On 09/18/2012 12:53 PM, Jeff Cody wrote:
> This is derived from the Supriya Kannery's reopen patches.
>
> This contains the raw-posix driver changes for the bdrv_reopen_*
> functions. All changes are staged into a temporary scratch buffer
> during the prepare() stage, and copied over to the live structure
> during commit(). Upon abort(), all changes are abandoned, and the
> live structures are unmodified.
>
> The _prepare() will create an extra fd - either by means of a dup,
> if possible, or opening a new fd if not (for instance, access
> control changes). Upon _commit(), the original fd is closed and
> the new fd is used. Upon _abort(), the duplicate/new fd is closed.
>
> Signed-off-by: Jeff Cody <jc...@redhat.com>
> ---
> block/raw-posix.c | 99
> +++++++++++++++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 99 insertions(+)
>
> diff --git a/block/raw-posix.c b/block/raw-posix.c
> index 6bf5480..edd1eca 100644
> --- a/block/raw-posix.c
> +++ b/block/raw-posix.c
> @@ -138,6 +138,15 @@ typedef struct BDRVRawState {
> #endif
> } BDRVRawState;
>
> +typedef struct BDRVRawReopenState {
> + int fd;
> + int open_flags;
> +#ifdef CONFIG_LINUX_AIO
> + int use_aio;
> + void *aio_ctx;
> +#endif
These members are conditional...
> +static int raw_reopen_prepare(BDRVReopenState *state,
> + BlockReopenQueue *queue, Error **errp)
> +{
> + BDRVRawState *s;
> + BDRVRawReopenState *raw_s;
> + int ret = 0;
> +
> + assert(state != NULL);
> + assert(state->bs != NULL);
> +
> + s = state->bs->opaque;
> +
> + state->opaque = g_malloc0(sizeof(BDRVRawReopenState));
> + raw_s = state->opaque;
> + raw_s->use_aio = s->use_aio;
> + raw_s->aio_ctx = s->aio_ctx;
...but you are unconditionally assigning into them. This will introduce
compile failures on other platforms.
> + if ((raw_s->open_flags & ~fcntl_flags) == (s->open_flags &
> ~fcntl_flags)) {
> + /* dup the original fd */
> + /* TODO: use qemu fcntl wrapper */
> + raw_s->fd = fcntl(s->fd, F_DUPFD_CLOEXEC, 0);
F_DUPFD_CLOEXEC is not defined everywhere yet; you still need to address
your TODO.
> +
> + /* If we cannot use fctnl, or fcntl failed, fall back to qemu_open() */
s/fctnl/fcntl/
> +static void raw_reopen_commit(BDRVReopenState *state)
> +{
> + BDRVRawReopenState *raw_s = state->opaque;
> + BDRVRawState *s = state->bs->opaque;
> +
> + s->open_flags = raw_s->open_flags;
> +
> + qemu_close(s->fd);
> + s->fd = raw_s->fd;
> + s->use_aio = raw_s->use_aio;
> + s->aio_ctx = raw_s->aio_ctx;
Again, more unconditional use of conditional members.
--
Eric Blake ebl...@redhat.com +1-919-301-3266
Libvirt virtualization library http://libvirt.org
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