From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([209.51.188.92]:51664) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gwVzX-0005BM-Mh for qemu-devel@nongnu.org; Wed, 20 Feb 2019 12:49:11 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gwVzW-00052L-3b for qemu-devel@nongnu.org; Wed, 20 Feb 2019 12:49:07 -0500 From: Kevin Wolf Date: Wed, 20 Feb 2019 18:48:30 +0100 Message-Id: <20190220174843.8847-1-kwolf@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Subject: [Qemu-devel] [PATCH v2 00/13] block: bdrv_set_aio_context() related fixes List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-block@nongnu.org Cc: kwolf@redhat.com, mreitz@redhat.com, eblake@redhat.com, pbonzini@redhat.com, qemu-devel@nongnu.org Background for this series is the following bug report, which is about a crash with virtio-blk + iothread and request resubmission for werror/rerr= or: https://bugzilla.redhat.com/show_bug.cgi?id=3D1671173 The reason is that bdrv_set_aio_context() didn't correctly quiesce everything. Instead, it had a local hack to call aio_poll() for the source AioContext, which covered some, but not all cases, and is wrong because you can only call aio_poll() from the home thread. So this series tries to make bdrv_drain() actually drain the known cases (fixes virtio-blk and the NBD client) and use the regular drain functions in bdrv_set_aio_context() instead of open-coding something similar. v2: - New patch 5: Remove now redundant assignments [Paolo] - Patch 8 (was 7): Instead of using aio_co_schedule() to switch the AioContext and modifying the coroutine code, enter the coroutine in a BH in the new AioContext and bdrv_dec_in_flight() in that BH [Paolo] - Patch 12 (was 11): Cover new =3D=3D old case in comment [Eric] Kevin Wolf (13): block-backend: Make blk_inc/dec_in_flight public virtio-blk: Increase in_flight for request restart BH nbd: Restrict connection_co reentrance io: Make qio_channel_yield() interruptible io: Remove redundant read/write_coroutine assignments nbd: Move nbd_read_eof() to nbd/client.c nbd: Use low-level QIOChannel API in nbd_read_eof() nbd: Increase bs->in_flight during AioContext switch block: Don't poll in bdrv_set_aio_context() block: Fix AioContext switch for drained node test-bdrv-drain: AioContext switch in drained section block: Use normal drain for bdrv_set_aio_context() aio-posix: Assert that aio_poll() is always called in home thread block/nbd-client.h | 1 + include/block/nbd.h | 3 +- include/io/channel.h | 9 ++++-- include/sysemu/block-backend.h | 2 ++ nbd/nbd-internal.h | 19 ------------- block.c | 26 ++++++++--------- block/block-backend.c | 4 +-- block/nbd-client.c | 36 +++++++++++++++++++++-- hw/block/virtio-blk.c | 4 +++ io/channel.c | 24 ++++++++++------ nbd/client.c | 52 ++++++++++++++++++++++++++++++++-- tests/test-bdrv-drain.c | 32 +++++++++++++++++++++ util/aio-posix.c | 3 +- 13 files changed, 164 insertions(+), 51 deletions(-) --=20 2.20.1