diff options
Diffstat (limited to 'block')
| -rw-r--r-- | block/blkdebug.c | 1 | ||||
| -rw-r--r-- | block/qcow2-refcount.c | 148 |
2 files changed, 147 insertions, 2 deletions
diff --git a/block/blkdebug.c b/block/blkdebug.c index ccb627ad93..5d33e03608 100644 --- a/block/blkdebug.c +++ b/block/blkdebug.c @@ -168,6 +168,7 @@ static const char *event_names[BLKDBG_EVENT_MAX] = { [BLKDBG_REFTABLE_LOAD] = "reftable_load", [BLKDBG_REFTABLE_GROW] = "reftable_grow", + [BLKDBG_REFTABLE_UPDATE] = "reftable_update", [BLKDBG_REFBLOCK_LOAD] = "refblock_load", [BLKDBG_REFBLOCK_UPDATE] = "refblock_update", diff --git a/block/qcow2-refcount.c b/block/qcow2-refcount.c index 2276b6f7f5..ba129de478 100644 --- a/block/qcow2-refcount.c +++ b/block/qcow2-refcount.c @@ -1338,6 +1338,121 @@ fail: } /* + * Writes one sector of the refcount table to the disk + */ +#define RT_ENTRIES_PER_SECTOR (512 / sizeof(uint64_t)) +static int write_reftable_entry(BlockDriverState *bs, int rt_index) +{ + BDRVQcowState *s = bs->opaque; + uint64_t buf[RT_ENTRIES_PER_SECTOR]; + int rt_start_index; + int i, ret; + + rt_start_index = rt_index & ~(RT_ENTRIES_PER_SECTOR - 1); + for (i = 0; i < RT_ENTRIES_PER_SECTOR; i++) { + buf[i] = cpu_to_be64(s->refcount_table[rt_start_index + i]); + } + + ret = qcow2_pre_write_overlap_check(bs, + QCOW2_OL_DEFAULT & ~QCOW2_OL_REFCOUNT_TABLE, + s->refcount_table_offset + rt_start_index * sizeof(uint64_t), + sizeof(buf)); + if (ret < 0) { + return ret; + } + + BLKDBG_EVENT(bs->file, BLKDBG_REFTABLE_UPDATE); + ret = bdrv_pwrite_sync(bs->file, s->refcount_table_offset + + rt_start_index * sizeof(uint64_t), buf, sizeof(buf)); + if (ret < 0) { + return ret; + } + + return 0; +} + +/* + * Allocates a new cluster for the given refcount block (represented by its + * offset in the image file) and copies the current content there. This function + * does _not_ decrement the reference count for the currently occupied cluster. + * + * This function prints an informative message to stderr on error (and returns + * -errno); on success, 0 is returned. + */ +static int64_t realloc_refcount_block(BlockDriverState *bs, int reftable_index, + uint64_t offset) +{ + BDRVQcowState *s = bs->opaque; + int64_t new_offset = 0; + void *refcount_block = NULL; + int ret; + + /* allocate new refcount block */ + new_offset = qcow2_alloc_clusters(bs, s->cluster_size); + if (new_offset < 0) { + fprintf(stderr, "Could not allocate new cluster: %s\n", + strerror(-new_offset)); + ret = new_offset; + goto fail; + } + + /* fetch current refcount block content */ + ret = qcow2_cache_get(bs, s->refcount_block_cache, offset, &refcount_block); + if (ret < 0) { + fprintf(stderr, "Could not fetch refcount block: %s\n", strerror(-ret)); + goto fail; + } + + /* new block has not yet been entered into refcount table, therefore it is + * no refcount block yet (regarding this check) */ + ret = qcow2_pre_write_overlap_check(bs, QCOW2_OL_DEFAULT, new_offset, + s->cluster_size); + if (ret < 0) { + fprintf(stderr, "Could not write refcount block; metadata overlap " + "check failed: %s\n", strerror(-ret)); + /* the image will be marked corrupt, so don't even attempt on freeing + * the cluster */ + new_offset = 0; + goto fail; + } + + /* write to new block */ + ret = bdrv_write(bs->file, new_offset / BDRV_SECTOR_SIZE, refcount_block, + s->cluster_sectors); + if (ret < 0) { + fprintf(stderr, "Could not write refcount block: %s\n", strerror(-ret)); + goto fail; + } + + /* update refcount table */ + assert(!(new_offset & (s->cluster_size - 1))); + s->refcount_table[reftable_index] = new_offset; + ret = write_reftable_entry(bs, reftable_index); + if (ret < 0) { + fprintf(stderr, "Could not update refcount table: %s\n", + strerror(-ret)); + goto fail; + } + +fail: + if (new_offset && (ret < 0)) { + qcow2_free_clusters(bs, new_offset, s->cluster_size, + QCOW2_DISCARD_ALWAYS); + } + if (refcount_block) { + if (ret < 0) { + qcow2_cache_put(bs, s->refcount_block_cache, &refcount_block); + } else { + ret = qcow2_cache_put(bs, s->refcount_block_cache, &refcount_block); + } + } + if (ret < 0) { + return ret; + } + return new_offset; +} + +/* * Checks an image for refcount consistency. * * Returns 0 if no errors are found, the number of errors in case the image is @@ -1413,10 +1528,39 @@ int qcow2_check_refcounts(BlockDriverState *bs, BdrvCheckResult *res, inc_refcounts(bs, res, refcount_table, nb_clusters, offset, s->cluster_size); if (refcount_table[cluster] != 1) { - fprintf(stderr, "ERROR refcount block %" PRId64 + fprintf(stderr, "%s refcount block %" PRId64 " refcount=%d\n", + fix & BDRV_FIX_ERRORS ? "Repairing" : + "ERROR", i, refcount_table[cluster]); - res->corruptions++; + + if (fix & BDRV_FIX_ERRORS) { + int64_t new_offset; + + new_offset = realloc_refcount_block(bs, i, offset); + if (new_offset < 0) { + res->corruptions++; + continue; + } + + /* update refcounts */ + if ((new_offset >> s->cluster_bits) >= nb_clusters) { + /* increase refcount_table size if necessary */ + int old_nb_clusters = nb_clusters; + nb_clusters = (new_offset >> s->cluster_bits) + 1; + refcount_table = g_realloc(refcount_table, + nb_clusters * sizeof(uint16_t)); + memset(&refcount_table[old_nb_clusters], 0, (nb_clusters + - old_nb_clusters) * sizeof(uint16_t)); + } + refcount_table[cluster]--; + inc_refcounts(bs, res, refcount_table, nb_clusters, + new_offset, s->cluster_size); + + res->corruptions_fixed++; + } else { + res->corruptions++; + } } } } |