linux.git/fs/nfsd, branch v5.7

SUNRPC: Fix backchannel RPC soft lockups

2020-04-17T16:40:31+00:00

Currently, after the forward channel connection goes away,
backchannel operations are causing soft lockups on the server
because call_transmit_status's SOFTCONN logic ignores ENOTCONN.
Such backchannel Calls are aggressively retried until the client
reconnects.

Backchannel Calls should use RPC_TASK_NOCONNECT rather than
RPC_TASK_SOFTCONN. If there is no forward connection, the server is
not capable of establishing a connection back to the client, thus
that backchannel request should fail before the server attempts to
send it. Commit 58255a4e3ce5 ("NFSD: NFSv4 callback client should
use RPC_TASK_SOFTCONN") was merged several years before
RPC_TASK_NOCONNECT was available.

Because setup_callback_client() explicitly sets NOPING, the NFSv4.0
callback connection depends on the first callback RPC to initiate
a connection to the client. Thus NFSv4.0 needs to continue to use
RPC_TASK_SOFTCONN.

Suggested-by: Trond Myklebust 
Signed-off-by: Chuck Lever 
Cc:  # v4.20+

nfsd: memory corruption in nfsd4_lock()

2020-04-13T14:28:21+00:00

New struct nfsd4_blocked_lock allocated in find_or_allocate_block()
does not initialized nbl_list and nbl_lru.
If conflock allocation fails rollback can call list_del_init()
access uninitialized fields and corrupt memory.

v2: just initialize nbl_list and nbl_lru right after nbl allocation.

Fixes: 76d348fadff5 ("nfsd: have nfsd4_lock use blocking locks for v4.1+ lock")
Signed-off-by: Vasily Averin 
Reviewed-by: Jeff Layton 
Signed-off-by: Chuck Lever

nfsd: fsnotify on rmdir under nfsd/clients/

2020-03-19T15:33:42+00:00

Userspace should be able to monitor nfsd/clients/ to see when clients
come and go, but we're failing to send fsnotify events.

Cc: stable@kernel.org
Signed-off-by: J. Bruce Fields 
Signed-off-by: Chuck Lever

nfsd4: kill warnings on testing stateids with mismatched clientids

2020-03-19T14:51:42+00:00

It's normal for a client to test a stateid from a previous instance,
e.g. after a network partition.

Signed-off-by: J. Bruce Fields 
Reviewed-by: Benjamin Coddington 
Signed-off-by: Chuck Lever

nfsd: remove read permission bit for ctl sysctl

2020-03-16T16:04:34+00:00

It's meant to be write-only.

Fixes: 89c905beccbb ("nfsd: allow forced expiration of NFSv4 clients")
Signed-off-by: Petr Vorel 
Signed-off-by: Chuck Lever

NFSD: Fix NFS server build errors

2020-03-16T16:04:34+00:00

yuehaibing@huawei.com reports the following build errors arise when
CONFIG_NFSD_V4_2_INTER_SSC is set and the NFS client is not built
into the kernel:

fs/nfsd/nfs4proc.o: In function `nfsd4_do_copy':
nfs4proc.c:(.text+0x23b7): undefined reference to `nfs42_ssc_close'
fs/nfsd/nfs4proc.o: In function `nfsd4_copy':
nfs4proc.c:(.text+0x5d2a): undefined reference to `nfs_sb_deactive'
fs/nfsd/nfs4proc.o: In function `nfsd4_do_async_copy':
nfs4proc.c:(.text+0x61d5): undefined reference to `nfs42_ssc_open'
nfs4proc.c:(.text+0x6389): undefined reference to `nfs_sb_deactive'

The new inter-server copy code invokes client functions. Until the
NFS server has infrastructure to load the appropriate NFS client
modules to handle inter-server copy requests, let's constrain the
way this feature is built.

Reported-by: YueHaibing 
Fixes: ce0887ac96d3 ("NFSD add nfs4 inter ssc to nfsd4_copy")
Signed-off-by: Chuck Lever 
Tested-by: YueHaibing  # build-tested

nfsd: export upcalls must not return ESTALE when mountd is down

2020-03-16T16:04:33+00:00

If the rpc.mountd daemon goes down, then that should not cause all
exports to start failing with ESTALE errors. Let's explicitly
distinguish between the cache upcall cases that need to time out,
and those that do not.

Signed-off-by: Trond Myklebust 
Signed-off-by: Chuck Lever

nfsd: Add tracepoints for update of the expkey and export cache entries

2020-03-16T16:04:33+00:00

Signed-off-by: Trond Myklebust 
Signed-off-by: Chuck Lever

nfsd: Add tracepoints for exp_find_key() and exp_get_by_name()

2020-03-16T16:04:33+00:00

Add tracepoints for upcalls.

Signed-off-by: Trond Myklebust 
Signed-off-by: Chuck Lever

nfsd: Add tracing to nfsd_set_fh_dentry()

2020-03-16T16:04:33+00:00

Add tracing to allow us to figure out where any stale filehandle issues
may be originating from.

Signed-off-by: Trond Myklebust 
Signed-off-by: Chuck Lever