On 29.09.26 18:51, Denis V. Lunev wrote:
+static int coroutine_fn GRAPH_RDLOCK
+block_copy_write_zeroes(BlockCopyState *s, int64_t offset, int64_t bytes,
+ bool *error_is_read)
+{
+ BdrvRequestFlags flags = s->write_flags & ~BDRV_REQ_WRITE_COMPRESSED;
+ int64_t chunk;
+ int ret = 0;
+
+ if (qatomic_read(&s->zero_widen)) {
+ ret = bdrv_co_pwrite_zeroes(s->target, offset, bytes,
+ flags | BDRV_REQ_NO_FALLBACK);
+ if (ret != -ENOTSUP) {
+ goto out;
+ }
+
+ /* Redoing the range is safe: zeroes over zeroes change nothing. */
+ qatomic_set(&s->zero_widen, false);
+ }
+
+ WITH_QEMU_LOCK_GUARD(&s->lock) {
+ chunk = block_copy_chunk_size(s);
+ }
+
+ while (bytes) {
+ int64_t n = MIN(bytes, chunk);
+
+ ret = bdrv_co_pwrite_zeroes(s->target, offset, n, flags);
also, here we ignore s->mem: we've allocated 0, but now use buffer of n bytes.
--
Best regards,
Vladimir
