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From: Ming Lei <ming.lei@redhat.com>
To: Christoph Hellwig <hch@lst.de>
Cc: Jens Axboe <axboe@kernel.dk>,
	"Martin K . Petersen" <martin.petersen@oracle.com>,
	Oleksii Kurochko <olkuroch@cisco.com>,
	Sagi Grimberg <sagi@grimberg.me>,
	Mike Snitzer <snitzer@redhat.com>,
	Ilya Dryomov <idryomov@gmail.com>,
	Dongsheng Yang <dongsheng.yang@easystack.cn>,
	ceph-devel@vger.kernel.org, dm-devel@redhat.com,
	linux-block@vger.kernel.org, linux-nvme@lists.infradead.org,
	Hannes Reinecke <hare@suse.de>
Subject: Re: [PATCH 3/6] block: add a hard-readonly flag to struct gendisk
Date: Tue, 8 Dec 2020 18:22:11 +0800	[thread overview]
Message-ID: <20201208102211.GC1202995@T590> (raw)
In-Reply-To: <20201207131918.2252553-4-hch@lst.de>

On Mon, Dec 07, 2020 at 02:19:15PM +0100, Christoph Hellwig wrote:
> Commit 20bd1d026aac ("scsi: sd: Keep disk read-only when re-reading
> partition") addressed a long-standing problem with user read-only
> policy being overridden as a result of a device-initiated revalidate.
> The commit has since been reverted due to a regression that left some
> USB devices read-only indefinitely.
> 
> To fix the underlying problems with revalidate we need to keep track
> of hardware state and user policy separately.
> 
> The gendisk has been updated to reflect the current hardware state set
> by the device driver. This is done to allow returning the device to
> the hardware state once the user clears the BLKROSET flag.
> 
> The resulting semantics are as follows:
> 
>  - If BLKROSET sets a given partition read-only, that partition will
>    remain read-only even if the underlying storage stack initiates a
>    revalidate. However, the BLKRRPART ioctl will cause the partition
>    table to be dropped and any user policy on partitions will be lost.
> 
>  - If BLKROSET has not been set, both the whole disk device and any
>    partitions will reflect the current write-protect state of the
>    underlying device.
> 
> Based on a patch from Martin K. Petersen <martin.petersen@oracle.com>.
> 
> Reported-by: Oleksii Kurochko <olkuroch@cisco.com>
> Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=201221
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> Reviewed-by: Hannes Reinecke <hare@suse.de>
> ---
>  block/blk-core.c        |  2 +-
>  block/genhd.c           | 33 +++++++++++++++++++--------------
>  block/partitions/core.c |  3 +--
>  include/linux/genhd.h   |  6 ++++--
>  4 files changed, 25 insertions(+), 19 deletions(-)
> 
> diff --git a/block/blk-core.c b/block/blk-core.c
> index ad041e903b0a8f..ecd68415c6acad 100644
> --- a/block/blk-core.c
> +++ b/block/blk-core.c
> @@ -693,7 +693,7 @@ static inline bool should_fail_request(struct block_device *part,
>  
>  static inline bool bio_check_ro(struct bio *bio)
>  {
> -	if (op_is_write(bio_op(bio)) && bio->bi_bdev->bd_read_only) {
> +	if (op_is_write(bio_op(bio)) && bdev_read_only(bio->bi_bdev))
>  		char b[BDEVNAME_SIZE];
>  
>  		if (op_is_flush(bio->bi_opf) && !bio_sectors(bio))
> diff --git a/block/genhd.c b/block/genhd.c
> index c87013879b8650..878f94727aaa96 100644
> --- a/block/genhd.c
> +++ b/block/genhd.c
> @@ -1425,27 +1425,32 @@ static void set_disk_ro_uevent(struct gendisk *gd, int ro)
>  	kobject_uevent_env(&disk_to_dev(gd)->kobj, KOBJ_CHANGE, envp);
>  }
>  
> -void set_disk_ro(struct gendisk *disk, int flag)
> +/**
> + * set_disk_ro - set a gendisk read-only
> + * @disk:	gendisk to operate on
> + * @ready_only:	%true to set the disk read-only, %false set the disk read/write
> + *
> + * This function is used to indicate whether a given disk device should have its
> + * read-only flag set. set_disk_ro() is typically used by device drivers to
> + * indicate whether the underlying physical device is write-protected.
> + */
> +void set_disk_ro(struct gendisk *disk, bool read_only)
>  {
> -	struct disk_part_iter piter;
> -	struct block_device *part;
> -
> -	if (disk->part0->bd_read_only != flag) {
> -		set_disk_ro_uevent(disk, flag);
> -		disk->part0->bd_read_only = flag;
> +	if (read_only) {
> +		if (test_and_set_bit(GD_READ_ONLY, &disk->state))
> +			return;
> +	} else {
> +		if (!test_and_clear_bit(GD_READ_ONLY, &disk->state))
> +			return;
>  	}
> -
> -	disk_part_iter_init(&piter, disk, DISK_PITER_INCL_EMPTY);
> -	while ((part = disk_part_iter_next(&piter)))
> -		part->bd_read_only = flag;
> -	disk_part_iter_exit(&piter);
> +	set_disk_ro_uevent(disk, read_only);
>  }
> -
>  EXPORT_SYMBOL(set_disk_ro);
>  
>  int bdev_read_only(struct block_device *bdev)
>  {
> -	return bdev->bd_read_only;
> +	return bdev->bd_read_only ||
> +		test_bit(GD_READ_ONLY, &bdev->bd_disk->state);
>  }
>  EXPORT_SYMBOL(bdev_read_only);

Maybe one inline version can be added for fast path(bio_check_ro()), and the approach
is good:

Reviewed-by: Ming Lei <ming.lei@redhat.com>

-- 
Ming


WARNING: multiple messages have this Message-ID (diff)
From: Ming Lei <ming.lei@redhat.com>
To: Christoph Hellwig <hch@lst.de>
Cc: Jens Axboe <axboe@kernel.dk>, Sagi Grimberg <sagi@grimberg.me>,
	Mike Snitzer <snitzer@redhat.com>,
	Oleksii Kurochko <olkuroch@cisco.com>,
	Dongsheng Yang <dongsheng.yang@easystack.cn>,
	linux-block@vger.kernel.org, dm-devel@redhat.com,
	linux-nvme@lists.infradead.org,
	"Martin K . Petersen" <martin.petersen@oracle.com>,
	Ilya Dryomov <idryomov@gmail.com>,
	ceph-devel@vger.kernel.org, Hannes Reinecke <hare@suse.de>
Subject: Re: [PATCH 3/6] block: add a hard-readonly flag to struct gendisk
Date: Tue, 8 Dec 2020 18:22:11 +0800	[thread overview]
Message-ID: <20201208102211.GC1202995@T590> (raw)
In-Reply-To: <20201207131918.2252553-4-hch@lst.de>

On Mon, Dec 07, 2020 at 02:19:15PM +0100, Christoph Hellwig wrote:
> Commit 20bd1d026aac ("scsi: sd: Keep disk read-only when re-reading
> partition") addressed a long-standing problem with user read-only
> policy being overridden as a result of a device-initiated revalidate.
> The commit has since been reverted due to a regression that left some
> USB devices read-only indefinitely.
> 
> To fix the underlying problems with revalidate we need to keep track
> of hardware state and user policy separately.
> 
> The gendisk has been updated to reflect the current hardware state set
> by the device driver. This is done to allow returning the device to
> the hardware state once the user clears the BLKROSET flag.
> 
> The resulting semantics are as follows:
> 
>  - If BLKROSET sets a given partition read-only, that partition will
>    remain read-only even if the underlying storage stack initiates a
>    revalidate. However, the BLKRRPART ioctl will cause the partition
>    table to be dropped and any user policy on partitions will be lost.
> 
>  - If BLKROSET has not been set, both the whole disk device and any
>    partitions will reflect the current write-protect state of the
>    underlying device.
> 
> Based on a patch from Martin K. Petersen <martin.petersen@oracle.com>.
> 
> Reported-by: Oleksii Kurochko <olkuroch@cisco.com>
> Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=201221
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> Reviewed-by: Hannes Reinecke <hare@suse.de>
> ---
>  block/blk-core.c        |  2 +-
>  block/genhd.c           | 33 +++++++++++++++++++--------------
>  block/partitions/core.c |  3 +--
>  include/linux/genhd.h   |  6 ++++--
>  4 files changed, 25 insertions(+), 19 deletions(-)
> 
> diff --git a/block/blk-core.c b/block/blk-core.c
> index ad041e903b0a8f..ecd68415c6acad 100644
> --- a/block/blk-core.c
> +++ b/block/blk-core.c
> @@ -693,7 +693,7 @@ static inline bool should_fail_request(struct block_device *part,
>  
>  static inline bool bio_check_ro(struct bio *bio)
>  {
> -	if (op_is_write(bio_op(bio)) && bio->bi_bdev->bd_read_only) {
> +	if (op_is_write(bio_op(bio)) && bdev_read_only(bio->bi_bdev))
>  		char b[BDEVNAME_SIZE];
>  
>  		if (op_is_flush(bio->bi_opf) && !bio_sectors(bio))
> diff --git a/block/genhd.c b/block/genhd.c
> index c87013879b8650..878f94727aaa96 100644
> --- a/block/genhd.c
> +++ b/block/genhd.c
> @@ -1425,27 +1425,32 @@ static void set_disk_ro_uevent(struct gendisk *gd, int ro)
>  	kobject_uevent_env(&disk_to_dev(gd)->kobj, KOBJ_CHANGE, envp);
>  }
>  
> -void set_disk_ro(struct gendisk *disk, int flag)
> +/**
> + * set_disk_ro - set a gendisk read-only
> + * @disk:	gendisk to operate on
> + * @ready_only:	%true to set the disk read-only, %false set the disk read/write
> + *
> + * This function is used to indicate whether a given disk device should have its
> + * read-only flag set. set_disk_ro() is typically used by device drivers to
> + * indicate whether the underlying physical device is write-protected.
> + */
> +void set_disk_ro(struct gendisk *disk, bool read_only)
>  {
> -	struct disk_part_iter piter;
> -	struct block_device *part;
> -
> -	if (disk->part0->bd_read_only != flag) {
> -		set_disk_ro_uevent(disk, flag);
> -		disk->part0->bd_read_only = flag;
> +	if (read_only) {
> +		if (test_and_set_bit(GD_READ_ONLY, &disk->state))
> +			return;
> +	} else {
> +		if (!test_and_clear_bit(GD_READ_ONLY, &disk->state))
> +			return;
>  	}
> -
> -	disk_part_iter_init(&piter, disk, DISK_PITER_INCL_EMPTY);
> -	while ((part = disk_part_iter_next(&piter)))
> -		part->bd_read_only = flag;
> -	disk_part_iter_exit(&piter);
> +	set_disk_ro_uevent(disk, read_only);
>  }
> -
>  EXPORT_SYMBOL(set_disk_ro);
>  
>  int bdev_read_only(struct block_device *bdev)
>  {
> -	return bdev->bd_read_only;
> +	return bdev->bd_read_only ||
> +		test_bit(GD_READ_ONLY, &bdev->bd_disk->state);
>  }
>  EXPORT_SYMBOL(bdev_read_only);

Maybe one inline version can be added for fast path(bio_check_ro()), and the approach
is good:

Reviewed-by: Ming Lei <ming.lei@redhat.com>

-- 
Ming


_______________________________________________
Linux-nvme mailing list
Linux-nvme@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-nvme

WARNING: multiple messages have this Message-ID (diff)
From: Ming Lei <ming.lei@redhat.com>
To: Christoph Hellwig <hch@lst.de>
Cc: Jens Axboe <axboe@kernel.dk>, Sagi Grimberg <sagi@grimberg.me>,
	Mike Snitzer <snitzer@redhat.com>,
	Oleksii Kurochko <olkuroch@cisco.com>,
	Dongsheng Yang <dongsheng.yang@easystack.cn>,
	linux-block@vger.kernel.org, dm-devel@redhat.com,
	linux-nvme@lists.infradead.org,
	"Martin K . Petersen" <martin.petersen@oracle.com>,
	Ilya Dryomov <idryomov@gmail.com>,
	ceph-devel@vger.kernel.org
Subject: Re: [dm-devel] [PATCH 3/6] block: add a hard-readonly flag to struct gendisk
Date: Tue, 8 Dec 2020 18:22:11 +0800	[thread overview]
Message-ID: <20201208102211.GC1202995@T590> (raw)
In-Reply-To: <20201207131918.2252553-4-hch@lst.de>

On Mon, Dec 07, 2020 at 02:19:15PM +0100, Christoph Hellwig wrote:
> Commit 20bd1d026aac ("scsi: sd: Keep disk read-only when re-reading
> partition") addressed a long-standing problem with user read-only
> policy being overridden as a result of a device-initiated revalidate.
> The commit has since been reverted due to a regression that left some
> USB devices read-only indefinitely.
> 
> To fix the underlying problems with revalidate we need to keep track
> of hardware state and user policy separately.
> 
> The gendisk has been updated to reflect the current hardware state set
> by the device driver. This is done to allow returning the device to
> the hardware state once the user clears the BLKROSET flag.
> 
> The resulting semantics are as follows:
> 
>  - If BLKROSET sets a given partition read-only, that partition will
>    remain read-only even if the underlying storage stack initiates a
>    revalidate. However, the BLKRRPART ioctl will cause the partition
>    table to be dropped and any user policy on partitions will be lost.
> 
>  - If BLKROSET has not been set, both the whole disk device and any
>    partitions will reflect the current write-protect state of the
>    underlying device.
> 
> Based on a patch from Martin K. Petersen <martin.petersen@oracle.com>.
> 
> Reported-by: Oleksii Kurochko <olkuroch@cisco.com>
> Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=201221
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> Reviewed-by: Hannes Reinecke <hare@suse.de>
> ---
>  block/blk-core.c        |  2 +-
>  block/genhd.c           | 33 +++++++++++++++++++--------------
>  block/partitions/core.c |  3 +--
>  include/linux/genhd.h   |  6 ++++--
>  4 files changed, 25 insertions(+), 19 deletions(-)
> 
> diff --git a/block/blk-core.c b/block/blk-core.c
> index ad041e903b0a8f..ecd68415c6acad 100644
> --- a/block/blk-core.c
> +++ b/block/blk-core.c
> @@ -693,7 +693,7 @@ static inline bool should_fail_request(struct block_device *part,
>  
>  static inline bool bio_check_ro(struct bio *bio)
>  {
> -	if (op_is_write(bio_op(bio)) && bio->bi_bdev->bd_read_only) {
> +	if (op_is_write(bio_op(bio)) && bdev_read_only(bio->bi_bdev))
>  		char b[BDEVNAME_SIZE];
>  
>  		if (op_is_flush(bio->bi_opf) && !bio_sectors(bio))
> diff --git a/block/genhd.c b/block/genhd.c
> index c87013879b8650..878f94727aaa96 100644
> --- a/block/genhd.c
> +++ b/block/genhd.c
> @@ -1425,27 +1425,32 @@ static void set_disk_ro_uevent(struct gendisk *gd, int ro)
>  	kobject_uevent_env(&disk_to_dev(gd)->kobj, KOBJ_CHANGE, envp);
>  }
>  
> -void set_disk_ro(struct gendisk *disk, int flag)
> +/**
> + * set_disk_ro - set a gendisk read-only
> + * @disk:	gendisk to operate on
> + * @ready_only:	%true to set the disk read-only, %false set the disk read/write
> + *
> + * This function is used to indicate whether a given disk device should have its
> + * read-only flag set. set_disk_ro() is typically used by device drivers to
> + * indicate whether the underlying physical device is write-protected.
> + */
> +void set_disk_ro(struct gendisk *disk, bool read_only)
>  {
> -	struct disk_part_iter piter;
> -	struct block_device *part;
> -
> -	if (disk->part0->bd_read_only != flag) {
> -		set_disk_ro_uevent(disk, flag);
> -		disk->part0->bd_read_only = flag;
> +	if (read_only) {
> +		if (test_and_set_bit(GD_READ_ONLY, &disk->state))
> +			return;
> +	} else {
> +		if (!test_and_clear_bit(GD_READ_ONLY, &disk->state))
> +			return;
>  	}
> -
> -	disk_part_iter_init(&piter, disk, DISK_PITER_INCL_EMPTY);
> -	while ((part = disk_part_iter_next(&piter)))
> -		part->bd_read_only = flag;
> -	disk_part_iter_exit(&piter);
> +	set_disk_ro_uevent(disk, read_only);
>  }
> -
>  EXPORT_SYMBOL(set_disk_ro);
>  
>  int bdev_read_only(struct block_device *bdev)
>  {
> -	return bdev->bd_read_only;
> +	return bdev->bd_read_only ||
> +		test_bit(GD_READ_ONLY, &bdev->bd_disk->state);
>  }
>  EXPORT_SYMBOL(bdev_read_only);

Maybe one inline version can be added for fast path(bio_check_ro()), and the approach
is good:

Reviewed-by: Ming Lei <ming.lei@redhat.com>

-- 
Ming

--
dm-devel mailing list
dm-devel@redhat.com
https://www.redhat.com/mailman/listinfo/dm-devel


  parent reply	other threads:[~2020-12-08 10:24 UTC|newest]

Thread overview: 82+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-12-07 13:19 split hard read-only vs read-only policy v2 Christoph Hellwig
2020-12-07 13:19 ` [dm-devel] " Christoph Hellwig
2020-12-07 13:19 ` Christoph Hellwig
2020-12-07 13:19 ` [PATCH 1/6] dm: use bdev_read_only to check if a device is read-only Christoph Hellwig
2020-12-07 13:19   ` [dm-devel] " Christoph Hellwig
2020-12-07 13:19   ` Christoph Hellwig
2020-12-08  5:23   ` Martin K. Petersen
2020-12-08  5:23     ` [dm-devel] " Martin K. Petersen
2020-12-08  5:23     ` Martin K. Petersen
2020-12-08  9:59   ` Ming Lei
2020-12-08  9:59     ` [dm-devel] " Ming Lei
2020-12-08  9:59     ` Ming Lei
2020-12-07 13:19 ` [PATCH 2/6] block: remove the NULL bdev check in bdev_read_only Christoph Hellwig
2020-12-07 13:19   ` [dm-devel] " Christoph Hellwig
2020-12-07 13:19   ` Christoph Hellwig
2020-12-08  5:23   ` Martin K. Petersen
2020-12-08  5:23     ` [dm-devel] " Martin K. Petersen
2020-12-08  5:23     ` Martin K. Petersen
2020-12-08 10:06   ` Ming Lei
2020-12-08 10:06     ` [dm-devel] " Ming Lei
2020-12-08 10:06     ` Ming Lei
2020-12-07 13:19 ` [PATCH 3/6] block: add a hard-readonly flag to struct gendisk Christoph Hellwig
2020-12-07 13:19   ` [dm-devel] " Christoph Hellwig
2020-12-07 13:19   ` Christoph Hellwig
2020-12-08  5:24   ` Martin K. Petersen
2020-12-08  5:24     ` [dm-devel] " Martin K. Petersen
2020-12-08  5:24     ` Martin K. Petersen
2020-12-08  5:28   ` Martin K. Petersen
2020-12-08  5:28     ` [dm-devel] " Martin K. Petersen
2020-12-08  5:28     ` Martin K. Petersen
2020-12-08 10:22   ` Ming Lei [this message]
2020-12-08 10:22     ` [dm-devel] " Ming Lei
2020-12-08 10:22     ` Ming Lei
2020-12-08 10:57     ` Christoph Hellwig
2020-12-08 10:57       ` [dm-devel] " Christoph Hellwig
2020-12-08 10:57       ` Christoph Hellwig
2020-12-07 13:19 ` [PATCH 4/6] block: propagate BLKROSET on the whole device to all partitions Christoph Hellwig
2020-12-07 13:19   ` [dm-devel] " Christoph Hellwig
2020-12-07 13:19   ` Christoph Hellwig
2020-12-08  5:27   ` Martin K. Petersen
2020-12-08  5:27     ` [dm-devel] " Martin K. Petersen
2020-12-08  5:27     ` Martin K. Petersen
2020-12-08  9:25     ` Christoph Hellwig
2020-12-08  9:25       ` [dm-devel] " Christoph Hellwig
2020-12-08  9:25       ` Christoph Hellwig
2020-12-08 12:41       ` Johannes Thumshirn
2020-12-08 12:41         ` [dm-devel] " Johannes Thumshirn
2020-12-08 12:41         ` Johannes Thumshirn
2020-12-08 10:29   ` Ming Lei
2020-12-08 10:29     ` [dm-devel] " Ming Lei
2020-12-08 10:29     ` Ming Lei
2020-12-08 10:59     ` Christoph Hellwig
2020-12-08 10:59       ` [dm-devel] " Christoph Hellwig
2020-12-08 10:59       ` Christoph Hellwig
2020-12-09  1:23       ` Ming Lei
2020-12-09  1:23         ` [dm-devel] " Ming Lei
2020-12-09  1:23         ` Ming Lei
2020-12-07 13:19 ` [PATCH 5/6] rbd: remove the ->set_read_only method Christoph Hellwig
2020-12-07 13:19   ` [dm-devel] " Christoph Hellwig
2020-12-07 13:19   ` Christoph Hellwig
2020-12-07 14:57   ` Ilya Dryomov
2020-12-07 14:57     ` [dm-devel] " Ilya Dryomov
2020-12-07 14:57     ` Ilya Dryomov
2020-12-08  5:30   ` Martin K. Petersen
2020-12-08  5:30     ` [dm-devel] " Martin K. Petersen
2020-12-08  5:30     ` Martin K. Petersen
2020-12-07 13:19 ` [PATCH 6/6] nvme: allow revalidate to set a namespace read-only Christoph Hellwig
2020-12-07 13:19   ` [dm-devel] " Christoph Hellwig
2020-12-07 13:19   ` Christoph Hellwig
2020-12-07 18:13   ` Keith Busch
2020-12-07 18:13     ` [dm-devel] " Keith Busch
2020-12-07 18:13     ` Keith Busch
2020-12-08  5:29   ` Martin K. Petersen
2020-12-08  5:29     ` [dm-devel] " Martin K. Petersen
2020-12-08  5:29     ` Martin K. Petersen
2020-12-10  7:50 ` split hard read-only vs read-only policy v2 Christoph Hellwig
2020-12-10  7:50   ` [dm-devel] " Christoph Hellwig
2020-12-10  7:50   ` Christoph Hellwig
2020-12-08 16:28 split hard read-only vs read-only policy v3 Christoph Hellwig
2020-12-08 16:28 ` [PATCH 3/6] block: add a hard-readonly flag to struct gendisk Christoph Hellwig
2020-12-08 16:28   ` Christoph Hellwig
2021-01-09 10:42 split hard read-only vs read-only policy v3 (resend) Christoph Hellwig
2021-01-09 10:42 ` [PATCH 3/6] block: add a hard-readonly flag to struct gendisk Christoph Hellwig
2021-01-09 10:42   ` Christoph Hellwig

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