Re: [PATCH AUTOSEL 5.9 089/147] dm: change max_io_len() to use blk_max_size_offset()

2020-11-01 Thread Sasha Levin

On Tue, Oct 27, 2020 at 08:19:59AM -0400, Mike Snitzer wrote:

On Mon, Oct 26 2020 at  7:48pm -0400,
Sasha Levin  wrote:


From: Mike Snitzer 

[ 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 
Signed-off-by: Sasha Levin 


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


Re: [PATCH AUTOSEL 5.9 089/147] dm: change max_io_len() to use blk_max_size_offset()

2020-10-27 Thread Mike Snitzer
On Mon, Oct 26 2020 at  7:48pm -0400,
Sasha Levin  wrote:

> From: Mike Snitzer 
> 
> [ 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 
> Signed-off-by: Sasha Levin 

Not sure why this commit elevated to stable@ picking it up, please
explain.

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
> 



[PATCH AUTOSEL 5.9 089/147] dm: change max_io_len() to use blk_max_size_offset()

2020-10-26 Thread Sasha Levin
From: Mike Snitzer 

[ 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 
Signed-off-by: Sasha Levin 
---
 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