ublk: consolidate UBLK_IO_FLAG_OWNED_BY_SRV checks

Every ublk I/O command except UBLK_IO_FETCH_REQ checks that the ublk_io
has UBLK_IO_FLAG_OWNED_BY_SRV set. Consolidate the separate checks into
a single one in __ublk_ch_uring_cmd(), analogous to those for
UBLK_IO_FLAG_ACTIVE and UBLK_IO_FLAG_NEED_GET_DATA.

Signed-off-by: Caleb Sander Mateos <csander@purestorage.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20250505172624.1121839-1-csander@purestorage.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c
index 2c8f28c0d0a1ca6b70eab33d91cb4d75c585b429..3650bab40dd0bf28bfba4a501c522bcc1018878a 100644 (file)
--- a/drivers/block/ublk_drv.c
+++ b/drivers/block/ublk_drv.c
@@ -1926,16 +1926,12 @@ static int ublk_register_io_buf(struct io_uring_cmd *cmd,
                                unsigned int index, unsigned int issue_flags)
 {
        struct ublk_device *ub = cmd->file->private_data;
-       const struct ublk_io *io = &ubq->ios[tag];
        struct request *req;
        int ret;
 
        if (!ublk_support_zero_copy(ubq))
                return -EINVAL;
 
-       if (!(io->flags & UBLK_IO_FLAG_OWNED_BY_SRV))
-               return -EINVAL;
-
        req = __ublk_check_and_get_req(ub, ubq, tag, 0);
        if (!req)
                return -EINVAL;
@@ -1951,17 +1947,12 @@ static int ublk_register_io_buf(struct io_uring_cmd *cmd,
 }
 
 static int ublk_unregister_io_buf(struct io_uring_cmd *cmd,
-                                 const struct ublk_queue *ubq, unsigned int tag,
+                                 const struct ublk_queue *ubq,
                                  unsigned int index, unsigned int issue_flags)
 {
-       const struct ublk_io *io = &ubq->ios[tag];
-
        if (!ublk_support_zero_copy(ubq))
                return -EINVAL;
 
-       if (!(io->flags & UBLK_IO_FLAG_OWNED_BY_SRV))
-               return -EINVAL;
-
        return io_buffer_unregister_bvec(cmd, index, issue_flags);
 }
 
@@ -2015,12 +2006,8 @@ static int ublk_commit_and_fetch(const struct ublk_queue *ubq,
                                 struct ublk_io *io, struct io_uring_cmd *cmd,
                                 const struct ublksrv_io_cmd *ub_cmd)
 {
-       struct request *req;
-
-       if (!(io->flags & UBLK_IO_FLAG_OWNED_BY_SRV))
-               return -EINVAL;
+       struct request *req = io->req;
 
-       req = io->req;
        if (ublk_need_map_io(ubq)) {
                /*
                 * COMMIT_AND_FETCH_REQ has to provide IO buffer if
@@ -2104,6 +2091,11 @@ static int __ublk_ch_uring_cmd(struct io_uring_cmd *cmd,
                goto out;
        }
 
+       /* only UBLK_IO_FETCH_REQ is allowed if io is not OWNED_BY_SRV */
+       if (!(io->flags & UBLK_IO_FLAG_OWNED_BY_SRV) &&
+           _IOC_NR(cmd_op) != UBLK_IO_FETCH_REQ)
+               goto out;
+
        /*
         * ensure that the user issues UBLK_IO_NEED_GET_DATA
         * iff the driver have set the UBLK_IO_FLAG_NEED_GET_DATA.
@@ -2121,7 +2113,7 @@ static int __ublk_ch_uring_cmd(struct io_uring_cmd *cmd,
        case UBLK_IO_REGISTER_IO_BUF:
                return ublk_register_io_buf(cmd, ubq, tag, ub_cmd->addr, issue_flags);
        case UBLK_IO_UNREGISTER_IO_BUF:
-               return ublk_unregister_io_buf(cmd, ubq, tag, ub_cmd->addr, issue_flags);
+               return ublk_unregister_io_buf(cmd, ubq, ub_cmd->addr, issue_flags);
        case UBLK_IO_FETCH_REQ:
                ret = ublk_fetch(cmd, ubq, io, ub_cmd->addr);
                if (ret)
@@ -2133,8 +2125,6 @@ static int __ublk_ch_uring_cmd(struct io_uring_cmd *cmd,
                        goto out;
                break;
        case UBLK_IO_NEED_GET_DATA:
-               if (!(io->flags & UBLK_IO_FLAG_OWNED_BY_SRV))
-                       goto out;
                io->addr = ub_cmd->addr;
                if (!ublk_get_data(ubq, io))
                        return -EIOCBQUEUED;