Switch /dev/snapshot reader to sws_module_ops approach so that we
can transparently rewrite the rest of the snapshot from pages pulling
to their pushing through layers.
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 | 73 +++++++++++++++++++++++++++++++++++++++++++++-----
1 files changed, 65 insertions(+), 8 deletions(-)
diff --git a/kernel/power/user.c b/kernel/power/user.c
index 748567d..1b5d2e1 100644
--- a/kernel/power/user.c
+++ b/kernel/power/user.c
@@ -76,6 +76,7 @@ static DECLARE_BITMAP(to_do_flags, 10);
#define TODO_FINISH 2
#define TODO_CLOSED 3
#define TODO_ERROR 4
+#define TODO_RD_RUNNING 5
static unsigned long user_storage_available(void)
{
@@ -123,12 +124,41 @@ static int put_user_writer(unsigned int flags, int error)
return error;
}
+static int get_user_reader(unsigned int *flags_p)
+{
+ return 0;
+}
+
+static int user_read_page(void *addr, struct bio **bio_chain)
+{
+ int err = 0;
+
+ to_do_buf = addr;
+ wmb();
+ set_bit(TODO_WORK, to_do_flags);
+ wake_up_interruptible(&to_do_wait);
+
+ wait_event(to_do_done, !test_bit(TODO_WORK, to_do_flags) ||
+ (err = test_bit(TODO_CLOSED, to_do_flags)));
+
+ return err ? -EIO : 0;
+}
+
+static int put_user_reader(void)
+{
+ return 0;
+}
+
struct sws_module_ops user_ops = {
.storage_available = user_storage_available,
.get_writer = get_user_writer,
.put_writer = put_user_writer,
.write_page = user_write_page,
+
+ .get_reader = get_user_reader,
+ .put_reader = put_user_reader,
+ .read_page = user_read_page,
};
static void snapshot_writer(struct work_struct *work)
@@ -142,6 +172,22 @@ static void snapshot_writer(struct work_struct *work)
static DECLARE_WORK(snapshot_writer_w, snapshot_writer);
+static void snapshot_reader(struct work_struct *work)
+{
+ int ret;
+
+ set_bit(TODO_RD_RUNNING, to_do_flags);
+ ret = swsusp_read(NULL);
+ if (ret) ...
