fs: make it possible to read the filesystem UUID

PATCH New Christian Gmeiner 3 participants 4 messages Nov 12, 2014 – Nov 24, 2014

Subsystems (2)

VFS ext4 file system

lore

Share & tools

lore

Christian Gmeiner

author

2014-11-12 13:35 UTC #0 lore raw

PATCH v3 1/1 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 <[email protected]>

Acked-by Stephen Warren <[email protected]>

---
 README               |  1 +
 common/Makefile      |  1 +
 common/cmd_fs_uuid.c | 26 ++++++++++++++++++++++++++
 fs/ext4/ext4fs.c     | 15 +++++++++++++++
 fs/fs.c              | 43 +++++++++++++++++++++++++++++++++++++++++++
 include/ext4fs.h     |  1 +
 include/fs.h         |  7 +++++++
 7 files changed, 94 insertions(+)
 create mode 100644 common/cmd_fs_uuid.c

README +1 -0

index c3a9dfc..b48de5f 100644
@@ -989,6 +989,7 @@ The following options need to be configured:
 		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

common/Makefile +1 -0

index 6cc4de8..508a0b2 100644
@@ -188,6 +188,7 @@ obj-y += usb.o usb_hub.o
 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

common/cmd_fs_uuid.c new file +26 -0

new file mode 100644
index 0000000..613f3a4
@@ -0,0 +1,26 @@
+/*
+ * 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"
+);

fs/ext4/ext4fs.c +15 -0

index cbdc220..87d5128 100644
@@ -231,3 +231,18 @@ int ext4_read_file(const char *filename, void *buf, int offset, int len)
 
 	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
+}

fs/fs.c +43 -0

94 lines not on this page · raw message

include/ext4fs.h +1 -0

index 6c419f3..38970e4 100644
@@ -145,4 +145,5 @@ int ext4fs_probe(block_dev_desc_t *fs_dev_desc,
 		 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

include/fs.h +7 -0

index 06a45f2..491c60a 100644
@@ -93,4 +93,11 @@ int file_exists(const char *dev_type, const char *dev_part, const char *file,
 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 */

Signature · 1 line

1.9.3

Christian Gmeiner

author

2014-11-12 13:35 UTC #1 lore raw

PATCH v2 1/1 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

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

Signed-off-by Christian Gmeiner <[email protected]>

---
 README               |  1 +
 common/Makefile      |  1 +
 common/cmd_fs_uuid.c | 26 ++++++++++++++++++++++++++
 fs/ext4/ext4fs.c     | 15 +++++++++++++++
 fs/fs.c              | 43 +++++++++++++++++++++++++++++++++++++++++++
 include/ext4fs.h     |  1 +
 include/fs.h         |  7 +++++++
 7 files changed, 94 insertions(+)
 create mode 100644 common/cmd_fs_uuid.c

README +1 -0

index 7b5538e..53b84a6 100644
@@ -989,6 +989,7 @@ The following options need to be configured:
 		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

common/Makefile +1 -0

index 6cc4de8..508a0b2 100644
@@ -188,6 +188,7 @@ obj-y += usb.o usb_hub.o
 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

common/cmd_fs_uuid.c new file +26 -0

new file mode 100644
index 0000000..613f3a4
@@ -0,0 +1,26 @@
+/*
+ * 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"
+);

fs/ext4/ext4fs.c +15 -0

index cbdc220..19757d2 100644
@@ -231,3 +231,18 @@ int ext4_read_file(const char *filename, void *buf, int offset, int len)
 
 	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;
+#endif
+
+	return -ENOSYS;
+}

fs/fs.c +43 -0

94 lines not on this page · raw message

include/ext4fs.h +1 -0

index 6c419f3..38970e4 100644
@@ -145,4 +145,5 @@ int ext4fs_probe(block_dev_desc_t *fs_dev_desc,
 		 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

include/fs.h +7 -0

index 06a45f2..491c60a 100644
@@ -93,4 +93,11 @@ int file_exists(const char *dev_type, const char *dev_part, const char *file,
 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 */

Signature · 1 line

1.9.3

Simon Glass

2014-11-13 02:37 UTC #2 lore raw

PATCH v2 1/1 fs: make it possible to read the filesystem UUID

Quoted 39 lines · Christian Gmeiner

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
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
=>

Quoted 1 line

Signed-off-by Christian Gmeiner <[email protected]>

Acked-by Simon Glass <[email protected]>

Tested on Pi with eMMC:

Tested-by Simon Glass <[email protected]>

Tom Rini

2014-11-24 22:11 UTC #3 lore raw

PATCH v3 1/1 fs: make it possible to read the filesystem UUID

In reply to Christian Gmeiner

Quoted 43 lines · Christian Gmeiner

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
=>

Quoted 2 lines

Signed-off-by Christian Gmeiner <[email protected]>
Acked-by Stephen Warren <[email protected]>

Applied to u-boot/master, thanks!

Signature · 8 lines

Tom
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 836 bytes
Desc: Digital signature
URL: <http://lists.denx.de/pipermail/u-boot/attachments/20141124/576ae251/attachment.pgp>