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From:   "Andreas Hindborg (Samsung)" <nmi@metaspace.dk>
To:     Damien Le Moal <dlemoal@kernel.org>
Cc:     Ming Lei <ming.lei@redhat.com>,
        open list <linux-kernel@vger.kernel.org>,
        Matias Bjorling <Matias.Bjorling@wdc.com>,
        Hans Holmberg <Hans.Holmberg@wdc.com>,
        Jens Axboe <axboe@kernel.dk>,
        Minwoo Im <minwoo.im.dev@gmail.com>,
        Aravind Ramesh <Aravind.Ramesh@wdc.com>, gost.dev@samsung.com,
        "open list:BLOCK LAYER" <linux-block@vger.kernel.org>,
        Christoph Hellwig <hch@infradead.org>
Subject: Re: [PATCH v5 2/5] ublk: move types to shared header file
Date:   Wed, 05 Jul 2023 12:50:28 +0200
In-reply-to: <b5dbd5e0-417d-e33b-baf0-b6109882bc3a@kernel.org>
Message-ID: <875y6yd3wz.fsf@metaspace.dk>
MIME-Version: 1.0
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Precedence: bulk


Damien Le Moal <dlemoal@kernel.org> writes:

> On 7/5/23 01:52, Andreas Hindborg wrote:
>> From: Andreas Hindborg <a.hindborg@samsung.com>
>> 
>> This change is in preparation for ublk zoned storage support.
>> 
>> Signed-off-by: Andreas Hindborg <a.hindborg@samsung.com>
>
> A couple of nits below. Otherwise looks OK to me.
>
> Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
>
> That said, your patch 5 still adds ublk-zoned.c, which Christoph commented that
> this may not be needed given that zone support does not add that much code.
> Without introducing this new file, this patch, as well as patch 3 would not be
> needed and patch 5 would be simplified a little.
>
> If you really prefer (or Ming does) having the zone code separated, I would
> suggest moving the ublk driver under its own "ublk" directory under
> drivers/block/ (similarly to nullblk). That would simplify the Kconfig too.

I am fine either way. I don't think Ming commented on this. It seems
both you and Christoph prefer just the 1 translation unit, so I might as
well change it back to that.

BR Andreas

>
>> ---
>>  MAINTAINERS              |   1 +
>>  drivers/block/ublk_drv.c |  92 +---------------------------------
>>  drivers/block/ublk_drv.h | 103 +++++++++++++++++++++++++++++++++++++++
>>  3 files changed, 105 insertions(+), 91 deletions(-)
>>  create mode 100644 drivers/block/ublk_drv.h
>> 
>> diff --git a/MAINTAINERS b/MAINTAINERS
>> index 27ef11624748..ace71c90751c 100644
>> --- a/MAINTAINERS
>> +++ b/MAINTAINERS
>> @@ -21554,6 +21554,7 @@ L:	linux-block@vger.kernel.org
>>  S:	Maintained
>>  F:	Documentation/block/ublk.rst
>>  F:	drivers/block/ublk_drv.c
>> +F:	drivers/block/ublk_drv.h
>>  F:	include/uapi/linux/ublk_cmd.h
>>  
>>  UCLINUX (M68KNOMMU AND COLDFIRE)
>> diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c
>> index 1c823750c95a..bca0c4e1cfd8 100644
>> --- a/drivers/block/ublk_drv.c
>> +++ b/drivers/block/ublk_drv.c
>> @@ -45,6 +45,7 @@
>>  #include <linux/namei.h>
>>  #include <linux/kref.h>
>>  #include <uapi/linux/ublk_cmd.h>
>> +#include "ublk_drv.h"
>>  
>>  #define UBLK_MINORS		(1U << MINORBITS)
>>  
>> @@ -62,63 +63,11 @@
>>  #define UBLK_PARAM_TYPE_ALL (UBLK_PARAM_TYPE_BASIC | \
>>  		UBLK_PARAM_TYPE_DISCARD | UBLK_PARAM_TYPE_DEVT)
>>  
>> -struct ublk_rq_data {
>> -	struct llist_node node;
>> -
>> -	struct kref ref;
>> -};
>>  
>>  struct ublk_uring_cmd_pdu {
>>  	struct ublk_queue *ubq;
>>  };
>>  
>> -/*
>> - * io command is active: sqe cmd is received, and its cqe isn't done
>> - *
>> - * If the flag is set, the io command is owned by ublk driver, and waited
>> - * for incoming blk-mq request from the ublk block device.
>> - *
>> - * If the flag is cleared, the io command will be completed, and owned by
>> - * ublk server.
>> - */
>> -#define UBLK_IO_FLAG_ACTIVE	0x01
>> -
>> -/*
>> - * IO command is completed via cqe, and it is being handled by ublksrv, and
>> - * not committed yet
>> - *
>> - * Basically exclusively with UBLK_IO_FLAG_ACTIVE, so can be served for
>> - * cross verification
>> - */
>> -#define UBLK_IO_FLAG_OWNED_BY_SRV 0x02
>> -
>> -/*
>> - * IO command is aborted, so this flag is set in case of
>> - * !UBLK_IO_FLAG_ACTIVE.
>> - *
>> - * After this flag is observed, any pending or new incoming request
>> - * associated with this io command will be failed immediately
>> - */
>> -#define UBLK_IO_FLAG_ABORTED 0x04
>> -
>> -/*
>> - * UBLK_IO_FLAG_NEED_GET_DATA is set because IO command requires
>> - * get data buffer address from ublksrv.
>> - *
>> - * Then, bio data could be copied into this data buffer for a WRITE request
>> - * after the IO command is issued again and UBLK_IO_FLAG_NEED_GET_DATA is unset.
>> - */
>> -#define UBLK_IO_FLAG_NEED_GET_DATA 0x08
>> -
>> -struct ublk_io {
>> -	/* userspace buffer address from io cmd */
>> -	__u64	addr;
>> -	unsigned int flags;
>> -	int res;
>> -
>> -	struct io_uring_cmd *cmd;
>> -};
>> -
>>  struct ublk_queue {
>>  	int q_id;
>>  	int q_depth;
>> @@ -140,45 +89,6 @@ struct ublk_queue {
>>  
>>  #define UBLK_DAEMON_MONITOR_PERIOD	(5 * HZ)
>>  
>> -struct ublk_device {
>> -	struct gendisk		*ub_disk;
>> -
>> -	char	*__queues;
>> -
>> -	unsigned int	queue_size;
>> -	struct ublksrv_ctrl_dev_info	dev_info;
>> -
>> -	struct blk_mq_tag_set	tag_set;
>> -
>> -	struct cdev		cdev;
>> -	struct device		cdev_dev;
>> -
>> -#define UB_STATE_OPEN		0
>> -#define UB_STATE_USED		1
>> -#define UB_STATE_DELETED	2
>> -	unsigned long		state;
>> -	int			ub_number;
>> -
>> -	struct mutex		mutex;
>> -
>> -	spinlock_t		mm_lock;
>> -	struct mm_struct	*mm;
>> -
>> -	struct ublk_params	params;
>> -
>> -	struct completion	completion;
>> -	unsigned int		nr_queues_ready;
>> -	unsigned int		nr_privileged_daemon;
>> -
>> -	/*
>> -	 * Our ubq->daemon may be killed without any notification, so
>> -	 * monitor each queue's daemon periodically
>> -	 */
>> -	struct delayed_work	monitor_work;
>> -	struct work_struct	quiesce_work;
>> -	struct work_struct	stop_work;
>> -};
>> -
>>  /* header of ublk_params */
>>  struct ublk_params_header {
>>  	__u32	len;
>> diff --git a/drivers/block/ublk_drv.h b/drivers/block/ublk_drv.h
>> new file mode 100644
>> index 000000000000..2a4ab721d513
>> --- /dev/null
>> +++ b/drivers/block/ublk_drv.h
>> @@ -0,0 +1,103 @@
>> +/* SPDX-License-Identifier: GPL-2.0 */
>> +
>> +#ifndef _UBLK_DRV_H
>> +#define _UBLK_DRV_H
>
> Nit: I think you can drop the leading "_".
>
>> +
>> +#include <uapi/linux/ublk_cmd.h>
>> +#include <linux/blk-mq.h>
>> +#include <linux/cdev.h>
>> +
>> +/*
>> + * io command is active: sqe cmd is received, and its cqe isn't done
>> + *
>> + * If the flag is set, the io command is owned by ublk driver, and waited
>> + * for incoming blk-mq request from the ublk block device.
>> + *
>> + * If the flag is cleared, the io command will be completed, and owned by
>> + * ublk server.
>> + */
>> +#define UBLK_IO_FLAG_ACTIVE	0x01
>> +
>> +/*
>> + * IO command is completed via cqe, and it is being handled by ublksrv, and
>> + * not committed yet
>> + *
>> + * Basically exclusively with UBLK_IO_FLAG_ACTIVE, so can be served for
>> + * cross verification
>> + */
>> +#define UBLK_IO_FLAG_OWNED_BY_SRV 0x02
>> +
>> +/*
>> + * IO command is aborted, so this flag is set in case of
>> + * !UBLK_IO_FLAG_ACTIVE.
>> + *
>> + * After this flag is observed, any pending or new incoming request
>> + * associated with this io command will be failed immediately
>> + */
>> +#define UBLK_IO_FLAG_ABORTED 0x04
>> +
>> +/*
>> + * UBLK_IO_FLAG_NEED_GET_DATA is set because IO command requires
>> + * get data buffer address from ublksrv.
>> + *
>> + * Then, bio data could be copied into this data buffer for a WRITE request
>> + * after the IO command is issued again and UBLK_IO_FLAG_NEED_GET_DATA is unset.
>> + */
>> +#define UBLK_IO_FLAG_NEED_GET_DATA 0x08
>> +
>> +
>
> Nit: extra blank line not needed.
>
>> +struct ublk_device {
>> +	struct gendisk		*ub_disk;
>> +
>> +	char	*__queues;
>> +
>> +	unsigned int	queue_size;
>> +	struct ublksrv_ctrl_dev_info	dev_info;
>> +
>> +	struct blk_mq_tag_set	tag_set;
>> +
>> +	struct cdev		cdev;
>> +	struct device		cdev_dev;
>> +
>> +#define UB_STATE_OPEN		0
>> +#define UB_STATE_USED		1
>> +#define UB_STATE_DELETED	2
>> +	unsigned long		state;
>> +	int			ub_number;
>> +
>> +	struct mutex		mutex;
>> +
>> +	spinlock_t		mm_lock;
>> +	struct mm_struct	*mm;
>> +
>> +	struct ublk_params	params;
>> +
>> +	struct completion	completion;
>> +	unsigned int		nr_queues_ready;
>> +	unsigned int		nr_privileged_daemon;
>> +
>> +	/*
>> +	 * Our ubq->daemon may be killed without any notification, so
>> +	 * monitor each queue's daemon periodically
>> +	 */
>> +	struct delayed_work	monitor_work;
>> +	struct work_struct	quiesce_work;
>> +	struct work_struct	stop_work;
>> +};
>> +
>> +struct ublk_rq_data {
>> +	struct llist_node node;
>> +
>> +	struct kref ref;
>> +};
>> +
>> +struct ublk_io {
>> +	/* userspace buffer address from io cmd */
>> +	__u64 addr;
>> +	unsigned int flags;
>> +	int res;
>> +
>> +	struct io_uring_cmd *cmd;
>> +};
>> +
>> +#endif