From: Greg KH Subject: [patch 093/104] jbd2: dont give up looking for space so easily in __jbd2_log_wait_for_space Date: Wed, 3 Dec 2008 11:56:36 -0800 Message-ID: <20081203195636.GP8950@kroah.com> References: <20081203193901.715896543@mini.kroah.org> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: Justin Forbes , Zwane Mwaikambo , Theodore Ts'o , Randy Dunlap , Dave Jones , Chuck Wolber , Chris Wedgwood , Michael Krufky , Chuck Ebbert , Domenico Andreoli , Willy Tarreau , Rodrigo Rubira Branco , Jake Edge , Eugene Teo , torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Toshiyuki Okajima , Ext4 Developers List , Duane Griffin To: linux-kernel@vger.kernel.org, stable@kernel.org Return-path: Received: from kroah.org ([198.145.64.141]:56731 "EHLO coco.kroah.org" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1754081AbYLCT57 (ORCPT ); Wed, 3 Dec 2008 14:57:59 -0500 Content-Disposition: inline; filename="jbd2-don-t-give-up-looking-for-space-so-easily-in-__jbd2_log_wait_for_space.patch" In-Reply-To: <20081203194725.GA8950@kroah.com> Sender: linux-ext4-owner@vger.kernel.org List-ID: 2.6.27-stable review patch. If anyone has any objections, please let u= s know. ------------------ =46rom: "Theodore Ts'o" (cherry picked from commit 8c3f25d8950c3e9fe6c9849f88679b3f2a071550) Commit 23f8b79e introducd a regression because it assumed that if there were no transactions ready to be checkpointed, that no progress could be made on making space available in the journal, and so the journal should be aborted. This assumption is false; it could be the case that simply calling jbd2_cleanup_journal_tail() will recover the necessary space, or, for small journals, the currently committing transaction could be responsible for chewing up the required space in the log, so we need to wait for the currently committing transaction to finish before trying to force a checkpoint operation. This patch fixes a bug reported by Mihai Harpau at: https://bugzilla.redhat.com/show_bug.cgi?id=3D469582 This patch fixes a bug reported by Fran=E7ois Valenduc at: http://bugzilla.kernel.org/show_bug.cgi?id=3D11840 Signed-off-by: "Theodore Ts'o" Cc: Duane Griffin Cc: Toshiyuki Okajima Signed-off-by: Greg Kroah-Hartman --- fs/jbd2/checkpoint.c | 32 +++++++++++++++++++++++++------- 1 file changed, 25 insertions(+), 7 deletions(-) --- a/fs/jbd2/checkpoint.c +++ b/fs/jbd2/checkpoint.c @@ -114,7 +114,7 @@ static int __try_to_free_cp_buf(struct j */ void __jbd2_log_wait_for_space(journal_t *journal) { - int nblocks; + int nblocks, space_left; assert_spin_locked(&journal->j_state_lock); =20 nblocks =3D jbd_space_needed(journal); @@ -127,25 +127,43 @@ void __jbd2_log_wait_for_space(journal_t /* * Test again, another process may have checkpointed while we * were waiting for the checkpoint lock. If there are no - * outstanding transactions there is nothing to checkpoint and - * we can't make progress. Abort the journal in this case. + * transactions ready to be checkpointed, try to recover + * journal space by calling cleanup_journal_tail(), and if + * that doesn't work, by waiting for the currently committing + * transaction to complete. If there is absolutely no way + * to make progress, this is either a BUG or corrupted + * filesystem, so abort the journal and leave a stack + * trace for forensic evidence. */ spin_lock(&journal->j_state_lock); spin_lock(&journal->j_list_lock); nblocks =3D jbd_space_needed(journal); - if (__jbd2_log_space_left(journal) < nblocks) { + space_left =3D __jbd2_log_space_left(journal); + if (space_left < nblocks) { int chkpt =3D journal->j_checkpoint_transactions !=3D NULL; + tid_t tid =3D 0; =20 + if (journal->j_committing_transaction) + tid =3D journal->j_committing_transaction->t_tid; spin_unlock(&journal->j_list_lock); spin_unlock(&journal->j_state_lock); if (chkpt) { jbd2_log_do_checkpoint(journal); + } else if (jbd2_cleanup_journal_tail(journal) =3D=3D 0) { + /* We were able to recover space; yay! */ + ; + } else if (tid) { + jbd2_log_wait_commit(journal, tid); } else { - printk(KERN_ERR "%s: no transactions\n", - __func__); + printk(KERN_ERR "%s: needed %d blocks and " + "only had %d space available\n", + __func__, nblocks, space_left); + printk(KERN_ERR "%s: no way to get more " + "journal space in %s\n", __func__, + journal->j_devname); + WARN_ON(1); jbd2_journal_abort(journal, 0); }