From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrey Zhadchenko Date: Mon, 10 Aug 2026 15:29:58 +0300 Subject: [Devel] [PATCH VZ10 4/6] drivers/md/dm-qcow2: fix seek skip to the next L2 table In-Reply-To: <20260810123000.19834-1-andrey.zhadchenko@virtuozzo.com> References: <20260810123000.19834-1-andrey.zhadchenko@virtuozzo.com> Message-ID: <20260810123000.19834-5-andrey.zhadchenko@virtuozzo.com> List-Id: get_next_l2() adds the number of remaining clusters to the current sector, so for a position which is not cluster aligned (e.g. the llseek offset itself) the result overshoots the L2 table boundary by the in-cluster offset. Compute the boundary from the cluster index instead of adding to the current position. https://virtuozzo.atlassian.net/browse/VSTOR-139407 Feature: dm-qcow2: block device over QCOW2 files driver Signed-off-by: Andrey Zhadchenko --- drivers/md/dm-qcow2-map.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/drivers/md/dm-qcow2-map.c b/drivers/md/dm-qcow2-map.c index d6d15b04215c6..776e89fc4eb1b 100644 --- a/drivers/md/dm-qcow2-map.c +++ b/drivers/md/dm-qcow2-map.c @@ -4405,12 +4405,12 @@ static struct qio *free_seek_qio_ret_higher(struct qio *qio) static inline sector_t get_next_l2(struct qio *qio) { struct qcow2 *qcow2 = qio->qcow2; - loff_t start, add; + u64 base_l2, add; - start = to_bytes(qio->bi_iter.bi_sector); - add = qcow2->l2_entries - (start / qcow2->clu_size) % qcow2->l2_entries; + base_l2 = to_bytes(qio->bi_iter.bi_sector) / qcow2->clu_size; + add = qcow2->l2_entries - base_l2 % qcow2->l2_entries; - return qio->bi_iter.bi_sector + (qcow2->clu_size / to_bytes(1)) * add; + return to_sector((base_l2 + add) * qcow2->clu_size); } static inline sector_t get_next_clu(struct qio *qio) -- 2.43.5