Merge tag '5.20-rc-ksmbd-server-fixes' of git://git.samba.org/ksmbd

[linux-2.6-microblaze.git] / drivers / block / ublk_drv.c

diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c
index 2b3cd67..2b7d1db 100644 (file)
--- a/drivers/block/ublk_drv.c
+++ b/drivers/block/ublk_drv.c
@@ -47,7 +47,9 @@
 #define UBLK_MINORS            (1U << MINORBITS)
 
 /* All UBLK_F_* have to be included into UBLK_F_ALL */
-#define UBLK_F_ALL (UBLK_F_SUPPORT_ZERO_COPY | UBLK_F_URING_CMD_COMP_IN_TASK)
+#define UBLK_F_ALL (UBLK_F_SUPPORT_ZERO_COPY \
+               | UBLK_F_URING_CMD_COMP_IN_TASK \
+               | UBLK_F_NEED_GET_DATA)
 
 /* All UBLK_PARAM_TYPE_* should be included here */
 #define UBLK_PARAM_TYPE_ALL (UBLK_PARAM_TYPE_BASIC | UBLK_PARAM_TYPE_DISCARD)
@@ -89,6 +91,15 @@ struct ublk_uring_cmd_pdu {
  */
 #define UBLK_IO_FLAG_ABORTED 0x04
 
+/*
+ * UBLK_IO_FLAG_NEED_GET_DATA is set because IO command requires
+ * get data buffer address from ublksrv.
+ *
+ * Then, bio data could be copied into this data buffer for a WRITE request
+ * after the IO command is issued again and UBLK_IO_FLAG_NEED_GET_DATA is unset.
+ */
+#define UBLK_IO_FLAG_NEED_GET_DATA 0x08
+
 struct ublk_io {
        /* userspace buffer address from io cmd */
        __u64   addr;
@@ -262,6 +273,13 @@ static inline bool ublk_can_use_task_work(const struct ublk_queue *ubq)
        return false;
 }
 
+static inline bool ublk_need_get_data(const struct ublk_queue *ubq)
+{
+       if (ubq->flags & UBLK_F_NEED_GET_DATA)
+               return true;
+       return false;
+}
+
 static struct ublk_device *ublk_get_device(struct ublk_device *ub)
 {
        if (kobject_get_unless_zero(&ub->cdev_dev.kobj))
@@ -603,6 +621,21 @@ static void __ublk_fail_req(struct ublk_io *io, struct request *req)
        }
 }
 
+static void ubq_complete_io_cmd(struct ublk_io *io, int res)
+{
+       /* mark this cmd owned by ublksrv */
+       io->flags |= UBLK_IO_FLAG_OWNED_BY_SRV;
+
+       /*
+        * clear ACTIVE since we are done with this sqe/cmd slot
+        * We can only accept io cmd in case of being not active.
+        */
+       io->flags &= ~UBLK_IO_FLAG_ACTIVE;
+
+       /* tell ublksrv one io request is coming */
+       io_uring_cmd_done(io->cmd, res, 0);
+}
+
 #define UBLK_REQUEUE_DELAY_MS  3
 
 static inline void __ublk_rq_task_work(struct request *req)
@@ -625,6 +658,30 @@ static inline void __ublk_rq_task_work(struct request *req)
                return;
        }
 
+       if (ublk_need_get_data(ubq) &&
+                       (req_op(req) == REQ_OP_WRITE ||
+                       req_op(req) == REQ_OP_FLUSH)) {
+               /*
+                * We have not handled UBLK_IO_NEED_GET_DATA command yet,
+                * so immepdately pass UBLK_IO_RES_NEED_GET_DATA to ublksrv
+                * and notify it.
+                */
+               if (!(io->flags & UBLK_IO_FLAG_NEED_GET_DATA)) {
+                       io->flags |= UBLK_IO_FLAG_NEED_GET_DATA;
+                       pr_devel("%s: need get data. op %d, qid %d tag %d io_flags %x\n",
+                                       __func__, io->cmd->cmd_op, ubq->q_id,
+                                       req->tag, io->flags);
+                       ubq_complete_io_cmd(io, UBLK_IO_RES_NEED_GET_DATA);
+                       return;
+               }
+               /*
+                * We have handled UBLK_IO_NEED_GET_DATA command,
+                * so clear UBLK_IO_FLAG_NEED_GET_DATA now and just
+                * do the copy work.
+                */
+               io->flags &= ~UBLK_IO_FLAG_NEED_GET_DATA;
+       }
+
        mapped_bytes = ublk_map_io(ubq, req, io);
 
        /* partially mapped, update io descriptor */
@@ -647,17 +704,7 @@ static inline void __ublk_rq_task_work(struct request *req)
                        mapped_bytes >> 9;
        }
 
-       /* mark this cmd owned by ublksrv */
-       io->flags |= UBLK_IO_FLAG_OWNED_BY_SRV;
-
-       /*
-        * clear ACTIVE since we are done with this sqe/cmd slot
-        * We can only accept io cmd in case of being not active.
-        */
-       io->flags &= ~UBLK_IO_FLAG_ACTIVE;
-
-       /* tell ublksrv one io request is coming */
-       io_uring_cmd_done(io->cmd, UBLK_IO_RES_OK, 0);
+       ubq_complete_io_cmd(io, UBLK_IO_RES_OK);
 }
 
 static void ublk_rq_task_work_cb(struct io_uring_cmd *cmd)
@@ -946,6 +993,25 @@ static void ublk_mark_io_ready(struct ublk_device *ub, struct ublk_queue *ubq)
        mutex_unlock(&ub->mutex);
 }
 
+static void ublk_handle_need_get_data(struct ublk_device *ub, int q_id,
+               int tag, struct io_uring_cmd *cmd)
+{
+       struct ublk_queue *ubq = ublk_get_queue(ub, q_id);
+       struct request *req = blk_mq_tag_to_rq(ub->tag_set.tags[q_id], tag);
+
+       if (ublk_can_use_task_work(ubq)) {
+               struct ublk_rq_data *data = blk_mq_rq_to_pdu(req);
+
+               /* should not fail since we call it just in ubq->ubq_daemon */
+               task_work_add(ubq->ubq_daemon, &data->work, TWA_SIGNAL_NO_IPI);
+       } else {
+               struct ublk_uring_cmd_pdu *pdu = ublk_get_uring_cmd_pdu(cmd);
+
+               pdu->req = req;
+               io_uring_cmd_complete_in_task(cmd, ublk_rq_task_work_cb);
+       }
+}
+
 static int ublk_ch_uring_cmd(struct io_uring_cmd *cmd, unsigned int issue_flags)
 {
        struct ublksrv_io_cmd *ub_cmd = (struct ublksrv_io_cmd *)cmd->cmd;
@@ -984,6 +1050,14 @@ static int ublk_ch_uring_cmd(struct io_uring_cmd *cmd, unsigned int issue_flags)
                goto out;
        }
 
+       /*
+        * ensure that the user issues UBLK_IO_NEED_GET_DATA
+        * iff the driver have set the UBLK_IO_FLAG_NEED_GET_DATA.
+        */
+       if ((!!(io->flags & UBLK_IO_FLAG_NEED_GET_DATA))
+                       ^ (cmd_op == UBLK_IO_NEED_GET_DATA))
+               goto out;
+
        switch (cmd_op) {
        case UBLK_IO_FETCH_REQ:
                /* UBLK_IO_FETCH_REQ is only allowed before queue is setup */
@@ -1017,6 +1091,14 @@ static int ublk_ch_uring_cmd(struct io_uring_cmd *cmd, unsigned int issue_flags)
                io->cmd = cmd;
                ublk_commit_completion(ub, ub_cmd);
                break;
+       case UBLK_IO_NEED_GET_DATA:
+               if (!(io->flags & UBLK_IO_FLAG_OWNED_BY_SRV))
+                       goto out;
+               io->addr = ub_cmd->addr;
+               io->cmd = cmd;
+               io->flags |= UBLK_IO_FLAG_ACTIVE;
+               ublk_handle_need_get_data(ub, ub_cmd->q_id, ub_cmd->tag, cmd);
+               break;
        default:
                goto out;
        }