static void ldlm_extent_policy(struct ldlm_resource *res,
struct ldlm_lock *lock, __u64 *flags)
{
- struct ldlm_extent new_ex = { .start = 0, .end = OBD_OBJECT_EOF };
-
- if (lock->l_export == NULL)
- /*
- * this is local lock taken by server (e.g., as a part of
- * OST-side locking, or unlink handling). Expansion doesn't
- * make a lot of sense for local locks, because they are
- * dropped immediately on operation completion and would only
- * conflict with other threads.
- */
- return;
+ struct ldlm_extent new_ex = { .start = 0, .end = OBD_OBJECT_EOF };
+
+ if (lock->l_export == NULL)
+ /*
+ * this is a local lock taken by server (e.g., as a part of
+ * OST-side locking, or unlink handling). Expansion doesn't
+ * make a lot of sense for local locks, because they are
+ * dropped immediately on operation completion and would only
+ * conflict with other threads.
+ */
+ return;
- if (lock->l_policy_data.l_extent.start == 0 &&
- lock->l_policy_data.l_extent.end == OBD_OBJECT_EOF)
- /* fast-path whole file locks */
- return;
+ if (lock->l_policy_data.l_extent.start == 0 &&
+ lock->l_policy_data.l_extent.end == OBD_OBJECT_EOF)
+ /* fast-path whole file locks */
+ return;
- ldlm_extent_internal_policy_granted(lock, &new_ex);
- ldlm_extent_internal_policy_waiting(lock, &new_ex);
+ /* Because reprocess_queue zeroes flags and uses it to return
+ * LDLM_FL_LOCK_CHANGED, we must check for the NO_EXPANSION flag
+ * in the lock flags rather than the 'flags' argument */
+ if (likely(!(lock->l_flags & LDLM_FL_NO_EXPANSION))) {
+ ldlm_extent_internal_policy_granted(lock, &new_ex);
+ ldlm_extent_internal_policy_waiting(lock, &new_ex);
+ } else {
+ LDLM_DEBUG(lock, "Not expanding manually requested lock.\n");
+ new_ex.start = lock->l_policy_data.l_extent.start;
+ new_ex.end = lock->l_policy_data.l_extent.end;
+ /* In case the request is not on correct boundaries, we call
+ * fixup. (normally called in ldlm_extent_internal_policy_*) */
+ ldlm_extent_internal_policy_fixup(lock, &new_ex, 0);
+ }
- if (new_ex.start != lock->l_policy_data.l_extent.start ||
- new_ex.end != lock->l_policy_data.l_extent.end) {
- *flags |= LDLM_FL_LOCK_CHANGED;
- lock->l_policy_data.l_extent.start = new_ex.start;
- lock->l_policy_data.l_extent.end = new_ex.end;
- }
+ if (!ldlm_extent_equal(&new_ex, &lock->l_policy_data.l_extent)) {
+ *flags |= LDLM_FL_LOCK_CHANGED;
+ lock->l_policy_data.l_extent.start = new_ex.start;
+ lock->l_policy_data.l_extent.end = new_ex.end;
+ }
}
static int ldlm_check_contention(struct ldlm_lock *lock, int contended_locks)
}
if (tree->lit_mode == LCK_GROUP) {
- if (*flags & LDLM_FL_BLOCK_NOWAIT) {
+ if (*flags & (LDLM_FL_BLOCK_NOWAIT |
+ LDLM_FL_SPECULATIVE)) {
compat = -EWOULDBLOCK;
goto destroylock;
}
continue;
}
- if (!work_list) {
- rc = interval_is_overlapped(tree->lit_root,&ex);
- if (rc)
- RETURN(0);
+ /* We've found a potentially blocking lock, check
+ * compatibility. This handles locks other than GROUP
+ * locks, which are handled separately above.
+ *
+ * Locks with FL_SPECULATIVE are asynchronous requests
+ * which must never wait behind another lock, so they
+ * fail if any conflicting lock is found. */
+ if (!work_list || (*flags & LDLM_FL_SPECULATIVE)) {
+ rc = interval_is_overlapped(tree->lit_root,
+ &ex);
+ if (rc) {
+ if (!work_list) {
+ RETURN(0);
+ } else {
+ compat = -EWOULDBLOCK;
+ goto destroylock;
+ }
+ }
} else {
interval_search(tree->lit_root, &ex,
ldlm_extent_compat_cb, &data);
* already blocked.
* If we are in nonblocking mode - return
* immediately */
- if (*flags & LDLM_FL_BLOCK_NOWAIT) {
+ if (*flags & (LDLM_FL_BLOCK_NOWAIT
+ | LDLM_FL_SPECULATIVE)) {
compat = -EWOULDBLOCK;
goto destroylock;
}
}
if (unlikely(lock->l_req_mode == LCK_GROUP)) {
- /* If compared lock is GROUP, then requested is PR/PW/
- * so this is not compatible; extent range does not
- * matter */
- if (*flags & LDLM_FL_BLOCK_NOWAIT) {
+ /* If compared lock is GROUP, then requested is
+ * PR/PW so this is not compatible; extent
+ * range does not matter */
+ if (*flags & (LDLM_FL_BLOCK_NOWAIT
+ | LDLM_FL_SPECULATIVE)) {
compat = -EWOULDBLOCK;
goto destroylock;
} else {
if (!work_list)
RETURN(0);
+ if (*flags & LDLM_FL_SPECULATIVE) {
+ compat = -EWOULDBLOCK;
+ goto destroylock;
+ }
+
/* don't count conflicting glimpse locks */
if (lock->l_req_mode == LCK_PR &&
lock->l_policy_data.l_extent.start == 0 &&
*err = ELDLM_OK;
if (intention == LDLM_PROCESS_RESCAN) {
- /* Careful observers will note that we don't handle -EWOULDBLOCK
- * here, but it's ok for a non-obvious reason -- compat_queue
- * can only return -EWOULDBLOCK if (flags & BLOCK_NOWAIT).
- * flags should always be zero here, and if that ever stops
- * being true, we want to find out. */
+ /* Careful observers will note that we don't handle -EWOULDBLOCK
+ * here, but it's ok for a non-obvious reason -- compat_queue
+ * can only return -EWOULDBLOCK if (flags & BLOCK_NOWAIT |
+ * SPECULATIVE). flags should always be zero here, and if that
+ * ever stops being true, we want to find out. */
LASSERT(*flags == 0);
rc = ldlm_extent_compat_queue(&res->lr_granted, lock, flags,
err, NULL, &contended_locks);
git://git.whamcloud.com / fs / lustre-release.git / blobdiff