[Qemu-devel] [PATCH 2/3] vmdk: Clean up backing file handling

[Kevin Wolf <kwolf@redhat.com>]

VMDK is doing interesting things when it needs to open a backing file. This
patch changes that part to look more like in other drivers. The nice side
effect is that the file name isn't needed any more in the open function.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 block/vmdk.c |   50 +++++++++-----------------------------------------
 1 files changed, 9 insertions(+), 41 deletions(-)

diff --git a/block/vmdk.c b/block/vmdk.c
index ae34121..781518a 100644
--- a/block/vmdk.c
+++ b/block/vmdk.c
@@ -76,7 +76,6 @@ typedef struct BDRVVmdkState {
 
     unsigned int cluster_sectors;
     uint32_t parent_cid;
-    int is_parent;
 } BDRVVmdkState;
 
 typedef struct VmdkMetaData {
@@ -344,13 +343,11 @@ static void vmdk_parent_close(BlockDriverState *bs)
         bdrv_close(bs->backing_hd);
 }
 
-static int parent_open = 0;
-static int vmdk_parent_open(BlockDriverState *bs, const char * filename)
+static int vmdk_parent_open(BlockDriverState *bs)
 {
     BDRVVmdkState *s = bs->opaque;
     char *p_name;
     char desc[DESC_SIZE];
-    char parent_img_name[1024];
 
     /* the descriptor offset = 0x200 */
     if (bdrv_pread(s->hd, 0x200, desc, DESC_SIZE) != DESC_SIZE)
@@ -358,7 +355,6 @@ static int vmdk_parent_open(BlockDriverState *bs, const char * filename)
 
     if ((p_name = strstr(desc,"parentFileNameHint")) != NULL) {
         char *end_name;
-        struct stat file_buf;
 
         p_name += sizeof("parentFileNameHint") + 1;
         if ((end_name = strchr(p_name,'\"')) == NULL)
@@ -367,24 +363,6 @@ static int vmdk_parent_open(BlockDriverState *bs, const char * filename)
             return -1;
 
         pstrcpy(bs->backing_file, end_name - p_name + 1, p_name);
-        if (stat(bs->backing_file, &file_buf) != 0) {
-            path_combine(parent_img_name, sizeof(parent_img_name),
-                         filename, bs->backing_file);
-        } else {
-            pstrcpy(parent_img_name, sizeof(parent_img_name),
-                    bs->backing_file);
-        }
-
-        bs->backing_hd = bdrv_new("");
-        if (!bs->backing_hd) {
-            failure:
-            bdrv_close(s->hd);
-            return -1;
-        }
-        parent_open = 1;
-        if (bdrv_open(bs->backing_hd, parent_img_name, 0, NULL) < 0)
-            goto failure;
-        parent_open = 0;
     }
 
     return 0;
@@ -396,11 +374,6 @@ static int vmdk_open(BlockDriverState *bs, const char *filename, int flags)
     uint32_t magic;
     int l1_size, i, ret;
 
-    if (parent_open) {
-        /* Parent must be opened as RO, no RDWR. */
-        flags = 0;
-    }
-
     ret = bdrv_file_open(&s->hd, filename, flags);
     if (ret < 0)
         return ret;
@@ -436,13 +409,8 @@ static int vmdk_open(BlockDriverState *bs, const char *filename, int flags)
         s->l1_table_offset = le64_to_cpu(header.rgd_offset) << 9;
         s->l1_backup_table_offset = le64_to_cpu(header.gd_offset) << 9;
 
-        if (parent_open)
-            s->is_parent = 1;
-        else
-            s->is_parent = 0;
-
         // try to open parent images, if exist
-        if (vmdk_parent_open(bs, filename) != 0)
+        if (vmdk_parent_open(bs) != 0)
             goto fail;
         // write the CID once after the image creation
         s->parent_cid = vmdk_read_cid(bs,1);
@@ -583,15 +551,15 @@ static uint64_t get_cluster_offset(BlockDriverState *bs, VmdkMetaData *m_data,
     if (!cluster_offset) {
         if (!allocate)
             return 0;
+
         // Avoid the L2 tables update for the images that have snapshots.
-        if (!s->is_parent) {
-            cluster_offset = bdrv_getlength(s->hd);
-            bdrv_truncate(s->hd, cluster_offset + (s->cluster_sectors << 9));
+        cluster_offset = bdrv_getlength(s->hd);
+        bdrv_truncate(s->hd, cluster_offset + (s->cluster_sectors << 9));
+
+        cluster_offset >>= 9;
+        tmp = cpu_to_le32(cluster_offset);
+        l2_table[l2_index] = tmp;
 
-            cluster_offset >>= 9;
-            tmp = cpu_to_le32(cluster_offset);
-            l2_table[l2_index] = tmp;
-        }
         /* First of all we write grain itself, to avoid race condition
          * that may to corrupt the image.
          * This problem may occur because of insufficient space on host disk
-- 
1.6.6.1