Contrary to the comment in __blkdev_issue_write_zeroes, nothing here
checks for a potential bi_size overflow. Add a helper mirroring
the secure erase code for the check.
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
---
block/blk-lib.c | 18 +++++++++++-------
1 file changed, 11 insertions(+), 7 deletions(-)
diff --git a/block/blk-lib.c b/block/blk-lib.c
index cf4f0ee6b14503..f338709aef0c30 100644
--- a/block/blk-lib.c
+++ b/block/blk-lib.c
@@ -103,24 +103,28 @@ int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
}
EXPORT_SYMBOL(blkdev_issue_discard);
+static sector_t bio_write_zeroes_limit(struct block_device *bdev)
+{
+ sector_t bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1;
+
+ return min(bdev_write_zeroes_sectors(bdev),
+ (UINT_MAX >> SECTOR_SHIFT) & ~bs_mask);
+}
+
static int __blkdev_issue_write_zeroes(struct block_device *bdev,
sector_t sector, sector_t nr_sects, gfp_t gfp_mask,
struct bio **biop, unsigned flags)
{
struct bio *bio = *biop;
- unsigned int max_sectors;
if (bdev_read_only(bdev))
return -EPERM;
-
- /* Ensure that max_sectors doesn't overflow bi_size */
- max_sectors = bdev_write_zeroes_sectors(bdev);
-
- if (max_sectors == 0)
+ if (!bdev_write_zeroes_sectors(bdev))
return -EOPNOTSUPP;
while (nr_sects) {
- unsigned int len = min_t(sector_t, nr_sects, max_sectors);
+ unsigned int len = min_t(sector_t, nr_sects,
+ bio_write_zeroes_limit(bdev));
bio = blk_next_bio(bio, bdev, 0, REQ_OP_WRITE_ZEROES, gfp_mask);
bio->bi_iter.bi_sector = sector;
--
2.43.0
