From 735513ff089e56379c2cfd290c5b3e1f1a13cbcc Mon Sep 17 00:00:00 2001 From: Max Reitz Date: Sat, 13 Jun 2015 16:22:12 +0200 Subject: [PATCH 18/42] qcow2: Split qcow2_check_refcounts() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Message-id: <1434212556-3927-19-git-send-email-mreitz@redhat.com> Patchwork-id: 66037 O-Subject: [RHEL-7.2 qemu-kvm PATCH 18/42] qcow2: Split qcow2_check_refcounts() Bugzilla: 1129893 RH-Acked-by: Jeffrey Cody RH-Acked-by: Fam Zheng RH-Acked-by: Stefan Hajnoczi BZ: 1129893 Put the code for calculating the reference counts and comparing them during qemu-img check into own functions. Signed-off-by: Max Reitz Reviewed-by: Benoît Canet Reviewed-by: Kevin Wolf Signed-off-by: Kevin Wolf (cherry picked from commit 6ca56bf5e90aa167395727667d17c699950c545c) Signed-off-by: Miroslav Rezanina Conflicts: block/qcow2-refcount.c 5839e53bbc0fec56021d758aab7610df421ed8c8 is missing downstream, which replaces g*_malloc*() by g*_new*() and g*_realloc() by g*_renew() all over the code base. Not backporting that commit results in only two conflicts which are trivial to resolve; backporting it would mean touching the whole code base, which I think is worse. Signed-off-by: Max Reitz --- block/qcow2-refcount.c | 151 +++++++++++++++++++++++++++++++++---------------- 1 file changed, 103 insertions(+), 48 deletions(-) diff --git a/block/qcow2-refcount.c b/block/qcow2-refcount.c index 0c5a6ad..08b2b62 100644 --- a/block/qcow2-refcount.c +++ b/block/qcow2-refcount.c @@ -1501,67 +1501,70 @@ fail: return new_offset; } +static int check_refblocks(BlockDriverState *bs, BdrvCheckResult *res, + BdrvCheckMode fix, uint16_t **refcount_table, + int64_t *nb_clusters); + /* - * 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, 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) { + *refcount_table = g_try_new0(uint16_t, *nb_clusters); + if (*nb_clusters && *refcount_table == NULL) { res->check_errors++; - return size; + return -ENOMEM; } - nb_clusters = size_to_clusters(s, size); - if (nb_clusters > INT_MAX) { - res->check_errors++; - return -EFBIG; - } - - refcount_table = g_malloc0(nb_clusters * sizeof(uint16_t)); - - res->bfi.total_clusters = - size_to_clusters(s, bs->total_sectors * BDRV_SECTOR_SIZE); - /* header */ - inc_refcounts(bs, res, refcount_table, nb_clusters, + inc_refcounts(bs, res, *refcount_table, *nb_clusters, 0, s->cluster_size); /* current L1 table */ - ret = check_refcounts_l1(bs, res, refcount_table, nb_clusters, + 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, + ret = check_refcounts_l1(bs, res, *refcount_table, *nb_clusters, sn->l1_table_offset, sn->l1_size, 0); if (ret < 0) { - goto fail; + return ret; } } - inc_refcounts(bs, res, refcount_table, nb_clusters, + inc_refcounts(bs, res, *refcount_table, *nb_clusters, s->snapshots_offset, s->snapshots_size); /* refcount data */ - inc_refcounts(bs, res, refcount_table, nb_clusters, + inc_refcounts(bs, res, *refcount_table, *nb_clusters, s->refcount_table_offset, s->refcount_table_size * sizeof(uint64_t)); + return check_refblocks(bs, res, fix, refcount_table, nb_clusters); +} + +/* + * 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) +{ + BDRVQcowState *s = bs->opaque; + int64_t i; + for(i = 0; i < s->refcount_table_size; i++) { uint64_t offset, cluster; offset = s->refcount_table[i]; @@ -1575,7 +1578,7 @@ int qcow2_check_refcounts(BlockDriverState *bs, BdrvCheckResult *res, continue; } - if (cluster >= nb_clusters) { + if (cluster >= *nb_clusters) { fprintf(stderr, "ERROR refcount block %" PRId64 " is outside image\n", i); res->corruptions++; @@ -1583,14 +1586,14 @@ int qcow2_check_refcounts(BlockDriverState *bs, BdrvCheckResult *res, } if (offset != 0) { - inc_refcounts(bs, res, refcount_table, nb_clusters, + inc_refcounts(bs, res, *refcount_table, *nb_clusters, offset, s->cluster_size); - if (refcount_table[cluster] != 1) { + if ((*refcount_table)[cluster] != 1) { fprintf(stderr, "%s refcount block %" PRId64 " refcount=%d\n", fix & BDRV_FIX_ERRORS ? "Repairing" : "ERROR", - i, refcount_table[cluster]); + i, (*refcount_table)[cluster]); if (fix & BDRV_FIX_ERRORS) { int64_t new_offset; @@ -1602,17 +1605,18 @@ int qcow2_check_refcounts(BlockDriverState *bs, BdrvCheckResult *res, } /* update refcounts */ - if ((new_offset >> s->cluster_bits) >= nb_clusters) { + 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)); + 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, + (*refcount_table)[cluster]--; + inc_refcounts(bs, res, *refcount_table, *nb_clusters, new_offset, s->cluster_size); res->corruptions_fixed++; @@ -1623,8 +1627,22 @@ int qcow2_check_refcounts(BlockDriverState *bs, BdrvCheckResult *res, } } - /* compare ref counts */ - for (i = 0, highest_cluster = 0; i < nb_clusters; i++) { + return 0; +} + +/* + * 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, int64_t *highest_cluster, + uint16_t *refcount_table, int64_t nb_clusters) +{ + BDRVQcowState *s = bs->opaque; + int64_t i; + int refcount1, refcount2, ret; + + 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", @@ -1636,11 +1654,10 @@ 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)) { @@ -1673,6 +1690,44 @@ int qcow2_check_refcounts(BlockDriverState *bs, BdrvCheckResult *res, } } } +} + +/* + * 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; + int64_t size, highest_cluster, nb_clusters; + 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; + } + + res->bfi.total_clusters = + size_to_clusters(s, bs->total_sectors * BDRV_SECTOR_SIZE); + + ret = calculate_refcounts(bs, res, fix, &refcount_table, &nb_clusters); + if (ret < 0) { + goto fail; + } + + compare_refcounts(bs, res, fix, &highest_cluster, refcount_table, + nb_clusters); /* check OFLAG_COPIED */ ret = check_oflag_copied(bs, res, fix); -- 1.8.3.1