Commit 73651042 authored by Naohiro Aota's avatar Naohiro Aota Committed by David Sterba
Browse files

btrfs: zoned: defer loading zone info after opening trees 



This is a preparation patch to implement zone emulation on a regular
device.

To emulate a zoned filesystem on a regular (non-zoned) device, we need to
decide an emulated zone size. Instead of making it a compile-time static
value, we'll make it configurable at mkfs time. Since we have one zone ==
one device extent restriction, we can determine the emulated zone size
from the size of a device extent. We can extend btrfs_get_dev_zone_info()
to show a regular device filled with conventional zones once the zone size
is decided.

The current call site of btrfs_get_dev_zone_info() during the mount process
is earlier than loading the file system trees so that we don't know the
size of a device extent at this point. Thus we can't slice a regular device
to conventional zones.

This patch introduces btrfs_get_dev_zone_info_all_devices to load the zone
info for all the devices. And, it places this function in open_ctree()
after loading the trees.

Reviewed-by: default avatarAnand Jain <anand.jain@oracle.com>
Reviewed-by: default avatarJosef Bacik <josef@toxicpanda.com>
Signed-off-by: default avatarNaohiro Aota <naohiro.aota@wdc.com>
Reviewed-by: default avatarDavid Sterba <dsterba@suse.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent c3b0e880

fs/btrfs/disk-io.c

+13 −0
Original line number Diff line number Diff line
@@ -3333,6 +3333,19 @@ int __cold open_ctree(struct super_block *sb, struct btrfs_fs_devices *fs_device 
	if (ret)

		goto fail_tree_roots;



	/*

	 * Get zone type information of zoned block devices. This will also

	 * handle emulation of a zoned filesystem if a regular device has the

	 * zoned incompat feature flag set.

	 */

	ret = btrfs_get_dev_zone_info_all_devices(fs_info);

	if (ret) {

		btrfs_err(fs_info,

			  "zoned: failed to read device zone info: %d",

			  ret);

		goto fail_block_groups;

	}



	/*

	 * If we have a uuid root and we're not being told to rescan we need to

	 * check the generation here so we can set the

fs/btrfs/volumes.c

+0 −4
Original line number Diff line number Diff line
@@ -669,10 +669,6 @@ static int btrfs_open_one_device(struct btrfs_fs_devices *fs_devices, 
	clear_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &device->dev_state);

	device->mode = flags;



	ret = btrfs_get_dev_zone_info(device);

	if (ret != 0)

		goto error_free_page;



	fs_devices->open_devices++;

	if (test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state) &&

	    device->devid != BTRFS_DEV_REPLACE_DEVID) {

fs/btrfs/zoned.c

+25 −0
Original line number Diff line number Diff line
@@ -143,6 +143,31 @@ static int btrfs_get_dev_zones(struct btrfs_device *device, u64 pos, 
	return 0;

}



int btrfs_get_dev_zone_info_all_devices(struct btrfs_fs_info *fs_info)

{

	struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;

	struct btrfs_device *device;

	int ret = 0;



	/* fs_info->zone_size might not set yet. Use the incomapt flag here. */

	if (!btrfs_fs_incompat(fs_info, ZONED))

		return 0;



	mutex_lock(&fs_devices->device_list_mutex);

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

		/* We can skip reading of zone info for missing devices */

		if (!device->bdev)

			continue;



		ret = btrfs_get_dev_zone_info(device);

		if (ret)

			break;

	}

	mutex_unlock(&fs_devices->device_list_mutex);



	return ret;

}



int btrfs_get_dev_zone_info(struct btrfs_device *device)

{

	struct btrfs_zoned_device_info *zone_info = NULL;

fs/btrfs/zoned.h

+6 −0
Original line number Diff line number Diff line
@@ -25,6 +25,7 @@ struct btrfs_zoned_device_info { 
#ifdef CONFIG_BLK_DEV_ZONED

int btrfs_get_dev_zone(struct btrfs_device *device, u64 pos,

		       struct blk_zone *zone);

int btrfs_get_dev_zone_info_all_devices(struct btrfs_fs_info *fs_info);

int btrfs_get_dev_zone_info(struct btrfs_device *device);

void btrfs_destroy_dev_zone_info(struct btrfs_device *device);

int btrfs_check_zoned_mode(struct btrfs_fs_info *fs_info);
@@ -42,6 +43,11 @@ static inline int btrfs_get_dev_zone(struct btrfs_device *device, u64 pos, 
	return 0;

}



static inline int btrfs_get_dev_zone_info_all_devices(struct btrfs_fs_info *fs_info)

{

	return 0;

}



static inline int btrfs_get_dev_zone_info(struct btrfs_device *device)

{

	return 0;