linux-sg2042/fs/nfs
Chuck Lever 53d4737580 NFS: NFSROOT should default to "proto=udp"
There have been a number of recent reports that NFSROOT is no longer
working with default mount options, but fails only with certain NICs.

Brian Downing <bdowning@lavos.net> bisected to commit 56463e50 "NFS:
Use super.c for NFSROOT mount option parsing".  Among other things,
this commit changes the default mount options for NFSROOT to use TCP
instead of UDP as the underlying transport.

TCP seems less able to deal with NICs that are slow to initialize.
The system logs that have accompanied reports of problems all show
that NFSROOT attempts to establish a TCP connection before the NIC is
fully initialized, and thus the TCP connection attempt fails.

When a TCP connection attempt fails during a mount operation, the
NFS stack needs to fail the operation.  Usually user space knows how
and when to retry it.  The network layer does not report a distinct
error code for this particular failure mode.  Thus, there isn't a
clean way for the RPC client to see that it needs to retry in this
case, but not in others.

Because NFSROOT is used in some environments where it is not possible
to update the kernel command line to specify "udp", the proper thing
to do is change NFSROOT to use UDP by default, as it did before commit
56463e50.

To make it easier to see how to change default mount options for
NFSROOT and to distinguish default settings from mandatory settings,
I've adjusted a couple of areas to document the specifics.

root_nfs_cat() is also modified to deal with commas properly when
concatenating strings containing mount option lists.  This keeps
root_nfs_cat() call sites simpler, now that we may be concatenating
multiple mount option strings.

Tested-by: Brian Downing <bdowning@lavos.net>
Tested-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Cc: <stable@kernel.org> # 2.6.37
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-03-11 15:38:07 -05:00
..
Kconfig lockd: push lock_flocks down 2010-10-27 21:39:39 +02:00
Makefile NFSv4.1: pnfs: filelayout: add driver's LAYOUTGET and GETDEVICEINFO infrastructure 2010-10-24 18:07:11 -04:00
cache_lib.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
cache_lib.h NFS: Add a dns resolver for use with NFSv4 referrals and migration 2009-08-19 18:22:15 -04:00
callback.c NFS do not find client in NFSv4 pg_authenticate 2011-01-25 15:26:51 -05:00
callback.h NFS do not find client in NFSv4 pg_authenticate 2011-01-25 15:26:51 -05:00
callback_proc.c NFS fix cb_sequence error processing 2011-01-25 15:26:51 -05:00
callback_xdr.c NFS do not find client in NFSv4 pg_authenticate 2011-01-25 15:26:51 -05:00
client.c NFS do not find client in NFSv4 pg_authenticate 2011-01-25 15:26:51 -05:00
delegation.c NFS: Fix an NFS client lockdep issue 2011-01-28 13:37:09 -05:00
delegation.h NFS: Move cl_delegations to the nfs_server struct 2011-01-06 14:57:46 -05:00
dir.c NFS: Use d_automount() rather than abusing follow_link() 2011-01-15 20:07:34 -05:00
direct.c NFS: Fix "kernel BUG at fs/aio.c:554!" 2011-01-25 15:24:47 -05:00
dns_resolve.c sunrpc: use seconds since boot in expiry cache 2010-09-07 19:21:20 -04:00
dns_resolve.h NFS: Use kernel DNS resolver [ver #2] 2010-08-11 17:11:28 +00:00
file.c NFS: Fix fcntl F_GETLK not reporting some conflicts 2010-12-07 19:30:43 -05:00
fscache-index.c NFS: Add read context retention for FS-Cache to call back with 2009-04-03 16:42:44 +01:00
fscache.c NFS: Squelch compiler warning 2010-05-14 15:09:31 -04:00
fscache.h NFS: Propagate 'fsc' mount option through automounts 2009-09-23 14:36:39 -04:00
getroot.c switch nfs to ->s_d_op 2011-01-12 20:02:45 -05:00
idmap.c nfs: fix mispelling of idmap CONFIG symbol 2011-01-04 13:10:39 -05:00
inode.c (try3-resend) Fix nfs_compat_user_ino64 so it doesn't cause problems if bit 31 or 63 are set in fileid 2011-03-10 15:04:58 -05:00
internal.h NFS do not find client in NFSv4 pg_authenticate 2011-01-25 15:26:51 -05:00
iostat.h NFS: Squelch compiler warning in nfs_add_server_stats() 2010-05-14 15:09:31 -04:00
mount_clnt.c NFS: Remove redundant unlikely() 2010-12-21 11:51:23 -05:00
namespace.c Unexport do_add_mount() and add in follow_automount(), not ->d_automount() 2011-01-15 20:07:48 -05:00
nfs2xdr.c Merge branch 'bugfixes' into nfs-for-2.6.38 2011-01-10 14:48:02 -05:00
nfs3acl.c NFS: Prevent memory allocation failure in nfsacl_encode() 2011-01-25 15:24:47 -05:00
nfs3proc.c NFS: readdir with vmapped pages 2010-10-23 15:27:35 -04:00
nfs3xdr.c NFS: Fix "kernel BUG at fs/nfs/nfs3xdr.c:1338!" 2011-01-25 15:24:47 -05:00
nfs4_fs.h NFSv4: nfs4_state_mark_reclaim_nograce() should be static 2011-03-11 15:18:36 -05:00
nfs4filelayout.c pnfs: add prefix to struct pnfs_layout_hdr fields 2011-01-06 14:46:31 -05:00
nfs4filelayout.h NFSv4.1: pnfs: filelayout: add driver's LAYOUTGET and GETDEVICEINFO infrastructure 2010-10-24 18:07:11 -04:00
nfs4filelayoutdev.c nfs: add kmalloc return value check in decode_and_add_ds 2011-03-10 15:04:55 -05:00
nfs4namespace.c NFSv4: Fix up the documentation for nfs_do_refmount 2010-05-14 15:09:29 -04:00
nfs4proc.c nfs4: remove duplicated #include 2011-03-11 15:18:37 -05:00
nfs4renewd.c NFS: Move cl_delegations to the nfs_server struct 2011-01-06 14:57:46 -05:00
nfs4state.c NFSv4: nfs4_state_mark_reclaim_nograce() should be static 2011-03-11 15:18:36 -05:00
nfs4xdr.c NFSv4: remove duplicate clientid in struct nfs_client 2011-03-10 15:05:00 -05:00
nfsroot.c NFS: NFSROOT should default to "proto=udp" 2011-03-11 15:38:07 -05:00
pagelist.c nfs: Take advantage of kmem_cache_zalloc() in nfs_page_alloc() 2010-12-21 11:51:24 -05:00
pnfs.c NFS improve pnfs_put_deviceid_cache debug print 2011-01-25 15:26:51 -05:00
pnfs.h pnfs: layout roc code 2011-01-06 14:46:32 -05:00
proc.c NFS: Don't leak in nfs_proc_symlink() 2011-01-04 13:10:36 -05:00
read.c nfs: remove extraneous and problematic calls to nfs_clear_request 2010-12-07 23:02:44 -05:00
super.c switch nfs to ->s_d_op 2011-01-12 20:02:45 -05:00
symlink.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
sysctl.c NFS: new idmapper 2010-10-07 18:48:49 -04:00
unlink.c SUNRPC: Close a race in __rpc_wait_for_completion_task() 2011-03-10 15:04:52 -05:00
write.c nfs: close NFSv4 COMMIT vs. CLOSE race 2011-03-10 15:04:53 -05:00