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Introduce bdrv_check (Kevin Wolf) 

From: Kevin Wolf <kwolf@redhat.com>

Introduce a new bdrv_check function pointer for block drivers. Modify qcow2 to
return an error status in check_refcounts(), so it can implement bdrv_check.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>


git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@7214 c046a42c-6fe2-441c-8c8c-71466251a162
This commit is contained in:
aliguori 2009-04-21 23:11:50 +00:00
parent 8ddbc04f06
commit e97fc193e1
4 changed files with 70 additions and 19 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

71
block-qcow2.c
View File

@ -177,9 +177,7 @@ static int64_t alloc_clusters(BlockDriverState *bs, int64_t size);
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)
{
@ -2564,8 +2562,14 @@ static void update_refcount(BlockDriverState *bs,
}
}
#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)
@ -2573,9 +2577,10 @@ static void inc_refcounts(BlockDriverState *bs,
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);
@ -2585,13 +2590,17 @@ static void inc_refcounts(BlockDriverState *bs,
if (k < 0 || k >= refcount_table_size) {
fprintf(stderr, "ERROR: invalid cluster offset=0x%" PRIx64 "\n",
cluster_offset);
errors++;
} else {
if (++refcount_table[k] == 0) {
fprintf(stderr, "ERROR: overflow cluster offset=0x%" PRIx64
"\n", cluster_offset);
errors++;
}
}
}
return errors;
}
static int check_refcounts_l1(BlockDriverState *bs,
@ -2603,11 +2612,12 @@ static int check_refcounts_l1(BlockDriverState *bs,
BDRVQcowState *s = bs->opaque;
uint64_t *l1_table, *l2_table, l2_offset, offset, l1_size2;
int l2_size, i, j, nb_csectors, refcount;
int errors = 0;
l2_table = NULL;
l1_size2 = l1_size * sizeof(uint64_t);
inc_refcounts(bs, refcount_table, refcount_table_size,
errors += inc_refcounts(bs, refcount_table, refcount_table_size,
l1_table_offset, l1_size2);
l1_table = qemu_malloc(l1_size2);
@ -2627,6 +2637,7 @@ static int check_refcounts_l1(BlockDriverState *bs,
if ((refcount == 1) != ((l2_offset & QCOW_OFLAG_COPIED) != 0)) {
fprintf(stderr, "ERROR OFLAG_COPIED: l2_offset=%" PRIx64
" refcount=%d\n", l2_offset, refcount);
errors++;
}
}
l2_offset &= ~QCOW_OFLAG_COPIED;
@ -2641,11 +2652,12 @@ static int check_refcounts_l1(BlockDriverState *bs,
"copied flag must never be set for compressed "
"clusters\n", offset >> s->cluster_bits);
offset &= ~QCOW_OFLAG_COPIED;
errors++;
}
nb_csectors = ((offset >> s->csize_shift) &
s->csize_mask) + 1;
offset &= s->cluster_offset_mask;
inc_refcounts(bs, refcount_table,
errors += inc_refcounts(bs, refcount_table,
refcount_table_size,
offset & ~511, nb_csectors * 512);
} else {
@ -2654,16 +2666,17 @@ static int check_refcounts_l1(BlockDriverState *bs,
if ((refcount == 1) != ((offset & QCOW_OFLAG_COPIED) != 0)) {
fprintf(stderr, "ERROR OFLAG_COPIED: offset=%"
PRIx64 " refcount=%d\n", offset, refcount);
errors++;
}
}
offset &= ~QCOW_OFLAG_COPIED;
inc_refcounts(bs, refcount_table,
errors += 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);
@ -2671,7 +2684,7 @@ static int check_refcounts_l1(BlockDriverState *bs,
}
qemu_free(l1_table);
qemu_free(l2_table);
return 0;
return errors;
fail:
fprintf(stderr, "ERROR: I/O error in check_refcounts_l1\n");
qemu_free(l1_table);
@ -2679,24 +2692,35 @@ static int check_refcounts_l1(BlockDriverState *bs,
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,
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++) {
@ -2704,18 +2728,18 @@ static void check_refcounts(BlockDriverState *bs)
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);
}
}
@ -2724,12 +2748,21 @@ static void check_refcounts(BlockDriverState *bs)
for(i = 0; i < nb_clusters; i++) {
refcount1 = get_refcount(bs, i);
refcount2 = refcount_table[i];
if (refcount1 != refcount2)
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
@ -2751,7 +2784,6 @@ static void dump_refcounts(BlockDriverState *bs)
}
}
#endif
#endif
static int qcow_put_buffer(BlockDriverState *bs, const uint8_t *buf,
int64_t pos, int size)
@ -2806,4 +2838,5 @@ BlockDriver bdrv_qcow2 = {
.bdrv_get_buffer = qcow_get_buffer,
.bdrv_create2 = qcow_create2,
.bdrv_check = qcow_check,
};

14
block.c
View File

@ -506,6 +506,20 @@ void bdrv_delete(BlockDriverState *bs)
qemu_free(bs);
}
/*
* Run consistency checks on an image
*
* Returns the number of errors or -errno when an internal error occurs
*/
int bdrv_check(BlockDriverState *bs)
{
if (bs->drv->bdrv_check == NULL) {
return -ENOTSUP;
}
return bs->drv->bdrv_check(bs);
}
/* commit COW file into the raw image */
int bdrv_commit(BlockDriverState *bs)
{

1
block.h
View File

@ -73,6 +73,7 @@ int bdrv_open(BlockDriverState *bs, const char *filename, int flags);
int bdrv_open2(BlockDriverState *bs, const char *filename, int flags,
BlockDriver *drv);
void bdrv_close(BlockDriverState *bs);
int bdrv_check(BlockDriverState *bs);
int bdrv_read(BlockDriverState *bs, int64_t sector_num,
uint8_t *buf, int nb_sectors);
int bdrv_write(BlockDriverState *bs, int64_t sector_num,

3
block_int.h
View File

@ -102,6 +102,9 @@ struct BlockDriver {
const char *backing_file, const char *backing_format,
int flags);
/* Returns number of errors in image, -errno for internal errors */
int (*bdrv_check)(BlockDriverState* bs);
struct BlockDriver *next;
};