Re: [RFC 08/15] PM / Hibernate: add user module_ops

Rafael J. Wysocki
2010-03-25T22:07:15Z

On Tuesday 23 March 2010, Jiri Slaby wrote:
> Add sws_module_ops into /dev/snapshot user interface, so far only with
> .storage_available. The structure will be shortly filled while converting
> it to ops.
>
> Also, when using this interface, switch to the ops on open/release.

Quite frankly, I don't really understand the purpose of this change in this
particular form. It looks like it may be folded into one of the subsequent
changes just fine.

Rafael

> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
> Cc: Nigel Cunningham <ncunningham@crca.org.au>
> Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
> ---
> kernel/power/user.c | 15 +++++++++++++++
> 1 files changed, 15 insertions(+), 0 deletions(-)
>
> diff --git a/kernel/power/user.c b/kernel/power/user.c
> index 68a99c1..20bf34c 100644
> --- a/kernel/power/user.c
> +++ b/kernel/power/user.c
> @@ -61,10 +61,20 @@ static struct snapshot_data {
> char frozen;
> char ready;
> char platform_support;
> + struct sws_module_ops *prev_ops;
> } snapshot_state;
>
> atomic_t snapshot_device_available = ATOMIC_INIT(1);
>
> +static unsigned long user_storage_available(void)
> +{
> + return ~0UL; /* we have no idea, maybe we will fail later */
> +}
> +
> +struct sws_module_ops user_ops = {
> + .storage_available = user_storage_available,
> +};
> +
> static int snapshot_open(struct inode *inode, struct file *filp)
> {
> struct snapshot_data *data;
> @@ -115,6 +125,10 @@ static int snapshot_open(struct inode *inode, struct file *filp)
> }
> if (error)
> atomic_inc(&snapshot_device_available);
> + else {
> + data->prev_ops = sws_io_ops;
> + sws_io_ops = &user_ops;
> + }
> data->frozen = 0;
> data->ready = 0;
> data->platform_support = 0;
> @@ -139,6 +153,7 @@ static int snapshot_release(struct inode *inode, struct file *filp)
> thaw_processes();
> pm_notifier_call_chain(data->mode == O_WRONLY ?
> PM_POST_HIBERNATION : PM_POST_RESTORE);
> + sws_io_ops = data->prev_ops;
> atomic_inc(&snapshot_device_available);
>
> mutex_unlock(&pm_mutex);
>