[PATCH] repair: replaced custom block allocation linked lists with list_heads

[Josef 'Jeff' Sipek]

The previous implementation of the linked lists was buggy, and leaked memory.

From: Josef 'Jeff' Sipek <jeffpc at josefsipek.net>

Cc: sandeen at sandeen.net
Signed-off-by: Josef 'Jeff' Sipek <jeffpc at josefsipek.net>
---

Yes, Eric, it wastes an extra pointer per node, but at least it works
compared to the code it replaces :)

 repair/incore.c     |   27 ---------------------------
 repair/incore.h     |   11 -----------
 repair/incore_ext.c |   27 ++++++++++++++++-----------
 3 files changed, 16 insertions(+), 49 deletions(-)

diff --git a/repair/incore.c b/repair/incore.c
index 84626c9..27604e2 100644
--- a/repair/incore.c
+++ b/repair/incore.c
@@ -25,33 +25,6 @@
 #include "err_protos.h"
 #include "threads.h"
 
-/*
- * push a block allocation record onto list.  assumes list
- * if set to NULL if empty.
- */
-void
-record_allocation(ba_rec_t *addr, ba_rec_t *list)
-{
-	addr->next = list;
-	list = addr;
-
-	return;
-}
-
-void
-free_allocations(ba_rec_t *list)
-{
-	ba_rec_t *current = list;
-
-	while (list != NULL)  {
-		list = list->next;
-		free(current);
-		current = list;
-	}
-
-	return;
-}
-
 /* ba bmap setupstuff.  setting/getting state is in incore.h  */
 
 void
diff --git a/repair/incore.h b/repair/incore.h
index 1f0f45a..a22ef0f 100644
--- a/repair/incore.h
+++ b/repair/incore.h
@@ -26,17 +26,6 @@
  */
 
 /*
- * block allocation lists
- */
-typedef struct ba_rec  {
-	void		*addr;
-	struct ba_rec	*next;
-} ba_rec_t;
-
-void			record_allocation(ba_rec_t *addr, ba_rec_t *list);
-void			free_allocations(ba_rec_t *list);
-
-/*
  * block bit map defs -- track state of each filesystem block.
  * ba_bmap is an array of bitstrings declared in the globals.h file.
  * the bitstrings are broken up into 64-bit chunks.  one bitstring per AG.
diff --git a/repair/incore_ext.c b/repair/incore_ext.c
index a2acbf4..d0b8cdc 100644
--- a/repair/incore_ext.c
+++ b/repair/incore_ext.c
@@ -31,12 +31,12 @@
  * paranoia -- account for any weird padding, 64/32-bit alignment, etc.
  */
 typedef struct extent_alloc_rec  {
-	ba_rec_t		alloc_rec;
+	struct list_head	list;
 	extent_tree_node_t	extents[ALLOC_NUM_EXTS];
 } extent_alloc_rec_t;
 
 typedef struct rt_extent_alloc_rec  {
-	ba_rec_t		alloc_rec;
+	struct list_head	list;
 	rt_extent_tree_node_t	extents[ALLOC_NUM_EXTS];
 } rt_extent_alloc_rec_t;
 
@@ -89,8 +89,8 @@ static avltree_desc_t	**extent_bcnt_ptrs;	/*
 /*
  * list of allocated "blocks" for easy freeing later
  */
-static ba_rec_t		*ba_list;
-static ba_rec_t		*rt_ba_list;
+static struct list_head	ba_list;
+static struct list_head	rt_ba_list;
 
 /*
  * locks.
@@ -120,7 +120,7 @@ mk_extent_tree_nodes(xfs_agblock_t new_startblock,
 			do_error(
 			_("couldn't allocate new extent descriptors.\n"));
 
-		record_allocation(&rec->alloc_rec, ba_list);
+		list_add(&rec->list, &ba_list);
 
 		new = &rec->extents[0];
 
@@ -678,7 +678,7 @@ mk_rt_extent_tree_nodes(xfs_drtbno_t new_startblock,
 			do_error(
 			_("couldn't allocate new extent descriptors.\n"));
 
-		record_allocation(&rec->alloc_rec, rt_ba_list);
+		list_add(&rec->list, &rt_ba_list);
 
 		new = &rec->extents[0];
 
@@ -755,12 +755,15 @@ release_rt_extent_tree()
 void
 free_rt_dup_extent_tree(xfs_mount_t *mp)
 {
+	rt_extent_alloc_rec_t *cur, *tmp;
+
 	ASSERT(mp->m_sb.sb_rblocks != 0);
 
-	free_allocations(rt_ba_list);
+	list_for_each_entry_safe(cur, tmp, &rt_ba_list, list)
+		free(cur);
+
 	free(rt_ext_tree_ptr);
 
-	rt_ba_list = NULL;
 	rt_ext_tree_ptr = NULL;
 
 	return;
@@ -895,8 +898,8 @@ incore_ext_init(xfs_mount_t *mp)
 	int i;
 	xfs_agnumber_t agcount = mp->m_sb.sb_agcount;
 
-	ba_list = NULL;
-	rt_ba_list = NULL;
+	list_head_init(&ba_list);
+	list_head_init(&rt_ba_list);
 	pthread_mutex_init(&ext_flist_lock, NULL);
 	pthread_mutex_init(&rt_ext_tree_lock, NULL);
 	pthread_mutex_init(&rt_ext_flist_lock, NULL);
@@ -954,9 +957,11 @@ incore_ext_init(xfs_mount_t *mp)
 void
 incore_ext_teardown(xfs_mount_t *mp)
 {
+	extent_alloc_rec_t *cur, *tmp;
 	xfs_agnumber_t i;
 
-	free_allocations(ba_list);
+	list_for_each_entry_safe(cur, tmp, &ba_list, list)
+		free(cur);
 
 	for (i = 0; i < mp->m_sb.sb_agcount; i++)  {
 		free(extent_tree_ptrs[i]);
-- 
1.6.2.107.ge47ee