1 files changed, 23 insertions, 10 deletions

diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c
index f736d8a2e771..0f6a54f14eff 100644
--- a/fs/cifs/cifsfs.c
+++ b/fs/cifs/cifsfs.c
@@ -618,16 +618,29 @@ static loff_t cifs_llseek(struct file *file, loff_t offset, int origin)
 {
         /* origin == SEEK_END => we must revalidate the cached file length */
         if (origin == SEEK_END) {
-                int retval;
-
-                /* some applications poll for the file length in this strange
-                   way so we must seek to end on non-oplocked files by
-                   setting the revalidate time to zero */
-                CIFS_I(file->f_path.dentry->d_inode)->time = 0;
-
-                retval = cifs_revalidate_file(file);
-                if (retval < 0)
-                        return (loff_t)retval;
+                int rc;
+                struct inode *inode = file->f_path.dentry->d_inode;
+
+                /*
+                 * We need to be sure that all dirty pages are written and the
+                 * server has the newest file length.
+                 */
+                if (!CIFS_I(inode)->clientCanCacheRead && inode->i_mapping &&
+                    inode->i_mapping->nrpages != 0) {
+                        rc = filemap_fdatawait(inode->i_mapping);
+                        mapping_set_error(inode->i_mapping, rc);
+                        return rc;
+                }
+                /*
+                 * Some applications poll for the file length in this strange
+                 * way so we must seek to end on non-oplocked files by
+                 * setting the revalidate time to zero.
+                 */
+                CIFS_I(inode)->time = 0;
+
+                rc = cifs_revalidate_file_attr(file);
+                if (rc < 0)
+                        return (loff_t)rc;
         }
         return generic_file_llseek_unlocked(file, offset, origin);
 }