selftests: ublk: add support for user copy to kublk

The ublk selftests mock ublk server kublk supports every data copy mode
except user copy. Add support for user copy to kublk, enabled via the
--user_copy (-u) command line argument. On writes, issue pread() calls
to copy the write data into the ublk_io's buffer before dispatching the
write to the target implementation. On reads, issue pwrite() calls to
copy read data from the ublk_io's buffer before committing the request.
Copy in 2 KB chunks to provide some coverage of the offseting logic.

Signed-off-by: Caleb Sander Mateos <csander@purestorage.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/tools/testing/selftests/ublk/file_backed.c b/tools/testing/selftests/ublk/file_backed.c
index cd9fe69ecce2016062657dd9d27593dd94c9ceb3..269d5f124e06a0387b522404d54a501be90f1529 100644 (file)
--- a/tools/testing/selftests/ublk/file_backed.c
+++ b/tools/testing/selftests/ublk/file_backed.c
@@ -34,8 +34,9 @@ static int loop_queue_tgt_rw_io(struct ublk_thread *t, struct ublk_queue *q,
        unsigned zc = ublk_queue_use_zc(q);
        unsigned auto_zc = ublk_queue_use_auto_zc(q);
        enum io_uring_op op = ublk_to_uring_op(iod, zc | auto_zc);
+       struct ublk_io *io = ublk_get_io(q, tag);
        struct io_uring_sqe *sqe[3];
-       void *addr = (zc | auto_zc) ? NULL : (void *)iod->addr;
+       void *addr = io->buf_addr;
 
        if (!zc || auto_zc) {
                ublk_io_alloc_sqes(t, sqe, 1);
@@ -56,7 +57,7 @@ static int loop_queue_tgt_rw_io(struct ublk_thread *t, struct ublk_queue *q,
 
        ublk_io_alloc_sqes(t, sqe, 3);
 
-       io_uring_prep_buf_register(sqe[0], q, tag, q->q_id, ublk_get_io(q, tag)->buf_index);
+       io_uring_prep_buf_register(sqe[0], q, tag, q->q_id, io->buf_index);
        sqe[0]->flags |= IOSQE_CQE_SKIP_SUCCESS | IOSQE_IO_HARDLINK;
        sqe[0]->user_data = build_user_data(tag,
                        ublk_cmd_op_nr(sqe[0]->cmd_op), 0, q->q_id, 1);
@@ -68,7 +69,7 @@ static int loop_queue_tgt_rw_io(struct ublk_thread *t, struct ublk_queue *q,
        sqe[1]->flags |= IOSQE_FIXED_FILE | IOSQE_IO_HARDLINK;
        sqe[1]->user_data = build_user_data(tag, ublk_op, 0, q->q_id, 1);
 
-       io_uring_prep_buf_unregister(sqe[2], q, tag, q->q_id, ublk_get_io(q, tag)->buf_index);
+       io_uring_prep_buf_unregister(sqe[2], q, tag, q->q_id, io->buf_index);
        sqe[2]->user_data = build_user_data(tag, ublk_cmd_op_nr(sqe[2]->cmd_op), 0, q->q_id, 1);
 
        return 2;

diff --git a/tools/testing/selftests/ublk/kublk.c b/tools/testing/selftests/ublk/kublk.c
index 4dd02cb083baafcf9d74ad31fa0f1e47d14c685f..185ba553686abea11e90919da7518fb07227915e 100644 (file)
--- a/tools/testing/selftests/ublk/kublk.c
+++ b/tools/testing/selftests/ublk/kublk.c
@@ -596,6 +596,38 @@ static void ublk_set_auto_buf_reg(const struct ublk_queue *q,
        sqe->addr = ublk_auto_buf_reg_to_sqe_addr(&buf);
 }
 
+/* Copy in pieces to test the buffer offset logic */
+#define UBLK_USER_COPY_LEN 2048
+
+static void ublk_user_copy(const struct ublk_io *io, __u8 match_ublk_op)
+{
+       const struct ublk_queue *q = ublk_io_to_queue(io);
+       const struct ublksrv_io_desc *iod = ublk_get_iod(q, io->tag);
+       __u64 off = ublk_user_copy_offset(q->q_id, io->tag);
+       __u8 ublk_op = ublksrv_get_op(iod);
+       __u32 len = iod->nr_sectors << 9;
+       void *addr = io->buf_addr;
+
+       if (ublk_op != match_ublk_op)
+               return;
+
+       while (len) {
+               __u32 copy_len = min(len, UBLK_USER_COPY_LEN);
+               ssize_t copied;
+
+               if (ublk_op == UBLK_IO_OP_WRITE)
+                       copied = pread(q->ublk_fd, addr, copy_len, off);
+               else if (ublk_op == UBLK_IO_OP_READ)
+                       copied = pwrite(q->ublk_fd, addr, copy_len, off);
+               else
+                       assert(0);
+               assert(copied == (ssize_t)copy_len);
+               addr += copy_len;
+               off += copy_len;
+               len -= copy_len;
+       }
+}
+
 int ublk_queue_io_cmd(struct ublk_thread *t, struct ublk_io *io)
 {
        struct ublk_queue *q = ublk_io_to_queue(io);
@@ -618,9 +650,12 @@ int ublk_queue_io_cmd(struct ublk_thread *t, struct ublk_io *io)
 
        if (io->flags & UBLKS_IO_NEED_GET_DATA)
                cmd_op = UBLK_U_IO_NEED_GET_DATA;
-       else if (io->flags & UBLKS_IO_NEED_COMMIT_RQ_COMP)
+       else if (io->flags & UBLKS_IO_NEED_COMMIT_RQ_COMP) {
+               if (ublk_queue_use_user_copy(q))
+                       ublk_user_copy(io, UBLK_IO_OP_READ);
+
                cmd_op = UBLK_U_IO_COMMIT_AND_FETCH_REQ;
-       else if (io->flags & UBLKS_IO_NEED_FETCH_RQ)
+       } else if (io->flags & UBLKS_IO_NEED_FETCH_RQ)
                cmd_op = UBLK_U_IO_FETCH_REQ;
 
        if (io_uring_sq_space_left(&t->ring) < 1)
@@ -649,7 +684,7 @@ int ublk_queue_io_cmd(struct ublk_thread *t, struct ublk_io *io)
        sqe[0]->rw_flags        = 0;
        cmd->tag        = io->tag;
        cmd->q_id       = q->q_id;
-       if (!ublk_queue_no_buf(q))
+       if (!ublk_queue_no_buf(q) && !ublk_queue_use_user_copy(q))
                cmd->addr       = (__u64) (uintptr_t) io->buf_addr;
        else
                cmd->addr       = 0;
@@ -751,6 +786,10 @@ static void ublk_handle_uring_cmd(struct ublk_thread *t,
 
        if (cqe->res == UBLK_IO_RES_OK) {
                assert(tag < q->q_depth);
+
+               if (ublk_queue_use_user_copy(q))
+                       ublk_user_copy(io, UBLK_IO_OP_WRITE);
+
                if (q->tgt_ops->queue_io)
                        q->tgt_ops->queue_io(t, q, tag);
        } else if (cqe->res == UBLK_IO_RES_NEED_GET_DATA) {
@@ -1507,7 +1546,7 @@ static void __cmd_create_help(char *exe, bool recovery)
 
        printf("%s %s -t [null|loop|stripe|fault_inject] [-q nr_queues] [-d depth] [-n dev_id]\n",
                        exe, recovery ? "recover" : "add");
-       printf("\t[--foreground] [--quiet] [-z] [--auto_zc] [--auto_zc_fallback] [--debug_mask mask] [-r 0|1 ] [-g]\n");
+       printf("\t[--foreground] [--quiet] [-z] [--auto_zc] [--auto_zc_fallback] [--debug_mask mask] [-r 0|1] [-g] [-u]\n");
        printf("\t[-e 0|1 ] [-i 0|1] [--no_ublk_fixed_fd]\n");
        printf("\t[--nthreads threads] [--per_io_tasks]\n");
        printf("\t[target options] [backfile1] [backfile2] ...\n");
@@ -1568,6 +1607,7 @@ int main(int argc, char *argv[])
                { "get_data",           1,      NULL, 'g'},
                { "auto_zc",            0,      NULL,  0 },
                { "auto_zc_fallback",   0,      NULL,  0 },
+               { "user_copy",          0,      NULL, 'u'},
                { "size",               1,      NULL, 's'},
                { "nthreads",           1,      NULL,  0 },
                { "per_io_tasks",       0,      NULL,  0 },
@@ -1593,7 +1633,7 @@ int main(int argc, char *argv[])
 
        opterr = 0;
        optind = 2;
-       while ((opt = getopt_long(argc, argv, "t:n:d:q:r:e:i:s:gaz",
+       while ((opt = getopt_long(argc, argv, "t:n:d:q:r:e:i:s:gazu",
                                  longopts, &option_idx)) != -1) {
                switch (opt) {
                case 'a':
@@ -1633,6 +1673,9 @@ int main(int argc, char *argv[])
                case 'g':
                        ctx.flags |= UBLK_F_NEED_GET_DATA;
                        break;
+               case 'u':
+                       ctx.flags |= UBLK_F_USER_COPY;
+                       break;
                case 's':
                        ctx.size = strtoull(optarg, NULL, 10);
                        break;

diff --git a/tools/testing/selftests/ublk/kublk.h b/tools/testing/selftests/ublk/kublk.h
index 6e8f381f34810d50c51f43638ece538a1e5dc3d1..8a83b90ec603ad00735a9393143b588a17a5c12f 100644 (file)
--- a/tools/testing/selftests/ublk/kublk.h
+++ b/tools/testing/selftests/ublk/kublk.h
@@ -208,6 +208,12 @@ static inline int ublk_io_auto_zc_fallback(const struct ublksrv_io_desc *iod)
        return !!(iod->op_flags & UBLK_IO_F_NEED_REG_BUF);
 }
 
+static inline __u64 ublk_user_copy_offset(unsigned q_id, unsigned tag)
+{
+       return UBLKSRV_IO_BUF_OFFSET +
+              ((__u64)q_id << UBLK_QID_OFF | (__u64)tag << UBLK_TAG_OFF);
+}
+
 static inline int is_target_io(__u64 user_data)
 {
        return (user_data & (1ULL << 63)) != 0;
@@ -405,6 +411,11 @@ static inline bool ublk_queue_auto_zc_fallback(const struct ublk_queue *q)
        return !!(q->flags & UBLKS_Q_AUTO_BUF_REG_FALLBACK);
 }
 
+static inline bool ublk_queue_use_user_copy(const struct ublk_queue *q)
+{
+       return !!(q->flags & UBLK_F_USER_COPY);
+}
+
 static inline int ublk_queue_no_buf(const struct ublk_queue *q)
 {
        return ublk_queue_use_zc(q) || ublk_queue_use_auto_zc(q);

diff --git a/tools/testing/selftests/ublk/stripe.c b/tools/testing/selftests/ublk/stripe.c
index 791fa8dc165109e810795406a1c71f582450e99a..fd412e1f01c0ee398343392662b78a8f9d4c65a2 100644 (file)
--- a/tools/testing/selftests/ublk/stripe.c
+++ b/tools/testing/selftests/ublk/stripe.c
@@ -134,7 +134,7 @@ static int stripe_queue_tgt_rw_io(struct ublk_thread *t, struct ublk_queue *q,
        struct stripe_array *s = alloc_stripe_array(conf, iod);
        struct ublk_io *io = ublk_get_io(q, tag);
        int i, extra = zc ? 2 : 0;
-       void *base = (zc | auto_zc) ? NULL : (void *)iod->addr;
+       void *base = io->buf_addr;
 
        io->private_data = s;
        calculate_stripe_array(conf, iod, s, base);