v4.19.13 snapshot.
diff --git a/fs/xfs/xfs_log.h b/fs/xfs/xfs_log.h
new file mode 100644
index 0000000..73a64bf
--- /dev/null
+++ b/fs/xfs/xfs_log.h
@@ -0,0 +1,158 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2000-2003,2005 Silicon Graphics, Inc.
+ * All Rights Reserved.
+ */
+#ifndef	__XFS_LOG_H__
+#define __XFS_LOG_H__
+
+struct xfs_log_vec {
+	struct xfs_log_vec	*lv_next;	/* next lv in build list */
+	int			lv_niovecs;	/* number of iovecs in lv */
+	struct xfs_log_iovec	*lv_iovecp;	/* iovec array */
+	struct xfs_log_item	*lv_item;	/* owner */
+	char			*lv_buf;	/* formatted buffer */
+	int			lv_bytes;	/* accounted space in buffer */
+	int			lv_buf_len;	/* aligned size of buffer */
+	int			lv_size;	/* size of allocated lv */
+};
+
+#define XFS_LOG_VEC_ORDERED	(-1)
+
+static inline void *
+xlog_prepare_iovec(struct xfs_log_vec *lv, struct xfs_log_iovec **vecp,
+		uint type)
+{
+	struct xfs_log_iovec *vec = *vecp;
+
+	if (vec) {
+		ASSERT(vec - lv->lv_iovecp < lv->lv_niovecs);
+		vec++;
+	} else {
+		vec = &lv->lv_iovecp[0];
+	}
+
+	vec->i_type = type;
+	vec->i_addr = lv->lv_buf + lv->lv_buf_len;
+
+	ASSERT(IS_ALIGNED((unsigned long)vec->i_addr, sizeof(uint64_t)));
+
+	*vecp = vec;
+	return vec->i_addr;
+}
+
+/*
+ * We need to make sure the next buffer is naturally aligned for the biggest
+ * basic data type we put into it.  We already accounted for this padding when
+ * sizing the buffer.
+ *
+ * However, this padding does not get written into the log, and hence we have to
+ * track the space used by the log vectors separately to prevent log space hangs
+ * due to inaccurate accounting (i.e. a leak) of the used log space through the
+ * CIL context ticket.
+ */
+static inline void
+xlog_finish_iovec(struct xfs_log_vec *lv, struct xfs_log_iovec *vec, int len)
+{
+	lv->lv_buf_len += round_up(len, sizeof(uint64_t));
+	lv->lv_bytes += len;
+	vec->i_len = len;
+}
+
+static inline void *
+xlog_copy_iovec(struct xfs_log_vec *lv, struct xfs_log_iovec **vecp,
+		uint type, void *data, int len)
+{
+	void *buf;
+
+	buf = xlog_prepare_iovec(lv, vecp, type);
+	memcpy(buf, data, len);
+	xlog_finish_iovec(lv, *vecp, len);
+	return buf;
+}
+
+/*
+ * Structure used to pass callback function and the function's argument
+ * to the log manager.
+ */
+typedef struct xfs_log_callback {
+	struct xfs_log_callback	*cb_next;
+	void			(*cb_func)(void *, int);
+	void			*cb_arg;
+} xfs_log_callback_t;
+
+/*
+ * By comparing each component, we don't have to worry about extra
+ * endian issues in treating two 32 bit numbers as one 64 bit number
+ */
+static inline xfs_lsn_t	_lsn_cmp(xfs_lsn_t lsn1, xfs_lsn_t lsn2)
+{
+	if (CYCLE_LSN(lsn1) != CYCLE_LSN(lsn2))
+		return (CYCLE_LSN(lsn1)<CYCLE_LSN(lsn2))? -999 : 999;
+
+	if (BLOCK_LSN(lsn1) != BLOCK_LSN(lsn2))
+		return (BLOCK_LSN(lsn1)<BLOCK_LSN(lsn2))? -999 : 999;
+
+	return 0;
+}
+
+#define	XFS_LSN_CMP(x,y) _lsn_cmp(x,y)
+
+/*
+ * Flags to xfs_log_force()
+ *
+ *	XFS_LOG_SYNC:	Synchronous force in-core log to disk
+ */
+#define XFS_LOG_SYNC		0x1
+
+/* Log manager interfaces */
+struct xfs_mount;
+struct xlog_in_core;
+struct xlog_ticket;
+struct xfs_log_item;
+struct xfs_item_ops;
+struct xfs_trans;
+
+xfs_lsn_t xfs_log_done(struct xfs_mount *mp,
+		       struct xlog_ticket *ticket,
+		       struct xlog_in_core **iclog,
+		       bool regrant);
+int	  xfs_log_force(struct xfs_mount *mp, uint flags);
+int	  xfs_log_force_lsn(struct xfs_mount *mp, xfs_lsn_t lsn, uint flags,
+		int *log_forced);
+int	  xfs_log_mount(struct xfs_mount	*mp,
+			struct xfs_buftarg	*log_target,
+			xfs_daddr_t		start_block,
+			int		 	num_bblocks);
+int	  xfs_log_mount_finish(struct xfs_mount *mp);
+int	xfs_log_mount_cancel(struct xfs_mount *);
+xfs_lsn_t xlog_assign_tail_lsn(struct xfs_mount *mp);
+xfs_lsn_t xlog_assign_tail_lsn_locked(struct xfs_mount *mp);
+void	  xfs_log_space_wake(struct xfs_mount *mp);
+int	  xfs_log_notify(struct xlog_in_core	*iclog,
+			 struct xfs_log_callback *callback_entry);
+int	  xfs_log_release_iclog(struct xfs_mount *mp,
+			 struct xlog_in_core	 *iclog);
+int	  xfs_log_reserve(struct xfs_mount *mp,
+			  int		   length,
+			  int		   count,
+			  struct xlog_ticket **ticket,
+			  uint8_t		   clientid,
+			  bool		   permanent);
+int	  xfs_log_regrant(struct xfs_mount *mp, struct xlog_ticket *tic);
+void      xfs_log_unmount(struct xfs_mount *mp);
+int	  xfs_log_force_umount(struct xfs_mount *mp, int logerror);
+
+struct xlog_ticket *xfs_log_ticket_get(struct xlog_ticket *ticket);
+void	  xfs_log_ticket_put(struct xlog_ticket *ticket);
+
+void	xfs_log_commit_cil(struct xfs_mount *mp, struct xfs_trans *tp,
+				xfs_lsn_t *commit_lsn, bool regrant);
+bool	xfs_log_item_in_current_chkpt(struct xfs_log_item *lip);
+
+void	xfs_log_work_queue(struct xfs_mount *mp);
+void	xfs_log_quiesce(struct xfs_mount *mp);
+bool	xfs_log_check_lsn(struct xfs_mount *, xfs_lsn_t);
+bool	xfs_log_in_recovery(struct xfs_mount *);
+
+#endif	/* __XFS_LOG_H__ */