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block: Add wr_highest_sector blockstat

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This adds the wr_highest_sector blockstat which implements what is generally
known as the high watermark. It is the highest offset of a sector written to
the respective BlockDriverState since it has been opened.

The query-blockstat QMP command is extended to add this value to the result,
and also to add the statistics of the underlying protocol in a new "parent"
field. Note that to get the "high watermark" of a qcow2 image, you need to look
into the wr_highest_sector field of the parent (which can be a file, a
host_device, ...). The wr_highest_sector of the qcow2 BlockDriverState itself
is the highest offset on the _virtual_ disk that the guest has written to.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This commit is contained in:
Kevin Wolf 2010-04-28 14:34:01 +02:00
parent 419b19d9b4
commit 294cc35f3d
2 changed files with 59 additions and 15 deletions
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73
block.c
View File

@ -880,6 +880,10 @@ int bdrv_write(BlockDriverState *bs, int64_t sector_num,
set_dirty_bitmap(bs, sector_num, nb_sectors, 1);
}
if (bs->wr_highest_sector < sector_num + nb_sectors - 1) {
bs->wr_highest_sector = sector_num + nb_sectors - 1;
}
return drv->bdrv_write(bs, sector_num, buf, nb_sectors);
}
@ -1530,6 +1534,35 @@ void bdrv_stats_print(Monitor *mon, const QObject *data)
qlist_iter(qobject_to_qlist(data), bdrv_stats_iter, mon);
}
static QObject* bdrv_info_stats_bs(BlockDriverState *bs)
{
QObject *res;
QDict *dict;
res = qobject_from_jsonf("{ 'stats': {"
"'rd_bytes': %" PRId64 ","
"'wr_bytes': %" PRId64 ","
"'rd_operations': %" PRId64 ","
"'wr_operations': %" PRId64 ","
"'wr_highest_offset': %" PRId64
"} }",
bs->rd_bytes, bs->wr_bytes,
bs->rd_ops, bs->wr_ops,
bs->wr_highest_sector * 512);
dict = qobject_to_qdict(res);
if (*bs->device_name) {
qdict_put(dict, "device", qstring_from_str(bs->device_name));
}
if (bs->file) {
QObject *parent = bdrv_info_stats_bs(bs->file);
qdict_put_obj(dict, "parent", parent);
}
return res;
}
/**
* bdrv_info_stats(): show block device statistics
*
@ -1544,19 +1577,34 @@ void bdrv_stats_print(Monitor *mon, const QObject *data)
* - "wr_bytes": bytes written
* - "rd_operations": read operations
* - "wr_operations": write operations
*
* - "wr_highest_offset": Highest offset of a sector written since the
* BlockDriverState has been opened
* - "parent": Contains recursively the statistics of the underlying
* protocol (e.g. the host file for a qcow2 image). If there is no
* underlying protocol, this field is omitted.
*
* Example:
*
* [ { "device": "ide0-hd0",
* "stats": { "rd_bytes": 512,
* "wr_bytes": 0,
* "rd_operations": 1,
* "wr_operations": 0 } },
* "wr_operations": 0,
* "wr_highest_offset": 0,
* "parent": {
* "stats": { "rd_bytes": 1024,
* "wr_bytes": 0,
* "rd_operations": 2,
* "wr_operations": 0,
* "wr_highest_offset": 0,
* }
* } } },
* { "device": "ide1-cd0",
* "stats": { "rd_bytes": 0,
* "wr_bytes": 0,
* "rd_operations": 0,
* "wr_operations": 0 } } ]
* "wr_operations": 0,
* "wr_highest_offset": 0 } },
*/
void bdrv_info_stats(Monitor *mon, QObject **ret_data)
{
@ -1567,15 +1615,7 @@ void bdrv_info_stats(Monitor *mon, QObject **ret_data)
devices = qlist_new();
QTAILQ_FOREACH(bs, &bdrv_states, list) {
obj = qobject_from_jsonf("{ 'device': %s, 'stats': {"
"'rd_bytes': %" PRId64 ","
"'wr_bytes': %" PRId64 ","
"'rd_operations': %" PRId64 ","
"'wr_operations': %" PRId64
"} }",
bs->device_name,
bs->rd_bytes, bs->wr_bytes,
bs->rd_ops, bs->wr_ops);
obj = bdrv_info_stats_bs(bs);
qlist_append_obj(devices, obj);
}
@ -1834,9 +1874,12 @@ BlockDriverAIOCB *bdrv_aio_writev(BlockDriverState *bs, int64_t sector_num,
cb, opaque);
if (ret) {
/* Update stats even though technically transfer has not happened. */
bs->wr_bytes += (unsigned) nb_sectors * BDRV_SECTOR_SIZE;
bs->wr_ops ++;
/* Update stats even though technically transfer has not happened. */
bs->wr_bytes += (unsigned) nb_sectors * BDRV_SECTOR_SIZE;
bs->wr_ops ++;
if (bs->wr_highest_sector < sector_num + nb_sectors - 1) {
bs->wr_highest_sector = sector_num + nb_sectors - 1;
}
}
return ret;

1
block_int.h
View File

@ -167,6 +167,7 @@ struct BlockDriverState {
uint64_t wr_bytes;
uint64_t rd_ops;
uint64_t wr_ops;
uint64_t wr_highest_sector;
/* Whether the disk can expand beyond total_sectors */
int growable;