fs: Add command to retrieve the filesystem type

New command to determine the filesystem type of a given partition.
Optionally stores the filesystem type in a environment variable.

Signed-off-by: Sjoerd Simons <sjoerd.simons@collabora.co.uk>
Reviewed-by: Stephen Warren <swarren@nvidia.com>

common/cmd_fs.c

@@ -81,3 +81,18 @@ U_BOOT_CMD(
 	"    - List files in directory 'directory' of partition 'part' on\n"
 	"      device type 'interface' instance 'dev'."
 )
+
+static int do_fstype_wrapper(cmd_tbl_t *cmdtp, int flag, int argc,
+				char * const argv[])
+{
+	return do_fs_type(cmdtp, flag, argc, argv);
+}
+
+U_BOOT_CMD(
+	fstype, 4, 1, do_fstype_wrapper,
+	"Look up a filesystem type",
+	"<interface> <dev>:<part>\n"
+	"- print filesystem type\n"
+	"fstype <interface> <dev>:<part> <varname>\n"
+	"- set environment variable to filesystem type\n"
+);

fs/fs.c

@@ -79,6 +79,7 @@ static inline int fs_uuid_unsupported(char *uuid_str)
 
 struct fstype_info {
 	int fstype;
+	char *name;
 	/*
 	 * Is it legal to pass NULL as .probe()'s  fs_dev_desc parameter? This
 	 * should be false in most cases. For "virtual" filesystems which
@@ -105,6 +106,7 @@ static struct fstype_info fstypes[] = {
 #ifdef CONFIG_FS_FAT
 	{
 		.fstype = FS_TYPE_FAT,
+		.name = "fat",
 		.null_dev_desc_ok = false,
 		.probe = fat_set_blk_dev,
 		.close = fat_close,
@@ -123,6 +125,7 @@ static struct fstype_info fstypes[] = {
 #ifdef CONFIG_FS_EXT4
 	{
 		.fstype = FS_TYPE_EXT,
+		.name = "ext4",
 		.null_dev_desc_ok = false,
 		.probe = ext4fs_probe,
 		.close = ext4fs_close,
@@ -141,6 +144,7 @@ static struct fstype_info fstypes[] = {
 #ifdef CONFIG_SANDBOX
 	{
 		.fstype = FS_TYPE_SANDBOX,
+		.name = "sandbox",
 		.null_dev_desc_ok = true,
 		.probe = sandbox_fs_set_blk_dev,
 		.close = sandbox_fs_close,
@@ -154,6 +158,7 @@ static struct fstype_info fstypes[] = {
 #endif
 	{
 		.fstype = FS_TYPE_ANY,
+		.name = "unsupported",
 		.null_dev_desc_ok = true,
 		.probe = fs_probe_unsupported,
 		.close = fs_close_unsupported,
@@ -190,6 +195,7 @@ int fs_set_blk_dev(const char *ifname, const char *dev_part_str, int fstype)
 	if (!relocated) {
 		for (i = 0, info = fstypes; i < ARRAY_SIZE(fstypes);
 				i++, info++) {
+			info->name += gd->reloc_off;
 			info->probe += gd->reloc_off;
 			info->close += gd->reloc_off;
 			info->ls += gd->reloc_off;
@@ -503,3 +509,24 @@ int do_fs_uuid(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[],
 
 	return CMD_RET_SUCCESS;
 }
+
+int do_fs_type(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
+{
+	struct fstype_info *info;
+
+	if (argc < 3 || argc > 4)
+		return CMD_RET_USAGE;
+
+	if (fs_set_blk_dev(argv[1], argv[2], FS_TYPE_ANY))
+		return 1;
+
+	info = fs_get_info(fs_type);
+
+	if (argc == 4)
+		setenv(argv[3], info->name);
+	else
+		printf("%s\n", info->name);
+
+	return CMD_RET_SUCCESS;
+}
+

include/fs.h

@@ -109,4 +109,10 @@ int do_save(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[],
 int do_fs_uuid(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[],
 		int fstype);
 
+/*
+ * Determine the type of the specified filesystem and print it. Optionally it is
+ * possible to store the type directly in env.
+ */
+int do_fs_type(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]);
+
 #endif /* _FS_H */