blockdev: acquire AioContext in block_set_io_throttle

The block_set_io_throttle QMP and HMP commands modify I/O throttling
limits for block devices.

Acquire the BlockDriverState's AioContext to protect against race
conditions with an IOThread that is running I/O for this device.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Benoit Canet <benoit@irqsave.net>
This commit is contained in:
Stefan Hajnoczi 2014-05-14 16:22:47 +02:00
parent 22524f7262
commit b15446fdbf

View File

@ -1703,6 +1703,7 @@ void qmp_block_set_io_throttle(const char *device, int64_t bps, int64_t bps_rd,
{
ThrottleConfig cfg;
BlockDriverState *bs;
AioContext *aio_context;
bs = bdrv_find(device);
if (!bs) {
@ -1746,6 +1747,9 @@ void qmp_block_set_io_throttle(const char *device, int64_t bps, int64_t bps_rd,
return;
}
aio_context = bdrv_get_aio_context(bs);
aio_context_acquire(aio_context);
if (!bs->io_limits_enabled && throttle_enabled(&cfg)) {
bdrv_io_limits_enable(bs);
} else if (bs->io_limits_enabled && !throttle_enabled(&cfg)) {
@ -1755,6 +1759,8 @@ void qmp_block_set_io_throttle(const char *device, int64_t bps, int64_t bps_rd,
if (bs->io_limits_enabled) {
bdrv_set_io_limits(bs, &cfg);
}
aio_context_release(aio_context);
}
int do_drive_del(Monitor *mon, const QDict *qdict, QObject **ret_data)