openwrt/target/linux/generic/patches-3.9/514-yaffs-3.6-use-delayed-work-instead-of-write_super.patch

--- a/fs/yaffs2/yaffs_vfs_glue.c
+++ b/fs/yaffs2/yaffs_vfs_glue.c
@@ -393,6 +393,84 @@ static void yaffs_touch_super(yaffs_dev_
 static int yaffs_vfs_setattr(struct inode *, struct iattr *);
 
 
+#if (LINUX_VERSION_CODE >= KERNEL_VERSION(3, 6, 0))
+
+#define yaffs_super_to_dev(sb)    ((struct yaffs_dev_s *)sb->s_fs_info)
+
+static inline struct yaffs_LinuxContext *
+yaffs_sb_to_ylc(struct super_block *sb)
+{
+	struct yaffs_dev_s *ydev;
+	struct yaffs_LinuxContext *ylc;
+
+	ydev = yaffs_super_to_dev(sb);
+	ylc = yaffs_dev_to_lc(ydev);
+	return ylc;
+}
+
+static inline struct super_block *yaffs_work_to_sb(struct work_struct *work)
+{
+	struct delayed_work *dwork;
+	struct yaffs_LinuxContext *ylc;
+
+	dwork = container_of(work, struct delayed_work, work);
+	ylc = container_of(dwork, struct yaffs_LinuxContext, sb_sync_dwork);
+	return ylc->superBlock;
+}
+
+static void yaffs_sb_sync_dwork_func(struct work_struct *work)
+{
+	struct super_block *sb = yaffs_work_to_sb(work);
+
+	yaffs_write_super(sb);
+}
+
+static void yaffs_init_sb_sync_dwork(struct yaffs_LinuxContext *ylc)
+{
+	INIT_DELAYED_WORK(&ylc->sb_sync_dwork, yaffs_sb_sync_dwork_func);
+}
+
+static void yaffs_cancel_sb_sync_dwork(struct super_block *sb)
+{
+	struct yaffs_LinuxContext *ylc = yaffs_sb_to_ylc(sb);
+
+	cancel_delayed_work_sync(&ylc->sb_sync_dwork);
+}
+
+static inline bool yaffs_sb_is_dirty(struct super_block *sb)
+{
+	struct yaffs_LinuxContext *ylc = yaffs_sb_to_ylc(sb);
+
+	return !!ylc->sb_dirty;
+}
+
+static inline void yaffs_sb_set_dirty(struct super_block *sb, int dirty)
+{
+	struct yaffs_LinuxContext *ylc = yaffs_sb_to_ylc(sb);
+
+	if (ylc->sb_dirty == dirty)
+		return;
+
+	ylc->sb_dirty = dirty;
+	if (dirty)
+		queue_delayed_work(system_long_wq, &ylc->sb_sync_dwork,
+				   msecs_to_jiffies(5000));
+}
+#else
+static inline bool yaffs_sb_is_dirty(struct super_block *sb)
+{
+	return !!sb->s_dirt;
+}
+
+static inline void yaffs_sb_set_dirty(struct super_block *sb, int dirty)
+{
+	sb->s_dirt = dirty;
+}
+
+static inline void yaffs_init_sb_sync_dwork(struct yaffs_LinuxContext *ylc) {}
+static inline void yaffs_cancel_sb_sync_dwork(struct super_block *sb) {}
+#endif /* >= 3.6.0 */
+
 static struct address_space_operations yaffs_file_address_operations = {
 	.readpage = yaffs_readpage,
 	.writepage = yaffs_writepage,
@@ -553,7 +631,9 @@ static const struct super_operations yaf
 	.clear_inode = yaffs_clear_inode,
 #endif
 	.sync_fs = yaffs_sync_fs,
+#if (LINUX_VERSION_CODE < KERNEL_VERSION(3, 6, 0))
 	.write_super = yaffs_write_super,
+#endif
 };
 
 
@@ -2340,7 +2420,7 @@ static int yaffs_do_sync_fs(struct super
 	T(YAFFS_TRACE_OS | YAFFS_TRACE_SYNC | YAFFS_TRACE_BACKGROUND,
 		(TSTR("yaffs_do_sync_fs: gc-urgency %d %s %s%s\n"),
 		gc_urgent,
-		sb->s_dirt ? "dirty" : "clean",
+		yaffs_sb_is_dirty(sb) ? "dirty" : "clean",
 		request_checkpoint ? "checkpoint requested" : "no checkpoint",
 		oneshot_checkpoint ? " one-shot" : "" ));
 
@@ -2349,9 +2429,9 @@ static int yaffs_do_sync_fs(struct super
 			oneshot_checkpoint) &&
 			!dev->is_checkpointed;
 
-	if (sb->s_dirt || do_checkpoint) {
+	if (yaffs_sb_is_dirty(sb) || do_checkpoint) {
 		yaffs_flush_super(sb, !dev->is_checkpointed && do_checkpoint);
-		sb->s_dirt = 0;
+		yaffs_sb_set_dirty(sb, 0);
 		if(oneshot_checkpoint)
 			yaffs_auto_checkpoint &= ~4;
 	}
@@ -2627,6 +2707,8 @@ static void yaffs_put_super(struct super
 
 	yaffs_flush_super(sb,1);
 
+	yaffs_cancel_sb_sync_dwork(sb);
+
 	if (yaffs_dev_to_lc(dev)->putSuperFunc)
 		yaffs_dev_to_lc(dev)->putSuperFunc(sb);
 
@@ -2665,7 +2747,7 @@ static void yaffs_touch_super(yaffs_dev_
 
 	T(YAFFS_TRACE_OS, (TSTR("yaffs_touch_super() sb = %p\n"), sb));
 	if (sb)
-		sb->s_dirt = 1;
+		yaffs_sb_set_dirty(sb, 1);
 }
 
 typedef struct {
@@ -2991,6 +3073,8 @@ static struct super_block *yaffs_interna
 	context->dev = dev;
 	context->superBlock = sb;
 
+	yaffs_init_sb_sync_dwork(context);
+
 	dev->read_only = read_only;
 
 #if (LINUX_VERSION_CODE > KERNEL_VERSION(2, 5, 0))
@@ -3177,7 +3261,7 @@ static struct super_block *yaffs_interna
 		return NULL;
 	}
 	sb->s_root = root;
-	sb->s_dirt = !dev->is_checkpointed;
+	yaffs_sb_set_dirty(sb, !dev->is_checkpointed);
 	T(YAFFS_TRACE_ALWAYS,
 		(TSTR("yaffs_read_super: is_checkpointed %d\n"),
 		dev->is_checkpointed));
--- a/fs/yaffs2/yaffs_linux.h
+++ b/fs/yaffs2/yaffs_linux.h
@@ -34,6 +34,11 @@ struct yaffs_LinuxContext {
 
 	struct task_struct *readdirProcess;
 	unsigned mount_id;
+
+#if (LINUX_VERSION_CODE >= KERNEL_VERSION(3, 6, 0))
+	struct delayed_work sb_sync_dwork;	/* superblock write-out work */
+	int sb_dirty;				/* superblock is dirty */
+#endif
 };
 
 #define yaffs_dev_to_lc(dev) ((struct yaffs_LinuxContext *)((dev)->os_context))
--- a/fs/yaffs2/yportenv.h
+++ b/fs/yaffs2/yportenv.h
@@ -49,6 +49,9 @@
 #include <linux/slab.h>
 #include <linux/vmalloc.h>
 #include <linux/xattr.h>
+#if (LINUX_VERSION_CODE >= KERNEL_VERSION(3, 6, 0))
+#include <linux/workqueue.h>
+#endif
 
 #define YCHAR char
 #define YUCHAR unsigned char