diff options
| -rw-r--r-- | block/qcow2-refcount.c | 188 |
1 files changed, 27 insertions, 161 deletions
diff --git a/block/qcow2-refcount.c b/block/qcow2-refcount.c index b87eafc..e964666 100644 --- a/block/qcow2-refcount.c +++ b/block/qcow2-refcount.c @@ -1452,127 +1452,12 @@ 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_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, the offset of the newly allocated cluster 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 done; - } - - /* 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_free_cluster; - } - - /* 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, 0, 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 */ - goto done; - } - - /* 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_free_cluster; - } - - /* update refcount table */ - assert(!offset_into_cluster(s, new_offset)); - 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_free_cluster; - } - - goto done; - -fail_free_cluster: - qcow2_free_clusters(bs, new_offset, s->cluster_size, QCOW2_DISCARD_OTHER); - -done: - if (refcount_block) { - /* This should never fail, as it would only do so if the given refcount - * block cannot be found in the cache. As this is impossible as long as - * there are no bugs, assert the success. */ - int tmp = qcow2_cache_put(bs, s->refcount_block_cache, &refcount_block); - assert(tmp == 0); - } - - if (ret < 0) { - return ret; - } - - return new_offset; -} - -/* * Checks consistency of refblocks and accounts for each refblock in * *refcount_table. */ static int check_refblocks(BlockDriverState *bs, BdrvCheckResult *res, - BdrvCheckMode fix, uint16_t **refcount_table, - int64_t *nb_clusters) + BdrvCheckMode fix, bool *rebuild, + uint16_t **refcount_table, int64_t *nb_clusters) { BDRVQcowState *s = bs->opaque; int64_t i, size; @@ -1588,6 +1473,7 @@ static int check_refblocks(BlockDriverState *bs, BdrvCheckResult *res, fprintf(stderr, "ERROR refcount block %" PRId64 " is not " "cluster aligned; refcount table entry corrupted\n", i); res->corruptions++; + *rebuild = true; continue; } @@ -1649,6 +1535,7 @@ static int check_refblocks(BlockDriverState *bs, BdrvCheckResult *res, resize_fail: res->corruptions++; + *rebuild = true; fprintf(stderr, "ERROR could not resize image: %s\n", strerror(-ret)); } else { @@ -1664,43 +1551,10 @@ resize_fail: return ret; } if ((*refcount_table)[cluster] != 1) { - fprintf(stderr, "%s refcount block %" PRId64 - " refcount=%d\n", - fix & BDRV_FIX_ERRORS ? "Repairing" : - "ERROR", - i, (*refcount_table)[cluster]); - - 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_renew(uint16_t, *refcount_table, - *nb_clusters); - memset(&(*refcount_table)[old_nb_clusters], 0, - (*nb_clusters - old_nb_clusters) * - sizeof(**refcount_table)); - } - (*refcount_table)[cluster]--; - ret = inc_refcounts(bs, res, refcount_table, nb_clusters, - new_offset, s->cluster_size); - if (ret < 0) { - return ret; - } - - res->corruptions_fixed++; - } else { - res->corruptions++; - } + fprintf(stderr, "ERROR refcount block %" PRId64 + " refcount=%d\n", i, (*refcount_table)[cluster]); + res->corruptions++; + *rebuild = true; } } } @@ -1712,8 +1566,8 @@ resize_fail: * Calculates an in-memory refcount table. */ static int calculate_refcounts(BlockDriverState *bs, BdrvCheckResult *res, - BdrvCheckMode fix, uint16_t **refcount_table, - int64_t *nb_clusters) + BdrvCheckMode fix, bool *rebuild, + uint16_t **refcount_table, int64_t *nb_clusters) { BDRVQcowState *s = bs->opaque; int64_t i; @@ -1765,7 +1619,7 @@ static int calculate_refcounts(BlockDriverState *bs, BdrvCheckResult *res, return ret; } - return check_refblocks(bs, res, fix, refcount_table, nb_clusters); + return check_refblocks(bs, res, fix, rebuild, refcount_table, nb_clusters); } /* @@ -1773,7 +1627,8 @@ static int calculate_refcounts(BlockDriverState *bs, BdrvCheckResult *res, * refcount as reported by the refcount structures on-disk. */ static void compare_refcounts(BlockDriverState *bs, BdrvCheckResult *res, - BdrvCheckMode fix, int64_t *highest_cluster, + BdrvCheckMode fix, bool *rebuild, + int64_t *highest_cluster, uint16_t *refcount_table, int64_t nb_clusters) { BDRVQcowState *s = bs->opaque; @@ -1798,7 +1653,9 @@ static void compare_refcounts(BlockDriverState *bs, BdrvCheckResult *res, if (refcount1 != refcount2) { /* Check if we're allowed to fix the mismatch */ int *num_fixed = NULL; - if (refcount1 > refcount2 && (fix & BDRV_FIX_LEAKS)) { + if (refcount1 == 0) { + *rebuild = true; + } else if (refcount1 > refcount2 && (fix & BDRV_FIX_LEAKS)) { num_fixed = &res->leaks_fixed; } else if (refcount1 < refcount2 && (fix & BDRV_FIX_ERRORS)) { num_fixed = &res->corruptions_fixed; @@ -1842,6 +1699,7 @@ int qcow2_check_refcounts(BlockDriverState *bs, BdrvCheckResult *res, BDRVQcowState *s = bs->opaque; int64_t size, highest_cluster, nb_clusters; uint16_t *refcount_table = NULL; + bool rebuild = false; int ret; size = bdrv_getlength(bs->file); @@ -1859,14 +1717,22 @@ int qcow2_check_refcounts(BlockDriverState *bs, BdrvCheckResult *res, res->bfi.total_clusters = size_to_clusters(s, bs->total_sectors * BDRV_SECTOR_SIZE); - ret = calculate_refcounts(bs, res, fix, &refcount_table, &nb_clusters); + ret = calculate_refcounts(bs, res, fix, &rebuild, &refcount_table, + &nb_clusters); if (ret < 0) { goto fail; } - compare_refcounts(bs, res, fix, &highest_cluster, refcount_table, + compare_refcounts(bs, res, fix, &rebuild, &highest_cluster, refcount_table, nb_clusters); + if (rebuild) { + fprintf(stderr, "ERROR need to rebuild refcount structures\n"); + res->check_errors++; + /* Just carry on, the rest does not rely on the on-disk refcount + * structures */ + } + /* check OFLAG_COPIED */ ret = check_oflag_copied(bs, res, fix); if (ret < 0) { |