btrfs: make free space cache size consistent across different PAGE_SIZE
Currently free space cache inode size is determined by two factors:
- block group size
- PAGE_SIZE
This means, for the same sized block groups, with different PAGE_SIZE,
it will result in different inode sizes.
This will not be a good thing for subpage support, so change the
requirement for PAGE_SIZE to sectorsize.
Now for the same 4K sectorsize btrfs, it should result the same inode
size no matter what the PAGE_SIZE is.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
diff --git a/fs/btrfs/block-group.c b/fs/btrfs/block-group.c
index 6d5c4e4..c42b652 100644
--- a/fs/btrfs/block-group.c
+++ b/fs/btrfs/block-group.c
@@ -2505,7 +2505,7 @@ static int cache_save_setup(struct btrfs_block_group *block_group,
struct extent_changeset *data_reserved = NULL;
u64 alloc_hint = 0;
int dcs = BTRFS_DC_ERROR;
- u64 num_pages = 0;
+ u64 cache_size = 0;
int retries = 0;
int ret = 0;
@@ -2617,20 +2617,20 @@ static int cache_save_setup(struct btrfs_block_group *block_group,
* taking up quite a bit since it's not folded into the other space
* cache.
*/
- num_pages = div_u64(block_group->length, SZ_256M);
- if (!num_pages)
- num_pages = 1;
+ cache_size = div_u64(block_group->length, SZ_256M);
+ if (!cache_size)
+ cache_size = 1;
- num_pages *= 16;
- num_pages *= PAGE_SIZE;
+ cache_size *= 16;
+ cache_size *= fs_info->sectorsize;
ret = btrfs_check_data_free_space(BTRFS_I(inode), &data_reserved, 0,
- num_pages);
+ cache_size);
if (ret)
goto out_put;
- ret = btrfs_prealloc_file_range_trans(inode, trans, 0, 0, num_pages,
- num_pages, num_pages,
+ ret = btrfs_prealloc_file_range_trans(inode, trans, 0, 0, cache_size,
+ cache_size, cache_size,
&alloc_hint);
/*
* Our cache requires contiguous chunks so that we don't modify a bunch