Add sa_spill_rele() interface

Add a SA interface which allows us to release the spill block
from a SA handle without destroying the handle.  This is useful
because we can then ensure that a copy of the dirty spill block
is not made at sync time due to the extra hold.  Susequent calls
to sa_update() or sa_lookup() with transparently refetch the
spill block dbuf from the ARC hash.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
This commit is contained in:
Brian Behlendorf 2012-03-05 15:14:15 -08:00
parent 2c6d0b1e07
commit 0ece356db5
2 changed files with 15 additions and 0 deletions

View File

@ -139,6 +139,7 @@ void sa_set_userp(sa_handle_t *, void *);
dmu_buf_t *sa_get_db(sa_handle_t *);
uint64_t sa_handle_object(sa_handle_t *);
boolean_t sa_attr_would_spill(sa_handle_t *, sa_attr_type_t, int size);
void sa_spill_rele(sa_handle_t *);
void sa_register_update_callback(objset_t *, sa_update_cb_t *);
int sa_setup(objset_t *, uint64_t, sa_attr_reg_t *, int, sa_attr_type_t **);
void sa_tear_down(objset_t *);

View File

@ -1333,6 +1333,19 @@ sa_idx_tab_hold(objset_t *os, sa_idx_tab_t *idx_tab)
(void) refcount_add(&idx_tab->sa_refcount, NULL);
}
void
sa_spill_rele(sa_handle_t *hdl)
{
mutex_enter(&hdl->sa_lock);
if (hdl->sa_spill) {
sa_idx_tab_rele(hdl->sa_os, hdl->sa_spill_tab);
dmu_buf_rele(hdl->sa_spill, NULL);
hdl->sa_spill = NULL;
hdl->sa_spill_tab = NULL;
}
mutex_exit(&hdl->sa_lock);
}
void
sa_handle_destroy(sa_handle_t *hdl)
{
@ -1994,6 +2007,7 @@ EXPORT_SYMBOL(sa_handle_get_from_db);
EXPORT_SYMBOL(sa_handle_destroy);
EXPORT_SYMBOL(sa_buf_hold);
EXPORT_SYMBOL(sa_buf_rele);
EXPORT_SYMBOL(sa_spill_rele);
EXPORT_SYMBOL(sa_lookup);
EXPORT_SYMBOL(sa_update);
EXPORT_SYMBOL(sa_remove);