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From: Greg KH <gregkh@linuxfoundation.org>
To: Ian Pilcher <arequipeno@gmail.com>
Cc: axboe@kernel.dk, pavel@ucw.cz, linux-leds@vger.kernel.org,
	linux-block@vger.kernel.org, linux-kernel@vger.kernel.org,
	kabel@kernel.org
Subject: Re: [PATCH v2 06/15] leds: trigger: blkdev: Add function to get gendisk by name
Date: Fri, 10 Sep 2021 08:45:06 +0200	[thread overview]
Message-ID: <YTr+8h12z7kMLlV/@kroah.com> (raw)
In-Reply-To: <20210909222513.2184795-7-arequipeno@gmail.com>

On Thu, Sep 09, 2021 at 05:25:04PM -0500, Ian Pilcher wrote:
> Add ledtrig_blkdev_get_disk() to find block device by name and increment
> its reference count.  (Caller must call put_disk().)  Must be built-in to
> access block_class and disk_type symbols.
> 
> Signed-off-by: Ian Pilcher <arequipeno@gmail.com>
> ---
>  drivers/leds/trigger/ledtrig-blkdev-core.c | 20 ++++++++++++++++++++
>  drivers/leds/trigger/ledtrig-blkdev.h      |  3 +++
>  2 files changed, 23 insertions(+)
> 
> diff --git a/drivers/leds/trigger/ledtrig-blkdev-core.c b/drivers/leds/trigger/ledtrig-blkdev-core.c
> index d7b02e760b06..5fd741aa14a6 100644
> --- a/drivers/leds/trigger/ledtrig-blkdev-core.c
> +++ b/drivers/leds/trigger/ledtrig-blkdev-core.c
> @@ -33,3 +33,23 @@ void ledtrig_blkdev_disk_cleanup(struct gendisk *const gd)
>  
>  	mutex_unlock(&ledtrig_blkdev_mutex);
>  }
> +
> +/* class_find_device() callback.  Must be built-in to access disk_type. */
> +static int blkdev_match_name(struct device *const dev, const void *const name)
> +{
> +	return dev->type == &disk_type
> +			&& sysfs_streq(dev_to_disk(dev)->disk_name, name);
> +}
> +
> +/* Must be built-in to access block_class */
> +struct gendisk *ledtrig_blkdev_get_disk(const char *const name)
> +{
> +	struct device *dev;
> +
> +	dev = class_find_device(&block_class, NULL, name, blkdev_match_name);
> +	if (dev == NULL)
> +		return NULL;

You now have bumped the reference count on this structure.  Where do you
decrement it when you are finished with it?

thanks,

greg k-h

  reply	other threads:[~2021-09-10  6:45 UTC|newest]

Thread overview: 37+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-09-09 22:24 [PATCH v2 00/15] Introduce block device LED trigger Ian Pilcher
2021-09-09 22:24 ` [PATCH v2 01/15] docs: Add block device (blkdev) LED trigger documentation Ian Pilcher
2021-09-09 22:25 ` [PATCH v2 02/15] leds: trigger: blkdev: Add build infrastructure Ian Pilcher
2021-09-10  1:32   ` Marek Behún
2021-09-09 22:25 ` [PATCH v2 03/15] leds: trigger: blkdev: Add functions needed by block changes Ian Pilcher
2021-09-09 22:25 ` [PATCH v2 04/15] block: Add block device LED trigger integrations Ian Pilcher
2021-09-09 23:27   ` Chaitanya Kulkarni
2021-09-10  1:23   ` Marek Behún
2021-09-10 15:00     ` Ian Pilcher
2021-09-10  1:38   ` Marek Behún
2021-09-09 22:25 ` [PATCH v2 05/15] leds: trigger: blkdev: Complete functions called by block subsys Ian Pilcher
2021-09-09 22:25 ` [PATCH v2 06/15] leds: trigger: blkdev: Add function to get gendisk by name Ian Pilcher
2021-09-10  6:45   ` Greg KH [this message]
2021-09-10 15:17     ` Ian Pilcher
2021-09-10 15:23       ` Greg KH
2021-09-10 16:28     ` Ian Pilcher
2021-09-09 22:25 ` [PATCH v2 07/15] leds: trigger: blkdev: Add constants and types Ian Pilcher
2021-09-09 22:25 ` [PATCH v2 08/15] leds: trigger: blkdev: Add stub LED trigger structure Ian Pilcher
2021-09-09 22:25 ` [PATCH v2 09/15] leds: trigger: blkdev: Check devices for activity and blink LEDs Ian Pilcher
2021-09-10  1:48   ` Marek Behún
2021-09-10  2:17   ` Marek Behún
2021-09-10 15:09     ` Ian Pilcher
2021-09-10 15:12       ` Marek Behún
2021-09-10 21:23         ` Ian Pilcher
2021-09-09 22:25 ` [PATCH v2 10/15] leds: trigger: blkdev: Add LED trigger activate function Ian Pilcher
2021-09-10  6:47   ` Greg KH
2021-09-10 16:10     ` Ian Pilcher
2021-09-09 22:25 ` [PATCH v2 11/15] leds: trigger: blkdev: Enable linking block devices to LEDs Ian Pilcher
2021-09-10  6:48   ` Greg KH
2021-09-10 16:25     ` Ian Pilcher
2021-09-09 22:25 ` [PATCH v2 12/15] leds: trigger: blkdev: Enable unlinking block devices from LEDs Ian Pilcher
2021-09-14  9:58   ` Dan Carpenter
2021-09-09 22:25 ` [PATCH v2 13/15] leds: trigger: blkdev: Add LED trigger deactivate function Ian Pilcher
2021-09-09 22:25 ` [PATCH v2 14/15] leds: trigger: blkdev: Add remaining sysfs attributes Ian Pilcher
2021-09-09 22:25 ` [PATCH v2 15/15] leds: trigger: blkdev: Add disk cleanup and init/exit functions Ian Pilcher
2021-09-10  2:09 ` [PATCH v2 00/15] Introduce block device LED trigger Marek Behún
2021-09-10 14:04   ` Ian Pilcher

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