Am 26.08.2013 um 15:04 hat Max Reitz geschrieben:
> This adds an incompatible bit indicating corruption to qcow2. Any image
> with this bit set may not be written to unless for repairing (and
> subsequently clearing the bit if the repair has been successful).
>
> Signed-off-by: Max Reitz <mre...@redhat.com>
> ---
> block/qcow2.c | 44 ++++++++++++++++++++++++++++++++++++++++++++
> block/qcow2.h | 7 ++++++-
> docs/specs/qcow2.txt | 7 ++++++-
> include/block/block.h | 2 ++
> qemu-img.c | 2 +-
> tests/qemu-iotests/031.out | 12 ++++++------
> tests/qemu-iotests/036.out | 2 +-
> 7 files changed, 66 insertions(+), 10 deletions(-)
>
> diff --git a/block/qcow2.c b/block/qcow2.c
> index 3376901..1d0d7ca 100644
> --- a/block/qcow2.c
> +++ b/block/qcow2.c
> @@ -272,6 +272,37 @@ static int qcow2_mark_clean(BlockDriverState *bs)
> return 0;
> }
>
> +/*
> + * Marks the image as corrupt.
> + */
> +int qcow2_mark_corrupt(BlockDriverState *bs)
> +{
> + BDRVQcowState *s = bs->opaque;
> +
> + s->incompatible_features |= QCOW2_INCOMPAT_CORRUPT;
> + return qcow2_update_header(bs);
> +}
> +
> +/*
> + * Marks the image as consistent, i.e., unsets the corrupt bit, and flushes
> + * before if necessary.
> + */
> +int qcow2_mark_consistent(BlockDriverState *bs)
> +{
> + BDRVQcowState *s = bs->opaque;
> +
> + if (s->incompatible_features & QCOW2_INCOMPAT_CORRUPT) {
> + int ret = bdrv_flush(bs);
> + if (ret < 0) {
> + return ret;
> + }
> +
> + s->incompatible_features &= ~QCOW2_INCOMPAT_CORRUPT;
> + return qcow2_update_header(bs);
> + }
> + return 0;
> +}
> +
> static int qcow2_check(BlockDriverState *bs, BdrvCheckResult *result,
> BdrvCheckMode fix)
> {
> @@ -402,6 +433,14 @@ static int qcow2_open(BlockDriverState *bs, QDict
> *options, int flags)
> goto fail;
> }
>
> + if (s->incompatible_features & QCOW2_INCOMPAT_CORRUPT) {
> + /* Corrupt images may not be written to unless they are being
> repaired */
> + if ((flags & BDRV_O_RDWR) && !(flags & BDRV_O_REPAIR)) {
Isn't BDRV_O_REPAIR equivalent to BDRV_O_CHECK && BDRV_O_RDWR, or is
there an advantage in using a new bit?
Looks good otherwise.
Kevin
