ocfs2: Clear undo bits when local alloc is freed

When the local alloc file changes windows, unused bits are freed back to the
global bitmap. By defnition, those bits can not be in use by any file. Also,
the local alloc will never have been able to allocate those bits if they
were part of a previous truncate. Therefore it makes sense that we should
clear unused local alloc bits in the undo buffer so that they can be used
immediatly.

[ Modified to call it ocfs2_release_clusters() -- Joel ]

Signed-off-by: Mark Fasheh <mfasheh@suse.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>

1 files changed, 74 insertions, 42 deletions

diff --git a/fs/ocfs2/suballoc.c b/fs/ocfs2/suballoc.c
index 0016503d83e..19ba00f2854 100644
--- a/fs/ocfs2/suballoc.c
+++ b/fs/ocfs2/suballoc.c
@@ -95,13 +95,6 @@ static inline int ocfs2_block_group_set_bits(handle_t *handle,
 					     struct buffer_head *group_bh,
 					     unsigned int bit_off,
 					     unsigned int num_bits);
-static inline int ocfs2_block_group_clear_bits(handle_t *handle,
-					       struct inode *alloc_inode,
-					       struct ocfs2_group_desc *bg,
-					       struct buffer_head *group_bh,
-					       unsigned int bit_off,
-					       unsigned int num_bits);
-
 static int ocfs2_relink_block_group(handle_t *handle,
 				    struct inode *alloc_inode,
 				    struct buffer_head *fe_bh,
@@ -1978,18 +1971,18 @@ int ocfs2_claim_clusters(struct ocfs2_super *osb,
 				      bits_wanted, cluster_start, num_clusters);
 }
 
-static inline int ocfs2_block_group_clear_bits(handle_t *handle,
-					       struct inode *alloc_inode,
-					       struct ocfs2_group_desc *bg,
-					       struct buffer_head *group_bh,
-					       unsigned int bit_off,
-					       unsigned int num_bits)
+static int ocfs2_block_group_clear_bits(handle_t *handle,
+					struct inode *alloc_inode,
+					struct ocfs2_group_desc *bg,
+					struct buffer_head *group_bh,
+					unsigned int bit_off,
+					unsigned int num_bits,
+					void (*undo_fn)(unsigned int bit,
+							unsigned long *bmap))
 {
 	int status;
 	unsigned int tmp;
-	int journal_type = OCFS2_JOURNAL_ACCESS_WRITE;
 	struct ocfs2_group_desc *undo_bg = NULL;
-	int cluster_bitmap = 0;
 
 	mlog_entry_void();
 
@@ -1999,20 +1992,18 @@ static inline int ocfs2_block_group_clear_bits(handle_t *handle,
 
 	mlog(0, "off = %u, num = %u\n", bit_off, num_bits);
 
-	if (ocfs2_is_cluster_bitmap(alloc_inode))
-		journal_type = OCFS2_JOURNAL_ACCESS_UNDO;
-
+	BUG_ON(undo_fn && !ocfs2_is_cluster_bitmap(alloc_inode));
 	status = ocfs2_journal_access_gd(handle, INODE_CACHE(alloc_inode),
-					 group_bh, journal_type);
+					 group_bh,
+					 undo_fn ?
+					 OCFS2_JOURNAL_ACCESS_UNDO :
+					 OCFS2_JOURNAL_ACCESS_WRITE);
 	if (status < 0) {
 		mlog_errno(status);
 		goto bail;
 	}
 
-	if (ocfs2_is_cluster_bitmap(alloc_inode))
-		cluster_bitmap = 1;
-
-	if (cluster_bitmap) {
+	if (undo_fn) {
 		jbd_lock_bh_state(group_bh);
 		undo_bg = (struct ocfs2_group_desc *)
 					bh2jh(group_bh)->b_committed_data;
@@ -2023,13 +2014,13 @@ static inline int ocfs2_block_group_clear_bits(handle_t *handle,
 	while(tmp--) {
 		ocfs2_clear_bit((bit_off + tmp),
 				(unsigned long *) bg->bg_bitmap);
-		if (cluster_bitmap)
-			ocfs2_set_bit(bit_off + tmp,
-				      (unsigned long *) undo_bg->bg_bitmap);
+		if (undo_fn)
+			undo_fn(bit_off + tmp,
+				(unsigned long *) undo_bg->bg_bitmap);
 	}
 	le16_add_cpu(&bg->bg_free_bits_count, num_bits);
 
-	if (cluster_bitmap)
+	if (undo_fn)
 		jbd_unlock_bh_state(group_bh);
 
 	status = ocfs2_journal_dirty(handle, group_bh);
@@ -2042,12 +2033,14 @@ bail:
 /*
  * expects the suballoc inode to already be locked.
  */
-int ocfs2_free_suballoc_bits(handle_t *handle,
-			     struct inode *alloc_inode,
-			     struct buffer_head *alloc_bh,
-			     unsigned int start_bit,
-			     u64 bg_blkno,
-			     unsigned int count)
+static int _ocfs2_free_suballoc_bits(handle_t *handle,
+				     struct inode *alloc_inode,
+				     struct buffer_head *alloc_bh,
+				     unsigned int start_bit,
+				     u64 bg_blkno,
+				     unsigned int count,
+				     void (*undo_fn)(unsigned int bit,
+						     unsigned long *bitmap))
 {
 	int status = 0;
 	u32 tmp_used;
@@ -2082,7 +2075,7 @@ int ocfs2_free_suballoc_bits(handle_t *handle,
 
 	status = ocfs2_block_group_clear_bits(handle, alloc_inode,
 					      group, group_bh,
-					      start_bit, count);
+					      start_bit, count, undo_fn);
 	if (status < 0) {
 		mlog_errno(status);
 		goto bail;
@@ -2113,6 +2106,17 @@ bail:
 	return status;
 }
 
+int ocfs2_free_suballoc_bits(handle_t *handle,
+			     struct inode *alloc_inode,
+			     struct buffer_head *alloc_bh,
+			     unsigned int start_bit,
+			     u64 bg_blkno,
+			     unsigned int count)
+{
+	return _ocfs2_free_suballoc_bits(handle, alloc_inode, alloc_bh,
+					 start_bit, bg_blkno, count, NULL);
+}
+
 int ocfs2_free_dinode(handle_t *handle,
 		      struct inode *inode_alloc_inode,
 		      struct buffer_head *inode_alloc_bh,
@@ -2126,11 +2130,13 @@ int ocfs2_free_dinode(handle_t *handle,
 					inode_alloc_bh, bit, bg_blkno, 1);
 }
 
-int ocfs2_free_clusters(handle_t *handle,
-		       struct inode *bitmap_inode,
-		       struct buffer_head *bitmap_bh,
-		       u64 start_blk,
-		       unsigned int num_clusters)
+static int _ocfs2_free_clusters(handle_t *handle,
+				struct inode *bitmap_inode,
+				struct buffer_head *bitmap_bh,
+				u64 start_blk,
+				unsigned int num_clusters,
+				void (*undo_fn)(unsigned int bit,
+						unsigned long *bitmap))
 {
 	int status;
 	u16 bg_start_bit;
@@ -2157,9 +2163,9 @@ int ocfs2_free_clusters(handle_t *handle,
 	mlog(0, "bg_blkno = %llu, bg_start_bit = %u\n",
 	     (unsigned long long)bg_blkno, bg_start_bit);
 
-	status = ocfs2_free_suballoc_bits(handle, bitmap_inode, bitmap_bh,
-					  bg_start_bit, bg_blkno,
-					  num_clusters);
+	status = _ocfs2_free_suballoc_bits(handle, bitmap_inode, bitmap_bh,
+					   bg_start_bit, bg_blkno,
+					   num_clusters, undo_fn);
 	if (status < 0) {
 		mlog_errno(status);
 		goto out;
@@ -2173,6 +2179,32 @@ out:
 	return status;
 }
 
+int ocfs2_free_clusters(handle_t *handle,
+			struct inode *bitmap_inode,
+			struct buffer_head *bitmap_bh,
+			u64 start_blk,
+			unsigned int num_clusters)
+{
+	return _ocfs2_free_clusters(handle, bitmap_inode, bitmap_bh,
+				    start_blk, num_clusters,
+				    _ocfs2_set_bit);
+}
+
+/*
+ * Give never-used clusters back to the global bitmap.  We don't need
+ * to protect these bits in the undo buffer.
+ */
+int ocfs2_release_clusters(handle_t *handle,
+			   struct inode *bitmap_inode,
+			   struct buffer_head *bitmap_bh,
+			   u64 start_blk,
+			   unsigned int num_clusters)
+{
+	return _ocfs2_free_clusters(handle, bitmap_inode, bitmap_bh,
+				    start_blk, num_clusters,
+				    _ocfs2_clear_bit);
+}
+
 static inline void ocfs2_debug_bg(struct ocfs2_group_desc *bg)
 {
 	printk("Block Group:\n");