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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: 515ce60613 ("scsi: sd_zbc: Fix sd_zbc_report_zones() buffer allocation")
Fixes: e76239a374 ("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>
alistair/sunxi64-5.4-dsi
Damien Le Moal 2019-07-01 14:09:18 +09:00 committed by Jens Axboe
parent b091ac6168
commit 26202928fa
2 changed files with 24 additions and 15 deletions

View File

@ -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;
struct blk_zone *zones;
size_t nrz = min(*nr_zones, BLK_ZONED_REPORT_MAX_ZONES);
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);
}
/*
* 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 @@ update:
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);

View File

@ -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,