On Wed, Nov 15, 2023 at 2:17 PM Xiubo Li <xiubli@xxxxxxxxxx> wrote: > > > On 11/15/23 20:32, Ilya Dryomov wrote: > > On Wed, Nov 15, 2023 at 1:35 AM Xiubo Li <xiubli@xxxxxxxxxx> wrote: > >> > >> On 11/14/23 23:31, Wenchao Hao wrote: > >>> This issue is reported by smatch, get_quota_realm() might return > >>> ERR_PTR, so we should using IS_ERR_OR_NULL here to check the return > >>> value. > >>> > >>> Signed-off-by: Wenchao Hao <haowenchao2@xxxxxxxxxx> > >>> --- > >>> fs/ceph/quota.c | 2 +- > >>> 1 file changed, 1 insertion(+), 1 deletion(-) > >>> > >>> diff --git a/fs/ceph/quota.c b/fs/ceph/quota.c > >>> index 9d36c3532de1..c4b2929c6a83 100644 > >>> --- a/fs/ceph/quota.c > >>> +++ b/fs/ceph/quota.c > >>> @@ -495,7 +495,7 @@ bool ceph_quota_update_statfs(struct ceph_fs_client *fsc, struct kstatfs *buf) > >>> realm = get_quota_realm(mdsc, d_inode(fsc->sb->s_root), > >>> QUOTA_GET_MAX_BYTES, true); > >>> up_read(&mdsc->snap_rwsem); > >>> - if (!realm) > >>> + if (IS_ERR_OR_NULL(realm)) > >>> return false; > >>> > >>> spin_lock(&realm->inodes_with_caps_lock); > >> Good catch. > >> > >> Reviewed-by: Xiubo Li <xiubli@xxxxxxxxxx> > >> > >> We should CC the stable mail list. > > Hi Xiubo, > > > > What exactly is being fixed here? get_quota_realm() is called with > > retry=true, which means that no errors can be returned -- EAGAIN, the > > only error that get_quota_realm() can otherwise generate, would be > > handled internally by retrying. > > Yeah, that's true. > > > Am I missing something that makes this qualify for stable? > > Actually it's just for the smatch check for now. > > IMO we shouldn't depend on the 'retry', just potentially for new changes > in future could return a ERR_PTR and cause potential bugs. At present, ceph_quota_is_same_realm() also depends on it -- note how old_realm isn't checked for errors at all and new_realm is only checked for EAGAIN there. > > If that's not worth to make it for stable, let's remove it. Yes, let's remove it. Please update the commit message as well, so that it's clear that this is squashing a static checker warning and doesn't actually fix any immediate bug. Thanks, Ilya