dm thin metadata: introduce dm_pool_metadata_set_read_only

Introduce dm_pool_metadata_set_read_only to put the underlying block
manager into read-only mode.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
This commit is contained in:
Joe Thornber 2012-07-27 15:08:15 +01:00 committed by Alasdair G Kergon
parent 310975573b
commit 12ba58af46
2 changed files with 22 additions and 4 deletions

View file

@ -184,6 +184,7 @@ struct dm_pool_metadata {
uint64_t trans_id; uint64_t trans_id;
unsigned long flags; unsigned long flags;
sector_t data_block_size; sector_t data_block_size;
bool read_only:1;
}; };
struct dm_thin_device { struct dm_thin_device {
@ -807,6 +808,7 @@ struct dm_pool_metadata *dm_pool_metadata_open(struct block_device *bdev,
init_rwsem(&pmd->root_lock); init_rwsem(&pmd->root_lock);
pmd->time = 0; pmd->time = 0;
INIT_LIST_HEAD(&pmd->thin_devices); INIT_LIST_HEAD(&pmd->thin_devices);
pmd->read_only = false;
pmd->bdev = bdev; pmd->bdev = bdev;
pmd->data_block_size = data_block_size; pmd->data_block_size = data_block_size;
@ -849,10 +851,12 @@ int dm_pool_metadata_close(struct dm_pool_metadata *pmd)
return -EBUSY; return -EBUSY;
} }
r = __commit_transaction(pmd); if (!pmd->read_only) {
if (r < 0) r = __commit_transaction(pmd);
DMWARN("%s: __commit_transaction() failed, error = %d", if (r < 0)
__func__, r); DMWARN("%s: __commit_transaction() failed, error = %d",
__func__, r);
}
__destroy_persistent_data_objects(pmd); __destroy_persistent_data_objects(pmd);
kfree(pmd); kfree(pmd);
@ -1587,3 +1591,11 @@ int dm_pool_resize_data_dev(struct dm_pool_metadata *pmd, dm_block_t new_count)
return r; return r;
} }
void dm_pool_metadata_read_only(struct dm_pool_metadata *pmd)
{
down_write(&pmd->root_lock);
pmd->read_only = true;
dm_bm_set_read_only(pmd->bm);
up_write(&pmd->root_lock);
}

View file

@ -174,6 +174,12 @@ int dm_pool_get_data_dev_size(struct dm_pool_metadata *pmd, dm_block_t *result);
*/ */
int dm_pool_resize_data_dev(struct dm_pool_metadata *pmd, dm_block_t new_size); int dm_pool_resize_data_dev(struct dm_pool_metadata *pmd, dm_block_t new_size);
/*
* Flicks the underlying block manager into read only mode, so you know
* that nothing is changing.
*/
void dm_pool_metadata_read_only(struct dm_pool_metadata *pmd);
/*----------------------------------------------------------------*/ /*----------------------------------------------------------------*/
#endif #endif