Commit f6fca391 authored by Stefan Roesch's avatar Stefan Roesch Committed by David Sterba
Browse files

btrfs: store chunk size in space-info struct 



The chunk size is stored in the btrfs_space_info structure.  It is
initialized at the start and is then used.

A new API is added to update the current chunk size.  This API is used
to be able to expose the chunk_size as a sysfs setting.

Signed-off-by: default avatarStefan Roesch <shr@fb.com>
Reviewed-by: default avatarDavid Sterba <dsterba@suse.com>
[ rename and merge helpers, switch atomic type to u64, style fixes ]
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent 71b68e9e

fs/btrfs/space-info.c

+32 −0
Original line number Diff line number Diff line
@@ -187,6 +187,37 @@ void btrfs_clear_space_info_full(struct btrfs_fs_info *info) 
 */

#define BTRFS_DEFAULT_ZONED_RECLAIM_THRESH			(75)



/*

 * Calculate chunk size depending on volume type (regular or zoned).

 */

static u64 calc_chunk_size(const struct btrfs_fs_info *fs_info, u64 flags)

{

	if (btrfs_is_zoned(fs_info))

		return fs_info->zone_size;



	ASSERT(flags & BTRFS_BLOCK_GROUP_TYPE_MASK);



	if (flags & BTRFS_BLOCK_GROUP_DATA)

		return SZ_1G;

	else if (flags & BTRFS_BLOCK_GROUP_SYSTEM)

		return SZ_32M;



	/* Handle BTRFS_BLOCK_GROUP_METADATA */

	if (fs_info->fs_devices->total_rw_bytes > 50ULL * SZ_1G)

		return SZ_1G;



	return SZ_256M;

}



/*

 * Update default chunk size.

 */

void btrfs_update_space_info_chunk_size(struct btrfs_space_info *space_info,

					u64 chunk_size)

{

	WRITE_ONCE(space_info->chunk_size, chunk_size);

}



static int create_space_info(struct btrfs_fs_info *info, u64 flags)

{
@@ -208,6 +239,7 @@ static int create_space_info(struct btrfs_fs_info *info, u64 flags) 
	INIT_LIST_HEAD(&space_info->tickets);

	INIT_LIST_HEAD(&space_info->priority_tickets);

	space_info->clamp = 1;

	btrfs_update_space_info_chunk_size(space_info, calc_chunk_size(info, flags));



	if (btrfs_is_zoned(info))

		space_info->bg_reclaim_threshold = BTRFS_DEFAULT_ZONED_RECLAIM_THRESH;

fs/btrfs/space-info.h

+4 −0
Original line number Diff line number Diff line
@@ -25,6 +25,8 @@ struct btrfs_space_info { 
	u64 max_extent_size;	/* This will hold the maximum extent size of

				   the space info if we had an ENOSPC in the

				   allocator. */

	/* Chunk size in bytes */

	u64 chunk_size;



	/*

	 * Once a block group drops below this threshold (percents) we'll
@@ -123,6 +125,8 @@ void btrfs_update_space_info(struct btrfs_fs_info *info, u64 flags, 
			     u64 total_bytes, u64 bytes_used,

			     u64 bytes_readonly, u64 bytes_zone_unusable,

			     struct btrfs_space_info **space_info);

void btrfs_update_space_info_chunk_size(struct btrfs_space_info *space_info,

					u64 chunk_size);

struct btrfs_space_info *btrfs_find_space_info(struct btrfs_fs_info *info,

					       u64 flags);

u64 __pure btrfs_space_info_used(struct btrfs_space_info *s_info,

fs/btrfs/volumes.c

+9 −19
Original line number Diff line number Diff line
@@ -5071,26 +5071,16 @@ static void init_alloc_chunk_ctl_policy_regular( 
				struct btrfs_fs_devices *fs_devices,

				struct alloc_chunk_ctl *ctl)

{

	u64 type = ctl->type;

	struct btrfs_space_info *space_info;



	if (type & BTRFS_BLOCK_GROUP_DATA) {

		ctl->max_stripe_size = SZ_1G;

		ctl->max_chunk_size = BTRFS_MAX_DATA_CHUNK_SIZE;

	} else if (type & BTRFS_BLOCK_GROUP_METADATA) {

		/* For larger filesystems, use larger metadata chunks */

		if (fs_devices->total_rw_bytes > 50ULL * SZ_1G)

			ctl->max_stripe_size = SZ_1G;

		else

			ctl->max_stripe_size = SZ_256M;

		ctl->max_chunk_size = ctl->max_stripe_size;

	} else if (type & BTRFS_BLOCK_GROUP_SYSTEM) {

		ctl->max_stripe_size = SZ_32M;

		ctl->max_chunk_size = 2 * ctl->max_stripe_size;

		ctl->devs_max = min_t(int, ctl->devs_max,

				      BTRFS_MAX_DEVS_SYS_CHUNK);

	} else {

		BUG();

	}

	space_info = btrfs_find_space_info(fs_devices->fs_info, ctl->type);

	ASSERT(space_info);



	ctl->max_chunk_size = READ_ONCE(space_info->chunk_size);

	ctl->max_stripe_size = ctl->max_chunk_size;



	if (ctl->type & BTRFS_BLOCK_GROUP_SYSTEM)

		ctl->devs_max = min_t(int, ctl->devs_max, BTRFS_MAX_DEVS_SYS_CHUNK);



	/* We don't want a chunk larger than 10% of writable space */

	ctl->max_chunk_size = min(div_factor(fs_devices->total_rw_bytes, 1),