Am 15.06.2012 22:47, schrieb Supriya Kannery:
> New command "block_set_hostcache" added for dynamically changing
> host pagecache setting of a block device.
>
> Usage:
> block_set_hostcache <device> <option>
> <device> = block device
> <option> = on/off
>
> Example:
> (qemu) block_set_hostcache ide0-hd0 off
>
> Signed-off-by: Supriya Kannery <supri...@linux.vnet.ibm.com>
>
> ---
> block.c | 54 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
> block.h | 2 ++
> blockdev.c | 26 ++++++++++++++++++++++++++
> blockdev.h | 2 ++
> hmp-commands.hx | 14 ++++++++++++++
> qmp-commands.hx | 27 +++++++++++++++++++++++++++
> 6 files changed, 125 insertions(+)
>
> Index: qemu/block.c
> ===================================================================
> --- qemu.orig/block.c
> +++ qemu/block.c
> @@ -858,6 +858,35 @@ unlink_and_fail:
> return ret;
> }
>
> +int bdrv_reopen(BlockDriverState *bs, int bdrv_flags)
> +{
> + BlockDriver *drv = bs->drv;
> + int ret = 0, open_flags;
> +
> + /* Quiesce IO for the given block device */
> + qemu_aio_flush();
bdrv_drain_all() should be used instead.
> + ret = bdrv_flush(bs);
> + if (ret != 0) {
> + qerror_report(QERR_DATA_SYNC_FAILED, bs->device_name);
> + return ret;
> + }
> + open_flags = bs->open_flags;
> + bdrv_close(bs);
> +
> + ret = bdrv_open(bs, bs->filename, bdrv_flags, drv);
> + if (ret < 0) {
> + /* Reopen failed. Try to open with original flags */
> + qerror_report(QERR_OPEN_FILE_FAILED, bs->filename);
> + ret = bdrv_open(bs, bs->filename, open_flags, drv);
> + if (ret < 0) {
> + /* Reopen failed with orig and modified flags */
> + abort();
Like Eric said, committing a broken version and then fixing it later in
the series isn't really nice. At least bs->drv = NULL; instead of
abort() is required. Starting with the real thing is probably even better.
Kevin
