Commit e9f5b6de authored by Kevin Wolf's avatar Kevin Wolf
Browse files

qcow2: Support external data file in qemu-img check 



For external data files, data clusters must be excluded from the
refcount calculations. Instead, an implicit refcount of 1 is assumed for
the COPIED flag.

Compressed clusters and internal snapshots are incompatible with
external data files, so print an error if they are in use for images
with an external data file.

Signed-off-by: default avatarKevin Wolf <kwolf@redhat.com>
parent aa8b34c1

block/qcow2-refcount.c

+30 −11
Original line number Diff line number Diff line
@@ -1605,6 +1605,13 @@ static int check_refcounts_l2(BlockDriverState *bs, BdrvCheckResult *res, 
                res->corruptions++;

            }



            if (has_data_file(bs)) {

                fprintf(stderr, "ERROR compressed cluster %d with data file, "

                        "entry=0x%" PRIx64 "\n", i, l2_entry);

                res->corruptions++;

                break;

            }



            /* Mark cluster as used */

            nb_csectors = ((l2_entry >> s->csize_shift) &

                           s->csize_mask) + 1;
@@ -1695,12 +1702,14 @@ static int check_refcounts_l2(BlockDriverState *bs, BdrvCheckResult *res, 
            }



            /* Mark cluster as used */

            ret = qcow2_inc_refcounts_imrt(bs, res,

                                           refcount_table, refcount_table_size,

            if (!has_data_file(bs)) {

                ret = qcow2_inc_refcounts_imrt(bs, res, refcount_table,

                                               refcount_table_size,

                                               offset, s->cluster_size);

                if (ret < 0) {

                    goto fail;

                }

            }

            break;

        }
@@ -1884,6 +1893,9 @@ static int check_oflag_copied(BlockDriverState *bs, BdrvCheckResult *res, 


            if (cluster_type == QCOW2_CLUSTER_NORMAL ||

                cluster_type == QCOW2_CLUSTER_ZERO_ALLOC) {

                if (has_data_file(bs)) {

                    refcount = 1;

                } else {

                    ret = qcow2_get_refcount(bs,

                                             data_offset >> s->cluster_bits,

                                             &refcount);
@@ -1891,6 +1903,7 @@ static int check_oflag_copied(BlockDriverState *bs, BdrvCheckResult *res, 
                        /* don't print message nor increment check_errors */

                        continue;

                    }

                }

                if ((refcount == 1) != ((l2_entry & QCOW_OFLAG_COPIED) != 0)) {

                    fprintf(stderr, "%s OFLAG_COPIED data cluster: "

                            "l2_entry=%" PRIx64 " refcount=%" PRIu64 "\n",
@@ -2083,6 +2096,12 @@ static int calculate_refcounts(BlockDriverState *bs, BdrvCheckResult *res, 
    }



    /* snapshots */

    if (has_data_file(bs) && s->nb_snapshots) {

        fprintf(stderr, "ERROR %d snapshots in image with data file\n",

                s->nb_snapshots);

        res->corruptions++;

    }



    for (i = 0; i < s->nb_snapshots; i++) {

        sn = s->snapshots + i;

        if (offset_into_cluster(s, sn->l1_table_offset)) {