cifs: take read lock on GlobalSMBSes_lock in is_valid_oplock_break

...rather than a write lock. It doesn't change the list so a read lock
should be sufficient.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>

1 files changed, 3 insertions, 3 deletions

diff --git a/fs/cifs/misc.c b/fs/cifs/misc.c
index f2d508df7ec5..191e6220bc76 100644
--- a/fs/cifs/misc.c
+++ b/fs/cifs/misc.c
@@ -562,14 +562,14 @@ is_valid_oplock_break(struct smb_hdr *buf, struct TCP_Server_Info *srv)
                                 continue;
 
                         cifs_stats_inc(&tcon->num_oplock_brks);
-                        write_lock(&GlobalSMBSeslock);
+                        read_lock(&GlobalSMBSeslock);
                         list_for_each(tmp2, &tcon->openFileList) {
                                 netfile = list_entry(tmp2, struct cifsFileInfo,
                                                      tlist);
                                 if (pSMB->Fid != netfile->netfid)
                                         continue;
 
-                                write_unlock(&GlobalSMBSeslock);
+                                read_unlock(&GlobalSMBSeslock);
                                 read_unlock(&cifs_tcp_ses_lock);
                                 cFYI(1, ("file id match, oplock break"));
                                 pCifsInode = CIFS_I(netfile->pInode);
@@ -584,7 +584,7 @@ is_valid_oplock_break(struct smb_hdr *buf, struct TCP_Server_Info *srv)
 
                                 return true;
                         }
-                        write_unlock(&GlobalSMBSeslock);
+                        read_unlock(&GlobalSMBSeslock);
                         read_unlock(&cifs_tcp_ses_lock);
                         cFYI(1, ("No matching file for oplock break"));
                         return true;