On Tue, Oct 10, 2017 at 02:57:24PM +0200, Jan Kara wrote:
> Eryu has reported that since commit 7b9ca4c61bc2 "quota: Reduce
> contention on dq_data_lock" test generic/233 occasionally fails. This is
> caused by the fact that since that commit we don't generate warning and
> set grace time for quota allocations that have DQUOT_SPACE_NOFAIL set
> (these are for example some metadata allocations in ext4). We need these
> allocations to behave regularly wrt warning generation and grace time
> setting so fix the code to return to the original behavior.
>
> Reported-by: Eryu Guan <eguan@xxxxxxxxxx>
With this patch applied, I ran generic/233 on ext4 for 150 iterations
without hitting a failure. Thanks!
Tested-by: Eryu Guan <eguan@xxxxxxxxxx>
> CC: stable@xxxxxxxxxxxxxxx
> Fixes: 7b9ca4c61bc278b771fb57d6290a31ab1fc7fdac
> Signed-off-by: Jan Kara <jack@xxxxxxx>
> ---
> fs/quota/dquot.c | 27 ++++++++++++++++-----------
> 1 file changed, 16 insertions(+), 11 deletions(-)
>
> I plan to queue this patch into my tree and send it to Linus for -rc5.
>
> diff --git a/fs/quota/dquot.c b/fs/quota/dquot.c
> index 50b0556a124f..52ad15192e72 100644
> --- a/fs/quota/dquot.c
> +++ b/fs/quota/dquot.c
> @@ -1297,21 +1297,18 @@ static int dquot_add_space(struct dquot *dquot, qsize_t space,
> spin_lock(&dquot->dq_dqb_lock);
> if (!sb_has_quota_limits_enabled(sb, dquot->dq_id.type) ||
> test_bit(DQ_FAKE_B, &dquot->dq_flags))
> - goto add;
> + goto finish;
>
> tspace = dquot->dq_dqb.dqb_curspace + dquot->dq_dqb.dqb_rsvspace
> + space + rsv_space;
>
> - if (flags & DQUOT_SPACE_NOFAIL)
> - goto add;
> -
> if (dquot->dq_dqb.dqb_bhardlimit &&
> tspace > dquot->dq_dqb.dqb_bhardlimit &&
> !ignore_hardlimit(dquot)) {
> if (flags & DQUOT_SPACE_WARN)
> prepare_warning(warn, dquot, QUOTA_NL_BHARDWARN);
> ret = -EDQUOT;
> - goto out;
> + goto finish;
> }
>
> if (dquot->dq_dqb.dqb_bsoftlimit &&
> @@ -1322,7 +1319,7 @@ static int dquot_add_space(struct dquot *dquot, qsize_t space,
> if (flags & DQUOT_SPACE_WARN)
> prepare_warning(warn, dquot, QUOTA_NL_BSOFTLONGWARN);
> ret = -EDQUOT;
> - goto out;
> + goto finish;
> }
>
> if (dquot->dq_dqb.dqb_bsoftlimit &&
> @@ -1338,13 +1335,21 @@ static int dquot_add_space(struct dquot *dquot, qsize_t space,
> * be always printed
> */
> ret = -EDQUOT;
> - goto out;
> + goto finish;
> }
> }
> -add:
> - dquot->dq_dqb.dqb_rsvspace += rsv_space;
> - dquot->dq_dqb.dqb_curspace += space;
> -out:
> +finish:
> + /*
> + * We have to be careful and go through warning generation & grace time
> + * setting even if DQUOT_SPACE_NOFAIL is set. That's why we check it
> + * only here...
> + */
> + if (flags & DQUOT_SPACE_NOFAIL)
> + ret = 0;
> + if (!ret) {
> + dquot->dq_dqb.dqb_rsvspace += rsv_space;
> + dquot->dq_dqb.dqb_curspace += space;
> + }
> spin_unlock(&dquot->dq_dqb_lock);
> return ret;
> }
> --
> 2.12.3
>