diff options
author | Joe Thornber | 2016-10-03 14:15:02 -0400 |
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committer | Mike Snitzer | 2017-02-16 13:12:45 -0500 |
commit | 6fe28dbf05e329ce136f38219d95a1826ceafebd (patch) | |
tree | e5619c3b907f006f72257fc74eccb941e1ae646b /drivers | |
parent | 9f9ef0657d53d988dc07b096052b3dd07d6e3c46 (diff) |
dm bitset: introduce cursor api
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Diffstat (limited to 'drivers')
-rw-r--r-- | drivers/md/persistent-data/dm-bitset.c | 69 | ||||
-rw-r--r-- | drivers/md/persistent-data/dm-bitset.h | 22 |
2 files changed, 91 insertions, 0 deletions
diff --git a/drivers/md/persistent-data/dm-bitset.c b/drivers/md/persistent-data/dm-bitset.c index 36f7cc2c7109..7cb28516cc19 100644 --- a/drivers/md/persistent-data/dm-bitset.c +++ b/drivers/md/persistent-data/dm-bitset.c @@ -168,4 +168,73 @@ int dm_bitset_test_bit(struct dm_disk_bitset *info, dm_block_t root, } EXPORT_SYMBOL_GPL(dm_bitset_test_bit); +static int cursor_next_array_entry(struct dm_bitset_cursor *c) +{ + int r; + __le64 *value; + + r = dm_array_cursor_next(&c->cursor); + if (r) + return r; + + dm_array_cursor_get_value(&c->cursor, (void **) &value); + c->array_index++; + c->bit_index = 0; + c->current_bits = le64_to_cpu(*value); + return 0; +} + +int dm_bitset_cursor_begin(struct dm_disk_bitset *info, + dm_block_t root, uint32_t nr_entries, + struct dm_bitset_cursor *c) +{ + int r; + __le64 *value; + + if (!nr_entries) + return -ENODATA; + + c->info = info; + c->entries_remaining = nr_entries; + + r = dm_array_cursor_begin(&info->array_info, root, &c->cursor); + if (r) + return r; + + dm_array_cursor_get_value(&c->cursor, (void **) &value); + c->array_index = 0; + c->bit_index = 0; + c->current_bits = le64_to_cpu(*value); + + return r; +} +EXPORT_SYMBOL_GPL(dm_bitset_cursor_begin); + +void dm_bitset_cursor_end(struct dm_bitset_cursor *c) +{ + return dm_array_cursor_end(&c->cursor); +} +EXPORT_SYMBOL_GPL(dm_bitset_cursor_end); + +int dm_bitset_cursor_next(struct dm_bitset_cursor *c) +{ + int r = 0; + + if (!c->entries_remaining) + return -ENODATA; + + c->entries_remaining--; + if (++c->bit_index > 63) + r = cursor_next_array_entry(c); + + return r; +} +EXPORT_SYMBOL_GPL(dm_bitset_cursor_next); + +bool dm_bitset_cursor_get_value(struct dm_bitset_cursor *c) +{ + return test_bit(c->bit_index, (unsigned long *) &c->current_bits); +} +EXPORT_SYMBOL_GPL(dm_bitset_cursor_get_value); + /*----------------------------------------------------------------*/ diff --git a/drivers/md/persistent-data/dm-bitset.h b/drivers/md/persistent-data/dm-bitset.h index c2287d672ef5..017c0d42cdbf 100644 --- a/drivers/md/persistent-data/dm-bitset.h +++ b/drivers/md/persistent-data/dm-bitset.h @@ -161,6 +161,28 @@ int dm_bitset_test_bit(struct dm_disk_bitset *info, dm_block_t root, int dm_bitset_flush(struct dm_disk_bitset *info, dm_block_t root, dm_block_t *new_root); +struct dm_bitset_cursor { + struct dm_disk_bitset *info; + struct dm_array_cursor cursor; + + uint32_t entries_remaining; + uint32_t array_index; + uint32_t bit_index; + uint64_t current_bits; +}; + +/* + * Make sure you've flush any dm_disk_bitset and updated the root before + * using this. + */ +int dm_bitset_cursor_begin(struct dm_disk_bitset *info, + dm_block_t root, uint32_t nr_entries, + struct dm_bitset_cursor *c); +void dm_bitset_cursor_end(struct dm_bitset_cursor *c); + +int dm_bitset_cursor_next(struct dm_bitset_cursor *c); +bool dm_bitset_cursor_get_value(struct dm_bitset_cursor *c); + /*----------------------------------------------------------------*/ #endif /* _LINUX_DM_BITSET_H */ |