nfs: teach the NFS client how to treat PG_swapcache pages

Replace all relevant occurences of page->index and page->mapping in the
NFS client with the new page_file_index() and page_file_mapping()
functions.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Acked-by: Rik van Riel <riel@redhat.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: David S. Miller <davem@davemloft.net>
Cc: Eric B Munson <emunson@mgebm.net>
Cc: Eric Paris <eparis@redhat.com>
Cc: James Morris <jmorris@namei.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Mike Christie <michaelc@cs.wisc.edu>
Cc: Neil Brown <neilb@suse.de>
Cc: Sebastian Andrzej Siewior <sebastian@breakpoint.cc>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: Xiaotian Feng <dfeng@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 4 insertions, 3 deletions

diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h
index cfafd13b6fe9..4be14b3e0a18 100644
--- a/fs/nfs/internal.h
+++ b/fs/nfs/internal.h
@@ -546,13 +546,14 @@ void nfs_super_set_maxbytes(struct super_block *sb, __u64 maxfilesize)
 static inline
 unsigned int nfs_page_length(struct page *page)
 {
-        loff_t i_size = i_size_read(page->mapping->host);
+        loff_t i_size = i_size_read(page_file_mapping(page)->host);
 
         if (i_size > 0) {
+                pgoff_t page_index = page_file_index(page);
                 pgoff_t end_index = (i_size - 1) >> PAGE_CACHE_SHIFT;
-                if (page->index < end_index)
+                if (page_index < end_index)
                         return PAGE_CACHE_SIZE;
-                if (page->index == end_index)
+                if (page_index == end_index)
                         return ((i_size - 1) & ~PAGE_CACHE_MASK) + 1;
         }
         return 0;