mm/gup: add FOLL_UNLOCKABLE

Setting FOLL_UNLOCKABLE allows GUP to lock/unlock the mmap lock on its
own.  It is a more explicit replacement for locked != NULL.  This clears
the way for passing in locked = 1, without intending that the lock can be
unlocked.

Set the flag in all cases where it is used, eg locked is present in the
external interface or locked is used internally with locked = 0.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Jason Gunthorpe <[email protected]>
Acked-by: Mike Rapoport (IBM) <[email protected]>
Reviewed-by: John Hubbard <[email protected]>
Cc: Alistair Popple <[email protected]>
Cc: Christoph Hellwig <[email protected]>
Cc: Claudio Imbrenda <[email protected]>
Cc: David Hildenbrand <[email protected]>
Cc: David Howells <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

0 files changed, 0 insertions, 0 deletions