readahead: record mmap read-around states in file_ra_state

[net-next-2.6.git] / mm / readahead.c

diff --git a/mm/readahead.c b/mm/readahead.c
index d7c6e143a1297fc4866b18b28f04be2f9aaf2ecb..a7f01fcce9e7958e155fbd8aee2ef1a9b2c28783 100644 (file)
--- a/mm/readahead.c
+++ b/mm/readahead.c
@@ -133,15 +133,12 @@ out:
 }
 
 /*
- * do_page_cache_readahead actually reads a chunk of disk.  It allocates all
+ * __do_page_cache_readahead() actually reads a chunk of disk.  It allocates all
  * the pages first, then submits them all for I/O. This avoids the very bad
  * behaviour which would occur if page allocations are causing VM writeback.
  * We really don't want to intermingle reads and writes like that.
  *
  * Returns the number of pages requested, or the maximum amount of I/O allowed.
- *
- * do_page_cache_readahead() returns -1 if it encountered request queue
- * congestion.
  */
 static int
 __do_page_cache_readahead(struct address_space *mapping, struct file *filp,
@@ -231,22 +228,6 @@ int force_page_cache_readahead(struct address_space *mapping, struct file *filp,
        return ret;
 }
 
-/*
- * This version skips the IO if the queue is read-congested, and will tell the
- * block layer to abandon the readahead if request allocation would block.
- *
- * force_page_cache_readahead() will ignore queue congestion and will block on
- * request queues.
- */
-int do_page_cache_readahead(struct address_space *mapping, struct file *filp,
-                       pgoff_t offset, unsigned long nr_to_read)
-{
-       if (bdi_read_congested(mapping->backing_dev_info))
-               return -1;
-
-       return __do_page_cache_readahead(mapping, filp, offset, nr_to_read, 0);
-}
-
 /*
  * Given a desired number of PAGE_CACHE_SIZE readahead pages, return a
  * sensible upper limit.
@@ -260,7 +241,7 @@ unsigned long max_sane_readahead(unsigned long nr)
 /*
  * Submit IO for the read-ahead request in file_ra_state.
  */
-static unsigned long ra_submit(struct file_ra_state *ra,
+unsigned long ra_submit(struct file_ra_state *ra,
                       struct address_space *mapping, struct file *filp)
 {
        int actual;