Commit fb8cc3b0 authored by Yu Kuai's avatar Yu Kuai
Browse files

md/md-bitmap: delay registration of bitmap_ops until creating bitmap 

Currently bitmap_ops is registered while allocating mddev, this is fine
when there is only one bitmap_ops.

Delay setting bitmap_ops until creating bitmap, so that user can choose
which bitmap to use before running the array.

Link: https://lore.kernel.org/linux-raid/20250721171557.34587-7-yukuai@kernel.org


Signed-off-by: default avatarYu Kuai <yukuai3@huawei.com>
Reviewed-by: default avatarHannes Reinecke <hare@suse.de>
Reviewed-by: default avatarLi Nan <linan122@huawei.com>
Reviewed-by: default avatarXiao Ni <xni@redhat.com>
parent 180b82c1

Documentation/admin-guide/md.rst

+3 −0
Original line number Diff line number Diff line
@@ -388,6 +388,9 @@ All md devices contain: 
     bitmap

         The default internal bitmap



If bitmap_type is not none, then additional bitmap attributes bitmap/xxx or

llbitmap/xxx will be created after md device KOBJ_CHANGE event.



If bitmap_type is bitmap, then the md device will also contain:



  bitmap/location

drivers/md/md.c

+53 −37
Original line number Diff line number Diff line
@@ -678,9 +678,11 @@ static void no_op(struct percpu_ref *r) {} 


static bool mddev_set_bitmap_ops(struct mddev *mddev)

{

	struct bitmap_operations *old = mddev->bitmap_ops;

	struct md_submodule_head *head;



	if (mddev->bitmap_id == ID_BITMAP_NONE)

	if (mddev->bitmap_id == ID_BITMAP_NONE ||

	    (old && old->head.id == mddev->bitmap_id))

		return true;



	xa_lock(&md_submodule);
@@ -698,6 +700,18 @@ static bool mddev_set_bitmap_ops(struct mddev *mddev) 


	mddev->bitmap_ops = (void *)head;

	xa_unlock(&md_submodule);



	if (!mddev_is_dm(mddev) && mddev->bitmap_ops->group) {

		if (sysfs_create_group(&mddev->kobj, mddev->bitmap_ops->group))

			pr_warn("md: cannot register extra bitmap attributes for %s\n",

				mdname(mddev));

		else

			/*

			 * Inform user with KOBJ_CHANGE about new bitmap

			 * attributes.

			 */

			kobject_uevent(&mddev->kobj, KOBJ_CHANGE);

	}

	return true;



err:
@@ -707,28 +721,26 @@ static bool mddev_set_bitmap_ops(struct mddev *mddev) 


static void mddev_clear_bitmap_ops(struct mddev *mddev)

{

	if (!mddev_is_dm(mddev) && mddev->bitmap_ops &&

	    mddev->bitmap_ops->group)

		sysfs_remove_group(&mddev->kobj, mddev->bitmap_ops->group);



	mddev->bitmap_ops = NULL;

}



int mddev_init(struct mddev *mddev)

{

	if (!IS_ENABLED(CONFIG_MD_BITMAP)) {

	if (!IS_ENABLED(CONFIG_MD_BITMAP))

		mddev->bitmap_id = ID_BITMAP_NONE;

	} else {

	else

		mddev->bitmap_id = ID_BITMAP;

		if (!mddev_set_bitmap_ops(mddev))

			return -EINVAL;

	}



	if (percpu_ref_init(&mddev->active_io, active_io_release,

			    PERCPU_REF_ALLOW_REINIT, GFP_KERNEL)) {

		mddev_clear_bitmap_ops(mddev);

			    PERCPU_REF_ALLOW_REINIT, GFP_KERNEL))

		return -ENOMEM;

	}



	if (percpu_ref_init(&mddev->writes_pending, no_op,

			    PERCPU_REF_ALLOW_REINIT, GFP_KERNEL)) {

		mddev_clear_bitmap_ops(mddev);

		percpu_ref_exit(&mddev->active_io);

		return -ENOMEM;

	}
@@ -766,7 +778,6 @@ EXPORT_SYMBOL_GPL(mddev_init); 


void mddev_destroy(struct mddev *mddev)

{

	mddev_clear_bitmap_ops(mddev);

	percpu_ref_exit(&mddev->active_io);

	percpu_ref_exit(&mddev->writes_pending);

}
@@ -6196,11 +6207,6 @@ struct mddev *md_alloc(dev_t dev, char *name) 
		return ERR_PTR(error);

	}



	if (md_bitmap_registered(mddev) && mddev->bitmap_ops->group)

		if (sysfs_create_group(&mddev->kobj, mddev->bitmap_ops->group))

			pr_warn("md: cannot register extra bitmap attributes for %s\n",

				mdname(mddev));



	kobject_uevent(&mddev->kobj, KOBJ_ADD);

	mddev->sysfs_state = sysfs_get_dirent_safe(mddev->kobj.sd, "array_state");

	mddev->sysfs_level = sysfs_get_dirent_safe(mddev->kobj.sd, "level");
@@ -6279,6 +6285,26 @@ static void md_safemode_timeout(struct timer_list *t) 


static int start_dirty_degraded;



static int md_bitmap_create(struct mddev *mddev)

{

	if (mddev->bitmap_id == ID_BITMAP_NONE)

		return -EINVAL;



	if (!mddev_set_bitmap_ops(mddev))

		return -ENOENT;



	return mddev->bitmap_ops->create(mddev);

}



static void md_bitmap_destroy(struct mddev *mddev)

{

	if (!md_bitmap_registered(mddev))

		return;



	mddev->bitmap_ops->destroy(mddev);

	mddev_clear_bitmap_ops(mddev);

}



int md_run(struct mddev *mddev)

{

	int err;
@@ -6443,9 +6469,9 @@ int md_run(struct mddev *mddev) 
			(unsigned long long)pers->size(mddev, 0, 0) / 2);

		err = -EINVAL;

	}

	if (err == 0 && pers->sync_request && md_bitmap_registered(mddev) &&

	if (err == 0 && pers->sync_request &&

	    (mddev->bitmap_info.file || mddev->bitmap_info.offset)) {

		err = mddev->bitmap_ops->create(mddev);

		err = md_bitmap_create(mddev);

		if (err)

			pr_warn("%s: failed to create bitmap (%d)\n",

				mdname(mddev), err);
@@ -6518,8 +6544,7 @@ int md_run(struct mddev *mddev) 
		pers->free(mddev, mddev->private);

	mddev->private = NULL;

	put_pers(pers);

	if (md_bitmap_registered(mddev))

		mddev->bitmap_ops->destroy(mddev);

	md_bitmap_destroy(mddev);

abort:

	bioset_exit(&mddev->io_clone_set);

exit_sync_set:
@@ -6542,7 +6567,7 @@ int do_md_run(struct mddev *mddev) 
	if (md_bitmap_registered(mddev)) {

		err = mddev->bitmap_ops->load(mddev);

		if (err) {

			mddev->bitmap_ops->destroy(mddev);

			md_bitmap_destroy(mddev);

			goto out;

		}

	}
@@ -6740,8 +6765,7 @@ static void __md_stop(struct mddev *mddev) 
{

	struct md_personality *pers = mddev->pers;



	if (md_bitmap_registered(mddev))

		mddev->bitmap_ops->destroy(mddev);

	md_bitmap_destroy(mddev);

	mddev_detach(mddev);

	spin_lock(&mddev->lock);

	mddev->pers = NULL;
@@ -7518,16 +7542,16 @@ static int set_bitmap_file(struct mddev *mddev, int fd) 
	err = 0;

	if (mddev->pers) {

		if (fd >= 0) {

			err = mddev->bitmap_ops->create(mddev);

			err = md_bitmap_create(mddev);

			if (!err)

				err = mddev->bitmap_ops->load(mddev);



			if (err) {

				mddev->bitmap_ops->destroy(mddev);

				md_bitmap_destroy(mddev);

				fd = -1;

			}

		} else if (fd < 0) {

			mddev->bitmap_ops->destroy(mddev);

			md_bitmap_destroy(mddev);

		}

	}
@@ -7812,14 +7836,6 @@ static int update_array_info(struct mddev *mddev, mdu_array_info_t *info) 
		rv = update_raid_disks(mddev, info->raid_disks);



	if ((state ^ info->state) & (1<<MD_SB_BITMAP_PRESENT)) {

		/*

		 * Metadata says bitmap existed, however kernel can't find

		 * registered bitmap.

		 */

		if (WARN_ON_ONCE(!md_bitmap_registered(mddev))) {

			rv = -EINVAL;

			goto err;

		}

		if (mddev->pers->quiesce == NULL || mddev->thread == NULL) {

			rv = -EINVAL;

			goto err;
@@ -7842,12 +7858,12 @@ static int update_array_info(struct mddev *mddev, mdu_array_info_t *info) 
				mddev->bitmap_info.default_offset;

			mddev->bitmap_info.space =

				mddev->bitmap_info.default_space;

			rv = mddev->bitmap_ops->create(mddev);

			rv = md_bitmap_create(mddev);

			if (!rv)

				rv = mddev->bitmap_ops->load(mddev);



			if (rv)

				mddev->bitmap_ops->destroy(mddev);

				md_bitmap_destroy(mddev);

		} else {

			struct md_bitmap_stats stats;
@@ -7873,7 +7889,7 @@ static int update_array_info(struct mddev *mddev, mdu_array_info_t *info) 
				put_cluster_ops(mddev);

				mddev->safemode_delay = DEFAULT_SAFEMODE_DELAY;

			}

			mddev->bitmap_ops->destroy(mddev);

			md_bitmap_destroy(mddev);

			mddev->bitmap_info.offset = 0;

		}

	}