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| author | Stefan Hajnoczi <stefanha@redhat.com> | 2014-08-04 16:56:33 +0100 |
|---|---|---|
| committer | Stefan Hajnoczi <stefanha@redhat.com> | 2014-08-29 15:59:17 +0100 |
| commit | 2cdff7f620ebd3b5246cf0c0d1f6fa0eededa4ca (patch) | |
| tree | 579628c500f643464fd8138d68257d1e9dfc1968 /block/qcow2.c | |
| parent | 12ade7609004bb1b09a845c144b36ea1850854c7 (diff) | |
linux-aio: avoid deadlock in nested aio_poll() calls
If two Linux AIO request completions are fetched in the same
io_getevents() call, QEMU will deadlock if request A's callback waits
for request B to complete using an aio_poll() loop. This was reported
to happen with the mirror blockjob.
This patch moves completion processing into a BH and makes it resumable.
Nested event loops can resume completion processing so that request B
will complete and the deadlock will not occur.
Cc: Kevin Wolf <kwolf@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Ming Lei <ming.lei@canonical.com>
Cc: Marcin Gibuła <m.gibula@beyond.pl>
Reported-by: Marcin Gibuła <m.gibula@beyond.pl>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Tested-by: Marcin Gibuła <m.gibula@beyond.pl>
Diffstat (limited to 'block/qcow2.c')
0 files changed, 0 insertions, 0 deletions