NFSv4.2: Add tracepoints for getxattr, setxattr, and removexattr

These functions take similar arguments, and can share a tracepoint class
for common formatting.
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

fs/nfs/nfs42proc.c

@@ -1175,6 +1175,7 @@ static int _nfs42_proc_removexattr(struct inode *inode, const char *name)
 
 	ret = nfs4_call_sync(server->client, server, &msg, &args.seq_args,
 	    &res.seq_res, 1);
+	trace_nfs4_removexattr(inode, name, ret);
 	if (!ret)
 		nfs4_update_changeattr(inode, &res.cinfo, timestamp, 0);
 
@@ -1214,6 +1215,7 @@ static int _nfs42_proc_setxattr(struct inode *inode, const char *name,
 
 	ret = nfs4_call_sync(server->client, server, &msg, &arg.seq_args,
 	    &res.seq_res, 1);
+	trace_nfs4_setxattr(inode, name, ret);
 
 	for (; np > 0; np--)
 		put_page(pages[np - 1]);
@@ -1246,6 +1248,7 @@ static ssize_t _nfs42_proc_getxattr(struct inode *inode, const char *name,
 
 	ret = nfs4_call_sync(server->client, server, &msg, &arg.seq_args,
 	    &res.seq_res, 0);
+	trace_nfs4_getxattr(inode, name, ret);
 	if (ret < 0)
 		return ret;
 

fs/nfs/nfs4trace.h

@@ -2496,6 +2496,52 @@ TRACE_EVENT(nfs4_offload_cancel,
 			__entry->stateid_seq, __entry->stateid_hash
 		)
 );
+
+DECLARE_EVENT_CLASS(nfs4_xattr_event,
+		TP_PROTO(
+			const struct inode *inode,
+			const char *name,
+			int error
+		),
+
+		TP_ARGS(inode, name, error),
+
+		TP_STRUCT__entry(
+			__field(unsigned long, error)
+			__field(dev_t, dev)
+			__field(u32, fhandle)
+			__field(u64, fileid)
+			__string(name, name)
+		),
+
+		TP_fast_assign(
+			__entry->error = error < 0 ? -error : 0;
+			__entry->dev = inode->i_sb->s_dev;
+			__entry->fileid = NFS_FILEID(inode);
+			__entry->fhandle = nfs_fhandle_hash(NFS_FH(inode));
+			__assign_str(name, name);
+		),
+
+		TP_printk(
+			"error=%ld (%s) fileid=%02x:%02x:%llu fhandle=0x%08x "
+			"name=%s",
+			-__entry->error, show_nfs4_status(__entry->error),
+			MAJOR(__entry->dev), MINOR(__entry->dev),
+			(unsigned long long)__entry->fileid,
+			__entry->fhandle, __get_str(name)
+		)
+);
+#define DEFINE_NFS4_XATTR_EVENT(name) \
+	DEFINE_EVENT(nfs4_xattr_event, name,  \
+			TP_PROTO( \
+				const struct inode *inode, \
+				const char *name, \
+				int error \
+			), \
+			TP_ARGS(inode, name, error))
+DEFINE_NFS4_XATTR_EVENT(nfs4_getxattr);
+DEFINE_NFS4_XATTR_EVENT(nfs4_setxattr);
+DEFINE_NFS4_XATTR_EVENT(nfs4_removexattr);
 #endif /* CONFIG_NFS_V4_2 */
 
 #endif /* CONFIG_NFS_V4_1 */