[PATCH] readahead: reset cache_hit earlier

We don't reset the cache hit count until after readahead does a successful
readahead.  This seems to leave a corner case open where we miss in cache,
but don't restart the readhead right away.
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

mm/readahead.c

@@ -540,6 +540,7 @@ void handle_ra_miss(struct address_space *mapping,
 {
 	ra->flags |= RA_FLAG_MISS;
 	ra->flags &= ~RA_FLAG_INCACHE;
+	ra->cache_hit = 0;
 }
 
 /*