/**
* 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);
}
void qed_read_l2_table(BDRVQEDState *s, QEDRequest *request, uint64_t offset,
BlockDriverCompletionFunc *cb, void *opaque)
{
QEDReadL2TableCB *read_l2_table_cb;
qed_unref_l2_cache_entry(request->l2_table);
/* Check for cached L2 entry */
request->l2_table = qed_find_l2_cache_entry(&s->l2_cache, offset);
if (request->l2_table) {
cb(opaque, 0);
return;
}
request->l2_table = qed_alloc_l2_cache_entry(&s->l2_cache);
request->l2_table->table = qed_alloc_table(s);
read_l2_table_cb = gencb_alloc(sizeof(*read_l2_table_cb), cb, opaque);
read_l2_table_cb->s = s;
read_l2_table_cb->l2_offset = offset;
read_l2_table_cb->request = request;
BLKDBG_EVENT(s->bs->file, BLKDBG_L2_LOAD);
qed_read_table(s, offset, request->l2_table->table,
qed_read_l2_table_cb, read_l2_table_cb);
}
/**
* 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);
}
