Ian Lepore 6cbd933b37 Changes to allow using BOOTP_NFSROOT and mounting an nfs root filesystem ... other than the one specified by the BOOTP server. This configures NFS using the BOOTP protocol while also respecting other root-path options such as setting vfs.root.mountfrom in the environment or using the RB_DFLTROOT boot option. It allows you to override the root path provided by the server, or to supply a root path when the server provides IP configuration but no root path info. This maintains the historical BOOTP_NFSROOT behavior of panicking on a failure to mount the root path provided by the server, unless you've provided an alternative via the ROOTDEVNAME kernel option or by setting vfs.root.mountfrom. The behavior of panicking when given no other options is preserved because it amounts to a bit of a retry loop that could eventually recover from a transient network or server problem. The user can now override the root path from loader(8) even if the kernel is compiled with BOOTP_NFSROOT. If vfs.root.mountfrom is set in the environment it is used unconditionally -- it always overrides the BOOTP info. If it begins with [old]nfs: then the BOOTP code uses it instead of the server-provided info. If it specifies some other filesystem then the bootp code will not panic like it used to and the code in vfs_mountroot.c will invoke the right filesystem to do the mount. If the kernel is compiled with the ROOTDEVNAME option, then that name is used by the BOOTP code if either * The server doesn't provide a pathname. * The boothowto flags include RB_DFLTROOT. The latter allows the user to compile in alternate path in ROOTDEVNAME such as ufs:/dev/da0s1a and boot from that path by setting boot_dftlroot=1 in loader(8) or using the '-r' option in boot(8). The one thing not provided here is automatic failover from a server-provided path to a compiled-in one without the user manually requesting that. The code just isn't currently structured in a way that makes that possible with a lot of rewrite. I think the ability to set vfs.root.mountfrom and to use ROOTDEVNAME automatically when the server doesn't provide a name covers the most common needs. A set of patches submitted by Lars Eggert provided the part I couldn't figure out by myself when I tried to do this last year; many thanks. Reviewed by: rodrigc		2013-07-31 19:14:00 +00:00
..
bootp_subr.c	Changes to allow using BOOTP_NFSROOT and mounting an nfs root filesystem	2013-07-31 19:14:00 +00:00
krpc_subr.c	Functions m_getm2() and m_get2() have different order of arguments,	2013-03-12 13:42:47 +00:00
krpc.h	Fix the experimental NFS client so that it does not bogusly	2011-04-25 22:22:51 +00:00
nfs_common.c	Use m_get() and m_getcl() instead of compat macros.	2013-03-15 10:21:18 +00:00
nfs_common.h	Remove the unused nfs_curusec().	2013-01-17 19:03:24 +00:00
nfs_diskless.c	Implemented a mount option "nocto" that disables cache coherency	2011-05-04 13:27:45 +00:00
nfs_fha.c	Move the NFS FHA (File Handle Affinity) code from sys/nfsserver to	2013-04-17 22:42:43 +00:00
nfs_fha.h	Move the NFS FHA (File Handle Affinity) code from sys/nfsserver to	2013-04-17 22:42:43 +00:00
nfs_kdtrace.h	Move sys/nfsclient/nfs_kdtrace.h to sys/nfs/nfs_kdtrace.h so	2011-05-06 20:02:19 +00:00
nfs_lock.c	Mark MALLOC_DEFINEs static that have no corresponding MALLOC_DECLAREs.	2011-11-07 06:44:47 +00:00
nfs_lock.h
nfs_mountcommon.h
nfs_nfssvc.c	Add an nfssvc() option to the kernel for the new NFS client	2012-12-02 01:16:04 +00:00
nfsdiskless.h	Fix the experimental NFS client so that it does not bogusly	2011-04-25 22:22:51 +00:00
nfsproto.h
nfssvc.h	Add an nfssvc() option to the kernel for the new NFS client	2012-12-02 01:16:04 +00:00
xdr_subs.h