VMDK: separate vmdk_open by format version

Separate vmdk_open by subformats to:
* vmdk_open_vmdk3
* vmdk_open_vmdk4
Signed-off-by: NFam Zheng <famcool@gmail.com>
Reviewed-by: NStefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

block/vmdk.c

@@ -458,33 +458,89 @@ static VmdkExtent *vmdk_add_extent(BlockDriverState *bs,
     return extent;
 }
 
-
-static int vmdk_open(BlockDriverState *bs, int flags)
+static int vmdk_init_tables(BlockDriverState *bs, VmdkExtent *extent)
 {
-    BDRVVmdkState *s = bs->opaque;
-    uint32_t magic;
-    int i;
-    uint32_t l1_size, l1_entry_sectors;
-    VmdkExtent *extent = NULL;
+    int ret;
+    int l1_size, i;
 
-    if (bdrv_pread(bs->file, 0, &magic, sizeof(magic)) != sizeof(magic))
-        goto fail;
+    /* read the L1 table */
+    l1_size = extent->l1_size * sizeof(uint32_t);
+    extent->l1_table = qemu_malloc(l1_size);
+    ret = bdrv_pread(extent->file,
+                    extent->l1_table_offset,
+                    extent->l1_table,
+                    l1_size);
+    if (ret < 0) {
+        goto fail_l1;
+    }
+    for (i = 0; i < extent->l1_size; i++) {
+        le32_to_cpus(&extent->l1_table[i]);
+    }
 
-    magic = be32_to_cpu(magic);
-    if (magic == VMDK3_MAGIC) {
+    if (extent->l1_backup_table_offset) {
+        extent->l1_backup_table = qemu_malloc(l1_size);
+        ret = bdrv_pread(extent->file,
+                        extent->l1_backup_table_offset,
+                        extent->l1_backup_table,
+                        l1_size);
+        if (ret < 0) {
+            goto fail_l1b;
+        }
+        for (i = 0; i < extent->l1_size; i++) {
+            le32_to_cpus(&extent->l1_backup_table[i]);
+        }
+    }
+
+    extent->l2_cache =
+        qemu_malloc(extent->l2_size * L2_CACHE_SIZE * sizeof(uint32_t));
+    return 0;
+ fail_l1b:
+    qemu_free(extent->l1_backup_table);
+ fail_l1:
+    qemu_free(extent->l1_table);
+    return ret;
+}
+
+static int vmdk_open_vmdk3(BlockDriverState *bs, int flags)
+{
+    int ret;
+    uint32_t magic;
     VMDK3Header header;
-        if (bdrv_pread(bs->file, sizeof(magic), &header, sizeof(header))
-                != sizeof(header)) {
+    VmdkExtent *extent;
+
+    ret = bdrv_pread(bs->file, sizeof(magic), &header, sizeof(header));
+    if (ret < 0) {
         goto fail;
     }
-        extent = vmdk_add_extent(bs, bs->file, false,
+    extent = vmdk_add_extent(bs,
+                             bs->file, false,
                              le32_to_cpu(header.disk_sectors),
-                              le32_to_cpu(header.l1dir_offset) << 9, 0,
-                              1 << 6, 1 << 9, le32_to_cpu(header.granularity));
-    } else if (magic == VMDK4_MAGIC) {
+                             le32_to_cpu(header.l1dir_offset) << 9,
+                             0, 1 << 6, 1 << 9,
+                             le32_to_cpu(header.granularity));
+    ret = vmdk_init_tables(bs, extent);
+    if (ret) {
+        /* vmdk_init_tables cleans up on fail, so only free allocation of
+         * vmdk_add_extent here. */
+        goto fail;
+    }
+    return 0;
+ fail:
+    vmdk_free_extents(bs);
+    return ret;
+}
+
+static int vmdk_open_vmdk4(BlockDriverState *bs, int flags)
+{
+    int ret;
+    uint32_t magic;
+    uint32_t l1_size, l1_entry_sectors;
     VMDK4Header header;
-        if (bdrv_pread(bs->file, sizeof(magic), &header, sizeof(header))
-                != sizeof(header)) {
+    BDRVVmdkState *s = bs->opaque;
+    VmdkExtent *extent;
+
+    ret = bdrv_pread(bs->file, sizeof(magic), &header, sizeof(header));
+    if (ret < 0) {
         goto fail;
     }
     l1_entry_sectors = le32_to_cpu(header.num_gtes_per_gte)
@@ -499,51 +555,41 @@ static int vmdk_open(BlockDriverState *bs, int flags)
                           le32_to_cpu(header.num_gtes_per_gte),
                           le64_to_cpu(header.granularity));
     if (extent->l1_entry_sectors <= 0) {
+        ret = -EINVAL;
         goto fail;
     }
-        // try to open parent images, if exist
-        if (vmdk_parent_open(bs) != 0)
-            goto fail;
-        // write the CID once after the image creation
-        s->parent_cid = vmdk_read_cid(bs,1);
-    } else {
-        goto fail;
-    }
-
-    /* read the L1 table */
-    l1_size = extent->l1_size * sizeof(uint32_t);
-    extent->l1_table = qemu_malloc(l1_size);
-    if (bdrv_pread(bs->file,
-            extent->l1_table_offset,
-            extent->l1_table,
-            l1_size)
-        != l1_size) {
+    /* try to open parent images, if exist */
+    ret = vmdk_parent_open(bs);
+    if (ret) {
         goto fail;
     }
-    for (i = 0; i < extent->l1_size; i++) {
-        le32_to_cpus(&extent->l1_table[i]);
-    }
-
-    if (extent->l1_backup_table_offset) {
-        extent->l1_backup_table = qemu_malloc(l1_size);
-        if (bdrv_pread(bs->file,
-                    extent->l1_backup_table_offset,
-                    extent->l1_backup_table,
-                    l1_size)
-                != l1_size) {
+    s->parent_cid = vmdk_read_cid(bs, 1);
+    ret = vmdk_init_tables(bs, extent);
+    if (ret) {
         goto fail;
     }
-        for (i = 0; i < extent->l1_size; i++) {
-            le32_to_cpus(&extent->l1_backup_table[i]);
-        }
-    }
-
-    extent->l2_cache =
-        qemu_malloc(extent->l2_size * L2_CACHE_SIZE * sizeof(uint32_t));
     return 0;
  fail:
     vmdk_free_extents(bs);
-    return -1;
+    return ret;
+}
+
+static int vmdk_open(BlockDriverState *bs, int flags)
+{
+    uint32_t magic;
+
+    if (bdrv_pread(bs->file, 0, &magic, sizeof(magic)) != sizeof(magic)) {
+        return -EIO;
+    }
+
+    magic = be32_to_cpu(magic);
+    if (magic == VMDK3_MAGIC) {
+        return vmdk_open_vmdk3(bs, flags);
+    } else if (magic == VMDK4_MAGIC) {
+        return vmdk_open_vmdk4(bs, flags);
+    } else {
+        return -EINVAL;
+    }
 }
 
 static int get_whole_cluster(BlockDriverState *bs,
@@ -630,11 +676,11 @@ static uint64_t get_cluster_offset(BlockDriverState *bs,
     if (!l2_offset) {
         return 0;
     }
-    for(i = 0; i < L2_CACHE_SIZE; i++) {
+    for (i = 0; i < L2_CACHE_SIZE; i++) {
         if (l2_offset == extent->l2_cache_offsets[i]) {
             /* increment the hit count */
             if (++extent->l2_cache_counts[i] == 0xffffffff) {
-                for(j = 0; j < L2_CACHE_SIZE; j++) {
+                for (j = 0; j < L2_CACHE_SIZE; j++) {
                     extent->l2_cache_counts[j] >>= 1;
                 }
             }
@@ -645,7 +691,7 @@ static uint64_t get_cluster_offset(BlockDriverState *bs,
     /* not found: load a new entry in the least used one */
     min_index = 0;
     min_count = 0xffffffff;
-    for(i = 0; i < L2_CACHE_SIZE; i++) {
+    for (i = 0; i < L2_CACHE_SIZE; i++) {
         if (extent->l2_cache_counts[i] < min_count) {
             min_count = extent->l2_cache_counts[i];
             min_index = i;