1 files changed, 48 insertions, 7 deletions

diff --git a/include/linux/backing-dev.h b/include/linux/backing-dev.h
index 928cd5484f4d..d045f5f615c7 100644
--- a/include/linux/backing-dev.h
+++ b/include/linux/backing-dev.h
@@ -13,6 +13,8 @@
 #include <linux/proportions.h>
 #include <linux/kernel.h>
 #include <linux/fs.h>
+#include <linux/sched.h>
+#include <linux/writeback.h>
 #include <asm/atomic.h>
 
 struct page;
@@ -23,7 +25,8 @@ struct dentry;
  * Bits in backing_dev_info.state
  */
 enum bdi_state {
-        BDI_pdflush,            /* A pdflush thread is working this device */
+        BDI_pending,            /* On its way to being activated */
+        BDI_wb_alloc,           /* Default embedded wb allocated */
         BDI_async_congested,    /* The async (write) queue is getting full */
         BDI_sync_congested,     /* The sync queue is getting full */
         BDI_unused,             /* Available bits start here */
@@ -39,9 +42,22 @@ enum bdi_stat_item {
 
 #define BDI_STAT_BATCH (8*(1+ilog2(nr_cpu_ids)))
 
+struct bdi_writeback {
+        struct list_head list;                  /* hangs off the bdi */
+
+        struct backing_dev_info *bdi;           /* our parent bdi */
+        unsigned int nr;
+
+        unsigned long last_old_flush;           /* last old data flush */
+
+        struct task_struct      *task;          /* writeback task */
+        struct list_head        b_dirty;        /* dirty inodes */
+        struct list_head        b_io;           /* parked for writeback */
+        struct list_head        b_more_io;      /* parked for more writeback */
+};
+
 struct backing_dev_info {
         struct list_head bdi_list;
-
         unsigned long ra_pages; /* max readahead in PAGE_CACHE_SIZE units */
         unsigned long state;    /* Always use atomic bitops on this */
         unsigned int capabilities; /* Device capabilities */
@@ -58,11 +74,15 @@ struct backing_dev_info {
         unsigned int min_ratio;
         unsigned int max_ratio, max_prop_frac;
 
-        struct device *dev;
+        struct bdi_writeback wb;  /* default writeback info for this bdi */
+        spinlock_t wb_lock;       /* protects update side of wb_list */
+        struct list_head wb_list; /* the flusher threads hanging off this bdi */
+        unsigned long wb_mask;    /* bitmask of registered tasks */
+        unsigned int wb_cnt;      /* number of registered tasks */
 
-        struct list_head        b_dirty;        /* dirty inodes */
-        struct list_head        b_io;           /* parked for writeback */
-        struct list_head        b_more_io;      /* parked for more writeback */
+        struct list_head work_list;
+
+        struct device *dev;
 
 #ifdef CONFIG_DEBUG_FS
         struct dentry *debug_dir;
@@ -77,10 +97,20 @@ int bdi_register(struct backing_dev_info *bdi, struct device *parent,
                 const char *fmt, ...);
 int bdi_register_dev(struct backing_dev_info *bdi, dev_t dev);
 void bdi_unregister(struct backing_dev_info *bdi);
+void bdi_start_writeback(struct writeback_control *wbc);
+int bdi_writeback_task(struct bdi_writeback *wb);
+int bdi_has_dirty_io(struct backing_dev_info *bdi);
 
-extern struct mutex bdi_lock;
+extern spinlock_t bdi_lock;
 extern struct list_head bdi_list;
 
+static inline int wb_has_dirty_io(struct bdi_writeback *wb)
+{
+        return !list_empty(&wb->b_dirty) ||
+               !list_empty(&wb->b_io) ||
+               !list_empty(&wb->b_more_io);
+}
+
 static inline void __add_bdi_stat(struct backing_dev_info *bdi,
                 enum bdi_stat_item item, s64 amount)
 {
@@ -270,6 +300,11 @@ static inline bool bdi_cap_swap_backed(struct backing_dev_info *bdi)
         return bdi->capabilities & BDI_CAP_SWAP_BACKED;
 }
 
+static inline bool bdi_cap_flush_forker(struct backing_dev_info *bdi)
+{
+        return bdi == &default_backing_dev_info;
+}
+
 static inline bool mapping_cap_writeback_dirty(struct address_space *mapping)
 {
         return bdi_cap_writeback_dirty(mapping->backing_dev_info);
@@ -285,4 +320,10 @@ static inline bool mapping_cap_swap_backed(struct address_space *mapping)
         return bdi_cap_swap_backed(mapping->backing_dev_info);
 }
 
+static inline int bdi_sched_wait(void *word)
+{
+        schedule();
+        return 0;
+}
+
 #endif          /* _LINUX_BACKING_DEV_H */