another swap/hibernate code cleanup for for-5.12/block

another swap/hibernate code cleanup for for-5.12/block

[Christoph Hellwig]

Hi Jens,

this cleans up another lose end in the swapfile.c after the previous
bio related cleanups.

[PATCH] mm: simplify swapdev_block

[Christoph Hellwig]

Open code the parts of map_swap_entry that was actually used by
swapdev_block, and remove the now unused map_swap_entry function.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 mm/swapfile.c | 30 +++---------------------------
 1 file changed, 3 insertions(+), 27 deletions(-)

diff --git a/mm/swapfile.c b/mm/swapfile.c
index 351999a84e6e4e..21a98cb8d646e3 100644
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -1790,9 +1790,6 @@ int free_swap_and_cache(swp_entry_t entry)
 }
 
 #ifdef CONFIG_HIBERNATION
-
-static sector_t map_swap_entry(swp_entry_t, struct block_device**);
-
 /*
  * Find the swap type that corresponds to given device (if any).
  *
@@ -1852,12 +1849,13 @@ int find_first_swap(dev_t *device)
  */
 sector_t swapdev_block(int type, pgoff_t offset)
 {
-	struct block_device *bdev;
 	struct swap_info_struct *si = swap_type_to_swap_info(type);
+	struct swap_extent *se;
 
 	if (!si || !(si->flags & SWP_WRITEOK))
 		return 0;
-	return map_swap_entry(swp_entry(type, offset), &bdev);
+	se = offset_to_swap_extent(si, offset);
+	return se->start_block + (offset - se->start_page);
 }
 
 /*
@@ -2283,28 +2281,6 @@ static void drain_mmlist(void)
 	spin_unlock(&mmlist_lock);
 }
 
-#ifdef CONFIG_HIBERNATION
-/*
- * Use this swapdev's extent info to locate the (PAGE_SIZE) block which
- * corresponds to page offset for the specified swap entry.
- * Note that the type of this function is sector_t, but it returns page offset
- * into the bdev, not sector offset.
- */
-static sector_t map_swap_entry(swp_entry_t entry, struct block_device **bdev)
-{
-	struct swap_info_struct *sis;
-	struct swap_extent *se;
-	pgoff_t offset;
-
-	sis = swp_swap_info(entry);
-	*bdev = sis->bdev;
-
-	offset = swp_offset(entry);
-	se = offset_to_swap_extent(sis, offset);
-	return se->start_block + (offset - se->start_page);
-}
-#endif
-
 /*
  * Free all of a swapdev's extent information
  */
-- 
2.29.2

Re: [PATCH] mm: simplify swapdev_block

[Rafael J. Wysocki]

On Tuesday, February 9, 2021 6:14:19 PM CET Christoph Hellwig wrote:
> Open code the parts of map_swap_entry that was actually used by
> swapdev_block, and remove the now unused map_swap_entry function.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>

Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

> ---
>  mm/swapfile.c | 30 +++---------------------------
>  1 file changed, 3 insertions(+), 27 deletions(-)
> 
> diff --git a/mm/swapfile.c b/mm/swapfile.c
> index 351999a84e6e4e..21a98cb8d646e3 100644
> --- a/mm/swapfile.c
> +++ b/mm/swapfile.c
> @@ -1790,9 +1790,6 @@ int free_swap_and_cache(swp_entry_t entry)
>  }
>  
>  #ifdef CONFIG_HIBERNATION
> -
> -static sector_t map_swap_entry(swp_entry_t, struct block_device**);
> -
>  /*
>   * Find the swap type that corresponds to given device (if any).
>   *
> @@ -1852,12 +1849,13 @@ int find_first_swap(dev_t *device)
>   */
>  sector_t swapdev_block(int type, pgoff_t offset)
>  {
> -	struct block_device *bdev;
>  	struct swap_info_struct *si = swap_type_to_swap_info(type);
> +	struct swap_extent *se;
>  
>  	if (!si || !(si->flags & SWP_WRITEOK))
>  		return 0;
> -	return map_swap_entry(swp_entry(type, offset), &bdev);
> +	se = offset_to_swap_extent(si, offset);
> +	return se->start_block + (offset - se->start_page);
>  }
>  
>  /*
> @@ -2283,28 +2281,6 @@ static void drain_mmlist(void)
>  	spin_unlock(&mmlist_lock);
>  }
>  
> -#ifdef CONFIG_HIBERNATION
> -/*
> - * Use this swapdev's extent info to locate the (PAGE_SIZE) block which
> - * corresponds to page offset for the specified swap entry.
> - * Note that the type of this function is sector_t, but it returns page offset
> - * into the bdev, not sector offset.
> - */
> -static sector_t map_swap_entry(swp_entry_t entry, struct block_device **bdev)
> -{
> -	struct swap_info_struct *sis;
> -	struct swap_extent *se;
> -	pgoff_t offset;
> -
> -	sis = swp_swap_info(entry);
> -	*bdev = sis->bdev;
> -
> -	offset = swp_offset(entry);
> -	se = offset_to_swap_extent(sis, offset);
> -	return se->start_block + (offset - se->start_page);
> -}
> -#endif
> -
>  /*
>   * Free all of a swapdev's extent information
>   */
> 

Re: another swap/hibernate code cleanup for for-5.12/block

[Jens Axboe]

On 2/9/21 10:14 AM, Christoph Hellwig wrote:
> Hi Jens,
> 
> this cleans up another lose end in the swapfile.c after the previous
> bio related cleanups.
> 

Applied, thanks.

-- 
Jens Axboe