CIFS: Reset read oplock to NONE if we have mandatory locks after reopen

We are already doing the same thing for an ordinary open case:
we can't keep read oplock on a file if we have mandatory byte-range
locks because pagereading can conflict with these locks on a server.
Fix it by setting oplock level to NONE.

Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <smfrench@gmail.com>

diff --git a/fs/cifs/file.c b/fs/cifs/file.c
index 07c14f9217cb873c40d30ac7516a3fc5babb5081..7f5f6176c6f15caff307e078320122141c119ab9 100644 (file)
--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c
@@ -739,6 +739,15 @@ reopen_success:
         * to the server to get the new inode info.
         */
 
+       /*
+        * If the server returned a read oplock and we have mandatory brlocks,
+        * set oplock level to None.
+        */
+       if (server->ops->is_read_op(oplock) && cifs_has_mand_locks(cinode)) {
+               cifs_dbg(FYI, "Reset oplock val from read to None due to mand locks\n");
+               oplock = 0;
+       }
+
        server->ops->set_fid(cfile, &cfile->fid, oplock);
        if (oparms.reconnect)
                cifs_relock_file(cfile);