From 6f163929379ab2eca661e425ddaf5d8238c89379 Mon Sep 17 00:00:00 2001
From: Karel Zak <kzak@redhat.com>
Date: Tue, 21 Apr 2015 14:32:31 +0200
Subject: [PATCH] libfdisk: fix script parser to support resize operations

Signed-off-by: Karel Zak <kzak@redhat.com>
---
 libfdisk/src/fdiskP.h | 15 +++++++++++++++
 libfdisk/src/script.c | 30 ++++++++++++++++++++++++++----
 2 files changed, 41 insertions(+), 4 deletions(-)

diff --git a/libfdisk/src/fdiskP.h b/libfdisk/src/fdiskP.h
index 0ca498d54f..5e8ed9c355 100644
--- a/libfdisk/src/fdiskP.h
+++ b/libfdisk/src/fdiskP.h
@@ -121,6 +121,9 @@ struct fdisk_partition {
 	fdisk_sector_t	start;			/* first sectors */
 	fdisk_sector_t	size;			/* size in sectors */
 
+	int		movestart;		/* FDISK_MOVE_* (scripts only) */
+	int		resize;			/* FDISK_RESIZE_* (scripts only) */
+
 	char		*name;			/* partition name */
 	char		*uuid;			/* partition UUID */
 	char		*attrs;			/* partition flags/attributes converted to string */
@@ -152,6 +155,18 @@ struct fdisk_partition {
 			wholedisk : 1;			/* special system partition */
 };
 
+enum {
+	FDISK_MOVE_NONE = 0,
+	FDISK_MOVE_DOWN = -1,
+	FDISK_MOVE_UP = 1
+};
+
+enum {
+	FDISK_RESIZE_NONE = 0,
+	FDISK_RESIZE_REDUCE = -1,
+	FDISK_RESIZE_ENLARGE = 1
+};
+
 #define FDISK_INIT_UNDEF(_x)	((_x) = (__typeof__(_x)) -1)
 #define FDISK_IS_UNDEF(_x)	((_x) == (__typeof__(_x)) -1)
 
diff --git a/libfdisk/src/script.c b/libfdisk/src/script.c
index a7e0d21d8b..469c1d4c1a 100644
--- a/libfdisk/src/script.c
+++ b/libfdisk/src/script.c
@@ -815,6 +815,9 @@ static struct fdisk_parttype *translate_type_shortcuts(struct fdisk_script *dp,
 	return type ? fdisk_label_parse_parttype(lb, type) : NULL;
 }
 
+#define TK_PLUS		1
+#define TK_MINUS	-1
+
 /* simple format:
  * <start>, <size>, <type>, <bootable>, ...
  */
@@ -840,6 +843,7 @@ static int parse_commas_line(struct fdisk_script *dp, char *s)
 	while (rc == 0 && p && *p) {
 		uint64_t num;
 		char *begin;
+		int sign = 0;
 
 		p = (char *) skip_blank(p);
 		item++;
@@ -847,25 +851,38 @@ static int parse_commas_line(struct fdisk_script *dp, char *s)
 		DBG(SCRIPT, ul_debugobj(dp, " parsing item %d ('%s')", item, p));
 		begin = p;
 
+		if (item != ITEM_BOOTABLE) {
+			sign = *p == '-' ? TK_MINUS : *p == '+' ? TK_PLUS : 0;
+			if (sign)
+				p++;
+		}
+
 		switch (item) {
 		case ITEM_START:
-			if (*p == ',' || *p == ';')
+			if (*p == ',' || *p == ';' || (sign && *p == '\0'))
 				fdisk_partition_start_follow_default(pa, 1);
 			else {
 				int pow = 0;
+
 				rc = next_number(&p, &num, &pow);
 				if (!rc) {
 					if (pow)	/* specified as <num><suffix> */
 						num /= dp->cxt->sector_size;
 					fdisk_partition_set_start(pa, num);
+					pa->movestart = sign == TK_MINUS ? FDISK_MOVE_DOWN :
+							sign == TK_PLUS  ? FDISK_MOVE_UP :
+							FDISK_MOVE_NONE;
 				}
 				fdisk_partition_start_follow_default(pa, 0);
 			}
 			break;
 		case ITEM_SIZE:
-			if (*p == ',' || *p == ';' || *p == '+')
+			if (*p == ',' || *p == ';' || (sign && *p == '\0')) {
 				fdisk_partition_end_follow_default(pa, 1);
-			else {
+				if (sign == TK_PLUS)
+					/* alone '+' means use all possible space, elone '-' means nothing */
+					pa->resize = FDISK_RESIZE_ENLARGE;
+			} else {
 				int pow = 0;
 				rc = next_number(&p, &num, &pow);
 				if (!rc) {
@@ -874,12 +891,15 @@ static int parse_commas_line(struct fdisk_script *dp, char *s)
 					else	 /* specified as number of sectors */
 						fdisk_partition_size_explicit(pa, 1);
 					fdisk_partition_set_size(pa, num);
+					pa->resize = sign == TK_MINUS ? FDISK_RESIZE_REDUCE :
+						     sign == TK_PLUS  ? FDISK_RESIZE_ENLARGE :
+							FDISK_RESIZE_NONE;
 				}
 				fdisk_partition_end_follow_default(pa, 0);
 			}
 			break;
 		case ITEM_TYPE:
-			if (*p == ',' || *p == ';')
+			if (*p == ',' || *p == ';' || (sign && *p == '\0'))
 				break;	/* use default type */
 
 			rc = next_string(&p, &str);
@@ -908,6 +928,8 @@ static int parse_commas_line(struct fdisk_script *dp, char *s)
 					pa->boot = 1;
 				else if (tk && *tk == '-' && *(tk + 1) == '\0')
 					pa->boot = 0;
+				else if (tk && *tk == '+' && *(tk + 1) == '\0')
+					pa->boot = 1;
 				else
 					rc = -EINVAL;
 			}
-- 
2.47.2