On 05/20/2015 12:22 PM, Daniel Phillips wrote: > On 05/20/2015 07:44 AM, Jan Kara wrote: >> On Tue 19-05-15 13:33:31, David Lang wrote: >> Yeah, that's what I meant. If you create a function which manipulates >> page cache, you better make it work with other functions manipulating page >> cache. Otherwise it's a landmine waiting to be tripped by some unsuspecting >> developer. Sure you can document all the conditions under which the >> function is safe to use but a function that has several paragraphs in front >> of it explaning when it is safe to use isn't very good API... > > Violent agreement, of course. To put it in concrete terms, each of > the page fork support functions must be examined and determined > sane. They are: > > * cow_replace_page_cache > * cow_delete_from_page_cache > * cow_clone_page > * page_cow_one > * page_cow_file > > Would it be useful to drill down into those, starting from the top > of the list? How do these interact with other page cache functions, like find_get_page() ? How does tux3 prevent a user of find_get_page() from reading from or writing into the pre-COW page, instead of the current page? -- All rights reversed -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
