Paul Eggert wrote: > Yes please. If chmod also does not work coreutils might need more > workarounds. > > Just to be clear; please try it on a file where chmod should fail > because you don't own the file and you're not root. chmod should fail > with EPERM in this case; it it fails with EACCES it's buggy. Thanks.
chmod fails with EACCES, hence per POSIX <https://pubs.opengroup.org/onlinepubs/9699919799/functions/chmod.html> it's buggy. See: On the server I have 2 files and 2 directories: # ls -ld dir1 dir1/file1 dir2 dir2/file2 drwxrwxr-x 2 bruno everyone 4096 Sep 2 12:58 dir1/ -rw-rw-r-- 1 bruno everyone 4 Sep 2 00:52 dir1/file1 drwxrwxrwx 2 admin administ 4096 Sep 2 00:54 dir2/ -rw-rw-r-- 1 admin administ 4 Sep 2 00:54 dir2/file2 The user that exports the mount point is 'bruno'. But since dir2 and dir2/file2 are not owned by 'bruno', an error will (and should) occur when these two are manipulated through the CIFS client. chown fails; that's the problem you already committed a workaround for: $ ./fchownat-test /media/nas/bruno/dir1/file1 lchown: Permission denied fchownat: Permission denied chown: Permission denied fchown: Permission denied $ ./fchownat-test /media/nas/bruno/dir1 lchown: Permission denied fchownat: Permission denied chown: Permission denied fchown: Permission denied $ ./fchownat-test /media/nas/bruno/dir2/file2 lchown: Permission denied fchownat: Permission denied chown: Permission denied fchown: Permission denied $ ./fchownat-test /media/nas/bruno/dir2 lchown: Permission denied fchownat: Permission denied chown: Permission denied fchown: Permission denied chmod also fails with EACCES instead of EPERM: $ ./fchmodat-test /media/nas/bruno/dir1/file1 $ ./fchmodat-test /media/nas/bruno/dir1 $ ./fchmodat-test /media/nas/bruno/dir2/file2 lchmod: Permission denied fchmodat: Permission denied chmod: Permission denied fchmod: Permission denied $ ./fchmodat-test /media/nas/bruno/dir2 lchmod: Permission denied fchmodat: Permission denied chmod: Permission denied fchmod: Permission denied The same thing with strace: $ strace ./fchmodat-test /media/nas/bruno/dir2/file2 ... newfstatat(AT_FDCWD, "/media/nas/bruno/dir2/file2", {st_mode=S_IFREG|0664, st_size=4, ...}, AT_SYMLINK_NOFOLLOW) = 0 openat(AT_FDCWD, "/media/nas/bruno/dir2/file2", O_RDONLY|O_NOFOLLOW|O_CLOEXEC|O_PATH) = 3 newfstatat(3, "", {st_mode=S_IFREG|0664, st_size=4, ...}, AT_EMPTY_PATH) = 0 chmod("/proc/self/fd/3", 0664) = -1 EACCES (Permission denied) close(3) = 0 dup(2) = 3 fcntl(3, F_GETFL) = 0x402 (flags O_RDWR|O_APPEND) getrandom("\x68\x8f\xbd\x08\xf8\x4b\xa9\xa5", 8, GRND_NONBLOCK) = 8 brk(NULL) = 0x5563c5d01000 brk(0x5563c5d22000) = 0x5563c5d22000 newfstatat(3, "", {st_mode=S_IFCHR|0600, st_rdev=makedev(0x88, 0x5), ...}, AT_EMPTY_PATH) = 0 write(3, "lchmod: Permission denied\n", 26lchmod: Permission denied ) = 26 close(3) = 0 openat(AT_FDCWD, "/media/nas/bruno/dir2/file2", O_RDONLY|O_NOFOLLOW|O_CLOEXEC|O_PATH) = 3 newfstatat(3, "", {st_mode=S_IFREG|0664, st_size=4, ...}, AT_EMPTY_PATH) = 0 chmod("/proc/self/fd/3", 0664) = -1 EACCES (Permission denied) close(3) = 0 dup(2) = 3 fcntl(3, F_GETFL) = 0x402 (flags O_RDWR|O_APPEND) newfstatat(3, "", {st_mode=S_IFCHR|0600, st_rdev=makedev(0x88, 0x5), ...}, AT_EMPTY_PATH) = 0 write(3, "fchmodat: Permission denied\n", 28fchmodat: Permission denied ) = 28 close(3) = 0 chmod("/media/nas/bruno/dir2/file2", 0664) = -1 EACCES (Permission denied) dup(2) = 3 fcntl(3, F_GETFL) = 0x402 (flags O_RDWR|O_APPEND) newfstatat(3, "", {st_mode=S_IFCHR|0600, st_rdev=makedev(0x88, 0x5), ...}, AT_EMPTY_PATH) = 0 write(3, "chmod: Permission denied\n", 25chmod: Permission denied ) = 25 close(3) = 0 openat(AT_FDCWD, "/media/nas/bruno/dir2/file2", O_RDONLY|O_NOFOLLOW) = 3 fchmod(3, 0664) = -1 EACCES (Permission denied) dup(2) = 4 fcntl(4, F_GETFL) = 0x402 (flags O_RDWR|O_APPEND) newfstatat(4, "", {st_mode=S_IFCHR|0600, st_rdev=makedev(0x88, 0x5), ...}, AT_EMPTY_PATH) = 0 write(4, "fchmod: Permission denied\n", 26fchmod: Permission denied ) = 26 close(4) = 0 exit_group(1) = ? +++ exited with 1 +++ $ strace ./fchmodat-test /media/nas/bruno/dir2 ... newfstatat(AT_FDCWD, "/media/nas/bruno/dir2", {st_mode=S_IFDIR|0777, st_size=0, ...}, AT_SYMLINK_NOFOLLOW) = 0 openat(AT_FDCWD, "/media/nas/bruno/dir2", O_RDONLY|O_NOFOLLOW|O_CLOEXEC|O_PATH) = 3 newfstatat(3, "", {st_mode=S_IFDIR|0777, st_size=0, ...}, AT_EMPTY_PATH) = 0 chmod("/proc/self/fd/3", 0777) = -1 EACCES (Permission denied) close(3) = 0 dup(2) = 3 fcntl(3, F_GETFL) = 0x402 (flags O_RDWR|O_APPEND) getrandom("\xf3\x8f\xf7\xff\xb4\x91\xcf\xcf", 8, GRND_NONBLOCK) = 8 brk(NULL) = 0x55b7056a1000 brk(0x55b7056c2000) = 0x55b7056c2000 newfstatat(3, "", {st_mode=S_IFCHR|0600, st_rdev=makedev(0x88, 0x5), ...}, AT_EMPTY_PATH) = 0 write(3, "lchmod: Permission denied\n", 26lchmod: Permission denied ) = 26 close(3) = 0 openat(AT_FDCWD, "/media/nas/bruno/dir2", O_RDONLY|O_NOFOLLOW|O_CLOEXEC|O_PATH) = 3 newfstatat(3, "", {st_mode=S_IFDIR|0777, st_size=0, ...}, AT_EMPTY_PATH) = 0 chmod("/proc/self/fd/3", 0777) = -1 EACCES (Permission denied) close(3) = 0 dup(2) = 3 fcntl(3, F_GETFL) = 0x402 (flags O_RDWR|O_APPEND) newfstatat(3, "", {st_mode=S_IFCHR|0600, st_rdev=makedev(0x88, 0x5), ...}, AT_EMPTY_PATH) = 0 write(3, "fchmodat: Permission denied\n", 28fchmodat: Permission denied ) = 28 close(3) = 0 chmod("/media/nas/bruno/dir2", 0777) = -1 EACCES (Permission denied) dup(2) = 3 fcntl(3, F_GETFL) = 0x402 (flags O_RDWR|O_APPEND) newfstatat(3, "", {st_mode=S_IFCHR|0600, st_rdev=makedev(0x88, 0x5), ...}, AT_EMPTY_PATH) = 0 write(3, "chmod: Permission denied\n", 25chmod: Permission denied ) = 25 close(3) = 0 openat(AT_FDCWD, "/media/nas/bruno/dir2", O_RDONLY|O_NOFOLLOW) = 3 fchmod(3, 0777) = -1 EACCES (Permission denied) dup(2) = 4 fcntl(4, F_GETFL) = 0x402 (flags O_RDWR|O_APPEND) newfstatat(4, "", {st_mode=S_IFCHR|0600, st_rdev=makedev(0x88, 0x5), ...}, AT_EMPTY_PATH) = 0 write(4, "fchmod: Permission denied\n", 26fchmod: Permission denied ) = 26 close(4) = 0 exit_group(1) = ? +++ exited with 1 +++ Bruno
