I used this as a reference in one of patch 1/5 in the recent series. Oren.
Serge E. Hallyn wrote: > Alas they uglify the error paths during restart, but I can't > count on two hands the number of times I've had to add these and > recompile to find one silly bug or other, so I suggest that it > may be worth having these in the code anyway. > > Signed-off-by: Serge E. Hallyn <[email protected]> > --- > checkpoint/restart.c | 50 > +++++++++++++++++++++++++++++++++++++++----------- > 1 files changed, 39 insertions(+), 11 deletions(-) > > diff --git a/checkpoint/restart.c b/checkpoint/restart.c > index 1085ed5..ebdd5ba 100644 > --- a/checkpoint/restart.c > +++ b/checkpoint/restart.c > @@ -662,6 +662,7 @@ static int restore_activate_next(struct ckpt_ctx *ctx) > rcu_read_unlock(); > > if (!task) { > + ckpt_debug("could not find task %d\n", pid); > restore_notify_error(ctx, -ESRCH); > return -ESRCH; > } > @@ -685,6 +686,7 @@ static int wait_task_active(struct ckpt_ctx *ctx) > ckpt_debug("active %d < %d (ret %d)\n", > ctx->active_pid, ctx->nr_pids, ret); > if (!ret && ckpt_test_ctx_error(ctx)) { > + ckpt_debug("wait_event_interruptible returned %d\n", ret); > force_sig(SIGKILL, current); > ret = -EBUSY; > } > @@ -827,20 +829,25 @@ static int do_restore_task(void) > > /* wait for our turn, do the restore, and tell next task in line */ > ret = wait_task_active(ctx); > - if (ret < 0) > + if (ret < 0) { > + ckpt_debug("wait_task_active returned %d\n", ret); > goto out; > + } > > ckpt_debug_log_running(ctx); > > zombie = restore_task(ctx); > if (zombie < 0) { > + ckpt_debug("restore_task returned %d\n", ret); > ret = zombie; > goto out; > } > > ret = restore_activate_next(ctx); > - if (ret < 0) > + if (ret < 0) { > + ckpt_debug("restore_activate_next returned %d\n", ret); > goto out; > + } > > /* > * zombie: we're done here; do_exit() will notice the @ctx on > @@ -855,6 +862,8 @@ static int do_restore_task(void) > > restore_task_done(ctx); > ret = wait_task_sync(ctx); > + if (ret) > + ckpt_debug("wait_task_sync returned %d\n", ret); > out: > old_ctx = xchg(¤t->checkpoint_ctx, NULL); > if (old_ctx) > @@ -970,12 +979,14 @@ static int wait_all_tasks_finish(struct ckpt_ctx *ctx) > > BUG_ON(ctx->active_pid != -1); > ret = restore_activate_next(ctx); > - if (ret < 0) > + if (ret < 0) { > + ckpt_debug("restore_activate_next returned %d\n", ret); > return ret; > + } > > ret = wait_for_completion_interruptible(&ctx->complete); > > - ckpt_debug("final sync kflags %#lx\n", ctx->kflags); > + ckpt_debug("final sync kflags %#lx (ret %d)\n", ctx->kflags, ret); > /* > * Usually when restart fails, the restarting task will first > * set @ctx->errno before waking us up. In the rare event that > @@ -1051,18 +1062,24 @@ static int do_restore_coord(struct ckpt_ctx *ctx, > pid_t pid) > ckpt_debug_log_running(ctx); > > ret = restore_read_header(ctx); > - if (ret < 0) > + if (ret < 0) { > + ckpt_debug("restore_read_header returned %d\n", ret); > return ret; > + } > ret = restore_read_tree(ctx); > - if (ret < 0) > + if (ret < 0) { > + ckpt_debug("restore_read_tree returned %d\n", ret); > return ret; > + } > > if ((ctx->uflags & RESTART_TASKSELF) && ctx->nr_pids != 1) > return -EINVAL; > > ret = init_restart_ctx(ctx, pid); > - if (ret < 0) > + if (ret < 0) { > + ckpt_debug("init_restart_ctx returned %d\n", ret); > return ret; > + } > > /* > * Populate own ->checkpoint_ctx: if an ancestor attempts to > @@ -1094,8 +1111,10 @@ static int do_restore_coord(struct ckpt_ctx *ctx, > pid_t pid) > } else { > /* prepare descendants' t->checkpoint_ctx point to coord */ > ret = prepare_descendants(ctx, ctx->root_task); > - if (ret < 0) > + if (ret < 0) { > + ckpt_debug("prepare_descendants returned %d", ret); > goto out; > + } > > /* tell tasks we're ready for them to dec ctx->nr_running */ > wake_up_all(&ctx->waitq); > @@ -1108,17 +1127,23 @@ static int do_restore_coord(struct ckpt_ctx *ctx, > pid_t pid) > > /* wait for all other tasks to complete do_restore_task() */ > ret = wait_all_tasks_finish(ctx); > - if (ret < 0) > + if (ret < 0) { > + ckpt_debug("wait_all_tasks_finish returned %d", ret); > goto out; > + } > } > > ret = deferqueue_run(ctx->deferqueue); /* run deferred work */ > - if (ret < 0) > + if (ret < 0) { > + ckpt_debug("deferqueue_run returned %d\n", ret); > goto out; > + } > > ret = restore_read_tail(ctx); > - if (ret < 0) > + if (ret < 0) { > + ckpt_debug("restore_read_tail returned %d\n", ret); > goto out; > + } > > if (ctx->uflags & RESTART_FROZEN) { > ret = cgroup_freezer_make_frozen(ctx->root_task); > @@ -1202,6 +1227,9 @@ long do_restart(struct ckpt_ctx *ctx, pid_t pid, > unsigned long flags) > else > ret = do_restore_task(); > > + if (ret < 0) > + ckpt_debug("ret %ld\n", ret); > + > /* restart(2) isn't idempotent: should not be auto-restarted */ > if (ret == -ERESTARTSYS || ret == -ERESTARTNOINTR || > ret == -ERESTARTNOHAND || ret == -ERESTART_RESTARTBLOCK) _______________________________________________ Containers mailing list [email protected] https://lists.linux-foundation.org/mailman/listinfo/containers _______________________________________________ Devel mailing list [email protected] https://openvz.org/mailman/listinfo/devel
