[PATCH 56/67] afs: Make afs_write_begin() return the THP subpage

David Howells
2021-10-18T15:06:28Z

generic_perform_write() can't handle a THP, so we have to return the
subpage of that THP from afs_write_begin() and then convert it back into
the head on entry to afs_write_end().

Signed-off-by: David Howells <dhowells@redhat.com>
---

fs/afs/write.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/fs/afs/write.c b/fs/afs/write.c
index 281f0e93e2c6..5cd417e95029 100644
--- a/fs/afs/write.c
+++ b/fs/afs/write.c
@@ -90,7 +90,7 @@ int afs_write_begin(struct file *file, struct address_space *mapping,
goto flush_conflicting_write;
}

- *_page = page;
+ *_page = find_subpage(page, pos / PAGE_SIZE);
_leave(" = 0");
return 0;

@@ -120,9 +120,10 @@ int afs_write_begin(struct file *file, struct address_space *mapping,
*/
int afs_write_end(struct file *file, struct address_space *mapping,
loff_t pos, unsigned len, unsigned copied,
- struct page *page, void *fsdata)
+ struct page *subpage, void *fsdata)
{
struct afs_vnode *vnode = AFS_FS_I(file_inode(file));
+ struct page *page = thp_head(subpage);
unsigned long priv;
unsigned int f, from = offset_in_thp(page, pos);
unsigned int t, to = from + copied;