ext4: convert ext4_mb_init_cache() to take a folio

All callers now have a folio, so convert this function from operating on
a page to operating on a folio.  The folio is assumed to be a single page.
Signe-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Link: https://lore.kernel.org/r/20240416172900.244637-4-willy@infradead.orgSigned-off-by: Theodore Ts'o <tytso@mit.edu>

fs/ext4/mballoc.c

@@ -1274,7 +1274,7 @@ static void mb_regenerate_buddy(struct ext4_buddy *e4b)
  * for this page; do not hold this lock when calling this routine!
  */
 
-static int ext4_mb_init_cache(struct page *page, char *incore, gfp_t gfp)
+static int ext4_mb_init_cache(struct folio *folio, char *incore, gfp_t gfp)
 {
 	ext4_group_t ngroups;
 	unsigned int blocksize;
@@ -1292,13 +1292,13 @@ static int ext4_mb_init_cache(struct page *page, char *incore, gfp_t gfp)
 	char *bitmap;
 	struct ext4_group_info *grinfo;
 
-	inode = page->mapping->host;
+	inode = folio->mapping->host;
 	sb = inode->i_sb;
 	ngroups = ext4_get_groups_count(sb);
 	blocksize = i_blocksize(inode);
 	blocks_per_page = PAGE_SIZE / blocksize;
 
-	mb_debug(sb, "init page %lu\n", page->index);
+	mb_debug(sb, "init folio %lu\n", folio->index);
 
 	groups_per_page = blocks_per_page >> 1;
 	if (groups_per_page == 0)
@@ -1313,9 +1313,9 @@ static int ext4_mb_init_cache(struct page *page, char *incore, gfp_t gfp)
 	} else
 		bh = &bhs;
 
-	first_group = page->index * blocks_per_page / 2;
+	first_group = folio->index * blocks_per_page / 2;
 
-	/* read all groups the page covers into the cache */
+	/* read all groups the folio covers into the cache */
 	for (i = 0, group = first_group; i < groups_per_page; i++, group++) {
 		if (group >= ngroups)
 			break;
@@ -1326,10 +1326,11 @@ static int ext4_mb_init_cache(struct page *page, char *incore, gfp_t gfp)
 		/*
 		 * If page is uptodate then we came here after online resize
 		 * which added some new uninitialized group info structs, so
-		 * we must skip all initialized uptodate buddies on the page,
+		 * we must skip all initialized uptodate buddies on the folio,
 		 * which may be currently in use by an allocating task.
 		 */
-		if (PageUptodate(page) && !EXT4_MB_GRP_NEED_INIT(grinfo)) {
+		if (folio_test_uptodate(folio) &&
+				!EXT4_MB_GRP_NEED_INIT(grinfo)) {
 			bh[i] = NULL;
 			continue;
 		}
@@ -1353,7 +1354,7 @@ static int ext4_mb_init_cache(struct page *page, char *incore, gfp_t gfp)
 			err = err2;
 	}
 
-	first_block = page->index * blocks_per_page;
+	first_block = folio->index * blocks_per_page;
 	for (i = 0; i < blocks_per_page; i++) {
 		group = (first_block + i) >> 1;
 		if (group >= ngroups)
@@ -1374,7 +1375,7 @@ static int ext4_mb_init_cache(struct page *page, char *incore, gfp_t gfp)
 		 * above
 		 *
 		 */
-		data = page_address(page) + (i * blocksize);
+		data = folio_address(folio) + (i * blocksize);
 		bitmap = bh[group - first_group]->b_data;
 
 		/*
@@ -1389,8 +1390,8 @@ static int ext4_mb_init_cache(struct page *page, char *incore, gfp_t gfp)
 		if ((first_block + i) & 1) {
 			/* this is block of buddy */
 			BUG_ON(incore == NULL);
-			mb_debug(sb, "put buddy for group %u in page %lu/%x\n",
-				group, page->index, i * blocksize);
+			mb_debug(sb, "put buddy for group %u in folio %lu/%x\n",
+				group, folio->index, i * blocksize);
 			trace_ext4_mb_buddy_bitmap_load(sb, group);
 			grinfo->bb_fragments = 0;
 			memset(grinfo->bb_counters, 0,
@@ -1408,8 +1409,8 @@ static int ext4_mb_init_cache(struct page *page, char *incore, gfp_t gfp)
 		} else {
 			/* this is block of bitmap */
 			BUG_ON(incore != NULL);
-			mb_debug(sb, "put bitmap for group %u in page %lu/%x\n",
-				group, page->index, i * blocksize);
+			mb_debug(sb, "put bitmap for group %u in folio %lu/%x\n",
+				group, folio->index, i * blocksize);
 			trace_ext4_mb_bitmap_load(sb, group);
 
 			/* see comments in ext4_mb_put_pa() */
@@ -1427,7 +1428,7 @@ static int ext4_mb_init_cache(struct page *page, char *incore, gfp_t gfp)
 			incore = data;
 		}
 	}
-	SetPageUptodate(page);
+	folio_mark_uptodate(folio);
 
 out:
 	if (bh) {
@@ -1539,7 +1540,7 @@ int ext4_mb_init_group(struct super_block *sb, ext4_group_t group, gfp_t gfp)
 	}
 
 	folio = e4b.bd_bitmap_folio;
-	ret = ext4_mb_init_cache(&folio->page, NULL, gfp);
+	ret = ext4_mb_init_cache(folio, NULL, gfp);
 	if (ret)
 		goto err;
 	if (!folio_test_uptodate(folio)) {
@@ -1558,7 +1559,7 @@ int ext4_mb_init_group(struct super_block *sb, ext4_group_t group, gfp_t gfp)
 	}
 	/* init buddy cache */
 	folio = e4b.bd_buddy_folio;
-	ret = ext4_mb_init_cache(&folio->page, e4b.bd_bitmap, gfp);
+	ret = ext4_mb_init_cache(folio, e4b.bd_bitmap, gfp);
 	if (ret)
 		goto err;
 	if (!folio_test_uptodate(folio)) {
@@ -1647,7 +1648,7 @@ ext4_mb_load_buddy_gfp(struct super_block *sb, ext4_group_t group,
 				goto err;
 			}
 			if (!folio_test_uptodate(folio)) {
-				ret = ext4_mb_init_cache(&folio->page, NULL, gfp);
+				ret = ext4_mb_init_cache(folio, NULL, gfp);
 				if (ret) {
 					folio_unlock(folio);
 					goto err;
@@ -1690,7 +1691,7 @@ ext4_mb_load_buddy_gfp(struct super_block *sb, ext4_group_t group,
 				goto err;
 			}
 			if (!folio_test_uptodate(folio)) {
-				ret = ext4_mb_init_cache(&folio->page, e4b->bd_bitmap,
+				ret = ext4_mb_init_cache(folio, e4b->bd_bitmap,
 							 gfp);
 				if (ret) {
 					folio_unlock(folio);