From feb051e6d8bc62e6b9e162ada4dc576c59edc00f Mon Sep 17 00:00:00 2001
Message-Id: <feb051e6d8bc62e6b9e162ada4dc576c59edc00f.1418766606.git.jen@redhat.com>
In-Reply-To: <6f81b4847eb68ebdf54a8f1a771e19d112d74152.1418766606.git.jen@redhat.com>
References: <6f81b4847eb68ebdf54a8f1a771e19d112d74152.1418766606.git.jen@redhat.com>
From: Fam Zheng <famz@redhat.com>
Date: Thu, 4 Dec 2014 00:05:06 -0600
Subject: [CHANGE 12/31] vmdk: push vmdk_read_desc up to caller
To: rhvirt-patches@redhat.com,
    jen@redhat.com

RH-Author: Fam Zheng <famz@redhat.com>
Message-id: <1417651524-18041-13-git-send-email-famz@redhat.com>
Patchwork-id: 62685
O-Subject: [RHEL-7.1 qemu-kvm PATCH v5 12/30] vmdk: push vmdk_read_desc up to caller
Bugzilla: 1134251
RH-Acked-by: Jeffrey Cody <jcody@redhat.com>
RH-Acked-by: Markus Armbruster <armbru@redhat.com>
RH-Acked-by: Max Reitz <mreitz@redhat.com>

From: Paolo Bonzini <pbonzini@redhat.com>

Currently, we just try reading a VMDK file as both image and descriptor.
This makes it hard to choose which of the two attempts gave the best error.
We'll decide in advance if the file looks like an image or a descriptor,
and this patch is the first step to that end.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
(cherry picked from commit d1833ef52be349e41d17e9c5ddaea8bb4ad3a7fb)
Signed-off-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Jeff E. Nelson <jen@redhat.com>
---
 block/vmdk.c | 55 +++++++++++++++++++++++++++++++------------------------
 1 file changed, 31 insertions(+), 24 deletions(-)

diff --git a/block/vmdk.c b/block/vmdk.c
index 425064c..458bceb 100644
--- a/block/vmdk.c
+++ b/block/vmdk.c
@@ -526,8 +526,8 @@ static int vmdk_open_vmfs_sparse(BlockDriverState *bs,
     return ret;
 }
 
-static int vmdk_open_desc_file(BlockDriverState *bs, int flags,
-                               uint64_t desc_offset, Error **errp);
+static int vmdk_open_desc_file(BlockDriverState *bs, int flags, char *buf,
+                               Error **errp);
 
 static char *vmdk_read_desc(BlockDriverState *file, uint64_t desc_offset,
                             Error **errp)
@@ -576,7 +576,13 @@ static int vmdk_open_vmdk4(BlockDriverState *bs,
     if (header.capacity == 0) {
         uint64_t desc_offset = le64_to_cpu(header.desc_offset);
         if (desc_offset) {
-            return vmdk_open_desc_file(bs, flags, desc_offset << 9, errp);
+            char *buf = vmdk_read_desc(file, desc_offset << 9, errp);
+            if (!buf) {
+                return -EINVAL;
+            }
+            ret = vmdk_open_desc_file(bs, flags, buf, errp);
+            g_free(buf);
+            return ret;
         }
     }
 
@@ -727,16 +733,12 @@ static int vmdk_parse_description(const char *desc, const char *opt_name,
 
 /* Open an extent file and append to bs array */
 static int vmdk_open_sparse(BlockDriverState *bs,
-                            BlockDriverState *file,
-                            int flags, Error **errp)
+                            BlockDriverState *file, int flags,
+                            char *buf, Error **errp)
 {
     uint32_t magic;
 
-    if (bdrv_pread(file, 0, &magic, sizeof(magic)) != sizeof(magic)) {
-        return -EIO;
-    }
-
-    magic = be32_to_cpu(magic);
+    magic = ldl_be_p(buf);
     switch (magic) {
         case VMDK3_MAGIC:
             return vmdk_open_vmfs_sparse(bs, file, flags, errp);
@@ -821,8 +823,14 @@ static int vmdk_parse_extents(const char *desc, BlockDriverState *bs,
             extent->flat_start_offset = flat_offset << 9;
         } else if (!strcmp(type, "SPARSE") || !strcmp(type, "VMFSSPARSE")) {
             /* SPARSE extent and VMFSSPARSE extent are both "COWD" sparse file*/
-            ret = vmdk_open_sparse(bs, extent_file, bs->open_flags, errp);
+            char *buf = vmdk_read_desc(extent_file, 0, errp);
+            if (!buf) {
+                ret = -EINVAL;
+            } else {
+                ret = vmdk_open_sparse(bs, extent_file, bs->open_flags, buf, errp);
+            }
             if (ret) {
+                g_free(buf);
                 bdrv_unref(extent_file);
                 return ret;
             }
@@ -845,20 +853,13 @@ next_line:
     return 0;
 }
 
-static int vmdk_open_desc_file(BlockDriverState *bs, int flags,
-                               uint64_t desc_offset, Error **errp)
+static int vmdk_open_desc_file(BlockDriverState *bs, int flags, char *buf,
+                               Error **errp)
 {
     int ret;
-    char *buf;
     char ct[128];
     BDRVVmdkState *s = bs->opaque;
 
-    buf = vmdk_read_desc(bs->file, desc_offset, errp);
-    if (!buf) {
-        return -EINVAL;
-        goto exit;
-    }
-
     if (vmdk_parse_description(buf, "createType", ct, sizeof(ct))) {
         error_setg(errp, "invalid VMDK image descriptor");
         ret = -EINVAL;
@@ -877,20 +878,25 @@ static int vmdk_open_desc_file(BlockDriverState *bs, int flags,
     s->desc_offset = 0;
     ret = vmdk_parse_extents(buf, bs, bs->file->filename, errp);
 exit:
-    g_free(buf);
     return ret;
 }
 
 static int vmdk_open(BlockDriverState *bs, QDict *options, int flags,
                      Error **errp)
 {
+    char *buf = NULL;
     int ret;
     BDRVVmdkState *s = bs->opaque;
 
-    if (vmdk_open_sparse(bs, bs->file, flags, errp) == 0) {
+    buf = vmdk_read_desc(bs->file, 0, errp);
+    if (!buf) {
+        return -EINVAL;
+    }
+
+    if (vmdk_open_sparse(bs, bs->file, flags, buf, errp) == 0) {
         s->desc_offset = 0x200;
     } else {
-        ret = vmdk_open_desc_file(bs, flags, 0, errp);
+        ret = vmdk_open_desc_file(bs, flags, buf, errp);
         if (ret) {
             goto fail;
         }
@@ -909,10 +915,11 @@ static int vmdk_open(BlockDriverState *bs, QDict *options, int flags,
               QERR_BLOCK_FORMAT_FEATURE_NOT_SUPPORTED,
               "vmdk", bs->device_name, "live migration");
     migrate_add_blocker(s->migration_blocker);
-
+    g_free(buf);
     return 0;
 
 fail:
+    g_free(buf);
     g_free(s->create_type);
     s->create_type = NULL;
     vmdk_free_extents(bs);
-- 
2.1.0