From bed8959d470a88c2dbe7dc4efceeace2a7a52c36 Mon Sep 17 00:00:00 2001
From: nick <nick@bytemark.co.uk>
Date: Wed, 24 Jul 2013 17:42:08 +0100
Subject: [PATCH] bitset: Fix large runs

---
 src/bitset.h              | 12 +++++++-----
 src/client.c              |  2 +-
 src/ioutil.c              |  2 +-
 src/mirror.c              |  4 ++++
 tests/unit/check_bitset.c | 18 ++++++++++++++++++
 5 files changed, 31 insertions(+), 7 deletions(-)

diff --git a/src/bitset.h b/src/bitset.h
index 28ba806..ae1326f 100644
--- a/src/bitset.h
+++ b/src/bitset.h
@@ -74,7 +74,7 @@ static inline void bit_clear_range(char* b, uint64_t from, uint64_t len)
   * up to a maximum number of bits ''len''.  Returns the number of contiguous
   * bits that are the same as the first one specified.
   */
-static inline int bit_run_count(char* b, uint64_t from, uint64_t len) {
+static inline uint64_t bit_run_count(char* b, uint64_t from, uint64_t len) {
 	uint64_t* current_block;
 	uint64_t count = 0;
 	int first_value = bit_is_set(b, from);
@@ -138,8 +138,8 @@ static inline struct bitset_mapping* bitset_alloc(
 
 #define INT_FIRST_AND_LAST \
   uint64_t first = from/set->resolution, \
-      last = (from+len-1)/set->resolution, \
-      bitlen = last-first+1
+      last = ((from+len)-1)/set->resolution, \
+      bitlen = (last-first)+1
 
 #define BITSET_LOCK \
   FATAL_IF_NEGATIVE(pthread_mutex_lock(&set->lock), "Error locking bitset")
@@ -214,10 +214,12 @@ static inline uint64_t bitset_run_count(
 	len = ( len + from ) > set->size ? ( set->size - from ) : len;
 
 	INT_FIRST_AND_LAST;
+
 	BITSET_LOCK;
-	run = (bit_run_count(set->bits, first, bitlen) * set->resolution) -
-	  (from % set->resolution);
+	run = bit_run_count(set->bits, first, bitlen) * set->resolution;
+	run -= (from % set->resolution);
 	BITSET_UNLOCK;
+
 	return run;
 }
 
diff --git a/src/client.c b/src/client.c
index b514446..fb7a366 100644
--- a/src/client.c
+++ b/src/client.c
@@ -140,7 +140,7 @@ void write_not_zeroes(struct client* client, uint64_t from, uint64_t len)
 			char zerobuffer[block_allocation_resolution];
 			/* not allocated, read in block_allocation_resoution */
 			while (run > 0) {
-				int blockrun = block_allocation_resolution -
+				uint64_t blockrun = block_allocation_resolution -
 				  (from % block_allocation_resolution);
 				if (blockrun > run)
 					blockrun = run;
diff --git a/src/ioutil.c b/src/ioutil.c
index b855912..bcdf7f3 100644
--- a/src/ioutil.c
+++ b/src/ioutil.c
@@ -270,7 +270,7 @@ int fd_is_closed( int fd_in )
 }
 
 
-static inline int io_errno_permanent()
+static inline int io_errno_permanent(void)
 {
 	return ( errno != EAGAIN && errno != EWOULDBLOCK && errno != EINTR );
 }
diff --git a/src/mirror.c b/src/mirror.c
index 71a4948..d544fb2 100644
--- a/src/mirror.c
+++ b/src/mirror.c
@@ -106,6 +106,10 @@ void mirror_reset( struct mirror * mirror )
 	NULLCHECK( mirror->dirty_map );
 	mirror_set_state( mirror, MS_INIT );
 	bitset_set(mirror->dirty_map);
+
+	uint64_t run = bitset_run_count(mirror->dirty_map, 0, mirror->dirty_map->size);
+	warn( "bitset_run_count: %"PRIu64, run);
+
 }
 
 
diff --git a/tests/unit/check_bitset.c b/tests/unit/check_bitset.c
index d093a5b..2324170 100644
--- a/tests/unit/check_bitset.c
+++ b/tests/unit/check_bitset.c
@@ -188,6 +188,9 @@ START_TEST( test_bitset_run_count )
 
 	assert_bitset_is( map, 0x0000000000000000 );
 
+	run = bitset_run_count( map, 0, 64 );
+	ck_assert_int_eq( 64, run );
+
 	bitset_set_range( map, 0, 32 );
 	assert_bitset_is( map, 0x00000000ffffffff );
 
@@ -215,6 +218,11 @@ START_TEST( test_bitset_run_count )
 	free( map );
 
 	map = bitset_alloc( 6400, 100 );
+	assert_bitset_is( map, 0x0000000000000000 );
+
+	run = bitset_run_count( map, 0, 6400 );
+	ck_assert_int_eq( 6400, run );
+
 	bitset_set_range( map, 0, 3200 );
 
 	run = bitset_run_count( map, 0, 6400 );
@@ -228,6 +236,16 @@ START_TEST( test_bitset_run_count )
 
 	run = bitset_run_count( map, 6500, 6400 );
 	ck_assert_int_eq( 0, run );
+	free( map );
+
+	// Now do something large and representative
+	map = bitset_alloc( 53687091200, 4096 );
+	bitset_set( map );
+	run = bitset_run_count( map, 0, 53687091200 );
+	ck_assert_int_eq( run, 53687091200 );
+
+	free( map );
+
 }
 END_TEST