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authorJoe Thornber <ejt@redhat.com>2013-03-02 02:45:51 +0400
committerAlasdair G Kergon <agk@redhat.com>2013-03-02 02:45:51 +0400
commit7a87edfee75151abb69d47dba2277ff2de0f6071 (patch)
tree1f0304a22e9ab66cb52cf052600516714f2dddf8 /drivers/md/persistent-data/dm-bitset.c
parent6513c29f44f2cc970c0e9fecfe5a6526c3e73025 (diff)
downloadlinux-7a87edfee75151abb69d47dba2277ff2de0f6071.tar.xz
dm persistent data: add bitset
Add a persistent bitset as a wrapper around dm-array. Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Diffstat (limited to 'drivers/md/persistent-data/dm-bitset.c')
-rw-r--r--drivers/md/persistent-data/dm-bitset.c163
1 files changed, 163 insertions, 0 deletions
diff --git a/drivers/md/persistent-data/dm-bitset.c b/drivers/md/persistent-data/dm-bitset.c
new file mode 100644
index 000000000000..cd9a86d4cdf0
--- /dev/null
+++ b/drivers/md/persistent-data/dm-bitset.c
@@ -0,0 +1,163 @@
+/*
+ * Copyright (C) 2012 Red Hat, Inc.
+ *
+ * This file is released under the GPL.
+ */
+
+#include "dm-bitset.h"
+#include "dm-transaction-manager.h"
+
+#include <linux/export.h>
+#include <linux/device-mapper.h>
+
+#define DM_MSG_PREFIX "bitset"
+#define BITS_PER_ARRAY_ENTRY 64
+
+/*----------------------------------------------------------------*/
+
+static struct dm_btree_value_type bitset_bvt = {
+ .context = NULL,
+ .size = sizeof(__le64),
+ .inc = NULL,
+ .dec = NULL,
+ .equal = NULL,
+};
+
+/*----------------------------------------------------------------*/
+
+void dm_disk_bitset_init(struct dm_transaction_manager *tm,
+ struct dm_disk_bitset *info)
+{
+ dm_array_info_init(&info->array_info, tm, &bitset_bvt);
+ info->current_index_set = false;
+}
+EXPORT_SYMBOL_GPL(dm_disk_bitset_init);
+
+int dm_bitset_empty(struct dm_disk_bitset *info, dm_block_t *root)
+{
+ return dm_array_empty(&info->array_info, root);
+}
+EXPORT_SYMBOL_GPL(dm_bitset_empty);
+
+int dm_bitset_resize(struct dm_disk_bitset *info, dm_block_t root,
+ uint32_t old_nr_entries, uint32_t new_nr_entries,
+ bool default_value, dm_block_t *new_root)
+{
+ uint32_t old_blocks = dm_div_up(old_nr_entries, BITS_PER_ARRAY_ENTRY);
+ uint32_t new_blocks = dm_div_up(new_nr_entries, BITS_PER_ARRAY_ENTRY);
+ __le64 value = default_value ? cpu_to_le64(~0) : cpu_to_le64(0);
+
+ __dm_bless_for_disk(&value);
+ return dm_array_resize(&info->array_info, root, old_blocks, new_blocks,
+ &value, new_root);
+}
+EXPORT_SYMBOL_GPL(dm_bitset_resize);
+
+int dm_bitset_del(struct dm_disk_bitset *info, dm_block_t root)
+{
+ return dm_array_del(&info->array_info, root);
+}
+EXPORT_SYMBOL_GPL(dm_bitset_del);
+
+int dm_bitset_flush(struct dm_disk_bitset *info, dm_block_t root,
+ dm_block_t *new_root)
+{
+ int r;
+ __le64 value;
+
+ if (!info->current_index_set)
+ return 0;
+
+ value = cpu_to_le64(info->current_bits);
+
+ __dm_bless_for_disk(&value);
+ r = dm_array_set_value(&info->array_info, root, info->current_index,
+ &value, new_root);
+ if (r)
+ return r;
+
+ info->current_index_set = false;
+ return 0;
+}
+EXPORT_SYMBOL_GPL(dm_bitset_flush);
+
+static int read_bits(struct dm_disk_bitset *info, dm_block_t root,
+ uint32_t array_index)
+{
+ int r;
+ __le64 value;
+
+ r = dm_array_get_value(&info->array_info, root, array_index, &value);
+ if (r)
+ return r;
+
+ info->current_bits = le64_to_cpu(value);
+ info->current_index_set = true;
+ info->current_index = array_index;
+ return 0;
+}
+
+static int get_array_entry(struct dm_disk_bitset *info, dm_block_t root,
+ uint32_t index, dm_block_t *new_root)
+{
+ int r;
+ unsigned array_index = index / BITS_PER_ARRAY_ENTRY;
+
+ if (info->current_index_set) {
+ if (info->current_index == array_index)
+ return 0;
+
+ r = dm_bitset_flush(info, root, new_root);
+ if (r)
+ return r;
+ }
+
+ return read_bits(info, root, array_index);
+}
+
+int dm_bitset_set_bit(struct dm_disk_bitset *info, dm_block_t root,
+ uint32_t index, dm_block_t *new_root)
+{
+ int r;
+ unsigned b = index % BITS_PER_ARRAY_ENTRY;
+
+ r = get_array_entry(info, root, index, new_root);
+ if (r)
+ return r;
+
+ set_bit(b, (unsigned long *) &info->current_bits);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(dm_bitset_set_bit);
+
+int dm_bitset_clear_bit(struct dm_disk_bitset *info, dm_block_t root,
+ uint32_t index, dm_block_t *new_root)
+{
+ int r;
+ unsigned b = index % BITS_PER_ARRAY_ENTRY;
+
+ r = get_array_entry(info, root, index, new_root);
+ if (r)
+ return r;
+
+ clear_bit(b, (unsigned long *) &info->current_bits);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(dm_bitset_clear_bit);
+
+int dm_bitset_test_bit(struct dm_disk_bitset *info, dm_block_t root,
+ uint32_t index, dm_block_t *new_root, bool *result)
+{
+ int r;
+ unsigned b = index % BITS_PER_ARRAY_ENTRY;
+
+ r = get_array_entry(info, root, index, new_root);
+ if (r)
+ return r;
+
+ *result = test_bit(b, (unsigned long *) &info->current_bits);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(dm_bitset_test_bit);
+
+/*----------------------------------------------------------------*/