As mentioned earlier, discarding data can be done either by issuing an
explicit discard or implicitly by reusing the LBA. Metadata chunks see
much more frequent reuse due to well it being metadata. So instead of
explicitly discarding metadata blocks, just leave them be and let the
latter implicit discarding be done for them.
Signed-off-by: Dennis Zhou <dennis@xxxxxxxxxx>
Reviewed-by: Josef Bacik <josef@xxxxxxxxxxxxxx>
---
fs/btrfs/block-group.h | 6 ++++++
fs/btrfs/discard.c | 12 ++++++++++--
2 files changed, 16 insertions(+), 2 deletions(-)
diff --git a/fs/btrfs/block-group.h b/fs/btrfs/block-group.h
index 601e1d217e22..ee8441439a56 100644
--- a/fs/btrfs/block-group.h
+++ b/fs/btrfs/block-group.h
@@ -182,6 +182,12 @@ static inline u64 btrfs_block_group_end(struct btrfs_block_group *block_group)
return (block_group->start + block_group->length);
}
+static inline bool btrfs_is_block_group_data(
+ struct btrfs_block_group *block_group)
+{
+ return (block_group->flags & BTRFS_BLOCK_GROUP_DATA);
+}
+
#ifdef CONFIG_BTRFS_DEBUG
static inline int btrfs_should_fragment_free_space(
struct btrfs_block_group *block_group)
diff --git a/fs/btrfs/discard.c b/fs/btrfs/discard.c
index 004d83b0a215..c8e923b3f2b9 100644
--- a/fs/btrfs/discard.c
+++ b/fs/btrfs/discard.c
@@ -50,6 +50,9 @@ static void __btrfs_add_to_discard_list(struct btrfs_discard_ctl *discard_ctl,
void btrfs_add_to_discard_list(struct btrfs_discard_ctl *discard_ctl,
struct btrfs_block_group *block_group)
{
+ if (!btrfs_is_block_group_data(block_group))
+ return;
+
spin_lock(&discard_ctl->lock);
__btrfs_add_to_discard_list(discard_ctl, block_group);
@@ -160,7 +163,11 @@ static struct btrfs_block_group *peek_discard_list(
if (block_group && now > block_group->discard_eligible_time) {
if (block_group->discard_index == BTRFS_DISCARD_INDEX_UNUSED &&
block_group->used != 0) {
- __btrfs_add_to_discard_list(discard_ctl, block_group);
+ if (btrfs_is_block_group_data(block_group))
+ __btrfs_add_to_discard_list(discard_ctl,
+ block_group);
+ else
+ list_del_init(&block_group->discard_list);
goto again;
}
if (block_group->discard_state == BTRFS_DISCARD_RESET_CURSOR) {
@@ -502,7 +509,8 @@ void btrfs_discard_update_discardable(struct btrfs_block_group *block_group,
s64 bytes_delta;
if (!block_group ||
- !btrfs_test_opt(block_group->fs_info, DISCARD_ASYNC))
+ !btrfs_test_opt(block_group->fs_info, DISCARD_ASYNC) ||
+ !btrfs_is_block_group_data(block_group))
return;
discard_ctl = &block_group->fs_info->discard_ctl;
--
2.17.1
