NFSv4: Fix the sync mount option for nfs4 mounts

The sync mount option stopped working for NFSv4 mounts after commit
c02d7adf8c5429727a98bad1d039bccad4c61c50 (NFSv4: Replace nfs4_path_walk() with
FS path lookup in a private namespace).  If MS_SYNCHRONOUS is set in the
super_block that we're cloning from, then it should be set in the new
super_block as well.

Signed-off-by: Scott Mayhew <smayhew@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

diff --git a/fs/nfs/super.c b/fs/nfs/super.c
index 71fdc0d..f6db66d 100644 (file)
--- a/fs/nfs/super.c
+++ b/fs/nfs/super.c
@@ -2478,6 +2478,10 @@ struct dentry *nfs_fs_mount_common(struct nfs_server *server,
        if (server->flags & NFS_MOUNT_NOAC)
                sb_mntdata.mntflags |= MS_SYNCHRONOUS;
 
+       if (mount_info->cloned != NULL && mount_info->cloned->sb != NULL)
+               if (mount_info->cloned->sb->s_flags & MS_SYNCHRONOUS)
+                       sb_mntdata.mntflags |= MS_SYNCHRONOUS;
+
        /* Get a superblock - note that we may end up sharing one that already exists */
        s = sget(nfs_mod->nfs_fs, compare_super, nfs_set_super, flags, &sb_mntdata);
        if (IS_ERR(s)) {