From f21dc3a4652eeb82117d7d55d975278fe1444b26 Mon Sep 17 00:00:00 2001 From: Stefan Weil Date: Wed, 12 May 2010 20:25:45 +0200 Subject: [PATCH] block/vdi: Fix image opening and creation for odd disk sizes MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit The fix is based on a patch from Kevin Wolf. Here his comment: "The number of blocks needs to be rounded up to cover all of the virtual hard disk. Without this fix, we can't even open our own images if their size is not a multiple of the block size." While Kevin's patch addressed vdi_create, my modification also fixes vdi_open which now accepts images with odd disk sizes. v3: Don't allow reading of disk images with too large disk sizes. Neither VBoxManage nor old versions of qemu-img read such images. This change requires rounding of odd disk sizes before we do the checks. Cc: Kevin Wolf Cc: François Revol Signed-off-by: Stefan Weil Signed-off-by: Kevin Wolf --- block/vdi.c | 23 ++++++++++++++++------- 1 file changed, 16 insertions(+), 7 deletions(-) diff --git a/block/vdi.c b/block/vdi.c index 3ea4103..ee8cc7b 100644 --- a/block/vdi.c +++ b/block/vdi.c @@ -393,6 +393,15 @@ static int vdi_open(BlockDriverState *bs, int flags) vdi_header_print(&header); #endif + if (header.disk_size % SECTOR_SIZE != 0) { + /* 'VBoxManage convertfromraw' can create images with odd disk sizes. + We accept them but round the disk size to the next multiple of + SECTOR_SIZE. */ + logout("odd disk size %" PRIu64 " B, round up\n", header.disk_size); + header.disk_size += SECTOR_SIZE - 1; + header.disk_size &= ~(SECTOR_SIZE - 1); + } + if (header.version != VDI_VERSION_1_1) { logout("unsupported version %u.%u\n", header.version >> 16, header.version & 0xffff); @@ -405,18 +414,15 @@ static int vdi_open(BlockDriverState *bs, int flags) /* We only support data blocks which start on a sector boundary. */ logout("unsupported data offset 0x%x B\n", header.offset_data); goto fail; - } else if (header.disk_size % SECTOR_SIZE != 0) { - logout("unsupported disk size %" PRIu64 " B\n", header.disk_size); - goto fail; } else if (header.sector_size != SECTOR_SIZE) { logout("unsupported sector size %u B\n", header.sector_size); goto fail; } else if (header.block_size != 1 * MiB) { logout("unsupported block size %u B\n", header.block_size); goto fail; - } else if ((header.disk_size + header.block_size - 1) / header.block_size != - (uint64_t)header.blocks_in_image) { - logout("unexpected block number %u B\n", header.blocks_in_image); + } else if (header.disk_size > + (uint64_t)header.blocks_in_image * header.block_size) { + logout("unsupported disk size %" PRIu64 " B\n", header.disk_size); goto fail; } else if (!uuid_is_null(header.uuid_link)) { logout("link uuid != 0, unsupported\n"); @@ -829,7 +835,10 @@ static int vdi_create(const char *filename, QEMUOptionParameter *options) return -errno; } - blocks = bytes / block_size; + /* We need enough blocks to store the given disk size, + so always round up. */ + blocks = (bytes + block_size - 1) / block_size; + bmap_size = blocks * sizeof(uint32_t); bmap_size = ((bmap_size + SECTOR_SIZE - 1) & ~(SECTOR_SIZE -1)); -- 2.7.4