diff options
| author | Ameer Hamza <[email protected]> | 2023-07-20 22:23:52 +0500 |
|---|---|---|
| committer | GitHub <[email protected]> | 2023-07-20 10:23:52 -0700 |
| commit | d9bb583c25d833e57c0842a81dca1bd50da5d9b1 (patch) | |
| tree | bff0987817a6d4cab358efac3ebce2aba2c72962 /module/zfs/vdev.c | |
| parent | 929173ab42fa9482455c8d51ed64326a3d983e41 (diff) | |
spa_min_alloc should be GCD, not min
Since spa_min_alloc may not be a power of 2, unlike ashifts, in the
case of DRAID, we should not select the minimal value among several
vdevs. Rounding to a multiple of it is unlikely to work for other
vdevs. Instead, using the greatest common divisor produces smaller
yet more reasonable results.
Reviewed-by: Brian Behlendorf <[email protected]>
Reviewed-by: Alexander Motin <[email protected]>
Signed-off-by: Ameer Hamza <[email protected]>
Closes #15067
Diffstat (limited to 'module/zfs/vdev.c')
| -rw-r--r-- | module/zfs/vdev.c | 36 |
1 files changed, 32 insertions, 4 deletions
diff --git a/module/zfs/vdev.c b/module/zfs/vdev.c index b6f8c0ab3..f3812b843 100644 --- a/module/zfs/vdev.c +++ b/module/zfs/vdev.c @@ -1399,6 +1399,36 @@ vdev_remove_parent(vdev_t *cvd) vdev_free(mvd); } +/* + * Choose GCD for spa_gcd_alloc. + */ +static uint64_t +vdev_gcd(uint64_t a, uint64_t b) +{ + while (b != 0) { + uint64_t t = b; + b = a % b; + a = t; + } + return (a); +} + +/* + * Set spa_min_alloc and spa_gcd_alloc. + */ +static void +vdev_spa_set_alloc(spa_t *spa, uint64_t min_alloc) +{ + if (min_alloc < spa->spa_min_alloc) + spa->spa_min_alloc = min_alloc; + if (spa->spa_gcd_alloc == INT_MAX) { + spa->spa_gcd_alloc = min_alloc; + } else { + spa->spa_gcd_alloc = vdev_gcd(min_alloc, + spa->spa_gcd_alloc); + } +} + void vdev_metaslab_group_create(vdev_t *vd) { @@ -1451,8 +1481,7 @@ vdev_metaslab_group_create(vdev_t *vd) spa->spa_min_ashift = vd->vdev_ashift; uint64_t min_alloc = vdev_get_min_alloc(vd); - if (min_alloc < spa->spa_min_alloc) - spa->spa_min_alloc = min_alloc; + vdev_spa_set_alloc(spa, min_alloc); } } } @@ -2213,8 +2242,7 @@ vdev_open(vdev_t *vd) if (vd->vdev_top == vd && vd->vdev_ashift != 0 && vd->vdev_islog == 0 && vd->vdev_aux == NULL) { uint64_t min_alloc = vdev_get_min_alloc(vd); - if (min_alloc < spa->spa_min_alloc) - spa->spa_min_alloc = min_alloc; + vdev_spa_set_alloc(spa, min_alloc); } /* |