Messages in this thread | | | From | Miklos Szeredi <> | Date | Mon, 18 Jul 2022 14:21:16 +0200 | Subject | Re: [PATCH] ovl: Handle ENOSYS when fileattr support is missing in lower/upper fs |
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On Mon, 18 Jul 2022 at 12:56, Christian Kohlschütter <christian@kohlschutter.com> wrote:
> However, users of fuse that have no business with overlayfs suddenly see their ioctl return ENOTTY instead of ENOSYS.
And returning ENOTTY is the correct behavior. See this comment in <asm-generic/errrno.h>:
/* * This error code is special: arch syscall entry code will return * -ENOSYS if users try to call a syscall that doesn't exist. To keep * failures of syscalls that really do exist distinguishable from * failures due to attempts to use a nonexistent syscall, syscall * implementations should refrain from returning -ENOSYS. */ #define ENOSYS 38 /* Invalid system call number */
Thanks, Miklos
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