[PATCH 0/3] md: Remove deprecated flavors

[PATCH 0/3] md: Remove deprecated flavors

[Song Liu]

Linear, multipath, and faulty have been marked as deprecated for 2.5 years.
Let's remove them.

Thanks,
Song

Song Liu (3):
  md: Remove deprecated CONFIG_MD_LINEAR
  md: Remove deprecated CONFIG_MD_MULTIPATH
  md: Remove deprecated CONFIG_MD_FAULTY

 drivers/md/Kconfig             |  34 ---
 drivers/md/Makefile            |  10 +-
 drivers/md/md-autodetect.c     |   8 +-
 drivers/md/md-faulty.c         | 365 --------------------------
 drivers/md/md-linear.c         | 318 ----------------------
 drivers/md/md-multipath.c      | 463 ---------------------------------
 drivers/md/md.c                | 186 ++++++-------
 include/uapi/linux/raid/md_p.h |   8 +-
 include/uapi/linux/raid/md_u.h |  11 +-
 9 files changed, 91 insertions(+), 1312 deletions(-)
 delete mode 100644 drivers/md/md-faulty.c
 delete mode 100644 drivers/md/md-linear.c
 delete mode 100644 drivers/md/md-multipath.c

--
2.34.1

[PATCH 1/3] md: Remove deprecated CONFIG_MD_LINEAR

[Song Liu]

md-linear has been marked as deprecated for 2.5 years. Remove it.

Cc: Christoph Hellwig <hch@lst.de>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Neil Brown <neilb@suse.de>
Cc: Guoqing Jiang <guoqing.jiang@linux.dev>
Cc: Mateusz Grzonka <mateusz.grzonka@intel.com>
Cc: Jes Sorensen <jes@trained-monkey.org>
Signed-off-by: Song Liu <song@kernel.org>
---
 drivers/md/Kconfig             |  13 --
 drivers/md/Makefile            |   6 +-
 drivers/md/md-autodetect.c     |   8 +-
 drivers/md/md-linear.c         | 318 ---------------------------------
 drivers/md/md.c                |   2 +-
 include/uapi/linux/raid/md_p.h |   8 +-
 include/uapi/linux/raid/md_u.h |   7 +-
 7 files changed, 8 insertions(+), 354 deletions(-)
 delete mode 100644 drivers/md/md-linear.c

diff --git a/drivers/md/Kconfig b/drivers/md/Kconfig
index 2a8b081bce7d..0c721e0e5921 100644
--- a/drivers/md/Kconfig
+++ b/drivers/md/Kconfig
@@ -61,19 +61,6 @@ config MD_BITMAP_FILE
 	  various kernel APIs and can only work with files on a file system not
 	  actually sitting on the MD device.
 
-config MD_LINEAR
-	tristate "Linear (append) mode (deprecated)"
-	depends on BLK_DEV_MD
-	help
-	  If you say Y here, then your multiple devices driver will be able to
-	  use the so-called linear mode, i.e. it will combine the hard disk
-	  partitions by simply appending one to the other.
-
-	  To compile this as a module, choose M here: the module
-	  will be called linear.
-
-	  If unsure, say Y.
-
 config MD_RAID0
 	tristate "RAID-0 (striping) mode"
 	depends on BLK_DEV_MD
diff --git a/drivers/md/Makefile b/drivers/md/Makefile
index 84291e38dca8..c72f76cf7b63 100644
--- a/drivers/md/Makefile
+++ b/drivers/md/Makefile
@@ -29,16 +29,14 @@ dm-zoned-y	+= dm-zoned-target.o dm-zoned-metadata.o dm-zoned-reclaim.o
 
 md-mod-y	+= md.o md-bitmap.o
 raid456-y	+= raid5.o raid5-cache.o raid5-ppl.o
-linear-y	+= md-linear.o
 multipath-y	+= md-multipath.o
 faulty-y	+= md-faulty.o
 
 # Note: link order is important.  All raid personalities
-# and must come before md.o, as they each initialise 
-# themselves, and md.o may use the personalities when it 
+# and must come before md.o, as they each initialise
+# themselves, and md.o may use the personalities when it
 # auto-initialised.
 
-obj-$(CONFIG_MD_LINEAR)		+= linear.o
 obj-$(CONFIG_MD_RAID0)		+= raid0.o
 obj-$(CONFIG_MD_RAID1)		+= raid1.o
 obj-$(CONFIG_MD_RAID10)		+= raid10.o
diff --git a/drivers/md/md-autodetect.c b/drivers/md/md-autodetect.c
index 4b80165afd23..b2a00f213c2c 100644
--- a/drivers/md/md-autodetect.c
+++ b/drivers/md/md-autodetect.c
@@ -49,7 +49,6 @@ static int md_setup_ents __initdata;
  *             instead of just one.  -- KTK
  * 18May2000: Added support for persistent-superblock arrays:
  *             md=n,0,factor,fault,device-list   uses RAID0 for device n
- *             md=n,-1,factor,fault,device-list  uses LINEAR for device n
  *             md=n,device-list      reads a RAID superblock from the devices
  *             elements in device-list are read by name_to_kdev_t so can be
  *             a hex number or something like /dev/hda1 /dev/sdb
@@ -88,7 +87,7 @@ static int __init md_setup(char *str)
 		md_setup_ents++;
 	switch (get_option(&str, &level)) {	/* RAID level */
 	case 2: /* could be 0 or -1.. */
-		if (level == 0 || level == LEVEL_LINEAR) {
+		if (level == 0) {
 			if (get_option(&str, &factor) != 2 ||	/* Chunk Size */
 					get_option(&str, &fault) != 2) {
 				printk(KERN_WARNING "md: Too few arguments supplied to md=.\n");
@@ -96,10 +95,7 @@ static int __init md_setup(char *str)
 			}
 			md_setup_args[ent].level = level;
 			md_setup_args[ent].chunk = 1 << (factor+12);
-			if (level ==  LEVEL_LINEAR)
-				pername = "linear";
-			else
-				pername = "raid0";
+			pername = "raid0";
 			break;
 		}
 		fallthrough;
diff --git a/drivers/md/md-linear.c b/drivers/md/md-linear.c
deleted file mode 100644
index 8eca7693b793..000000000000
--- a/drivers/md/md-linear.c
+++ /dev/null
@@ -1,318 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0-or-later
-/*
-   linear.c : Multiple Devices driver for Linux
-	      Copyright (C) 1994-96 Marc ZYNGIER
-	      <zyngier@ufr-info-p7.ibp.fr> or
-	      <maz@gloups.fdn.fr>
-
-   Linear mode management functions.
-
-*/
-
-#include <linux/blkdev.h>
-#include <linux/raid/md_u.h>
-#include <linux/seq_file.h>
-#include <linux/module.h>
-#include <linux/slab.h>
-#include <trace/events/block.h>
-#include "md.h"
-#include "md-linear.h"
-
-/*
- * find which device holds a particular offset
- */
-static inline struct dev_info *which_dev(struct mddev *mddev, sector_t sector)
-{
-	int lo, mid, hi;
-	struct linear_conf *conf;
-
-	lo = 0;
-	hi = mddev->raid_disks - 1;
-	conf = mddev->private;
-
-	/*
-	 * Binary Search
-	 */
-
-	while (hi > lo) {
-
-		mid = (hi + lo) / 2;
-		if (sector < conf->disks[mid].end_sector)
-			hi = mid;
-		else
-			lo = mid + 1;
-	}
-
-	return conf->disks + lo;
-}
-
-static sector_t linear_size(struct mddev *mddev, sector_t sectors, int raid_disks)
-{
-	struct linear_conf *conf;
-	sector_t array_sectors;
-
-	conf = mddev->private;
-	WARN_ONCE(sectors || raid_disks,
-		  "%s does not support generic reshape\n", __func__);
-	array_sectors = conf->array_sectors;
-
-	return array_sectors;
-}
-
-static struct linear_conf *linear_conf(struct mddev *mddev, int raid_disks)
-{
-	struct linear_conf *conf;
-	struct md_rdev *rdev;
-	int i, cnt;
-
-	conf = kzalloc(struct_size(conf, disks, raid_disks), GFP_KERNEL);
-	if (!conf)
-		return NULL;
-
-	/*
-	 * conf->raid_disks is copy of mddev->raid_disks. The reason to
-	 * keep a copy of mddev->raid_disks in struct linear_conf is,
-	 * mddev->raid_disks may not be consistent with pointers number of
-	 * conf->disks[] when it is updated in linear_add() and used to
-	 * iterate old conf->disks[] earray in linear_congested().
-	 * Here conf->raid_disks is always consitent with number of
-	 * pointers in conf->disks[] array, and mddev->private is updated
-	 * with rcu_assign_pointer() in linear_addr(), such race can be
-	 * avoided.
-	 */
-	conf->raid_disks = raid_disks;
-
-	cnt = 0;
-	conf->array_sectors = 0;
-
-	rdev_for_each(rdev, mddev) {
-		int j = rdev->raid_disk;
-		struct dev_info *disk = conf->disks + j;
-		sector_t sectors;
-
-		if (j < 0 || j >= raid_disks || disk->rdev) {
-			pr_warn("md/linear:%s: disk numbering problem. Aborting!\n",
-				mdname(mddev));
-			goto out;
-		}
-
-		disk->rdev = rdev;
-		if (mddev->chunk_sectors) {
-			sectors = rdev->sectors;
-			sector_div(sectors, mddev->chunk_sectors);
-			rdev->sectors = sectors * mddev->chunk_sectors;
-		}
-
-		disk_stack_limits(mddev->gendisk, rdev->bdev,
-				  rdev->data_offset << 9);
-
-		conf->array_sectors += rdev->sectors;
-		cnt++;
-	}
-	if (cnt != raid_disks) {
-		pr_warn("md/linear:%s: not enough drives present. Aborting!\n",
-			mdname(mddev));
-		goto out;
-	}
-
-	/*
-	 * Here we calculate the device offsets.
-	 */
-	conf->disks[0].end_sector = conf->disks[0].rdev->sectors;
-
-	for (i = 1; i < raid_disks; i++)
-		conf->disks[i].end_sector =
-			conf->disks[i-1].end_sector +
-			conf->disks[i].rdev->sectors;
-
-	return conf;
-
-out:
-	kfree(conf);
-	return NULL;
-}
-
-static int linear_run (struct mddev *mddev)
-{
-	struct linear_conf *conf;
-	int ret;
-
-	if (md_check_no_bitmap(mddev))
-		return -EINVAL;
-	conf = linear_conf(mddev, mddev->raid_disks);
-
-	if (!conf)
-		return 1;
-	mddev->private = conf;
-	md_set_array_sectors(mddev, linear_size(mddev, 0, 0));
-
-	ret =  md_integrity_register(mddev);
-	if (ret) {
-		kfree(conf);
-		mddev->private = NULL;
-	}
-	return ret;
-}
-
-static int linear_add(struct mddev *mddev, struct md_rdev *rdev)
-{
-	/* Adding a drive to a linear array allows the array to grow.
-	 * It is permitted if the new drive has a matching superblock
-	 * already on it, with raid_disk equal to raid_disks.
-	 * It is achieved by creating a new linear_private_data structure
-	 * and swapping it in in-place of the current one.
-	 * The current one is never freed until the array is stopped.
-	 * This avoids races.
-	 */
-	struct linear_conf *newconf, *oldconf;
-
-	if (rdev->saved_raid_disk != mddev->raid_disks)
-		return -EINVAL;
-
-	rdev->raid_disk = rdev->saved_raid_disk;
-	rdev->saved_raid_disk = -1;
-
-	newconf = linear_conf(mddev,mddev->raid_disks+1);
-
-	if (!newconf)
-		return -ENOMEM;
-
-	/* newconf->raid_disks already keeps a copy of * the increased
-	 * value of mddev->raid_disks, WARN_ONCE() is just used to make
-	 * sure of this. It is possible that oldconf is still referenced
-	 * in linear_congested(), therefore kfree_rcu() is used to free
-	 * oldconf until no one uses it anymore.
-	 */
-	oldconf = rcu_dereference_protected(mddev->private,
-			lockdep_is_held(&mddev->reconfig_mutex));
-	mddev->raid_disks++;
-	WARN_ONCE(mddev->raid_disks != newconf->raid_disks,
-		"copied raid_disks doesn't match mddev->raid_disks");
-	rcu_assign_pointer(mddev->private, newconf);
-	md_set_array_sectors(mddev, linear_size(mddev, 0, 0));
-	set_capacity_and_notify(mddev->gendisk, mddev->array_sectors);
-	kfree_rcu(oldconf, rcu);
-	return 0;
-}
-
-static void linear_free(struct mddev *mddev, void *priv)
-{
-	struct linear_conf *conf = priv;
-
-	kfree(conf);
-}
-
-static bool linear_make_request(struct mddev *mddev, struct bio *bio)
-{
-	struct dev_info *tmp_dev;
-	sector_t start_sector, end_sector, data_offset;
-	sector_t bio_sector = bio->bi_iter.bi_sector;
-
-	if (unlikely(bio->bi_opf & REQ_PREFLUSH)
-	    && md_flush_request(mddev, bio))
-		return true;
-
-	tmp_dev = which_dev(mddev, bio_sector);
-	start_sector = tmp_dev->end_sector - tmp_dev->rdev->sectors;
-	end_sector = tmp_dev->end_sector;
-	data_offset = tmp_dev->rdev->data_offset;
-
-	if (unlikely(bio_sector >= end_sector ||
-		     bio_sector < start_sector))
-		goto out_of_bounds;
-
-	if (unlikely(is_rdev_broken(tmp_dev->rdev))) {
-		md_error(mddev, tmp_dev->rdev);
-		bio_io_error(bio);
-		return true;
-	}
-
-	if (unlikely(bio_end_sector(bio) > end_sector)) {
-		/* This bio crosses a device boundary, so we have to split it */
-		struct bio *split = bio_split(bio, end_sector - bio_sector,
-					      GFP_NOIO, &mddev->bio_set);
-		bio_chain(split, bio);
-		submit_bio_noacct(bio);
-		bio = split;
-	}
-
-	md_account_bio(mddev, &bio);
-	bio_set_dev(bio, tmp_dev->rdev->bdev);
-	bio->bi_iter.bi_sector = bio->bi_iter.bi_sector -
-		start_sector + data_offset;
-
-	if (unlikely((bio_op(bio) == REQ_OP_DISCARD) &&
-		     !bdev_max_discard_sectors(bio->bi_bdev))) {
-		/* Just ignore it */
-		bio_endio(bio);
-	} else {
-		if (mddev->gendisk)
-			trace_block_bio_remap(bio, disk_devt(mddev->gendisk),
-					      bio_sector);
-		mddev_check_write_zeroes(mddev, bio);
-		submit_bio_noacct(bio);
-	}
-	return true;
-
-out_of_bounds:
-	pr_err("md/linear:%s: make_request: Sector %llu out of bounds on dev %pg: %llu sectors, offset %llu\n",
-	       mdname(mddev),
-	       (unsigned long long)bio->bi_iter.bi_sector,
-	       tmp_dev->rdev->bdev,
-	       (unsigned long long)tmp_dev->rdev->sectors,
-	       (unsigned long long)start_sector);
-	bio_io_error(bio);
-	return true;
-}
-
-static void linear_status (struct seq_file *seq, struct mddev *mddev)
-{
-	seq_printf(seq, " %dk rounding", mddev->chunk_sectors / 2);
-}
-
-static void linear_error(struct mddev *mddev, struct md_rdev *rdev)
-{
-	if (!test_and_set_bit(MD_BROKEN, &mddev->flags)) {
-		char *md_name = mdname(mddev);
-
-		pr_crit("md/linear%s: Disk failure on %pg detected, failing array.\n",
-			md_name, rdev->bdev);
-	}
-}
-
-static void linear_quiesce(struct mddev *mddev, int state)
-{
-}
-
-static struct md_personality linear_personality =
-{
-	.name		= "linear",
-	.level		= LEVEL_LINEAR,
-	.owner		= THIS_MODULE,
-	.make_request	= linear_make_request,
-	.run		= linear_run,
-	.free		= linear_free,
-	.status		= linear_status,
-	.hot_add_disk	= linear_add,
-	.size		= linear_size,
-	.quiesce	= linear_quiesce,
-	.error_handler	= linear_error,
-};
-
-static int __init linear_init (void)
-{
-	return register_md_personality (&linear_personality);
-}
-
-static void linear_exit (void)
-{
-	unregister_md_personality (&linear_personality);
-}
-
-module_init(linear_init);
-module_exit(linear_exit);
-MODULE_LICENSE("GPL");
-MODULE_DESCRIPTION("Linear device concatenation personality for MD (deprecated)");
-MODULE_ALIAS("md-personality-1"); /* LINEAR - deprecated*/
-MODULE_ALIAS("md-linear");
-MODULE_ALIAS("md-level--1");
diff --git a/drivers/md/md.c b/drivers/md/md.c
index 4e9fe5cbeedc..8649b63cd93b 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -8090,7 +8090,7 @@ void md_error(struct mddev *mddev, struct md_rdev *rdev)
 		return;
 	mddev->pers->error_handler(mddev, rdev);
 
-	if (mddev->pers->level == 0 || mddev->pers->level == LEVEL_LINEAR)
+	if (mddev->pers->level == 0)
 		return;
 
 	if (mddev->degraded && !test_bit(MD_BROKEN, &mddev->flags))
diff --git a/include/uapi/linux/raid/md_p.h b/include/uapi/linux/raid/md_p.h
index 6c0aa577730f..b36e282a413d 100644
--- a/include/uapi/linux/raid/md_p.h
+++ b/include/uapi/linux/raid/md_p.h
@@ -2,15 +2,11 @@
 /*
    md_p.h : physical layout of Linux RAID devices
           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_P_H
@@ -237,7 +233,7 @@ struct mdp_superblock_1 {
 	char	set_name[32];	/* set and interpreted by user-space */
 
 	__le64	ctime;		/* lo 40 bits are seconds, top 24 are microseconds or 0*/
-	__le32	level;		/* -4 (multipath), -1 (linear), 0,1,4,5 */
+	__le32	level;		/* -4 (multipath), 0,1,4,5 */
 	__le32	layout;		/* only for raid5 and raid10 currently */
 	__le64	size;		/* used size of component devices, in 512byte sectors */
 
diff --git a/include/uapi/linux/raid/md_u.h b/include/uapi/linux/raid/md_u.h
index 105307244961..c285f76e5d8d 100644
--- a/include/uapi/linux/raid/md_u.h
+++ b/include/uapi/linux/raid/md_u.h
@@ -2,15 +2,11 @@
 /*
    md_u.h : user <=> kernel API between Linux raidtools and RAID drivers
           Copyright (C) 1998 Ingo Molnar
-	  
+
    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 _UAPI_MD_U_H
@@ -109,7 +105,6 @@ typedef struct mdu_array_info_s {
 
 /* non-obvious values for 'level' */
 #define	LEVEL_MULTIPATH		(-4)
-#define	LEVEL_LINEAR		(-1)
 #define	LEVEL_FAULTY		(-5)
 
 /* we need a value for 'no level specified' and 0
-- 
2.34.1

[PATCH 2/3] md: Remove deprecated CONFIG_MD_MULTIPATH

[Song Liu]

md-multipath has been marked as deprecated for 2.5 years. Remove it.

Cc: Christoph Hellwig <hch@lst.de>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Neil Brown <neilb@suse.de>
Cc: Guoqing Jiang <guoqing.jiang@linux.dev>
Cc: Mateusz Grzonka <mateusz.grzonka@intel.com>
Cc: Jes Sorensen <jes@trained-monkey.org>
Signed-off-by: Song Liu <song@kernel.org>
---
 drivers/md/Kconfig             |  11 -
 drivers/md/Makefile            |   2 -
 drivers/md/md-multipath.c      | 463 ---------------------------------
 drivers/md/md.c                | 185 ++++++-------
 include/uapi/linux/raid/md_p.h |   2 +-
 include/uapi/linux/raid/md_u.h |   1 -
 6 files changed, 81 insertions(+), 583 deletions(-)
 delete mode 100644 drivers/md/md-multipath.c

diff --git a/drivers/md/Kconfig b/drivers/md/Kconfig
index 0c721e0e5921..de4f47fe5a03 100644
--- a/drivers/md/Kconfig
+++ b/drivers/md/Kconfig
@@ -159,17 +159,6 @@ config MD_RAID456
 
 	  If unsure, say Y.
 
-config MD_MULTIPATH
-	tristate "Multipath I/O support (deprecated)"
-	depends on BLK_DEV_MD
-	help
-	  MD_MULTIPATH provides a simple multi-path personality for use
-	  the MD framework.  It is not under active development.  New
-	  projects should consider using DM_MULTIPATH which has more
-	  features and more testing.
-
-	  If unsure, say N.
-
 config MD_FAULTY
 	tristate "Faulty test module for MD (deprecated)"
 	depends on BLK_DEV_MD
diff --git a/drivers/md/Makefile b/drivers/md/Makefile
index c72f76cf7b63..6287c73399e7 100644
--- a/drivers/md/Makefile
+++ b/drivers/md/Makefile
@@ -29,7 +29,6 @@ dm-zoned-y	+= dm-zoned-target.o dm-zoned-metadata.o dm-zoned-reclaim.o
 
 md-mod-y	+= md.o md-bitmap.o
 raid456-y	+= raid5.o raid5-cache.o raid5-ppl.o
-multipath-y	+= md-multipath.o
 faulty-y	+= md-faulty.o
 
 # Note: link order is important.  All raid personalities
@@ -41,7 +40,6 @@ obj-$(CONFIG_MD_RAID0)		+= raid0.o
 obj-$(CONFIG_MD_RAID1)		+= raid1.o
 obj-$(CONFIG_MD_RAID10)		+= raid10.o
 obj-$(CONFIG_MD_RAID456)	+= raid456.o
-obj-$(CONFIG_MD_MULTIPATH)	+= multipath.o
 obj-$(CONFIG_MD_FAULTY)		+= faulty.o
 obj-$(CONFIG_MD_CLUSTER)	+= md-cluster.o
 obj-$(CONFIG_BCACHE)		+= bcache/
diff --git a/drivers/md/md-multipath.c b/drivers/md/md-multipath.c
deleted file mode 100644
index 19c8625ea642..000000000000
--- a/drivers/md/md-multipath.c
+++ /dev/null
@@ -1,463 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0-or-later
-/*
- * multipath.c : Multiple Devices driver for Linux
- *
- * Copyright (C) 1999, 2000, 2001 Ingo Molnar, Red Hat
- *
- * Copyright (C) 1996, 1997, 1998 Ingo Molnar, Miguel de Icaza, Gadi Oxman
- *
- * MULTIPATH management functions.
- *
- * derived from raid1.c.
- */
-
-#include <linux/blkdev.h>
-#include <linux/module.h>
-#include <linux/raid/md_u.h>
-#include <linux/seq_file.h>
-#include <linux/slab.h>
-#include "md.h"
-#include "md-multipath.h"
-
-#define MAX_WORK_PER_DISK 128
-
-#define	NR_RESERVED_BUFS	32
-
-static int multipath_map (struct mpconf *conf)
-{
-	int i, disks = conf->raid_disks;
-
-	/*
-	 * Later we do read balancing on the read side
-	 * now we use the first available disk.
-	 */
-
-	for (i = 0; i < disks; i++) {
-		struct md_rdev *rdev = conf->multipaths[i].rdev;
-
-		if (rdev && test_bit(In_sync, &rdev->flags) &&
-		    !test_bit(Faulty, &rdev->flags)) {
-			atomic_inc(&rdev->nr_pending);
-			return i;
-		}
-	}
-
-	pr_crit_ratelimited("multipath_map(): no more operational IO paths?\n");
-	return (-1);
-}
-
-static void multipath_reschedule_retry (struct multipath_bh *mp_bh)
-{
-	unsigned long flags;
-	struct mddev *mddev = mp_bh->mddev;
-	struct mpconf *conf = mddev->private;
-
-	spin_lock_irqsave(&conf->device_lock, flags);
-	list_add(&mp_bh->retry_list, &conf->retry_list);
-	spin_unlock_irqrestore(&conf->device_lock, flags);
-	md_wakeup_thread(mddev->thread);
-}
-
-/*
- * multipath_end_bh_io() is called when we have finished servicing a multipathed
- * operation and are ready to return a success/failure code to the buffer
- * cache layer.
- */
-static void multipath_end_bh_io(struct multipath_bh *mp_bh, blk_status_t status)
-{
-	struct bio *bio = mp_bh->master_bio;
-	struct mpconf *conf = mp_bh->mddev->private;
-
-	bio->bi_status = status;
-	bio_endio(bio);
-	mempool_free(mp_bh, &conf->pool);
-}
-
-static void multipath_end_request(struct bio *bio)
-{
-	struct multipath_bh *mp_bh = bio->bi_private;
-	struct mpconf *conf = mp_bh->mddev->private;
-	struct md_rdev *rdev = conf->multipaths[mp_bh->path].rdev;
-
-	if (!bio->bi_status)
-		multipath_end_bh_io(mp_bh, 0);
-	else if (!(bio->bi_opf & REQ_RAHEAD)) {
-		/*
-		 * oops, IO error:
-		 */
-		md_error (mp_bh->mddev, rdev);
-		pr_info("multipath: %pg: rescheduling sector %llu\n",
-			rdev->bdev,
-			(unsigned long long)bio->bi_iter.bi_sector);
-		multipath_reschedule_retry(mp_bh);
-	} else
-		multipath_end_bh_io(mp_bh, bio->bi_status);
-	rdev_dec_pending(rdev, conf->mddev);
-}
-
-static bool multipath_make_request(struct mddev *mddev, struct bio * bio)
-{
-	struct mpconf *conf = mddev->private;
-	struct multipath_bh * mp_bh;
-	struct multipath_info *multipath;
-
-	if (unlikely(bio->bi_opf & REQ_PREFLUSH)
-	    && md_flush_request(mddev, bio))
-		return true;
-
-	md_account_bio(mddev, &bio);
-	mp_bh = mempool_alloc(&conf->pool, GFP_NOIO);
-
-	mp_bh->master_bio = bio;
-	mp_bh->mddev = mddev;
-
-	mp_bh->path = multipath_map(conf);
-	if (mp_bh->path < 0) {
-		bio_io_error(bio);
-		mempool_free(mp_bh, &conf->pool);
-		return true;
-	}
-	multipath = conf->multipaths + mp_bh->path;
-
-	bio_init_clone(multipath->rdev->bdev, &mp_bh->bio, bio, GFP_NOIO);
-
-	mp_bh->bio.bi_iter.bi_sector += multipath->rdev->data_offset;
-	mp_bh->bio.bi_opf |= REQ_FAILFAST_TRANSPORT;
-	mp_bh->bio.bi_end_io = multipath_end_request;
-	mp_bh->bio.bi_private = mp_bh;
-	mddev_check_write_zeroes(mddev, &mp_bh->bio);
-	submit_bio_noacct(&mp_bh->bio);
-	return true;
-}
-
-static void multipath_status(struct seq_file *seq, struct mddev *mddev)
-{
-	struct mpconf *conf = mddev->private;
-	int i;
-
-	lockdep_assert_held(&mddev->lock);
-
-	seq_printf (seq, " [%d/%d] [", conf->raid_disks,
-		    conf->raid_disks - mddev->degraded);
-	for (i = 0; i < conf->raid_disks; i++) {
-		struct md_rdev *rdev = READ_ONCE(conf->multipaths[i].rdev);
-
-		seq_printf(seq, "%s",
-			   rdev && test_bit(In_sync, &rdev->flags) ? "U" : "_");
-	}
-	seq_putc(seq, ']');
-}
-
-/*
- * Careful, this can execute in IRQ contexts as well!
- */
-static void multipath_error (struct mddev *mddev, struct md_rdev *rdev)
-{
-	struct mpconf *conf = mddev->private;
-
-	if (conf->raid_disks - mddev->degraded <= 1) {
-		/*
-		 * Uh oh, we can do nothing if this is our last path, but
-		 * first check if this is a queued request for a device
-		 * which has just failed.
-		 */
-		pr_warn("multipath: only one IO path left and IO error.\n");
-		/* leave it active... it's all we have */
-		return;
-	}
-	/*
-	 * Mark disk as unusable
-	 */
-	if (test_and_clear_bit(In_sync, &rdev->flags)) {
-		unsigned long flags;
-		spin_lock_irqsave(&conf->device_lock, flags);
-		mddev->degraded++;
-		spin_unlock_irqrestore(&conf->device_lock, flags);
-	}
-	set_bit(Faulty, &rdev->flags);
-	set_bit(MD_SB_CHANGE_DEVS, &mddev->sb_flags);
-	pr_err("multipath: IO failure on %pg, disabling IO path.\n"
-	       "multipath: Operation continuing on %d IO paths.\n",
-	       rdev->bdev,
-	       conf->raid_disks - mddev->degraded);
-}
-
-static void print_multipath_conf(struct mpconf *conf)
-{
-	int i;
-	struct multipath_info *tmp;
-
-	pr_debug("MULTIPATH conf printout:\n");
-	if (!conf) {
-		pr_debug("(conf==NULL)\n");
-		return;
-	}
-	pr_debug(" --- wd:%d rd:%d\n", conf->raid_disks - conf->mddev->degraded,
-		 conf->raid_disks);
-
-	lockdep_assert_held(&conf->mddev->reconfig_mutex);
-	for (i = 0; i < conf->raid_disks; i++) {
-		tmp = conf->multipaths + i;
-		if (tmp->rdev)
-			pr_debug(" disk%d, o:%d, dev:%pg\n",
-				 i,!test_bit(Faulty, &tmp->rdev->flags),
-				 tmp->rdev->bdev);
-	}
-}
-
-static int multipath_add_disk(struct mddev *mddev, struct md_rdev *rdev)
-{
-	struct mpconf *conf = mddev->private;
-	int err = -EEXIST;
-	int path;
-	struct multipath_info *p;
-	int first = 0;
-	int last = mddev->raid_disks - 1;
-
-	if (rdev->raid_disk >= 0)
-		first = last = rdev->raid_disk;
-
-	print_multipath_conf(conf);
-
-	for (path = first; path <= last; path++)
-		if ((p=conf->multipaths+path)->rdev == NULL) {
-			disk_stack_limits(mddev->gendisk, rdev->bdev,
-					  rdev->data_offset << 9);
-
-			err = md_integrity_add_rdev(rdev, mddev);
-			if (err)
-				break;
-			spin_lock_irq(&conf->device_lock);
-			mddev->degraded--;
-			rdev->raid_disk = path;
-			set_bit(In_sync, &rdev->flags);
-			spin_unlock_irq(&conf->device_lock);
-			WRITE_ONCE(p->rdev, rdev);
-			err = 0;
-			break;
-		}
-
-	print_multipath_conf(conf);
-
-	return err;
-}
-
-static int multipath_remove_disk(struct mddev *mddev, struct md_rdev *rdev)
-{
-	struct mpconf *conf = mddev->private;
-	int err = 0;
-	int number = rdev->raid_disk;
-	struct multipath_info *p = conf->multipaths + number;
-
-	print_multipath_conf(conf);
-
-	if (rdev == p->rdev) {
-		if (test_bit(In_sync, &rdev->flags) ||
-		    atomic_read(&rdev->nr_pending)) {
-			pr_warn("hot-remove-disk, slot %d is identified but is still operational!\n", number);
-			err = -EBUSY;
-			goto abort;
-		}
-		WRITE_ONCE(p->rdev, NULL);
-		err = md_integrity_register(mddev);
-	}
-abort:
-
-	print_multipath_conf(conf);
-	return err;
-}
-
-/*
- * This is a kernel thread which:
- *
- *	1.	Retries failed read operations on working multipaths.
- *	2.	Updates the raid superblock when problems encounter.
- *	3.	Performs writes following reads for array syncronising.
- */
-
-static void multipathd(struct md_thread *thread)
-{
-	struct mddev *mddev = thread->mddev;
-	struct multipath_bh *mp_bh;
-	struct bio *bio;
-	unsigned long flags;
-	struct mpconf *conf = mddev->private;
-	struct list_head *head = &conf->retry_list;
-
-	md_check_recovery(mddev);
-	for (;;) {
-		spin_lock_irqsave(&conf->device_lock, flags);
-		if (list_empty(head))
-			break;
-		mp_bh = list_entry(head->prev, struct multipath_bh, retry_list);
-		list_del(head->prev);
-		spin_unlock_irqrestore(&conf->device_lock, flags);
-
-		bio = &mp_bh->bio;
-		bio->bi_iter.bi_sector = mp_bh->master_bio->bi_iter.bi_sector;
-
-		if ((mp_bh->path = multipath_map (conf))<0) {
-			pr_err("multipath: %pg: unrecoverable IO read error for block %llu\n",
-			       bio->bi_bdev,
-			       (unsigned long long)bio->bi_iter.bi_sector);
-			multipath_end_bh_io(mp_bh, BLK_STS_IOERR);
-		} else {
-			pr_err("multipath: %pg: redirecting sector %llu to another IO path\n",
-			       bio->bi_bdev,
-			       (unsigned long long)bio->bi_iter.bi_sector);
-			*bio = *(mp_bh->master_bio);
-			bio->bi_iter.bi_sector +=
-				conf->multipaths[mp_bh->path].rdev->data_offset;
-			bio_set_dev(bio, conf->multipaths[mp_bh->path].rdev->bdev);
-			bio->bi_opf |= REQ_FAILFAST_TRANSPORT;
-			bio->bi_end_io = multipath_end_request;
-			bio->bi_private = mp_bh;
-			submit_bio_noacct(bio);
-		}
-	}
-	spin_unlock_irqrestore(&conf->device_lock, flags);
-}
-
-static sector_t multipath_size(struct mddev *mddev, sector_t sectors, int raid_disks)
-{
-	WARN_ONCE(sectors || raid_disks,
-		  "%s does not support generic reshape\n", __func__);
-
-	return mddev->dev_sectors;
-}
-
-static int multipath_run (struct mddev *mddev)
-{
-	struct mpconf *conf;
-	int disk_idx;
-	struct multipath_info *disk;
-	struct md_rdev *rdev;
-	int working_disks;
-	int ret;
-
-	if (md_check_no_bitmap(mddev))
-		return -EINVAL;
-
-	if (mddev->level != LEVEL_MULTIPATH) {
-		pr_warn("multipath: %s: raid level not set to multipath IO (%d)\n",
-			mdname(mddev), mddev->level);
-		goto out;
-	}
-	/*
-	 * copy the already verified devices into our private MULTIPATH
-	 * bookkeeping area. [whatever we allocate in multipath_run(),
-	 * should be freed in multipath_free()]
-	 */
-
-	conf = kzalloc(sizeof(struct mpconf), GFP_KERNEL);
-	mddev->private = conf;
-	if (!conf)
-		goto out;
-
-	conf->multipaths = kcalloc(mddev->raid_disks,
-				   sizeof(struct multipath_info),
-				   GFP_KERNEL);
-	if (!conf->multipaths)
-		goto out_free_conf;
-
-	working_disks = 0;
-	rdev_for_each(rdev, mddev) {
-		disk_idx = rdev->raid_disk;
-		if (disk_idx < 0 ||
-		    disk_idx >= mddev->raid_disks)
-			continue;
-
-		disk = conf->multipaths + disk_idx;
-		disk->rdev = rdev;
-		disk_stack_limits(mddev->gendisk, rdev->bdev,
-				  rdev->data_offset << 9);
-
-		if (!test_bit(Faulty, &rdev->flags))
-			working_disks++;
-	}
-
-	conf->raid_disks = mddev->raid_disks;
-	conf->mddev = mddev;
-	spin_lock_init(&conf->device_lock);
-	INIT_LIST_HEAD(&conf->retry_list);
-
-	if (!working_disks) {
-		pr_warn("multipath: no operational IO paths for %s\n",
-			mdname(mddev));
-		goto out_free_conf;
-	}
-	mddev->degraded = conf->raid_disks - working_disks;
-
-	ret = mempool_init_kmalloc_pool(&conf->pool, NR_RESERVED_BUFS,
-					sizeof(struct multipath_bh));
-	if (ret)
-		goto out_free_conf;
-
-	rcu_assign_pointer(mddev->thread,
-			   md_register_thread(multipathd, mddev, "multipath"));
-	if (!mddev->thread)
-		goto out_free_conf;
-
-	pr_info("multipath: array %s active with %d out of %d IO paths\n",
-		mdname(mddev), conf->raid_disks - mddev->degraded,
-		mddev->raid_disks);
-	/*
-	 * Ok, everything is just fine now
-	 */
-	md_set_array_sectors(mddev, multipath_size(mddev, 0, 0));
-
-	if (md_integrity_register(mddev))
-		goto out_free_conf;
-
-	return 0;
-
-out_free_conf:
-	mempool_exit(&conf->pool);
-	kfree(conf->multipaths);
-	kfree(conf);
-	mddev->private = NULL;
-out:
-	return -EIO;
-}
-
-static void multipath_free(struct mddev *mddev, void *priv)
-{
-	struct mpconf *conf = priv;
-
-	mempool_exit(&conf->pool);
-	kfree(conf->multipaths);
-	kfree(conf);
-}
-
-static struct md_personality multipath_personality =
-{
-	.name		= "multipath",
-	.level		= LEVEL_MULTIPATH,
-	.owner		= THIS_MODULE,
-	.make_request	= multipath_make_request,
-	.run		= multipath_run,
-	.free		= multipath_free,
-	.status		= multipath_status,
-	.error_handler	= multipath_error,
-	.hot_add_disk	= multipath_add_disk,
-	.hot_remove_disk= multipath_remove_disk,
-	.size		= multipath_size,
-};
-
-static int __init multipath_init (void)
-{
-	return register_md_personality (&multipath_personality);
-}
-
-static void __exit multipath_exit (void)
-{
-	unregister_md_personality (&multipath_personality);
-}
-
-module_init(multipath_init);
-module_exit(multipath_exit);
-MODULE_LICENSE("GPL");
-MODULE_DESCRIPTION("simple multi-path personality for MD (deprecated)");
-MODULE_ALIAS("md-personality-7"); /* MULTIPATH */
-MODULE_ALIAS("md-multipath");
-MODULE_ALIAS("md-level--4");
diff --git a/drivers/md/md.c b/drivers/md/md.c
index 8649b63cd93b..7b5e6dd67dab 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -1286,17 +1286,11 @@ static int super_90_load(struct md_rdev *rdev, struct md_rdev *refdev, int minor
 	rdev->sb_size = MD_SB_BYTES;
 	rdev->badblocks.shift = -1;
 
-	if (sb->level == LEVEL_MULTIPATH)
-		rdev->desc_nr = -1;
-	else
-		rdev->desc_nr = sb->this_disk.number;
-
-	/* not spare disk, or LEVEL_MULTIPATH */
-	if (sb->level == LEVEL_MULTIPATH ||
-		(rdev->desc_nr >= 0 &&
-		 rdev->desc_nr < MD_SB_DISKS &&
-		 sb->disks[rdev->desc_nr].state &
-		 ((1<<MD_DISK_SYNC) | (1 << MD_DISK_ACTIVE))))
+	rdev->desc_nr = sb->this_disk.number;
+
+	/* not spare disk */
+	if (rdev->desc_nr >= 0 && rdev->desc_nr < MD_SB_DISKS &&
+	    sb->disks[rdev->desc_nr].state & ((1<<MD_DISK_SYNC) | (1 << MD_DISK_ACTIVE)))
 		spare_disk = false;
 
 	if (!refdev) {
@@ -1442,31 +1436,28 @@ static int super_90_validate(struct mddev *mddev, struct md_rdev *rdev)
 			return 0;
 	}
 
-	if (mddev->level != LEVEL_MULTIPATH) {
-		desc = sb->disks + rdev->desc_nr;
+	desc = sb->disks + rdev->desc_nr;
 
-		if (desc->state & (1<<MD_DISK_FAULTY))
-			set_bit(Faulty, &rdev->flags);
-		else if (desc->state & (1<<MD_DISK_SYNC) /* &&
-			    desc->raid_disk < mddev->raid_disks */) {
-			set_bit(In_sync, &rdev->flags);
+	if (desc->state & (1<<MD_DISK_FAULTY))
+		set_bit(Faulty, &rdev->flags);
+	else if (desc->state & (1<<MD_DISK_SYNC)) {
+		set_bit(In_sync, &rdev->flags);
+		rdev->raid_disk = desc->raid_disk;
+		rdev->saved_raid_disk = desc->raid_disk;
+	} else if (desc->state & (1<<MD_DISK_ACTIVE)) {
+		/* active but not in sync implies recovery up to
+		 * reshape position.  We don't know exactly where
+		 * that is, so set to zero for now
+		 */
+		if (mddev->minor_version >= 91) {
+			rdev->recovery_offset = 0;
 			rdev->raid_disk = desc->raid_disk;
-			rdev->saved_raid_disk = desc->raid_disk;
-		} else if (desc->state & (1<<MD_DISK_ACTIVE)) {
-			/* active but not in sync implies recovery up to
-			 * reshape position.  We don't know exactly where
-			 * that is, so set to zero for now */
-			if (mddev->minor_version >= 91) {
-				rdev->recovery_offset = 0;
-				rdev->raid_disk = desc->raid_disk;
-			}
 		}
-		if (desc->state & (1<<MD_DISK_WRITEMOSTLY))
-			set_bit(WriteMostly, &rdev->flags);
-		if (desc->state & (1<<MD_DISK_FAILFAST))
-			set_bit(FailFast, &rdev->flags);
-	} else /* MULTIPATH are always insync */
-		set_bit(In_sync, &rdev->flags);
+	}
+	if (desc->state & (1<<MD_DISK_WRITEMOSTLY))
+		set_bit(WriteMostly, &rdev->flags);
+	if (desc->state & (1<<MD_DISK_FAILFAST))
+		set_bit(FailFast, &rdev->flags);
 	return 0;
 }
 
@@ -1756,10 +1747,7 @@ static int super_1_load(struct md_rdev *rdev, struct md_rdev *refdev, int minor_
 	    && rdev->new_data_offset < sb_start + (rdev->sb_size/512))
 		return -EINVAL;
 
-	if (sb->level == cpu_to_le32(LEVEL_MULTIPATH))
-		rdev->desc_nr = -1;
-	else
-		rdev->desc_nr = le32_to_cpu(sb->dev_number);
+	rdev->desc_nr = le32_to_cpu(sb->dev_number);
 
 	if (!rdev->bb_page) {
 		rdev->bb_page = alloc_page(GFP_KERNEL);
@@ -1812,12 +1800,10 @@ static int super_1_load(struct md_rdev *rdev, struct md_rdev *refdev, int minor_
 	    sb->level != 0)
 		return -EINVAL;
 
-	/* not spare disk, or LEVEL_MULTIPATH */
-	if (sb->level == cpu_to_le32(LEVEL_MULTIPATH) ||
-		(rdev->desc_nr >= 0 &&
-		rdev->desc_nr < le32_to_cpu(sb->max_dev) &&
-		(le16_to_cpu(sb->dev_roles[rdev->desc_nr]) < MD_DISK_ROLE_MAX ||
-		 le16_to_cpu(sb->dev_roles[rdev->desc_nr]) == MD_DISK_ROLE_JOURNAL)))
+	/* not spare disk */
+	if (rdev->desc_nr >= 0 && rdev->desc_nr < le32_to_cpu(sb->max_dev) &&
+	    (le16_to_cpu(sb->dev_roles[rdev->desc_nr]) < MD_DISK_ROLE_MAX ||
+	     le16_to_cpu(sb->dev_roles[rdev->desc_nr]) == MD_DISK_ROLE_JOURNAL))
 		spare_disk = false;
 
 	if (!refdev) {
@@ -1860,6 +1846,7 @@ static int super_1_validate(struct mddev *mddev, struct md_rdev *rdev)
 {
 	struct mdp_superblock_1 *sb = page_address(rdev->sb_page);
 	__u64 ev1 = le64_to_cpu(sb->events);
+	int role;
 
 	rdev->raid_disk = -1;
 	clear_bit(Faulty, &rdev->flags);
@@ -1973,58 +1960,55 @@ static int super_1_validate(struct mddev *mddev, struct md_rdev *rdev)
 			/* just a hot-add of a new device, leave raid_disk at -1 */
 			return 0;
 	}
-	if (mddev->level != LEVEL_MULTIPATH) {
-		int role;
-		if (rdev->desc_nr < 0 ||
-		    rdev->desc_nr >= le32_to_cpu(sb->max_dev)) {
-			role = MD_DISK_ROLE_SPARE;
-			rdev->desc_nr = -1;
-		} else
-			role = le16_to_cpu(sb->dev_roles[rdev->desc_nr]);
-		switch(role) {
-		case MD_DISK_ROLE_SPARE: /* spare */
-			break;
-		case MD_DISK_ROLE_FAULTY: /* faulty */
-			set_bit(Faulty, &rdev->flags);
-			break;
-		case MD_DISK_ROLE_JOURNAL: /* journal device */
-			if (!(le32_to_cpu(sb->feature_map) & MD_FEATURE_JOURNAL)) {
-				/* journal device without journal feature */
-				pr_warn("md: journal device provided without journal feature, ignoring the device\n");
-				return -EINVAL;
-			}
-			set_bit(Journal, &rdev->flags);
-			rdev->journal_tail = le64_to_cpu(sb->journal_tail);
-			rdev->raid_disk = 0;
-			break;
-		default:
-			rdev->saved_raid_disk = role;
-			if ((le32_to_cpu(sb->feature_map) &
-			     MD_FEATURE_RECOVERY_OFFSET)) {
-				rdev->recovery_offset = le64_to_cpu(sb->recovery_offset);
-				if (!(le32_to_cpu(sb->feature_map) &
-				      MD_FEATURE_RECOVERY_BITMAP))
-					rdev->saved_raid_disk = -1;
-			} else {
-				/*
-				 * If the array is FROZEN, then the device can't
-				 * be in_sync with rest of array.
-				 */
-				if (!test_bit(MD_RECOVERY_FROZEN,
-					      &mddev->recovery))
-					set_bit(In_sync, &rdev->flags);
-			}
-			rdev->raid_disk = role;
-			break;
+
+	if (rdev->desc_nr < 0 ||
+	    rdev->desc_nr >= le32_to_cpu(sb->max_dev)) {
+		role = MD_DISK_ROLE_SPARE;
+		rdev->desc_nr = -1;
+	} else
+		role = le16_to_cpu(sb->dev_roles[rdev->desc_nr]);
+	switch (role) {
+	case MD_DISK_ROLE_SPARE: /* spare */
+		break;
+	case MD_DISK_ROLE_FAULTY: /* faulty */
+		set_bit(Faulty, &rdev->flags);
+		break;
+	case MD_DISK_ROLE_JOURNAL: /* journal device */
+		if (!(le32_to_cpu(sb->feature_map) & MD_FEATURE_JOURNAL)) {
+			/* journal device without journal feature */
+			pr_warn("md: journal device provided without journal feature, ignoring the device\n");
+			return -EINVAL;
 		}
-		if (sb->devflags & WriteMostly1)
-			set_bit(WriteMostly, &rdev->flags);
-		if (sb->devflags & FailFast1)
-			set_bit(FailFast, &rdev->flags);
-		if (le32_to_cpu(sb->feature_map) & MD_FEATURE_REPLACEMENT)
-			set_bit(Replacement, &rdev->flags);
-	} else /* MULTIPATH are always insync */
-		set_bit(In_sync, &rdev->flags);
+		set_bit(Journal, &rdev->flags);
+		rdev->journal_tail = le64_to_cpu(sb->journal_tail);
+		rdev->raid_disk = 0;
+		break;
+	default:
+		rdev->saved_raid_disk = role;
+		if ((le32_to_cpu(sb->feature_map) &
+		     MD_FEATURE_RECOVERY_OFFSET)) {
+			rdev->recovery_offset = le64_to_cpu(sb->recovery_offset);
+			if (!(le32_to_cpu(sb->feature_map) &
+			      MD_FEATURE_RECOVERY_BITMAP))
+				rdev->saved_raid_disk = -1;
+		} else {
+			/*
+			 * If the array is FROZEN, then the device can't
+			 * be in_sync with rest of array.
+			 */
+			if (!test_bit(MD_RECOVERY_FROZEN,
+				      &mddev->recovery))
+				set_bit(In_sync, &rdev->flags);
+		}
+		rdev->raid_disk = role;
+		break;
+	}
+	if (sb->devflags & WriteMostly1)
+		set_bit(WriteMostly, &rdev->flags);
+	if (sb->devflags & FailFast1)
+		set_bit(FailFast, &rdev->flags);
+	if (le32_to_cpu(sb->feature_map) & MD_FEATURE_REPLACEMENT)
+		set_bit(Replacement, &rdev->flags);
 
 	return 0;
 }
@@ -2842,10 +2826,6 @@ void md_update_sb(struct mddev *mddev, int force_change)
 		} else
 			pr_debug("md: %pg (skipping faulty)\n",
 				 rdev->bdev);
-
-		if (mddev->level == LEVEL_MULTIPATH)
-			/* only need to write one superblock... */
-			break;
 	}
 	if (md_super_wait(mddev) < 0)
 		goto rewrite;
@@ -3846,13 +3826,8 @@ static int analyze_sbs(struct mddev *mddev)
 				continue;
 			}
 		}
-		if (mddev->level == LEVEL_MULTIPATH) {
-			rdev->desc_nr = i++;
-			rdev->raid_disk = rdev->desc_nr;
-			set_bit(In_sync, &rdev->flags);
-		} else if (rdev->raid_disk >=
-			    (mddev->raid_disks - min(0, mddev->delta_disks)) &&
-			   !test_bit(Journal, &rdev->flags)) {
+		if (rdev->raid_disk >= (mddev->raid_disks - min(0, mddev->delta_disks)) &&
+		    !test_bit(Journal, &rdev->flags)) {
 			rdev->raid_disk = -1;
 			clear_bit(In_sync, &rdev->flags);
 		}
diff --git a/include/uapi/linux/raid/md_p.h b/include/uapi/linux/raid/md_p.h
index b36e282a413d..5a43c23f53bf 100644
--- a/include/uapi/linux/raid/md_p.h
+++ b/include/uapi/linux/raid/md_p.h
@@ -233,7 +233,7 @@ struct mdp_superblock_1 {
 	char	set_name[32];	/* set and interpreted by user-space */
 
 	__le64	ctime;		/* lo 40 bits are seconds, top 24 are microseconds or 0*/
-	__le32	level;		/* -4 (multipath), 0,1,4,5 */
+	__le32	level;		/* 0,1,4,5 */
 	__le32	layout;		/* only for raid5 and raid10 currently */
 	__le64	size;		/* used size of component devices, in 512byte sectors */
 
diff --git a/include/uapi/linux/raid/md_u.h b/include/uapi/linux/raid/md_u.h
index c285f76e5d8d..b44bbc356643 100644
--- a/include/uapi/linux/raid/md_u.h
+++ b/include/uapi/linux/raid/md_u.h
@@ -104,7 +104,6 @@ typedef struct mdu_array_info_s {
 } mdu_array_info_t;
 
 /* non-obvious values for 'level' */
-#define	LEVEL_MULTIPATH		(-4)
 #define	LEVEL_FAULTY		(-5)
 
 /* we need a value for 'no level specified' and 0
-- 
2.34.1

[PATCH 3/3] md: Remove deprecated CONFIG_MD_FAULTY

[Song Liu]

md-faulty has been marked as deprecated for 2.5 years. Remove it.

Cc: Christoph Hellwig <hch@lst.de>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Neil Brown <neilb@suse.de>
Cc: Guoqing Jiang <guoqing.jiang@linux.dev>
Cc: Mateusz Grzonka <mateusz.grzonka@intel.com>
Cc: Jes Sorensen <jes@trained-monkey.org>
Signed-off-by: Song Liu <song@kernel.org>
---
 drivers/md/Kconfig             |  10 -
 drivers/md/Makefile            |   2 -
 drivers/md/md-faulty.c         | 365 ---------------------------------
 include/uapi/linux/raid/md_u.h |   3 -
 4 files changed, 380 deletions(-)
 delete mode 100644 drivers/md/md-faulty.c

diff --git a/drivers/md/Kconfig b/drivers/md/Kconfig
index de4f47fe5a03..f6dc2acdf1ed 100644
--- a/drivers/md/Kconfig
+++ b/drivers/md/Kconfig
@@ -159,16 +159,6 @@ config MD_RAID456
 
 	  If unsure, say Y.
 
-config MD_FAULTY
-	tristate "Faulty test module for MD (deprecated)"
-	depends on BLK_DEV_MD
-	help
-	  The "faulty" module allows for a block device that occasionally returns
-	  read or write errors.  It is useful for testing.
-
-	  In unsure, say N.
-
-
 config MD_CLUSTER
 	tristate "Cluster Support for MD"
 	depends on BLK_DEV_MD
diff --git a/drivers/md/Makefile b/drivers/md/Makefile
index 6287c73399e7..027d7cfeca3f 100644
--- a/drivers/md/Makefile
+++ b/drivers/md/Makefile
@@ -29,7 +29,6 @@ dm-zoned-y	+= dm-zoned-target.o dm-zoned-metadata.o dm-zoned-reclaim.o
 
 md-mod-y	+= md.o md-bitmap.o
 raid456-y	+= raid5.o raid5-cache.o raid5-ppl.o
-faulty-y	+= md-faulty.o
 
 # Note: link order is important.  All raid personalities
 # and must come before md.o, as they each initialise
@@ -40,7 +39,6 @@ obj-$(CONFIG_MD_RAID0)		+= raid0.o
 obj-$(CONFIG_MD_RAID1)		+= raid1.o
 obj-$(CONFIG_MD_RAID10)		+= raid10.o
 obj-$(CONFIG_MD_RAID456)	+= raid456.o
-obj-$(CONFIG_MD_FAULTY)		+= faulty.o
 obj-$(CONFIG_MD_CLUSTER)	+= md-cluster.o
 obj-$(CONFIG_BCACHE)		+= bcache/
 obj-$(CONFIG_BLK_DEV_MD)	+= md-mod.o
diff --git a/drivers/md/md-faulty.c b/drivers/md/md-faulty.c
deleted file mode 100644
index a039e8e20f55..000000000000
--- a/drivers/md/md-faulty.c
+++ /dev/null
@@ -1,365 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0-or-later
-/*
- * faulty.c : Multiple Devices driver for Linux
- *
- * Copyright (C) 2004 Neil Brown
- *
- * fautly-device-simulator personality for md
- */
-
-
-/*
- * The "faulty" personality causes some requests to fail.
- *
- * Possible failure modes are:
- *   reads fail "randomly" but succeed on retry
- *   writes fail "randomly" but succeed on retry
- *   reads for some address fail and then persist until a write
- *   reads for some address fail and then persist irrespective of write
- *   writes for some address fail and persist
- *   all writes fail
- *
- * Different modes can be active at a time, but only
- * one can be set at array creation.  Others can be added later.
- * A mode can be one-shot or recurrent with the recurrence being
- * once in every N requests.
- * The bottom 5 bits of the "layout" indicate the mode.  The
- * remainder indicate a period, or 0 for one-shot.
- *
- * There is an implementation limit on the number of concurrently
- * persisting-faulty blocks. When a new fault is requested that would
- * exceed the limit, it is ignored.
- * All current faults can be clear using a layout of "0".
- *
- * Requests are always sent to the device.  If they are to fail,
- * we clone the bio and insert a new b_end_io into the chain.
- */
-
-#define	WriteTransient	0
-#define	ReadTransient	1
-#define	WritePersistent	2
-#define	ReadPersistent	3
-#define	WriteAll	4 /* doesn't go to device */
-#define	ReadFixable	5
-#define	Modes	6
-
-#define	ClearErrors	31
-#define	ClearFaults	30
-
-#define AllPersist	100 /* internal use only */
-#define	NoPersist	101
-
-#define	ModeMask	0x1f
-#define	ModeShift	5
-
-#define MaxFault	50
-#include <linux/blkdev.h>
-#include <linux/module.h>
-#include <linux/raid/md_u.h>
-#include <linux/slab.h>
-#include "md.h"
-#include <linux/seq_file.h>
-
-
-static void faulty_fail(struct bio *bio)
-{
-	struct bio *b = bio->bi_private;
-
-	b->bi_iter.bi_size = bio->bi_iter.bi_size;
-	b->bi_iter.bi_sector = bio->bi_iter.bi_sector;
-
-	bio_put(bio);
-
-	bio_io_error(b);
-}
-
-struct faulty_conf {
-	int period[Modes];
-	atomic_t counters[Modes];
-	sector_t faults[MaxFault];
-	int	modes[MaxFault];
-	int nfaults;
-	struct md_rdev *rdev;
-};
-
-static int check_mode(struct faulty_conf *conf, int mode)
-{
-	if (conf->period[mode] == 0 &&
-	    atomic_read(&conf->counters[mode]) <= 0)
-		return 0; /* no failure, no decrement */
-
-
-	if (atomic_dec_and_test(&conf->counters[mode])) {
-		if (conf->period[mode])
-			atomic_set(&conf->counters[mode], conf->period[mode]);
-		return 1;
-	}
-	return 0;
-}
-
-static int check_sector(struct faulty_conf *conf, sector_t start, sector_t end, int dir)
-{
-	/* If we find a ReadFixable sector, we fix it ... */
-	int i;
-	for (i=0; i<conf->nfaults; i++)
-		if (conf->faults[i] >= start &&
-		    conf->faults[i] < end) {
-			/* found it ... */
-			switch (conf->modes[i] * 2 + dir) {
-			case WritePersistent*2+WRITE: return 1;
-			case ReadPersistent*2+READ: return 1;
-			case ReadFixable*2+READ: return 1;
-			case ReadFixable*2+WRITE:
-				conf->modes[i] = NoPersist;
-				return 0;
-			case AllPersist*2+READ:
-			case AllPersist*2+WRITE: return 1;
-			default:
-				return 0;
-			}
-		}
-	return 0;
-}
-
-static void add_sector(struct faulty_conf *conf, sector_t start, int mode)
-{
-	int i;
-	int n = conf->nfaults;
-	for (i=0; i<conf->nfaults; i++)
-		if (conf->faults[i] == start) {
-			switch(mode) {
-			case NoPersist: conf->modes[i] = mode; return;
-			case WritePersistent:
-				if (conf->modes[i] == ReadPersistent ||
-				    conf->modes[i] == ReadFixable)
-					conf->modes[i] = AllPersist;
-				else
-					conf->modes[i] = WritePersistent;
-				return;
-			case ReadPersistent:
-				if (conf->modes[i] == WritePersistent)
-					conf->modes[i] = AllPersist;
-				else
-					conf->modes[i] = ReadPersistent;
-				return;
-			case ReadFixable:
-				if (conf->modes[i] == WritePersistent ||
-				    conf->modes[i] == ReadPersistent)
-					conf->modes[i] = AllPersist;
-				else
-					conf->modes[i] = ReadFixable;
-				return;
-			}
-		} else if (conf->modes[i] == NoPersist)
-			n = i;
-
-	if (n >= MaxFault)
-		return;
-	conf->faults[n] = start;
-	conf->modes[n] = mode;
-	if (conf->nfaults == n)
-		conf->nfaults = n+1;
-}
-
-static bool faulty_make_request(struct mddev *mddev, struct bio *bio)
-{
-	struct faulty_conf *conf = mddev->private;
-	int failit = 0;
-
-	if (bio_data_dir(bio) == WRITE) {
-		/* write request */
-		if (atomic_read(&conf->counters[WriteAll])) {
-			/* special case - don't decrement, don't submit_bio_noacct,
-			 * just fail immediately
-			 */
-			bio_io_error(bio);
-			return true;
-		}
-
-		if (check_sector(conf, bio->bi_iter.bi_sector,
-				 bio_end_sector(bio), WRITE))
-			failit = 1;
-		if (check_mode(conf, WritePersistent)) {
-			add_sector(conf, bio->bi_iter.bi_sector,
-				   WritePersistent);
-			failit = 1;
-		}
-		if (check_mode(conf, WriteTransient))
-			failit = 1;
-	} else {
-		/* read request */
-		if (check_sector(conf, bio->bi_iter.bi_sector,
-				 bio_end_sector(bio), READ))
-			failit = 1;
-		if (check_mode(conf, ReadTransient))
-			failit = 1;
-		if (check_mode(conf, ReadPersistent)) {
-			add_sector(conf, bio->bi_iter.bi_sector,
-				   ReadPersistent);
-			failit = 1;
-		}
-		if (check_mode(conf, ReadFixable)) {
-			add_sector(conf, bio->bi_iter.bi_sector,
-				   ReadFixable);
-			failit = 1;
-		}
-	}
-
-	md_account_bio(mddev, &bio);
-	if (failit) {
-		struct bio *b = bio_alloc_clone(conf->rdev->bdev, bio, GFP_NOIO,
-						&mddev->bio_set);
-
-		b->bi_private = bio;
-		b->bi_end_io = faulty_fail;
-		bio = b;
-	} else
-		bio_set_dev(bio, conf->rdev->bdev);
-
-	submit_bio_noacct(bio);
-	return true;
-}
-
-static void faulty_status(struct seq_file *seq, struct mddev *mddev)
-{
-	struct faulty_conf *conf = mddev->private;
-	int n;
-
-	if ((n=atomic_read(&conf->counters[WriteTransient])) != 0)
-		seq_printf(seq, " WriteTransient=%d(%d)",
-			   n, conf->period[WriteTransient]);
-
-	if ((n=atomic_read(&conf->counters[ReadTransient])) != 0)
-		seq_printf(seq, " ReadTransient=%d(%d)",
-			   n, conf->period[ReadTransient]);
-
-	if ((n=atomic_read(&conf->counters[WritePersistent])) != 0)
-		seq_printf(seq, " WritePersistent=%d(%d)",
-			   n, conf->period[WritePersistent]);
-
-	if ((n=atomic_read(&conf->counters[ReadPersistent])) != 0)
-		seq_printf(seq, " ReadPersistent=%d(%d)",
-			   n, conf->period[ReadPersistent]);
-
-
-	if ((n=atomic_read(&conf->counters[ReadFixable])) != 0)
-		seq_printf(seq, " ReadFixable=%d(%d)",
-			   n, conf->period[ReadFixable]);
-
-	if ((n=atomic_read(&conf->counters[WriteAll])) != 0)
-		seq_printf(seq, " WriteAll");
-
-	seq_printf(seq, " nfaults=%d", conf->nfaults);
-}
-
-
-static int faulty_reshape(struct mddev *mddev)
-{
-	int mode = mddev->new_layout & ModeMask;
-	int count = mddev->new_layout >> ModeShift;
-	struct faulty_conf *conf = mddev->private;
-
-	if (mddev->new_layout < 0)
-		return 0;
-
-	/* new layout */
-	if (mode == ClearFaults)
-		conf->nfaults = 0;
-	else if (mode == ClearErrors) {
-		int i;
-		for (i=0 ; i < Modes ; i++) {
-			conf->period[i] = 0;
-			atomic_set(&conf->counters[i], 0);
-		}
-	} else if (mode < Modes) {
-		conf->period[mode] = count;
-		if (!count) count++;
-		atomic_set(&conf->counters[mode], count);
-	} else
-		return -EINVAL;
-	mddev->new_layout = -1;
-	mddev->layout = -1; /* makes sure further changes come through */
-	return 0;
-}
-
-static sector_t faulty_size(struct mddev *mddev, sector_t sectors, int raid_disks)
-{
-	WARN_ONCE(raid_disks,
-		  "%s does not support generic reshape\n", __func__);
-
-	if (sectors == 0)
-		return mddev->dev_sectors;
-
-	return sectors;
-}
-
-static int faulty_run(struct mddev *mddev)
-{
-	struct md_rdev *rdev;
-	int i;
-	struct faulty_conf *conf;
-
-	if (md_check_no_bitmap(mddev))
-		return -EINVAL;
-
-	conf = kmalloc(sizeof(*conf), GFP_KERNEL);
-	if (!conf)
-		return -ENOMEM;
-
-	for (i=0; i<Modes; i++) {
-		atomic_set(&conf->counters[i], 0);
-		conf->period[i] = 0;
-	}
-	conf->nfaults = 0;
-
-	rdev_for_each(rdev, mddev) {
-		conf->rdev = rdev;
-		disk_stack_limits(mddev->gendisk, rdev->bdev,
-				  rdev->data_offset << 9);
-	}
-
-	md_set_array_sectors(mddev, faulty_size(mddev, 0, 0));
-	mddev->private = conf;
-
-	faulty_reshape(mddev);
-
-	return 0;
-}
-
-static void faulty_free(struct mddev *mddev, void *priv)
-{
-	struct faulty_conf *conf = priv;
-
-	kfree(conf);
-}
-
-static struct md_personality faulty_personality =
-{
-	.name		= "faulty",
-	.level		= LEVEL_FAULTY,
-	.owner		= THIS_MODULE,
-	.make_request	= faulty_make_request,
-	.run		= faulty_run,
-	.free		= faulty_free,
-	.status		= faulty_status,
-	.check_reshape	= faulty_reshape,
-	.size		= faulty_size,
-};
-
-static int __init raid_init(void)
-{
-	return register_md_personality(&faulty_personality);
-}
-
-static void raid_exit(void)
-{
-	unregister_md_personality(&faulty_personality);
-}
-
-module_init(raid_init);
-module_exit(raid_exit);
-MODULE_LICENSE("GPL");
-MODULE_DESCRIPTION("Fault injection personality for MD (deprecated)");
-MODULE_ALIAS("md-personality-10"); /* faulty */
-MODULE_ALIAS("md-faulty");
-MODULE_ALIAS("md-level--5");
diff --git a/include/uapi/linux/raid/md_u.h b/include/uapi/linux/raid/md_u.h
index b44bbc356643..7be89a4906e7 100644
--- a/include/uapi/linux/raid/md_u.h
+++ b/include/uapi/linux/raid/md_u.h
@@ -103,9 +103,6 @@ typedef struct mdu_array_info_s {
 
 } mdu_array_info_t;
 
-/* non-obvious values for 'level' */
-#define	LEVEL_FAULTY		(-5)
-
 /* we need a value for 'no level specified' and 0
  * means 'raid0', so we need something else.  This is
  * for internal use only
-- 
2.34.1

Re: [PATCH 1/3] md: Remove deprecated CONFIG_MD_LINEAR

[Christoph Hellwig]

Looks good:

Reviewed-by: Christoph Hellwig <hch@lst.de>

Re: [PATCH 2/3] md: Remove deprecated CONFIG_MD_MULTIPATH

[Christoph Hellwig]

Looks good:

Reviewed-by: Christoph Hellwig <hch@lst.de>

Re: [PATCH 3/3] md: Remove deprecated CONFIG_MD_FAULTY

[Christoph Hellwig]

Looks good:

Reviewed-by: Christoph Hellwig <hch@lst.de>

Re: [PATCH 1/3] md: Remove deprecated CONFIG_MD_LINEAR

[Hannes Reinecke]

On 12/14/23 23:21, Song Liu wrote:
> md-linear has been marked as deprecated for 2.5 years. Remove it.
> 
> Cc: Christoph Hellwig <hch@lst.de>
> Cc: Jens Axboe <axboe@kernel.dk>
> Cc: Neil Brown <neilb@suse.de>
> Cc: Guoqing Jiang <guoqing.jiang@linux.dev>
> Cc: Mateusz Grzonka <mateusz.grzonka@intel.com>
> Cc: Jes Sorensen <jes@trained-monkey.org>
> Signed-off-by: Song Liu <song@kernel.org>
> ---
>   drivers/md/Kconfig             |  13 --
>   drivers/md/Makefile            |   6 +-
>   drivers/md/md-autodetect.c     |   8 +-
>   drivers/md/md-linear.c         | 318 ---------------------------------
>   drivers/md/md.c                |   2 +-
>   include/uapi/linux/raid/md_p.h |   8 +-
>   include/uapi/linux/raid/md_u.h |   7 +-
>   7 files changed, 8 insertions(+), 354 deletions(-)
>   delete mode 100644 drivers/md/md-linear.c
> 
Reviewed-by: Hannes Reinecke <hare@suse.de>

Cheers,

Hannes
-- 
Dr. Hannes Reinecke                Kernel Storage Architect
hare@suse.de                              +49 911 74053 688
SUSE Software Solutions GmbH, Maxfeldstr. 5, 90409 Nürnberg
HRB 36809 (AG Nürnberg), GF: Ivo Totev, Andrew McDonald,
Werner Knoblich

Re: [PATCH 2/3] md: Remove deprecated CONFIG_MD_MULTIPATH

[Hannes Reinecke]

On 12/14/23 23:21, Song Liu wrote:
> md-multipath has been marked as deprecated for 2.5 years. Remove it.
> 
> Cc: Christoph Hellwig <hch@lst.de>
> Cc: Jens Axboe <axboe@kernel.dk>
> Cc: Neil Brown <neilb@suse.de>
> Cc: Guoqing Jiang <guoqing.jiang@linux.dev>
> Cc: Mateusz Grzonka <mateusz.grzonka@intel.com>
> Cc: Jes Sorensen <jes@trained-monkey.org>
> Signed-off-by: Song Liu <song@kernel.org>
> ---
>   drivers/md/Kconfig             |  11 -
>   drivers/md/Makefile            |   2 -
>   drivers/md/md-multipath.c      | 463 ---------------------------------
>   drivers/md/md.c                | 185 ++++++-------
>   include/uapi/linux/raid/md_p.h |   2 +-
>   include/uapi/linux/raid/md_u.h |   1 -
>   6 files changed, 81 insertions(+), 583 deletions(-)
>   delete mode 100644 drivers/md/md-multipath.c
> 
About time :-)

Reviewed-by: Hannes Reinecke <hare@suse.de>

Cheers,

Hannes
-- 
Dr. Hannes Reinecke                Kernel Storage Architect
hare@suse.de                              +49 911 74053 688
SUSE Software Solutions GmbH, Maxfeldstr. 5, 90409 Nürnberg
HRB 36809 (AG Nürnberg), GF: Ivo Totev, Andrew McDonald,
Werner Knoblich

Re: [PATCH 3/3] md: Remove deprecated CONFIG_MD_FAULTY

[Hannes Reinecke]

On 12/14/23 23:21, Song Liu wrote:
> md-faulty has been marked as deprecated for 2.5 years. Remove it.
> 
> Cc: Christoph Hellwig <hch@lst.de>
> Cc: Jens Axboe <axboe@kernel.dk>
> Cc: Neil Brown <neilb@suse.de>
> Cc: Guoqing Jiang <guoqing.jiang@linux.dev>
> Cc: Mateusz Grzonka <mateusz.grzonka@intel.com>
> Cc: Jes Sorensen <jes@trained-monkey.org>
> Signed-off-by: Song Liu <song@kernel.org>
> ---
>   drivers/md/Kconfig             |  10 -
>   drivers/md/Makefile            |   2 -
>   drivers/md/md-faulty.c         | 365 ---------------------------------
>   include/uapi/linux/raid/md_u.h |   3 -
>   4 files changed, 380 deletions(-)
>   delete mode 100644 drivers/md/md-faulty.c
> 
Reviewed-by: Hannes Reinecke <hare@suse.de>

Cheers,

Hannes
-- 
Dr. Hannes Reinecke                Kernel Storage Architect
hare@suse.de                              +49 911 74053 688
SUSE Software Solutions GmbH, Maxfeldstr. 5, 90409 Nürnberg
HRB 36809 (AG Nürnberg), GF: Ivo Totev, Andrew McDonald,
Werner Knoblich

Re: [PATCH 0/3] md: Remove deprecated flavors

[Mariusz Tkaczyk]

On Thu, 14 Dec 2023 14:21:04 -0800
Song Liu <song@kernel.org> wrote:

> Linear, multipath, and faulty have been marked as deprecated for 2.5 years.
> Let's remove them.
> 
> Thanks,
> Song

Hi Song,
Great idea!

Please note that there are mdadm tests for those levels. I can approve it only
when mdadm clean-up is merged. Our tests must pass continuously.

It is a nice code complexity improvement so let me know if you would
like to get my help with mdadm patches.

Thanks,
Mariusz

Re: [PATCH 0/3] md: Remove deprecated flavors

[Song Liu]

Hi Mariusz,

On Fri, Dec 15, 2023 at 3:51 AM Mariusz Tkaczyk
<mariusz.tkaczyk@linux.intel.com> wrote:
>
> On Thu, 14 Dec 2023 14:21:04 -0800
> Song Liu <song@kernel.org> wrote:
>
> > Linear, multipath, and faulty have been marked as deprecated for 2.5 years.
> > Let's remove them.
> >
> > Thanks,
> > Song
>
> Hi Song,
> Great idea!
>
> Please note that there are mdadm tests for those levels. I can approve it only
> when mdadm clean-up is merged. Our tests must pass continuously.

Is the continuous test result available publicly?

>
> It is a nice code complexity improvement so let me know if you would
> like to get my help with mdadm patches.

On my local tests with mdadm, I need to make changes to the following
tests:

00linear...
00names...
00raid0...
00readonly...
02lineargrow...
03r0assem...
04r0update...
04update-metadata...

The changes are all straightforward (just remove things related to
linear/multipath/faulty).

Thanks,
Song

Re: [PATCH 0/3] md: Remove deprecated flavors

[Mariusz Tkaczyk]

On Fri, 15 Dec 2023 07:37:54 -0800
Song Liu <song@kernel.org> wrote:

> Hi Mariusz,
> 
> On Fri, Dec 15, 2023 at 3:51 AM Mariusz Tkaczyk
> <mariusz.tkaczyk@linux.intel.com> wrote:
> >
> > On Thu, 14 Dec 2023 14:21:04 -0800
> > Song Liu <song@kernel.org> wrote:
> >  
> > > Linear, multipath, and faulty have been marked as deprecated for 2.5
> > > years. Let's remove them.
> > >
> > > Thanks,
> > > Song  
> >
> > Hi Song,
> > Great idea!
> >
> > Please note that there are mdadm tests for those levels. I can approve it
> > only when mdadm clean-up is merged. Our tests must pass continuously.  
> 
> Is the continuous test result available publicly?

We are working on public CI (Paul owns it). On my side I'm not executing all
tests, IMSM only. In this case it is obvious that mdadm tests will stop passing,
I don't need results to see that. We should keep both mdadm and md compatible.
We are continuously adding new MD regression tests to mdadm (at least Kuai is
doing that) so we should also care about removing things.

> 
> >
> > It is a nice code complexity improvement so let me know if you would
> > like to get my help with mdadm patches.  
> 
> On my local tests with mdadm, I need to make changes to the following
> tests:
> 
> 00linear...
> 00names...
> 00raid0...
> 00readonly...
> 02lineargrow...
> 03r0assem...
> 04r0update...
> 04update-metadata...
> 
> The changes are all straightforward (just remove things related to
> linear/multipath/faulty).
> 

Please do not forgot remove dead code from mdadm. For example simple find
"multipath" (case insensitive) reefers me to multiple places with special
handling for this level. We need to remove it from code and documentation.
Can you handle this too?

Oh and last one, I can't find update for md man in your changes. Could you
please remove those levels from md man?

Thanks,
Mariusz

Re: [PATCH 0/3] md: Remove deprecated flavors

[Song Liu]

Hi Mariusz,

On Mon, Dec 18, 2023 at 12:32 AM Mariusz Tkaczyk
<mariusz.tkaczyk@linux.intel.com> wrote:
>
[...]
> > >
> > > Please note that there are mdadm tests for those levels. I can approve it
> > > only when mdadm clean-up is merged. Our tests must pass continuously.
> >
> > Is the continuous test result available publicly?
>
> We are working on public CI (Paul owns it). On my side I'm not executing all
> tests, IMSM only. In this case it is obvious that mdadm tests will stop passing,
> I don't need results to see that. We should keep both mdadm and md compatible.
> We are continuously adding new MD regression tests to mdadm (at least Kuai is
> doing that) so we should also care about removing things.
>
> >
> > >
> > > It is a nice code complexity improvement so let me know if you would
> > > like to get my help with mdadm patches.
> >
> > On my local tests with mdadm, I need to make changes to the following
> > tests:
> >
> > 00linear...
> > 00names...
> > 00raid0...
> > 00readonly...
> > 02lineargrow...
> > 03r0assem...
> > 04r0update...
> > 04update-metadata...
> >
> > The changes are all straightforward (just remove things related to
> > linear/multipath/faulty).
> >
>
> Please do not forgot remove dead code from mdadm. For example simple find
> "multipath" (case insensitive) reefers me to multiple places with special
> handling for this level. We need to remove it from code and documentation.
> Can you handle this too?

I think this is a bigger discussion: will mdadm stop supporting these
flavors on
older kernels? Say, mdadm-5.0+ (or a different number) will not support
multipath flavor on older kernels?

>
> Oh and last one, I can't find update for md man in your changes. Could you
> please remove those levels from md man?

man side is easier. Once we know which major will have this set (6.8 or later),
we can update the man pages with the information.

Thanks,
Song

Re: [PATCH 0/3] md: Remove deprecated flavors

[Mariusz Tkaczyk]

On Mon, 18 Dec 2023 08:11:53 -0800
Song Liu <song@kernel.org> wrote:

> Hi Mariusz,
> 
> On Mon, Dec 18, 2023 at 12:32 AM Mariusz Tkaczyk
> <mariusz.tkaczyk@linux.intel.com> wrote:
> >  
> [...]
> > > >
> > > > Please note that there are mdadm tests for those levels. I can approve
> > > > it only when mdadm clean-up is merged. Our tests must pass
> > > > continuously.  
> > >
> > > Is the continuous test result available publicly?  
> >
> > We are working on public CI (Paul owns it). On my side I'm not executing all
> > tests, IMSM only. In this case it is obvious that mdadm tests will stop
> > passing, I don't need results to see that. We should keep both mdadm and md
> > compatible. We are continuously adding new MD regression tests to mdadm (at
> > least Kuai is doing that) so we should also care about removing things.
> >  
> > >  
> > > >
> > > > It is a nice code complexity improvement so let me know if you would
> > > > like to get my help with mdadm patches.  
> > >
> > > On my local tests with mdadm, I need to make changes to the following
> > > tests:
> > >
> > > 00linear...
> > > 00names...
> > > 00raid0...
> > > 00readonly...
> > > 02lineargrow...
> > > 03r0assem...
> > > 04r0update...
> > > 04update-metadata...
> > >
> > > The changes are all straightforward (just remove things related to
> > > linear/multipath/faulty).
> > >  
> >
> > Please do not forgot remove dead code from mdadm. For example simple find
> > "multipath" (case insensitive) reefers me to multiple places with special
> > handling for this level. We need to remove it from code and documentation.
> > Can you handle this too?  
> 
> I think this is a bigger discussion: will mdadm stop supporting these
> flavors on
> older kernels? Say, mdadm-5.0+ (or a different number) will not support
> multipath flavor on older kernels?
> 

Good point, I forgot that we are keeping backward compatibility with old
kernels. Currently 3.10 is the lowest one supported so agree, we need to keep
this code. Thanks for clarifying!

> >
> > Oh and last one, I can't find update for md man in your changes. Could you
> > please remove those levels from md man?  
> 
> man side is easier. Once we know which major will have this set (6.8 or
> later), we can update the man pages with the information.

Understood!

No further questions, please just remove tests and eventually add warning when
creating those levels in mdadm i.e "Linear/Multipath/Faulty are deprecated and
will be removed in next releases".

Thanks,
Mariusz

Re: [PATCH 1/3] md: Remove deprecated CONFIG_MD_LINEAR

[Geert Uytterhoeven]

Hi Song,

On Thu, Dec 14, 2023 at 11:22 PM Song Liu <song@kernel.org> wrote:
> md-linear has been marked as deprecated for 2.5 years. Remove it.
>
> Cc: Christoph Hellwig <hch@lst.de>
> Cc: Jens Axboe <axboe@kernel.dk>
> Cc: Neil Brown <neilb@suse.de>
> Cc: Guoqing Jiang <guoqing.jiang@linux.dev>
> Cc: Mateusz Grzonka <mateusz.grzonka@intel.com>
> Cc: Jes Sorensen <jes@trained-monkey.org>
> Signed-off-by: Song Liu <song@kernel.org>

Thanks for your patch, which is now commit 849d18e27be9a125 ("md:
Remove deprecated CONFIG_MD_LINEAR") upstream.

> --- a/drivers/md/Kconfig
> +++ b/drivers/md/Kconfig
> @@ -61,19 +61,6 @@ config MD_BITMAP_FILE
>           various kernel APIs and can only work with files on a file system not
>           actually sitting on the MD device.
>
> -config MD_LINEAR
> -       tristate "Linear (append) mode (deprecated)"
> -       depends on BLK_DEV_MD
> -       help
> -         If you say Y here, then your multiple devices driver will be able to
> -         use the so-called linear mode, i.e. it will combine the hard disk
> -         partitions by simply appending one to the other.
> -
> -         To compile this as a module, choose M here: the module
> -         will be called linear.
> -
> -         If unsure, say Y.
> -

Is this what you need to recover data from disks salvaged from a
commercial NAS configured in JBOD mode?
If yes, and there is no better way to do that, you probably do not
want to drop this support.  Actual NAS systems running Linux might
use this as well.

>  config MD_RAID0
>         tristate "RAID-0 (striping) mode"
>         depends on BLK_DEV_MD

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds

Re: [PATCH 1/3] md: Remove deprecated CONFIG_MD_LINEAR

[Song Liu]

Hi Geert,

On Fri, Jan 12, 2024 at 1:28 AM Geert Uytterhoeven <geert@linux-m68k.org> wrote:
>
[...]
>
> > --- a/drivers/md/Kconfig
> > +++ b/drivers/md/Kconfig
> > @@ -61,19 +61,6 @@ config MD_BITMAP_FILE
> >           various kernel APIs and can only work with files on a file system not
> >           actually sitting on the MD device.
> >
> > -config MD_LINEAR
> > -       tristate "Linear (append) mode (deprecated)"
> > -       depends on BLK_DEV_MD
> > -       help
> > -         If you say Y here, then your multiple devices driver will be able to
> > -         use the so-called linear mode, i.e. it will combine the hard disk
> > -         partitions by simply appending one to the other.
> > -
> > -         To compile this as a module, choose M here: the module
> > -         will be called linear.
> > -
> > -         If unsure, say Y.
> > -
>
> Is this what you need to recover data from disks salvaged from a
> commercial NAS configured in JBOD mode?
> If yes, and there is no better way to do that, you probably do not
> want to drop this support.  Actual NAS systems running Linux might
> use this as well.

Thanks for the heads-up. I honestly don't know about this use case.
Where can I find/get more information about it?

Thanks,
Song

Re: [PATCH 1/3] md: Remove deprecated CONFIG_MD_LINEAR

[Christoph Hellwig]

On Fri, Jan 12, 2024 at 09:08:04AM -0800, Song Liu wrote:
> Thanks for the heads-up. I honestly don't know about this use case.
> Where can I find/get more information about it?

What NAS uses md linear?

Either way you can always set up a dm-linear table to get at the
data.

Re: [PATCH 1/3] md: Remove deprecated CONFIG_MD_LINEAR

[Jens Axboe]

On 1/12/24 10:10 AM, Christoph Hellwig wrote:
> On Fri, Jan 12, 2024 at 09:08:04AM -0800, Song Liu wrote:
>> Thanks for the heads-up. I honestly don't know about this use case.
>> Where can I find/get more information about it?
> 
> What NAS uses md linear?
> 
> Either way you can always set up a dm-linear table to get at the
> data.

Or just boot an older kernel... Seems like a bit of a contrived use
case to cater to.

-- 
Jens Axboe

Re: [PATCH 1/3] md: Remove deprecated CONFIG_MD_LINEAR

[Geert Uytterhoeven]

Hi Christoph,

On Fri, Jan 12, 2024 at 6:10 PM Christoph Hellwig <hch@lst.de> wrote:
> On Fri, Jan 12, 2024 at 09:08:04AM -0800, Song Liu wrote:
> > Thanks for the heads-up. I honestly don't know about this use case.
> > Where can I find/get more information about it?
>
> What NAS uses md linear?

No idea, I was just wondering....
Lots of NASes sold support JBOD (yes, I know I should not use anything
that lacks mirroring for data I care about ;-)

> Either way you can always set up a dm-linear table to get at the
> data.

If dm-linear offers the same functionality, I have no objection.

Note to self: learn about the difference between dm and md, finally...

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds