On Tue, Apr 29, 2025 at 07:15:37PM -0600, Gustavo A. R. Silva wrote: > -Wflex-array-member-not-at-end was introduced in GCC-14, and we are > getting ready to enable it, globally. > > Use the `DEFINE_FLEX()` helper for on-stack definitions of a flexible > structure where the size of the flexible-array member is known at > compile-time, and refactor the rest of the code, accordingly. > > So, with these changes, fix the following warning: > > fs/bcachefs/disk_accounting.c:429:51: warning: structure containing a > flexible array member is not at the end of another structure > [-Wflex-array-member-not-at-end]
We also have bch_replicas_padded, does that also need a fix? And, DEFINE_FLEX() is gross, can we try to stop reinventing language syntax with macros? Could we not have done this with an __attribute__(())? Or just swap the anonymous struct for a union, since that's apparently what DEFINE_FLEX() does? > > Signed-off-by: Gustavo A. R. Silva <[email protected]> > --- > fs/bcachefs/disk_accounting.c | 16 +++++++--------- > 1 file changed, 7 insertions(+), 9 deletions(-) > > diff --git a/fs/bcachefs/disk_accounting.c b/fs/bcachefs/disk_accounting.c > index 7be71952425c..381e666679d2 100644 > --- a/fs/bcachefs/disk_accounting.c > +++ b/fs/bcachefs/disk_accounting.c > @@ -425,24 +425,22 @@ int bch2_fs_replicas_usage_read(struct bch_fs *c, > darray_char *usage) > > percpu_down_read(&c->mark_lock); > darray_for_each(acc->k, i) { > - struct { > - struct bch_replicas_usage r; > - u8 pad[BCH_BKEY_PTRS_MAX]; > - } u; > + DEFINE_FLEX(struct bch_replicas_usage, u, r.devs, r.nr_devs, > + BCH_BKEY_PTRS_MAX); > > - if (!accounting_to_replicas(&u.r.r, i->pos)) > + if (!accounting_to_replicas(&u->r, i->pos)) > continue; > > u64 sectors; > bch2_accounting_mem_read_counters(acc, i - acc->k.data, > §ors, 1, false); > - u.r.sectors = sectors; > + u->sectors = sectors; > > - ret = darray_make_room(usage, replicas_usage_bytes(&u.r)); > + ret = darray_make_room(usage, replicas_usage_bytes(u)); > if (ret) > break; > > - memcpy(&darray_top(*usage), &u.r, replicas_usage_bytes(&u.r)); > - usage->nr += replicas_usage_bytes(&u.r); > + memcpy(&darray_top(*usage), u, replicas_usage_bytes(u)); > + usage->nr += replicas_usage_bytes(u); > } > percpu_up_read(&c->mark_lock); > > -- > 2.43.0 >
