[PATCH] Convert NFS client to use ->readpages()

  - Add the library function read_cache_pages(), which is used in a
    similar fashion to the single page 'read_cache_page()'. It hides
    the details of the LRU cache etc. from a filesystem that wants to
    to populate an address space with a list of pages.

  - Fix NFS so that readahead uses the ->readpages() interface. Means
    that we can immediately schedule an RPC call in order to complete
    the I/O, rather than relying on somebody later triggering it by
    calling lock_page() (and hence sync_page()). The sync_page()
    method is race-prone, since the waiting page may try to call it
    before we've finished initializing the 'struct nfs_page'.

  - Clear out nfs_sync_page(), the nfs_inode->read list, and
    friends. When the I/O completion gets scheduled in ->readpage(),
    ->readpages(), they have no reason to exist.

1 files changed, 1 insertions, 0 deletions

diff --git a/kernel/ksyms.c b/kernel/ksyms.c
index c41423568d02..fac863fb462e 100644
--- a/kernel/ksyms.c
+++ b/kernel/ksyms.c
@@ -284,6 +284,7 @@ EXPORT_SYMBOL(find_lock_page);
 EXPORT_SYMBOL(find_or_create_page);
 EXPORT_SYMBOL(grab_cache_page_nowait);
 EXPORT_SYMBOL(read_cache_page);
+EXPORT_SYMBOL(read_cache_pages);
 EXPORT_SYMBOL(mark_page_accessed);
 EXPORT_SYMBOL(vfs_readlink);
 EXPORT_SYMBOL(vfs_follow_link);