root / block / qcow2-refcount.c @ 018faafd
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/*
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* Block driver for the QCOW version 2 format
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*
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* Copyright (c) 2004-2006 Fabrice Bellard
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy
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* of this software and associated documentation files (the "Software"), to deal
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* in the Software without restriction, including without limitation the rights
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* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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* copies of the Software, and to permit persons to whom the Software is
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* furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in
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* all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
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* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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* THE SOFTWARE.
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*/
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#include "qemu-common.h" |
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#include "block_int.h" |
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#include "block/qcow2.h" |
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|
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static int64_t alloc_clusters_noref(BlockDriverState *bs, int64_t size);
|
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static int QEMU_WARN_UNUSED_RESULT update_refcount(BlockDriverState *bs, |
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int64_t offset, int64_t length, |
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int addend);
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|
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static int cache_refcount_updates = 0; |
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static int write_refcount_block(BlockDriverState *bs) |
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{ |
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BDRVQcowState *s = bs->opaque; |
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size_t size = s->cluster_size; |
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|
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if (s->refcount_block_cache_offset == 0) { |
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return 0; |
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} |
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|
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BLKDBG_EVENT(bs->file, BLKDBG_REFBLOCK_UPDATE); |
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if (bdrv_pwrite(bs->file, s->refcount_block_cache_offset,
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s->refcount_block_cache, size) != size) |
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{ |
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return -EIO;
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} |
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return 0; |
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} |
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|
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/*********************************************************/
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/* refcount handling */
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|
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int qcow2_refcount_init(BlockDriverState *bs)
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{ |
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BDRVQcowState *s = bs->opaque; |
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int ret, refcount_table_size2, i;
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|
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s->refcount_block_cache = qemu_malloc(s->cluster_size); |
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refcount_table_size2 = s->refcount_table_size * sizeof(uint64_t);
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s->refcount_table = qemu_malloc(refcount_table_size2); |
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if (s->refcount_table_size > 0) { |
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BLKDBG_EVENT(bs->file, BLKDBG_REFTABLE_LOAD); |
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ret = bdrv_pread(bs->file, s->refcount_table_offset, |
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s->refcount_table, refcount_table_size2); |
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if (ret != refcount_table_size2)
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goto fail;
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for(i = 0; i < s->refcount_table_size; i++) |
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be64_to_cpus(&s->refcount_table[i]); |
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} |
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return 0; |
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fail:
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return -ENOMEM;
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} |
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|
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void qcow2_refcount_close(BlockDriverState *bs)
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{ |
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BDRVQcowState *s = bs->opaque; |
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qemu_free(s->refcount_block_cache); |
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qemu_free(s->refcount_table); |
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} |
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|
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|
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static int load_refcount_block(BlockDriverState *bs, |
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int64_t refcount_block_offset) |
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{ |
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BDRVQcowState *s = bs->opaque; |
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int ret;
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|
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if (cache_refcount_updates) {
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write_refcount_block(bs); |
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} |
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|
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BLKDBG_EVENT(bs->file, BLKDBG_REFBLOCK_LOAD); |
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ret = bdrv_pread(bs->file, refcount_block_offset, s->refcount_block_cache, |
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s->cluster_size); |
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if (ret != s->cluster_size)
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return -EIO;
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s->refcount_block_cache_offset = refcount_block_offset; |
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return 0; |
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} |
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|
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/*
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* Returns the refcount of the cluster given by its index. Any non-negative
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* return value is the refcount of the cluster, negative values are -errno
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* and indicate an error.
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*/
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static int get_refcount(BlockDriverState *bs, int64_t cluster_index) |
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{ |
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BDRVQcowState *s = bs->opaque; |
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int refcount_table_index, block_index;
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int64_t refcount_block_offset; |
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int ret;
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refcount_table_index = cluster_index >> (s->cluster_bits - REFCOUNT_SHIFT); |
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if (refcount_table_index >= s->refcount_table_size)
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return 0; |
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refcount_block_offset = s->refcount_table[refcount_table_index]; |
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if (!refcount_block_offset)
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return 0; |
126 |
if (refcount_block_offset != s->refcount_block_cache_offset) {
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/* better than nothing: return allocated if read error */
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ret = load_refcount_block(bs, refcount_block_offset); |
129 |
if (ret < 0) { |
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return ret;
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} |
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} |
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block_index = cluster_index & |
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((1 << (s->cluster_bits - REFCOUNT_SHIFT)) - 1); |
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return be16_to_cpu(s->refcount_block_cache[block_index]);
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} |
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|
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/*
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* Rounds the refcount table size up to avoid growing the table for each single
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* refcount block that is allocated.
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*/
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static unsigned int next_refcount_table_size(BDRVQcowState *s, |
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unsigned int min_size) |
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{ |
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unsigned int min_clusters = (min_size >> (s->cluster_bits - 3)) + 1; |
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unsigned int refcount_table_clusters = |
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MAX(1, s->refcount_table_size >> (s->cluster_bits - 3)); |
148 |
|
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while (min_clusters > refcount_table_clusters) {
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refcount_table_clusters = (refcount_table_clusters * 3 + 1) / 2; |
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} |
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return refcount_table_clusters << (s->cluster_bits - 3); |
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} |
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|
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/* Checks if two offsets are described by the same refcount block */
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static int in_same_refcount_block(BDRVQcowState *s, uint64_t offset_a, |
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uint64_t offset_b) |
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{ |
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uint64_t block_a = offset_a >> (2 * s->cluster_bits - REFCOUNT_SHIFT);
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uint64_t block_b = offset_b >> (2 * s->cluster_bits - REFCOUNT_SHIFT);
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return (block_a == block_b);
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} |
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/*
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* Loads a refcount block. If it doesn't exist yet, it is allocated first
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* (including growing the refcount table if needed).
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*
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* Returns the offset of the refcount block on success or -errno in error case
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*/
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static int64_t alloc_refcount_block(BlockDriverState *bs, int64_t cluster_index)
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{ |
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BDRVQcowState *s = bs->opaque; |
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unsigned int refcount_table_index; |
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int ret;
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BLKDBG_EVENT(bs->file, BLKDBG_REFBLOCK_ALLOC); |
180 |
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/* Find the refcount block for the given cluster */
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refcount_table_index = cluster_index >> (s->cluster_bits - REFCOUNT_SHIFT); |
183 |
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if (refcount_table_index < s->refcount_table_size) {
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uint64_t refcount_block_offset = |
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s->refcount_table[refcount_table_index]; |
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/* If it's already there, we're done */
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if (refcount_block_offset) {
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if (refcount_block_offset != s->refcount_block_cache_offset) {
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ret = load_refcount_block(bs, refcount_block_offset); |
193 |
if (ret < 0) { |
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return ret;
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} |
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} |
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return refcount_block_offset;
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} |
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} |
200 |
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/*
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* If we came here, we need to allocate something. Something is at least
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* a cluster for the new refcount block. It may also include a new refcount
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* table if the old refcount table is too small.
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*
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* Note that allocating clusters here needs some special care:
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*
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* - We can't use the normal qcow2_alloc_clusters(), it would try to
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* increase the refcount and very likely we would end up with an endless
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* recursion. Instead we must place the refcount blocks in a way that
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* they can describe them themselves.
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*
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* - We need to consider that at this point we are inside update_refcounts
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* and doing the initial refcount increase. This means that some clusters
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* have already been allocated by the caller, but their refcount isn't
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* accurate yet. free_cluster_index tells us where this allocation ends
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* as long as we don't overwrite it by freeing clusters.
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*
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* - alloc_clusters_noref and qcow2_free_clusters may load a different
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* refcount block into the cache
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*/
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if (cache_refcount_updates) {
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ret = write_refcount_block(bs); |
225 |
if (ret < 0) { |
226 |
return ret;
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} |
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} |
229 |
|
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/* Allocate the refcount block itself and mark it as used */
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uint64_t new_block = alloc_clusters_noref(bs, s->cluster_size); |
232 |
|
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#ifdef DEBUG_ALLOC2
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fprintf(stderr, "qcow2: Allocate refcount block %d for %" PRIx64
|
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" at %" PRIx64 "\n", |
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refcount_table_index, cluster_index << s->cluster_bits, new_block); |
237 |
#endif
|
238 |
|
239 |
if (in_same_refcount_block(s, new_block, cluster_index << s->cluster_bits)) {
|
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/* Zero the new refcount block before updating it */
|
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memset(s->refcount_block_cache, 0, s->cluster_size);
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s->refcount_block_cache_offset = new_block; |
243 |
|
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/* The block describes itself, need to update the cache */
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int block_index = (new_block >> s->cluster_bits) &
|
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((1 << (s->cluster_bits - REFCOUNT_SHIFT)) - 1); |
247 |
s->refcount_block_cache[block_index] = cpu_to_be16(1);
|
248 |
} else {
|
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/* Described somewhere else. This can recurse at most twice before we
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250 |
* arrive at a block that describes itself. */
|
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ret = update_refcount(bs, new_block, s->cluster_size, 1);
|
252 |
if (ret < 0) { |
253 |
goto fail_block;
|
254 |
} |
255 |
|
256 |
/* Initialize the new refcount block only after updating its refcount,
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257 |
* update_refcount uses the refcount cache itself */
|
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memset(s->refcount_block_cache, 0, s->cluster_size);
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259 |
s->refcount_block_cache_offset = new_block; |
260 |
} |
261 |
|
262 |
/* Now the new refcount block needs to be written to disk */
|
263 |
BLKDBG_EVENT(bs->file, BLKDBG_REFBLOCK_ALLOC_WRITE); |
264 |
ret = bdrv_pwrite(bs->file, new_block, s->refcount_block_cache, |
265 |
s->cluster_size); |
266 |
if (ret < 0) { |
267 |
goto fail_block;
|
268 |
} |
269 |
|
270 |
/* If the refcount table is big enough, just hook the block up there */
|
271 |
if (refcount_table_index < s->refcount_table_size) {
|
272 |
uint64_t data64 = cpu_to_be64(new_block); |
273 |
BLKDBG_EVENT(bs->file, BLKDBG_REFBLOCK_ALLOC_HOOKUP); |
274 |
ret = bdrv_pwrite(bs->file, |
275 |
s->refcount_table_offset + refcount_table_index * sizeof(uint64_t),
|
276 |
&data64, sizeof(data64));
|
277 |
if (ret < 0) { |
278 |
goto fail_block;
|
279 |
} |
280 |
|
281 |
s->refcount_table[refcount_table_index] = new_block; |
282 |
return new_block;
|
283 |
} |
284 |
|
285 |
/*
|
286 |
* If we come here, we need to grow the refcount table. Again, a new
|
287 |
* refcount table needs some space and we can't simply allocate to avoid
|
288 |
* endless recursion.
|
289 |
*
|
290 |
* Therefore let's grab new refcount blocks at the end of the image, which
|
291 |
* will describe themselves and the new refcount table. This way we can
|
292 |
* reference them only in the new table and do the switch to the new
|
293 |
* refcount table at once without producing an inconsistent state in
|
294 |
* between.
|
295 |
*/
|
296 |
BLKDBG_EVENT(bs->file, BLKDBG_REFTABLE_GROW); |
297 |
|
298 |
/* Calculate the number of refcount blocks needed so far */
|
299 |
uint64_t refcount_block_clusters = 1 << (s->cluster_bits - REFCOUNT_SHIFT);
|
300 |
uint64_t blocks_used = (s->free_cluster_index + |
301 |
refcount_block_clusters - 1) / refcount_block_clusters;
|
302 |
|
303 |
/* And now we need at least one block more for the new metadata */
|
304 |
uint64_t table_size = next_refcount_table_size(s, blocks_used + 1);
|
305 |
uint64_t last_table_size; |
306 |
uint64_t blocks_clusters; |
307 |
do {
|
308 |
uint64_t table_clusters = size_to_clusters(s, table_size); |
309 |
blocks_clusters = 1 +
|
310 |
((table_clusters + refcount_block_clusters - 1)
|
311 |
/ refcount_block_clusters); |
312 |
uint64_t meta_clusters = table_clusters + blocks_clusters; |
313 |
|
314 |
last_table_size = table_size; |
315 |
table_size = next_refcount_table_size(s, blocks_used + |
316 |
((meta_clusters + refcount_block_clusters - 1)
|
317 |
/ refcount_block_clusters)); |
318 |
|
319 |
} while (last_table_size != table_size);
|
320 |
|
321 |
#ifdef DEBUG_ALLOC2
|
322 |
fprintf(stderr, "qcow2: Grow refcount table %" PRId32 " => %" PRId64 "\n", |
323 |
s->refcount_table_size, table_size); |
324 |
#endif
|
325 |
|
326 |
/* Create the new refcount table and blocks */
|
327 |
uint64_t meta_offset = (blocks_used * refcount_block_clusters) * |
328 |
s->cluster_size; |
329 |
uint64_t table_offset = meta_offset + blocks_clusters * s->cluster_size; |
330 |
uint16_t *new_blocks = qemu_mallocz(blocks_clusters * s->cluster_size); |
331 |
uint64_t *new_table = qemu_mallocz(table_size * sizeof(uint64_t));
|
332 |
|
333 |
assert(meta_offset >= (s->free_cluster_index * s->cluster_size)); |
334 |
|
335 |
/* Fill the new refcount table */
|
336 |
memcpy(new_table, s->refcount_table, |
337 |
s->refcount_table_size * sizeof(uint64_t));
|
338 |
new_table[refcount_table_index] = new_block; |
339 |
|
340 |
int i;
|
341 |
for (i = 0; i < blocks_clusters; i++) { |
342 |
new_table[blocks_used + i] = meta_offset + (i * s->cluster_size); |
343 |
} |
344 |
|
345 |
/* Fill the refcount blocks */
|
346 |
uint64_t table_clusters = size_to_clusters(s, table_size * sizeof(uint64_t));
|
347 |
int block = 0; |
348 |
for (i = 0; i < table_clusters + blocks_clusters; i++) { |
349 |
new_blocks[block++] = cpu_to_be16(1);
|
350 |
} |
351 |
|
352 |
/* Write refcount blocks to disk */
|
353 |
BLKDBG_EVENT(bs->file, BLKDBG_REFBLOCK_ALLOC_WRITE_BLOCKS); |
354 |
ret = bdrv_pwrite(bs->file, meta_offset, new_blocks, |
355 |
blocks_clusters * s->cluster_size); |
356 |
qemu_free(new_blocks); |
357 |
if (ret < 0) { |
358 |
goto fail_table;
|
359 |
} |
360 |
|
361 |
/* Write refcount table to disk */
|
362 |
for(i = 0; i < table_size; i++) { |
363 |
cpu_to_be64s(&new_table[i]); |
364 |
} |
365 |
|
366 |
BLKDBG_EVENT(bs->file, BLKDBG_REFBLOCK_ALLOC_WRITE_TABLE); |
367 |
ret = bdrv_pwrite(bs->file, table_offset, new_table, |
368 |
table_size * sizeof(uint64_t));
|
369 |
if (ret < 0) { |
370 |
goto fail_table;
|
371 |
} |
372 |
|
373 |
for(i = 0; i < table_size; i++) { |
374 |
cpu_to_be64s(&new_table[i]); |
375 |
} |
376 |
|
377 |
/* Hook up the new refcount table in the qcow2 header */
|
378 |
uint8_t data[12];
|
379 |
cpu_to_be64w((uint64_t*)data, table_offset); |
380 |
cpu_to_be32w((uint32_t*)(data + 8), table_clusters);
|
381 |
BLKDBG_EVENT(bs->file, BLKDBG_REFBLOCK_ALLOC_SWITCH_TABLE); |
382 |
ret = bdrv_pwrite(bs->file, offsetof(QCowHeader, refcount_table_offset), |
383 |
data, sizeof(data));
|
384 |
if (ret < 0) { |
385 |
goto fail_table;
|
386 |
} |
387 |
|
388 |
/* And switch it in memory */
|
389 |
uint64_t old_table_offset = s->refcount_table_offset; |
390 |
uint64_t old_table_size = s->refcount_table_size; |
391 |
|
392 |
qemu_free(s->refcount_table); |
393 |
s->refcount_table = new_table; |
394 |
s->refcount_table_size = table_size; |
395 |
s->refcount_table_offset = table_offset; |
396 |
|
397 |
/* Free old table. Remember, we must not change free_cluster_index */
|
398 |
uint64_t old_free_cluster_index = s->free_cluster_index; |
399 |
qcow2_free_clusters(bs, old_table_offset, old_table_size * sizeof(uint64_t));
|
400 |
s->free_cluster_index = old_free_cluster_index; |
401 |
|
402 |
ret = load_refcount_block(bs, new_block); |
403 |
if (ret < 0) { |
404 |
goto fail_block;
|
405 |
} |
406 |
|
407 |
return new_block;
|
408 |
|
409 |
fail_table:
|
410 |
qemu_free(new_table); |
411 |
fail_block:
|
412 |
s->refcount_block_cache_offset = 0;
|
413 |
return ret;
|
414 |
} |
415 |
|
416 |
#define REFCOUNTS_PER_SECTOR (512 >> REFCOUNT_SHIFT) |
417 |
static int write_refcount_block_entries(BlockDriverState *bs, |
418 |
int64_t refcount_block_offset, int first_index, int last_index) |
419 |
{ |
420 |
BDRVQcowState *s = bs->opaque; |
421 |
size_t size; |
422 |
int ret;
|
423 |
|
424 |
if (cache_refcount_updates) {
|
425 |
return 0; |
426 |
} |
427 |
|
428 |
if (first_index < 0) { |
429 |
return 0; |
430 |
} |
431 |
|
432 |
first_index &= ~(REFCOUNTS_PER_SECTOR - 1);
|
433 |
last_index = (last_index + REFCOUNTS_PER_SECTOR) |
434 |
& ~(REFCOUNTS_PER_SECTOR - 1);
|
435 |
|
436 |
size = (last_index - first_index) << REFCOUNT_SHIFT; |
437 |
|
438 |
BLKDBG_EVENT(bs->file, BLKDBG_REFBLOCK_UPDATE_PART); |
439 |
ret = bdrv_pwrite(bs->file, |
440 |
refcount_block_offset + (first_index << REFCOUNT_SHIFT), |
441 |
&s->refcount_block_cache[first_index], size); |
442 |
if (ret < 0) { |
443 |
return ret;
|
444 |
} |
445 |
|
446 |
return 0; |
447 |
} |
448 |
|
449 |
/* XXX: cache several refcount block clusters ? */
|
450 |
static int QEMU_WARN_UNUSED_RESULT update_refcount(BlockDriverState *bs, |
451 |
int64_t offset, int64_t length, int addend)
|
452 |
{ |
453 |
BDRVQcowState *s = bs->opaque; |
454 |
int64_t start, last, cluster_offset; |
455 |
int64_t refcount_block_offset = 0;
|
456 |
int64_t table_index = -1, old_table_index;
|
457 |
int first_index = -1, last_index = -1; |
458 |
int ret;
|
459 |
|
460 |
#ifdef DEBUG_ALLOC2
|
461 |
printf("update_refcount: offset=%" PRId64 " size=%" PRId64 " addend=%d\n", |
462 |
offset, length, addend); |
463 |
#endif
|
464 |
if (length < 0) { |
465 |
return -EINVAL;
|
466 |
} else if (length == 0) { |
467 |
return 0; |
468 |
} |
469 |
|
470 |
start = offset & ~(s->cluster_size - 1);
|
471 |
last = (offset + length - 1) & ~(s->cluster_size - 1); |
472 |
for(cluster_offset = start; cluster_offset <= last;
|
473 |
cluster_offset += s->cluster_size) |
474 |
{ |
475 |
int block_index, refcount;
|
476 |
int64_t cluster_index = cluster_offset >> s->cluster_bits; |
477 |
int64_t new_block; |
478 |
|
479 |
/* Only write refcount block to disk when we are done with it */
|
480 |
old_table_index = table_index; |
481 |
table_index = cluster_index >> (s->cluster_bits - REFCOUNT_SHIFT); |
482 |
if ((old_table_index >= 0) && (table_index != old_table_index)) { |
483 |
|
484 |
ret = write_refcount_block_entries(bs, refcount_block_offset, |
485 |
first_index, last_index); |
486 |
if (ret < 0) { |
487 |
return ret;
|
488 |
} |
489 |
|
490 |
first_index = -1;
|
491 |
last_index = -1;
|
492 |
} |
493 |
|
494 |
/* Load the refcount block and allocate it if needed */
|
495 |
new_block = alloc_refcount_block(bs, cluster_index); |
496 |
if (new_block < 0) { |
497 |
ret = new_block; |
498 |
goto fail;
|
499 |
} |
500 |
refcount_block_offset = new_block; |
501 |
|
502 |
/* we can update the count and save it */
|
503 |
block_index = cluster_index & |
504 |
((1 << (s->cluster_bits - REFCOUNT_SHIFT)) - 1); |
505 |
if (first_index == -1 || block_index < first_index) { |
506 |
first_index = block_index; |
507 |
} |
508 |
if (block_index > last_index) {
|
509 |
last_index = block_index; |
510 |
} |
511 |
|
512 |
refcount = be16_to_cpu(s->refcount_block_cache[block_index]); |
513 |
refcount += addend; |
514 |
if (refcount < 0 || refcount > 0xffff) { |
515 |
ret = -EINVAL; |
516 |
goto fail;
|
517 |
} |
518 |
if (refcount == 0 && cluster_index < s->free_cluster_index) { |
519 |
s->free_cluster_index = cluster_index; |
520 |
} |
521 |
s->refcount_block_cache[block_index] = cpu_to_be16(refcount); |
522 |
} |
523 |
|
524 |
ret = 0;
|
525 |
fail:
|
526 |
|
527 |
/* Write last changed block to disk */
|
528 |
if (refcount_block_offset != 0) { |
529 |
int wret;
|
530 |
wret = write_refcount_block_entries(bs, refcount_block_offset, |
531 |
first_index, last_index); |
532 |
if (wret < 0) { |
533 |
return ret < 0 ? ret : wret; |
534 |
} |
535 |
} |
536 |
|
537 |
/*
|
538 |
* Try do undo any updates if an error is returned (This may succeed in
|
539 |
* some cases like ENOSPC for allocating a new refcount block)
|
540 |
*/
|
541 |
if (ret < 0) { |
542 |
int dummy;
|
543 |
dummy = update_refcount(bs, offset, cluster_offset - offset, -addend); |
544 |
} |
545 |
|
546 |
return ret;
|
547 |
} |
548 |
|
549 |
/*
|
550 |
* Increases or decreases the refcount of a given cluster by one.
|
551 |
* addend must be 1 or -1.
|
552 |
*
|
553 |
* If the return value is non-negative, it is the new refcount of the cluster.
|
554 |
* If it is negative, it is -errno and indicates an error.
|
555 |
*/
|
556 |
static int update_cluster_refcount(BlockDriverState *bs, |
557 |
int64_t cluster_index, |
558 |
int addend)
|
559 |
{ |
560 |
BDRVQcowState *s = bs->opaque; |
561 |
int ret;
|
562 |
|
563 |
ret = update_refcount(bs, cluster_index << s->cluster_bits, 1, addend);
|
564 |
if (ret < 0) { |
565 |
return ret;
|
566 |
} |
567 |
|
568 |
return get_refcount(bs, cluster_index);
|
569 |
} |
570 |
|
571 |
|
572 |
|
573 |
/*********************************************************/
|
574 |
/* cluster allocation functions */
|
575 |
|
576 |
|
577 |
|
578 |
/* return < 0 if error */
|
579 |
static int64_t alloc_clusters_noref(BlockDriverState *bs, int64_t size)
|
580 |
{ |
581 |
BDRVQcowState *s = bs->opaque; |
582 |
int i, nb_clusters;
|
583 |
|
584 |
nb_clusters = size_to_clusters(s, size); |
585 |
retry:
|
586 |
for(i = 0; i < nb_clusters; i++) { |
587 |
int64_t next_cluster_index = s->free_cluster_index++; |
588 |
if (get_refcount(bs, next_cluster_index) != 0) |
589 |
goto retry;
|
590 |
} |
591 |
#ifdef DEBUG_ALLOC2
|
592 |
printf("alloc_clusters: size=%" PRId64 " -> %" PRId64 "\n", |
593 |
size, |
594 |
(s->free_cluster_index - nb_clusters) << s->cluster_bits); |
595 |
#endif
|
596 |
return (s->free_cluster_index - nb_clusters) << s->cluster_bits;
|
597 |
} |
598 |
|
599 |
int64_t qcow2_alloc_clusters(BlockDriverState *bs, int64_t size) |
600 |
{ |
601 |
int64_t offset; |
602 |
int ret;
|
603 |
|
604 |
BLKDBG_EVENT(bs->file, BLKDBG_CLUSTER_ALLOC); |
605 |
offset = alloc_clusters_noref(bs, size); |
606 |
ret = update_refcount(bs, offset, size, 1);
|
607 |
if (ret < 0) { |
608 |
return ret;
|
609 |
} |
610 |
return offset;
|
611 |
} |
612 |
|
613 |
/* only used to allocate compressed sectors. We try to allocate
|
614 |
contiguous sectors. size must be <= cluster_size */
|
615 |
int64_t qcow2_alloc_bytes(BlockDriverState *bs, int size)
|
616 |
{ |
617 |
BDRVQcowState *s = bs->opaque; |
618 |
int64_t offset, cluster_offset; |
619 |
int free_in_cluster;
|
620 |
|
621 |
BLKDBG_EVENT(bs->file, BLKDBG_CLUSTER_ALLOC_BYTES); |
622 |
assert(size > 0 && size <= s->cluster_size);
|
623 |
if (s->free_byte_offset == 0) { |
624 |
s->free_byte_offset = qcow2_alloc_clusters(bs, s->cluster_size); |
625 |
if (s->free_byte_offset < 0) { |
626 |
return s->free_byte_offset;
|
627 |
} |
628 |
} |
629 |
redo:
|
630 |
free_in_cluster = s->cluster_size - |
631 |
(s->free_byte_offset & (s->cluster_size - 1));
|
632 |
if (size <= free_in_cluster) {
|
633 |
/* enough space in current cluster */
|
634 |
offset = s->free_byte_offset; |
635 |
s->free_byte_offset += size; |
636 |
free_in_cluster -= size; |
637 |
if (free_in_cluster == 0) |
638 |
s->free_byte_offset = 0;
|
639 |
if ((offset & (s->cluster_size - 1)) != 0) |
640 |
update_cluster_refcount(bs, offset >> s->cluster_bits, 1);
|
641 |
} else {
|
642 |
offset = qcow2_alloc_clusters(bs, s->cluster_size); |
643 |
if (offset < 0) { |
644 |
return offset;
|
645 |
} |
646 |
cluster_offset = s->free_byte_offset & ~(s->cluster_size - 1);
|
647 |
if ((cluster_offset + s->cluster_size) == offset) {
|
648 |
/* we are lucky: contiguous data */
|
649 |
offset = s->free_byte_offset; |
650 |
update_cluster_refcount(bs, offset >> s->cluster_bits, 1);
|
651 |
s->free_byte_offset += size; |
652 |
} else {
|
653 |
s->free_byte_offset = offset; |
654 |
goto redo;
|
655 |
} |
656 |
} |
657 |
return offset;
|
658 |
} |
659 |
|
660 |
void qcow2_free_clusters(BlockDriverState *bs,
|
661 |
int64_t offset, int64_t size) |
662 |
{ |
663 |
int ret;
|
664 |
|
665 |
BLKDBG_EVENT(bs->file, BLKDBG_CLUSTER_FREE); |
666 |
ret = update_refcount(bs, offset, size, -1);
|
667 |
if (ret < 0) { |
668 |
fprintf(stderr, "qcow2_free_clusters failed: %s\n", strerror(-ret));
|
669 |
/* TODO Remember the clusters to free them later and avoid leaking */
|
670 |
} |
671 |
} |
672 |
|
673 |
/*
|
674 |
* free_any_clusters
|
675 |
*
|
676 |
* free clusters according to its type: compressed or not
|
677 |
*
|
678 |
*/
|
679 |
|
680 |
void qcow2_free_any_clusters(BlockDriverState *bs,
|
681 |
uint64_t cluster_offset, int nb_clusters)
|
682 |
{ |
683 |
BDRVQcowState *s = bs->opaque; |
684 |
|
685 |
/* free the cluster */
|
686 |
|
687 |
if (cluster_offset & QCOW_OFLAG_COMPRESSED) {
|
688 |
int nb_csectors;
|
689 |
nb_csectors = ((cluster_offset >> s->csize_shift) & |
690 |
s->csize_mask) + 1;
|
691 |
qcow2_free_clusters(bs, |
692 |
(cluster_offset & s->cluster_offset_mask) & ~511,
|
693 |
nb_csectors * 512);
|
694 |
return;
|
695 |
} |
696 |
|
697 |
qcow2_free_clusters(bs, cluster_offset, nb_clusters << s->cluster_bits); |
698 |
|
699 |
return;
|
700 |
} |
701 |
|
702 |
|
703 |
|
704 |
/*********************************************************/
|
705 |
/* snapshots and image creation */
|
706 |
|
707 |
|
708 |
|
709 |
void qcow2_create_refcount_update(QCowCreateState *s, int64_t offset,
|
710 |
int64_t size) |
711 |
{ |
712 |
int refcount;
|
713 |
int64_t start, last, cluster_offset; |
714 |
uint16_t *p; |
715 |
|
716 |
start = offset & ~(s->cluster_size - 1);
|
717 |
last = (offset + size - 1) & ~(s->cluster_size - 1); |
718 |
for(cluster_offset = start; cluster_offset <= last;
|
719 |
cluster_offset += s->cluster_size) { |
720 |
p = &s->refcount_block[cluster_offset >> s->cluster_bits]; |
721 |
refcount = be16_to_cpu(*p); |
722 |
refcount++; |
723 |
*p = cpu_to_be16(refcount); |
724 |
} |
725 |
} |
726 |
|
727 |
/* update the refcounts of snapshots and the copied flag */
|
728 |
int qcow2_update_snapshot_refcount(BlockDriverState *bs,
|
729 |
int64_t l1_table_offset, int l1_size, int addend) |
730 |
{ |
731 |
BDRVQcowState *s = bs->opaque; |
732 |
uint64_t *l1_table, *l2_table, l2_offset, offset, l1_size2, l1_allocated; |
733 |
int64_t old_offset, old_l2_offset; |
734 |
int l2_size, i, j, l1_modified, l2_modified, nb_csectors, refcount;
|
735 |
|
736 |
qcow2_l2_cache_reset(bs); |
737 |
cache_refcount_updates = 1;
|
738 |
|
739 |
l2_table = NULL;
|
740 |
l1_table = NULL;
|
741 |
l1_size2 = l1_size * sizeof(uint64_t);
|
742 |
if (l1_table_offset != s->l1_table_offset) {
|
743 |
if (l1_size2 != 0) { |
744 |
l1_table = qemu_mallocz(align_offset(l1_size2, 512));
|
745 |
} else {
|
746 |
l1_table = NULL;
|
747 |
} |
748 |
l1_allocated = 1;
|
749 |
if (bdrv_pread(bs->file, l1_table_offset,
|
750 |
l1_table, l1_size2) != l1_size2) |
751 |
goto fail;
|
752 |
for(i = 0;i < l1_size; i++) |
753 |
be64_to_cpus(&l1_table[i]); |
754 |
} else {
|
755 |
assert(l1_size == s->l1_size); |
756 |
l1_table = s->l1_table; |
757 |
l1_allocated = 0;
|
758 |
} |
759 |
|
760 |
l2_size = s->l2_size * sizeof(uint64_t);
|
761 |
l2_table = qemu_malloc(l2_size); |
762 |
l1_modified = 0;
|
763 |
for(i = 0; i < l1_size; i++) { |
764 |
l2_offset = l1_table[i]; |
765 |
if (l2_offset) {
|
766 |
old_l2_offset = l2_offset; |
767 |
l2_offset &= ~QCOW_OFLAG_COPIED; |
768 |
l2_modified = 0;
|
769 |
if (bdrv_pread(bs->file, l2_offset, l2_table, l2_size) != l2_size)
|
770 |
goto fail;
|
771 |
for(j = 0; j < s->l2_size; j++) { |
772 |
offset = be64_to_cpu(l2_table[j]); |
773 |
if (offset != 0) { |
774 |
old_offset = offset; |
775 |
offset &= ~QCOW_OFLAG_COPIED; |
776 |
if (offset & QCOW_OFLAG_COMPRESSED) {
|
777 |
nb_csectors = ((offset >> s->csize_shift) & |
778 |
s->csize_mask) + 1;
|
779 |
if (addend != 0) { |
780 |
int ret;
|
781 |
ret = update_refcount(bs, |
782 |
(offset & s->cluster_offset_mask) & ~511,
|
783 |
nb_csectors * 512, addend);
|
784 |
if (ret < 0) { |
785 |
goto fail;
|
786 |
} |
787 |
} |
788 |
/* compressed clusters are never modified */
|
789 |
refcount = 2;
|
790 |
} else {
|
791 |
if (addend != 0) { |
792 |
refcount = update_cluster_refcount(bs, offset >> s->cluster_bits, addend); |
793 |
} else {
|
794 |
refcount = get_refcount(bs, offset >> s->cluster_bits); |
795 |
} |
796 |
|
797 |
if (refcount < 0) { |
798 |
goto fail;
|
799 |
} |
800 |
} |
801 |
|
802 |
if (refcount == 1) { |
803 |
offset |= QCOW_OFLAG_COPIED; |
804 |
} |
805 |
if (offset != old_offset) {
|
806 |
l2_table[j] = cpu_to_be64(offset); |
807 |
l2_modified = 1;
|
808 |
} |
809 |
} |
810 |
} |
811 |
if (l2_modified) {
|
812 |
if (bdrv_pwrite(bs->file,
|
813 |
l2_offset, l2_table, l2_size) != l2_size) |
814 |
goto fail;
|
815 |
} |
816 |
|
817 |
if (addend != 0) { |
818 |
refcount = update_cluster_refcount(bs, l2_offset >> s->cluster_bits, addend); |
819 |
} else {
|
820 |
refcount = get_refcount(bs, l2_offset >> s->cluster_bits); |
821 |
} |
822 |
if (refcount < 0) { |
823 |
goto fail;
|
824 |
} else if (refcount == 1) { |
825 |
l2_offset |= QCOW_OFLAG_COPIED; |
826 |
} |
827 |
if (l2_offset != old_l2_offset) {
|
828 |
l1_table[i] = l2_offset; |
829 |
l1_modified = 1;
|
830 |
} |
831 |
} |
832 |
} |
833 |
if (l1_modified) {
|
834 |
for(i = 0; i < l1_size; i++) |
835 |
cpu_to_be64s(&l1_table[i]); |
836 |
if (bdrv_pwrite(bs->file, l1_table_offset, l1_table,
|
837 |
l1_size2) != l1_size2) |
838 |
goto fail;
|
839 |
for(i = 0; i < l1_size; i++) |
840 |
be64_to_cpus(&l1_table[i]); |
841 |
} |
842 |
if (l1_allocated)
|
843 |
qemu_free(l1_table); |
844 |
qemu_free(l2_table); |
845 |
cache_refcount_updates = 0;
|
846 |
write_refcount_block(bs); |
847 |
return 0; |
848 |
fail:
|
849 |
if (l1_allocated)
|
850 |
qemu_free(l1_table); |
851 |
qemu_free(l2_table); |
852 |
cache_refcount_updates = 0;
|
853 |
write_refcount_block(bs); |
854 |
return -EIO;
|
855 |
} |
856 |
|
857 |
|
858 |
|
859 |
|
860 |
/*********************************************************/
|
861 |
/* refcount checking functions */
|
862 |
|
863 |
|
864 |
|
865 |
/*
|
866 |
* Increases the refcount for a range of clusters in a given refcount table.
|
867 |
* This is used to construct a temporary refcount table out of L1 and L2 tables
|
868 |
* which can be compared the the refcount table saved in the image.
|
869 |
*
|
870 |
* Returns the number of errors in the image that were found
|
871 |
*/
|
872 |
static int inc_refcounts(BlockDriverState *bs, |
873 |
uint16_t *refcount_table, |
874 |
int refcount_table_size,
|
875 |
int64_t offset, int64_t size) |
876 |
{ |
877 |
BDRVQcowState *s = bs->opaque; |
878 |
int64_t start, last, cluster_offset; |
879 |
int k;
|
880 |
int errors = 0; |
881 |
|
882 |
if (size <= 0) |
883 |
return 0; |
884 |
|
885 |
start = offset & ~(s->cluster_size - 1);
|
886 |
last = (offset + size - 1) & ~(s->cluster_size - 1); |
887 |
for(cluster_offset = start; cluster_offset <= last;
|
888 |
cluster_offset += s->cluster_size) { |
889 |
k = cluster_offset >> s->cluster_bits; |
890 |
if (k < 0 || k >= refcount_table_size) { |
891 |
fprintf(stderr, "ERROR: invalid cluster offset=0x%" PRIx64 "\n", |
892 |
cluster_offset); |
893 |
errors++; |
894 |
} else {
|
895 |
if (++refcount_table[k] == 0) { |
896 |
fprintf(stderr, "ERROR: overflow cluster offset=0x%" PRIx64
|
897 |
"\n", cluster_offset);
|
898 |
errors++; |
899 |
} |
900 |
} |
901 |
} |
902 |
|
903 |
return errors;
|
904 |
} |
905 |
|
906 |
/*
|
907 |
* Increases the refcount in the given refcount table for the all clusters
|
908 |
* referenced in the L2 table. While doing so, performs some checks on L2
|
909 |
* entries.
|
910 |
*
|
911 |
* Returns the number of errors found by the checks or -errno if an internal
|
912 |
* error occurred.
|
913 |
*/
|
914 |
static int check_refcounts_l2(BlockDriverState *bs, |
915 |
uint16_t *refcount_table, int refcount_table_size, int64_t l2_offset,
|
916 |
int check_copied)
|
917 |
{ |
918 |
BDRVQcowState *s = bs->opaque; |
919 |
uint64_t *l2_table, offset; |
920 |
int i, l2_size, nb_csectors, refcount;
|
921 |
int errors = 0; |
922 |
|
923 |
/* Read L2 table from disk */
|
924 |
l2_size = s->l2_size * sizeof(uint64_t);
|
925 |
l2_table = qemu_malloc(l2_size); |
926 |
|
927 |
if (bdrv_pread(bs->file, l2_offset, l2_table, l2_size) != l2_size)
|
928 |
goto fail;
|
929 |
|
930 |
/* Do the actual checks */
|
931 |
for(i = 0; i < s->l2_size; i++) { |
932 |
offset = be64_to_cpu(l2_table[i]); |
933 |
if (offset != 0) { |
934 |
if (offset & QCOW_OFLAG_COMPRESSED) {
|
935 |
/* Compressed clusters don't have QCOW_OFLAG_COPIED */
|
936 |
if (offset & QCOW_OFLAG_COPIED) {
|
937 |
fprintf(stderr, "ERROR: cluster %" PRId64 ": " |
938 |
"copied flag must never be set for compressed "
|
939 |
"clusters\n", offset >> s->cluster_bits);
|
940 |
offset &= ~QCOW_OFLAG_COPIED; |
941 |
errors++; |
942 |
} |
943 |
|
944 |
/* Mark cluster as used */
|
945 |
nb_csectors = ((offset >> s->csize_shift) & |
946 |
s->csize_mask) + 1;
|
947 |
offset &= s->cluster_offset_mask; |
948 |
errors += inc_refcounts(bs, refcount_table, |
949 |
refcount_table_size, |
950 |
offset & ~511, nb_csectors * 512); |
951 |
} else {
|
952 |
/* QCOW_OFLAG_COPIED must be set iff refcount == 1 */
|
953 |
if (check_copied) {
|
954 |
uint64_t entry = offset; |
955 |
offset &= ~QCOW_OFLAG_COPIED; |
956 |
refcount = get_refcount(bs, offset >> s->cluster_bits); |
957 |
if (refcount < 0) { |
958 |
fprintf(stderr, "Can't get refcount for offset %"
|
959 |
PRIx64 ": %s\n", entry, strerror(-refcount));
|
960 |
} |
961 |
if ((refcount == 1) != ((entry & QCOW_OFLAG_COPIED) != 0)) { |
962 |
fprintf(stderr, "ERROR OFLAG_COPIED: offset=%"
|
963 |
PRIx64 " refcount=%d\n", entry, refcount);
|
964 |
errors++; |
965 |
} |
966 |
} |
967 |
|
968 |
/* Mark cluster as used */
|
969 |
offset &= ~QCOW_OFLAG_COPIED; |
970 |
errors += inc_refcounts(bs, refcount_table, |
971 |
refcount_table_size, |
972 |
offset, s->cluster_size); |
973 |
|
974 |
/* Correct offsets are cluster aligned */
|
975 |
if (offset & (s->cluster_size - 1)) { |
976 |
fprintf(stderr, "ERROR offset=%" PRIx64 ": Cluster is not " |
977 |
"properly aligned; L2 entry corrupted.\n", offset);
|
978 |
errors++; |
979 |
} |
980 |
} |
981 |
} |
982 |
} |
983 |
|
984 |
qemu_free(l2_table); |
985 |
return errors;
|
986 |
|
987 |
fail:
|
988 |
fprintf(stderr, "ERROR: I/O error in check_refcounts_l1\n");
|
989 |
qemu_free(l2_table); |
990 |
return -EIO;
|
991 |
} |
992 |
|
993 |
/*
|
994 |
* Increases the refcount for the L1 table, its L2 tables and all referenced
|
995 |
* clusters in the given refcount table. While doing so, performs some checks
|
996 |
* on L1 and L2 entries.
|
997 |
*
|
998 |
* Returns the number of errors found by the checks or -errno if an internal
|
999 |
* error occurred.
|
1000 |
*/
|
1001 |
static int check_refcounts_l1(BlockDriverState *bs, |
1002 |
uint16_t *refcount_table, |
1003 |
int refcount_table_size,
|
1004 |
int64_t l1_table_offset, int l1_size,
|
1005 |
int check_copied)
|
1006 |
{ |
1007 |
BDRVQcowState *s = bs->opaque; |
1008 |
uint64_t *l1_table, l2_offset, l1_size2; |
1009 |
int i, refcount, ret;
|
1010 |
int errors = 0; |
1011 |
|
1012 |
l1_size2 = l1_size * sizeof(uint64_t);
|
1013 |
|
1014 |
/* Mark L1 table as used */
|
1015 |
errors += inc_refcounts(bs, refcount_table, refcount_table_size, |
1016 |
l1_table_offset, l1_size2); |
1017 |
|
1018 |
/* Read L1 table entries from disk */
|
1019 |
if (l1_size2 == 0) { |
1020 |
l1_table = NULL;
|
1021 |
} else {
|
1022 |
l1_table = qemu_malloc(l1_size2); |
1023 |
if (bdrv_pread(bs->file, l1_table_offset,
|
1024 |
l1_table, l1_size2) != l1_size2) |
1025 |
goto fail;
|
1026 |
for(i = 0;i < l1_size; i++) |
1027 |
be64_to_cpus(&l1_table[i]); |
1028 |
} |
1029 |
|
1030 |
/* Do the actual checks */
|
1031 |
for(i = 0; i < l1_size; i++) { |
1032 |
l2_offset = l1_table[i]; |
1033 |
if (l2_offset) {
|
1034 |
/* QCOW_OFLAG_COPIED must be set iff refcount == 1 */
|
1035 |
if (check_copied) {
|
1036 |
refcount = get_refcount(bs, (l2_offset & ~QCOW_OFLAG_COPIED) |
1037 |
>> s->cluster_bits); |
1038 |
if (refcount < 0) { |
1039 |
fprintf(stderr, "Can't get refcount for l2_offset %"
|
1040 |
PRIx64 ": %s\n", l2_offset, strerror(-refcount));
|
1041 |
} |
1042 |
if ((refcount == 1) != ((l2_offset & QCOW_OFLAG_COPIED) != 0)) { |
1043 |
fprintf(stderr, "ERROR OFLAG_COPIED: l2_offset=%" PRIx64
|
1044 |
" refcount=%d\n", l2_offset, refcount);
|
1045 |
errors++; |
1046 |
} |
1047 |
} |
1048 |
|
1049 |
/* Mark L2 table as used */
|
1050 |
l2_offset &= ~QCOW_OFLAG_COPIED; |
1051 |
errors += inc_refcounts(bs, refcount_table, |
1052 |
refcount_table_size, |
1053 |
l2_offset, |
1054 |
s->cluster_size); |
1055 |
|
1056 |
/* L2 tables are cluster aligned */
|
1057 |
if (l2_offset & (s->cluster_size - 1)) { |
1058 |
fprintf(stderr, "ERROR l2_offset=%" PRIx64 ": Table is not " |
1059 |
"cluster aligned; L1 entry corrupted\n", l2_offset);
|
1060 |
errors++; |
1061 |
} |
1062 |
|
1063 |
/* Process and check L2 entries */
|
1064 |
ret = check_refcounts_l2(bs, refcount_table, refcount_table_size, |
1065 |
l2_offset, check_copied); |
1066 |
if (ret < 0) { |
1067 |
goto fail;
|
1068 |
} |
1069 |
errors += ret; |
1070 |
} |
1071 |
} |
1072 |
qemu_free(l1_table); |
1073 |
return errors;
|
1074 |
|
1075 |
fail:
|
1076 |
fprintf(stderr, "ERROR: I/O error in check_refcounts_l1\n");
|
1077 |
qemu_free(l1_table); |
1078 |
return -EIO;
|
1079 |
} |
1080 |
|
1081 |
/*
|
1082 |
* Checks an image for refcount consistency.
|
1083 |
*
|
1084 |
* Returns 0 if no errors are found, the number of errors in case the image is
|
1085 |
* detected as corrupted, and -errno when an internal error occured.
|
1086 |
*/
|
1087 |
int qcow2_check_refcounts(BlockDriverState *bs)
|
1088 |
{ |
1089 |
BDRVQcowState *s = bs->opaque; |
1090 |
int64_t size; |
1091 |
int nb_clusters, refcount1, refcount2, i;
|
1092 |
QCowSnapshot *sn; |
1093 |
uint16_t *refcount_table; |
1094 |
int ret, errors = 0; |
1095 |
|
1096 |
size = bdrv_getlength(bs->file); |
1097 |
nb_clusters = size_to_clusters(s, size); |
1098 |
refcount_table = qemu_mallocz(nb_clusters * sizeof(uint16_t));
|
1099 |
|
1100 |
/* header */
|
1101 |
errors += inc_refcounts(bs, refcount_table, nb_clusters, |
1102 |
0, s->cluster_size);
|
1103 |
|
1104 |
/* current L1 table */
|
1105 |
ret = check_refcounts_l1(bs, refcount_table, nb_clusters, |
1106 |
s->l1_table_offset, s->l1_size, 1);
|
1107 |
if (ret < 0) { |
1108 |
return ret;
|
1109 |
} |
1110 |
errors += ret; |
1111 |
|
1112 |
/* snapshots */
|
1113 |
for(i = 0; i < s->nb_snapshots; i++) { |
1114 |
sn = s->snapshots + i; |
1115 |
check_refcounts_l1(bs, refcount_table, nb_clusters, |
1116 |
sn->l1_table_offset, sn->l1_size, 0);
|
1117 |
} |
1118 |
errors += inc_refcounts(bs, refcount_table, nb_clusters, |
1119 |
s->snapshots_offset, s->snapshots_size); |
1120 |
|
1121 |
/* refcount data */
|
1122 |
errors += inc_refcounts(bs, refcount_table, nb_clusters, |
1123 |
s->refcount_table_offset, |
1124 |
s->refcount_table_size * sizeof(uint64_t));
|
1125 |
for(i = 0; i < s->refcount_table_size; i++) { |
1126 |
int64_t offset; |
1127 |
offset = s->refcount_table[i]; |
1128 |
|
1129 |
/* Refcount blocks are cluster aligned */
|
1130 |
if (offset & (s->cluster_size - 1)) { |
1131 |
fprintf(stderr, "ERROR refcount block %d is not "
|
1132 |
"cluster aligned; refcount table entry corrupted\n", i);
|
1133 |
errors++; |
1134 |
} |
1135 |
|
1136 |
if (offset != 0) { |
1137 |
errors += inc_refcounts(bs, refcount_table, nb_clusters, |
1138 |
offset, s->cluster_size); |
1139 |
if (refcount_table[offset / s->cluster_size] != 1) { |
1140 |
fprintf(stderr, "ERROR refcount block %d refcount=%d\n",
|
1141 |
i, refcount_table[offset / s->cluster_size]); |
1142 |
} |
1143 |
} |
1144 |
} |
1145 |
|
1146 |
/* compare ref counts */
|
1147 |
for(i = 0; i < nb_clusters; i++) { |
1148 |
refcount1 = get_refcount(bs, i); |
1149 |
if (refcount1 < 0) { |
1150 |
fprintf(stderr, "Can't get refcount for cluster %d: %s\n",
|
1151 |
i, strerror(-refcount1)); |
1152 |
} |
1153 |
|
1154 |
refcount2 = refcount_table[i]; |
1155 |
if (refcount1 != refcount2) {
|
1156 |
fprintf(stderr, "ERROR cluster %d refcount=%d reference=%d\n",
|
1157 |
i, refcount1, refcount2); |
1158 |
errors++; |
1159 |
} |
1160 |
} |
1161 |
|
1162 |
qemu_free(refcount_table); |
1163 |
|
1164 |
return errors;
|
1165 |
} |
1166 |
|