From b15446fdbf4ac2b29f6ee5080630a80715abfc20 Mon Sep 17 00:00:00 2001 From: Stefan Hajnoczi Date: Wed, 14 May 2014 16:22:47 +0200 Subject: 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 Reviewed-by: Benoit Canet --- blockdev.c | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'blockdev.c') diff --git a/blockdev.c b/blockdev.c index 9b5261b765..4cbcc56b5e 100644 --- a/blockdev.c +++ b/blockdev.c @@ -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) -- cgit v1.2.1