diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index f066ccb5dddf9ba62113557154c1e6d2fe6ca561..ad1983524f97d7d97de7c5cafc6934736187fb72 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -1009,6 +1009,85 @@ static noinline int btrfs_ioctl_snap_create_v2(struct file *file, return ret; } +static noinline int btrfs_ioctl_subvol_getflags(struct file *file, + void __user *arg) +{ + struct inode *inode = fdentry(file)->d_inode; + struct btrfs_root *root = BTRFS_I(inode)->root; + int ret = 0; + u64 flags = 0; + + if (inode->i_ino != BTRFS_FIRST_FREE_OBJECTID) + return -EINVAL; + + down_read(&root->fs_info->subvol_sem); + if (btrfs_root_readonly(root)) + flags |= BTRFS_SUBVOL_RDONLY; + up_read(&root->fs_info->subvol_sem); + + if (copy_to_user(arg, &flags, sizeof(flags))) + ret = -EFAULT; + + return ret; +} + +static noinline int btrfs_ioctl_subvol_setflags(struct file *file, + void __user *arg) +{ + struct inode *inode = fdentry(file)->d_inode; + struct btrfs_root *root = BTRFS_I(inode)->root; + struct btrfs_trans_handle *trans; + u64 root_flags; + u64 flags; + int ret = 0; + + if (root->fs_info->sb->s_flags & MS_RDONLY) + return -EROFS; + + if (inode->i_ino != BTRFS_FIRST_FREE_OBJECTID) + return -EINVAL; + + if (copy_from_user(&flags, arg, sizeof(flags))) + return -EFAULT; + + if (flags & ~BTRFS_SUBVOL_CREATE_ASYNC) + return -EINVAL; + + if (flags & ~BTRFS_SUBVOL_RDONLY) + return -EOPNOTSUPP; + + down_write(&root->fs_info->subvol_sem); + + /* nothing to do */ + if (!!(flags & BTRFS_SUBVOL_RDONLY) == btrfs_root_readonly(root)) + goto out; + + root_flags = btrfs_root_flags(&root->root_item); + if (flags & BTRFS_SUBVOL_RDONLY) + btrfs_set_root_flags(&root->root_item, + root_flags | BTRFS_ROOT_SUBVOL_RDONLY); + else + btrfs_set_root_flags(&root->root_item, + root_flags & ~BTRFS_ROOT_SUBVOL_RDONLY); + + trans = btrfs_start_transaction(root, 1); + if (IS_ERR(trans)) { + ret = PTR_ERR(trans); + goto out_reset; + } + + ret = btrfs_update_root(trans, root, + &root->root_key, &root->root_item); + + btrfs_commit_transaction(trans, root); +out_reset: + if (ret) + btrfs_set_root_flags(&root->root_item, root_flags); +out: + up_write(&root->fs_info->subvol_sem); + return ret; +} + /* * helper to check if the subvolume references other subvolumes */ @@ -2282,6 +2361,10 @@ long btrfs_ioctl(struct file *file, unsigned int return btrfs_ioctl_snap_create(file, argp, 1); case BTRFS_IOC_SNAP_DESTROY: return btrfs_ioctl_snap_destroy(file, argp); + case BTRFS_IOC_SUBVOL_GETFLAGS: + return btrfs_ioctl_subvol_getflags(file, argp); + case BTRFS_IOC_SUBVOL_SETFLAGS: + return btrfs_ioctl_subvol_setflags(file, argp); case BTRFS_IOC_DEFAULT_SUBVOL: return btrfs_ioctl_default_subvol(file, argp); case BTRFS_IOC_DEFRAG: diff --git a/fs/btrfs/ioctl.h b/fs/btrfs/ioctl.h index 52ae489974be80f7349c855cca1a6b23b88b32d5..1223223351fa08bcf1f38b31b8f1a3bb087ee65a 100644 --- a/fs/btrfs/ioctl.h +++ b/fs/btrfs/ioctl.h @@ -194,4 +194,6 @@ struct btrfs_ioctl_space_args { #define BTRFS_IOC_WAIT_SYNC _IOW(BTRFS_IOCTL_MAGIC, 22, __u64) #define BTRFS_IOC_SNAP_CREATE_V2 _IOW(BTRFS_IOCTL_MAGIC, 23, \ struct btrfs_ioctl_vol_args_v2) +#define BTRFS_IOC_SUBVOL_GETFLAGS _IOW(BTRFS_IOCTL_MAGIC, 25, __u64) +#define BTRFS_IOC_SUBVOL_SETFLAGS _IOW(BTRFS_IOCTL_MAGIC, 26, __u64) #endif