From mboxrd@z Thu Jan 1 00:00:00 1970 From: Greg KH Subject: [patch 20/39] jbd2: Add barrier not supported test to journal_wait_on_commit_record Date: Wed, 18 Feb 2009 13:32:51 -0800 Message-ID: <20090218213251.GU19814@kroah.com> References: <20090218212144.965748151@mini.kroah.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii 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, linux-ext4@vger.kernel.org To: linux-kernel@vger.kernel.org, stable@kernel.org Return-path: Received: from kroah.org ([198.145.64.141]:56261 "EHLO coco.kroah.org" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1756920AbZBRVfq (ORCPT ); Wed, 18 Feb 2009 16:35:46 -0500 Content-Disposition: inline; filename="jbd2-add-barrier-not-supported-test-to-journal_wait_on_commit_record.patch" In-Reply-To: <20090218213021.GA19814@kroah.com> Sender: linux-ext4-owner@vger.kernel.org List-ID: 2.6.28-stable review patch. If anyone has any objections, please let us know. ------------------ From: "Theodore Ts'o" (cherry picked from commit fd98496f467b3d26d05ab1498f41718b5ef13de5) Xen doesn't report that barriers are not supported until buffer I/O is reported as completed, instead of when the buffer I/O is submitted. Add a check and a fallback codepath to journal_wait_on_commit_record() to detect this case, so that attempts to mount ext4 filesystems on LVM/devicemapper devices on Xen guests don't blow up with an "Aborting journal on device XXX"; "Remounting filesystem read-only" error. Thanks to Andreas Sundstrom for reporting this issue. Signed-off-by: "Theodore Ts'o" Signed-off-by: Greg Kroah-Hartman --- fs/jbd2/commit.c | 27 +++++++++++++++++++++++++-- 1 file changed, 25 insertions(+), 2 deletions(-) --- a/fs/jbd2/commit.c +++ b/fs/jbd2/commit.c @@ -25,6 +25,7 @@ #include #include #include +#include /* * Default IO end handler for temporary BJ_IO buffer_heads. @@ -168,12 +169,34 @@ static int journal_submit_commit_record( * This function along with journal_submit_commit_record * allows to write the commit record asynchronously. */ -static int journal_wait_on_commit_record(struct buffer_head *bh) +static int journal_wait_on_commit_record(journal_t *journal, + struct buffer_head *bh) { int ret = 0; +retry: clear_buffer_dirty(bh); wait_on_buffer(bh); + if (buffer_eopnotsupp(bh) && (journal->j_flags & JBD2_BARRIER)) { + printk(KERN_WARNING + "JBD2: wait_on_commit_record: sync failed on %s - " + "disabling barriers\n", journal->j_devname); + spin_lock(&journal->j_state_lock); + journal->j_flags &= ~JBD2_BARRIER; + spin_unlock(&journal->j_state_lock); + + lock_buffer(bh); + clear_buffer_dirty(bh); + set_buffer_uptodate(bh); + bh->b_end_io = journal_end_buffer_io_sync; + + ret = submit_bh(WRITE_SYNC, bh); + if (ret) { + unlock_buffer(bh); + return ret; + } + goto retry; + } if (unlikely(!buffer_uptodate(bh))) ret = -EIO; @@ -799,7 +822,7 @@ wait_for_iobuf: __jbd2_journal_abort_hard(journal); } if (!err && !is_journal_aborted(journal)) - err = journal_wait_on_commit_record(cbh); + err = journal_wait_on_commit_record(journal, cbh); if (err) jbd2_journal_abort(journal, err);