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

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

diff --git a/fs/nfs/write.c b/fs/nfs/write.c
index 266fea7..0eca6a5 100644 (file)
--- 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 1b38c20..3de334c 100644 (file)
--- 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__