if (ret < 0) {
return ret;
}
- ret = vhdx_update_header(bs, s, generate_data_write_guid, log_guid);
- return ret;
+ return vhdx_update_header(bs, s, generate_data_write_guid, log_guid);
}
/* opens the specified header block from the VHDX file header section */
uint64_t signature;
Error *local_err = NULL;
- bs->file = bdrv_open_child(NULL, options, "file", bs, &child_file,
- false, errp);
+ bs->file = bdrv_open_child(NULL, options, "file", bs, &child_of_bds,
+ BDRV_CHILD_IMAGE, false, errp);
if (!bs->file) {
return -EINVAL;
}
/*
* Allocate a new payload block at the end of the file.
*
- * Allocation will happen at 1MB alignment inside the file
+ * Allocation will happen at 1MB alignment inside the file.
+ *
+ * If @need_zero is set on entry but not cleared on return, then truncation
+ * could not guarantee that the new portion reads as zero, and the caller
+ * will take care of it instead.
*
* Returns the file offset start of the new payload block
*/
static int vhdx_allocate_block(BlockDriverState *bs, BDRVVHDXState *s,
- uint64_t *new_offset)
+ uint64_t *new_offset, bool *need_zero)
{
int64_t current_len;
return -EINVAL;
}
+ if (*need_zero) {
+ int ret;
+
+ ret = bdrv_truncate(bs->file, *new_offset + s->block_size, false,
+ PREALLOC_MODE_OFF, BDRV_REQ_ZERO_WRITE, NULL);
+ if (ret != -ENOTSUP) {
+ *need_zero = false;
+ return ret;
+ }
+ }
+
return bdrv_truncate(bs->file, *new_offset + s->block_size, false,
PREALLOC_MODE_OFF, 0, NULL);
}
/* in this case, we need to preserve zero writes for
* data that is not part of this write, so we must pad
* the rest of the buffer to zeroes */
-
- /* if we are on a posix system with ftruncate() that extends
- * a file, then it is zero-filled for us. On Win32, the raw
- * layer uses SetFilePointer and SetFileEnd, which does not
- * zero fill AFAIK */
-
- /* Queue another write of zero buffers if the underlying file
- * does not zero-fill on file extension */
-
- if (bdrv_has_zero_init_truncate(bs->file->bs) == 0) {
- use_zero_buffers = true;
-
+ use_zero_buffers = true;
+ /* fall through */
+ case PAYLOAD_BLOCK_NOT_PRESENT: /* fall through */
+ case PAYLOAD_BLOCK_UNMAPPED:
+ case PAYLOAD_BLOCK_UNMAPPED_v095:
+ case PAYLOAD_BLOCK_UNDEFINED:
+ bat_prior_offset = sinfo.file_offset;
+ ret = vhdx_allocate_block(bs, s, &sinfo.file_offset,
+ &use_zero_buffers);
+ if (ret < 0) {
+ goto exit;
+ }
+ /*
+ * once we support differencing files, this may also be
+ * partially present
+ */
+ /* update block state to the newly specified state */
+ vhdx_update_bat_table_entry(bs, s, &sinfo, &bat_entry,
+ &bat_entry_offset,
+ PAYLOAD_BLOCK_FULLY_PRESENT);
+ bat_update = true;
+ /*
+ * Since we just allocated a block, file_offset is the
+ * beginning of the payload block. It needs to be the
+ * write address, which includes the offset into the
+ * block, unless the entire block needs to read as
+ * zeroes but truncation was not able to provide them,
+ * in which case we need to fill in the rest.
+ */
+ if (!use_zero_buffers) {
+ sinfo.file_offset += sinfo.block_offset;
+ } else {
/* zero fill the front, if any */
if (sinfo.block_offset) {
iov1.iov_len = sinfo.block_offset;
}
/* our actual data */
- qemu_iovec_concat(&hd_qiov, qiov, bytes_done,
+ qemu_iovec_concat(&hd_qiov, qiov, bytes_done,
sinfo.bytes_avail);
/* zero fill the back, if any */
sectors_to_write += iov2.iov_len >> BDRV_SECTOR_BITS;
}
}
- /* fall through */
- case PAYLOAD_BLOCK_NOT_PRESENT: /* fall through */
- case PAYLOAD_BLOCK_UNMAPPED:
- case PAYLOAD_BLOCK_UNMAPPED_v095:
- case PAYLOAD_BLOCK_UNDEFINED:
- bat_prior_offset = sinfo.file_offset;
- ret = vhdx_allocate_block(bs, s, &sinfo.file_offset);
- if (ret < 0) {
- goto exit;
- }
- /* once we support differencing files, this may also be
- * partially present */
- /* update block state to the newly specified state */
- vhdx_update_bat_table_entry(bs, s, &sinfo, &bat_entry,
- &bat_entry_offset,
- PAYLOAD_BLOCK_FULLY_PRESENT);
- bat_update = true;
- /* since we just allocated a block, file_offset is the
- * beginning of the payload block. It needs to be the
- * write address, which includes the offset into the block */
- if (!use_zero_buffers) {
- sinfo.file_offset += sinfo.block_offset;
- }
+
/* fall through */
case PAYLOAD_BLOCK_FULLY_PRESENT:
/* if the file offset address is in the header zone,
.bdrv_open = vhdx_open,
.bdrv_close = vhdx_close,
.bdrv_reopen_prepare = vhdx_reopen_prepare,
- .bdrv_child_perm = bdrv_format_default_perms,
+ .bdrv_child_perm = bdrv_default_perms,
.bdrv_co_readv = vhdx_co_readv,
.bdrv_co_writev = vhdx_co_writev,
.bdrv_co_create = vhdx_co_create,
.bdrv_co_check = vhdx_co_check,
.bdrv_has_zero_init = vhdx_has_zero_init,
+ .is_format = true,
.create_opts = &vhdx_create_opts,
};
projects / mirror_qemu.git / blobdiff