netfs: Further cleanups after struct netfs_inode wrapper introduced

Change the signature of netfs helper functions to take a struct netfs_inode
pointer rather than a struct inode pointer where appropriate, thereby
relieving the need for the network filesystem to convert its internal inode
format down to the VFS inode only for netfslib to bounce it back up.  For
type safety, it's better not to do that (and it's less typing too).

Give netfs_write_begin() an extra argument to pass in a pointer to the
netfs_inode struct rather than deriving it internally from the file
pointer.  Note that the ->write_begin() and ->write_end() ops are intended
to be replaced in the future by netfslib code that manages this without the
need to call in twice for each page.

netfs_readpage() and similar are intended to be pointed at directly by the
address_space_operations table, so must stick to the signature dictated by
the function pointers there.

Changes
=======
- Updated the kerneldoc comments and documentation [DH].

Signed-off-by: David Howells <dhowells@redhat.com>
cc: linux-cachefs@redhat.com
Link: https://lore.kernel.org/r/CAHk-=wgkwKyNmNdKpQkqZ6DnmUL-x9hp0YBnUGjaPFEAdxDTbw@mail.gmail.com/

3 files changed, 4 insertions, 3 deletions

diff --git a/fs/ceph/addr.c b/fs/ceph/addr.c
index f5f116ed1b9e..9763e7ea8148 100644
--- a/fs/ceph/addr.c
+++ b/fs/ceph/addr.c
@@ -1322,10 +1322,11 @@ static int ceph_write_begin(struct file *file, struct address_space *mapping,
 			    struct page **pagep, void **fsdata)
 {
 	struct inode *inode = file_inode(file);
+	struct ceph_inode_info *ci = ceph_inode(inode);
 	struct folio *folio = NULL;
 	int r;
 
-	r = netfs_write_begin(file, inode->i_mapping, pos, len, &folio, NULL);
+	r = netfs_write_begin(&ci->netfs, file, inode->i_mapping, pos, len, &folio, NULL);
 	if (r == 0)
 		folio_wait_fscache(folio);
 	if (r < 0) {
diff --git a/fs/ceph/cache.h b/fs/ceph/cache.h
index 26c6ae06e2f4..dc502daac49a 100644
--- a/fs/ceph/cache.h
+++ b/fs/ceph/cache.h
@@ -28,7 +28,7 @@ void ceph_fscache_invalidate(struct inode *inode, bool dio_write);
 
 static inline struct fscache_cookie *ceph_fscache_cookie(struct ceph_inode_info *ci)
 {
-	return netfs_i_cookie(&ci->netfs.inode);
+	return netfs_i_cookie(&ci->netfs);
 }
 
 static inline void ceph_fscache_resize(struct inode *inode, loff_t to)
diff --git a/fs/ceph/inode.c b/fs/ceph/inode.c
index 650746b3ba99..56c53ab3618e 100644
--- a/fs/ceph/inode.c
+++ b/fs/ceph/inode.c
@@ -460,7 +460,7 @@ struct inode *ceph_alloc_inode(struct super_block *sb)
 	dout("alloc_inode %p\n", &ci->netfs.inode);
 
 	/* Set parameters for the netfs library */
-	netfs_inode_init(&ci->netfs.inode, &ceph_netfs_ops);
+	netfs_inode_init(&ci->netfs, &ceph_netfs_ops);
 
 	spin_lock_init(&ci->i_ceph_lock);