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[Qemu-devel] [PATCH 0/2] ide/atapi: partially avoid deadlock if the stor
From: |
Peter Lieven |
Subject: |
[Qemu-devel] [PATCH 0/2] ide/atapi: partially avoid deadlock if the storage backend is dead |
Date: |
Thu, 20 Aug 2015 10:14:06 +0200 |
the blk_drain_all() that is executed if the guest issues a DMA cancel
leads to a stuck main loop if the storage backend (e.g. a NFS share)
is unresponsive.
This scenario is a common case for CDROM images mounted from an
NFS share. In this case a broken NFS server can take down the
whole VM even if the mounted CDROM is not used and was just not
unmounted after usage.
This approach avoids the blk_drain_all for read-only media and
cancelles the AIO locally and makes the callback a NOP if the
original request is completed after the NFS share is responsive
again.
Peter Lieven (2):
block/io: allow AIOCB without callback
ide/atapi: partially avoid deadlock if the storage backend is dead
block/io.c | 8 ++++++--
hw/ide/pci.c | 32 ++++++++++++++++++--------------
2 files changed, 24 insertions(+), 16 deletions(-)
--
1.9.1
- [Qemu-devel] [PATCH 0/2] ide/atapi: partially avoid deadlock if the storage backend is dead,
Peter Lieven <=