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

Jiri Slaby
2010-03-23T16:17:36Z

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.

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);
--
1.7.0.2