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From: Allison Collins <allison.henderson@oracle.com>
To: "Darrick J. Wong" <darrick.wong@oracle.com>
Cc: linux-xfs@vger.kernel.org
Subject: Re: [PATCH 02/18] xfs: fix inode quota reservation checks
Date: Tue, 30 Jun 2020 14:35:10 -0700
Message-ID: <a66191f5-8b70-5806-c031-675ffc38b737@oracle.com> (raw)
In-Reply-To: <159353172261.2864738.3201442261854530990.stgit@magnolia>



On 6/30/20 8:42 AM, Darrick J. Wong wrote:
> From: Darrick J. Wong <darrick.wong@oracle.com>
> 
> xfs_trans_dqresv is the function that we use to make reservations
> against resource quotas.  Each resource contains two counters: the
> q_core counter, which tracks resources allocated on disk; and the dquot
> reservation counter, which tracks how much of that resource has either
> been allocated or reserved by threads that are working on metadata
> updates.
> 
> For disk blocks, we compare the proposed reservation counter against the
> hard and soft limits to decide if we're going to fail the operation.
> However, for inodes we inexplicably compare against the q_core counter,
> not the incore reservation count.
> 
> Since the q_core counter is always lower than the reservation count and
> we unlock the dquot between reservation and transaction commit, this
> means that multiple threads can reserve the last inode count before we
> hit the hard limit, and when they commit, we'll be well over the hard
> limit.
> 
> Fix this by checking against the incore inode reservation counter, since
> we would appear to maintain that correctly (and that's what we report in
> GETQUOTA).
> 
> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Ok, makes sense
Reviewed-by: Allison Collins <allison.henderson@oracle.com>

> ---
>   fs/xfs/xfs_trans_dquot.c |    2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> 
> diff --git a/fs/xfs/xfs_trans_dquot.c b/fs/xfs/xfs_trans_dquot.c
> index c0f73b82c055..ed0ce8b301b4 100644
> --- a/fs/xfs/xfs_trans_dquot.c
> +++ b/fs/xfs/xfs_trans_dquot.c
> @@ -647,7 +647,7 @@ xfs_trans_dqresv(
>   			}
>   		}
>   		if (ninos > 0) {
> -			total_count = be64_to_cpu(dqp->q_core.d_icount) + ninos;
> +			total_count = dqp->q_res_icount + ninos;
>   			timer = be32_to_cpu(dqp->q_core.d_itimer);
>   			warns = be16_to_cpu(dqp->q_core.d_iwarns);
>   			warnlimit = defq->iwarnlimit;
> 

  reply index

Thread overview: 94+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-06-30 15:41 [PATCH 00/18] xfs: remove xfs_disk_quot from incore dquot Darrick J. Wong
2020-06-30 15:41 ` [PATCH 01/18] xfs: clear XFS_DQ_FREEING if we can't lock the dquot buffer to flush Darrick J. Wong
2020-06-30 21:35   ` Allison Collins
2020-07-01  8:32   ` Chandan Babu R
2020-07-01  8:33   ` Christoph Hellwig
2020-07-01 22:42     ` Dave Chinner
2020-06-30 15:42 ` [PATCH 02/18] xfs: fix inode quota reservation checks Darrick J. Wong
2020-06-30 21:35   ` Allison Collins [this message]
2020-07-01  8:33   ` Chandan Babu R
2020-07-01  8:34   ` Christoph Hellwig
2020-06-30 15:42 ` [PATCH 03/18] xfs: validate ondisk/incore dquot flags Darrick J. Wong
2020-06-30 21:35   ` Allison Collins
2020-07-01  8:33   ` Chandan Babu R
2020-07-01  8:42   ` Christoph Hellwig
2020-07-01 18:25     ` Darrick J. Wong
2020-07-02  6:30       ` Christoph Hellwig
2020-07-02 15:13         ` Darrick J. Wong
2020-07-01 22:41   ` Dave Chinner
2020-07-01 23:16     ` Darrick J. Wong
2020-06-30 15:42 ` [PATCH 04/18] xfs: stop using q_core.d_flags in the quota code Darrick J. Wong
2020-07-01  8:34   ` Chandan Babu R
2020-07-01  8:47   ` Christoph Hellwig
2020-07-01 19:02     ` Darrick J. Wong
2020-07-01 20:15   ` Allison Collins
2020-07-01 22:50   ` Dave Chinner
2020-07-01 23:19     ` Darrick J. Wong
2020-07-01 23:44       ` Dave Chinner
2020-07-01 23:50         ` Darrick J. Wong
2020-07-03  0:58           ` Dave Chinner
2020-07-03 18:01             ` Darrick J. Wong
2020-06-30 15:42 ` [PATCH 05/18] xfs: stop using q_core.d_id " Darrick J. Wong
2020-07-01  8:33   ` Chandan Babu R
2020-07-01  8:48   ` Christoph Hellwig
2020-07-01 20:16   ` Allison Collins
2020-06-30 15:42 ` [PATCH 06/18] xfs: use a per-resource struct for incore dquot data Darrick J. Wong
2020-07-01  8:33   ` Chandan Babu R
2020-07-01  8:49   ` Christoph Hellwig
2020-07-01 20:16   ` Allison Collins
2020-06-30 15:42 ` [PATCH 07/18] xfs: stop using q_core limits in the quota code Darrick J. Wong
2020-07-01  8:33   ` Chandan Babu R
2020-07-01  8:50   ` Christoph Hellwig
2020-07-01 20:16   ` Allison Collins
2020-07-01 23:01   ` Dave Chinner
2020-07-01 23:13     ` Darrick J. Wong
2020-07-01 23:33       ` Darrick J. Wong
2020-07-01 23:45         ` Dave Chinner
2020-06-30 15:42 ` [PATCH 08/18] xfs: stop using q_core counters " Darrick J. Wong
2020-07-01  8:33   ` Chandan Babu R
2020-07-01  8:51   ` Christoph Hellwig
2020-07-01 23:20   ` Allison Collins
2020-06-30 15:42 ` [PATCH 09/18] xfs: stop using q_core warning " Darrick J. Wong
2020-07-01  8:33   ` Chandan Babu R
2020-07-01  8:51   ` Christoph Hellwig
2020-07-01 23:20   ` Allison Collins
2020-06-30 15:42 ` [PATCH 10/18] xfs: stop using q_core timers " Darrick J. Wong
2020-07-01  8:34   ` Chandan Babu R
2020-07-01  8:51   ` Christoph Hellwig
2020-07-01 23:20   ` Allison Collins
2020-06-30 15:43 ` [PATCH 11/18] xfs: remove qcore from incore dquots Darrick J. Wong
2020-07-01  8:34   ` Chandan Babu R
2020-07-01  8:52   ` Christoph Hellwig
2020-07-01 23:07   ` Dave Chinner
2020-07-01 23:14     ` Darrick J. Wong
2020-07-02  2:06   ` Allison Collins
2020-06-30 15:43 ` [PATCH 12/18] xfs: refactor default quota limits by resource Darrick J. Wong
2020-07-01  8:52   ` Chandan Babu R
2020-07-01  8:53   ` Christoph Hellwig
2020-07-01 23:30   ` Dave Chinner
2020-07-02  0:07     ` Darrick J. Wong
2020-07-02  2:06   ` Allison Collins
2020-06-30 15:43 ` [PATCH 13/18] xfs: remove unnecessary arguments from quota adjust functions Darrick J. Wong
2020-07-01  8:53   ` Christoph Hellwig
2020-07-01  8:58   ` Chandan Babu R
2020-07-02  2:06   ` Allison Collins
2020-06-30 15:43 ` [PATCH 14/18] xfs: refactor quota exceeded test Darrick J. Wong
2020-07-01  8:56   ` Christoph Hellwig
2020-07-01 17:51     ` Darrick J. Wong
2020-07-01 18:48       ` Eric Sandeen
2020-07-01 23:34       ` Dave Chinner
2020-07-01 10:19   ` Chandan Babu R
2020-07-02 18:57   ` Allison Collins
2020-06-30 15:43 ` [PATCH 15/18] xfs: refactor xfs_qm_scall_setqlim Darrick J. Wong
2020-07-01  8:56   ` Christoph Hellwig
2020-07-03  4:11   ` Allison Collins
2020-07-03 12:39   ` Chandan Babu R
2020-06-30 15:43 ` [PATCH 16/18] xfs: refactor xfs_trans_dqresv Darrick J. Wong
2020-07-03  4:11   ` Allison Collins
2020-07-03 13:00   ` Chandan Babu R
2020-06-30 15:43 ` [PATCH 17/18] xfs: refactor xfs_trans_apply_dquot_deltas Darrick J. Wong
2020-07-04 20:41   ` Allison Collins
2020-07-06 13:40   ` Chandan Babu R
2020-06-30 15:43 ` [PATCH 18/18] xfs: add more dquot tracepoints Darrick J. Wong
2020-07-04 20:41   ` Allison Collins
2020-07-06 13:42   ` Chandan Babu R

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