static void virtio_blk_handle_request(VirtIOBlockReq *req,
MultiReqBuffer *mrb)
{
if (req->elem.out_num < 1 || req->elem.in_num < 1) {
fprintf(stderr, "virtio-blk missing headers\n");
exit(1);
}
if (req->elem.out_sg[0].iov_len < sizeof(*req->out) ||
req->elem.in_sg[req->elem.in_num - 1].iov_len < sizeof(*req->in)) {
fprintf(stderr, "virtio-blk header not in correct element\n");
exit(1);
}
req->out = (void *)req->elem.out_sg[0].iov_base;
req->in = (void *)req->elem.in_sg[req->elem.in_num - 1].iov_base;
if (req->out->type & VIRTIO_BLK_T_FLUSH) {
virtio_blk_handle_flush(req, mrb);
} else if (req->out->type & VIRTIO_BLK_T_SCSI_CMD) {
virtio_blk_handle_scsi(req);
} else if (req->out->type & VIRTIO_BLK_T_OUT) {
qemu_iovec_init_external(&req->qiov, &req->elem.out_sg[1],
req->elem.out_num - 1);
virtio_blk_handle_write(req, mrb);
} else {
qemu_iovec_init_external(&req->qiov, &req->elem.in_sg[0],
req->elem.in_num - 1);
virtio_blk_handle_read(req);
}
}
static void virtio_blk_handle_request(VirtIOBlockReq *req,
MultiReqBuffer *mrb)
{
uint32_t type;
if (req->elem.out_num < 1 || req->elem.in_num < 1) {
error_report("virtio-blk missing headers");
exit(1);
}
if (req->elem.out_sg[0].iov_len < sizeof(*req->out) ||
req->elem.in_sg[req->elem.in_num - 1].iov_len < sizeof(*req->in)) {
error_report("virtio-blk header not in correct element");
exit(1);
}
req->out = (void *)req->elem.out_sg[0].iov_base;
req->in = (void *)req->elem.in_sg[req->elem.in_num - 1].iov_base;
type = ldl_p(&req->out->type);
if (type & VIRTIO_BLK_T_FLUSH) {
virtio_blk_handle_flush(req, mrb);
} else if (type & VIRTIO_BLK_T_SCSI_CMD) {
virtio_blk_handle_scsi(req);
} else if (type & VIRTIO_BLK_T_GET_ID) {
VirtIOBlock *s = req->dev;
/*
* NB: per existing s/n string convention the string is
* terminated by '\0' only when shorter than buffer.
*/
strncpy(req->elem.in_sg[0].iov_base,
s->blk.serial ? s->blk.serial : "",
MIN(req->elem.in_sg[0].iov_len, VIRTIO_BLK_ID_BYTES));
virtio_blk_req_complete(req, VIRTIO_BLK_S_OK);
g_free(req);
} else if (type & VIRTIO_BLK_T_OUT) {
qemu_iovec_init_external(&req->qiov, &req->elem.out_sg[1],
req->elem.out_num - 1);
virtio_blk_handle_write(req, mrb);
} else if (type == VIRTIO_BLK_T_IN || type == VIRTIO_BLK_T_BARRIER) {
/* VIRTIO_BLK_T_IN is 0, so we can't just & it. */
qemu_iovec_init_external(&req->qiov, &req->elem.in_sg[0],
req->elem.in_num - 1);
virtio_blk_handle_read(req);
} else {
virtio_blk_req_complete(req, VIRTIO_BLK_S_UNSUPP);
g_free(req);
}
}
/**
* Update header in-place (does not rewrite backing filename or other strings)
*
* This function only updates known header fields in-place and does not affect
* extra data after the QED header.
*/
static void qed_write_header(BDRVQEDState *s, BlockDriverCompletionFunc cb,
void *opaque)
{
/* We must write full sectors for O_DIRECT but cannot necessarily generate
* the data following the header if an unrecognized compat feature is
* active. Therefore, first read the sectors containing the header, update
* them, and write back.
*/
int nsectors = (sizeof(QEDHeader) + BDRV_SECTOR_SIZE - 1) /
BDRV_SECTOR_SIZE;
size_t len = nsectors * BDRV_SECTOR_SIZE;
QEDWriteHeaderCB *write_header_cb = gencb_alloc(sizeof(*write_header_cb),
cb, opaque);
write_header_cb->s = s;
write_header_cb->nsectors = nsectors;
write_header_cb->buf = qemu_blockalign(s->bs, len);
write_header_cb->iov.iov_base = write_header_cb->buf;
write_header_cb->iov.iov_len = len;
qemu_iovec_init_external(&write_header_cb->qiov, &write_header_cb->iov, 1);
bdrv_aio_readv(s->bs->file, 0, &write_header_cb->qiov, nsectors,
qed_write_header_read_cb, write_header_cb);
}
static void virtio_blk_handle_request(VirtIOBlockReq *req,
MultiReqBuffer *mrb)
{
if (req->elem.out_num < 1 || req->elem.in_num < 1) {
fprintf(stderr, "virtio-blk missing headers\n");
exit(1);
}
if (req->elem.out_sg[0].iov_len < sizeof(*req->out) ||
req->elem.in_sg[req->elem.in_num - 1].iov_len < sizeof(*req->in)) {
fprintf(stderr, "virtio-blk header not in correct element\n");
exit(1);
}
req->out = (void *)req->elem.out_sg[0].iov_base;
req->in = (void *)req->elem.in_sg[req->elem.in_num - 1].iov_base;
if (req->out->type & VIRTIO_BLK_T_FLUSH) {
virtio_blk_handle_flush(mrb->blkreq, &mrb->num_writes,
req, &mrb->old_bs);
} else if (req->out->type & VIRTIO_BLK_T_SCSI_CMD) {
virtio_blk_handle_scsi(req);
} else if (req->out->type & VIRTIO_BLK_T_GET_ID) {
VirtIOBlock *s = req->dev;
/*
* NB: per existing s/n string convention the string is
* terminated by '\0' only when shorter than buffer.
*/
strncpy(req->elem.in_sg[0].iov_base,
s->blk->serial ? s->blk->serial : "",
MIN(req->elem.in_sg[0].iov_len, VIRTIO_BLK_ID_BYTES));
virtio_blk_req_complete(req, VIRTIO_BLK_S_OK);
qemu_free(req);
} else if (req->out->type & VIRTIO_BLK_T_OUT) {
qemu_iovec_init_external(&req->qiov, &req->elem.out_sg[1],
req->elem.out_num - 1);
virtio_blk_handle_write(mrb->blkreq, &mrb->num_writes,
req, &mrb->old_bs);
} else {
qemu_iovec_init_external(&req->qiov, &req->elem.in_sg[0],
req->elem.in_num - 1);
virtio_blk_handle_read(req);
}
}
static void virtio_blk_handle_request(VirtIOBlockReq *req,
MultiReqBuffer *mrb)
{
uint32_t type;
if (req->elem.out_num < 1 || req->elem.in_num < 1) {
error_report("virtio-blk missing headers");
exit(1);
}
if (req->elem.out_sg[0].iov_len < sizeof(*req->out) ||
req->elem.in_sg[req->elem.in_num - 1].iov_len < sizeof(*req->in)) {
error_report("virtio-blk header not in correct element");
exit(1);
}
req->out = (void *)req->elem.out_sg[0].iov_base;
req->in = (void *)req->elem.in_sg[req->elem.in_num - 1].iov_base;
type = ldl_p(&req->out->type);
if (type & VIRTIO_BLK_T_FLUSH) {
virtio_blk_handle_flush(req, mrb);
} else if (type & VIRTIO_BLK_T_SCSI_CMD) {
virtio_blk_handle_scsi(req);
} else if (type & VIRTIO_BLK_T_GET_ID) {
VirtIOBlock *s = req->dev;
memcpy(req->elem.in_sg[0].iov_base, s->sn,
MIN(req->elem.in_sg[0].iov_len, sizeof(s->sn)));
virtio_blk_req_complete(req, VIRTIO_BLK_S_OK);
} else if (type & VIRTIO_BLK_T_OUT) {
qemu_iovec_init_external(&req->qiov, &req->elem.out_sg[1],
req->elem.out_num - 1);
virtio_blk_handle_write(req, mrb);
} else {
qemu_iovec_init_external(&req->qiov, &req->elem.in_sg[0],
req->elem.in_num - 1);
virtio_blk_handle_read(req);
}
}
static ssize_t block_writev_buffer(void *opaque, struct iovec *iov, int iovcnt,
int64_t pos)
{
int ret;
QEMUIOVector qiov;
qemu_iovec_init_external(&qiov, iov, iovcnt);
ret = bdrv_writev_vmstate(opaque, &qiov, pos);
if (ret < 0) {
return ret;
}
return qiov.size;
}
/**
* Write out an updated part or all of a table
*
* @s: QED state
* @offset: Offset of table in image file, in bytes
* @table: Table
* @index: Index of first element
* @n: Number of elements
* @flush: Whether or not to sync to disk
* @cb: Completion function
* @opaque: Argument for completion function
*/
static void qed_write_table(BDRVQEDState *s, uint64_t offset, QEDTable *table,
unsigned int index, unsigned int n, bool flush,
BlockDriverCompletionFunc *cb, void *opaque)
{
QEDWriteTableCB *write_table_cb;
BlockDriverAIOCB *aiocb;
unsigned int sector_mask = BDRV_SECTOR_SIZE / sizeof(uint64_t) - 1;
unsigned int start, end, i;
size_t len_bytes;
trace_qed_write_table(s, offset, table, index, n);
/* Calculate indices of the first and one after last elements */
start = index & ~sector_mask;
end = (index + n + sector_mask) & ~sector_mask;
len_bytes = (end - start) * sizeof(uint64_t);
write_table_cb = gencb_alloc(sizeof(*write_table_cb), cb, opaque);
write_table_cb->s = s;
write_table_cb->orig_table = table;
write_table_cb->flush = flush;
write_table_cb->table = qemu_blockalign(s->bs, len_bytes);
write_table_cb->iov.iov_base = write_table_cb->table->offsets;
write_table_cb->iov.iov_len = len_bytes;
qemu_iovec_init_external(&write_table_cb->qiov, &write_table_cb->iov, 1);
/* Byteswap table */
for (i = start; i < end; i++) {
uint64_t le_offset = cpu_to_le64(table->offsets[i]);
write_table_cb->table->offsets[i - start] = le_offset;
}
/* Adjust for offset into table */
offset += start * sizeof(uint64_t);
aiocb = bdrv_aio_writev(s->bs->file, offset / BDRV_SECTOR_SIZE,
&write_table_cb->qiov,
write_table_cb->qiov.size / BDRV_SECTOR_SIZE,
qed_write_table_cb, write_table_cb);
if (!aiocb) {
qed_write_table_cb(write_table_cb, -EIO);
}
}
static void qed_read_table(BDRVQEDState *s, uint64_t offset, QEDTable *table,
BlockDriverCompletionFunc *cb, void *opaque)
{
QEDReadTableCB *read_table_cb = gencb_alloc(sizeof(*read_table_cb),
cb, opaque);
QEMUIOVector *qiov = &read_table_cb->qiov;
trace_qed_read_table(s, offset, table);
read_table_cb->s = s;
read_table_cb->table = table;
read_table_cb->iov.iov_base = table->offsets,
read_table_cb->iov.iov_len = s->header.cluster_size * s->header.table_size,
qemu_iovec_init_external(qiov, &read_table_cb->iov, 1);
bdrv_aio_readv(s->bs->file, offset / BDRV_SECTOR_SIZE, qiov,
qiov->size / BDRV_SECTOR_SIZE,
qed_read_table_cb, read_table_cb);
}
static int compare_full_images (void)
{
CompareFullCB *cf;
int old_copy_on_read = FALSE;
printf ("Performing a full comparison of the truth image and "
"the test image...\n");
if (!strncmp (bs->drv->format_name, "fvd", 3)) {
/* Disable copy-on-read when scanning through the entire image. */
old_copy_on_read = fvd_get_copy_on_read (bs);
fvd_set_copy_on_read (bs, FALSE);
}
cf = g_malloc(sizeof(CompareFullCB));
cf->max_nb_sectors = 1048576L / 512;
cf->nb_sectors = MIN (cf->max_nb_sectors, total_sectors);
if (posix_memalign ((void **) &cf->truth_buf, 512,
cf->max_nb_sectors * 512) != 0) {
die ("posix_memalign");
}
cf->iov.iov_base = qemu_blockalign (bs, cf->max_nb_sectors * 512);
cf->iov.iov_len = cf->nb_sectors * 512;
cf->sector_num = 0;
qemu_iovec_init_external (&cf->qiov, &cf->iov, 1);
if (!bdrv_aio_readv (bs, cf->sector_num, &cf->qiov,
cf->nb_sectors, compare_full_images_cb, cf)) {
die ("bdrv_aio_readv\n");
}
sim_all_tasks ();
if (!strncmp (bs->drv->format_name, "fvd", 3)) {
fvd_set_copy_on_read (bs, old_copy_on_read);
}
return 0;
}
static void compare_full_images_cb (void *opaque, int ret)
{
CompareFullCB *cf = opaque;
if (ret) {
/* Failed. Retry the operation. */
bdrv_aio_readv (bs, cf->sector_num, &cf->qiov, cf->nb_sectors,
compare_full_images_cb, cf);
return;
}
truth_io (cf->truth_buf, cf->sector_num, cf->nb_sectors, TRUE);
verify (cf->truth_buf, cf->iov.iov_base, cf->sector_num, cf->nb_sectors);
cf->sector_num += cf->nb_sectors;
if (cf->sector_num >= total_sectors) {
/* Finished. */
free (cf->truth_buf);
qemu_vfree (cf->iov.iov_base);
g_free(cf);
return;
}
/* Read more data to compare. */
if (cf->sector_num + cf->max_nb_sectors > total_sectors) {
cf->nb_sectors = total_sectors - cf->sector_num;
} else {
cf->nb_sectors = cf->max_nb_sectors;
}
cf->iov.iov_len = cf->nb_sectors * 512;
qemu_iovec_init_external (&cf->qiov, &cf->iov, 1);
if (!bdrv_aio_readv (bs, cf->sector_num, &cf->qiov,
cf->nb_sectors, compare_full_images_cb, cf)) {
die ("bdrv_aio_readv\n");
}
}
void virtio_blk_handle_request(VirtIOBlockReq *req, MultiReqBuffer *mrb)
{
uint32_t type;
struct iovec *in_iov = req->elem->in_sg;
struct iovec *iov = req->elem->out_sg;
unsigned in_num = req->elem->in_num;
unsigned out_num = req->elem->out_num;
if (req->elem->out_num < 1 || req->elem->in_num < 1) {
error_report("virtio-blk missing headers");
exit(1);
}
if (unlikely(iov_to_buf(iov, out_num, 0, &req->out,
sizeof(req->out)) != sizeof(req->out))) {
error_report("virtio-blk request outhdr too short");
exit(1);
}
iov_discard_front(&iov, &out_num, sizeof(req->out));
if (in_num < 1 ||
in_iov[in_num - 1].iov_len < sizeof(struct virtio_blk_inhdr)) {
error_report("virtio-blk request inhdr too short");
exit(1);
}
req->in = (void *)in_iov[in_num - 1].iov_base
+ in_iov[in_num - 1].iov_len
- sizeof(struct virtio_blk_inhdr);
iov_discard_back(in_iov, &in_num, sizeof(struct virtio_blk_inhdr));
type = virtio_ldl_p(VIRTIO_DEVICE(req->dev), &req->out.type);
if (type & VIRTIO_BLK_T_FLUSH) {
virtio_blk_handle_flush(req, mrb);
} else if (type & VIRTIO_BLK_T_SCSI_CMD) {
virtio_blk_handle_scsi(req);
} else if (type & VIRTIO_BLK_T_GET_ID) {
VirtIOBlock *s = req->dev;
/*
* NB: per existing s/n string convention the string is
* terminated by '\0' only when shorter than buffer.
*/
strncpy(req->elem->in_sg[0].iov_base,
s->blk.serial ? s->blk.serial : "",
MIN(req->elem->in_sg[0].iov_len, VIRTIO_BLK_ID_BYTES));
virtio_blk_req_complete(req, VIRTIO_BLK_S_OK);
virtio_blk_free_request(req);
} else if (type & VIRTIO_BLK_T_OUT) {
qemu_iovec_init_external(&req->qiov, &req->elem->out_sg[1],
req->elem->out_num - 1);
virtio_blk_handle_write(req, mrb);
} else if (type == VIRTIO_BLK_T_IN || type == VIRTIO_BLK_T_BARRIER) {
/* VIRTIO_BLK_T_IN is 0, so we can't just & it. */
qemu_iovec_init_external(&req->qiov, &req->elem->in_sg[0],
req->elem->in_num - 1);
virtio_blk_handle_read(req);
} else {
virtio_blk_req_complete(req, VIRTIO_BLK_S_UNSUPP);
virtio_blk_free_request(req);
}
}
static void prepare_read_write (RandomIO * r)
{
/* Do a READ or WRITE? */
if (random () % 2) {
r->type = OP_READ;
} else {
r->type = OP_WRITE;
}
/* Find the next region to perform io. */
do {
if (parallel <= 1 || (random () % 2 == 0)) {
/* Perform a random I/O. */
r->sector_num = rand64 () % total_sectors;
} else {
/* Perform an I/O next to a currently ongoing I/O. */
int id;
do {
id = random () % parallel;
} while (id == r->tester);
RandomIO *p = &testers[id];
r->sector_num =
p->sector_num + 2 * io_size - rand64 () % (4 * io_size);
if (r->sector_num < 0) {
r->sector_num = 0;
} else if (r->sector_num >= total_sectors) {
r->sector_num = total_sectors - 1;
}
}
r->nb_sectors = 1 + rand64 () % io_size;
if (r->sector_num + r->nb_sectors > total_sectors) {
r->nb_sectors = total_sectors - r->sector_num;
}
} while (check_conflict (r));
if (r->type == OP_WRITE) {
/* Fill test_buf with random data. */
int i, j;
for (i = 0; i < r->nb_sectors; i++) {
const uint64_t TEST_MAGIC = 0x0123456789ABCDEFULL;
/* This first 8 bytes of the sector stores the current testing
* round. The next 8 bytes store a magic number. This info helps
* debugging. */
uint64_t *p = (uint64_t *) & r->test_buf[i * 512];
*p = r->uuid;
cpu_to_be64s (p);
p++;
*p = TEST_MAGIC;
cpu_to_be64s (p);
/* The rest of the sector are filled with random data. */
uint32_t *q = (uint32_t *) (p + 1);
int n = (512 - 2 * sizeof (uint64_t)) / sizeof (uint32_t);
for (j = 0; j < n; j++) {
*q++ = random ();
}
}
}
/* Determine the number of iov. */
int niov = 0;
uint8_t *p = r->test_buf;
int left = r->nb_sectors;
do {
if (niov == max_iov - 1) {
r->qiov.iov[niov].iov_len = left * 512;
r->qiov.iov[niov].iov_base = p;
niov++;
break;
}
int nb = 1 + random () % left;
r->qiov.iov[niov].iov_len = nb * 512;
r->qiov.iov[niov].iov_base = p;
p += r->qiov.iov[niov].iov_len;
left -= nb;
niov++;
} while (left > 0);
qemu_iovec_init_external (&r->qiov, r->qiov.iov, niov);
}
/* Store data in the compact image. The argument 'soft_write' means
* the store was caused by copy-on-read or prefetching, which need not
* update metadata immediately. */
static BlockDriverAIOCB *store_data_in_compact_image (FvdAIOCB * acb,
int soft_write,
FvdAIOCB * parent_acb,
BlockDriverState * bs,
int64_t sector_num,
QEMUIOVector * orig_qiov,
const int nb_sectors,
BlockDriverCompletionFunc
* cb, void *opaque)
{
BDRVFvdState *s = bs->opaque;
const uint32_t first_chunk = sector_num / s->chunk_size;
const uint32_t last_chunk = (sector_num + nb_sectors - 1) / s->chunk_size;
int table_dirty = FALSE;
uint32_t chunk;
int64_t start_sec;
/* Check if storag space is allocated. */
for (chunk = first_chunk; chunk <= last_chunk; chunk++) {
if (IS_EMPTY (s->table[chunk])) {
uint32_t id = allocate_chunk (bs);
if (IS_EMPTY (id)) {
return NULL;
}
id |= DIRTY_TABLE;
WRITE_TABLE (s->table[chunk], id);
table_dirty = TRUE;
} else if (IS_DIRTY (s->table[chunk])) {
/* This is possible if a previous soft-write allocated the storage
* space but did not flush the table entry change to the journal
* and hence did not clean the dirty bit. This is also possible
* with two concurrent hard-writes. The first hard-write allocated
* the storage space but has not flushed the table entry change to
* the journal yet and hence the table entry remains dirty. In
* this case, the second hard-write will also try to flush this
* dirty table entry to the journal. The outcome is correct since
* they store the same metadata change in the journal (although
* twice). For this race condition, we prefer to have two writes
* to the journal rather than introducing a locking mechanism,
* because this happens rarely and those two writes to the journal
* are likely to be merged by the kernel into a single write since
* they are likely to update back-to-back sectors in the journal.
* A locking mechanism would be less efficient, because the large
* size of chunks would cause unnecessary locking due to ``false
* sharing'' of a chunk by two writes. */
table_dirty = TRUE;
}
}
const int update_table = (!soft_write && table_dirty);
size_t iov_left;
uint8_t *iov_buf;
int nb, iov_index, nqiov, niov;
uint32_t prev;
if (first_chunk == last_chunk) {
goto handle_one_continuous_region;
}
/* Count the number of qiov and iov needed to cover the continuous regions
* of the compact image. */
iov_left = orig_qiov->iov[0].iov_len;
iov_buf = orig_qiov->iov[0].iov_base;
iov_index = 0;
nqiov = 0;
niov = 0;
prev = READ_TABLE (s->table[first_chunk]);
/* Data in the first chunk. */
nb = s->chunk_size - (sector_num % s->chunk_size);
for (chunk = first_chunk + 1; chunk <= last_chunk; chunk++) {
uint32_t current = READ_TABLE (s->table[chunk]);
int64_t data_size;
if (chunk < last_chunk) {
data_size = s->chunk_size;
} else {
data_size = (sector_num + nb_sectors) % s->chunk_size;
if (data_size == 0) {
data_size = s->chunk_size;
}
}
if (current == prev + 1) {
nb += data_size; /* Continue the previous region. */
} else {
/* Terminate the previous region. */
niov +=
count_iov (orig_qiov->iov, &iov_index, &iov_buf, &iov_left,
nb * 512);
nqiov++;
nb = data_size; /* Data in the new region. */
}
prev = current;
}
if (nqiov == 0) {
handle_one_continuous_region:
/* A simple case. All data can be written out in one qiov and no new
* chunks are allocated. */
start_sec = READ_TABLE (s->table[first_chunk]) * s->chunk_size +
(sector_num % s->chunk_size);
if (!update_table && !acb) {
if (parent_acb) {
QDEBUG ("STORE: acb%llu-%p "
"store_directly_without_table_update\n",
parent_acb->uuid, parent_acb);
}
return bdrv_aio_writev (s->fvd_data, s->data_offset + start_sec,
orig_qiov, nb_sectors, cb, opaque);
}
if (!acb && !(acb = init_store_acb (soft_write, orig_qiov, bs,
sector_num, nb_sectors, parent_acb, cb, opaque))) {
return NULL;
}
QDEBUG ("STORE: acb%llu-%p store_directly sector_num=%" PRId64
" nb_sectors=%d\n", acb->uuid, acb, acb->sector_num,
acb->nb_sectors);
acb->store.update_table = update_table;
acb->store.num_children = 1;
acb->store.one_child.hd_acb =
bdrv_aio_writev (s->fvd_data, s->data_offset + start_sec, orig_qiov,
nb_sectors, finish_store_data_in_compact_image,
&acb->store.one_child);
if (acb->store.one_child.hd_acb) {
acb->store.one_child.acb = acb;
return &acb->common;
} else {
my_qemu_aio_unref (acb);
return NULL;
}
}
/* qiov for the last continuous region. */
niov += count_iov (orig_qiov->iov, &iov_index, &iov_buf,
&iov_left, nb * 512);
nqiov++;
ASSERT (iov_index == orig_qiov->niov - 1 && iov_left == 0);
/* Need to submit multiple requests to the lower layer. */
if (!acb && !(acb = init_store_acb (soft_write, orig_qiov, bs, sector_num,
nb_sectors, parent_acb, cb, opaque))) {
return NULL;
}
acb->store.update_table = update_table;
acb->store.num_children = nqiov;
if (!parent_acb) {
QDEBUG ("STORE: acb%llu-%p start sector_num=%" PRId64
" nb_sectors=%d\n", acb->uuid, acb, acb->sector_num,
acb->nb_sectors);
}
/* Allocate memory and create multiple requests. */
const size_t metadata_size = nqiov * (sizeof (CompactChildCB) +
sizeof (QEMUIOVector))
+ niov * sizeof (struct iovec);
acb->store.children = (CompactChildCB *) my_qemu_malloc (metadata_size);
QEMUIOVector *q = (QEMUIOVector *) (acb->store.children + nqiov);
struct iovec *v = (struct iovec *) (q + nqiov);
start_sec = READ_TABLE (s->table[first_chunk]) * s->chunk_size +
(sector_num % s->chunk_size);
nqiov = 0;
iov_index = 0;
iov_left = orig_qiov->iov[0].iov_len;
iov_buf = orig_qiov->iov[0].iov_base;
prev = READ_TABLE (s->table[first_chunk]);
/* Data in the first chunk. */
if (first_chunk == last_chunk) {
nb = nb_sectors;
}
else {
nb = s->chunk_size - (sector_num % s->chunk_size);
}
for (chunk = first_chunk + 1; chunk <= last_chunk; chunk++) {
uint32_t current = READ_TABLE (s->table[chunk]);
int64_t data_size;
if (chunk < last_chunk) {
data_size = s->chunk_size;
} else {
data_size = (sector_num + nb_sectors) % s->chunk_size;
if (data_size == 0) {
data_size = s->chunk_size;
}
}
if (current == prev + 1) {
nb += data_size; /* Continue the previous region. */
} else {
/* Terminate the previous continuous region. */
niov = setup_iov (orig_qiov->iov, v, &iov_index,
&iov_buf, &iov_left, nb * 512);
qemu_iovec_init_external (q, v, niov);
QDEBUG ("STORE: acb%llu-%p create_child %d sector_num=%" PRId64
" nb_sectors=%d niov=%d\n", acb->uuid, acb, nqiov,
start_sec, q->size / 512, q->niov);
acb->store.children[nqiov].hd_acb =
bdrv_aio_writev (s->fvd_data, s->data_offset + start_sec, q,
q->size / 512,
finish_store_data_in_compact_image,
&acb->store.children[nqiov]);
if (!acb->store.children[nqiov].hd_acb) {
goto fail;
}
acb->store.children[nqiov].acb = acb;
v += niov;
q++;
nqiov++;
start_sec = current * s->chunk_size; /* Begin of the new region. */
nb = data_size; /* Data in the new region. */
}
prev = current;
}
/* Requst for the last chunk. */
niov = setup_iov (orig_qiov->iov, v, &iov_index, &iov_buf,
&iov_left, nb * 512);
ASSERT (iov_index == orig_qiov->niov - 1 && iov_left == 0);
qemu_iovec_init_external (q, v, niov);
QDEBUG ("STORE: acb%llu-%p create_child_last %d sector_num=%" PRId64
" nb_sectors=%d niov=%d\n", acb->uuid, acb, nqiov, start_sec,
q->size / 512, q->niov);
acb->store.children[nqiov].hd_acb =
bdrv_aio_writev (s->fvd_data, s->data_offset + start_sec, q,
q->size / 512, finish_store_data_in_compact_image,
&acb->store.children[nqiov]);
if (acb->store.children[nqiov].hd_acb) {
acb->store.children[nqiov].acb = acb;
return &acb->common;
}
int i;
fail:
QDEBUG ("STORE: acb%llu-%p failed\n", acb->uuid, acb);
for (i = 0; i < nqiov; i++) {
bdrv_aio_cancel (acb->store.children[i].hd_acb);
}
my_qemu_free (acb->store.children);
my_qemu_aio_unref (acb);
return NULL;
}
