If the NLM daemon is killed on the NFS server, we can currently end up
hanging forever on an 'unlock' request, instead of aborting. Basically,
if the rpcbind request fails, or the server keeps returning garbage, we
really want to quit instead of retrying.
Tested-by: Vasily Averin <vvs@sw.ru>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: stable@kernel.org
Nick Bowler <nbowler@elliptictech.com> reports:
> We were just having some NFS server troubles, and my client machine
> running 2.6.38-rc1+ (specifically, commit 2b1caf6ed7) crashed
> hard (syslog output appended to this mail).
>
> I'm not sure what the exact timeline was or how to reproduce this,
> but the server was rebooted during all this. Since I've never seen
> this happen before, it is possibly a regression from previous kernel
> releases. However, I recently updated my nfs-utils (on the client) to
> version 1.2.3, so that might be related as well.
[ BUG output redacted ]
When done searching, the for_each_host loop in next_host_state() falls
through and returns the final host on the host chain without bumping
it's reference count.
Since the host's ref count is only one at that point, releasing the
host in nlm_host_rebooted() attempts to destroy the host prematurely,
and therefore hits a BUG().
Likely, the original intent of the for_each_host behavior in
next_host_state() was to handle the case when the host chain is empty.
Searching the chain and finding no suitable host to return needs to be
handled as well.
Defensively restructure next_host_state() always to return NULL when
the loop falls through.
Introduced by commit b10e30f6 "lockd: reorganize nlm_host_rebooted".
Cc: J. Bruce Fields <bfields@fieldses.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Clean up.
nlm_hosts now contains only server-side entries. Rename it to match
convention of client side cache.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Clean up.
Change nlmsvc_lookup_host() to be purpose-built for server-side
nlm_host management. This replaces the generic nlm_lookup_host()
helper function, just like on the client side. The lookup logic is
specialized for server host lookups.
The server side cache also gets its own specialized equivalent of the
nlm_release_host() function.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
NFS clients don't need the garbage collection processing that is
performed on nlm_host structures. The client picks up an nlm_host at
mount time and holds a reference to it until the file system is
unmounted.
Servers, on the other hand, don't have a precise way to tell when an
nlm_host is no longer being used, so zero refcount nlm_host entries
are left to expire in the cache after a time.
Basically there's nothing holding a reference to an nlm_host between
individual server-side NLM requests, but we can't afford the expense
of recreating them for every new NLM request from a client. The
nlm_host cache adds some lifetime hysteresis to entries in the cache
so the next time a particular nlm_host is needed, it's likely to be
discovered by a lookup rather than created from whole cloth.
With the new implementation, client nlm_host cache items are no longer
garbage collected, and are destroyed directly by a new release
function specialized for client entries, nlmclnt_release_host(). They
are cached in their own data structure, and have their own lookup
logic, simplified and specialized for client nlm_host entries.
However, the client nlm_host cache still shares reboot recovery logic
with the server nlm_host cache. The NSM "peer rebooted" downcall for
clients and servers still come through the same RPC call. This is a
legacy formal API that would be difficult to alter, and besides, the
user space NSM implementation can't tell the difference between peers
that are clients or servers.
For this reason, the client cache continues to share the
nlm_host_mutex (and reboot recovery logic) with the server cache.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
The nlm_release_call() function is invoked from both the server and
the client side. We're about to introduce a distinct server- and
client-side nlm_release_host(), so nlm_release_call() must first be
split into a client-side and a server-side version.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Refactor the tail of nlm_gc_hosts() into nlm_destroy_host() so that
this logic can be used separately from garbage collection.
Rename it _locked() to document that it must be called with the hosts
cache mutex held.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Refactor nlm_host allocation and initialization into a separate
function. This will be the common piece of server and client nlm_host
lookup logic after the nlm_host cache is split.
Small change: use kmalloc() instead of kzalloc(), as we're overwriting
almost all fields in the new nlm_host struct with non-zero values
immediately after it is allocated. An added benefit is we now have an
explicit reference to each field name where it is initialized (for all
you cscope fans out there).
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Minor reorganization; no change in behavior. This will save some
duplicated code after we split the client and server host caches.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
[ cel: Forward-ported to 2.6.37 ]
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
We've got a lot of loops like this, and I find them a little easier to
read with the macros. More such loops are coming.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
[ cel: Forward-ported to 2.6.37 ]
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Now that all client-side XDR decoder routines use xdr_streams, there
should be no need to support the legacy calling sequence [rpc_rqst *,
__be32 *, RPC res *] anywhere. We can construct an xdr_stream in the
generic RPC code, instead of in each decoder function.
This is a refactoring change. It should not cause different behavior.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Tested-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Now that all client-side XDR encoder routines use xdr_streams, there
should be no need to support the legacy calling sequence [rpc_rqst *,
__be32 *, RPC arg *] anywhere. We can construct an xdr_stream in the
generic RPC code, instead of in each encoder function.
Also, all the client-side encoder functions return 0 now, making a
return value superfluous. Take this opportunity to convert them to
return void instead.
This is a refactoring change. It should not cause different behavior.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Tested-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Clean up.
The trend in the other XDR encoder functions is to BUG() when encoding
problems occur, since a problem here is always due to a local coding
error. Then, instead of a status, zero is unconditionally returned.
Update the NSM XDR encoders to behave this way.
To finish the update, use the new-style be32_to_cpup() and
cpu_to_be32() macros, and compute the buffer sizes using raw integers
instead of sizeof(). This matches the conventions used in other XDR
functions
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Tested-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
We'd like to prevent local buffer overflows caused by malicious or
broken servers. New xdr_stream style decoders can do that.
For efficiency, we also want to be able to pass xdr_streams from
call_encode() to all XDR encoding functions, rather than building
an xdr_stream in every XDR encoding function in the kernel.
Same idea as the NLM v3 XDR overhaul.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Tested-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
We'd like to prevent local buffer overflows caused by malicious or
broken servers. New xdr_stream style decoders can do that.
For efficiency, we also eventually want to be able to pass xdr_streams
from call_encode() and call_decode() to all XDR encoding functions,
rather than building an xdr_stream in every XDR encoding and decoding
function in the kernel.
To do all of this, rewrite the XDR encoding and decoding functions in
fs/lockd/xdr.c to use xdr_streams. This makes them more or less
incompatible with server-side XDR helper functions, so break them out
into a separate source file.
Static helper functions are left without the "inline" directive. This
allows the compiler to choose automatically how to optimize these for
size or speed.
SHARE-related functionality doesn't seem to be used, as those
functions are hiding behind a #define that isn't set anywhere that I
can find. And, they've been in there forever (at least as far back as
the kernel's git history goes), yet remain unused. Let's take the
opportunity to bin them. It should be easy enough for someone to
introduce proper XDR functions if at some point SHARE-related NLM
functionality is desired.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Tested-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
The big kernel lock has been removed from all these files at some point,
leaving only the #include.
Remove this too as a cleanup.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Nick Bowler reports:
There are no unusual messages on the client... but I just logged into
the server and I see lots of messages of the following form:
nfsd: request from insecure port (192.168.8.199:35766)!
nfsd: request from insecure port (192.168.8.199:35766)!
nfsd: request from insecure port (192.168.8.199:35766)!
nfsd: request from insecure port (192.168.8.199:35766)!
nfsd: request from insecure port (192.168.8.199:35766)!
Bisected to commit 9247685088 (SUNRPC:
Properly initialize sock_xprt.srcaddr in all cases)
Apparently, removing the 'transport->srcaddr.ss_family = family' from
xs_create_sock() triggers this due to nlmclnt_lookup_host() incorrectly
initialising the srcaddr family to AF_UNSPEC.
Reported-by: Nick Bowler <nbowler@elliptictech.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
nlmsvc_notify_blocked walks the nlm_blocked list,
which requires nlm_blocked_lock.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
lockd should use lock_flocks() instead of lock_kernel()
to lock against posix locks accessing the i_flock list.
This is a prerequisite to turning lock_flocks into a
spinlock.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: J. Bruce Fields <bfields@redhat.com>
* 'for-2.6.37' of git://linux-nfs.org/~bfields/linux: (99 commits)
svcrpc: svc_tcp_sendto XPT_DEAD check is redundant
svcrpc: no need for XPT_DEAD check in svc_xprt_enqueue
svcrpc: assume svc_delete_xprt() called only once
svcrpc: never clear XPT_BUSY on dead xprt
nfsd4: fix connection allocation in sequence()
nfsd4: only require krb5 principal for NFSv4.0 callbacks
nfsd4: move minorversion to client
nfsd4: delay session removal till free_client
nfsd4: separate callback change and callback probe
nfsd4: callback program number is per-session
nfsd4: track backchannel connections
nfsd4: confirm only on succesful create_session
nfsd4: make backchannel sequence number per-session
nfsd4: use client pointer to backchannel session
nfsd4: move callback setup into session init code
nfsd4: don't cache seq_misordered replies
SUNRPC: Properly initialize sock_xprt.srcaddr in all cases
SUNRPC: Use conventional switch statement when reclassifying sockets
sunrpc/xprtrdma: clean up workqueue usage
sunrpc: Turn list_for_each-s into the ..._entry-s
...
Fix up trivial conflicts (two different deprecation notices added in
separate branches) in Documentation/feature-removal-schedule.txt
