fs: tracepoints around multigrain timestamp events

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>
Link: https://lore.kernel.org/r/20241002-mgtime-v10-6-d1c4717f5284@kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>

diff --git a/fs/inode.c b/fs/inode.c
index 7d1ede60e549683502911f3bb3a3a079768e449b..f7a25c511d6b7069fa235135cf3bad0cda32815b 100644 (file)
--- 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 dd480bf51a2a764e5eb1d0a213c5ec8b640db911..6eb6c39d003755f9e602996ed93dcbd863847820 100644 (file)
--- 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 (file)
index 0000000..c9e5ec9
--- /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>