The patch below does not apply to the 5.1-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 26202928fafad8bda8b478edb7e62c885be623d7 Mon Sep 17 00:00:00 2001

From: Damien Le Moal damien.lemoal@wdc.com Date: Mon, 1 Jul 2019 14:09:18 +0900 Subject: [PATCH] block: Limit zone array allocation size

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. Also further reduce the likelyhood of such failures by using kvcalloc() (that is vmalloc()) instead of allocating contiguous pages with alloc_pages().

Fixes: 515ce6061312 ("scsi: sd_zbc: Fix sd_zbc_report_zones() buffer allocation") Fixes: e76239a3748c ("block: add a report_zones method") Cc: stable@vger.kernel.org Reviewed-by: Christoph Hellwig hch@lst.de Reviewed-by: Martin K. Petersen martin.petersen@oracle.com Signed-off-by: Damien Le Moal damien.lemoal@wdc.com Signed-off-by: Jens Axboe axboe@kernel.dk

diff --git a/block/blk-zoned.c b/block/blk-zoned.c index 58ced170b424..6c503824ba3f 100644 --- a/block/blk-zoned.c +++ b/block/blk-zoned.c @@ -14,6 +14,8 @@ #include <linux/rbtree.h> #include <linux/blkdev.h> #include <linux/blk-mq.h> +#include <linux/mm.h> +#include <linux/vmalloc.h> #include <linux/sched/mm.h>

#include "blk.h" @@ -371,22 +373,25 @@ 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); + + /* + * GFP_KERNEL here is meaningless as the caller task context has + * the PF_MEMALLOC_NOIO flag set in blk_revalidate_disk_zones() + * with memalloc_noio_save(). + */ + zones = kvcalloc(nrz, sizeof(struct blk_zone), GFP_KERNEL); + if (!zones) { + *nr_zones = 0; + return NULL; }

- return NULL; + *nr_zones = nrz; + + return zones; }

void blk_queue_free_zone_bitmaps(struct request_queue *q) @@ -448,7 +453,7 @@ 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;

@@ -487,8 +492,7 @@ int blk_revalidate_disk_zones(struct gendisk *disk) out: memalloc_noio_restore(noio_flag);

- 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 05036e3e3458..1ef375dafb1c 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,