fdisk: add mbr_get_partition()

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

6 files changed, 18 insertions, 18 deletions

diff --git a/fdisks/fdiskdoslabel.c b/fdisks/fdiskdoslabel.c
index 637afd888..278197002 100644
--- a/fdisks/fdiskdoslabel.c
+++ b/fdisks/fdiskdoslabel.c
@@ -159,7 +159,7 @@ void dos_init(struct fdisk_context *cxt)
 	for (i = 0; i < 4; i++) {
 		struct pte *pe = &ptes[i];
 
-		pe->pt_entry = pt_offset(cxt->firstsector, i);
+		pe->pt_entry = mbr_get_partition(cxt->firstsector, i);
 		pe->ex_entry = NULL;
 		pe->offset = 0;
 		pe->sectorbuffer = cxt->firstsector;
@@ -286,7 +286,7 @@ static void read_extended(struct fdisk_context *cxt, int ext)
 		if (!extended_offset)
 			extended_offset = dos_partition_get_start(p);
 
-		q = p = pt_offset(pe->sectorbuffer, 0);
+		q = p = mbr_get_partition(pe->sectorbuffer, 0);
 		for (i = 0; i < 4; i++, p++) if (dos_partition_get_size(p)) {
 			if (IS_EXTENDED (p->sys_ind)) {
 				if (pe->ex_entry)
@@ -408,7 +408,7 @@ static void get_partition_table_geometry(struct fdisk_context *cxt,
 
 	hh = ss = 0;
 	for (i=0; i<4; i++) {
-		p = pt_offset(bufp, i);
+		p = mbr_get_partition(bufp, i);
 		if (p->sys_ind != 0) {
 			h = p->eh + 1;
 			s = (p->es & 077);
@@ -772,7 +772,7 @@ static int add_partition(struct fdisk_context *cxt, int n, struct fdisk_parttype
 		pen->ex_entry = p;
 		pe4->offset = extended_offset = start;
 		pe4->sectorbuffer = xcalloc(1, cxt->sector_size);
-		pe4->pt_entry = pt_offset(pe4->sectorbuffer, 0);
+		pe4->pt_entry = mbr_get_partition(pe4->sectorbuffer, 0);
 		pe4->ex_entry = pe4->pt_entry + 1;
 		pe4->changed = 1;
 		cxt->label->nparts_max = 5;
@@ -791,7 +791,7 @@ static int add_logical(struct fdisk_context *cxt)
 		struct pte *pe = &ptes[cxt->label->nparts_max];
 
 		pe->sectorbuffer = xcalloc(1, cxt->sector_size);
-		pe->pt_entry = pt_offset(pe->sectorbuffer, 0);
+		pe->pt_entry = mbr_get_partition(pe->sectorbuffer, 0);
 		pe->ex_entry = pe->pt_entry + 1;
 		pe->offset = 0;
 		pe->changed = 1;
diff --git a/fdisks/fdiskdoslabel.h b/fdisks/fdiskdoslabel.h
index efac02ecc..bf58b8065 100644
--- a/fdisks/fdiskdoslabel.h
+++ b/fdisks/fdiskdoslabel.h
@@ -22,9 +22,6 @@ struct pte {
 
 extern struct pte ptes[MAXIMUM_PARTS];
 
-#define pt_offset(b, n)	((struct dos_partition *)((b) + 0x1be + \
-					      (n) * sizeof(struct dos_partition)))
-
 extern sector_t extended_offset;
 
 extern struct dos_partition *dos_get_pt_entry(int);
diff --git a/include/pt-mbr.h b/include/pt-mbr.h
index 5e5e60376..1279e3cf2 100644
--- a/include/pt-mbr.h
+++ b/include/pt-mbr.h
@@ -12,6 +12,12 @@ struct dos_partition {
 
 #define MBR_PT_OFFSET		0x1be
 
+static inline struct dos_partition *mbr_get_partition(unsigned char *mbr, int i)
+{
+	return (struct dos_partition *)
+		(mbr + MBR_PT_OFFSET + (i * sizeof(struct dos_partition)));
+}
+
 /* assemble badly aligned little endian integer */
 static inline unsigned int __dos_assemble_4le(const unsigned char *p)
 {
diff --git a/libblkid/src/partitions/dos.c b/libblkid/src/partitions/dos.c
index c92d8ec0f..14f326d20 100644
--- a/libblkid/src/partitions/dos.c
+++ b/libblkid/src/partitions/dos.c
@@ -60,7 +60,7 @@ static int parse_dos_extended(blkid_probe pr, blkid_parttable tab,
 		if (!mbr_is_valid_magic(data))
 			goto leave;
 
-		p0 = (struct dos_partition *) (data + MBR_PT_OFFSET);
+		p0 = mbr_get_partition(data, 0);
 
 		/* Usually, the first entry is the real data partition,
 		 * the 2nd entry is the next extended partition, or empty,
@@ -159,7 +159,7 @@ static int probe_dos_pt(blkid_probe pr,
 		goto nothing;
 	}
 
-	p0 = (struct dos_partition *) (data + MBR_PT_OFFSET);
+	p0 = mbr_get_partition(data, 0);
 
 	/*
 	 * Reject PT where boot indicator is not 0 or 0x80.
@@ -180,8 +180,7 @@ static int probe_dos_pt(blkid_probe pr,
 		}
 	}
 
-	blkid_probe_use_wiper(pr, MBR_PT_OFFSET,
-				  512 - MBR_PT_OFFSET);
+	blkid_probe_use_wiper(pr, MBR_PT_OFFSET, 512 - MBR_PT_OFFSET);
 
 	id = mbr_get_id(data);
 	if (id)
diff --git a/libblkid/src/partitions/gpt.c b/libblkid/src/partitions/gpt.c
index eea9ba437..9894417e7 100644
--- a/libblkid/src/partitions/gpt.c
+++ b/libblkid/src/partitions/gpt.c
@@ -172,9 +172,7 @@ static int is_pmbr_valid(blkid_probe pr)
 	if (!mbr_is_valid_magic(data))
 		goto failed;
 
-	p = (struct dos_partition *) (data + MBR_PT_OFFSET);
-
-	for (i = 0; i < 4; i++, p++) {
+	for (i = 0, p = mbr_get_partition(data, 0); i < 4; i++, p++) {
 		if (p->sys_ind == MBR_GPT_PARTITION)
 			goto ok;
 	}
diff --git a/libblkid/src/partitions/minix.c b/libblkid/src/partitions/minix.c
index 2aad80f64..0a597fbc4 100644
--- a/libblkid/src/partitions/minix.c
+++ b/libblkid/src/partitions/minix.c
@@ -46,13 +46,13 @@ static int probe_minix_pt(blkid_probe pr,
 		/* caller does not ask for details about partitions */
 		return 0;
 
-	p = (struct dos_partition *) (data + MBR_PT_OFFSET);
-
 	tab = blkid_partlist_new_parttable(ls, "minix", MBR_PT_OFFSET);
 	if (!tab)
 		goto err;
 
-	for (i = 0; i < MINIX_MAXPARTITIONS; i++, p++) {
+	for (i = 0, p = mbr_get_partition(data, 0);
+			i < MINIX_MAXPARTITIONS; i++, p++) {
+
 		uint32_t start, size;
 		blkid_partition par;