int
zil_claim(char *osname, void *txarg)
{
dmu_tx_t *tx = txarg;
uint64_t first_txg = dmu_tx_get_txg(tx);
zilog_t *zilog;
zil_header_t *zh;
objset_t *os;
int error;
error = dmu_objset_open(osname, DMU_OST_ANY, DS_MODE_USER, &os);
if (error) {
cmn_err(CE_WARN, "can't open objset for %s", osname);
return (0);
}
zilog = dmu_objset_zil(os);
zh = zil_header_in_syncing_context(zilog);
/*
* Record here whether the zil has any records to replay.
* If the header block pointer is null or the block points
* to the stubby then we know there are no valid log records.
* We use the header to store this state as the the zilog gets
* freed later in dmu_objset_close().
* The flags (and the rest of the header fields) are cleared in
* zil_sync() as a result of a zil_destroy(), after replaying the log.
*
* Note, the intent log can be empty but still need the
* stubby to be claimed.
*/
if (!zil_empty(zilog))
zh->zh_flags |= ZIL_REPLAY_NEEDED;
/*
* Claim all log blocks if we haven't already done so, and remember
* the highest claimed sequence number. This ensures that if we can
* read only part of the log now (e.g. due to a missing device),
* but we can read the entire log later, we will not try to replay
* or destroy beyond the last block we successfully claimed.
*/
ASSERT3U(zh->zh_claim_txg, <=, first_txg);
if (zh->zh_claim_txg == 0 && !BP_IS_HOLE(&zh->zh_log)) {
zh->zh_claim_txg = first_txg;
zh->zh_claim_seq = zil_parse(zilog, zil_claim_log_block,
zil_claim_log_record, tx, first_txg);
dsl_dataset_dirty(dmu_objset_ds(os), tx);
}
ASSERT3U(first_txg, ==, (spa_last_synced_txg(zilog->zl_spa) + 1));
dmu_objset_close(os);
return (0);
}
/*
* Report whether all transactions are committed
*/
int
zil_is_committed(zilog_t *zilog)
{
lwb_t *lwb;
int ret;
mutex_enter(&zilog->zl_lock);
while (zilog->zl_writer)
cv_wait(&zilog->zl_cv_writer, &zilog->zl_lock);
/* recent unpushed intent log transactions? */
if (!list_is_empty(&zilog->zl_itx_list)) {
ret = B_FALSE;
goto out;
}
/* intent log never used? */
lwb = list_head(&zilog->zl_lwb_list);
if (lwb == NULL) {
ret = B_TRUE;
goto out;
}
/*
* more than 1 log buffer means zil_sync() hasn't yet freed
* entries after a txg has committed
*/
if (list_next(&zilog->zl_lwb_list, lwb)) {
ret = B_FALSE;
goto out;
}
ASSERT(zil_empty(zilog));
ret = B_TRUE;
out:
cv_broadcast(&zilog->zl_cv_writer);
mutex_exit(&zilog->zl_lock);
return (ret);
}