root / block / qcow2-refcount.c @ c2bc78b6
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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/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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/* 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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refcount_table_size2 = s->refcount_table_size * sizeof(uint64_t);
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s->refcount_table = g_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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g_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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void **refcount_block)
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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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BLKDBG_EVENT(bs->file, BLKDBG_REFBLOCK_LOAD); |
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ret = qcow2_cache_get(bs, s->refcount_block_cache, refcount_block_offset, |
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refcount_block); |
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|
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return ret;
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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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uint16_t *refcount_block; |
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uint16_t refcount; |
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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; |
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|
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ret = qcow2_cache_get(bs, s->refcount_block_cache, refcount_block_offset, |
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(void**) &refcount_block);
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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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refcount = be16_to_cpu(refcount_block[block_index]); |
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ret = qcow2_cache_put(bs, s->refcount_block_cache, |
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(void**) &refcount_block);
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if (ret < 0) { |
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return ret;
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} |
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return refcount;
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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)); |
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|
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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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} |
134 |
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return refcount_table_clusters << (s->cluster_bits - 3); |
136 |
} |
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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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/*
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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 0 on success or -errno in error case
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*/
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static int alloc_refcount_block(BlockDriverState *bs, |
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int64_t cluster_index, uint16_t **refcount_block) |
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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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|
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BLKDBG_EVENT(bs->file, BLKDBG_REFBLOCK_ALLOC); |
163 |
|
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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); |
166 |
|
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if (refcount_table_index < s->refcount_table_size) {
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|
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uint64_t refcount_block_offset = |
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s->refcount_table[refcount_table_index] & REFT_OFFSET_MASK; |
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/* If it's already there, we're done */
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if (refcount_block_offset) {
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return load_refcount_block(bs, refcount_block_offset,
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(void**) refcount_block);
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} |
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} |
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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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*refcount_block = NULL;
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/* We write to the refcount table, so we might depend on L2 tables */
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ret = qcow2_cache_flush(bs, s->l2_table_cache); |
205 |
if (ret < 0) { |
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return ret;
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} |
208 |
|
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/* Allocate the refcount block itself and mark it as used */
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int64_t new_block = alloc_clusters_noref(bs, s->cluster_size); |
211 |
if (new_block < 0) { |
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return new_block;
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} |
214 |
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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); |
219 |
#endif
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|
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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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ret = qcow2_cache_get_empty(bs, s->refcount_block_cache, new_block, |
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(void**) refcount_block);
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225 |
if (ret < 0) { |
226 |
goto fail_block;
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227 |
} |
228 |
|
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memset(*refcount_block, 0, s->cluster_size);
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230 |
|
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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); |
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(*refcount_block)[block_index] = cpu_to_be16(1);
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} else {
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/* Described somewhere else. This can recurse at most twice before we
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* arrive at a block that describes itself. */
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ret = update_refcount(bs, new_block, s->cluster_size, 1);
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if (ret < 0) { |
240 |
goto fail_block;
|
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} |
242 |
|
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ret = qcow2_cache_flush(bs, s->refcount_block_cache); |
244 |
if (ret < 0) { |
245 |
goto fail_block;
|
246 |
} |
247 |
|
248 |
/* Initialize the new refcount block only after updating its refcount,
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* update_refcount uses the refcount cache itself */
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250 |
ret = qcow2_cache_get_empty(bs, s->refcount_block_cache, new_block, |
251 |
(void**) refcount_block);
|
252 |
if (ret < 0) { |
253 |
goto fail_block;
|
254 |
} |
255 |
|
256 |
memset(*refcount_block, 0, s->cluster_size);
|
257 |
} |
258 |
|
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/* Now the new refcount block needs to be written to disk */
|
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BLKDBG_EVENT(bs->file, BLKDBG_REFBLOCK_ALLOC_WRITE); |
261 |
qcow2_cache_entry_mark_dirty(s->refcount_block_cache, *refcount_block); |
262 |
ret = qcow2_cache_flush(bs, s->refcount_block_cache); |
263 |
if (ret < 0) { |
264 |
goto fail_block;
|
265 |
} |
266 |
|
267 |
/* If the refcount table is big enough, just hook the block up there */
|
268 |
if (refcount_table_index < s->refcount_table_size) {
|
269 |
uint64_t data64 = cpu_to_be64(new_block); |
270 |
BLKDBG_EVENT(bs->file, BLKDBG_REFBLOCK_ALLOC_HOOKUP); |
271 |
ret = bdrv_pwrite_sync(bs->file, |
272 |
s->refcount_table_offset + refcount_table_index * sizeof(uint64_t),
|
273 |
&data64, sizeof(data64));
|
274 |
if (ret < 0) { |
275 |
goto fail_block;
|
276 |
} |
277 |
|
278 |
s->refcount_table[refcount_table_index] = new_block; |
279 |
return 0; |
280 |
} |
281 |
|
282 |
ret = qcow2_cache_put(bs, s->refcount_block_cache, (void**) refcount_block);
|
283 |
if (ret < 0) { |
284 |
goto fail_block;
|
285 |
} |
286 |
|
287 |
/*
|
288 |
* If we come here, we need to grow the refcount table. Again, a new
|
289 |
* refcount table needs some space and we can't simply allocate to avoid
|
290 |
* endless recursion.
|
291 |
*
|
292 |
* Therefore let's grab new refcount blocks at the end of the image, which
|
293 |
* will describe themselves and the new refcount table. This way we can
|
294 |
* reference them only in the new table and do the switch to the new
|
295 |
* refcount table at once without producing an inconsistent state in
|
296 |
* between.
|
297 |
*/
|
298 |
BLKDBG_EVENT(bs->file, BLKDBG_REFTABLE_GROW); |
299 |
|
300 |
/* Calculate the number of refcount blocks needed so far */
|
301 |
uint64_t refcount_block_clusters = 1 << (s->cluster_bits - REFCOUNT_SHIFT);
|
302 |
uint64_t blocks_used = (s->free_cluster_index + |
303 |
refcount_block_clusters - 1) / refcount_block_clusters;
|
304 |
|
305 |
/* And now we need at least one block more for the new metadata */
|
306 |
uint64_t table_size = next_refcount_table_size(s, blocks_used + 1);
|
307 |
uint64_t last_table_size; |
308 |
uint64_t blocks_clusters; |
309 |
do {
|
310 |
uint64_t table_clusters = |
311 |
size_to_clusters(s, table_size * sizeof(uint64_t));
|
312 |
blocks_clusters = 1 +
|
313 |
((table_clusters + refcount_block_clusters - 1)
|
314 |
/ refcount_block_clusters); |
315 |
uint64_t meta_clusters = table_clusters + blocks_clusters; |
316 |
|
317 |
last_table_size = table_size; |
318 |
table_size = next_refcount_table_size(s, blocks_used + |
319 |
((meta_clusters + refcount_block_clusters - 1)
|
320 |
/ refcount_block_clusters)); |
321 |
|
322 |
} while (last_table_size != table_size);
|
323 |
|
324 |
#ifdef DEBUG_ALLOC2
|
325 |
fprintf(stderr, "qcow2: Grow refcount table %" PRId32 " => %" PRId64 "\n", |
326 |
s->refcount_table_size, table_size); |
327 |
#endif
|
328 |
|
329 |
/* Create the new refcount table and blocks */
|
330 |
uint64_t meta_offset = (blocks_used * refcount_block_clusters) * |
331 |
s->cluster_size; |
332 |
uint64_t table_offset = meta_offset + blocks_clusters * s->cluster_size; |
333 |
uint16_t *new_blocks = g_malloc0(blocks_clusters * s->cluster_size); |
334 |
uint64_t *new_table = g_malloc0(table_size * sizeof(uint64_t));
|
335 |
|
336 |
assert(meta_offset >= (s->free_cluster_index * s->cluster_size)); |
337 |
|
338 |
/* Fill the new refcount table */
|
339 |
memcpy(new_table, s->refcount_table, |
340 |
s->refcount_table_size * sizeof(uint64_t));
|
341 |
new_table[refcount_table_index] = new_block; |
342 |
|
343 |
int i;
|
344 |
for (i = 0; i < blocks_clusters; i++) { |
345 |
new_table[blocks_used + i] = meta_offset + (i * s->cluster_size); |
346 |
} |
347 |
|
348 |
/* Fill the refcount blocks */
|
349 |
uint64_t table_clusters = size_to_clusters(s, table_size * sizeof(uint64_t));
|
350 |
int block = 0; |
351 |
for (i = 0; i < table_clusters + blocks_clusters; i++) { |
352 |
new_blocks[block++] = cpu_to_be16(1);
|
353 |
} |
354 |
|
355 |
/* Write refcount blocks to disk */
|
356 |
BLKDBG_EVENT(bs->file, BLKDBG_REFBLOCK_ALLOC_WRITE_BLOCKS); |
357 |
ret = bdrv_pwrite_sync(bs->file, meta_offset, new_blocks, |
358 |
blocks_clusters * s->cluster_size); |
359 |
g_free(new_blocks); |
360 |
if (ret < 0) { |
361 |
goto fail_table;
|
362 |
} |
363 |
|
364 |
/* Write refcount table to disk */
|
365 |
for(i = 0; i < table_size; i++) { |
366 |
cpu_to_be64s(&new_table[i]); |
367 |
} |
368 |
|
369 |
BLKDBG_EVENT(bs->file, BLKDBG_REFBLOCK_ALLOC_WRITE_TABLE); |
370 |
ret = bdrv_pwrite_sync(bs->file, table_offset, new_table, |
371 |
table_size * sizeof(uint64_t));
|
372 |
if (ret < 0) { |
373 |
goto fail_table;
|
374 |
} |
375 |
|
376 |
for(i = 0; i < table_size; i++) { |
377 |
be64_to_cpus(&new_table[i]); |
378 |
} |
379 |
|
380 |
/* Hook up the new refcount table in the qcow2 header */
|
381 |
uint8_t data[12];
|
382 |
cpu_to_be64w((uint64_t*)data, table_offset); |
383 |
cpu_to_be32w((uint32_t*)(data + 8), table_clusters);
|
384 |
BLKDBG_EVENT(bs->file, BLKDBG_REFBLOCK_ALLOC_SWITCH_TABLE); |
385 |
ret = bdrv_pwrite_sync(bs->file, offsetof(QCowHeader, refcount_table_offset), |
386 |
data, sizeof(data));
|
387 |
if (ret < 0) { |
388 |
goto fail_table;
|
389 |
} |
390 |
|
391 |
/* And switch it in memory */
|
392 |
uint64_t old_table_offset = s->refcount_table_offset; |
393 |
uint64_t old_table_size = s->refcount_table_size; |
394 |
|
395 |
g_free(s->refcount_table); |
396 |
s->refcount_table = new_table; |
397 |
s->refcount_table_size = table_size; |
398 |
s->refcount_table_offset = table_offset; |
399 |
|
400 |
/* Free old table. Remember, we must not change free_cluster_index */
|
401 |
uint64_t old_free_cluster_index = s->free_cluster_index; |
402 |
qcow2_free_clusters(bs, old_table_offset, old_table_size * sizeof(uint64_t));
|
403 |
s->free_cluster_index = old_free_cluster_index; |
404 |
|
405 |
ret = load_refcount_block(bs, new_block, (void**) refcount_block);
|
406 |
if (ret < 0) { |
407 |
return ret;
|
408 |
} |
409 |
|
410 |
return 0; |
411 |
|
412 |
fail_table:
|
413 |
g_free(new_table); |
414 |
fail_block:
|
415 |
if (*refcount_block != NULL) { |
416 |
qcow2_cache_put(bs, s->refcount_block_cache, (void**) refcount_block);
|
417 |
} |
418 |
return ret;
|
419 |
} |
420 |
|
421 |
/* XXX: cache several refcount block clusters ? */
|
422 |
static int QEMU_WARN_UNUSED_RESULT update_refcount(BlockDriverState *bs, |
423 |
int64_t offset, int64_t length, int addend)
|
424 |
{ |
425 |
BDRVQcowState *s = bs->opaque; |
426 |
int64_t start, last, cluster_offset; |
427 |
uint16_t *refcount_block = NULL;
|
428 |
int64_t old_table_index = -1;
|
429 |
int ret;
|
430 |
|
431 |
#ifdef DEBUG_ALLOC2
|
432 |
fprintf(stderr, "update_refcount: offset=%" PRId64 " size=%" PRId64 " addend=%d\n", |
433 |
offset, length, addend); |
434 |
#endif
|
435 |
if (length < 0) { |
436 |
return -EINVAL;
|
437 |
} else if (length == 0) { |
438 |
return 0; |
439 |
} |
440 |
|
441 |
if (addend < 0) { |
442 |
qcow2_cache_set_dependency(bs, s->refcount_block_cache, |
443 |
s->l2_table_cache); |
444 |
} |
445 |
|
446 |
start = offset & ~(s->cluster_size - 1);
|
447 |
last = (offset + length - 1) & ~(s->cluster_size - 1); |
448 |
for(cluster_offset = start; cluster_offset <= last;
|
449 |
cluster_offset += s->cluster_size) |
450 |
{ |
451 |
int block_index, refcount;
|
452 |
int64_t cluster_index = cluster_offset >> s->cluster_bits; |
453 |
int64_t table_index = |
454 |
cluster_index >> (s->cluster_bits - REFCOUNT_SHIFT); |
455 |
|
456 |
/* Load the refcount block and allocate it if needed */
|
457 |
if (table_index != old_table_index) {
|
458 |
if (refcount_block) {
|
459 |
ret = qcow2_cache_put(bs, s->refcount_block_cache, |
460 |
(void**) &refcount_block);
|
461 |
if (ret < 0) { |
462 |
goto fail;
|
463 |
} |
464 |
} |
465 |
|
466 |
ret = alloc_refcount_block(bs, cluster_index, &refcount_block); |
467 |
if (ret < 0) { |
468 |
goto fail;
|
469 |
} |
470 |
} |
471 |
old_table_index = table_index; |
472 |
|
473 |
qcow2_cache_entry_mark_dirty(s->refcount_block_cache, refcount_block); |
474 |
|
475 |
/* we can update the count and save it */
|
476 |
block_index = cluster_index & |
477 |
((1 << (s->cluster_bits - REFCOUNT_SHIFT)) - 1); |
478 |
|
479 |
refcount = be16_to_cpu(refcount_block[block_index]); |
480 |
refcount += addend; |
481 |
if (refcount < 0 || refcount > 0xffff) { |
482 |
ret = -EINVAL; |
483 |
goto fail;
|
484 |
} |
485 |
if (refcount == 0 && cluster_index < s->free_cluster_index) { |
486 |
s->free_cluster_index = cluster_index; |
487 |
} |
488 |
refcount_block[block_index] = cpu_to_be16(refcount); |
489 |
} |
490 |
|
491 |
ret = 0;
|
492 |
fail:
|
493 |
/* Write last changed block to disk */
|
494 |
if (refcount_block) {
|
495 |
int wret;
|
496 |
wret = qcow2_cache_put(bs, s->refcount_block_cache, |
497 |
(void**) &refcount_block);
|
498 |
if (wret < 0) { |
499 |
return ret < 0 ? ret : wret; |
500 |
} |
501 |
} |
502 |
|
503 |
/*
|
504 |
* Try do undo any updates if an error is returned (This may succeed in
|
505 |
* some cases like ENOSPC for allocating a new refcount block)
|
506 |
*/
|
507 |
if (ret < 0) { |
508 |
int dummy;
|
509 |
dummy = update_refcount(bs, offset, cluster_offset - offset, -addend); |
510 |
(void)dummy;
|
511 |
} |
512 |
|
513 |
return ret;
|
514 |
} |
515 |
|
516 |
/*
|
517 |
* Increases or decreases the refcount of a given cluster by one.
|
518 |
* addend must be 1 or -1.
|
519 |
*
|
520 |
* If the return value is non-negative, it is the new refcount of the cluster.
|
521 |
* If it is negative, it is -errno and indicates an error.
|
522 |
*/
|
523 |
static int update_cluster_refcount(BlockDriverState *bs, |
524 |
int64_t cluster_index, |
525 |
int addend)
|
526 |
{ |
527 |
BDRVQcowState *s = bs->opaque; |
528 |
int ret;
|
529 |
|
530 |
ret = update_refcount(bs, cluster_index << s->cluster_bits, 1, addend);
|
531 |
if (ret < 0) { |
532 |
return ret;
|
533 |
} |
534 |
|
535 |
return get_refcount(bs, cluster_index);
|
536 |
} |
537 |
|
538 |
|
539 |
|
540 |
/*********************************************************/
|
541 |
/* cluster allocation functions */
|
542 |
|
543 |
|
544 |
|
545 |
/* return < 0 if error */
|
546 |
static int64_t alloc_clusters_noref(BlockDriverState *bs, int64_t size)
|
547 |
{ |
548 |
BDRVQcowState *s = bs->opaque; |
549 |
int i, nb_clusters, refcount;
|
550 |
|
551 |
nb_clusters = size_to_clusters(s, size); |
552 |
retry:
|
553 |
for(i = 0; i < nb_clusters; i++) { |
554 |
int64_t next_cluster_index = s->free_cluster_index++; |
555 |
refcount = get_refcount(bs, next_cluster_index); |
556 |
|
557 |
if (refcount < 0) { |
558 |
return refcount;
|
559 |
} else if (refcount != 0) { |
560 |
goto retry;
|
561 |
} |
562 |
} |
563 |
#ifdef DEBUG_ALLOC2
|
564 |
fprintf(stderr, "alloc_clusters: size=%" PRId64 " -> %" PRId64 "\n", |
565 |
size, |
566 |
(s->free_cluster_index - nb_clusters) << s->cluster_bits); |
567 |
#endif
|
568 |
return (s->free_cluster_index - nb_clusters) << s->cluster_bits;
|
569 |
} |
570 |
|
571 |
int64_t qcow2_alloc_clusters(BlockDriverState *bs, int64_t size) |
572 |
{ |
573 |
int64_t offset; |
574 |
int ret;
|
575 |
|
576 |
BLKDBG_EVENT(bs->file, BLKDBG_CLUSTER_ALLOC); |
577 |
offset = alloc_clusters_noref(bs, size); |
578 |
if (offset < 0) { |
579 |
return offset;
|
580 |
} |
581 |
|
582 |
ret = update_refcount(bs, offset, size, 1);
|
583 |
if (ret < 0) { |
584 |
return ret;
|
585 |
} |
586 |
|
587 |
return offset;
|
588 |
} |
589 |
|
590 |
int qcow2_alloc_clusters_at(BlockDriverState *bs, uint64_t offset,
|
591 |
int nb_clusters)
|
592 |
{ |
593 |
BDRVQcowState *s = bs->opaque; |
594 |
uint64_t cluster_index; |
595 |
uint64_t old_free_cluster_index; |
596 |
int i, refcount, ret;
|
597 |
|
598 |
/* Check how many clusters there are free */
|
599 |
cluster_index = offset >> s->cluster_bits; |
600 |
for(i = 0; i < nb_clusters; i++) { |
601 |
refcount = get_refcount(bs, cluster_index++); |
602 |
|
603 |
if (refcount < 0) { |
604 |
return refcount;
|
605 |
} else if (refcount != 0) { |
606 |
break;
|
607 |
} |
608 |
} |
609 |
|
610 |
/* And then allocate them */
|
611 |
old_free_cluster_index = s->free_cluster_index; |
612 |
s->free_cluster_index = cluster_index + i; |
613 |
|
614 |
ret = update_refcount(bs, offset, i << s->cluster_bits, 1);
|
615 |
if (ret < 0) { |
616 |
return ret;
|
617 |
} |
618 |
|
619 |
s->free_cluster_index = old_free_cluster_index; |
620 |
|
621 |
return i;
|
622 |
} |
623 |
|
624 |
/* only used to allocate compressed sectors. We try to allocate
|
625 |
contiguous sectors. size must be <= cluster_size */
|
626 |
int64_t qcow2_alloc_bytes(BlockDriverState *bs, int size)
|
627 |
{ |
628 |
BDRVQcowState *s = bs->opaque; |
629 |
int64_t offset, cluster_offset; |
630 |
int free_in_cluster;
|
631 |
|
632 |
BLKDBG_EVENT(bs->file, BLKDBG_CLUSTER_ALLOC_BYTES); |
633 |
assert(size > 0 && size <= s->cluster_size);
|
634 |
if (s->free_byte_offset == 0) { |
635 |
offset = qcow2_alloc_clusters(bs, s->cluster_size); |
636 |
if (offset < 0) { |
637 |
return offset;
|
638 |
} |
639 |
s->free_byte_offset = offset; |
640 |
} |
641 |
redo:
|
642 |
free_in_cluster = s->cluster_size - |
643 |
(s->free_byte_offset & (s->cluster_size - 1));
|
644 |
if (size <= free_in_cluster) {
|
645 |
/* enough space in current cluster */
|
646 |
offset = s->free_byte_offset; |
647 |
s->free_byte_offset += size; |
648 |
free_in_cluster -= size; |
649 |
if (free_in_cluster == 0) |
650 |
s->free_byte_offset = 0;
|
651 |
if ((offset & (s->cluster_size - 1)) != 0) |
652 |
update_cluster_refcount(bs, offset >> s->cluster_bits, 1);
|
653 |
} else {
|
654 |
offset = qcow2_alloc_clusters(bs, s->cluster_size); |
655 |
if (offset < 0) { |
656 |
return offset;
|
657 |
} |
658 |
cluster_offset = s->free_byte_offset & ~(s->cluster_size - 1);
|
659 |
if ((cluster_offset + s->cluster_size) == offset) {
|
660 |
/* we are lucky: contiguous data */
|
661 |
offset = s->free_byte_offset; |
662 |
update_cluster_refcount(bs, offset >> s->cluster_bits, 1);
|
663 |
s->free_byte_offset += size; |
664 |
} else {
|
665 |
s->free_byte_offset = offset; |
666 |
goto redo;
|
667 |
} |
668 |
} |
669 |
|
670 |
/* The cluster refcount was incremented, either by qcow2_alloc_clusters()
|
671 |
* or explicitly by update_cluster_refcount(). Refcount blocks must be
|
672 |
* flushed before the caller's L2 table updates.
|
673 |
*/
|
674 |
qcow2_cache_set_dependency(bs, s->l2_table_cache, s->refcount_block_cache); |
675 |
return offset;
|
676 |
} |
677 |
|
678 |
void qcow2_free_clusters(BlockDriverState *bs,
|
679 |
int64_t offset, int64_t size) |
680 |
{ |
681 |
int ret;
|
682 |
|
683 |
BLKDBG_EVENT(bs->file, BLKDBG_CLUSTER_FREE); |
684 |
ret = update_refcount(bs, offset, size, -1);
|
685 |
if (ret < 0) { |
686 |
fprintf(stderr, "qcow2_free_clusters failed: %s\n", strerror(-ret));
|
687 |
/* TODO Remember the clusters to free them later and avoid leaking */
|
688 |
} |
689 |
} |
690 |
|
691 |
/*
|
692 |
* Free a cluster using its L2 entry (handles clusters of all types, e.g.
|
693 |
* normal cluster, compressed cluster, etc.)
|
694 |
*/
|
695 |
void qcow2_free_any_clusters(BlockDriverState *bs,
|
696 |
uint64_t l2_entry, int nb_clusters)
|
697 |
{ |
698 |
BDRVQcowState *s = bs->opaque; |
699 |
|
700 |
switch (qcow2_get_cluster_type(l2_entry)) {
|
701 |
case QCOW2_CLUSTER_COMPRESSED:
|
702 |
{ |
703 |
int nb_csectors;
|
704 |
nb_csectors = ((l2_entry >> s->csize_shift) & |
705 |
s->csize_mask) + 1;
|
706 |
qcow2_free_clusters(bs, |
707 |
(l2_entry & s->cluster_offset_mask) & ~511,
|
708 |
nb_csectors * 512);
|
709 |
} |
710 |
break;
|
711 |
case QCOW2_CLUSTER_NORMAL:
|
712 |
qcow2_free_clusters(bs, l2_entry & L2E_OFFSET_MASK, |
713 |
nb_clusters << s->cluster_bits); |
714 |
break;
|
715 |
case QCOW2_CLUSTER_UNALLOCATED:
|
716 |
case QCOW2_CLUSTER_ZERO:
|
717 |
break;
|
718 |
default:
|
719 |
abort(); |
720 |
} |
721 |
} |
722 |
|
723 |
|
724 |
|
725 |
/*********************************************************/
|
726 |
/* snapshots and image creation */
|
727 |
|
728 |
|
729 |
|
730 |
/* update the refcounts of snapshots and the copied flag */
|
731 |
int qcow2_update_snapshot_refcount(BlockDriverState *bs,
|
732 |
int64_t l1_table_offset, int l1_size, int addend) |
733 |
{ |
734 |
BDRVQcowState *s = bs->opaque; |
735 |
uint64_t *l1_table, *l2_table, l2_offset, offset, l1_size2, l1_allocated; |
736 |
int64_t old_offset, old_l2_offset; |
737 |
int i, j, l1_modified = 0, nb_csectors, refcount; |
738 |
int ret;
|
739 |
|
740 |
l2_table = NULL;
|
741 |
l1_table = NULL;
|
742 |
l1_size2 = l1_size * sizeof(uint64_t);
|
743 |
|
744 |
/* WARNING: qcow2_snapshot_goto relies on this function not using the
|
745 |
* l1_table_offset when it is the current s->l1_table_offset! Be careful
|
746 |
* when changing this! */
|
747 |
if (l1_table_offset != s->l1_table_offset) {
|
748 |
l1_table = g_malloc0(align_offset(l1_size2, 512));
|
749 |
l1_allocated = 1;
|
750 |
|
751 |
ret = bdrv_pread(bs->file, l1_table_offset, l1_table, l1_size2); |
752 |
if (ret < 0) { |
753 |
goto fail;
|
754 |
} |
755 |
|
756 |
for(i = 0;i < l1_size; i++) |
757 |
be64_to_cpus(&l1_table[i]); |
758 |
} else {
|
759 |
assert(l1_size == s->l1_size); |
760 |
l1_table = s->l1_table; |
761 |
l1_allocated = 0;
|
762 |
} |
763 |
|
764 |
for(i = 0; i < l1_size; i++) { |
765 |
l2_offset = l1_table[i]; |
766 |
if (l2_offset) {
|
767 |
old_l2_offset = l2_offset; |
768 |
l2_offset &= L1E_OFFSET_MASK; |
769 |
|
770 |
ret = qcow2_cache_get(bs, s->l2_table_cache, l2_offset, |
771 |
(void**) &l2_table);
|
772 |
if (ret < 0) { |
773 |
goto fail;
|
774 |
} |
775 |
|
776 |
for(j = 0; j < s->l2_size; j++) { |
777 |
offset = be64_to_cpu(l2_table[j]); |
778 |
if (offset != 0) { |
779 |
old_offset = offset; |
780 |
offset &= ~QCOW_OFLAG_COPIED; |
781 |
if (offset & QCOW_OFLAG_COMPRESSED) {
|
782 |
nb_csectors = ((offset >> s->csize_shift) & |
783 |
s->csize_mask) + 1;
|
784 |
if (addend != 0) { |
785 |
int ret;
|
786 |
ret = update_refcount(bs, |
787 |
(offset & s->cluster_offset_mask) & ~511,
|
788 |
nb_csectors * 512, addend);
|
789 |
if (ret < 0) { |
790 |
goto fail;
|
791 |
} |
792 |
} |
793 |
/* compressed clusters are never modified */
|
794 |
refcount = 2;
|
795 |
} else {
|
796 |
uint64_t cluster_index = (offset & L2E_OFFSET_MASK) >> s->cluster_bits; |
797 |
if (addend != 0) { |
798 |
refcount = update_cluster_refcount(bs, cluster_index, addend); |
799 |
} else {
|
800 |
refcount = get_refcount(bs, cluster_index); |
801 |
} |
802 |
|
803 |
if (refcount < 0) { |
804 |
ret = refcount; |
805 |
goto fail;
|
806 |
} |
807 |
} |
808 |
|
809 |
if (refcount == 1) { |
810 |
offset |= QCOW_OFLAG_COPIED; |
811 |
} |
812 |
if (offset != old_offset) {
|
813 |
if (addend > 0) { |
814 |
qcow2_cache_set_dependency(bs, s->l2_table_cache, |
815 |
s->refcount_block_cache); |
816 |
} |
817 |
l2_table[j] = cpu_to_be64(offset); |
818 |
qcow2_cache_entry_mark_dirty(s->l2_table_cache, l2_table); |
819 |
} |
820 |
} |
821 |
} |
822 |
|
823 |
ret = qcow2_cache_put(bs, s->l2_table_cache, (void**) &l2_table);
|
824 |
if (ret < 0) { |
825 |
goto fail;
|
826 |
} |
827 |
|
828 |
|
829 |
if (addend != 0) { |
830 |
refcount = update_cluster_refcount(bs, l2_offset >> s->cluster_bits, addend); |
831 |
} else {
|
832 |
refcount = get_refcount(bs, l2_offset >> s->cluster_bits); |
833 |
} |
834 |
if (refcount < 0) { |
835 |
ret = refcount; |
836 |
goto fail;
|
837 |
} else if (refcount == 1) { |
838 |
l2_offset |= QCOW_OFLAG_COPIED; |
839 |
} |
840 |
if (l2_offset != old_l2_offset) {
|
841 |
l1_table[i] = l2_offset; |
842 |
l1_modified = 1;
|
843 |
} |
844 |
} |
845 |
} |
846 |
|
847 |
ret = bdrv_flush(bs); |
848 |
fail:
|
849 |
if (l2_table) {
|
850 |
qcow2_cache_put(bs, s->l2_table_cache, (void**) &l2_table);
|
851 |
} |
852 |
|
853 |
/* Update L1 only if it isn't deleted anyway (addend = -1) */
|
854 |
if (addend >= 0 && l1_modified) { |
855 |
for(i = 0; i < l1_size; i++) |
856 |
cpu_to_be64s(&l1_table[i]); |
857 |
if (bdrv_pwrite_sync(bs->file, l1_table_offset, l1_table,
|
858 |
l1_size2) < 0)
|
859 |
goto fail;
|
860 |
for(i = 0; i < l1_size; i++) |
861 |
be64_to_cpus(&l1_table[i]); |
862 |
} |
863 |
if (l1_allocated)
|
864 |
g_free(l1_table); |
865 |
return ret;
|
866 |
} |
867 |
|
868 |
|
869 |
|
870 |
|
871 |
/*********************************************************/
|
872 |
/* refcount checking functions */
|
873 |
|
874 |
|
875 |
|
876 |
/*
|
877 |
* Increases the refcount for a range of clusters in a given refcount table.
|
878 |
* This is used to construct a temporary refcount table out of L1 and L2 tables
|
879 |
* which can be compared the the refcount table saved in the image.
|
880 |
*
|
881 |
* Modifies the number of errors in res.
|
882 |
*/
|
883 |
static void inc_refcounts(BlockDriverState *bs, |
884 |
BdrvCheckResult *res, |
885 |
uint16_t *refcount_table, |
886 |
int refcount_table_size,
|
887 |
int64_t offset, int64_t size) |
888 |
{ |
889 |
BDRVQcowState *s = bs->opaque; |
890 |
int64_t start, last, cluster_offset; |
891 |
int k;
|
892 |
|
893 |
if (size <= 0) |
894 |
return;
|
895 |
|
896 |
start = offset & ~(s->cluster_size - 1);
|
897 |
last = (offset + size - 1) & ~(s->cluster_size - 1); |
898 |
for(cluster_offset = start; cluster_offset <= last;
|
899 |
cluster_offset += s->cluster_size) { |
900 |
k = cluster_offset >> s->cluster_bits; |
901 |
if (k < 0) { |
902 |
fprintf(stderr, "ERROR: invalid cluster offset=0x%" PRIx64 "\n", |
903 |
cluster_offset); |
904 |
res->corruptions++; |
905 |
} else if (k >= refcount_table_size) { |
906 |
fprintf(stderr, "Warning: cluster offset=0x%" PRIx64 " is after " |
907 |
"the end of the image file, can't properly check refcounts.\n",
|
908 |
cluster_offset); |
909 |
res->check_errors++; |
910 |
} else {
|
911 |
if (++refcount_table[k] == 0) { |
912 |
fprintf(stderr, "ERROR: overflow cluster offset=0x%" PRIx64
|
913 |
"\n", cluster_offset);
|
914 |
res->corruptions++; |
915 |
} |
916 |
} |
917 |
} |
918 |
} |
919 |
|
920 |
/* Flags for check_refcounts_l1() and check_refcounts_l2() */
|
921 |
enum {
|
922 |
CHECK_OFLAG_COPIED = 0x1, /* check QCOW_OFLAG_COPIED matches refcount */ |
923 |
CHECK_FRAG_INFO = 0x2, /* update BlockFragInfo counters */ |
924 |
}; |
925 |
|
926 |
/*
|
927 |
* Increases the refcount in the given refcount table for the all clusters
|
928 |
* referenced in the L2 table. While doing so, performs some checks on L2
|
929 |
* entries.
|
930 |
*
|
931 |
* Returns the number of errors found by the checks or -errno if an internal
|
932 |
* error occurred.
|
933 |
*/
|
934 |
static int check_refcounts_l2(BlockDriverState *bs, BdrvCheckResult *res, |
935 |
uint16_t *refcount_table, int refcount_table_size, int64_t l2_offset,
|
936 |
int flags)
|
937 |
{ |
938 |
BDRVQcowState *s = bs->opaque; |
939 |
uint64_t *l2_table, l2_entry; |
940 |
uint64_t next_contiguous_offset = 0;
|
941 |
int i, l2_size, nb_csectors, refcount;
|
942 |
|
943 |
/* Read L2 table from disk */
|
944 |
l2_size = s->l2_size * sizeof(uint64_t);
|
945 |
l2_table = g_malloc(l2_size); |
946 |
|
947 |
if (bdrv_pread(bs->file, l2_offset, l2_table, l2_size) != l2_size)
|
948 |
goto fail;
|
949 |
|
950 |
/* Do the actual checks */
|
951 |
for(i = 0; i < s->l2_size; i++) { |
952 |
l2_entry = be64_to_cpu(l2_table[i]); |
953 |
|
954 |
switch (qcow2_get_cluster_type(l2_entry)) {
|
955 |
case QCOW2_CLUSTER_COMPRESSED:
|
956 |
/* Compressed clusters don't have QCOW_OFLAG_COPIED */
|
957 |
if (l2_entry & QCOW_OFLAG_COPIED) {
|
958 |
fprintf(stderr, "ERROR: cluster %" PRId64 ": " |
959 |
"copied flag must never be set for compressed "
|
960 |
"clusters\n", l2_entry >> s->cluster_bits);
|
961 |
l2_entry &= ~QCOW_OFLAG_COPIED; |
962 |
res->corruptions++; |
963 |
} |
964 |
|
965 |
/* Mark cluster as used */
|
966 |
nb_csectors = ((l2_entry >> s->csize_shift) & |
967 |
s->csize_mask) + 1;
|
968 |
l2_entry &= s->cluster_offset_mask; |
969 |
inc_refcounts(bs, res, refcount_table, refcount_table_size, |
970 |
l2_entry & ~511, nb_csectors * 512); |
971 |
|
972 |
if (flags & CHECK_FRAG_INFO) {
|
973 |
res->bfi.allocated_clusters++; |
974 |
res->bfi.compressed_clusters++; |
975 |
|
976 |
/* Compressed clusters are fragmented by nature. Since they
|
977 |
* take up sub-sector space but we only have sector granularity
|
978 |
* I/O we need to re-read the same sectors even for adjacent
|
979 |
* compressed clusters.
|
980 |
*/
|
981 |
res->bfi.fragmented_clusters++; |
982 |
} |
983 |
break;
|
984 |
|
985 |
case QCOW2_CLUSTER_ZERO:
|
986 |
if ((l2_entry & L2E_OFFSET_MASK) == 0) { |
987 |
break;
|
988 |
} |
989 |
/* fall through */
|
990 |
|
991 |
case QCOW2_CLUSTER_NORMAL:
|
992 |
{ |
993 |
/* QCOW_OFLAG_COPIED must be set iff refcount == 1 */
|
994 |
uint64_t offset = l2_entry & L2E_OFFSET_MASK; |
995 |
|
996 |
if (flags & CHECK_OFLAG_COPIED) {
|
997 |
refcount = get_refcount(bs, offset >> s->cluster_bits); |
998 |
if (refcount < 0) { |
999 |
fprintf(stderr, "Can't get refcount for offset %"
|
1000 |
PRIx64 ": %s\n", l2_entry, strerror(-refcount));
|
1001 |
goto fail;
|
1002 |
} |
1003 |
if ((refcount == 1) != ((l2_entry & QCOW_OFLAG_COPIED) != 0)) { |
1004 |
fprintf(stderr, "ERROR OFLAG_COPIED: offset=%"
|
1005 |
PRIx64 " refcount=%d\n", l2_entry, refcount);
|
1006 |
res->corruptions++; |
1007 |
} |
1008 |
} |
1009 |
|
1010 |
if (flags & CHECK_FRAG_INFO) {
|
1011 |
res->bfi.allocated_clusters++; |
1012 |
if (next_contiguous_offset &&
|
1013 |
offset != next_contiguous_offset) { |
1014 |
res->bfi.fragmented_clusters++; |
1015 |
} |
1016 |
next_contiguous_offset = offset + s->cluster_size; |
1017 |
} |
1018 |
|
1019 |
/* Mark cluster as used */
|
1020 |
inc_refcounts(bs, res, refcount_table,refcount_table_size, |
1021 |
offset, s->cluster_size); |
1022 |
|
1023 |
/* Correct offsets are cluster aligned */
|
1024 |
if (offset & (s->cluster_size - 1)) { |
1025 |
fprintf(stderr, "ERROR offset=%" PRIx64 ": Cluster is not " |
1026 |
"properly aligned; L2 entry corrupted.\n", offset);
|
1027 |
res->corruptions++; |
1028 |
} |
1029 |
break;
|
1030 |
} |
1031 |
|
1032 |
case QCOW2_CLUSTER_UNALLOCATED:
|
1033 |
break;
|
1034 |
|
1035 |
default:
|
1036 |
abort(); |
1037 |
} |
1038 |
} |
1039 |
|
1040 |
g_free(l2_table); |
1041 |
return 0; |
1042 |
|
1043 |
fail:
|
1044 |
fprintf(stderr, "ERROR: I/O error in check_refcounts_l2\n");
|
1045 |
g_free(l2_table); |
1046 |
return -EIO;
|
1047 |
} |
1048 |
|
1049 |
/*
|
1050 |
* Increases the refcount for the L1 table, its L2 tables and all referenced
|
1051 |
* clusters in the given refcount table. While doing so, performs some checks
|
1052 |
* on L1 and L2 entries.
|
1053 |
*
|
1054 |
* Returns the number of errors found by the checks or -errno if an internal
|
1055 |
* error occurred.
|
1056 |
*/
|
1057 |
static int check_refcounts_l1(BlockDriverState *bs, |
1058 |
BdrvCheckResult *res, |
1059 |
uint16_t *refcount_table, |
1060 |
int refcount_table_size,
|
1061 |
int64_t l1_table_offset, int l1_size,
|
1062 |
int flags)
|
1063 |
{ |
1064 |
BDRVQcowState *s = bs->opaque; |
1065 |
uint64_t *l1_table, l2_offset, l1_size2; |
1066 |
int i, refcount, ret;
|
1067 |
|
1068 |
l1_size2 = l1_size * sizeof(uint64_t);
|
1069 |
|
1070 |
/* Mark L1 table as used */
|
1071 |
inc_refcounts(bs, res, refcount_table, refcount_table_size, |
1072 |
l1_table_offset, l1_size2); |
1073 |
|
1074 |
/* Read L1 table entries from disk */
|
1075 |
if (l1_size2 == 0) { |
1076 |
l1_table = NULL;
|
1077 |
} else {
|
1078 |
l1_table = g_malloc(l1_size2); |
1079 |
if (bdrv_pread(bs->file, l1_table_offset,
|
1080 |
l1_table, l1_size2) != l1_size2) |
1081 |
goto fail;
|
1082 |
for(i = 0;i < l1_size; i++) |
1083 |
be64_to_cpus(&l1_table[i]); |
1084 |
} |
1085 |
|
1086 |
/* Do the actual checks */
|
1087 |
for(i = 0; i < l1_size; i++) { |
1088 |
l2_offset = l1_table[i]; |
1089 |
if (l2_offset) {
|
1090 |
/* QCOW_OFLAG_COPIED must be set iff refcount == 1 */
|
1091 |
if (flags & CHECK_OFLAG_COPIED) {
|
1092 |
refcount = get_refcount(bs, (l2_offset & ~QCOW_OFLAG_COPIED) |
1093 |
>> s->cluster_bits); |
1094 |
if (refcount < 0) { |
1095 |
fprintf(stderr, "Can't get refcount for l2_offset %"
|
1096 |
PRIx64 ": %s\n", l2_offset, strerror(-refcount));
|
1097 |
goto fail;
|
1098 |
} |
1099 |
if ((refcount == 1) != ((l2_offset & QCOW_OFLAG_COPIED) != 0)) { |
1100 |
fprintf(stderr, "ERROR OFLAG_COPIED: l2_offset=%" PRIx64
|
1101 |
" refcount=%d\n", l2_offset, refcount);
|
1102 |
res->corruptions++; |
1103 |
} |
1104 |
} |
1105 |
|
1106 |
/* Mark L2 table as used */
|
1107 |
l2_offset &= L1E_OFFSET_MASK; |
1108 |
inc_refcounts(bs, res, refcount_table, refcount_table_size, |
1109 |
l2_offset, s->cluster_size); |
1110 |
|
1111 |
/* L2 tables are cluster aligned */
|
1112 |
if (l2_offset & (s->cluster_size - 1)) { |
1113 |
fprintf(stderr, "ERROR l2_offset=%" PRIx64 ": Table is not " |
1114 |
"cluster aligned; L1 entry corrupted\n", l2_offset);
|
1115 |
res->corruptions++; |
1116 |
} |
1117 |
|
1118 |
/* Process and check L2 entries */
|
1119 |
ret = check_refcounts_l2(bs, res, refcount_table, |
1120 |
refcount_table_size, l2_offset, flags); |
1121 |
if (ret < 0) { |
1122 |
goto fail;
|
1123 |
} |
1124 |
} |
1125 |
} |
1126 |
g_free(l1_table); |
1127 |
return 0; |
1128 |
|
1129 |
fail:
|
1130 |
fprintf(stderr, "ERROR: I/O error in check_refcounts_l1\n");
|
1131 |
res->check_errors++; |
1132 |
g_free(l1_table); |
1133 |
return -EIO;
|
1134 |
} |
1135 |
|
1136 |
/*
|
1137 |
* Checks an image for refcount consistency.
|
1138 |
*
|
1139 |
* Returns 0 if no errors are found, the number of errors in case the image is
|
1140 |
* detected as corrupted, and -errno when an internal error occurred.
|
1141 |
*/
|
1142 |
int qcow2_check_refcounts(BlockDriverState *bs, BdrvCheckResult *res,
|
1143 |
BdrvCheckMode fix) |
1144 |
{ |
1145 |
BDRVQcowState *s = bs->opaque; |
1146 |
int64_t size, i, highest_cluster; |
1147 |
int nb_clusters, refcount1, refcount2;
|
1148 |
QCowSnapshot *sn; |
1149 |
uint16_t *refcount_table; |
1150 |
int ret;
|
1151 |
|
1152 |
size = bdrv_getlength(bs->file); |
1153 |
nb_clusters = size_to_clusters(s, size); |
1154 |
refcount_table = g_malloc0(nb_clusters * sizeof(uint16_t));
|
1155 |
|
1156 |
res->bfi.total_clusters = |
1157 |
size_to_clusters(s, bs->total_sectors * BDRV_SECTOR_SIZE); |
1158 |
|
1159 |
/* header */
|
1160 |
inc_refcounts(bs, res, refcount_table, nb_clusters, |
1161 |
0, s->cluster_size);
|
1162 |
|
1163 |
/* current L1 table */
|
1164 |
ret = check_refcounts_l1(bs, res, refcount_table, nb_clusters, |
1165 |
s->l1_table_offset, s->l1_size, |
1166 |
CHECK_OFLAG_COPIED | CHECK_FRAG_INFO); |
1167 |
if (ret < 0) { |
1168 |
goto fail;
|
1169 |
} |
1170 |
|
1171 |
/* snapshots */
|
1172 |
for(i = 0; i < s->nb_snapshots; i++) { |
1173 |
sn = s->snapshots + i; |
1174 |
ret = check_refcounts_l1(bs, res, refcount_table, nb_clusters, |
1175 |
sn->l1_table_offset, sn->l1_size, 0);
|
1176 |
if (ret < 0) { |
1177 |
goto fail;
|
1178 |
} |
1179 |
} |
1180 |
inc_refcounts(bs, res, refcount_table, nb_clusters, |
1181 |
s->snapshots_offset, s->snapshots_size); |
1182 |
|
1183 |
/* refcount data */
|
1184 |
inc_refcounts(bs, res, refcount_table, nb_clusters, |
1185 |
s->refcount_table_offset, |
1186 |
s->refcount_table_size * sizeof(uint64_t));
|
1187 |
|
1188 |
for(i = 0; i < s->refcount_table_size; i++) { |
1189 |
uint64_t offset, cluster; |
1190 |
offset = s->refcount_table[i]; |
1191 |
cluster = offset >> s->cluster_bits; |
1192 |
|
1193 |
/* Refcount blocks are cluster aligned */
|
1194 |
if (offset & (s->cluster_size - 1)) { |
1195 |
fprintf(stderr, "ERROR refcount block %" PRId64 " is not " |
1196 |
"cluster aligned; refcount table entry corrupted\n", i);
|
1197 |
res->corruptions++; |
1198 |
continue;
|
1199 |
} |
1200 |
|
1201 |
if (cluster >= nb_clusters) {
|
1202 |
fprintf(stderr, "ERROR refcount block %" PRId64
|
1203 |
" is outside image\n", i);
|
1204 |
res->corruptions++; |
1205 |
continue;
|
1206 |
} |
1207 |
|
1208 |
if (offset != 0) { |
1209 |
inc_refcounts(bs, res, refcount_table, nb_clusters, |
1210 |
offset, s->cluster_size); |
1211 |
if (refcount_table[cluster] != 1) { |
1212 |
fprintf(stderr, "ERROR refcount block %" PRId64
|
1213 |
" refcount=%d\n",
|
1214 |
i, refcount_table[cluster]); |
1215 |
res->corruptions++; |
1216 |
} |
1217 |
} |
1218 |
} |
1219 |
|
1220 |
/* compare ref counts */
|
1221 |
for (i = 0, highest_cluster = 0; i < nb_clusters; i++) { |
1222 |
refcount1 = get_refcount(bs, i); |
1223 |
if (refcount1 < 0) { |
1224 |
fprintf(stderr, "Can't get refcount for cluster %" PRId64 ": %s\n", |
1225 |
i, strerror(-refcount1)); |
1226 |
res->check_errors++; |
1227 |
continue;
|
1228 |
} |
1229 |
|
1230 |
refcount2 = refcount_table[i]; |
1231 |
|
1232 |
if (refcount1 > 0 || refcount2 > 0) { |
1233 |
highest_cluster = i; |
1234 |
} |
1235 |
|
1236 |
if (refcount1 != refcount2) {
|
1237 |
|
1238 |
/* Check if we're allowed to fix the mismatch */
|
1239 |
int *num_fixed = NULL; |
1240 |
if (refcount1 > refcount2 && (fix & BDRV_FIX_LEAKS)) {
|
1241 |
num_fixed = &res->leaks_fixed; |
1242 |
} else if (refcount1 < refcount2 && (fix & BDRV_FIX_ERRORS)) { |
1243 |
num_fixed = &res->corruptions_fixed; |
1244 |
} |
1245 |
|
1246 |
fprintf(stderr, "%s cluster %" PRId64 " refcount=%d reference=%d\n", |
1247 |
num_fixed != NULL ? "Repairing" : |
1248 |
refcount1 < refcount2 ? "ERROR" :
|
1249 |
"Leaked",
|
1250 |
i, refcount1, refcount2); |
1251 |
|
1252 |
if (num_fixed) {
|
1253 |
ret = update_refcount(bs, i << s->cluster_bits, 1,
|
1254 |
refcount2 - refcount1); |
1255 |
if (ret >= 0) { |
1256 |
(*num_fixed)++; |
1257 |
continue;
|
1258 |
} |
1259 |
} |
1260 |
|
1261 |
/* And if we couldn't, print an error */
|
1262 |
if (refcount1 < refcount2) {
|
1263 |
res->corruptions++; |
1264 |
} else {
|
1265 |
res->leaks++; |
1266 |
} |
1267 |
} |
1268 |
} |
1269 |
|
1270 |
res->image_end_offset = (highest_cluster + 1) * s->cluster_size;
|
1271 |
ret = 0;
|
1272 |
|
1273 |
fail:
|
1274 |
g_free(refcount_table); |
1275 |
|
1276 |
return ret;
|
1277 |
} |
1278 |
|