From ccd992355df7192993c666236047820244914598 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Tue, 16 Apr 2024 21:19:13 +0200 Subject: Adding upstream version 1.21.8. Signed-off-by: Daniel Baumann --- src/os/removeall_at.go | 199 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 199 insertions(+) create mode 100644 src/os/removeall_at.go (limited to 'src/os/removeall_at.go') diff --git a/src/os/removeall_at.go b/src/os/removeall_at.go new file mode 100644 index 0000000..8ea5df4 --- /dev/null +++ b/src/os/removeall_at.go @@ -0,0 +1,199 @@ +// Copyright 2018 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +//go:build unix + +package os + +import ( + "internal/syscall/unix" + "io" + "syscall" +) + +func removeAll(path string) error { + if path == "" { + // fail silently to retain compatibility with previous behavior + // of RemoveAll. See issue 28830. + return nil + } + + // The rmdir system call does not permit removing ".", + // so we don't permit it either. + if endsWithDot(path) { + return &PathError{Op: "RemoveAll", Path: path, Err: syscall.EINVAL} + } + + // Simple case: if Remove works, we're done. + err := Remove(path) + if err == nil || IsNotExist(err) { + return nil + } + + // RemoveAll recurses by deleting the path base from + // its parent directory + parentDir, base := splitPath(path) + + parent, err := Open(parentDir) + if IsNotExist(err) { + // If parent does not exist, base cannot exist. Fail silently + return nil + } + if err != nil { + return err + } + defer parent.Close() + + if err := removeAllFrom(parent, base); err != nil { + if pathErr, ok := err.(*PathError); ok { + pathErr.Path = parentDir + string(PathSeparator) + pathErr.Path + err = pathErr + } + return err + } + return nil +} + +func removeAllFrom(parent *File, base string) error { + parentFd := int(parent.Fd()) + // Simple case: if Unlink (aka remove) works, we're done. + err := ignoringEINTR(func() error { + return unix.Unlinkat(parentFd, base, 0) + }) + if err == nil || IsNotExist(err) { + return nil + } + + // EISDIR means that we have a directory, and we need to + // remove its contents. + // EPERM or EACCES means that we don't have write permission on + // the parent directory, but this entry might still be a directory + // whose contents need to be removed. + // Otherwise just return the error. + if err != syscall.EISDIR && err != syscall.EPERM && err != syscall.EACCES { + return &PathError{Op: "unlinkat", Path: base, Err: err} + } + + // Is this a directory we need to recurse into? + var statInfo syscall.Stat_t + statErr := ignoringEINTR(func() error { + return unix.Fstatat(parentFd, base, &statInfo, unix.AT_SYMLINK_NOFOLLOW) + }) + if statErr != nil { + if IsNotExist(statErr) { + return nil + } + return &PathError{Op: "fstatat", Path: base, Err: statErr} + } + if statInfo.Mode&syscall.S_IFMT != syscall.S_IFDIR { + // Not a directory; return the error from the unix.Unlinkat. + return &PathError{Op: "unlinkat", Path: base, Err: err} + } + + // Remove the directory's entries. + var recurseErr error + for { + const reqSize = 1024 + var respSize int + + // Open the directory to recurse into + file, err := openFdAt(parentFd, base) + if err != nil { + if IsNotExist(err) { + return nil + } + recurseErr = &PathError{Op: "openfdat", Path: base, Err: err} + break + } + + for { + numErr := 0 + + names, readErr := file.Readdirnames(reqSize) + // Errors other than EOF should stop us from continuing. + if readErr != nil && readErr != io.EOF { + file.Close() + if IsNotExist(readErr) { + return nil + } + return &PathError{Op: "readdirnames", Path: base, Err: readErr} + } + + respSize = len(names) + for _, name := range names { + err := removeAllFrom(file, name) + if err != nil { + if pathErr, ok := err.(*PathError); ok { + pathErr.Path = base + string(PathSeparator) + pathErr.Path + } + numErr++ + if recurseErr == nil { + recurseErr = err + } + } + } + + // If we can delete any entry, break to start new iteration. + // Otherwise, we discard current names, get next entries and try deleting them. + if numErr != reqSize { + break + } + } + + // Removing files from the directory may have caused + // the OS to reshuffle it. Simply calling Readdirnames + // again may skip some entries. The only reliable way + // to avoid this is to close and re-open the + // directory. See issue 20841. + file.Close() + + // Finish when the end of the directory is reached + if respSize < reqSize { + break + } + } + + // Remove the directory itself. + unlinkError := ignoringEINTR(func() error { + return unix.Unlinkat(parentFd, base, unix.AT_REMOVEDIR) + }) + if unlinkError == nil || IsNotExist(unlinkError) { + return nil + } + + if recurseErr != nil { + return recurseErr + } + return &PathError{Op: "unlinkat", Path: base, Err: unlinkError} +} + +// openFdAt opens path relative to the directory in fd. +// Other than that this should act like openFileNolog. +// This acts like openFileNolog rather than OpenFile because +// we are going to (try to) remove the file. +// The contents of this file are not relevant for test caching. +func openFdAt(dirfd int, name string) (*File, error) { + var r int + for { + var e error + r, e = unix.Openat(dirfd, name, O_RDONLY|syscall.O_CLOEXEC, 0) + if e == nil { + break + } + + // See comment in openFileNolog. + if e == syscall.EINTR { + continue + } + + return nil, e + } + + if !supportsCloseOnExec { + syscall.CloseOnExec(r) + } + + // We use kindNoPoll because we know that this is a directory. + return newFile(r, name, kindNoPoll), nil +} -- cgit v1.2.3