ovl: split out ovl_get_lower_layers() from ovl_fill_super()

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>

diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c
index aadd07a1e9c1be5f831691d89d45a0ce22bc818f..537412ad12a007196effb7007d384c3ed036b2a6 100644 (file)
--- a/fs/overlayfs/super.c
+++ b/fs/overlayfs/super.c
@@ -1038,6 +1038,55 @@ out_free_stack:
        goto out;
 }
 
+static int ovl_get_lower_layers(struct ovl_fs *ufs, struct path *stack,
+                               unsigned int numlower)
+{
+       int err;
+       unsigned int i;
+
+       err = -ENOMEM;
+       ufs->lower_layers = kcalloc(numlower, sizeof(struct ovl_layer),
+                                   GFP_KERNEL);
+       if (ufs->lower_layers == NULL)
+               goto out;
+       for (i = 0; i < numlower; i++) {
+               struct vfsmount *mnt;
+               dev_t dev;
+
+               err = get_anon_bdev(&dev);
+               if (err) {
+                       pr_err("overlayfs: failed to get anonymous bdev for lowerpath\n");
+                       goto out;
+               }
+
+               mnt = clone_private_mount(&stack[i]);
+               err = PTR_ERR(mnt);
+               if (IS_ERR(mnt)) {
+                       pr_err("overlayfs: failed to clone lowerpath\n");
+                       free_anon_bdev(dev);
+                       goto out;
+               }
+               /*
+                * Make lower layers R/O.  That way fchmod/fchown on lower file
+                * will fail instead of modifying lower fs.
+                */
+               mnt->mnt_flags |= MNT_READONLY | MNT_NOATIME;
+
+               ufs->lower_layers[ufs->numlower].mnt = mnt;
+               ufs->lower_layers[ufs->numlower].pseudo_dev = dev;
+               ufs->numlower++;
+
+               /* Check if all lower layers are on same sb */
+               if (i == 0)
+                       ufs->same_sb = mnt->mnt_sb;
+               else if (ufs->same_sb != mnt->mnt_sb)
+                       ufs->same_sb = NULL;
+       }
+       err = 0;
+out:
+       return err;
+}
+
 static int ovl_fill_super(struct super_block *sb, void *data, int silent)
 {
        struct path upperpath = { };
@@ -1103,44 +1152,9 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent)
                        goto out_put_workdir;
        }
 
-       err = -ENOMEM;
-       ufs->lower_layers = kcalloc(numlower, sizeof(struct ovl_layer),
-                                   GFP_KERNEL);
-       if (ufs->lower_layers == NULL)
-               goto out_put_workdir;
-       for (i = 0; i < numlower; i++) {
-               struct vfsmount *mnt;
-               dev_t dev;
-
-               err = get_anon_bdev(&dev);
-               if (err) {
-                       pr_err("overlayfs: failed to get anonymous bdev for lowerpath\n");
-                       goto out_put_lower_layers;
-               }
-
-               mnt = clone_private_mount(&stack[i]);
-               err = PTR_ERR(mnt);
-               if (IS_ERR(mnt)) {
-                       pr_err("overlayfs: failed to clone lowerpath\n");
-                       free_anon_bdev(dev);
-                       goto out_put_lower_layers;
-               }
-               /*
-                * Make lower layers R/O.  That way fchmod/fchown on lower file
-                * will fail instead of modifying lower fs.
-                */
-               mnt->mnt_flags |= MNT_READONLY | MNT_NOATIME;
-
-               ufs->lower_layers[ufs->numlower].mnt = mnt;
-               ufs->lower_layers[ufs->numlower].pseudo_dev = dev;
-               ufs->numlower++;
-
-               /* Check if all lower layers are on same sb */
-               if (i == 0)
-                       ufs->same_sb = mnt->mnt_sb;
-               else if (ufs->same_sb != mnt->mnt_sb)
-                       ufs->same_sb = NULL;
-       }
+       err = ovl_get_lower_layers(ufs, stack, numlower);
+       if (err)
+               goto out_put_lower_layers;
 
        /* If the upper fs is nonexistent, we mark overlayfs r/o too */
        if (!ufs->upper_mnt)