[PATCH 3/8] cachefiles: Fix missing pos updates in cachefiles_ondemand_fd_write_iter()

[David Howells]

Zizhi Wo <wozizhi at huawei.com> wrote:

> In the erofs on-demand loading scenario, read and write operations are
> usually delivered through "off" and "len" contained in read req in user
> mode. Naturally, pwrite is used to specify a specific offset to complete
> write operations.
> 
> However, if the write(not pwrite) syscall is called multiple times in the
> read-ahead scenario, we need to manually update ki_pos after each write
> operation to update file->f_pos.
> 
> This step is currently missing from the cachefiles_ondemand_fd_write_iter
> function, added to address this issue.
> 
> Fixes: c8383054506c ("cachefiles: notify the user daemon when looking up cookie")
> Signed-off-by: Zizhi Wo <wozizhi at huawei.com>

Acked-by: David Howells <dhowells at redhat.com>