Commit 9b696229 authored by Joe Thornber's avatar Joe Thornber Committed by Mike Snitzer

dm persistent data: add cursor skip functions to the cursor APIs

Signed-off-by: default avatarJoe Thornber <ejt@redhat.com>
Signed-off-by: default avatarMike Snitzer <snitzer@redhat.com>
parent 683bb1a3
......@@ -976,6 +976,27 @@ int dm_array_cursor_next(struct dm_array_cursor *c)
}
EXPORT_SYMBOL_GPL(dm_array_cursor_next);
int dm_array_cursor_skip(struct dm_array_cursor *c, uint32_t count)
{
int r;
do {
uint32_t remaining = le32_to_cpu(c->ab->nr_entries) - c->index;
if (count < remaining) {
c->index += count;
return 0;
}
count -= remaining;
r = dm_array_cursor_next(c);
} while (!r);
return r;
}
EXPORT_SYMBOL_GPL(dm_array_cursor_skip);
void dm_array_cursor_get_value(struct dm_array_cursor *c, void **value_le)
{
*value_le = element_at(c->info, c->ab, c->index);
......
......@@ -207,6 +207,7 @@ void dm_array_cursor_end(struct dm_array_cursor *c);
uint32_t dm_array_cursor_index(struct dm_array_cursor *c);
int dm_array_cursor_next(struct dm_array_cursor *c);
int dm_array_cursor_skip(struct dm_array_cursor *c, uint32_t count);
/*
* value_le is only valid while the cursor points at the current value.
......
......@@ -273,6 +273,41 @@ int dm_bitset_cursor_next(struct dm_bitset_cursor *c)
}
EXPORT_SYMBOL_GPL(dm_bitset_cursor_next);
int dm_bitset_cursor_skip(struct dm_bitset_cursor *c, uint32_t count)
{
int r;
__le64 *value;
uint32_t nr_array_skip;
uint32_t remaining_in_word = 64 - c->bit_index;
if (c->entries_remaining < count)
return -ENODATA;
if (count < remaining_in_word) {
c->bit_index += count;
c->entries_remaining -= count;
return 0;
} else {
c->entries_remaining -= remaining_in_word;
count -= remaining_in_word;
}
nr_array_skip = (count / 64) + 1;
r = dm_array_cursor_skip(&c->cursor, nr_array_skip);
if (r)
return r;
dm_array_cursor_get_value(&c->cursor, (void **) &value);
c->entries_remaining -= count;
c->array_index += nr_array_skip;
c->bit_index = count & 63;
c->current_bits = le64_to_cpu(*value);
return 0;
}
EXPORT_SYMBOL_GPL(dm_bitset_cursor_skip);
bool dm_bitset_cursor_get_value(struct dm_bitset_cursor *c)
{
return test_bit(c->bit_index, (unsigned long *) &c->current_bits);
......
......@@ -197,6 +197,7 @@ int dm_bitset_cursor_begin(struct dm_disk_bitset *info,
void dm_bitset_cursor_end(struct dm_bitset_cursor *c);
int dm_bitset_cursor_next(struct dm_bitset_cursor *c);
int dm_bitset_cursor_skip(struct dm_bitset_cursor *c, uint32_t count);
bool dm_bitset_cursor_get_value(struct dm_bitset_cursor *c);
/*----------------------------------------------------------------*/
......
......@@ -1144,6 +1144,17 @@ int dm_btree_cursor_next(struct dm_btree_cursor *c)
}
EXPORT_SYMBOL_GPL(dm_btree_cursor_next);
int dm_btree_cursor_skip(struct dm_btree_cursor *c, uint32_t count)
{
int r = 0;
while (count-- && !r)
r = dm_btree_cursor_next(c);
return r;
}
EXPORT_SYMBOL_GPL(dm_btree_cursor_skip);
int dm_btree_cursor_get_value(struct dm_btree_cursor *c, uint64_t *key, void *value_le)
{
if (c->depth) {
......
......@@ -209,6 +209,7 @@ int dm_btree_cursor_begin(struct dm_btree_info *info, dm_block_t root,
bool prefetch_leaves, struct dm_btree_cursor *c);
void dm_btree_cursor_end(struct dm_btree_cursor *c);
int dm_btree_cursor_next(struct dm_btree_cursor *c);
int dm_btree_cursor_skip(struct dm_btree_cursor *c, uint32_t count);
int dm_btree_cursor_get_value(struct dm_btree_cursor *c, uint64_t *key, void *value_le);
#endif /* _LINUX_DM_BTREE_H */
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