On Thu, May 15 2025, Pasha Tatashin wrote:
> Implements the core logic within luo_files.c to invoke the prepare,
> reboot, finish, and cancel callbacks for preserved file instances,
> replacing the previous stub implementations. It also handles
> the persistence and retrieval of the u64 data payload associated with
> each file via the LUO FDT.
>
> This completes the core mechanism enabling registered filesystem
> handlers to actively manage file state across the live update
> transition using the LUO framework.
>
> Signed-off-by: Pasha Tatashin <pasha.tatashin@xxxxxxxxxx>
> ---
> drivers/misc/liveupdate/luo_files.c | 105 +++++++++++++++++++++++++++-
> 1 file changed, 103 insertions(+), 2 deletions(-)
>
[...]
> @@ -305,7 +369,29 @@ int luo_do_files_prepare_calls(void)
> */
> int luo_do_files_freeze_calls(void)
> {
> - return 0;
> + unsigned long token;
> + struct luo_file *h;
> + int ret;
> +
> + xa_for_each(&luo_files_xa_out, token, h) {
Should we also ensure at this point that there are no open handles to
this file? How else would a file system ensure the file is in quiescent
state to do its final serialization?
This conflicts with my suggestion to have freeze callbacks never fail,
but now that I think of it, this is also important, so maybe we have to
live with freeze that can fail.
> + if (h->fs->freeze) {
> + ret = h->fs->freeze(h->file, h->fs->arg,
> + &h->private_data);
> + if (ret < 0) {
> + pr_err("Freeze callback failed for file token %#0llx handler '%s' [%d]\n",
> + (u64)token, h->fs->compatible, ret);
> + __luo_do_files_cancel_calls(h);
> +
> + return ret;
> + }
> + }
> + }
> +
> + ret = luo_files_commit_data_to_fdt();
> + if (ret)
> + __luo_do_files_cancel_calls(NULL);
> +
> + return ret;
> }
>
> /**
> @@ -316,7 +402,20 @@ int luo_do_files_freeze_calls(void)
> */
> void luo_do_files_finish_calls(void)
> {
> + unsigned long token;
> + struct luo_file *h;
> +
> luo_files_recreate_luo_files_xa_in();
> + xa_for_each(&luo_files_xa_in, token, h) {
> + mutex_lock(&h->mutex);
> + if (h->state == LIVEUPDATE_STATE_UPDATED && h->fs->finish) {
> + h->fs->finish(h->file, h->fs->arg,
> + h->private_data,
> + h->reclaimed);
> + h->state = LIVEUPDATE_STATE_NORMAL;
> + }
> + mutex_unlock(&h->mutex);
> + }
We can also clean up luo_files_xa_in at this point, right?
> }
>
> /**
> @@ -330,6 +429,8 @@ void luo_do_files_finish_calls(void)
> */
> void luo_do_files_cancel_calls(void)
> {
> + __luo_do_files_cancel_calls(NULL);
> + luo_files_commit_data_to_fdt();
> }
>
> /**
--
Regards,
Pratyush Yadav
