[Ocfs2-tools-devel] [PATCH 1/1] ocfs2-tools: Add setting custom UUID in tunefs.ocfs2

[Tiger Yang]

This patch enhance uuid-reset operation to set custom UUID.
The format of the UUID could be 32 bytes or 36 bytes.
For example: 178BDC83D50241EF94EB474A677d498B or
178BDC83-D502-41EF-94EB-474A677D498B.

Signed-off-by: Tiger Yang <tiger.yang at oracle.com>
---
 tunefs.ocfs2/ocfs2ne.c         |    8 +++--
 tunefs.ocfs2/op_reset_uuid.c   |   74 +++++++++++++++++++++++++++++++++++++--
 tunefs.ocfs2/tunefs.ocfs2.8.in |    4 +-
 3 files changed, 77 insertions(+), 9 deletions(-)

diff --git a/tunefs.ocfs2/ocfs2ne.c b/tunefs.ocfs2/ocfs2ne.c
index 48760c6..51e07a8 100644
--- a/tunefs.ocfs2/ocfs2ne.c
+++ b/tunefs.ocfs2/ocfs2ne.c
@@ -490,10 +490,12 @@ static struct tunefs_option list_sparse_option = {
 
 static struct tunefs_option reset_uuid_option = {
 	.opt_option	= {
-		.name	= "uuid-reset",
-		.val	= 'U',
+		.name		= "uuid-reset",
+		.val		= 'U',
+		.has_arg	= 2,
 	},
-	.opt_help	= "-U|--uuid-reset",
+	.opt_help	= "-U[new-uuid]|--uuid-reset[=new-uuid]",
+	.opt_handle	= &generic_handle_arg,
 	.opt_op		= &reset_uuid_op,
 };
 
diff --git a/tunefs.ocfs2/op_reset_uuid.c b/tunefs.ocfs2/op_reset_uuid.c
index 25a21fb..ae15f1d 100644
--- a/tunefs.ocfs2/op_reset_uuid.c
+++ b/tunefs.ocfs2/op_reset_uuid.c
@@ -27,8 +27,26 @@
 
 #include "libocfs2ne.h"
 
+/*
+ *	Translate 32 bytes uuid to 36 bytes uuid format.
+ *	for example:
+ *	32 bytes uuid: 178BDC83D50241EF94EB474A677D498B
+ *	36 bytes uuid: 178BDC83-D502-41EF-94EB-474A677D498B
+ */
+static void uuid_translate(char *uuid_32, char *uuid_36)
+{
+	int i;
+	char *cp = uuid_32;
+	for (i = 0; i < 36; i++) {
+		if ((i == 8) || (i == 13) || (i == 18) || (i == 23)) {
+			uuid_36[i] = '-';
+			continue;
+		}
+		uuid_36[i] = *cp++;
+	}
+}
 
-static errcode_t update_volume_uuid(ocfs2_filesys *fs)
+static errcode_t update_volume_uuid(ocfs2_filesys *fs, char *uuid)
 {
 	errcode_t err;
 	unsigned char new_uuid[OCFS2_VOL_UUID_LEN];
@@ -42,7 +60,19 @@ static errcode_t update_volume_uuid(ocfs2_filesys *fs)
 	if (!prog)
 		return TUNEFS_ET_NO_MEMORY;
 
-	uuid_generate(new_uuid);
+	if (uuid == NULL)
+		uuid_generate(new_uuid);
+	else {
+		if (strlen(uuid) == 32) {
+			char uuid_36[37] = {'\0'};
+
+			/*translate 32 bytes uuid to 36 bytes uuid*/
+			uuid_translate(uuid, uuid_36);
+			/*uuid_parse only support 36 bytes uuid*/
+			uuid_parse(uuid_36, new_uuid);
+		} else
+			uuid_parse(uuid, new_uuid);
+	}
 	memcpy(OCFS2_RAW_SB(fs->fs_super)->s_uuid, new_uuid,
 	       OCFS2_VOL_UUID_LEN);
 
@@ -55,13 +85,49 @@ static errcode_t update_volume_uuid(ocfs2_filesys *fs)
 	return err;
 }
 
+static int reset_uuid_parse_option(struct tunefs_operation *op, char *arg)
+{
+	int i;
+	char *cp = arg;
+	int len;
+
+	if (arg == NULL)
+		goto out;
+
+	len = strlen(arg);
+	/*check the uuid length, we support 32/36 bytes uuid format*/
+	if (len != 32 && len != 36)
+		goto bail;
+
+	/*check wheter each character of uuid is a hexadecimal digit*/
+	for (i = 0; i < len; i++, cp++) {
+		if (len == 36) {
+			if ((i == 8) || (i == 13) || (i == 18) || (i == 23)) {
+				if (*cp == '-')
+					continue;
+				else
+					goto bail;
+			}
+		}
+		if (!isxdigit(*cp))
+			goto bail;
+	}
+out:
+	op->to_private = arg;
+	return 0;
+bail:
+	errorf("Invalid UUID\n");
+	return 1;
+}
+
 static int reset_uuid_run(struct tunefs_operation *op, ocfs2_filesys *fs,
 			  int flags)
 {
 	int rc = 0;
 	errcode_t err;
+	char *uuid = op->to_private;
 
-	err = update_volume_uuid(fs);
+	err = update_volume_uuid(fs, uuid);
 	if (err) {
 		tcom_err(err, "- unable to reset the uuid on device \"%s\"",
 			 fs->fs_devname);
@@ -75,7 +141,7 @@ static int reset_uuid_run(struct tunefs_operation *op, ocfs2_filesys *fs,
 DEFINE_TUNEFS_OP(reset_uuid,
 		 "Usage: op_reset_uuid [opts] <device>\n",
 		 TUNEFS_FLAG_RW,
-		 NULL,
+		 reset_uuid_parse_option,
 		 reset_uuid_run);
 
 #ifdef DEBUG_EXE
diff --git a/tunefs.ocfs2/tunefs.ocfs2.8.in b/tunefs.ocfs2/tunefs.ocfs2.8.in
index 3bebd41..5f7c237 100644
--- a/tunefs.ocfs2/tunefs.ocfs2.8.in
+++ b/tunefs.ocfs2/tunefs.ocfs2.8.in
@@ -78,8 +78,8 @@ printf(3) type formatters. The list of type specifiers is as follows:
 Quiet mode.
 
 .TP
-\fB\-U, \-\-uuid\-reset\fR
-Change the volume UUID (auto-generated) for the file system.
+\fB\-U, \-\-uuid\-reset\fR[=\fInew-uuid]\fR
+Set the volume UUID for the file system. If not provided, will auto generate a new UUID. The format of the provided UUID should be 178BDC83D50241EF94EB474A677D498B or 178BDC83-D502-41EF-94EB-474A677D498B.
 
 .TP
 \fB\-v, \-\-verbose\fR
-- 
1.5.2.3