Commit 1134e5ae authored by Mike Anderson's avatar Mike Anderson Committed by Linus Torvalds
Browse files

[PATCH] dm table: store md 



Store an up-pointer to the owning struct mapped_device in every table when it
is created.

Access it with:
  struct mapped_device *dm_table_get_md(struct dm_table *t)

Tables linked to md must be destroyed before the md itself.

Signed-off-by: default avatarMike Anderson <andmike@us.ibm.com>
Signed-off-by: default avatarAlasdair G Kergon <agk@redhat.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 9ade92a9

drivers/md/dm-ioctl.c

+21 −11
Original line number Diff line number Diff line
@@ -244,9 +244,9 @@ static void __hash_remove(struct hash_cell *hc) 
		dm_table_put(table);

	}



	dm_put(hc->md);

	if (hc->new_map)

		dm_table_put(hc->new_map);

	dm_put(hc->md);

	free_cell(hc);

}
@@ -985,33 +985,43 @@ static int table_load(struct dm_ioctl *param, size_t param_size) 
	int r;

	struct hash_cell *hc;

	struct dm_table *t;

	struct mapped_device *md;



	md = find_device(param);

	if (!md)

		return -ENXIO;



	r = dm_table_create(&t, get_mode(param), param->target_count);

	r = dm_table_create(&t, get_mode(param), param->target_count, md);

	if (r)

		return r;

		goto out;



	r = populate_table(t, param, param_size);

	if (r) {

		dm_table_put(t);

		return r;

		goto out;

	}



	down_write(&_hash_lock);

	hc = __find_device_hash_cell(param);

	if (!hc) {

		DMWARN("device doesn't appear to be in the dev hash table.");

		up_write(&_hash_lock);

	hc = dm_get_mdptr(md);

	if (!hc || hc->md != md) {

		DMWARN("device has been removed from the dev hash table.");

		dm_table_put(t);

		return -ENXIO;

		up_write(&_hash_lock);

		r = -ENXIO;

		goto out;

	}



	if (hc->new_map)

		dm_table_put(hc->new_map);

	hc->new_map = t;

	up_write(&_hash_lock);



	param->flags |= DM_INACTIVE_PRESENT_FLAG;

	r = __dev_status(md, param);



out:

	dm_put(md);



	r = __dev_status(hc->md, param);

	up_write(&_hash_lock);

	return r;

}

drivers/md/dm-table.c

+12 −1
Original line number Diff line number Diff line
@@ -22,6 +22,7 @@ 
#define CHILDREN_PER_NODE (KEYS_PER_NODE + 1)



struct dm_table {

	struct mapped_device *md;

	atomic_t holders;



	/* btree table */
@@ -206,7 +207,8 @@ static int alloc_targets(struct dm_table *t, unsigned int num) 
	return 0;

}



int dm_table_create(struct dm_table **result, int mode, unsigned num_targets)

int dm_table_create(struct dm_table **result, int mode,

		    unsigned num_targets, struct mapped_device *md)

{

	struct dm_table *t = kmalloc(sizeof(*t), GFP_KERNEL);
@@ -229,6 +231,7 @@ int dm_table_create(struct dm_table **result, int mode, unsigned num_targets) 
	}



	t->mode = mode;

	t->md = md;

	*result = t;

	return 0;

}
@@ -952,12 +955,20 @@ int dm_table_flush_all(struct dm_table *t) 
	return ret;

}



struct mapped_device *dm_table_get_md(struct dm_table *t)

{

	dm_get(t->md);



	return t->md;

}



EXPORT_SYMBOL(dm_vcalloc);

EXPORT_SYMBOL(dm_get_device);

EXPORT_SYMBOL(dm_put_device);

EXPORT_SYMBOL(dm_table_event);

EXPORT_SYMBOL(dm_table_get_size);

EXPORT_SYMBOL(dm_table_get_mode);

EXPORT_SYMBOL(dm_table_get_md);

EXPORT_SYMBOL(dm_table_put);

EXPORT_SYMBOL(dm_table_get);

EXPORT_SYMBOL(dm_table_unplug_all);

drivers/md/dm.c

+3 −3
Original line number Diff line number Diff line
@@ -1007,18 +1007,18 @@ void dm_get(struct mapped_device *md) 


void dm_put(struct mapped_device *md)

{

	struct dm_table *map = dm_get_table(md);

	struct dm_table *map;



	if (atomic_dec_and_test(&md->holders)) {

		map = dm_get_table(md);

		if (!dm_suspended(md)) {

			dm_table_presuspend_targets(map);

			dm_table_postsuspend_targets(map);

		}

		__unbind(md);

		dm_table_put(map);

		free_dev(md);

	}



	dm_table_put(map);

}



/*

drivers/md/dm.h

+3 −1
Original line number Diff line number Diff line
@@ -89,7 +89,8 @@ int dm_suspended(struct mapped_device *md); 
 * Functions for manipulating a table.  Tables are also reference

 * counted.

 *---------------------------------------------------------------*/

int dm_table_create(struct dm_table **result, int mode, unsigned num_targets);

int dm_table_create(struct dm_table **result, int mode,

		    unsigned num_targets, struct mapped_device *md);



void dm_table_get(struct dm_table *t);

void dm_table_put(struct dm_table *t);
@@ -107,6 +108,7 @@ void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q); 
unsigned int dm_table_get_num_targets(struct dm_table *t);

struct list_head *dm_table_get_devices(struct dm_table *t);

int dm_table_get_mode(struct dm_table *t);

struct mapped_device *dm_table_get_md(struct dm_table *t);

void dm_table_presuspend_targets(struct dm_table *t);

void dm_table_postsuspend_targets(struct dm_table *t);

void dm_table_resume_targets(struct dm_table *t);

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