fdisk: align end of partition when defined by +size{K,M,G}

It's better to have disks without gaps between partitions, so it's
better to align ends of partitions.

Note, we don't care about end of partitions when the last sector has
been explicitly requested by user.

Signed-off-by: Karel Zak <kzak@redhat.com>

1 files changed, 35 insertions, 13 deletions

diff --git a/fdisk/fdisk.c b/fdisk/fdisk.c
index 424ad0d40..32032a3ce 100644
--- a/fdisk/fdisk.c
+++ b/fdisk/fdisk.c
@@ -1033,7 +1033,6 @@ get_partition_table_geometry(void) {
 	}
 }
 
-
 /*
  * Sets LBA of the first partition
  */
@@ -1321,16 +1320,9 @@ read_hex(struct systypes *sys)
         }
 }
 
-/*
- * Print the message MESG, then read an integer in LOW..HIGH.
- * If the user hits Enter, DFLT is returned, provided that is in LOW..HIGH.
- * Answers like +10 are interpreted as offsets from BASE.
- *
- * There is no default if DFLT is not between LOW and HIGH.
- */
-unsigned int
-read_int(unsigned int low, unsigned int dflt, unsigned int high,
-	 unsigned int base, char *mesg)
+static unsigned int
+read_int_sx(unsigned int low, unsigned int dflt, unsigned int high,
+	 unsigned int base, char *mesg, int *suffix)
 {
 	unsigned int i;
 	int default_ok = 1;
@@ -1429,6 +1421,8 @@ read_int(unsigned int low, unsigned int dflt, unsigned int high,
 				bytes += unit/2;	/* round */
 				bytes /= unit;
 				i = bytes;
+				if (suffix)
+					*suffix = absolute;
 			}
 			if (minus)
 				i = -i;
@@ -1450,6 +1444,21 @@ read_int(unsigned int low, unsigned int dflt, unsigned int high,
 	return i;
 }
 
+/*
+ * Print the message MESG, then read an integer in LOW..HIGH.
+ * If the user hits Enter, DFLT is returned, provided that is in LOW..HIGH.
+ * Answers like +10 are interpreted as offsets from BASE.
+ *
+ * There is no default if DFLT is not between LOW and HIGH.
+ */
+unsigned int
+read_int(unsigned int low, unsigned int dflt, unsigned int high,
+	 unsigned int base, char *mesg)
+{
+	return read_int_sx(low, dflt, high, base, mesg, NULL);
+}
+
+
 int
 get_partition(int warn, int max) {
 	struct pte *pe;
@@ -2298,17 +2307,30 @@ add_partition(int n, int sys) {
 	if (cround(start) == cround(limit)) {
 		stop = limit;
 	} else {
+		int sx = 0;
+
 		snprintf(mesg, sizeof(mesg),
 			_("Last %1$s, +%2$s or +size{K,M,G}"),
 			 str_units(SINGULAR), str_units(PLURAL));
 
-		stop = read_int(cround(start), cround(limit), cround(limit),
-				cround(start), mesg);
+		stop = read_int_sx(cround(start), cround(limit), cround(limit),
+				cround(start), mesg, &sx);
 		if (display_in_cyl_units) {
 			stop = stop * units_per_sector - 1;
 			if (stop >limit)
 				stop = limit;
 		}
+
+		if (sx && alignment_required) {
+			/* the last sector has not been exactly requested (but
+			 * defined by +size{K,M,G} convention), so be smart
+			 * and align the end of the partition. The next
+			 * partition will start at phy.block boundary.
+			 */
+			stop = align_lba_in_range(stop, start, limit) - 1;
+			if (stop > limit)
+				stop = limit;
+		}
 	}
 
 	set_partition(n, 0, start, stop, sys);