On Wed, Apr 01, 2009 at 07:28:03AM +1100, Greg Banks wrote:
> Add two control files to /proc/fs/nfsd:
>
> * "stats_enabled" can be used to disable or enable the gathering
> of per-client and per-export statistics in the server.
>
> * "stats_prune_period" can be used to set the period at
> which the pruning timer runs, in seconds. Unused stats
> entries will survive at most twice that time.
>
> Signed-off-by: Greg Banks <gnb@xxxxxxx>
> ---
>
> fs/nfsd/nfsctl.c | 99 ++++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 99 insertions(+)
>
> Index: bfields/fs/nfsd/nfsctl.c
> ===================================================================
> --- bfields.orig/fs/nfsd/nfsctl.c
> +++ bfields/fs/nfsd/nfsctl.c
> @@ -64,6 +64,8 @@ enum {
> NFSD_Versions,
> NFSD_Ports,
> NFSD_MaxBlkSize,
> + NFSD_Stats_Enabled,
> + NFSD_Stats_Prune_Period,
> /*
> * The below MUST come last. Otherwise we leave a hole in nfsd_files[]
> * with !CONFIG_NFSD_V4 and simple_fill_super() goes oops
> @@ -92,6 +94,8 @@ static ssize_t write_pool_threads(struct
> static ssize_t write_versions(struct file *file, char *buf, size_t size);
> static ssize_t write_ports(struct file *file, char *buf, size_t size);
> static ssize_t write_maxblksize(struct file *file, char *buf, size_t size);
> +static ssize_t write_stats_enabled(struct file *file, char *buf, size_t size);
> +static ssize_t write_stats_prune_period(struct file *file, char *buf, size_t size);
> #ifdef CONFIG_NFSD_V4
> static ssize_t write_leasetime(struct file *file, char *buf, size_t size);
> static ssize_t write_recoverydir(struct file *file, char *buf, size_t size);
> @@ -113,6 +117,8 @@ static ssize_t (*write_op[])(struct file
> [NFSD_Versions] = write_versions,
> [NFSD_Ports] = write_ports,
> [NFSD_MaxBlkSize] = write_maxblksize,
> + [NFSD_Stats_Enabled] = write_stats_enabled,
> + [NFSD_Stats_Prune_Period] = write_stats_prune_period,
> #ifdef CONFIG_NFSD_V4
> [NFSD_Leasetime] = write_leasetime,
> [NFSD_RecoveryDir] = write_recoverydir,
> @@ -1121,6 +1127,97 @@ static ssize_t write_maxblksize(struct f
> return sprintf(buf, "%d\n", nfsd_max_blksize);
> }
>
> +extern int nfsd_stats_enabled;
> +
> +/**
> + * write_stats_enabled - Set or report whether per-client/
> + * per-export stats are enabled.
> + *
> + * Input:
> + * buf: ignored
> + * size: zero
> + *
> + * OR
> + *
> + * Input:
> + * buf: C string containing an unsigned
> + * integer value representing the new value
> + * size: non-zero length of C string in @buf
> + * Output:
> + * On success: passed-in buffer filled with '\n'-terminated C string
> + * containing numeric value of the current setting
> + * return code is the size in bytes of the string
> + * On error: return code is zero or a negative errno value
> + */
> +static ssize_t write_stats_enabled(struct file *file, char *buf, size_t size)
> +{
> + char *mesg = buf;
> + if (size > 0) {
> + int enabled;
> + int rv = get_int(&mesg, &enabled);
> + if (rv)
> + return rv;
> + /* check `enabled' against allowed range */
> + if (enabled < 0 || enabled > 1)
> + return -EINVAL;
> + /*
> + * We can change the enabled flag at any time without
> + * locking. All it controls is whether stats are
> + * gathered for new incoming NFS calls. Old gathered
> + * stats still sit around in the hash tables until
> + * naturally pruned.
> + */
> + nfsd_stats_enabled = enabled;
> + }
> + return sprintf(buf, "%d\n", nfsd_stats_enabled);
> +}
> +
> +extern int nfsd_stats_prune_period;
> +
> +/**
> + * write_stats_prune_period - Set or report the period for pruning
> + * old per-client/per-export stats entries,
> + * in seconds.
> + *
> + * Input:
> + * buf: ignored
> + * size: zero
> + *
> + * OR
> + *
> + * Input:
> + * buf: C string containing an unsigned
> + * integer value representing the new value
> + * size: non-zero length of C string in @buf
> + * Output:
> + * On success: passed-in buffer filled with '\n'-terminated C string
> + * containing numeric value of the current setting
> + * return code is the size in bytes of the string
> + * On error: return code is zero or a negative errno value
> + */
Just an idle remark, don't worry about this for now, but: we might want
to rein in this write_*() comment format a little some day. A lot of
the content seems duplicated.
--b.
> +static ssize_t write_stats_prune_period(struct file *file, char *buf, size_t size)
> +{
> + char *mesg = buf;
> + if (size > 0) {
> + int period;
> + int rv = get_int(&mesg, &period);
> + if (rv)
> + return rv;
> + /* check `period' against allowed range */
> + if (period < 10 || period > 14*86400)
> + return -EINVAL;
> + /*
> + * We can change the period at any time without
> + * locking. All it controls is the timeout on the
> + * next run of the prune timer. This might cause
> + * some unexpected behaviour if the period is
> + * changed from really high to really low.
> + */
> + nfsd_stats_prune_period = period;
> + }
> + return sprintf(buf, "%d\n", nfsd_stats_prune_period);
> +}
> +
> #ifdef CONFIG_NFSD_V4
> extern time_t nfs4_leasetime(void);
>
> @@ -1263,6 +1360,8 @@ static int nfsd_fill_super(struct super_
> [NFSD_Versions] = {"versions", &transaction_ops, S_IWUSR|S_IRUSR},
> [NFSD_Ports] = {"portlist", &transaction_ops, S_IWUSR|S_IRUGO},
> [NFSD_MaxBlkSize] = {"max_block_size", &transaction_ops, S_IWUSR|S_IRUGO},
> + [NFSD_Stats_Enabled] = {"stats_enabled", &transaction_ops, S_IWUSR|S_IRUGO},
> + [NFSD_Stats_Prune_Period] = {"stats_prune_period", &transaction_ops, S_IWUSR|S_IRUGO},
> #ifdef CONFIG_NFSD_V4
> [NFSD_Leasetime] = {"nfsv4leasetime", &transaction_ops, S_IWUSR|S_IRUSR},
> [NFSD_RecoveryDir] = {"nfsv4recoverydir", &transaction_ops, S_IWUSR|S_IRUSR},
>
> --
> Greg
--
To unsubscribe from this list: send the line "unsubscribe linux-nfs" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
