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/

1 files changed, 5 insertions, 4 deletions

diff --git a/Documentation/filesystems/netfs_library.rst b/Documentation/filesystems/netfs_library.rst
index 3276c3d55142..9332f66373ee 100644
--- a/Documentation/filesystems/netfs_library.rst
+++ b/Documentation/filesystems/netfs_library.rst
@@ -79,7 +79,7 @@ To help deal with the per-inode context, a number helper functions are
 provided.  Firstly, a function to perform basic initialisation on a context and
 set the operations table pointer::
 
-	void netfs_inode_init(struct inode *inode,
+	void netfs_inode_init(struct netfs_inode *ctx,
 			      const struct netfs_request_ops *ops);
 
 then a function to cast from the VFS inode structure to the netfs context::
@@ -89,7 +89,7 @@ then a function to cast from the VFS inode structure to the netfs context::
 and finally, a function to get the cache cookie pointer from the context
 attached to an inode (or NULL if fscache is disabled)::
 
-	struct fscache_cookie *netfs_i_cookie(struct inode *inode);
+	struct fscache_cookie *netfs_i_cookie(struct netfs_inode *ctx);
 
 
 Buffered Read Helpers
@@ -136,8 +136,9 @@ Three read helpers are provided::
 
 	void netfs_readahead(struct readahead_control *ractl);
 	int netfs_read_folio(struct file *file,
-			   struct folio *folio);
-	int netfs_write_begin(struct file *file,
+			     struct folio *folio);
+	int netfs_write_begin(struct netfs_inode *ctx,
+			      struct file *file,
 			      struct address_space *mapping,
 			      loff_t pos,
 			      unsigned int len,