ovl: force read-only sb on failure to create index dir

With index feature enabled, on failure to create index dir, overlay is
being mounted read-only.  However, we do not forbid user to remount overlay
read-write.  Fix that by setting ofs->workdir to NULL, which prevents
remount read-write.

Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>

diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c
index 94ca095b2a9eaa9e7e0e67cb49e626664156e166..f41ef1dd384c87bc29902490b65457287dfc5a6c 100644 (file)
--- a/fs/overlayfs/super.c
+++ b/fs/overlayfs/super.c
@@ -1352,12 +1352,13 @@ static int ovl_get_indexdir(struct super_block *sb, struct ovl_fs *ofs,
                goto out;
        }
 
+       /* index dir will act also as workdir */
+       iput(ofs->workdir_trap);
+       ofs->workdir_trap = NULL;
+       dput(ofs->workdir);
+       ofs->workdir = NULL;
        ofs->indexdir = ovl_workdir_create(ofs, OVL_INDEXDIR_NAME, true);
        if (ofs->indexdir) {
-               /* index dir will act also as workdir */
-               iput(ofs->workdir_trap);
-               ofs->workdir_trap = NULL;
-               dput(ofs->workdir);
                ofs->workdir = dget(ofs->indexdir);
 
                err = ovl_setup_trap(sb, ofs->indexdir, &ofs->indexdir_trap,
@@ -1869,7 +1870,7 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent)
        if (!ovl_upper_mnt(ofs))
                sb->s_flags |= SB_RDONLY;
 
-       if (!(ovl_force_readonly(ofs)) && ofs->config.index) {
+       if (!ovl_force_readonly(ofs) && ofs->config.index) {
                err = ovl_get_indexdir(sb, ofs, oe, &upperpath);
                if (err)
                        goto out_free_oe;