blkdev_uring_cmd() checks IORING_URING_CMD_REISSUE to determine whether this is the first issue. However, this flag lives in cmd->flags instead of issue_flags. Coincidentally, IO_URING_F_NONBLOCK shares bit 31 with IORING_URING_CMD_REISSUE. As a result, the SQE read was never performed, bic->len remained zero, and every BLOCK_URING_CMD_DISCARD failed with -EINVAL. Fix it by checking cmd->flags as intended. Fixes: 212ec34e4e72 ("block: only read from sqe on initial invocation of blkdev_uring_cmd") Signed-off-by: Yitang Yang --- block/ioctl.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/block/ioctl.c b/block/ioctl.c index ab2c9ed79946..3d4ea1537457 100644 --- a/block/ioctl.c +++ b/block/ioctl.c @@ -951,7 +951,7 @@ int blkdev_uring_cmd(struct io_uring_cmd *cmd, unsigned int issue_flags) u32 cmd_op = cmd->cmd_op; /* Read what we need from the SQE on the first issue */ - if (!(issue_flags & IORING_URING_CMD_REISSUE)) { + if (!(cmd->flags & IORING_URING_CMD_REISSUE)) { const struct io_uring_sqe *sqe = cmd->sqe; if (unlikely(sqe->ioprio || sqe->__pad1 || sqe->len || -- 2.43.0