* THE SOFTWARE.
*/
+#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 "qemu/bswap.h"
#include "trace.h"
int qcow2_grow_l1_table(BlockDriverState *bs, uint64_t min_size,
}
}
- if (new_l1_size > INT_MAX / sizeof(uint64_t)) {
+ QEMU_BUILD_BUG_ON(QCOW_MAX_L1_SIZE > INT_MAX);
+ if (new_l1_size > QCOW_MAX_L1_SIZE / sizeof(uint64_t)) {
return -EFBIG;
}
}
memset(new_l1_table, 0, align_offset(new_l1_size2, 512));
- memcpy(new_l1_table, s->l1_table, s->l1_size * sizeof(uint64_t));
+ if (s->l1_size) {
+ memcpy(new_l1_table, s->l1_table, s->l1_size * sizeof(uint64_t));
+ }
/* write new table (align to cluster) */
BLKDBG_EVENT(bs->file, BLKDBG_L1_GROW_ALLOC_TABLE);
BLKDBG_EVENT(bs->file, BLKDBG_L1_GROW_WRITE_TABLE);
for(i = 0; i < s->l1_size; i++)
new_l1_table[i] = cpu_to_be64(new_l1_table[i]);
- ret = bdrv_pwrite_sync(bs->file->bs, new_l1_table_offset,
+ ret = bdrv_pwrite_sync(bs->file, new_l1_table_offset,
new_l1_table, new_l1_size2);
if (ret < 0)
goto fail;
/* set new table */
BLKDBG_EVENT(bs->file, BLKDBG_L1_GROW_ACTIVATE_TABLE);
- cpu_to_be32w((uint32_t*)data, new_l1_size);
+ stl_be_p(data, new_l1_size);
stq_be_p(data + 4, new_l1_table_offset);
- ret = bdrv_pwrite_sync(bs->file->bs, offsetof(QCowHeader, l1_size),
+ ret = bdrv_pwrite_sync(bs->file, offsetof(QCowHeader, l1_size),
data, sizeof(data));
if (ret < 0) {
goto fail;
uint64_t **l2_table)
{
BDRVQcow2State *s = bs->opaque;
- int ret;
-
- ret = qcow2_cache_get(bs, s->l2_table_cache, l2_offset, (void**) l2_table);
- return ret;
+ return qcow2_cache_get(bs, s->l2_table_cache, l2_offset,
+ (void **)l2_table);
}
/*
}
BLKDBG_EVENT(bs->file, BLKDBG_L1_UPDATE);
- ret = bdrv_pwrite_sync(bs->file->bs,
+ ret = bdrv_pwrite_sync(bs->file,
s->l1_table_offset + 8 * l1_start_index,
buf, sizeof(buf));
if (ret < 0) {
return 0;
}
-static int coroutine_fn copy_sectors(BlockDriverState *bs,
- uint64_t start_sect,
- uint64_t cluster_offset,
- int n_start, int n_end)
+static int coroutine_fn do_perform_cow(BlockDriverState *bs,
+ uint64_t src_cluster_offset,
+ uint64_t cluster_offset,
+ int offset_in_cluster,
+ int bytes)
{
BDRVQcow2State *s = bs->opaque;
QEMUIOVector qiov;
struct iovec iov;
- int n, ret;
-
- n = n_end - n_start;
- if (n <= 0) {
- return 0;
- }
+ int ret;
- iov.iov_len = n * BDRV_SECTOR_SIZE;
+ iov.iov_len = bytes;
iov.iov_base = qemu_try_blockalign(bs, iov.iov_len);
if (iov.iov_base == NULL) {
return -ENOMEM;
* interface. This avoids double I/O throttling and request tracking,
* which can lead to deadlock when block layer copy-on-read is enabled.
*/
- ret = bs->drv->bdrv_co_readv(bs, start_sect + n_start, n, &qiov);
+ ret = bs->drv->bdrv_co_preadv(bs, src_cluster_offset + offset_in_cluster,
+ bytes, &qiov, 0);
if (ret < 0) {
goto out;
}
if (bs->encrypted) {
Error *err = NULL;
+ int64_t sector = (src_cluster_offset + offset_in_cluster)
+ >> BDRV_SECTOR_BITS;
assert(s->cipher);
- if (qcow2_encrypt_sectors(s, start_sect + n_start,
- iov.iov_base, iov.iov_base, n,
- true, &err) < 0) {
+ assert((offset_in_cluster & ~BDRV_SECTOR_MASK) == 0);
+ assert((bytes & ~BDRV_SECTOR_MASK) == 0);
+ if (qcow2_encrypt_sectors(s, sector, iov.iov_base, iov.iov_base,
+ bytes >> BDRV_SECTOR_BITS, true, &err) < 0) {
ret = -EIO;
error_free(err);
goto out;
}
ret = qcow2_pre_write_overlap_check(bs, 0,
- cluster_offset + n_start * BDRV_SECTOR_SIZE, n * BDRV_SECTOR_SIZE);
+ cluster_offset + offset_in_cluster, bytes);
if (ret < 0) {
goto out;
}
BLKDBG_EVENT(bs->file, BLKDBG_COW_WRITE);
- ret = bdrv_co_writev(bs->file->bs, (cluster_offset >> 9) + n_start, n,
- &qiov);
+ ret = bdrv_co_pwritev(bs->file, cluster_offset + offset_in_cluster,
+ bytes, &qiov, 0);
if (ret < 0) {
goto out;
}
/*
* get_cluster_offset
*
- * For a given offset of the disk image, find the cluster offset in
- * qcow2 file. The offset is stored in *cluster_offset.
+ * For a given offset of the virtual disk, find the cluster type and offset in
+ * the qcow2 file. The offset is stored in *cluster_offset.
*
- * on entry, *num is the number of contiguous sectors we'd like to
- * access following offset.
+ * On entry, *bytes is the maximum number of contiguous bytes starting at
+ * offset that we are interested in.
*
- * on exit, *num is the number of contiguous sectors we can read.
+ * On exit, *bytes is the number of bytes starting at offset that have the same
+ * cluster type and (if applicable) are stored contiguously in the image file.
+ * Compressed clusters are always returned one by one.
*
* Returns the cluster type (QCOW2_CLUSTER_*) on success, -errno in error
* cases.
*/
int qcow2_get_cluster_offset(BlockDriverState *bs, uint64_t offset,
- int *num, uint64_t *cluster_offset)
+ unsigned int *bytes, uint64_t *cluster_offset)
{
BDRVQcow2State *s = bs->opaque;
unsigned int l2_index;
uint64_t l1_index, l2_offset, *l2_table;
int l1_bits, c;
- unsigned int index_in_cluster, nb_clusters;
- uint64_t nb_available, nb_needed;
+ unsigned int offset_in_cluster;
+ uint64_t bytes_available, bytes_needed, nb_clusters;
int ret;
- index_in_cluster = (offset >> 9) & (s->cluster_sectors - 1);
- nb_needed = *num + index_in_cluster;
+ offset_in_cluster = offset_into_cluster(s, offset);
+ bytes_needed = (uint64_t) *bytes + offset_in_cluster;
l1_bits = s->l2_bits + s->cluster_bits;
- /* compute how many bytes there are between the offset and
- * the end of the l1 entry
- */
+ /* compute how many bytes there are between the start of the cluster
+ * containing offset and the end of the l1 entry */
+ bytes_available = (1ULL << l1_bits) - (offset & ((1ULL << l1_bits) - 1))
+ + offset_in_cluster;
- nb_available = (1ULL << l1_bits) - (offset & ((1ULL << l1_bits) - 1));
-
- /* compute the number of available sectors */
-
- nb_available = (nb_available >> 9) + index_in_cluster;
-
- if (nb_needed > nb_available) {
- nb_needed = nb_available;
+ if (bytes_needed > bytes_available) {
+ bytes_needed = bytes_available;
}
- assert(nb_needed <= INT_MAX);
*cluster_offset = 0;
l2_index = (offset >> s->cluster_bits) & (s->l2_size - 1);
*cluster_offset = be64_to_cpu(l2_table[l2_index]);
- /* nb_needed <= INT_MAX, thus nb_clusters <= INT_MAX, too */
- nb_clusters = size_to_clusters(s, nb_needed << 9);
+ nb_clusters = size_to_clusters(s, bytes_needed);
+ /* bytes_needed <= *bytes + offset_in_cluster, both of which are unsigned
+ * integers; the minimum cluster size is 512, so this assertion is always
+ * true */
+ assert(nb_clusters <= INT_MAX);
ret = qcow2_get_cluster_type(*cluster_offset);
switch (ret) {
qcow2_cache_put(bs, s->l2_table_cache, (void**) &l2_table);
- nb_available = (c * s->cluster_sectors);
+ bytes_available = (int64_t)c * s->cluster_size;
out:
- if (nb_available > nb_needed)
- nb_available = nb_needed;
+ if (bytes_available > bytes_needed) {
+ bytes_available = bytes_needed;
+ }
- *num = nb_available - index_in_cluster;
+ /* bytes_available <= bytes_needed <= *bytes + offset_in_cluster;
+ * subtracting offset_in_cluster will therefore definitely yield something
+ * not exceeding UINT_MAX */
+ assert(bytes_available - offset_in_cluster <= UINT_MAX);
+ *bytes = bytes_available - offset_in_cluster;
return ret;
BDRVQcow2State *s = bs->opaque;
int ret;
- if (r->nb_sectors == 0) {
+ if (r->nb_bytes == 0) {
return 0;
}
qemu_co_mutex_unlock(&s->lock);
- ret = copy_sectors(bs, m->offset / BDRV_SECTOR_SIZE, m->alloc_offset,
- r->offset / BDRV_SECTOR_SIZE,
- r->offset / BDRV_SECTOR_SIZE + r->nb_sectors);
+ ret = do_perform_cow(bs, m->offset, m->alloc_offset, r->offset, r->nb_bytes);
qemu_co_mutex_lock(&s->lock);
if (ret < 0) {
assert(l2_index + m->nb_clusters <= s->l2_size);
for (i = 0; i < m->nb_clusters; i++) {
/* if two concurrent writes happen to the same unallocated cluster
- * each write allocates separate cluster and writes data concurrently.
- * The first one to complete updates l2 table with pointer to its
- * cluster the second one has to do RMW (which is done above by
- * copy_sectors()), update l2 table with its cluster pointer and free
- * old cluster. This is what this loop does */
- if(l2_table[l2_index + i] != 0)
+ * each write allocates separate cluster and writes data concurrently.
+ * The first one to complete updates l2 table with pointer to its
+ * cluster the second one has to do RMW (which is done above by
+ * perform_cow()), update l2 table with its cluster pointer and free
+ * old cluster. This is what this loop does */
+ if (l2_table[l2_index + i] != 0) {
old_cluster[j++] = l2_table[l2_index + i];
+ }
l2_table[l2_index + i] = cpu_to_be64((cluster_offset +
(i << s->cluster_bits)) | QCOW_OFLAG_COPIED);
/*
* Save info needed for meta data update.
*
- * requested_sectors: Number of sectors from the start of the first
+ * requested_bytes: Number of bytes from the start of the first
* newly allocated cluster to the end of the (possibly shortened
* before) write request.
*
- * avail_sectors: Number of sectors from the start of the first
+ * avail_bytes: Number of bytes from the start of the first
* newly allocated to the end of the last newly allocated cluster.
*
- * nb_sectors: The number of sectors from the start of the first
+ * nb_bytes: The number of bytes from the start of the first
* newly allocated cluster to the end of the area that the write
* request actually writes to (excluding COW at the end)
*/
- int requested_sectors =
- (*bytes + offset_into_cluster(s, guest_offset))
- >> BDRV_SECTOR_BITS;
- int avail_sectors = nb_clusters
- << (s->cluster_bits - BDRV_SECTOR_BITS);
- int alloc_n_start = offset_into_cluster(s, guest_offset)
- >> BDRV_SECTOR_BITS;
- int nb_sectors = MIN(requested_sectors, avail_sectors);
+ uint64_t requested_bytes = *bytes + offset_into_cluster(s, guest_offset);
+ int avail_bytes = MIN(INT_MAX, nb_clusters << s->cluster_bits);
+ int nb_bytes = MIN(requested_bytes, avail_bytes);
QCowL2Meta *old_m = *m;
*m = g_malloc0(sizeof(**m));
.alloc_offset = alloc_cluster_offset,
.offset = start_of_cluster(s, guest_offset),
.nb_clusters = nb_clusters,
- .nb_available = nb_sectors,
.cow_start = {
.offset = 0,
- .nb_sectors = alloc_n_start,
+ .nb_bytes = offset_into_cluster(s, guest_offset),
},
.cow_end = {
- .offset = nb_sectors * BDRV_SECTOR_SIZE,
- .nb_sectors = avail_sectors - nb_sectors,
+ .offset = nb_bytes,
+ .nb_bytes = avail_bytes - nb_bytes,
},
};
qemu_co_queue_init(&(*m)->dependent_requests);
QLIST_INSERT_HEAD(&s->cluster_allocs, *m, next_in_flight);
*host_offset = alloc_cluster_offset + offset_into_cluster(s, guest_offset);
- *bytes = MIN(*bytes, (nb_sectors * BDRV_SECTOR_SIZE)
- - offset_into_cluster(s, guest_offset));
+ *bytes = MIN(*bytes, nb_bytes - offset_into_cluster(s, guest_offset));
assert(*bytes != 0);
return 1;
* Return 0 on success and -errno in error cases
*/
int qcow2_alloc_cluster_offset(BlockDriverState *bs, uint64_t offset,
- int *num, uint64_t *host_offset, QCowL2Meta **m)
+ unsigned int *bytes, uint64_t *host_offset,
+ QCowL2Meta **m)
{
BDRVQcow2State *s = bs->opaque;
uint64_t start, remaining;
uint64_t cur_bytes;
int ret;
- trace_qcow2_alloc_clusters_offset(qemu_coroutine_self(), offset, *num);
-
- assert((offset & ~BDRV_SECTOR_MASK) == 0);
+ trace_qcow2_alloc_clusters_offset(qemu_coroutine_self(), offset, *bytes);
again:
start = offset;
- remaining = (uint64_t)*num << BDRV_SECTOR_BITS;
+ remaining = *bytes;
cluster_offset = 0;
*host_offset = 0;
cur_bytes = 0;
}
}
- *num -= remaining >> BDRV_SECTOR_BITS;
- assert(*num > 0);
+ *bytes -= remaining;
+ assert(*bytes > 0);
assert(*host_offset != 0);
return 0;
sector_offset = coffset & 511;
csize = nb_csectors * 512 - sector_offset;
BLKDBG_EVENT(bs->file, BLKDBG_READ_COMPRESSED);
- ret = bdrv_read(bs->file->bs, coffset >> 9, s->cluster_data,
+ ret = bdrv_read(bs->file, coffset >> 9, s->cluster_data,
nb_csectors);
if (ret < 0) {
return ret;
* clusters.
*/
static int zero_single_l2(BlockDriverState *bs, uint64_t offset,
- uint64_t nb_clusters)
+ uint64_t nb_clusters, int flags)
{
BDRVQcow2State *s = bs->opaque;
uint64_t *l2_table;
/* Update L2 entries */
qcow2_cache_entry_mark_dirty(bs, s->l2_table_cache, l2_table);
- if (old_offset & QCOW_OFLAG_COMPRESSED) {
+ if (old_offset & QCOW_OFLAG_COMPRESSED || flags & BDRV_REQ_MAY_UNMAP) {
l2_table[l2_index + i] = cpu_to_be64(QCOW_OFLAG_ZERO);
qcow2_free_any_clusters(bs, old_offset, 1, QCOW2_DISCARD_REQUEST);
} else {
return nb_clusters;
}
-int qcow2_zero_clusters(BlockDriverState *bs, uint64_t offset, int nb_sectors)
+int qcow2_zero_clusters(BlockDriverState *bs, uint64_t offset, int nb_sectors,
+ int flags)
{
BDRVQcow2State *s = bs->opaque;
uint64_t nb_clusters;
s->cache_discards = true;
while (nb_clusters > 0) {
- ret = zero_single_l2(bs, offset, nb_clusters);
+ ret = zero_single_l2(bs, offset, nb_clusters, flags);
if (ret < 0) {
goto fail;
}
static int expand_zero_clusters_in_l1(BlockDriverState *bs, uint64_t *l1_table,
int l1_size, int64_t *visited_l1_entries,
int64_t l1_entries,
- BlockDriverAmendStatusCB *status_cb)
+ BlockDriverAmendStatusCB *status_cb,
+ void *cb_opaque)
{
BDRVQcow2State *s = bs->opaque;
bool is_active_l1 = (l1_table == s->l1_table);
/* unallocated */
(*visited_l1_entries)++;
if (status_cb) {
- status_cb(bs, *visited_l1_entries, l1_entries);
+ status_cb(bs, *visited_l1_entries, l1_entries, cb_opaque);
}
continue;
}
(void **)&l2_table);
} else {
/* load inactive L2 tables from disk */
- ret = bdrv_read(bs->file->bs, l2_offset / BDRV_SECTOR_SIZE,
+ ret = bdrv_read(bs->file, l2_offset / BDRV_SECTOR_SIZE,
(void *)l2_table, s->cluster_sectors);
}
if (ret < 0) {
goto fail;
}
- ret = bdrv_write_zeroes(bs->file->bs, offset / BDRV_SECTOR_SIZE,
- s->cluster_sectors, 0);
+ ret = bdrv_pwrite_zeroes(bs->file, offset, s->cluster_size, 0);
if (ret < 0) {
if (!preallocated) {
qcow2_free_clusters(bs, offset, s->cluster_size,
goto fail;
}
- ret = bdrv_write(bs->file->bs, l2_offset / BDRV_SECTOR_SIZE,
+ ret = bdrv_write(bs->file, l2_offset / BDRV_SECTOR_SIZE,
(void *)l2_table, s->cluster_sectors);
if (ret < 0) {
goto fail;
(*visited_l1_entries)++;
if (status_cb) {
- status_cb(bs, *visited_l1_entries, l1_entries);
+ status_cb(bs, *visited_l1_entries, l1_entries, cb_opaque);
}
}
* qcow2 version which doesn't yet support metadata zero clusters.
*/
int qcow2_expand_zero_clusters(BlockDriverState *bs,
- BlockDriverAmendStatusCB *status_cb)
+ BlockDriverAmendStatusCB *status_cb,
+ void *cb_opaque)
{
BDRVQcow2State *s = bs->opaque;
uint64_t *l1_table = NULL;
ret = expand_zero_clusters_in_l1(bs, s->l1_table, s->l1_size,
&visited_l1_entries, l1_entries,
- status_cb);
+ status_cb, cb_opaque);
if (ret < 0) {
goto fail;
}
}
for (i = 0; i < s->nb_snapshots; i++) {
- int l1_sectors = (s->snapshots[i].l1_size * sizeof(uint64_t) +
- BDRV_SECTOR_SIZE - 1) / BDRV_SECTOR_SIZE;
+ int l1_sectors = DIV_ROUND_UP(s->snapshots[i].l1_size *
+ sizeof(uint64_t), BDRV_SECTOR_SIZE);
l1_table = g_realloc(l1_table, l1_sectors * BDRV_SECTOR_SIZE);
- ret = bdrv_read(bs->file->bs,
+ ret = bdrv_read(bs->file,
s->snapshots[i].l1_table_offset / BDRV_SECTOR_SIZE,
(void *)l1_table, l1_sectors);
if (ret < 0) {
ret = expand_zero_clusters_in_l1(bs, l1_table, s->snapshots[i].l1_size,
&visited_l1_entries, l1_entries,
- status_cb);
+ status_cb, cb_opaque);
if (ret < 0) {
goto fail;
}
projects / mirror_qemu.git / blobdiff