On Fri, Nov 04, 2016 at 05:25:13AM +0100, Jan Kara wrote: > Currently finish_mkwrite_fault() returns 0 when PTE got changed before > we acquired PTE lock and VM_FAULT_WRITE when we succeeded in modifying > the PTE. This is somewhat confusing since 0 generally means success, it > is also inconsistent with finish_fault() which returns 0 on success. > Change finish_mkwrite_fault() to return 0 on success and VM_FAULT_NOPAGE > when PTE changed. Practically, there should be no behavioral difference > since we bail out from the fault the same way regardless whether we > return 0, VM_FAULT_NOPAGE, or VM_FAULT_WRITE. Also note that > VM_FAULT_WRITE has no effect for shared mappings since the only two > places that check it - KSM and GUP - care about private mappings only. > Generally the meaning of VM_FAULT_WRITE for shared mappings is not well > defined and we should probably clean that up. > > Signed-off-by: Jan Kara <jack@xxxxxxx> Sounds right. Acked-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx> -- Kirill A. Shutemov -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>