On Tue, Oct 27, 2020 at 08:19:59AM -0400, Mike Snitzer wrote:
On Mon, Oct 26 2020 at 7:48pm -0400,
Sasha Levin <sashal@xxxxxxxxxx> wrote:
From: Mike Snitzer <snitzer@xxxxxxxxxx>
[ Upstream commit 5091cdec56faeaefa79de4b6cb3c3c55e50d1ac3 ]
Using blk_max_size_offset() enables DM core's splitting to impose
ti->max_io_len (via q->limits.chunk_sectors) and also fallback to
respecting q->limits.max_sectors if chunk_sectors isn't set.
Signed-off-by: Mike Snitzer <snitzer@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
Not sure why this commit elevated to stable@ picking it up, please
explain.
I misread the series this patch was in as being a fix rather than only
the first patch, sorry :(
But you cannot take this commit standalone. These commits are prereqs:
22ada802ede8 block: use lcm_not_zero() when stacking chunk_sectors
07d098e6bbad block: allow 'chunk_sectors' to be non-power-of-2
882ec4e609c1 dm table: stack 'chunk_sectors' limit to account for target-specific splitting
This goes for all stable@ trees you AUTOSEL'd commit 5091cdec56f for.
Mike
---
drivers/md/dm.c | 20 ++++++++------------
1 file changed, 8 insertions(+), 12 deletions(-)
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index 6ed05ca65a0f8..3982012b1309c 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -1051,22 +1051,18 @@ static sector_t max_io_len_target_boundary(sector_t sector, struct dm_target *ti
static sector_t max_io_len(sector_t sector, struct dm_target *ti)
{
sector_t len = max_io_len_target_boundary(sector, ti);
- sector_t offset, max_len;
+ sector_t max_len;
/*
* Does the target need to split even further?
+ * - q->limits.chunk_sectors reflects ti->max_io_len so
+ * blk_max_size_offset() provides required splitting.
+ * - blk_max_size_offset() also respects q->limits.max_sectors
*/
- if (ti->max_io_len) {
- offset = dm_target_offset(ti, sector);
- if (unlikely(ti->max_io_len & (ti->max_io_len - 1)))
- max_len = sector_div(offset, ti->max_io_len);
- else
- max_len = offset & (ti->max_io_len - 1);
- max_len = ti->max_io_len - max_len;
-
- if (len > max_len)
- len = max_len;
- }
+ max_len = blk_max_size_offset(dm_table_get_md(ti->table)->queue,
+ dm_target_offset(ti, sector));
+ if (len > max_len)
+ len = max_len;
return len;
}
--
2.25.1
--
Thanks,
Sasha
