NFS: Ensure that nfs_wb_page() calls writepage when necessary.

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

2 files changed, 31 insertions, 4 deletions

diff --git a/fs/nfs/write.c b/fs/nfs/write.c
index 266fea71cfc0..0eca6a542106 100644
--- a/fs/nfs/write.c
+++ b/fs/nfs/write.c
@@ -247,7 +247,7 @@ static int wb_priority(struct writeback_control *wbc)
 /*
  * Write an mmapped page to the server.
  */
-int nfs_writepage(struct page *page, struct writeback_control *wbc)
+static int nfs_writepage_locked(struct page *page, struct writeback_control *wbc)
 {
         struct nfs_open_context *ctx;
         struct inode *inode = page->mapping->host;
@@ -265,7 +265,7 @@ int nfs_writepage(struct page *page, struct writeback_control *wbc)
                 if (!flushme)
                         goto out;
                 /* Ensure we've flushed out the invalid write */
-                nfs_wb_page_priority(inode, page, wb_priority(wbc));
+                nfs_wb_page_priority(inode, page, wb_priority(wbc) | FLUSH_STABLE | FLUSH_NOWRITEPAGE);
         }
 
         offset = nfs_page_length(page);
@@ -283,6 +283,14 @@ int nfs_writepage(struct page *page, struct writeback_control *wbc)
 out:
         if (!wbc->for_writepages)
                 nfs_flush_mapping(page->mapping, wbc, wb_priority(wbc));
+        return err;
+}
+
+int nfs_writepage(struct page *page, struct writeback_control *wbc)
+{
+        int err;
+
+        err = nfs_writepage_locked(page, wbc);
         unlock_page(page);
         return err; 
 }
@@ -1435,8 +1443,26 @@ static int nfs_wb_page_priority(struct inode *inode, struct page *page, int how)
 {
         loff_t range_start = page_offset(page);
         loff_t range_end = range_start + (loff_t)(PAGE_CACHE_SIZE - 1);
+        struct writeback_control wbc = {
+                .bdi = page->mapping->backing_dev_info,
+                .sync_mode = WB_SYNC_ALL,
+                .nr_to_write = LONG_MAX,
+                .range_start = range_start,
+                .range_end = range_end,
+        };
+        int ret;
 
-        return nfs_sync_mapping_range(inode->i_mapping, range_start, range_end, how | FLUSH_STABLE);
+        BUG_ON(!PageLocked(page));
+        if (!(how & FLUSH_NOWRITEPAGE) && clear_page_dirty_for_io(page)) {
+                ret = nfs_writepage_locked(page, &wbc);
+                if (ret < 0)
+                        goto out;
+        }
+        ret = nfs_sync_mapping_wait(page->mapping, &wbc, how);
+        if (ret >= 0)
+                return 0;
+out:
+        return ret;
 }
 
 /*
@@ -1444,7 +1470,7 @@ static int nfs_wb_page_priority(struct inode *inode, struct page *page, int how)
  */
 int nfs_wb_page(struct inode *inode, struct page* page)
 {
-        return nfs_wb_page_priority(inode, page, 0);
+        return nfs_wb_page_priority(inode, page, FLUSH_STABLE);
 }
 
 int nfs_set_page_dirty(struct page *page)
diff --git a/include/linux/nfs_fs.h b/include/linux/nfs_fs.h
index 1b38c2085a53..3de334c72b1f 100644
--- a/include/linux/nfs_fs.h
+++ b/include/linux/nfs_fs.h
@@ -33,6 +33,7 @@
 #define FLUSH_HIGHPRI           16      /* high priority memory reclaim flush */
 #define FLUSH_NOCOMMIT          32      /* Don't send the NFSv3/v4 COMMIT */
 #define FLUSH_INVALIDATE        64      /* Invalidate the page cache */
+#define FLUSH_NOWRITEPAGE       128     /* Don't call writepage() */
 
 #ifdef __KERNEL__