Merge bk://bk.arm.linux.org.uk/linux-2.6-rmk

into ppc970.osdl.org:/home/torvalds/v2.6/linux

1 files changed, 22 insertions, 2 deletions

diff --git a/include/linux/backing-dev.h b/include/linux/backing-dev.h
index 94c93c9c5f66..00371734995c 100644
--- a/include/linux/backing-dev.h
+++ b/include/linux/backing-dev.h
@@ -20,26 +20,46 @@ enum bdi_state {
 	BDI_unused,		/* Available bits start here */
 };
 
+typedef int (congested_fn)(void *, int);
+
 struct backing_dev_info {
 	unsigned long ra_pages;	/* max readahead in PAGE_CACHE_SIZE units */
 	unsigned long state;	/* Always use atomic bitops on this */
 	int memory_backed;	/* Cannot clean pages with writepage */
+	congested_fn *congested_fn; /* Function pointer if device is md/dm */
+	void *congested_data;	/* Pointer to aux data for congested func */
+	void (*unplug_io_fn)(struct backing_dev_info *);
+	void *unplug_io_data;
 };
 
 extern struct backing_dev_info default_backing_dev_info;
+void default_unplug_io_fn(struct backing_dev_info *bdi);
 
 int writeback_acquire(struct backing_dev_info *bdi);
 int writeback_in_progress(struct backing_dev_info *bdi);
 void writeback_release(struct backing_dev_info *bdi);
 
+static inline int bdi_congested(struct backing_dev_info *bdi, int bdi_bits)
+{
+	if (bdi->congested_fn)
+		return bdi->congested_fn(bdi->congested_data, bdi_bits);
+	return (bdi->state & bdi_bits);
+}
+
 static inline int bdi_read_congested(struct backing_dev_info *bdi)
 {
-	return test_bit(BDI_read_congested, &bdi->state);
+	return bdi_congested(bdi, 1 << BDI_read_congested);
 }
 
 static inline int bdi_write_congested(struct backing_dev_info *bdi)
 {
-	return test_bit(BDI_write_congested, &bdi->state);
+	return bdi_congested(bdi, 1 << BDI_write_congested);
+}
+
+static inline int bdi_rw_congested(struct backing_dev_info *bdi)
+{
+	return bdi_congested(bdi, (1 << BDI_read_congested)|
+				  (1 << BDI_write_congested));
 }
 
 #endif		/* _LINUX_BACKING_DEV_H */