Commit f083b09b authored by Mike Snitzer's avatar Mike Snitzer
Browse files

dm: set DM_TARGET_WILDCARD feature on "error" target 



The DM_TARGET_WILDCARD feature indicates that the "error" target may
replace any target; even immutable targets.  This feature will be useful
to preserve the ability to replace the "multipath" target even once it
is formally converted over to having the DM_TARGET_IMMUTABLE feature.

Also, implicit in the DM_TARGET_WILDCARD feature flag being set is that
.map, .map_rq, .clone_and_map_rq and .release_clone_rq are all defined
in the target_type.

Signed-off-by: default avatarMike Snitzer <snitzer@redhat.com>
parent e522c039

drivers/md/dm-ioctl.c

+2 −1
Original line number Diff line number Diff line
@@ -1291,7 +1291,8 @@ static int table_load(struct dm_ioctl *param, size_t param_size) 


	immutable_target_type = dm_get_immutable_target_type(md);

	if (immutable_target_type &&

	    (immutable_target_type != dm_table_get_immutable_target_type(t))) {

	    (immutable_target_type != dm_table_get_immutable_target_type(t)) &&

	    !dm_table_get_wildcard_target(t)) {

		DMWARN("can't replace immutable target type %s",

		       immutable_target_type->name);

		r = -EINVAL;

drivers/md/dm-table.c

+14 −0
Original line number Diff line number Diff line
@@ -920,6 +920,20 @@ struct target_type *dm_table_get_immutable_target_type(struct dm_table *t) 
	return t->immutable_target_type;

}



struct dm_target *dm_table_get_wildcard_target(struct dm_table *t)

{

	struct dm_target *uninitialized_var(ti);

	unsigned i = 0;



	while (i < dm_table_get_num_targets(t)) {

		ti = dm_table_get_target(t, i++);

		if (dm_target_is_wildcard(ti->type))

			return ti;

	}



	return NULL;

}



bool dm_table_request_based(struct dm_table *t)

{

	return __table_type_request_based(dm_table_get_type(t));

drivers/md/dm-target.c

+2 −1
Original line number Diff line number Diff line
@@ -150,7 +150,8 @@ static void io_err_release_clone_rq(struct request *clone) 


static struct target_type error_target = {

	.name = "error",

	.version = {1, 3, 0},

	.version = {1, 4, 0},

	.features = DM_TARGET_WILDCARD,

	.ctr  = io_err_ctr,

	.dtr  = io_err_dtr,

	.map  = io_err_map,

drivers/md/dm.h

+1 −0
Original line number Diff line number Diff line
@@ -73,6 +73,7 @@ int dm_table_resume_targets(struct dm_table *t); 
int dm_table_any_congested(struct dm_table *t, int bdi_bits);

unsigned dm_table_get_type(struct dm_table *t);

struct target_type *dm_table_get_immutable_target_type(struct dm_table *t);

struct dm_target *dm_table_get_wildcard_target(struct dm_table *t);

bool dm_table_request_based(struct dm_table *t);

bool dm_table_mq_request_based(struct dm_table *t);

void dm_table_free_md_mempools(struct dm_table *t);

include/linux/device-mapper.h

+7 −0
Original line number Diff line number Diff line
@@ -189,6 +189,13 @@ struct target_type { 
#define DM_TARGET_IMMUTABLE		0x00000004

#define dm_target_is_immutable(type)	((type)->features & DM_TARGET_IMMUTABLE)



/*

 * Indicates that a target may replace any target; even immutable targets.

 * .map, .map_rq, .clone_and_map_rq and .release_clone_rq are all defined.

 */

#define DM_TARGET_WILDCARD		0x00000008

#define dm_target_is_wildcard(type)	((type)->features & DM_TARGET_WILDCARD)



/*

 * Some targets need to be sent the same WRITE bio severals times so

 * that they can send copies of it to different devices.  This function

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