teach shmem_get_link() to work in RCU mode
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/mm/shmem.c b/mm/shmem.c
index 684dbc3..0605716 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -2501,12 +2501,20 @@
{
struct page *page = NULL;
int error;
- if (!dentry)
- return ERR_PTR(-ECHILD);
- error = shmem_getpage(inode, 0, &page, SGP_READ, NULL);
- if (error)
- return ERR_PTR(error);
- unlock_page(page);
+ if (!dentry) {
+ page = find_get_page(inode->i_mapping, 0);
+ if (!page)
+ return ERR_PTR(-ECHILD);
+ if (!PageUptodate(page)) {
+ put_page(page);
+ return ERR_PTR(-ECHILD);
+ }
+ } else {
+ error = shmem_getpage(inode, 0, &page, SGP_READ, NULL);
+ if (error)
+ return ERR_PTR(error);
+ unlock_page(page);
+ }
*cookie = page;
return page_address(page);
}