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[Qemu-devel] [PULL 11/15] migration: re-active images while migration be
From: |
Dr. David Alan Gilbert (git) |
Subject: |
[Qemu-devel] [PULL 11/15] migration: re-active images while migration been canceled after inactive them |
Date: |
Tue, 24 Jan 2017 18:47:38 +0000 |
From: zhanghailiang <address@hidden>
commit fe904ea8242cbae2d7e69c052c754b8f5f1ba1d6 fixed a case
which migration aborted QEMU because it didn't regain the control
of images while some errors happened.
Actually, there are another two cases can trigger the same error reports:
" bdrv_co_do_pwritev: Assertion `!(bs->open_flags & 0x0800)' failed",
Case 1, codes path:
migration_thread()
migration_completion()
bdrv_inactivate_all() ----------------> inactivate images
qemu_savevm_state_complete_precopy()
socket_writev_buffer() --------> error because destination fails
qemu_fflush() ----------------> set error on migration stream
-> qmp_migrate_cancel() ----------------> user cancelled migration concurrently
-> migrate_set_state() ------------------> set migrate CANCELLIN
migration_completion() -----------------> go on to fail_invalidate
if (s->state == MIGRATION_STATUS_ACTIVE) -> Jump this branch
Case 2, codes path:
migration_thread()
migration_completion()
bdrv_inactivate_all() ----------------> inactivate images
migreation_completion() finished
-> qmp_migrate_cancel() ---------------> user cancelled migration concurrently
qemu_mutex_lock_iothread();
qemu_bh_schedule (s->cleanup_bh);
As we can see from above, qmp_migrate_cancel can slip in whenever
migration_thread does not hold the global lock. If this happens after
bdrv_inactive_all() been called, the above error reports will appear.
To prevent this, we can call bdrv_invalidate_cache_all() in qmp_migrate_cancel()
directly if we find images become inactive.
Besides, bdrv_invalidate_cache_all() in migration_completion() doesn't have the
protection of big lock, fix it by add the missing qemu_mutex_lock_iothread();
Signed-off-by: zhanghailiang <address@hidden>
Message-Id: <address@hidden>
Reviewed-by: Dr. David Alan Gilbert <address@hidden>
Reviewed-by: Stefan Hajnoczi <address@hidden>
Signed-off-by: Dr. David Alan Gilbert <address@hidden>
---
include/migration/migration.h | 3 +++
migration/migration.c | 15 +++++++++++++++
2 files changed, 18 insertions(+)
diff --git a/include/migration/migration.h b/include/migration/migration.h
index 7881e89..af9135f 100644
--- a/include/migration/migration.h
+++ b/include/migration/migration.h
@@ -180,6 +180,9 @@ struct MigrationState
/* Flag set once the migration thread is running (and needs joining) */
bool migration_thread_running;
+ /* Flag set once the migration thread called bdrv_inactivate_all */
+ bool block_inactive;
+
/* Queue of outstanding page requests from the destination */
QemuMutex src_page_req_mutex;
QSIMPLEQ_HEAD(src_page_requests, MigrationSrcPageRequest)
src_page_requests;
diff --git a/migration/migration.c b/migration/migration.c
index 7dcb7d7..f8a4500 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -1006,6 +1006,16 @@ static void migrate_fd_cancel(MigrationState *s)
if (s->state == MIGRATION_STATUS_CANCELLING && f) {
qemu_file_shutdown(f);
}
+ if (s->state == MIGRATION_STATUS_CANCELLING && s->block_inactive) {
+ Error *local_err = NULL;
+
+ bdrv_invalidate_cache_all(&local_err);
+ if (local_err) {
+ error_report_err(local_err);
+ } else {
+ s->block_inactive = false;
+ }
+ }
}
void add_migration_state_change_notifier(Notifier *notify)
@@ -1745,6 +1755,7 @@ static void migration_completion(MigrationState *s, int
current_active_state,
if (ret >= 0) {
qemu_file_set_rate_limit(s->to_dst_file, INT64_MAX);
qemu_savevm_state_complete_precopy(s->to_dst_file, false);
+ s->block_inactive = true;
}
}
qemu_mutex_unlock_iothread();
@@ -1795,10 +1806,14 @@ fail_invalidate:
if (s->state == MIGRATION_STATUS_ACTIVE) {
Error *local_err = NULL;
+ qemu_mutex_lock_iothread();
bdrv_invalidate_cache_all(&local_err);
if (local_err) {
error_report_err(local_err);
+ } else {
+ s->block_inactive = false;
}
+ qemu_mutex_unlock_iothread();
}
fail:
--
2.9.3
- [Qemu-devel] [PULL 09/15] migration: disallow migrate_add_blocker during migration, (continued)
- [Qemu-devel] [PULL 09/15] migration: disallow migrate_add_blocker during migration, Dr. David Alan Gilbert (git), 2017/01/24
- [Qemu-devel] [PULL 02/15] migration: extend VMStateInfo, Dr. David Alan Gilbert (git), 2017/01/24
- Re: [Qemu-devel] [PULL 02/15] migration: extend VMStateInfo, Fam Zheng, 2017/01/25
- Re: [Qemu-devel] [PULL 02/15] migration: extend VMStateInfo, Dr. David Alan Gilbert, 2017/01/25
- Re: [Qemu-devel] [PULL 02/15] migration: extend VMStateInfo, Cornelia Huck, 2017/01/25
- Re: [Qemu-devel] [PULL 02/15] migration: extend VMStateInfo, Fam Zheng, 2017/01/25
- Re: [Qemu-devel] [PULL 02/15] migration: extend VMStateInfo, Cornelia Huck, 2017/01/25
- Re: [Qemu-devel] [PULL 02/15] migration: extend VMStateInfo, Dr. David Alan Gilbert, 2017/01/25
[Qemu-devel] [PULL 03/15] migration: migrate QTAILQ, Dr. David Alan Gilbert (git), 2017/01/24
[Qemu-devel] [PULL 08/15] migration: Allow "device add" options to only add migratable devices, Dr. David Alan Gilbert (git), 2017/01/24
[Qemu-devel] [PULL 11/15] migration: re-active images while migration been canceled after inactive them,
Dr. David Alan Gilbert (git) <=
[Qemu-devel] [PULL 14/15] migration: transform remaining DPRINTF into trace_, Dr. David Alan Gilbert (git), 2017/01/24
[Qemu-devel] [PULL 15/15] migration/tracing: Add tracing on save, Dr. David Alan Gilbert (git), 2017/01/24
Re: [Qemu-devel] [PULL 00/15] migration queue, Peter Maydell, 2017/01/25