diff options
Diffstat (limited to 'pkg/sentry/vfs')
-rw-r--r-- | pkg/sentry/vfs/BUILD | 2 | ||||
-rw-r--r-- | pkg/sentry/vfs/file_description.go | 18 | ||||
-rw-r--r-- | pkg/sentry/vfs/file_description_impl_util.go | 25 | ||||
-rw-r--r-- | pkg/sentry/vfs/lock.go (renamed from pkg/sentry/vfs/lock/lock.go) | 43 | ||||
-rw-r--r-- | pkg/sentry/vfs/lock/BUILD | 13 |
5 files changed, 62 insertions, 39 deletions
diff --git a/pkg/sentry/vfs/BUILD b/pkg/sentry/vfs/BUILD index 16d9f3a28..642769e7c 100644 --- a/pkg/sentry/vfs/BUILD +++ b/pkg/sentry/vfs/BUILD @@ -44,6 +44,7 @@ go_library( "filesystem_impl_util.go", "filesystem_type.go", "inotify.go", + "lock.go", "mount.go", "mount_unsafe.go", "options.go", @@ -72,7 +73,6 @@ go_library( "//pkg/sentry/memmap", "//pkg/sentry/socket/unix/transport", "//pkg/sentry/uniqueid", - "//pkg/sentry/vfs/lock", "//pkg/sync", "//pkg/syserror", "//pkg/usermem", diff --git a/pkg/sentry/vfs/file_description.go b/pkg/sentry/vfs/file_description.go index 13c48824e..e0538ea53 100644 --- a/pkg/sentry/vfs/file_description.go +++ b/pkg/sentry/vfs/file_description.go @@ -438,14 +438,10 @@ type FileDescriptionImpl interface { UnlockBSD(ctx context.Context, uid lock.UniqueID) error // LockPOSIX tries to acquire a POSIX-style advisory file lock. - // - // TODO(gvisor.dev/issue/1480): POSIX-style file locking - LockPOSIX(ctx context.Context, uid lock.UniqueID, t lock.LockType, rng lock.LockRange, block lock.Blocker) error + LockPOSIX(ctx context.Context, uid lock.UniqueID, t lock.LockType, start, length uint64, whence int16, block lock.Blocker) error // UnlockPOSIX releases a POSIX-style advisory file lock. - // - // TODO(gvisor.dev/issue/1480): POSIX-style file locking - UnlockPOSIX(ctx context.Context, uid lock.UniqueID, rng lock.LockRange) error + UnlockPOSIX(ctx context.Context, uid lock.UniqueID, start, length uint64, whence int16) error } // Dirent holds the information contained in struct linux_dirent64. @@ -764,3 +760,13 @@ func (fd *FileDescription) LockBSD(ctx context.Context, lockType lock.LockType, func (fd *FileDescription) UnlockBSD(ctx context.Context) error { return fd.impl.UnlockBSD(ctx, fd) } + +// LockPOSIX locks a POSIX-style file range lock. +func (fd *FileDescription) LockPOSIX(ctx context.Context, uid lock.UniqueID, t lock.LockType, start, end uint64, whence int16, block lock.Blocker) error { + return fd.impl.LockPOSIX(ctx, uid, t, start, end, whence, block) +} + +// UnlockPOSIX unlocks a POSIX-style file range lock. +func (fd *FileDescription) UnlockPOSIX(ctx context.Context, uid lock.UniqueID, start, end uint64, whence int16) error { + return fd.impl.UnlockPOSIX(ctx, uid, start, end, whence) +} diff --git a/pkg/sentry/vfs/file_description_impl_util.go b/pkg/sentry/vfs/file_description_impl_util.go index af7213dfd..1e66997ce 100644 --- a/pkg/sentry/vfs/file_description_impl_util.go +++ b/pkg/sentry/vfs/file_description_impl_util.go @@ -23,7 +23,6 @@ import ( "gvisor.dev/gvisor/pkg/sentry/arch" fslock "gvisor.dev/gvisor/pkg/sentry/fs/lock" "gvisor.dev/gvisor/pkg/sentry/memmap" - "gvisor.dev/gvisor/pkg/sentry/vfs/lock" "gvisor.dev/gvisor/pkg/sync" "gvisor.dev/gvisor/pkg/syserror" "gvisor.dev/gvisor/pkg/usermem" @@ -369,14 +368,19 @@ func GenericConfigureMMap(fd *FileDescription, m memmap.Mappable, opts *memmap.M // LockFD may be used by most implementations of FileDescriptionImpl.Lock* // functions. Caller must call Init(). type LockFD struct { - locks *lock.FileLocks + locks *FileLocks } // Init initializes fd with FileLocks to use. -func (fd *LockFD) Init(locks *lock.FileLocks) { +func (fd *LockFD) Init(locks *FileLocks) { fd.locks = locks } +// Locks returns the locks associated with this file. +func (fd *LockFD) Locks() *FileLocks { + return fd.locks +} + // LockBSD implements vfs.FileDescriptionImpl.LockBSD. func (fd *LockFD) LockBSD(ctx context.Context, uid fslock.UniqueID, t fslock.LockType, block fslock.Blocker) error { return fd.locks.LockBSD(uid, t, block) @@ -388,17 +392,6 @@ func (fd *LockFD) UnlockBSD(ctx context.Context, uid fslock.UniqueID) error { return nil } -// LockPOSIX implements vfs.FileDescriptionImpl.LockPOSIX. -func (fd *LockFD) LockPOSIX(ctx context.Context, uid fslock.UniqueID, t fslock.LockType, rng fslock.LockRange, block fslock.Blocker) error { - return fd.locks.LockPOSIX(uid, t, rng, block) -} - -// UnlockPOSIX implements vfs.FileDescriptionImpl.UnlockPOSIX. -func (fd *LockFD) UnlockPOSIX(ctx context.Context, uid fslock.UniqueID, rng fslock.LockRange) error { - fd.locks.UnlockPOSIX(uid, rng) - return nil -} - // NoLockFD implements Lock*/Unlock* portion of FileDescriptionImpl interface // returning ENOLCK. type NoLockFD struct{} @@ -414,11 +407,11 @@ func (NoLockFD) UnlockBSD(ctx context.Context, uid fslock.UniqueID) error { } // LockPOSIX implements vfs.FileDescriptionImpl.LockPOSIX. -func (NoLockFD) LockPOSIX(ctx context.Context, uid fslock.UniqueID, t fslock.LockType, rng fslock.LockRange, block fslock.Blocker) error { +func (NoLockFD) LockPOSIX(ctx context.Context, uid fslock.UniqueID, t fslock.LockType, start, length uint64, whence int16, block fslock.Blocker) error { return syserror.ENOLCK } // UnlockPOSIX implements vfs.FileDescriptionImpl.UnlockPOSIX. -func (NoLockFD) UnlockPOSIX(ctx context.Context, uid fslock.UniqueID, rng fslock.LockRange) error { +func (NoLockFD) UnlockPOSIX(ctx context.Context, uid fslock.UniqueID, start, length uint64, whence int16) error { return syserror.ENOLCK } diff --git a/pkg/sentry/vfs/lock/lock.go b/pkg/sentry/vfs/lock.go index 724dfe743..6c7583a81 100644 --- a/pkg/sentry/vfs/lock/lock.go +++ b/pkg/sentry/vfs/lock.go @@ -17,9 +17,11 @@ // // The actual implementations can be found in the lock package under // sentry/fs/lock. -package lock +package vfs import ( + "gvisor.dev/gvisor/pkg/abi/linux" + "gvisor.dev/gvisor/pkg/context" fslock "gvisor.dev/gvisor/pkg/sentry/fs/lock" "gvisor.dev/gvisor/pkg/syserror" ) @@ -56,7 +58,11 @@ func (fl *FileLocks) UnlockBSD(uid fslock.UniqueID) { } // 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 { +func (fl *FileLocks) LockPOSIX(ctx context.Context, fd *FileDescription, uid fslock.UniqueID, t fslock.LockType, start, length uint64, whence int16, block fslock.Blocker) error { + rng, err := computeRange(ctx, fd, start, length, whence) + if err != nil { + return err + } if fl.posix.LockRegion(uid, t, rng, block) { return nil } @@ -67,6 +73,37 @@ func (fl *FileLocks) LockPOSIX(uid fslock.UniqueID, t fslock.LockType, rng fsloc // // 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) { +func (fl *FileLocks) UnlockPOSIX(ctx context.Context, fd *FileDescription, uid fslock.UniqueID, start, length uint64, whence int16) error { + rng, err := computeRange(ctx, fd, start, length, whence) + if err != nil { + return err + } fl.posix.UnlockRegion(uid, rng) + return nil +} + +func computeRange(ctx context.Context, fd *FileDescription, start uint64, length uint64, whence int16) (fslock.LockRange, error) { + var off int64 + switch whence { + case linux.SEEK_SET: + off = 0 + case linux.SEEK_CUR: + // Note that Linux does not hold any mutexes while retrieving the file + // offset, see fs/locks.c:flock_to_posix_lock and fs/locks.c:fcntl_setlk. + curOff, err := fd.Seek(ctx, 0, linux.SEEK_CUR) + if err != nil { + return fslock.LockRange{}, err + } + off = curOff + case linux.SEEK_END: + stat, err := fd.Stat(ctx, StatOptions{Mask: linux.STATX_SIZE}) + if err != nil { + return fslock.LockRange{}, err + } + off = int64(stat.Size) + default: + return fslock.LockRange{}, syserror.EINVAL + } + + return fslock.ComputeRange(int64(start), int64(length), off) } diff --git a/pkg/sentry/vfs/lock/BUILD b/pkg/sentry/vfs/lock/BUILD deleted file mode 100644 index d9ab063b7..000000000 --- a/pkg/sentry/vfs/lock/BUILD +++ /dev/null @@ -1,13 +0,0 @@ -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", - ], -) |