[PATCH] use 1MB partition alignment with GPT and disks with !512b sector sizes

[Matt Domsch]

---
 include/parted/constraint.h |    3 +++
 include/parted/natmath.h    |    1 +
 libparted/cs/constraint.c   |   16 ++++++++++++++++
 libparted/cs/natmath.c      |    6 ++++++
 libparted/labels/gpt.c      |    7 ++++++-
 5 files changed, 32 insertions(+), 1 deletions(-)

diff --git a/include/parted/constraint.h b/include/parted/constraint.h
index 6496926..f2ffb0e 100644
--- a/include/parted/constraint.h
+++ b/include/parted/constraint.h
@@ -65,6 +65,9 @@ extern PedConstraint*
 ped_constraint_new_from_max (const PedGeometry* max);
 
 extern PedConstraint*
+ped_constraint_new_from_max_1MB_aligned (const PedGeometry* max);
+
+extern PedConstraint*
 ped_constraint_duplicate (const PedConstraint* constraint);
 
 extern void
diff --git a/include/parted/natmath.h b/include/parted/natmath.h
index 596d98a..0bbd507 100644
--- a/include/parted/natmath.h
+++ b/include/parted/natmath.h
@@ -86,6 +86,7 @@ ped_alignment_is_aligned (const PedAlignment* align, const PedGeometry* geom,
 
 extern const PedAlignment* ped_alignment_any;
 extern const PedAlignment* ped_alignment_none;
+extern const PedAlignment* ped_alignment_1MB;
 
 static inline PedSector
 ped_div_round_up (PedSector numerator, PedSector divisor)
diff --git a/libparted/cs/constraint.c b/libparted/cs/constraint.c
index e094e5b..fd18fef 100644
--- a/libparted/cs/constraint.c
+++ b/libparted/cs/constraint.c
@@ -173,6 +173,22 @@ ped_constraint_new_from_max (const PedGeometry* max)
 }
 
 /**
+ * Return a constraint that requires a region to be entirely contained inside
+ * \p max, starting on a 1MB boundary and ending wherever.
+ *
+ * \return \c NULL on failure.
+ */
+PedConstraint*
+ped_constraint_new_from_max_1MB_aligned (const PedGeometry* max)
+{
+	PED_ASSERT (max != NULL, return NULL);
+
+	return ped_constraint_new (
+		        ped_alignment_1MB, ped_alignment_any,
+			max, max, 1, max->length);
+}
+
+/**
  * Duplicate a constraint.
  *
  * \return \c NULL on failure.
diff --git a/libparted/cs/natmath.c b/libparted/cs/natmath.c
index 7511fbd..aff0e67 100644
--- a/libparted/cs/natmath.c
+++ b/libparted/cs/natmath.c
@@ -48,8 +48,14 @@ static const PedAlignment _any = {
 	grain_size:	1
 };
 
+static const PedAlignment _1MB = {
+	offset:		0,
+	grain_size:	2048,
+};
+
 const PedAlignment* ped_alignment_any = &_any;
 const PedAlignment* ped_alignment_none = NULL;
+const PedAlignment* ped_alignment_1MB = &_1MB;
 
 /* This function returns "a mod b", the way C should have done it!
  * Mathematicians prefer -3 mod 4 to be 3.  Reason: division by N
diff --git a/libparted/labels/gpt.c b/libparted/labels/gpt.c
index abfb242..9d3df10 100644
--- a/libparted/labels/gpt.c
+++ b/libparted/labels/gpt.c
@@ -1485,7 +1485,12 @@ _non_metadata_constraint (const PedDisk* disk)
 {
 	GPTDiskData* gpt_disk_data = disk->disk_specific;
 
-	return ped_constraint_new_from_max (&gpt_disk_data->data_area);
+	/* Vista now does this for all disks, not just those with >512b sectors */
+	if (disk->dev->sector_size > PED_SECTOR_SIZE_DEFAULT)
+		return ped_constraint_new_from_max_1MB_aligned (&gpt_disk_data->data_area);
+	else
+		return ped_constraint_new_from_max (&gpt_disk_data->data_area);
+
 }
 
 static int
-- 
1.6.0.5


-- 
Matt Domsch
Linux Technology Strategist, Dell Office of the CTO
linux.dell.com & www.dell.com/linux