Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / drivers / md / persistent-data / dm-bitset.c

diff --git a/kernel/drivers/md/persistent-data/dm-bitset.c b/kernel/drivers/md/persistent-data/dm-bitset.c
new file mode 100644 (file)
index 0000000..36f7cc2
--- /dev/null
+++ b/kernel/drivers/md/persistent-data/dm-bitset.c
@@ -0,0 +1,171 @@
+/*
+ * 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 || !info->dirty)
+               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;
+       info->dirty = 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;
+       info->dirty = false;
+
+       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);
+       info->dirty = true;
+
+       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);
+       info->dirty = true;
+
+       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);
+
+/*----------------------------------------------------------------*/