readahead: remove sync/async readahead call dependency

[mv-sheeva.git] / mm / readahead.c

diff --git a/mm/readahead.c b/mm/readahead.c
index 16378b90843eccad3b5ec76da1565672a6577b3b..d7c6e143a1297fc4866b18b28f04be2f9aaf2ecb 100644 (file)
--- a/mm/readahead.c
+++ b/mm/readahead.c
@@ -421,6 +421,16 @@ ondemand_readahead(struct address_space *mapping,
        ra->async_size = ra->size > req_size ? ra->size - req_size : ra->size;
 
 readit:
+       /*
+        * Will this read hit the readahead marker made by itself?
+        * If so, trigger the readahead marker hit now, and merge
+        * the resulted next readahead window into the current one.
+        */
+       if (offset == ra->start && ra->size == ra->async_size) {
+               ra->async_size = get_next_ra_size(ra, max);
+               ra->size += ra->async_size;
+       }
+
        return ra_submit(ra, mapping, filp);
 }