Re: [PATCH v2 6/6] smb/client: fix stale page cache in insert/collapse range

> @@ -4107,11 +4117,20 @@ static long smb3_insert_range(struct file *file, struct cifs_tcon *tcon,
>                 goto out;
>
>         filemap_invalidate_lock(inode->i_mapping);
> -       rc = filemap_write_and_wait_range(inode->i_mapping, off, new_eof - 1);
> +       rc = filemap_write_and_wait_range(inode->i_mapping,
> +                                         round_down(off, PAGE_SIZE),
> +                                         old_eof - 1);
>         if (rc < 0)
>                 goto out_2;
> -       truncate_pagecache_range(inode, off, old_eof);
>         netfs_wait_for_outstanding_io(inode);
> +       /*
> +        * Invalidate cached folios from the page containing off to EOF before
> +        * moving data on the server, so subsequent reads do not see stale data.
> +        */
> +       rc = invalidate_inode_pages2_range(inode->i_mapping,
> +                                          off >> PAGE_SHIFT, -1);
> +       if (rc < 0)
> +               goto out_2;
Could we also invalidate the fscache ? If yes, we need to check
collapse range, zero range and punch hole as well.