Hi,
the 2.6 behaviour of the root-path option seems to have changed: in 2.4
it was possible to do this in the DHCP configuration:
option root-path "192.168.1.1:/path/to/root";
to specify an NFS server other than the TFTP boot server where the
kernel comes from; in 2.6 the code in ipconfig.c which parses this
option for the IP address has been removed.
Was this done on purpuse or by accident? What's the "correct" way to
specify the address?
Robert
--
Dipl.-Ing. Robert Schwebel | http://www.pengutronix.de
Pengutronix - Linux Solutions for Science and Industry
Handelsregister: Amtsgericht Hildesheim, HRA 2686
Hornemannstra?e 12, 31137 Hildesheim, Germany
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Robert Schwebel <[email protected]> wrote:
>
> Hi,
>
> the 2.6 behaviour of the root-path option seems to have changed: in 2.4
> it was possible to do this in the DHCP configuration:
>
> option root-path "192.168.1.1:/path/to/root";
>
> to specify an NFS server other than the TFTP boot server where the
> kernel comes from; in 2.6 the code in ipconfig.c which parses this
> option for the IP address has been removed.
>
> Was this done on purpuse or by accident? What's the "correct" way to
> specify the address?
Actually it seems that this functionality was added to 2.4 after 2.5 was
forked off and never got forward ported. I don't know if this was
deliberate or just an oversight.
The original patch seems to apply to 2.5 OK. You get to test it ;)
# This is a BitKeeper generated diff -Nru style patch.
#
# ChangeSet
# 2002/04/01 18:50:30-03:00 [email protected]
# [PATCH] Patch to pull NFS server address off root_server_path
#
# Hi Marcelo,
#
# I've submitted the following patch to Trond Myklebust, who seems to
# think it is OK. Dave Jones has also included it in his 2.5 kernel
# series...
#
# The following patch pulls an NFS server IP address off
# root_server_path (handed out via the DHCP root-path option), if it is
# present. For example, you can do this sort of thing in dhcpd.conf:
#
# root-path = 192.168.1.33:/tftpboot/yip.zImage
#
# This lets you mount your root filesystem off a different machine than
# you booted from, without needing to use kernel command-line
# parameters.
#
# The patch appears to be backwards compatible.
#
# RFC2132 says this about the root-path option:
#
# This option specifies the path-name that contains the client's root
# disk. The path is formatted as a character string consisting of
# characters from the NVT ASCII character set.
#
# This is sufficiently vague to allow the path-name to include an
# IP-address. Also, I found some documentation for FreeBSD saying it
# does this too, so it must be right, because those FreeBSD guys are
# really smart... :-)
#
# The only downside of the patch is that the summary that ipconfig
# prints can be a little odd when the kernel command line overrides
# whatever ipconfig gets from (say) DHCP. The address from the kernel
# command line seems to get stripped off early, so ipconfig reports it,
# but it doesn't report the kernel command line NFS path, since that's
# handled a bit later... This small cosmetic problem looks difficult to
# "fix" without rewriting quite a bit of stuff...
#
# peace & happiness,
# martin
#
# net/ipv4/ipconfig.c
# 2002/03/12 11:42:15-03:00 [email protected] +39 -0
# Patch to pull NFS server address off root_server_path
#
# include/linux/nfs_fs.h
# 2002/03/12 11:25:14-03:00 [email protected] +3 -0
# Patch to pull NFS server address off root_server_path
#
# fs/nfs/nfsroot.c
# 2002/03/12 11:25:14-03:00 [email protected] +1 -32
# Patch to pull NFS server address off root_server_path
#
diff -Nru a/fs/nfs/nfsroot.c b/fs/nfs/nfsroot.c
--- a/fs/nfs/nfsroot.c Wed Jan 28 22:00:06 2004
+++ b/fs/nfs/nfsroot.c Wed Jan 28 22:00:06 2004
@@ -163,37 +163,6 @@
/*
- * Extract IP address from the parameter string if needed. Note that we
- * need to have root_server_addr set _before_ IPConfig gets called as it
- * can override it.
- */
-static void __init root_nfs_parse_addr(char *name)
-{
- int octets = 0;
- char *cp, *cq;
-
- cp = cq = name;
- while (octets < 4) {
- while (*cp >= '0' && *cp <= '9')
- cp++;
- if (cp == cq || cp - cq > 3)
- break;
- if (*cp == '.' || octets == 3)
- octets++;
- if (octets < 4)
- cp++;
- cq = cp;
- }
- if (octets == 4 && (*cp == ':' || *cp == '\0')) {
- if (*cp == ':')
- *cp++ = '\0';
- root_server_addr = in_aton(name);
- strcpy(name, cp);
- }
-}
-
-
-/*
* Parse option string.
*/
static void __init root_nfs_parse(char *name, char *buf)
@@ -344,7 +313,7 @@
line[sizeof(nfs_root_name) - strlen(NFS_ROOT) - 1] = '\0';
sprintf(nfs_root_name, NFS_ROOT, line);
}
- root_nfs_parse_addr(nfs_root_name);
+ root_server_addr = root_nfs_parse_addr(nfs_root_name);
return 1;
}
diff -Nru a/include/linux/nfs_fs.h b/include/linux/nfs_fs.h
--- a/include/linux/nfs_fs.h Wed Jan 28 22:00:06 2004
+++ b/include/linux/nfs_fs.h Wed Jan 28 22:00:06 2004
@@ -276,6 +276,9 @@
extern int nfs_mount(struct sockaddr_in *, char *, struct nfs_fh *);
extern int nfs3_mount(struct sockaddr_in *, char *, struct nfs_fh *);
+/* linux/net/ipv4/ipconfig.c: trims ip addr off front of name, too. */
+extern u32 root_nfs_parse_addr(char *name); /*__init*/
+
/*
* inline functions
*/
diff -Nru a/net/ipv4/ipconfig.c b/net/ipv4/ipconfig.c
--- a/net/ipv4/ipconfig.c Wed Jan 28 22:00:06 2004
+++ b/net/ipv4/ipconfig.c Wed Jan 28 22:00:06 2004
@@ -1105,6 +1105,40 @@
#endif /* CONFIG_PROC_FS */
/*
+ * Extract IP address from the parameter string if needed. Note that we
+ * need to have root_server_addr set _before_ IPConfig gets called as it
+ * can override it.
+ */
+u32 __init root_nfs_parse_addr(char *name)
+{
+ u32 addr;
+ int octets = 0;
+ char *cp, *cq;
+
+ cp = cq = name;
+ while (octets < 4) {
+ while (*cp >= '0' && *cp <= '9')
+ cp++;
+ if (cp == cq || cp - cq > 3)
+ break;
+ if (*cp == '.' || octets == 3)
+ octets++;
+ if (octets < 4)
+ cp++;
+ cq = cp;
+ }
+ if (octets == 4 && (*cp == ':' || *cp == '\0')) {
+ if (*cp == ':')
+ *cp++ = '\0';
+ addr = in_aton(name);
+ strcpy(name, cp);
+ } else
+ addr = INADDR_NONE;
+
+ return addr;
+}
+
+/*
* IP Autoconfig dispatcher.
*/
@@ -1112,6 +1146,7 @@
{
int retries = CONF_OPEN_RETRIES;
unsigned long jiff;
+ u32 addr;
#ifdef CONFIG_PROC_FS
proc_net_create("pnp", 0, pnp_get_info);
@@ -1196,6 +1231,10 @@
/* Device selected manually or only one device -> use it */
ic_dev = ic_first_dev->dev;
}
+
+ addr = root_nfs_parse_addr(root_server_path);
+ if (root_server_addr == INADDR_NONE)
+ root_server_addr = addr;
/*
* Use defaults whereever applicable.