If a device that is holding a reservation changes its registered key,
but the path holding the reservation is unavailable, libmpathpersist
must preempt the old key to update the reservation. If the key is
changed using REGISTER AND IGNORE, set_ignored_key() determines the old
key to preempt. Unfortunately, commit 165427dda broke it, by comparing
the wrong key against the actual reservation key. Then commit cf0eea85
broke it more, by using mpp->reservation_key after it had been updated,
so it was no longer the old key. Fix this by correctly comparing the old
key against the actual reservation key.
Fixes: 165427dda ("libmpathpersist: Add safety check for preempting on key
change")
Signed-off-by: Benjamin Marzinski <[email protected]>
---
libmpathpersist/mpath_persist_int.c | 13 +++++++------
1 file changed, 7 insertions(+), 6 deletions(-)
diff --git a/libmpathpersist/mpath_persist_int.c
b/libmpathpersist/mpath_persist_int.c
index ab3d70cd..476c3433 100644
--- a/libmpathpersist/mpath_persist_int.c
+++ b/libmpathpersist/mpath_persist_int.c
@@ -791,16 +791,17 @@ static int reservation_key_matches(struct multipath *mpp,
uint8_t *key, int nois
* currently registered key for use in preempt_missing_path(), but only if
* the key is holding the reservation.
*/
-static void set_ignored_key(struct multipath *mpp, uint8_t *key)
+static void set_ignored_key(struct multipath *mpp, uint8_t *curr_key,
+ uint8_t *key)
{
memset(key, 0, 8);
- if (!get_be64(mpp->reservation_key))
+ if (memcmp(curr_key, key, 8) == 0)
return;
if (get_prhold(mpp->alias) == PR_UNSET)
return;
- if (reservation_key_matches(mpp, key, 0) == YNU_NO)
+ if (reservation_key_matches(mpp, curr_key, 0) == YNU_NO)
return;
- memcpy(key, &mpp->reservation_key, 8);
+ memcpy(key, curr_key, 8);
}
int do_mpath_persistent_reserve_out(vector curmp, vector pathvec, int fd,
@@ -824,6 +825,7 @@ int do_mpath_persistent_reserve_out(vector curmp, vector
pathvec, int fd,
select_reservation_key(conf, mpp);
put_multipath_config(conf);
+ memcpy(&oldkey, &mpp->reservation_key, 8);
unregistering = (memcmp(&zerokey, paramp->sa_key, 8) == 0);
if (mpp->prkey_source == PRKEY_SOURCE_FILE &&
(rq_servact == MPATH_PROUT_REG_IGN_SA ||
@@ -832,7 +834,6 @@ int do_mpath_persistent_reserve_out(vector curmp, vector
pathvec, int fd,
memcmp(paramp->key, &zerokey, 8) == 0 ||
memcmp(paramp->key, &mpp->reservation_key, 8) == 0)))) {
updated_prkey = true;
- memcpy(&oldkey, &mpp->reservation_key, 8);
memcpy(&mpp->reservation_key, paramp->sa_key, 8);
if (update_prkey_flags(mpp->alias,
get_be64(mpp->reservation_key),
paramp->sa_flags)) {
@@ -895,7 +896,7 @@ int do_mpath_persistent_reserve_out(vector curmp, vector
pathvec, int fd,
put_multipath_config(conf);
if (rq_servact == MPATH_PROUT_REG_IGN_SA)
- set_ignored_key(mpp, paramp->key);
+ set_ignored_key(mpp, (uint8_t *)&oldkey, paramp->key);
switch(rq_servact)
{
--
2.50.1
