From 4489a9bae66da4fd6c56bce1daef41b948638892 Mon Sep 17 00:00:00 2001
From: Joe Thornber <ejt@redhat.com>
Date: Mon, 14 Aug 2017 10:13:32 +0100
Subject: [PATCH] [block-cache] reverse earlier patch which took out manual
 counts for nr_dirty etc.

The block list type doesn't have a constant time size() method.
---
 block-cache/block_cache.cc | 11 +++++++++--
 block-cache/block_cache.h  |  2 ++
 2 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/block-cache/block_cache.cc b/block-cache/block_cache.cc
index 5f76dec..7f603c2 100644
--- a/block-cache/block_cache.cc
+++ b/block-cache/block_cache.cc
@@ -105,14 +105,17 @@ block_cache::complete_io(block &b, int result)
 {
 	b.error_ = result;
 	b.clear_flags(BF_IO_PENDING);
+	nr_io_pending_--;
 
 	if (b.error_) {
 		b.unlink();
 		errored_.push_back(b);
 
 	} else {
-		if (b.test_flags(BF_DIRTY))
+		if (b.test_flags(BF_DIRTY)) {
 			b.clear_flags(BF_DIRTY | BF_PREVIOUSLY_DIRTY);
+			nr_dirty_--;
+		}
 
 		b.unlink();
 		clean_.push_back(b);
@@ -132,6 +135,7 @@ block_cache::issue_low_level(block &b, enum io_iocb_cmd opcode, const char *desc
 
 	assert(!b.test_flags(BF_IO_PENDING));
 	b.set_flags(BF_IO_PENDING);
+	nr_io_pending_++;
 	b.unlink();
 	io_pending_.push_back(b);
 
@@ -370,6 +374,8 @@ block_cache::calc_nr_buckets(unsigned nr_blocks)
 
 block_cache::block_cache(int fd, sector_t block_size, uint64_t on_disk_blocks, size_t mem)
 	: nr_locked_(0),
+	  nr_dirty_(0),
+	  nr_io_pending_(0),
 	  read_hits_(0),
 	  read_misses_(0),
 	  write_zeroes_(0),
@@ -549,7 +555,7 @@ block_cache::get(block_address index, unsigned flags, validator::ptr v)
 void
 block_cache::preemptive_writeback()
 {
-	unsigned nr_available = nr_cache_blocks_ - (dirty_.size() - io_pending_.size());
+	unsigned nr_available = nr_cache_blocks_ - (nr_dirty_ - nr_io_pending_);
 	if (nr_available < (WRITEBACK_LOW_THRESHOLD_PERCENT * nr_cache_blocks_ / 100))
 		writeback((WRITEBACK_HIGH_THRESHOLD_PERCENT * nr_cache_blocks_ / 100) - nr_available);
 
@@ -569,6 +575,7 @@ block_cache::release(block_cache::block &b)
 		if (!b.test_flags(BF_PREVIOUSLY_DIRTY)) {
 			b.unlink();
 			dirty_.push_back(b);
+			nr_dirty_++;
 			b.set_flags(BF_PREVIOUSLY_DIRTY);
 		}
 
diff --git a/block-cache/block_cache.h b/block-cache/block_cache.h
index 89f8d09..d6cd1c9 100644
--- a/block-cache/block_cache.h
+++ b/block-cache/block_cache.h
@@ -267,7 +267,9 @@ namespace bcache {
 		block_list clean_;
 
 		unsigned nr_locked_;
+		unsigned nr_dirty_;
 
+		unsigned nr_io_pending_;
 		block_list io_pending_;
 
 		typedef bi::member_hook<block,