Re: [libvirt] [RFC PATCH] qcow2: Fix race in cache invalidation

Right. Cool. So is below what was suggested? I am doublechecking as it does not solve the original issue - the bottomhalf is called first and then nbd_trip() crashes in qcow2_co_flush_to_os(). diff --git a/block.c b/block.c index d06dd51..1e6dfd1 100644 --- a/block.c +++ b/block.c @@ -5037,20 +5037,22 @@ void bdrv_invalidate_cache(BlockDriverState *bs, Error **errp) if (local_err) { error_propagate(errp, local_err); return; } ret = refresh_total_sectors(bs, bs->total_sectors); if (ret < 0) { error_setg_errno(errp, -ret, "Could not refresh total sector count"); return; } + + bdrv_drain_all(); }

+static QEMUBH *migration_complete_bh; +static void process_incoming_migration_complete(void *opaque); + static void process_incoming_migration_co(void *opaque) { QEMUFile *f = opaque; - Error *local_err = NULL; int ret; ret = qemu_loadvm_state(f); qemu_fclose(f);

free_xbzrle_decoded_buf(); if (ret < 0) { error_report("load of migration failed: %s", strerror(-ret)); exit(EXIT_FAILURE); } qemu_announce_self(); bdrv_clear_incoming_migration_all(); + + migration_complete_bh = aio_bh_new(qemu_get_aio_context(), + process_incoming_migration_complete, + NULL); + qemu_bh_schedule(migration_complete_bh); +} + +static void process_incoming_migration_complete(void *opaque) +{ + Error *local_err = NULL; + /* Make sure all file formats flush their mutable metadata */ bdrv_invalidate_cache_all(&local_err); if (local_err) { qerror_report_err(local_err); error_free(local_err); exit(EXIT_FAILURE); } if (autostart) { vm_start(); } else { runstate_set(RUN_STATE_PAUSED); } + qemu_bh_delete(migration_complete_bh); + migration_complete_bh = NULL; }