NFSv4: Add tracepoints for debugging file locking

Set up basic tracepoints for debugging NFSv4 file lock/unlock

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

2 files changed, 82 insertions, 2 deletions

diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index d609198724ed..6d12c3eda17a 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -4964,8 +4964,9 @@ static int nfs4_proc_getlk(struct nfs4_state *state, int cmd, struct file_lock *
         int err;
 
         do {
-                err = nfs4_handle_exception(NFS_SERVER(state->inode),
-                                _nfs4_proc_getlk(state, cmd, request),
+                err = _nfs4_proc_getlk(state, cmd, request);
+                trace_nfs4_get_lock(request, state, cmd, err);
+                err = nfs4_handle_exception(NFS_SERVER(state->inode), err,
                                 &exception);
         } while (exception.retry);
         return err;
@@ -5163,6 +5164,7 @@ static int nfs4_proc_unlck(struct nfs4_state *state, int cmd, struct file_lock *
         rpc_put_task(task);
 out:
         request->fl_flags = fl_flags;
+        trace_nfs4_unlock(request, state, F_SETLK, status);
         return status;
 }
 
@@ -5386,6 +5388,7 @@ static int nfs4_lock_reclaim(struct nfs4_state *state, struct file_lock *request
                 if (test_bit(NFS_DELEGATED_STATE, &state->flags) != 0)
                         return 0;
                 err = _nfs4_do_setlk(state, F_SETLK, request, NFS_LOCK_RECLAIM);
+                trace_nfs4_lock_reclaim(request, state, F_SETLK, err);
                 if (err != -NFS4ERR_DELAY)
                         break;
                 nfs4_handle_exception(server, err, &exception);
@@ -5408,6 +5411,7 @@ static int nfs4_lock_expired(struct nfs4_state *state, struct file_lock *request
                 if (test_bit(NFS_DELEGATED_STATE, &state->flags) != 0)
                         return 0;
                 err = _nfs4_do_setlk(state, F_SETLK, request, NFS_LOCK_EXPIRED);
+                trace_nfs4_lock_expired(request, state, F_SETLK, err);
                 switch (err) {
                 default:
                         goto out;
@@ -5530,6 +5534,7 @@ static int nfs4_proc_setlk(struct nfs4_state *state, int cmd, struct file_lock *
 
         do {
                 err = _nfs4_proc_setlk(state, cmd, request);
+                trace_nfs4_set_lock(request, state, cmd, err);
                 if (err == -NFS4ERR_DENIED)
                         err = -EAGAIN;
                 err = nfs4_handle_exception(NFS_SERVER(state->inode),
diff --git a/fs/nfs/nfs4trace.h b/fs/nfs/nfs4trace.h
index a558dc9c7c52..3f124dbcd60a 100644
--- a/fs/nfs/nfs4trace.h
+++ b/fs/nfs/nfs4trace.h
@@ -336,6 +336,81 @@ TRACE_EVENT(nfs4_close,
                 )
 );
 
+#define show_lock_cmd(type) \
+        __print_symbolic((int)type, \
+                { F_GETLK, "GETLK" }, \
+                { F_SETLK, "SETLK" }, \
+                { F_SETLKW, "SETLKW" })
+#define show_lock_type(type) \
+        __print_symbolic((int)type, \
+                { F_RDLCK, "RDLCK" }, \
+                { F_WRLCK, "WRLCK" }, \
+                { F_UNLCK, "UNLCK" })
+
+DECLARE_EVENT_CLASS(nfs4_lock_event,
+                TP_PROTO(
+                        const struct file_lock *request,
+                        const struct nfs4_state *state,
+                        int cmd,
+                        int error
+                ),
+
+                TP_ARGS(request, state, cmd, error),
+
+                TP_STRUCT__entry(
+                        __field(int, error)
+                        __field(int, cmd)
+                        __field(char, type)
+                        __field(loff_t, start)
+                        __field(loff_t, end)
+                        __field(dev_t, dev)
+                        __field(u32, fhandle)
+                        __field(u64, fileid)
+                ),
+
+                TP_fast_assign(
+                        const struct inode *inode = state->inode;
+
+                        __entry->error = error;
+                        __entry->cmd = cmd;
+                        __entry->type = request->fl_type;
+                        __entry->start = request->fl_start;
+                        __entry->end = request->fl_end;
+                        __entry->dev = inode->i_sb->s_dev;
+                        __entry->fileid = NFS_FILEID(inode);
+                        __entry->fhandle = nfs_fhandle_hash(NFS_FH(inode));
+                ),
+
+                TP_printk(
+                        "error=%d (%s) cmd=%s:%s range=%lld:%lld "
+                        "fileid=%02x:%02x:%llu fhandle=0x%08x",
+                        __entry->error,
+                        show_nfsv4_errors(__entry->error),
+                        show_lock_cmd(__entry->cmd),
+                        show_lock_type(__entry->type),
+                        (long long)__entry->start,
+                        (long long)__entry->end,
+                        MAJOR(__entry->dev), MINOR(__entry->dev),
+                        (unsigned long long)__entry->fileid,
+                        __entry->fhandle
+                )
+);
+
+#define DEFINE_NFS4_LOCK_EVENT(name) \
+        DEFINE_EVENT(nfs4_lock_event, name, \
+                        TP_PROTO( \
+                                const struct file_lock *request, \
+                                const struct nfs4_state *state, \
+                                int cmd, \
+                                int error \
+                        ), \
+                        TP_ARGS(request, state, cmd, error))
+DEFINE_NFS4_LOCK_EVENT(nfs4_get_lock);
+DEFINE_NFS4_LOCK_EVENT(nfs4_set_lock);
+DEFINE_NFS4_LOCK_EVENT(nfs4_lock_reclaim);
+DEFINE_NFS4_LOCK_EVENT(nfs4_lock_expired);
+DEFINE_NFS4_LOCK_EVENT(nfs4_unlock);
+
 #endif /* _TRACE_NFS4_H */
 
 #undef TRACE_INCLUDE_PATH