From 1abc85b8d026a2d72442b0edaee5213d0ee73c1f Mon Sep 17 00:00:00 2001 From: Michal Schmidt Date: Thu, 25 Oct 2012 02:31:49 +0200 Subject: [PATCH] job: avoid recursion into transaction code from job cancelation I hit an "assert(j->installed)" failure in transaction_apply(). Looking into the backtrace I saw what happened: 1. The system was booting. var.mount/start was an installed job. 2. I pressed Ctrl+Alt+Del. 3. reboot.target was going to be isolated. 4. transaction_apply() proceeded to install a var.mount/stop job. 5. job_install() canceled the conflicting start job. 6. Depending jobs ended recursively with JOB_DEPENDENCY, among them was local-fs.target/start. 7. Its OnFailure action triggered - emergency.target was now going to be isolated. 8. We recursed back into transaction_apply() where the half-installed var.mount/stop job confused us. Recursing from job installation back into the transaction code cannot be a good idea. Avoid the problem by canceling the conflicting job non-recursively in job_install(). I don't think we'll miss anything by not recursing here. After all, we are called from transaction_apply(). We will not be installing just this one job, but all jobs from a transaction. All requirement dependencies will be included in it and will be installed separately. Every transaction job will get a chance to cancel its own conflicting installed job. --- src/core/job.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/src/core/job.c b/src/core/job.c index cb5674b..f08b8cb 100644 --- a/src/core/job.c +++ b/src/core/job.c @@ -180,7 +180,7 @@ Job* job_install(Job *j) { if (uj) { if (j->type != JOB_NOP && job_type_is_conflicting(uj->type, j->type)) - job_finish_and_invalidate(uj, JOB_CANCELED, true); + job_finish_and_invalidate(uj, JOB_CANCELED, false); else { /* not conflicting, i.e. mergeable */ -- 1.7.10.4