diff mbox series

fsi: sbefifo: Use interruptible mutex locking

Message ID 20210803213016.44739-1-eajames@linux.ibm.com
State New
Headers show
Series fsi: sbefifo: Use interruptible mutex locking | expand

Commit Message

Eddie James Aug. 3, 2021, 9:30 p.m. UTC
Some SBE operations have extremely large responses and can require
several minutes to process the response. During this time, the device
lock must be held. If another process attempts an operation, it will
wait for the mutex for longer than the kernel hung task watchdog
allows. Therefore, use the interruptible function to lock the mutex.

Signed-off-by: Eddie James <eajames@linux.ibm.com>
---
 drivers/fsi/fsi-sbefifo.c | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

Comments

Joel Stanley Oct. 15, 2021, 5:31 a.m. UTC | #1
On Tue, 3 Aug 2021 at 21:30, Eddie James <eajames@linux.ibm.com> wrote:
>
> Some SBE operations have extremely large responses and can require
> several minutes to process the response. During this time, the device
> lock must be held. If another process attempts an operation, it will
> wait for the mutex for longer than the kernel hung task watchdog
> allows. Therefore, use the interruptible function to lock the mutex.
>
> Signed-off-by: Eddie James <eajames@linux.ibm.com>

I think this is okay. I'm not familiar with the use of
mutex_lock_interruptible, so if anyone else wants to ask questions
please do.

Reviewed-by: Joel Stanley <joel@jms.id.au>

> ---
>  drivers/fsi/fsi-sbefifo.c | 12 +++++++++---
>  1 file changed, 9 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/fsi/fsi-sbefifo.c b/drivers/fsi/fsi-sbefifo.c
> index 84cb965bfed5..a8d8e47e6fb2 100644
> --- a/drivers/fsi/fsi-sbefifo.c
> +++ b/drivers/fsi/fsi-sbefifo.c
> @@ -740,7 +740,9 @@ int sbefifo_submit(struct device *dev, const __be32 *command, size_t cmd_len,
>          iov_iter_kvec(&resp_iter, WRITE, &resp_iov, 1, rbytes);
>
>         /* Perform the command */
> -       mutex_lock(&sbefifo->lock);
> +       rc = mutex_lock_interruptible(&sbefifo->lock);
> +       if (rc)
> +               return rc;
>         rc = __sbefifo_submit(sbefifo, command, cmd_len, &resp_iter);
>         mutex_unlock(&sbefifo->lock);
>
> @@ -820,7 +822,9 @@ static ssize_t sbefifo_user_read(struct file *file, char __user *buf,
>         iov_iter_init(&resp_iter, WRITE, &resp_iov, 1, len);
>
>         /* Perform the command */
> -       mutex_lock(&sbefifo->lock);
> +       rc = mutex_lock_interruptible(&sbefifo->lock);
> +       if (rc)
> +               goto bail;
>         rc = __sbefifo_submit(sbefifo, user->pending_cmd, cmd_len, &resp_iter);
>         mutex_unlock(&sbefifo->lock);
>         if (rc < 0)
> @@ -875,7 +879,9 @@ static ssize_t sbefifo_user_write(struct file *file, const char __user *buf,
>                 user->pending_len = 0;
>
>                 /* Trigger reset request */
> -               mutex_lock(&sbefifo->lock);
> +               rc = mutex_lock_interruptible(&sbefifo->lock);
> +               if (rc)
> +                       goto bail;
>                 rc = sbefifo_request_reset(user->sbefifo);
>                 mutex_unlock(&sbefifo->lock);
>                 if (rc == 0)
> --
> 2.27.0
>
diff mbox series

Patch

diff --git a/drivers/fsi/fsi-sbefifo.c b/drivers/fsi/fsi-sbefifo.c
index 84cb965bfed5..a8d8e47e6fb2 100644
--- a/drivers/fsi/fsi-sbefifo.c
+++ b/drivers/fsi/fsi-sbefifo.c
@@ -740,7 +740,9 @@  int sbefifo_submit(struct device *dev, const __be32 *command, size_t cmd_len,
         iov_iter_kvec(&resp_iter, WRITE, &resp_iov, 1, rbytes);
 
 	/* Perform the command */
-	mutex_lock(&sbefifo->lock);
+	rc = mutex_lock_interruptible(&sbefifo->lock);
+	if (rc)
+		return rc;
 	rc = __sbefifo_submit(sbefifo, command, cmd_len, &resp_iter);
 	mutex_unlock(&sbefifo->lock);
 
@@ -820,7 +822,9 @@  static ssize_t sbefifo_user_read(struct file *file, char __user *buf,
 	iov_iter_init(&resp_iter, WRITE, &resp_iov, 1, len);
 
 	/* Perform the command */
-	mutex_lock(&sbefifo->lock);
+	rc = mutex_lock_interruptible(&sbefifo->lock);
+	if (rc)
+		goto bail;
 	rc = __sbefifo_submit(sbefifo, user->pending_cmd, cmd_len, &resp_iter);
 	mutex_unlock(&sbefifo->lock);
 	if (rc < 0)
@@ -875,7 +879,9 @@  static ssize_t sbefifo_user_write(struct file *file, const char __user *buf,
 		user->pending_len = 0;
 
 		/* Trigger reset request */
-		mutex_lock(&sbefifo->lock);
+		rc = mutex_lock_interruptible(&sbefifo->lock);
+		if (rc)
+			goto bail;
 		rc = sbefifo_request_reset(user->sbefifo);
 		mutex_unlock(&sbefifo->lock);
 		if (rc == 0)