Commit 56fbb0a4 authored by Naohiro Aota's avatar Naohiro Aota Committed by David Sterba
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btrfs: zoned: properly finish block group on metadata write 



Commit be1a1d7a ("btrfs: zoned: finish fully written block group")
introduced zone finishing code both for data and metadata end_io path.
However, the metadata side is not working as it should. First, it
compares logical address (eb->start + eb->len) with offset within a
block group (cache->zone_capacity) in submit_eb_page(). That essentially
disabled zone finishing on metadata end_io path.

Furthermore, fixing the issue above revealed we cannot call
btrfs_zone_finish_endio() in end_extent_buffer_writeback(). We cannot
call btrfs_lookup_block_group() which require spin lock inside end_io
context.

Introduce btrfs_schedule_zone_finish_bg() to wait for the extent buffer
writeback and do the zone finish IO in a workqueue.

Also, drop EXTENT_BUFFER_ZONE_FINISH as it is no longer used.

Fixes: be1a1d7a ("btrfs: zoned: finish fully written block group")
CC: stable@vger.kernel.org # 5.16+
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 8b8a5399

fs/btrfs/block-group.h

+2 −0
Original line number Diff line number Diff line
@@ -212,6 +212,8 @@ struct btrfs_block_group { 
	u64 meta_write_pointer;

	struct map_lookup *physical_map;

	struct list_head active_bg_list;

	struct work_struct zone_finish_work;

	struct extent_buffer *last_eb;

};



static inline u64 btrfs_block_group_end(struct btrfs_block_group *block_group)

fs/btrfs/extent_io.c

+1 −5
Original line number Diff line number Diff line
@@ -4251,9 +4251,6 @@ void wait_on_extent_buffer_writeback(struct extent_buffer *eb) 


static void end_extent_buffer_writeback(struct extent_buffer *eb)

{

	if (test_bit(EXTENT_BUFFER_ZONE_FINISH, &eb->bflags))

		btrfs_zone_finish_endio(eb->fs_info, eb->start, eb->len);



	clear_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags);

	smp_mb__after_atomic();

	wake_up_bit(&eb->bflags, EXTENT_BUFFER_WRITEBACK);
@@ -4843,8 +4840,7 @@ static int submit_eb_page(struct page *page, struct writeback_control *wbc, 
		/*

		 * Implies write in zoned mode. Mark the last eb in a block group.

		 */

		if (cache->seq_zone && eb->start + eb->len == cache->zone_capacity)

			set_bit(EXTENT_BUFFER_ZONE_FINISH, &eb->bflags);

		btrfs_schedule_zone_finish_bg(cache, eb);

		btrfs_put_block_group(cache);

	}

	ret = write_one_eb(eb, wbc, epd);

fs/btrfs/extent_io.h

+0 −1
Original line number Diff line number Diff line
@@ -26,7 +26,6 @@ enum { 
	/* write IO error */

	EXTENT_BUFFER_WRITE_ERR,

	EXTENT_BUFFER_NO_CHECK,

	EXTENT_BUFFER_ZONE_FINISH,

};



/* these are flags for __process_pages_contig */

fs/btrfs/zoned.c

+31 −0
Original line number Diff line number Diff line
@@ -2046,6 +2046,37 @@ void btrfs_zone_finish_endio(struct btrfs_fs_info *fs_info, u64 logical, u64 len 
	btrfs_put_block_group(block_group);

}



static void btrfs_zone_finish_endio_workfn(struct work_struct *work)

{

	struct btrfs_block_group *bg =

		container_of(work, struct btrfs_block_group, zone_finish_work);



	wait_on_extent_buffer_writeback(bg->last_eb);

	free_extent_buffer(bg->last_eb);

	btrfs_zone_finish_endio(bg->fs_info, bg->start, bg->length);

	btrfs_put_block_group(bg);

}



void btrfs_schedule_zone_finish_bg(struct btrfs_block_group *bg,

				   struct extent_buffer *eb)

{

	if (!bg->seq_zone || eb->start + eb->len * 2 <= bg->start + bg->zone_capacity)

		return;



	if (WARN_ON(bg->zone_finish_work.func == btrfs_zone_finish_endio_workfn)) {

		btrfs_err(bg->fs_info, "double scheduling of bg %llu zone finishing",

			  bg->start);

		return;

	}



	/* For the work */

	btrfs_get_block_group(bg);

	atomic_inc(&eb->refs);

	bg->last_eb = eb;

	INIT_WORK(&bg->zone_finish_work, btrfs_zone_finish_endio_workfn);

	queue_work(system_unbound_wq, &bg->zone_finish_work);

}



void btrfs_clear_data_reloc_bg(struct btrfs_block_group *bg)

{

	struct btrfs_fs_info *fs_info = bg->fs_info;

fs/btrfs/zoned.h

+5 −0
Original line number Diff line number Diff line
@@ -72,6 +72,8 @@ int btrfs_zone_finish(struct btrfs_block_group *block_group); 
bool btrfs_can_activate_zone(struct btrfs_fs_devices *fs_devices, u64 flags);

void btrfs_zone_finish_endio(struct btrfs_fs_info *fs_info, u64 logical,

			     u64 length);

void btrfs_schedule_zone_finish_bg(struct btrfs_block_group *bg,

				   struct extent_buffer *eb);

void btrfs_clear_data_reloc_bg(struct btrfs_block_group *bg);

void btrfs_free_zone_cache(struct btrfs_fs_info *fs_info);

bool btrfs_zoned_should_reclaim(struct btrfs_fs_info *fs_info);
@@ -230,6 +232,9 @@ static inline bool btrfs_can_activate_zone(struct btrfs_fs_devices *fs_devices, 
static inline void btrfs_zone_finish_endio(struct btrfs_fs_info *fs_info,

					   u64 logical, u64 length) { }



static inline void btrfs_schedule_zone_finish_bg(struct btrfs_block_group *bg,

						 struct extent_buffer *eb) { }



static inline void btrfs_clear_data_reloc_bg(struct btrfs_block_group *bg) { }



static inline void btrfs_free_zone_cache(struct btrfs_fs_info *fs_info) { }