Some targets may perform io of their own volition, eg. a mirror
performing recovery, a cache target pulling in different chunks. We
cannot let them perform this io while the device is suspended. This
patch adds 2 new methods to the target type, which instruct the target
to suspend/resume itself. All targets start in the suspended state,
so should expect an initial resume call. Simple targets do not need
to implement these functions.
--- diff/drivers/md/dm-table.c 2003-06-09 15:05:02.000000000 +0100
+++ source/drivers/md/dm-table.c 2003-06-09 15:05:08.000000000 +0100
@@ -776,6 +776,31 @@
add_wait_queue(&t->eventq, wq);
}
+void dm_table_suspend_targets(struct dm_table *t)
+{
+ int i;
+
+ for (i = 0; i < t->num_targets; i++) {
+ struct dm_target *ti = t->targets + i;
+
+ if (ti->type->suspend)
+ ti->type->suspend(ti);
+ }
+}
+
+void dm_table_resume_targets(struct dm_table *t)
+{
+ int i;
+
+ for (i = 0; i < t->num_targets; i++) {
+ struct dm_target *ti = t->targets + i;
+
+ if (ti->type->resume)
+ ti->type->resume(ti);
+ }
+}
+
+
EXPORT_SYMBOL(dm_get_device);
EXPORT_SYMBOL(dm_put_device);
EXPORT_SYMBOL(dm_table_event);
--- diff/drivers/md/dm.c 2003-06-09 15:05:02.000000000 +0100
+++ source/drivers/md/dm.c 2003-06-09 15:05:08.000000000 +0100
@@ -678,6 +678,7 @@
free_dev(md);
return r;
}
+ dm_table_resume_targets(md->map);
*result = md;
return 0;
@@ -692,6 +693,8 @@
{
if (atomic_dec_and_test(&md->holders)) {
DMWARN("destroying md");
+ if (!test_bit(DMF_SUSPENDED, &md->flags))
+ dm_table_suspend_targets(md->map);
__unbind(md);
free_dev(md);
}
@@ -781,6 +784,7 @@
down_write(&md->lock);
remove_wait_queue(&md->wait, &wait);
set_bit(DMF_SUSPENDED, &md->flags);
+ dm_table_suspend_targets(md->map);
up_write(&md->lock);
return 0;
@@ -797,6 +801,7 @@
return -EINVAL;
}
+ dm_table_resume_targets(md->map);
clear_bit(DMF_SUSPENDED, &md->flags);
clear_bit(DMF_BLOCK_IO, &md->flags);
def = md->deferred;
--- diff/drivers/md/dm.h 2003-06-09 15:05:02.000000000 +0100
+++ source/drivers/md/dm.h 2003-06-09 15:05:08.000000000 +0100
@@ -104,6 +104,8 @@
struct list_head *dm_table_get_devices(struct dm_table *t);
int dm_table_get_mode(struct dm_table *t);
void dm_table_add_wait_queue(struct dm_table *t, wait_queue_t *wq);
+void dm_table_suspend_targets(struct dm_table *t);
+void dm_table_resume_targets(struct dm_table *t);
/*-----------------------------------------------------------------
* A registry of target types.
--- diff/include/linux/device-mapper.h 2003-06-09 15:05:02.000000000 +0100
+++ source/include/linux/device-mapper.h 2003-06-09 15:05:08.000000000 +0100
@@ -33,6 +33,10 @@
* > 0: simple remap complete
*/
typedef int (*dm_map_fn) (struct dm_target *ti, struct bio *bio);
+
+typedef void (*dm_suspend_fn) (struct dm_target *ti);
+typedef void (*dm_resume_fn) (struct dm_target *ti);
+
typedef int (*dm_status_fn) (struct dm_target *ti, status_type_t status_type,
char *result, unsigned int maxlen);
@@ -56,6 +60,8 @@
dm_ctr_fn ctr;
dm_dtr_fn dtr;
dm_map_fn map;
+ dm_suspend_fn suspend;
+ dm_resume_fn resume;
dm_status_fn status;
};
-
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This archive was generated by hypermail 2b29 : Sun Jun 15 2003 - 22:00:20 EST