+/*
+ * journal_trim_extent_overlap
+ *
+ * Return 1 if there are any pending TRIMs that overlap with the given offset and length
+ * Return 0 otherwise.
+ */
+
+int journal_trim_extent_overlap (journal *jnl, uint64_t offset, uint64_t length, uint64_t *end) {
+ transaction *tr = NULL;
+ int overlap = 0;
+
+ uint64_t overlap_start;
+ uint64_t overlap_len;
+ tr = jnl->active_tr;
+ CHECK_TRANSACTION(tr);
+
+ /*
+ * There are two lists that need to be examined for potential overlaps:
+ *
+ * The first is the current transaction. Since this function requires that
+ * a transaction be active when this is called, this is the "active_tr"
+ * pointer in the journal struct. This has a trimlist pointer which needs
+ * to be searched.
+ */
+ overlap = trim_search_extent (&tr->trim, offset, length, &overlap_start, &overlap_len);
+ if (overlap == 0) {
+ /*
+ * The second is the async trim list, which is only done if the current
+ * transaction group (active transaction) did not overlap with our target
+ * extent. This async trim list is the set of all previously
+ * committed transaction groups whose I/Os are now in-flight. We need to hold the
+ * trim lock in order to search this list. If we grab the list before the
+ * TRIM has completed, then we will compare it. If it is grabbed AFTER the
+ * TRIM has completed, then the pointer will be zeroed out and we won't have
+ * to check anything.
+ */
+ lck_rw_lock_shared (&jnl->trim_lock);
+ if (jnl->async_trim != NULL) {
+ overlap = trim_search_extent(jnl->async_trim, offset, length, &overlap_start, &overlap_len);
+ }
+ lck_rw_unlock_shared (&jnl->trim_lock);
+ }
+
+ if (overlap) {
+ /* compute the end (min) of the overlapping range */
+ if ( (overlap_start + overlap_len) < (offset + length)) {
+ *end = (overlap_start + overlap_len);
+ }
+ else {
+ *end = (offset + length);
+ }
+ }
+
+
+ return overlap;
+}
+
+/*
+ * journal_request_immediate_flush
+ *
+ * FS requests that the journal flush immediately upon the
+ * active transaction's completion.
+ *
+ * Returns 0 if operation succeeds
+ * Returns EPERM if we failed to leave hint
+ */
+int
+journal_request_immediate_flush (journal *jnl) {
+
+ transaction *tr = NULL;
+ /*
+ * Is a transaction still in process? You must do
+ * this while there are txns open
+ */
+ tr = jnl->active_tr;
+ if (tr != NULL) {
+ CHECK_TRANSACTION(tr);
+ tr->flush_on_completion = TRUE;
+ }
+ else {
+ return EPERM;
+ }
+ return 0;
+}
+
+
projects / apple / xnu.git / blobdiff