From: Robin Dong <san...@taobao.com> In disk mode, we calculate number of md vnode by using "nr = disk_space / WEIGHT_MIN", when disk_space is smaller than WEIGHT_MIN (4G currently), the 'nr' will be zero.
Imaging a sheep daemon who has two data paths. One data path has 8GB space, but another data path has only 1GB space. The nr_disk is 2 and all the vnode in md.vroot is for the 8GB data path. Then the larger data path get a disk fail and be removed from md hashing ring, now the md.vroot has no vnode but nr_disk is 1. When the code routine comes to md_get_object_dir_nolock(), it will call oid_to_vdisk() and get NULL result which will make sheep daemon coredump. To fix this problem, we should calculate number of vnode by DIV_ROUND_UP in disk mode. Signed-off-by: Robin Dong <san...@taobao.com> --- include/sheep.h | 2 +- sheep/md.c | 4 ++-- 2 files changed, 3 insertions(+), 3 deletions(-) diff --git a/include/sheep.h b/include/sheep.h index 785883e..e062372 100644 --- a/include/sheep.h +++ b/include/sheep.h @@ -216,7 +216,7 @@ node_disk_to_vnodes(const struct sd_node *n, struct rb_root *vroot) if (!n->disks[j].disk_id) continue; hval = fnv_64a_64(node_hval, n->disks[j].disk_id); - disk_vnodes = n->disks[j].disk_space / WEIGHT_MIN; + disk_vnodes = DIV_ROUND_UP(n->disks[j].disk_space, WEIGHT_MIN); total += disk_vnodes; for (int k = 0; k < disk_vnodes; k++) { hval = sd_hash_next(hval); diff --git a/sheep/md.c b/sheep/md.c index b95e032..7d45213 100644 --- a/sheep/md.c +++ b/sheep/md.c @@ -77,7 +77,7 @@ static void create_vdisks(const struct disk *disk) if (is_cluster_diskmode(&sys->cinfo)) { node_hval = sd_hash(&n->nid, offsetof(typeof(n->nid), io_addr)); hval = fnv_64a_64(node_hval, hval); - nr = disk->space / WEIGHT_MIN; + nr = DIV_ROUND_UP(disk->space, WEIGHT_MIN); if (0 == n->nid.port) return; } else @@ -110,7 +110,7 @@ static void remove_vdisks(const struct disk *disk) if (is_cluster_diskmode(&sys->cinfo)) { node_hval = sd_hash(&n->nid, offsetof(typeof(n->nid), io_addr)); hval = fnv_64a_64(node_hval, hval); - nr = disk->space / WEIGHT_MIN; + nr = DIV_ROUND_UP(disk->space, WEIGHT_MIN); } else nr = vdisk_number(disk); -- 1.7.12.4 -- sheepdog mailing list sheepdog@lists.wpkg.org http://lists.wpkg.org/mailman/listinfo/sheepdog