@@ -214,9 +214,16 @@ static int mergable_maps(struct extent_map *prev, struct extent_map *next)
ASSERT(next->block_start != EXTENT_MAP_DELALLOC &&
prev->block_start != EXTENT_MAP_DELALLOC);
+ if (prev->map_lookup || next->map_lookup)
+ ASSERT(test_bit(EXTENT_FLAG_FS_MAPPING, &prev->flags) &&
+ test_bit(EXTENT_FLAG_FS_MAPPING, &next->flags));
+
+ if (prev->bdev || next->bdev)
+ ASSERT(prev->bdev == next->bdev);
+
if (extent_map_end(prev) == next->start &&
prev->flags == next->flags &&
- prev->bdev == next->bdev &&
+ prev->map_lookup == next->map_lookup &&
((next->block_start == EXTENT_MAP_HOLE &&
prev->block_start == EXTENT_MAP_HOLE) ||
(next->block_start == EXTENT_MAP_INLINE &&
@@ -42,7 +42,7 @@ struct extent_map {
u64 block_len;
u64 generation;
unsigned long flags;
- union {
+ struct {
struct block_device *bdev;
/*
This is a preparatory patch for removing extent_map::bdev. There's some history behind the code so this is only precaution to catch if things break before the actual removal happens. Logically, comparing a raw low-level block device (bdev) does not make sense for extent maps (high-level objects). This had no effect in practice but was quite confusing in the code. The lookup_map is set iff EXTENT_FLAG_FS_MAPPING is set. The two pointers were stored in the same bytes and used potentially in two meanings. Now they're split, so the asserts are in place to check that the condition will not change. The lookup map pointer misused bdev, this has been changed in commit 95617d69326c ("btrfs: cleanup, stop casting for extent_map->lookup everywhere") to the explicit type. But the semantics hasn't changed and bdev was not actually used to decide if maps are mergeable. Signed-off-by: David Sterba <dsterba@suse.com> --- fs/btrfs/extent_map.c | 9 ++++++++- fs/btrfs/extent_map.h | 2 +- 2 files changed, 9 insertions(+), 2 deletions(-)