Re: [PATCH v4 3/8] mtd: ubi: block: don't return on error when removing

[Richard Weinberger <richard@nod.at>]

----- Ursprüngliche Mail -----
> Von: "Daniel Golle" <daniel@makrotopia.org>
> An: "Randy Dunlap" <rdunlap@infradead.org>, "Miquel Raynal" <miquel.raynal@bootlin.com>, "richard" <richard@nod.at>,
> "Vignesh Raghavendra" <vigneshr@ti.com>, "Rob Herring" <robh+dt@kernel.org>, "Krzysztof Kozlowski"
> <krzysztof.kozlowski+dt@linaro.org>, "Conor Dooley" <conor+dt@kernel.org>, "Daniel Golle" <daniel@makrotopia.org>,
> "linux-mtd" <linux-mtd@lists.infradead.org>, "devicetree" <devicetree@vger.kernel.org>, "linux-kernel"
> <linux-kernel@vger.kernel.org>
> Gesendet: Freitag, 11. August 2023 03:37:12
> Betreff: [PATCH v4 3/8] mtd: ubi: block: don't return on error when removing

> There is no point on returning the error from ubiblock_remove in case
> it is being called due to a volume removal event -- the volume is gone,
> we should destroy and remove the ubiblock device no matter what.
> 
> Introduce new boolean parameter 'force' to tell ubiblock_remove to go
> on even in case the ubiblock device is still busy. Use that new option
> when calling ubiblock_remove due to a UBI_VOLUME_REMOVED event.
> 
> Signed-off-by: Daniel Golle <daniel@makrotopia.org>
> ---
> drivers/mtd/ubi/block.c | 6 +++---
> drivers/mtd/ubi/cdev.c  | 2 +-
> drivers/mtd/ubi/ubi.h   | 4 ++--
> 3 files changed, 6 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/mtd/ubi/block.c b/drivers/mtd/ubi/block.c
> index 437c5b83ffe51..69fa6fecb8494 100644
> --- a/drivers/mtd/ubi/block.c
> +++ b/drivers/mtd/ubi/block.c
> @@ -456,7 +456,7 @@ static void ubiblock_cleanup(struct ubiblock *dev)
> 	idr_remove(&ubiblock_minor_idr, dev->gd->first_minor);
> }
> 
> -int ubiblock_remove(struct ubi_volume_info *vi)
> +int ubiblock_remove(struct ubi_volume_info *vi, bool force)
> {
> 	struct ubiblock *dev;
> 	int ret;
> @@ -470,7 +470,7 @@ int ubiblock_remove(struct ubi_volume_info *vi)
> 
> 	/* Found a device, let's lock it so we can check if it's busy */
> 	mutex_lock(&dev->dev_mutex);
> -	if (dev->refcnt > 0) {
> +	if (dev->refcnt > 0 && !force) {
> 		ret = -EBUSY;
> 		goto out_unlock_dev;

Is it really safe to destroy the blk queue (via ubiblock_cleanup()) if refcnt is > 0?

Thanks,
//richard