tux3: Add/rename helpers to manage dirty buffers

1) Instead of set_buffer_dirty_when(), this adds
tux3_set_buffer_dirty_list(). This takes "delta" and "list_head"
parameter to manage buffer in tux3.

2) Add tux3_set_buffer_dirty() (note: set_buffer_dirty() is already
used in kernel). This helper to insert the buffer to inode's dirty
heads.

Tux3 will use those 2 functions to manage dirty buffers.

Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>

3 files changed, 62 insertions, 7 deletions

diff --git a/fs/tux3/buffer.c b/fs/tux3/buffer.c
index 338e9291ad068f..b7e211461e23fa 100644
--- a/fs/tux3/buffer.c
+++ b/fs/tux3/buffer.c
@@ -8,13 +8,35 @@
 #define trace trace_on
 #endif
 
-void set_buffer_state_list(struct buffer_head *buffer, unsigned state,
-			   struct list_head *list)
+/* FIXME: we should rewrite with own buffer management */
+void tux3_set_buffer_dirty_list(struct buffer_head *buffer, int delta,
+				struct list_head *head)
 {
-	/* FIXME: this would be broken */
-	assert(state >= BUFFER_DIRTY);
-	list_move_tail(&buffer->b_assoc_buffers, list);
+	struct inode *inode = buffer_inode(buffer);
+	struct address_space *mapping = inode->i_mapping;
+	struct address_space *buffer_mapping = buffer->b_page->mapping;
+
 	mark_buffer_dirty(buffer);
+
+	if (!mapping->assoc_mapping)
+		mapping->assoc_mapping = buffer_mapping;
+	else
+		BUG_ON(mapping->assoc_mapping != buffer_mapping);
+
+	if (!buffer->b_assoc_map) {
+		spin_lock(&buffer_mapping->private_lock);
+		list_move_tail(&buffer->b_assoc_buffers, head);
+		buffer->b_assoc_map = mapping;
+		spin_unlock(&buffer_mapping->private_lock);
+	}
+}
+
+/* FIXME: we should rewrite with own buffer management */
+void tux3_set_buffer_dirty(struct buffer_head *buffer, int delta)
+{
+	struct dirty_buffers *dirty = inode_dirty_heads(buffer_inode(buffer));
+	struct list_head *head = dirty_head_when(dirty, delta);
+	tux3_set_buffer_dirty_list(buffer, delta, head);
 }
 
 void init_dirty_buffers(struct dirty_buffers *dirty)
diff --git a/fs/tux3/buffer.h b/fs/tux3/buffer.h
index e2b1e087a5c305..f55cd091bcdf85 100644
--- a/fs/tux3/buffer.h
+++ b/fs/tux3/buffer.h
@@ -38,8 +38,9 @@ static inline int buffer_can_modify(struct buffer_head *buffer, unsigned delta)
 	return buffer_dirty(buffer);
 }
 
-void set_buffer_state_list(struct buffer_head *buffer, unsigned state,
-			   struct list_head *list);
+void tux3_set_buffer_dirty_list(struct buffer_head *buffer, int delta,
+				struct list_head *head);
+void tux3_set_buffer_dirty(struct buffer_head *buffer, int delta);
 void init_dirty_buffers(struct dirty_buffers *dirty);
 #endif /* !__KERNEL__ */
 #endif /* !TUX3_BUFFER_H */
diff --git a/fs/tux3/writeback.c b/fs/tux3/writeback.c
index 73474bb17e38b3..a79d7de84b6f54 100644
--- a/fs/tux3/writeback.c
+++ b/fs/tux3/writeback.c
@@ -3,17 +3,49 @@
  */
 
 #include "tux3.h"
+#include "buffer.h"
 
 #ifndef trace
 #define trace trace_on
 #endif
 
+/* FIXME: we should rewrite with own buffer management. */
 void tux3_mark_buffer_dirty(struct buffer_head *buffer)
 {
+	/*
+	 * Very *carefully* optimize the it-is-already-dirty case.
+	 *
+	 * Don't let the final "is it dirty" escape to before we
+	 * perhaps modified the buffer.
+	 */
+	if (buffer_dirty(buffer)) {
+		smp_mb();
+		if (buffer_dirty(buffer))
+			return;
+	}
+
+	tux3_set_buffer_dirty(buffer, DEFAULT_DIRTY_WHEN);
 }
 
+/* FIXME: we should rewrite with own buffer management. */
 void tux3_mark_buffer_rollup(struct buffer_head *buffer)
 {
+	struct sb *sb = tux_sb(buffer_inode(buffer)->i_sb);
+
+	/*
+	 * Very *carefully* optimize the it-is-already-dirty case.
+	 *
+	 * Don't let the final "is it dirty" escape to before we
+	 * perhaps modified the buffer.
+	 */
+	if (buffer_dirty(buffer)) {
+		smp_mb();
+		if (buffer_dirty(buffer))
+			return;
+	}
+
+	tux3_set_buffer_dirty_list(buffer, sb->rollup,
+				   dirty_head_when(&sb->pinned, sb->rollup));
 }
 
 int tux3_flush_inode(struct inode *inode, unsigned delta)