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().
- when a pathgroup is deleted in update_pathvec_from_dm(). In this
case, pgindex needs to be invalidated for all paths in all pathgroups
after the one that was deleted.
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")
Fixes: https://github.com/opensvc/multipath-tools/issues/105
Signed-off-by: Martin Wilck <mwilck@xxxxxxxx>
---
libmultipath/pgpolicies.c | 6 ++++++
libmultipath/structs.c | 12 +++++++++++-
libmultipath/structs_vec.c | 15 +++++++++++++++
3 files changed, 32 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..35883fc 100644
--- a/libmultipath/structs_vec.c
+++ b/libmultipath/structs_vec.c
@@ -108,6 +108,7 @@ static bool update_pathvec_from_dm(vector pathvec, struct multipath *mpp,
struct config *conf;
bool mpp_has_wwid;
bool must_reload = false;
+ bool pg_deleted = false;
if (!mpp->pg)
return false;
@@ -125,6 +126,10 @@ static bool update_pathvec_from_dm(vector pathvec, struct multipath *mpp,
vector_foreach_slot(pgp->paths, pp, j) {
+ /* A pathgroup has been deleted before. Invalidate pgindex */
+ if (pg_deleted)
+ pp->pgindex = 0;
+
if (pp->mpp && pp->mpp != mpp) {
condlog(0, "BUG: %s: found path %s which is already in %s",
mpp->alias, pp->dev, pp->mpp->alias);
@@ -139,6 +144,13 @@ 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;
@@ -237,6 +249,8 @@ static bool update_pathvec_from_dm(vector pathvec, struct multipath *mpp,
vector_del_slot(mpp->pg, i--);
free_pathgroup(pgp, KEEP_PATHS);
must_reload = true;
+ /* Invalidate pgindex for all other pathgroups */
+ pg_deleted = true;
}
mpp->need_reload = mpp->need_reload || must_reload;
return must_reload;
@@ -354,6 +368,7 @@ 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
