[PATCH 7.2 v3 03/12] mm/huge_memory: remove READ_ONLY_THP_FOR_FS from file_thp_enabled()

[Zi Yan]

Replace it with a check on the max folio order of the file's address space
mapping, making sure PMD THP is supported. Also remove the read-only fd
check, since collapse_file() now makes sure all to-be-collapsed folios are
clean and the created PMD file THP can be handled by FSes properly.

Signed-off-by: Zi Yan <ziy@xxxxxxxxxx>
---
 mm/huge_memory.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 970e077019b7..7e9cf8c0985f 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -86,9 +86,6 @@ static inline bool file_thp_enabled(struct vm_area_struct *vma)
 {
 	struct inode *inode;
 
-	if (!IS_ENABLED(CONFIG_READ_ONLY_THP_FOR_FS))
-		return false;
-
 	if (!vma->vm_file)
 		return false;
 
@@ -97,7 +94,10 @@ static inline bool file_thp_enabled(struct vm_area_struct *vma)
 	if (IS_ANON_FILE(inode))
 		return false;
 
-	return !inode_is_open_for_write(inode) && S_ISREG(inode->i_mode);
+	if (!mapping_pmd_thp_support(inode->i_mapping))
+		return false;
+
+	return S_ISREG(inode->i_mode);
 }
 
 /* If returns true, we are unable to access the VMA's folios. */
-- 
2.43.0