On Thu, May 12, 2022 at 09:19:30AM +0800, luzhipeng wrote:
> Add a new 'guest-get-diskstats' command for report disk io statistics
> for Linux guests. This can be usefull for getting io flow or handling
> IO fault, no need to enter guests.
>
> Signed-off-by: luzhipeng <luzhip...@cestc.cn>
> ---
> qga/commands-posix.c | 94 ++++++++++++++++++++++++++++++++++++++++++++
> qga/commands-win32.c | 6 +++
> qga/qapi-schema.json | 86 ++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 186 insertions(+)
>
> diff --git a/qga/commands-posix.c b/qga/commands-posix.c
> index 69f209af87..2b96c9ae6e 100644
> --- a/qga/commands-posix.c
> +++ b/qga/commands-posix.c
> @@ -2783,6 +2783,93 @@ GuestMemoryBlockInfo
> *qmp_guest_get_memory_block_info(Error **errp)
> return info;
> }
>
> +#define MAX_NAME_LEN 128
> +static GuestDiskStatsInfoList *guest_get_diskstats(Error **errp)
> +{
> +#ifdef CONFIG_LINUX
> + GuestDiskStatsInfoList *head = NULL, **tail = &head;
> + const char *diskstats = "/proc/diskstats";
> + FILE *fp;
> + size_t n;
> + char *line = NULL;
> + char dev_name[MAX_NAME_LEN];
> + int i;
> + unsigned int ios_pgr, tot_ticks, rq_ticks, wr_ticks, dc_ticks, fl_ticks;
> + unsigned long rd_ios, rd_merges_or_rd_sec, rd_ticks_or_wr_sec, wr_ios;
> + unsigned long wr_merges, rd_sec_or_wr_ios, wr_sec;
> + unsigned long dc_ios, dc_merges, dc_sec, fl_ios;
> + unsigned int major, minor;
> +
> + fp = fopen(diskstats, "r");
> + if (fp == NULL) {
> + error_setg_errno(errp, errno, "open(\"%s\")", diskstats);
> + return NULL;
> + }
> + while (getline(&line, &n, fp) != -1) {
> + i = sscanf(line, "%u %u %s %lu %lu %lu"
> + "%lu %lu %lu %lu %u %u %u %u"
> + "%lu %lu %lu %u %lu %u",
> + &major, &minor, dev_name,
> + &rd_ios, &rd_merges_or_rd_sec, &rd_sec_or_wr_ios,
> + &rd_ticks_or_wr_sec, &wr_ios, &wr_merges, &wr_sec,
> + &wr_ticks, &ios_pgr, &tot_ticks, &rq_ticks,
> + &dc_ios, &dc_merges, &dc_sec, &dc_ticks,
> + &fl_ios, &fl_ticks);
Nothing free's the 'line' buffer after this point.
> + GuestDiskStatsInfo *diskstatinfo = g_malloc0(sizeof *diskstatinfo);
Our preferred style is g_new0 rather than g_malloc0 eg
g_new0(GuestDiskStatsInfo, 1)
> + GuestDiskStats *diskstat = g_malloc0(sizeof *diskstat);
> + if (i >= 14) {
> + diskstatinfo->name = g_strdup(dev_name);
> + diskstatinfo->major = major;
> + diskstatinfo->minor = minor;
> + diskstat->rd_ios = rd_ios;
> + diskstat->rd_merges = rd_merges_or_rd_sec;
> + diskstat->rd_sectors = rd_sec_or_wr_ios;
> + diskstat->rd_ticks = rd_ticks_or_wr_sec;
> + diskstat->wr_ios = wr_ios;
> + diskstat->wr_merges = wr_merges;
> + diskstat->wr_sectors = wr_sec;
> + diskstat->wr_ticks = wr_ticks;
> + diskstat->ios_pgr = ios_pgr;
> + diskstat->tot_ticks = tot_ticks;
> + diskstat->rq_ticks = rq_ticks;
> + if (i >= 18) {
> + diskstat->dc_ios = dc_ios;
> + diskstat->dc_merges = dc_merges;
> + diskstat->dc_sectors = dc_sec;
> + diskstat->dc_ticks = dc_ticks;
> + }
> + if (i >= 20) {
> + diskstat->fl_ios = fl_ios;
> + diskstat->fl_ticks = fl_ticks;
> + }
> + diskstatinfo->stats = diskstat;
> + QAPI_LIST_APPEND(tail, diskstatinfo);
> + } else if (i == 7) {
> + diskstatinfo->name = g_strdup(dev_name);
> + diskstatinfo->major = major;
> + diskstatinfo->minor = minor;
> + diskstat->rd_ios = rd_ios;
> + diskstat->rd_sectors = rd_merges_or_rd_sec;
> + diskstat->wr_ios = rd_sec_or_wr_ios;
> + diskstat->wr_sectors = rd_ticks_or_wr_sec;
In this branch nothing adds 'diskstat' to 'diskstatinfo', nor
'diskstatinfo' to 'tail'.
> + } else {
> + g_free(diskstat);
> + g_free(diskstatinfo);
> + }
THe whole body structure needs changing IMHO
GuestDiskStatsInfo *diskstatinfo;
GuestDiskStats *diskstat;
i = scanf(....)
if (i < 7)
continue
diskstatinfo = g_new0(GuestDiskStatsInfo, 1);
diskstat = g_new0(GuestDiskStats, 1);
...fill in first 7 fields...
if (i >= 14) {
...next fields...
}
if (i >= 18) {
...next fields...
}
if (i >= 20) {
...next fields...
}
diskstatinfo->stats = diskstat;
QAPI_LIST_APPEND(tail, diskstatinfo);
> + }
> + fclose(fp);
> + return head;
> +#else
> + g_debug("disk stats reporting available only for Linux");
> + return NULL;
> +#endif
> +}
> +
> +GuestDiskStatsInfoList *qmp_guest_get_diskstats(Error **errp)
> +{
> + return guest_get_diskstats(errp);
> +}
> +
> #else /* defined(__linux__) */
>
> void qmp_guest_suspend_disk(Error **errp)
> @@ -3131,6 +3218,13 @@ GuestDiskInfoList *qmp_guest_get_disks(Error **errp)
> return NULL;
> }
>
> +GuestDiskStatsInfoList *qmp_guest_get_diskstats(Error **errp)
> +{
> + error_setg(errp, QERR_UNSUPPORTED);
> + return NULL;
> +}
> +
> +
> #endif /* CONFIG_FSFREEZE */
>
> #if !defined(CONFIG_FSTRIM)
> diff --git a/qga/commands-win32.c b/qga/commands-win32.c
> index d56b5fd2a7..dcdeb76a68 100644
> --- a/qga/commands-win32.c
> +++ b/qga/commands-win32.c
> @@ -2532,3 +2532,9 @@ char *qga_get_host_name(Error **errp)
>
> return g_utf16_to_utf8(tmp, size, NULL, NULL, NULL);
> }
> +
> +GuestDiskStatsInfoList *qmp_guest_get_diskstats(Error **errp)
> +{
> + error_setg(errp, QERR_UNSUPPORTED);
> + return NULL;
> +}
> diff --git a/qga/qapi-schema.json b/qga/qapi-schema.json
> index 4d8e506c9e..ec48629476 100644
> --- a/qga/qapi-schema.json
> +++ b/qga/qapi-schema.json
> @@ -1490,3 +1490,89 @@
> { 'command': 'guest-ssh-remove-authorized-keys',
> 'data': { 'username': 'str', 'keys': ['str'] },
> 'if': 'CONFIG_POSIX' }
> +
> +##
> +# @GuestDiskStats:
> +#
> +# @rd-sectors: of sectors read
s/: of sectors read/: Number of sectors read/
and use ': Number of' for all cases below that start ': of'
> +#
> +# @wr-sectors: of sectors write
> +#
> +# @dc-sectors: of sectors discard
> +#
> +# @rd-ios: of read operations issued to the device
> +#
> +# @rd-merges: of read requests merged
> +#
> +# @wr-ios: of write operations issued to the device
> +#
> +# @wr-merges: of write requests merged
> +#
> +# @dc-ios: of discard operations issued to the device
> +#
> +# @dc-merges: of discard requests merged
> +#
> +# @fl-ios: of flush requests issued to the device
> +#
> +# @rd-ticks: Time of read requests in queue
Document what units is time measured in. ie how long is
a 'tick' ? Ideally we should report in a standardized
OS independant unit such as "milliseconds" (assuming
we don't need more granularity micro/nano ?)
> +#
> +# @wr-ticks: Time of write requests in queue
> +#
> +# @dc-ticks: Time of discard requests in queue
> +#
> +# @fl-ticks: Time of flush requests in queue
> +#
> +# @ios-pgr: of I/Os in progress
'in flight' rather than 'in progress' perhaps
> +#
> +# @tot-ticks: of ticks total (for this device) for I/O
> +#
> +# @rq-ticks: of ticks requests spent in queue
> +#
> +# Since: 7.1
> +##
> +{ 'struct': 'GuestDiskStats',
> + 'data': {'rd-sectors': 'uint64',
> + 'wr-sectors': 'uint64',
> + 'dc-sectors': 'uint64',
> + 'rd-ios': 'uint64',
> + 'rd-merges': 'uint64',
> + 'wr-ios': 'uint64',
> + 'wr-merges': 'uint64',
> + 'dc-ios': 'uint64',
> + 'dc-merges': 'uint64',
> + 'fl-ios': 'uint64',
> + 'rd-ticks': 'uint64',
> + 'wr-ticks': 'uint64',
> + 'dc-ticks': 'uint64',
> + 'fl-ticks': 'uint64',
> + 'ios-in-flight': 'uint64',
> + 'tot-ticks': 'uint64',
> + 'rq-ticks': 'uint64'
> + } }
I wonder if we should just spell out the words instead
of abbreviating here ie
{ 'struct': 'GuestDiskStats',
'data': {'read-sectors': 'uint64',
'write-sectors': 'uint64',
'discard-sectors': 'uint64',
'read-ios': 'uint64',
'read-merges': 'uint64',
'write-ios': 'uint64',
'write-merges': 'uint64',
'discard-ios': 'uint64',
'discard-merges': 'uint64',
'flush-ios': 'uint64',
'read-ticks': 'uint64',
'write-ticks': 'uint64',
'discard-ticks': 'uint64',
'flush-ticks': 'uint64',
'ios-pgr': 'uint64',
'total-ticks': 'uint64',
'queued-ticks': 'uint64'
} }
> +
> +##
> +# @GuestDiskStatsInfo:
> +#
> +# @name disk name
> +#
> +# @major major of disk
> +#
> +# @minor minor of disk
> +##
> +{ 'struct': 'GuestDiskStatsInfo',
> + 'data': {'name': 'str',
> + 'major': 'uint64',
> + 'minor': 'uint64',
> + 'stats': 'GuestDiskStats' } }
> +
> +##
> +# @guest-get-diskstats:
> +#
> +# Retrieve information about disk io.
> +# Returns: List of disk stats of guest.
> +#
> +# Since: 7.1
> +##
> +{ 'command': 'guest-get-diskstats',
> + 'returns': ['GuestDiskStatsInfo']
> +}
> --
> 2.31.1
>
>
>
>
With regards,
Daniel
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