kernel/linux.git/include/linux/lockd, branch v7.0.14

lockd: fix TEST handling when not all permissions are available.

2026-06-27T10:07:38+00:00

[ Upstream commit 0b474240327cebeff08ad429e8ed3cfc6c8ee816 ] The F_GETLK fcntl can work with either read access or write access or both. It can query F_RDLCK and F_WRLCK locks in either case. However lockd currently treats F_GETLK similar to F_SETLK in that read access is required to query an F_RDLCK lock and write access is required to query a F_WRLCK lock. This is wrong and can cause problems - e.g. when qemu accesses a read-only (e.g. iso) filesystem image over NFS (though why it queries if it can get a write lock - I don't know. But it does, and this works with local filesystems). So we need TEST requests to be handled differently. To do this: - change nlm_do_fopen() to accept O_RDWR as a mode and in that case succeed if either a O_RDONLY or O_WRONLY file can be opened. - change nlm_lookup_file() to accept a mode argument from caller, instead of deducing base on lock time, and pass that on to nlm_do_fopen() - change nlm4svc_retrieve_args() and nlmsvc_retrieve_args() to detect TEST requests and pass O_RDWR as a mode to nlm_lookup_file, passing the same mode as before for other requests. Also set lock->fl.c.flc_file to whichever file is available for TEST requests. - change nlmsvc_testlock() to also not calculate the mode, but to use whatever was stored in lock->fl.c.flc_file. This behaviour of lockd - requesting O_WRONLY access to TEST for exclusive locks - has been present at least since git history began. However it was hidden until recently because knfsd ignored the access requested by lockd and required only READ access for all locking requests (unless the underlying filesystem provided an f_op->open function which checked access permissions). The commit mentioned in Fixes: below changed nfsd_permission() to NOT override the access request for LOCK requests and this exposed the bug that we are now fixing. Note that there is another issue that this patch does not address. The flock(.., LOCK_EX) call is permitted on a read-only file descriptor. Linux NFS maps this to NLM locking as whole-file byte-range locks. nfsd will see this as though it were fcntl( F_SETLK (F_WRLCK)) and will now require write access, which it might not be able to get. It is not clear if this is a problem in practice, or what the best solution might be. So no attempt is made to address it. Reported-by: Tj Link: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1128861 Fixes: 4cc9b9f2bf4d ("nfsd: refine and rename NFSD_MAY_LOCK") Reviewed-by: Jeff Layton Signed-off-by: NeilBrown Signed-off-by: Chuck Lever Signed-off-by: Sasha Levin

lockd: don't allow locking on reexported NFSv2/3

2025-11-20T21:29:35+00:00

Since commit 9254c8ae9b81 ("nfsd: disallow file locking and delegations for NFSv4 reexport"), file locking when reexporting an NFS mount via NFSv4 is expressly prohibited by nfsd. Do the same in lockd: Add a new nlmsvc_file_cannot_lock() helper that will test whether file locking is allowed for a given file, and return nlm_lck_denied_nolocks if it isn't. Signed-off-by: Jeff Layton Tested-by: Olga Kornievskaia Signed-off-by: Chuck Lever

lockd: Remove unused parameter to nlmsvc_testlock()

2024-11-19T01:23:04+00:00

The nlm_cookie parameter has been unused since commit 09802fd2a8ca ("lockd: rip out deferred lock handling from testlock codepath"). Reviewed-by: Jeff Layton Reviewed-by: NeilBrown Signed-off-by: Chuck Lever

lockd: Remove unused typedef

2024-11-19T01:23:03+00:00

Clean up: Looks like the last usage of this typedef was removed by commit 026fec7e7c47 ("sunrpc: properly type pc_decode callbacks") in 2017. Reviewed-by: Jeff Layton Reviewed-by: NeilBrown Signed-off-by: Chuck Lever

lockd: discard nlmsvc_timeout

2024-09-01T14:04:56+00:00

nlmsvc_timeout always has the same value as (nlm_timeout * HZ), so use that in the one place that nlmsvc_timeout is used. In truth it *might* not always be the same as nlmsvc_timeout is only set when lockd is started while nlm_timeout can be set at anytime via sysctl. I think this difference it not helpful so removing it is good. Also remove the test for nlm_timout being 0. This is not possible - unless a module parameter is used to set the minimum timeout to 0, and if that happens then it probably should be honoured. Signed-off-by: NeilBrown Signed-off-by: Chuck Lever

lockd: adapt to breakup of struct file_lock

2024-02-05T12:11:43+00:00

Most of the existing APIs have remained the same, but subsystems that access file_lock fields directly need to reach into struct file_lock_core now. Signed-off-by: Jeff Layton Link: https://lore.kernel.org/r/20240131-flsplit-v3-40-c6129007ee8d@kernel.org Reviewed-by: NeilBrown Signed-off-by: Christian Brauner

filelock: split common fields into struct file_lock_core

2024-02-05T12:11:38+00:00

In a future patch, we're going to split file leases into their own structure. Since a lot of the underlying machinery uses the same fields move those into a new file_lock_core, and embed that inside struct file_lock. For now, add some macros to ensure that we can continue to build while the conversion is in progress. Signed-off-by: Jeff Layton Link: https://lore.kernel.org/r/20240131-flsplit-v3-17-c6129007ee8d@kernel.org Reviewed-by: NeilBrown Signed-off-by: Christian Brauner

SUNRPC: change how svc threads are asked to exit.

2023-10-16T16:44:04+00:00

svc threads are currently stopped using kthread_stop(). This requires identifying a specific thread. However we don't care which thread stops, just as long as one does. So instead, set a flag in the svc_pool to say that a thread needs to die, and have each thread check this flag instead of calling kthread_should_stop(). The first thread to find and clear this flag then moves towards exiting. This removes an explicit dependency on sp_all_threads which will make a future patch simpler. Signed-off-by: NeilBrown Signed-off-by: Chuck Lever

SUNRPC: remove timeout arg from svc_recv()

2023-08-29T21:45:22+00:00

Most svc threads have no interest in a timeout. nfsd sets it to 1 hour, but this is a wart of no significance. lockd uses the timeout so that it can call nlmsvc_retry_blocked(). It also sometimes calls svc_wake_up() to ensure this is called. So change lockd to be consistent and always use svc_wake_up() to trigger nlmsvc_retry_blocked() - using a timer instead of a timeout to svc_recv(). And change svc_recv() to not take a timeout arg. This makes the sp_threads_timedout counter always zero. Signed-off-by: NeilBrown Signed-off-by: Chuck Lever

NFS: add a sysfs link to the lockd rpc_client

2023-06-19T19:06:07+00:00

After lockd is started, add a symlink for lockd's rpc_client under NFS' superblock sysfs. Signed-off-by: Benjamin Coddington Signed-off-by: Trond Myklebust