From 68a7da9549ac4f6290fe85d2dab550e11f16b209 Mon Sep 17 00:00:00 2001 From: Dean Deng Date: Fri, 31 Jul 2020 00:38:57 -0700 Subject: Clean up vfs2 fallocate. Move to setstat.go and add a FileDescription wrapper method. PiperOrigin-RevId: 324165277 --- pkg/sentry/syscalls/linux/vfs2/filesystem.go | 50 ---------------------------- pkg/sentry/syscalls/linux/vfs2/setstat.go | 50 ++++++++++++++++++++++++++++ pkg/sentry/vfs/file_description.go | 7 +++- 3 files changed, 56 insertions(+), 51 deletions(-) (limited to 'pkg') diff --git a/pkg/sentry/syscalls/linux/vfs2/filesystem.go b/pkg/sentry/syscalls/linux/vfs2/filesystem.go index 6b14c2bef..b6d2ddd65 100644 --- a/pkg/sentry/syscalls/linux/vfs2/filesystem.go +++ b/pkg/sentry/syscalls/linux/vfs2/filesystem.go @@ -18,7 +18,6 @@ import ( "gvisor.dev/gvisor/pkg/abi/linux" "gvisor.dev/gvisor/pkg/sentry/arch" "gvisor.dev/gvisor/pkg/sentry/kernel" - "gvisor.dev/gvisor/pkg/sentry/limits" "gvisor.dev/gvisor/pkg/sentry/vfs" "gvisor.dev/gvisor/pkg/syserror" "gvisor.dev/gvisor/pkg/usermem" @@ -245,55 +244,6 @@ func renameat(t *kernel.Task, olddirfd int32, oldpathAddr usermem.Addr, newdirfd }) } -// Fallocate implements linux system call fallocate(2). -func Fallocate(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) { - fd := args[0].Int() - mode := args[1].Uint64() - offset := args[2].Int64() - length := args[3].Int64() - - file := t.GetFileVFS2(fd) - - if file == nil { - return 0, nil, syserror.EBADF - } - defer file.DecRef() - - if !file.IsWritable() { - return 0, nil, syserror.EBADF - } - - if mode != 0 { - return 0, nil, syserror.ENOTSUP - } - - if offset < 0 || length <= 0 { - return 0, nil, syserror.EINVAL - } - - size := offset + length - - if size < 0 { - return 0, nil, syserror.EFBIG - } - - limit := limits.FromContext(t).Get(limits.FileSize).Cur - - if uint64(size) >= limit { - t.SendSignal(&arch.SignalInfo{ - Signo: int32(linux.SIGXFSZ), - Code: arch.SignalInfoUser, - }) - return 0, nil, syserror.EFBIG - } - - return 0, nil, file.Impl().Allocate(t, mode, uint64(offset), uint64(length)) - - // File length modified, generate notification. - // TODO(gvisor.dev/issue/1479): Reenable when Inotify is ported. - // file.Dirent.InotifyEvent(linux.IN_MODIFY, 0) -} - // Rmdir implements Linux syscall rmdir(2). func Rmdir(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) { pathAddr := args[0].Pointer() diff --git a/pkg/sentry/syscalls/linux/vfs2/setstat.go b/pkg/sentry/syscalls/linux/vfs2/setstat.go index 6daedd173..37fa56c19 100644 --- a/pkg/sentry/syscalls/linux/vfs2/setstat.go +++ b/pkg/sentry/syscalls/linux/vfs2/setstat.go @@ -20,6 +20,7 @@ import ( "gvisor.dev/gvisor/pkg/sentry/arch" "gvisor.dev/gvisor/pkg/sentry/kernel" "gvisor.dev/gvisor/pkg/sentry/kernel/auth" + "gvisor.dev/gvisor/pkg/sentry/limits" "gvisor.dev/gvisor/pkg/sentry/vfs" "gvisor.dev/gvisor/pkg/syserror" "gvisor.dev/gvisor/pkg/usermem" @@ -211,6 +212,55 @@ func Ftruncate(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Sys return 0, nil, handleSetSizeError(t, err) } +// Fallocate implements linux system call fallocate(2). +func Fallocate(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) { + fd := args[0].Int() + mode := args[1].Uint64() + offset := args[2].Int64() + length := args[3].Int64() + + file := t.GetFileVFS2(fd) + + if file == nil { + return 0, nil, syserror.EBADF + } + defer file.DecRef() + + if !file.IsWritable() { + return 0, nil, syserror.EBADF + } + + if mode != 0 { + return 0, nil, syserror.ENOTSUP + } + + if offset < 0 || length <= 0 { + return 0, nil, syserror.EINVAL + } + + size := offset + length + + if size < 0 { + return 0, nil, syserror.EFBIG + } + + limit := limits.FromContext(t).Get(limits.FileSize).Cur + + if uint64(size) >= limit { + t.SendSignal(&arch.SignalInfo{ + Signo: int32(linux.SIGXFSZ), + Code: arch.SignalInfoUser, + }) + return 0, nil, syserror.EFBIG + } + + return 0, nil, file.Allocate(t, mode, uint64(offset), uint64(length)) + + // File length modified, generate notification. + // TODO(gvisor.dev/issue/1479): Reenable when Inotify is ported. + // file.Dirent.InotifyEvent(linux.IN_MODIFY, 0) +} + // Utime implements Linux syscall utime(2). func Utime(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) { pathAddr := args[0].Pointer() diff --git a/pkg/sentry/vfs/file_description.go b/pkg/sentry/vfs/file_description.go index 0c42574db..93861fb4a 100644 --- a/pkg/sentry/vfs/file_description.go +++ b/pkg/sentry/vfs/file_description.go @@ -354,7 +354,7 @@ type FileDescriptionImpl interface { // represented by the FileDescription. StatFS(ctx context.Context) (linux.Statfs, error) - // Allocate grows file represented by FileDescription to offset + length bytes. + // Allocate grows the file to offset + length bytes. // Only mode == 0 is supported currently. Allocate(ctx context.Context, mode, offset, length uint64) error @@ -563,6 +563,11 @@ func (fd *FileDescription) StatFS(ctx context.Context) (linux.Statfs, error) { return fd.impl.StatFS(ctx) } +// Allocate grows file represented by FileDescription to offset + length bytes. +func (fd *FileDescription) Allocate(ctx context.Context, mode, offset, length uint64) error { + return fd.impl.Allocate(ctx, mode, offset, length) +} + // Readiness implements waiter.Waitable.Readiness. // // It returns fd's I/O readiness. -- cgit v1.2.3