On Mon, 10/12 10:31, Kevin Wolf wrote: > Am 09.10.2015 um 18:27 hat Fam Zheng geschrieben: > > On Fri, 10/09 16:31, Kevin Wolf wrote: > > > Am 09.10.2015 um 07:45 hat Fam Zheng geschrieben: > > > > Signed-off-by: Fam Zheng <f...@redhat.com> > > > > --- > > > > aio-posix.c | 3 ++- > > > > aio-win32.c | 3 ++- > > > > async.c | 42 ++++++++++++++++++++++++++++++++++++++++++ > > > > include/block/aio.h | 30 ++++++++++++++++++++++++++++++ > > > > 4 files changed, 76 insertions(+), 2 deletions(-) > > > > > > > > diff --git a/aio-posix.c b/aio-posix.c > > > > index d25fcfc..a261892 100644 > > > > --- a/aio-posix.c > > > > +++ b/aio-posix.c > > > > @@ -261,7 +261,8 @@ bool aio_poll(AioContext *ctx, bool blocking) > > > > > > > > /* fill pollfds */ > > > > QLIST_FOREACH(node, &ctx->aio_handlers, node) { > > > > - if (!node->deleted && node->pfd.events) { > > > > + if (!node->deleted && node->pfd.events > > > > + && !aio_type_disabled(ctx, node->type)) { > > > > add_pollfd(node); > > > > } > > > > } > > > > diff --git a/aio-win32.c b/aio-win32.c > > > > index f5ecf57..66cff60 100644 > > > > --- a/aio-win32.c > > > > +++ b/aio-win32.c > > > > @@ -309,7 +309,8 @@ bool aio_poll(AioContext *ctx, bool blocking) > > > > /* fill fd sets */ > > > > count = 0; > > > > QLIST_FOREACH(node, &ctx->aio_handlers, node) { > > > > - if (!node->deleted && node->io_notify) { > > > > + if (!node->deleted && node->io_notify > > > > + && !aio_type_disabled(ctx, node->type)) { > > > > events[count++] = event_notifier_get_handle(node->e); > > > > } > > > > } > > > > diff --git a/async.c b/async.c > > > > index 244bf79..855b9d5 100644 > > > > --- a/async.c > > > > +++ b/async.c > > > > @@ -361,3 +361,45 @@ void aio_context_release(AioContext *ctx) > > > > { > > > > rfifolock_unlock(&ctx->lock); > > > > } > > > > + > > > > +bool aio_type_disabled(AioContext *ctx, int type) > > > > +{ > > > > + int i = 1; > > > > + int n = 0; > > > > + > > > > + while (type) { > > > > + bool b = type & 0x1; > > > > + type >>= 1; > > > > + n++; > > > > > > Any specific reason for leaving client_disable_counters[0] unused? > > > > No, I should have started from 0. > > > > > > > > > + i <<= 1; > > > > > > i is never read. > > > > > > > + if (!b) { > > > > + continue; > > > > + } > > > > + if (ctx->client_disable_counters[n]) { > > > > + return true; > > > > + } > > > > + } > > > > + return false; > > > > +} > > > > > > In general I wonder whether this function really needs to take a mask > > > with possibly multiple set bits instead of just a single type. > > > > Previous versions used to have more types than "internal" and "external", > > so it > > has been a mask. So yes, I think a single type will be better now. > > > > > > > > > +void aio_disable_enable_clients(AioContext *ctx, int clients_mask, > > > > + bool is_disable) > > > > +{ > > > > + int i = 1; > > > > + int n = 0; > > > > + aio_context_acquire(ctx); > > > > + > > > > + while (clients_mask) { > > > > + bool b = clients_mask & 0x1; > > > > + clients_mask >>= 1; > > > > + n++; > > > > + i <<= 1; > > > > > > This i isn't used either. > > > > > > > + if (!b) { > > > > + continue; > > > > + } > > > > + if (ctx->client_disable_counters[n]) { > > > > + return true; > > > > + } > > > > > > Wait, why are you checking the state instead of setting it? > > > > Oops, apparent I screwed my workspaces as I do remember coding this > > assignment. > > And I must have used a wrong command when building the tree so that I don't > > even catch the compiling error. :( > > > > > > > > How did you test this series? > > > > So far only smoke testing and qemu-iotests, because I don't have a good > > idea of > > testifying the transaction's atomicity. Any suggestions? > > Perhaps you could use blkdebug to delay something in the middle of the > transaction while your guest keeps writing stuff? That should result in > 100% reproducability. > > I guess you actually need to make sure that your guest doesn't do any > I/O, then set the blkdebug breakpoint, send the transaction, and once a > request is stopped, you start some I/O in the guest. Resume as soon as > you know that something bad happened. > > Possibly you need to add a new blkdebug event to find a good place to > suspend a transaction request. >
It's difficult to "start some I/O" in the guest in the middle of transaction, even with help of blkdebug, because BQL is hold during the whole transaction. I think it would be a bit easier to program a VCPU to constantly submit I/O requests to the vq, but that's far from enough. Anyway I'll start by writing some unit test code instead, in tests/test-aio.c. Fam