[PATCH 5/7] xfs: incorporate sysfs/kobject in xfsstats: handlers take kobjects.

Bill O'Donnell
2015-09-25T23:23:52Z

This patch is the next step toward per-fs xfs stats. Allocate &
deallocate per-fs stats structures and set up the sysfs entries for them.

Instead of a single global xfsstats structure, add kobject and a pointer
to a per-cpu struct xfsstats. Modify the macros that manipulate the stats
accordingly: XFS_STATS_INC, XFS_STATS_DEC, and XFS_STATS_ADD now access
xfsstats->xs_stats.

The sysfs functions need to get from the kobject back to the xfsstats
structure which contains it, and pass the pointer to the ->xs_stats
percpu structure into the show & clear routines.

Signed-off-by: Bill O'Donnell <billodo@redhat.com>
---
fs/xfs/xfs_linux.h | 7 +++++++
fs/xfs/xfs_stats.c | 47 ++++++++++++++++++++++++-----------------------
fs/xfs/xfs_stats.h | 13 ++++++-------
fs/xfs/xfs_super.c | 15 ++++++++-------
fs/xfs/xfs_sysctl.c | 2 +-
fs/xfs/xfs_sysfs.c | 17 +++++++++++++++--
6 files changed, 61 insertions(+), 40 deletions(-)

diff --git a/fs/xfs/xfs_linux.h b/fs/xfs/xfs_linux.h
index 85f883d..f1a8505 100644
--- a/fs/xfs/xfs_linux.h
+++ b/fs/xfs/xfs_linux.h
@@ -171,6 +171,13 @@ struct xfs_kobj {
struct completion complete;
};

+struct xstats {
+ struct xfsstats __percpu *xs_stats;
+ struct xfs_kobj xs_kobj;
+};
+
+extern struct xstats xfsstats;
+
/* Kernel uid/gid conversion. These are used to convert to/from the on disk
* uid_t/gid_t types to the kuid_t/kgid_t types that the kernel uses internally.
* The conversion here is type only, the value will remain the same since we
diff --git a/fs/xfs/xfs_stats.c b/fs/xfs/xfs_stats.c
index dc6ca67..ab79973 100644
--- a/fs/xfs/xfs_stats.c
+++ b/fs/xfs/xfs_stats.c
@@ -18,18 +18,18 @@
#include "xfs.h"
#include <linux/proc_fs.h>

-DEFINE_PER_CPU(struct xfsstats, xfsstats);
+struct xstats xfsstats;

-static int counter_val(int idx)
+static int counter_val(struct xfsstats __percpu *stats, int idx)
{
int val = 0, cpu;

for_each_possible_cpu(cpu)
- val += *(((__u32 *)&per_cpu(xfsstats, cpu) + idx));
+ val += *(((__u32 *)&per_cpu(*stats, cpu) + idx));
return val;
}

-int xfs_stats_format(char *buf)
+int xfs_stats_format(struct xfsstats __percpu *stats, char *buf)
{
int i, j;
int len = 0;
@@ -73,14 +73,14 @@ int xfs_stats_format(char *buf)
/* inner loop does each group */
for (; j < xstats[i].endpoint; j++)
len += snprintf(buf + len, PATH_MAX - len, " %u",
- counter_val(j));
+ counter_val(stats, j));
len += snprintf(buf + len, PATH_MAX - len, "\n");
}
/* extra precision counters */
for_each_possible_cpu(i) {
- xs_xstrat_bytes += per_cpu(xfsstats, i).xs_xstrat_bytes;
- xs_write_bytes += per_cpu(xfsstats, i).xs_write_bytes;
- xs_read_bytes += per_cpu(xfsstats, i).xs_read_bytes;
+ xs_xstrat_bytes += per_cpu(*stats, i).xs_xstrat_bytes;
+ xs_write_bytes += per_cpu(*stats, i).xs_write_bytes;
+ xs_read_bytes += per_cpu(*stats, i).xs_read_bytes;
}

len += snprintf(buf+len, PATH_MAX-len, "xpc %Lu %Lu %Lu\n",
@@ -95,7 +95,7 @@ int xfs_stats_format(char *buf)
return len;
}

-void xfs_stats_clearall(void)
+void xfs_stats_clearall(struct xfsstats __percpu *stats)
{
int c;
__uint32_t vn_active;
@@ -104,10 +104,10 @@ void xfs_stats_clearall(void)
for_each_possible_cpu(c) {
preempt_disable();
/* save vn_active, it's a universal truth! */
- vn_active = per_cpu(xfsstats, c).vn_active;
- memset(&per_cpu(xfsstats, c), 0,
- sizeof(struct xfsstats));
- per_cpu(xfsstats, c).vn_active = vn_active;
+ vn_active = per_cpu(*stats, c).vn_active;
+ memset(&per_cpu(*stats, c), 0,
+ sizeof(*stats));
+ per_cpu(*stats, c).vn_active = vn_active;
preempt_enable();
}
}
@@ -119,9 +119,10 @@ static int xqm_proc_show(struct seq_file *m, void *v)
/* maximum; incore; ratio free to inuse; freelist */
seq_printf(m, "%d\t%d\t%d\t%u\n",
0,
- counter_val(XFSSTAT_END_XQMSTAT),
+ counter_val(xfsstats.xs_stats, XFSSTAT_END_XQMSTAT),
0,
- counter_val(XFSSTAT_END_XQMSTAT + 1));
+ counter_val(xfsstats.xs_stats,
+ XFSSTAT_END_XQMSTAT + 1));
return 0;
}

@@ -145,7 +146,7 @@ static int xqmstat_proc_show(struct seq_file *m, void *v)

seq_printf(m, "qm");
for (j = XFSSTAT_END_IBT_V2; j < XFSSTAT_END_XQMSTAT; j++)
- seq_printf(m, " %u", counter_val(j));
+ seq_printf(m, " %u", counter_val(xfsstats.xs_stats, j));
seq_putc(m, '\n');
return 0;
}
@@ -171,28 +172,28 @@ xfs_init_procfs(void)
goto out;

if (!proc_symlink("fs/xfs/stat", NULL,
- "/sys/fs/xfs/stats/stats"))
+ "/sys/fs/xfs/stats/stats"))
goto out_remove_xfs_dir;

#ifdef CONFIG_XFS_QUOTA
if (!proc_create("fs/xfs/xqmstat", 0, NULL,
- &xqmstat_proc_fops))
+ &xqmstat_proc_fops))
goto out_remove_stat_file;
if (!proc_create("fs/xfs/xqm", 0, NULL,
- &xqm_proc_fops))
+ &xqm_proc_fops))
goto out_remove_xqmstat_file;
#endif
return 0;

#ifdef CONFIG_XFS_QUOTA
- out_remove_xqmstat_file:
+out_remove_xqmstat_file:
remove_proc_entry("fs/xfs/xqmstat", NULL);
- out_remove_stat_file:
+out_remove_stat_file:
remove_proc_entry("fs/xfs/stat", NULL);
#endif
- out_remove_xfs_dir:
+out_remove_xfs_dir:
remove_proc_entry("fs/xfs", NULL);
- out:
+out:
return -ENOMEM;
}

diff --git a/fs/xfs/xfs_stats.h b/fs/xfs/xfs_stats.h
index 18807b5..672fe83 100644
--- a/fs/xfs/xfs_stats.h
+++ b/fs/xfs/xfs_stats.h
@@ -18,9 +18,6 @@
#ifndef __XFS_STATS_H__
#define __XFS_STATS_H__

-int xfs_stats_format(char *buf);
-void xfs_stats_clearall(void);
-
#if defined(CONFIG_PROC_FS) && !defined(XFS_STATS_OFF)

#include <linux/percpu.h>
@@ -217,15 +214,17 @@ struct xfsstats {
__uint64_t xs_read_bytes;
};

-DECLARE_PER_CPU(struct xfsstats, xfsstats);
+int xfs_stats_format(struct xfsstats __percpu *stats, char *buf);
+void xfs_stats_clearall(struct xfsstats __percpu *stats);
+extern struct xstats xfsstats;

/*
* We don't disable preempt, not too worried about poking the
* wrong CPU's stat for now (also aggregated before reporting).
*/
-#define XFS_STATS_INC(v) (per_cpu(xfsstats, current_cpu()).v++)
-#define XFS_STATS_DEC(v) (per_cpu(xfsstats, current_cpu()).v--)
-#define XFS_STATS_ADD(v, inc) (per_cpu(xfsstats, current_cpu()).v += (inc))
+#define XFS_STATS_INC(v) (per_cpu(*xfsstats.xs_stats, current_cpu()).v++)
+#define XFS_STATS_DEC(v) (per_cpu(*xfsstats.xs_stats, current_cpu()).v--)
+#define XFS_STATS_ADD(v, inc) (per_cpu(*xfsstats.xs_stats, current_cpu()).v += (inc))

extern int xfs_init_procfs(void);
extern void xfs_cleanup_procfs(void);
diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c
index 0dfc53b..23e5681 100644
--- a/fs/xfs/xfs_super.c
+++ b/fs/xfs/xfs_super.c
@@ -61,7 +61,6 @@ static kmem_zone_t *xfs_ioend_zone;
mempool_t *xfs_ioend_pool;

static struct kset *xfs_kset; /* top-level xfs sysfs dir */
-static struct xfs_kobj xfs_stats_kobj; /* global stats sysfs attrs */
#ifdef DEBUG
static struct xfs_kobj xfs_dbg_kobj; /* global debug sysfs attrs */
#endif
@@ -1802,6 +1801,7 @@ xfs_destroy_workqueues(void)
destroy_workqueue(xfs_alloc_wq);
}

+
STATIC int __init
init_xfs_fs(void)
{
@@ -1842,8 +1842,9 @@ init_xfs_fs(void)
goto out_sysctl_unregister;
}

- xfs_stats_kobj.kobject.kset = xfs_kset;
- error = xfs_sysfs_init(&xfs_stats_kobj, &xfs_stats_ktype, NULL,
+ xfsstats.xs_stats = alloc_percpu(struct xfsstats);
+ xfsstats.xs_kobj.kobject.kset = xfs_kset;
+ error = xfs_sysfs_init(&xfsstats.xs_kobj, &xfs_stats_ktype, NULL,
"stats");
if (error)
goto out_kset_unregister;
@@ -1852,7 +1853,7 @@ init_xfs_fs(void)
xfs_dbg_kobj.kobject.kset = xfs_kset;
error = xfs_sysfs_init(&xfs_dbg_kobj, &xfs_dbg_ktype, NULL, "debug");
if (error)
- goto out_remove_stats_kobj;
+ goto out_remove_stats;
#endif

error = xfs_qm_init();
@@ -1869,9 +1870,9 @@ init_xfs_fs(void)
out_remove_dbg_kobj:
#ifdef DEBUG
xfs_sysfs_del(&xfs_dbg_kobj);
- out_remove_stats_kobj:
+ out_remove_stats:
#endif
- xfs_sysfs_del(&xfs_stats_kobj);
+ free_percpu(xfsstats.xs_stats);
out_kset_unregister:
kset_unregister(xfs_kset);
out_sysctl_unregister:
@@ -1898,7 +1899,7 @@ exit_xfs_fs(void)
#ifdef DEBUG
xfs_sysfs_del(&xfs_dbg_kobj);
#endif
- xfs_sysfs_del(&xfs_stats_kobj);
+ free_percpu(xfsstats.xs_stats);
kset_unregister(xfs_kset);
xfs_sysctl_unregister();
xfs_cleanup_procfs();
diff --git a/fs/xfs/xfs_sysctl.c b/fs/xfs/xfs_sysctl.c
index 5defabb..aed74d3 100644
--- a/fs/xfs/xfs_sysctl.c
+++ b/fs/xfs/xfs_sysctl.c
@@ -37,7 +37,7 @@ xfs_stats_clear_proc_handler(
ret = proc_dointvec_minmax(ctl, write, buffer, lenp, ppos);

if (!ret && write && *valp) {
- xfs_stats_clearall();
+ xfs_stats_clearall(xfsstats.xs_stats);
xfs_stats_clear = 0;
}

diff --git a/fs/xfs/xfs_sysfs.c b/fs/xfs/xfs_sysfs.c
index ab4850b..3275408 100644
--- a/fs/xfs/xfs_sysfs.c
+++ b/fs/xfs/xfs_sysfs.c
@@ -131,12 +131,23 @@ struct kobj_type xfs_dbg_ktype = {

/* stats */

+static inline struct xstats *
+to_xstats(struct kobject *kobject)
+{
+ struct xfs_kobj *kobj = to_kobj(kobject);
+
+ return container_of(kobj, struct xstats, xs_kobj);
+}
+
+
STATIC ssize_t
stats_show(
struct kobject *kobject,
char *buf)
{
- return xfs_stats_format(buf);
+ struct xstats *stats = to_xstats(kobject);
+
+ return xfs_stats_format(stats->xs_stats, buf);
}
XFS_SYSFS_ATTR_RO(stats);

@@ -148,6 +159,7 @@ stats_clear_store(
{
int ret;
int val;
+ struct xstats *stats = to_xstats(kobject);

ret = kstrtoint(buf, 0, &val);
if (ret)
@@ -155,7 +167,8 @@ stats_clear_store(

if (val != 1)
return -EINVAL;
- xfs_stats_clearall();
+
+ xfs_stats_clearall(stats->xs_stats);
return count;
}
XFS_SYSFS_ATTR_WO(stats_clear);