From f4d852fcd6fbc380fccd37766ebd854d824c6755 Mon Sep 17 00:00:00 2001
From: Paul Keith <javelinanddart@gmail.com>
Date: Fri, 2 Mar 2018 05:10:27 +0100
Subject: [PATCH] fs: sdfat: Add config option to register sdFAT for VFAT

Change-Id: I72ba7a14b56175535884390e8601960b5d8ed1cf
Signed-off-by: Paul Keith <javelinanddart@gmail.com>
---
 fs/sdfat/Kconfig |  7 +++++++
 fs/sdfat/sdfat.c | 45 +++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 52 insertions(+)

diff --git a/fs/sdfat/Kconfig b/fs/sdfat/Kconfig
index 3fe86e72c40b..1b67632c7d39 100644
--- a/fs/sdfat/Kconfig
+++ b/fs/sdfat/Kconfig
@@ -22,6 +22,13 @@ config SDFAT_USE_FOR_EXFAT
 	help
 	  If you want to register sdFAT as available for exFAT, say Y.
 
+config SDFAT_USE_FOR_VFAT
+	bool "Register sdFAT as VFAT"
+	default y
+	depends on SDFAT_FS && !VFAT_FS
+	help
+	  If you want to register sdFAT as available for VFAT, say Y.
+
 config SDFAT_DELAYED_META_DIRTY
 	bool "Enable delayed metadata dirty"
 	default y
diff --git a/fs/sdfat/sdfat.c b/fs/sdfat/sdfat.c
index 9d50d0ce72de..c1a2c2ec1b67 100644
--- a/fs/sdfat/sdfat.c
+++ b/fs/sdfat/sdfat.c
@@ -4532,6 +4532,12 @@ enum {
 	Opt_discard,
 	Opt_fs,
 	Opt_adj_req,
+#ifdef CONFIG_SDFAT_USE_FOR_VFAT
+	Opt_shortname_lower,
+	Opt_shortname_win95,
+	Opt_shortname_winnt,
+	Opt_shortname_mixed,
+#endif /* CONFIG_SDFAT_USE_FOR_VFAT */
 };
 
 static const match_table_t sdfat_tokens = {
@@ -4560,6 +4566,12 @@ static const match_table_t sdfat_tokens = {
 	{Opt_discard, "discard"},
 	{Opt_fs, "fs=%s"},
 	{Opt_adj_req, "adj_req"},
+#ifdef CONFIG_SDFAT_USE_FOR_VFAT
+	{Opt_shortname_lower, "shortname=lower"},
+	{Opt_shortname_win95, "shortname=win95"},
+	{Opt_shortname_winnt, "shortname=winnt"},
+	{Opt_shortname_mixed, "shortname=mixed"},
+#endif /* CONFIG_SDFAT_USE_FOR_VFAT */
 	{Opt_err, NULL}
 };
 
@@ -4726,6 +4738,14 @@ static int parse_options(struct super_block *sb, char *options, int silent,
 			IMSG("adjust request config is not enabled. ignore\n");
 #endif
 			break;
+#ifdef CONFIG_SDFAT_USE_FOR_VFAT
+		case Opt_shortname_lower:
+		case Opt_shortname_win95:
+		case Opt_shortname_mixed:
+			pr_warn("[SDFAT] DRAGONS AHEAD! sdFAT only understands \"shortname=winnt\"!\n");
+		case Opt_shortname_winnt:
+			break;
+#endif /* CONFIG_SDFAT_USE_FOR_VFAT */
 		default:
 			if (!silent) {
 				sdfat_msg(sb, KERN_ERR,
@@ -5065,6 +5085,20 @@ static struct file_system_type exfat_fs_type = {
 };
 #endif /* CONFIG_SDFAT_USE_FOR_EXFAT */
 
+#ifdef CONFIG_SDFAT_USE_FOR_VFAT
+static struct file_system_type vfat_fs_type = {
+	.owner       = THIS_MODULE,
+	.name        = "vfat",
+	.mount       = sdfat_fs_mount,
+#ifdef CONFIG_SDFAT_DBG_IOCTL
+	.kill_sb    = sdfat_debug_kill_sb,
+#else
+	.kill_sb    = kill_block_super,
+#endif /* CONFIG_SDFAT_DBG_IOCTL */
+	.fs_flags    = FS_REQUIRES_DEV,
+};
+#endif /* CONFIG_SDFAT_USE_FOR_VFAT */
+
 static int __init init_sdfat_fs(void)
 {
 	int err;
@@ -5111,6 +5145,14 @@ static int __init init_sdfat_fs(void)
 	}
 #endif /* CONFIG_SDFAT_USE_FOR_EXFAT */
 
+#ifdef CONFIG_SDFAT_USE_FOR_VFAT
+	err = register_filesystem(&vfat_fs_type);
+	if (err) {
+		pr_err("[SDFAT] failed to register for vfat filesystem\n");
+		goto error;
+	}
+#endif /* CONFIG_SDFAT_USE_FOR_VFAT */
+
 	return 0;
 error:
 	sdfat_statistics_uninit();
@@ -5143,6 +5185,9 @@ static void __exit exit_sdfat_fs(void)
 #ifdef CONFIG_SDFAT_USE_FOR_EXFAT
 	unregister_filesystem(&exfat_fs_type);
 #endif /* CONFIG_SDFAT_USE_FOR_EXFAT */
+#ifdef CONFIG_SDFAT_USE_FOR_VFAT
+	unregister_filesystem(&vfat_fs_type);
+#endif /* CONFIG_SDFAT_USE_FOR_VFAT */
 	fsapi_shutdown();
 }
 
-- 
2.20.1