btrfs: prepare btrfs_page_mkwrite() for large data folios

The function btrfs_page_mkwrite() has an explicit ASSERT() checking the
folio order.

To make it support large data folios, we need to:

- Remove the ASSERT(folio_order(folio) == 0)

- Use folio_contains() to check if the folio covers the last page

Otherwise the code is already supporting large folios well.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

1 files changed, 1 insertions, 3 deletions

diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index cbe98e825162..d024f31731dc 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -1855,8 +1855,6 @@ static vm_fault_t btrfs_page_mkwrite(struct vm_fault *vmf)
 	u64 page_end;
 	u64 end;
 
-	ASSERT(folio_order(folio) == 0);
-
 	reserved_space = fsize;
 
 	sb_start_pagefault(inode->i_sb);
@@ -1921,7 +1919,7 @@ again:
 		goto again;
 	}
 
-	if (folio->index == ((size - 1) >> PAGE_SHIFT)) {
+	if (folio_contains(folio, (size - 1) >> PAGE_SHIFT)) {
 		reserved_space = round_up(size - page_start, fs_info->sectorsize);
 		if (reserved_space < fsize) {
 			end = page_start + reserved_space - 1;