kernel/linux.git/fs/lockd/svc4proc.c, branch v6.6.148

lockd: fix vfs_test_lock() calls

2026-01-11T14:22:23+00:00

[ Upstream commit a49a2a1baa0c553c3548a1c414b6a3c005a8deba ] Usage of vfs_test_lock() is somewhat confused. Documentation suggests it is given a "lock" but this is not the case. It is given a struct file_lock which contains some details of the sort of lock it should be looking for. In particular passing a "file_lock" containing fl_lmops or fl_ops is meaningless and possibly confusing. This is particularly problematic in lockd. nlmsvc_testlock() receives an initialised "file_lock" from xdr-decode, including manager ops and an owner. It then mistakenly passes this to vfs_test_lock() which might replace the owner and the ops. This can lead to confusion when freeing the lock. The primary role of the 'struct file_lock' passed to vfs_test_lock() is to report a conflicting lock that was found, so it makes more sense for nlmsvc_testlock() to pass "conflock", which it uses for returning the conflicting lock. With this change, freeing of the lock is not confused and code in __nlm4svc_proc_test() and __nlmsvc_proc_test() can be simplified. Documentation for vfs_test_lock() is improved to reflect its real purpose, and a WARN_ON_ONCE() is added to avoid a similar problem in the future. Reported-by: Olga Kornievskaia Closes: https://lore.kernel.org/all/20251021130506.45065-1-okorniev@redhat.com Signed-off-by: NeilBrown Fixes: 20fa19027286 ("nfs: add export operations") Cc: stable@vger.kernel.org Reviewed-by: Jeff Layton Signed-off-by: Chuck Lever [ adapted fl->c.flc_* field references to flat fl->fl_* naming convention ] Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

lockd: set missing fl_flags field when retrieving args

2022-12-10T16:01:11+00:00

Signed-off-by: Jeff Layton Signed-off-by: Chuck Lever

SUNRPC: Parametrize how much of argsize should be zeroed

2022-09-26T18:02:42+00:00

Currently, SUNRPC clears the whole of .pc_argsize before processing each incoming RPC transaction. Add an extra parameter to struct svc_procedure to enable upper layers to reduce the amount of each operation's argument structure that is zeroed by SUNRPC. The size of struct nfsd4_compoundargs, in particular, is a lot to clear on each incoming RPC Call. A subsequent patch will cut this down to something closer to what NFSv2 and NFSv3 uses. This patch should cause no behavior changes. Signed-off-by: Chuck Lever

lockd: detect and reject lock arguments that overflow

2022-08-04T14:28:48+00:00

lockd doesn't currently vet the start and length in nlm4 requests like it should, and can end up generating lock requests with arguments that overflow when passed to the filesystem. The NLM4 protocol uses unsigned 64-bit arguments for both start and length, whereas struct file_lock tracks the start and end as loff_t values. By the time we get around to calling nlm4svc_retrieve_args, we've lost the information that would allow us to determine if there was an overflow. Start tracking the actual start and len for NLM4 requests in the nlm_lock. In nlm4svc_retrieve_args, vet these values to ensure they won't cause an overflow, and return NLM4_FBIG if they do. Link: https://bugzilla.linux-nfs.org/show_bug.cgi?id=392 Reported-by: Jan Kasiak Signed-off-by: Jeff Layton Signed-off-by: Chuck Lever Cc: # 5.14+

NLM: Defend against file_lock changes after vfs_test_lock()

2022-07-30T00:08:56+00:00

Instead of trusting that struct file_lock returns completely unchanged after vfs_test_lock() when there's no conflicting lock, stash away our nlm_lockowner reference so we can properly release it for all cases. This defends against another file_lock implementation overwriting fl_owner when the return type is F_UNLCK. Reported-by: Roberto Bergantinos Corpas Tested-by: Roberto Bergantinos Corpas Signed-off-by: Benjamin Coddington Signed-off-by: Chuck Lever

SUNRPC: Trace calls to .rpc_call_done

2021-10-20T22:09:54+00:00

Introduce a single tracepoint that can replace simple dprintk call sites in upper layer "rpc_call_done" callbacks. Example: kworker/u24:2-1254 [001] 771.026677: rpc_stats_latency: task:00000001@00000002 xid=0x16a6f3c0 rpcbindv2 GETPORT backlog=446 rtt=101 execute=555 kworker/u24:2-1254 [001] 771.026677: rpc_task_call_done: task:00000001@00000002 flags=ASYNC|DYNAMIC|SOFT|SOFTCONN|SENT runstate=RUNNING|ACTIVE status=0 action=rpcb_getport_done kworker/u24:2-1254 [001] 771.026678: rpcb_setport: task:00000001@00000002 status=0 port=20048 Signed-off-by: Chuck Lever Signed-off-by: Trond Myklebust

Keep read and write fds with each nlm_file

2021-08-23T22:05:31+00:00

We shouldn't really be using a read-only file descriptor to take a write lock. Most filesystems will put up with it. But NFS, for example, won't. Signed-off-by: J. Bruce Fields Signed-off-by: Chuck Lever

nlm: minor nlm_lookup_file argument change

2021-08-23T16:56:03+00:00

It'll come in handy to get the whole nlm_lock. Signed-off-by: J. Bruce Fields Signed-off-by: Chuck Lever

SUNRPC: Make trace_svc_process() display the RPC procedure symbolically

2021-01-25T14:36:23+00:00

The next few patches will employ these strings to help make server- side trace logs more human-readable. A similar technique is already in use in kernel RPC client code. Signed-off-by: Chuck Lever

lockd: Replace PROC() macro with open code

2020-10-02T13:37:41+00:00

Clean up: Follow-up on ten-year-old commit b9081d90f5b9 ("NFS: kill off complicated macro 'PROC'") by performing the same conversion in the lockd code. To reduce the chance of error, I copied the original C preprocessor output and then made some minor edits. Signed-off-by: Chuck Lever Signed-off-by: J. Bruce Fields