[Libguestfs] [PATCH 08/10] resize: caculate surplus for resize extended partition

[Chen Hanxiao]

Signed-off-by: Chen Hanxiao <chenhanxiao at cn.fujitsu.com>
---
 resize/resize.ml | 34 +++++++++++++++++++++++++++++++++-
 1 file changed, 33 insertions(+), 1 deletion(-)

diff --git a/resize/resize.ml b/resize/resize.ml
index d5c457c..67321c2 100644
--- a/resize/resize.ml
+++ b/resize/resize.ml
@@ -727,6 +727,7 @@ read the man page virt-resize(1).
     (* We need some overhead for partitioning. *)
     let overhead =
       let maxl64 = List.fold_left max 0L in
+      let alignment = if alignment = 1L then 2L else alignment in
 
       let nr_partitions = List.length partitions in
 
@@ -753,6 +754,31 @@ read the man page virt-resize(1).
         start_overhead_sects +^ alignment_sects +^ gpt_end_sects in
       sectsize *^ overhead_sects in
 
+    let required_logical = List.fold_left (
+      fun total p ->
+        if p.p_mbr_p_type <> LogicalPartition then 0L else
+          let newsize =
+            match p.p_operation with
+            | OpCopy | OpIgnore -> roundup64 p.p_part.G.part_size (alignment *^ sectsize)
+            | OpDelete -> 0L
+            | OpResize newsize -> roundup64 newsize (alignment *^ sectsize) in
+          total +^ newsize
+    ) 0L partitions in
+
+    let required_logical = required_logical +^ alignment *^ sectsize in
+    let required_extended = List.fold_left (
+      fun total p ->
+        let newsize =
+        match p.p_type with
+        | ContentExtendedPartition ->
+          (* resizing extended partition by --resize or --expand is supported *)
+          (match p.p_operation with
+           | OpResize newsize -> newsize
+           | _ -> p.p_part.G.part_size)
+        | _ -> 0L in
+        total +^ newsize
+    ) 0L partitions in
+
     let required = List.fold_left (
       fun total p ->
         let newsize =
@@ -765,13 +791,19 @@ read the man page virt-resize(1).
         total +^ newsize
     ) 0L partitions in
 
+    let required = required +^
+      if required_extended > required_logical then
+        required_extended else required_logical in
+
     let surplus = outsize -^ (required +^ overhead) in
 
     if verbose then
       printf "calculate surplus: outsize=%Ld required=%Ld overhead=%Ld surplus=%Ld\n%!"
         outsize required overhead surplus;
 
-    surplus
+    (* XXX: fix of expanding a logical partition. without the sectsize,
+     * we'll get a deficit of 512 bytes. *)
+    surplus +^ sectsize
   in
 
   (* Handle --expand and --shrink options. *)
-- 
2.1.0