quota: Handle Q_GETNEXTQUOTA when quota is disabled
Currently we oopsed when Q_GETNEXTQUOTA got called when quota was
disabled. Properly check whether quota is enabled for the filesystem
before calling into quota format handler.
Reported-by: Ted Tso <tytso@mit.edu>
Signed-off-by: Jan Kara <jack@suse.cz>
diff --git a/fs/quota/dquot.c b/fs/quota/dquot.c
index ba827da..ff21980 100644
--- a/fs/quota/dquot.c
+++ b/fs/quota/dquot.c
@@ -2047,11 +2047,20 @@
struct quota_info *dqopt = sb_dqopt(sb);
int err;
- if (!dqopt->ops[qid->type]->get_next_id)
- return -ENOSYS;
+ mutex_lock(&dqopt->dqonoff_mutex);
+ if (!sb_has_quota_active(sb, qid->type)) {
+ err = -ESRCH;
+ goto out;
+ }
+ if (!dqopt->ops[qid->type]->get_next_id) {
+ err = -ENOSYS;
+ goto out;
+ }
mutex_lock(&dqopt->dqio_mutex);
err = dqopt->ops[qid->type]->get_next_id(sb, qid);
mutex_unlock(&dqopt->dqio_mutex);
+out:
+ mutex_unlock(&dqopt->dqonoff_mutex);
return err;
}