fs: make it possible to read the filesystem UUID

Some filesystems have a UUID stored in its superblock. To allow using root=UUID=... for the kernel command line we need a way to read-out the filesystem UUID. changes rfc -> v1: - make the environment variable an option parameter. If not given, the UUID is printed out. If given, it is stored in the env variable. - corrected typos - return error codes changes v1 -> v2: - fix return code of do_fs_uuid(..) - document do_fs_uuid(..) - implement fs_uuid_unsuported(..) be more consistent with the way other optional functionality works changes v2 -> v3: - change ext4fs_uuid(..) to make use of #if .. #else .. #endif construct to get rid of unreachable code Hit any key to stop autoboot: 0 => fsuuid fsuuid - Look up a filesystem UUID Usage: fsuuid <interface> <dev>:<part> - print filesystem UUID fsuuid <interface> <dev>:<part> <varname> - set environment variable to filesystem UUID => fsuuid mmc 0:1 d9f9fc05-45ae-4a36-a616-fccce0e4f887 => fsuuid mmc 0:2 eb3db83c-7b28-499f-95ce-9e0bb21cda81 => fsuuid mmc 0:1 uuid1 => fsuuid mmc 0:2 uuid2 => printenv uuid1 uuid1=d9f9fc05-45ae-4a36-a616-fccce0e4f887 => printenv uuid2 uuid2=eb3db83c-7b28-499f-95ce-9e0bb21cda81 => Signed-off-by: Christian Gmeiner <christian.gmeiner@gmail.com> Acked-by: Stephen Warren <swarren@nvidia.com>

fs: make it possible to read the filesystem UUID
Some filesystems have a UUID stored in its superblock. To allow using root=UUID=... for the kernel command line we need a way to read-out the filesystem UUID. changes rfc -> v1: - make the environment variable an option parameter. If not given, the UUID is printed out. If given, it is stored in the env variable. - corrected typos - return error codes changes v1 -> v2: - fix return code of do_fs_uuid(..) - document do_fs_uuid(..) - implement fs_uuid_unsuported(..) be more consistent with the way other optional functionality works changes v2 -> v3: - change ext4fs_uuid(..) to make use of #if .. #else .. #endif construct to get rid of unreachable code Hit any key to stop autoboot: 0 => fsuuid fsuuid - Look up a filesystem UUID Usage: fsuuid <interface> <dev>:<part> - print filesystem UUID fsuuid <interface> <dev>:<part> <varname> - set environment variable to filesystem UUID => fsuuid mmc 0:1 d9f9fc05-45ae-4a36-a616-fccce0e4f887 => fsuuid mmc 0:2 eb3db83c-7b28-499f-95ce-9e0bb21cda81 => fsuuid mmc 0:1 uuid1 => fsuuid mmc 0:2 uuid2 => printenv uuid1 uuid1=d9f9fc05-45ae-4a36-a616-fccce0e4f887 => printenv uuid2 uuid2=eb3db83c-7b28-499f-95ce-9e0bb21cda81 => Signed-off-by: Christian Gmeiner <christian.gmeiner@gmail.com> Acked-by: Stephen Warren <swarren@nvidia.com>
Christian Gmeiner · Tom Rini
1 parent 1b51d32c0f
Showing 7 changed files with 94 additions and 0 deletions Side-by-side Diff
README
common/Makefile
common/cmd_fs_uuid.c
fs/ext4/ext4fs.c
fs/fs.c
include/ext4fs.h
include/fs.h
@@ -989,6 +989,7 @@
 		CONFIG_CMD_EXT4		* ext4 command support
 		CONFIG_CMD_FS_GENERIC	* filesystem commands (e.g. load, ls)
 					  that work for multiple fs types
+		CONFIG_CMD_FS_UUID	* Look up a filesystem UUID
 		CONFIG_CMD_SAVEENV	  saveenv
 		CONFIG_CMD_FDC		* Floppy Disk Support
 		CONFIG_CMD_FAT		* FAT command support
@@ -188,6 +188,7 @@
 obj-$(CONFIG_USB_STORAGE) += usb_storage.o
 endif
 obj-$(CONFIG_CMD_FASTBOOT) += cmd_fastboot.o
+obj-$(CONFIG_CMD_FS_UUID) += cmd_fs_uuid.o
  
 obj-$(CONFIG_CMD_USB_MASS_STORAGE) += cmd_usb_mass_storage.o
 obj-$(CONFIG_CMD_THOR_DOWNLOAD) += cmd_thordown.o
+/*
+ * cmd_fs_uuid.c -- fsuuid command
+ *
+ * Copyright (C) 2014, Bachmann electronic GmbH
+ *
+ * SPDX-License-Identifier:    GPL-2.0+
+ */
+
+#include <common.h>
+#include <command.h>
+#include <fs.h>
+
+static int do_fs_uuid_wrapper(cmd_tbl_t *cmdtp, int flag,
+	int argc, char * const argv[])
+{
+	return do_fs_uuid(cmdtp, flag, argc, argv, FS_TYPE_ANY);
+}
+
+U_BOOT_CMD(
+	fsuuid, 4, 1, do_fs_uuid_wrapper,
+	"Look up a filesystem UUID",
+	"<interface> <dev>:<part>\n"
+	"    - print filesystem UUID\n"
+	"fsuuid <interface> <dev>:<part> <varname>\n"
+	"    - set environment variable to filesystem UUID\n"
+);
@@ -231,4 +231,19 @@
  
 	return len_read;
 }
+
+int ext4fs_uuid(char *uuid_str)
+{
+	if (ext4fs_root == NULL)
+		return -1;
+
+#ifdef CONFIG_LIB_UUID
+	uuid_bin_to_str((unsigned char *)ext4fs_root->sblock.unique_id,
+			uuid_str, UUID_STR_FORMAT_STD);
+
+	return 0;
+#else
+	return -ENOSYS;
+#endif
+}
@@ -15,6 +15,7 @@
  */
  
 #include <config.h>
+#include <errno.h>
 #include <common.h>
 #include <part.h>
 #include <ext4fs.h>
@@ -67,6 +68,11 @@
 {
 }
  
+static inline int fs_uuid_unsupported(char *uuid_str)
+{
+	return -1;
+}
+
 struct fstype_info {
 	int fstype;
 	/*
@@ -86,6 +92,7 @@
 	int (*read)(const char *filename, void *buf, int offset, int len);
 	int (*write)(const char *filename, void *buf, int offset, int len);
 	void (*close)(void);
+	int (*uuid)(char *uuid_str);
 };
  
 static struct fstype_info fstypes[] = {
@@ -100,6 +107,7 @@
 		.size = fat_size,
 		.read = fat_read_file,
 		.write = fs_write_unsupported,
+		.uuid = fs_uuid_unsupported,
 	},
 #endif
 #ifdef CONFIG_FS_EXT4
@@ -113,6 +121,7 @@
 		.size = ext4fs_size,
 		.read = ext4_read_file,
 		.write = fs_write_unsupported,
+		.uuid = ext4fs_uuid,
 	},
 #endif
 #ifdef CONFIG_SANDBOX
@@ -126,6 +135,7 @@
 		.size = sandbox_fs_size,
 		.read = fs_read_sandbox,
 		.write = fs_write_sandbox,
+		.uuid = fs_uuid_unsupported,
 	},
 #endif
 	{
@@ -138,6 +148,7 @@
 		.size = fs_size_unsupported,
 		.read = fs_read_unsupported,
 		.write = fs_write_unsupported,
+		.uuid = fs_uuid_unsupported,
 	},
 };
  
@@ -206,6 +217,13 @@
 	fs_type = FS_TYPE_ANY;
 }
  
+int fs_uuid(char *uuid_str)
+{
+	struct fstype_info *info = fs_get_info(fs_type);
+
+	return info->uuid(uuid_str);
+}
+
 int fs_ls(const char *dirname)
 {
 	int ret;
@@ -442,5 +460,30 @@
 	puts("\n");
  
 	return 0;
+}
+
+int do_fs_uuid(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[],
+		int fstype)
+{
+	int ret;
+	char uuid[37];
+	memset(uuid, 0, sizeof(uuid));
+
+	if (argc < 3 || argc > 4)
+		return CMD_RET_USAGE;
+
+	if (fs_set_blk_dev(argv[1], argv[2], fstype))
+		return 1;
+
+	ret = fs_uuid(uuid);
+	if (ret)
+		return CMD_RET_FAILURE;
+
+	if (argc == 4)
+		setenv(argv[3], uuid);
+	else
+		printf("%s\n", uuid);
+
+	return CMD_RET_SUCCESS;
 }
@@ -145,5 +145,6 @@
 		 disk_partition_t *fs_partition);
 int ext4_read_file(const char *filename, void *buf, int offset, int len);
 int ext4_read_superblock(char *buffer);
+int ext4fs_uuid(char *uuid_str);
 #endif
@@ -93,5 +93,12 @@
 int do_save(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[],
 		int fstype);
  
+/*
+ * Determine the UUID of the specified filesystem and print it. Optionally it is
+ * possible to store the UUID directly in env.
+ */
+int do_fs_uuid(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[],
+		int fstype);
+
 #endif /* _FS_H */
...	...	@@ -989,6 +989,7 @@
989	989	CONFIG_CMD_EXT4 * ext4 command support
990	990	CONFIG_CMD_FS_GENERIC * filesystem commands (e.g. load, ls)
991	991	that work for multiple fs types
	992	+ CONFIG_CMD_FS_UUID * Look up a filesystem UUID
992	993	CONFIG_CMD_SAVEENV saveenv
993	994	CONFIG_CMD_FDC * Floppy Disk Support
994	995	CONFIG_CMD_FAT * FAT command support
...	...	@@ -188,6 +188,7 @@
188	188	obj-$(CONFIG_USB_STORAGE) += usb_storage.o
189	189	endif
190	190	obj-$(CONFIG_CMD_FASTBOOT) += cmd_fastboot.o
	191	+obj-$(CONFIG_CMD_FS_UUID) += cmd_fs_uuid.o
191	192
192	193	obj-$(CONFIG_CMD_USB_MASS_STORAGE) += cmd_usb_mass_storage.o
193	194	obj-$(CONFIG_CMD_THOR_DOWNLOAD) += cmd_thordown.o
	1	+/*
	2	+ * cmd_fs_uuid.c -- fsuuid command
	3	+ *
	4	+ * Copyright (C) 2014, Bachmann electronic GmbH
	5	+ *
	6	+ * SPDX-License-Identifier: GPL-2.0+
	7	+ */
	8	+
	9	+#include <common.h>
	10	+#include <command.h>
	11	+#include <fs.h>
	12	+
	13	+static int do_fs_uuid_wrapper(cmd_tbl_t *cmdtp, int flag,
	14	+ int argc, char * const argv[])
	15	+{
	16	+ return do_fs_uuid(cmdtp, flag, argc, argv, FS_TYPE_ANY);
	17	+}
	18	+
	19	+U_BOOT_CMD(
	20	+ fsuuid, 4, 1, do_fs_uuid_wrapper,
	21	+ "Look up a filesystem UUID",
	22	+ "<interface> <dev>:<part>\n"
	23	+ " - print filesystem UUID\n"
	24	+ "fsuuid <interface> <dev>:<part> <varname>\n"
	25	+ " - set environment variable to filesystem UUID\n"
	26	+);
...	...	@@ -231,4 +231,19 @@
231	231
232	232	return len_read;
233	233	}
	234	+
	235	+int ext4fs_uuid(char *uuid_str)
	236	+{
	237	+ if (ext4fs_root == NULL)
	238	+ return -1;
	239	+
	240	+#ifdef CONFIG_LIB_UUID
	241	+ uuid_bin_to_str((unsigned char *)ext4fs_root->sblock.unique_id,
	242	+ uuid_str, UUID_STR_FORMAT_STD);
	243	+
	244	+ return 0;
	245	+#else
	246	+ return -ENOSYS;
	247	+#endif
	248	+}
...	...	@@ -15,6 +15,7 @@
15	15	*/
16	16
17	17	#include <config.h>
	18	+#include <errno.h>
18	19	#include <common.h>
19	20	#include <part.h>
20	21	#include <ext4fs.h>
...	...	@@ -67,6 +68,11 @@
67	68	{
68	69	}
69	70
	71	+static inline int fs_uuid_unsupported(char *uuid_str)
	72	+{
	73	+ return -1;
	74	+}
	75	+
70	76	struct fstype_info {
71	77	int fstype;
72	78	/*
...	...	@@ -86,6 +92,7 @@
86	92	int (read)(const char filename, void *buf, int offset, int len);
87	93	int (write)(const char filename, void *buf, int offset, int len);
88	94	void (*close)(void);
	95	+ int (uuid)(char uuid_str);
89	96	};
90	97
91	98	static struct fstype_info fstypes[] = {
...	...	@@ -100,6 +107,7 @@
100	107	.size = fat_size,
101	108	.read = fat_read_file,
102	109	.write = fs_write_unsupported,
	110	+ .uuid = fs_uuid_unsupported,
103	111	},
104	112	#endif
105	113	#ifdef CONFIG_FS_EXT4
...	...	@@ -113,6 +121,7 @@
113	121	.size = ext4fs_size,
114	122	.read = ext4_read_file,
115	123	.write = fs_write_unsupported,
	124	+ .uuid = ext4fs_uuid,
116	125	},
117	126	#endif
118	127	#ifdef CONFIG_SANDBOX
...	...	@@ -126,6 +135,7 @@
126	135	.size = sandbox_fs_size,
127	136	.read = fs_read_sandbox,
128	137	.write = fs_write_sandbox,
	138	+ .uuid = fs_uuid_unsupported,
129	139	},
130	140	#endif
131	141	{
...	...	@@ -138,6 +148,7 @@
138	148	.size = fs_size_unsupported,
139	149	.read = fs_read_unsupported,
140	150	.write = fs_write_unsupported,
	151	+ .uuid = fs_uuid_unsupported,
141	152	},
142	153	};
143	154
...	...	@@ -206,6 +217,13 @@
206	217	fs_type = FS_TYPE_ANY;
207	218	}
208	219
	220	+int fs_uuid(char *uuid_str)
	221	+{
	222	+ struct fstype_info *info = fs_get_info(fs_type);
	223	+
	224	+ return info->uuid(uuid_str);
	225	+}
	226	+
209	227	int fs_ls(const char *dirname)
210	228	{
211	229	int ret;
...	...	@@ -442,5 +460,30 @@
442	460	puts("\n");
443	461
444	462	return 0;
	463	+}
	464	+
	465	+int do_fs_uuid(cmd_tbl_t cmdtp, int flag, int argc, char const argv[],
	466	+ int fstype)
	467	+{
	468	+ int ret;
	469	+ char uuid[37];
	470	+ memset(uuid, 0, sizeof(uuid));
	471	+
	472	+ if (argc < 3 \|\| argc > 4)
	473	+ return CMD_RET_USAGE;
	474	+
	475	+ if (fs_set_blk_dev(argv[1], argv[2], fstype))
	476	+ return 1;
	477	+
	478	+ ret = fs_uuid(uuid);
	479	+ if (ret)
	480	+ return CMD_RET_FAILURE;
	481	+
	482	+ if (argc == 4)
	483	+ setenv(argv[3], uuid);
	484	+ else
	485	+ printf("%s\n", uuid);
	486	+
	487	+ return CMD_RET_SUCCESS;
445	488	}
...	...	@@ -145,5 +145,6 @@
145	145	disk_partition_t *fs_partition);
146	146	int ext4_read_file(const char filename, void buf, int offset, int len);
147	147	int ext4_read_superblock(char *buffer);
	148	+int ext4fs_uuid(char *uuid_str);
148	149	#endif
...	...	@@ -93,5 +93,12 @@
93	93	int do_save(cmd_tbl_t cmdtp, int flag, int argc, char const argv[],
94	94	int fstype);
95	95
	96	+/*
	97	+ * Determine the UUID of the specified filesystem and print it. Optionally it is
	98	+ * possible to store the UUID directly in env.
	99	+ */
	100	+int do_fs_uuid(cmd_tbl_t cmdtp, int flag, int argc, char const argv[],
	101	+ int fstype);
	102	+
96	103	#endif /* _FS_H */