int __jbd2_log_start_commit(journal_t *journal, tid_t target)
{
/*
- * Are we already doing a recent enough commit?
+ * The only transaction we can possibly wait upon is the
+ * currently running transaction (if it exists). Otherwise,
+ * the target tid must be an old one.
*/
- if (!tid_geq(journal->j_commit_request, target)) {
+ if (journal->j_running_transaction &&
+ journal->j_running_transaction->t_tid == target) {
/*
* We want a new commit: OK, mark the request and wakeup the
* commit thread. We do _not_ do the commit ourselves.
journal->j_commit_sequence);
wake_up(&journal->j_wait_commit);
return 1;
- }
+ } else if (!tid_geq(journal->j_commit_request, target))
+ /* This should never happen, but if it does, preserve
+ the evidence before kjournald goes into a loop and
+ increments j_commit_sequence beyond all recognition. */
+ WARN_ONCE(1, "jbd: bad log_start_commit: %u %u %u %u\n",
+ journal->j_commit_request,
+ journal->j_commit_sequence,
+ target, journal->j_running_transaction ?
+ journal->j_running_transaction->t_tid : 0);
return 0;
}
return ret;
}
+/*
+ * Return 1 if a given transaction has not yet sent barrier request
+ * connected with a transaction commit. If 0 is returned, transaction
+ * may or may not have sent the barrier. Used to avoid sending barrier
+ * twice in common cases.
+ */
+int jbd2_trans_will_send_data_barrier(journal_t *journal, tid_t tid)
+{
+ int ret = 0;
+ transaction_t *commit_trans;
+
+ if (!(journal->j_flags & JBD2_BARRIER))
+ return 0;
+ read_lock(&journal->j_state_lock);
+ /* Transaction already committed? */
+ if (tid_geq(journal->j_commit_sequence, tid))
+ goto out;
+ commit_trans = journal->j_committing_transaction;
+ if (!commit_trans || commit_trans->t_tid != tid) {
+ ret = 1;
+ goto out;
+ }
+ /*
+ * Transaction is being committed and we already proceeded to
+ * submitting a flush to fs partition?
+ */
+ if (journal->j_fs_dev != journal->j_dev) {
+ if (!commit_trans->t_need_data_flush ||
+ commit_trans->t_state >= T_COMMIT_DFLUSH)
+ goto out;
+ } else {
+ if (commit_trans->t_state >= T_COMMIT_JFLUSH)
+ goto out;
+ }
+ ret = 1;
+out:
+ read_unlock(&journal->j_state_lock);
+ return ret;
+}
+EXPORT_SYMBOL(jbd2_trans_will_send_data_barrier);
+
/*
* Wait for a specified commit to complete.
* The caller may not hold the journal lock.
new_dev = kmalloc(sizeof(struct devname_cache), GFP_KERNEL);
if (!new_dev)
return "NODEV-ALLOCFAILURE"; /* Something non-NULL */
+ bd = bdget(device);
spin_lock(&devname_cache_lock);
if (devcache[i]) {
if (devcache[i]->device == device) {
kfree(new_dev);
+ bdput(bd);
ret = devcache[i]->devname;
spin_unlock(&devname_cache_lock);
return ret;
}
devcache[i] = new_dev;
devcache[i]->device = device;
- bd = bdget(device);
if (bd) {
bdevname(bd, devcache[i]->devname);
bdput(bd);