diff options
| -rw-r--r-- | block.c | 20 |
1 files changed, 20 insertions, 0 deletions
@@ -1463,6 +1463,17 @@ static int bdrv_rw_co(BlockDriverState *bs, int64_t sector_num, uint8_t *buf, qemu_iovec_init_external(&qiov, &iov, 1); + /** + * In sync call context, when the vcpu is blocked, this throttling timer + * will not fire; so the I/O throttling function has to be disabled here + * if it has been enabled. + */ + if (bs->io_limits_enabled) { + fprintf(stderr, "Disabling I/O throttling on '%s' due " + "to synchronous I/O.\n", bdrv_get_device_name(bs)); + bdrv_io_limits_disable(bs); + } + if (qemu_in_coroutine()) { /* Fast-path if already in coroutine context */ bdrv_rw_co_entry(&rwco); @@ -1969,10 +1980,19 @@ static int guess_disk_lchs(BlockDriverState *bs, struct partition *p; uint32_t nr_sects; uint64_t nb_sectors; + bool enabled; bdrv_get_geometry(bs, &nb_sectors); + /** + * The function will be invoked during startup not only in sync I/O mode, + * but also in async I/O mode. So the I/O throttling function has to + * be disabled temporarily here, not permanently. + */ + enabled = bs->io_limits_enabled; + bs->io_limits_enabled = false; ret = bdrv_read(bs, 0, buf, 1); + bs->io_limits_enabled = enabled; if (ret < 0) return -1; /* test msdos magic */ |