Commit b2a11465 authored by Jonathan Brassow's avatar Jonathan Brassow Committed by Alasdair G Kergon
Browse files

dm exception store: separate type from instance 



Introduce struct dm_exception_store_type.

Signed-off-by: default avatarJonathan Brassow <jbrassow@redhat.com>
Signed-off-by: default avatarAlasdair G Kergon <agk@redhat.com>
parent ec44ab9d

drivers/md/dm-exception-store.h

+11 −2
Original line number Diff line number Diff line
@@ -37,11 +37,15 @@ struct dm_snap_exception { 
 * Abstraction to handle the meta/layout of exception stores (the

 * COW device).

 */

struct dm_exception_store {

struct dm_exception_store;

struct dm_exception_store_type {

	int (*ctr) (struct dm_exception_store *store,

		    unsigned argc, char **argv);



	/*

	 * Destroys this object when you've finished with it.

	 */

	void (*destroy) (struct dm_exception_store *store);

	void (*dtr) (struct dm_exception_store *store);



	/*

	 * The target shouldn't read the COW device until this is
@@ -81,8 +85,13 @@ struct dm_exception_store { 
	void (*fraction_full) (struct dm_exception_store *store,

			       sector_t *numerator,

			       sector_t *denominator);

};



struct dm_exception_store {

	struct dm_exception_store_type type;



	struct dm_snapshot *snap;



	void *context;

};

drivers/md/dm-snap-persistent.c

+7 −6
Original line number Diff line number Diff line
@@ -683,12 +683,13 @@ int dm_create_persistent(struct dm_exception_store *store) 
		return -ENOMEM;

	}



	store->destroy = persistent_destroy;

	store->read_metadata = persistent_read_metadata;

	store->prepare_exception = persistent_prepare_exception;

	store->commit_exception = persistent_commit_exception;

	store->drop_snapshot = persistent_drop_snapshot;

	store->fraction_full = persistent_fraction_full;

	store->type.dtr = persistent_destroy;

	store->type.read_metadata = persistent_read_metadata;

	store->type.prepare_exception = persistent_prepare_exception;

	store->type.commit_exception = persistent_commit_exception;

	store->type.drop_snapshot = persistent_drop_snapshot;

	store->type.fraction_full = persistent_fraction_full;



	store->context = ps;



	return 0;

drivers/md/dm-snap-transient.c

+7 −7
Original line number Diff line number Diff line
@@ -39,7 +39,7 @@ static int transient_read_metadata(struct dm_exception_store *store, 
static int transient_prepare_exception(struct dm_exception_store *store,

				       struct dm_snap_exception *e)

{

	struct transient_c *tc = (struct transient_c *) store->context;

	struct transient_c *tc = store->context;

	sector_t size = get_dev_size(store->snap->cow->bdev);



	if (size < (tc->next_free + store->snap->chunk_size))
@@ -71,12 +71,12 @@ int dm_create_transient(struct dm_exception_store *store) 
{

	struct transient_c *tc;



	store->destroy = transient_destroy;

	store->read_metadata = transient_read_metadata;

	store->prepare_exception = transient_prepare_exception;

	store->commit_exception = transient_commit_exception;

	store->drop_snapshot = NULL;

	store->fraction_full = transient_fraction_full;

	store->type.dtr = transient_destroy;

	store->type.read_metadata = transient_read_metadata;

	store->type.prepare_exception = transient_prepare_exception;

	store->type.commit_exception = transient_commit_exception;

	store->type.drop_snapshot = NULL;

	store->type.fraction_full = transient_fraction_full;



	tc = kmalloc(sizeof(struct transient_c), GFP_KERNEL);

	if (!tc)

drivers/md/dm-snap.c

+10 −10
Original line number Diff line number Diff line
@@ -665,7 +665,7 @@ static int snapshot_ctr(struct dm_target *ti, unsigned int argc, char **argv) 
	spin_lock_init(&s->tracked_chunk_lock);



	/* Metadata must only be loaded into one table at once */

	r = s->store.read_metadata(&s->store, dm_add_exception, (void *)s);

	r = s->store.type.read_metadata(&s->store, dm_add_exception, (void *)s);

	if (r < 0) {

		ti->error = "Failed to read snapshot metadata";

		goto bad_load_and_register;
@@ -700,7 +700,7 @@ static int snapshot_ctr(struct dm_target *ti, unsigned int argc, char **argv) 
	dm_kcopyd_client_destroy(s->kcopyd_client);



 bad5:

	s->store.destroy(&s->store);

	s->store.type.dtr(&s->store);



 bad4:

	exit_exception_table(&s->pending, pending_cache);
@@ -725,7 +725,7 @@ static void __free_exceptions(struct dm_snapshot *s) 
	exit_exception_table(&s->pending, pending_cache);

	exit_exception_table(&s->complete, exception_cache);



	s->store.destroy(&s->store);

	s->store.type.dtr(&s->store);

}



static void snapshot_dtr(struct dm_target *ti)
@@ -820,8 +820,8 @@ static void __invalidate_snapshot(struct dm_snapshot *s, int err) 
	else if (err == -ENOMEM)

		DMERR("Invalidating snapshot: Unable to allocate exception.");



	if (s->store.drop_snapshot)

		s->store.drop_snapshot(&s->store);

	if (s->store.type.drop_snapshot)

		s->store.type.drop_snapshot(&s->store);



	s->valid = 0;
@@ -943,8 +943,8 @@ static void copy_callback(int read_err, unsigned long write_err, void *context) 


	else

		/* Update the metadata if we are persistent */

		s->store.commit_exception(&s->store, &pe->e, commit_callback,

					  pe);

		s->store.type.commit_exception(&s->store, &pe->e,

					       commit_callback, pe);

}



/*
@@ -1010,7 +1010,7 @@ __find_pending_exception(struct dm_snapshot *s, 
	atomic_set(&pe->ref_count, 0);

	pe->started = 0;



	if (s->store.prepare_exception(&s->store, &pe->e)) {

	if (s->store.type.prepare_exception(&s->store, &pe->e)) {

		free_pending_exception(pe);

		return NULL;

	}
@@ -1149,9 +1149,9 @@ static int snapshot_status(struct dm_target *ti, status_type_t type, 
		if (!snap->valid)

			snprintf(result, maxlen, "Invalid");

		else {

			if (snap->store.fraction_full) {

			if (snap->store.type.fraction_full) {

				sector_t numerator, denominator;

				snap->store.fraction_full(&snap->store,

				snap->store.type.fraction_full(&snap->store,

							  &numerator,

							  &denominator);

				snprintf(result, maxlen, "%llu/%llu",