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authorJoe Thornber <ejt@redhat.com>2016-10-03 14:15:02 -0400
committerMike Snitzer <snitzer@redhat.com>2017-02-16 13:12:45 -0500
commit6fe28dbf05e329ce136f38219d95a1826ceafebd (patch)
treee5619c3b907f006f72257fc74eccb941e1ae646b /drivers/md/persistent-data
parent9f9ef0657d53d988dc07b096052b3dd07d6e3c46 (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/md/persistent-data')
-rw-r--r--drivers/md/persistent-data/dm-bitset.c69
-rw-r--r--drivers/md/persistent-data/dm-bitset.h22
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 */