On 7/5/23 1:13 PM, Matthew Wilcox wrote:
On Wed, Jul 05, 2023 at 12:43:34PM -0700, Sidhartha Kumar wrote:/* * Check if the backing address space wants to know that the page is * about to become writable */ if (vma->vm_ops->page_mkwrite) { - unlock_page(vmf->page); + folio_unlock(folio); tmp = do_page_mkwrite(vmf); if (unlikely(!tmp || (tmp & (VM_FAULT_ERROR | VM_FAULT_NOPAGE)))) { - put_page(vmf->page); + folio_put(folio);This is _probably_ OK. However, do_page_mkwrite() calls vm_ops->page_mkwrite(), and I think it's theoretically possible for the driver to replace vmf->page with a different one. The chance of them actually doing that is pretty low (particularly if they return error or nopage!), but I'm going to flag it just in case it comes up. Also, should we pass a folio to do_page_mkwrite() instead of having it extract the folio from vmf->page?
I can take a look at doing this in a follow-up patch.
Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Did you mean for this to be reviewed-by? Thanks, Sidhartha Kumar
