pp->pgindex is set in disassemble_map() when a map is parsed. There are various possiblities for this index to become invalid. pp->pgindex is only used in enable_group() and followover_should_fallback(), and both callers take no action if it is 0, which is the right thing to do if we don't know the path's pathgroup. Make sure pp->pgindex is reset to 0 in various places: - when it's orphaned, - before (re)grouping paths, - when we detect a bad mpp assignment in update_pathvec_from_dm(). The hunk in group_paths is mostly redundant with the hunk in free_pgvec(), but because we're looping over pg->paths in the former and over pg->pgp in the latter, I think it's better too play safe. Fixes: 99db1bd ("[multipathd] re-enable disabled PG when at least one path is up") Signed-off-by: Martin Wilck <mwilck@xxxxxxxx> --- libmultipath/pgpolicies.c | 6 ++++++ libmultipath/structs.c | 12 +++++++++++- libmultipath/structs_vec.c | 8 ++++++++ 3 files changed, 25 insertions(+), 1 deletion(-) diff --git a/libmultipath/pgpolicies.c b/libmultipath/pgpolicies.c index edc3c61..23ef2bd 100644 --- a/libmultipath/pgpolicies.c +++ b/libmultipath/pgpolicies.c @@ -127,6 +127,8 @@ fail: int group_paths(struct multipath *mp, int marginal_pathgroups) { vector normal, marginal; + struct path *pp; + int i; if (!mp->pg) mp->pg = vector_alloc(); @@ -138,6 +140,10 @@ int group_paths(struct multipath *mp, int marginal_pathgroups) if (!mp->pgpolicyfn) goto fail; + /* Reset pgindex, we're going to invalidate it */ + vector_foreach_slot(mp->paths, pp, i) + pp->pgindex = 0; + if (!marginal_pathgroups || split_marginal_paths(mp->paths, &normal, &marginal) != 0) { if (mp->pgpolicyfn(mp, mp->paths) != 0) diff --git a/libmultipath/structs.c b/libmultipath/structs.c index 61c8f32..4851725 100644 --- a/libmultipath/structs.c +++ b/libmultipath/structs.c @@ -239,8 +239,18 @@ free_pgvec (vector pgvec, enum free_path_mode free_paths) if (!pgvec) return; - vector_foreach_slot(pgvec, pgp, i) + vector_foreach_slot(pgvec, pgp, i) { + + /* paths are going to be re-grouped, reset pgindex */ + if (free_paths != FREE_PATHS) { + struct path *pp; + int j; + + vector_foreach_slot(pgp->paths, pp, j) + pp->pgindex = 0; + } free_pathgroup(pgp, free_paths); + } vector_free(pgvec); } diff --git a/libmultipath/structs_vec.c b/libmultipath/structs_vec.c index d22056c..64c5ad5 100644 --- a/libmultipath/structs_vec.c +++ b/libmultipath/structs_vec.c @@ -139,6 +139,13 @@ static bool update_pathvec_from_dm(vector pathvec, struct multipath *mpp, must_reload = true; dm_fail_path(mpp->alias, pp->dev_t); vector_del_slot(pgp->paths, j--); + /* + * pp->pgindex has been set in disassemble_map(), + * which has probably been called just before for + * mpp. So he pgindex relates to mpp and may be + * wrong for pp->mpp. Invalidate it. + */ + pp->pgindex = 0; continue; } pp->mpp = mpp; @@ -354,6 +361,7 @@ void orphan_path(struct path *pp, const char *reason) { condlog(3, "%s: orphan path, %s", pp->dev, reason); pp->mpp = NULL; + pp->pgindex = 0; uninitialize_path(pp); } -- 2.47.0