From 99bc710f03b7f625b055c0934e66d85a5415e1a3 Mon Sep 17 00:00:00 2001
From: Zach Brown <zab@versity.com>
Date: Wed, 29 Apr 2020 14:54:59 -0700
Subject: [PATCH] scoutfs: remove tiny btree block option

It used to take significant effort to create very tall btrees because
they only stored small references to large LSM segments.  Now they store
all file system metadata and we can easily create sufficiently large
btrees for testing.  We don't need the tiny btree option.

Signed-off-by: Zach Brown <zab@versity.com>
---
 kmod/src/format.h  |  8 --------
 kmod/src/options.c | 16 ----------------
 kmod/src/options.h |  5 -----
 3 files changed, 29 deletions(-)

diff --git a/kmod/src/format.h b/kmod/src/format.h
index e8b4ec86..822675e6 100644
--- a/kmod/src/format.h
+++ b/kmod/src/format.h
@@ -201,14 +201,6 @@ struct scoutfs_avl_node {
 /* each value ends with an offset which lets compaction iterate over values */
 #define SCOUTFS_BTREE_VAL_OWNER_BYTES	sizeof(__le16)
 
-/*
- * When debugging we can tune the splitting and merging thresholds to
- * create much larger trees by having blocks with many fewer items.  We
- * implement this by pretending the blocks are tiny.  They're still
- * large enough for a handful of items.
- */
-#define SCOUTFS_BTREE_TINY_BLOCK_SIZE	512
-
 /*
  * A 4EB test image measured a worst case height of 17.  This is plenty
  * generous.
diff --git a/kmod/src/options.c b/kmod/src/options.c
index 332b1cda..e7fe1843 100644
--- a/kmod/src/options.c
+++ b/kmod/src/options.c
@@ -33,19 +33,10 @@ static const match_table_t tokens = {
 
 struct options_sb_info {
 	struct dentry *debugfs_dir;
-	u32 btree_force_tiny_blocks;
 };
 
 u32 scoutfs_option_u32(struct super_block *sb, int token)
 {
-	struct scoutfs_sb_info *sbi = SCOUTFS_SB(sb);
-	struct options_sb_info *osi = sbi->options;
-
-	switch(token) {
-		case Opt_btree_force_tiny_blocks:
-			return osi->btree_force_tiny_blocks;
-	}
-
 	WARN_ON_ONCE(1);
 	return 0;
 }
@@ -143,13 +134,6 @@ int scoutfs_options_setup(struct super_block *sb)
 		goto out;
 	}
 
-	if (!debugfs_create_bool("btree_force_tiny_blocks", 0644,
-				 osi->debugfs_dir,
-				 &osi->btree_force_tiny_blocks)) {
-		ret = -ENOMEM;
-		goto out;
-	}
-
 	ret = 0;
 out:
 	if (ret)
diff --git a/kmod/src/options.h b/kmod/src/options.h
index 0078dca2..d02b40d6 100644
--- a/kmod/src/options.h
+++ b/kmod/src/options.h
@@ -6,11 +6,6 @@
 #include "format.h"
 
 enum {
-	/*
-	 * For debugging we can quickly create huge trees by limiting
-	 * the number of items in each block as though the blocks were tiny.
-	 */
-	Opt_btree_force_tiny_blocks,
 	Opt_server_addr,
 	Opt_err,
 };