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| author | Stefan Weil <weil@mail.berlios.de> | 2009-10-26 16:11:16 +0100 |
|---|---|---|
| committer | Anthony Liguori <aliguori@us.ibm.com> | 2009-11-09 08:43:01 -0600 |
| commit | d191d12d5f479422e16ed1d12b0222547b29036a (patch) | |
| tree | dafeb368cfc86e2a8b7d69100a5d167fc363febd /block | |
| parent | b4558d7481aefc865b0b52bf9b285ebcf2e8b59f (diff) | |
| download | qemu-d191d12d5f479422e16ed1d12b0222547b29036a.zip qemu-d191d12d5f479422e16ed1d12b0222547b29036a.tar.gz qemu-d191d12d5f479422e16ed1d12b0222547b29036a.tar.bz2 | |
qcow2: Allow qcow2 disk images with size zero
Images with disk size 0 may be used for
VM snapshots, but not to save normal block data.
It is possible to create such images using
qemu-img, but opening them later fails.
So even "qemu-img info image.qcow2" is not
possible for an image created with
"qemu-img create -f qcow2 image.qcow2 0".
This is fixed here.
Signed-off-by: Stefan Weil <weil@mail.berlios.de>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Diffstat (limited to 'block')
| -rw-r--r-- | block/qcow2-cluster.c | 3 | ||||
| -rw-r--r-- | block/qcow2.c | 19 |
2 files changed, 13 insertions, 9 deletions
diff --git a/block/qcow2-cluster.c b/block/qcow2-cluster.c index e444e53..f88118c 100644 --- a/block/qcow2-cluster.c +++ b/block/qcow2-cluster.c @@ -39,6 +39,9 @@ int qcow2_grow_l1_table(BlockDriverState *bs, int min_size) new_l1_size = s->l1_size; if (min_size <= new_l1_size) return 0; + if (new_l1_size == 0) { + new_l1_size = 1; + } while (min_size > new_l1_size) { new_l1_size = (new_l1_size * 3 + 1) / 2; } diff --git a/block/qcow2.c b/block/qcow2.c index a9e7682..3954cf1 100644 --- a/block/qcow2.c +++ b/block/qcow2.c @@ -166,8 +166,7 @@ static int qcow_open(BlockDriverState *bs, const char *filename, int flags) if (header.magic != QCOW_MAGIC || header.version != QCOW_VERSION) goto fail; - if (header.size <= 1 || - header.cluster_bits < MIN_CLUSTER_BITS || + if (header.cluster_bits < MIN_CLUSTER_BITS || header.cluster_bits > MAX_CLUSTER_BITS) goto fail; if (header.crypt_method > QCOW_CRYPT_AES) @@ -200,13 +199,15 @@ static int qcow_open(BlockDriverState *bs, const char *filename, int flags) if (s->l1_size < s->l1_vm_state_index) goto fail; s->l1_table_offset = header.l1_table_offset; - s->l1_table = qemu_mallocz( - align_offset(s->l1_size * sizeof(uint64_t), 512)); - if (bdrv_pread(s->hd, s->l1_table_offset, s->l1_table, s->l1_size * sizeof(uint64_t)) != - s->l1_size * sizeof(uint64_t)) - goto fail; - for(i = 0;i < s->l1_size; i++) { - be64_to_cpus(&s->l1_table[i]); + if (s->l1_size > 0) { + s->l1_table = qemu_mallocz( + align_offset(s->l1_size * sizeof(uint64_t), 512)); + if (bdrv_pread(s->hd, s->l1_table_offset, s->l1_table, s->l1_size * sizeof(uint64_t)) != + s->l1_size * sizeof(uint64_t)) + goto fail; + for(i = 0;i < s->l1_size; i++) { + be64_to_cpus(&s->l1_table[i]); + } } /* alloc L2 cache */ s->l2_cache = qemu_malloc(s->l2_size * L2_CACHE_SIZE * sizeof(uint64_t)); |