Use a folio internally to shmem_write_end() which saves a number of
calls to compound_head() and lets us get rid of the custom code to
zero out the rest of a THP and supports folios of arbitrary size.
Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
---
mm/shmem.c | 30 ++++++++++--------------------
1 file changed, 10 insertions(+), 20 deletions(-)
diff --git a/mm/shmem.c b/mm/shmem.c
index bc5c156ef470..c5048c6c83dd 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -2578,33 +2578,23 @@ shmem_write_end(struct file *file, struct address_space *mapping,
loff_t pos, unsigned len, unsigned copied,
struct page *page, void *fsdata)
{
+ struct folio *folio = page_folio(page);
struct inode *inode = mapping->host;
if (pos + copied > inode->i_size)
i_size_write(inode, pos + copied);
- if (!PageUptodate(page)) {
- struct page *head = compound_head(page);
- if (PageTransCompound(page)) {
- int i;
-
- for (i = 0; i < HPAGE_PMD_NR; i++) {
- if (head + i == page)
- continue;
- clear_highpage(head + i);
- flush_dcache_page(head + i);
- }
- }
- if (copied < PAGE_SIZE) {
- unsigned from = pos & (PAGE_SIZE - 1);
- zero_user_segments(page, 0, from,
- from + copied, PAGE_SIZE);
+ if (!folio_test_uptodate(folio)) {
+ if (copied < folio_size(folio)) {
+ size_t from = offset_in_folio(folio, pos);
+ folio_zero_segments(folio, 0, from,
+ from + copied, folio_size(folio));
}
- SetPageUptodate(head);
+ folio_mark_uptodate(folio);
}
- set_page_dirty(page);
- unlock_page(page);
- put_page(page);
+ folio_mark_dirty(folio);
+ folio_unlock(folio);
+ folio_put(folio);
return copied;
}
--
2.35.1
