NFS: Clean up nfs_writepages()

Just call write_cache_pages directly instead of hacking the writeback
control structure in order to find out if we were called from writepages()
or directly from the VM.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

1 files changed, 33 insertions, 24 deletions

diff --git a/fs/nfs/write.c b/fs/nfs/write.c
index 0c346d79fb34..667ff27ef235 100644
--- a/fs/nfs/write.c
+++ b/fs/nfs/write.c
@@ -292,41 +292,51 @@ static int nfs_page_async_flush(struct nfs_pageio_descriptor *pgio,
         return 0;
 }
 
-/*
- * Write an mmapped page to the server.
- */
-static int nfs_writepage_locked(struct page *page, struct writeback_control *wbc)
+static int nfs_do_writepage(struct page *page, struct writeback_control *wbc, struct nfs_pageio_descriptor *pgio)
 {
-        struct nfs_pageio_descriptor mypgio, *pgio;
         struct inode *inode = page->mapping->host;
-        int err;
 
         nfs_inc_stats(inode, NFSIOS_VFSWRITEPAGE);
         nfs_add_stats(inode, NFSIOS_WRITEPAGES, 1);
 
-        if (wbc->for_writepages)
-                pgio = wbc->fs_private;
-        else {
-                nfs_pageio_init_write(&mypgio, inode, wb_priority(wbc));
-                pgio = &mypgio;
-        }
-
         nfs_pageio_cond_complete(pgio, page->index);
+        return nfs_page_async_flush(pgio, page);
+}
 
-        err = nfs_page_async_flush(pgio, page);
+/*
+ * Write an mmapped page to the server.
+ */
+static int nfs_writepage_locked(struct page *page, struct writeback_control *wbc)
+{
+        struct nfs_pageio_descriptor pgio;
+        int err;
 
-        if (!wbc->for_writepages)
-                nfs_pageio_complete(pgio);
-        return err;
+        nfs_pageio_init_write(&pgio, page->mapping->host, wb_priority(wbc));
+        err = nfs_do_writepage(page, wbc, &pgio);
+        nfs_pageio_complete(&pgio);
+        if (err < 0)
+                return err;
+        if (pgio.pg_error < 0)
+                return pgio.pg_error;
+        return 0;
 }
 
 int nfs_writepage(struct page *page, struct writeback_control *wbc)
 {
-        int err;
+        int ret;
 
-        err = nfs_writepage_locked(page, wbc);
+        ret = nfs_writepage_locked(page, wbc);
         unlock_page(page);
-        return err; 
+        return ret;
+}
+
+static int nfs_writepages_callback(struct page *page, struct writeback_control *wbc, void *data)
+{
+        int ret;
+
+        ret = nfs_do_writepage(page, wbc, data);
+        unlock_page(page);
+        return ret;
 }
 
 int nfs_writepages(struct address_space *mapping, struct writeback_control *wbc)
@@ -338,12 +348,11 @@ int nfs_writepages(struct address_space *mapping, struct writeback_control *wbc)
         nfs_inc_stats(inode, NFSIOS_VFSWRITEPAGES);
 
         nfs_pageio_init_write(&pgio, inode, wb_priority(wbc));
-        wbc->fs_private = &pgio;
-        err = generic_writepages(mapping, wbc);
+        err = write_cache_pages(mapping, wbc, nfs_writepages_callback, &pgio);
         nfs_pageio_complete(&pgio);
-        if (err)
+        if (err < 0)
                 return err;
-        if (pgio.pg_error)
+        if (pgio.pg_error < 0)
                 return pgio.pg_error;
         return 0;
 }