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Re: [Qemu-devel] [PATCH 1/8] qcow2: Factor out refcount accounting for c
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From: |
Benoît Canet |
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Subject: |
Re: [Qemu-devel] [PATCH 1/8] qcow2: Factor out refcount accounting for check |
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Date: |
Thu, 14 Aug 2014 13:56:15 +0200 |
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User-agent: |
Mutt/1.5.23 (2014-03-12) |
The Wednesday 13 Aug 2014 à 23:01:43 (+0200), Max Reitz wrote :
> Put the code for calculating the reference counts during qemu-img check
> into an own function.
>
> Signed-off-by: Max Reitz <address@hidden>
> ---
> block/qcow2-refcount.c | 202
> +++++++++++++++++++++++++++++--------------------
> 1 file changed, 122 insertions(+), 80 deletions(-)
>
> diff --git a/block/qcow2-refcount.c b/block/qcow2-refcount.c
> index d60e2fe..9793c27 100644
> --- a/block/qcow2-refcount.c
> +++ b/block/qcow2-refcount.c
> @@ -1496,71 +1496,17 @@ done:
> }
>
> /*
> - * 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.
> + * Checks consistency of refblocks and accounts for each refblock in
> + * *refcount_table.
> */
> -int qcow2_check_refcounts(BlockDriverState *bs, BdrvCheckResult *res,
> - BdrvCheckMode fix)
> +static int check_refblocks(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;
> - 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_malloc0(nb_clusters * sizeof(uint16_t));
> - 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);
> -
> - /* 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;
> - }
> + int64_t i;
>
> - /* snapshots */
> - 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);
> - if (ret < 0) {
> - goto fail;
> - }
> - }
> - inc_refcounts(bs, res, refcount_table, nb_clusters,
> - s->snapshots_offset, s->snapshots_size);
> -
> - /* 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++) {
> + for (i = 0; i < s->refcount_table_size; i++) {
> uint64_t offset, cluster;
> offset = s->refcount_table[i];
> cluster = offset >> s->cluster_bits;
> @@ -1568,12 +1514,12 @@ int qcow2_check_refcounts(BlockDriverState *bs,
> BdrvCheckResult *res,
> /* 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);
> + "cluster aligned; refcount table entry corrupted\n", i);
> res->corruptions++;
> continue;
> }
>
> - if (cluster >= nb_clusters) {
> + if (cluster >= *nb_clusters) {
> fprintf(stderr, "ERROR refcount block %" PRId64
> " is outside image\n", i);
> res->corruptions++;
> @@ -1581,14 +1527,14 @@ int qcow2_check_refcounts(BlockDriverState *bs,
> BdrvCheckResult *res,
> }
>
> if (offset != 0) {
> - inc_refcounts(bs, res, refcount_table, nb_clusters,
> - offset, s->cluster_size);
> - if (refcount_table[cluster] != 1) {
> + 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]);
> + " refcount=%d\n",
> + fix & BDRV_FIX_ERRORS ? "Repairing" :
> + "ERROR",
> + i, (*refcount_table)[cluster]);
>
> if (fix & BDRV_FIX_ERRORS) {
> int64_t new_offset;
> @@ -1600,18 +1546,25 @@ 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_try_realloc(*refcount_table,
> + *nb_clusters * sizeof(uint16_t));
> + if (!*refcount_table) {
> + res->check_errors++;
> + return -ENOMEM;
> + }
> +
> + 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);
> + (*refcount_table)[cluster]--;
> + inc_refcounts(bs, res, *refcount_table, *nb_clusters,
> + new_offset, s->cluster_size);
>
> res->corruptions_fixed++;
> } else {
> @@ -1621,6 +1574,95 @@ int qcow2_check_refcounts(BlockDriverState *bs,
> BdrvCheckResult *res,
> }
> }
>
> + return 0;
> +}
> +
> +/*
> + * Calculates an in-memory refcount table.
> + */
> +static int calculate_refcounts(BlockDriverState *bs, BdrvCheckResult *res,
> + BdrvCheckMode fix, uint16_t **refcount_table,
> + int64_t *nb_clusters)
> +{
> + BDRVQcowState *s = bs->opaque;
> + QCowSnapshot *sn;
> + int64_t i;
> + int ret;
> +
> + if (!*refcount_table) {
> + *refcount_table = g_try_malloc0(*nb_clusters * sizeof(uint16_t));
> + if (*nb_clusters && !*refcount_table) {
> + res->check_errors++;
> + return -ENOMEM;
> + }
> + }
> +
> + /* header */
> + 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,
> + s->l1_table_offset, s->l1_size,
> CHECK_FRAG_INFO);
> + if (ret < 0) {
> + return ret;
> + }
> +
> + /* snapshots */
> + 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);
> + if (ret < 0) {
> + return ret;
> + }
> + }
> + inc_refcounts(bs, res, *refcount_table, *nb_clusters,
> + s->snapshots_offset, s->snapshots_size);
> +
> + /* refcount data */
> + 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 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, i, highest_cluster, nb_clusters;
> + int refcount1, refcount2;
> + uint16_t *refcount_table = NULL;
> + 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 ref counts */
> for (i = 0, highest_cluster = 0; i < nb_clusters; i++) {
> refcount1 = get_refcount(bs, i);
> --
> 2.0.3
>
>
The diff is impressive but the patch is mostly moving stuff around.
So
Reviewed-by: Benoit Canet <address@hidden>