From: Damien Le Moal damien.lemoal@wdc.com
commit 26202928fafad8bda8b478edb7e62c885be623d7 upstream.
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 Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- block/blk-zoned.c | 46 ++++++++++++++++++++++++++++++---------------- include/linux/blkdev.h | 5 +++++ 2 files changed, 35 insertions(+), 16 deletions(-)
--- a/block/blk-zoned.c +++ b/block/blk-zoned.c @@ -13,6 +13,9 @@ #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"
@@ -372,22 +375,25 @@ static inline unsigned long *blk_alloc_z * 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) @@ -414,6 +420,7 @@ int blk_revalidate_disk_zones(struct gen unsigned long *seq_zones_wlock = NULL, *seq_zones_bitmap = NULL; unsigned int i, rep_nr_zones = 0, z = 0, nrz; struct blk_zone *zones = NULL; + unsigned int noio_flag; sector_t sector = 0; int ret = 0;
@@ -426,6 +433,12 @@ int blk_revalidate_disk_zones(struct gen return 0; }
+ /* + * Ensure that all memory allocations in this context are done as + * if GFP_NOIO was specified. + */ + noio_flag = memalloc_noio_save(); + if (!blk_queue_is_zoned(q) || !nr_zones) { nr_zones = 0; goto update; @@ -442,7 +455,7 @@ int blk_revalidate_disk_zones(struct gen
/* 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;
@@ -479,8 +492,9 @@ update: blk_mq_unfreeze_queue(q);
out: - free_pages((unsigned long)zones, - get_order(rep_nr_zones * sizeof(struct blk_zone))); + memalloc_noio_restore(noio_flag); + + kvfree(zones); kfree(seq_zones_wlock); kfree(seq_zones_bitmap);
--- 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,