diff options
| -rw-r--r-- | drivers/md/bcache/bkey.c | 47 |
1 files changed, 34 insertions, 13 deletions
diff --git a/drivers/md/bcache/bkey.c b/drivers/md/bcache/bkey.c index 03410c92f91d..760f52e5e4dd 100644 --- a/drivers/md/bcache/bkey.c +++ b/drivers/md/bcache/bkey.c @@ -605,6 +605,20 @@ void bch_bkey_format_add_pos(struct bkey_format_state *s, struct bpos p) __bkey_format_add(s, field++, p.snapshot); } +/* + * We don't want it to be possible for the packed format to represent fields + * bigger than a u64... that will cause confusion and issues (like with + * bkey_packed_successor()) + */ +static void set_format_field(struct bkey_format *f, enum bch_bkey_fields i, + unsigned bits, u64 offset) +{ + offset = bits == 64 ? 0 : min(offset, U64_MAX - ((1ULL << bits) - 1)); + + f->bits_per_field[i] = bits; + f->field_offset[i] = cpu_to_le64(offset); +} + struct bkey_format bch_bkey_format_done(struct bkey_format_state *s) { unsigned i, bits = KEY_PACKED_BITS_START; @@ -613,26 +627,33 @@ struct bkey_format bch_bkey_format_done(struct bkey_format_state *s) }; for (i = 0; i < ARRAY_SIZE(s->field_min); i++) { - u64 field_offset = min(s->field_min[i], s->field_max[i]); - ret.bits_per_field[i] = fls64(s->field_max[i] - field_offset); + s->field_min[i] = min(s->field_min[i], s->field_max[i]); - /* - * We don't want it to be possible for the packed format to - * represent fields bigger than a u64... that will cause - * confusion and issues (like with bkey_packed_successor()) - */ - - field_offset = ret.bits_per_field[i] != 64 - ? min(field_offset, U64_MAX - - ((1ULL << ret.bits_per_field[i]) - 1)) - : 0; - ret.field_offset[i] = cpu_to_le64(field_offset); + set_format_field(&ret, i, + fls64(s->field_max[i] - s->field_min[i]), + s->field_min[i]); bits += ret.bits_per_field[i]; } ret.key_u64s = DIV_ROUND_UP(bits, 64); + /* if we have enough spare bits, round fields up to nearest byte */ + bits = ret.key_u64s * 64 - bits; + + for (i = 0; i < ARRAY_SIZE(ret.bits_per_field); i++) { + unsigned r = round_up(ret.bits_per_field[i], 8) - + ret.bits_per_field[i]; + + if (r <= bits) { + set_format_field(&ret, i, + ret.bits_per_field[i] + r, + le64_to_cpu(ret.field_offset[i])); + bits -= r; + } + } + + EBUG_ON(bch_bkey_format_validate(&ret)); return ret; } |