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Commit 7ba15b7d authored by Stefan Behrens's avatar Stefan Behrens Committed by Josef Bacik
Browse files

Btrfs: add two more find_device() methods 



The new function btrfs_find_device_missing_or_by_path() will be
used for the device replace procedure. This function itself calls
the second new function btrfs_find_device_by_path().
Unfortunately, it is not possible to currently make the rest of the
code use these functions as well, since all functions that look
similar at first view are all a little bit different in what they
are doing. But in the future, new code could benefit from these
two new functions, and currently, device replace uses them.

Signed-off-by: default avatarStefan Behrens <sbehrens@giantdisaster.de>
Signed-off-by: default avatarChris Mason <chris.mason@fusionio.com>
parent beaf8ab3

fs/btrfs/volumes.c

+59 −0
Original line number Diff line number Diff line
@@ -1522,6 +1522,65 @@ int btrfs_rm_device(struct btrfs_root *root, char *device_path) 
	goto error_brelse;

}



int btrfs_find_device_by_path(struct btrfs_root *root, char *device_path,

			      struct btrfs_device **device)

{

	int ret = 0;

	struct btrfs_super_block *disk_super;

	u64 devid;

	u8 *dev_uuid;

	struct block_device *bdev;

	struct buffer_head *bh;



	*device = NULL;

	ret = btrfs_get_bdev_and_sb(device_path, FMODE_READ,

				    root->fs_info->bdev_holder, 0, &bdev, &bh);

	if (ret)

		return ret;

	disk_super = (struct btrfs_super_block *)bh->b_data;

	devid = btrfs_stack_device_id(&disk_super->dev_item);

	dev_uuid = disk_super->dev_item.uuid;

	*device = btrfs_find_device(root, devid, dev_uuid,

				    disk_super->fsid);

	brelse(bh);

	if (!*device)

		ret = -ENOENT;

	blkdev_put(bdev, FMODE_READ);

	return ret;

}



int btrfs_find_device_missing_or_by_path(struct btrfs_root *root,

					 char *device_path,

					 struct btrfs_device **device)

{

	*device = NULL;

	if (strcmp(device_path, "missing") == 0) {

		struct list_head *devices;

		struct btrfs_device *tmp;



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

		/*

		 * It is safe to read the devices since the volume_mutex

		 * is held by the caller.

		 */

		list_for_each_entry(tmp, devices, dev_list) {

			if (tmp->in_fs_metadata && !tmp->bdev) {

				*device = tmp;

				break;

			}

		}



		if (!*device) {

			pr_err("btrfs: no missing device found\n");

			return -ENOENT;

		}



		return 0;

	} else {

		return btrfs_find_device_by_path(root, device_path, device);

	}

}



/*

 * does all the dirty work required for changing file system's UUID.

 */

fs/btrfs/volumes.h

+5 −0
Original line number Diff line number Diff line
@@ -268,6 +268,11 @@ int btrfs_scan_one_device(const char *path, fmode_t flags, void *holder, 
			  struct btrfs_fs_devices **fs_devices_ret);

int btrfs_close_devices(struct btrfs_fs_devices *fs_devices);

void btrfs_close_extra_devices(struct btrfs_fs_devices *fs_devices);

int btrfs_find_device_missing_or_by_path(struct btrfs_root *root,

					 char *device_path,

					 struct btrfs_device **device);

int btrfs_find_device_by_path(struct btrfs_root *root, char *device_path,

			      struct btrfs_device **device);

int btrfs_add_device(struct btrfs_trans_handle *trans,

		     struct btrfs_root *root,

		     struct btrfs_device *device);