#include "qemu/osdep.h"
#include <zlib.h>
+#include "qapi/error.h"
#include "qemu-common.h"
#include "block/block_int.h"
-#include "block/qcow2.h"
+#include "qcow2.h"
#include "qemu/bswap.h"
#include "trace.h"
new_l1_size2 = sizeof(uint64_t) * new_l1_size;
new_l1_table = qemu_try_blockalign(bs->file->bs,
- align_offset(new_l1_size2, 512));
+ ROUND_UP(new_l1_size2, 512));
if (new_l1_table == NULL) {
return -ENOMEM;
}
- memset(new_l1_table, 0, align_offset(new_l1_size2, 512));
+ memset(new_l1_table, 0, ROUND_UP(new_l1_size2, 512));
if (s->l1_size) {
memcpy(new_l1_table, s->l1_table, s->l1_size * sizeof(uint64_t));
/* the L1 position has not yet been updated, so these clusters must
* indeed be completely free */
ret = qcow2_pre_write_overlap_check(bs, 0, new_l1_table_offset,
- new_l1_size2);
+ new_l1_size2, false);
if (ret < 0) {
goto fail;
}
}
ret = qcow2_pre_write_overlap_check(bs, QCOW2_OL_ACTIVE_L1,
- s->l1_table_offset + 8 * l1_start_index, sizeof(buf));
+ s->l1_table_offset + 8 * l1_start_index, sizeof(buf), false);
if (ret < 0) {
return ret;
}
goto fail;
}
+ /* The offset must fit in the offset field of the L1 table entry */
+ assert((l2_offset & L1E_OFFSET_MASK) == l2_offset);
+
/* If we're allocating the table at offset 0 then something is wrong */
if (l2_offset == 0) {
qcow2_signal_corruption(bs, true, -1, -1, "Preventing invalid "
* as contiguous. (This allows it, for example, to stop at the first compressed
* cluster which may require a different handling)
*/
-static int count_contiguous_clusters(int nb_clusters, int cluster_size,
- uint64_t *l2_slice, uint64_t stop_flags)
+static int count_contiguous_clusters(BlockDriverState *bs, int nb_clusters,
+ int cluster_size, uint64_t *l2_slice, uint64_t stop_flags)
{
int i;
QCow2ClusterType first_cluster_type;
uint64_t first_entry = be64_to_cpu(l2_slice[0]);
uint64_t offset = first_entry & mask;
- if (!offset) {
+ first_cluster_type = qcow2_get_cluster_type(bs, first_entry);
+ if (first_cluster_type == QCOW2_CLUSTER_UNALLOCATED) {
return 0;
}
/* must be allocated */
- first_cluster_type = qcow2_get_cluster_type(first_entry);
assert(first_cluster_type == QCOW2_CLUSTER_NORMAL ||
first_cluster_type == QCOW2_CLUSTER_ZERO_ALLOC);
}
}
- return i;
+ return i;
}
/*
* Checks how many consecutive unallocated clusters in a given L2
* slice have the same cluster type.
*/
-static int count_contiguous_clusters_unallocated(int nb_clusters,
+static int count_contiguous_clusters_unallocated(BlockDriverState *bs,
+ int nb_clusters,
uint64_t *l2_slice,
QCow2ClusterType wanted_type)
{
wanted_type == QCOW2_CLUSTER_UNALLOCATED);
for (i = 0; i < nb_clusters; i++) {
uint64_t entry = be64_to_cpu(l2_slice[i]);
- QCow2ClusterType type = qcow2_get_cluster_type(entry);
+ QCow2ClusterType type = qcow2_get_cluster_type(bs, entry);
if (type != wanted_type) {
break;
unsigned offset_in_cluster,
QEMUIOVector *qiov)
{
+ BDRVQcow2State *s = bs->opaque;
int ret;
if (qiov->size == 0) {
}
ret = qcow2_pre_write_overlap_check(bs, 0,
- cluster_offset + offset_in_cluster, qiov->size);
+ cluster_offset + offset_in_cluster, qiov->size, true);
if (ret < 0) {
return ret;
}
BLKDBG_EVENT(bs->file, BLKDBG_COW_WRITE);
- ret = bdrv_co_pwritev(bs->file, cluster_offset + offset_in_cluster,
+ ret = bdrv_co_pwritev(s->data_file, cluster_offset + offset_in_cluster,
qiov->size, qiov, 0);
if (ret < 0) {
return ret;
* true */
assert(nb_clusters <= INT_MAX);
- type = qcow2_get_cluster_type(*cluster_offset);
+ type = qcow2_get_cluster_type(bs, *cluster_offset);
if (s->qcow_version < 3 && (type == QCOW2_CLUSTER_ZERO_PLAIN ||
type == QCOW2_CLUSTER_ZERO_ALLOC)) {
qcow2_signal_corruption(bs, true, -1, -1, "Zero cluster entry found"
}
switch (type) {
case QCOW2_CLUSTER_COMPRESSED:
+ if (has_data_file(bs)) {
+ qcow2_signal_corruption(bs, true, -1, -1, "Compressed cluster "
+ "entry found in image with external data "
+ "file (L2 offset: %#" PRIx64 ", L2 index: "
+ "%#x)", l2_offset, l2_index);
+ ret = -EIO;
+ goto fail;
+ }
/* Compressed clusters can only be processed one by one */
c = 1;
*cluster_offset &= L2E_COMPRESSED_OFFSET_SIZE_MASK;
case QCOW2_CLUSTER_ZERO_PLAIN:
case QCOW2_CLUSTER_UNALLOCATED:
/* how many empty clusters ? */
- c = count_contiguous_clusters_unallocated(nb_clusters,
+ c = count_contiguous_clusters_unallocated(bs, nb_clusters,
&l2_slice[l2_index], type);
*cluster_offset = 0;
break;
case QCOW2_CLUSTER_ZERO_ALLOC:
case QCOW2_CLUSTER_NORMAL:
/* how many allocated clusters ? */
- c = count_contiguous_clusters(nb_clusters, s->cluster_size,
+ c = count_contiguous_clusters(bs, nb_clusters, s->cluster_size,
&l2_slice[l2_index], QCOW_OFLAG_ZERO);
*cluster_offset &= L2E_OFFSET_MASK;
if (offset_into_cluster(s, *cluster_offset)) {
ret = -EIO;
goto fail;
}
+ if (has_data_file(bs) && *cluster_offset != offset - offset_in_cluster)
+ {
+ qcow2_signal_corruption(bs, true, -1, -1,
+ "External data file host cluster offset %#"
+ PRIx64 " does not match guest cluster "
+ "offset: %#" PRIx64
+ ", L2 index: %#x)", *cluster_offset,
+ offset - offset_in_cluster, l2_index);
+ ret = -EIO;
+ goto fail;
+ }
break;
default:
abort();
/*
* alloc_compressed_cluster_offset
*
- * For a given offset of the disk image, return cluster offset in
- * qcow2 file.
- *
- * If the offset is not found, allocate a new compressed cluster.
- *
- * Return the cluster offset if successful,
- * Return 0, otherwise.
+ * For a given offset on the virtual disk, allocate a new compressed cluster
+ * and put the host offset of the cluster into *host_offset. If a cluster is
+ * already allocated at the offset, return an error.
*
+ * Return 0 on success and -errno in error cases
*/
-
-uint64_t qcow2_alloc_compressed_cluster_offset(BlockDriverState *bs,
- uint64_t offset,
- int compressed_size)
+int qcow2_alloc_compressed_cluster_offset(BlockDriverState *bs,
+ uint64_t offset,
+ int compressed_size,
+ uint64_t *host_offset)
{
BDRVQcow2State *s = bs->opaque;
int l2_index, ret;
int64_t cluster_offset;
int nb_csectors;
+ if (has_data_file(bs)) {
+ return 0;
+ }
+
ret = get_cluster_table(bs, offset, &l2_slice, &l2_index);
if (ret < 0) {
- return 0;
+ return ret;
}
/* Compression can't overwrite anything. Fail if the cluster was already
cluster_offset = be64_to_cpu(l2_slice[l2_index]);
if (cluster_offset & L2E_OFFSET_MASK) {
qcow2_cache_put(s->l2_table_cache, (void **) &l2_slice);
- return 0;
+ return -EIO;
}
cluster_offset = qcow2_alloc_bytes(bs, compressed_size);
if (cluster_offset < 0) {
qcow2_cache_put(s->l2_table_cache, (void **) &l2_slice);
- return 0;
+ return cluster_offset;
}
nb_csectors = ((cluster_offset + compressed_size - 1) >> 9) -
l2_slice[l2_index] = cpu_to_be64(cluster_offset);
qcow2_cache_put(s->l2_table_cache, (void **) &l2_slice);
- return cluster_offset;
+ *host_offset = cluster_offset & s->cluster_offset_mask;
+ return 0;
}
static int perform_cow(BlockDriverState *bs, QCowL2Meta *m)
return ret;
}
+/**
+ * Frees the allocated clusters because the request failed and they won't
+ * actually be linked.
+ */
+void qcow2_alloc_cluster_abort(BlockDriverState *bs, QCowL2Meta *m)
+{
+ BDRVQcow2State *s = bs->opaque;
+ qcow2_free_clusters(bs, m->alloc_offset, m->nb_clusters << s->cluster_bits,
+ QCOW2_DISCARD_NEVER);
+}
+
/*
* Returns the number of contiguous clusters that can be used for an allocating
* write, but require COW to be performed (this includes yet unallocated space,
* which must copy from the backing file)
*/
-static int count_cow_clusters(BDRVQcow2State *s, int nb_clusters,
+static int count_cow_clusters(BlockDriverState *bs, int nb_clusters,
uint64_t *l2_slice, int l2_index)
{
int i;
for (i = 0; i < nb_clusters; i++) {
uint64_t l2_entry = be64_to_cpu(l2_slice[l2_index + i]);
- QCow2ClusterType cluster_type = qcow2_get_cluster_type(l2_entry);
+ QCow2ClusterType cluster_type = qcow2_get_cluster_type(bs, l2_entry);
switch(cluster_type) {
case QCOW2_CLUSTER_NORMAL:
/*
* Checks how many already allocated clusters that don't require a copy on
- * write there are at the given guest_offset (up to *bytes). If
- * *host_offset is not zero, only physically contiguous clusters beginning at
- * this host offset are counted.
+ * write there are at the given guest_offset (up to *bytes). If *host_offset is
+ * not INV_OFFSET, only physically contiguous clusters beginning at this host
+ * offset are counted.
*
* Note that guest_offset may not be cluster aligned. In this case, the
* returned *host_offset points to exact byte referenced by guest_offset and
trace_qcow2_handle_copied(qemu_coroutine_self(), guest_offset, *host_offset,
*bytes);
- assert(*host_offset == 0 || offset_into_cluster(s, guest_offset)
- == offset_into_cluster(s, *host_offset));
+ assert(*host_offset == INV_OFFSET || offset_into_cluster(s, guest_offset)
+ == offset_into_cluster(s, *host_offset));
/*
* Calculate the number of clusters to look for. We stop at L2 slice
cluster_offset = be64_to_cpu(l2_slice[l2_index]);
/* Check how many clusters are already allocated and don't need COW */
- if (qcow2_get_cluster_type(cluster_offset) == QCOW2_CLUSTER_NORMAL
+ if (qcow2_get_cluster_type(bs, cluster_offset) == QCOW2_CLUSTER_NORMAL
&& (cluster_offset & QCOW_OFLAG_COPIED))
{
/* If a specific host_offset is required, check it */
goto out;
}
- if (*host_offset != 0 && !offset_matches) {
+ if (*host_offset != INV_OFFSET && !offset_matches) {
*bytes = 0;
ret = 0;
goto out;
/* We keep all QCOW_OFLAG_COPIED clusters */
keep_clusters =
- count_contiguous_clusters(nb_clusters, s->cluster_size,
+ count_contiguous_clusters(bs, nb_clusters, s->cluster_size,
&l2_slice[l2_index],
QCOW_OFLAG_COPIED | QCOW_OFLAG_ZERO);
assert(keep_clusters <= nb_clusters);
* contain the number of clusters that have been allocated and are contiguous
* in the image file.
*
- * If *host_offset is non-zero, it specifies the offset in the image file at
- * which the new clusters must start. *nb_clusters can be 0 on return in this
- * case if the cluster at host_offset is already in use. If *host_offset is
- * zero, the clusters can be allocated anywhere in the image file.
+ * If *host_offset is not INV_OFFSET, it specifies the offset in the image file
+ * at which the new clusters must start. *nb_clusters can be 0 on return in
+ * this case if the cluster at host_offset is already in use. If *host_offset
+ * is INV_OFFSET, the clusters can be allocated anywhere in the image file.
*
* *host_offset is updated to contain the offset into the image file at which
* the first allocated cluster starts.
trace_qcow2_do_alloc_clusters_offset(qemu_coroutine_self(), guest_offset,
*host_offset, *nb_clusters);
+ if (has_data_file(bs)) {
+ assert(*host_offset == INV_OFFSET ||
+ *host_offset == start_of_cluster(s, guest_offset));
+ *host_offset = start_of_cluster(s, guest_offset);
+ return 0;
+ }
+
/* Allocate new clusters */
trace_qcow2_cluster_alloc_phys(qemu_coroutine_self());
- if (*host_offset == 0) {
+ if (*host_offset == INV_OFFSET) {
int64_t cluster_offset =
qcow2_alloc_clusters(bs, *nb_clusters * s->cluster_size);
if (cluster_offset < 0) {
/*
* Allocates new clusters for an area that either is yet unallocated or needs a
- * copy on write. If *host_offset is non-zero, clusters are only allocated if
- * the new allocation can match the specified host offset.
+ * copy on write. If *host_offset is not INV_OFFSET, clusters are only
+ * allocated if the new allocation can match the specified host offset.
*
* Note that guest_offset may not be cluster aligned. In this case, the
* returned *host_offset points to exact byte referenced by guest_offset and
int ret;
bool keep_old_clusters = false;
- uint64_t alloc_cluster_offset = 0;
+ uint64_t alloc_cluster_offset = INV_OFFSET;
trace_qcow2_handle_alloc(qemu_coroutine_self(), guest_offset, *host_offset,
*bytes);
if (entry & QCOW_OFLAG_COMPRESSED) {
nb_clusters = 1;
} else {
- nb_clusters = count_cow_clusters(s, nb_clusters, l2_slice, l2_index);
+ nb_clusters = count_cow_clusters(bs, nb_clusters, l2_slice, l2_index);
}
/* This function is only called when there were no non-COW clusters, so if
* wrong with our code. */
assert(nb_clusters > 0);
- if (qcow2_get_cluster_type(entry) == QCOW2_CLUSTER_ZERO_ALLOC &&
+ if (qcow2_get_cluster_type(bs, entry) == QCOW2_CLUSTER_ZERO_ALLOC &&
(entry & QCOW_OFLAG_COPIED) &&
- (!*host_offset ||
+ (*host_offset == INV_OFFSET ||
start_of_cluster(s, *host_offset) == (entry & L2E_OFFSET_MASK)))
{
int preallocated_nb_clusters;
* would be fine, too, but count_cow_clusters() above has limited
* nb_clusters already to a range of COW clusters */
preallocated_nb_clusters =
- count_contiguous_clusters(nb_clusters, s->cluster_size,
+ count_contiguous_clusters(bs, nb_clusters, s->cluster_size,
&l2_slice[l2_index], QCOW_OFLAG_COPIED);
assert(preallocated_nb_clusters > 0);
qcow2_cache_put(s->l2_table_cache, (void **) &l2_slice);
- if (!alloc_cluster_offset) {
+ if (alloc_cluster_offset == INV_OFFSET) {
/* Allocate, if necessary at a given offset in the image file */
- alloc_cluster_offset = start_of_cluster(s, *host_offset);
+ alloc_cluster_offset = *host_offset == INV_OFFSET ? INV_OFFSET :
+ start_of_cluster(s, *host_offset);
ret = do_alloc_cluster_offset(bs, guest_offset, &alloc_cluster_offset,
&nb_clusters);
if (ret < 0) {
return 0;
}
- /* !*host_offset would overwrite the image header and is reserved for
- * "no host offset preferred". If 0 was a valid host offset, it'd
- * trigger the following overlap check; do that now to avoid having an
- * invalid value in *host_offset. */
- if (!alloc_cluster_offset) {
- ret = qcow2_pre_write_overlap_check(bs, 0, alloc_cluster_offset,
- nb_clusters * s->cluster_size);
- assert(ret < 0);
- goto fail;
- }
+ assert(alloc_cluster_offset != INV_OFFSET);
}
/*
again:
start = offset;
remaining = *bytes;
- cluster_offset = 0;
- *host_offset = 0;
+ cluster_offset = INV_OFFSET;
+ *host_offset = INV_OFFSET;
cur_bytes = 0;
*m = NULL;
while (true) {
- if (!*host_offset) {
+ if (*host_offset == INV_OFFSET && cluster_offset != INV_OFFSET) {
*host_offset = start_of_cluster(s, cluster_offset);
}
start += cur_bytes;
remaining -= cur_bytes;
- cluster_offset += cur_bytes;
+
+ if (cluster_offset != INV_OFFSET) {
+ cluster_offset += cur_bytes;
+ }
if (remaining == 0) {
break;
*bytes -= remaining;
assert(*bytes > 0);
- assert(*host_offset != 0);
+ assert(*host_offset != INV_OFFSET);
return 0;
}
-static int decompress_buffer(uint8_t *out_buf, int out_buf_size,
- const uint8_t *buf, int buf_size)
-{
- z_stream strm1, *strm = &strm1;
- int ret, out_len;
-
- memset(strm, 0, sizeof(*strm));
-
- strm->next_in = (uint8_t *)buf;
- strm->avail_in = buf_size;
- strm->next_out = out_buf;
- strm->avail_out = out_buf_size;
-
- ret = inflateInit2(strm, -12);
- if (ret != Z_OK)
- return -1;
- ret = inflate(strm, Z_FINISH);
- out_len = strm->next_out - out_buf;
- if ((ret != Z_STREAM_END && ret != Z_BUF_ERROR) ||
- out_len != out_buf_size) {
- inflateEnd(strm);
- return -1;
- }
- inflateEnd(strm);
- return 0;
-}
-
-int qcow2_decompress_cluster(BlockDriverState *bs, uint64_t cluster_offset)
-{
- BDRVQcow2State *s = bs->opaque;
- int ret, csize, nb_csectors, sector_offset;
- uint64_t coffset;
-
- coffset = cluster_offset & s->cluster_offset_mask;
- if (s->cluster_cache_offset != coffset) {
- nb_csectors = ((cluster_offset >> s->csize_shift) & s->csize_mask) + 1;
- sector_offset = coffset & 511;
- csize = nb_csectors * 512 - sector_offset;
-
- /* Allocate buffers on first decompress operation, most images are
- * uncompressed and the memory overhead can be avoided. The buffers
- * are freed in .bdrv_close().
- */
- if (!s->cluster_data) {
- /* one more sector for decompressed data alignment */
- s->cluster_data = qemu_try_blockalign(bs->file->bs,
- QCOW_MAX_CRYPT_CLUSTERS * s->cluster_size + 512);
- if (!s->cluster_data) {
- return -ENOMEM;
- }
- }
- if (!s->cluster_cache) {
- s->cluster_cache = g_malloc(s->cluster_size);
- }
-
- BLKDBG_EVENT(bs->file, BLKDBG_READ_COMPRESSED);
- ret = bdrv_read(bs->file, coffset >> 9, s->cluster_data,
- nb_csectors);
- if (ret < 0) {
- return ret;
- }
- if (decompress_buffer(s->cluster_cache, s->cluster_size,
- s->cluster_data + sector_offset, csize) < 0) {
- return -EIO;
- }
- s->cluster_cache_offset = coffset;
- }
- return 0;
-}
-
/*
* This discards as many clusters of nb_clusters as possible at once (i.e.
* all clusters in the same L2 slice) and returns the number of discarded
* If full_discard is true, the sector should not read back as zeroes,
* but rather fall through to the backing file.
*/
- switch (qcow2_get_cluster_type(old_l2_entry)) {
+ switch (qcow2_get_cluster_type(bs, old_l2_entry)) {
case QCOW2_CLUSTER_UNALLOCATED:
if (full_discard || !bs->backing) {
continue;
* Minimize L2 changes if the cluster already reads back as
* zeroes with correct allocation.
*/
- cluster_type = qcow2_get_cluster_type(old_offset);
+ cluster_type = qcow2_get_cluster_type(bs, old_offset);
if (cluster_type == QCOW2_CLUSTER_ZERO_PLAIN ||
(cluster_type == QCOW2_CLUSTER_ZERO_ALLOC && !unmap)) {
continue;
int64_t cleared;
int ret;
+ /* If we have to stay in sync with an external data file, zero out
+ * s->data_file first. */
+ if (data_file_is_raw(bs)) {
+ assert(has_data_file(bs));
+ ret = bdrv_co_pwrite_zeroes(s->data_file, offset, bytes, flags);
+ if (ret < 0) {
+ return ret;
+ }
+ }
+
/* Caller must pass aligned values, except at image end */
assert(QEMU_IS_ALIGNED(offset, s->cluster_size));
assert(QEMU_IS_ALIGNED(end_offset, s->cluster_size) ||
uint64_t l2_entry = be64_to_cpu(l2_slice[j]);
int64_t offset = l2_entry & L2E_OFFSET_MASK;
QCow2ClusterType cluster_type =
- qcow2_get_cluster_type(l2_entry);
+ qcow2_get_cluster_type(bs, l2_entry);
if (cluster_type != QCOW2_CLUSTER_ZERO_PLAIN &&
cluster_type != QCOW2_CLUSTER_ZERO_ALLOC) {
}
ret = qcow2_pre_write_overlap_check(bs, 0, offset,
- s->cluster_size);
+ s->cluster_size, true);
if (ret < 0) {
if (cluster_type == QCOW2_CLUSTER_ZERO_PLAIN) {
qcow2_free_clusters(bs, offset, s->cluster_size,
goto fail;
}
- ret = bdrv_pwrite_zeroes(bs->file, offset, s->cluster_size, 0);
+ ret = bdrv_pwrite_zeroes(s->data_file, offset,
+ s->cluster_size, 0);
if (ret < 0) {
if (cluster_type == QCOW2_CLUSTER_ZERO_PLAIN) {
qcow2_free_clusters(bs, offset, s->cluster_size,
if (l2_dirty) {
ret = qcow2_pre_write_overlap_check(
bs, QCOW2_OL_INACTIVE_L2 | QCOW2_OL_ACTIVE_L2,
- slice_offset, slice_size2);
+ slice_offset, slice_size2, false);
if (ret < 0) {
goto fail;
}
}
for (i = 0; i < s->nb_snapshots; i++) {
- int l1_sectors = DIV_ROUND_UP(s->snapshots[i].l1_size *
- sizeof(uint64_t), BDRV_SECTOR_SIZE);
+ int l1_size2;
+ uint64_t *new_l1_table;
+ Error *local_err = NULL;
+
+ ret = qcow2_validate_table(bs, s->snapshots[i].l1_table_offset,
+ s->snapshots[i].l1_size, sizeof(uint64_t),
+ QCOW_MAX_L1_SIZE, "Snapshot L1 table",
+ &local_err);
+ if (ret < 0) {
+ error_report_err(local_err);
+ goto fail;
+ }
- uint64_t *new_l1_table =
- g_try_realloc(l1_table, l1_sectors * BDRV_SECTOR_SIZE);
+ l1_size2 = s->snapshots[i].l1_size * sizeof(uint64_t);
+ new_l1_table = g_try_realloc(l1_table, l1_size2);
if (!new_l1_table) {
ret = -ENOMEM;
l1_table = new_l1_table;
- ret = bdrv_read(bs->file,
- s->snapshots[i].l1_table_offset / BDRV_SECTOR_SIZE,
- (void *)l1_table, l1_sectors);
+ ret = bdrv_pread(bs->file, s->snapshots[i].l1_table_offset,
+ l1_table, l1_size2);
if (ret < 0) {
goto fail;
}
projects / mirror_qemu.git / blobdiff