diff options
Diffstat (limited to 'block')
| -rw-r--r-- | block/qcow2-cluster.c | 6 | ||||
| -rw-r--r-- | block/qcow2-refcount.c | 873 | ||||
| -rw-r--r-- | block/qcow2.c | 7 | ||||
| -rw-r--r-- | block/qcow2.h | 4 | ||||
| -rw-r--r-- | block/raw-posix.c | 26 | ||||
| -rw-r--r-- | block/vdi.c | 9 |
6 files changed, 653 insertions, 272 deletions
diff --git a/block/qcow2-cluster.c b/block/qcow2-cluster.c index f7dd8c0985..4d888c785f 100644 --- a/block/qcow2-cluster.c +++ b/block/qcow2-cluster.c @@ -164,12 +164,14 @@ static int l2_load(BlockDriverState *bs, uint64_t l2_offset, int qcow2_write_l1_entry(BlockDriverState *bs, int l1_index) { BDRVQcowState *s = bs->opaque; - uint64_t buf[L1_ENTRIES_PER_SECTOR]; + uint64_t buf[L1_ENTRIES_PER_SECTOR] = { 0 }; int l1_start_index; int i, ret; l1_start_index = l1_index & ~(L1_ENTRIES_PER_SECTOR - 1); - for (i = 0; i < L1_ENTRIES_PER_SECTOR; i++) { + for (i = 0; i < L1_ENTRIES_PER_SECTOR && l1_start_index + i < s->l1_size; + i++) + { buf[i] = cpu_to_be64(s->l1_table[l1_start_index + i]); } diff --git a/block/qcow2-refcount.c b/block/qcow2-refcount.c index c31d85a840..1477031206 100644 --- a/block/qcow2-refcount.c +++ b/block/qcow2-refcount.c @@ -100,7 +100,7 @@ static int get_refcount(BlockDriverState *bs, int64_t cluster_index) uint16_t *refcount_block; uint16_t refcount; - refcount_table_index = cluster_index >> (s->cluster_bits - REFCOUNT_SHIFT); + refcount_table_index = cluster_index >> s->refcount_block_bits; if (refcount_table_index >= s->refcount_table_size) return 0; refcount_block_offset = @@ -121,8 +121,7 @@ static int get_refcount(BlockDriverState *bs, int64_t cluster_index) return ret; } - block_index = cluster_index & - ((1 << (s->cluster_bits - REFCOUNT_SHIFT)) - 1); + block_index = cluster_index & (s->refcount_block_size - 1); refcount = be16_to_cpu(refcount_block[block_index]); ret = qcow2_cache_put(bs, s->refcount_block_cache, @@ -157,8 +156,8 @@ static unsigned int next_refcount_table_size(BDRVQcowState *s, static int in_same_refcount_block(BDRVQcowState *s, uint64_t offset_a, uint64_t offset_b) { - uint64_t block_a = offset_a >> (2 * s->cluster_bits - REFCOUNT_SHIFT); - uint64_t block_b = offset_b >> (2 * s->cluster_bits - REFCOUNT_SHIFT); + uint64_t block_a = offset_a >> (s->cluster_bits + s->refcount_block_bits); + uint64_t block_b = offset_b >> (s->cluster_bits + s->refcount_block_bits); return (block_a == block_b); } @@ -179,7 +178,7 @@ static int alloc_refcount_block(BlockDriverState *bs, BLKDBG_EVENT(bs->file, BLKDBG_REFBLOCK_ALLOC); /* Find the refcount block for the given cluster */ - refcount_table_index = cluster_index >> (s->cluster_bits - REFCOUNT_SHIFT); + refcount_table_index = cluster_index >> s->refcount_block_bits; if (refcount_table_index < s->refcount_table_size) { @@ -256,7 +255,7 @@ static int alloc_refcount_block(BlockDriverState *bs, /* The block describes itself, need to update the cache */ int block_index = (new_block >> s->cluster_bits) & - ((1 << (s->cluster_bits - REFCOUNT_SHIFT)) - 1); + (s->refcount_block_size - 1); (*refcount_block)[block_index] = cpu_to_be16(1); } else { /* Described somewhere else. This can recurse at most twice before we @@ -328,8 +327,7 @@ static int alloc_refcount_block(BlockDriverState *bs, BLKDBG_EVENT(bs->file, BLKDBG_REFTABLE_GROW); /* Calculate the number of refcount blocks needed so far */ - uint64_t refcount_block_clusters = 1 << (s->cluster_bits - REFCOUNT_SHIFT); - uint64_t blocks_used = DIV_ROUND_UP(cluster_index, refcount_block_clusters); + uint64_t blocks_used = DIV_ROUND_UP(cluster_index, s->refcount_block_size); if (blocks_used > QCOW_MAX_REFTABLE_SIZE / sizeof(uint64_t)) { return -EFBIG; @@ -343,14 +341,14 @@ static int alloc_refcount_block(BlockDriverState *bs, uint64_t table_clusters = size_to_clusters(s, table_size * sizeof(uint64_t)); blocks_clusters = 1 + - ((table_clusters + refcount_block_clusters - 1) - / refcount_block_clusters); + ((table_clusters + s->refcount_block_size - 1) + / s->refcount_block_size); uint64_t meta_clusters = table_clusters + blocks_clusters; last_table_size = table_size; table_size = next_refcount_table_size(s, blocks_used + - ((meta_clusters + refcount_block_clusters - 1) - / refcount_block_clusters)); + ((meta_clusters + s->refcount_block_size - 1) + / s->refcount_block_size)); } while (last_table_size != table_size); @@ -360,7 +358,7 @@ static int alloc_refcount_block(BlockDriverState *bs, #endif /* Create the new refcount table and blocks */ - uint64_t meta_offset = (blocks_used * refcount_block_clusters) * + uint64_t meta_offset = (blocks_used * s->refcount_block_size) * s->cluster_size; uint64_t table_offset = meta_offset + blocks_clusters * s->cluster_size; uint64_t *new_table = g_try_new0(uint64_t, table_size); @@ -560,8 +558,7 @@ static int QEMU_WARN_UNUSED_RESULT update_refcount(BlockDriverState *bs, { int block_index, refcount; int64_t cluster_index = cluster_offset >> s->cluster_bits; - int64_t table_index = - cluster_index >> (s->cluster_bits - REFCOUNT_SHIFT); + int64_t table_index = cluster_index >> s->refcount_block_bits; /* Load the refcount block and allocate it if needed */ if (table_index != old_table_index) { @@ -583,8 +580,7 @@ static int QEMU_WARN_UNUSED_RESULT update_refcount(BlockDriverState *bs, qcow2_cache_entry_mark_dirty(s->refcount_block_cache, refcount_block); /* we can update the count and save it */ - block_index = cluster_index & - ((1 << (s->cluster_bits - REFCOUNT_SHIFT)) - 1); + block_index = cluster_index & (s->refcount_block_size - 1); refcount = be16_to_cpu(refcount_block[block_index]); refcount += addend; @@ -1081,36 +1077,52 @@ fail: * * Modifies the number of errors in res. */ -static void inc_refcounts(BlockDriverState *bs, - BdrvCheckResult *res, - uint16_t *refcount_table, - int refcount_table_size, - int64_t offset, int64_t size) +static int inc_refcounts(BlockDriverState *bs, + BdrvCheckResult *res, + uint16_t **refcount_table, + int64_t *refcount_table_size, + int64_t offset, int64_t size) { BDRVQcowState *s = bs->opaque; uint64_t start, last, cluster_offset, k; - if (size <= 0) - return; + if (size <= 0) { + return 0; + } start = start_of_cluster(s, offset); last = start_of_cluster(s, offset + size - 1); for(cluster_offset = start; cluster_offset <= last; cluster_offset += s->cluster_size) { k = cluster_offset >> s->cluster_bits; - if (k >= refcount_table_size) { - fprintf(stderr, "Warning: cluster offset=0x%" PRIx64 " is after " - "the end of the image file, can't properly check refcounts.\n", - cluster_offset); - res->check_errors++; - } else { - if (++refcount_table[k] == 0) { - fprintf(stderr, "ERROR: overflow cluster offset=0x%" PRIx64 - "\n", cluster_offset); - res->corruptions++; + if (k >= *refcount_table_size) { + int64_t old_refcount_table_size = *refcount_table_size; + uint16_t *new_refcount_table; + + *refcount_table_size = k + 1; + new_refcount_table = g_try_realloc(*refcount_table, + *refcount_table_size * + sizeof(**refcount_table)); + if (!new_refcount_table) { + *refcount_table_size = old_refcount_table_size; + res->check_errors++; + return -ENOMEM; } + *refcount_table = new_refcount_table; + + memset(*refcount_table + old_refcount_table_size, 0, + (*refcount_table_size - old_refcount_table_size) * + sizeof(**refcount_table)); + } + + if (++(*refcount_table)[k] == 0) { + fprintf(stderr, "ERROR: overflow cluster offset=0x%" PRIx64 + "\n", cluster_offset); + res->corruptions++; } } + + return 0; } /* Flags for check_refcounts_l1() and check_refcounts_l2() */ @@ -1127,20 +1139,24 @@ enum { * error occurred. */ static int check_refcounts_l2(BlockDriverState *bs, BdrvCheckResult *res, - uint16_t *refcount_table, int refcount_table_size, int64_t l2_offset, + uint16_t **refcount_table, int64_t *refcount_table_size, int64_t l2_offset, int flags) { BDRVQcowState *s = bs->opaque; uint64_t *l2_table, l2_entry; uint64_t next_contiguous_offset = 0; - int i, l2_size, nb_csectors; + int i, l2_size, nb_csectors, ret; /* Read L2 table from disk */ l2_size = s->l2_size * sizeof(uint64_t); l2_table = g_malloc(l2_size); - if (bdrv_pread(bs->file, l2_offset, l2_table, l2_size) != l2_size) + ret = bdrv_pread(bs->file, l2_offset, l2_table, l2_size); + if (ret < 0) { + fprintf(stderr, "ERROR: I/O error in check_refcounts_l2\n"); + res->check_errors++; goto fail; + } /* Do the actual checks */ for(i = 0; i < s->l2_size; i++) { @@ -1161,8 +1177,11 @@ static int check_refcounts_l2(BlockDriverState *bs, BdrvCheckResult *res, nb_csectors = ((l2_entry >> s->csize_shift) & s->csize_mask) + 1; l2_entry &= s->cluster_offset_mask; - inc_refcounts(bs, res, refcount_table, refcount_table_size, - l2_entry & ~511, nb_csectors * 512); + ret = inc_refcounts(bs, res, refcount_table, refcount_table_size, + l2_entry & ~511, nb_csectors * 512); + if (ret < 0) { + goto fail; + } if (flags & CHECK_FRAG_INFO) { res->bfi.allocated_clusters++; @@ -1197,8 +1216,11 @@ static int check_refcounts_l2(BlockDriverState *bs, BdrvCheckResult *res, } /* Mark cluster as used */ - inc_refcounts(bs, res, refcount_table,refcount_table_size, - offset, s->cluster_size); + ret = inc_refcounts(bs, res, refcount_table, refcount_table_size, + offset, s->cluster_size); + if (ret < 0) { + goto fail; + } /* Correct offsets are cluster aligned */ if (offset_into_cluster(s, offset)) { @@ -1221,9 +1243,8 @@ static int check_refcounts_l2(BlockDriverState *bs, BdrvCheckResult *res, return 0; fail: - fprintf(stderr, "ERROR: I/O error in check_refcounts_l2\n"); g_free(l2_table); - return -EIO; + return ret; } /* @@ -1236,33 +1257,38 @@ fail: */ static int check_refcounts_l1(BlockDriverState *bs, BdrvCheckResult *res, - uint16_t *refcount_table, - int refcount_table_size, + uint16_t **refcount_table, + int64_t *refcount_table_size, int64_t l1_table_offset, int l1_size, int flags) { BDRVQcowState *s = bs->opaque; - uint64_t *l1_table, l2_offset, l1_size2; + uint64_t *l1_table = NULL, l2_offset, l1_size2; int i, ret; l1_size2 = l1_size * sizeof(uint64_t); /* Mark L1 table as used */ - inc_refcounts(bs, res, refcount_table, refcount_table_size, - l1_table_offset, l1_size2); + ret = inc_refcounts(bs, res, refcount_table, refcount_table_size, + l1_table_offset, l1_size2); + if (ret < 0) { + goto fail; + } /* Read L1 table entries from disk */ - if (l1_size2 == 0) { - l1_table = NULL; - } else { + if (l1_size2 > 0) { l1_table = g_try_malloc(l1_size2); if (l1_table == NULL) { ret = -ENOMEM; + res->check_errors++; goto fail; } - if (bdrv_pread(bs->file, l1_table_offset, - l1_table, l1_size2) != l1_size2) + ret = bdrv_pread(bs->file, l1_table_offset, l1_table, l1_size2); + if (ret < 0) { + fprintf(stderr, "ERROR: I/O error in check_refcounts_l1\n"); + res->check_errors++; goto fail; + } for(i = 0;i < l1_size; i++) be64_to_cpus(&l1_table[i]); } @@ -1273,8 +1299,11 @@ static int check_refcounts_l1(BlockDriverState *bs, if (l2_offset) { /* Mark L2 table as used */ l2_offset &= L1E_OFFSET_MASK; - inc_refcounts(bs, res, refcount_table, refcount_table_size, - l2_offset, s->cluster_size); + ret = inc_refcounts(bs, res, refcount_table, refcount_table_size, + l2_offset, s->cluster_size); + if (ret < 0) { + goto fail; + } /* L2 tables are cluster aligned */ if (offset_into_cluster(s, l2_offset)) { @@ -1295,10 +1324,8 @@ static int check_refcounts_l1(BlockDriverState *bs, return 0; fail: - fprintf(stderr, "ERROR: I/O error in check_refcounts_l1\n"); - res->check_errors++; g_free(l1_table); - return -EIO; + return ret; } /* @@ -1421,248 +1448,190 @@ fail: } /* - * Writes one sector of the refcount table to the disk + * Checks consistency of refblocks and accounts for each refblock in + * *refcount_table. */ -#define RT_ENTRIES_PER_SECTOR (512 / sizeof(uint64_t)) -static int write_reftable_entry(BlockDriverState *bs, int rt_index) +static int check_refblocks(BlockDriverState *bs, BdrvCheckResult *res, + BdrvCheckMode fix, bool *rebuild, + uint16_t **refcount_table, int64_t *nb_clusters) { BDRVQcowState *s = bs->opaque; - uint64_t buf[RT_ENTRIES_PER_SECTOR]; - int rt_start_index; - int i, ret; + int64_t i, size; + int 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]); - } + for(i = 0; i < s->refcount_table_size; i++) { + uint64_t offset, cluster; + offset = s->refcount_table[i]; + cluster = offset >> s->cluster_bits; - 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; - } + /* Refcount blocks are cluster aligned */ + if (offset_into_cluster(s, offset)) { + fprintf(stderr, "ERROR refcount block %" PRId64 " is not " + "cluster aligned; refcount table entry corrupted\n", i); + res->corruptions++; + *rebuild = true; + continue; + } - 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; - } + if (cluster >= *nb_clusters) { + fprintf(stderr, "%s refcount block %" PRId64 " is outside image\n", + fix & BDRV_FIX_ERRORS ? "Repairing" : "ERROR", i); - return 0; -} + if (fix & BDRV_FIX_ERRORS) { + int64_t old_nb_clusters = *nb_clusters; + uint16_t *new_refcount_table; -/* - * 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; + if (offset > INT64_MAX - s->cluster_size) { + ret = -EINVAL; + goto resize_fail; + } - /* 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; - } + ret = bdrv_truncate(bs->file, offset + s->cluster_size); + if (ret < 0) { + goto resize_fail; + } + size = bdrv_getlength(bs->file); + if (size < 0) { + ret = size; + goto resize_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_free_cluster; - } + *nb_clusters = size_to_clusters(s, size); + assert(*nb_clusters >= old_nb_clusters); - /* 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; - } + new_refcount_table = g_try_realloc(*refcount_table, + *nb_clusters * + sizeof(**refcount_table)); + if (!new_refcount_table) { + *nb_clusters = old_nb_clusters; + res->check_errors++; + return -ENOMEM; + } + *refcount_table = new_refcount_table; - /* 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; - } + memset(*refcount_table + old_nb_clusters, 0, + (*nb_clusters - old_nb_clusters) * + sizeof(**refcount_table)); - /* 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; + if (cluster >= *nb_clusters) { + ret = -EINVAL; + goto resize_fail; + } -fail_free_cluster: - qcow2_free_clusters(bs, new_offset, s->cluster_size, QCOW2_DISCARD_OTHER); + res->corruptions_fixed++; + ret = inc_refcounts(bs, res, refcount_table, nb_clusters, + offset, s->cluster_size); + if (ret < 0) { + return ret; + } + /* No need to check whether the refcount is now greater than 1: + * This area was just allocated and zeroed, so it can only be + * exactly 1 after inc_refcounts() */ + continue; -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); - } +resize_fail: + res->corruptions++; + *rebuild = true; + fprintf(stderr, "ERROR could not resize image: %s\n", + strerror(-ret)); + } else { + res->corruptions++; + } + continue; + } - if (ret < 0) { - return ret; + if (offset != 0) { + ret = inc_refcounts(bs, res, refcount_table, nb_clusters, + offset, s->cluster_size); + if (ret < 0) { + return ret; + } + if ((*refcount_table)[cluster] != 1) { + fprintf(stderr, "ERROR refcount block %" PRId64 + " refcount=%d\n", i, (*refcount_table)[cluster]); + res->corruptions++; + *rebuild = true; + } + } } - return new_offset; + return 0; } /* - * Checks an image for refcount consistency. - * - * Returns 0 if no errors are found, the number of errors in case the image is - * detected as corrupted, and -errno when an internal error occurred. + * Calculates an in-memory refcount table. */ -int qcow2_check_refcounts(BlockDriverState *bs, BdrvCheckResult *res, - BdrvCheckMode fix) +static int calculate_refcounts(BlockDriverState *bs, BdrvCheckResult *res, + BdrvCheckMode fix, bool *rebuild, + uint16_t **refcount_table, int64_t *nb_clusters) { BDRVQcowState *s = bs->opaque; - int64_t size, i, highest_cluster, nb_clusters; - int refcount1, refcount2; + int64_t i; QCowSnapshot *sn; - uint16_t *refcount_table; int ret; - size = bdrv_getlength(bs->file); - if (size < 0) { - res->check_errors++; - return size; - } - - nb_clusters = size_to_clusters(s, size); - if (nb_clusters > INT_MAX) { - res->check_errors++; - return -EFBIG; - } - - refcount_table = g_try_new0(uint16_t, nb_clusters); - if (nb_clusters && refcount_table == NULL) { - res->check_errors++; - return -ENOMEM; + if (!*refcount_table) { + *refcount_table = g_try_new0(uint16_t, *nb_clusters); + if (*nb_clusters && *refcount_table == NULL) { + res->check_errors++; + return -ENOMEM; + } } - res->bfi.total_clusters = - size_to_clusters(s, bs->total_sectors * BDRV_SECTOR_SIZE); - /* header */ - inc_refcounts(bs, res, refcount_table, nb_clusters, - 0, s->cluster_size); + ret = inc_refcounts(bs, res, refcount_table, nb_clusters, + 0, s->cluster_size); + if (ret < 0) { + return ret; + } /* current L1 table */ ret = check_refcounts_l1(bs, res, refcount_table, nb_clusters, s->l1_table_offset, s->l1_size, CHECK_FRAG_INFO); if (ret < 0) { - goto fail; + return ret; } /* snapshots */ - for(i = 0; i < s->nb_snapshots; i++) { + for (i = 0; i < s->nb_snapshots; i++) { sn = s->snapshots + i; ret = check_refcounts_l1(bs, res, refcount_table, nb_clusters, - sn->l1_table_offset, sn->l1_size, 0); + sn->l1_table_offset, sn->l1_size, 0); if (ret < 0) { - goto fail; + return ret; } } - inc_refcounts(bs, res, refcount_table, nb_clusters, - s->snapshots_offset, s->snapshots_size); + ret = inc_refcounts(bs, res, refcount_table, nb_clusters, + s->snapshots_offset, s->snapshots_size); + if (ret < 0) { + return ret; + } /* refcount data */ - inc_refcounts(bs, res, refcount_table, nb_clusters, - s->refcount_table_offset, - s->refcount_table_size * sizeof(uint64_t)); - - for(i = 0; i < s->refcount_table_size; i++) { - uint64_t offset, cluster; - offset = s->refcount_table[i]; - cluster = offset >> s->cluster_bits; - - /* Refcount blocks are cluster aligned */ - if (offset_into_cluster(s, offset)) { - fprintf(stderr, "ERROR refcount block %" PRId64 " is not " - "cluster aligned; refcount table entry corrupted\n", i); - res->corruptions++; - continue; - } - - if (cluster >= nb_clusters) { - fprintf(stderr, "ERROR refcount block %" PRId64 - " is outside image\n", i); - res->corruptions++; - continue; - } - - if (offset != 0) { - inc_refcounts(bs, res, refcount_table, nb_clusters, - offset, s->cluster_size); - 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; - } + ret = inc_refcounts(bs, res, refcount_table, nb_clusters, + s->refcount_table_offset, + s->refcount_table_size * sizeof(uint64_t)); + if (ret < 0) { + return ret; + } - /* 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(uint16_t)); - } - refcount_table[cluster]--; - inc_refcounts(bs, res, refcount_table, nb_clusters, - new_offset, s->cluster_size); + return check_refblocks(bs, res, fix, rebuild, refcount_table, nb_clusters); +} - res->corruptions_fixed++; - } else { - res->corruptions++; - } - } - } - } +/* + * Compares the actual reference count for each cluster in the image against the + * refcount as reported by the refcount structures on-disk. + */ +static void compare_refcounts(BlockDriverState *bs, BdrvCheckResult *res, + BdrvCheckMode fix, bool *rebuild, + int64_t *highest_cluster, + uint16_t *refcount_table, int64_t nb_clusters) +{ + BDRVQcowState *s = bs->opaque; + int64_t i; + int refcount1, refcount2, ret; - /* compare ref counts */ - for (i = 0, highest_cluster = 0; i < nb_clusters; i++) { + for (i = 0, *highest_cluster = 0; i < nb_clusters; i++) { refcount1 = get_refcount(bs, i); if (refcount1 < 0) { fprintf(stderr, "Can't get refcount for cluster %" PRId64 ": %s\n", @@ -1674,14 +1643,15 @@ int qcow2_check_refcounts(BlockDriverState *bs, BdrvCheckResult *res, refcount2 = refcount_table[i]; if (refcount1 > 0 || refcount2 > 0) { - highest_cluster = i; + *highest_cluster = i; } 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; @@ -1711,6 +1681,397 @@ int qcow2_check_refcounts(BlockDriverState *bs, BdrvCheckResult *res, } } } +} + +/* + * Allocates clusters using an in-memory refcount table (IMRT) in contrast to + * the on-disk refcount structures. + * + * On input, *first_free_cluster tells where to start looking, and need not + * actually be a free cluster; the returned offset will not be before that + * cluster. On output, *first_free_cluster points to the first gap found, even + * if that gap was too small to be used as the returned offset. + * + * Note that *first_free_cluster is a cluster index whereas the return value is + * an offset. + */ +static int64_t alloc_clusters_imrt(BlockDriverState *bs, + int cluster_count, + uint16_t **refcount_table, + int64_t *imrt_nb_clusters, + int64_t *first_free_cluster) +{ + BDRVQcowState *s = bs->opaque; + int64_t cluster = *first_free_cluster, i; + bool first_gap = true; + int contiguous_free_clusters; + + /* Starting at *first_free_cluster, find a range of at least cluster_count + * continuously free clusters */ + for (contiguous_free_clusters = 0; + cluster < *imrt_nb_clusters && + contiguous_free_clusters < cluster_count; + cluster++) + { + if (!(*refcount_table)[cluster]) { + contiguous_free_clusters++; + if (first_gap) { + /* If this is the first free cluster found, update + * *first_free_cluster accordingly */ + *first_free_cluster = cluster; + first_gap = false; + } + } else if (contiguous_free_clusters) { + contiguous_free_clusters = 0; + } + } + + /* If contiguous_free_clusters is greater than zero, it contains the number + * of continuously free clusters until the current cluster; the first free + * cluster in the current "gap" is therefore + * cluster - contiguous_free_clusters */ + + /* If no such range could be found, grow the in-memory refcount table + * accordingly to append free clusters at the end of the image */ + if (contiguous_free_clusters < cluster_count) { + int64_t old_imrt_nb_clusters = *imrt_nb_clusters; + uint16_t *new_refcount_table; + + /* contiguous_free_clusters clusters are already empty at the image end; + * we need cluster_count clusters; therefore, we have to allocate + * cluster_count - contiguous_free_clusters new clusters at the end of + * the image (which is the current value of cluster; note that cluster + * may exceed old_imrt_nb_clusters if *first_free_cluster pointed beyond + * the image end) */ + *imrt_nb_clusters = cluster + cluster_count - contiguous_free_clusters; + new_refcount_table = g_try_realloc(*refcount_table, + *imrt_nb_clusters * + sizeof(**refcount_table)); + if (!new_refcount_table) { + *imrt_nb_clusters = old_imrt_nb_clusters; + return -ENOMEM; + } + *refcount_table = new_refcount_table; + + memset(*refcount_table + old_imrt_nb_clusters, 0, + (*imrt_nb_clusters - old_imrt_nb_clusters) * + sizeof(**refcount_table)); + } + + /* Go back to the first free cluster */ + cluster -= contiguous_free_clusters; + for (i = 0; i < cluster_count; i++) { + (*refcount_table)[cluster + i] = 1; + } + + return cluster << s->cluster_bits; +} + +/* + * Creates a new refcount structure based solely on the in-memory information + * given through *refcount_table. All necessary allocations will be reflected + * in that array. + * + * On success, the old refcount structure is leaked (it will be covered by the + * new refcount structure). + */ +static int rebuild_refcount_structure(BlockDriverState *bs, + BdrvCheckResult *res, + uint16_t **refcount_table, + int64_t *nb_clusters) +{ + BDRVQcowState *s = bs->opaque; + int64_t first_free_cluster = 0, reftable_offset = -1, cluster = 0; + int64_t refblock_offset, refblock_start, refblock_index; + uint32_t reftable_size = 0; + uint64_t *on_disk_reftable = NULL; + uint16_t *on_disk_refblock; + int i, ret = 0; + struct { + uint64_t reftable_offset; + uint32_t reftable_clusters; + } QEMU_PACKED reftable_offset_and_clusters; + + qcow2_cache_empty(bs, s->refcount_block_cache); + +write_refblocks: + for (; cluster < *nb_clusters; cluster++) { + if (!(*refcount_table)[cluster]) { + continue; + } + + refblock_index = cluster >> s->refcount_block_bits; + refblock_start = refblock_index << s->refcount_block_bits; + + /* Don't allocate a cluster in a refblock already written to disk */ + if (first_free_cluster < refblock_start) { + first_free_cluster = refblock_start; + } + refblock_offset = alloc_clusters_imrt(bs, 1, refcount_table, + nb_clusters, &first_free_cluster); + if (refblock_offset < 0) { + fprintf(stderr, "ERROR allocating refblock: %s\n", + strerror(-refblock_offset)); + res->check_errors++; + ret = refblock_offset; + goto fail; + } + + if (reftable_size <= refblock_index) { + uint32_t old_reftable_size = reftable_size; + uint64_t *new_on_disk_reftable; + + reftable_size = ROUND_UP((refblock_index + 1) * sizeof(uint64_t), + s->cluster_size) / sizeof(uint64_t); + new_on_disk_reftable = g_try_realloc(on_disk_reftable, + reftable_size * + sizeof(uint64_t)); + if (!new_on_disk_reftable) { + res->check_errors++; + ret = -ENOMEM; + goto fail; + } + on_disk_reftable = new_on_disk_reftable; + + memset(on_disk_reftable + old_reftable_size, 0, + (reftable_size - old_reftable_size) * sizeof(uint64_t)); + + /* The offset we have for the reftable is now no longer valid; + * this will leak that range, but we can easily fix that by running + * a leak-fixing check after this rebuild operation */ + reftable_offset = -1; + } + on_disk_reftable[refblock_index] = refblock_offset; + + /* If this is apparently the last refblock (for now), try to squeeze the + * reftable in */ + if (refblock_index == (*nb_clusters - 1) >> s->refcount_block_bits && + reftable_offset < 0) + { + uint64_t reftable_clusters = size_to_clusters(s, reftable_size * + sizeof(uint64_t)); + reftable_offset = alloc_clusters_imrt(bs, reftable_clusters, + refcount_table, nb_clusters, + &first_free_cluster); + if (reftable_offset < 0) { + fprintf(stderr, "ERROR allocating reftable: %s\n", + strerror(-reftable_offset)); + res->check_errors++; + ret = reftable_offset; + goto fail; + } + } + + ret = qcow2_pre_write_overlap_check(bs, 0, refblock_offset, + s->cluster_size); + if (ret < 0) { + fprintf(stderr, "ERROR writing refblock: %s\n", strerror(-ret)); + goto fail; + } + + on_disk_refblock = qemu_blockalign0(bs->file, s->cluster_size); + for (i = 0; i < s->refcount_block_size && + refblock_start + i < *nb_clusters; i++) + { + on_disk_refblock[i] = + cpu_to_be16((*refcount_table)[refblock_start + i]); + } + + ret = bdrv_write(bs->file, refblock_offset / BDRV_SECTOR_SIZE, + (void *)on_disk_refblock, s->cluster_sectors); + qemu_vfree(on_disk_refblock); + if (ret < 0) { + fprintf(stderr, "ERROR writing refblock: %s\n", strerror(-ret)); + goto fail; + } + + /* Go to the end of this refblock */ + cluster = refblock_start + s->refcount_block_size - 1; + } + + if (reftable_offset < 0) { + uint64_t post_refblock_start, reftable_clusters; + + post_refblock_start = ROUND_UP(*nb_clusters, s->refcount_block_size); + reftable_clusters = size_to_clusters(s, + reftable_size * sizeof(uint64_t)); + /* Not pretty but simple */ + if (first_free_cluster < post_refblock_start) { + first_free_cluster = post_refblock_start; + } + reftable_offset = alloc_clusters_imrt(bs, reftable_clusters, + refcount_table, nb_clusters, + &first_free_cluster); + if (reftable_offset < 0) { + fprintf(stderr, "ERROR allocating reftable: %s\n", + strerror(-reftable_offset)); + res->check_errors++; + ret = reftable_offset; + goto fail; + } + + goto write_refblocks; + } + + assert(on_disk_reftable); + + for (refblock_index = 0; refblock_index < reftable_size; refblock_index++) { + cpu_to_be64s(&on_disk_reftable[refblock_index]); + } + + ret = qcow2_pre_write_overlap_check(bs, 0, reftable_offset, + reftable_size * sizeof(uint64_t)); + if (ret < 0) { + fprintf(stderr, "ERROR writing reftable: %s\n", strerror(-ret)); + goto fail; + } + + assert(reftable_size < INT_MAX / sizeof(uint64_t)); + ret = bdrv_pwrite(bs->file, reftable_offset, on_disk_reftable, + reftable_size * sizeof(uint64_t)); + if (ret < 0) { + fprintf(stderr, "ERROR writing reftable: %s\n", strerror(-ret)); + goto fail; + } + + /* Enter new reftable into the image header */ + cpu_to_be64w(&reftable_offset_and_clusters.reftable_offset, + reftable_offset); + cpu_to_be32w(&reftable_offset_and_clusters.reftable_clusters, + size_to_clusters(s, reftable_size * sizeof(uint64_t))); + ret = bdrv_pwrite_sync(bs->file, offsetof(QCowHeader, + refcount_table_offset), + &reftable_offset_and_clusters, + sizeof(reftable_offset_and_clusters)); + if (ret < 0) { + fprintf(stderr, "ERROR setting reftable: %s\n", strerror(-ret)); + goto fail; + } + + for (refblock_index = 0; refblock_index < reftable_size; refblock_index++) { + be64_to_cpus(&on_disk_reftable[refblock_index]); + } + s->refcount_table = on_disk_reftable; + s->refcount_table_offset = reftable_offset; + s->refcount_table_size = reftable_size; + + return 0; + +fail: + g_free(on_disk_reftable); + return ret; +} + +/* + * Checks an image for refcount consistency. + * + * Returns 0 if no errors are found, the number of errors in case the image is + * detected as corrupted, and -errno when an internal error occurred. + */ +int qcow2_check_refcounts(BlockDriverState *bs, BdrvCheckResult *res, + BdrvCheckMode fix) +{ + BDRVQcowState *s = bs->opaque; + BdrvCheckResult pre_compare_res; + int64_t size, highest_cluster, nb_clusters; + uint16_t *refcount_table = NULL; + bool rebuild = false; + int ret; + + size = bdrv_getlength(bs->file); + if (size < 0) { + res->check_errors++; + return size; + } + + nb_clusters = size_to_clusters(s, size); + if (nb_clusters > INT_MAX) { + res->check_errors++; + return -EFBIG; + } + + res->bfi.total_clusters = + size_to_clusters(s, bs->total_sectors * BDRV_SECTOR_SIZE); + + ret = calculate_refcounts(bs, res, fix, &rebuild, &refcount_table, + &nb_clusters); + if (ret < 0) { + goto fail; + } + + /* In case we don't need to rebuild the refcount structure (but want to fix + * something), this function is immediately called again, in which case the + * result should be ignored */ + pre_compare_res = *res; + compare_refcounts(bs, res, 0, &rebuild, &highest_cluster, refcount_table, + nb_clusters); + + if (rebuild && (fix & BDRV_FIX_ERRORS)) { + BdrvCheckResult old_res = *res; + int fresh_leaks = 0; + + fprintf(stderr, "Rebuilding refcount structure\n"); + ret = rebuild_refcount_structure(bs, res, &refcount_table, + &nb_clusters); + if (ret < 0) { + goto fail; + } + + res->corruptions = 0; + res->leaks = 0; + + /* Because the old reftable has been exchanged for a new one the + * references have to be recalculated */ + rebuild = false; + memset(refcount_table, 0, nb_clusters * sizeof(uint16_t)); + ret = calculate_refcounts(bs, res, 0, &rebuild, &refcount_table, + &nb_clusters); + if (ret < 0) { + goto fail; + } + + if (fix & BDRV_FIX_LEAKS) { + /* The old refcount structures are now leaked, fix it; the result + * can be ignored, aside from leaks which were introduced by + * rebuild_refcount_structure() that could not be fixed */ + BdrvCheckResult saved_res = *res; + *res = (BdrvCheckResult){ 0 }; + + compare_refcounts(bs, res, BDRV_FIX_LEAKS, &rebuild, + &highest_cluster, refcount_table, nb_clusters); + if (rebuild) { + fprintf(stderr, "ERROR rebuilt refcount structure is still " + "broken\n"); + } + + /* Any leaks accounted for here were introduced by + * rebuild_refcount_structure() because that function has created a + * new refcount structure from scratch */ + fresh_leaks = res->leaks; + *res = saved_res; + } + + if (res->corruptions < old_res.corruptions) { + res->corruptions_fixed += old_res.corruptions - res->corruptions; + } + if (res->leaks < old_res.leaks) { + res->leaks_fixed += old_res.leaks - res->leaks; + } + res->leaks += fresh_leaks; + } else if (fix) { + if (rebuild) { + fprintf(stderr, "ERROR need to rebuild refcount structures\n"); + res->check_errors++; + ret = -EIO; + goto fail; + } + + if (res->leaks || res->corruptions) { + *res = pre_compare_res; + compare_refcounts(bs, res, fix, &rebuild, &highest_cluster, + refcount_table, nb_clusters); + } + } /* check OFLAG_COPIED */ ret = check_oflag_copied(bs, res, fix); diff --git a/block/qcow2.c b/block/qcow2.c index 156a219993..d031515838 100644 --- a/block/qcow2.c +++ b/block/qcow2.c @@ -698,6 +698,9 @@ static int qcow2_open(BlockDriverState *bs, QDict *options, int flags, s->l2_bits = s->cluster_bits - 3; /* L2 is always one cluster */ s->l2_size = 1 << s->l2_bits; + /* 2^(s->refcount_order - 3) is the refcount width in bytes */ + s->refcount_block_bits = s->cluster_bits - (s->refcount_order - 3); + s->refcount_block_size = 1 << s->refcount_block_bits; bs->total_sectors = header.size / 512; s->csize_shift = (62 - (s->cluster_bits - 8)); s->csize_mask = (1 << (s->cluster_bits - 8)) - 1; @@ -907,7 +910,7 @@ static int qcow2_open(BlockDriverState *bs, QDict *options, int flags, (s->incompatible_features & QCOW2_INCOMPAT_DIRTY)) { BdrvCheckResult result = {0}; - ret = qcow2_check(bs, &result, BDRV_FIX_ERRORS); + ret = qcow2_check(bs, &result, BDRV_FIX_ERRORS | BDRV_FIX_LEAKS); if (ret < 0) { error_setg_errno(errp, -ret, "Could not repair dirty image"); goto fail; @@ -1871,7 +1874,7 @@ static int qcow2_create2(const char *filename, int64_t total_size, .l1_size = cpu_to_be32(0), .refcount_table_offset = cpu_to_be64(cluster_size), .refcount_table_clusters = cpu_to_be32(1), - .refcount_order = cpu_to_be32(3 + REFCOUNT_SHIFT), + .refcount_order = cpu_to_be32(4), .header_length = cpu_to_be32(sizeof(*header)), }; diff --git a/block/qcow2.h b/block/qcow2.h index 7d61e615ff..577ccd1bf0 100644 --- a/block/qcow2.h +++ b/block/qcow2.h @@ -59,8 +59,6 @@ /* The cluster reads as all zeros */ #define QCOW_OFLAG_ZERO (1ULL << 0) -#define REFCOUNT_SHIFT 1 /* refcount size is 2 bytes */ - #define MIN_CLUSTER_BITS 9 #define MAX_CLUSTER_BITS 21 @@ -223,6 +221,8 @@ typedef struct BDRVQcowState { int l2_size; int l1_size; int l1_vm_state_index; + int refcount_block_bits; + int refcount_block_size; int csize_shift; int csize_mask; uint64_t cluster_offset_mask; diff --git a/block/raw-posix.c b/block/raw-posix.c index ee4ca3c01e..475cf74655 100644 --- a/block/raw-posix.c +++ b/block/raw-posix.c @@ -150,6 +150,7 @@ typedef struct BDRVRawState { bool has_discard:1; bool has_write_zeroes:1; bool discard_zeroes:1; + bool needs_alignment; #ifdef CONFIG_FIEMAP bool skip_fiemap; #endif @@ -230,7 +231,7 @@ static void raw_probe_alignment(BlockDriverState *bs, int fd, Error **errp) /* For /dev/sg devices the alignment is not really used. With buffered I/O, we don't have any restrictions. */ - if (bs->sg || !(s->open_flags & O_DIRECT)) { + if (bs->sg || !s->needs_alignment) { bs->request_alignment = 1; s->buf_align = 1; return; @@ -446,6 +447,9 @@ static int raw_open_common(BlockDriverState *bs, QDict *options, s->has_discard = true; s->has_write_zeroes = true; + if ((bs->open_flags & BDRV_O_NOCACHE) != 0) { + s->needs_alignment = true; + } if (fstat(s->fd, &st) < 0) { error_setg_errno(errp, errno, "Could not stat file"); @@ -472,6 +476,17 @@ static int raw_open_common(BlockDriverState *bs, QDict *options, } #endif } +#ifdef __FreeBSD__ + if (S_ISCHR(st.st_mode)) { + /* + * The file is a char device (disk), which on FreeBSD isn't behind + * a pager, so force all requests to be aligned. This is needed + * so QEMU makes sure all IO operations on the device are aligned + * to sector size, or else FreeBSD will reject them with EINVAL. + */ + s->needs_alignment = true; + } +#endif #ifdef CONFIG_XFS if (platform_test_xfs_fd(s->fd)) { @@ -1076,11 +1091,12 @@ static BlockAIOCB *raw_aio_submit(BlockDriverState *bs, return NULL; /* - * If O_DIRECT is used the buffer needs to be aligned on a sector - * boundary. Check if this is the case or tell the low-level - * driver that it needs to copy the buffer. + * Check if the underlying device requires requests to be aligned, + * and if the request we are trying to submit is aligned or not. + * If this is the case tell the low-level driver that it needs + * to copy the buffer. */ - if ((bs->open_flags & BDRV_O_NOCACHE)) { + if (s->needs_alignment) { if (!bdrv_qiov_is_aligned(bs, qiov)) { type |= QEMU_AIO_MISALIGNED; #ifdef CONFIG_LINUX_AIO diff --git a/block/vdi.c b/block/vdi.c index 9604721476..19701ee00d 100644 --- a/block/vdi.c +++ b/block/vdi.c @@ -407,8 +407,7 @@ static int vdi_open(BlockDriverState *bs, QDict *options, int flags, We accept them but round the disk size to the next multiple of SECTOR_SIZE. */ logout("odd disk size %" PRIu64 " B, round up\n", header.disk_size); - header.disk_size += SECTOR_SIZE - 1; - header.disk_size &= ~(SECTOR_SIZE - 1); + header.disk_size = ROUND_UP(header.disk_size, SECTOR_SIZE); } if (header.signature != VDI_SIGNATURE) { @@ -475,7 +474,7 @@ static int vdi_open(BlockDriverState *bs, QDict *options, int flags, s->header = header; bmap_size = header.blocks_in_image * sizeof(uint32_t); - bmap_size = (bmap_size + SECTOR_SIZE - 1) / SECTOR_SIZE; + bmap_size = DIV_ROUND_UP(bmap_size, SECTOR_SIZE); s->bmap = qemu_try_blockalign(bs->file, bmap_size * SECTOR_SIZE); if (s->bmap == NULL) { ret = -ENOMEM; @@ -736,10 +735,10 @@ static int vdi_create(const char *filename, QemuOpts *opts, Error **errp) /* We need enough blocks to store the given disk size, so always round up. */ - blocks = (bytes + block_size - 1) / block_size; + blocks = DIV_ROUND_UP(bytes, block_size); bmap_size = blocks * sizeof(uint32_t); - bmap_size = ((bmap_size + SECTOR_SIZE - 1) & ~(SECTOR_SIZE -1)); + bmap_size = ROUND_UP(bmap_size, SECTOR_SIZE); memset(&header, 0, sizeof(header)); pstrcpy(header.text, sizeof(header.text), VDI_TEXT); |