}
#endif /* HAVE_SERVER_SUPPORT */
+struct ldlm_kms_shift_args {
+ __u64 old_kms;
+ __u64 kms;
+ bool complete;
+};
+
+/* Callback for interval_iterate functions, used by ldlm_extent_shift_Kms */
+static enum interval_iter ldlm_kms_shift_cb(struct interval_node *n,
+ void *args)
+{
+ struct ldlm_kms_shift_args *arg = args;
+ struct ldlm_interval *node = to_ldlm_interval(n);
+ struct ldlm_lock *tmplock;
+ struct ldlm_lock *lock = NULL;
+
+ ENTRY;
+
+ /* Since all locks in an interval have the same extent, we can just
+ * use the first lock without kms_ignore set. */
+ list_for_each_entry(tmplock, &node->li_group, l_sl_policy) {
+ if (ldlm_is_kms_ignore(tmplock))
+ continue;
+
+ lock = tmplock;
+
+ break;
+ }
+
+ /* No locks in this interval without kms_ignore set */
+ if (!lock)
+ RETURN(INTERVAL_ITER_CONT);
+
+ /* If we find a lock with a greater or equal kms, we are not the
+ * highest lock (or we share that distinction with another lock), and
+ * don't need to update KMS. Return old_kms and stop looking. */
+ if (lock->l_policy_data.l_extent.end >= arg->old_kms) {
+ arg->kms = arg->old_kms;
+ arg->complete = true;
+ RETURN(INTERVAL_ITER_STOP);
+ }
+
+ if (lock->l_policy_data.l_extent.end + 1 > arg->kms)
+ arg->kms = lock->l_policy_data.l_extent.end + 1;
+
+ /* Since interval_iterate_reverse starts with the highest lock and
+ * works down, for PW locks, we only need to check if we should update
+ * the kms, then stop walking the tree. PR locks are not exclusive, so
+ * the highest start does not imply the highest end and we must
+ * continue. (Only one group lock is allowed per resource, so this is
+ * irrelevant for group locks.)*/
+ if (lock->l_granted_mode == LCK_PW)
+ RETURN(INTERVAL_ITER_STOP);
+ else
+ RETURN(INTERVAL_ITER_CONT);
+}
+
/* When a lock is cancelled by a client, the KMS may undergo change if this
- * is the "highest lock". This function returns the new KMS value.
+ * is the "highest lock". This function returns the new KMS value, updating
+ * it only if we were the highest lock.
+ *
* Caller must hold lr_lock already.
*
* NB: A lock on [x,y] protects a KMS of up to y + 1 bytes! */
__u64 ldlm_extent_shift_kms(struct ldlm_lock *lock, __u64 old_kms)
{
- struct ldlm_resource *res = lock->l_resource;
- struct list_head *tmp;
- struct ldlm_lock *lck;
- __u64 kms = 0;
- ENTRY;
+ struct ldlm_resource *res = lock->l_resource;
+ struct ldlm_interval_tree *tree;
+ struct ldlm_kms_shift_args args;
+ int idx = 0;
+
+ ENTRY;
+
+ args.old_kms = old_kms;
+ args.kms = 0;
+ args.complete = false;
- /* don't let another thread in ldlm_extent_shift_kms race in
- * just after we finish and take our lock into account in its
- * calculation of the kms */
+ /* don't let another thread in ldlm_extent_shift_kms race in
+ * just after we finish and take our lock into account in its
+ * calculation of the kms */
ldlm_set_kms_ignore(lock);
- list_for_each(tmp, &res->lr_granted) {
- lck = list_entry(tmp, struct ldlm_lock, l_res_link);
+ /* We iterate over the lock trees, looking for the largest kms smaller
+ * than the current one. */
+ for (idx = 0; idx < LCK_MODE_NUM; idx++) {
+ tree = &res->lr_itree[idx];
- if (ldlm_is_kms_ignore(lck))
- continue;
+ /* If our already known kms is >= than the highest 'end' in
+ * this tree, we don't need to check this tree, because
+ * the kms from a tree can be lower than in_max_high (due to
+ * kms_ignore), but it can never be higher. */
+ if (!tree->lit_root || args.kms >= tree->lit_root->in_max_high)
+ continue;
- if (lck->l_policy_data.l_extent.end >= old_kms)
- RETURN(old_kms);
+ interval_iterate_reverse(tree->lit_root, ldlm_kms_shift_cb,
+ &args);
- /* This extent _has_ to be smaller than old_kms (checked above)
- * so kms can only ever be smaller or the same as old_kms. */
- if (lck->l_policy_data.l_extent.end + 1 > kms)
- kms = lck->l_policy_data.l_extent.end + 1;
- }
- LASSERTF(kms <= old_kms, "kms %llu old_kms %llu\n", kms, old_kms);
+ /* this tells us we're not the highest lock, so we don't need
+ * to check the remaining trees */
+ if (args.complete)
+ break;
+ }
+
+ LASSERTF(args.kms <= args.old_kms, "kms %llu old_kms %llu\n", args.kms,
+ args.old_kms);
- RETURN(kms);
+ RETURN(args.kms);
}
EXPORT_SYMBOL(ldlm_extent_shift_kms);
git://git.whamcloud.com / fs / lustre-release.git / blobdiff