Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
From:   Jeffle Xu <jefflexu@linux.alibaba.com>
To:     dhowells@redhat.com, linux-cachefs@redhat.com, xiang@kernel.org,
        chao@kernel.org, linux-erofs@lists.ozlabs.org
Cc:     linux-fsdevel@vger.kernel.org, joseph.qi@linux.alibaba.com,
        bo.liu@linux.alibaba.com, tao.peng@linux.alibaba.com,
        gerry@linux.alibaba.com, eguan@linux.alibaba.com,
        linux-kernel@vger.kernel.org
Subject: [PATCH v2 09/20] erofs: add mode checking helper
Date:   Tue, 18 Jan 2022 21:12:05 +0800
Message-Id: <20220118131216.85338-10-jefflexu@linux.alibaba.com>
In-Reply-To: <20220118131216.85338-1-jefflexu@linux.alibaba.com>
References: <20220118131216.85338-1-jefflexu@linux.alibaba.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

Until then erofs is exactly blockdev based filesystem. In other using
scenarios (e.g. container image), erofs needs to run upon files.

This patch set is going to introduces a new nodev mode, in which erofs
could be mounted from a bootstrap blob file containing complete erofs
image.

Add a helper checking which mode erofs works in.

Signed-off-by: Jeffle Xu <jefflexu@linux.alibaba.com>
---
 fs/erofs/internal.h | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/fs/erofs/internal.h b/fs/erofs/internal.h
index f9f94d63d40f..2b9337d385ce 100644
--- a/fs/erofs/internal.h
+++ b/fs/erofs/internal.h
@@ -161,6 +161,11 @@ struct erofs_sb_info {
 #define set_opt(opt, option)	((opt)->mount_opt |= EROFS_MOUNT_##option)
 #define test_opt(opt, option)	((opt)->mount_opt & EROFS_MOUNT_##option)
 
+static inline bool erofs_bdev_mode(struct super_block *sb)
+{
+	return sb->s_bdev;
+}
+
 enum {
 	EROFS_ZIP_CACHE_DISABLED,
 	EROFS_ZIP_CACHE_READAHEAD,
-- 
2.27.0