[PATCH 02/10] block: factor out a bio_secure_erase_limit helper

Christoph Hellwig
2024-07-01T16:52:33Z

Add a helper to size the maximum secure erase bio without exceeding the
queue limit or overlowing the bi_size member.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
block/blk-lib.c | 16 +++++++++-------
1 file changed, 9 insertions(+), 7 deletions(-)

diff --git a/block/blk-lib.c b/block/blk-lib.c
index 4aabfc4a7eaa20..ff12c3d2de5aae 100644
--- a/block/blk-lib.c
+++ b/block/blk-lib.c
@@ -285,20 +285,22 @@ int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
}
EXPORT_SYMBOL(blkdev_issue_zeroout);

+static sector_t bio_secure_erase_limit(struct block_device *bdev)
+{
+ sector_t bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1;
+
+ return min(bdev_max_secure_erase_sectors(bdev),
+ (UINT_MAX >> SECTOR_SHIFT) & ~bs_mask);
+}
+
int blkdev_issue_secure_erase(struct block_device *bdev, sector_t sector,
sector_t nr_sects, gfp_t gfp)
{
- sector_t bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1;
- unsigned int max_sectors = bdev_max_secure_erase_sectors(bdev);
+ unsigned int max_sectors = bio_secure_erase_limit(bdev);
struct bio *bio = NULL;
struct blk_plug plug;
int ret = 0;

- /* make sure that "len << SECTOR_SHIFT" doesn't overflow */
- if (max_sectors > UINT_MAX >> SECTOR_SHIFT)
- max_sectors = UINT_MAX >> SECTOR_SHIFT;
- max_sectors &= ~bs_mask;
-
blk_start_plug(&plug);
while (nr_sects) {
unsigned int len = min_t(sector_t, nr_sects, max_sectors);
--
2.43.0