From: Mingming Subject: Re: [PATCH] Ext4: avoid multiple quota reservation when retry block reservation for delalloc Date: Mon, 21 Sep 2009 16:18:02 -0700 Message-ID: <1253575082.9099.14.camel@mingming-laptop> References: <1253551950.9099.10.camel@mingming-laptop> <20090921181527.GA27777@duck.suse.cz> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="=-iWh6UW2FC5RpiWdbggKP" Cc: linux-ext4@vger.kernel.org, tytso@mit.edu To: Jan Kara Return-path: Received: from e36.co.us.ibm.com ([32.97.110.154]:44455 "EHLO e36.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754391AbZIUXSB (ORCPT ); Mon, 21 Sep 2009 19:18:01 -0400 Received: from d03relay04.boulder.ibm.com (d03relay04.boulder.ibm.com [9.17.195.106]) by e36.co.us.ibm.com (8.14.3/8.13.1) with ESMTP id n8LNGAIV006943 for ; Mon, 21 Sep 2009 17:16:10 -0600 Received: from d03av02.boulder.ibm.com (d03av02.boulder.ibm.com [9.17.195.168]) by d03relay04.boulder.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id n8LNI4Lp217384 for ; Mon, 21 Sep 2009 17:18:04 -0600 Received: from d03av02.boulder.ibm.com (loopback [127.0.0.1]) by d03av02.boulder.ibm.com (8.12.11.20060308/8.13.3) with ESMTP id n8LNI4eg009981 for ; Mon, 21 Sep 2009 17:18:04 -0600 In-Reply-To: <20090921181527.GA27777@duck.suse.cz> Sender: linux-ext4-owner@vger.kernel.org List-ID: --=-iWh6UW2FC5RpiWdbggKP Content-Type: text/plain Content-Transfer-Encoding: 7bit On Mon, 2009-09-21 at 20:15 +0200, Jan Kara wrote: > On Mon 21-09-09 09:52:30, Mingming wrote: > > Ext4: release reserved quota before block reservation for delalloc retry > > > > ext4_da_reserve_space() can reserve quota blocks multiple times if > > ext4_claim_free_blocks() fail and we retry the allocation. We should > > release the quota reservation before restarting. > > > > Bug found be Jan Kara. > ^^ by attached is the updated patch with this typo fixed. > > > > Signed-off-by: Mingming Cao > > > > --- > > fs/ext4/inode.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > Index: linux-2.6.31-rc4/fs/ext4/inode.c > > =================================================================== > > --- linux-2.6.31-rc4.orig/fs/ext4/inode.c > > +++ linux-2.6.31-rc4/fs/ext4/inode.c > > @@ -1785,11 +1785,11 @@ repeat: > > > > if (ext4_claim_free_blocks(sbi, total)) { > > spin_unlock(&EXT4_I(inode)->i_block_reservation_lock); > > + vfs_dq_release_reservation_block(inode, total); > > if (ext4_should_retry_alloc(inode->i_sb, &retries)) { > > yield(); > > goto repeat; > > } > > - vfs_dq_release_reservation_block(inode, total); > > return -ENOSPC; > > } > > EXT4_I(inode)->i_reserved_data_blocks += nrblocks; > > > The patch is fine. Acked-by: Jan Kara Thanks! > But it's certainly not the issue hit by Pavol but I'm out of ideas where > could be a problem provided he runs with extents... > I am not sure where is the problem reported by Pavol by looking at the code either. Perhaps enable some debugging code, but I am under impression that the system is in-use now... Mingming --=-iWh6UW2FC5RpiWdbggKP Content-Disposition: attachment; filename="quota-dealloc-fix.patch" Content-Type: text/x-patch; name="quota-dealloc-fix.patch"; charset="UTF-8" Content-Transfer-Encoding: 7bit Ext4: release reserved quota when block reservation for delalloc retry ext4_da_reserve_space() can reserve quota blocks multiple times if ext4_claim_free_blocks() fail and we retry the allocation. We should release the quota reservation before restarting. Bug found by Jan Kara. Signed-off-by: Mingming Cao --- fs/ext4/inode.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) Index: linux-2.6.31-rc4/fs/ext4/inode.c =================================================================== --- linux-2.6.31-rc4.orig/fs/ext4/inode.c +++ linux-2.6.31-rc4/fs/ext4/inode.c @@ -1785,11 +1785,11 @@ repeat: if (ext4_claim_free_blocks(sbi, total)) { spin_unlock(&EXT4_I(inode)->i_block_reservation_lock); + vfs_dq_release_reservation_block(inode, total); if (ext4_should_retry_alloc(inode->i_sb, &retries)) { yield(); goto repeat; } - vfs_dq_release_reservation_block(inode, total); return -ENOSPC; } EXT4_I(inode)->i_reserved_data_blocks += nrblocks; --=-iWh6UW2FC5RpiWdbggKP--