[PATCH 1/2] block: decouple secure erase size limit from discard size limit

From: ziniu . wang_1

Date: Fri Dec 12 2025 - 03:31:59 EST


From: Luke Wang <ziniu.wang_1@xxxxxxx>

Secure erase should use max_secure_erase_sectors instead of being limited
by max_discard_sectors. Separate the handling of REQ_OP_SECURE_ERASE from
REQ_OP_DISCARD to allow each operation to use its own size limit.

Signed-off-by: Luke Wang <ziniu.wang_1@xxxxxxx>
---
block/blk-merge.c | 9 +++++++--
block/blk.h | 6 +++++-
2 files changed, 12 insertions(+), 3 deletions(-)

diff --git a/block/blk-merge.c b/block/blk-merge.c
index d3115d7469df..0885e4b982ed 100644
--- a/block/blk-merge.c
+++ b/block/blk-merge.c
@@ -169,8 +169,13 @@ struct bio *bio_split_discard(struct bio *bio, const struct queue_limits *lim,

granularity = max(lim->discard_granularity >> 9, 1U);

- max_discard_sectors =
- min(lim->max_discard_sectors, bio_allowed_max_sectors(lim));
+ if (bio_op(bio) == REQ_OP_SECURE_ERASE)
+ max_discard_sectors = min(lim->max_secure_erase_sectors,
+ bio_allowed_max_sectors(lim));
+ else
+ max_discard_sectors = min(lim->max_discard_sectors,
+ bio_allowed_max_sectors(lim));
+
max_discard_sectors -= max_discard_sectors % granularity;
if (unlikely(!max_discard_sectors))
return bio;
diff --git a/block/blk.h b/block/blk.h
index e4c433f62dfc..4cd5a91346d8 100644
--- a/block/blk.h
+++ b/block/blk.h
@@ -208,10 +208,14 @@ static inline unsigned int blk_queue_get_max_sectors(struct request *rq)
struct request_queue *q = rq->q;
enum req_op op = req_op(rq);

- if (unlikely(op == REQ_OP_DISCARD || op == REQ_OP_SECURE_ERASE))
+ if (unlikely(op == REQ_OP_DISCARD))
return min(q->limits.max_discard_sectors,
UINT_MAX >> SECTOR_SHIFT);

+ if (unlikely(op == REQ_OP_SECURE_ERASE))
+ return min(q->limits.max_secure_erase_sectors,
+ UINT_MAX >> SECTOR_SHIFT);
+
if (unlikely(op == REQ_OP_WRITE_ZEROES))
return q->limits.max_write_zeroes_sectors;

--
2.34.1