@ -1948,21 +1904,16 @@ static int ublk_ctrl_start_recovery(struct io_uring_cmd *cmd)
ret = 0;
out_unlock:
mutex_unlock(&ub->mutex);
- ublk_put_device(ub);
return ret;
}

-static int ublk_ctrl_end_recovery(struct io_uring_cmd *cmd)
+static int ublk_ctrl_end_recovery(struct ublk_device *ub,
+ struct io_uring_cmd *cmd)
{
struct ublksrv_ctrl_cmd *header = (struct ublksrv_ctrl_cmd *)cmd->cmd;
int ublksrv_pid = (int)header->data[0];
- struct ublk_device *ub;
int ret = -EINVAL;

- ub = ublk_get_device_from_id(header->dev_id);
- if (!ub)
- return ret;
-
pr_devel("%s: Waiting for new ubq_daemons(nr: %d) are ready, dev id %d...\n",
__func__, ub->dev_info.nr_hw_queues, header->dev_id);
/* wait until new ubq_daemon sending all FETCH_REQ */
@@ -1990,7 +1941,6 @@ static int ublk_ctrl_end_recovery(struct io_uring_cmd *cmd)
ret = 0;
out_unlock:
mutex_unlock(&ub->mutex);
- ublk_put_device(ub);
return ret;
}

@@ -1998,6 +1948,7 @@ 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;
+ struct ublk_device *ub = NULL;
int ret = -EINVAL;

ublk_ctrl_cmd_dump(cmd);
@@ -2009,41 +1960,50 @@ static int ublk_ctrl_uring_cmd(struct io_uring_cmd *cmd,
if (!capable(CAP_SYS_ADMIN))
goto out;

- ret = -ENODEV;
+ if (cmd->cmd_op != UBLK_CMD_ADD_DEV) {
+ ret = -ENODEV;
+ ub = ublk_get_device_from_id(header->dev_id);
+ if (!ub)
+ goto out;
+ }
+
switch (cmd->cmd_op) {
case UBLK_CMD_START_DEV:
- ret = ublk_ctrl_start_dev(cmd);
+ ret = ublk_ctrl_start_dev(ub, cmd);
break;
case UBLK_CMD_STOP_DEV:
- ret = ublk_ctrl_stop_dev(cmd);
+ ret = ublk_ctrl_stop_dev(ub);
break;
case UBLK_CMD_GET_DEV_INFO:
- ret = ublk_ctrl_get_dev_info(cmd);
+ ret = ublk_ctrl_get_dev_info(ub, cmd);
break;
case UBLK_CMD_ADD_DEV:
ret = ublk_ctrl_add_dev(cmd);
break;
case UBLK_CMD_DEL_DEV:
- ret = ublk_ctrl_del_dev(header->dev_id);
+ ret = ublk_ctrl_del_dev(&ub);
break;
case UBLK_CMD_GET_QUEUE_AFFINITY:
- ret = ublk_ctrl_get_queue_affinity(cmd);
+ ret = ublk_ctrl_get_queue_affinity(ub, cmd);
break;
case UBLK_CMD_GET_PARAMS:
- ret = ublk_ctrl_get_params(cmd);
+ ret = ublk_ctrl_get_params(ub, cmd);
break;
case UBLK_CMD_SET_PARAMS:
- ret = ublk_ctrl_set_params(cmd);
+ ret = ublk_ctrl_set_params(ub, cmd);
break;
case UBLK_CMD_START_USER_RECOVERY:
- ret = ublk_ctrl_start_recovery(cmd);
+ ret = ublk_ctrl_start_recovery(ub, cmd);
break;
case UBLK_CMD_END_USER_RECOVERY:
- ret = ublk_ctrl_end_recovery(cmd);
+ ret = ublk_ctrl_end_recovery(ub, cmd);
break;
default:
+ ret = -ENOTSUPP;
break;
}
+ if (ub)
+ ublk_put_device(ub);
out:
io_uring_cmd_done(cmd, ret, 0);
pr_devel("%s: cmd done ret %d cmd_op %x, dev id %d qid %d\n",
--
2.31.1