From: Pavel Emelianov Subject: Re: [PATCH] Check for error returned by kthread_create on creating journal thread Date: Mon, 16 Apr 2007 15:10:42 +0400 Message-ID: <462359B2.7070706@sw.ru> References: <4623289A.1000101@sw.ru> <20070416102107.GA12818@infradead.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: sct@redhat.com, akpm@linux-foundation.org, linux-ext4@vger.kernel.org, Linux Kernel Mailing List , devel@openvz.org To: Christoph Hellwig Return-path: In-Reply-To: <20070416102107.GA12818@infradead.org> Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-ext4.vger.kernel.org Christoph Hellwig wrote: > On Mon, Apr 16, 2007 at 11:41:14AM +0400, Pavel Emelianov wrote: >> If the thread failed to create the subsequent wait_event >> will hang forever. >> >> This is likely to happen if kernel hits max_threads limit. >> >> Will be critical for virtualization systems that limit the >> number of tasks and kernel memory usage within the container. > >> --- ./fs/jbd/journal.c.jbdthreads 2007-04-16 11:17:36.000000000 +0400 >> +++ ./fs/jbd/journal.c 2007-04-16 11:30:09.000000000 +0400 >> @@ -211,10 +211,16 @@ end_loop: >> return 0; >> } >> >> -static void journal_start_thread(journal_t *journal) >> +static int journal_start_thread(journal_t *journal) >> { >> - kthread_run(kjournald, journal, "kjournald"); >> + struct task_struct *t; >> + >> + t = kthread_run(kjournald, journal, "kjournald"); >> + if (IS_ERR(t)) >> + return PTR_ERR(t); >> + >> wait_event(journal->j_wait_done_commit, journal->j_task != 0); > > Note that this wait_event should exist at all, and the return Should NOT you mean? > value of kthread_run should be assigned to journal->j_task. Also > the code doesn't use the kthread primitives in other places leading > to crufty code. Well, this could be done with a separate patch, I think. > - > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ >