diff options
Diffstat (limited to 'pkg/sentry/vfs/lock/lock.go')
| -rw-r--r-- | pkg/sentry/vfs/lock/lock.go | 72 |
1 files changed, 0 insertions, 72 deletions
diff --git a/pkg/sentry/vfs/lock/lock.go b/pkg/sentry/vfs/lock/lock.go deleted file mode 100644 index 724dfe743..000000000 --- a/pkg/sentry/vfs/lock/lock.go +++ /dev/null @@ -1,72 +0,0 @@ -// Copyright 2020 The gVisor Authors. -// -// Licensed under the Apache License, Version 2.0 (the "License"); -// you may not use this file except in compliance with the License. -// You may obtain a copy of the License at -// -// http://www.apache.org/licenses/LICENSE-2.0 -// -// Unless required by applicable law or agreed to in writing, software -// distributed under the License is distributed on an "AS IS" BASIS, -// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. -// See the License for the specific language governing permissions and -// limitations under the License. - -// Package lock provides POSIX and BSD style file locking for VFS2 file -// implementations. -// -// The actual implementations can be found in the lock package under -// sentry/fs/lock. -package lock - -import ( - fslock "gvisor.dev/gvisor/pkg/sentry/fs/lock" - "gvisor.dev/gvisor/pkg/syserror" -) - -// FileLocks supports POSIX and BSD style locks, which correspond to fcntl(2) -// and flock(2) respectively in Linux. It can be embedded into various file -// implementations for VFS2 that support locking. -// -// Note that in Linux these two types of locks are _not_ cooperative, because -// race and deadlock conditions make merging them prohibitive. We do the same -// and keep them oblivious to each other. -type FileLocks struct { - // bsd is a set of BSD-style advisory file wide locks, see flock(2). - bsd fslock.Locks - - // posix is a set of POSIX-style regional advisory locks, see fcntl(2). - posix fslock.Locks -} - -// LockBSD tries to acquire a BSD-style lock on the entire file. -func (fl *FileLocks) LockBSD(uid fslock.UniqueID, t fslock.LockType, block fslock.Blocker) error { - if fl.bsd.LockRegion(uid, t, fslock.LockRange{0, fslock.LockEOF}, block) { - return nil - } - return syserror.ErrWouldBlock -} - -// UnlockBSD releases a BSD-style lock on the entire file. -// -// This operation is always successful, even if there did not exist a lock on -// the requested region held by uid in the first place. -func (fl *FileLocks) UnlockBSD(uid fslock.UniqueID) { - fl.bsd.UnlockRegion(uid, fslock.LockRange{0, fslock.LockEOF}) -} - -// LockPOSIX tries to acquire a POSIX-style lock on a file region. -func (fl *FileLocks) LockPOSIX(uid fslock.UniqueID, t fslock.LockType, rng fslock.LockRange, block fslock.Blocker) error { - if fl.posix.LockRegion(uid, t, rng, block) { - return nil - } - return syserror.ErrWouldBlock -} - -// UnlockPOSIX releases a POSIX-style lock on a file region. -// -// This operation is always successful, even if there did not exist a lock on -// the requested region held by uid in the first place. -func (fl *FileLocks) UnlockPOSIX(uid fslock.UniqueID, rng fslock.LockRange) { - fl.posix.UnlockRegion(uid, rng) -} |