Btrfs: run chunk allocations while we do delayed refs
Btrfs tries to batch extent allocation tree changes to improve performance
and reduce metadata trashing. But it doesn't allocate new metadata chunks
while it is doing allocations for the extent allocation tree.
This commit changes the delayed refence code to do chunk allocations if we're
getting low on room. It prevents crashes and improves performance.
Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index f5fbe57..71549d1 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -2267,9 +2267,7 @@
BUG_ON(ret);
kfree(extent_op);
- cond_resched();
- spin_lock(&delayed_refs->lock);
- continue;
+ goto next;
}
list_del_init(&locked_ref->cluster);
@@ -2289,7 +2287,11 @@
btrfs_put_delayed_ref(ref);
kfree(extent_op);
count++;
-
+next:
+ do_chunk_alloc(trans, root->fs_info->extent_root,
+ 2 * 1024 * 1024,
+ btrfs_get_alloc_profile(root, 0),
+ CHUNK_ALLOC_NO_FORCE);
cond_resched();
spin_lock(&delayed_refs->lock);
}
@@ -2317,6 +2319,10 @@
if (root == root->fs_info->extent_root)
root = root->fs_info->tree_root;
+ do_chunk_alloc(trans, root->fs_info->extent_root,
+ 2 * 1024 * 1024, btrfs_get_alloc_profile(root, 0),
+ CHUNK_ALLOC_NO_FORCE);
+
delayed_refs = &trans->transaction->delayed_refs;
INIT_LIST_HEAD(&cluster);
again:
diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index 81376d9..360c2df 100644
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -467,19 +467,12 @@
btrfs_trans_release_metadata(trans, root);
trans->block_rsv = NULL;
- while (count < 4) {
+ while (count < 2) {
unsigned long cur = trans->delayed_ref_updates;
trans->delayed_ref_updates = 0;
if (cur &&
trans->transaction->delayed_refs.num_heads_ready > 64) {
trans->delayed_ref_updates = 0;
-
- /*
- * do a full flush if the transaction is trying
- * to close
- */
- if (trans->transaction->delayed_refs.flushing)
- cur = 0;
btrfs_run_delayed_refs(trans, root, cur);
} else {
break;