Commit daa0fde3 authored by Naohiro Aota's avatar Naohiro Aota Committed by David Sterba
Browse files

btrfs: zoned: fix data relocation block group reservation 



btrfs_zoned_reserve_data_reloc_bg() is called on mount and at that point,
all data block groups belong to the primary data space_info. So, we don't
find anything in the data relocation space_info.

Also, the condition "bg->used > 0" can select a block group with full of
zone_unusable bytes for the candidate. As we cannot allocate from the block
group, it is useless to reserve it as the data relocation block group.

Furthermore, because of the space_info separation, we need to migrate the
selected block group to the data relocation space_info. If not, the extent
allocator cannot use the block group to do the allocation.

This commit fixes these three issues.

Fixes: e606ff985ec7 ("btrfs: zoned: reserve data_reloc block group on mount")
Reviewed-by: default avatarJohannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: default avatarNaohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent f0ba0e71

fs/btrfs/zoned.c

+47 −8
Original line number Diff line number Diff line
@@ -17,6 +17,7 @@ 
#include "accessors.h"

#include "bio.h"

#include "transaction.h"

#include "sysfs.h"



/* Maximum number of zones to report per blkdev_report_zones() call */

#define BTRFS_REPORT_NR_ZONES   4096
@@ -2519,12 +2520,12 @@ void btrfs_clear_data_reloc_bg(struct btrfs_block_group *bg) 
void btrfs_zoned_reserve_data_reloc_bg(struct btrfs_fs_info *fs_info)

{

	struct btrfs_space_info *data_sinfo = fs_info->data_sinfo;

	struct btrfs_space_info *space_info = data_sinfo->sub_group[0];

	struct btrfs_space_info *space_info = data_sinfo;

	struct btrfs_trans_handle *trans;

	struct btrfs_block_group *bg;

	struct list_head *bg_list;

	u64 alloc_flags;

	bool initial = false;

	bool first = true;

	bool did_chunk_alloc = false;

	int index;

	int ret;
@@ -2538,21 +2539,52 @@ void btrfs_zoned_reserve_data_reloc_bg(struct btrfs_fs_info *fs_info) 
	if (sb_rdonly(fs_info->sb))

		return;



	ASSERT(space_info->subgroup_id == BTRFS_SUB_GROUP_DATA_RELOC);

	alloc_flags = btrfs_get_alloc_profile(fs_info, space_info->flags);

	index = btrfs_bg_flags_to_raid_index(alloc_flags);



	bg_list = &data_sinfo->block_groups[index];

	/* Scan the data space_info to find empty block groups. Take the second one. */

again:

	bg_list = &space_info->block_groups[index];

	list_for_each_entry(bg, bg_list, list) {

		if (bg->used > 0)

		if (bg->alloc_offset != 0)

			continue;



		if (!initial) {

			initial = true;

		if (first) {

			first = false;

			continue;

		}



		if (space_info == data_sinfo) {

			/* Migrate the block group to the data relocation space_info. */

			struct btrfs_space_info *reloc_sinfo = data_sinfo->sub_group[0];

			int factor;



			ASSERT(reloc_sinfo->subgroup_id == BTRFS_SUB_GROUP_DATA_RELOC);

			factor = btrfs_bg_type_to_factor(bg->flags);



			down_write(&space_info->groups_sem);

			list_del_init(&bg->list);

			/* We can assume this as we choose the second empty one. */

			ASSERT(!list_empty(&space_info->block_groups[index]));

			up_write(&space_info->groups_sem);



			spin_lock(&space_info->lock);

			space_info->total_bytes -= bg->length;

			space_info->disk_total -= bg->length * factor;

			/* There is no allocation ever happened. */

			ASSERT(bg->used == 0);

			ASSERT(bg->zone_unusable == 0);

			/* No super block in a block group on the zoned setup. */

			ASSERT(bg->bytes_super == 0);

			spin_unlock(&space_info->lock);



			bg->space_info = reloc_sinfo;

			if (reloc_sinfo->block_group_kobjs[index] == NULL)

				btrfs_sysfs_add_block_group_type(bg);



			btrfs_add_bg_to_space_info(fs_info, bg);

		}



		fs_info->data_reloc_bg = bg->start;

		set_bit(BLOCK_GROUP_FLAG_ZONED_DATA_RELOC, &bg->runtime_flags);

		btrfs_zone_activate(bg);
@@ -2567,11 +2599,18 @@ void btrfs_zoned_reserve_data_reloc_bg(struct btrfs_fs_info *fs_info) 
	if (IS_ERR(trans))

		return;



	/* Allocate new BG in the data relocation space_info. */

	space_info = data_sinfo->sub_group[0];

	ASSERT(space_info->subgroup_id == BTRFS_SUB_GROUP_DATA_RELOC);

	ret = btrfs_chunk_alloc(trans, space_info, alloc_flags, CHUNK_ALLOC_FORCE);

	btrfs_end_transaction(trans);

	if (ret == 1) {

		/*

		 * We allocated a new block group in the data relocation space_info. We

		 * can take that one.

		 */

		first = false;

		did_chunk_alloc = true;

		bg_list = &space_info->block_groups[index];

		goto again;

	}

}