linux-toradex.git/fs/lockd, branch v2.6.28.9

lockd: fix regression in lockd's handling of blocked locks

2009-02-17T17:28:51+00:00

commit 9d9b87c1218be78ddecbc85ec3bb91c79c1d56ab upstream.

If a client requests a blocking lock, is denied, then requests it again,
then here in nlmsvc_lock() we will call vfs_lock_file() without FL_SLEEP
set, because we've already queued a block and don't need the locks code
to do it again.

But that means vfs_lock_file() will return -EAGAIN instead of
FILE_LOCK_DENIED.  So we still need to translate that -EAGAIN return
into a nlm_lck_blocked error in this case, and put ourselves back on
lockd's block list.

The bug was introduced by bde74e4bc64415b1 "locks: add special return
value for asynchronous locks".

Thanks to Frank van Maarseveen for the report; his original test
case was essentially

	for i in `seq 30`; do flock /nfsmount/foo sleep 10 & done

Tested-by: Frank van Maarseveen 
Reported-by: Frank van Maarseveen 
Cc: Miklos Szeredi 
Signed-off-by: J. Bruce Fields 
Signed-off-by: Greg Kroah-Hartman

NLM: client-side nlm_lookup_host() should avoid matching on srcaddr

2008-11-24T19:29:07+00:00

Since commit c98451bd, the loop in nlm_lookup_host() unconditionally
compares the host's h_srcaddr field to the incoming source address.
For client-side nlm_host entries, both are always AF_UNSPEC, so this
check is unnecessary.

Since commit 781b61a6, which added support for AF_INET6 addresses to
nlm_cmp_addr(), nlm_cmp_addr() now returns FALSE for AF_UNSPEC
addresses, which causes nlm_lookup_host() to create a fresh nlm_host
entry every time it is called on the client.

These extra entries will eventually expire once the server is
unmounted, so the impact of this regression, introduced with lockd
IPv6 support in 2.6.28, should be minor.

We could fix this by adding an arm in nlm_cmp_addr() for AF_UNSPEC
addresses, but really, nlm_lookup_host() shouldn't be matching on the
srcaddr field for client-side nlm_host lookups.

Signed-off-by: Chuck Lever 
Signed-off-by: J. Bruce Fields

nfsd: clean up grace period on early exit

2008-11-24T16:12:48+00:00

If nfsd was shut down before the grace period ended, we could end up
with a freed object still on grace_list.  Thanks to Jeff Moyer for
reporting the resulting list corruption warnings.

Signed-off-by: J. Bruce Fields 
Tested-by: Jeff Moyer

NLM: Set address family before calling nlm_host_rebooted()

2008-10-30T21:19:30+00:00

The nlm_host_rebooted() function uses nlm_cmp_addr() to find an
nsm_handle that matches the rebooted peer.  In order for this to work,
the passed-in address must have a proper address family.

This fixes a post-2.6.28 regression introduced by commit 781b61a6, which
added AF_INET6 support to nlm_cmp_addr().  Before that commit,
nlm_cmp_addr() didn't care about the address family; it compared only
the sin_addr.s_addr field for equality.

Signed-off-by: Chuck Lever 
Signed-off-by: J. Bruce Fields

NLM: Remove "proto" argument from lockd_up()

2008-10-04T21:12:27+00:00

Clean up: Now that lockd_up() starts listeners for both transports, the
"proto" argument is no longer needed.

Signed-off-by: Chuck Lever 
Cc: Neil Brown 
Signed-off-by: J. Bruce Fields

NLM: Always start both UDP and TCP listeners

2008-10-04T21:08:16+00:00

Commit 24e36663, which first appeared in 2.6.19, changed lockd so that
the client side starts a UDP listener only if there is a UDP NFSv2/v3
mount.  Its description notes:

    This... means that lockd will *not* listen on UDP if the only
    mounts are TCP mount (and nfsd hasn't started).

    The latter is the only one that concerns me at all - I don't know
    if this might be a problem with some servers.

Unfortunately it is a problem for Linux itself.  The rpc.statd daemon
on Linux uses UDP for contacting the local lockd, no matter which
protocol is used for NFS mounts.  Without a local lockd UDP listener,
NFSv2/v3 lock recovery from Linux NFS clients always fails.

Revert parts of commit 24e36663 so lockd_up() always starts both
listeners.

Signed-off-by: Chuck Lever 
Cc: Neil Brown 
Signed-off-by: J. Bruce Fields

lockd: Remove unused fields in the nlm_reboot structure

2008-10-03T21:02:35+00:00

The nlm_reboot structure is used to store information provided by the
NSM_NOTIFY procedure.  This procedure is not specified by the NLM or NSM
protocols, other than to say that the procedure can be used to transmit
information private to a particular NLM/NSM implementation.

For Linux, the callback arguments include the name of the monitored host,
the new NSM state of the host, and a 16-byte private opaque.

As a clean up, remove the unused fields and the server-side XDR logic that
decodes them.

Signed-off-by: Chuck Lever 
Signed-off-by: J. Bruce Fields

lockd: Add helper to sanity check incoming NOTIFY requests

2008-10-03T21:02:35+00:00

lockd accepts SM_NOTIFY calls only from a privileged process on the
local system.  If lockd uses an AF_INET6 listener, the sender's address
(ie the local rpc.statd) will be the IPv6 loopback address, not the
IPv4 loopback address.

Make sure the privilege test in nlmsvc_proc_sm_notify() and
nlm4svc_proc_sm_notify() works for both AF_INET and AF_INET6 family
addresses by refactoring the test into a helper and adding support for
IPv6 addresses.

Signed-off-by: Chuck Lever 
Signed-off-by: J. Bruce Fields

lockd: change nlmclnt_grant() to take a "struct sockaddr *"

2008-10-03T21:02:35+00:00

Adjust the signature and callers of nlmclnt_grant() to pass a "struct
sockaddr *" instead of a "struct sockaddr_in *" in order to support IPv6
addresses.

Signed-off-by: Chuck Lever 
Signed-off-by: J. Bruce Fields

lockd: Adjust nlmsvc_lookup_host() to accomodate AF_INET6 addresses

2008-10-03T21:02:35+00:00

Fix up nlmsvc_lookup_host() to pass AF_INET6 source addresses to
nlm_lookup_host().

Signed-off-by: Chuck Lever 
Signed-off-by: J. Bruce Fields