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path: root/include/linux/filelock.h
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2024-08-30vfs: dodge smp_mb in break_lease and break_deleg in the common caseMateusz Guzik1-2/+12
These inlines show up in the fast path (e.g., in do_dentry_open()) and induce said full barrier regarding i_flctx access when in most cases the pointer is NULL. The pointer can be safely checked before issuing the barrier, dodging it in most cases as a result. It is plausible the consume fence would be sufficient, but I don't want to go audit all callers regarding what they before calling here. Signed-off-by: Mateusz Guzik <mjguzik@gmail.com> Link: https://lore.kernel.org/r/20240806172846.886570-1-mjguzik@gmail.com Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-02-12filelock: always define for_each_file_lock()Jeff Layton1-5/+3
...and eliminate the stub version when CONFIG_FILE_LOCKING is disabled. This silences the following warning that crept in recently: fs/ceph/locks.c: In function 'ceph_count_locks': fs/ceph/locks.c:380:27: error: unused variable 'lock' [-Werror=unused-variable] 380 | struct file_lock *lock; Reported-by: kernel test robot <lkp@intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202402062210.3YyBVGF1-lkp@intel.com/ Fixes: 75cabec0111b ("filelock: add some new helper functions") Signed-off-by: Jeff Layton <jlayton@kernel.org> Link: https://lore.kernel.org/r/20240212-flsplit3-v1-1-019f0ad6bf69@kernel.org Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-02-05filelock: don't do security checks on nfsd setlease callsJeff Layton1-0/+7
Zdenek reported seeing some AVC denials due to nfsd trying to set delegations: type=AVC msg=audit(09.11.2023 09:03:46.411:496) : avc: denied { lease } for pid=5127 comm=rpc.nfsd capability=lease scontext=system_u:system_r:nfsd_t:s0 tcontext=system_u:system_r:nfsd_t:s0 tclass=capability permissive=0 When setting delegations on behalf of nfsd, we don't want to do all of the normal capabilty and LSM checks. nfsd is a kernel thread and runs with CAP_LEASE set, so the uid checks end up being a no-op in most cases anyway. Some nfsd functions can end up running in normal process context when tearing down the server. At that point, the CAP_LEASE check can fail and cause the client to not tear down delegations when expected. Also, the way the per-fs ->setlease handlers work today is a little convoluted. The non-trivial ones are wrappers around generic_setlease, so when they fail due to permission problems they usually they end up doing a little extra work only to determine that they can't set the lease anyway. It would be more efficient to do those checks earlier. Transplant the permission checking from generic_setlease to vfs_setlease, which will make the permission checking happen earlier on filesystems that have a ->setlease operation. Add a new kernel_setlease function that bypasses these checks, and switch nfsd to use that instead of vfs_setlease. There is one behavioral change here: prior this patch the setlease_notifier would fire even if the lease attempt was going to fail the security checks later. With this change, it doesn't fire until the caller has passed them. I think this is a desirable change overall. nfsd is the only user of the setlease_notifier and it doesn't benefit from being notified about failed attempts. Cc: Ondrej Mosnáček <omosnacek@gmail.com> Reported-by: Zdenek Pytela <zpytela@redhat.com> Closes: https://bugzilla.redhat.com/show_bug.cgi?id=2248830 Signed-off-by: Jeff Layton <jlayton@kernel.org> Link: https://lore.kernel.org/r/20240205-bz2248830-v1-1-d0ec0daecba1@kernel.org Acked-by: Tom Talpey <tom@talpey.com> Reviewed-by: NeilBrown <neilb@suse.de> Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-02-05filelock: split leases out of struct file_lockJeff Layton1-16/+33
Add a new struct file_lease and move the lease-specific fields from struct file_lock to it. Convert the appropriate API calls to take struct file_lease instead, and convert the callers to use them. There is zero overlap between the lock manager operations for file locks and the ones for file leases, so split the lease-related operations off into a new lease_manager_operations struct. Signed-off-by: Jeff Layton <jlayton@kernel.org> Link: https://lore.kernel.org/r/20240131-flsplit-v3-47-c6129007ee8d@kernel.org Reviewed-by: NeilBrown <neilb@suse.de> Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-02-05filelock: remove temporary compatibility macrosJeff Layton1-16/+0
Everything has been converted to access fl_core fields directly, so we can now drop these. Signed-off-by: Jeff Layton <jlayton@kernel.org> Link: https://lore.kernel.org/r/20240131-flsplit-v3-46-c6129007ee8d@kernel.org Reviewed-by: NeilBrown <neilb@suse.de> Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-02-05filelock: convert fl_blocker to file_lock_coreJeff Layton1-1/+1
Both locks and leases deal with fl_blocker. Switch the fl_blocker pointer in struct file_lock_core to point to the file_lock_core of the blocker instead of a file_lock structure. Signed-off-by: Jeff Layton <jlayton@kernel.org> Link: https://lore.kernel.org/r/20240131-flsplit-v3-26-c6129007ee8d@kernel.org Reviewed-by: NeilBrown <neilb@suse.de> Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-02-05filelock: split common fields into struct file_lock_coreJeff Layton1-18/+39
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 <jlayton@kernel.org> Link: https://lore.kernel.org/r/20240131-flsplit-v3-17-c6129007ee8d@kernel.org Reviewed-by: NeilBrown <neilb@suse.de> Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-02-05filelock: add some new helper functionsJeff Layton1-0/+44
In later patches we're going to embed some common fields into a new structure inside struct file_lock. Smooth the transition by adding some new helper functions, and converting the core file locking code to use them. Signed-off-by: Jeff Layton <jlayton@kernel.org> Link: https://lore.kernel.org/r/20240131-flsplit-v3-4-c6129007ee8d@kernel.org Reviewed-by: NeilBrown <neilb@suse.de> Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-02-02filelock: fl_pid field should be signed intJeff Layton1-1/+1
This field has been unsigned for a very long time, but most users of the struct file_lock and the file locking internals themselves treat it as a signed value. Change it to be pid_t (which is a signed int). Signed-off-by: Jeff Layton <jlayton@kernel.org> Link: https://lore.kernel.org/r/20240131-flsplit-v3-1-c6129007ee8d@kernel.org Reviewed-by: NeilBrown <neilb@suse.de> Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-07-10fs: Pass argument to fcntl_setlease as intLuca Vizzarro1-6/+6
The interface for fcntl expects the argument passed for the command F_SETLEASE to be of type int. The current code wrongly treats it as a long. In order to avoid access to undefined bits, we should explicitly cast the argument to int. Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Christian Brauner <brauner@kernel.org> Cc: Jeff Layton <jlayton@kernel.org> Cc: Chuck Lever <chuck.lever@oracle.com> Cc: Trond Myklebust <trond.myklebust@hammerspace.com> Cc: Anna Schumaker <anna@kernel.org> Cc: Kevin Brodsky <Kevin.Brodsky@arm.com> Cc: Vincenzo Frascino <Vincenzo.Frascino@arm.com> Cc: Szabolcs Nagy <Szabolcs.Nagy@arm.com> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: David Laight <David.Laight@ACULAB.com> Cc: Mark Rutland <Mark.Rutland@arm.com> Cc: linux-fsdevel@vger.kernel.org Cc: linux-cifs@vger.kernel.org Cc: linux-nfs@vger.kernel.org Cc: linux-morello@op-lists.linaro.org Signed-off-by: Luca Vizzarro <Luca.Vizzarro@arm.com> Message-Id: <20230414152459.816046-3-Luca.Vizzarro@arm.com> Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-01-11fs: remove locks_inodeJeff Layton1-3/+1
locks_inode was turned into a wrapper around file_inode in de2a4a501e71 (Partially revert "locks: fix file locking on overlayfs"). Finish replacing locks_inode invocations everywhere with file_inode. Acked-by: Miklos Szeredi <mszeredi@redhat.com> Acked-by: Al Viro <viro@zeniv.linux.org.uk> Reviewed-by: David Howells <dhowells@redhat.com> Signed-off-by: Jeff Layton <jlayton@kernel.org>
2023-01-11filelock: move file locking definitions to separate header fileJeff Layton1-0/+441
The file locking definitions have lived in fs.h since the dawn of time, but they are only used by a small subset of the source files that include it. Move the file locking definitions to a new header file, and add the appropriate #include directives to the source files that need them. By doing this we trim down fs.h a bit and limit the amount of rebuilding that has to be done when we make changes to the file locking APIs. Reviewed-by: Xiubo Li <xiubli@redhat.com> Reviewed-by: Christian Brauner (Microsoft) <brauner@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: David Howells <dhowells@redhat.com> Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> Acked-by: Chuck Lever <chuck.lever@oracle.com> Acked-by: Joseph Qi <joseph.qi@linux.alibaba.com> Acked-by: Steve French <stfrench@microsoft.com> Acked-by: Al Viro <viro@zeniv.linux.org.uk> Acked-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Jeff Layton <jlayton@kernel.org>