On Wed, Nov 06, 2024 at 10:05:41AM +0800, Hongbo Li wrote:
> When alloc percpu counters in bch2_fs_counters_init, we do not
> initialize it. When nr < BCH_COUNTER_NR, the variables after
> counters[nr - 1] are not initialized. Considering __GFP_ZERO flags
> aren't guaranteed to be all zeros on different archs for percpu
> allocations, so here initialize this variable explicitly.
???
mm/percpu.c:1898
>
> Fixes: 104c69745fdf ("bcachefs: Add persistent counters")
> Signed-off-by: Hongbo Li <[email protected]>
> ---
> fs/bcachefs/sb-counters.c | 7 ++++++-
> 1 file changed, 6 insertions(+), 1 deletion(-)
>
> diff --git a/fs/bcachefs/sb-counters.c b/fs/bcachefs/sb-counters.c
> index 6992e7469112..92cb3745d1c2 100644
> --- a/fs/bcachefs/sb-counters.c
> +++ b/fs/bcachefs/sb-counters.c
> @@ -50,7 +50,7 @@ int bch2_sb_counters_to_cpu(struct bch_fs *c)
>
> for (i = 0; i < min_t(unsigned int, nr, BCH_COUNTER_NR); i++) {
> val = le64_to_cpu(ctrs->d[i]);
> - percpu_u64_set(&c->counters[i], val);
> + this_cpu_write(c->counters[i], val);
> c->counters_on_mount[i] = val;
> }
> return 0;
> @@ -86,10 +86,15 @@ void bch2_fs_counters_exit(struct bch_fs *c)
>
> int bch2_fs_counters_init(struct bch_fs *c)
> {
> + unsigned int i;
> +
> c->counters = __alloc_percpu(sizeof(u64) * BCH_COUNTER_NR, sizeof(u64));
> if (!c->counters)
> return -BCH_ERR_ENOMEM_fs_counters_init;
>
> + for (i = 0; i < BCH_COUNTER_NR; i++)
> + percpu_u64_set(&c->counters[i], 0);
> +
> return bch2_sb_counters_to_cpu(c);
> }
>
> --
> 2.34.1
>
