return r;
}
+/*
+ * Target argument parsing helpers.
+ */
+static int validate_next_arg(struct dm_arg *arg, struct dm_arg_set *arg_set,
+ unsigned *value, char **error, unsigned grouped)
+{
+ const char *arg_str = dm_shift_arg(arg_set);
+
+ if (!arg_str ||
+ (sscanf(arg_str, "%u", value) != 1) ||
+ (*value < arg->min) ||
+ (*value > arg->max) ||
+ (grouped && arg_set->argc < *value)) {
+ *error = arg->error;
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+int dm_read_arg(struct dm_arg *arg, struct dm_arg_set *arg_set,
+ unsigned *value, char **error)
+{
+ return validate_next_arg(arg, arg_set, value, error, 0);
+}
+EXPORT_SYMBOL(dm_read_arg);
+
+int dm_read_arg_group(struct dm_arg *arg, struct dm_arg_set *arg_set,
+ unsigned *value, char **error)
+{
+ return validate_next_arg(arg, arg_set, value, error, 1);
+}
+EXPORT_SYMBOL(dm_read_arg_group);
+
+const char *dm_shift_arg(struct dm_arg_set *as)
+{
+ char *r;
+
+ if (as->argc) {
+ as->argc--;
+ r = *as->argv;
+ as->argv++;
+ return r;
+ }
+
+ return NULL;
+}
+EXPORT_SYMBOL(dm_shift_arg);
+
+void dm_consume_args(struct dm_arg_set *as, unsigned num_args)
+{
+ BUG_ON(as->argc < num_args);
+ as->argc -= num_args;
+ as->argv += num_args;
+}
+EXPORT_SYMBOL(dm_consume_args);
+
static int dm_table_set_type(struct dm_table *t)
{
unsigned i;
blk_get_integrity(template_disk));
}
+static int device_flush_capable(struct dm_target *ti, struct dm_dev *dev,
+ sector_t start, sector_t len, void *data)
+{
+ unsigned flush = (*(unsigned *)data);
+ struct request_queue *q = bdev_get_queue(dev->bdev);
+
+ return q && (q->flush_flags & flush);
+}
+
+static bool dm_table_supports_flush(struct dm_table *t, unsigned flush)
+{
+ struct dm_target *ti;
+ unsigned i = 0;
+
+ /*
+ * Require at least one underlying device to support flushes.
+ * t->devices includes internal dm devices such as mirror logs
+ * so we need to use iterate_devices here, which targets
+ * supporting flushes must provide.
+ */
+ while (i < dm_table_get_num_targets(t)) {
+ ti = dm_table_get_target(t, i++);
+
+ if (!ti->num_flush_requests)
+ continue;
+
+ if (ti->type->iterate_devices &&
+ ti->type->iterate_devices(ti, device_flush_capable, &flush))
+ return 1;
+ }
+
+ return 0;
+}
+
void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q,
struct queue_limits *limits)
{
+ unsigned flush = 0;
+
/*
* Copy table's limits to the DM device's request_queue
*/
else
queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, q);
+ if (dm_table_supports_flush(t, REQ_FLUSH)) {
+ flush |= REQ_FLUSH;
+ if (dm_table_supports_flush(t, REQ_FUA))
+ flush |= REQ_FUA;
+ }
+ blk_queue_flush(q, flush);
+
dm_table_set_integrity(t);
/*