bcachefs: Convert snapshot table to RCU array

This switches the generic radix tree for the in-memory table of snapshot
nodes to a simple rcu array. This means we have to add new locking to
deal with reallocations, but is faster than traversing the radix tree.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

1 files changed, 4 insertions, 0 deletions

diff --git a/fs/bcachefs/subvolume_types.h b/fs/bcachefs/subvolume_types.h
index 750d975ac468..c596e4270690 100644
--- a/fs/bcachefs/subvolume_types.h
+++ b/fs/bcachefs/subvolume_types.h
@@ -16,6 +16,10 @@ struct snapshot_t {
 	u32			equiv;
 };
 
+struct snapshot_table {
+	struct snapshot_t	s[0];
+};
+
 typedef struct {
 	u32		subvol;
 	u64		inum;