Looks good.
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@xxxxxxx>
On 6/27/19 2:29 AM, Damien Le Moal wrote:
> Limit the size of the struct blk_zone array used in
> blk_revalidate_disk_zones() to avoid memory allocation failures leading
> to disk revalidation failure. Further reduce the likelyhood of these
> failures by using kvmalloc() instead of directly allocating contiguous
> pages.
>
> Fixes: 515ce6061312 ("scsi: sd_zbc: Fix sd_zbc_report_zones() buffer allocation")
> Fixes: e76239a3748c ("block: add a report_zones method")
> Cc: stable@xxxxxxxxxxxxxxx
> Signed-off-by: Damien Le Moal <damien.lemoal@xxxxxxx>
> Reviewed-by: Bart Van Assche <bvanassche@xxxxxxx>
> ---
> block/blk-zoned.c | 29 +++++++++++++----------------
> include/linux/blkdev.h | 5 +++++
> 2 files changed, 18 insertions(+), 16 deletions(-)
>
> diff --git a/block/blk-zoned.c b/block/blk-zoned.c
> index ae7e91bd0618..26f878b9b5f5 100644
> --- a/block/blk-zoned.c
> +++ b/block/blk-zoned.c
> @@ -373,22 +373,20 @@ static inline unsigned long *blk_alloc_zone_bitmap(int node,
> * Allocate an array of struct blk_zone to get nr_zones zone information.
> * The allocated array may be smaller than nr_zones.
> */
> -static struct blk_zone *blk_alloc_zones(int node, unsigned int *nr_zones)
> +static struct blk_zone *blk_alloc_zones(unsigned int *nr_zones)
> {
> - size_t size = *nr_zones * sizeof(struct blk_zone);
> - struct page *page;
> - int order;
> -
> - for (order = get_order(size); order >= 0; order--) {
> - page = alloc_pages_node(node, GFP_NOIO | __GFP_ZERO, order);
> - if (page) {
> - *nr_zones = min_t(unsigned int, *nr_zones,
> - (PAGE_SIZE << order) / sizeof(struct blk_zone));
> - return page_address(page);
> - }
> + struct blk_zone *zones;
> + size_t nrz = min(*nr_zones, BLK_ZONED_REPORT_MAX_ZONES);
> +
> + zones = kvcalloc(nrz, sizeof(struct blk_zone), GFP_NOIO);
> + if (!zones) {
> + *nr_zones = 0;
> + return NULL;
> }
>
> - return NULL;
> + *nr_zones = nrz;
> +
> + return zones;
> }
>
> void blk_queue_free_zone_bitmaps(struct request_queue *q)
> @@ -443,7 +441,7 @@ int blk_revalidate_disk_zones(struct gendisk *disk)
>
> /* Get zone information and initialize seq_zones_bitmap */
> rep_nr_zones = nr_zones;
> - zones = blk_alloc_zones(q->node, &rep_nr_zones);
> + zones = blk_alloc_zones(&rep_nr_zones);
> if (!zones)
> goto out;
>
> @@ -480,8 +478,7 @@ int blk_revalidate_disk_zones(struct gendisk *disk)
> blk_mq_unfreeze_queue(q);
>
> out:
> - free_pages((unsigned long)zones,
> - get_order(rep_nr_zones * sizeof(struct blk_zone)));
> + kvfree(zones);
> kfree(seq_zones_wlock);
> kfree(seq_zones_bitmap);
>
> diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
> index 592669bcc536..f7faac856017 100644
> --- a/include/linux/blkdev.h
> +++ b/include/linux/blkdev.h
> @@ -344,6 +344,11 @@ struct queue_limits {
>
> #ifdef CONFIG_BLK_DEV_ZONED
>
> +/*
> + * Maximum number of zones to report with a single report zones command.
> + */
> +#define BLK_ZONED_REPORT_MAX_ZONES 8192U
> +
> extern unsigned int blkdev_nr_zones(struct block_device *bdev);
> extern int blkdev_report_zones(struct block_device *bdev,
> sector_t sector, struct blk_zone *zones,
>
