[2/6] btrfs: add a @fsize parameter to btrfs_alloc_subpage()

Commit Message

Qu Wenruo March 10, 2025, 7:35 a.m. UTC

Since we can no longer assume page sized folio for data filemap folios,
allow btrfs_alloc_subpage() to accept a new parameter, @fsize,
indicating the folio size.

This doesn't follow the regular behavior of passing a folio directly,
because this function is shared by both data and metadata folios, and
for metadata folios we have extra allocation policy to ensure no larger
folios whose sizes are larger than nodesize (unless it's page sized).

Signed-off-by: Qu Wenruo <[e-mail]>
---
 fs/btrfs/extent_io.c | 2 +-
 fs/btrfs/subpage.c   | 8 ++++----
 fs/btrfs/subpage.h   | 2 +-
 3 files changed, 6 insertions(+), 6 deletions(-)

Patch

diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index d2a7472f28b6..337d2bed98d9 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -3257,7 +3257,7 @@  struct extent_buffer *alloc_extent_buffer(struct btrfs_fs_info *fs_info,
 	 * manually if we exit earlier.
 	 */
 	if (btrfs_meta_is_subpage(fs_info)) {
-		prealloc = btrfs_alloc_subpage(fs_info, BTRFS_SUBPAGE_METADATA);
+		prealloc = btrfs_alloc_subpage(fs_info, PAGE_SIZE, BTRFS_SUBPAGE_METADATA);
 		if (IS_ERR(prealloc)) {
 			ret = PTR_ERR(prealloc);
 			goto out;
diff --git a/fs/btrfs/subpage.c b/fs/btrfs/subpage.c
index 1392b4eaa1f9..6e776c3bd873 100644
--- a/fs/btrfs/subpage.c
+++ b/fs/btrfs/subpage.c
@@ -86,7 +86,7 @@  int btrfs_attach_subpage(const struct btrfs_fs_info *fs_info,
 	if (type == BTRFS_SUBPAGE_DATA && !btrfs_is_subpage(fs_info, folio))
 		return 0;
 
-	subpage = btrfs_alloc_subpage(fs_info, type);
+	subpage = btrfs_alloc_subpage(fs_info, folio_size(folio), type);
 	if (IS_ERR(subpage))
 		return  PTR_ERR(subpage);
 
@@ -113,16 +113,16 @@  void btrfs_detach_subpage(const struct btrfs_fs_info *fs_info, struct folio *fol
 }
 
 struct btrfs_subpage *btrfs_alloc_subpage(const struct btrfs_fs_info *fs_info,
-					  enum btrfs_subpage_type type)
+				size_t fsize, enum btrfs_subpage_type type)
 {
 	struct btrfs_subpage *ret;
 	unsigned int real_size;
 
-	ASSERT(fs_info->sectorsize < PAGE_SIZE);
+	ASSERT(fs_info->sectorsize < fsize);
 
 	real_size = struct_size(ret, bitmaps,
 			BITS_TO_LONGS(btrfs_bitmap_nr_max *
-				      (PAGE_SIZE >> fs_info->sectorsize_bits)));
+				      (fsize >> fs_info->sectorsize_bits)));
 	ret = kzalloc(real_size, GFP_NOFS);
 	if (!ret)
 		return ERR_PTR(-ENOMEM);
diff --git a/fs/btrfs/subpage.h b/fs/btrfs/subpage.h
index baa23258e7fa..083390e76d13 100644
--- a/fs/btrfs/subpage.h
+++ b/fs/btrfs/subpage.h
@@ -112,7 +112,7 @@  void btrfs_detach_subpage(const struct btrfs_fs_info *fs_info, struct folio *fol
 
 /* Allocate additional data where page represents more than one sector */
 struct btrfs_subpage *btrfs_alloc_subpage(const struct btrfs_fs_info *fs_info,
-					  enum btrfs_subpage_type type);
+				size_t fsize, enum btrfs_subpage_type type);
 void btrfs_free_subpage(struct btrfs_subpage *subpage);
 
 void btrfs_folio_inc_eb_refs(const struct btrfs_fs_info *fs_info, struct folio *folio);