From: "Aneesh Kumar K.V" Subject: Re: [PATCH] ext4: Fix delalloc sync hang with journal lock inversion Date: Thu, 22 May 2008 15:55:48 +0530 Message-ID: <20080522102548.GB30056@skywalker> References: <1211391859-17399-1-git-send-email-aneesh.kumar@linux.vnet.ibm.com> <1211391859-17399-2-git-send-email-aneesh.kumar@linux.vnet.ibm.com> <1211391859-17399-3-git-send-email-aneesh.kumar@linux.vnet.ibm.com> <1211391859-17399-4-git-send-email-aneesh.kumar@linux.vnet.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: linux-ext4@vger.kernel.org, tytso@mit.edu, sandeen@redhat.com To: cmm@us.ibm.com Return-path: Received: from e28smtp07.in.ibm.com ([59.145.155.7]:33595 "EHLO e28esmtp07.in.ibm.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1758404AbYEVK0S (ORCPT ); Thu, 22 May 2008 06:26:18 -0400 Received: from d28relay02.in.ibm.com (d28relay02.in.ibm.com [9.184.220.59]) by e28esmtp07.in.ibm.com (8.13.1/8.13.1) with ESMTP id m4MAPpUb012130 for ; Thu, 22 May 2008 15:55:51 +0530 Received: from d28av05.in.ibm.com (d28av05.in.ibm.com [9.184.220.67]) by d28relay02.in.ibm.com (8.13.8/8.13.8/NCO v8.7) with ESMTP id m4MAPc95344282 for ; Thu, 22 May 2008 15:55:38 +0530 Received: from d28av05.in.ibm.com (loopback [127.0.0.1]) by d28av05.in.ibm.com (8.13.1/8.13.3) with ESMTP id m4MAPoug027591 for ; Thu, 22 May 2008 15:55:50 +0530 Content-Disposition: inline In-Reply-To: <1211391859-17399-4-git-send-email-aneesh.kumar@linux.vnet.ibm.com> Sender: linux-ext4-owner@vger.kernel.org List-ID: On Wed, May 21, 2008 at 11:14:17PM +0530, Aneesh Kumar K.V wrote: > Signed-off-by: Aneesh Kumar K.V > --- > fs/ext4/inode.c | 10 +++++++--- > 1 files changed, 7 insertions(+), 3 deletions(-) > > diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c > index 46cc610..076d00f 100644 > --- a/fs/ext4/inode.c > +++ b/fs/ext4/inode.c > @@ -1571,13 +1571,17 @@ static int ext4_da_writepages(struct address_space *mapping, > */ > if (wbc->nr_to_write > EXT4_MAX_WRITEBACK_PAGES) > wbc->nr_to_write = EXT4_MAX_WRITEBACK_PAGES; > - to_write -= wbc->nr_to_write; > > + to_write -= wbc->nr_to_write; > ret = mpage_da_writepages(mapping, wbc, ext4_da_get_block_write); > ext4_journal_stop(handle); > - to_write +=wbc->nr_to_write; > + if (wbc->nr_to_write) { > + /* We failed to write what we requested for */ > + to_write += wbc->nr_to_write; > + break; > + } > + wbc->nr_to_write = to_write; > } > - > out_writepages: > wbc->nr_to_write = to_write; > wbc->range_cyclic = range_cyclic; We need related fix for ext4_da_writepage. We need to allocate blocks in ext4_da_writepage and we are called with page_lock. The handle will be NULL in the below case and that would result in ext4_get_block starting a new transaction when allocating blocks. static int __ext4_da_writepage(struct page *page, struct writeback_control *wbc) { struct inode *inode = page->mapping->host; handle_t *handle = NULL; int ret = 0; handle = ext4_journal_current_handle(); if (test_opt(inode->i_sb, NOBH) && ext4_should_writeback_data(inode)) ret = nobh_writepage(page, ext4_get_block, wbc); else ret = block_write_full_page(page, ext4_get_block, wbc); if (!ret && inode->i_size > EXT4_I(inode)->i_disksize) { EXT4_I(inode)->i_disksize = inode->i_size; ext4_mark_inode_dirty(handle, inode); } return ret; } -aneesh