diff options
| author | Joe Thornber <thornber@redhat.com> | 2011-10-31 20:19:11 +0000 |
|---|---|---|
| committer | Alasdair G Kergon <agk@redhat.com> | 2011-10-31 20:19:11 +0000 |
| commit | 3241b1d3e0aaafbfcd320f4d71ade629728cc4f4 (patch) | |
| tree | 499461f724d4db3d7118641f4a20f5be23549edd /drivers/md/persistent-data/dm-persistent-data-internal.h | |
| parent | 95d402f057f2e208e4631893f6cd4a59c7c05e41 (diff) | |
dm: add persistent data library
The persistent-data library offers a re-usable framework for the storage
and management of on-disk metadata in device-mapper targets.
It's used by the thin-provisioning target in the next patch and in an
upcoming hierarchical storage target.
For further information, please read
Documentation/device-mapper/persistent-data.txt
Signed-off-by: Joe Thornber <thornber@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Diffstat (limited to 'drivers/md/persistent-data/dm-persistent-data-internal.h')
| -rw-r--r-- | drivers/md/persistent-data/dm-persistent-data-internal.h | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/drivers/md/persistent-data/dm-persistent-data-internal.h b/drivers/md/persistent-data/dm-persistent-data-internal.h new file mode 100644 index 000000000000..c49e26fff36c --- /dev/null +++ b/drivers/md/persistent-data/dm-persistent-data-internal.h @@ -0,0 +1,19 @@ +/* + * Copyright (C) 2011 Red Hat, Inc. + * + * This file is released under the GPL. + */ + +#ifndef _DM_PERSISTENT_DATA_INTERNAL_H +#define _DM_PERSISTENT_DATA_INTERNAL_H + +#include "dm-block-manager.h" + +static inline unsigned dm_hash_block(dm_block_t b, unsigned hash_mask) +{ + const unsigned BIG_PRIME = 4294967291UL; + + return (((unsigned) b) * BIG_PRIME) & hash_mask; +} + +#endif /* _PERSISTENT_DATA_INTERNAL_H */ |