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-rw-r--r--contrib/qemu/block/qcow2-cache.c323
1 files changed, 0 insertions, 323 deletions
diff --git a/contrib/qemu/block/qcow2-cache.c b/contrib/qemu/block/qcow2-cache.c
deleted file mode 100644
index 2f3114ecc24..00000000000
--- a/contrib/qemu/block/qcow2-cache.c
+++ /dev/null
@@ -1,323 +0,0 @@
-/*
- * L2/refcount table cache for the QCOW2 format
- *
- * Copyright (c) 2010 Kevin Wolf <kwolf@redhat.com>
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in
- * all copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
- * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
- * THE SOFTWARE.
- */
-
-#include "block/block_int.h"
-#include "qemu-common.h"
-#include "qcow2.h"
-#include "trace.h"
-
-typedef struct Qcow2CachedTable {
- void* table;
- int64_t offset;
- bool dirty;
- int cache_hits;
- int ref;
-} Qcow2CachedTable;
-
-struct Qcow2Cache {
- Qcow2CachedTable* entries;
- struct Qcow2Cache* depends;
- int size;
- bool depends_on_flush;
-};
-
-Qcow2Cache *qcow2_cache_create(BlockDriverState *bs, int num_tables)
-{
- BDRVQcowState *s = bs->opaque;
- Qcow2Cache *c;
- int i;
-
- c = g_malloc0(sizeof(*c));
- c->size = num_tables;
- c->entries = g_malloc0(sizeof(*c->entries) * num_tables);
-
- for (i = 0; i < c->size; i++) {
- c->entries[i].table = qemu_blockalign(bs, s->cluster_size);
- }
-
- return c;
-}
-
-int qcow2_cache_destroy(BlockDriverState* bs, Qcow2Cache *c)
-{
- int i;
-
- for (i = 0; i < c->size; i++) {
- assert(c->entries[i].ref == 0);
- qemu_vfree(c->entries[i].table);
- }
-
- g_free(c->entries);
- g_free(c);
-
- return 0;
-}
-
-static int qcow2_cache_flush_dependency(BlockDriverState *bs, Qcow2Cache *c)
-{
- int ret;
-
- ret = qcow2_cache_flush(bs, c->depends);
- if (ret < 0) {
- return ret;
- }
-
- c->depends = NULL;
- c->depends_on_flush = false;
-
- return 0;
-}
-
-static int qcow2_cache_entry_flush(BlockDriverState *bs, Qcow2Cache *c, int i)
-{
- BDRVQcowState *s = bs->opaque;
- int ret = 0;
-
- if (!c->entries[i].dirty || !c->entries[i].offset) {
- return 0;
- }
-
- trace_qcow2_cache_entry_flush(qemu_coroutine_self(),
- c == s->l2_table_cache, i);
-
- if (c->depends) {
- ret = qcow2_cache_flush_dependency(bs, c);
- } else if (c->depends_on_flush) {
- ret = bdrv_flush(bs->file);
- if (ret >= 0) {
- c->depends_on_flush = false;
- }
- }
-
- if (ret < 0) {
- return ret;
- }
-
- if (c == s->refcount_block_cache) {
- BLKDBG_EVENT(bs->file, BLKDBG_REFBLOCK_UPDATE_PART);
- } else if (c == s->l2_table_cache) {
- BLKDBG_EVENT(bs->file, BLKDBG_L2_UPDATE);
- }
-
- ret = bdrv_pwrite(bs->file, c->entries[i].offset, c->entries[i].table,
- s->cluster_size);
- if (ret < 0) {
- return ret;
- }
-
- c->entries[i].dirty = false;
-
- return 0;
-}
-
-int qcow2_cache_flush(BlockDriverState *bs, Qcow2Cache *c)
-{
- BDRVQcowState *s = bs->opaque;
- int result = 0;
- int ret;
- int i;
-
- trace_qcow2_cache_flush(qemu_coroutine_self(), c == s->l2_table_cache);
-
- for (i = 0; i < c->size; i++) {
- ret = qcow2_cache_entry_flush(bs, c, i);
- if (ret < 0 && result != -ENOSPC) {
- result = ret;
- }
- }
-
- if (result == 0) {
- ret = bdrv_flush(bs->file);
- if (ret < 0) {
- result = ret;
- }
- }
-
- return result;
-}
-
-int qcow2_cache_set_dependency(BlockDriverState *bs, Qcow2Cache *c,
- Qcow2Cache *dependency)
-{
- int ret;
-
- if (dependency->depends) {
- ret = qcow2_cache_flush_dependency(bs, dependency);
- if (ret < 0) {
- return ret;
- }
- }
-
- if (c->depends && (c->depends != dependency)) {
- ret = qcow2_cache_flush_dependency(bs, c);
- if (ret < 0) {
- return ret;
- }
- }
-
- c->depends = dependency;
- return 0;
-}
-
-void qcow2_cache_depends_on_flush(Qcow2Cache *c)
-{
- c->depends_on_flush = true;
-}
-
-static int qcow2_cache_find_entry_to_replace(Qcow2Cache *c)
-{
- int i;
- int min_count = INT_MAX;
- int min_index = -1;
-
-
- for (i = 0; i < c->size; i++) {
- if (c->entries[i].ref) {
- continue;
- }
-
- if (c->entries[i].cache_hits < min_count) {
- min_index = i;
- min_count = c->entries[i].cache_hits;
- }
-
- /* Give newer hits priority */
- /* TODO Check how to optimize the replacement strategy */
- c->entries[i].cache_hits /= 2;
- }
-
- if (min_index == -1) {
- /* This can't happen in current synchronous code, but leave the check
- * here as a reminder for whoever starts using AIO with the cache */
- abort();
- }
- return min_index;
-}
-
-static int qcow2_cache_do_get(BlockDriverState *bs, Qcow2Cache *c,
- uint64_t offset, void **table, bool read_from_disk)
-{
- BDRVQcowState *s = bs->opaque;
- int i;
- int ret;
-
- trace_qcow2_cache_get(qemu_coroutine_self(), c == s->l2_table_cache,
- offset, read_from_disk);
-
- /* Check if the table is already cached */
- for (i = 0; i < c->size; i++) {
- if (c->entries[i].offset == offset) {
- goto found;
- }
- }
-
- /* If not, write a table back and replace it */
- i = qcow2_cache_find_entry_to_replace(c);
- trace_qcow2_cache_get_replace_entry(qemu_coroutine_self(),
- c == s->l2_table_cache, i);
- if (i < 0) {
- return i;
- }
-
- ret = qcow2_cache_entry_flush(bs, c, i);
- if (ret < 0) {
- return ret;
- }
-
- trace_qcow2_cache_get_read(qemu_coroutine_self(),
- c == s->l2_table_cache, i);
- c->entries[i].offset = 0;
- if (read_from_disk) {
- if (c == s->l2_table_cache) {
- BLKDBG_EVENT(bs->file, BLKDBG_L2_LOAD);
- }
-
- ret = bdrv_pread(bs->file, offset, c->entries[i].table, s->cluster_size);
- if (ret < 0) {
- return ret;
- }
- }
-
- /* Give the table some hits for the start so that it won't be replaced
- * immediately. The number 32 is completely arbitrary. */
- c->entries[i].cache_hits = 32;
- c->entries[i].offset = offset;
-
- /* And return the right table */
-found:
- c->entries[i].cache_hits++;
- c->entries[i].ref++;
- *table = c->entries[i].table;
-
- trace_qcow2_cache_get_done(qemu_coroutine_self(),
- c == s->l2_table_cache, i);
-
- return 0;
-}
-
-int qcow2_cache_get(BlockDriverState *bs, Qcow2Cache *c, uint64_t offset,
- void **table)
-{
- return qcow2_cache_do_get(bs, c, offset, table, true);
-}
-
-int qcow2_cache_get_empty(BlockDriverState *bs, Qcow2Cache *c, uint64_t offset,
- void **table)
-{
- return qcow2_cache_do_get(bs, c, offset, table, false);
-}
-
-int qcow2_cache_put(BlockDriverState *bs, Qcow2Cache *c, void **table)
-{
- int i;
-
- for (i = 0; i < c->size; i++) {
- if (c->entries[i].table == *table) {
- goto found;
- }
- }
- return -ENOENT;
-
-found:
- c->entries[i].ref--;
- *table = NULL;
-
- assert(c->entries[i].ref >= 0);
- return 0;
-}
-
-void qcow2_cache_entry_mark_dirty(Qcow2Cache *c, void *table)
-{
- int i;
-
- for (i = 0; i < c->size; i++) {
- if (c->entries[i].table == table) {
- goto found;
- }
- }
- abort();
-
-found:
- c->entries[i].dirty = true;
-}
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