Re: [PATCH] vfs: allow FILE_EXTENT_SAME (dedupe_file_range) on a file opened ro

From: Mark Fasheh
Date: Mon Jul 18 2016 - 15:52:26 EST

On Mon, Jul 18, 2016 at 12:13:38AM +0200, Adam Borowski wrote:
> Instead of checking the mode of the file descriptor, let's check whether it
> could have been opened rw. This allows fixing intermittent exec failures
> when deduping a live system: anyone trying to exec a file currently being
> deduped gets ETXTBSY.
> Issuing this ioctl on a ro file was already allowed for root/cap.
> Tested on btrfs and not-yet-merged xfs, as only them implement this ioctl.
> Signed-off-by: Adam Borowski <kilobyte@xxxxxxxxxx>

Reviewed-by: Mark Fasheh <mfasheh@xxxxxxx>

Mark Fasheh