diff options
| -rw-r--r-- | block/cow.c | 44 |
1 files changed, 29 insertions, 15 deletions
diff --git a/block/cow.c b/block/cow.c index 3c527358c6..bb5927c6aa 100644 --- a/block/cow.c +++ b/block/cow.c @@ -64,15 +64,26 @@ static int cow_open(BlockDriverState *bs, int flags) struct cow_header_v2 cow_header; int bitmap_size; int64_t size; + int ret; /* see if it is a cow image */ - if (bdrv_pread(bs->file, 0, &cow_header, sizeof(cow_header)) != - sizeof(cow_header)) { + ret = bdrv_pread(bs->file, 0, &cow_header, sizeof(cow_header)); + if (ret < 0) { + goto fail; + } + + if (be32_to_cpu(cow_header.magic) != COW_MAGIC) { + ret = -EINVAL; goto fail; } - if (be32_to_cpu(cow_header.magic) != COW_MAGIC || - be32_to_cpu(cow_header.version) != COW_VERSION) { + if (be32_to_cpu(cow_header.version) != COW_VERSION) { + char version[64]; + snprintf(version, sizeof(version), + "COW version %d", cow_header.version); + qerror_report(QERR_UNKNOWN_BLOCK_FORMAT_FEATURE, + bs->device_name, "cow", version); + ret = -ENOTSUP; goto fail; } @@ -88,7 +99,7 @@ static int cow_open(BlockDriverState *bs, int flags) qemu_co_mutex_init(&s->lock); return 0; fail: - return -1; + return ret; } /* @@ -182,17 +193,19 @@ static int coroutine_fn cow_read(BlockDriverState *bs, int64_t sector_num, ret = bdrv_pread(bs->file, s->cow_sectors_offset + sector_num * 512, buf, n * 512); - if (ret != n * 512) - return -1; + if (ret < 0) { + return ret; + } } else { if (bs->backing_hd) { /* read from the base image */ ret = bdrv_read(bs->backing_hd, sector_num, buf, n); - if (ret < 0) - return -1; + if (ret < 0) { + return ret; + } } else { - memset(buf, 0, n * 512); - } + memset(buf, 0, n * 512); + } } nb_sectors -= n; sector_num += n; @@ -220,8 +233,9 @@ static int cow_write(BlockDriverState *bs, int64_t sector_num, ret = bdrv_pwrite(bs->file, s->cow_sectors_offset + sector_num * 512, buf, nb_sectors * 512); - if (ret != nb_sectors * 512) - return -1; + if (ret < 0) { + return ret; + } return cow_update_bitmap(bs, sector_num, nb_sectors); } @@ -288,14 +302,14 @@ static int cow_create(const char *filename, QEMUOptionParameter *options) cow_header.sectorsize = cpu_to_be32(512); cow_header.size = cpu_to_be64(image_sectors * 512); ret = bdrv_pwrite(cow_bs, 0, &cow_header, sizeof(cow_header)); - if (ret != sizeof(cow_header)) { + if (ret < 0) { goto exit; } /* resize to include at least all the bitmap */ ret = bdrv_truncate(cow_bs, sizeof(cow_header) + ((image_sectors + 7) >> 3)); - if (ret) { + if (ret < 0) { goto exit; } |