Re: [PATCH 5/4] 9p: pass the correct prototype to read_cache_page

From: Christoph Hellwig
Date: Thu May 02 2019 - 09:04:45 EST

On Thu, May 02, 2019 at 12:08:29AM -0600, William Kucharski wrote:
> 1) You need to pass "filp" rather than "filp->private_data" to read_cache_pages()
> in v9fs_fid_readpage().

With this patch v9fs_fid_readpage takes a void pointer that must be
a FID, and we pass the FID everywhere:

- v9fs_vfs_readpage passes filp->private_data
- v9fs_vfs_readpages passes filp->private_data through
- v9fs_write_begin passes the local fid variable

> The patched code passes "filp->private_data" as the "data" parameter to
> read_cache_pages(), which would generate a call to:
> filler(data, page)
> which would become a call to:
> static int v9fs_vfs_readpage(struct file *filp, struct page *page)
> {
> return v9fs_fid_readpage(filp->private_data, page);
> }

Except that we don't pass v9fs_vfs_readpage as the filler any more,
we now pass v9fs_fid_readpage.