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 58ced170..6c50382 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;
+ 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 @@ 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);
