Merge remote-tracking branch 'mreitz/block' into queue-block

* mreitz/block:
  block/vdi: Limit maximum size even futher

3 files changed, 27 insertions, 14 deletions

diff --git a/block/vdi.c b/block/vdi.c
index e1d211c9f7..39070b75e8 100644
--- a/block/vdi.c
+++ b/block/vdi.c
@@ -120,8 +120,18 @@ typedef unsigned char uuid_t[16];
 
 #define VDI_IS_ALLOCATED(X) ((X) < VDI_DISCARDED)
 
-/* max blocks in image is (0xffffffff / 4) */
-#define VDI_BLOCKS_IN_IMAGE_MAX  0x3fffffff
+/* The bmap will take up VDI_BLOCKS_IN_IMAGE_MAX * sizeof(uint32_t) bytes; since
+ * the bmap is read and written in a single operation, its size needs to be
+ * limited to INT_MAX; furthermore, when opening an image, the bmap size is
+ * rounded up to be aligned on BDRV_SECTOR_SIZE.
+ * Therefore this should satisfy the following:
+ * VDI_BLOCKS_IN_IMAGE_MAX * sizeof(uint32_t) + BDRV_SECTOR_SIZE == INT_MAX + 1
+ * (INT_MAX + 1 is the first value not representable as an int)
+ * This guarantees that any value below or equal to the constant will, when
+ * multiplied by sizeof(uint32_t) and rounded up to a BDRV_SECTOR_SIZE boundary,
+ * still be below or equal to INT_MAX. */
+#define VDI_BLOCKS_IN_IMAGE_MAX \
+    ((unsigned)((INT_MAX + 1u - BDRV_SECTOR_SIZE) / sizeof(uint32_t)))
 #define VDI_DISK_SIZE_MAX        ((uint64_t)VDI_BLOCKS_IN_IMAGE_MAX * \
                                   (uint64_t)DEFAULT_CLUSTER_SIZE)
 
diff --git a/tests/qemu-iotests/084 b/tests/qemu-iotests/084
index 2712c023a9..733018d4a8 100755
--- a/tests/qemu-iotests/084
+++ b/tests/qemu-iotests/084
@@ -66,15 +66,15 @@ stat -c"disk image file size in bytes: %s" "${TEST_IMG}"
 
 # check for image size too large
 # poke max image size, and appropriate blocks_in_image value
-echo "Test 1: Maximum size (1024 TB):"
-poke_file "$TEST_IMG" "$ds_offset" "\x00\x00\xf0\xff\xff\xff\x03\x00"
-poke_file "$TEST_IMG" "$bii_offset" "\xff\xff\xff\x3f"
+echo "Test 1: Maximum size (512 TB - 128 MB):"
+poke_file "$TEST_IMG" "$ds_offset" "\x00\x00\x00\xf8\xff\xff\x01\x00"
+poke_file "$TEST_IMG" "$bii_offset" "\x80\xff\xff\x1f"
 _img_info
 
 echo
-echo "Test 2: Size too large (1024TB + 1)"
+echo "Test 2: Size too large (512 TB - 128 MB + 64 kB)"
 # This should be too large (-EINVAL):
-poke_file "$TEST_IMG" "$ds_offset" "\x00\x00\xf1\xff\xff\xff\x03\x00"
+poke_file "$TEST_IMG" "$ds_offset" "\x00\x00\x01\xf8\xff\xff\x01\x00"
 _img_info
 
 echo
@@ -89,9 +89,9 @@ _img_info
 
 echo
 echo "Test 4: Size valid (64M), but Blocks In Image exceeds max allowed"
-# Now check the bounds of blocks_in_image - 0x3fffffff should be the max
+# Now check the bounds of blocks_in_image - 0x1fffff80 should be the max
 # value here, and we should get -ENOTSUP
-poke_file "$TEST_IMG" "$bii_offset" "\x00\x00\x00\x40"
+poke_file "$TEST_IMG" "$bii_offset" "\x81\xff\xff\x1f"
 _img_info
 
 # Finally, 1MB is the only block size supported.  Verify that
diff --git a/tests/qemu-iotests/084.out b/tests/qemu-iotests/084.out
index ea29ae0b9d..5ece8299c8 100644
--- a/tests/qemu-iotests/084.out
+++ b/tests/qemu-iotests/084.out
@@ -17,17 +17,20 @@ file format: IMGFMT
 virtual size: 64M (67108864 bytes)
 cluster_size: 1048576
 disk image file size in bytes: 1024
-Test 1: Maximum size (1024 TB):
-qemu-img: Could not open 'TEST_DIR/t.IMGFMT': Could not open 'TEST_DIR/t.IMGFMT': Invalid argument
+Test 1: Maximum size (512 TB - 128 MB):
+image: TEST_DIR/t.IMGFMT
+file format: IMGFMT
+virtual size: 512T (562949819203584 bytes)
+cluster_size: 1048576
 
-Test 2: Size too large (1024TB + 1)
-qemu-img: Could not open 'TEST_DIR/t.IMGFMT': Unsupported VDI image size (size is 0x3fffffff10000, max supported is 0x3fffffff00000)
+Test 2: Size too large (512 TB - 128 MB + 64 kB)
+qemu-img: Could not open 'TEST_DIR/t.IMGFMT': Unsupported VDI image size (size is 0x1fffff8010000, max supported is 0x1fffff8000000)
 
 Test 3: Size valid (64M), but Blocks In Image too small (63)
 qemu-img: Could not open 'TEST_DIR/t.IMGFMT': unsupported VDI image (disk size 67108864, image bitmap has room for 66060288)
 
 Test 4: Size valid (64M), but Blocks In Image exceeds max allowed
-qemu-img: Could not open 'TEST_DIR/t.IMGFMT': unsupported VDI image (too many blocks 1073741824, max is 1073741823)
+qemu-img: Could not open 'TEST_DIR/t.IMGFMT': unsupported VDI image (too many blocks 536870785, max is 536870784)
 
 Test 5: Valid Image: 64MB, Blocks In Image 64, Block Size 1MB
 image: TEST_DIR/t.IMGFMT