void
dmu_objset_evict_dbufs(objset_t *os)
{
dnode_t dn_marker;
dnode_t *dn;
mutex_enter(&os->os_lock);
dn = list_head(&os->os_dnodes);
while (dn != NULL) {
/*
* Skip dnodes without holds. We have to do this dance
* because dnode_add_ref() only works if there is already a
* hold. If the dnode has no holds, then it has no dbufs.
*/
if (dnode_add_ref(dn, FTAG)) {
list_insert_after(&os->os_dnodes, dn, &dn_marker);
mutex_exit(&os->os_lock);
dnode_evict_dbufs(dn);
dnode_rele(dn, FTAG);
mutex_enter(&os->os_lock);
dn = list_next(&os->os_dnodes, &dn_marker);
list_remove(&os->os_dnodes, &dn_marker);
} else {
dn = list_next(&os->os_dnodes, dn);
}
}
mutex_exit(&os->os_lock);
if (DMU_USERUSED_DNODE(os) != NULL) {
dnode_evict_dbufs(DMU_GROUPUSED_DNODE(os));
dnode_evict_dbufs(DMU_USERUSED_DNODE(os));
}
dnode_evict_dbufs(DMU_META_DNODE(os));
}
int
dmu_objset_evict_dbufs(objset_t *os)
{
dnode_t *dn;
mutex_enter(&os->os_lock);
/* process the mdn last, since the other dnodes have holds on it */
list_remove(&os->os_dnodes, DMU_META_DNODE(os));
list_insert_tail(&os->os_dnodes, DMU_META_DNODE(os));
/*
* Find the first dnode with holds. We have to do this dance
* because dnode_add_ref() only works if you already have a
* hold. If there are no holds then it has no dbufs so OK to
* skip.
*/
for (dn = list_head(&os->os_dnodes);
dn && !dnode_add_ref(dn, FTAG);
dn = list_next(&os->os_dnodes, dn))
continue;
while (dn) {
dnode_t *next_dn = dn;
do {
next_dn = list_next(&os->os_dnodes, next_dn);
} while (next_dn && !dnode_add_ref(next_dn, FTAG));
mutex_exit(&os->os_lock);
dnode_evict_dbufs(dn);
dnode_rele(dn, FTAG);
mutex_enter(&os->os_lock);
dn = next_dn;
}
dn = list_head(&os->os_dnodes);
mutex_exit(&os->os_lock);
return (dn != DMU_META_DNODE(os));
}