On 2019-10-22 00:00, Honggang LI wrote:
> +static bool use_imm_data(void)
> +{
> +#ifdef __linux__
> + bool ret = false;
> + char flag = 0;
> + int cnt;
> + int fd = open("/sys/module/ib_srp/parameters/use_imm_data", O_RDONLY);
> +
> + if (fd < 0)
> + return false;
> + cnt = read(fd, &flag, 1);
> + if (cnt != 1)
> + return false;
> +
> + if (!strncmp(&flag, "Y", 1))
> + ret = true;
> + close(fd);
> + return ret;
> +#else
> + return false;
> +#endif
> +}
There is already plenty of Linux-specific code in srp_daemon. The #ifdef
__linux__ / #endif guard does not seem useful to me.
There is a file descriptor leak in the above function, namely if read()
returns another value than 1.
The use_imm_data kernel module parameter was introduced in kernel v5.0
(commit 882981f4a411; "RDMA/srp: Add support for immediate data"). The
max_it_iu_size will be introduced in kernel v5.5 (commit 547ed331bbe8;
"RDMA/srp: Add parse function for maximum initiator to target IU size").
So the above check will help for kernel versions before v5.0 but not for
kernel versions [v5.0..v5.5). If that is really what you want, please
explain this in a comment above the use_imm_data() function.
Thanks,
Bart.
