diff options
| author | Mikulas Patocka <mpatocka@redhat.com> | 2026-07-10 18:32:49 +0200 |
|---|---|---|
| committer | Mikulas Patocka <mpatocka@redhat.com> | 2026-07-10 18:39:17 +0200 |
| commit | 422f1d4f141eaa3a6e4199ceec86cc6b9bf26570 (patch) | |
| tree | 76bd7c98c3d7925da3c095e4f0dc91914d06aba3 /drivers/md | |
| parent | 8ec4d9c5a5cf4b61fc087f871465b1f79b393325 (diff) | |
dm-bufio: fix wrong count calculation in dm_bufio_issue_discard
block_to_sector converts a block number to a sector number and adds
c->start to the result. It is inappropriate to use this function for
converting the number of blocks to a number to sectors because c->start
would be incorrectly added to the result.
Luckily, the only target that uses dm_bufio_issue_discard is dm-ebs,
which sets c->start to 0, so this bug is latent.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Assisted-by: Claude:claude-opus-4-6
Fixes: 6fbeb0048e6b ("dm bufio: implement discard")
Cc: stable@vger.kernel.org
Diffstat (limited to 'drivers/md')
| -rw-r--r-- | drivers/md/dm-bufio.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/drivers/md/dm-bufio.c b/drivers/md/dm-bufio.c index 26fedf5883ef..a458b9fd2fcd 100644 --- a/drivers/md/dm-bufio.c +++ b/drivers/md/dm-bufio.c @@ -2238,7 +2238,9 @@ int dm_bufio_issue_discard(struct dm_bufio_client *c, sector_t block, sector_t c struct dm_io_region io_reg = { .bdev = c->bdev, .sector = block_to_sector(c, block), - .count = block_to_sector(c, count), + .count = likely(c->sectors_per_block_bits >= 0) ? + count << c->sectors_per_block_bits : + count * (c->block_size >> SECTOR_SHIFT), }; if (WARN_ON_ONCE(dm_bufio_in_request())) |