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  1. 03 Dec, 2009 10 commits
    • Chuck Lever's avatar
      SUNRPC: Allow RPCs to fail quickly if the server is unreachable · 09a21c41
      Chuck Lever authored 
      The kernel sometimes makes RPC calls to services that aren't running.
Because the kernel's RPC client always assumes the hard retry semantic
when reconnecting a connection-oriented RPC transport, the underlying
reconnect logic takes a long while to time out, even though the remote
may have responded immediately with ECONNREFUSED.

In certain cases, like upcalls to our local rpcbind daemon, or for NFS
mount requests, we'd like the kernel to fail immediately if the remote
service isn't reachable.  This allows another transport to be tried
immediately, or the pending request can be abandoned quickly.

Introduce a per-request flag which controls how call_transmit_status()
behaves when request transmission fails because the server cannot be
reached.

We don't want soft connection semantics to apply to other errors.  The
default case of the switch statement in call_transmit_status() no
longer falls through; the fall through code is copied to the default
case, and a "break;" is added.

The transport's connection re-establishment timeout is also ignored for
such requests.  We want the request to fail immediately, so the
reconnect delay is skipped.  Additionally, we don't want a connect
failure here to further increase the reconnect timeout value, since
this request will not be retried.
Signed-off-by: default avatarChuck Lever <chuck.lever@oracle.com>
Signed-off-by: default avatarTrond Myklebust <Trond.Myklebust@netapp.com>
      09a21c41
    • Chuck Lever's avatar
      SUNRPC: Check explicitly for tk_status == 0 in call_transmit_status() · 206a134b
      Chuck Lever authored 
      The success case, where task->tk_status == 0, is by far the most
frequent case in call_transmit_status().

The default: arm of the switch statement in call_transmit_status()
handles the 0 case.  default: was moved close to the top of the switch
statement in call_transmit_status() under the theory that the compiler
places object code for the earliest arms of a switch statement first,
making the CPU do less work.

The default: arm of a switch statement, however, is executed only
after all the other cases have been checked.  Even if the compiler
rearranges the object code, the default: arm is the "last resort",
meaning all of the other cases have been explicitly exhausted.  That
makes the current arrangement about as inefficient as it gets for the
common case.

To fix this, add an explicit check for zero before the switch
statement.  That forces the compiler to do the zero check first, no
matter what optimizations it might try to do to the switch statement.
Signed-off-by: default avatarChuck Lever <chuck.lever@oracle.com>
Signed-off-by: default avatarTrond Myklebust <Trond.Myklebust@netapp.com>
      206a134b
    • Chuck Lever's avatar
      NFS: Revert default r/wsize behavior · dd47f96c
      Chuck Lever authored 
      When the "rsize=" or "wsize=" mount options are not specified,
text-based mounts have slightly different behavior than legacy binary
mounts.  Text-based mounts use the smaller of the server's maximum
and the client's maximum, but binary mounts use the smaller of the
server's _preferred_ size and the client's maximum.

This difference is actually pretty subtle.  Most servers advertise
the same value as their maximum and their preferred transfer size, so
the end result is the same in most cases.

The reason for this difference is that for text-based mounts, if
r/wsize are not specified, they are set to the largest value supported
by the client.  For legacy mounts, the values are set to zero if these
options are not specified.

nfs_server_set_fsinfo() can negotiate the transfer size defaults
correctly in any case.  There's no need to specify any particular
value as default in the text-based option parsing logic.

Note that nfs4 doesn't use nfs_server_set_fsinfo(), but the mount.nfs4
command does set rsize and wsize to 0 if the user didn't specify these
options.  So, make the same change for text-based NFSv4 mounts.

Thanks to James Pearson <james-p@moving-picture.com> for reporting and
diagnosing the problem.
Signed-off-by: default avatarChuck Lever <chuck.lever@oracle.com>
Signed-off-by: default avatarTrond Myklebust <Trond.Myklebust@netapp.com>
      dd47f96c
    • Chuck Lever's avatar
      NFS: Display compressed (shorthand) IPv6 in /proc/mounts · d250e190
      Chuck Lever authored 
      Recent changes to snprintf() introduced the %pI6c formatter, which can
display an IPv6 address with standard shorthanding.  Use this new
formatter when displaying IPv6 server addresses in /proc/mounts.
Signed-off-by: default avatarChuck Lever <chuck.lever@oracle.com>
Signed-off-by: default avatarTrond Myklebust <Trond.Myklebust@netapp.com>
      d250e190
    • Chuck Lever's avatar
      SUNRPC: Display compressed (shorthand) IPv6 presentation addresses · dd1fd90f
      Chuck Lever authored 
      Recent changes to snprintf() introduced the %pI6c formatter, which can
display an IPv6 address with standard shorthanding.  Using a
shorthanded address can save us a few bytes of memory for each stored
presentation address, or a few bytes on the wire when sending these in
a universal address.
Signed-off-by: default avatarChuck Lever <chuck.lever@oracle.com>
Signed-off-by: default avatarTrond Myklebust <Trond.Myklebust@netapp.com>
      dd1fd90f
    • Richard Kennedy's avatar
      NFS: reorder nfs4_sequence_regs to remove 8 bytes of padding on 64 bits · a01878aa
      Richard Kennedy authored 
      reorder nfs4_sequence_args to remove 8 bytes of padding on 64 bit
builds.

The size of this structure drops to 24 bytes from 32 and reduces the
text size of nfs.ko.
On my x86_64 size reports

		text       data     bss
2.6.32-rc5 	200996	   8512	    432	 209940	  33414	nfs.ko
+patch 		200884	   8512	    432	 209828	  333a4	nfs.ko
Signed-off-by: default avatarRichard Kennedy <richard@rsk.demon.co.uk>
Signed-off-by: default avatarTrond Myklebust <Trond.Myklebust@netapp.com>
      a01878aa
    • Jeff Layton's avatar
      NFS: convert proto= option to use netids rather than a protoname · ee671b01
      Jeff Layton authored 
      Solaris uses netids as values for the proto= option, so that when
someone specifies "tcp6" they get traffic over TCP + IPv6. Until
recently, this has never really been an issue for Linux since it didn't
support NFS over IPv6. The netid and the protocol name were generally
always the same (modulo any strange configuration in /etc/netconfig).

The solaris manpage documents their proto= option as:

    proto= _netid_ | rdma

This patch is intended to bring Linux closer to how the Solaris proto=
option works, by declaring a static netid mapping in the kernel and
converting the proto= and mountproto= options to follow it and display
the proper values in /proc/mounts.

Much of this functionality will need to be provided by a userspace
mount.nfs patch. Chuck Lever has a patch to change mount.nfs in
the same way. In principle, we could do *all* of this in userspace but
that would mean that the options in /proc/mounts may not match the
options used by userspace.

The alternative to the static mapping here is to add a mechanism to
upcall to userspace for netid's. I'm not opposed to that option, but
it'll probably mean more overhead (and quite a bit more code). Rather
than shoot for that at first, I figured it was probably better to
start simply.

Comments welcome.
Signed-off-by: default avatarJeff Layton <jlayton@redhat.com>
Signed-off-by: default avatarTrond Myklebust <Trond.Myklebust@netapp.com>
      ee671b01
    • J. Bruce Fields's avatar
      The rpc server does not require that service threads take the BKL. · d4e935bd
      J. Bruce Fields authored 
      Signed-off-by: default avatarJ. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: default avatarTrond Myklebust <Trond.Myklebust@netapp.com>
      d4e935bd
    • Trond Myklebust's avatar
      NFS: BKL removal from the mount code... · 96f287b0
      Trond Myklebust authored 
      None of the code in nfs_umount_begin() or nfs_remount() has any BKL
dependency.
Signed-off-by: default avatarTrond Myklebust <Trond.Myklebust@netapp.com>
      96f287b0
    • Linus Torvalds's avatar
      Linux 2.6.32 · 22763c5c
      Linus Torvalds authored
      22763c5c
  3. 02 Dec, 2009 26 commits
  5. 01 Dec, 2009 4 commits
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