Il 11/04/2012 16:46, Liu Yuan ha scritto:
> From: Liu Yuan <tailai...@taobao.com>
>
> The 'qemu-img convert -h' advertise that the default cache mode is
> 'writeback', while in fact it is 'unsafe'.
>
> This patch 1) fix the help manual and 2) let bdrv_close() call bdrv_flush()
> 3) explicitly calls bdrv_close() to flush the dirty bits.
>
> 3) is needed because some backend storage doesn't have a self-flush
> mechanism(for e.g., sheepdog), so we need to call bdrv_close() to make
> sure the image is really writen to the storage instead of hanging around
> writeback cache forever.
>
> Signed-off-by: Liu Yuan <tailai...@taobao.com>
> ---
> block.c | 1 +
> qemu-img.c | 7 +++++--
> 2 files changed, 6 insertions(+), 2 deletions(-)
>
> diff --git a/block.c b/block.c
> index c0c90f0..1ee2bf0 100644
> --- a/block.c
> +++ b/block.c
> @@ -812,6 +812,7 @@ unlink_and_fail:
>
> void bdrv_close(BlockDriverState *bs)
> {
> + bdrv_flush(bs);
> if (bs->drv) {
> if (bs->job) {
> block_job_cancel_sync(bs->job);
> diff --git a/qemu-img.c b/qemu-img.c
> index 6a61ca8..846f707 100644
> --- a/qemu-img.c
> +++ b/qemu-img.c
> @@ -66,8 +66,8 @@ static void help(void)
> " 'filename' is a disk image filename\n"
> " 'fmt' is the disk image format. It is guessed automatically in
> most cases\n"
> " 'cache' is the cache mode used to write the output disk image,
> the valid\n"
> - " options are: 'none', 'writeback' (default), 'writethrough',
> 'directsync'\n"
> - " and 'unsafe'\n"
> + " options are: 'none', 'writeback', 'writethrough',
> 'directsync'\n"
> + " and 'unsafe' (default)\n"
> " 'size' is the disk image size in bytes. Optional suffixes\n"
> " 'k' or 'K' (kilobyte, 1024), 'M' (megabyte, 1024k), 'G'
> (gigabyte, 1024M)\n"
> " and T (terabyte, 1024G) are supported. 'b' is ignored.\n"
> @@ -1036,6 +1036,9 @@ out:
> free_option_parameters(param);
> qemu_vfree(buf);
> if (out_bs) {
> + if (ret == 0) {
> + bdrv_close(out_bs);
> + }
bdrv_delete already does this.
Paolo
> bdrv_delete(out_bs);
> }
> if (bs) {
