userfaultfd: convert mcontinue_atomic_pte() to use a folio

shmem_getpage() is being replaced by shmem_get_folio() so use a folio
throughout this function.  Saves several calls to compound_head().

Link: https://lkml.kernel.org/r/20220902194653.1739778-33-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/mm/userfaultfd.c b/mm/userfaultfd.c
index 7327b25..9c035be 100644 (file)
--- a/mm/userfaultfd.c
+++ b/mm/userfaultfd.c
@@ -243,20 +243,22 @@ static int mcontinue_atomic_pte(struct mm_struct *dst_mm,
 {
        struct inode *inode = file_inode(dst_vma->vm_file);
        pgoff_t pgoff = linear_page_index(dst_vma, dst_addr);
+       struct folio *folio;
        struct page *page;
        int ret;
 
-       ret = shmem_getpage(inode, pgoff, &page, SGP_NOALLOC);
-       /* Our caller expects us to return -EFAULT if we failed to find page. */
+       ret = shmem_get_folio(inode, pgoff, &folio, SGP_NOALLOC);
+       /* Our caller expects us to return -EFAULT if we failed to find folio */
        if (ret == -ENOENT)
                ret = -EFAULT;
        if (ret)
                goto out;
-       if (!page) {
+       if (!folio) {
                ret = -EFAULT;
                goto out;
        }
 
+       page = folio_file_page(folio, pgoff);
        if (PageHWPoison(page)) {
                ret = -EIO;
                goto out_release;
@@ -267,13 +269,13 @@ static int mcontinue_atomic_pte(struct mm_struct *dst_mm,
        if (ret)
                goto out_release;
 
-       unlock_page(page);
+       folio_unlock(folio);
        ret = 0;
 out:
        return ret;
 out_release:
-       unlock_page(page);
-       put_page(page);
+       folio_unlock(folio);
+       folio_put(folio);
        goto out;
 }