[Devel] [vzlin-dev] [PATCH vz7] md: propagate QUEUE_FLAG_SG_GAPS

Vasily Averin vvs at virtuozzo.com
Thu Dec 8 21:21:43 PST 2016


Maxim,
will you sent this to mainline too ?

thank you,
	Vasily Averin

On 12/09/2016 08:17 AM, Maxim Patlasov wrote:
> NVMe disk driver disables sg gaps by setting the flag in its queue.
> md-raids must propagate the flag to its queue as well. Otherwise, an upper
> user will get OK from bio_add_page() even if a gap exists, and that bio
> with a gap will crash NVMe driver who doesn't expect gaps.
> (see bvec_gap_to_prev for the definotion of gap)
> 
> https://jira.sw.ru/browse/PSBM-56838
> 
> Signed-off-by: Maxim Patlasov <mpatlasov at virtuozzo.com>
> ---
>  drivers/md/linear.c    |    9 +++++++++
>  drivers/md/raid0.c     |    8 ++++++++
>  drivers/md/raid1.c     |   11 +++++++++++
>  drivers/md/raid10.c    |   12 ++++++++++++
>  drivers/md/raid5.c     |   10 ++++++++++
>  include/linux/blkdev.h |    1 +
>  6 files changed, 51 insertions(+)
> 
> diff --git a/drivers/md/linear.c b/drivers/md/linear.c
> index 3310b59..e57b8ff 100644
> --- a/drivers/md/linear.c
> +++ b/drivers/md/linear.c
> @@ -128,6 +128,7 @@ static struct linear_conf *linear_conf(struct mddev *mddev, int raid_disks)
>  	struct md_rdev *rdev;
>  	int i, cnt;
>  	bool discard_supported = false;
> +	bool sg_gaps_disabled = false;
>  
>  	conf = kzalloc (sizeof (*conf) + raid_disks*sizeof(struct dev_info),
>  			GFP_KERNEL);
> @@ -163,6 +164,9 @@ static struct linear_conf *linear_conf(struct mddev *mddev, int raid_disks)
>  
>  		if (blk_queue_discard(bdev_get_queue(rdev->bdev)))
>  			discard_supported = true;
> +
> +		if (blk_queue_sg_gaps(bdev_get_queue(rdev->bdev)))
> +			sg_gaps_disabled = true;
>  	}
>  	if (cnt != raid_disks) {
>  		printk(KERN_ERR "md/linear:%s: not enough drives present. Aborting!\n",
> @@ -175,6 +179,11 @@ static struct linear_conf *linear_conf(struct mddev *mddev, int raid_disks)
>  	else
>  		queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, mddev->queue);
>  
> +	if (!sg_gaps_disabled)
> +		queue_flag_clear_unlocked(QUEUE_FLAG_SG_GAPS, mddev->queue);
> +	else
> +		queue_flag_set_unlocked(QUEUE_FLAG_SG_GAPS, mddev->queue);
> +
>  	/*
>  	 * Here we calculate the device offsets.
>  	 */
> diff --git a/drivers/md/raid0.c b/drivers/md/raid0.c
> index 100ef23..2b77d0f 100644
> --- a/drivers/md/raid0.c
> +++ b/drivers/md/raid0.c
> @@ -435,6 +435,7 @@ static int raid0_run(struct mddev *mddev)
>  	if (mddev->queue) {
>  		struct md_rdev *rdev;
>  		bool discard_supported = false;
> +		bool sg_gaps_disabled = false;
>  
>  		blk_queue_max_hw_sectors(mddev->queue, mddev->chunk_sectors);
>  		blk_queue_max_write_same_sectors(mddev->queue, mddev->chunk_sectors);
> @@ -449,6 +450,8 @@ static int raid0_run(struct mddev *mddev)
>  					  rdev->data_offset << 9);
>  			if (blk_queue_discard(bdev_get_queue(rdev->bdev)))
>  				discard_supported = true;
> +			if (blk_queue_sg_gaps(bdev_get_queue(rdev->bdev)))
> +				sg_gaps_disabled = true;
>  		}
>  
>  		/* Unfortunately, some devices have awful discard performance,
> @@ -470,6 +473,11 @@ static int raid0_run(struct mddev *mddev)
>  			queue_flag_clear_unlocked(QUEUE_FLAG_DISCARD, mddev->queue);
>  		else
>  			queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, mddev->queue);
> +
> +		if (!sg_gaps_disabled)
> +			queue_flag_clear_unlocked(QUEUE_FLAG_SG_GAPS, mddev->queue);
> +		else
> +			queue_flag_set_unlocked(QUEUE_FLAG_SG_GAPS, mddev->queue);
>  	}
>  
>  	/* calculate array device size */
> diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
> index b45b64c..a1763b5 100644
> --- a/drivers/md/raid1.c
> +++ b/drivers/md/raid1.c
> @@ -1663,6 +1663,8 @@ static int raid1_add_disk(struct mddev *mddev, struct md_rdev *rdev)
>  	md_integrity_add_rdev(rdev, mddev);
>  	if (mddev->queue && blk_queue_discard(bdev_get_queue(rdev->bdev)))
>  		queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, mddev->queue);
> +	if (mddev->queue && blk_queue_sg_gaps(bdev_get_queue(rdev->bdev)))
> +		queue_flag_set_unlocked(QUEUE_FLAG_SG_GAPS, mddev->queue);
>  	print_conf(conf);
>  	return err;
>  }
> @@ -2905,6 +2907,7 @@ static int run(struct mddev *mddev)
>  	struct md_rdev *rdev;
>  	int ret;
>  	bool discard_supported = false;
> +	bool sg_gaps_disabled = false;
>  
>  	if (mddev->level != 1) {
>  		printk(KERN_ERR "md/raid1:%s: raid level not set to mirroring (%d)\n",
> @@ -2939,6 +2942,8 @@ static int run(struct mddev *mddev)
>  				  rdev->data_offset << 9);
>  		if (blk_queue_discard(bdev_get_queue(rdev->bdev)))
>  			discard_supported = true;
> +		if (blk_queue_sg_gaps(bdev_get_queue(rdev->bdev)))
> +			sg_gaps_disabled = true;
>  	}
>  
>  	mddev->degraded = 0;
> @@ -2976,6 +2981,12 @@ static int run(struct mddev *mddev)
>  		else
>  			queue_flag_clear_unlocked(QUEUE_FLAG_DISCARD,
>  						  mddev->queue);
> +		if (sg_gaps_disabled)
> +			queue_flag_set_unlocked(QUEUE_FLAG_SG_GAPS,
> +						mddev->queue);
> +		else
> +			queue_flag_clear_unlocked(QUEUE_FLAG_SG_GAPS,
> +						  mddev->queue);
>  	}
>  
>  	ret =  md_integrity_register(mddev);
> diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
> index f0c7f3b..52f8d73 100644
> --- a/drivers/md/raid10.c
> +++ b/drivers/md/raid10.c
> @@ -1865,6 +1865,8 @@ static int raid10_add_disk(struct mddev *mddev, struct md_rdev *rdev)
>  	md_integrity_add_rdev(rdev, mddev);
>  	if (mddev->queue && blk_queue_discard(bdev_get_queue(rdev->bdev)))
>  		queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, mddev->queue);
> +	if (mddev->queue && blk_queue_sg_gaps(bdev_get_queue(rdev->bdev)))
> +		queue_flag_set_unlocked(QUEUE_FLAG_SG_GAPS, mddev->queue);
>  
>  	print_conf(conf);
>  	return err;
> @@ -3650,6 +3652,7 @@ static int run(struct mddev *mddev)
>  	sector_t min_offset_diff = 0;
>  	int first = 1;
>  	bool discard_supported = false;
> +	bool sg_gaps_disabled = false;
>  
>  	if (mddev->private == NULL) {
>  		conf = setup_conf(mddev);
> @@ -3717,6 +3720,9 @@ static int run(struct mddev *mddev)
>  
>  		if (blk_queue_discard(bdev_get_queue(rdev->bdev)))
>  			discard_supported = true;
> +
> +		if (blk_queue_sg_gaps(bdev_get_queue(rdev->bdev)))
> +			sg_gaps_disabled = true;
>  	}
>  
>  	if (mddev->queue) {
> @@ -3726,6 +3732,12 @@ static int run(struct mddev *mddev)
>  		else
>  			queue_flag_clear_unlocked(QUEUE_FLAG_DISCARD,
>  						  mddev->queue);
> +		if (sg_gaps_disabled)
> +			queue_flag_set_unlocked(QUEUE_FLAG_SG_GAPS,
> +						mddev->queue);
> +		else
> +			queue_flag_clear_unlocked(QUEUE_FLAG_SG_GAPS,
> +						  mddev->queue);
>  	}
>  	/* need to check that every block has at least one working mirror */
>  	if (!enough(conf, -1)) {
> diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
> index 50902ad1..862b86f 100644
> --- a/drivers/md/raid5.c
> +++ b/drivers/md/raid5.c
> @@ -6814,6 +6814,7 @@ static int run(struct mddev *mddev)
>  	if (mddev->queue) {
>  		int chunk_size;
>  		bool discard_supported = true;
> +		bool sg_gaps_disabled = false;
>  		/* read-ahead size must cover two whole stripes, which
>  		 * is 2 * (datadisks) * chunksize where 'n' is the
>  		 * number of raid devices
> @@ -6878,6 +6879,8 @@ static int run(struct mddev *mddev)
>  				}
>  				discard_supported = false;
>  			}
> +			if (blk_queue_sg_gaps(bdev_get_queue(rdev->bdev)))
> +				sg_gaps_disabled = true;
>  		}
>  
>  		if (discard_supported &&
> @@ -6888,6 +6891,13 @@ static int run(struct mddev *mddev)
>  		else
>  			queue_flag_clear_unlocked(QUEUE_FLAG_DISCARD,
>  						mddev->queue);
> +
> +		if (sg_gaps_disabled)
> +			queue_flag_set_unlocked(QUEUE_FLAG_SG_GAPS,
> +						mddev->queue);
> +		else
> +			queue_flag_clear_unlocked(QUEUE_FLAG_SG_GAPS,
> +						mddev->queue);
>  	}
>  
>  	return 0;
> diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
> index 8b400c6..e3752b1 100644
> --- a/include/linux/blkdev.h
> +++ b/include/linux/blkdev.h
> @@ -639,6 +639,7 @@ static inline void queue_flag_clear(unsigned int flag, struct request_queue *q)
>  #define blk_queue_discard(q)	test_bit(QUEUE_FLAG_DISCARD, &(q)->queue_flags)
>  #define blk_queue_secdiscard(q)	(blk_queue_discard(q) && \
>  	test_bit(QUEUE_FLAG_SECDISCARD, &(q)->queue_flags))
> +#define blk_queue_sg_gaps(q)	test_bit(QUEUE_FLAG_SG_GAPS, &(q)->queue_flags)
>  
>  #define blk_noretry_request(rq) \
>  	((rq)->cmd_flags & (REQ_FAILFAST_DEV|REQ_FAILFAST_TRANSPORT| \
> 
> 


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