Commit ecda7c02 authored by Nikos Tsironis's avatar Nikos Tsironis Committed by Mike Snitzer
Browse files

dm thin metadata: Add support for a pre-commit callback 



Add support for one pre-commit callback which is run right before the
metadata are committed.

This allows the thin provisioning target to run a callback before the
metadata are committed and is required by the next commit.

Cc: stable@vger.kernel.org
Signed-off-by: default avatarNikos Tsironis <ntsironis@arrikto.com>
Acked-by: default avatarJoe Thornber <ejt@redhat.com>
Signed-off-by: default avatarMike Snitzer <snitzer@redhat.com>
parent 8b3fd1f5

drivers/md/dm-thin-metadata.c

+29 −0
Original line number Diff line number Diff line
@@ -188,6 +188,15 @@ struct dm_pool_metadata { 
	unsigned long flags;

	sector_t data_block_size;



	/*

	 * Pre-commit callback.

	 *

	 * This allows the thin provisioning target to run a callback before

	 * the metadata are committed.

	 */

	dm_pool_pre_commit_fn pre_commit_fn;

	void *pre_commit_context;



	/*

	 * We reserve a section of the metadata for commit overhead.

	 * All reported space does *not* include this.
@@ -826,6 +835,14 @@ static int __commit_transaction(struct dm_pool_metadata *pmd) 
	if (unlikely(!pmd->in_service))

		return 0;



	if (pmd->pre_commit_fn) {

		r = pmd->pre_commit_fn(pmd->pre_commit_context);

		if (r < 0) {

			DMERR("pre-commit callback failed");

			return r;

		}

	}



	r = __write_changed_details(pmd);

	if (r < 0)

		return r;
@@ -892,6 +909,8 @@ struct dm_pool_metadata *dm_pool_metadata_open(struct block_device *bdev, 
	pmd->in_service = false;

	pmd->bdev = bdev;

	pmd->data_block_size = data_block_size;

	pmd->pre_commit_fn = NULL;

	pmd->pre_commit_context = NULL;



	r = __create_persistent_data_objects(pmd, format_device);

	if (r) {
@@ -2044,6 +2063,16 @@ int dm_pool_register_metadata_threshold(struct dm_pool_metadata *pmd, 
	return r;

}



void dm_pool_register_pre_commit_callback(struct dm_pool_metadata *pmd,

					  dm_pool_pre_commit_fn fn,

					  void *context)

{

	pmd_write_lock_in_core(pmd);

	pmd->pre_commit_fn = fn;

	pmd->pre_commit_context = context;

	pmd_write_unlock(pmd);

}



int dm_pool_metadata_set_needs_check(struct dm_pool_metadata *pmd)

{

	int r = -EINVAL;

drivers/md/dm-thin-metadata.h

+7 −0
Original line number Diff line number Diff line
@@ -230,6 +230,13 @@ bool dm_pool_metadata_needs_check(struct dm_pool_metadata *pmd); 
 */

void dm_pool_issue_prefetches(struct dm_pool_metadata *pmd);



/* Pre-commit callback */

typedef int (*dm_pool_pre_commit_fn)(void *context);



void dm_pool_register_pre_commit_callback(struct dm_pool_metadata *pmd,

					  dm_pool_pre_commit_fn fn,

					  void *context);



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



#endif

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