diff options
| -rw-r--r-- | migration/migration.c | 39 | ||||
| -rw-r--r-- | migration/migration.h | 8 | ||||
| -rw-r--r-- | migration/ram.c | 1 |
3 files changed, 35 insertions, 13 deletions
diff --git a/migration/migration.c b/migration/migration.c index 21b94f75a3..62dbcb7d52 100644 --- a/migration/migration.c +++ b/migration/migration.c @@ -1879,9 +1879,11 @@ static void migrate_fd_cancel(MigrationState *s) QEMUFile *f = migrate_get_current()->to_dst_file; trace_migrate_fd_cancel(); - if (s->rp_state.from_dst_file) { - /* shutdown the rp socket, so causing the rp thread to shutdown */ - qemu_file_shutdown(s->rp_state.from_dst_file); + WITH_QEMU_LOCK_GUARD(&s->qemu_file_lock) { + if (s->rp_state.from_dst_file) { + /* shutdown the rp socket, so causing the rp thread to shutdown */ + qemu_file_shutdown(s->rp_state.from_dst_file); + } } do { @@ -2686,6 +2688,23 @@ static int migrate_handle_rp_resume_ack(MigrationState *s, uint32_t value) return 0; } +/* Release ms->rp_state.from_dst_file in a safe way */ +static void migration_release_from_dst_file(MigrationState *ms) +{ + QEMUFile *file; + + WITH_QEMU_LOCK_GUARD(&ms->qemu_file_lock) { + /* + * Reset the from_dst_file pointer first before releasing it, as we + * can't block within lock section + */ + file = ms->rp_state.from_dst_file; + ms->rp_state.from_dst_file = NULL; + } + + qemu_fclose(file); +} + /* * Handles messages sent on the return path towards the source VM * @@ -2827,11 +2846,13 @@ out: * Maybe there is something we can do: it looks like a * network down issue, and we pause for a recovery. */ - qemu_fclose(rp); - ms->rp_state.from_dst_file = NULL; + migration_release_from_dst_file(ms); rp = NULL; if (postcopy_pause_return_path_thread(ms)) { - /* Reload rp, reset the rest */ + /* + * Reload rp, reset the rest. Referencing it is safe since + * it's reset only by us above, or when migration completes + */ rp = ms->rp_state.from_dst_file; ms->rp_state.error = false; goto retry; @@ -2843,8 +2864,7 @@ out: } trace_source_return_path_thread_end(); - ms->rp_state.from_dst_file = NULL; - qemu_fclose(rp); + migration_release_from_dst_file(ms); rcu_unregister_thread(); return NULL; } @@ -2852,7 +2872,6 @@ out: static int open_return_path_on_source(MigrationState *ms, bool create_thread) { - ms->rp_state.from_dst_file = qemu_file_get_return_path(ms->to_dst_file); if (!ms->rp_state.from_dst_file) { return -1; @@ -3746,7 +3765,7 @@ static void *migration_thread(void *opaque) * If we opened the return path, we need to make sure dst has it * opened as well. */ - if (s->rp_state.from_dst_file) { + if (s->rp_state.rp_thread_created) { /* Now tell the dest that it should open its end so it can reply */ qemu_savevm_send_open_return_path(s->to_dst_file); diff --git a/migration/migration.h b/migration/migration.h index c302879fad..7a5aa8c2fd 100644 --- a/migration/migration.h +++ b/migration/migration.h @@ -154,12 +154,13 @@ struct MigrationState { QemuThread thread; QEMUBH *vm_start_bh; QEMUBH *cleanup_bh; + /* Protected by qemu_file_lock */ QEMUFile *to_dst_file; QIOChannelBuffer *bioc; /* - * Protects to_dst_file pointer. We need to make sure we won't - * yield or hang during the critical section, since this lock will - * be used in OOB command handler. + * Protects to_dst_file/from_dst_file pointers. We need to make sure we + * won't yield or hang during the critical section, since this lock will be + * used in OOB command handler. */ QemuMutex qemu_file_lock; @@ -192,6 +193,7 @@ struct MigrationState { /* State related to return path */ struct { + /* Protected by qemu_file_lock */ QEMUFile *from_dst_file; QemuThread rp_thread; bool error; diff --git a/migration/ram.c b/migration/ram.c index b5fc454b2f..f728f5072f 100644 --- a/migration/ram.c +++ b/migration/ram.c @@ -4012,6 +4012,7 @@ static void ram_dirty_bitmap_reload_notify(MigrationState *s) int ram_dirty_bitmap_reload(MigrationState *s, RAMBlock *block) { int ret = -EINVAL; + /* from_dst_file is always valid because we're within rp_thread */ QEMUFile *file = s->rp_state.from_dst_file; unsigned long *le_bitmap, nbits = block->used_length >> TARGET_PAGE_BITS; uint64_t local_size = DIV_ROUND_UP(nbits, 8); |