Commit 81bce3cf authored by Hongbo Li's avatar Hongbo Li Committed by Kent Overstreet
Browse files

bcachefs: support get fs label 



Implement support for FS_IOC_GETFSLABEL ioctl to read filesystem
label.

Signed-off-by: default avatarHongbo Li <lihongbo22@huawei.com>
Signed-off-by: default avatarKent Overstreet <kent.overstreet@linux.dev>
parent 8a4ef7e2

fs/bcachefs/fs-ioctl.c

+30 −0
Original line number Diff line number Diff line
@@ -277,6 +277,30 @@ static int bch2_ioc_getversion(struct bch_inode_info *inode, u32 __user *arg) 
	return put_user(inode->v.i_generation, arg);

}



static int bch2_ioc_getlabel(struct bch_fs *c, char __user *user_label)

{

	int ret;

	size_t len;

	char label[BCH_SB_LABEL_SIZE];



	BUILD_BUG_ON(BCH_SB_LABEL_SIZE >= FSLABEL_MAX);



	mutex_lock(&c->sb_lock);

	memcpy(label, c->disk_sb.sb->label, BCH_SB_LABEL_SIZE);

	mutex_unlock(&c->sb_lock);



	len = strnlen(label, BCH_SB_LABEL_SIZE);

	if (len == BCH_SB_LABEL_SIZE) {

		bch_warn(c,

			"label is too long, return the first %zu bytes",

			--len);

	}



	ret = copy_to_user(user_label, label, len);



	return ret ? -EFAULT : 0;

}



static int bch2_ioc_goingdown(struct bch_fs *c, u32 __user *arg)

{

	u32 flags;
@@ -511,6 +535,10 @@ long bch2_fs_file_ioctl(struct file *file, unsigned cmd, unsigned long arg) 
		ret = -ENOTTY;

		break;



	case FS_IOC_GETFSLABEL:

		ret = bch2_ioc_getlabel(c, (void __user *) arg);

		break;



	case FS_IOC_GOINGDOWN:

		ret = bch2_ioc_goingdown(c, (u32 __user *) arg);

		break;
@@ -555,6 +583,8 @@ long bch2_compat_fs_ioctl(struct file *file, unsigned cmd, unsigned long arg) 
	case FS_IOC32_GETVERSION:

		cmd = FS_IOC_GETVERSION;

		break;

	case FS_IOC_GETFSLABEL:

		break;

	default:

		return -ENOIOCTLCMD;

	}