Commit 243cf8d1 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by David Sterba
Browse files

btrfs: calculate file system wide queue limit for zoned mode 



To be able to split a write into properly sized zone append commands,
we need a queue_limits structure that contains the least common
denominator suitable for all devices.

Reviewed-by: default avatarJosef Bacik <josef@toxicpanda.com>
Reviewed-by: default avatarJohannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarDavid Sterba <dsterba@suse.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent 35a8d7da

fs/btrfs/fs.h

+4 −1
Original line number Diff line number Diff line
@@ -3,6 +3,7 @@ 
#ifndef BTRFS_FS_H

#define BTRFS_FS_H



#include <linux/blkdev.h>

#include <linux/fs.h>

#include <linux/btrfs_tree.h>

#include <linux/sizes.h>
@@ -748,8 +749,10 @@ struct btrfs_fs_info { 
	 */

	u64 zone_size;



	/* Max size to emit ZONE_APPEND write command */

	/* Constraints for ZONE_APPEND commands: */

	struct queue_limits limits;

	u64 max_zone_append_size;



	struct mutex zoned_meta_io_lock;

	spinlock_t treelog_bg_lock;

	u64 treelog_bg;

fs/btrfs/zoned.c

+26 −26
Original line number Diff line number Diff line
@@ -421,25 +421,6 @@ int btrfs_get_dev_zone_info(struct btrfs_device *device, bool populate_cache) 
	nr_sectors = bdev_nr_sectors(bdev);

	zone_info->zone_size_shift = ilog2(zone_info->zone_size);

	zone_info->nr_zones = nr_sectors >> ilog2(zone_sectors);

	/*

	 * We limit max_zone_append_size also by max_segments *

	 * PAGE_SIZE. Technically, we can have multiple pages per segment. But,

	 * since btrfs adds the pages one by one to a bio, and btrfs cannot

	 * increase the metadata reservation even if it increases the number of

	 * extents, it is safe to stick with the limit.

	 *

	 * With the zoned emulation, we can have non-zoned device on the zoned

	 * mode. In this case, we don't have a valid max zone append size. So,

	 * use max_segments * PAGE_SIZE as the pseudo max_zone_append_size.

	 */

	if (bdev_is_zoned(bdev)) {

		zone_info->max_zone_append_size = min_t(u64,

			(u64)bdev_max_zone_append_sectors(bdev) << SECTOR_SHIFT,

			(u64)bdev_max_segments(bdev) << PAGE_SHIFT);

	} else {

		zone_info->max_zone_append_size =

			(u64)bdev_max_segments(bdev) << PAGE_SHIFT;

	}

	if (!IS_ALIGNED(nr_sectors, zone_sectors))

		zone_info->nr_zones++;
@@ -719,9 +700,9 @@ static int btrfs_check_for_zoned_device(struct btrfs_fs_info *fs_info) 


int btrfs_check_zoned_mode(struct btrfs_fs_info *fs_info)

{

	struct queue_limits *lim = &fs_info->limits;

	struct btrfs_device *device;

	u64 zone_size = 0;

	u64 max_zone_append_size = 0;

	int ret;



	/*
@@ -731,6 +712,8 @@ int btrfs_check_zoned_mode(struct btrfs_fs_info *fs_info) 
	if (!btrfs_fs_incompat(fs_info, ZONED))

		return btrfs_check_for_zoned_device(fs_info);



	blk_set_stacking_limits(lim);



	list_for_each_entry(device, &fs_info->fs_devices->devices, dev_list) {

		struct btrfs_zoned_device_info *zone_info = device->zone_info;
@@ -745,10 +728,17 @@ int btrfs_check_zoned_mode(struct btrfs_fs_info *fs_info) 
				  zone_info->zone_size, zone_size);

			return -EINVAL;

		}

		if (!max_zone_append_size ||

		    (zone_info->max_zone_append_size &&

		     zone_info->max_zone_append_size < max_zone_append_size))

			max_zone_append_size = zone_info->max_zone_append_size;



		/*

		 * With the zoned emulation, we can have non-zoned device on the

		 * zoned mode. In this case, we don't have a valid max zone

		 * append size.

		 */

		if (bdev_is_zoned(device->bdev)) {

			blk_stack_limits(lim,

					 &bdev_get_queue(device->bdev)->limits,

					 0);

		}

	}



	/*
@@ -769,7 +759,17 @@ int btrfs_check_zoned_mode(struct btrfs_fs_info *fs_info) 
	}



	fs_info->zone_size = zone_size;

	fs_info->max_zone_append_size = ALIGN_DOWN(max_zone_append_size,

	/*

	 * Also limit max_zone_append_size by max_segments * PAGE_SIZE.

	 * Technically, we can have multiple pages per segment. But, since

	 * we add the pages one by one to a bio, and cannot increase the

	 * metadata reservation even if it increases the number of extents, it

	 * is safe to stick with the limit.

	 */

	fs_info->max_zone_append_size = ALIGN_DOWN(

		min3((u64)lim->max_zone_append_sectors << SECTOR_SHIFT,

		     (u64)lim->max_sectors << SECTOR_SHIFT,

		     (u64)lim->max_segments << PAGE_SHIFT),

		fs_info->sectorsize);

	fs_info->fs_devices->chunk_alloc_policy = BTRFS_CHUNK_ALLOC_ZONED;

	if (fs_info->max_zone_append_size < fs_info->max_extent_size)

fs/btrfs/zoned.h

+0 −1
Original line number Diff line number Diff line
@@ -20,7 +20,6 @@ struct btrfs_zoned_device_info { 
	 */

	u64 zone_size;

	u8  zone_size_shift;

	u64 max_zone_append_size;

	u32 nr_zones;

	unsigned int max_active_zones;

	atomic_t active_zones_left;