Re: [PATCH] fix the poll method of bsg file operations in Block layer SCSI generic driver

[Davidlohr Bueso <dave@gnu.org>]

On Wed, 2010-11-10 at 21:58 +0800, Hillf Danton wrote:
> Though it looks like a typo, the check for POLLOUT is computed incorrectly.
> 
> Signed-off-by: Hillf Danton <dhillf@gmail.com>
> ---
> 
> --- a/block/bsg.c	2010-09-13 07:07:38.000000000 +0800
> +++ b/block/bsg.c	2010-11-10 21:40:30.000000000 +0800
> @@ -874,6 +874,8 @@ static unsigned int bsg_poll(struct file
>  	if (!list_empty(&bd->done_list))
>  		mask |= POLLIN | POLLRDNORM;
>  	if (bd->queued_cmds >= bd->max_queue)
> +		;
> +	else
>  		mask |= POLLOUT;
>  	spin_unlock_irq(&bd->lock);

How about something more like this:

diff --git a/block/bsg.c b/block/bsg.c
index f20d6a7..2663db3 100644
--- a/block/bsg.c
+++ b/block/bsg.c
@@ -870,7 +870,7 @@ static unsigned int bsg_poll(struct file *file,
poll_table *wait)
        spin_lock_irq(&bd->lock);
        if (!list_empty(&bd->done_list))
                mask |= POLLIN | POLLRDNORM;
-       if (bd->queued_cmds >= bd->max_queue)
+       if (bd->queued_cmds < bd->max_queue)
                mask |= POLLOUT;
        spin_unlock_irq(&bd->lock);


Thanks,
Davidlohr



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