From 6c1da04ed152cc08f30b0fdad56780dd3f08fb81 Mon Sep 17 00:00:00 2001 Message-Id: <6c1da04ed152cc08f30b0fdad56780dd3f08fb81.1418787305.git.jen@redhat.com> In-Reply-To: References: From: Stefan Hajnoczi Date: Wed, 10 Dec 2014 13:53:33 -0600 Subject: [CHANGE 11/12] block/migration: Disable cache invalidate for incoming migration To: rhvirt-patches@redhat.com, jen@redhat.com RH-Author: Stefan Hajnoczi Message-id: <1418219613-27149-1-git-send-email-stefanha@redhat.com> Patchwork-id: 62815 O-Subject: [RHEV-7.1 qemu-kvm-rhev PATCH] block/migration: Disable cache invalidate for incoming migration Bugzilla: 1171552 RH-Acked-by: Fam Zheng RH-Acked-by: Max Reitz RH-Acked-by: Paolo Bonzini From: Alexey Kardashevskiy When migrated using libvirt with "--copy-storage-all", at the end of migration there is race between NBD mirroring task trying to do flush and migration completion, both end up invalidating cache. Since qcow2 driver does not handle this situation very well, random crashes happen. This disables the BDRV_O_INCOMING flag for the block device being migrated once the cache has been invalidated. Signed-off-by: Alexey Kardashevskiy Reviewed-by: Paolo Bonzini fixed parens by hand Signed-off-by: Juan Quintela (cherry picked from commit 7ea2d269cb84ca7a2f4b7c3735634176f7c1dc35) Signed-off-by: Stefan Hajnoczi Signed-off-by: Jeff E. Nelson Conflicts: nbd.c Context conflict due to dataplane changes in QEMU 2.2 that are not yet in RHEL 7.1 qemu-kvm-rhev. Signed-off-by: Jeff E. Nelson --- block.c | 18 +++++------------- migration.c | 1 - nbd.c | 6 ++++++ 3 files changed, 11 insertions(+), 14 deletions(-) diff --git a/block.c b/block.c index cef9bda..29173d4 100644 --- a/block.c +++ b/block.c @@ -5019,6 +5019,11 @@ void bdrv_invalidate_cache(BlockDriverState *bs, Error **errp) return; } + if (!(bs->open_flags & BDRV_O_INCOMING)) { + return; + } + bs->open_flags &= ~BDRV_O_INCOMING; + if (bs->drv->bdrv_invalidate_cache) { bs->drv->bdrv_invalidate_cache(bs, &local_err); } else if (bs->file) { @@ -5054,19 +5059,6 @@ void bdrv_invalidate_cache_all(Error **errp) } } -void bdrv_clear_incoming_migration_all(void) -{ - BlockDriverState *bs; - - QTAILQ_FOREACH(bs, &bdrv_states, device_list) { - AioContext *aio_context = bdrv_get_aio_context(bs); - - aio_context_acquire(aio_context); - bs->open_flags = bs->open_flags & ~(BDRV_O_INCOMING); - aio_context_release(aio_context); - } -} - int bdrv_flush(BlockDriverState *bs) { Coroutine *co; diff --git a/migration.c b/migration.c index deeb491..ba28e6c 100644 --- a/migration.c +++ b/migration.c @@ -103,7 +103,6 @@ static void process_incoming_migration_co(void *opaque) } qemu_announce_self(); - bdrv_clear_incoming_migration_all(); /* Make sure all file formats flush their mutable metadata */ bdrv_invalidate_cache_all(&local_err); if (local_err) { diff --git a/nbd.c b/nbd.c index e7d1cee..9bb14a6 100644 --- a/nbd.c +++ b/nbd.c @@ -933,6 +933,12 @@ NBDExport *nbd_export_new(BlockDriverState *bs, off_t dev_offset, exp->size = size == -1 ? bdrv_getlength(bs) : size; exp->close = close; bdrv_ref(bs); + /* + * NBD exports are used for non-shared storage migration. Make sure + * that BDRV_O_INCOMING is cleared and the image is ready for write + * access since the export could be available before migration handover. + */ + bdrv_invalidate_cache(bs, NULL); return exp; } -- 2.1.0