Merge tag 'md-6.14-20250113' of https://git.kernel.org/pub/scm/linux/kernel/git/mdraid/linux into for-6.14/block

Pull MD updates from Song:

"1. Reintroduce md-linear, by Yu Kuai.
 2. md-bitmap refactor and fix, by Yu Kuai.
 3. Replace kmap_atomic with kmap_local_page, by David Reaver."

* tag 'md-6.14-20250113' of https://git.kernel.org/pub/scm/linux/kernel/git/mdraid/linux:
  md/md-bitmap: move bitmap_{start, end}write to md upper layer
  md/raid5: implement pers->bitmap_sector()
  md: add a new callback pers->bitmap_sector()
  md/md-bitmap: remove the last parameter for bimtap_ops->endwrite()
  md/md-bitmap: factor behind write counters out from bitmap_{start/end}write()
  md: Replace deprecated kmap_atomic() with kmap_local_page()
  md: reintroduce md-linear

Author: axboe

drivers/md/Kconfig

@@ -61,6 +61,19 @@ 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"
+	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

drivers/md/Makefile

@@ -29,12 +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
 
 # 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
 # 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

drivers/md/md-autodetect.c

@@ -49,6 +49,7 @@ 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
@@ -87,15 +88,18 @@ 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) {
+		if (level == 0 || level == LEVEL_LINEAR) {
 			if (get_option(&str, &factor) != 2 ||	/* Chunk Size */
 					get_option(&str, &fault) != 2) {
 				printk(KERN_WARNING "md: Too few arguments supplied to md=.\n");
 				return 0;
 			}
 			md_setup_args[ent].level = level;
 			md_setup_args[ent].chunk = 1 << (factor+12);
-			pername = "raid0";
+			if (level ==  LEVEL_LINEAR)
+				pername = "linear";
+			else
+				pername = "raid0";
 			break;
 		}
 		fallthrough;

drivers/md/md-bitmap.c

@@ -682,7 +682,7 @@ static void bitmap_update_sb(void *data)
 		return;
 	if (!bitmap->storage.sb_page) /* no superblock */
 		return;
-	sb = kmap_atomic(bitmap->storage.sb_page);
+	sb = kmap_local_page(bitmap->storage.sb_page);
 	sb->events = cpu_to_le64(bitmap->mddev->events);
 	if (bitmap->mddev->events < bitmap->events_cleared)
 		/* rocking back to read-only */
@@ -702,7 +702,7 @@ static void bitmap_update_sb(void *data)
 	sb->nodes = cpu_to_le32(bitmap->mddev->bitmap_info.nodes);
 	sb->sectors_reserved = cpu_to_le32(bitmap->mddev->
 					   bitmap_info.space);
-	kunmap_atomic(sb);
+	kunmap_local(sb);
 
 	if (bitmap->storage.file)
 		write_file_page(bitmap, bitmap->storage.sb_page, 1);
@@ -717,7 +717,7 @@ static void bitmap_print_sb(struct bitmap *bitmap)
 
 	if (!bitmap || !bitmap->storage.sb_page)
 		return;
-	sb = kmap_atomic(bitmap->storage.sb_page);
+	sb = kmap_local_page(bitmap->storage.sb_page);
 	pr_debug("%s: bitmap file superblock:\n", bmname(bitmap));
 	pr_debug("         magic: %08x\n", le32_to_cpu(sb->magic));
 	pr_debug("       version: %u\n", le32_to_cpu(sb->version));
@@ -736,7 +736,7 @@ static void bitmap_print_sb(struct bitmap *bitmap)
 	pr_debug("     sync size: %llu KB\n",
 		 (unsigned long long)le64_to_cpu(sb->sync_size)/2);
 	pr_debug("max write behind: %u\n", le32_to_cpu(sb->write_behind));
-	kunmap_atomic(sb);
+	kunmap_local(sb);
 }
 
 /*
@@ -760,15 +760,15 @@ static int md_bitmap_new_disk_sb(struct bitmap *bitmap)
 		return -ENOMEM;
 	bitmap->storage.sb_index = 0;
 
-	sb = kmap_atomic(bitmap->storage.sb_page);
+	sb = kmap_local_page(bitmap->storage.sb_page);
 
 	sb->magic = cpu_to_le32(BITMAP_MAGIC);
 	sb->version = cpu_to_le32(BITMAP_MAJOR_HI);
 
 	chunksize = bitmap->mddev->bitmap_info.chunksize;
 	BUG_ON(!chunksize);
 	if (!is_power_of_2(chunksize)) {
-		kunmap_atomic(sb);
+		kunmap_local(sb);
 		pr_warn("bitmap chunksize not a power of 2\n");
 		return -EINVAL;
 	}
@@ -803,7 +803,7 @@ static int md_bitmap_new_disk_sb(struct bitmap *bitmap)
 	sb->events_cleared = cpu_to_le64(bitmap->mddev->events);
 	bitmap->mddev->bitmap_info.nodes = 0;
 
-	kunmap_atomic(sb);
+	kunmap_local(sb);
 
 	return 0;
 }
@@ -865,7 +865,7 @@ static int md_bitmap_read_sb(struct bitmap *bitmap)
 		return err;
 
 	err = -EINVAL;
-	sb = kmap_atomic(sb_page);
+	sb = kmap_local_page(sb_page);
 
 	chunksize = le32_to_cpu(sb->chunksize);
 	daemon_sleep = le32_to_cpu(sb->daemon_sleep) * HZ;
@@ -932,7 +932,7 @@ static int md_bitmap_read_sb(struct bitmap *bitmap)
 	err = 0;
 
 out:
-	kunmap_atomic(sb);
+	kunmap_local(sb);
 	if (err == 0 && nodes && (bitmap->cluster_slot < 0)) {
 		/* Assigning chunksize is required for "re_read" */
 		bitmap->mddev->bitmap_info.chunksize = chunksize;
@@ -1161,12 +1161,12 @@ static void md_bitmap_file_set_bit(struct bitmap *bitmap, sector_t block)
 	bit = file_page_offset(&bitmap->storage, chunk);
 
 	/* set the bit */
-	kaddr = kmap_atomic(page);
+	kaddr = kmap_local_page(page);
 	if (test_bit(BITMAP_HOSTENDIAN, &bitmap->flags))
 		set_bit(bit, kaddr);
 	else
 		set_bit_le(bit, kaddr);
-	kunmap_atomic(kaddr);
+	kunmap_local(kaddr);
 	pr_debug("set file bit %lu page %lu\n", bit, index);
 	/* record page number so it gets flushed to disk when unplug occurs */
 	set_page_attr(bitmap, index - node_offset, BITMAP_PAGE_DIRTY);
@@ -1190,12 +1190,12 @@ static void md_bitmap_file_clear_bit(struct bitmap *bitmap, sector_t block)
 	if (!page)
 		return;
 	bit = file_page_offset(&bitmap->storage, chunk);
-	paddr = kmap_atomic(page);
+	paddr = kmap_local_page(page);
 	if (test_bit(BITMAP_HOSTENDIAN, &bitmap->flags))
 		clear_bit(bit, paddr);
 	else
 		clear_bit_le(bit, paddr);
-	kunmap_atomic(paddr);
+	kunmap_local(paddr);
 	if (!test_page_attr(bitmap, index - node_offset, BITMAP_PAGE_NEEDWRITE)) {
 		set_page_attr(bitmap, index - node_offset, BITMAP_PAGE_PENDING);
 		bitmap->allclean = 0;
@@ -1214,12 +1214,12 @@ static int md_bitmap_file_test_bit(struct bitmap *bitmap, sector_t block)
 	if (!page)
 		return -EINVAL;
 	bit = file_page_offset(&bitmap->storage, chunk);
-	paddr = kmap_atomic(page);
+	paddr = kmap_local_page(page);
 	if (test_bit(BITMAP_HOSTENDIAN, &bitmap->flags))
 		set = test_bit(bit, paddr);
 	else
 		set = test_bit_le(bit, paddr);
-	kunmap_atomic(paddr);
+	kunmap_local(paddr);
 	return set;
 }
 
@@ -1388,9 +1388,9 @@ static int md_bitmap_init_from_disk(struct bitmap *bitmap, sector_t start)
 			 * If the bitmap is out of date, dirty the whole page
 			 * and write it out
 			 */
-			paddr = kmap_atomic(page);
+			paddr = kmap_local_page(page);
 			memset(paddr + offset, 0xff, PAGE_SIZE - offset);
-			kunmap_atomic(paddr);
+			kunmap_local(paddr);
 
 			filemap_write_page(bitmap, i, true);
 			if (test_bit(BITMAP_WRITE_ERROR, &bitmap->flags)) {
@@ -1406,12 +1406,12 @@ static int md_bitmap_init_from_disk(struct bitmap *bitmap, sector_t start)
 		void *paddr;
 		bool was_set;
 
-		paddr = kmap_atomic(page);
+		paddr = kmap_local_page(page);
 		if (test_bit(BITMAP_HOSTENDIAN, &bitmap->flags))
 			was_set = test_bit(bit, paddr);
 		else
 			was_set = test_bit_le(bit, paddr);
-		kunmap_atomic(paddr);
+		kunmap_local(paddr);
 
 		if (was_set) {
 			/* if the disk bit is set, set the memory bit */
@@ -1546,10 +1546,10 @@ static void bitmap_daemon_work(struct mddev *mddev)
 		bitmap_super_t *sb;
 		bitmap->need_sync = 0;
 		if (bitmap->storage.filemap) {
-			sb = kmap_atomic(bitmap->storage.sb_page);
+			sb = kmap_local_page(bitmap->storage.sb_page);
 			sb->events_cleared =
 				cpu_to_le64(bitmap->events_cleared);
-			kunmap_atomic(sb);
+			kunmap_local(sb);
 			set_page_attr(bitmap, 0,
 				      BITMAP_PAGE_NEEDWRITE);
 		}
@@ -1671,24 +1671,13 @@ __acquires(bitmap->lock)
 }
 
 static int bitmap_startwrite(struct mddev *mddev, sector_t offset,
-			     unsigned long sectors, bool behind)
+			     unsigned long sectors)
 {
 	struct bitmap *bitmap = mddev->bitmap;
 
 	if (!bitmap)
 		return 0;
 
-	if (behind) {
-		int bw;
-		atomic_inc(&bitmap->behind_writes);
-		bw = atomic_read(&bitmap->behind_writes);
-		if (bw > bitmap->behind_writes_used)
-			bitmap->behind_writes_used = bw;
-
-		pr_debug("inc write-behind count %d/%lu\n",
-			 bw, bitmap->mddev->bitmap_info.max_write_behind);
-	}
-
 	while (sectors) {
 		sector_t blocks;
 		bitmap_counter_t *bmc;
@@ -1737,21 +1726,13 @@ static int bitmap_startwrite(struct mddev *mddev, sector_t offset,
 }
 
 static void bitmap_endwrite(struct mddev *mddev, sector_t offset,
-			    unsigned long sectors, bool success, bool behind)
+			    unsigned long sectors)
 {
 	struct bitmap *bitmap = mddev->bitmap;
 
 	if (!bitmap)
 		return;
 
-	if (behind) {
-		if (atomic_dec_and_test(&bitmap->behind_writes))
-			wake_up(&bitmap->behind_wait);
-		pr_debug("dec write-behind count %d/%lu\n",
-			 atomic_read(&bitmap->behind_writes),
-			 bitmap->mddev->bitmap_info.max_write_behind);
-	}
-
 	while (sectors) {
 		sector_t blocks;
 		unsigned long flags;
@@ -1764,15 +1745,16 @@ static void bitmap_endwrite(struct mddev *mddev, sector_t offset,
 			return;
 		}
 
-		if (success && !bitmap->mddev->degraded &&
-		    bitmap->events_cleared < bitmap->mddev->events) {
-			bitmap->events_cleared = bitmap->mddev->events;
-			bitmap->need_sync = 1;
-			sysfs_notify_dirent_safe(bitmap->sysfs_can_clear);
-		}
-
-		if (!success && !NEEDED(*bmc))
+		if (!bitmap->mddev->degraded) {
+			if (bitmap->events_cleared < bitmap->mddev->events) {
+				bitmap->events_cleared = bitmap->mddev->events;
+				bitmap->need_sync = 1;
+				sysfs_notify_dirent_safe(
+						bitmap->sysfs_can_clear);
+			}
+		} else if (!NEEDED(*bmc)) {
 			*bmc |= NEEDED_MASK;
+		}
 
 		if (COUNTER(*bmc) == COUNTER_MAX)
 			wake_up(&bitmap->overflow_wait);
@@ -2062,6 +2044,37 @@ static void md_bitmap_free(void *data)
 	kfree(bitmap);
 }
 
+static void bitmap_start_behind_write(struct mddev *mddev)
+{
+	struct bitmap *bitmap = mddev->bitmap;
+	int bw;
+
+	if (!bitmap)
+		return;
+
+	atomic_inc(&bitmap->behind_writes);
+	bw = atomic_read(&bitmap->behind_writes);
+	if (bw > bitmap->behind_writes_used)
+		bitmap->behind_writes_used = bw;
+
+	pr_debug("inc write-behind count %d/%lu\n",
+		 bw, bitmap->mddev->bitmap_info.max_write_behind);
+}
+
+static void bitmap_end_behind_write(struct mddev *mddev)
+{
+	struct bitmap *bitmap = mddev->bitmap;
+
+	if (!bitmap)
+		return;
+
+	if (atomic_dec_and_test(&bitmap->behind_writes))
+		wake_up(&bitmap->behind_wait);
+	pr_debug("dec write-behind count %d/%lu\n",
+		 atomic_read(&bitmap->behind_writes),
+		 bitmap->mddev->bitmap_info.max_write_behind);
+}
+
 static void bitmap_wait_behind_writes(struct mddev *mddev)
 {
 	struct bitmap *bitmap = mddev->bitmap;
@@ -2981,6 +2994,9 @@ static struct bitmap_operations bitmap_ops = {
 	.dirty_bits		= bitmap_dirty_bits,
 	.unplug			= bitmap_unplug,
 	.daemon_work		= bitmap_daemon_work,
+
+	.start_behind_write	= bitmap_start_behind_write,
+	.end_behind_write	= bitmap_end_behind_write,
 	.wait_behind_writes	= bitmap_wait_behind_writes,
 
 	.startwrite		= bitmap_startwrite,

drivers/md/md-bitmap.h

@@ -84,12 +84,15 @@ struct bitmap_operations {
 			   unsigned long e);
 	void (*unplug)(struct mddev *mddev, bool sync);
 	void (*daemon_work)(struct mddev *mddev);
+
+	void (*start_behind_write)(struct mddev *mddev);
+	void (*end_behind_write)(struct mddev *mddev);
 	void (*wait_behind_writes)(struct mddev *mddev);
 
 	int (*startwrite)(struct mddev *mddev, sector_t offset,
-			  unsigned long sectors, bool behind);
+			  unsigned long sectors);
 	void (*endwrite)(struct mddev *mddev, sector_t offset,
-			 unsigned long sectors, bool success, bool behind);
+			 unsigned long sectors);
 	bool (*start_sync)(struct mddev *mddev, sector_t offset,
 			   sector_t *blocks, bool degraded);
 	void (*end_sync)(struct mddev *mddev, sector_t offset, sector_t *blocks);