From 3430f169983db0f3577c198e9ef8d99e66cac28e Mon Sep 17 00:00:00 2001
From: Zygo Blaxell <bees@furryterror.org>
Date: Tue, 21 Feb 2023 00:04:31 -0500
Subject: [PATCH] context: create a Pool of BtrfsIoctlLogicalInoArgs objects

Each object contains a 16 MiB buffer, which is very heavy for some
malloc implementations.

Keep the objects in a Pool so that their buffers are only allocated and
deallocated once in the process lifetime.

Signed-off-by: Zygo Blaxell <bees@furryterror.org>
---
 src/bees-context.cc | 15 ++++++++++++++-
 src/bees.h          |  3 +++
 2 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/src/bees-context.cc b/src/bees-context.cc
index 83edf30..f17212c 100644
--- a/src/bees-context.cc
+++ b/src/bees-context.cc
@@ -757,6 +757,15 @@ BeesResolveAddrResult::BeesResolveAddrResult()
 {
 }
 
+shared_ptr<BtrfsIoctlLogicalInoArgs>
+BeesContext::logical_ino(const uint64_t logical, const bool all_refs)
+{
+	const auto rv = m_logical_ino_pool();
+	rv->set_logical(logical);
+	rv->set_flags(all_refs ? BTRFS_LOGICAL_INO_ARGS_IGNORE_OFFSET : 0);
+	return rv;
+}
+
 BeesResolveAddrResult
 BeesContext::resolve_addr_uncached(BeesAddress addr)
 {
@@ -768,7 +777,8 @@ BeesContext::resolve_addr_uncached(BeesAddress addr)
 	// transaction latency, competing threads, and freeze/SIGSTOP
 	// pausing the bees process.
 
-        BtrfsIoctlLogicalInoArgs log_ino(addr.get_physical_or_zero());
+	const auto log_ino_ptr = logical_ino(addr.get_physical_or_zero(), false);
+	auto &log_ino = *log_ino_ptr;
 
 	// Time how long this takes
 	Timer resolve_timer;
@@ -910,6 +920,9 @@ BeesContext::start()
 	m_tmpfile_pool.generator([=]() -> shared_ptr<BeesTempFile> {
 		return make_shared<BeesTempFile>(shared_from_this());
 	});
+	m_logical_ino_pool.generator([]() {
+		return make_shared<BtrfsIoctlLogicalInoArgs>(0);
+	});
 	m_tmpfile_pool.checkin([](const shared_ptr<BeesTempFile> &btf) {
 		catch_all([&](){
 			btf->reset();
diff --git a/src/bees.h b/src/bees.h
index 30175e4..4dbc005 100644
--- a/src/bees.h
+++ b/src/bees.h
@@ -714,6 +714,7 @@ class BeesContext : public enable_shared_from_this<BeesContext> {
 	shared_ptr<BeesHashTable>			m_hash_table;
 	shared_ptr<BeesRoots>				m_roots;
 	Pool<BeesTempFile>				m_tmpfile_pool;
+	Pool<BtrfsIoctlLogicalInoArgs>			m_logical_ino_pool;
 
 	LRUCache<BeesResolveAddrResult, BeesAddress>	m_resolve_cache;
 
@@ -753,6 +754,8 @@ public:
 
 	bool scan_forward(const BeesFileRange &bfr);
 
+	shared_ptr<BtrfsIoctlLogicalInoArgs> logical_ino(uint64_t bytenr, bool all_refs);
+
 	bool is_root_ro(uint64_t root);
 	BeesRangePair dup_extent(const BeesFileRange &src, const shared_ptr<BeesTempFile> &tmpfile);
 	bool dedup(const BeesRangePair &brp);