Introduce compute_block_group_usage() and compute_block_group_usage().
And call the latter in btrfs_make_block_group() and
btrfs_read_block_groups().
compute_priority_level use ilog2(free) to compute priority level.
Signed-off-by: Su Yue <suy.fnst@xxxxxxxxxxxxxx>
---
fs/btrfs/extent-tree.c | 60 ++++++++++++++++++++++++++++++++++++++++++
1 file changed, 60 insertions(+)
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index d242a1174e50..0f4c5b1e0bcc 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -10091,6 +10091,7 @@ static int check_chunk_block_group_mappings(struct btrfs_fs_info *fs_info)
return ret;
}
+static long compute_block_group_priority(struct btrfs_block_group_cache *bg);
int btrfs_read_block_groups(struct btrfs_fs_info *info)
{
struct btrfs_path *path;
@@ -10224,6 +10225,8 @@ int btrfs_read_block_groups(struct btrfs_fs_info *info)
link_block_group(cache);
+ cache->priority = compute_block_group_priority(cache);
+
set_avail_alloc_bits(info, cache->flags);
if (btrfs_chunk_readonly(info, cache->key.objectid)) {
inc_block_group_ro(cache, 1);
@@ -10373,6 +10376,8 @@ int btrfs_make_block_group(struct btrfs_trans_handle *trans, u64 bytes_used,
link_block_group(cache);
+ cache->priority = compute_block_group_priority(cache);
+
list_add_tail(&cache->bg_list, &trans->new_bgs);
set_avail_alloc_bits(fs_info, type);
@@ -11190,3 +11195,58 @@ void btrfs_mark_bg_unused(struct btrfs_block_group_cache *bg)
}
spin_unlock(&fs_info->unused_bgs_lock);
}
+
+enum btrfs_priority_shift {
+ PRIORITY_USAGE_SHIFT = 0
+};
+
+static inline u8
+compute_block_group_usage(struct btrfs_block_group_cache *cache)
+{
+ u64 num_bytes;
+ u8 usage;
+
+ num_bytes = cache->reserved + cache->bytes_super +
+ btrfs_block_group_used(&cache->item);
+
+ usage = div_u64(num_bytes, div_factor_fine(cache->key.offset, 1));
+
+ return usage;
+}
+
+static long compute_block_group_priority(struct btrfs_block_group_cache *bg)
+{
+ u8 usage;
+ long priority = 0;
+
+ if (btrfs_test_opt(bg->fs_info, PRIORITY_USAGE)) {
+ usage = compute_block_group_usage(bg);
+ priority |= usage << PRIORITY_USAGE_SHIFT;
+ }
+
+ return priority;
+}
+
+static int compute_priority_level(struct btrfs_fs_info *fs_info,
+ long priority)
+{
+ int level = 0;
+
+ if (btrfs_test_opt(fs_info, PRIORITY_USAGE)) {
+ u8 free;
+
+ WARN_ON(priority < 0);
+ free = 100 - (priority >> PRIORITY_USAGE_SHIFT);
+
+ if (free == 0)
+ level = 0;
+ else if (free == 100)
+ level = ilog2(free) + 1;
+ else
+ level = ilog2(free);
+ /* log2(1) == 0, leave level 0 for unused block_groups */
+ level = ilog2(100) + 1 - level;
+ }
+
+ return level;
+}
--
2.19.1
