From f4cc2a48472f19f4dcb03d24f399c5d02b7f781f Mon Sep 17 00:00:00 2001 From: Joe Thornber Date: Thu, 12 Jul 2012 12:35:18 +0100 Subject: [PATCH 32/34] dm thin metadata: introduce dm_pool_metadata_read_only Ensures the underlying block manager is put into read-only mode. Signed-off-by: Joe Thornber Signed-off-by: Mike Snitzer --- drivers/md/dm-thin-metadata.c | 20 ++++++++++++++++---- drivers/md/dm-thin-metadata.h | 6 ++++++ 2 files changed, 22 insertions(+), 4 deletions(-) Index: linux-2.6/drivers/md/dm-thin-metadata.c =================================================================== --- linux-2.6.orig/drivers/md/dm-thin-metadata.c +++ linux-2.6/drivers/md/dm-thin-metadata.c @@ -184,6 +184,7 @@ struct dm_pool_metadata { uint64_t trans_id; unsigned long flags; sector_t data_block_size; + bool read_only:1; }; struct dm_thin_device { @@ -811,6 +812,7 @@ struct dm_pool_metadata *dm_pool_metadat init_rwsem(&pmd->root_lock); pmd->time = 0; INIT_LIST_HEAD(&pmd->thin_devices); + pmd->read_only = 0; pmd->bdev = bdev; pmd->data_block_size = data_block_size; @@ -853,10 +855,12 @@ int dm_pool_metadata_close(struct dm_poo return -EBUSY; } - r = __commit_transaction(pmd); - if (r < 0) - DMWARN("%s: __commit_transaction() failed, error = %d", - __func__, r); + if (!pmd->read_only) { + r = __commit_transaction(pmd); + if (r < 0) + DMWARN("%s: __commit_transaction() failed, error = %d", + __func__, r); + } __destroy_persistent_data_objects(pmd); kfree(pmd); @@ -1591,3 +1595,11 @@ int dm_pool_resize_data_dev(struct dm_po return r; } + +void dm_pool_metadata_read_only(struct dm_pool_metadata *pmd) +{ + down_write(&pmd->root_lock); + pmd->read_only = 1; + dm_bm_read_only(pmd->bm); + up_write(&pmd->root_lock); +} Index: linux-2.6/drivers/md/dm-thin-metadata.h =================================================================== --- linux-2.6.orig/drivers/md/dm-thin-metadata.h +++ linux-2.6/drivers/md/dm-thin-metadata.h @@ -179,6 +179,12 @@ int dm_pool_get_data_dev_size(struct dm_ */ 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