#include <linux/blkdev_compat.h>
unsigned int zvol_major = ZVOL_MAJOR;
-unsigned int zvol_threads = 0;
+unsigned int zvol_threads = 32;
static taskq_t *zvol_taskq;
static kmutex_t zvol_state_lock;
blk_end_request(req, -error, size);
}
+#ifdef HAVE_BLK_QUEUE_DISCARD
+static void
+zvol_discard(void *arg)
+{
+ struct request *req = (struct request *)arg;
+ struct request_queue *q = req->q;
+ zvol_state_t *zv = q->queuedata;
+ uint64_t offset = blk_rq_pos(req) << 9;
+ uint64_t size = blk_rq_bytes(req);
+ int error;
+ rl_t *rl;
+
+ if (offset + size > zv->zv_volsize) {
+ blk_end_request(req, -EIO, size);
+ return;
+ }
+
+ if (size == 0) {
+ blk_end_request(req, 0, size);
+ return;
+ }
+
+ rl = zfs_range_lock(&zv->zv_znode, offset, size, RL_WRITER);
+
+ error = dmu_free_long_range(zv->zv_objset, ZVOL_OBJ, offset, size);
+
+ /*
+ * TODO: maybe we should add the operation to the log.
+ */
+
+ zfs_range_unlock(rl);
+
+ blk_end_request(req, -error, size);
+}
+#endif /* HAVE_BLK_QUEUE_DISCARD */
+
/*
* Common read path running under the zvol taskq context. This function
* is responsible for copying the requested data out of the DMU and in to
break;
}
+#ifdef HAVE_BLK_QUEUE_DISCARD
+ if (req->cmd_flags & VDEV_REQ_DISCARD) {
+ zvol_dispatch(zvol_discard, req);
+ break;
+ }
+#endif /* HAVE_BLK_QUEUE_DISCARD */
+
zvol_dispatch(zvol_write, req);
break;
default:
set_capacity(zv->zv_disk, zv->zv_volsize >> 9);
+ blk_queue_max_hw_sectors(zv->zv_queue, UINT_MAX);
+ blk_queue_max_segments(zv->zv_queue, UINT16_MAX);
+ blk_queue_max_segment_size(zv->zv_queue, UINT_MAX);
+ blk_queue_physical_block_size(zv->zv_queue, zv->zv_volblocksize);
+ blk_queue_io_opt(zv->zv_queue, zv->zv_volblocksize);
+#ifdef HAVE_BLK_QUEUE_DISCARD
+ blk_queue_max_discard_sectors(zv->zv_queue, UINT_MAX);
+ queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, zv->zv_queue);
+#endif
+#ifdef HAVE_BLK_QUEUE_NONROT
+ queue_flag_set_unlocked(QUEUE_FLAG_NONROT, zv->zv_queue);
+#endif
+
if (zil_replay_disable)
zil_destroy(dmu_objset_zil(os), B_FALSE);
else
{
int error;
- if (!zvol_threads)
- zvol_threads = num_online_cpus();
-
+ /*
+ * The zvol taskqs are created with TASKQ_NORECLAIM so they may be
+ * used safely as a swap device. If direct reclaim is allowed then
+ * they quickly deadlock in one of the internal memory allocations.
+ */
zvol_taskq = taskq_create(ZVOL_DRIVER, zvol_threads, maxclsyspri,
- zvol_threads, INT_MAX, TASKQ_PREPOPULATE);
+ zvol_threads, INT_MAX,
+ TASKQ_PREPOPULATE | TASKQ_NORECLAIM);
if (zvol_taskq == NULL) {
printk(KERN_INFO "ZFS: taskq_create() failed\n");
return (-ENOMEM);