CIFS: Simplify invalidate part (try #5)

Simplify many places when we call cifs_revalidate/invalidate to make
it do what it exactly needs.

Reviewed-by: Jeff Layton <jlayton@samba.org>
Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Steve French <sfrench@us.ibm.com>

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);
 }