--- /dev/null
+// SPDX-License-Identifier: GPL-2.0
+
+#include "kublk.h"
+
+static void backing_file_tgt_deinit(struct ublk_dev *dev)
+{
+ int i;
+
+ for (i = 1; i < dev->nr_fds; i++) {
+ fsync(dev->fds[i]);
+ close(dev->fds[i]);
+ }
+}
+
+static int backing_file_tgt_init(struct ublk_dev *dev)
+{
+ int fd, i;
+
+ assert(dev->nr_fds == 1);
+
+ for (i = 0; i < dev->tgt.nr_backing_files; i++) {
+ char *file = dev->tgt.backing_file[i];
+ unsigned long bytes;
+ struct stat st;
+
+ ublk_dbg(UBLK_DBG_DEV, "%s: file %d: %s\n", __func__, i, file);
+
+ fd = open(file, O_RDWR | O_DIRECT);
+ if (fd < 0) {
+ ublk_err("%s: backing file %s can't be opened: %s\n",
+ __func__, file, strerror(errno));
+ return -EBADF;
+ }
+
+ if (fstat(fd, &st) < 0) {
+ close(fd);
+ return -EBADF;
+ }
+
+ if (S_ISREG(st.st_mode))
+ bytes = st.st_size;
+ else if (S_ISBLK(st.st_mode)) {
+ if (ioctl(fd, BLKGETSIZE64, &bytes) != 0)
+ return -1;
+ } else {
+ return -EINVAL;
+ }
+
+ dev->tgt.backing_file_size[i] = bytes;
+ dev->fds[dev->nr_fds] = fd;
+ dev->nr_fds += 1;
+ }
+
+ return 0;
+}
+
+static int loop_queue_tgt_io(struct ublk_queue *q, int tag)
+{
+ const struct ublksrv_io_desc *iod = ublk_get_iod(q, tag);
+ struct io_uring_sqe *sqe = ublk_queue_alloc_sqe(q);
+ unsigned ublk_op = ublksrv_get_op(iod);
+
+ if (!sqe)
+ return -ENOMEM;
+
+ switch (ublk_op) {
+ case UBLK_IO_OP_FLUSH:
+ io_uring_prep_sync_file_range(sqe, 1 /*fds[1]*/,
+ iod->nr_sectors << 9,
+ iod->start_sector << 9,
+ IORING_FSYNC_DATASYNC);
+ io_uring_sqe_set_flags(sqe, IOSQE_FIXED_FILE);
+ break;
+ case UBLK_IO_OP_WRITE_ZEROES:
+ case UBLK_IO_OP_DISCARD:
+ return -ENOTSUP;
+ case UBLK_IO_OP_READ:
+ io_uring_prep_read(sqe, 1 /*fds[1]*/,
+ (void *)iod->addr,
+ iod->nr_sectors << 9,
+ iod->start_sector << 9);
+ io_uring_sqe_set_flags(sqe, IOSQE_FIXED_FILE);
+ break;
+ case UBLK_IO_OP_WRITE:
+ io_uring_prep_write(sqe, 1 /*fds[1]*/,
+ (void *)iod->addr,
+ iod->nr_sectors << 9,
+ iod->start_sector << 9);
+ io_uring_sqe_set_flags(sqe, IOSQE_FIXED_FILE);
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ q->io_inflight++;
+ /* bit63 marks us as tgt io */
+ sqe->user_data = build_user_data(tag, ublk_op, 0, 1);
+
+ ublk_dbg(UBLK_DBG_IO, "%s: tag %d ublk io %x %llx %u\n", __func__, tag,
+ iod->op_flags, iod->start_sector, iod->nr_sectors << 9);
+ return 1;
+}
+
+static int ublk_loop_queue_io(struct ublk_queue *q, int tag)
+{
+ int queued = loop_queue_tgt_io(q, tag);
+
+ if (queued < 0)
+ ublk_complete_io(q, tag, queued);
+
+ return 0;
+}
+
+static void ublk_loop_io_done(struct ublk_queue *q, int tag,
+ const struct io_uring_cqe *cqe)
+{
+ int cqe_tag = user_data_to_tag(cqe->user_data);
+
+ assert(tag == cqe_tag);
+ ublk_complete_io(q, tag, cqe->res);
+ q->io_inflight--;
+}
+
+static int ublk_loop_tgt_init(struct ublk_dev *dev)
+{
+ unsigned long long bytes;
+ int ret;
+ struct ublk_params p = {
+ .types = UBLK_PARAM_TYPE_BASIC,
+ .basic = {
+ .logical_bs_shift = 9,
+ .physical_bs_shift = 12,
+ .io_opt_shift = 12,
+ .io_min_shift = 9,
+ .max_sectors = dev->dev_info.max_io_buf_bytes >> 9,
+ },
+ };
+
+ assert(dev->tgt.nr_backing_files == 1);
+ ret = backing_file_tgt_init(dev);
+ if (ret)
+ return ret;
+
+ bytes = dev->tgt.backing_file_size[0];
+ dev->tgt.dev_size = bytes;
+ p.basic.dev_sectors = bytes >> 9;
+ dev->tgt.params = p;
+
+ return 0;
+}
+
+const struct ublk_tgt_ops loop_tgt_ops = {
+ .name = "loop",
+ .init_tgt = ublk_loop_tgt_init,
+ .deinit_tgt = backing_file_tgt_deinit,
+ .queue_io = ublk_loop_queue_io,
+ .tgt_io_done = ublk_loop_io_done,
+};
unsigned int ublk_dbg_mask = UBLK_LOG;
static const struct ublk_tgt_ops *tgt_ops_list[] = {
&null_tgt_ops,
+ &loop_tgt_ops,
};
static const struct ublk_tgt_ops *ublk_find_tgt(const char *name)
struct ublksrv_ctrl_dev_info *info;
struct ublk_dev *dev;
int dev_id = ctx->dev_id;
- int ret;
+ int ret, i;
ops = ublk_find_tgt(tgt_type);
if (!ops) {
dev->tgt.sq_depth = depth;
dev->tgt.cq_depth = depth;
+ for (i = 0; i < MAX_BACK_FILES; i++) {
+ if (ctx->files[i]) {
+ strcpy(dev->tgt.backing_file[i], ctx->files[i]);
+ dev->tgt.nr_backing_files++;
+ }
+ }
+
ret = ublk_ctrl_add_dev(dev);
if (ret < 0) {
ublk_err("%s: can't add dev id %d, type %s ret %d\n",
static int cmd_dev_help(char *exe)
{
- printf("%s add -t [null] [-q nr_queues] [-d depth] [-n dev_id]\n", exe);
+ printf("%s add -t [null|loop] [-q nr_queues] [-d depth] [-n dev_id] [backfile1] [backfile2] ...\n", exe);
printf("\t default: nr_queues=2(max 4), depth=128(max 128), dev_id=-1(auto allocation)\n");
printf("%s del [-n dev_id] -a \n", exe);
printf("\t -a delete all devices -n delete specified device\n");
projects / users / willy / linux.git / commitdiff