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| author | Paolo Bonzini <pbonzini@redhat.com> | 2017-02-13 14:52:20 +0100 |
|---|---|---|
| committer | Stefan Hajnoczi <stefanha@redhat.com> | 2017-02-21 11:14:07 +0000 |
| commit | 35f106e68464d4ed9f2059a93f5c2ecd0750c05b (patch) | |
| tree | b841c1abf0c79614ae64307f939435eb8f3d33f4 /block | |
| parent | 0c330a734b51c177ab8488932ac3b0c4d63a718a (diff) | |
| download | qemu-35f106e68464d4ed9f2059a93f5c2ecd0750c05b.zip qemu-35f106e68464d4ed9f2059a93f5c2ecd0750c05b.tar.gz qemu-35f106e68464d4ed9f2059a93f5c2ecd0750c05b.tar.bz2 | |
block-backend: allow blk_prw from coroutine context
qcow2_create2 calls this. Do not run a nested event loop, as that
breaks when aio_co_wake tries to queue the coroutine on the co_queue_wakeup
list of the currently running one.
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Message-id: 20170213135235.12274-4-pbonzini@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Diffstat (limited to 'block')
| -rw-r--r-- | block/block-backend.c | 12 |
1 files changed, 8 insertions, 4 deletions
diff --git a/block/block-backend.c b/block/block-backend.c index efbf398..1177598 100644 --- a/block/block-backend.c +++ b/block/block-backend.c @@ -880,7 +880,6 @@ static int blk_prw(BlockBackend *blk, int64_t offset, uint8_t *buf, { QEMUIOVector qiov; struct iovec iov; - Coroutine *co; BlkRwCo rwco; iov = (struct iovec) { @@ -897,9 +896,14 @@ static int blk_prw(BlockBackend *blk, int64_t offset, uint8_t *buf, .ret = NOT_DONE, }; - co = qemu_coroutine_create(co_entry, &rwco); - qemu_coroutine_enter(co); - BDRV_POLL_WHILE(blk_bs(blk), rwco.ret == NOT_DONE); + if (qemu_in_coroutine()) { + /* Fast-path if already in coroutine context */ + co_entry(&rwco); + } else { + Coroutine *co = qemu_coroutine_create(co_entry, &rwco); + qemu_coroutine_enter(co); + BDRV_POLL_WHILE(blk_bs(blk), rwco.ret == NOT_DONE); + } return rwco.ret; } |