Hi,
Comment embedded below:
----- Original Message -----
> This patch makes the quota subsystem only report once that a
> particular user/group has exceeded their allotted quota.
>
> Previously, it was possible for a program to continuously try
> exceeding quota (despite receiving EDQUOT) and in turn trigger
> gfs2 to issue a kernel log message about quota exceed. In theory,
> this could get out of hand and flood the log and the filesystem
> hosting the log files.
>
> Resolves: rhbz#1174295
> Signed-off-by: Abhi Das <a...@redhat.com>
> ---
> fs/gfs2/incore.h | 1 +
> fs/gfs2/quota.c | 13 +++++++++----
> 2 files changed, 10 insertions(+), 4 deletions(-)
>
> diff --git a/fs/gfs2/incore.h b/fs/gfs2/incore.h
> index 58b75ab..304a223 100644
> --- a/fs/gfs2/incore.h
> +++ b/fs/gfs2/incore.h
> @@ -432,6 +432,7 @@ enum {
> QDF_CHANGE = 1,
> QDF_LOCKED = 2,
> QDF_REFRESH = 3,
> + QDF_QMSG_QUIET = 4,
> };
>
> struct gfs2_quota_data {
> diff --git a/fs/gfs2/quota.c b/fs/gfs2/quota.c
> index 01f4d40..3dc13b53 100644
> --- a/fs/gfs2/quota.c
> +++ b/fs/gfs2/quota.c
> @@ -649,6 +649,8 @@ static void do_qc(struct gfs2_quota_data *qd, s64 change)
> slot_hold(qd);
> }
>
> + if (change < 0) /* Reset quiet flag if we freed some blocks */
> + clear_bit(QDF_QMSG_QUIET, &qd->qd_flags);
> mutex_unlock(&sdp->sd_quota_mutex);
> }
>
> @@ -1187,10 +1189,13 @@ int gfs2_quota_check(struct gfs2_inode *ip, kuid_t
> uid, kgid_t gid,
> /* If no min_target specified or we don't meet
> * min_target, return -EDQUOT */
> if (!ap->min_target || ap->min_target > ap->allowed) {
> - print_message(qd, "exceeded");
> - quota_send_warning(qd->qd_id,
> - sdp->sd_vfs->s_dev,
> - QUOTA_NL_BHARDWARN);
> + if (!test_bit(QDF_QMSG_QUIET, &qd->qd_flags)) {
> + print_message(qd, "exceeded");
> + quota_send_warning(qd->qd_id,
> + sdp->sd_vfs->s_dev,
> + QUOTA_NL_BHARDWARN);
> + set_bit(QDF_QMSG_QUIET, &qd->qd_flags);
> + }
Looks good, except that this is a perfect place to use test_and_set_bit().
I don't know the gfs2 quota code like you do, but does the bit also need to
be cleared if the user's quotas are increased?
Regards,
Bob Peterson
Red Hat File Systems
