From a156fc08b7fd289bfc9979c77445f9e4741a7dfd Mon Sep 17 00:00:00 2001 From: Richard Miller Date: Mon, 19 Feb 2018 12:34:53 +0000 Subject: syscall: ensure Mkdir(path) on Plan 9 fails if path exists On Plan 9, the underlying create() syscall with DMDIR flag, which is used to implement Mkdir, will fail silently if the path exists and is not a directory. Work around this by checking for existence first and rejecting Mkdir with error EEXIST if the path is found. Fixes #23918 Change-Id: I439115662307923c9f498d3e7b1f32c6d205e1ad Reviewed-on: https://go-review.googlesource.com/94777 Reviewed-by: David du Colombier <0intro@gmail.com> --- src/syscall/syscall_plan9.go | 15 +++++++++++++++ 1 file changed, 15 insertions(+) (limited to 'src/syscall') diff --git a/src/syscall/syscall_plan9.go b/src/syscall/syscall_plan9.go index 12b61ee164..7595126faa 100644 --- a/src/syscall/syscall_plan9.go +++ b/src/syscall/syscall_plan9.go @@ -14,6 +14,7 @@ package syscall import "unsafe" const ImplementsGetwd = true +const bitSize16 = 2 // ErrorString implements Error's String method by returning itself. type ErrorString string @@ -164,6 +165,20 @@ func Seek(fd int, offset int64, whence int) (newoffset int64, err error) { } func Mkdir(path string, mode uint32) (err error) { + // If path exists and is not a directory, Create will fail silently. + // Work around this by rejecting Mkdir if path exists. + statbuf := make([]byte, bitSize16) + // Remove any trailing slashes from path, otherwise the Stat will + // fail with ENOTDIR. + n := len(path) + for n > 1 && path[n-1] == '/' { + n-- + } + _, err = Stat(path[0:n], statbuf) + if err == nil { + return EEXIST + } + fd, err := Create(path, O_RDONLY, DMDIR|mode) if fd != -1 { -- cgit v1.3