[PATCH] Allow file systems to differentiate between data and meta reads

We can use this information for making more intelligent priority
decisions, and it will also be useful for blktrace.

Signed-off-by: Jens Axboe <axboe@suse.de>
diff --git a/include/linux/bio.h b/include/linux/bio.h
index 76bdaea..711c321 100644
--- a/include/linux/bio.h
+++ b/include/linux/bio.h
@@ -148,6 +148,7 @@
 #define BIO_RW_BARRIER	2
 #define BIO_RW_FAILFAST	3
 #define BIO_RW_SYNC	4
+#define BIO_RW_META	5
 
 /*
  * upper 16 bits of bi_rw define the io priority of this bio
@@ -178,6 +179,7 @@
 #define bio_sync(bio)		((bio)->bi_rw & (1 << BIO_RW_SYNC))
 #define bio_failfast(bio)	((bio)->bi_rw & (1 << BIO_RW_FAILFAST))
 #define bio_rw_ahead(bio)	((bio)->bi_rw & (1 << BIO_RW_AHEAD))
+#define bio_rw_meta(bio)	((bio)->bi_rw & (1 << BIO_RW_META))
 
 /*
  * will die