On Wed, Nov 13, 2019 at 07:29:59PM -0000, Christos Zoulas wrote: > Yes, but open(O_EXCL) does not protect you against mmapped segments > (which has the potential to kill running processes that use shared > libraries/jar/other mapped files) or crashing in the middle of > writing a file and leaving stuff 1/2 written. For me safety trumps > speed (after all we don't mount our filesystems async :-), so I > would prefer that the default is slow and safe as opposed to fast > and unsafe, like the old pax/tar did:
O_EXCL|O_CREAT does not allow overwriting mmapped text segments. Always writing new files and renaming doesn't make live updates safe either. E.g. consider the case of a new symbol being updates to a shared library. Joerg
