On Tue, Jan 13, 2015 at 02:44:25PM +0100, Markus Pargmann wrote:
> Adding support to nbd to use it as a root device. This code essentially
> provides a minimal nbd-client implementation within the kernel. It opens
> a socket and makes the negotiation with the server. Afterwards it passes
> the socket to the normal nbd-code to handle the connection.
>
> The arguments for the server are passed via module parameter. The
> module parameter has the format
> '[<SERVER_IP>:]<SERVER_PORT>/<EXPORT_NAME>'.
> SERVER_IP is optional. If it is not available it will use the
> root_server_addr transmitted through DHCP.
>
> Based on those arguments, the connection to the server is established
> and is connected to the nbd0 device. The rootdevice therefore is
> root=/dev/nbd0.
>
> Signed-off-by: Markus Pargmann <mpa@...1897...>
> ---
> drivers/block/nbd.c | 306 ++++++++++++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 306 insertions(+)
>
> diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c
> index 11f7644be111..ac881ae3c15a 100644
> --- a/drivers/block/nbd.c
> +++ b/drivers/block/nbd.c
> @@ -32,12 +32,17 @@
> #include <net/sock.h>
> #include <linux/net.h>
> #include <linux/kthread.h>
> +#include <net/ipconfig.h>
> +#include <linux/in.h>
> +#include <linux/tcp.h>
>
> #include <asm/uaccess.h>
> #include <asm/types.h>
>
> #include <linux/nbd.h>
>
> +#define ADDR_NONE cpu_to_be32(INADDR_NONE)
> +
> #define NBD_MAGIC 0x68797548
>
> #ifdef NDEBUG
> @@ -71,6 +76,20 @@ static int max_part;
> */
> static DEFINE_SPINLOCK(nbd_lock);
>
> +static const char nbd_magic[] = "NBDMAGIC";
> +static const u64 nbd_opts_magic = 0x49484156454F5054LL;
> +
> +/* Options used for the kernel driver */
> +#define NBD_OPT_EXPORT_NAME 1
> +
> +#define NBD_DEFAULT_BLOCKSIZE 1024
> +
> +extern __be32 root_nfs_parse_addr(char *name);
> +
> +static __be32 nbd_server_addr = ADDR_NONE;
> +static __be32 nbd_server_port;
> +static char nbd_server_export[128] = "";
> +
> #ifndef NDEBUG
> static const char *ioctl_cmd_to_ascii(int cmd)
> {
> @@ -105,6 +124,52 @@ static const char *nbdcmd_to_ascii(int cmd)
> }
> #endif /* NDEBUG */
>
> +/*
> + * Parse format "[<SERVER_IP>:]<SERVER_PORT>/<EXPORT_NAME>"
> + */
> +static int nbd_server_addr_set(const char *val, const struct kernel_param *kp)
> +{
> + char *export;
> + u16 port;
> + int ret;
> + char buf[128];
> +
> + strncpy(buf, val, 128);
> +
> + nbd_server_addr = root_nfs_parse_addr(buf);
> +
> + if (*buf == '\0') {
> + ret = -EINVAL;
> + goto free_buf;
> + }
> + export = strchr(buf, '/');
> + if (!export || *(export + 1) == '\0') {
> + ret = -EINVAL;
> + goto free_buf;
> + }
> + *export = '\0';
> + ++export;
> +
> + ret = kstrtou16(buf, 10, &port);
> + if (ret)
> + goto free_buf;
> +
> + memmove(buf, export, strlen(export) + 1);
This memmove() is a leftover from a previous version, it is removed for
the next series version. I also added some documentation patches that
describe this feature in Documentation/blockdev/nbd.txt. I will send it
at the end of this week.
Best regards,
Markus
--
Pengutronix e.K. | |
Industrial Linux Solutions | http://www.pengutronix.de/ |
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