Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit b3075717 authored by Chris Mason's avatar Chris Mason
Browse files

Btrfs: Add a special device list for chunk allocations 



This allows other code that needs to walk every device in the FS to do so
without locking against allocations.

Signed-off-by: default avatarChris Mason <chris.mason@oracle.com>
parent 3c12ac72

fs/btrfs/volumes.c

+10 −5
Original line number Diff line number Diff line
@@ -111,6 +111,7 @@ static int device_list_add(const char *path, 
		if (!fs_devices)

			return -ENOMEM;

		INIT_LIST_HEAD(&fs_devices->devices);

		INIT_LIST_HEAD(&fs_devices->alloc_list);

		list_add(&fs_devices->list, &fs_uuids);

		memcpy(fs_devices->fsid, disk_super->fsid, BTRFS_FSID_SIZE);

		fs_devices->latest_devid = devid;
@@ -139,6 +140,7 @@ static int device_list_add(const char *path, 
			return -ENOMEM;

		}

		list_add(&device->dev_list, &fs_devices->devices);

		list_add(&device->dev_alloc_list, &fs_devices->alloc_list);

		fs_devices->num_devices++;

	}
@@ -660,7 +662,7 @@ int btrfs_alloc_chunk(struct btrfs_trans_handle *trans, 
	struct btrfs_device *device = NULL;

	struct btrfs_chunk *chunk;

	struct list_head private_devs;

	struct list_head *dev_list = &extent_root->fs_info->fs_devices->devices;

	struct list_head *dev_list;

	struct list_head *cur;

	struct extent_map_tree *em_tree;

	struct map_lookup *map;
@@ -682,6 +684,7 @@ int btrfs_alloc_chunk(struct btrfs_trans_handle *trans, 
	int stripe_len = 64 * 1024;

	struct btrfs_key key;



	dev_list = &extent_root->fs_info->fs_devices->alloc_list;

	if (list_empty(dev_list))

		return -ENOSPC;
@@ -752,12 +755,12 @@ int btrfs_alloc_chunk(struct btrfs_trans_handle *trans, 


	/* build a private list of devices we will allocate from */

	while(index < num_stripes) {

		device = list_entry(cur, struct btrfs_device, dev_list);

		device = list_entry(cur, struct btrfs_device, dev_alloc_list);



		avail = device->total_bytes - device->bytes_used;

		cur = cur->next;

		if (avail >= min_free) {

			list_move_tail(&device->dev_list, &private_devs);

			list_move_tail(&device->dev_alloc_list, &private_devs);

			index++;

			if (type & BTRFS_BLOCK_GROUP_DUP)

				index++;
@@ -812,12 +815,12 @@ printk("new chunk type %Lu start %Lu size %Lu\n", type, key.offset, *num_bytes); 
		struct btrfs_stripe *stripe;

		BUG_ON(list_empty(&private_devs));

		cur = private_devs.next;

		device = list_entry(cur, struct btrfs_device, dev_list);

		device = list_entry(cur, struct btrfs_device, dev_alloc_list);



		/* loop over this device again if we're doing a dup group */

		if (!(type & BTRFS_BLOCK_GROUP_DUP) ||

		    (index == num_stripes - 1))

			list_move_tail(&device->dev_list, dev_list);

			list_move_tail(&device->dev_alloc_list, dev_list);



		ret = btrfs_alloc_dev_extent(trans, device,

			     info->chunk_root->root_key.objectid,
@@ -1329,6 +1332,8 @@ static int read_one_dev(struct btrfs_root *root, 
			return -ENOMEM;

		list_add(&device->dev_list,

			 &root->fs_info->fs_devices->devices);

		list_add(&device->dev_alloc_list,

			 &root->fs_info->fs_devices->alloc_list);

		device->barriers = 1;

		spin_lock_init(&device->io_lock);

	}

fs/btrfs/volumes.h

+7 −0
Original line number Diff line number Diff line
@@ -24,9 +24,12 @@ 
struct buffer_head;

struct btrfs_device {

	struct list_head dev_list;

	struct list_head dev_alloc_list;

	struct btrfs_root *dev_root;

	struct buffer_head *pending_io;



	int barriers;



	spinlock_t io_lock;



	struct block_device *bdev;
@@ -70,7 +73,11 @@ struct btrfs_fs_devices { 
	u64 num_devices;

	struct block_device *latest_bdev;

	struct block_device *lowest_bdev;

	/* all of the devices in the FS */

	struct list_head devices;



	/* devices not currently being allocated */

	struct list_head alloc_list;

	struct list_head list;

};