[PATCH v9 05/12] fs: tracepoints around multigrain timestamp events

Jeff Layton
2024-10-02T18:50:06Z

Add some tracepoints around various multigrain timestamp events.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Tested-by: Randy Dunlap <rdunlap@infradead.org> # documentation bits
Signed-off-by: Jeff Layton <jlayton@kernel.org>
---
fs/inode.c | 9 ++-
fs/stat.c | 3 +
include/trace/events/timestamp.h | 124 +++++++++++++++++++++++++++++++++++++++
3 files changed, 135 insertions(+), 1 deletion(-)

diff --git a/fs/inode.c b/fs/inode.c
index 7d1ede60e549..f7a25c511d6b 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -22,6 +22,9 @@
#include <linux/iversion.h>
#include <linux/rw_hint.h>
#include <trace/events/writeback.h>
+#define CREATE_TRACE_POINTS
+#include <trace/events/timestamp.h>
+
#include "internal.h"

/*
@@ -2603,6 +2606,7 @@ EXPORT_SYMBOL(inode_nohighmem);

struct timespec64 inode_set_ctime_to_ts(struct inode *inode, struct timespec64 ts)
{
+ trace_inode_set_ctime_to_ts(inode, &ts);
set_normalized_timespec64(&ts, ts.tv_sec, ts.tv_nsec);
inode->i_ctime_sec = ts.tv_sec;
inode->i_ctime_nsec = ts.tv_nsec;
@@ -2689,14 +2693,17 @@ struct timespec64 inode_set_ctime_current(struct inode *inode)
}

/* No need to cmpxchg if it's exactly the same */
- if (cns == now.tv_nsec && inode->i_ctime_sec == now.tv_sec)
+ if (cns == now.tv_nsec && inode->i_ctime_sec == now.tv_sec) {
+ trace_ctime_xchg_skip(inode, &now);
goto out;
+ }
cur = cns;
retry:
/* Try to swap the nsec value into place. */
if (try_cmpxchg(&inode->i_ctime_nsec, &cur, now.tv_nsec)) {
/* If swap occurred, then we're (mostly) done */
inode->i_ctime_sec = now.tv_sec;
+ trace_ctime_ns_xchg(inode, cns, now.tv_nsec, cur);
} else {
/*
* Was the change due to someone marking the old ctime QUERIED?
diff --git a/fs/stat.c b/fs/stat.c
index dd480bf51a2a..6eb6c39d0037 100644
--- a/fs/stat.c
+++ b/fs/stat.c
@@ -23,6 +23,8 @@
#include <linux/uaccess.h>
#include <asm/unistd.h>

+#include <trace/events/timestamp.h>
+
#include "internal.h"
#include "mount.h"

@@ -56,6 +58,7 @@ void fill_mg_cmtime(struct kstat *stat, u32 request_mask, struct inode *inode)
if (!(stat->ctime.tv_nsec & I_CTIME_QUERIED))
stat->ctime.tv_nsec = ((u32)atomic_fetch_or(I_CTIME_QUERIED, pcn));
stat->ctime.tv_nsec &= ~I_CTIME_QUERIED;
+ trace_fill_mg_cmtime(inode, &stat->ctime, &stat->mtime);
}
EXPORT_SYMBOL(fill_mg_cmtime);

diff --git a/include/trace/events/timestamp.h b/include/trace/events/timestamp.h
new file mode 100644
index 000000000000..c9e5ec930054
--- /dev/null
+++ b/include/trace/events/timestamp.h
@@ -0,0 +1,124 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM timestamp
+
+#if !defined(_TRACE_TIMESTAMP_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_TIMESTAMP_H
+
+#include <linux/tracepoint.h>
+#include <linux/fs.h>
+
+#define CTIME_QUERIED_FLAGS \
+ { I_CTIME_QUERIED, "Q" }
+
+DECLARE_EVENT_CLASS(ctime,
+ TP_PROTO(struct inode *inode,
+ struct timespec64 *ctime),
+
+ TP_ARGS(inode, ctime),
+
+ TP_STRUCT__entry(
+ __field(dev_t, dev)
+ __field(ino_t, ino)
+ __field(time64_t, ctime_s)
+ __field(u32, ctime_ns)
+ __field(u32, gen)
+ ),
+
+ TP_fast_assign(
+ __entry->dev = inode->i_sb->s_dev;
+ __entry->ino = inode->i_ino;
+ __entry->gen = inode->i_generation;
+ __entry->ctime_s = ctime->tv_sec;
+ __entry->ctime_ns = ctime->tv_nsec;
+ ),
+
+ TP_printk("ino=%d:%d:%ld:%u ctime=%lld.%u",
+ MAJOR(__entry->dev), MINOR(__entry->dev), __entry->ino, __entry->gen,
+ __entry->ctime_s, __entry->ctime_ns
+ )
+);
+
+DEFINE_EVENT(ctime, inode_set_ctime_to_ts,
+ TP_PROTO(struct inode *inode,
+ struct timespec64 *ctime),
+ TP_ARGS(inode, ctime));
+
+DEFINE_EVENT(ctime, ctime_xchg_skip,
+ TP_PROTO(struct inode *inode,
+ struct timespec64 *ctime),
+ TP_ARGS(inode, ctime));
+
+TRACE_EVENT(ctime_ns_xchg,
+ TP_PROTO(struct inode *inode,
+ u32 old,
+ u32 new,
+ u32 cur),
+
+ TP_ARGS(inode, old, new, cur),
+
+ TP_STRUCT__entry(
+ __field(dev_t, dev)
+ __field(ino_t, ino)
+ __field(u32, gen)
+ __field(u32, old)
+ __field(u32, new)
+ __field(u32, cur)
+ ),
+
+ TP_fast_assign(
+ __entry->dev = inode->i_sb->s_dev;
+ __entry->ino = inode->i_ino;
+ __entry->gen = inode->i_generation;
+ __entry->old = old;
+ __entry->new = new;
+ __entry->cur = cur;
+ ),
+
+ TP_printk("ino=%d:%d:%ld:%u old=%u:%s new=%u cur=%u:%s",
+ MAJOR(__entry->dev), MINOR(__entry->dev), __entry->ino, __entry->gen,
+ __entry->old & ~I_CTIME_QUERIED,
+ __print_flags(__entry->old & I_CTIME_QUERIED, "|", CTIME_QUERIED_FLAGS),
+ __entry->new,
+ __entry->cur & ~I_CTIME_QUERIED,
+ __print_flags(__entry->cur & I_CTIME_QUERIED, "|", CTIME_QUERIED_FLAGS)
+ )
+);
+
+TRACE_EVENT(fill_mg_cmtime,
+ TP_PROTO(struct inode *inode,
+ struct timespec64 *ctime,
+ struct timespec64 *mtime),
+
+ TP_ARGS(inode, ctime, mtime),
+
+ TP_STRUCT__entry(
+ __field(dev_t, dev)
+ __field(ino_t, ino)
+ __field(time64_t, ctime_s)
+ __field(time64_t, mtime_s)
+ __field(u32, ctime_ns)
+ __field(u32, mtime_ns)
+ __field(u32, gen)
+ ),
+
+ TP_fast_assign(
+ __entry->dev = inode->i_sb->s_dev;
+ __entry->ino = inode->i_ino;
+ __entry->gen = inode->i_generation;
+ __entry->ctime_s = ctime->tv_sec;
+ __entry->mtime_s = mtime->tv_sec;
+ __entry->ctime_ns = ctime->tv_nsec;
+ __entry->mtime_ns = mtime->tv_nsec;
+ ),
+
+ TP_printk("ino=%d:%d:%ld:%u ctime=%lld.%u mtime=%lld.%u",
+ MAJOR(__entry->dev), MINOR(__entry->dev), __entry->ino, __entry->gen,
+ __entry->ctime_s, __entry->ctime_ns,
+ __entry->mtime_s, __entry->mtime_ns
+ )
+);
+#endif /* _TRACE_TIMESTAMP_H */
+
+/* This part must be outside protection */
+#include <trace/define_trace.h>

--
2.46.2