Commit 951e05a9 authored by Nikolay Borisov's avatar Nikolay Borisov Committed by David Sterba
Browse files

btrfs: Remove impossible condition from mergable_maps 



We can never have extents marked as EXTENT_MAP_DELALLOC since this
value is only ever used by btrfs_get_extent_fiemap. In this case the
extent map is created by btrfs_get_extent_fiemap and is never really
published, this flag is used to return the corresponding userspace one.
Considering this, it's pointless having a check for EXTENT_MAP_DELALLOC
in mergable_maps. Just remove it.

Signed-off-by: default avatarNikolay Borisov <nborisov@suse.com>
Reviewed-by: default avatarDavid Sterba <dsterba@suse.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent d00c2d9c

fs/btrfs/extent_map.c

+3 −2
Original line number Diff line number Diff line
@@ -210,6 +210,9 @@ static int mergable_maps(struct extent_map *prev, struct extent_map *next) 
	if (!list_empty(&prev->list) || !list_empty(&next->list))

		return 0;



	ASSERT(next->block_start != EXTENT_MAP_DELALLOC &&

	       prev->block_start != EXTENT_MAP_DELALLOC);



	if (extent_map_end(prev) == next->start &&

	    prev->flags == next->flags &&

	    prev->bdev == next->bdev &&
@@ -217,8 +220,6 @@ static int mergable_maps(struct extent_map *prev, struct extent_map *next) 
	      prev->block_start == EXTENT_MAP_HOLE) ||

	     (next->block_start == EXTENT_MAP_INLINE &&

	      prev->block_start == EXTENT_MAP_INLINE) ||

	     (next->block_start == EXTENT_MAP_DELALLOC &&

	      prev->block_start == EXTENT_MAP_DELALLOC) ||

	     (next->block_start < EXTENT_MAP_LAST_BYTE - 1 &&

	      next->block_start == extent_map_block_end(prev)))) {

		return 1;

fs/btrfs/extent_map.h

+1 −0
Original line number Diff line number Diff line
@@ -9,6 +9,7 @@ 
#define EXTENT_MAP_LAST_BYTE ((u64)-4)

#define EXTENT_MAP_HOLE ((u64)-3)

#define EXTENT_MAP_INLINE ((u64)-2)

/* used only during fiemap calls */

#define EXTENT_MAP_DELALLOC ((u64)-1)



/* bits for the extent_map::flags field */

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