Le Thursday 23 Jan 2014 à 16:48:55 (-0500), Jeff Cody a écrit :
> Currently, if an image file is logically larger than its backing file,
> commiting it via 'qemu-img commit' will fail.
>
> For instance, if we have a base image with a virtual size 10G, and a
> snapshot image of size 20G, then committing the snapshot offline with
> 'qemu-img commit' will likely fail.
>
> This will automatically attempt to resize the base image, if the
> snapshot image to be committed is larger.
>
> Signed-off-by: Jeff Cody <jc...@redhat.com>
> Reviewed-by: Fam Zheng <f...@redhat.com>
> Reviewed-by: Eric Blake <ebl...@redhat.com>
> ---
> block.c | 23 ++++++++++++++++++++---
> 1 file changed, 20 insertions(+), 3 deletions(-)
>
> diff --git a/block.c b/block.c
> index 64e7d22..dea7591 100644
> --- a/block.c
> +++ b/block.c
> @@ -1876,10 +1876,10 @@ int bdrv_check(BlockDriverState *bs, BdrvCheckResult
> *res, BdrvCheckMode fix)
> int bdrv_commit(BlockDriverState *bs)
> {
> BlockDriver *drv = bs->drv;
> - int64_t sector, total_sectors;
> + int64_t sector, total_sectors, length, backing_length;
> int n, ro, open_flags;
> int ret = 0;
> - uint8_t *buf;
> + uint8_t *buf = NULL;
Why assign NULL to buf ? Is it related to the rest of the patch ?
Reviewed-by: Benoit Canet <ben...@irqsave.net>
> char filename[PATH_MAX];
>
> if (!drv)
> @@ -1904,7 +1904,24 @@ int bdrv_commit(BlockDriverState *bs)
> }
> }
>
> - total_sectors = bdrv_getlength(bs) >> BDRV_SECTOR_BITS;
> + length = bdrv_getlength(bs);
> + backing_length = bdrv_getlength(bs->backing_hd);
> +
> + if (length < 0 || backing_length < 0) {
> + goto ro_cleanup;
> + }
> +
> + /* If our top snapshot is larger than the backing file image,
> + * grow the backing file image if possible. If not possible,
> + * we must return an error */
> + if (length > backing_length) {
> + ret = bdrv_truncate(bs->backing_hd, length);
> + if (ret < 0) {
> + goto ro_cleanup;
> + }
> + }
> +
> + total_sectors = length >> BDRV_SECTOR_BITS;
> buf = g_malloc(COMMIT_BUF_SECTORS * BDRV_SECTOR_SIZE);
>
> for (sector = 0; sector < total_sectors; sector += n) {
> --
> 1.8.3.1
>
>
