ovl: split out ovl_get_upperpath() from ovl_fill_super()

It's okay to get rid of the intermediate error label due to ufs being
zeroed on allocation.

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

diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c
index bc87294..c1abd66 100644 (file)
--- a/fs/overlayfs/super.c
+++ b/fs/overlayfs/super.c
@@ -827,6 +827,39 @@ static const struct xattr_handler *ovl_xattr_handlers[] = {
        NULL
 };
 
+static int ovl_get_upperpath(struct ovl_fs *ufs, struct path *upperpath)
+{
+       int err;
+
+       err = ovl_mount_dir(ufs->config.upperdir, upperpath);
+       if (err)
+               goto out;
+
+       /* Upper fs should not be r/o */
+       if (sb_rdonly(upperpath->mnt->mnt_sb)) {
+               pr_err("overlayfs: upper fs is r/o, try multi-lower layers mount\n");
+               err = -EINVAL;
+               goto out;
+       }
+
+       err = ovl_check_namelen(upperpath, ufs, ufs->config.upperdir);
+       if (err)
+               goto out;
+
+       err = -EBUSY;
+       if (ovl_inuse_trylock(upperpath->dentry)) {
+               ufs->upperdir_locked = true;
+       } else if (ufs->config.index) {
+               pr_err("overlayfs: upperdir is in-use by another mount, mount with '-o index=off' to override exclusive upperdir protection.\n");
+               goto out;
+       } else {
+               pr_warn("overlayfs: upperdir is in-use by another mount, accessing files from both mounts will result in undefined behavior.\n");
+       }
+       err = 0;
+out:
+       return err;
+}
+
 static int ovl_fill_super(struct super_block *sb, void *data, int silent)
 {
        struct path upperpath = { };
@@ -870,30 +903,9 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent)
                        goto out_free_config;
                }
 
-               err = ovl_mount_dir(ufs->config.upperdir, &upperpath);
+               err = ovl_get_upperpath(ufs, &upperpath);
                if (err)
-                       goto out_free_config;
-
-               /* Upper fs should not be r/o */
-               if (sb_rdonly(upperpath.mnt->mnt_sb)) {
-                       pr_err("overlayfs: upper fs is r/o, try multi-lower layers mount\n");
-                       err = -EINVAL;
-                       goto out_put_upperpath;
-               }
-
-               err = ovl_check_namelen(&upperpath, ufs, ufs->config.upperdir);
-               if (err)
-                       goto out_put_upperpath;
-
-               err = -EBUSY;
-               if (ovl_inuse_trylock(upperpath.dentry)) {
-                       ufs->upperdir_locked = true;
-               } else if (ufs->config.index) {
-                       pr_err("overlayfs: upperdir is in-use by another mount, mount with '-o index=off' to override exclusive upperdir protection.\n");
-                       goto out_put_upperpath;
-               } else {
-                       pr_warn("overlayfs: upperdir is in-use by another mount, accessing files from both mounts will result in undefined behavior.\n");
-               }
+                       goto out_unlock_upperdentry;
 
                err = ovl_mount_dir(ufs->config.workdir, &workpath);
                if (err)
@@ -1196,7 +1208,6 @@ out_put_workpath:
 out_unlock_upperdentry:
        if (ufs->upperdir_locked)
                ovl_inuse_unlock(upperpath.dentry);
-out_put_upperpath:
        path_put(&upperpath);
 out_free_config:
        kfree(ufs->config.lowerdir);