Merge tag 'folio-5.17' of git://git.infradead.org/users/willy/pagecache

Pull folio conversion updates from Matthew Wilcox:
 "Convert much of the page cache to use folios

  This stops just short of actually enabling large folios. It converts
  everything that I noticed needs to be converted, but there may still
  be places I've overlooked which still have page size assumptions.

  The big change here is using large entries in the page cache XArray
  instead of many small entries. That only affects shmem for now, but
  it's a pretty big change for shmem since it changes where memory needs
  to be allocated (at split time instead of insertion)"

* tag 'folio-5.17' of git://git.infradead.org/users/willy/pagecache: (49 commits)
  mm: Use multi-index entries in the page cache
  XArray: Add xas_advance()
  truncate,shmem: Handle truncates that split large folios
  truncate: Convert invalidate_inode_pages2_range to folios
  fs: Convert vfs_dedupe_file_range_compare to folios
  mm: Remove pagevec_remove_exceptionals()
  mm: Convert find_lock_entries() to use a folio_batch
  filemap: Return only folios from find_get_entries()
  filemap: Convert filemap_get_read_batch() to use a folio_batch
  filemap: Convert filemap_read() to use a folio
  truncate: Add invalidate_complete_folio2()
  truncate: Convert invalidate_inode_pages2_range() to use a folio
  truncate: Skip known-truncated indices
  truncate,shmem: Add truncate_inode_folio()
  shmem: Convert part of shmem_undo_range() to use a folio
  mm: Add unmap_mapping_folio()
  truncate: Add truncate_cleanup_folio()
  filemap: Add filemap_release_folio()
  filemap: Use a folio in filemap_page_mkwrite
  filemap: Use a folio in filemap_map_pages
  ...

2 files changed, 17 insertions, 19 deletions

diff --git a/lib/iov_iter.c b/lib/iov_iter.c
index 66a740e6e153..b0e0acdf96c1 100644
--- a/lib/iov_iter.c
+++ b/lib/iov_iter.c
@@ -69,42 +69,40 @@
 #define iterate_xarray(i, n, base, len, __off, STEP) {		\
 	__label__ __out;					\
 	size_t __off = 0;					\
-	struct page *head = NULL;				\
+	struct folio *folio;					\
 	loff_t start = i->xarray_start + i->iov_offset;		\
-	unsigned offset = start % PAGE_SIZE;			\
 	pgoff_t index = start / PAGE_SIZE;			\
-	int j;							\
-								\
 	XA_STATE(xas, i->xarray, index);			\
 								\
+	len = PAGE_SIZE - offset_in_page(start);		\
 	rcu_read_lock();					\
-	xas_for_each(&xas, head, ULONG_MAX) {			\
+	xas_for_each(&xas, folio, ULONG_MAX) {			\
 		unsigned left;					\
-		if (xas_retry(&xas, head))			\
+		size_t offset;					\
+		if (xas_retry(&xas, folio))			\
 			continue;				\
-		if (WARN_ON(xa_is_value(head)))			\
+		if (WARN_ON(xa_is_value(folio)))		\
 			break;					\
-		if (WARN_ON(PageHuge(head)))			\
+		if (WARN_ON(folio_test_hugetlb(folio)))		\
 			break;					\
-		for (j = (head->index < index) ? index - head->index : 0; \
-		     j < thp_nr_pages(head); j++) {		\
-			void *kaddr = kmap_local_page(head + j);	\
-			base = kaddr + offset;			\
-			len = PAGE_SIZE - offset;		\
+		offset = offset_in_folio(folio, start + __off);	\
+		while (offset < folio_size(folio)) {		\
+			base = kmap_local_folio(folio, offset);	\
 			len = min(n, len);			\
 			left = (STEP);				\
-			kunmap_local(kaddr);			\
+			kunmap_local(base);			\
 			len -= left;				\
 			__off += len;				\
 			n -= len;				\
 			if (left || n == 0)			\
 				goto __out;			\
-			offset = 0;				\
+			offset += len;				\
+			len = PAGE_SIZE;			\
 		}						\
 	}							\
 __out:								\
 	rcu_read_unlock();					\
-	i->iov_offset += __off;						\
+	i->iov_offset += __off;					\
 	n = __off;						\
 }
 
diff --git a/lib/xarray.c b/lib/xarray.c
index f5d8f54907b4..6f47f6375808 100644
--- a/lib/xarray.c
+++ b/lib/xarray.c
@@ -157,7 +157,7 @@ static void xas_move_index(struct xa_state *xas, unsigned long offset)
 	xas->xa_index += offset << shift;
 }
 
-static void xas_advance(struct xa_state *xas)
+static void xas_next_offset(struct xa_state *xas)
 {
 	xas->xa_offset++;
 	xas_move_index(xas, xas->xa_offset);
@@ -1250,7 +1250,7 @@ void *xas_find(struct xa_state *xas, unsigned long max)
 		xas->xa_offset = ((xas->xa_index - 1) & XA_CHUNK_MASK) + 1;
 	}
 
-	xas_advance(xas);
+	xas_next_offset(xas);
 
 	while (xas->xa_node && (xas->xa_index <= max)) {
 		if (unlikely(xas->xa_offset == XA_CHUNK_SIZE)) {
@@ -1268,7 +1268,7 @@ void *xas_find(struct xa_state *xas, unsigned long max)
 		if (entry && !xa_is_sibling(entry))
 			return entry;
 
-		xas_advance(xas);
+		xas_next_offset(xas);
 	}
 
 	if (!xas->xa_node)