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Subject: [PATCH v3 29/32] NFSD: Move nfsd_file_trace_alloc() tracepoint
From:   Chuck Lever <chuck.lever@oracle.com>
To:     linux-nfs@vger.kernel.org, netdev@vger.kernel.org
Cc:     david@fromorbit.com, jlayton@redhat.com, tgraf@suug.ch
Date:   Fri, 08 Jul 2022 14:26:49 -0400
Message-ID: <165730480977.28142.6276202322556034271.stgit@klimt.1015granger.net>
In-Reply-To: <165730437087.28142.6731645688073512500.stgit@klimt.1015granger.net>
References: <165730437087.28142.6731645688073512500.stgit@klimt.1015granger.net>
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Avoid recording the allocation of an nfsd_file item that is
immediately released because a matching item was already
inserted in the hash.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
---
 fs/nfsd/filecache.c |    2 +-
 fs/nfsd/trace.h     |   25 ++++++++++++++++++++++++-
 2 files changed, 25 insertions(+), 2 deletions(-)

diff --git a/fs/nfsd/filecache.c b/fs/nfsd/filecache.c
index 21bc7b9c25f3..a904364551e8 100644
--- a/fs/nfsd/filecache.c
+++ b/fs/nfsd/filecache.c
@@ -309,7 +309,6 @@ nfsd_file_alloc(struct nfsd_file_lookup_key *key, unsigned int may)
 				__set_bit(NFSD_FILE_BREAK_READ, &nf->nf_flags);
 		}
 		nf->nf_mark = NULL;
-		trace_nfsd_file_alloc(nf);
 	}
 	return nf;
 }
@@ -1146,6 +1145,7 @@ nfsd_file_do_acquire(struct svc_rqst *rqstp, struct svc_fh *fhp,
 	return status;
 
 open_file:
+	trace_nfsd_file_alloc(nf);
 	nf->nf_mark = nfsd_file_mark_find_or_create(nf);
 	if (nf->nf_mark) {
 		if (open) {
diff --git a/fs/nfsd/trace.h b/fs/nfsd/trace.h
index 1c4cf9d2dd8e..96bb6629541e 100644
--- a/fs/nfsd/trace.h
+++ b/fs/nfsd/trace.h
@@ -776,12 +776,35 @@ DEFINE_EVENT(nfsd_file_class, name, \
 	TP_PROTO(struct nfsd_file *nf), \
 	TP_ARGS(nf))
 
-DEFINE_NFSD_FILE_EVENT(nfsd_file_alloc);
 DEFINE_NFSD_FILE_EVENT(nfsd_file_put_final);
 DEFINE_NFSD_FILE_EVENT(nfsd_file_unhash);
 DEFINE_NFSD_FILE_EVENT(nfsd_file_put);
 DEFINE_NFSD_FILE_EVENT(nfsd_file_unhash_and_dispose);
 
+TRACE_EVENT(nfsd_file_alloc,
+	TP_PROTO(
+		const struct nfsd_file *nf
+	),
+	TP_ARGS(nf),
+	TP_STRUCT__entry(
+		__field(const void *, nf_inode)
+		__field(unsigned long, nf_flags)
+		__field(unsigned long, nf_may)
+		__field(unsigned int, nf_ref)
+	),
+	TP_fast_assign(
+		__entry->nf_inode = nf->nf_inode;
+		__entry->nf_flags = nf->nf_flags;
+		__entry->nf_ref = refcount_read(&nf->nf_ref);
+		__entry->nf_may = nf->nf_may;
+	),
+	TP_printk("inode=%p ref=%u flags=%s may=%s",
+		__entry->nf_inode, __entry->nf_ref,
+		show_nf_flags(__entry->nf_flags),
+		show_nfsd_may_flags(__entry->nf_may)
+	)
+);
+
 TRACE_EVENT(nfsd_file_acquire,
 	TP_PROTO(
 		const struct svc_rqst *rqstp,