v2: - rebased on top of series 'ide: abort TRIM operation for invalid range'
(http://lists.nongnu.org/archive/html/qemu-devel/2017-12/msg01432.html)
Now invalid trim requests are properly accounted
- patches 1/2 - qapi fields regrouped together
v1: http://lists.nongnu.org/archive/html/qemu-devel/2017-11/msg03664.html
----
qmp query-blockstats provides stats info for write/read/flush ops.
Patches 1-5 implement the similar for discard (unmap) command for scsi
and ide disks.
Discard stat "unmap_ops / unmap_bytes" is supposed to account the ops that
have completed without an error.
However, discard operation is advisory. Specifically,
- common block layer ignores ENOTSUP error code.
That might be returned if the block driver does not support discard,
or discard has been configured to be ignored.
- format drivers such as qcow2 may ignore discard if they were configured
to ignore that, or if the corresponding area is already marked unused
(unallocated / zero clusters).
And what is actually useful is the number of bytes actually discarded
down on the host filesystem.
To achieve that, driver-specific statistics has been added to blockstats
(patch 7).
With patch 6, file-posix driver accounts discard operations on its level too.
query-blockstat result:
(note the difference between blockdevice unmap and file discard stats. qcow2
sends a few ops down to the file as the clusters are actually unallocated
on qcow2 level)
{"return": [
{"device": "drive-scsi0-0-0-0"
"parent": {
"stats": {
> "unmap_operations": 0
> "unmap_merged": 0
"flush_total_time_ns": 0
"wr_highest_offset": 8111718400
[..]
"invalid_wr_operations": 0
"invalid_rd_operations": 0}
"node-name": "#block047"
> "driver_stats": {
> "type": "file"
> "data": {
> "discard_bytes_ok": 1572864
> "discard_nb_failed": 0
> "discard_nb_ok": 5}}}
"stats": {
> "unmap_operations": 472
> "unmap_merged": 0
"flush_total_time_ns": 44530540
"wr_highest_offset": 7106662400
"wr_total_time_ns": 45518856
"failed_wr_operations": 0
"failed_rd_operations": 0
"wr_merged": 0
"wr_bytes": 889856
"timed_stats": []
> "failed_unmap_operations": 0
"failed_flush_operations": 0
"account_invalid": true
"rd_total_time_ns": 3306264098
> "invalid_unmap_operations": 0
"flush_operations": 18
"wr_operations": 120
> "unmap_bytes": 12312014848
"rd_merged": 0
"rd_bytes": 137103360
> "unmap_total_time_ns": 22664692
"invalid_flush_operations": 0
"account_failed": true
"idle_time_ns": 437316567
"rd_operations": 5636
"invalid_wr_operations": 0
"invalid_rd_operations": 0}
"node-name": "#block128"}
{"device": "drive-ide0-0-0"
[..]
Anton Nefedov (8):
qapi: group BlockDeviceStats fields
qapi: add unmap to BlockDeviceStats
ide: account UNMAP (TRIM) operations
scsi: store unmap offset and nb_sectors in request struct
scsi: move unmap error checking to the complete callback
scsi: account unmap operations
file-posix: account discard operations
qapi: query-blockstat: add driver specific file-posix stats
qapi/block-core.json | 78 ++++++++++++++++++++++++++++++++++++++++++----
include/block/accounting.h | 1 +
include/block/block.h | 1 +
include/block/block_int.h | 1 +
block.c | 9 ++++++
block/file-posix.c | 42 +++++++++++++++++++++++--
block/qapi.c | 11 +++++++
hw/ide/core.c | 13 ++++++++
hw/scsi/scsi-disk.c | 29 ++++++++++-------
9 files changed, 166 insertions(+), 19 deletions(-)
--
2.7.4
