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-rw-r--r--pkg/sentry/fsimpl/tmpfs/BUILD3
-rw-r--r--pkg/sentry/fsimpl/tmpfs/regular_file.go23
-rw-r--r--pkg/sentry/fsimpl/tmpfs/regular_file_test.go56
-rw-r--r--pkg/sentry/fsimpl/tmpfs/tmpfs.go43
-rw-r--r--pkg/sentry/vfs/lock/BUILD13
-rw-r--r--pkg/sentry/vfs/lock/lock.go72
6 files changed, 210 insertions, 0 deletions
diff --git a/pkg/sentry/fsimpl/tmpfs/BUILD b/pkg/sentry/fsimpl/tmpfs/BUILD
index c61366224..57abd5583 100644
--- a/pkg/sentry/fsimpl/tmpfs/BUILD
+++ b/pkg/sentry/fsimpl/tmpfs/BUILD
@@ -38,6 +38,7 @@ go_library(
"//pkg/sentry/arch",
"//pkg/sentry/fs",
"//pkg/sentry/fs/fsutil",
+ "//pkg/sentry/fs/lock",
"//pkg/sentry/kernel",
"//pkg/sentry/kernel/auth",
"//pkg/sentry/kernel/pipe",
@@ -47,6 +48,7 @@ go_library(
"//pkg/sentry/platform",
"//pkg/sentry/usage",
"//pkg/sentry/vfs",
+ "//pkg/sentry/vfs/lock",
"//pkg/sync",
"//pkg/syserror",
"//pkg/usermem",
@@ -86,6 +88,7 @@ go_test(
"//pkg/context",
"//pkg/fspath",
"//pkg/sentry/contexttest",
+ "//pkg/sentry/fs/lock",
"//pkg/sentry/kernel/auth",
"//pkg/sentry/kernel/contexttest",
"//pkg/sentry/vfs",
diff --git a/pkg/sentry/fsimpl/tmpfs/regular_file.go b/pkg/sentry/fsimpl/tmpfs/regular_file.go
index e9e6faf67..dab346a41 100644
--- a/pkg/sentry/fsimpl/tmpfs/regular_file.go
+++ b/pkg/sentry/fsimpl/tmpfs/regular_file.go
@@ -23,6 +23,7 @@ import (
"gvisor.dev/gvisor/pkg/context"
"gvisor.dev/gvisor/pkg/safemem"
"gvisor.dev/gvisor/pkg/sentry/fs/fsutil"
+ "gvisor.dev/gvisor/pkg/sentry/fs/lock"
"gvisor.dev/gvisor/pkg/sentry/kernel/auth"
"gvisor.dev/gvisor/pkg/sentry/memmap"
"gvisor.dev/gvisor/pkg/sentry/pgalloc"
@@ -192,6 +193,28 @@ func (fd *regularFileFD) Sync(ctx context.Context) error {
return nil
}
+// LockBSD implements vfs.FileDescriptionImpl.LockBSD.
+func (fd *regularFileFD) LockBSD(ctx context.Context, uid lock.UniqueID, t lock.LockType, block lock.Blocker) error {
+ return fd.inode().lockBSD(uid, t, block)
+}
+
+// UnlockBSD implements vfs.FileDescriptionImpl.UnlockBSD.
+func (fd *regularFileFD) UnlockBSD(ctx context.Context, uid lock.UniqueID) error {
+ fd.inode().unlockBSD(uid)
+ return nil
+}
+
+// LockPOSIX implements vfs.FileDescriptionImpl.LockPOSIX.
+func (fd *regularFileFD) LockPOSIX(ctx context.Context, uid lock.UniqueID, t lock.LockType, rng lock.LockRange, block lock.Blocker) error {
+ return fd.inode().lockPOSIX(uid, t, rng, block)
+}
+
+// UnlockPOSIX implements vfs.FileDescriptionImpl.UnlockPOSIX.
+func (fd *regularFileFD) UnlockPOSIX(ctx context.Context, uid lock.UniqueID, rng lock.LockRange) error {
+ fd.inode().unlockPOSIX(uid, rng)
+ return nil
+}
+
// regularFileReadWriter implements safemem.Reader and Safemem.Writer.
type regularFileReadWriter struct {
file *regularFile
diff --git a/pkg/sentry/fsimpl/tmpfs/regular_file_test.go b/pkg/sentry/fsimpl/tmpfs/regular_file_test.go
index 32552e261..2b52992ea 100644
--- a/pkg/sentry/fsimpl/tmpfs/regular_file_test.go
+++ b/pkg/sentry/fsimpl/tmpfs/regular_file_test.go
@@ -24,9 +24,11 @@ import (
"gvisor.dev/gvisor/pkg/abi/linux"
"gvisor.dev/gvisor/pkg/context"
"gvisor.dev/gvisor/pkg/fspath"
+ "gvisor.dev/gvisor/pkg/sentry/fs/lock"
"gvisor.dev/gvisor/pkg/sentry/kernel/auth"
"gvisor.dev/gvisor/pkg/sentry/kernel/contexttest"
"gvisor.dev/gvisor/pkg/sentry/vfs"
+ "gvisor.dev/gvisor/pkg/syserror"
"gvisor.dev/gvisor/pkg/usermem"
)
@@ -260,6 +262,60 @@ func TestPWrite(t *testing.T) {
}
}
+func TestLocks(t *testing.T) {
+ ctx := contexttest.Context(t)
+ fd, cleanup, err := newFileFD(ctx, 0644)
+ if err != nil {
+ t.Fatal(err)
+ }
+ defer cleanup()
+
+ var (
+ uid1 lock.UniqueID
+ uid2 lock.UniqueID
+ // Non-blocking.
+ block lock.Blocker
+ )
+
+ uid1 = 123
+ uid2 = 456
+
+ if err := fd.Impl().LockBSD(ctx, uid1, lock.ReadLock, block); err != nil {
+ t.Fatalf("fd.Impl().LockBSD failed: err = %v", err)
+ }
+ if err := fd.Impl().LockBSD(ctx, uid2, lock.ReadLock, block); err != nil {
+ t.Fatalf("fd.Impl().LockBSD failed: err = %v", err)
+ }
+ if got, want := fd.Impl().LockBSD(ctx, uid2, lock.WriteLock, block), syserror.ErrWouldBlock; got != want {
+ t.Fatalf("fd.Impl().LockBSD failed: got = %v, want = %v", got, want)
+ }
+ if err := fd.Impl().UnlockBSD(ctx, uid1); err != nil {
+ t.Fatalf("fd.Impl().UnlockBSD failed: err = %v", err)
+ }
+ if err := fd.Impl().LockBSD(ctx, uid2, lock.WriteLock, block); err != nil {
+ t.Fatalf("fd.Impl().LockBSD failed: err = %v", err)
+ }
+
+ rng1 := lock.LockRange{0, 1}
+ rng2 := lock.LockRange{1, 2}
+
+ if err := fd.Impl().LockPOSIX(ctx, uid1, lock.ReadLock, rng1, block); err != nil {
+ t.Fatalf("fd.Impl().LockPOSIX failed: err = %v", err)
+ }
+ if err := fd.Impl().LockPOSIX(ctx, uid2, lock.ReadLock, rng2, block); err != nil {
+ t.Fatalf("fd.Impl().LockPOSIX failed: err = %v", err)
+ }
+ if err := fd.Impl().LockPOSIX(ctx, uid1, lock.WriteLock, rng1, block); err != nil {
+ t.Fatalf("fd.Impl().LockPOSIX failed: err = %v", err)
+ }
+ if got, want := fd.Impl().LockPOSIX(ctx, uid2, lock.ReadLock, rng1, block), syserror.ErrWouldBlock; got != want {
+ t.Fatalf("fd.Impl().LockPOSIX failed: got = %v, want = %v", got, want)
+ }
+ if err := fd.Impl().UnlockPOSIX(ctx, uid1, rng1); err != nil {
+ t.Fatalf("fd.Impl().UnlockPOSIX failed: err = %v", err)
+ }
+}
+
func TestPRead(t *testing.T) {
ctx := contexttest.Context(t)
fd, cleanup, err := newFileFD(ctx, 0644)
diff --git a/pkg/sentry/fsimpl/tmpfs/tmpfs.go b/pkg/sentry/fsimpl/tmpfs/tmpfs.go
index 88dbd6e35..2108d0f4d 100644
--- a/pkg/sentry/fsimpl/tmpfs/tmpfs.go
+++ b/pkg/sentry/fsimpl/tmpfs/tmpfs.go
@@ -30,10 +30,12 @@ import (
"gvisor.dev/gvisor/pkg/abi/linux"
"gvisor.dev/gvisor/pkg/context"
+ fslock "gvisor.dev/gvisor/pkg/sentry/fs/lock"
"gvisor.dev/gvisor/pkg/sentry/kernel/auth"
"gvisor.dev/gvisor/pkg/sentry/kernel/time"
"gvisor.dev/gvisor/pkg/sentry/pgalloc"
"gvisor.dev/gvisor/pkg/sentry/vfs"
+ "gvisor.dev/gvisor/pkg/sentry/vfs/lock"
"gvisor.dev/gvisor/pkg/sync"
"gvisor.dev/gvisor/pkg/syserror"
)
@@ -153,6 +155,9 @@ type inode struct {
rdevMajor uint32
rdevMinor uint32
+ // Advisory file locks, which lock at the inode level.
+ locks lock.FileLocks
+
impl interface{} // immutable
}
@@ -352,6 +357,44 @@ func (i *inode) setStat(stat linux.Statx) error {
return nil
}
+// TODO(gvisor.dev/issue/1480): support file locking for file types other than regular.
+func (i *inode) lockBSD(uid fslock.UniqueID, t fslock.LockType, block fslock.Blocker) error {
+ switch i.impl.(type) {
+ case *regularFile:
+ return i.locks.LockBSD(uid, t, block)
+ }
+ return syserror.EBADF
+}
+
+// TODO(gvisor.dev/issue/1480): support file locking for file types other than regular.
+func (i *inode) unlockBSD(uid fslock.UniqueID) error {
+ switch i.impl.(type) {
+ case *regularFile:
+ i.locks.UnlockBSD(uid)
+ return nil
+ }
+ return syserror.EBADF
+}
+
+// TODO(gvisor.dev/issue/1480): support file locking for file types other than regular.
+func (i *inode) lockPOSIX(uid fslock.UniqueID, t fslock.LockType, rng fslock.LockRange, block fslock.Blocker) error {
+ switch i.impl.(type) {
+ case *regularFile:
+ return i.locks.LockPOSIX(uid, t, rng, block)
+ }
+ return syserror.EBADF
+}
+
+// TODO(gvisor.dev/issue/1480): support file locking for file types other than regular.
+func (i *inode) unlockPOSIX(uid fslock.UniqueID, rng fslock.LockRange) error {
+ switch i.impl.(type) {
+ case *regularFile:
+ i.locks.UnlockPOSIX(uid, rng)
+ return nil
+ }
+ return syserror.EBADF
+}
+
// allocatedBlocksForSize returns the number of 512B blocks needed to
// accommodate the given size in bytes, as appropriate for struct
// stat::st_blocks and struct statx::stx_blocks. (Note that this 512B block
diff --git a/pkg/sentry/vfs/lock/BUILD b/pkg/sentry/vfs/lock/BUILD
new file mode 100644
index 000000000..d9ab063b7
--- /dev/null
+++ b/pkg/sentry/vfs/lock/BUILD
@@ -0,0 +1,13 @@
+load("//tools:defs.bzl", "go_library")
+
+package(licenses = ["notice"])
+
+go_library(
+ name = "lock",
+ srcs = ["lock.go"],
+ visibility = ["//pkg/sentry:internal"],
+ deps = [
+ "//pkg/sentry/fs/lock",
+ "//pkg/syserror",
+ ],
+)
diff --git a/pkg/sentry/vfs/lock/lock.go b/pkg/sentry/vfs/lock/lock.go
new file mode 100644
index 000000000..724dfe743
--- /dev/null
+++ b/pkg/sentry/vfs/lock/lock.go
@@ -0,0 +1,72 @@
+// 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)
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-02 12:26:44 +0000