Merge branch 'tunnels'

[linux.git] / mm / readahead.c

diff --git a/mm/readahead.c b/mm/readahead.c
index 0de2360d65f3f4f4cce4e0ae94f02d78a51a2429..0ca36a7770b1b974eaea70d6357b7cdbd73aad3d 100644 (file)
--- a/mm/readahead.c
+++ b/mm/readahead.c
@@ -8,9 +8,7 @@
  */
 
 #include <linux/kernel.h>
-#include <linux/fs.h>
 #include <linux/gfp.h>
-#include <linux/mm.h>
 #include <linux/export.h>
 #include <linux/blkdev.h>
 #include <linux/backing-dev.h>
@@ -20,6 +18,8 @@
 #include <linux/syscalls.h>
 #include <linux/file.h>
 
+#include "internal.h"
+
 /*
  * Initialise a struct file's readahead state.  Assumes that the caller has
  * memset *ra to zero.
@@ -149,8 +149,7 @@ out:
  *
  * Returns the number of pages requested, or the maximum amount of I/O allowed.
  */
-static int
-__do_page_cache_readahead(struct address_space *mapping, struct file *filp,
+int __do_page_cache_readahead(struct address_space *mapping, struct file *filp,
                        pgoff_t offset, unsigned long nr_to_read,
                        unsigned long lookahead_size)
 {
@@ -179,7 +178,7 @@ __do_page_cache_readahead(struct address_space *mapping, struct file *filp,
                rcu_read_lock();
                page = radix_tree_lookup(&mapping->page_tree, page_offset);
                rcu_read_unlock();
-               if (page)
+               if (page && !radix_tree_exceptional_entry(page))
                        continue;
 
                page = page_cache_alloc_readahead(mapping);
@@ -233,28 +232,14 @@ int force_page_cache_readahead(struct address_space *mapping, struct file *filp,
        return 0;
 }
 
+#define MAX_READAHEAD   ((512*4096)/PAGE_CACHE_SIZE)
 /*
  * Given a desired number of PAGE_CACHE_SIZE readahead pages, return a
  * sensible upper limit.
  */
 unsigned long max_sane_readahead(unsigned long nr)
 {
-       return min(nr, (node_page_state(numa_node_id(), NR_INACTIVE_FILE)
-               + node_page_state(numa_node_id(), NR_FREE_PAGES)) / 2);
-}
-
-/*
- * Submit IO for the read-ahead request in file_ra_state.
- */
-unsigned long ra_submit(struct file_ra_state *ra,
-                      struct address_space *mapping, struct file *filp)
-{
-       int actual;
-
-       actual = __do_page_cache_readahead(mapping, filp,
-                                       ra->start, ra->size, ra->async_size);
-
-       return actual;
+       return min(nr, MAX_READAHEAD);
 }
 
 /*
@@ -347,7 +332,7 @@ static pgoff_t count_history_pages(struct address_space *mapping,
        pgoff_t head;
 
        rcu_read_lock();
-       head = radix_tree_prev_hole(&mapping->page_tree, offset - 1, max);
+       head = page_cache_prev_hole(mapping, offset - 1, max);
        rcu_read_unlock();
 
        return offset - 1 - head;
@@ -427,7 +412,7 @@ ondemand_readahead(struct address_space *mapping,
                pgoff_t start;
 
                rcu_read_lock();
-               start = radix_tree_next_hole(&mapping->page_tree, offset+1,max);
+               start = page_cache_next_hole(mapping, offset + 1, max);
                rcu_read_unlock();
 
                if (!start || start - offset > max)