From: akpm@linux-foundation.org Subject: + jbd-check-for-error-returned-by-kthread_create-on-creating-journal-thread.patch added to -mm tree Date: Fri, 20 Apr 2007 15:38:17 -0700 Message-ID: <200704202238.l3KMcHML025474@shell0.pdx.osdl.net> Cc: xemul@sw.ru, hch@lst.de, linux-ext4@vger.kernel.org To: mm-commits@vger.kernel.org Return-path: Received: from smtp1.linux-foundation.org ([65.172.181.25]:60841 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754514AbXDTWic (ORCPT ); Fri, 20 Apr 2007 18:38:32 -0400 Sender: linux-ext4-owner@vger.kernel.org List-Id: linux-ext4.vger.kernel.org The patch titled jbd: check for error returned by kthread_create on creating journal thread has been added to the -mm tree. Its filename is jbd-check-for-error-returned-by-kthread_create-on-creating-journal-thread.patch *** Remember to use Documentation/SubmitChecklist when testing your code *** See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find out what to do about this ------------------------------------------------------ Subject: jbd: check for error returned by kthread_create on creating journal thread From: Pavel Emelianov 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. (akpm: JBD should be converted fully to the kthread API: kthread_should_stop() and kthread_stop()). Cc: Cc: Christoph Hellwig Signed-off-by: Andrew Morton --- fs/jbd/journal.c | 13 +++++++++---- fs/jbd2/journal.c | 13 +++++++++---- 2 files changed, 18 insertions(+), 8 deletions(-) diff -puN fs/jbd/journal.c~jbd-check-for-error-returned-by-kthread_create-on-creating-journal-thread fs/jbd/journal.c --- a/fs/jbd/journal.c~jbd-check-for-error-returned-by-kthread_create-on-creating-journal-thread +++ a/fs/jbd/journal.c @@ -210,10 +210,16 @@ 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); + return 0; } static void journal_kill_thread(journal_t *journal) @@ -839,8 +845,7 @@ static int journal_reset(journal_t *jour /* Add the dynamic fields and write it to disk. */ journal_update_superblock(journal, 1); - journal_start_thread(journal); - return 0; + return journal_start_thread(journal); } /** diff -puN fs/jbd2/journal.c~jbd-check-for-error-returned-by-kthread_create-on-creating-journal-thread fs/jbd2/journal.c --- a/fs/jbd2/journal.c~jbd-check-for-error-returned-by-kthread_create-on-creating-journal-thread +++ a/fs/jbd2/journal.c @@ -210,10 +210,16 @@ end_loop: return 0; } -static void jbd2_journal_start_thread(journal_t *journal) +static int jbd2_journal_start_thread(journal_t *journal) { - kthread_run(kjournald2, journal, "kjournald2"); + struct task_struct *t; + + t = kthread_run(kjournald2, journal, "kjournald2"); + if (IS_ERR(t)) + return PTR_ERR(t); + wait_event(journal->j_wait_done_commit, journal->j_task != 0); + return 0; } static void journal_kill_thread(journal_t *journal) @@ -839,8 +845,7 @@ static int journal_reset(journal_t *jour /* Add the dynamic fields and write it to disk. */ jbd2_journal_update_superblock(journal, 1); - jbd2_journal_start_thread(journal); - return 0; + return jbd2_journal_start_thread(journal); } /** _ Patches currently in -mm which might be from xemul@sw.ru are origin.patch lockdep-treats-down_write_trylock-like-regular-down_write.patch introduce-a-handy-list_first_entry-macro-v2.patch report-that-kernel-is-tainted-if-there-were-an-oops-before.patch jbd-check-for-error-returned-by-kthread_create-on-creating-journal-thread.patch