static int64_t alloc_bytes(BlockDriverState *bs, int size);
static void free_clusters(BlockDriverState *bs,
int64_t offset, int64_t size);
-#ifdef DEBUG_ALLOC
-static void check_refcounts(BlockDriverState *bs);
-#endif
+static int check_refcounts(BlockDriverState *bs);
static int qcow_probe(const uint8_t *buf, int buf_size, const char *filename)
{
acb->sector_num = sector_num;
acb->qiov = qiov;
if (qiov->niov > 1) {
- acb->buf = acb->orig_buf = qemu_memalign(512, qiov->size);
+ acb->buf = acb->orig_buf = qemu_blockalign(bs, qiov->size);
if (is_write)
qemu_iovec_to_buffer(qiov, acb->buf);
} else {
}
}
-#ifdef DEBUG_ALLOC
-static void inc_refcounts(BlockDriverState *bs,
+/*
+ * Increases the refcount for a range of clusters in a given refcount table.
+ * This is used to construct a temporary refcount table out of L1 and L2 tables
+ * which can be compared the the refcount table saved in the image.
+ *
+ * Returns the number of errors in the image that were found
+ */
+static int inc_refcounts(BlockDriverState *bs,
uint16_t *refcount_table,
int refcount_table_size,
int64_t offset, int64_t size)
BDRVQcowState *s = bs->opaque;
int64_t start, last, cluster_offset;
int k;
+ int errors = 0;
if (size <= 0)
- return;
+ return 0;
start = offset & ~(s->cluster_size - 1);
last = (offset + size - 1) & ~(s->cluster_size - 1);
cluster_offset += s->cluster_size) {
k = cluster_offset >> s->cluster_bits;
if (k < 0 || k >= refcount_table_size) {
- printf("ERROR: invalid cluster offset=0x%llx\n", cluster_offset);
+ fprintf(stderr, "ERROR: invalid cluster offset=0x%" PRIx64 "\n",
+ cluster_offset);
+ errors++;
} else {
if (++refcount_table[k] == 0) {
- printf("ERROR: overflow cluster offset=0x%llx\n", cluster_offset);
+ fprintf(stderr, "ERROR: overflow cluster offset=0x%" PRIx64
+ "\n", cluster_offset);
+ errors++;
+ }
+ }
+ }
+
+ return errors;
+}
+
+/*
+ * Increases the refcount in the given refcount table for the all clusters
+ * referenced in the L2 table. While doing so, performs some checks on L2
+ * entries.
+ *
+ * Returns the number of errors found by the checks or -errno if an internal
+ * error occurred.
+ */
+static int check_refcounts_l2(BlockDriverState *bs,
+ uint16_t *refcount_table, int refcount_table_size, int64_t l2_offset,
+ int check_copied)
+{
+ BDRVQcowState *s = bs->opaque;
+ uint64_t *l2_table, offset;
+ int i, l2_size, nb_csectors, refcount;
+ int errors = 0;
+
+ /* Read L2 table from disk */
+ l2_size = s->l2_size * sizeof(uint64_t);
+ l2_table = qemu_malloc(l2_size);
+
+ if (bdrv_pread(s->hd, l2_offset, l2_table, l2_size) != l2_size)
+ goto fail;
+
+ /* Do the actual checks */
+ for(i = 0; i < s->l2_size; i++) {
+ offset = be64_to_cpu(l2_table[i]);
+ if (offset != 0) {
+ if (offset & QCOW_OFLAG_COMPRESSED) {
+ /* Compressed clusters don't have QCOW_OFLAG_COPIED */
+ if (offset & QCOW_OFLAG_COPIED) {
+ fprintf(stderr, "ERROR: cluster %" PRId64 ": "
+ "copied flag must never be set for compressed "
+ "clusters\n", offset >> s->cluster_bits);
+ offset &= ~QCOW_OFLAG_COPIED;
+ errors++;
+ }
+
+ /* Mark cluster as used */
+ nb_csectors = ((offset >> s->csize_shift) &
+ s->csize_mask) + 1;
+ offset &= s->cluster_offset_mask;
+ errors += inc_refcounts(bs, refcount_table,
+ refcount_table_size,
+ offset & ~511, nb_csectors * 512);
+ } else {
+ /* QCOW_OFLAG_COPIED must be set iff refcount == 1 */
+ if (check_copied) {
+ uint64_t entry = offset;
+ offset &= ~QCOW_OFLAG_COPIED;
+ refcount = get_refcount(bs, offset >> s->cluster_bits);
+ if ((refcount == 1) != ((entry & QCOW_OFLAG_COPIED) != 0)) {
+ fprintf(stderr, "ERROR OFLAG_COPIED: offset=%"
+ PRIx64 " refcount=%d\n", entry, refcount);
+ errors++;
+ }
+ }
+
+ /* Mark cluster as used */
+ offset &= ~QCOW_OFLAG_COPIED;
+ errors += inc_refcounts(bs, refcount_table,
+ refcount_table_size,
+ offset, s->cluster_size);
+
+ /* Correct offsets are cluster aligned */
+ if (offset & (s->cluster_size - 1)) {
+ fprintf(stderr, "ERROR offset=%" PRIx64 ": Cluster is not "
+ "properly aligned; L2 entry corrupted.\n", offset);
+ errors++;
+ }
}
}
}
+
+ qemu_free(l2_table);
+ return errors;
+
+fail:
+ fprintf(stderr, "ERROR: I/O error in check_refcounts_l1\n");
+ qemu_free(l2_table);
+ return -EIO;
}
+/*
+ * Increases the refcount for the L1 table, its L2 tables and all referenced
+ * clusters in the given refcount table. While doing so, performs some checks
+ * on L1 and L2 entries.
+ *
+ * Returns the number of errors found by the checks or -errno if an internal
+ * error occurred.
+ */
static int check_refcounts_l1(BlockDriverState *bs,
uint16_t *refcount_table,
int refcount_table_size,
int check_copied)
{
BDRVQcowState *s = bs->opaque;
- uint64_t *l1_table, *l2_table, l2_offset, offset, l1_size2;
- int l2_size, i, j, nb_csectors, refcount;
+ uint64_t *l1_table, l2_offset, l1_size2;
+ int i, refcount, ret;
+ int errors = 0;
- l2_table = NULL;
l1_size2 = l1_size * sizeof(uint64_t);
- inc_refcounts(bs, refcount_table, refcount_table_size,
+ /* Mark L1 table as used */
+ errors += inc_refcounts(bs, refcount_table, refcount_table_size,
l1_table_offset, l1_size2);
+ /* Read L1 table entries from disk */
l1_table = qemu_malloc(l1_size2);
if (bdrv_pread(s->hd, l1_table_offset,
l1_table, l1_size2) != l1_size2)
for(i = 0;i < l1_size; i++)
be64_to_cpus(&l1_table[i]);
- l2_size = s->l2_size * sizeof(uint64_t);
- l2_table = qemu_malloc(l2_size);
+ /* Do the actual checks */
for(i = 0; i < l1_size; i++) {
l2_offset = l1_table[i];
if (l2_offset) {
+ /* QCOW_OFLAG_COPIED must be set iff refcount == 1 */
if (check_copied) {
- refcount = get_refcount(bs, (l2_offset & ~QCOW_OFLAG_COPIED) >> s->cluster_bits);
+ refcount = get_refcount(bs, (l2_offset & ~QCOW_OFLAG_COPIED)
+ >> s->cluster_bits);
if ((refcount == 1) != ((l2_offset & QCOW_OFLAG_COPIED) != 0)) {
- printf("ERROR OFLAG_COPIED: l2_offset=%llx refcount=%d\n",
- l2_offset, refcount);
+ fprintf(stderr, "ERROR OFLAG_COPIED: l2_offset=%" PRIx64
+ " refcount=%d\n", l2_offset, refcount);
+ errors++;
}
}
+
+ /* Mark L2 table as used */
l2_offset &= ~QCOW_OFLAG_COPIED;
- if (bdrv_pread(s->hd, l2_offset, l2_table, l2_size) != l2_size)
- goto fail;
- for(j = 0; j < s->l2_size; j++) {
- offset = be64_to_cpu(l2_table[j]);
- if (offset != 0) {
- if (offset & QCOW_OFLAG_COMPRESSED) {
- if (offset & QCOW_OFLAG_COPIED) {
- printf("ERROR: cluster %lld: copied flag must never be set for compressed clusters\n",
- offset >> s->cluster_bits);
- offset &= ~QCOW_OFLAG_COPIED;
- }
- nb_csectors = ((offset >> s->csize_shift) &
- s->csize_mask) + 1;
- offset &= s->cluster_offset_mask;
- inc_refcounts(bs, refcount_table,
- refcount_table_size,
- offset & ~511, nb_csectors * 512);
- } else {
- if (check_copied) {
- refcount = get_refcount(bs, (offset & ~QCOW_OFLAG_COPIED) >> s->cluster_bits);
- if ((refcount == 1) != ((offset & QCOW_OFLAG_COPIED) != 0)) {
- printf("ERROR OFLAG_COPIED: offset=%llx refcount=%d\n",
- offset, refcount);
- }
- }
- offset &= ~QCOW_OFLAG_COPIED;
- inc_refcounts(bs, refcount_table,
- refcount_table_size,
- offset, s->cluster_size);
- }
- }
- }
- inc_refcounts(bs, refcount_table,
+ errors += inc_refcounts(bs, refcount_table,
refcount_table_size,
l2_offset,
s->cluster_size);
+
+ /* L2 tables are cluster aligned */
+ if (l2_offset & (s->cluster_size - 1)) {
+ fprintf(stderr, "ERROR l2_offset=%" PRIx64 ": Table is not "
+ "cluster aligned; L1 entry corrupted\n", l2_offset);
+ errors++;
+ }
+
+ /* Process and check L2 entries */
+ ret = check_refcounts_l2(bs, refcount_table, refcount_table_size,
+ l2_offset, check_copied);
+ if (ret < 0) {
+ goto fail;
+ }
+ errors += ret;
}
}
qemu_free(l1_table);
- qemu_free(l2_table);
- return 0;
- fail:
- printf("ERROR: I/O error in check_refcounts_l1\n");
+ return errors;
+
+fail:
+ fprintf(stderr, "ERROR: I/O error in check_refcounts_l1\n");
qemu_free(l1_table);
- qemu_free(l2_table);
return -EIO;
}
-static void check_refcounts(BlockDriverState *bs)
+/*
+ * 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 occured.
+ */
+static int check_refcounts(BlockDriverState *bs)
{
BDRVQcowState *s = bs->opaque;
int64_t size;
int nb_clusters, refcount1, refcount2, i;
QCowSnapshot *sn;
uint16_t *refcount_table;
+ int ret, errors = 0;
size = bdrv_getlength(s->hd);
nb_clusters = size_to_clusters(s, size);
refcount_table = qemu_mallocz(nb_clusters * sizeof(uint16_t));
/* header */
- inc_refcounts(bs, refcount_table, nb_clusters,
+ errors += inc_refcounts(bs, refcount_table, nb_clusters,
0, s->cluster_size);
- check_refcounts_l1(bs, refcount_table, nb_clusters,
+ /* current L1 table */
+ ret = check_refcounts_l1(bs, refcount_table, nb_clusters,
s->l1_table_offset, s->l1_size, 1);
+ if (ret < 0) {
+ return ret;
+ }
+ errors += ret;
/* snapshots */
for(i = 0; i < s->nb_snapshots; i++) {
check_refcounts_l1(bs, refcount_table, nb_clusters,
sn->l1_table_offset, sn->l1_size, 0);
}
- inc_refcounts(bs, refcount_table, nb_clusters,
+ errors += inc_refcounts(bs, refcount_table, nb_clusters,
s->snapshots_offset, s->snapshots_size);
/* refcount data */
- inc_refcounts(bs, refcount_table, nb_clusters,
+ errors += inc_refcounts(bs, refcount_table, nb_clusters,
s->refcount_table_offset,
s->refcount_table_size * sizeof(uint64_t));
for(i = 0; i < s->refcount_table_size; i++) {
int64_t offset;
offset = s->refcount_table[i];
if (offset != 0) {
- inc_refcounts(bs, refcount_table, nb_clusters,
+ errors += inc_refcounts(bs, refcount_table, nb_clusters,
offset, s->cluster_size);
}
}
for(i = 0; i < nb_clusters; i++) {
refcount1 = get_refcount(bs, i);
refcount2 = refcount_table[i];
- if (refcount1 != refcount2)
- printf("ERROR cluster %d refcount=%d reference=%d\n",
+ if (refcount1 != refcount2) {
+ fprintf(stderr, "ERROR cluster %d refcount=%d reference=%d\n",
i, refcount1, refcount2);
+ errors++;
+ }
}
qemu_free(refcount_table);
+
+ return errors;
+}
+
+static int qcow_check(BlockDriverState *bs)
+{
+ return check_refcounts(bs);
}
#if 0
}
}
#endif
-#endif
static int qcow_put_buffer(BlockDriverState *bs, const uint8_t *buf,
int64_t pos, int size)
.bdrv_get_buffer = qcow_get_buffer,
.bdrv_create2 = qcow_create2,
+ .bdrv_check = qcow_check,
};
projects / qemu / blobdiff