Commit 32a9991f authored by David Sterba's avatar David Sterba
Browse files

btrfs: factor sysfs code out of link_block_group 



The part of link_block_group that just creates the sysfs object is
independent and can be factored out to a helper.

Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent 89439109

fs/btrfs/extent-tree.c

+2 −35
Original line number Diff line number Diff line
@@ -4,7 +4,6 @@ 
 */



#include <linux/sched.h>

#include <linux/sched/mm.h>

#include <linux/sched/signal.h>

#include <linux/pagemap.h>

#include <linux/writeback.h>
@@ -7573,7 +7572,6 @@ int btrfs_free_block_groups(struct btrfs_fs_info *info) 
static void link_block_group(struct btrfs_block_group_cache *cache)

{

	struct btrfs_space_info *space_info = cache->space_info;

	struct btrfs_fs_info *fs_info = cache->fs_info;

	int index = btrfs_bg_flags_to_raid_index(cache->flags);

	bool first = false;
@@ -7583,39 +7581,8 @@ static void link_block_group(struct btrfs_block_group_cache *cache) 
	list_add_tail(&cache->list, &space_info->block_groups[index]);

	up_write(&space_info->groups_sem);



	if (first) {

		struct raid_kobject *rkobj;

		unsigned int nofs_flag;

		int ret;



		/*

		 * Setup a NOFS context because kobject_add(), deep in its call

		 * chain, does GFP_KERNEL allocations, and we are often called

		 * in a context where if reclaim is triggered we can deadlock

		 * (we are either holding a transaction handle or some lock

		 * required for a transaction commit).

		 */

		nofs_flag = memalloc_nofs_save();

		rkobj = kzalloc(sizeof(*rkobj), GFP_KERNEL);

		if (!rkobj) {

			memalloc_nofs_restore(nofs_flag);

			btrfs_warn(cache->fs_info,

				"couldn't alloc memory for raid level kobject");

			return;

		}

		rkobj->flags = cache->flags;

		kobject_init(&rkobj->kobj, &btrfs_raid_ktype);

		ret = kobject_add(&rkobj->kobj, &space_info->kobj, "%s",

				  btrfs_bg_type_to_raid_name(rkobj->flags));

		memalloc_nofs_restore(nofs_flag);

		if (ret) {

			kobject_put(&rkobj->kobj);

			btrfs_warn(fs_info,

			   "failed to add kobject for block cache, ignoring");

			return;

		}

		space_info->block_group_kobjs[index] = &rkobj->kobj;

	}

	if (first)

		btrfs_sysfs_add_block_group_type(cache);

}



static struct btrfs_block_group_cache *

fs/btrfs/sysfs.c

+46 −0
Original line number Diff line number Diff line
@@ -4,6 +4,7 @@ 
 */



#include <linux/sched.h>

#include <linux/sched/mm.h>

#include <linux/slab.h>

#include <linux/spinlock.h>

#include <linux/completion.h>
@@ -749,6 +750,51 @@ static void init_feature_attrs(void) 
	}

}



/*

 * Create a sysfs entry for a given block group type at path

 * /sys/fs/btrfs/UUID/allocation/data/TYPE

 */

void btrfs_sysfs_add_block_group_type(struct btrfs_block_group_cache *cache)

{

	struct btrfs_fs_info *fs_info = cache->fs_info;

	struct btrfs_space_info *space_info = cache->space_info;

	struct raid_kobject *rkobj;

	const int index = btrfs_bg_flags_to_raid_index(cache->flags);

	unsigned int nofs_flag;

	int ret;



	/*

	 * Setup a NOFS context because kobject_add(), deep in its call chain,

	 * does GFP_KERNEL allocations, and we are often called in a context

	 * where if reclaim is triggered we can deadlock (we are either holding

	 * a transaction handle or some lock required for a transaction

	 * commit).

	 */

	nofs_flag = memalloc_nofs_save();



	rkobj = kzalloc(sizeof(*rkobj), GFP_NOFS);

	if (!rkobj) {

		memalloc_nofs_restore(nofs_flag);

		btrfs_warn(cache->fs_info,

				"couldn't alloc memory for raid level kobject");

		return;

	}



	rkobj->flags = cache->flags;

	kobject_init(&rkobj->kobj, &btrfs_raid_ktype);

	ret = kobject_add(&rkobj->kobj, &space_info->kobj, "%s",

			  btrfs_bg_type_to_raid_name(rkobj->flags));

	memalloc_nofs_restore(nofs_flag);

	if (ret) {

		kobject_put(&rkobj->kobj);

		btrfs_warn(fs_info,

			"failed to add kobject for block cache, ignoring");

		return;

	}



	space_info->block_group_kobjs[index] = &rkobj->kobj;

}



/* when one_device is NULL, it removes all device links */



int btrfs_sysfs_rm_device_link(struct btrfs_fs_devices *fs_devices,

fs/btrfs/sysfs.h

+1 −0
Original line number Diff line number Diff line
@@ -96,5 +96,6 @@ int __init btrfs_init_sysfs(void); 
void __cold btrfs_exit_sysfs(void);

int btrfs_sysfs_add_mounted(struct btrfs_fs_info *fs_info);

void btrfs_sysfs_remove_mounted(struct btrfs_fs_info *fs_info);

void btrfs_sysfs_add_block_group_type(struct btrfs_block_group_cache *cache);



#endif