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Commit 9c81075f authored by Jonathan Brassow's avatar Jonathan Brassow Committed by NeilBrown
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MD: support initial bitmap creation in-kernel 



Add bitmap support to the device-mapper specific metadata area.

This patch allows the creation of the bitmap metadata area upon
initial array creation via device-mapper.

Signed-off-by: default avatarJonathan Brassow <jbrassow@redhat.com>
Signed-off-by: default avatarNeilBrown <neilb@suse.de>
parent 076f968b

drivers/md/bitmap.c

+88 −5
Original line number Diff line number Diff line
@@ -534,6 +534,82 @@ void bitmap_print_sb(struct bitmap *bitmap) 
	kunmap_atomic(sb, KM_USER0);

}



/*

 * bitmap_new_disk_sb

 * @bitmap

 *

 * This function is somewhat the reverse of bitmap_read_sb.  bitmap_read_sb

 * reads and verifies the on-disk bitmap superblock and populates bitmap_info.

 * This function verifies 'bitmap_info' and populates the on-disk bitmap

 * structure, which is to be written to disk.

 *

 * Returns: 0 on success, -Exxx on error

 */

static int bitmap_new_disk_sb(struct bitmap *bitmap)

{

	bitmap_super_t *sb;

	unsigned long chunksize, daemon_sleep, write_behind;

	int err = -EINVAL;



	bitmap->sb_page = alloc_page(GFP_KERNEL);

	if (IS_ERR(bitmap->sb_page)) {

		err = PTR_ERR(bitmap->sb_page);

		bitmap->sb_page = NULL;

		return err;

	}

	bitmap->sb_page->index = 0;



	sb = kmap_atomic(bitmap->sb_page, KM_USER0);



	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, KM_USER0);

		printk(KERN_ERR "bitmap chunksize not a power of 2\n");

		return -EINVAL;

	}

	sb->chunksize = cpu_to_le32(chunksize);



	daemon_sleep = bitmap->mddev->bitmap_info.daemon_sleep;

	if (!daemon_sleep ||

	    (daemon_sleep < 1) || (daemon_sleep > MAX_SCHEDULE_TIMEOUT)) {

		printk(KERN_INFO "Choosing daemon_sleep default (5 sec)\n");

		daemon_sleep = 5 * HZ;

	}

	sb->daemon_sleep = cpu_to_le32(daemon_sleep);

	bitmap->mddev->bitmap_info.daemon_sleep = daemon_sleep;



	/*

	 * FIXME: write_behind for RAID1.  If not specified, what

	 * is a good choice?  We choose COUNTER_MAX / 2 arbitrarily.

	 */

	write_behind = bitmap->mddev->bitmap_info.max_write_behind;

	if (write_behind > COUNTER_MAX)

		write_behind = COUNTER_MAX / 2;

	sb->write_behind = cpu_to_le32(write_behind);

	bitmap->mddev->bitmap_info.max_write_behind = write_behind;



	/* keep the array size field of the bitmap superblock up to date */

	sb->sync_size = cpu_to_le64(bitmap->mddev->resync_max_sectors);



	memcpy(sb->uuid, bitmap->mddev->uuid, 16);



	bitmap->flags |= BITMAP_STALE;

	sb->state |= cpu_to_le32(BITMAP_STALE);

	bitmap->events_cleared = bitmap->mddev->events;

	sb->events_cleared = cpu_to_le64(bitmap->mddev->events);



	bitmap->flags |= BITMAP_HOSTENDIAN;

	sb->version = cpu_to_le32(BITMAP_MAJOR_HOSTENDIAN);



	kunmap_atomic(sb, KM_USER0);



	return 0;

}



/* read the superblock from the bitmap file and initialize some bitmap fields */

static int bitmap_read_sb(struct bitmap *bitmap)

{
@@ -1076,8 +1152,8 @@ static int bitmap_init_from_disk(struct bitmap *bitmap, sector_t start) 
	}



	printk(KERN_INFO "%s: bitmap initialized from disk: "

		"read %lu/%lu pages, set %lu bits\n",

		bmname(bitmap), bitmap->file_pages, num_pages, bit_cnt);

	       "read %lu/%lu pages, set %lu of %lu bits\n",

	       bmname(bitmap), bitmap->file_pages, num_pages, bit_cnt, chunks);



	return 0;
@@ -1728,9 +1804,16 @@ int bitmap_create(mddev_t *mddev) 
		vfs_fsync(file, 1);

	}

	/* read superblock from bitmap file (this sets mddev->bitmap_info.chunksize) */

	if (!mddev->bitmap_info.external)

	if (!mddev->bitmap_info.external) {

		/*

		 * If 'MD_ARRAY_FIRST_USE' is set, then device-mapper is

		 * instructing us to create a new on-disk bitmap instance.

		 */

		if (test_and_clear_bit(MD_ARRAY_FIRST_USE, &mddev->flags))

			err = bitmap_new_disk_sb(bitmap);

		else

			err = bitmap_read_sb(bitmap);

	else {

	} else {

		err = 0;

		if (mddev->bitmap_info.chunksize == 0 ||

		    mddev->bitmap_info.daemon_sleep == 0)

drivers/md/md.h

+1 −0
Original line number Diff line number Diff line
@@ -124,6 +124,7 @@ struct mddev_s 
#define MD_CHANGE_DEVS	0	/* Some device status has changed */

#define MD_CHANGE_CLEAN 1	/* transition to or from 'clean' */

#define MD_CHANGE_PENDING 2	/* switch from 'clean' to 'active' in progress */

#define MD_ARRAY_FIRST_USE 3    /* First use of array, needs initialization */



	int				suspended;

	atomic_t			active_io;