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| author | Max Reitz <mreitz@redhat.com> | 2020-01-22 17:45:28 +0100 |
|---|---|---|
| committer | Max Reitz <mreitz@redhat.com> | 2020-02-20 16:43:42 +0100 |
| commit | 78c81a3f108870d325b0a39d88711366afe6f703 (patch) | |
| tree | 40bcae73956c2f70c6bb90f4eaa41fc16641c88d /block | |
| parent | b7e9eae98c160f3e7eb9ffbedba8821e358d963c (diff) | |
| download | qemu-78c81a3f108870d325b0a39d88711366afe6f703.zip qemu-78c81a3f108870d325b0a39d88711366afe6f703.tar.gz qemu-78c81a3f108870d325b0a39d88711366afe6f703.tar.bz2 | |
block/nbd: Fix hang in .bdrv_close()
When nbd_close() is called from a coroutine, the connection_co never
gets to run, and thus nbd_teardown_connection() hangs.
This is because aio_co_enter() only puts the connection_co into the main
coroutine's wake-up queue, so this main coroutine needs to yield and
wait for connection_co to terminate.
Suggested-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20200122164532.178040-2-mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Diffstat (limited to 'block')
| -rw-r--r-- | block/nbd.c | 14 |
1 files changed, 13 insertions, 1 deletions
diff --git a/block/nbd.c b/block/nbd.c index d085554..6d3b22f 100644 --- a/block/nbd.c +++ b/block/nbd.c @@ -70,6 +70,7 @@ typedef struct BDRVNBDState { CoMutex send_mutex; CoQueue free_sema; Coroutine *connection_co; + Coroutine *teardown_co; QemuCoSleepState *connection_co_sleep_ns_state; bool drained; bool wait_drained_end; @@ -203,7 +204,15 @@ static void nbd_teardown_connection(BlockDriverState *bs) qemu_co_sleep_wake(s->connection_co_sleep_ns_state); } } - BDRV_POLL_WHILE(bs, s->connection_co); + if (qemu_in_coroutine()) { + s->teardown_co = qemu_coroutine_self(); + /* connection_co resumes us when it terminates */ + qemu_coroutine_yield(); + s->teardown_co = NULL; + } else { + BDRV_POLL_WHILE(bs, s->connection_co); + } + assert(!s->connection_co); } static bool nbd_client_connecting(BDRVNBDState *s) @@ -395,6 +404,9 @@ static coroutine_fn void nbd_connection_entry(void *opaque) s->ioc = NULL; } + if (s->teardown_co) { + aio_co_wake(s->teardown_co); + } aio_wait_kick(); } |