Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/drivers/md/md.h b/drivers/md/md.h
index 8afd6bf..c5e3ff3 100644
--- a/drivers/md/md.h
+++ b/drivers/md/md.h
@@ -1,15 +1,8 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
 /*
    md.h : kernel internal structure of the Linux MD driver
           Copyright (C) 1996-98 Ingo Molnar, Gadi Oxman
 
-   This program is free software; you can redistribute it and/or modify
-   it under the terms of the GNU General Public License as published by
-   the Free Software Foundation; either version 2, or (at your option)
-   any later version.
-
-   You should have received a copy of the GNU General Public License
-   (for example /usr/src/linux/COPYING); if not, write to the Free
-   Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */
 
 #ifndef _MD_MD_H
@@ -116,6 +109,14 @@
 					   * for reporting to userspace and storing
 					   * in superblock.
 					   */
+
+	/*
+	 * The members for check collision of write behind IOs.
+	 */
+	struct list_head wb_list;
+	spinlock_t wb_list_lock;
+	wait_queue_head_t wb_io_wait;
+
 	struct work_struct del_work;	/* used for delayed sysfs removal */
 
 	struct kernfs_node *sysfs_state; /* handle for 'state'
@@ -200,6 +201,10 @@
 				 * it didn't fail, so don't use FailFast
 				 * any more for metadata
 				 */
+	WBCollisionCheck,	/*
+				 * multiqueue device should check if there
+				 * is collision between write behind bios.
+				 */
 };
 
 static inline int is_badblock(struct md_rdev *rdev, sector_t s, int sectors,
@@ -243,6 +248,12 @@
 	MD_UPDATING_SB,		/* md_check_recovery is updating the metadata
 				 * without explicitly holding reconfig_mutex.
 				 */
+	MD_NOT_READY,		/* do_md_run() is active, so 'array_state'
+				 * must not report that array is ready yet
+				 */
+	MD_BROKEN,              /* This is used in RAID-0/LINEAR only, to stop
+				 * I/O in case an array member is gone/failed.
+				 */
 };
 
 enum mddev_sb_flags {
@@ -252,17 +263,12 @@
 	MD_SB_NEED_REWRITE,	/* metadata write needs to be repeated */
 };
 
-#define NR_FLUSH_INFOS 8
-#define NR_FLUSH_BIOS 64
-struct flush_info {
-	struct bio			*bio;
-	struct mddev			*mddev;
-	struct work_struct		flush_work;
-	atomic_t			flush_pending;
-};
-struct flush_bio {
-	struct flush_info *fi;
-	struct md_rdev *rdev;
+#define NR_WB_INFOS	8
+/* record current range of write behind IOs */
+struct wb_info {
+	sector_t lo;
+	sector_t hi;
+	struct list_head list;
 };
 
 struct mddev {
@@ -470,14 +476,24 @@
 						   * metadata and bitmap writes
 						   */
 
-	mempool_t			*flush_pool;
-	mempool_t			*flush_bio_pool;
+	/* Generic flush handling.
+	 * The last to finish preflush schedules a worker to submit
+	 * the rest of the request (without the REQ_PREFLUSH flag).
+	 */
+	struct bio *flush_bio;
+	atomic_t flush_pending;
+	ktime_t start_flush, last_flush; /* last_flush is when the last completed
+					  * flush was started.
+					  */
+	struct work_struct flush_work;
 	struct work_struct event_work;	/* used by dm to report failure event */
+	mempool_t *wb_info_pool;
 	void (*sync_super)(struct mddev *mddev, struct md_rdev *rdev);
 	struct md_cluster_info		*cluster_info;
 	unsigned int			good_device_nr;	/* good device num within cluster raid */
 
 	bool	has_superblocks:1;
+	bool	fail_last_dev:1;
 };
 
 enum recovery_flags {
@@ -557,6 +573,7 @@
 	int (*check_reshape) (struct mddev *mddev);
 	int (*start_reshape) (struct mddev *mddev);
 	void (*finish_reshape) (struct mddev *mddev);
+	void (*update_reshape_pos) (struct mddev *mddev);
 	/* quiesce suspends or resumes internal processing.
 	 * 1 - stop new actions and wait for action io to complete
 	 * 0 - return to normal behaviour
@@ -720,9 +737,24 @@
 extern void md_reload_sb(struct mddev *mddev, int raid_disk);
 extern void md_update_sb(struct mddev *mddev, int force);
 extern void md_kick_rdev_from_array(struct md_rdev * rdev);
+extern void mddev_create_wb_pool(struct mddev *mddev, struct md_rdev *rdev,
+				 bool is_suspend);
 struct md_rdev *md_find_rdev_nr_rcu(struct mddev *mddev, int nr);
 struct md_rdev *md_find_rdev_rcu(struct mddev *mddev, dev_t dev);
 
+static inline bool is_mddev_broken(struct md_rdev *rdev, const char *md_type)
+{
+	int flags = rdev->bdev->bd_disk->flags;
+
+	if (!(flags & GENHD_FL_UP)) {
+		if (!test_and_set_bit(MD_BROKEN, &rdev->mddev->flags))
+			pr_warn("md: %s: %s array has a missing/failed member\n",
+				mdname(rdev->mddev), md_type);
+		return true;
+	}
+	return false;
+}
+
 static inline void rdev_dec_pending(struct md_rdev *rdev, struct mddev *mddev)
 {
 	int faulty = test_bit(Faulty, &rdev->flags);